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Biomaterials for liver tissue engineering.
Jain, Era; Damania, Apeksha; Kumar, Ashok
Liver extracellular matrix (ECM) composition, topography and biomechanical properties influence cell-matrix interactions. The ECM presents guiding cues for hepatocyte phenotype maintenance, differentiation and proliferation both in vitro and in vivo. Current understanding of such cell-guiding cues along with advancement of techniques for scaffold fabrication has led to evolution of matrices for liver tissue culture from simple porous scaffolds to more complex 3D matrices with microarchitecture similar to in vivo. Natural and synthetic polymeric biomaterials fabricated in different topographies and porous matrices have been used for hepatocyte culture. Heterotypic and homotypic cell interactions are necessary for developing an adult liver as well as an artificial liver. A high oxygen demand of hepatocytes as well as graded oxygen distribution in liver is another challenging attribute of the normal liver architecture that further adds to the complexity of engineered substrate design. A balanced interplay of cell-matrix interactions along with cell-cell interactions and adequate supply of oxygen and nutrient determines the success of an engineered substrate for liver cells. Techniques devised to incorporate these features of hepatic function and mimic liver architecture range from maintaining liver cells in mm-sized tailor-made scaffolds to a more bottoms up approach that starts from building the microscopic subunit of the whole tissue. In this review, we discuss briefly various biomaterials used for liver tissue engineering with respect to design parameters such as scaffold composition and chemistry, biomechanical properties, topography, cell-cell interactions and oxygenation.
NMR-based metabolic profiling in healthy individuals overfed different types of fat: links to changes in liver fat accumulation and lean tissue mass
Elmsjö, A; Rosqvist, F; Engskog, M K R; Haglöf, J; Kullberg, J; Iggman, D; Johansson, L; Ahlström, H; Arvidsson, T; Risérus, U; Pettersson, C
Background: Overeating different dietary fatty acids influence the amount of liver fat stored during weight gain, however, the mechanisms responsible are unclear. We aimed to identify non-lipid metabolites that may differentiate between saturated (SFA) and polyunsaturated fatty acid (PUFA) overfeeding using a non-targeted metabolomic approach. We also investigated the possible relationships between plasma metabolites and body fat accumulation. Methods: In a randomized study (LIPOGAIN study), n=39 healthy individuals were overfed with muffins containing SFA or PUFA. Plasma samples were precipitated with cold acetonitrile and analyzed by nuclear magnetic resonance (NMR) spectroscopy. Pattern recognition techniques were used to overview the data, identify variables contributing to group classification and to correlate metabolites with fat accumulation. Results: We previously reported that SFA causes a greater accumulation of liver fat, visceral fat and total body fat, whereas lean tissue levels increases less compared with PUFA, despite comparable weight gain. In this study, lactate and acetate were identified as important contributors to group classification between SFA and PUFA (P<0.05). Furthermore, the fat depots (total body fat, visceral adipose tissue and liver fat) and lean tissue correlated (P(corr)>0.5) all with two or more metabolites (for example, branched amino acids, alanine, acetate and lactate). The metabolite composition differed in a manner that may indicate higher insulin sensitivity after a diet with PUFA compared with SFA, but this needs to be confirmed in future studies. Conclusion: A non-lipid metabolic profiling approach only identified a few metabolites that differentiated between SFA and PUFA overfeeding. Whether these metabolite changes are involved in depot-specific fat storage and increased lean tissue mass during overeating needs further investigation. PMID:26479316
Engineering of implantable liver tissues.
Sakai, Yasuyuki; Nishikawa, M; Evenou, F; Hamon, M; Huang, H; Montagne, K P; Kojima, N; Fujii, T; Niino, T
In this chapter, from the engineering point of view, we introduce the results from our group and related research on three typical configurations of engineered liver tissues; cell sheet-based tissues, sheet-like macroporous scaffold-based tissues, and tissues based on special scaffolds that comprise a flow channel network. The former two do not necessitate in vitro prevascularization and are thus promising in actual human clinical trials for liver diseases that can be recovered by relatively smaller tissue mass. The third approach can implant a much larger mass but is still not yet feasible. In all cases, oxygen supply is the key engineering factor. For the first configuration, direct oxygen supply using an oxygen-permeable polydimethylsiloxane membrane enables various liver cells to exhibit distinct behaviors, complete double layers of mature hepatocytes and fibroblasts, spontaneous thick tissue formation of hepatocarcinoma cells and fetal hepatocytes. Actual oxygen concentration at the cell level can be strictly controlled in this culture system. Using this property, we found that initially low then subsequently high oxygen concentrations were favorable to growth and maturation of fetal cells. For the second configuration, combination of poly-L: -lactic acid 3D scaffolds and appropriate growth factor cocktails provides a suitable microenvironment for the maturation of cells in vitro but the cell growth is limited to a certain distance from the inner surfaces of the macropores. However, implantation to the mesentery leaves of animals allows the cells again to proliferate and pack the remaining spaces of the macroporous structure, suggesting the high feasibility of 3D culture of hepatocyte progenitors for liver tissue-based therapies. For the third configuration, we proposed a design criterion concerning the dimensions of flow channels based on oxygen diffusion and consumption around the channel. Due to the current limitation in the resolution of 3D
Multiscale tissue engineering for liver reconstruction.
Sudo, Ryo
The liver is a target of in vitro tissue engineering despite its capability to regenerate in vivo. The construction of liver tissues in vitro remains challenging. In this review, conventional 3D cultures of hepatocytes are first discussed. Recent advances in the 3D culturing of liver cells are then summarized in the context of in vitro liver tissue reconstruction at the micro- and macroscales. The application of microfluidics technology to liver tissue engineering has been introduced as a bottom-up approach performed at the microscale, whereas whole-organ bioengineering technology was introduced as a top-down approach performed at the macroscale. Mesoscale approaches are also discussed in considering the integration of micro- and macroscale approaches. Multiple parallel multiscale liver tissue engineering studies are ongoing; however, no tissue-engineered liver that is appropriate for clinical use has yet been realized. The integration of multiscale tissue engineering studies is essential for further understanding of liver reconstruction strategies.
Cell and tissue engineering for liver disease.
Bhatia, Sangeeta N; Underhill, Gregory H; Zaret, Kenneth S; Fox, Ira J
Despite the tremendous hurdles presented by the complexity of the liver's structure and function, advances in liver physiology, stem cell biology and reprogramming, and the engineering of tissues and devices are accelerating the development of cell-based therapies for treating liver disease and liver failure. This State of the Art Review discusses both the near- and long-term prospects for such cell-based therapies and the unique challenges for clinical translation.
Diffuse reflectance spectroscopy of liver tissue
NASA Astrophysics Data System (ADS)
Reistad, Nina; Nilsson, Jan; Vilhelmsson Timmermand, Oskar; Sturesson, Christian; Andersson-Engels, Stefan
Diffuse reflectance spectroscopy (DRS) with a fiber-optic contact probe is a cost-effective, rapid, and non-invasive optical method used to extract diagnosis information of tissue. By combining commercially available VIS- and NIR-spectrometers with various fiber-optic contact-probes, we have access to the full wavelength range from around 400 to 1600 nm. Using this flexible and portable spectroscopy system, we have acquired ex-vivo DRS-spectra from murine, porcine, and human liver tissue. For extracting the tissue optical properties from the measured spectra, we have employed and compared predictions from two models for light propagation in tissue, diffusion theory model (DT) and Monte Carlo simulations (MC). The focus in this work is on the capacity of this DRS-technique in discriminating metastatic tumor tissue from normal liver tissue as well as in assessing and characterizing damage to non-malignant liver tissue induced by preoperative chemotherapy for colorectal liver metastases.
Cell and Tissue Engineering for Liver Disease
Bhatia, Sangeeta N.; Underhill, Gregory H.; Zaret, Kenneth S.; Fox, Ira J.
Despite the tremendous hurdles presented by the complexity of the liver's structure and function, advances in liver physiology, stem cell biology and reprogramming, and the engineering of tissues and devices are accelerating the development of cell-based therapies for treating liver disease and liver failure. This State of the Art Review discusses both the near and long-term prospects for such cell-based therapies and the unique challenges for clinical translation. PMID:25031271
The liver tissue bank and clinical database in China.
Yang, Yuan; Liu, Yi-Min; Wei, Ming-Yue; Wu, Yi-Fei; Gao, Jun-Hui; Liu, Lei; Zhou, Wei-Ping; Wang, Hong-Yang; Wu, Meng-Chao
To develop a standardized and well-rounded material available for hepatology research, the National Liver Tissue Bank (NLTB) Project began in 2008 in China to make well-characterized and optimally preserved liver tumor tissue and clinical database. From Dec 2008 to Jun 2010, over 3000 individuals have been enrolled as liver tumor donors to the NLTB, including 2317 cases of newly diagnosed hepatocellular carcinoma (HCC) and about 1000 cases of diagnosed benign or malignant liver tumors. The clinical database and sample store can be managed easily and correctly with the data management platform used. We believe that the high-quality samples with detailed information database will become the cornerstone of hepatology research especially in studies exploring the diagnosis and new treatments for HCC and other liver diseases.
Research progress in liver tissue engineering.
Zhang, Lei; Guan, Zheng; Ye, Jun-Song; Yin, Yan-Feng; Stoltz, Jean-François; de Isla, Natalia
Liver transplantation is the definitive treatment for patients with end-stage liver diseases (ESLD). However, it is hampered by shortage of liver donor. Liver tissue engineering, aiming at fabricating new livers in vitro, provides a potential resolution for donor shortage. Three elements need to be considered in liver tissue engineering: seeding cell resources, scaffolds and bioreactors. Studies have shown potential cell sources as hepatocytes, hepatic cell line, mesenchymal stem cells and others. They need scaffolds with perfect biocompatiblity, suitable micro-structure and appropriate degradation rate, which are essential charateristics for cell attachment, proliferation and secretion in forming extracellular matrix. The most promising scaffolds in research include decellularized whole liver, collagens and biocompatible plastic. The development and function of cells in scaffold need a microenvironment which can provide them with oxygen, nutrition, growth factors, et al. Bioreactor is expected to fulfill these requirements by mimicking the living condition in vivo. Although there is great progress in these three domains, a large gap stays still between their researches and applications. Herein, we summarized the recent development in these three major fields which are indispensable in liver tissue engineering.
Dynamic compressive response of bovine liver tissues.
Pervin, Farhana; Chen, Weinong W; Weerasooriya, Tusit
This study aims to experimentally determine the strain rate effects on the compressive stress-strain behavior of bovine liver tissues. Fresh liver tissues were used to make specimens for mechanical loading. Experiments at quasi-static strain rates were conducted at 0.01 and 0.1 s(-1). Intermediate-rate experiments were performed at 1, 10, and 100 s(-1). High strain rate (1000, 2000, and 3000 s(-1)) experiments were conducted using a Kolsky bar modified for soft material characterization. A hollow transmission bar with semi-conductor strain gages was used to sense the weak forces from the soft specimens. Quartz-crystal force transducers were used to monitor valid testing conditions on the tissue specimens. The experiment results show that the compressive stress-strain response of the liver tissue is non-linear and highly rate-sensitive, especially when the strain rate is in the Kolsky bar range. The tissue stiffens significantly with increasing strain rate. The responses from liver tissues along and perpendicular to the liver surface were consistent, indicating isotropic behavior.
Microengineered liver tissues for drug testing.
Khetani, Salman R; Berger, Dustin R; Ballinger, Kimberly R; Davidson, Matthew D; Lin, Christine; Ware, Brenton R
Drug-induced liver injury (DILI) is a leading cause of drug attrition. Significant and well-documented differences between animals and humans in liver pathways now necessitate the use of human-relevant in vitro liver models for testing new chemical entities during preclinical drug development. Consequently, several human liver models with various levels of in vivo-like complexity have been developed for assessment of drug metabolism, toxicity, and efficacy on liver diseases. Recent trends leverage engineering tools, such as those adapted from the semiconductor industry, to enable precise control over the microenvironment of liver cells and to allow for miniaturization into formats amenable for higher throughput drug screening. Integration of liver models into organs-on-a-chip devices, permitting crosstalk between tissue types, is actively being pursued to obtain a systems-level understanding of drug effects. Here, we review the major trends, challenges, and opportunities associated with development and implementation of engineered liver models created from primary cells, cell lines, and stem cell-derived hepatocyte-like cells. We also present key applications where such models are currently making an impact and highlight areas for improvement. In the future, engineered liver models will prove useful for selecting drugs that are efficacious, safer, and, in some cases, personalized for specific patient populations.
Humanized mice with ectopic artificial liver tissues.
Chen, Alice A; Thomas, David K; Ong, Luvena L; Schwartz, Robert E; Golub, Todd R; Bhatia, Sangeeta N
"Humanized" mice offer a window into aspects of human physiology that are otherwise inaccessible. The best available methods for liver humanization rely on cell transplantation into immunodeficient mice with liver injury but these methods have not gained widespread use due to the duration and variability of hepatocyte repopulation. In light of the significant progress that has been achieved in clinical cell transplantation through tissue engineering, we sought to develop a humanized mouse model based on the facile and ectopic implantation of a tissue-engineered human liver. These human ectopic artificial livers (HEALs) stabilize the function of cryopreserved primary human hepatocytes through juxtacrine and paracrine signals in polymeric scaffolds. In contrast to current methods, HEALs can be efficiently established in immunocompetent mice with normal liver function. Mice transplanted with HEALs exhibit humanized liver functions persistent for weeks, including synthesis of human proteins, human drug metabolism, drug-drug interaction, and drug-induced liver injury. Here, mice with HEALs are used to predict the disproportionate metabolism and toxicity of "major" human metabolites using multiple routes of administration and monitoring. These advances may enable manufacturing of reproducible in vivo models for diverse drug development and research applications.
Conducting scaffolds for liver tissue engineering.
Rad, Armin Tahmasbi; Ali, Naushad; Kotturi, Hari Shankar R; Yazdimamaghani, Mostafa; Smay, Jim; Vashaee, Daryoosh; Tayebi, Lobat
It is known that there is a correlation between a cell membrane potential and the proliferation of the cell. The high proliferation capacity of liver cells can also be attributed to its specific cell membrane potential as liver cell is recognized as one of the most depolarized of all differentiated cells. We hypothesized that this phenomenon can be emphasized by growing liver cells in conducting scaffolds that can increase the electrical communication among the cells. In this article, using tissue engineering techniques, we grew hepatocyte cells in scaffolds with various compositions. It was found that the scaffolds containing conducting polymer of poly (3,4-ethylenedioxythiophene) (PEDOT) provide the best condition for attachment and proliferation of the cells. More specifically, the blend of hyaluronan, PEDOT, and collagen (I) as dopants in gelatin-chitosan-based scaffold presented the best cell/scaffold interactions for regeneration of liver cells.
Cells and materials for liver tissue engineering.
Li, Yuan-Sheng; Harn, Horng-Jyh; Hsieh, Dean-Kuo; Wen, Tung-Chou; Subeq, Yi-Maun; Sun, Li-Yi; Lin, Shinn-Zong; Chiou, Tzyy-Wen
Liver transplantation is currently the most efficacious treatment for end-stage liver diseases. However, one main problem with liver transplantation is the limited number of donor organs that are available. Therefore, liver tissue engineering based on cell transplantation that combines materials to mimic the liver is under investigation with the goal of restoring normal liver functions. Tissue engineering aims to mimic the interactions among cells with a scaffold. Particular materials or a matrix serve as a scaffold and provide a three-dimensional environment for cell proliferation and interaction. Moreover, the scaffold plays a role in regulating cell maturation and function via these interactions. In cultures of hepatic lineage cells, regulation of cell proliferation and specific function using biocompatible synthetic, biodegradable bioderived matrices, protein-coated materials, surface-modified nanofibers, and decellularized biomatrix has been demonstrated. Furthermore, beneficial effects of addition of growth factor cocktails to a flow bioreactor or coculture system on cell viability and function have been observed. In addition, a system for growing stem cells, liver progenitor cells, and primary hepatocytes for transplantation into animal models was developed, which produces hepatic lineage cells that are functional and that show long-term proliferation following transplantation. The major limitation of cells proliferated with matrix-based transplantation systems is the high initial cell loss and dysfunction, which may be due to the absence of blood flow and the changes in nutrients. Thus, the development of vascular-like scaffold structures, the formation of functional bile ducts, and the maintenance of complex metabolic functions remain as major problems in hepatic tissue engineering and will need to be addressed to enable further advances toward clinical applications.
[Treatment of liver failure using tissue engineering techniques].
Pokrywczyńska, Marta; Drewa, Tomasz
Liver transplantation is the only efficient method of treatment of liver failure. Short time between liver end-stage insufficiency and transplantation procedure is the main problem limiting the number of liver transplants. In this paper the methods of liver support in patients awaiting a liver transplant using tissue engineering techniques were introduced. The methods of liver support using bioartificial liver and isolated hepatocytes transplantation were described.
Liver-cell patterning lab chip: mimicking the morphology of liver lobule tissue.
Ho, Chen-Ta; Lin, Ruei-Zeng; Chen, Rong-Jhe; Chin, Chung-Kuang; Gong, Song-En; Chang, Hwan-You; Peng, Hwei-Ling; Hsu, Long; Yew, Tri-Rung; Chang, Shau-Feng; Liu, Cheng-Hsien
A lobule-mimetic cell-patterning technique for on-chip reconstruction of centimetre-scale liver tissue of heterogeneous hepatic and endothelial cells via an enhanced field-induced dielectrophoresis (DEP) trap is demonstrated and reported. By mimicking the basic morphology of liver tissue, the classic hepatic lobule, the lobule-mimetic-stellate-electrodes array was designed for cell patterning. Through DEP manipulation, well-defined and enhanced spatial electric field gradients were created for in-parallel manipulation of massive individual cells. With this liver-cell patterning labchip design, the original randomly distributed hepatic and endothelial cells inside the microfluidic chamber can be manipulated separately and aligned into the desired pattern that mimicks the morphology of liver lobule tissue. Experimental results showed that both hepatic and endothelial cells were orderly guided, snared, and aligned along the field-induced orientation to form the lobule-mimetic pattern. About 95% cell viability of hepatic and endothelial cells was also observed after cell-patterning demonstration via a fluorescent assay technique. The liver function of CYP450-1A1 enzyme activity showed an 80% enhancement for our engineered liver tissue (HepG2+HUVECs) compared to the non-patterned pure HepG2 for two-day culturing.
Liver tissue engineering: promises and prospects of new technology.
Zheng, Ming-Hua; Ye, Chao; Braddock, Martin; Chen, Yong-Ping
Today, many patients suffer from acute liver failure and hepatoma. This is an area of high unmet clinical need as these conditions are associated with very high mortality. There is an urgent need to develop techniques that will enable liver tissue engineering or generate a bioartificial liver, which will maintain or improve liver function or offer the possibility of liver replacement. Liver tissue engineering is an innovative way of constructing an implantable liver and has the potential to alleviate the shortage of organ donors for orthotopic liver transplantation. In this review we describe, from an engineering perspective, progress in the field of liver tissue engineering, including three main aspects involving cell sources, scaffolds and vascularization.
Microporous membrane-based liver tissue engineering for the reconstruction of three-dimensional functional liver tissues in vitro.
Kasuya, Junichi; Tanishita, Kazuo
To meet the increasing demand for liver tissue engineering, various three-dimensional (3D) liver cell culture techniques have been developed. Nevertheless, conventional liver cell culture techniques involving the suspending cells in extracellular matrix (ECM) components and the seeding of cells into 3D biodegradable scaffolds have an intrinsic shortcoming, low cell-scaffold ratios. We have developed a microporous membrane-based liver cell culture technique. Cell behaviors and tissue organization can be controlled by membrane geometry, and cell-dense thick tissues can be reconstructed by layering cells cultured on biodegradable microporous membranes. Applications extend from liver parenchymal cell monoculture to multi-cell type cultures for the reconstruction of 3D functional liver tissue. This review focuses on the expanding role for microporous membranes in liver tissue engineering, primarily from our research.
Cell Sources, Liver Support Systems and Liver Tissue Engineering: Alternatives to Liver Transplantation
Lee, Soo Young; Kim, Han Joon; Choi, Dongho
The liver is the largest organ in the body; it has a complex architecture, wide range of functions and unique regenerative capacity. The growing incidence of liver diseases worldwide requires increased numbers of liver transplant and leads to an ongoing shortage of donor livers. To meet the huge demand, various alternative approaches are being investigated including, hepatic cell transplantation, artificial devices and bioprinting of the organ itself. Adult hepatocytes are the preferred cell sources, but they have limited availability, are difficult to isolate, propagate poor and undergo rapid functional deterioration in vitro. There have been efforts to overcome these drawbacks; by improving culture condition for hepatocytes, providing adequate extracellular matrix, co-culturing with extra-parenchymal cells and identifying other cell sources. Differentiation of human stem cells to hepatocytes has become a major interest in the field of stem cell research and has progressed greatly. At the same time, use of decellularized organ matrices and 3 D printing are emerging cutting-edge technologies for tissue engineering, opening up new paths for liver regenerative medicine. This review provides a compact summary of the issues, and the locations of liver support systems and tissue engineering, with an emphasis on reproducible and useful sources of hepatocytes including various candidates formed by differentiation from stem cells. PMID:26019753
Cell sources, liver support systems and liver tissue engineering: alternatives to liver transplantation.
Lee, Soo Young; Kim, Han Joon; Choi, Dongho
The liver is the largest organ in the body; it has a complex architecture, wide range of functions and unique regenerative capacity. The growing incidence of liver diseases worldwide requires increased numbers of liver transplant and leads to an ongoing shortage of donor livers. To meet the huge demand, various alternative approaches are being investigated including, hepatic cell transplantation, artificial devices and bioprinting of the organ itself. Adult hepatocytes are the preferred cell sources, but they have limited availability, are difficult to isolate, propagate poor and undergo rapid functional deterioration in vitro. There have been efforts to overcome these drawbacks; by improving culture condition for hepatocytes, providing adequate extracellular matrix, co-culturing with extra-parenchymal cells and identifying other cell sources. Differentiation of human stem cells to hepatocytes has become a major interest in the field of stem cell research and has progressed greatly. At the same time, use of decellularized organ matrices and 3 D printing are emerging cutting-edge technologies for tissue engineering, opening up new paths for liver regenerative medicine. This review provides a compact summary of the issues, and the locations of liver support systems and tissue engineering, with an emphasis on reproducible and useful sources of hepatocytes including various candidates formed by differentiation from stem cells.
Cell patterning for liver tissue engineering via dielectrophoretic mechanisms.
Yahya, Wan Nurlina Wan; Kadri, Nahrizul Adib; Ibrahim, Fatimah
Liver transplantation is the most common treatment for patients with end-stage liver failure. However, liver transplantation is greatly limited by a shortage of donors. Liver tissue engineering may offer an alternative by providing an implantable engineered liver. Currently, diverse types of engineering approaches for in vitro liver cell culture are available, including scaffold-based methods, microfluidic platforms, and micropatterning techniques. Active cell patterning via dielectrophoretic (DEP) force showed some advantages over other methods, including high speed, ease of handling, high precision and being label-free. This article summarizes liver function and regenerative mechanisms for better understanding in developing engineered liver. We then review recent advances in liver tissue engineering techniques and focus on DEP-based cell patterning, including microelectrode design and patterning configuration.
Cell Patterning for Liver Tissue Engineering via Dielectrophoretic Mechanisms
Yahya, Wan Nurlina Wan; Kadri, Nahrizul Adib; Ibrahim, Fatimah
Liver transplantation is the most common treatment for patients with end-stage liver failure. However, liver transplantation is greatly limited by a shortage of donors. Liver tissue engineering may offer an alternative by providing an implantable engineered liver. Currently, diverse types of engineering approaches for in vitro liver cell culture are available, including scaffold-based methods, microfluidic platforms, and micropatterning techniques. Active cell patterning via dielectrophoretic (DEP) force showed some advantages over other methods, including high speed, ease of handling, high precision and being label-free. This article summarizes liver function and regenerative mechanisms for better understanding in developing engineered liver. We then review recent advances in liver tissue engineering techniques and focus on DEP-based cell patterning, including microelectrode design and patterning configuration. PMID:24991941
Decellularized liver as a practical scaffold with a vascular network template for liver tissue engineering.
Shirakigawa, Nana; Ijima, Hiroyuki; Takei, Takayuki
The construction of a functional liver-tissue equivalent using tissue engineering is a very important goal because the liver is a central organ in the body. However, the construction of functional organ-scale liver tissue is impossible because it requires a high-density blood vessel network. In this study, we focused on decellularization technology to solve this problem. Decellularized liver tissue with a fine vascular tree network template was obtained using Triton X-100. The distance between each vascular structure was less than 1 mm. Endothelialization of the blood vessel network with human umbilical vein endothelial cells (HUVECs) was successfully performed without any leakage of HUVECs to the outside of the vessel structure. Furthermore, hepatocytes/spheroids could be located around the blood vessel structure. This study indicates that decellularized liver tissue is a potential scaffold for creating a practical liver tissue using tissue engineering technology.
Method for Processing Liver Spheroids Using an Automatic Tissue Processor
METHOD FOR PROCESSING LIVER SPHEROIDS USING AN AUTOMATIC TISSUE PROCESSOR ECBC-TN-070 Russell M. Dorsey...response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and...COVERED (From - To) Jul 2014 – Jul 2015 4. TITLE AND SUBTITLE Method for Processing Liver Spheroids Using an Automatic Tissue Processor 5a
Liver cell therapy and tissue engineering for transplantation.
Vacanti, Joseph P; Kulig, Katherine M
Liver transplantation remains the only definitive treatment for liver failure and is available to only a tiny fraction of patients with end-stage liver diseases. Major limitations for the procedure include donor organ shortage, high cost, high level of required expertise, and long-term consequences of immune suppression. Alternative cell-based liver therapies could potentially greatly expand the number of patients provided with effective treatment. Investigative research into augmenting or replacing liver function extends into three general strategies. Bioartificial livers (BALs) are extracorporeal devices that utilize cartridges of primary hepatocytes or cell lines to process patient plasma. Injection of liver cell suspensions aims to foster organ regeneration or provide a missing metabolic function arising from a genetic defect. Tissue engineering recreates the organ in vitro for subsequent implantation to augment or replace patient liver function. Translational models and clinical trials have highlighted both the immense challenges involved and some striking examples of success.
Liver Progenitors Isolated from Adult Healthy Mouse Liver Efficiently Differentiate to Functional Hepatocytes In Vitro and Repopulate Liver Tissue.
Tanimizu, Naoki; Ichinohe, Norihisa; Ishii, Masayuki; Kino, Junichi; Mizuguchi, Toru; Hirata, Koichi; Mitaka, Toshihiro
It has been proposed that tissue stem cells supply multiple epithelial cells in mature tissues and organs. However, it is unclear whether tissue stem cells generally contribute to cellular turnover in normal healthy organs. Here, we show that liver progenitors distinct from bipotent liver stem/progenitor cells (LPCs) persistently exist in mouse livers and potentially contribute to tissue maintenance. We found that, in addition to LPCs isolated as EpCAM(+) cells, liver progenitors were enriched in CD45(-) TER119(-) CD31(-) EpCAM(-) ICAM-1(+) fraction isolated from late-fetal and postnatal livers. ICAM-1(+) liver progenitors were abundant by 4 weeks (4W) after birth. Although their number decreased with age, ICAM-1(+) liver progenitors existed in livers beyond that stage. We established liver progenitor clones derived from ICAM-1(+) cells between 1 and 20W and found that those clones efficiently differentiated into mature hepatocytes (MHs), which secreted albumin, eliminated ammonium ion, stored glycogen, and showed cytochrome P450 activity. Even after long-term culture, those clones kept potential to differentiate to MHs. When ICAM-1(+) clones were transplanted into nude mice after retrorsine treatment and 70% partial hepatectomy, donor cells were incorporated into liver plates and expressed hepatocyte nuclear factor 4α, CCAAT/enhancer binding protein α, and carbamoylphosphate synthetase I. Moreover, after short-term treatment with oncostatin M, ICAM-1(+) clones could efficiently repopulate the recipient liver tissues. Our results indicate that liver progenitors that can efficiently differentiate to MHs exist in normal adult livers. Those liver progenitors could be an important source of new MHs for tissue maintenance and repair in vivo, and for regenerative medicine ex vivo. Stem Cells 2016;34:2889-2901.
Liver tissue engineering and cell sources: issues and challenges.
Palakkan, Anwar A; Hay, David C; Anil Kumar, P R; Kumary, T V; Ross, James A
Liver diseases are of major concern as they now account for millions of deaths annually. As a result of the increased incidence of liver disease, many patients die on the transplant waiting list, before a donor organ becomes available. To meet the huge demand for donor liver, alternative approaches using liver tissue engineering principles are being actively pursued. Even though adult hepatocytes, the primary cells of the liver are most preferred for tissue engineering of liver, their limited availability, isolation from diseased organs, lack of in vitro propagation and deterioration of function acts as a major drawback to their use. Various approaches have been taken to prevent the functional deterioration of hepatocytes including the provision of an adequate extracellular matrix and co-culture with non-parenchymal cells of liver. Great progress has also been made to differentiate human stem cells to hepatocytes and to use them for liver tissue engineering applications. This review provides an overview of recent challenges, issues and cell sources with regard to liver tissue engineering.
Transport advances in disposable bioreactors for liver tissue engineering.
Catapano, Gerardo; Patzer, John F; Gerlach, Jörg Christian
Acute liver failure (ALF) is a devastating diagnosis with an overall survival of approximately 60%. Liver transplantation is the therapy of choice for ALF patients but is limited by the scarce availability of donor organs. The prognosis of ALF patients may improve if essential liver functions are restored during liver failure by means of auxiliary methods because liver tissue has the capability to regenerate and heal. Bioartificial liver (BAL) approaches use liver tissue or cells to provide ALF patients with liver-specific metabolism and synthesis products necessary to relieve some of the symptoms and to promote liver tissue regeneration. The most promising BAL treatments are based on the culture of tissue engineered (TE) liver constructs, with mature liver cells or cells that may differentiate into hepatocytes to perform liver-specific functions, in disposable continuous-flow bioreactors. In fact, adult hepatocytes perform all essential liver functions. Clinical evaluations of the proposed BALs show that they are safe but have not clearly proven the efficacy of treatment as compared to standard supportive treatments. Ambiguous clinical results, the time loss of cellular activity during treatment, and the presence of a necrotic core in the cell compartment of many bioreactors suggest that improvement of transport of nutrients, and metabolic wastes and products to or from the cells in the bioreactor is critical for the development of therapeutically effective BALs. In this chapter, advanced strategies that have been proposed over to improve mass transport in the bioreactors at the core of a BAL for the treatment of ALF patients are reviewed.
Transport Advances in Disposable Bioreactors for Liver Tissue Engineering
NASA Astrophysics Data System (ADS)
Catapano, Gerardo; Patzer, John F.; Gerlach, Jörg Christian
Acute liver failure (ALF) is a devastating diagnosis with an overall survival of approximately 60%. Liver transplantation is the therapy of choice for ALF patients but is limited by the scarce availability of donor organs. The prognosis of ALF patients may improve if essential liver functions are restored during liver failure by means of auxiliary methods because liver tissue has the capability to regenerate and heal. Bioartificial liver (BAL) approaches use liver tissue or cells to provide ALF patients with liver-specific metabolism and synthesis products necessary to relieve some of the symptoms and to promote liver tissue regeneration. The most promising BAL treatments are based on the culture of tissue engineered (TE) liver constructs, with mature liver cells or cells that may differentiate into hepatocytes to perform liver-specific functions, in disposable continuous-flow bioreactors. In fact, adult hepatocytes perform all essential liver functions. Clinical evaluations of the proposed BALs show that they are safe but have not clearly proven the efficacy of treatment as compared to standard supportive treatments. Ambiguous clinical results, the time loss of cellular activity during treatment, and the presence of a necrotic core in the cell compartment of many bioreactors suggest that improvement of transport of nutrients, and metabolic wastes and products to or from the cells in the bioreactor is critical for the development of therapeutically effective BALs. In this chapter, advanced strategies that have been proposed over to improve mass transport in the bioreactors at the core of a BAL for the treatment of ALF patients are reviewed.
High intensity interval training improves liver and adipose tissue insulin sensitivity
Marcinko, Katarina; Sikkema, Sarah R.; Samaan, M. Constantine; Kemp, Bruce E.; Fullerton, Morgan D.; Steinberg, Gregory R.
Objective Endurance exercise training reduces insulin resistance, adipose tissue inflammation and non-alcoholic fatty liver disease (NAFLD), an effect often associated with modest weight loss. Recent studies have indicated that high-intensity interval training (HIIT) lowers blood glucose in individuals with type 2 diabetes independently of weight loss; however, the organs affected and mechanisms mediating the glucose lowering effects are not known. Intense exercise increases phosphorylation and inhibition of acetyl-CoA carboxylase (ACC) by AMP-activated protein kinase (AMPK) in muscle, adipose tissue and liver. AMPK and ACC are key enzymes regulating fatty acid metabolism, liver fat content, adipose tissue inflammation and insulin sensitivity but the importance of this pathway in regulating insulin sensitivity with HIIT is unknown. Methods In the current study, the effects of 6 weeks of HIIT were examined using obese mice with serine–alanine knock-in mutations on the AMPK phosphorylation sites of ACC1 and ACC2 (AccDKI) or wild-type (WT) controls. Results HIIT lowered blood glucose and increased exercise capacity, food intake, basal activity levels, carbohydrate oxidation and liver and adipose tissue insulin sensitivity in HFD-fed WT and AccDKI mice. These changes occurred independently of weight loss or reductions in adiposity, inflammation and liver lipid content. Conclusions These data indicate that HIIT lowers blood glucose levels by improving adipose and liver insulin sensitivity independently of changes in adiposity, adipose tissue inflammation, liver lipid content or AMPK phosphorylation of ACC. PMID:26909307
Immunogenicity of decellularized porcine liver for bioengineered hepatic tissue.
Mirmalek-Sani, Sayed-Hadi; Sullivan, David C; Zimmerman, Cynthia; Shupe, Thomas D; Petersen, Bryon E
Liver disease affects millions of patients each year. The field of regenerative medicine promises alternative therapeutic approaches, including the potential to bioengineer replacement hepatic tissue. One approach combines cells with acellular scaffolds derived from animal tissue. The goal of this study was to scale up our rodent liver decellularization method to livers of a clinically relevant size. Porcine livers were cannulated via the hepatic artery, then perfused with PBS, followed by successive Triton X-100 and SDS solutions in saline buffer. After several days of rinsing, decellularized liver samples were histologically analyzed. In addition, biopsy specimens of decellularized scaffolds were seeded with hepatoblastoma cells for cytotoxicity testing or implanted s.c. into rodents to investigate scaffold immunogenicity. Histological staining confirmed cellular clearance from pig livers, with removal of nuclei and cytoskeletal components and widespread preservation of structural extracellular molecules. Scanning electron microscopy confirmed preservation of an intact liver capsule, a porous acellular lattice structure with intact vessels and striated basement membrane. Liver scaffolds supported cells over 21 days, and no increased immune response was seen with either allogeneic (rat-into-rat) or xenogeneic (pig-into-rat) transplants over 28 days, compared with sham-operated on controls. These studies demonstrate that successful decellularization of the porcine liver could be achieved with protocols developed for rat livers, yielding nonimmunogenic scaffolds for future hepatic bioengineering studies.
Liver transplantation in the mouse: Insights into liver immunobiology, tissue injury, and allograft tolerance.
Yokota, Shinichiro; Yoshida, Osamu; Ono, Yoshihiro; Geller, David A; Thomson, Angus W
The surgically demanding mouse orthotopic liver transplant model was first described in 1991. It has proved to be a powerful research tool for the investigation of liver biology, tissue injury, the regulation of alloimmunity and tolerance induction, and the pathogenesis of specific liver diseases. Liver transplantation in mice has unique advantages over transplantation of the liver in larger species, such as the rat or pig, because the mouse genome is well characterized and there is much greater availability of both genetically modified animals and research reagents. Liver transplant experiments using various transgenic or gene knockout mice have provided valuable mechanistic insights into the immunobiology and pathobiology of the liver and the regulation of graft rejection and tolerance over the past 25 years. The molecular pathways identified in the regulation of tissue injury and promotion of liver transplant tolerance provide new potential targets for therapeutic intervention to control adverse inflammatory responses/immune-mediated events in the hepatic environment and systemically. In conclusion, orthotopic liver transplantation in the mouse is a valuable model for gaining improved insights into liver biology, immunopathology, and allograft tolerance that may result in therapeutic innovation in the liver and in the treatment of other diseases.
Fetal and adult liver stem cells for liver regeneration and tissue engineering.
Fiegel, H C; Lange, Claudia; Kneser, U; Lambrecht, W; Zander, A R; Rogiers, X; Kluth, D
For the development of innovative cell-based liver directed therapies, e.g. liver tissue engineering, the use of stem cells might be very attractive to overcome the limitation of donor liver tissue. Liver specific differentiation of embryonic, fetal or adult stem cells is currently under investigation. Different types of fetal liver (stem) cells during development were identified, and their advantageous growth potential and bipotential differentiation capacity were shown. However, ethical and legal issues have to be addressed before using fetal cells. Use of adult stem cells is clinically established, e.g. transplantation of hematopoietic stem cells. Other bone marrow derived liver stem cells might be mesenchymal stem cells (MSC). However, the transdifferentiation potential is still in question due to the observation of cellular fusion in several in vivo experiments. In vitro experiments revealed a crucial role of the environment (e.g. growth factors and extracellular matrix) for specific differentiation of stem cells. Co-cultured liver cells also seemed to be important for hepatic gene expression of MSC. For successful liver cell transplantation, a novel approach of tissue engineering by orthotopic transplantation of gel-immobilized cells could be promising, providing optimal environment for the injected cells. Moreover, an orthotopic tissue engineering approach using bipotential stem cells could lead to a repopulation of the recipients liver with healthy liver and biliary cells, thus providing both hepatic functions and biliary excretion. Future studies have to investigate, which stem cell and environmental conditions would be most suitable for the use of stem cells for liver regeneration or tissue engineering approaches.
Functional tissue engineering of the liver and islets.
Ohashi, Kazuo; Okano, Teruo
Cell-based therapies by using hepatocytes and islets have recently been evaluated as a new therapeutic modality for patients with many forms of liver diseases and insulin-deficient diabetes mellitus. In most of the recently conducted clinical trials, cells have been delivered into liver vasculatures by infusing them through the portal circulation. More recently, tissue engineering-based approaches have spurred significant interests, using hepatocytes and islets in which small but functional new tissues would be created in vivo. Under circumstances in which a higher level of cell engraftment could be obtained, these approaches could provide therapeutic effects. Considerable efforts have been given to sustaining engineered tissues and maintaining their therapeutic effects. This review highlights several strategies that can achieve a higher level of cell survival for creating new functional liver and islet tissues.
[Tissue oxygen exchange and oxidative processes in long-livers: age peculiarities].
Korkushko, O V; Ivanov, L A; Shatilo, V B
This work was undertaken to study tissue oxygen exchange and oxidative processes in the long-lived individuals who were assumed as the physiologically aging individuals. Oxygen tension was assessed in forearm subcutaneous cellular tissue by means of the polarographic method while performing 10 min oxygen inhalation tests (with spontaneous oxygemogram recording) and a 10 min clamping of vessels. The obtained data served as the tissue oxygen exchange indicator. This approach made us possible to evaluate the oxygen delivery and oxygen uptake. To study qualitative characteristics of oxidative processes, we assessed vacat-oxygen of the blood and urine and estimated the underoxidation coefficient proposed by Muller. We have found that tissue respiration intensity falls, the amount of underoxidated products of the blood and urine rises, and the underoxidation coefficient increases in aging. The decrease of tissue oxygen respiration intensity in subcutaneous cellular tissue reflects the development of tissue hypoxia associated with reduced activity of the enzymes, being involved in oxygen exchange. An age-related decrease of tissue perfusion leads to the formation of circulatory hypoxia and also contributes considerably to tissue hypoxia formation. The revealed changes in the tissue oxygen exchange and oxidative processes in the long-livers are generally correspondent to those that can be seen in the people of 80-89 years. This finding speaks in favor of the physiological aging in the long-livers.
Hyperplasia vs hypertrophy in tissue regeneration after extensive liver resection
Marongiu, Fabio; Marongiu, Michela; Contini, Antonella; Serra, Monica; Cadoni, Erika; Murgia, Riccardo; Laconi, Ezio
AIM To address to what extent hypertrophy and hyperplasia contribute to liver mass restoration after major tissue loss. METHODS The ability of the liver to regenerate is remarkable on both clinical and biological grounds. Basic mechanisms underlying this process have been intensively investigated. However, it is still debated to what extent hypertrophy and hyperplasia contribute to liver mass restoration after major tissue loss. We addressed this issue using a genetically tagged system. We were able to follow the fate of single transplanted hepatocytes during the regenerative response elicited by 2/3 partial surgical hepatectomy (PH) in rats. Clusters of transplanted cells were 3D reconstructed and their size distribution was evaluated over time after PH. RESULTS Liver size and liver DNA content were largely recovered 10 d post-PH, as expected (e.g., total DNA/liver/100 g b.w. was 6.37 ± 0.21 before PH and returned to 6.10 ± 0.36 10 d after PH). Data indicated that about 2/3 of the original residual hepatocytes entered S-phase in response to PH. Analysis of cluster size distribution at 24, 48, 96 h and 10 d after PH revealed that about half of the remnant hepatocytes completed at least 2 cell cycles. Average size of hepatocytes increased at 24 h (248.50 μm2 ± 7.82 μm2, P = 0.0015), but returned to control values throughout the regenerative process (up to 10 d post-PH, 197.9 μm2 ± 6.44 μm2, P = 0.11). A sizeable fraction of the remnant hepatocyte population does not participate actively in tissue mass restoration. CONCLUSION Hyperplasia stands as the major mechanism contributing to liver mass restoration after PH, with hypertrophy playing a transient role in the process. PMID:28348481
Ultrasonic characterization of porcine liver tissue at frequency between 25 to 55 MHz
Liu, Xiao-Zhou; Gong, Xiu-Fen; Zhang, Dong; Ye, Shi-Gong; Rui, Bing
AIM: To study the relation between acoustic parameters and histological structure of biological tissue and to provide the basis for high-resolution image of biological tissues and quantitative ultrasonic diagnosis of liver disease. METHODS: Ultrasonic imaging and tissue characterization of four normal porcine liver and five cirrhotic liver tissue samples were performed using a high frequency imaging system. RESULTS: The acoustic parameters of cirrhotic liver tissue were larger than those of normal liver tissue. The sound velocity was 1577 m/s in normal liver tissue and 1631 m/s in cirrhotic liver tissue. At 35 MHz, the attenuation coefficient was 3.0 dB/mm in normal liver tissue and 4.1 dB/mm in cirrhotic liver tissue. The backscatter coefficient was 0.00431 dB/Srmm in cirrhotic liver tissue and 0.00303 dB/Srmm in normal liver tissue. The backscatter coefficient increased with the frequency. The high frequency images coincided with their histological features. CONCLUSION: The acoustic parameters, especially the sound backscatter coefficient, are sensitive to the changes of liver tissues and can be used to differentiate between the normal and pathological liver tissues. High frequency image system is a useful device for high-resolution image and tissue characterization. PMID:16610036
Comparison of premortem and postmortem estimates of plutonium deposited in the skeleton and liver of six individuals
Sula, M.J.; Bihl, D.E.; Carbaugh, E.H.; Kathren, R.L.
Assessment of organ burdens after internal exposures to radionuclides is often necessary to evaluate the health and regulatory implications of the exposure. The assessment of plutonium activity in skeleton and liver is usually estimated from measurements of plutonium excreted via urine. As part of the overall evaluation of internal dose assessment techniques, it is useful to compare the results of organ burden estimates made from evaluation of urinary excretion data with those made at death from tissue samples collected posthumously from the individual. Estimates of plutonium in the skeleton and liver, based on postmortem analysis of tissue samples for six individuals, were obtained from the US Transuranium Registry (USTR). Bioassay data and other radiation exposure information obtained from the individuals' files were used to estimate their skeleton and liver burdens at the times of their deaths, and these estimates were compared to those obtained through tissue analysis. 6 refs., 2 tabs.
Molecular characterization, tissue expression, and polymorphism analysis of liver-type fatty acid binding protein in Landes geese.
Song, Z; Shao, D; Sun, X X; Niu, J W; Gong, D Q
Liver weight is an important economic trait in the fatty goose liver industry. Liver-type fatty acid binding protein (L-FABP) is involved in the formation and metabolism of fatty acids. Thus, we hypothesized that sequence polymorphisms in L-FABP were associated with fatty liver weight in goose. We first isolated, sequenced, and characterized the goose L-FABP gene, which had not been previously reported. The goose L-FABP gene was 2490 bp and included 4 exons coding for a 126-amino acid protein. Analysis of expression levels of the goose L-FABP gene in different tissues showed that the expression level in the liver tissue was higher than in other tissues, and was significantly higher in the liver tissue of overfed geese than in control geese. Moreover, a single nucleotide polymorphism located at 774 bp in the gene was identified in a Landes goose population. To test whether this single nucleotide polymorphism was associated with fatty liver production, liver weight and the ratio of liver to carcass weights were determined for the 3 genotypes with this single nucleotide polymorphism (TT, TG, GG) in overfed Landes geese. Our data indicate that individuals with the GG genotype had higher values for the variables measured than those with the other 2 genotypes, suggesting that L-FABP can be a selection marker for the trait of fatty liver production in goose.
Detection of liver cancer and abnormal liver tissue by Raman spectroscopy and fluorescence
NASA Astrophysics Data System (ADS)
Li, Xiaozhou; Ding, Jianhua; Zhang, Xiujun; Lin, Junxiu; Wang, Deli
In this paper, laser induced human serum Raman spectra of liver cancer are measured. The spectra differences in serum from normal people and liver disease patients are analyzed. For the typical spectrum of normal serum, there are three sharp Raman peaks and relative intensity of Raman peaks excited by 514.5nm is higher than that excited by 488.0nm. For the Raman spectrum of liver cancer serum there are no peaks or very weak Raman peaks at the same positions. Results from more than two hundred case measurements show that clinical diagnostic accuracy is 92.86%. And then, the liver fibrosis and liver cirrhosis are studied applying the technology of LIF. To liver cirrhosis, the shape of Raman peak is similar to normal and fluorescence spectrum is similar to that of liver cancer from statistic data. The experiment indicates that there is notable fluorescence difference between the abnormal and normal liver tissue and have blue shift in fluorescence peak. Except for human serum, we use rats serum for researching either. Compared with results of path al examination, we analyze the spectra of normal cases, hepatic fibrosis and hepatocirrhosis respectively in an attempt to find some difference between them. Red shift of fluorescence peak is observed with disease evolution using 514.5nm excitation of an Ar-ion laser. However, no distinct changes happen with 488.0nm excitation. These results have important reference values to explore the method of laser spectrum diagnosis.
Liver tissue engineering utilizing hepatocytes propagated in mouse livers in vivo.
Ohashi, Kazuo; Tatsumi, Kohei; Tateno, Chise; Kataoka, Miho; Utoh, Rie; Yoshizato, Katsutoshi; Okano, Teruo
Recent advances in tissue engineering technologies have highlighted the ability to create functional liver systems using isolated hepatocytes in vivo. Considering the serious shortage of donor livers that can be used for hepatocyte isolation, it has remained imperative to establish a hepatocyte propagation protocol to provide highly efficient cell recovery allowing for subsequent tissue engineering procedures. Donor primary hepatocytes were isolated from human α-1 antitrypsin (hA1AT) transgenic mice and were transplanted into the recipient liver of urokinase-type plasminogen activator-severe combined immunodeficiency (uPA/SCID) mice. Transplanted donor hepatocytes actively proliferated within the recipient liver of the uPA/SCID mice. At week 8 or later, full repopulation of the uPA/SCID livers with the transplanted hA1AT hepatocytes were confirmed by blood examination and histological assessment. Proliferated hA1AT hepatocytes were recovered from the recipient uPA/SCID mice, and we generated hepatocyte sheets using these recovered hepatocytes for subsequent transplantation into the subcutaneous space of mice. Stable persistency of the subcutaneously engineered liver tissues was confirmed for up to 90 days, which was the length of our present study. These new data demonstrate the feasibility in propagating murine hepatocytes prior to the development of hepatic cells and bioengineered liver systems. The ability to regenerate and expand hepatocytes has potential clinical value whereby procurement of small amounts of tissue could be expanded to sufficient quantities prior to their use in hepatocyte transplantation or other hepatocyte-based therapies.
Classification of kidney and liver tissue using ultrasound backscatter data
NASA Astrophysics Data System (ADS)
Aalamifar, Fereshteh; Rivaz, Hassan; Cerrolaza, Juan J.; Jago, James; Safdar, Nabile; Boctor, Emad M.; Linguraru, Marius G.
Ultrasound (US) tissue characterization provides valuable information for the initialization of automatic segmentation algorithms, and can further provide complementary information for diagnosis of pathologies. US tissue characterization is challenging due to the presence of various types of image artifacts and dependence on the sonographer's skills. One way of overcoming this challenge is by characterizing images based on the distribution of the backscatter data derived from the interaction between US waves and tissue. The goal of this work is to classify liver versus kidney tissue in 3D volumetric US data using the distribution of backscatter US data recovered from end-user displayed Bmode image available in clinical systems. To this end, we first propose the computation of a large set of features based on the homodyned-K distribution of the speckle as well as the correlation coefficients between small patches in 3D images. We then utilize the random forests framework to select the most important features for classification. Experiments on in-vivo 3D US data from nine pediatric patients with hydronephrosis showed an average accuracy of 94% for the classification of liver and kidney tissues showing a good potential of this work to assist in the classification and segmentation of abdominal soft tissue.
Perfused multiwell plate for 3D liver tissue engineering.
Domansky, Karel; Inman, Walker; Serdy, James; Dash, Ajit; Lim, Matthew H M; Griffith, Linda G
In vitro models that capture the complexity of in vivo tissue and organ behaviors in a scalable and easy-to-use format are desirable for drug discovery. To address this, we have developed a bioreactor that fosters maintenance of 3D tissue cultures under constant perfusion and we have integrated multiple bioreactors into an array in a multiwell plate format. All bioreactors are fluidically isolated from each other. Each bioreactor in the array contains a scaffold that supports formation of hundreds of 3D microscale tissue units. The tissue units are perfused with cell culture medium circulated within the bioreactor by integrated pneumatic diaphragm micropumps. Electronic controls for the pumps are kept outside the incubator and connected to the perfused multiwell by pneumatic lines. The docking design and open-well bioreactor layout make handling perfused multiwell plates similar to using standard multiwell tissue culture plates. A model of oxygen consumption and transport in the circulating culture medium was used to predict appropriate operating parameters for primary liver cultures. Oxygen concentrations at key locations in the system were then measured as a function of flow rate and time after initiation of culture to determine oxygen consumption rates. After seven days of culture, tissue formed from cells seeded in the perfused multiwell reactor remained functionally viable as assessed by immunostaining for hepatocyte and liver sinusoidal endothelial cell (LSEC) phenotypic markers.
Purpose-driven biomaterials research in liver-tissue engineering.
Ananthanarayanan, Abhishek; Narmada, Balakrishnan Chakrapani; Mo, Xuejun; McMillian, Michael; Yu, Hanry
Bottom-up engineering of microscale tissue ("microtissue") constructs to recapitulate partially the complex structure-function relationships of liver parenchyma has been realized through the development of sophisticated biomaterial scaffolds, liver-cell sources, and in vitro culture techniques. With regard to in vivo applications, the long-lived stem/progenitor cell constructs can improve cell engraftment, whereas the short-lived, but highly functional hepatocyte constructs stimulate host liver regeneration. With regard to in vitro applications, microtissue constructs are being adapted or custom-engineered into cell-based assays for testing acute, chronic and idiosyncratic toxicities of drugs or pathogens. Systems-level methods and computational models that represent quantitative relationships between biomaterial scaffolds, cells and microtissue constructs will further enable their rational design for optimal integration into specific biomedical applications.
Synthesis of hepatic lipase in liver and extrahepatic tissues
Doolittle, M.H.; Wong, H.; Davis, R.C.; Schotz, M.C.
Immunoprecipitations of hepatic lipase from pulse-labeled rat liver have demonstrated that hepatic lipase is synthesized in two distinct molecular weight forms, HL-I (Mr = 51,000) and HL-II (Mr = 53,000). Both forms are immunologically related to purified hepatic lipase, but not to lipoprotein lipase. HL-I and HL-II are also kinetically related and represent different stages of intracellular processing. Glycosidase experiments suggest that HL-I is the high mannose microsomal form of the mature, sialylated HL-II enzyme. Hepatic lipase activity was detected in liver and adrenal gland but was absent in brain, heart, kidney, testes, small intestine, lung, and spleen. The adrenal and liver lipase activities were inhibited in a similar dose-dependent manner by hepatic lipase antiserum. Immunoblot analysis of partially purified adrenal lipase showed an immunoreactive band co-migrating with HL-II at 53,000 daltons which was absent in a control blot treated with preimmune serum. Adrenal lipase and authentic hepatic lipase yielded similar peptide maps, confirming the presence of the lipase in adrenal gland. However, incorporation of L-(/sup 35/S)methionine into immunoprecipitable hepatic lipase was not detected in this tissue. In addition, Northern blot analysis showed the presence of hepatic lipase mRNA in liver but not adrenal gland. The presence of hepatic lipase in adrenal gland in the absence of detectable synthesis or messenger suggests that hepatic lipase originates in liver and is transported to this extrahepatic site.
3D liver models on a microplatform: well-defined culture, engineering of liver tissue and liver-on-a-chip.
Yoon No, Da; Lee, Kwang-Ho; Lee, Jaeseo; Lee, Sang-Hoon
The liver, the largest organ in the human body, is a multi-functional organ with diverse metabolic activities that plays a critical role in maintaining the body and sustaining life. Although the liver has excellent regenerative and recuperative properties, damages caused by chronic liver diseases or viral infection may lead to permanent loss of liver functions. Studies of liver disease mechanism have focused on drug screening and liver tissue engineering techniques, including strategies based on in vitro models. However, conventional liver models are plagued by a number of limitations, which have motivated the development of 'liver-on-a-chip' and microplatform-based bioreactors that can provide well-defined microenvironments. Microtechnology is a promising tool for liver tissue engineering and liver system development, as it can mimic the complex in vivo microenvironment and microlevel ultrastructure, by using a small number of human cells under two-dimensional (2D) and three-dimensional (3D) culture conditions. These systems provided by microtechnology allow improved liver-specific functions and can be expanded to encompass diverse 3D culture methods, which are critical for the maintenance of liver functions and recapitulation of the features of the native liver. In this review, we provide an overview of microtechnologies that have been used for liver studies, describe biomimetic technologies for constructing microscale 2D and 3D liver models as well as liver-on-a-chip systems and microscale bioreactors, and introduce applications of liver microtechnology and future trends in the field.
Nano scaffolds and stem cell therapy in liver tissue engineering
NASA Astrophysics Data System (ADS)
Montaser, Laila M.; Fawzy, Sherin M.
Tissue engineering and regenerative medicine have been constantly developing of late due to the major progress in cell and organ transplantation, as well as advances in materials science and engineering. Although stem cells hold great potential for the treatment of many injuries and degenerative diseases, several obstacles must be overcome before their therapeutic application can be realized. These include the development of advanced techniques to understand and control functions of micro environmental signals and novel methods to track and guide transplanted stem cells. A major complication encountered with stem cell therapies has been the failure of injected cells to engraft to target tissues. The application of nanotechnology to stem cell biology would be able to address those challenges. Combinations of stem cell therapy and nanotechnology in tissue engineering and regenerative medicine have achieved significant advances. These combinations allow nanotechnology to engineer scaffolds with various features to control stem cell fate decisions. Fabrication of Nano fiber cell scaffolds onto which stem cells can adhere and spread, forming a niche-like microenvironment which can guide stem cells to proceed to heal damaged tissues. In this paper, current and emergent approach based on stem cells in the field of liver tissue engineering is presented for specific application. The combination of stem cells and tissue engineering opens new perspectives in tissue regeneration for stem cell therapy because of the potential to control stem cell behavior with the physical and chemical characteristics of the engineered scaffold environment.
Engineering liver tissue spheroids with inverted colloidal crystal scaffolds.
Lee, Jungwoo; Cuddihy, Meghan J; Cater, George M; Kotov, Nicholas A
Multicellular spheroids provide a new three-dimensional (3D) level of control over morphology and function of ex vivo cultured tissues. They also represent a valuable experimental technique for drug discovery and cell biology. Nevertheless, the dependence of many cellular processes on the cluster diameter remains unclear. To provide a tool for the systematic evaluation of such dependences, we introduce here inverted colloidal crystal (ICC) scaffolds. Uniformly sized pores in ICC cell matrixes afford a high yield production of controlled size spheroids in standard 96 well-plates. Transparent hydrogel matrix and ship-in-bottle effect also allows for convenient monitoring of cell processes by traditional optical techniques. Different developmental stages of 46.5-151.6 microm spheroids from HepG2 hepatocytes with vivid morphological similarities to liver tissue (bile canaliculi) were observed. The liver-specific functions of HepG2 cells were systematically investigated and compared for spheroids of different diameters as well as 2D cultures. Clear trends of albumin production and CYP450 activity were observed; diffusion processes and effect of cellular aggregation on metabolic activity were identified to be the primary contributors to the size dependence of the liver functions in HepG2 spheroids in ICC scaffolds. Since the aggregation of cells into clusters is a universal biological process, these findings and scaffolds can be applied to many other relevant cell types.
Distinct populations of endoderm cells converge to generate the embryonic liver bud and ventral foregut tissues.
Tremblay, Kimberly D; Zaret, Kenneth S
The location and movement of mammalian gut tissue progenitors, prior to the expression of tissue-specific genes, has been unknown, but this knowledge is essential to identify transitions that lead to cell type specification. To address this, we used vital dyes to label exposed anterior endoderm cells of early somite stage mouse embryos, cultured the embryos into the tissue bud phase of development, and determined the tissue fate of the dye labeled cells. This approach was performed at three embryonic stages that are prior to, or coincident with, foregut tissue patterning (1-3 somites, 4-6 somites, and 7-10 somites). Short-term labeling experiments tracked the movement of tissue progenitor cells during foregut closure. Surprisingly, we found that two distinct types of endoderm-progenitor cells, lateral and medial, arising from three spatially separated embryonic domains, converge to generate the epithelial cells of the liver bud. Whereas the lateral endoderm-progenitors give rise to descendants that are constrained in tissue fate and position along the anterior-posterior axis of the gut, the medial gut endoderm-progenitors give rise to descendants that stream along the anterior-posterior axis at the ventral midline and contribute to multiple gut tissues. The fate map reveals extensive morphogenetic movement of progenitors prior to tissue specification, it permits a detailed analysis of endoderm tissue patterning, and it illustrates that diverse progenitor domains can give rise to individual tissue cell types.
Characterization of a liver organoid tissue composed of hepatocytes and fibroblasts in dense collagen fibrils.
Tamai, Miho; Adachi, Eijiro; Tagawa, Yoh-ichi
The adult liver is wrapped in a connective tissue sheet called the liver capsule, which consists of collagen fibrils and fibroblasts. In this study, we set out to construct a liver organoid tissue that would be comparable to the endogenous liver, using a bioreactor. In vitro liver organoid tissue was generated by combining collagen fibrils, fibroblasts, and primary murine hepatocytes or Hep G2 on a mesh of poly-lactic acid fabric using a bioreactor. Then, the suitability of this liver organoid tissue for transplantation was tested by implanting the constructs into partially hepatectomized BALB/cA-nu/nu mice. As determined by using scanning and transmission electron microscopes, the liver organoid tissues were composed of densely packed collagen fibrils with fibroblasts and aggregates of oval or spherical hepatocytes. Angiogenesis was induced after the transplantation, and blood vessels connected the liver organoid tissue with the surrounding tissue. Thus, a novel approach was applied to generate transplantable liver organoid tissue within a condensed collagen fibril matrix. These results suggested that a dense collagen network populated with fibroblasts can hold a layer of concentrated hepatocytes, providing a three-dimensional microenvrionment suitable for the reestablishment of cell-cell and cell-extracellular matrix (ECM) interactions, and resulting in the maintenance of their liver-specific functions. This liver organoid tissue may be useful for the study of intrahepatic functions of various cells, cytokines, and ECMs, and may fulfill the fundamental requirements of a donor tissue.
Global Proteome Changes in Liver Tissue 6 Weeks after FOLFOX Treatment of Colorectal Cancer Liver Metastases
Urdzik, Jozef; Vildhede, Anna; Wiśniewski, Jacek R.; Duraj, Frans; Haglund, Ulf; Artursson, Per; Norén, Agneta
(1) Oxaliplatin-based chemotherapy for colorectal cancer liver metastasis is associated with sinusoidal injury of liver parenchyma. The effects of oxaliplatin-induced liver injury on the protein level remain unknown. (2) Protein expression in liver tissue was analyzed—from eight patients treated with FOLFOX (combination of fluorouracil, leucovorin, and oxaliplatin) and seven controls—by label-free liquid chromatography mass spectrometry. Recursive feature elimination–support vector machine and Welch t-test were used to identify classifying and relevantly changed proteins, respectively. Resulting proteins were analyzed for associations with gene ontology categories and pathways. (3) A total of 5891 proteins were detected. A set of 184 (3.1%) proteins classified the groups with a 20% error rate, but relevant change was observed only in 55 (0.9%) proteins. The classifying proteins were associated with changes in DNA replication (p < 0.05) through upregulation of the minichromosome maintenance complex and with the innate immune response (p < 0.05). The importance of DNA replication changes was supported by the results of Welch t-test (p < 0.05). (4) Six weeks after FOLFOX treatment, less than 1% of identified proteins showed changes in expression associated with DNA replication, cell cycle entry, and innate immune response. We hypothesize that the changes remain after recovery from FOLFOX treatment injury. PMID:28248240
Primary liver cells cultured on carbon nanotube substrates for liver tissue engineering and drug discovery applications.
Che Abdullah, Che Azurahanim; Azad, Chihye Lewis; Ovalle-Robles, Raquel; Fang, Shaoli; Lima, Marcio D; Lepró, Xavier; Collins, Steve; Baughman, Ray H; Dalton, Alan B; Plant, Nick J; Sear, Richard P
Here, we explore the use of two- and three-dimensional scaffolds of multiwalled-carbon nanotubes (MWNTs) for hepatocyte cell culture. Our objective is to study the use of these scaffolds in liver tissue engineering and drug discovery. In our experiments, primary rat hepatocytes, the parenchymal (main functional) cell type in the liver, were cultured on aligned nanogrooved MWNT sheets, MWNT yarns, or standard 2-dimensional culture conditions as a control. We find comparable cell viability between all three culture conditions but enhanced production of the hepatocyte-specific marker albumin for cells cultured on MWNTs. The basal activity of two clinically relevant cytochrome P450 enzymes, CYP1A2 and CYP3A4, are similar on all substrates, but we find enhanced induction of CYP1A2 for cells on the MWNT sheets. Our data thus supports the use of these substrates for applications including tissue engineering and enhancing liver-specific functions, as well as in in vitro model systems with enhanced predictive capability in drug discovery and development.
Development of Liver Decellularized Extracellular Matrix Bioink for Three-Dimensional Cell Printing-Based Liver Tissue Engineering.
Lee, Hyungseok; Han, Wonil; Kim, Hyeonji; Ha, Dong-Heon; Jang, Jinah; Kim, Byoung Soo; Cho, Dong-Woo
The liver is an important organ and plays major roles in the human body. Because of the lack of liver donors after liver failure and drug-induced liver injury, much research has focused on developing liver alternatives and liver in vitro models for transplantation and drug screening. Although numerous studies have been conducted, these systems cannot faithfully mimic the complexity of the liver. Recently, three-dimensional (3D) cell printing technology has emerged as one of a number of innovative technologies that may help to overcome this limitation. However, a great deal of work in developing biomaterials optimized for 3D cell printing-based liver tissue engineering remains. Therefore, in this work, we developed a liver decellularized extracellular matrix (dECM) bioink for 3D cell printing applications and evaluated its characteristics. The liver dECM bioink retained the major ECM components of the liver while cellular components were effectively removed and further exhibited suitable and adjustable properties for 3D cell printing. We further studied printing parameters with the liver dECM bioink to verify the versatility and fidelity of the printing process. Stem cell differentiation and HepG2 cell functions in the liver dECM bioink in comparison to those of commercial collagen bioink were also evaluated, and the liver dECM bioink was found to induce stem cell differentiation and enhance HepG2 cell function. Consequently, the results demonstrate that the proposed liver dECM bioink is a promising bioink candidate for 3D cell printing-based liver tissue engineering.
Engineering functional two- and three-dimensional liver systems in vivo using hepatic tissue sheets.
Ohashi, Kazuo; Yokoyama, Takashi; Yamato, Masayuki; Kuge, Hiroyuki; Kanehiro, Hiromichi; Tsutsumi, Masahiro; Amanuma, Toshihiro; Iwata, Hiroo; Yang, Joseph; Okano, Teruo; Nakajima, Yoshiyuki
Hepatic tissue engineering using primary hepatocytes has been considered a valuable new therapeutic modality for several classes of liver diseases. Recent progress in the development of clinically feasible liver tissue engineering approaches, however, has been hampered mainly by insufficient cell-to-cell contact of the engrafted hepatocytes. We developed a method to engineer a uniformly continuous sheet of hepatic tissue using isolated primary hepatocytes cultured on temperature-responsive surfaces. Sheets of hepatic tissue transplanted into the subcutaneous space resulted in efficient engraftment to the surrounding cells, with the formation of two-dimensional hepatic tissues that stably persisted for longer than 200 d. The engineered hepatic tissues also showed several characteristics of liver-specific functionality. Additionally, when the hepatic tissue sheets were layered in vivo, three-dimensional miniature liver systems having persistent survivability could be also engineered. This technology for liver tissue engineering is simple, minimally invasive and free of potentially immunogenic biodegradable scaffolds.
Liver tissue engineering at extrahepatic sites in mice as a potential new therapy for genetic liver diseases.
Ohashi, Kazuo; Waugh, Jacob M; Dake, Michael D; Yokoyama, Takashi; Kuge, Hiroyuki; Nakajima, Yoshiyuki; Yamanouchi, Masaki; Naka, Hiroyuki; Yoshioka, Akira; Kay, Mark A
Liver tissue engineering using hepatocyte transplantation has been proposed as an alternative to whole-organ transplantation or liver-directed gene therapy to correct various types of hepatic insufficiency. Hepatocytes are not sustained when transplanted under the kidney capsule of syngeneic mice. However, when we transplanted hepatocytes with the extracellular matrix components extracted from Engelbreth-Holm-Swarm cells, hepatocytes survived for at least 140 days and formed small liver tissues. Liver engineering in hemophilia A mice reconstituted 5% to 10% of normal clotting activity, enough to reduce the bleeding time and have a therapeutic benefit. Conversely, the subcutaneous space did not support the persistent survival of hepatocytes with Engelbreth-Holm-Swarm gel matrix. We hypothesized that establishing a local vascular network at the transplantation site would reduce graft loss. To test this idea, we provided a potent angiogenic agent before hepatocyte transplantation into the subcutaneous space. With this procedure, persistent survival was achieved for the length of the experiment (120 days). To establish that these engineered liver tissues also retained their native regeneration potential in vivo, we induced two different modes of proliferative stimulus to the naive liver and confirmed that hepatocytes within the extrahepatic tissues regenerated with activity similar to that of naive liver. In conclusion, our studies indicate that liver tissues can be engineered and maintained at extrahepatic sites, retain their capacity for regeneration in vivo, and used to successfully treat genetic disorders.
Inter-Tissue Gene Co-Expression Networks between Metabolically Healthy and Unhealthy Obese Individuals
Kogelman, Lisette J. A.; Fu, Jingyuan; Franke, Lude; Greve, Jan Willem; Hofker, Marten; Rensen, Sander S.; Kadarmideen, Haja N.
Background Obesity is associated with severe co-morbidities such as type 2 diabetes and nonalcoholic steatohepatitis. However, studies have shown that 10–25 percent of the severely obese individuals are metabolically healthy. To date, the identification of genetic factors underlying the metabolically healthy obese (MHO) state is limited. Systems genetics approaches have led to the identification of genes and pathways in complex diseases. Here, we have used such approaches across tissues to detect genes and pathways involved in obesity-induced disease development. Methods Expression data of 60 severely obese individuals was accessible, of which 28 individuals were MHO and 32 were metabolically unhealthy obese (MUO). A whole genome expression profile of four tissues was available: liver, muscle, subcutaneous adipose tissue and visceral adipose tissue. Using insulin-related genes, we used the weighted gene co-expression network analysis (WGCNA) method to build within- and inter-tissue gene networks. We identified genes that were differentially connected between MHO and MUO individuals, which were further investigated by homing in on the modules they were active in. To identify potentially causal genes, we integrated genomic and transcriptomic data using an eQTL mapping approach. Results Both IL-6 and IL1B were identified as highly differentially co-expressed genes across tissues between MHO and MUO individuals, showing their potential role in obesity-induced disease development. WGCNA showed that those genes were clustering together within tissues, and further analysis showed different co-expression patterns between MHO and MUO subnetworks. A potential causal role for metabolic differences under similar obesity state was detected for PTPRE, IL-6R and SLC6A5. Conclusions We used a novel integrative approach by integration of co-expression networks across tissues to elucidate genetic factors related to obesity-induced metabolic disease development. The identified
Modeling and analysis of coagulated liver tissue and its interaction with a scalpel blade.
Leong, Florence; Huang, Wei-Hsuan; Chui, Chee-Kong
Radiofrequency-assisted methods have been used in hepatectomy--the resection process of removing liver tissue which encapsulates the tumor from the liver organ. A prototype was built to enable smooth surgical transition between radiofrequency ablation and liver resection. There is a lack of literature on mechanical properties of radiofrequency-ablated liver tissue and the tool-tissue interaction during cutting. This led to our study on coagulated tissue mechanical properties and modeling of its dynamic interaction with a scalpel blade. A novel mechanical model was proposed to mimic the mechanical behavior of radiofrequency-ablated liver tissue. The model is able to account for the viscoelastic behavior of the ablated tissue in both compression and relaxation tests. Experiments were performed to validate the proposed model. In addition, a knife blade-tissue interaction model is proposed to demonstrate the potential of integrating the proposed model for application in device design.
Normal Liver Tissue Density Dose Response in Patients Treated With Stereotactic Body Radiation Therapy for Liver Metastases
Howells, Christopher C.; Stinauer, Michelle A.; Diot, Quentin; Westerly, David C.; Schefter, Tracey E.; Kavanagh, Brian D.; Miften, Moyed
Purpose: To evaluate the temporal dose response of normal liver tissue for patients with liver metastases treated with stereotactic body radiation therapy (SBRT). Methods and Materials: Ninety-nine noncontrast follow-up computed tomography (CT) scans of 34 patients who received SBRT between 2004 and 2011 were retrospectively analyzed at a median of 8 months post-SBRT (range, 0.7-36 months). SBRT-induced normal liver tissue density changes in follow-up CT scans were evaluated at 2, 6, 10, 15, and 27 months. The dose distributions from planning CTs were mapped to follow-up CTs to relate the mean Hounsfield unit change ({Delta}HU) to dose received over the range 0-55 Gy in 3-5 fractions. An absolute density change of 7 HU was considered a significant radiographic change in normal liver tissue. Results: Increasing radiation dose was linearly correlated with lower post-SBRT liver tissue density (slope, -0.65 {Delta}HU/5 Gy). The threshold for significant change (-7 {Delta}HU) was observed in the range of 30-35 Gy. This effect did not vary significantly over the time intervals evaluated. Conclusions: SBRT induces a dose-dependent and relatively time-independent hypodense radiation reaction within normal liver tissue that is characterized by a decrease of >7 HU in liver density for doses >30-35 Gy.
Iron in spleen and liver: Some cases of normal tissues and tissues from patients with hematological malignancies
NASA Astrophysics Data System (ADS)
Alenkina, Irina V.; Oshtrakh, Michael I.; Felner, Israel; Vinogradov, Alexander V.; Konstantinova, Tatiana S.; Semionkin, Vladimir A.
Iron deposits in spleen and liver tissues obtained from several healthy people and patients with mantle cell lymphoma, acute myeloid leukemia and primary myelofibrosis were studied using Mössbauer spectroscopy and magnetization measurements. The results obtained demonstrated differences in the iron content in tissues as well as some variations in the ferrihydrite-like iron core structure in the iron storage proteins in these tissues. The presence of tiny amount of magnetite and paramagnetic component in spleen and liver tissue was also detected in different quantities in the studied tissues.
Hepatic tissue engineering: from transplantation to customized cell-based liver directed therapies from the laboratory.
Fiegel, Henning C; Kaufmann, Peter M; Bruns, Helge; Kluth, Dietrich; Horch, Raymund E; Vacanti, Joseph P; Kneser, Ulrich
Today, liver transplantation is still the only curative treatment for liver failure due to end-stages liver diseases. Donor organ shortage, high cost and the need of immunosuppressive medications are still the major limitations in the field of liver transplantation. Thus, alternative innovative cell-based liver directed therapies, e.g. liver tissue engineering, are under investigation with the aim, that in future an artificial liver tissue could be created and be used for the replacement of the liver function in patients. Using cells instead of organs in this setting should permit (i) expansion of cells in an in vitro phase, (ii) genetic or immunological manipulation of cells for transplantation, (iii) tissue typing and cryopreservation in a cell bank, and (iv) the ex vivo genetic modification of patient's own cells prior re-implantation. Function and differentiation of liver cells are influenced by the three-dimensional organ architecture. The use of polymeric matrices permits the three dimensional formation of a neo-tissue and specific stimulation by adequate modification of the matrix-surface which might be essential for appropriate differentiation of transplanted cells. Additionally, culturing hepatocytes on three dimensional matrices permits culture in a flow bioreactor system with increased function and survival of the cultured cells. Based on bioreactor technology, bioartificial liver devices (BAL) are developed for extracorporeal liver support. Although BALs improved clinical and metabolic conditions, increased patient survival rates have not been proven yet. For intra-corporeal liver replacement, a concept which combines Tissue Engineering using three-dimensional, highly porous matrices with cell transplantation could be useful. In such a concept, whole liver mass transplantation, long term engraftment and function as well as correction of a metabolic defect in animal models could be achieved with a principally reversible procedure. Future studies have to
Scale-dependent mechanical properties of native and decellularized liver tissue.
Evans, Douglas W; Moran, Emma C; Baptista, Pedro M; Soker, Shay; Sparks, Jessica L
Decellularization, a technique used in liver regenerative medicine, is the removal of all the cellular components from a tissue or organ, leaving behind an intact structure of extracellular matrix. The biomechanical properties of this novel scaffold material are currently unknown and are important due to the mechanosensitivity of liver cells. Characterizing this material is important for bioengineering liver tissue from this decellularized scaffold as well as creating new 3-dimensional mimetic structures of liver extracellular matrix. This study set out to characterize the biomechanical properties of perfused liver tissue in its native and decellularized states on both a macro- and nano-scale. Poroviscoelastic finite element models were then used to extract the fluid and solid mechanical properties from the experimental data. Tissue-level spherical indentation-relaxation tests were performed on 5 native livers and 8 decellularized livers at two indentation rates and at multiple perfusion rates. Cellular-level spherical nanoindentation was performed on 2 native livers and 1 decellularized liver. Tissue-level results found native liver tissue to possess a long-term Young's modulus of 10.5 kPa and decellularized tissue a modulus of 1.18 kPa. Cellular-level testing found native tissue to have a long-term Young's modulus of 4.40 kPa and decellularized tissue to have a modulus of 0.91 kPa. These results are important for regenerative medicine and tissue engineering where cellular response is dependent on the mechanical properties of the engineered scaffold.
Engineering liver tissues under the kidney capsule site provides therapeutic effects to hemophilia B mice.
Ohashi, Kazuo; Tatsumi, Kohei; Utoh, Rie; Takagi, Soichi; Shima, Midori; Okano, Teruo
Recent advances in liver tissue engineering have encouraged further investigation into the evaluation of therapeutic benefits based on animal disease models. In the present study, liver tissues were engineered in coagulation factor IX knockout (FIX-KO) mice, a mouse model of hemophilia B, to determine if the tissue engineering approach would provide therapeutic benefits. Primary hepatocytes were isolated from the liver of wild-type mice and suspended in a mixture of culture medium and extracellular matrix components. The hepatocyte suspension was injected into the space under the bilateral kidney capsules of the FIX-KO mice to engineer liver tissues. The plasma FIX activities (FIX:C) of the untreated FIX-KO mice were undetectable at any time point. In contrast, the liver tissue engineered FIX-KO mice achieved 1.5-2.5% of plasma FIX activities (FIX:C) and this elevated FIX:C level persisted throughout the 90 day experimental period. Significant FIX mRNA expression levels were found in the engineered liver tissues at levels similar to the wild-type livers. The present study demonstrates that liver tissue engineering could provide therapeutic benefits in the treatment of hemophilia B.
The analysis of γ-glutamyl transpeptidase gene in different type liver tissues
Han, Guo-Qing; Qin, Cheng-Yong; Shu, Rong-Hua
AIM: To probe the value of γ-glutamyl transpeptidase (GGT) messenger RNA in monitoring canceration of liver cells and for early diagnosis of hepatocellular carcinoma (HCC), by researching the types of GGT messenger RNA (GGTmRNA) in liver tissues and peripheral blood of different hepatopathy. METHODS: The three types of GGTmRNA (A, B, C) in liver tissues and peripheral blood from the patients with HCC, noncancerous hepatopathy, hepatic benign tumor, secondary carcinoma of liver, and healthy persons were detected by reverse-transcription polymerase chain reaction (RT-PCR). RESULTS: (1) In normal liver tissues, type A was predominantly found (100.00%), type B was not found, type C was found occasionally (25.00%); (2) The distribution of types of GGTmRNA in liver tissues with acute hepatitis, chronic hepatitis, cirrhosis, alcoholic hepatopathy was similar as in normal liver tissues (P > 0.05), but type B was found in 3 of 18 patients with chronic hepatitis (16.67%), and also in 3 of 11 patients with cirrhosis (27.27%); (3) There was no significant difference of types of GGTmRNA between liver tissues with hepatic benign tumor, secondary carcinoma of liver and normal liver tissues (P > 0.05); (4) Type B was predominant in cancerous tissues with HCC (87.5%), the prevalence of type B in cancerous tissues was significantly higher than that in normal liver tissues (0/12) (P < 0.05), but the prevalence of type A in cancerous tissues (46.88%) was significantly lower than that in normal liver tissues (100.00%) (P < 0.05), and the prevalence of type C (6.25%) in cancerous was the same as that in normal liver tissues (25.00%) (P > 0.05). In noncancerous tissues of livers with HCC, the main types were type A and type B, the prevalence of type A (85.71%, 90.48%) and type C (14.29%, 9.52%) in noncancerous tissues of liver with HCC was similar as that in normal liver tissues (A: 100.00%; C: 25.00%) (P > 0.05), but the prevalence of type B (80.95%, 76.19%) in noncancerous tissues of
Tumor regulation of the tissue environment in the liver.
Eggert, Tobias; Greten, Tim F
The tumor microenvironment (TME) in the liver plays an important role in primary and metastatic liver tumor formation and tumor growth promotion. Cellular and non-cellular components of the TME significantly influence tumor development, growth, metastatic spread, anti-tumor immunity and response to tumor therapy. The cellular components of the TME in the liver not only consist of infiltrating immune cells, but also of liver-resident cells such as liver sinusoidal endothelial cells (LSEC) and hepatic stellate cells (HSC), which promote tumor growth by negatively regulating tumor-associated immune responses. In this review, we characterize cells of the TME with pro- and anti-tumor function in primary and metastatic liver tumors. Furthermore, we summarize mechanisms that permit growth of hepatic tumors despite the occurrence of spontaneous anti-tumor immune responses and how novel therapeutic approaches targeting the TME could unleash tumor-specific immune responses to improve survival of liver cancer patients.
A disintegrin and metalloprotease 10 (ADAM10) is a central regulator of murine liver tissue homeostasis
Köhn-Gaone, Julia; Chalupsky, Karel; Lüllmann-Rauch, Renate; Barikbin, Roja; Bergmann, Juri; Wöhner, Birte; Zbodakova, Olga; Leuschner, Ivo; Martin, Gregor; Tiegs, Gisa; Rose-John, Stefan; Sedlacek, Radislav; Tirnitz-Parker, Janina E.E.; Saftig, Paul; Schmidt-Arras, Dirk
A Disintegrin And Metalloprotease (ADAM) 10 exerts essential roles during organ development and tissue integrity in different organs, mainly through activation of the Notch pathway. However, only little is known about its implication in liver tissue physiology. Here we show that in contrast to its role in other tissues, ADAM10 is dispensable for the Notch2-dependent biliary tree formation. However, we demonstrate that expression of bile acid transporters is dependent on ADAM10. Consequently, mice deficient for Adam10 in hepatocytes, cholangiocytes and liver progenitor cells develop spontaneous hepatocyte necrosis and concomitant liver fibrosis. We furthermore observed a strongly augmented ductular reaction in 15-week old ADAM10Δhep/Δch mice and demonstrate that c-Met dependent liver progenitor cell activation is enhanced. Additionally, liver progenitor cells are primed to hepatocyte differentiation in the absence of ADAM10. These findings show that ADAM10 is a novel central node controlling liver tissue homeostasis. Highlights: Loss of ADAM10 in murine liver results in hepatocyte necrosis and concomitant liver fibrosis. ADAM10 directly regulates expression of bile acid transporters but is dispensable for Notch2-dependent formation of the biliary system. Activation of liver progenitor cells is enhanced through increased c-Met signalling, in the absence of ADAM10. Differentiation of liver progenitor cells to hepatocytes is augmented in the absence of ADAM10. PMID:26942887
Body burden contaminants in whole fish tissue and livers from the Slave River (NWT)
McCarthy, L.H.; Stephens, G.R.; Peddle, J.; Lafontaine, C.; Whittle, D.M.; Harbicht, S.
The Slave River Environmental Monitoring Program was established in 1990 to assess whether the commercial and subsistence fisheries in the region were being impacted by downstream transport and subsequent bioaccumulation of contaminants in the fish. Lake whitefish (Coregonus clupeaformis), northern pike (Esox lucius), burbot (Lota lota), walleye (Stizostedion vitreum), and longnose suckers (Catostomus catostomus) were collected in the Slave River at Fort Smith (NWT) and whole fish tissue was evaluated for contaminant accumulation. Due to their high lipid concentration and their importance as food source, burbot livers were also analyzed. A broad organochlorine scan was conducted for selected dioxins and furans, total PCB concentrations and individual congeners, pesticide residues such as DDT and its metabolites, dieldrin, lindane, mirex, and toxaphene. Also, PAHs, and various chlorinated phenolics such as chlorophenols, chlorocatechols, and chloroguaiacols were also examined. Although contaminants were detected in the fish, concentrations generally were minimal. Levels of total PCBs in whole fish tissue ranged from 0.006 to 0.08 mg/kg, while average concentrations in burbot livers were 0.23 mg/kg. The toxic dioxin isomer 2,3,7,8-TCDD was detected once in whole fish tissue (walleye) at levels of 0.86 pg/g, while concentrations in burbot livers ranged from 1.2 to 9.96 pg/g. Higher levels of TCDD (11.4 pg/g) were noted in fish caught at the reference site Chitty/Alexie Lake, although this body of water has no known sources of dioxins and furans. The presence of these compounds indicates a long-range transport and deposition mechanism. Toxaphene concentrations in fish averaged 0.3 mg/kg, while concentrations of p,p{prime}-DDE ranged from 0.001 to 0.008 mg/kg over the monitoring period. Levels of PAHs and chlorinated phenolics were generally below analytical detection limits, as were most of the pesticide residues.
Tissue lipid composition in fatty liver and kidney syndrome in chicks.
Whitehead, C C
The lipid composition of the liver, kidneys, heart and adipose tissue of chicks affected by the fatty liver and kidney syndrome were analysed. Livers and kidneys showed 400 to 500 per cent increases in heart lipid levels. Liver and kidney triglycerides contained increased proportions of mono-unsaturated fatty acids, mainly palmitoleic acid, at the expense of the saturated fatty acids, mainly stearic acid. Phospholipid and adipose tissue fatty acid composition were not markedly altered. The abnormalities were regressing in birds recovering from the syndrome.
Mercury concentrations in muscle and liver tissue of fish from marshes along the Magdalena River, Colombia.
Alvarez, Santiago; Kolok, Alan S; Jimenez, Luz Fernanda; Granados, Carlos; Palacio, Jaime A
The present research determined the total mercury concentrations in muscle and liver tissue in fish collected from the Magdalena River watershed. A total of 378 muscle samples and 102 liver samples were included in the analysis. The highest mean mercury level in muscle tissue was found in the noncarnivore, Pimelodus blochii. However, as a group, carnivores had significantly higher (p < 0.05) mercury levels in their muscle tissue than noncarnivores. A significant correlation (p < 0.05) was obtained between fish mass and mercury concentrations in muscle or liver in four species. No differences were observed in total mercury concentration based either on species or gender.
TLR4-dependent immune response promotes radiation-induced liver disease by changing the liver tissue interstitial microenvironment during liver cancer radiotherapy.
Zhi-Feng, Wu; Le-Yuan, Zhou; Xiao-Hui, Zhou; Ya-Bo, Gao; Jian-Ying, Zhang; Yong, Hu; Zhao-Chong, Zeng
Liver tissue interstitial fluid (TIF) a special microenvironment around liver cells, which may play a vital role in cell communication during liver injury. Moreover, toll-like receptor 4 (TLR4) is an important trigger of the immune response that may also play a role in liver injuries, including radiation-induced liver disease (RILD). Therefore, the purpose of this study was to identify the roles of the TLR4-dependent immune response and TIFs in RILD after radiation therapy (RT) for liver cancer. This study consisted of two phases, and in the primary phase, the livers of TLR4 mutant (TLR4(-)) and normal (TLR4(+)) mice were irradiated with 30 Gy. TIF was then obtained from mouse livers and assessed by cytokine array analysis 20 days after irradiation, and cytokines in the TIFs, TLR4 and RILD were analyzed. In the second or validation phase, hepatocytes were isolated from TLR4(+) or TLR4(-) mice irradiated with 8 Gy and were co-cultured with TIFs from mouse livers, apoptosis of the hepatocytes was then measured using flow cytometry. We found that severe RILD was accompanied by higher expression of granulocyte macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor-related apoptosis inducing ligand (TRAIL) and vascular endothelial growth factor receptor 2(VEGFR-2) in liver TIFs, from in TLR4(+) mice compared with TLR4(-) mice (P < 0.05). In both TLR4(+) and TLR4(-) hepatocytes, apoptosis after irradiaton was increased significantly after co-culture in TIFs from TLR4(+) mice that had their livers irradiated, compared with TIFs from TLR4(-) mice that had their livers irradiated or TIFs from unirradiated mice (P < 0.05). In summary, these findings indicate that the TLR4-dependent immune response may promote RILD by enhancing the expression of GM-CSF, VEGFR-2 and TRAIL in liver TIFs.
Tissue distribution comparison between healthy and fatty liver rats after oral administration of hawthorn leaf extract.
Yin, Jingjing; Qu, Jianguo; Zhang, Wenjie; Lu, Dongrui; Gao, Yucong; Ying, Xixiang; Kang, Tingguo
Hawthorn leaves, a well-known traditional Chinese medicine, have been widely used for treating cardiovascular and fatty liver diseases. The present study aimed to investigate the therapeutic basis treating fatty liver disease by comparing the tissue distribution of six compounds of hawthorn leaf extract (HLE) in fatty liver rats and healthy rats after oral administration at first day, half month and one month, separately. Therefore, a sensitive and specific HPLC method with internal standard was developed and validated to determine chlorogenic acid, vitexin-4''-O-glucoside, vitexin-2''-O-rhamnoside, vitexin, rutin and hyperoside in the tissues including heart, liver, spleen, kidney, stomach and intestine. The results indicated that the six compounds in HLE presented some bioactivity in treating rat fatty liver as the concentrations of the six compounds varied significantly in inter- and intragroup comparisons (healthy and/or fatty liver group).
Human exposure to metals: levels in autopsy tissues of individuals living near a hazardous waste incinerator.
Mari, Montse; Nadal, Martí; Schuhmacher, Marta; Barbería, Eneko; García, Francisco; Domingo, José L
The concentrations of a number of metals were determined in the brain, bone, kidney, liver, and lung of 20 autopsied subjects who had lived, at least 10 years, in the neighborhood of a hazardous waste incinerator (HWI) in Tarragona (Catalonia, Spain). Results were compared with those obtained in 1998 (baseline survey) and previous surveys (2003 and 2007). Arsenic, Be, Ni, Tl, and V showed concentrations below the corresponding detection limits in all tissues. Cadmium showed the highest levels in the kidney, with a mean value of 21.15 μg/g. However, Cd was found below the detection limit in the brain and bone. Chromium showed similar concentrations in the kidney, brain, and lung (range of mean values, 0.57-0.66 μg/g) and higher in the bone (1.38 μg/g). In turn, Hg was below the detection limit in all tissues with the exception of the kidney, where the mean concentration was 0.15 μg/g (range, <0.05-0.58 μg/g). On the other hand, Mn could be detected in all tissues showing the highest levels in the liver and kidney (1.45 and 1.09 μg/g, respectively). Moreover, Pb showed the highest concentrations in bone (mean, 1.39 μg/g; range, <0.025-4.88 μg/g). Finally, Sn could be detected only in some tissue samples, reaching the highest values in the bone (0.17 μg/g). The current metal levels in human tissues from individuals living near the HWI of Tarragona are comparable and of a similar magnitude to previously reported results corresponding to general populations, as well as those of our previous surveys.
The nanomechanical signature of liver cancer tissues and its molecular origin
NASA Astrophysics Data System (ADS)
Tian, Mengxin; Li, Yiran; Liu, Weiren; Jin, Lei; Jiang, Xifei; Wang, Xinyan; Ding, Zhenbin; Peng, Yuanfei; Zhou, Jian; Fan, Jia; Cao, Yi; Wang, Wei; Shi, Yinghong
Patients with cirrhosis are at higher risk of developing hepatocellular carcinoma (HCC), the second most frequent cause of cancer-related deaths. Although HCC diagnosis based on conventional morphological characteristics serves as the ``gold standard'' in the clinic, there is a high demand for more convenient and effective diagnostic methods that employ new biophysical perspectives. Here, we show that the nanomechanical signature of liver tissue is directly correlated with the development of HCC. Using indentation-type atomic force microscopy (IT-AFM), we demonstrate that the lowest elasticity peak (LEP) in the Young's modulus distribution of surgically removed liver cancer tissues can serve as a mechanical fingerprint to evaluate the malignancy of liver cancer. Cirrhotic tissues shared the same LEP as normal tissues. However, a noticeable downward shift in the LEP was detected when the cirrhotic tissues progressed to a malignant state, making the tumor tissues more prone to microvascular invasion. Cell-level mechanistic studies revealed that the expression level of a Rho-family effector (mDia1) was consistent with the mechanical trend exhibited by the tissue. Our findings indicate that the mechanical profiles of liver cancer tissues directly varied with tumor progression, providing an additional platform for the future diagnosis of HCC.Patients with cirrhosis are at higher risk of developing hepatocellular carcinoma (HCC), the second most frequent cause of cancer-related deaths. Although HCC diagnosis based on conventional morphological characteristics serves as the ``gold standard'' in the clinic, there is a high demand for more convenient and effective diagnostic methods that employ new biophysical perspectives. Here, we show that the nanomechanical signature of liver tissue is directly correlated with the development of HCC. Using indentation-type atomic force microscopy (IT-AFM), we demonstrate that the lowest elasticity peak (LEP) in the Young's modulus
... Series Urinary Tract Imaging Urodynamic Testing Virtual Colonoscopy Liver Biopsy What is a liver biopsy? A liver biopsy is a procedure that ... remove the liver tissue sample. What is the liver and what does it do? The liver is ...
MicroRNAs in liver tissue engineering - New promises for failing organs.
Raschzok, Nathanael; Sallmon, Hannes; Pratschke, Johann; Sauer, Igor M
miRNA-based technologies provide attractive tools for several liver tissue engineering approaches. Herein, we review the current state of miRNA applications in liver tissue engineering. Several miRNAs have been implicated in hepatic disease and proper hepatocyte function. However, the clinical translation of these findings into tissue engineering has just begun. miRNAs have been successfully used to induce proliferation of mature hepatocytes and improve the differentiation of hepatic precursor cells. Nonetheless, miRNA-based approaches beyond cell generation have not yet entered preclinical or clinical investigations. Moreover, miRNA-based concepts for the biliary tree have yet to be developed. Further research on miRNA based modifications, however, holds the promise of enabling significant improvements to liver tissue engineering approaches due to their ability to regulate and fine-tune all biological processes relevant to hepatic tissue engineering, such as proliferation, differentiation, growth, and cell function.
[Study of remanent magnetization of the human body: lung and liver tissues].
Sakai, H; Wang, H; Murai, Y; Soukejima, S; Kagamimori, S
In this study, we used lung and liver tissue specimens distracted from tissue to investigate remanant magnetization, and found that specimens with a volume of 6 mm3 had an intensity of 10(-10) Am2, which was significantly stronger than the noise level of the superconducting magnetometer. This finding indicates that both lung and liver tissues contain magnetic materials. We speculated that biological magnetite is the magnetic material in these tissues. In addition, we found that lung tissue specimens with strong magnetization had correspondingly strong magnetized findings in the liver tissue specimens. In a comparison of magnetization in lung cancer tissue specimens and normal lung tissue, no significant relationship was noted, but two of the lung cancer tissue specimens showed strong magnetization. The number of lung cancer specimens studies was insufficient to investigate the relation between the magnetization (accumulation of magnetic materials) and lung cancer, and further studies are necessary. The magnetic properties of two lung cancer tissue specimens showing strong magnetization were further investigated, and an alternating field demagnetization experiment showed that their magnetization was composed of a unit stable vector, which indicates that the lung tissue may have been magnetized after the accumulation of magnetic materials. The Wohlfarth ratio (Moskowitz et al., 1989) of them was less than 0.5, which suggests that magnetic materials are distributed in clusters in lung tissue.
Liver tissue engineering in the evaluation of drug safety.
Dash, Ajit; Inman, Walker; Hoffmaster, Keith; Sevidal, Samantha; Kelly, Joan; Obach, R Scott; Griffith, Linda G; Tannenbaum, Steven R
Assessment of drug-liver interactions is an integral part of predicting the safety profile of new drugs. Existing model systems range from in vitro cell culture models to FDA-mandated animal tests. Data from these models often fail, however, to predict human liver toxicity, resulting in costly failures of clinical trials. In vitro screens based on cultured hepatocytes are now commonly used in early stages of development, but many toxic responses in vivo seem to be mediated by a complex interplay among several different cell types. We discuss some of the evolving trends in liver cell culture systems applied to drug safety assessment and describe an experimental model that captures complex liver physiology through incorporation of heterotypic cell-cell interactions, 3D architecture and perfused flow. We demonstrate how heterotypic interactions in this system can be manipulated to recreate an inflammatory environment and apply the model to test compounds that potentially exhibit idiosyncratic drug toxicity. Finally, we provide a perspective on how the range of existing and emerging in vitro liver culture approaches, from simple to complex, might serve needs across the range of stages in drug discovery and development, including applications in molecular therapeutics.
Activin A-Smad Signaling Mediates Connective Tissue Growth Factor Synthesis in Liver Progenitor Cells
Ding, Ze-Yang; Jin, Guan-Nan; Wang, Wei; Sun, Yi-Min; Chen, Wei-Xun; Chen, Lin; Liang, Hui-Fang; Datta, Pran K.; Zhang, Ming-Zhi; Zhang, Bixiang; Chen, Xiao-Ping
Liver progenitor cells (LPCs) are activated in chronic liver damage and may contribute to liver fibrosis. Our previous investigation reported that LPCs produced connective tissue growth factor (CTGF/CCN2), an inducer of liver fibrosis, yet the regulatory mechanism of the production of CTGF/CCN2 in LPCs remains elusive. In this study, we report that Activin A is an inducer of CTGF/CCN2 in LPCs. Here we show that expression of both Activin A and CTGF/CCN2 were upregulated in the cirrhotic liver, and the expression of Activin A positively correlates with that of CTGF/CCN2 in liver tissues. We go on to show that Activin A induced de novo synthesis of CTGF/CCN2 in LPC cell lines LE/6 and WB-F344. Furthermore, Activin A contributed to autonomous production of CTGF/CCN2 in liver progenitor cells (LPCs) via activation of the Smad signaling pathway. Smad2, 3 and 4 were all required for this induction. Collectively, these results provide evidence for the fibrotic role of LPCs in the liver and suggest that the Activin A-Smad-CTGF/CCN2 signaling in LPCs may be a therapeutic target of liver fibrosis. PMID:27011166
Activin A-Smad Signaling Mediates Connective Tissue Growth Factor Synthesis in Liver Progenitor Cells.
Ding, Ze-Yang; Jin, Guan-Nan; Wang, Wei; Sun, Yi-Min; Chen, Wei-Xun; Chen, Lin; Liang, Hui-Fang; Datta, Pran K; Zhang, Ming-Zhi; Zhang, Bixiang; Chen, Xiao-Ping
Liver progenitor cells (LPCs) are activated in chronic liver damage and may contribute to liver fibrosis. Our previous investigation reported that LPCs produced connective tissue growth factor (CTGF/CCN2), an inducer of liver fibrosis, yet the regulatory mechanism of the production of CTGF/CCN2 in LPCs remains elusive. In this study, we report that Activin A is an inducer of CTGF/CCN2 in LPCs. Here we show that expression of both Activin A and CTGF/CCN2 were upregulated in the cirrhotic liver, and the expression of Activin A positively correlates with that of CTGF/CCN2 in liver tissues. We go on to show that Activin A induced de novo synthesis of CTGF/CCN2 in LPC cell lines LE/6 and WB-F344. Furthermore, Activin A contributed to autonomous production of CTGF/CCN2 in liver progenitor cells (LPCs) via activation of the Smad signaling pathway. Smad2, 3 and 4 were all required for this induction. Collectively, these results provide evidence for the fibrotic role of LPCs in the liver and suggest that the Activin A-Smad-CTGF/CCN2 signaling in LPCs may be a therapeutic target of liver fibrosis.
Self-assembling functionalized nanopeptides for immediate hemostasis and accelerative liver tissue regeneration
NASA Astrophysics Data System (ADS)
Cheng, Tzu-Yun; Wu, Hsi-Chin; Huang, Ming-Yuan; Chang, Wen-Han; Lee, Chao-Hsiung; Wang, Tzu-Wei
Traumatic injury or surgery may trigger extensive bleeding. However, conventional hemostatic methods have limited efficacy and may cause surrounding tissue damage. In this study, we use self-assembling peptides (SAPs) and specifically extend fragments of functional motifs derived from fibronectin and laminin to evaluate the capability of these functionalized SAPs in the effect of hemostasis and liver tissue regeneration. From the results, these peptides can self-assemble into nanofibrous network structure and gelate into hydrogel with pH adjustment. In animal studies, the efficacy of hemostasis is achieved immediately within seconds in a rat liver model. The histological analyses by hematoxylin-eosin stain and immunohistochemistry reveal that SAPs with these functionalized motifs significantly enhance liver tissue regeneration. In brief, these SAPs may have potential as pharmacological tools to extensively advance clinical therapeutic applications in hemostasis and tissue regeneration in the field of regenerative medicine.Traumatic injury or surgery may trigger extensive bleeding. However, conventional hemostatic methods have limited efficacy and may cause surrounding tissue damage. In this study, we use self-assembling peptides (SAPs) and specifically extend fragments of functional motifs derived from fibronectin and laminin to evaluate the capability of these functionalized SAPs in the effect of hemostasis and liver tissue regeneration. From the results, these peptides can self-assemble into nanofibrous network structure and gelate into hydrogel with pH adjustment. In animal studies, the efficacy of hemostasis is achieved immediately within seconds in a rat liver model. The histological analyses by hematoxylin-eosin stain and immunohistochemistry reveal that SAPs with these functionalized motifs significantly enhance liver tissue regeneration. In brief, these SAPs may have potential as pharmacological tools to extensively advance clinical therapeutic applications
Organochlorine and heavy metal concentrations in blubber and liver tissue collected from Queensland (Australia) dugong (Dugong dugon).
Haynes, David; Carter, Steve; Gaus, Caroline; Müller, Jochen; Dennison, William
Tissue samples of liver and blubber were salvaged from fifty-three dugong (Dugong dugon) carcasses stranded along the Queensland coast between 1996 and 2000. Liver tissue was analysed for a range of heavy metals and blubber samples were analysed for organochlorine compounds. Metal concentrations were similar in male and female animals and were generally highest in mature animals. Liver concentrations of arsenic, chromium, iron, lead, manganese, mercury and nickel in a number of individual animals were elevated in comparison to concentrations previously reported in Australian dugong. Dieldrin, DDT (and its breakdown products) and/or heptachlor epoxide were detected in 59% of dugong blubber samples. In general, concentrations of organochlorines were similar to those reported in dugong 20 years earlier, and were low in comparison to concentrations recorded from marine mammal tissue collected elsewhere in the world. With the exception of lead, the extent of carcass decomposition, the presence of disease or evidence of animal starvation prior to death did not significantly affect dugong tissue concentrations of metals or organochlorines. The results of the study suggest that bioaccumulation of metals and organochlorine compounds (other than dioxins) does not represent a significant risk to Great Barrier Reef dugong populations, particularly in the context of other pressures associated with coastal development and other anthropogenic activities.
A Model for Micro-Dosimetry in Virtual Liver Tissues
Motivation: Humans are potentially exposed to over 6,000 environmental chemicals. The liver is the primary organ for metabolism and often the first site of chemical-induced toxicity in animal testing, but it remains difficult to translate these outcomes to humans. To address thi...
False positive reaction for carboxyhemoglobin in blood from liver tissue.
Lund, A
On spectrophotometric determination of carboxyhemoglobin in blood collected from the liver of three bodies at three days post-mortem, false positive results were found (5--15 per cent saturation), since samples of heart blood collected a few hours after death did not contain carboxyhemoglobin.
The nanomechanical signature of liver cancer tissues and its molecular origin.
Tian, Mengxin; Li, Yiran; Liu, Weiren; Jin, Lei; Jiang, Xifei; Wang, Xinyan; Ding, Zhenbin; Peng, Yuanfei; Zhou, Jian; Fan, Jia; Cao, Yi; Wang, Wei; Shi, Yinghong
Patients with cirrhosis are at higher risk of developing hepatocellular carcinoma (HCC), the second most frequent cause of cancer-related deaths. Although HCC diagnosis based on conventional morphological characteristics serves as the "gold standard" in the clinic, there is a high demand for more convenient and effective diagnostic methods that employ new biophysical perspectives. Here, we show that the nanomechanical signature of liver tissue is directly correlated with the development of HCC. Using indentation-type atomic force microscopy (IT-AFM), we demonstrate that the lowest elasticity peak (LEP) in the Young's modulus distribution of surgically removed liver cancer tissues can serve as a mechanical fingerprint to evaluate the malignancy of liver cancer. Cirrhotic tissues shared the same LEP as normal tissues. However, a noticeable downward shift in the LEP was detected when the cirrhotic tissues progressed to a malignant state, making the tumor tissues more prone to microvascular invasion. Cell-level mechanistic studies revealed that the expression level of a Rho-family effector (mDia1) was consistent with the mechanical trend exhibited by the tissue. Our findings indicate that the mechanical profiles of liver cancer tissues directly varied with tumor progression, providing an additional platform for the future diagnosis of HCC.
Histopathologic changes in liver and kidney tissues induced by carbaryl in Bufotes variabilis (Anura: Bufonidae).
Çakıcı, Özlem
The purpose of this work was to investigate for the first time histopathologic effects of carbaryl in liver and kidney tissues of Bufotes variabilis. After 96h following exposure to carbaryl (low dose: 0.05, medium dose: 0.1 and high dose: 0.2mg/g), the toads were euthanized and dissected. In liver tissue, vacuolization in hepatocytes, necrosis, mononuclear cell infiltration, an increase in melanomacrophage number, enlargement of sinusoids, hemorrhage and congestion were determined in exposed toads. In kidney tissue, mononuclear cell infiltration, hypertrophied Bowman's capsule cells, deformation, vacuolization, karyolysis and necrosis of renal tubule epithelium, brush border destruction, glomerular shrinkage, hemorrhage and fibrosis were observed in carbaryl-treated groups. According to this investigation, carbaryl caused histopathologic damages in liver and kidney tissues of B. variabilis.
Vascularized subcutaneous human liver tissue from engineered hepatocyte/fibroblast sheets in mice.
Sakai, Yusuke; Yamanouchi, Kosho; Ohashi, Kazuo; Koike, Makiko; Utoh, Rie; Hasegawa, Hideko; Muraoka, Izumi; Suematsu, Takashi; Soyama, Akihiko; Hidaka, Masaaki; Takatsuki, Mitsuhisa; Kuroki, Tamotsu; Eguchi, Susumu
Subcutaneous liver tissue engineering is an attractive and minimally invasive approach used to curative treat hepatic failure and inherited liver diseases. However, graft failure occurs frequently due to insufficient infiltration of blood vessels (neoangiogenesis), while the maintenance of hepatocyte phenotype and function requires in vivo development of the complex cellular organization of the hepatic lobule. Here we describe a subcutaneous human liver construction allowing for rapidly vascularized grafts by transplanting engineered cellular sheets consisting of human primary hepatocytes adhered onto a fibroblast layer. The engineered hepatocyte/fibroblast sheets (EHFSs) showed superior expression levels of vascularization-associated growth factors (vascular endothelial growth factor, transforming growth factor beta 1, and hepatocyte growth factor) in vitro. EHFSs developed into vascularized subcutaneous human liver tissues contained glycogen stores, synthesized coagulation factor IX, and showed significantly higher synthesis rates of liver-specific proteins (albumin and alpha 1 anti-trypsin) in vivo than tissues from hepatocyte-only sheets. The present study describes a new approach for vascularized human liver organogenesis under mouse skin. This approach could prove valuable for establishing novel cell therapies for liver diseases.
The influence of tissue procurement procedures on RNA integrity, gene expression, and morphology in porcine and human liver tissue.
Kap, Marcel; Sieuwerts, Anieta M; Kubista, Mikael; Oomen, Monique; Arshad, Shazia; Riegman, Peter
The advent of molecular characterization of tissues has brought an increasing emphasis on the quality of biospecimens, starting with the tissue procurement process. RNA levels are particularly affected by factors in the collection process, but the influence of different pre-analytical factors is not well understood. Here we present the influence of tissue specimen size, as well as the transport and freezing protocols, on RNA quality. Large, medium, and smaller porcine liver samples were stored either dry, on moist gauze, or in salt solution for various times, and then frozen in either liquid nitrogen or in pre-cooled isopentane. Large and small human liver samples were frozen in pre-cooled isopentane either immediately or after one hour at room temperature. The small samples were stored dry, on moist gauze, or in salt solution. RNA was isolated and RIN values were measured. The RNA for six standard reference genes from human liver was analyzed by RT-qPCR, and tissue morphology was assessed for artifacts of freezing. Experiments using porcine liver samples showed that RNA derived from smaller samples was more degraded after one hour of cold ischemia, and that cooled transport is preferable. Human liver samples showed significant RNA degradation after 1 h of cold ischemia, which was more pronounced in smaller samples. RNA integrity was not significantly influenced by the transport or freezing method, but changes in gene expression were observed in samples either transported on gauze or in salt solution. Based on observations in liver samples, smaller samples are more subject to gene expression variability introduced by post-excision sample handling than are larger samples. Small biopsies should be transported on ice and snap frozen as soon as possible after acquisition from the patient.
Liver function in alpha-1-antitrypsin deficient individuals at 37 to 40 years of age
Mostafavi, Behrouz; Diaz, Sandra; Tanash, Hanan A.; Piitulainen, Eeva
Abstract Severe alpha-1-antitrypsin (AAT) deficiency (PiZZ) is a risk factor for liver disease, but the prevalence of liver cirrhosis and hepatocellular cancer in PiZZ adults is unknown. The risk of liver disease in adults with moderate AAT deficiency (PiSZ) is also unknown. A cohort of 127 PiZZ, 2 PiZnull, 54 PiSZ, and 1 PiSnull individuals were identified by the Swedish national neonatal AAT screening program between 1972 and 1974, when all 200,000 newborn infants in Sweden were screened for AAT deficiency. The cohort has been followed up since birth. Our aim was to study liver function and signs of liver disease in this cohort at 37 to 40 years of age in comparison with a matched, random sample of control subjects identified from the population registry. Eighty seven PiZZ, 32 PiSZ, and 92 control subjects (PiMM) answered a questionnaire on medication and alcohol consumption and provided blood samples. Liver stiffness was assessed by Acoustic Radiation Force Impulse (ARFI) elastography in 32 PiZZ, 15 PiSZ, and 51 PiMM subjects. The median of liver function tests and procollagen-III-peptide were within the normal range in all Pi subgroups. However, the PiZZ men had significantly higher plasma bilirubin than the PiMM men (P = 0.018). Plasma ɣ-glutamyl transferase (GGT) was significantly higher in the PiZZ men (P = 0.009) and the PiSZ men (P = 0.021) compared with the PiMM men. The median of liver stiffness was significantly higher in the PiZZ men (P = 0.037) and the PiSZ men (P = 0.032) compared with the PiMM men. The PiZZ women taking medication influencing liver enzymes had significantly higher GGT than the PiMM women on the corresponding treatment (P = 0.023). These AAT-deficient individuals identified by neonatal screening have normal plasma levels of liver function tests, and no clinical signs indicating liver disease at the age of 37 to 40 years. However, bilirubin, GGT, and liver stiffness are significantly higher in PiZZ men than Pi
Fetal liver endothelium regulates the seeding of tissue-resident macrophages.
Rantakari, Pia; Jäppinen, Norma; Lokka, Emmi; Mokkala, Elias; Gerke, Heidi; Peuhu, Emilia; Ivaska, Johanna; Elima, Kati; Auvinen, Kaisa; Salmi, Marko
Macrophages are required for normal embryogenesis, tissue homeostasis and immunity against microorganisms and tumours. Adult tissue-resident macrophages largely originate from long-lived, self-renewing embryonic precursors and not from haematopoietic stem-cell activity in the bone marrow. Although fate-mapping studies have uncovered a great amount of detail on the origin and kinetics of fetal macrophage development in the yolk sac and liver, the molecules that govern the tissue-specific migration of these cells remain completely unknown. Here we show that an endothelium-specific molecule, plasmalemma vesicle-associated protein (PLVAP), regulates the seeding of fetal monocyte-derived macrophages to tissues in mice. We found that PLVAP-deficient mice have completely normal levels of both yolk-sac- and bone-marrow-derived macrophages, but that fetal liver monocyte-derived macrophage populations were practically missing from tissues. Adult PLVAP-deficient mice show major alterations in macrophage-dependent iron recycling and mammary branching morphogenesis. PLVAP forms diaphragms in the fenestrae of liver sinusoidal endothelium during embryogenesis, interacts with chemoattractants and adhesion molecules and regulates the egress of fetal liver monocytes to the systemic vasculature. Thus, PLVAP selectively controls the exit of macrophage precursors from the fetal liver and, to our knowledge, is the first molecule identified in any organ as regulating the migratory events during embryonic macrophage ontogeny.
Specific molecular signatures of non-tumor liver tissue may predict a risk of hepatocarcinogenesis
Utsunomiya, Tohru; Shimada, Mitsuo; Morine, Yuji; Tajima, Atsushi; Imoto, Issei
Hepatocellular carcinoma (HCC) is one of the most common human cancers and a major cause of cancer-related death worldwide. The bleak outcomes of HCC patients even after curative treatment have been, at least partially, attributed to its multicentric origin. Therefore, it is necessary to examine not only tumor tissue but also non-tumor liver tissue to investigate the molecular mechanisms operating during hepatocarcinogenesis based on the concept of "field cancerization". Several studies previously investigated the association of molecular alterations in non-tumor liver tissue with clinical features and prognosis in HCC patients on a genome-wide scale. In particular, specific alterations of DNA methylation profiles have been confirmed in non-tumor liver tissue. This review focuses on the possible clinical value of array-based comprehensive analyses of molecular alterations, especially aberrant DNA methylation, in non-tumor liver tissue to clarify the risk of hepatocarcinogenesis. Carcinogenetic risk estimation based on specific methylation signatures may be advantageous for close follow-up of patients who are at high risk of HCC development. Furthermore, epigenetic therapies for patients with chronic liver diseases may be helpful to reduce the risk of HCC development because epigenetic alterations are potentially reversible, and thus provide promising molecular targets for therapeutic intervention. PMID:24766251
Development of a 3D cell printed construct considering angiogenesis for liver tissue engineering.
Lee, Jin Woo; Choi, Yeong-Jin; Yong, Woon-Jae; Pati, Falguni; Shim, Jin-Hyung; Kang, Kyung Shin; Kang, In-Hye; Park, Jaesung; Cho, Dong-Woo
Several studies have focused on the regeneration of liver tissue in a two-dimensional (2D) planar environment, whereas actual liver tissue is three-dimensional (3D). Cell printing technology has been successfully utilized for building 3D structures; however, the poor mechanical properties of cell-laden hydrogels are a major concern. Here, we demonstrate the printing of a 3D cell-laden construct and its application to liver tissue engineering using 3D cell printing technology through a multi-head tissue/organ building system. Polycaprolactone (PCL) was used as a framework material because of its excellent mechanical properties. Collagen bioink containing three different types of cells-hepatocytes (HCs), human umbilical vein endothelial cells , and human lung fibroblasts--was infused into the canals of a PCL framework to induce the formation of capillary--like networks and liver cell growth. A co-cultured 3D microenvironment of the three types of cells was successfully established and maintained. The vascular formation and functional abilities of HCs (i.e., albumin secretion and urea synthesis) demonstrated that the heterotypic interaction among HCs and nonparenchymal cells increased the survivability and functionality of HCs within the collagen gel. Therefore, our results demonstrate the prospect of using cell printing technology for the creation of heterotypic cellular interaction within a structure for liver tissue engineering.
Photothermal ablation of liver tissue with 1940-nm thulium fiber laser: an ex vivo study on lamb liver
NASA Astrophysics Data System (ADS)
Alagha, Heba Z.; Gülsoy, Murat
The purpose of this study was to investigate the ablation efficiency of 1940-nm thulium fiber laser on liver tissue, while utilizing a real-time measurement system to monitor the temperature rise in adjacent tissues. Thulium fiber laser was delivered to lamb liver tissue samples via 400-μm bare tip fiber in contact mode. Eight different laser parameter combinations [power, continuous-wave (cw)/pulsed-modulated (pm) mode, and exposure time] were used. Exposure times were chosen to give the same total applied energy of 4 J for comparative purposes. Following laser irradiations, tissues were processed and stained with hematoxylin and eosin for macroscopic evaluation of ablation areas and total altered areas, and ablation efficiencies were calculated. Temperature of the nearby tissue at a distance of 1 mm from the fiber was measured, and rate of temperature change was calculated. A strong correlation between the rate of temperature change and ablation area was noted. Thermal effects increased with increasing power for both modes. The continuous-wave mode yielded higher ablation efficiencies than the pulse-modulated mode. Histological evaluation revealed a narrow vacuolization zone and negligible carbonization for higher-power values.
Application potential of mesenchymal stem cells derived from Wharton's jelly in liver tissue engineering.
Zhang, Lei; Zhao, Yong-Hen; Guan, Zheng; Ye, Jun-Song; de Isla, Natalia; Stoltz, Jean-François
The shortage of organ resource has been limiting the application of liver transplantation. Bioartificial liver construction is increasingly focused as a replacement treatment. To product a bioartificial liver, three elements must be considered: seeding cells, scaffold and bioreactor. Recent studies have shown that several methods can successfully differentiate MSC (mesenchymal stem cells) derived from Wharton's jelly into hepatocyte, such as stimulating MSC by cytokines and growth factors, direct and indirect co-culture MSC with hepatocytes, or promote MSC differentiation by 3-dimensional matrix. In some cases, differentiation of MSC into hepatocytes can also be an alternative approach for whole organ transplantation in treatment of acute and chronic liver diseases. In this review, the characterization of MSC from Wharton's jelly, their potential of application in liver tissue engineering on base of decellularized scaffold, their status of banking and their preclinical work performed will be discussed.
Metabolic impact of the glycerol channels AQP7 and AQP9 in adipose tissue and liver.
Lebeck, Janne
Obesity and secondary development of type 2 diabetes (T2D) are major health care problems throughout the developed world. Accumulating evidence suggest that glycerol metabolism contributes to the pathophysiology of obesity and T2D. Glycerol is a small molecule that serves as an important intermediate between carbohydrate and lipid metabolism. It is stored primarily in adipose tissue as the backbone of triglyceride (TG) and during states of metabolic stress, such as fasting and diabetes, it is released for metabolism in other tissues. In the liver, glycerol serves as a gluconeogenic precursor and it is used for the esterification of free fatty acid into TGs. Aquaporin 7 (AQP7) in adipose tissue and AQP9 in the liver are transmembrane proteins that belong to the subset of AQPs called aquaglyceroporins. AQP7 facilitates the efflux of glycerol from adipose tissue and AQP7 deficiency has been linked to TG accumulation in adipose tissue and adult onset obesity. On the other hand, AQP9 expressed in liver facilitates the hepatic uptake of glycerol and thereby the availability of glycerol for de novo synthesis of glucose and TG that both are involved in the pathophysiology of diabetes. The aim of this review was to summarize the current knowledge on the role of the two glycerol channels in controlling glycerol metabolism in adipose tissue and liver.
Total mercury in liver and muscle tissue of two coastal sharks from the northwest of Mexico.
Hurtado-Banda, Rocío; Gomez-Alvarez, Agustín; Márquez-Farías, J Fernando; Cordoba-Figueroa, Marcial; Navarro-García, Gerardo; Medina-Juárez, Luis Angel
Total mercury (THg) in liver and muscle of three costal sharks from Mexico were evaluated. The highest concentrations of THg in muscle tissue of juveniles were found in Sphyrna lewini (0.82 ± 0.33 mg kg(-1) wet basis). Rhizoprionodon longurio adults had the highest concentrations (0.92 ± 1.03 mg kg(-1)). THg concentrations in liver were low compared to those found in muscle tissue; higher levels were found in liver of juvenile S. lewini (0.250 ± 0.07 mg kg(-1)). Results showed that 35 % of muscle tissue samples are above the precautionary limit (0.50 mg kg(-1) of THg) and a 7 % exceeded the maximum limit for human consumption (1 mg kg(-1)).
Histopathology effects of nickel nanoparticles on lungs, liver, and spleen tissues in male mice
NASA Astrophysics Data System (ADS)
Ajdari, Marziyeh; Ziaee Ghahnavieh, Marziyeh
Because of the classification of the nickel compounds as carcinogenic substances, there is a need for in vivo tests to nickel nanoparticles (NiNPs) for observing their effects on health experimentally. Spherical NiNPs with 10 nm in diameter and 75 ppm concentration were applied for investigating their toxicities within male albino mice as an in vivo model. We randomly made sham group, control group, and 75 ppm group (with five animals in each group). Then, the nanoparticles were injected into mice intraperitonealy for 7 days and after that their lungs, liver, and spleen were removed for histopathological observations. At the end of the test, section microscopic observations of liver, spleen, and lung in sham and control groups showed normal tissues but these tissues underwent significant abnormal effects in 75 ppm group. NiNPs can cause undesirable effects in lungs, liver, and spleen tissues with same condition of this study.
New physiologically-relevant liver tissue model based on hierarchically cocultured primary rat hepatocytes with liver endothelial cells.
Xiao, Wenjin; Perry, Guillaume; Komori, Kikuo; Sakai, Yasuyuki
To develop an in vitro liver tissue equivalent, hepatocytes should be cocultured with liver non-parenchymal cells to mimic the in vivo physiological microenvironments. In this work, we describe a physiologically-relevant liver tissue model by hierarchically organizing layers of primary rat hepatocytes and human liver sinusoidal endothelial cells (TMNK-1) on an oxygen-permeable polydimethylsiloxane (PDMS) membrane, which facilitates direct oxygenation by diffusion through the membrane. This in vivo-mimicking hierarchical coculture was obtained by simply proceeding the overlay of TMNK-1 cells on the hepatocyte layer re-formed on the collagen immobilized PDMS membranes. The comparison of hepatic functionalities was achieved between coculture and sandwich culture with Matrigel, in the presence and absence of direct oxygenation. A complete double-layered structure of functional liver cells with vertical contact between hepatocytes and TMNK-1 was successfully constructed in the coculture with direct oxygen supply and was well-maintained for 14 days. The hepatocytes in this hierarchical culture exhibited improved survival, functional bile canaliculi formation, cellular level polarization and maintenance of metabolic activities including Cyp1A1/2 activity and albumin production. By contrast, the two cell populations formed discontinuous monolayers on the same surfaces in the non-oxygen-permeable cultures. These results demonstrate that (i) the direct oxygenation through the PDMS membranes enables very simple formation of a hierarchical structure consisting of a hepatocyte layer and a layer of TMNK-1 and (ii) we may include other non-parenchymal cells in this format easily, which can be widely applicable to other epithelial organs.
Functional life-long maintenance of engineered liver tissue in mice following transplantation under the kidney capsule.
Ohashi, Kazuo; Koyama, Fumikazu; Tatsumi, Kohei; Shima, Midori; Park, Frank; Nakajima, Yoshiyuki; Okano, Teruo
The ability to engineer biologically active cells and tissue matrices with long-term functional maintenance has been a principal focus for investigators in the field of hepatocyte transplantation and liver tissue engineering. The present study was designed to determine the efficacy and temporal persistence of functional engineered liver tissue following transplantation under the kidney capsule of a normal mouse. Hepatocytes were isolated from human alpha-1 antitrypsin (hA1AT) transgenic mouse livers. Hepatocytes were subsequently transplanted under the kidney capsule space in combination with extracellular matrix components (Matrigel) for engineering liver tissues. The primary outcome of interest was to assess the level of engineering liver tissue function over the experimental period, which was 450 days. Long-term survival by the engineered liver tissue was confirmed by measuring the serum level of hA1AT in the recipient mice throughout the experimental period. In addition, administration of chemical compounds at day 450 resulted in the ability of the engineered liver tissue to metabolize exogenously circulating compounds and induce drug-metabolizing enzyme production. Moreover, we were able to document that the engineered tissues could retain their native regenerative potential similar to that of naïve livers. Overall, these results demonstrated that liver tissues could be engineered at a heterologous site while stably maintaining its functionality for nearly the life span of a normal mouse.
Meta-analysis of expression of hepatic organic anion-transporting polypeptide (OATP) transporters in cellular systems relative to human liver tissue.
Badée, Justine; Achour, Brahim; Rostami-Hodjegan, Amin; Galetin, Aleksandra
Organic anion-transporting polypeptide (OATP)1B1, OATP1B3, and OATP2B1 transporters play an important role in hepatic drug disposition. Recently, an increasing number of studies have reported proteomic expression data for OATP transporters. However, systematic analysis and understanding of the actual differences in OATP expression between liver tissue and commonly used cellular systems is lacking. In the current study, meta-analysis was performed to assess the protein expression of OATP transporters reported in hepatocytes relative to liver tissue and to identify any potential correlations in transporter expression levels in the same individual. OATP1B1 was identified as the most abundant uptake transporter at 5.9 ± 8.3, 5.8 ± 3.3, and 4.2 ± 1.7 fmol/μg protein in liver tissue, sandwich-cultured human hepatocytes (SCHH), and cryopreserved suspended hepatocytes, respectively. The rank order in average expression in liver tissue and cellular systems was OATP1B1 > OATP1B3 ≈ OATP2B1. Abundance levels of the OATP transporters investigated were not significantly different between liver and cellular systems, with the exception of OATP2B1 expression in SCHH relative to liver tissue. Analysis of OATP1B1, OATP1B3, and OATP2B1 liver expression data in the same individuals (n = 86) identified weak (OATP1B1-OATP2B1) to moderately (OATP1B3-OATP2B1) significant correlations. A significant weak correlation was noted between OATP1B1 abundance and age of human donors, whereas expression of the OATPs investigated was independent of sex. Implications of the current analysis on the in vitro-in vivo extrapolation of transporter-mediated drug disposition using physiologically based pharmacokinetic models are discussed.
Analysis of normal and diseased liver tissue using auto-fluorescence and Raman spectroscopy
NASA Astrophysics Data System (ADS)
Li, Xiaozhou; Jia, Chunde; Lin, Junxiu; Kang, Youping
In this paper, laser induced human serum Raman spectra of liver cancer are measured. The spectra differences in serum from normal people and liver cancer patients are analyzed. For the typical spectrum of normal serum, there are three sharp Raman peaks and relative intensity of Raman peaks excited by 514.5 nm is higher than that excited by 488.0 nm. However, for the Raman spectrum of liver cancer serum there are no peaks or very weak Raman peaks at the same positions. Results from more than two hundred case measurements show that clinical diagnostic accuracy is 92.86%. And then, the liver fibrosis and liver cirrhosis are studied applying the technology of LIF. To liver cirrhosis, the shape of Raman peak is similar to normal and fluorescence spectrum is similar to that of liver cancer from statistic data. The experiment indicates that there is notable fluorescence difference between the abnormal and normal liver tissue and have blue shift in fluorescence peak. These results have important reference values to explore the method of laser spectrum diagnosis.
Sex-specific metabolic interactions between liver and adipose tissue in MCD diet-induced non-alcoholic fatty liver disease
Lee, Yun-Hee; Kim, Sou Hyun; Kim, Sang-Nam; Kwon, Hyun-Jung; Kim, Jeong-Dong; Oh, Ji Youn; Jung, Young-Suk
Higher susceptibility to metabolic disease in male exemplifies the importance of sexual dimorphism in pathogenesis. We hypothesized that the higher incidence of non-alcoholic fatty liver disease in males involves sex-specific metabolic interactions between liver and adipose tissue. In the present study, we used a methionine-choline deficient (MCD) diet-induced fatty liver mouse model to investigate sex differences in the metabolic response of the liver and adipose tissue. After 2 weeks on an MCD-diet, fatty liver was induced in a sex-specific manner, affecting male mice more severely than females. The MCD-diet increased lipolytic enzymes in the gonadal white adipose tissue (gWAT) of male mice, whereas it increased expression of uncoupling protein 1 and other brown adipocyte markers in the gWAT of female mice. Moreover, gWAT from female mice demonstrated higher levels of oxygen consumption and mitochondrial content compared to gWAT from male mice. FGF21 expression was increased in liver tissue by the MCD diet, and the degree of upregulation was significantly higher in the livers of female mice. The endocrine effect of FGF21 was responsible, in part, for the sex-specific browning of gonadal white adipose tissue. Collectively, these data demonstrated that distinctively female-specific browning of white adipose tissue aids in protecting female mice against MCD diet-induced fatty liver disease. PMID:27409675
Predose and Postdose Blood Gene Expression Profiles Identify the Individuals Susceptible to Acetaminophen-Induced Liver Injury in Rats
Lu, Xiaoyan; Hu, Bin; Zheng, Jie; Ji, Cai; Fan, Xiaohui; Gao, Yue
The extent of drug-induced liver injury (DILI) can vary greatly between different individuals. Thus, it is crucial to identify susceptible population to DILI. The aim of this study was to determine whether transcriptomics analysis of predose and postdose rat blood would allow prediction of susceptible individuals to DILI using the widely applied analgesic acetaminophen (APAP) as a model drug. Based on ranking in alanine aminotransferase levels, five most susceptible and five most resistant rats were identified as two sub-groups after APAP treatment. Predose and postdose gene expression profiles of blood samples from these rats were determined by microarray analysis. The expression of 158 genes innately differed in the susceptible rats from the resistant rats in predose data. In order to identify more reliable biomarkers related to drug responses for detecting individuals susceptibility to APAP-induced liver injury (AILI), the changes of these genes' expression posterior to APAP treatment were detected. Through the further screening method based on the trends of gene expression between the two sub-groups before and after drug treatment, 10 genes were identified as potential predose biomarkers to distinguish between the susceptible and resistant rats. Among them, four genes, Incenp, Rpgrip1, Sbf1, and Mmp12, were found to be reproducibly in real-time PCR with an independent set of animals. They were all innately higher expressed in resistant rats to AILI, which are closely related to cell proliferation and tissue repair functions. It indicated that rats with higher ability of cell proliferation and tissue repair prior to drug treatment might be more resistant to AILI. In this study, we demonstrated that combination of predose and postdose gene expression profiles in blood might identify the drug related inter-individual variation in DILI, which is a novel and important methodology for identifying susceptible population to DILI. PMID:26512990
Tissue responsiveness to estradiol and genistein in the sea bass liver and scale.
Pinto, Patrícia I S; Estêvão, M Dulce; Andrade, André; Santos, Soraia; Power, Deborah M
As in mammals, estrogens in fish are essential for reproduction but also important regulators of mineral homeostasis. Fish scales are a non-conventional target tissue responsive to estradiol and constitute a good model to study mineralized tissues effects and mechanisms of action of estrogenic compounds, including phytoestrogens. The responsiveness to estradiol and the phytoestrogen genistein, was compared between the scales and the liver, a classical estrogenic target, in sea bass (Dicentrarchus labrax). Injection with estradiol and genistein significantly increased circulating vitellogenin (for both compounds) and mineral levels (estradiol only) and genistein also significantly increased scale enzymatic activities suggesting it increased mineral turnover. The repertoire, abundance and estrogenic regulation of nuclear estrogen receptors (ESR1, 2a and 2b) and membrane G-protein receptors (GPER and GPER-like) were different between liver and scales, which presumably explains the tissue-specific changes detected in estrogen-responsive gene expression. In scales changes in gene expression mainly consisted of small rapid increases, while in liver strong, sustained increases/decreases in gene expression occurred. Similar but not overlapping gene expression changes were observed in response to both estradiol and genistein. This study demonstrates for the first time the expression of membrane estrogen receptors in scales and that estrogens and phytoestrogens, to which fish may be exposed in the wild or in aquaculture, both affect liver and mineralized tissues in a tissue-specific manner.
Cellular-mediated immune responses in the liver tissue of patients with severe Plasmodium falciparum malaria.
Punsawadl, Chuchard; Setthapramote, Chayanee; Viriyavejakul, Parnpen
The immune responses against Plasmodiumfalciparum malaria infections are complex and poorly understood. No published studies have yet reported the lymphocyte subsets involved in the human liver tissue of P. falciparum malaria patients. To understand the cellular-mediated immune responses in the liver during malaria infection, we determined the numbers of the various lymphocyte subsets in tissue samples obtained at autopsy from patients who died with P. falciparum malaria infection. All the liver tissue specimens had been stored at the Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University, Thailand. On the basis of total bilirubin (TB) levels prior to death, patients were divided into 2 groups: those with hyperbilirubinemia [total bilirubin (TB) > or =51.3 micromol/l) (n = 9)] and those without hyperbilirubinemia (TB < 51.3 micromol/l) (n = 12). Normal liver specimens (n = 10) were used as controls. An immunohistochemistry method was used to analyze the types and numbers of lymphocytes (T and B lymphocytes), and Kupffer cells, using specific antibodies against CD3+, CD4+, CD8+, CD20+, and CD68+. Our findings reveal the numbers of T lymphocytes (CD3+ T-cells) and their subsets (CD4+ and CD8+ T-cells) were significantly greater in the portal tracts and sinusoids of liver tissue obtained from P. falciparum malaria cases with hyperbilirubinemia than those without hyperbilirubinemia or controls. CD8+ T-cells were the major lymphocyte subset in the liver tissue of patients with severe falciparum malaria. A significant positive correlation was seen between the numbers of CD4+ and CD8+ T-cells and the liver enzyme levels among P. falciparum malaria patients. The number of CD68+ cells (Kupffer cells) was significantly greater in the liver sinusoids of P. falciparum malaria cases with hyperbilirubinemia than those without hyperbilirubinemia. These findings suggest T-cells, especially CD8+ T-cells and Kupffer cells are an important part of the
Epicardial Adipose Tissue (EAT) Thickness Is Associated with Cardiovascular and Liver Damage in Nonalcoholic Fatty Liver Disease
Pisano, Giuseppina; Consonni, Dario; Tiraboschi, Silvia; Baragetti, Andrea; Bertelli, Cristina; Norata, Giuseppe Danilo; Dongiovanni, Paola; Valenti, Luca; Grigore, Liliana; Tonella, Tatiana; Catapano, Alberico; Fargion, Silvia
Background and Aims Epicardial adipose tissue (EAT) has been proposed as a cardiometabolic and hepatic fibrosis risk factor in patients with non alcoholic fatty liver disease (NAFLD). Aim of this study was to evaluate the role of EAT in NAFLD by analyzing 1) the association between EAT, the other metabolic parameters and the severity of steatosis 2) the relationship between cardiovascular (cIMT, cplaques, E/A), liver (presence of NASH and significant fibrosis) damage and metabolic risk factors including EAT 3) the relationship between EAT and genetic factors strongly influencing liver steatosis. Methods In a cross-sectional study, we considered 512 consecutive patients with NAFLD (confirmed by biopsy in 100). EAT, severity of steatosis, carotid intima-media thickness (cIMT) and plaques were evaluated by ultrasonography and results analysed by multiple linear and logistic regression models. Variables independently associated with EAT (mm) were female gender (p = 0.003), age (p = 0.001), BMI (p = 0.01), diastolic blood pressure (p = 0.009), steatosis grade 2 (p = 0.01) and 3 (p = 0.04), fatty liver index (p = 0.001) and statin use (p = 0.03). Variables independently associated with carotid IMT were age (p = 0.0001), hypertension (p = 0.009), diabetes (p = 0.04), smoking habits (p = 0.04) and fatty liver index (p = 0.02), with carotid plaques age (p = 0.0001), BMI (p = 0.03), EAT (p = 0.02),) and hypertension (p = 0.02), and with E/A age (p = 0.0001), diabetes (p = 0.005), hypertension (p = 0.04) and fatty liver index (p = 0.004). In the 100 patients with available liver histology non alcoholic steatohepatitis (NASH) was independently associated with EAT (p = 0.04) and diabetes (p = 0.054) while significant fibrosis with EAT (p = 0.02), diabetes (p = 0.01) and waist circumference (p = 0.05). No association between EAT and PNPLA3 and TM6SF2 polymorphisms was found. Conclusion In patients with NAFLD, EAT is associated with the severity of liver and vascular damage
Optical spectroscopy for differentiation of liver tissue under distinct stages of fibrosis: an ex vivo study
NASA Astrophysics Data System (ADS)
Fabila, D. A.; Hernández, L. F.; de la Rosa, J.; Stolik, S.; Arroyo-Camarena, U. D.; López-Vancell, M. D.; Escobedo, G.
Liver fibrosis is the decisive step towards the development of cirrhosis; its early detection affects crucially the diagnosis of liver disease, its prognosis and therapeutic decision making. Nowadays, several techniques are employed to this task. However, they have the limitation in estimating different stages of the pathology. In this paper we present a preliminary study to evaluate if optical spectroscopy can be employed as an auxiliary tool of diagnosis of biopsies of human liver tissue to differentiate the fibrosis stages. Ex vivo fluorescence and diffuse reflectance spectra were acquired from biopsies using a portable fiber-optic system. Empirical discrimination algorithms based on fluorescence intensity ratio at 500 nm and 680 nm as well as diffuse reflectance intensity at 650 nm were developed. Sensitivity and specificity of around 80% and 85% were respectively achieved. The obtained results show that combined use of fluorescence and diffuse reflectance spectroscopy could represent a novel and useful tool in the early evaluation of liver fibrosis.
Exposure to industrial wideband noise increases connective tissue in the rat liver.
Oliveira, Maria João R; Freitas, Diamantino; Carvalho, António P O; Guimarães, Laura; Pinto, Ana; Águas, Artur P
Rats were daily exposed (eight hours/day) for a period of four weeks to the same high-intensity wideband noise that was recorded before in a large textile plant. Histologic observation of liver sections of the rats was used to perform quantitative comparison of hepatic connective tissue (dyed by Masson trichromic staining) between the noise-exposed and control animals. For that, we have photographed at random centrolobular areas of stained rat liver sections. We found that noise exposure resulted in significant enhancement in the area of collagen-rich connective tissue present in the centrolobular domain of the rat liver. Our data strengthen previous evidence showing that fibrotic transformation is a systemic effect of chronic exposure of rodents and humans to industrial wideband noise.
The alterations in the extracellular matrix composition guide the repair of damaged liver tissue.
Klaas, Mariliis; Kangur, Triin; Viil, Janeli; Mäemets-Allas, Kristina; Minajeva, Ave; Vadi, Krista; Antsov, Mikk; Lapidus, Natalia; Järvekülg, Martin; Jaks, Viljar
While the cellular mechanisms of liver regeneration have been thoroughly studied, the role of extracellular matrix (ECM) in liver regeneration is still poorly understood. We utilized a proteomics-based approach to identify the shifts in ECM composition after CCl4 or DDC treatment and studied their effect on the proliferation of liver cells by combining biophysical and cell culture methods. We identified notable alterations in the ECM structural components (eg collagens I, IV, V, fibronectin, elastin) as well as in non-structural proteins (eg olfactomedin-4, thrombospondin-4, armadillo repeat-containing x-linked protein 2 (Armcx2)). Comparable alterations in ECM composition were seen in damaged human livers. The increase in collagen content and decrease in elastic fibers resulted in rearrangement and increased stiffness of damaged liver ECM. Interestingly, the alterations in ECM components were nonhomogenous and differed between periportal and pericentral areas and thus our experiments demonstrated the differential ability of selected ECM components to regulate the proliferation of hepatocytes and biliary cells. We define for the first time the alterations in the ECM composition of livers recovering from damage and present functional evidence for a coordinated ECM remodelling that ensures an efficient restoration of liver tissue.
The alterations in the extracellular matrix composition guide the repair of damaged liver tissue
Klaas, Mariliis; Kangur, Triin; Viil, Janeli; Mäemets-Allas, Kristina; Minajeva, Ave; Vadi, Krista; Antsov, Mikk; Lapidus, Natalia; Järvekülg, Martin; Jaks, Viljar
While the cellular mechanisms of liver regeneration have been thoroughly studied, the role of extracellular matrix (ECM) in liver regeneration is still poorly understood. We utilized a proteomics-based approach to identify the shifts in ECM composition after CCl4 or DDC treatment and studied their effect on the proliferation of liver cells by combining biophysical and cell culture methods. We identified notable alterations in the ECM structural components (eg collagens I, IV, V, fibronectin, elastin) as well as in non-structural proteins (eg olfactomedin-4, thrombospondin-4, armadillo repeat-containing x-linked protein 2 (Armcx2)). Comparable alterations in ECM composition were seen in damaged human livers. The increase in collagen content and decrease in elastic fibers resulted in rearrangement and increased stiffness of damaged liver ECM. Interestingly, the alterations in ECM components were nonhomogenous and differed between periportal and pericentral areas and thus our experiments demonstrated the differential ability of selected ECM components to regulate the proliferation of hepatocytes and biliary cells. We define for the first time the alterations in the ECM composition of livers recovering from damage and present functional evidence for a coordinated ECM remodelling that ensures an efficient restoration of liver tissue. PMID:27264108
Micronucleus test in rodent tissues other than liver or erythrocytes: Report of the IWGT working group.
Uno, Yoshifumi; Morita, Takeshi; Luijten, Mirjam; Beevers, Carol; Hamada, Shuichi; Itoh, Satoru; Ohyama, Wakako; Takasawa, Hironao
At the 6th International Workshop on Genotoxicity Testing, the liver micronucleus test (MNT) working group briefly discussed the MNT using tissues other than liver/erythrocytes. Many tissues other than liver/erythrocytes have been studied, primarily for research purposes. They have included the colon and intestinal epithelium, skin, spleen, lung, stomach, bladder, buccal mucosa, vagina, and fetal/neonatal tissues. These tissues were chosen because they were target sites of carcinogens, and/or relevant to a specific route of exposure. Recently, there has been particular focus on the gastrointestinal (GI) tract as it is a contact site associated with high exposure following oral gavage. Furthermore GI tumors are observed with high frequency in human populations. A collaborative study of the rat glandular stomach and colon MNT was conducted in conjunction with a collaborative study of the repeated-dose liver MNT. Based on limited data currently available, the rodent MNT using the glandular stomach and/or colon seems to detect genotoxic carcinogens with GI tract target-organ specificity. The working group concluded that the GI tract MNT would be a promising method to examine clastogenicity or aneugenicity of test chemicals in the stomach and/or colon. Further data will be needed to fully establish the methods, and to identify the sensitivity and specificity of the GI tract MNT.
Inflammatory response in visceral fat tissue and liver is prenatally programmed: experimental research.
Bezpalko, L; Gavrilyuk, O; Zayachkivska, O
To investigate the mechanisms of developmental programming we analyzed the effects of maternal stress and food intake on physiological activity of adipose tissue and hepatocellular organization in the offsprings. The experiments were conducted in nonlinear female rats (n=20) and their male offsprings (n=28). During their pregnancy female rats were exposed to social and emotional stress using Pratt's model, and nutritional insults: high sugar diet (HSD) with chronic access to 30% solution of saccharose in drinking water ad libitum, high fat diet (HFD) containing 45% calories from fat or their combination - high sugar and high fat diet (HSFD). The effects of maternal stress and nutrition on severity of visceral fat and liver changes were then examined in offsprings, along with changes in serum levels of the pro- and anti-inflammatory cytokines: IL-1b, IL-8 (in rats known as GRO/CINC-1), leptin and adiponectin, respectively. Maternal exposure to stress in combination with HSFD resulted in the most prominent changes in the offsprings: histological changes in the visceral fat tissue and liver with cell reorganization and signs of inflammation, 217% increase in IL-1β level, 99% increase in GRO/CINC-1 level, 79% increase in leptin level and 41% decrease in adiponectin level. The leptin/adiponectin index was elevated in all study groups and reached 158% in HSD group, 138% in HFD group and was two times higher in HSFD group vs control. The rat model used in this study provides novel insight into development of nonalcoholic fatty liver disease. Expressed pro- and anti-inflammatory cytokines may indicate early changes in liver and adipose tissue functioning and leptin/adiponectin index could be a novel non-invasive marker of metabolic-related liver alteration. Healthy nutrition and stress management during prenatal period may serve as a valid strategy to prevent liver and adipose tissue inflammation/alteration and metabolic disorders in adulthood.
Heavy metal and selenium concentrations in liver tissue from wild American alligator (Alligator mississippiensis) livers near Charleston, South Carolina.
Campbell, Joshua W; Waters, Matthew N; Tarter, Anna; Jackson, Jennifer
Liver samples from 33 wild American alligators (Alligator mississippiensis) livers from the Charleston, South Carolina, area were analyzed for arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), mercury (Hg), nickel (Ni), lead (Pb), and selenium (Se) concentrations. Alligators are top predators and are considered a good biomonitoring species for various toxins, including heavy metals. Alligators from other areas in the US have shown high concentrations of mercury and other heavy metals, but the Charleston area, which is highly industrialized, has not been investigated. We found wide variation in hepatic heavy metal and selenium concentrations among alligators. Length and sex did not show a strong relationship with any metal based on statistical analysis. However, cluster analysis revealed three groupings of alligators based on liver metal concentrations. Alligators with low Se:Hg ratios also had high concentrations of Hg. Due to the wide variation in metal concentrations among individual alligators, we postulate that individual diet and microhabitat usage could be the cause for this variation.
Validation of finite element models of liver tissue using micro-CT.
Shi, Hongjian; Farag, Aly A; Fahmi, Rachid; Chen, Dongqing
In this work, we aim at validating some soft tissue deformation models using high-resolution micro-computed tomography (Micro-CT) images. The imaging technique plays a key role in detecting the tissue deformation details in the contact region between the tissue and the surgical tool (probe) for small force loads and provides good capabilities of creating accurate 3-D models of soft tissues. Surgical simulations rely on accurate representation of the mechanical response of soft tissues subjected to surgical manipulations. Several finite-element models have been suggested to characterize soft tissues. However, validating these models for specific tissues still remain a challenge. In this study, ex vivo lamb liver tissue is chosen to validate the linear elastic model (LEM), the linear viscoelastic model (LVEM), and the neo-Hooke hyperelastic model (NHM). We find that the LEM is more applicable to lamb liver than the LVEM for smaller force loads (< 20 g) and that the NHM is closer to reality than the LVEM for the range of force loads from 5 to 40 g.
In vivo quantification of motion in liver parenchyma and its application in shistosomiasis tissue characterization
NASA Astrophysics Data System (ADS)
Badawi, Ahmed M.; Hashem, Ahmed M.; Youssef, Abou-Bakr M.; Abdel-Wahab, Mohamed F.
Schistosomiasis is a major problem in Egypt, despite an active control program it is estimated to exist in about 1/3 of the population. Deposition of less functioning fibrous tissues in the liver is the major contributory factor to the hepatic pathology. Fibrous tissues consist of a complex array of connective matrix material and a variety of collagen isotopes. As a result of an increased stromal density (collagen content), the parenchyma became more ectogenic and less elastic (hard). In this study we investigated the effect of cardiac mechanical impulses from the heart and aorta on the kinetics of the liver parenchyma. Under conditions of controlled patient movements and suspended respiration, a 30 frame per second of 588 X 512 ultrasound images (cineloop, 32 pels per cm) are captured from an aTL ultrasound machine then digitized. The image acquisition is triggered by the R wave of the ECG of the patient. The motion that has a forced oscillation form in the liver parenchyma is quantified by tracking of small box (20 - 30 pels) in 16 directions for all the successive 30 frames. The tracking was done using block matching techniques (the max correlation between boxes in time, frequency domains, and the minimum SAD (sum absolute difference) between boxes). The motion is quantified for many regions at different positions within the liver parenchyma for 80 cases of variable degrees of schisto., cirrhotic livers, and for normal livers. The velocity of the tissue is calculated from the displacement (quantified motion), time between frames, and the scan time for the ultrasound scanner. We found that the motion in liver parenchyma is small in the order of very few millimeters, and the attenuation of the mechanical wave for one ECG cycle is higher in the schisto. and cirrhotic livers than in the normal ones. Finally quantification of motion in liver parenchyma due to cardiac impulses under controlled limb movement and respiration may be of value in the characterization of
Elemental composition of liver and kidney tissues of rough-toothed dolphins (Steno bredanensis).
Mackey, E A; Oflaz, R D; Epstein, M S; Buehler, B; Porter, B J; Rowles, T; Wise, S A; Becker, P R
On December 14, 1997, 62 rough-toothed dolphins (Steno bredanensis) stranded on Cape San Blas, on the Florida coast of the Gulf of Mexico. Approximately 30 animals died either on the beach or in rehabilitation facilities. Two were successfully rehabilitated and released. Liver, kidney, blubber, and muscle tissues were collected from 15 animals that died on the beach. Portions of the liver and kidney from each dolphin were analyzed using instrumental neutron activation analysis and inductively coupled plasma mass spectrometry to determine mass fractions of 37 elements. Levels of several electrolytes (Na, Cl, K, Br, Rb, I, Cs) and of the essential trace elements Fe, Cu, and Zn in both tissues were similar to those found in other Odontoceti. Mass fractions of Ca ranged from 60 mg/kg to 1,200 mg/kg (wet mass basis), indicating significant inhomogeneity in the kidney tissues of several animals. Necropsy reports noted that the kidneys of many of these animals contained fibrous nodules. The measured Ca inhomogeneity may be due to mineralization of the fibrous kidney tissue. Hepatic levels of Hg and Se were at the high end of the ranges generally found in livers of other Odontoceti and were slightly higher in animals with fibrous kidneys than in the others. Mass fractions of Se, Ag, and Hg in liver tissues increased with the size and age of the animals indicating accumulation of these elements in the liver with age. Results also indicate that Se and Hg accumulate in rough-toothed dolphin kidney. Accumulation of these elements with age has been reported commonly for marine mammals and other species.
Hepatic fibrosis and factors associated with liver stiffness in HIV mono-infected individuals
Ferenci, Tamás; Makara, Mihály; Horváth, Gábor; Szlávik, János; Rupnik, Zsófia; Kormos, Luca; Gerlei, Zsuzsanna; Sulyok, Zita; Vályi-Nagy, István
Background Liver disease has become an important cause of morbidity and mortality even in those HIV-infected individuals who are devoid of hepatitis virus co-infection. The aim of this study was to evaluate the degree of hepatic fibrosis and the role of associated factors using liver stiffness measurement in HIV mono-infected patients without significant alcohol intake. Methods We performed a cross-sectional study of 101 HIV mono-infected patients recruited prospectively from March 1, 2014 to October 30, 2014 at the Center for HIV, St István and St László Hospital, Budapest, Hungary. To determine hepatic fibrosis, liver stiffness was measured with transient elastography. Demographic, immunologic and other clinical parameters were collected to establish a multivariate model. Bayesian Model Averaging (BMA) was performed to identify predictors of liver stiffness. Results Liver stiffness ranged from 3.0–34.3 kPa, with a median value of 5.1 kPa (IQR 1.7). BMA provided a very high support for age (Posterior Effect Probability-PEP: 84.5%), moderate for BMI (PEP: 49.3%), CD4/8 ratio (PEP: 44.2%) and lipodystrophy (PEP: 44.0%). For all remaining variables, the model rather provides evidence against their effect. These results overall suggest that age and BMI have a positive association with LS, while CD4/8 ratio and lipodystrophy are negatively associated. Discussion Our findings shed light on the possible importance of ageing, overweight and HIV-induced immune dysregulation in the development of liver fibrosis in the HIV-infected population. Nonetheless, further controlled studies are warranted to clarify causal relations. PMID:28097068
Dietary conjugated linoleic acid modify gene expression in liver, muscles, and fat tissues of finishing pigs.
Tous, N; Theil, P K; Lauridsen, C; Lizardo, R; Vilà, B; Esteve-Garcia, E
The aim of this study was to investigate underlying mechanisms of dietary conjugated linoleic acid (CLA) on lipid metabolism in various tissues of pigs. Sixteen gilts (73 ± 3 kg) were fed a control (containing sunflower oil) or an experimental diet in which 4% of sunflower oil was replaced by CLA, and slaughtered at an average BW of 117 ± 4.9 kg. Transcription of peroxisome proliferator-activated receptor alpha (PPARα), peroxisome proliferator-activated receptor gamma (PPARγ), fatty acid synthase (FAS), sterol regulatory element binding protein (SREBP1), acetyl-CoA carboxylase (ACC), lipoprotein lipase (LPL), delta-6-desaturase (D6D), and stearoyl CoA desaturase (SCD) were determined by real-time PCR in longissimus thoracis (LT) and semimembranosus (SM) muscles, LT subcutaneous and SM intermuscular fat, and in the liver. Fatty acid (FA) composition was analyzed using gas chromatography in these tissues, except for SM intermuscular fat. Dietary CLA increased PPARγ in LT muscle (P < 0.05), whereas CLA reduced PPARα transcription in all tissues studied (P < 0.05) with the exception of intermuscular fat. Transcription of genes related to FA synthesis was reduced by CLA in SM muscle and liver (SREBP1, both P < 0.1; ACC, P < 0.01 in SM; and FAS, P < 0.01 in liver), whereas CLA reduced (P < 0.05) LPL and D6D transcriptions in SM muscle and reduced (P < 0.05) SCD in liver but increased (P < 0.05) SCD in LT muscle and intermuscular fat. Saturated FA were increased in all studied tissues (P < 0.01), while monosaturated and polyunsaturated FA were reduced in a tissue-specific way by CLA. It was concluded that dietary CLA affected transcription of genes and fat metabolism in a tissue-specific manner.
Quantification of total mercury in liver and heart tissue of Harbor Seals (Phoca vitulina) from Alaska USA
Marino, Kady B.; Hoover-Miller, Anne; Conlon, Suzanne; Prewitt, Jill; O'Shea, Stephen K.
This study quantified the Hg levels in the liver (n=98) and heart (n=43) tissues of Harbor Seals (Phoca vitulina) (n=102) harvested from Prince William Sound and Kodiak Island Alaska. Mercury tissue dry weight (dw) concentrations in the liver ranged from 1.7 to 393 ppm dw, and in the heart from 0.19 to 4.99 ppm dw. Results of this study indicate liver and heart tissues' Hg ppm dw concentrations significantly increase with age. Male Harbor Seals bioaccumulated Hg in both their liver and heart tissues at a significantly faster rate than females. The liver Hg bioaccumulation rates between the harvest locations Kodiak Island and Prince William Sound were not found to be significantly different. On adsorption Hg is transported throughout the Harbor Seal's body with the partition coefficient higher for the liver than the heart. No significant differences in the bio-distribution (liver:heart Hg ppm dw ratios (n=38)) values were found with respect to either age, sex or geographic harvest location. In this study the age at which Hg liver and heart bioaccumulation levels become significantly distinct in male and female Harbor Seals were identified through a Tukey's analysis. Of notably concern to human health was a male Harbor Seal's liver tissue harvested from Kodiak Island region. Mercury accumulation in this sample tissue was determined through a Q-test to be an outlier, having far higher Hg concentrarion (liver 392 Hg ppm dw) than the general population sampled. - Highlights: Black-Right-Pointing-Pointer Mercury accumulation in the liver and heart of seals exceed food safety guidelines. Black-Right-Pointing-Pointer Accumulation rate is greater in males than females with age. Black-Right-Pointing-Pointer Liver mercury accumulation is greater than in the heart tissues. Black-Right-Pointing-Pointer Mercury determination by USA EPA Method 7473 using thermal decomposition.
Gap junctions in several tissues share antigenic determinants with liver gap junctions.
Dermietzel, R; Leibstein, A; Frixen, U; Janssen-Timmen, U; Traub, O; Willecke, K
Using affinity-purified antibodies against mouse liver gap junction protein (26 K), discrete fluorescent spots were seen by indirect immunofluorescence labelling on apposed membranes of contiguous cells in several mouse and rat tissues: pancreas (exocrine part), kidney, small intestine (epithelium and circular smooth muscle), Fallopian tube, endometrium, and myometrium of delivering rats. No reaction was seen on sections of myocardium, ovaries and lens. Specific labelling of gap junction plaques was demonstrated by immunoelectron microscopy on ultrathin frozen sections through liver and the exocrine part of pancreas after treatment with gold protein A. Weak immunoreactivity was found on the endocrine part of the pancreas (i.e., Langerhans islets) after glibenclamide treatment of mice and rats, which causes an increase of insulin secretion and of the size as well as the number of gap junction plaques in cells of Langerhans islets. Furthermore, the affinity purified anti-liver 26 K antibodies were shown by immunoblot to react with proteins of similar mol. wt. in pancreas and kidney membranes. Taken together these results suggest that gap junctions from several, morphogenetically different tissues have specific antigenic sites in common. The different extent of specific immunoreactivity of anti-liver 26 K antibodies with different tissues is likely due to differences in size and number of gap junctions although structural differences cannot be excluded. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:6209130
Liver but not adipose tissue is responsive to the pattern of enteral feeding
Otero, Yolanda F.; Lundblad, Tammy M.; Ford, Eric A.; House, Lawrence M.; McGuinness, Owen P.
Abstract Nutritional support is an important aspect of medical care, providing calories to patients with compromised nutrient intake. Metabolism has a diurnal pattern, responding to the light cycle and food intake, which in turn can drive changes in liver and adipose tissue metabolism. In this study, we assessed the response of liver and white adipose tissue (WAT) to different feeding patterns under nutritional support (total enteral nutrition or TEN). Mice received continuous isocaloric TEN for 10 days or equal calories of chow once a day (Ch). TEN was given either at a constant (CN, same infusion rate during 24 h) or variable rate (VN, 80% of calories fed at night, 20% at day). Hepatic lipogenesis and carbohydrate‐responsive element‐binding protein (ChREBP) expression increased in parallel with the diurnal feeding pattern. Relative to Ch, both patterns of enteral feeding increased adiposity. This increase was not associated with enhanced lipogenic gene expression in WAT; moreover, lipogenesis was unaffected by the feeding pattern. Surprisingly, leptin and adiponectin expression increased. Moreover, nutritional support markedly increased hepatic and adipose FGF21 expression in CN and VN, despite being considered a fasting hormone. In summary, liver but not WAT, respond to the pattern of feeding. While hepatic lipid metabolism adapts to the pattern of nutrient availability, WAT does not. Moreover, sustained delivery of nutrients in an isocaloric diet can cause adiposity without the proinflammatory state observed in hypercaloric feeding. Thus, the liver but not adipose tissue is responsive to the pattern of feeding behavior. PMID:24744913
Triglyceride kinetics, tissue lipoprotein lipase, and liver lipogenesis in septic rats
Lanza-Jacoby, S.; Tabares, A. )
The mechanism for the development of hypertriglyceridemia during gram-negative sepsis was studied by examining liver production and clearance of very-low-density lipoprotein (VLDL) triglyceride (TG). To assess liver output and peripheral clearance the kinetics of VLDL-TG were determined by a constant iv infusion of (2-3H)glycerol-labeled VLDL. Clearance of VLDL-TG was also evaluated by measuring activities of lipoprotein lipase (LPL) in heart, soleus muscle, and adipose tissue from fasted control, fasted E. coli-treated, fed control, and fed E. coli-treated rats. Lewis inbred rats, 275-300 g, were made septic with 8 x 10(7) live E. coli colonies per 100 g body wt. Twenty-four hours after E. coli injection, serum TG, free fatty acids (FFA), and cholesterol of fasted E. coli-treated rats were elevated by 170, 76, and 16%, respectively. The elevation of serum TG may be attributed to the 67% decrease in clearance rate of VLDL-TG in fasted E. coli-treated rats compared with their fasted controls. The suppressed activities of LPL in adipose tissue, skeletal muscle, and heart were consistent with reduced clearance of TG. Secretion of VLDL-TG declined by 31% in livers of fasted E. coli-treated rats, which was accompanied by a twofold increase in the composition of liver TG. Rates of in vivo TG synthesis in livers of the fasted E. coli-treated rats were twofold higher than in those of fasted control rats. Decreased rate of TG appearance along with the increase in liver synthesis of TG contributed to the elevation of liver lipids in the fasted E. coli-treated rats.
Extrapolation of Normal Tissue Complication Probability for Different Fractionations in Liver Irradiation
Tai An; Erickson, Beth; Li, X. Allen
Purpose: The ability to predict normal tissue complication probability (NTCP) is essential for NTCP-based treatment planning. The purpose of this work is to estimate the Lyman NTCP model parameters for liver irradiation from published clinical data of different fractionation regimens. A new expression of normalized total dose (NTD) is proposed to convert NTCP data between different treatment schemes. Method and Materials: The NTCP data of radiation- induced liver disease (RILD) from external beam radiation therapy for primary liver cancer patients were selected for analysis. The data were collected from 4 institutions for tumor sizes in the range of of 8-10 cm. The dose per fraction ranged from 1.5 Gy to 6 Gy. A modified linear-quadratic model with two components corresponding to radiosensitive and radioresistant cells in the normal liver tissue was proposed to understand the new NTD formalism. Results: There are five parameters in the model: TD{sub 50}, m, n, {alpha}/{beta} and f. With two parameters n and {alpha}/{beta} fixed to be 1.0 and 2.0 Gy, respectively, the extracted parameters from the fitting are TD{sub 50}(1) = 40.3 {+-} 8.4Gy, m =0.36 {+-} 0.09, f = 0.156 {+-} 0.074 Gy and TD{sub 50}(1) = 23.9 {+-} 5.3Gy, m = 0.41 {+-} 0.15, f = 0.0 {+-} 0.04 Gy for patients with liver cirrhosis scores of Child-Pugh A and Child-Pugh B, respectively. The fitting results showed that the liver cirrhosis score significantly affects fractional dose dependence of NTD. Conclusion: The Lyman parameters generated presently and the new form of NTD may be used to predict NTCP for treatment planning of innovative liver irradiation with different fractionations, such as hypofractioned stereotactic body radiation therapy.
Obstructive jaundice leads to accumulation of oxidized low density lipoprotein in human liver tissue.
Comert, Mustafa; Ustundag, Yucel; Tekin, Ishak Ozel; Gun, Banu Dogan; Barut, Figen
Oxidized low density lipoprotein (ox-LDL) molecule is one of the most important modified lipoproteins produced during the oxidative stress. Modified lipoproteins have been defined as being part of the immune inflammatory mechanisms in association with oxidant stress. We have reported the accumulation of ox-LDL in Balb/c mice liver after bile duct ligation previously. Here, we investigated this finding in human beings with obstructive jaundice. Our study demonstrates that obstructive jaundice results in tremendous accumulation of ox-LDL in the liver tissue of patients.
Non-lethal sampling of liver tissue for toxicologic evaluation of Florida cottonmouths snakes, Agkistrodon piscivorus conanti.
Quesada, Rolando J; McCleary, Ryan J R; Heard, Darryl J; Lillywhite, Harvey B
Due to their longevity, strong site tenure, poikilothermic metabolism, and low-energy specializations, reptiles might serve as excellent environmental sentinels. Cottonmouth snakes are generalist predators and scavengers, and as such, may have higher exposure to persistent environmental contaminants as a result of bioaccumulation. Traditionally, assessment and monitoring of contaminant exposure in reptiles have involved lethal sampling techniques. In this paper, we describe a non-destructive technique for sampling liver tissue in live anesthetized Florida cottonmouths. Wild-caught snakes (n = 21) were anesthetized with propofol, and a liver wedge biopsy was obtained by clamping the edge of the organ with two small hemostatic mosquito forceps via right-sided coeliotomy incision. A minimum required tissue sample weighing >100 mg was harvested from all except one of the animals. No mortalities occurred during the procedures or recovery from anesthesia, and all snakes were released back into the field after the animal had consumed prey and defecated, usually within 2 weeks following surgery. Hemorrhage was a minor complication in most snakes, especially those with friable discolored livers. The procedure appeared to have no short-term deleterious effects, and two biopsied individuals were captured after being released into the field and appeared to be normal and healthy. However, follow-up studies and recapture of more snakes are needed to assess long-term survivability. Our non-destructive liver sampling technique might be implemented in toxicological studies of other squamates and could help to minimize the lethal sampling of threatened species.
Shallow hypothermia depends on the level of fatty acid unsaturation in adipose and liver tissues in a tropical heterothermic primate.
Vuarin, Pauline; Henry, Pierre-Yves; Guesnet, Philippe; Alessandri, Jean-Marc; Aujard, Fabienne; Perret, Martine; Pifferi, Fabien
Optimal levels of unsaturated fatty acids have positive impacts on the use of prolonged bouts of hypothermia in mammalian hibernators, which generally have to face low winter ambient temperatures. Unsaturated fatty acids can maintain the fluidity of fat and membrane phospholipids at low body temperatures. However, less attention has been paid to their role in the regulation of shallow hypothermia, and in tropical species, which may be challenged more by seasonal energetic and/or water shortages than by low temperatures. The present study assessed the relationship between the fatty acids content of white adipose and liver tissues and the expression of shallow hypothermia in a tropical heterothermic primate, the gray mouse lemur (Microcebus murinus). The adipose tissue is the main tissue for fat storage and the liver is involved in lipid metabolism, so both tissues were expected to influence hypothermia dependence on fatty acids. As mouse lemurs largely avoid deep hypothermia (i.e. torpor) use under standard captive conditions, the expression of hypothermia was triggered by food-restricting experimental animals. Hypothermia depth increased with time, with a stronger increase for individuals that exhibited higher contents of unsaturated fatty acids suggesting that they were more flexible in their use of hypothermia. However these same animals delayed the use of long hypothermia bouts relative to individuals with a higher level of saturated fatty acids. This study evidences for the first time that body fatty acids unsaturation levels influence the regulation of body temperature not only in cold-exposed hibernators but also in tropical, facultative heterotherms.
Evaluation of 2-year-old intrasplenic fetal liver tissue transplants in rats.
Lupp, Amelie; Danz, Manfred; Müller, Dieter
Liver cell transplantation into host organs like the spleen may possibly provide a temporary relief after extensive liver resection or severe liver disease or may enable treatment of an enzyme deficiency. With time, however, dedifferentiation or malignant transformation of the ectopically transplanted cells may be possible. Thus, in the present study syngenic fetal liver tissue suspensions were transplanted into the spleen of adult male rats and evaluated 2 years thereafter in comparison to orthotopic livers for histopathological changes and (as markers for preneoplastic transformation) for cytochrome P450 (P450) and glutathione S-transferase (GST) isoform expression. Because inducibility of P450 and GST isoforms may be changed in preneoplastic foci, prior to sacrifice animals were additionally treated either with beta-naphthoflavone, phenobarbital, dexamethasone, or the respective solvent. In the 2-year-old grafts more than 70% of the spleen mass was occupied by the transplant. The transplanted hepatocytes were arranged in cord-like structures. Also few bile ducts were present. Morphologically, no signs of malignancy were visible. With all rats, transplant recipients as well as controls, however, discrete nodular structures were seen in the livers. Due to age, both livers and transplants displayed only a low P450 2B1 and 3A2 and GST class alpha and mu isoform expression. No immunostaining for P450 1A1 was visible. At both sites, beta-naphthoflavone, phenobarbital, or dexamethasone treatment enhanced P450 1A1, P450 2B1 and 3A2, or P450 3A2 expression, respectively. No immunostaining for GST class pi isoforms was seen in the transplants. The livers of both transplant recipients and control rats, however, displayed GST pi-positive foci, corresponding to the nodular structures seen histomorphologically. Compared to the surrounding tissue, these foci also exhibited a more pronounced staining for GST class alpha and mu isoforms and a stronger inducibility of the P450 1A
Normal and Fibrotic Rat Livers Demonstrate Shear Strain Softening and Compression Stiffening: A Model for Soft Tissue Mechanics
Cao, Xuan; van Oosten, Anne; Shenoy, Vivek B.; Janmey, Paul A.; Wells, Rebecca G.
Tissues including liver stiffen and acquire more extracellular matrix with fibrosis. The relationship between matrix content and stiffness, however, is non-linear, and stiffness is only one component of tissue mechanics. The mechanical response of tissues such as liver to physiological stresses is not well described, and models of tissue mechanics are limited. To better understand the mechanics of the normal and fibrotic rat liver, we carried out a series of studies using parallel plate rheometry, measuring the response to compressive, extensional, and shear strains. We found that the shear storage and loss moduli G' and G" and the apparent Young's moduli measured by uniaxial strain orthogonal to the shear direction increased markedly with both progressive fibrosis and increasing compression, that livers shear strain softened, and that significant increases in shear modulus with compressional stress occurred within a range consistent with increased sinusoidal pressures in liver disease. Proteoglycan content and integrin-matrix interactions were significant determinants of liver mechanics, particularly in compression. We propose a new non-linear constitutive model of the liver. A key feature of this model is that, while it assumes overall liver incompressibility, it takes into account water flow and solid phase compressibility. In sum, we report a detailed study of non-linear liver mechanics under physiological strains in the normal state, early fibrosis, and late fibrosis. We propose a constitutive model that captures compression stiffening, tension softening, and shear softening, and can be understood in terms of the cellular and matrix components of the liver. PMID:26735954
Hepatocyte Tissue Factor Contributes to the Hypercoagulable State in a Mouse Model of Chronic Liver Injury
Rautou, Pierre-Emmanuel; Tatsumi, Kohei; Antoniak, Silvio; Owens, A. Phillip; Sparkenbaugh, Erica; Holle, Lori A.; Wolberg, Alisa S.; Kopec, Anna K.; Pawlinski, Rafal; Luyendyk, James P.; Mackman, Nigel
Summary Background & Aims Patients with chronic liver disease and cirrhosis have a dysregulated coagulation system and are prone to thrombosis. The basis for this hypercoagulable state is not completely understood. Tissue factor (TF) is the primary initiator of coagulation in vivo. Patients with cirrhosis have increased TF activity in white blood cells and circulating microparticles. The aim of our study was to determine the contribution of TF to the hypercoagulable state in a mouse model of chronic liver injury. Methods We measured levels of TF activity in the liver, white blood cells and circulating microparticles, and a marker of activation of coagulation [thrombinantithrombin complexes (TATc)] in the plasma of mice subjected to bile duct ligation for 12 days. We used wild-type mice, mice with a global TF deficiency (low TF mice), and mice deficient for TF in either myeloid cells (TFflox/flox, LysMCre mice) or in hepatocytes (TFflox/flox, AlbCre). Results Wild-type mice with liver injury had increased levels of white blood cell, microparticle TF activity and TATc compared to sham mice. Low TF mice and mice lacking TF in hepatocytes had reduced levels of TF in the liver and in microparticles and exhibited reduced activation of coagulation without a change in liver fibrosis. In contrast, mice lacking TF in myeloid cells had reduced white blood cell TF but no change in microparticle TF activity or TATc. Conclusions Hepatocyte TF activates coagulation in a mouse model of chronic liver injury. TF may contribute to the hypercoagulable state associated with chronic liver diseases in patients. PMID:26325534
In situ hybridization for the detection of hepatitis C virus RNA in human liver tissue.
Li, G; Li, K; Lea, A S; Li, N L; Abdulla, N E; Eltorky, M A; Ferguson, M R
In situ hybridization (ISH) enables visualization of specific nucleic acid in morphologically preserved cells and tissue sections. Detection of the HCV genomes in clinical specimens is useful for differential diagnosis, particularly between recurrent HCV infection and acute cellular rejection in transplant specimens. We optimized an ISH protocol that demonstrated sensitivity and specificity for detecting genomic and replicative form of HCV RNA in tissue biopsies. Digoxigenin (Dig)-labelled sense and anti-sense riboprobes were synthesized using a plasmid containing a fragment of the highly conserved HCV noncoding region as a template. The efficiency of the Dig-labelled riboprobes in detecting genomic and replicative-intermediate HCV RNA was analysed in 30 liver biopsies from patients infected or uninfected with HCV in a blinded study. A Huh7 cell line that stably replicates genome-length HCV RNA was developed to be used as a positive control. Negative control riboprobes were used in parallel to evaluate and control for background staining. The anti-sense probe detected HCV RNA in 20/21 specimens from HCV-infected liver tissues obtained from patients and in 0/9 samples from patients with non-HCV-related liver diseases, resulting in a sensitivity and specificity of 95% and 100%, respectively. HCV genomic RNA was variably distributed in tissue sections and was located primarily in the perinuclear regions in hepatocytes. Detection of HCV RNA by our optimized ISH protocol appears to be a sensitive and specific method when processing clinical specimens. It may also be revealing when exploring the pathophysiology of HCV infection by verifying the presence of viral genetic material within heptocytes and other cellular elements of diseased liver tissue. This methodology might also evaluate the response to antiviral therapies by demonstrating the absence or alteration of genetic material in clinical specimens from successfully treated patients.
Noninvasive magnetic resonance imaging of the development of individual colon cancer tumors in rat liver.
Mook, Olaf R F; Jonker, Ard; Strang, Aart C; Veltien, Andor; Gambarota, Giulio; Frederiks, Wilma M; Heerschap, Arend; Van Noorden, Cornelis J F
Monitoring tumor development is essential for the understanding of mechanisms involved in tumor progression and to determine efficacy of therapy. One of the evolving approaches is longitudinal noninvasive magnetic resonance imaging (MRI) of tumors in experimental models. We applied high-resolution MRI at 7 Tesla to study the development of colon cancer tumors in rat liver. MRI acquisition was triggered to the respiratory cycle to minimize motion artifacts. A special radio frequency (RF) coil was designed to acquire detailed T1-weighted and T2-weighted images of the liver. T2-weighted images identified hyperintense lesions representing tumors with a minimum diameter of 2 mm, enabling the determination of growth rates and morphological aspects of individual tumors. It is concluded that high-resolution MRI using a dedicated RF coil and triggering to the respiratory cycle is an excellent tool for quantitative and morphological analysis of individual diffusely distributed tumors throughout the liver. However, at present, MRI requires expensive equipment and expertise and is a time-consuming methodology. Therefore, it should preferably be used for dedicated applications rather than for high-throughput assessment of total tumor load in animals.
In vitro measurements of temperature-dependent specific heat of liver tissue.
Haemmerich, Dieter; dos Santos, Icaro; Schutt, David J; Webster, John G; Mahvi, David M
We measured the specific heat of liver tissue in vitro by uniformly heating liver samples between two electrodes. We insulated the samples by expanded polystyrene, and corrected for heat loss and water loss. The specific heat of the liver is temperature-dependent, and increases by 17% at 83.5 degrees C (p < 0.05), compared to temperatures below 65 degrees C. The average specific heat was 3411 J kg(-1)K(-1) at 25 degrees C, and 4187 J kg(-1)K(-1) at 83.5 degrees C. Water loss from the samples was significant above 70 degrees C, with approximately 20% of reduction in sample mass at 90 degrees C.
A rare condition: Ectopic liver tissue with its unique blood supply encountered during laparoscopic cholecystectomy
Bal, Ahmet; Yilmaz, Sezgin; Yavas, Betul Demirciler; Ozdemir, Cigdem; Ozsoy, Mustafa; Akici, Murat; Kalkan, Mustafa; Ersen, Ogun; Saripinar, Baris; Arikan, Yuksel
Introduction Developmental abnormalities of liver including ectopic liver tissue (ELT) are rare conditions. Few cases presenting ELT have been reported in literature till now. Even though the most common area seen is gallbladder, it is detected both abdominal and thoracic sites. There is a relationship between HCC and ectopic liver that necessitates the removal. Presentation of case A 51-year-old female was hospitalized because of abdominal pain. Gallstone and bile duct dilatation were determined during ultrasonographic (USG) evaluation. The patient was operated for cholecystectomy following a successful endoscopic retrograde cholangiopancreatography (ERCP). During operation, a mass located on gallbladder with its unique vascular support was identified and resected together with gallbladder. The mass had a separate vascular stalk arising from liver parenchyma substance and it was clipped with laparoscopic staples. The histopathological examination revealed that the mass adherent to gallbladder was ectopic liver confirming the intraoperative observation. The postoperative course of patient was uneventfull and she was discharged at the second day after the operation. Discussion Ectopic liver tissue is incidentally found both in abdominal and thoracic cavity. ELT can rarely be diagnosed before surgical procedures or autopsies. It can be overlooked easily by radiological techniques. Although it does not usually produce any symptom clinically, it can rarely result in serious complications such as bleeding, pyloric and portal vein obstruction. ELT also has the capacity of malignant transformation to hepatocellular carcinoma that makes it essential to be removed. Conclusion Although ELT is rarely seen, it should be removed when recognized in order to prevent the complications and malignant transformation. PMID:25723748
Trans-10,cis-12-CLA-caused lipodystrophy is associated with profound changes of fatty acid profiles of liver, white adipose tissue and erythrocytes in mice: possible link to tissue-specific alterations of fatty acid desaturation.
Jaudszus, Anke; Moeckel, Peter; Hamelmann, Eckard; Jahreis, Gerhard
Dietary supplementation with conjugated linoleic acid (CLA) has been shown to reduce body fat mass. To investigate the effects of individual CLA isomers on the fatty acid profiles of lipogenic (liver and white adipose) and lipid sensitive (erythrocyte) tissues, BALB/c mice were fed with 1 of 2 diets supplemented with either a c9,t11-CLA-enriched and t10,c12-CLA-free or a CLA-mixture containing both isomers in equal amounts (1% w/w of the diet) for 5 weeks. A control group was fed with a diet enriched in sunflower oil to energy balance the CLA. Compared to the t10,c12-CLA-free and the control diets, we observed a significant reduction of adipose tissue accompanied by fatty livers in the CLA-mix-fed group. These alterations in body fat distribution entailed a conspicuous shift of the fatty acid profiles of adipose tissue and livers. Liver enlargement was mainly caused by accumulation of C18 monoenes that accounted for 67 ± 1% of total fatty acid methyl esters. The significant reduction of the 18:0/18:1 desaturation index in the liver upon CLA-mix diet indicated high stearoyl-CoA desaturase activity. In contrast, reduction in white adipose tissue was largely driven by percental reduction of monounsaturated fatty acids (p ≤ 0.001). 16:0/ 16:1 and 18:0/18:1 desaturation indices for white adipose tissue significantly increased, suggesting an inhibition of stearoyl-CoA desaturase upon CLA-mix diet. The fatty acid profile of the erythrocytes widely reflected that of livers, depending on the supplemented diet. These profound changes in fatty acid composition of lipogenic organs due to t10,c12-CLA intake may be the consequence of functional alterations of lipid metabolism.
Hydrolysis of pyrethroids by human and rat tissues: Examination of intestinal, liver and serum carboxylesterases
Crow, J. Allen; Borazjani, Abdolsamad; Potter, Philip M.; Ross, Matthew K. . E-mail: email@example.com
Hydrolytic metabolism of pyrethroid insecticides in humans is one of the major catabolic pathways that clear these compounds from the body. Rodent models are often used to determine the disposition and clearance rates of these esterified compounds. In this study the distribution and activities of esterases that catalyze pyrethroid metabolism have been investigated in vitro using several human and rat tissues, including small intestine, liver and serum. The major esterase in human intestine is carboxylesterase 2 (hCE2). We found that the pyrethroid trans-permethrin is effectively hydrolyzed by a sample of pooled human intestinal microsomes (5 individuals), while deltamethrin and bioresmethrin are not. This result correlates well with the substrate specificity of recombinant hCE2 enzyme. In contrast, a sample of pooled rat intestinal microsomes (5 animals) hydrolyze trans-permethrin 4.5-fold slower than the sample of human intestinal microsomes. Furthermore, it is demonstrated that pooled samples of cytosol from human or rat liver are {approx} 2-fold less hydrolytically active (normalized per mg protein) than the corresponding microsomal fraction toward pyrethroid substrates; however, the cytosolic fractions do have significant amounts ({approx} 40%) of the total esteratic activity. Moreover, a 6-fold interindividual variation in carboxylesterase 1 protein expression in human hepatic cytosols was observed. Human serum was shown to lack pyrethroid hydrolytic activity, but rat serum has hydrolytic activity that is attributed to a single CE isozyme. We purified the serum CE enzyme to homogeneity to determine its contribution to pyrethroid metabolism in the rat. Both trans-permethrin and bioresmethrin were effectively cleaved by this serum CE, but deltamethrin, esfenvalerate, alpha-cypermethrin and cis-permethrin were slowly hydrolyzed. Lastly, two model lipase enzymes were examined for their ability to hydrolyze pyrethroids. However, no hydrolysis products could be
Transcriptome difference and potential crosstalk between liver and mammary tissue in mid-lactation primiparous dairy cows
Bu, Dengpan; Bionaz, Massimo; Wang, Mengzhi; Nan, Xuemei; Ma, Lu; Wang, Jiaqi
Liver and mammary gland are among the most important organs during lactation in dairy cows. With the purpose of understanding both the different and the complementary roles and the crosstalk of those two organs during lactation, a transcriptome analysis was performed on liver and mammary tissues of 10 primiparous dairy cows in mid-lactation. The analysis was performed using a 4×44K Bovine Agilent microarray chip. The transcriptome difference between the two tissues was analyzed using SAS JMP Genomics using ANOVA with a false discovery rate correction (FDR). The analysis uncovered >9,000 genes differentially expressed (DEG) between the two tissues with a FDR<0.001. The functional analysis of the DEG uncovered a larger metabolic (especially related to lipid) and inflammatory response capacity in liver compared with mammary tissue while the mammary tissue had a larger protein synthesis and secretion, proliferation/differentiation, signaling, and innate immune system capacity compared with the liver. A plethora of endogenous compounds, cytokines, and transcription factors were estimated to control the DEG between the two tissues. Compared with mammary tissue, the liver transcriptome appeared to be under control of a large array of ligand-dependent nuclear receptors and, among endogenous chemical, fatty acids and bacteria-derived compounds. Compared with liver, the transcriptome of the mammary tissue was potentially under control of a large number of growth factors and miRNA. The in silico crosstalk analysis between the two tissues revealed an overall large communication with a reciprocal control of lipid metabolism, innate immune system adaptation, and proliferation/differentiation. In summary the transcriptome analysis confirmed prior known differences between liver and mammary tissue, especially considering the indication of a larger metabolic activity in liver compared with the mammary tissue and the larger protein synthesis, communication, and proliferative
Mueller matrix microscope: a quantitative tool to facilitate detections and fibrosis scorings of liver cirrhosis and cancer tissues.
Wang, Ye; He, Honghui; Chang, Jintao; He, Chao; Liu, Shaoxiong; Li, Migao; Zeng, Nan; Wu, Jian; Ma, Hui
Today the increasing cancer incidence rate is becoming one of the biggest threats to human health.Among all types of cancers, liver cancer ranks in the top five in both frequency and mortality rate all over the world. During the development of liver cancer, fibrosis often evolves as part of a healing process in response to liver damage, resulting in cirrhosis of liver tissues. In a previous study, we applied the Mueller matrix microscope to pathological liver tissue samples and found that both the Mueller matrix polar decomposition (MMPD) and Mueller matrix transformation (MMT) parameters are closely related to the fibrous microstructures. In this paper,we take this one step further to quantitatively facilitate the fibrosis detections and scorings of pathological liver tissue samples in different stages from cirrhosis to cancer using the Mueller matrix microscope. The experimental results of MMPD and MMT parameters for the fibrotic liver tissue samples in different stages are measured and analyzed. We also conduct Monte Carlo simulations based on the sphere birefringence model to examine in detail the influence of structural changes in different fibrosis stages on the imaging parameters. Both the experimental and simulated results indicate that the polarized light microscope and transformed Mueller matrix parameter scan provide additional quantitative information helpful for fibrosis detections and scorings of liver cirrhosis and cancers. Therefore, the polarized light microscope and transformed Mueller matrix parameters have a good application prospect in liver cancer diagnosis.
Mueller matrix microscope: a quantitative tool to facilitate detections and fibrosis scorings of liver cirrhosis and cancer tissues
NASA Astrophysics Data System (ADS)
Wang, Ye; He, Honghui; Chang, Jintao; He, Chao; Liu, Shaoxiong; Li, Migao; Zeng, Nan; Wu, Jian; Ma, Hui
Today the increasing cancer incidence rate is becoming one of the biggest threats to human health. Among all types of cancers, liver cancer ranks in the top five in both frequency and mortality rate all over the world. During the development of liver cancer, fibrosis often evolves as part of a healing process in response to liver damage, resulting in cirrhosis of liver tissues. In a previous study, we applied the Mueller matrix microscope to pathological liver tissue samples and found that both the Mueller matrix polar decomposition (MMPD) and Mueller matrix transformation (MMT) parameters are closely related to the fibrous microstructures. In this paper, we take this one step further to quantitatively facilitate the fibrosis detections and scorings of pathological liver tissue samples in different stages from cirrhosis to cancer using the Mueller matrix microscope. The experimental results of MMPD and MMT parameters for the fibrotic liver tissue samples in different stages are measured and analyzed. We also conduct Monte Carlo simulations based on the sphere birefringence model to examine in detail the influence of structural changes in different fibrosis stages on the imaging parameters. Both the experimental and simulated results indicate that the polarized light microscope and transformed Mueller matrix parameters can provide additional quantitative information helpful for fibrosis detections and scorings of liver cirrhosis and cancers. Therefore, the polarized light microscope and transformed Mueller matrix parameters have a good application prospect in liver cancer diagnosis.
[Effect of lipiodol emulsion and local hyperthermia on hepatic tissue blood flow in rabbits with VX-2 liver tumor].
Suzuki, K; Tada, I; Okada, K; Kim, Y I; Kobayashi, M
The effect of intra-arterial infusion of lipiodol-emulsion and local hyperthermia on tissue blood flow was examined in experimental hepatic tumor and normal liver of rabbits. VX-2 tumor was implanted in liver of rabbit. The tissue blood flow was estimated by hydrogen gas clearance method when the tumor grew to about 2 cm. Tissue blood flow in tumor (64.5 ml/min/100 g) was significantly less than in normal liver (90.8 ml/min/100 g) (p less than 0.005). The intra-arterial infusion of lipiodol-emulsion did not alter the flow in either tissue. However, the addition of hyperthermia induced a substantial rise of tissue blood flow in normal liver (35% increase, from 93.8 to 127 ml/min/100 g) when compared with in VX-2 tumor (8.9% increase, from 65.1 to 71.8 ml/min/100 g). These were accompanied by a selective heating of liver tumor; the tumor temperature rose to 43 degrees C, although that of normal liver remained at 38 degrees C. Our results suggested that a specific temperature rise of liver tumor after infusion of lipiodol-emulsion and local heating might be related to a different response of microcirculation in tumor and normal liver to the hyperthermia.
Tissue engineering and organ structure: a vascularized approach to liver and lung.
Hoganson, David M; Pryor, Howard I; Vacanti, Joseph P
Over the past two decades, great strides have been made in the field of tissue engineering. Many of the initial attempts to develop an engineered tissue construct were based on the concept of seeding cells onto an avascular scaffold. Using advanced manufacturing technologies, the creation of a preformed vascular scaffold has become a reality. This article discusses some of the issues surrounding the development of such a vascular scaffold. We then examine of the challenges associated with applying this scaffold technology to two vital organ constructs: liver and lung.
From Endoderm to Liver Bud: Paradigms of Cell Type Specification and Tissue Morphogenesis.
Zaret, Kenneth S
The early specification, rapid growth and morphogenesis, and conserved functions of the embryonic liver across diverse model organisms have made the system an experimentally facile paradigm for understanding basic regulatory mechanisms that govern cell differentiation and organogenesis. This essay highlights concepts that have emerged from studies of the discrete steps of foregut endoderm development into the liver bud, as well as from modeling the steps via embryonic stem cell differentiation. Such concepts include understanding the chromatin basis for the competence of progenitor cells to develop into specific lineages; the importance of combinatorial signaling from different sources to induce cell fates; the impact of inductive signaling on preexisting chromatin states; the ability of separately specified domains of cells to merge into a common tissue; and the marked cell biological dynamics, including interactions with the developing vasculature, which establish the initial morphogenesis and patterning of a tissue. The principles gleaned from these studies, focusing on the 2 days it takes for the endoderm to develop into a liver bud, should be instructive for many other organogenic systems and for manipulating tissues in regenerative contexts for biomedical purposes.
Postpartal Subclinical Endometritis Alters Transcriptome Profiles in Liver and Adipose Tissue of Dairy Cows
Akbar, Haji; Cardoso, Felipe C.; Meier, Susanne; Burke, Christopher; McDougall, Scott; Mitchell, Murray; Walker, Caroline; Rodriguez-Zas, Sandra L.; Everts, Robin E.; Lewin, Harris A.; Roche, John R.; Loor, Juan J.
Transcriptome alterations in liver and adipose tissue of cows with subclinical endometritis (SCE) at 29 d postpartum were evaluated. Bioinformatics analysis was performed using the Dynamic Impact Approach by means of KEGG and DAVID databases. Milk production, blood metabolites (non-esterified fatty acids, magnesium), and disease biomarkers (albumin, aspartate aminotransferase) did not differ greatly between healthy and SCE cows. In liver tissue of cows with SCE, alterations in gene expression revealed an activation of complement and coagulation cascade, steroid hormone biosynthesis, apoptosis, inflammation, oxidative stress, MAPK signaling, and the formation of fibrinogen complex. Bioinformatics analysis also revealed an inhibition of vitamin B3 and B6 metabolism with SCE. In adipose, the most activated pathways by SCE were nicotinate and nicotinamide metabolism, long-chain fatty acid transport, oxidative phosphorylation, inflammation, T cell and B cell receptor signaling, and mTOR signaling. Results indicate that SCE in dairy cattle during early lactation induces molecular alterations in liver and adipose tissue indicative of immune activation and cellular stress. PMID:24578603
Determining the optimal decellularization and sterilization protocol for preparing a tissue scaffold of a human-sized liver tissue.
Kajbafzadeh, Abdol-Mohammad; Javan-Farazmand, Niloufar; Monajemzadeh, Maryam; Baghayee, Arash
Attaining a well-qualified whole decellularized organ applicable for an enduring and successful transplantation, decellularization protocols should be organ specific in terms of decellularizing agents and time of tissue exposure. Since a bioscaffold resulting from a large solid organ should have the potential to preserve its three-dimensional architecture and consistency for at least several months in the site of transplantation, evaluating the mechanical properties of the bioscaffold is mandatory before transplantation. In the current study, we compared five different decellularization protocols and also two main decellularization techniques (perfusion vs. diffusion) to decellularize the sheep liver, which is similar to the human liver in terms of size and anatomy. Moreover, we assessed the retaining of vascular network by dye injection and angiography. We also determined the most proper sterilization method by comparing six different sterilization methods. The mechanical properties of the scaffolds were assessed by applying tensile strength, suture retention, and compressive strength tests. The perfusion technique showed better results compared to the diffusion technique. The protocol containing ammonium hydroxide and triton X-100 was the most proper decellularization protocol leading to completely decellularized livers along with intact vascular network. Furthermore, we noted that application of streptokinase in washing step facilitates decellularization. Our results also showed that a combination of two sterilization methods is necessary for complete sterilization of a sheep liver and peracetic acid or ethylene oxide+gamma irradiation was associated with the best outcome. Determining the most appropriate decellularization and sterilization method for each organ along with assessing the mechanical properties of the resulting bioscaffold are principal steps before fabricating efficient artificial organs in the foreseeable future.
Functional liver tissue engineering by an adult mouse liver-derived neuro-glia antigen 2-expressing stem/progenitor population.
Zhang, Hongyu; Siegel, Christopher T; Li, Jing; Lai, Jiejuan; Shuai, Ling; Lai, Xiangdong; Zhang, Yujun; Jiang, Yan; Bie, Ping; Bai, Lianhua
Deaths due to end-stage liver diseases (ESLD) are increasingly registered annually in the world. Liver transplantation is the ultimate treatment for ESLD to date, which has been hampered by a critical shortage of organs. The potential of decellularized liver scaffolds (DLS) derived from solid organs as a three dimensional (3D) platform has been evolved as a promising approach in liver tissue engineering for translating functional liver organ replacements, but questions still exist regarding the optimal cell population for seeding in DLS and the preparation of the DLS themselves. The aim of our study was to utilize a sodium dodecyl sulfate (SDS) decellularization procedure in combination with a low concentration of trypsin (0.005%)-EDTA (0.002%) process to manufacture DLS from whole mouse livers and recellularized with hepatic stem/progenitors for use in liver tissue engineering and injured liver treatment. Results showed that the DLS generated with all the necessary microstructure and the extracellular components to support seeded hepatic stem/progenitor cell attachment, functional hepatic cell differentiation. Hepatic differentiation from stem/progenitor cells loaded by DLS was more efficient than that of the stem/progenitor cells in the 2D cell culture model. In summary, the method of DLS loaded by hepatic stem/progenitor cells provided by this study was effective in maintaining DLS extracellular matrix (ECM) to introduce seeded stem/progenitor cell differentiation, hepatic-like tissue formation and functional hepatic protein production in vitro that promoted functional recovery and survival in a mouse model of dimethylnitrosamine (DEN)-induced liver cirrhosis after auxiliary heterotopic liver transplantation.
Cloning changes the response to obesity of innate immune factors in blood, liver, and adipose tissues in domestic pigs.
Rødgaard, Tina; Skovgaard, Kerstin; Stagsted, Jan; Heegaard, Peter M H
The objective of this study was to evaluate the usefulness of cloned pigs as porcine obesity models reflecting obesity-associated changes in innate immune factor gene expression profiles. Liver and adipose tissue expression of 43 innate immune genes as well as serum concentrations of six immune factors were analyzed in lean and diet-induced obese cloned domestic pigs and compared to normal domestic pigs (obese and lean). The number of genes affected by obesity was lower in cloned animals than in control animals. All genes affected by obesity in adipose tissues of clones were downregulated; both upregulation and downregulation were observed in the controls. Cloning resulted in a less differentiated adipose tissue expression pattern. Finally, the serum concentrations of two acute-phase proteins (APPs), haptoglobin (HP) and orosomucoid (ORM), were increased in obese clones as compared to obese controls as well as lean clones and controls. Generally, the variation in phenotype between individual pigs was not reduced in cloned siblings as compared to normal siblings. Therefore, we conclude that cloning limits both the number of genes responding to obesity as well as the degree of tissue-differentiated gene expression, concomitantly with an increase in APP serum concentrations only seen in cloned, obese pigs. This may suggest that the APP response seen in obese, cloned pigs is a consequence of the characteristic skewed gene response to obesity in cloned pigs, as described in this work. This should be taken into consideration when using cloned animals as models for innate responses to obesity.
Liver Growth Factor as a Tissue Regenerating Factor in Neurodegenerative Diseases
Gonzalo-Gobernado, Rafael; Calatrava-Ferreras, Lucia; Perucho, Juan; Reimers, Diana; Casarejos, María J.; Herranz, Antonio S.; Jiménez-Escrig, Adriano; Díaz-Gil, Juan J.; Bazán, Eulalia
Liver growth factor (LGF) is a hepatic mitogen purified by our group in 1986. In the following years we demonstrated its activity both in "in vivo" and "in vitro" systems, stimulating hepatocytes mitogenesis as well as liver regeneration in several models of liver injury. Furthermore, we established its chemical composition (albumin-bilirubin complex) and its mitogenic actions in liver. From 2000 onwards we used LGF as a tissue regenerating factor in several models of extrahepatic diseases. The use of Liver growth factor as a neural tissue regenerator has been recently protected (Patent No US 2014/8,642,551 B2). LGF administration stimulates neurogenesis and neuron survival, promotes migration of newly generated neurons, and induces the outgrowth of striatal dopaminergic terminals in 6-hidroxydopamine-lesioned rats. Furthermore, LGF treatment raises striatal dopamine levels and protects dopaminergic neurons in hemiparkinsonian animals. LGF also stimulates survival of grafted foetal neural stem cells in the damaged striatum, reduces rotational behaviour and improves motor coordination. Interestingly, LGF also exerts a neuroprotective role both in an experimental model of cerebellar ataxia and in a model of Friedrich´s ataxia. Microglia seem to be the cellular target of LGF in the CNS. Moreover, the activity of the factor could be mediated by the stimulation of MAPK´s signalling pathway and by regulating critical proteins for cell survival, such as Bcl-2 and phospho-CREB. Since the factor shows neuroprotective and neurorestorative effects we propose LGF as a patented novel therapeutic tool that may be useful for the treatment of Parkinson´s disease and cerebellar ataxias. Currently, our studies have been extended to other neurological disorders such as Alzheimer's disease (Patent No: US 2014/0113859 A1). PMID:25537484
The protective effect of N-acetylcysteine against acrylamide toxicity in liver and small and large intestine tissues.
Altinoz, E; Turkoz, Y; Vardi, N
The aim of this study was to investigate the protective effects of N-acetylcysteine against acrylamide toxicity in liver and small and large intestine tissues in rats.The rats were divided into four groups. Acrylamide administration increased MDA levels in all tissues significantly (p < 0.05). But acrylamide+NAC administration decreased MDA levels significantly as compared to the acrylamide group, and lowered it to a level close to the control group values (p < 0.05). GSH levels in liver and small intestine tissues reduced significantly in the acrylamide group (p < 0.05). But acrylamide+NAC administration increased GSH levels significantly in all tissues. Whereas GST activity decreased significantly in the acrylamide group in liver and small intestine tissues as compared to the other groups (p < 0.05), the GST activity increased significantly in the acrylamide+NAC group in all tissues as compared to the acrylamide group (p < 0.05). Liver histopathology showed that the liver epithelial cells were damaged significantly in the acrylamide group. Small intestine histopathology showed that the intestinal villous epithelial cells were damaged significantly in the acrylamide group.Our results indicate that a high level of acrylamide causes oxidative damage in liver and small and large intestine tissues, while N-acetylcysteine administration in a pharmacological dose shows to have an antioxidant effect in preventing this damage (Tab. 2, Fig. 2, Ref. 66).
Fluorodeoxyglucose Positron Emission Tomography Response and Normal Tissue Regeneration After Stereotactic Body Radiotherapy to Liver Metastases
Stinauer, Michelle A.; Diot, Quentin; Westerly, David C.; Schefter, Tracey E.; Kavanagh, Brian D.
Purpose: To characterize changes in standardized uptake value (SUV) in positron emission tomography (PET) scans and determine the pace of normal tissue regeneration after stereotactic body radiation therapy (SBRT) for solid tumor liver metastases. Methods and Materials: We reviewed records of patients with liver metastases treated with SBRT to {>=}40 Gy in 3-5 fractions. Evaluable patients had pretreatment PET and {>=}1 post-treatment PET. Each PET/CT scan was fused to the planning computed tomography (CT) scan. The maximum SUV (SUV{sub max}) for each lesion and the total liver volume were measured on each PET/CT scan. Maximum SUV levels before and after SBRT were recorded. Results: Twenty-seven patients with 35 treated liver lesions were studied. The median follow-up was 15.7 months (range, 1.5-38.4 mo), with 5 PET scans per patient (range, 2-14). Exponential decay curve fitting (r=0.97) showed that SUV{sub max} declined to a plateau of 3.1 for controlled lesions at 5 months after SBRT. The estimated SUV{sub max} decay half-time was 2.0 months. The SUV{sub max} in controlled lesions fluctuated up to 4.2 during follow-up and later declined; this level is close to 2 standard deviations above the mean normal liver SUV{sub max} (4.01). A failure cutoff of SUV{sub max} {>=}6 is twice the calculated plateau SUV{sub max} of controlled lesions. Parenchymal liver volume decreased by 20% at 3-6 months and regenerated to a new baseline level approximately 10% below the pretreatment level at 12 months. Conclusions: Maximum SUV decreases over the first months after SBRT to plateau at 3.1, similar to the median SUV{sub max} of normal livers. Transient moderate increases in SUV{sub max} may be observed after SBRT. We propose a cutoff SUV{sub max} {>=}6, twice the baseline normal liver SUV{sub max}, to score local failure by PET criteria. Post-SBRT values between 4 and 6 would be suspicious for local tumor persistence or recurrence. The volume of normal liver reached nadir 3
Measurement and simulation of water transport during freezing in mammalian liver tissue.
Pazhayannur, P V; Bischof, J C
Optimization of cryosurgical procedures on deep tissues such as liver requires an increased understanding of the fundamental mechanisms of ice formation and water transport in tissues during freezing. In order to further investigate and quantify the amount of water transport that occurs during freezing in tissue, this study reports quantitative and dynamic experimental data and theoretical modeling of rat liver freezing under controlled conditions. The rat liver was frozen by one of four methods of cooling: Method 1-ultrarapid "slam cooling" (> or = 1000 degrees C/min) for control samples; Method 2-equilibrium freezing achieved by equilibrating tissue at different subzero temperatures (-4, -6, -8, -10 degrees C); Method 3-two-step freezing, which involves cooling at 5 degrees C/min. to -4, -6, -8, -10 or -20 degrees C followed immediately by slam cooling; or Method 4-constant and controlled freezing at rates from 5-400 degrees C/min. on a directional cooling stage. After freezing, the tissue was freeze substituted, embedded in resin, sectioned, stained, and imaged under a light microscope fitted with a digitizing system. Image analysis techniques were then used to determine the relative cellular to extracellular volumes of the tissue. The osmotically inactive cell volume was determined to be 0.35 by constructing a Boyle van't Hoff plot using cellular volumes from Method 2. The dynamic volume of the rat liver cells during cooling was obtained using cellular volumes from Method 3 (two-step freezing at 5 degrees C/min). A nonlinear regression fit of a Krogh cylinder model to the volumetric shrinkage data in Method 3 yielded the biophysical parameters of water transport in rat liver tissue of: Lpg = 3.1 x 10(-13) m3/Ns (1.86 microns/min-atm) and ELp = 290 kJ/mole (69.3 kcal/mole), with chi-squared variance of 0.00124. These parameters were then incorporated into the Krogh cylinder model and used to simulate water transport in rat liver tissue during constant cooling at
Dietary response of sympatric deer to fire using stable isotope analysis of liver tissue
Walter, W. David; Zimmerman, T.J.; Leslie, David M.; Jenks, J.A.
Carbon (??13C) and nitrogen (??15N) isotopes in biological samples from large herbivores identify photosynthetic pathways (C3 vs. C4) of plants they consumed and can elucidate potential nutritional characteristics of dietary selection. Because large herbivores consume a diversity of forage types, ??13C and ??15N in their tissue can index ingested and assimilated diets through time. We assessed ??13C and ??15N in metabolically active liver tissue of sympatric mule deer (Odocoileus hemionus) and white-tailed deer (O. virginianus) to identify dietary disparity resulting from use of burned and unburned areas in a largely forested landscape. Interspecific variation in dietary disparity of deer was documented 2-3 years post-fire in response to lag-time effects of vegetative response to burning and seasonal (i.e., summer, winter) differences in forage type. Liver ??13C for mule deer were lower during winter and higher during summer 2 years post-fire on burned habitat compared to unburned habitat suggesting different forages were consumed by mule deer in response to fire. Liver ??15N for both species were higher on burned than unburned habitat during winter and summer suggesting deer consumed more nutritious forage on burned habitat during both seasons 2 and 3 years post-fire. Unlike traditional methods of dietary assessment that do not measure uptake of carbon and nitrogen from dietary components, analyses of stable isotopes in liver or similar tissue elucidated ??13C and ??15N assimilation from seasonal dietary components and resulting differences in the foraging ecology of sympatric species in response to fire.
[The role of pro- and antioxidant processes in the liver tissue of guinea pigs in pathogenesis of allergic alveolitis].
Shchepans'kyĭ, F I; Reheda, M S
It was shown that allergic alveolitis development is accompanied by increase of superoxyddismutase and catalase activity as well as an increase of dien conjugates and malonic dialdehyde content in Guinea pig liver. The administration of alfa-tokoferol acetate, an antioxidant resulted in decrease of these indices in the liver tissue that testifies its correcting influence upon PLO and antioxidant system processes.
Copper concentration of liver tissue under long-term copper-histidine therapy in a patient with Menkes disease.
Kroepfl, T; Mair, E; Deutsch, J; Brunner-Krainz, M; Paschke, E; Plecko, B
Copper-histidine is the treatment of choice in Menkes disease but bears the potential risk of copper overload and induced liver cirrhosis. We report normal copper concentrations of liver tissue over an 8-year treatment period with copper-histidine.
Liver tissue characterization from uniaxial stress-strain data using probabilistic and inverse finite element methods.
Fu, Y B; Chui, C K; Teo, C L
Biological soft tissue is highly inhomogeneous with scattered stress-strain curves. Assuming that the instantaneous strain at a specific stress varies according to a normal distribution, a nondeterministic approach is proposed to model the scattered stress-strain relationship of the tissue samples under compression. Material parameters of the liver tissue modeled using Mooney-Rivlin hyperelastic constitutive equation were represented by a statistical function with normal distribution. Mean and standard deviation of the material parameters were determined using inverse finite element method and inverse mean-value first-order second-moment (IMVFOSM) method respectively. This method was verified using computer simulation based on direct Monte-Carlo (MC) method. The simulated cumulative distribution function (CDF) corresponded well with that of the experimental stress-strain data. The resultant nondeterministic material parameters were able to model the stress-strain curves from other separately conducted liver tissue compression tests. Stress-strain data from these new tests could be predicted using the nondeterministic material parameters.
Dynamic expression of extracellular signal-regulated kinase in rat liver tissue during hepatic fibrogenesis
Zhang, Xiao-Lan; Liu, Jin-Ming; Yang, Chang-Chun; Zheng, Yi-Lin; Liu, Li; Wang, Zhan-Kui; Jiang, Hui-Qing
AIM: To investigate whether extracellular signal-regulated kinase 1 (ERK1) is activated and associated with hepatic stellate cell (HSC) proliferation in fibrotic rat liver tissue. METHODS: Rat hepatic fibrosis was induced by bile duct ligation (BDL). Histopathological changes were evaluated by hematoxylin and eosin staining, and Masson's trichrome method. ERK1 mRNA in rat liver tissue was determined by reverse transcription-polymerase chain reaction, while the distribution of ERK1 was assessed by immunohistochemistry. ERK1 protein was detected by Western blotting analysis. The number of activated HSCs was quantified after alpha smooth muscle actin (α-SMA) staining. RESULTS: With the development of hepatic fibrosis, the positive staining cells of α-SMA increased obviously, and mainly resided in the portal ducts. Fiber septa and perisinuses were accompanied with proliferating bile ducts. The positive staining areas of the rat livers in model groups 1-4 wk after ligation of common bile duct (12.88% ± 2.63%, 22.65% ± 2.16%, 27.45% ± 1.86%, 35.25% ± 2.34%, respectively) were significantly larger than those in the control group (5.88% ± 1.46%, P < 0.01). With the development of hepatic fibrosis, the positive cells of ERK1 increased a lot, and were mainly distributed in portal ducts, fiber septa around the bile ducts, vascular endothelial cells and perisinusoidal cells. Western blotting analysis displayed that the expression of ERK1 and ERK2 protein was up-regulated during the model course, and its level was the highest 4 wk after operation, being 3.9-fold and 7.2-fold higher in fibrotic rat liver than in controls. ERK1 mRNA was expressed in normal rat livers as well, which was up-regulated two days after BDL and reached the highest 4 wk after BDL. The expression of ERK1 was positively correlated with α-SMA expression (r = 0.958,P < 0.05). CONCLUSION: The expression of ERK1 protein and mRNA is greatly increased in fibrotic rat liver tissues, which may play a
Comprehensive DNA methylation analysis of hepatitis B virus genome in infected liver tissues
Jain, Surbhi; Chang, Ting-Tsung; Chen, Sitong; Boldbaatar, Batbold; Clemens, Adam; Lin, Selena Y.; Yan, Ran; Hu, Chi-Tan; Guo, Haitao; Block, Timothy M.; Song, Wei; Su, Ying-Hsiu
Hepatitis B virus (HBV) is a hepatotropic virus causing hepatitis, cirrhosis and hepatocellular carcinoma (HCC). The methylation status of the HBV DNA in its different forms can potentially provide insight into the pathogenesis of HBV-related liver diseases, including HCC, however this is unclear. The goal of this study is to obtain comprehensive DNA methylation profiles of the three putative CpG islands in the HBV DNA in infected livers, with respect to liver disease progression. The extent of methylation in these CpG islands was first assessed using bisulfite PCR sequencing with a small set of tissue samples, followed by analysis using both quantitative bisulfite-specific PCR and quantitative methylation-specific PCR assays in a larger sample size (n = 116). The level of HBV CpG island 3 methylation significantly correlated with hepatocarcinogenesis. We also obtained, for the first time, evidence of rare, non-CpG methylation in CpG island 2 of the HBV genome in infected liver. Comparing methylation of the HBV genome to three known HCC-associated host genes, APC, GSTP1, and RASSF1A, we did not identify a significant correlation between these two groups. PMID:26000761
Comprehensive DNA methylation analysis of hepatitis B virus genome in infected liver tissues.
Jain, Surbhi; Chang, Ting-Tsung; Chen, Sitong; Boldbaatar, Batbold; Clemens, Adam; Lin, Selena Y; Yan, Ran; Hu, Chi-Tan; Guo, Haitao; Block, Timothy M; Song, Wei; Su, Ying-Hsiu
Hepatitis B virus (HBV) is a hepatotropic virus causing hepatitis, cirrhosis and hepatocellular carcinoma (HCC). The methylation status of the HBV DNA in its different forms can potentially provide insight into the pathogenesis of HBV-related liver diseases, including HCC, however this is unclear. The goal of this study is to obtain comprehensive DNA methylation profiles of the three putative CpG islands in the HBV DNA in infected livers, with respect to liver disease progression. The extent of methylation in these CpG islands was first assessed using bisulfite PCR sequencing with a small set of tissue samples, followed by analysis using both quantitative bisulfite-specific PCR and quantitative methylation-specific PCR assays in a larger sample size (n = 116). The level of HBV CpG island 3 methylation significantly correlated with hepatocarcinogenesis. We also obtained, for the first time, evidence of rare, non-CpG methylation in CpG island 2 of the HBV genome in infected liver. Comparing methylation of the HBV genome to three known HCC-associated host genes, APC, GSTP1, and RASSF1A, we did not identify a significant correlation between these two groups.
Tissue inhibitor of metalloproteinase-1 and -2 RNA expression in rat and human liver fibrosis.
Herbst, H.; Wege, T.; Milani, S.; Pellegrini, G.; Orzechowski, H. D.; Bechstein, W. O.; Neuhaus, P.; Gressner, A. M.; Schuppan, D.
The remodeling of extracellular matrix during chronic liver disease may partially be attributed to altered activity of matrix metalloproteinases and their tissue inhibitors (TIMPs). Expression of TIMP-1 and -2 was studied by in situ hybridization combined with immunohistochemistry in rat (acute and chronic carbon tetrachloride intoxication and secondary biliary fibrosis) and human livers and on isolated rat hepatic stellate cells. TIMP-1 and -2 transcripts appeared in rat livers within 1 to 3 hours after intoxication, pointing to a role in the protection against accidental activation of matrix metalloproteinases, and were present at high levels in all fibrotic rat and human livers predominantly in stellate cells. TIMP-2 RNA distribution largely matched with previously reported patterns of matrix metalloproteinase-2 (72-kd gelatinase) expression, suggesting generation of a TIMP-2/matrix metalloproteinase-2 complex (large inhibitor of metalloproteinases). Isolated stellate cells expressed TIMP-1 and -2 RNA. Addition of transforming growth factor-beta 1 enhanced TIMP-1 and matrix metalloproteinase-2 RNA levels in vitro, whereas TIMP-2-specific signals were reduced, likely to result in a stoichiometric excess of matrix-metalloproteinase-2 over TIMP-2. In the context of previous demonstrations of transforming growth factor-beta 1 and matrix metalloproteinase-2 in vivo, these patterns suggest an intrahepatic environment permitting only limited matrix degradation, ultimately resulting in redistribution of extracellular matrix with relative accumulation of collagen type 1. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:9137090
Confirmation of Drug Delivery after Liver Chemoembolization: Direct Tissue Doxorubicin Measurement by UHPLC-MS-MS
Baumgarten, Sigrid; Gaba, Ron C.; van Breemen, Richard B.
Because liver cancer is rarely suitable for surgery, transcatheter arterial chemoembolization (TACE) is used for palliative therapy. In this procedure, an emulsion of doxorubicin in iodized oil is injected directly into liver tumors through a catheter positioned within the artery supplying blood flow to the tumor. At present, there is limited understanding of factors affecting the delivery and dispersion of doxorubicin within treated tumors during TACE. This study addresses the development and application of an ultrahigh pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS-MS) method for rapid confirmation of drug delivery after TACE in a rabbit VX2 liver cancer model. Doxorubicin levels in liver tumors were measured using UHPLC-MS-MS and compared with computed tomography measured levels of iodized oil, a metric used clinically to indicate drug delivery. We found that tissue drug levels determined using UHPLC-MS-MS did not correlate with the regional iodized oil concentration (vehicle) within tumors following TACE, suggesting that chemotherapeutic drugs like doxorubicin spread throughout tumors, and that lack of iodized oil staining in portions of a tumor does not necessarily indicate inadequate therapy during TACE. PMID:22454282
Inflammation inhibits the expression of phosphoenolpyruvate carboxykinase in liver and adipose tissue.
Feingold, Kenneth R; Moser, Arthur; Shigenaga, Judy K; Grunfeld, Carl
Inhibition of adipocyte triglyceride biosynthesis is required for fatty acid mobilization during inflammation. Triglyceride biosynthesis requires glycerol 3-phosphate and phosphoenolpyruvate carboxykinase (PEPCK) plays a key role. We demonstrate that LPS, zymosan, and TNF-α decrease PEPCK in liver and fat. Turpentine decreases PEPCK in liver, but not in fat. The LPS-induced decrease in PEPCK does not occur in TLR4 deficient animals, indicating that this receptor is required. The LPS-induced decrease in hepatic PEPCK does not occur in TNF receptor/IL-1 receptor knockout mice, but occurs in fat, indicating that TNF-α/IL-1 is essential for the decrease in liver but not fat. In 3T3-L1 adipocytes TNF-α, IL-1, IL-6, and IFNγ inhibit PEPCK indicating that there are multiple pathways by which PEPCK is decreased in adipocytes. The binding of PPARγ and RXRα to the PPARγ response element in the PEPCK promoter is markedly decreased in adipose tissue nuclear extracts from LPS treated animals. Lipopolysaccharide and zymosan reduce PPARγ and RXRα expression in fat, suggesting that a decrease in PPARγ and RXRα accounts for the decrease in PEPCK. Thus, there are multiple cytokine pathways by which inflammation inhibits PEPCK expression in adipose tissue which could contribute to the increased mobilization of fatty acids during inflammation.
A High Linoleic Acid Diet does not Induce Inflammation in Mouse Liver or Adipose Tissue.
Vaughan, Roger A; Garrison, Richard L; Stamatikos, Alexis D; Kang, Minsung; Cooper, Jamie A; Paton, Chad M
Recently, the pro-inflammatory effects of linoleic acid (LNA) have been re-examined. It is now becoming clear that relatively few studies have adequately assessed the effects of LNA, independent of obesity. The purpose of this work was to compare the effects of several fat-enriched but non-obesigenic diets on inflammation to provide a more accurate assessment of LNA's ability to induce inflammation. Specifically, 8-week-old male C57Bl/6 mice were fed either saturated (SFA), monounsaturated (MUFA), LNA, or alpha-linolenic acid enriched diets (50 % Kcal from fat, 22 % wt/wt) for 4 weeks. Chow and high-fat, hyper-caloric diets were used as negative and positive controls, respectively. Expression of pro-inflammatory and pro-coagulant markers from epididymal fat, liver, and plasma were measured along with food intake and body weights. Mice fed the high SFA, MUFA, and high-fat diets exhibited increased pro-inflammatory markers in liver and adipose tissue; however, mice fed LNA for four weeks did not display significant changes in pro-inflammatory or pro-coagulant markers in epididymal fat, liver, or plasma. The present study demonstrates that LNA alone is insufficient to induce inflammation. Instead, it is more likely that hyper-caloric diets are responsible for diet-induced inflammation possibly due to adipose tissue remodeling.
Mechanical dissociation of swine liver to produce organoid units for tissue engineering and in vitro disease modeling.
Irani, Katayun; Pomerantseva, Irina; Hart, Alison R; Sundback, Cathryn A; Neville, Craig M; Vacanti, Joseph P
The complex intricate architecture of the liver is crucial to hepatic function. Standard protocols used for enzymatic digestion to isolate hepatocytes destroy tissue structure and result in significant loss of synthetic, metabolic, and detoxification processes. We describe a process using mechanical dissociation to generate hepatic organoids with preserved intrinsic tissue architecture from swine liver. Oxygen-supplemented perfusion culture better preserved organoid viability, morphology, serum protein synthesis, and urea production, compared with standard and oxygen-supplemented static culture. Hepatic organoids offer an alternative source for hepatic assist devices, engineered liver, disease modeling, and xenobiotic testing.
Protective effects of erdosteine on rotenone-induced oxidant injury in liver tissue.
Terzi, Alpaslan; Iraz, Mustafa; Sahin, Semsettin; Ilhan, Atilla; Idiz, Nuri; Fadillioglu, Ersin
Rotenone, an insecticide of botanical origin, causes toxicity through inhibition of complex I of the respiratory chain in mitochondria. This study was undertaken to determine whether rotenone-induced liver oxidant injury is prevented by erdosteine, a mucolytic agent showing antioxidant properties. There were four groups of Male Wistar Albino rats: group one was untreated as control; the other groups were treated with erdosteine (50 mg/kg per day, orally), rotenone (2.5 mg/mL once and 1 mL/kg per day for 60 days, i.p.) or rotenone plus erdosteine, respectively. Rotenone treatment without erdosteine increased xanthine oxidase (XO) enzyme activity and also increased lipid peroxidation in liver tissue (P < 0.05). The rats treated with rotenone plus erdosteine produced a significant decrease in lipid peroxidation and XO activities in comparison with rotenone group (P < 0.05). Erdosteine treatment with rotenone led to an increase in catalase (CAT) and superoxide dismutase (SOD) activities in comparison with the rotenone group (P < 0.05). There was no significant difference in nitric oxide (NO) level between groups. There were negative correlations between CAT activity and malondialdehyde (MDA) level (r = -0.934, P < 0.05) with between CAT and SOD activities (r = -0.714, P < 0.05), and a positive correlation between SOD activity and MDA level (r = 0.828, P < 0.05) in rotenone group. In the rotenone plus erdosteine group, there was a negative correlation between XO activity and NO level in liver tissue (r = -0.833, P < 0.05). In the light of these findings, erdosteine may be a protective agent for rotenone-induced liver oxidative injury in rats.
Complex responses to Si quantum dots accumulation in carp liver tissue: Beyond oxidative stress.
Serban, Andreea Iren; Stanca, Loredana; Sima, Cornelia; Staicu, Andrea Cristina; Zarnescu, Otilia; Dinischiotu, Anca
The use of quantum dots (QDs) in biomedical applications is limited due to their inherent toxicity caused by the heavy metal core of the particles. Consequently, silicon-based QDs are expected to display diminished toxicity. We investigated the in vivo effects induced by Si/SiO2 QDs intraperitoneally injected in crucian carp liver. The QDs contained a crystalline Si core encased in a SiO2 shell, with a size between 2.75 and 11.25nm and possess intrinsic fluorescence (Ex 325nm/Em ∼690nm). Tissue fluorescence microscopy analysis revealed the presence of QDs in the liver for at least 2weeks after injection. Although protein and lipid oxidative stress markers showed the onset of oxidative stress, the hepatic tissue exhibited significant antioxidant adaptations (increase of antioxidant enzymes, recovery of glutathione levels), sustained by the activation of Hsp30 and Hsp70 chaperoning proteins. The increased activity of cyclooxigenase-2 (COX-2) and matrix metalloproteinases (MMPs) support the idea that Si/SiO2 QDs have a potential to induce inflammatory response, a scenario also indicated by the profile of Hsp60 and Hsp90 heat shock proteins. MMPs profile and the recovery of oxidative stress markers suggested a tissue remodelation phase after 3weeks from QDs administration.
Methodologies of tissue preservation and analysis of the glycogen content of the broiler chick liver.
Bennett, L W; Keirs, R W; Peebles, E D; Gerard, P D
The current study was performed to develop convenient, rapid, reliable, and pragmatic methodologies by which to harvest and preserve liver tissue glycogen and to analyze its levels within reasonable limits of quantification and with extended chromophore stability. Absorbance values decreased by 2 h and again by 24 h after preparation of the iodine-potassium iodide chromophore, whereas absorbance values of the phenol-sulfuric acid chromophore remained constant over the same time period. These absorbance trends for each chromophore followed full color development within 5 min after combining the analyte with the respective chromophore reagent. Use of the phenol-sulfuric acid reagent allowed for a 10-fold reduction in assay limits of detection and quantification when compared with the iodine-potassium iodide reagent. Furthermore, glycogen concentration-absorbance relationships were affected by the source (i.e., rabbit liver vs. bovine liver) of glycogen standards when the iodine-potassium iodide chromophore was used, but the source of the standards had no influence when the phenol-sulfuric acid chromophore was used. The indifference of the phenol-sulfuric acid method to the glycogen source, as exhibited by similar linear regressions of absorbance, may be attributed to actual determination of glucose subunit concentrations after complete glycogen hydrolysis by sulfuric acid. This is in contrast to the actual measurement of whole glycogen, which may exhibit source- or time-related molecular structural differences. The iodine-potassium iodide methodology is a test of whole glycogen concentrations; therefore, it may be influenced by glycogen structural differences. Liver tissue sample weight (between 0.16 and 0.36 g) and processing, which included mincing, immediate freezing, or refrigeration in 10% perchloric acid for 1 wk prior to tissue grinding, had no effect on glycogen concentrations that were analyzed by using the phenol-sulfuric acid reagent. These results
Experimental study of non-alcoholic fatty liver disease (NAFLD) on a model of starving chickens: is generalization of steatosis accompanied by fibrosis of the liver tissue?
Makovicky, Peter; Dudova, Marketa; Tumova, Eva; Rajmon, Radko; Vodkova, Zuzana
The objective of this work was to study the mechanism of liver parenchyma development under the influence of restriction of diet. Useful information is presented about the pathologic features associated with diet restriction in a chicken animal model of NAFLD. There were 96 chickens of two genotypes, Ross 308 and Cobb 500, in the experiment. The control group was fed a standard mixture ad libitum (ADL). The first experimental group, under restriction from the age of 2 weeks, was fed 80% ADL. The second experimental group was fed 65% ADL from the age of 2 weeks. There were 16 animals in each group. The experiment lasted 5 weeks. Liver parenchyma samples were obtained at the age of 35 days by the necropsy method and then processed by standard histologic methods. The slices were stained by standard staining: hematoxylin-eosin and by Sirius red kit for collagen type I and reticulin visualization. Hepatocyte diameter and the proportion of interstitial tissue to the parenchyma of the liver were measured objectively. Microvesicular liver steatosis was observed after 35 days of restriction. Hepatocyte diameter was significantly influenced by sex, genotype, and the experimental group. The proportion of interstitial tissue to the liver parenchyma was highly influenced by genotype and group, but there were no interactions. An increase in the steatosis histologic grade is associated with inflammatory changes, with decrease of hepatocyte diameter and with a decreasing proportion of interstitial tissue to the liver parenchyma. The results show that early restriction is not associated with the development of fibrosis of the liver tissue.
From the Cover: Cell-replacement therapy for diabetes: Generating functional insulin-producing tissue from adult human liver cells
NASA Astrophysics Data System (ADS)
Sapir, Tamar; Shternhall, Keren; Meivar-Levy, Irit; Blumenfeld, Tamar; Cohen, Hamutal; Skutelsky, Ehud; Eventov-Friedman, Smadar; Barshack, Iris; Goldberg, Iris; Pri-Chen, Sarah; Ben-Dor, Lya; Polak-Charcon, Sylvie; Karasik, Avraham; Shimon, Ilan; Mor, Eytan; Ferber, Sarah
Shortage in tissue availability from cadaver donors and the need for life-long immunosuppression severely restrict the large-scale application of cell-replacement therapy for diabetic patients. This study suggests the potential use of adult human liver as alternate tissue for autologous beta-cell-replacement therapy. By using pancreatic and duodenal homeobox gene 1 (PDX-1) and soluble factors, we induced a comprehensive developmental shift of adult human liver cells into functional insulin-producing cells. PDX-1-treated human liver cells express insulin, store it in defined granules, and secrete the hormone in a glucose-regulated manner. When transplanted under the renal capsule of diabetic, immunodeficient mice, the cells ameliorated hyperglycemia for prolonged periods of time. Inducing developmental redirection of adult liver offers the potential of a cell-replacement therapy for diabetics by allowing the patient to be the donor of his own insulin-producing tissue. pancreas | transdifferentiation
Rare entity: Ectopic liver tissue in the wall of the gallbladder - A case report.
Arslan, Yusuf; Altintoprak, Fatih; Serin, Kursat R; Kivilcim, Taner; Yalkin, Omer; Ozkan, Orhan V; Celebi, Fehmi
Ectopic liver tissue (ELT) is a rare condition, which is usually not diagnosed preoperatively, but coincidentally during abdominal surgery. While the location of ELT can vary, it is usually localized on the gallbladder wall or in close proximity. ELT is associated with various complications, a major complication being extrahepatic hepatocellular carcinoma. A 59-year-old female underwent elective surgery for chronic cholecystitis with stones. During laparoscopic exploration, a 2-cm-diameter ELT was detected in the anterior gallbladder wall and a laparoscopic cholecystectomy was performed. The case is presented due to the rare nature of ELT and as a reminder of ELT-related complications.
Exploration of steroidogenesis-related genes in testes, ovaries, adrenals, liver and adipose tissue in pigs.
Robic, Annie; Feve, Katia; Louveau, Isabelle; Riquet, Juliette; Prunier, Armelle
To explore the metabolism of steroids in the pig species, a qualitative PCR analysis was performed for the main transcript of 27 genes involved in steroid metabolism. We compared samples of testes, adipose tissue and liver from immature and peripubertal males, adrenal cortex from peripubertal males, ovaries from cyclic females and adipose tissue from peripubertal females. Some genes were shown to have a tissue-specific expression. Two of them were expressed only in testes, ovaries and adrenals: CYP11A1 and CYP11B. The CYP21 and HSD17B3 genes, were expressed respectively only in adrenals and only in testes. Very few differences were observed between transcriptional patterns of peripubertal testes and adrenal glands as well as between male and female fat tissues. However, the expression of genes involved in the sulfonation of steroids was higher in testes than in adrenals from males. Main differences between ovaries and testes were observed for HSD17B1/2/3, AKR1C-pig6 and sulfotransferase genes (SULT2A1/SULT2B1). The present study shows that the SRD5A2 and CYP21 genes were not involved in the testicular biosynthesis of androstenone. It also shows that porcine adrenal glands produce essentially corticosteroids and that fat tissue is unable to produce de novo steroids.
Quantization of liver tissue in dual kVp computed tomography using linear discriminant analysis
NASA Astrophysics Data System (ADS)
Tkaczyk, J. Eric; Langan, David; Wu, Xiaoye; Xu, Daniel; Benson, Thomas; Pack, Jed D.; Schmitz, Andrea; Hara, Amy; Palicek, William; Licato, Paul; Leverentz, Jaynne
Linear discriminate analysis (LDA) is applied to dual kVp CT and used for tissue characterization. The potential to quantitatively model both malignant and benign, hypo-intense liver lesions is evaluated by analysis of portal-phase, intravenous CT scan data obtained on human patients. Masses with an a priori classification are mapped to a distribution of points in basis material space. The degree of localization of tissue types in the material basis space is related to both quantum noise and real compositional differences. The density maps are analyzed with LDA and studied with system simulations to differentiate these factors. The discriminant analysis is formulated so as to incorporate the known statistical properties of the data. Effective kVp separation and mAs relates to precision of tissue localization. Bias in the material position is related to the degree of X-ray scatter and partial-volume effect. Experimental data and simulations demonstrate that for single energy (HU) imaging or image-based decomposition pixel values of water-like tissues depend on proximity to other iodine-filled bodies. Beam-hardening errors cause a shift in image value on the scale of that difference sought between in cancerous and cystic lessons. In contrast, projection-based decomposition or its equivalent when implemented on a carefully calibrated system can provide accurate data. On such a system, LDA may provide novel quantitative capabilities for tissue characterization in dual energy CT.
Saikokeishito Extract Exerts a Therapeutic Effect on alpha-Naphthylisothiocyanate-Induced Liver Injury in Rats through Attenuation of Enhanced Neutrophil Infiltration and Oxidative Stress in the Liver Tissue.
Ohta, Yoshiji; Kongo-Nishimura, Mutsumi; Hayashi, Takahiro; Kitagawa, Akira; Matsura, Tatsuya; Yamada, Kazuo
We examined whether Saikokeishito extract (TJ-10), a traditional Japanese herbal medicine, exerts a therapeutic effect on alpha-naphthylisothiocyanate (ANIT)-induced liver injury in rats through attenuation of enhanced neutrophil infiltration and oxidative stress in the liver tissue. In rats treated once with ANIT (75 mg/kg, i.p.), liver injury with cholestasis occurred 24 h after treatment and progressed at 48 h. When ANIT-treated rats orally received TJ-10 (0.26, 1.3 or 2.6 g/kg) at 24 h after the treatment, progressive liver injury with cholestasis was significantly attenuated at 48 h after the treatment at the dose of 1.3 or 2.6 g/kg. At 24 h after ANIT treatment, increases in hepatic lipid peroxide and reduced glutathione contents and myeloperoxidase activity occurred with decreases in hepatic superoxide dismutase and glutathione reductase activities. At 48 h after ANIT treatment, these changes except for reduced glutathione were enhanced with decreases in catalase, Se-glutathione peroxidase, and glucose-6-phosphate dehydrogenase activities. TJ-10 (1.3 or 2.6 g/kg) post-administered to ANIT-treated rats attenuated these changes found at 48 h after the treatment significantly. These results indicate that TJ-10 exerts a therapeutic effect on ANIT-induced liver injury in rats possibly through attenuation of enhanced neutrophil infiltration and oxidative stress in the liver tissue.
Fatty Acid Composition of Muscle, Adipose Tissue and Liver from Muskoxen (Ovibos moschatus) Living in West Greenland
Alves, Susana P.; Raundrup, Katrine; Cabo, Ângelo; Bessa, Rui J. B.; Almeida, André M.
Information about lipid content and fatty acid (FA) composition of muskoxen (Ovibos moschatos) edible tissues is very limited in comparison to other meat sources. Thus, this work aims to present the first in-depth characterization of the FA profile of meat, subcutaneous adipose tissue and liver of muskoxen living in West Greenland. Furthermore, we aim to evaluate the effect of sex in the FA composition of these edible tissues. Samples from muscle (Longissimus dorsi), subcutaneous adipose tissue and liver were collected from female and male muskoxen, which were delivered at the butchery in Kangerlussuaq (West Greenland) during the winter hunting season. The lipid content of muscle, adipose tissue and liver averaged 284, 846 and 173 mg/g of dry tissue, respectively. This large lipid contents confirms that in late winter, when forage availability is scarce, muskoxen from West Greenland still have high fat reserves, demonstrating that they are well adapted to seasonal feed restriction. A detailed characterization of FA and dimethylacetal composition of muskoxen muscle, subcutaneous adipose tissue and liver showed that there are little differences on FA composition between sexes. Nevertheless, the 18:1cis-9 was the most abundant FA in muscle and adipose tissue, reaching 43% of total FA in muscle. The high content of 18:1cis-9 suggests that it can be selectively stored in muskoxen tissues. Regarding the nutritional composition of muskoxen edible tissues, they are not a good source of polyunsaturated FA; however, they may contribute to a higher fat intake. Information about the FA composition of muskoxen meat and liver is scarce, so this work can contribute to the characterization of the nutritional fat properties of muskoxen edible tissues and can be also useful to update food composition databases. PMID:26678792
Therapeutic potential of adipose tissue-derived stem cells for liver failure according to the transplantation routes
Kim, Say-June; Park, Ki Cheol; Lee, Jung Uee; Kim, Kwan-Ju
Purpose Even though adipose tissue-derived stem cells (ADSCs) have been spotlighted as a possible alternative for liver transplantation in an experimental setting, the mechanism by which ADSCs improve liver dysfunction remains poorly characterized. The objective of this study was to evaluate the therapeutic ability of undifferentiated ADSCs, and find a few clues on how ADSCs alleviate liver damage by comparing the transplantation routes. Methods In vitro generated human ADSCs were checked for surface markers and stage-specific genes for characterization. Afterwards, they were transplanted into C57BL/6 mice with CCl4-induced liver injury. The transplantations were made via tail vein, portal vein, and direct liver parenchymal injection. At 1 and 3 post-transplantation days, serum biochemical parameters and/or liver specimens were evaluated. Results We have shown here that ADSCs have the characteristics of mesenchymal stem cells, and belong to endodermal and/or early hepatic differentiation stage. After transplantation into the mice with acute liver failure, markers of liver injury, such as alanineaminotransferase, aspartateaminotransferase, as well as ammonia, decreased. Of these transplantation routes, transplantation via tail vein rendered the most prominent reduction in the biochemical parameters. Conclusion Undifferentiated ADSCs have the ability to improve hepatic function in mice with acute liver injury. Moreover, our transplantation route study supports the theory that ADSCs in systemic circulation can exert endocrine or paracrine effects to ameliorate the injured liver. PMID:22066119
Body-on-a-chip simulation with gastrointestinal tract and liver tissues suggests that ingested nanoparticles have the potential to cause liver injury.
Esch, Mandy B; Mahler, Gretchen J; Stokol, Tracy; Shuler, Michael L
The use of nanoparticles in medical applications is highly anticipated, and at the same time little is known about how these nanoparticles affect human tissues. Here we have simulated the oral uptake of 50 nm carboxylated polystyrene nanoparticles with a microscale body-on-a-chip system (also referred to as multi-tissue microphysiological system or micro Cell Culture Analog). Using the 'GI tract-liver-other tissues' system allowed us to observe compounding effects and detect liver tissue injury at lower nanoparticle concentrations than was expected from experiments with single tissues. To construct this system, we combined in vitro models of the human intestinal epithelium, represented by a co-culture of enterocytes (Caco-2) and mucin-producing cells (TH29-MTX), and the liver, represented by HepG2/C3A cells, within one microfluidic device. The device also contained chambers that together represented the liquid portions of all other organs of the human body. Measuring the transport of 50 nm carboxylated polystyrene nanoparticles across the Caco-2/HT29-MTX co-culture, we found that this multi-cell layer presents an effective barrier to 90.5 ± 2.9% of the nanoparticles. Further, our simulation suggests that a larger fraction of the 9.5 ± 2.9% nanoparticles that travelled across the Caco-2/HT29-MTX cell layer were not large nanoparticle aggregates, but primarily single nanoparticles and small aggregates. After crossing the GI tract epithelium, nanoparticles that were administered in high doses estimated in terms of possible daily human consumption (240 and 480 × 10(11) nanoparticles mL(-1)) induced the release of aspartate aminotransferase (AST), an intracellular enzyme of the liver that indicates liver cell injury. Our results indicate that body-on-a-chip devices are highly relevant in vitro models for evaluating nanoparticle interactions with human tissues.
Changes in backscatter of liver tissue due to thermal coagulation induced by focused ultrasound.
Shishitani, Takashi; Matsuzawa, Ryo; Yoshizawa, Shin; Umemura, Shin-ichiro
Ultrasonic imaging has advantages in its self-consistency in guiding and monitoring ultrasonic treatment such as high-intensity focused ultrasound (HIFU) treatment. Changes in ultrasonic backscatter of tissues due to HIFU treatment have been observed, but their mechanism is still under discussion. In this paper, ultrasonic backscatter of excised and degassed porcine liver tissue was observed before and after HIFU exposure using a diagnostic scanner, and its acoustic impedance was mapped using an ultrasonic microscope. The histology of its pathological specimen was also observed using an optical microscope. The observed decrease in backscatter intensity due to HIFU exposure was consistent with a spatial Fourier analysis of the histology, which also showed changes due to the exposure. The observed increase in acoustic impedance due to the exposure was also consistent with the histological change assuming that the increase was primarily caused by the increase in the concentration of hepatic cells.
Proteome Characteristics of Non-Alcoholic Steatohepatitis Liver Tissue and Associated Hepatocellular Carcinomas
Kakehashi, Anna; Stefanov, Vasily E.; Ishii, Naomi; Okuno, Takahiro; Fujii, Hideki; Kawai, Kazuaki; Kawada, Norifumi; Wanibuchi, Hideki
To uncover mechanisms of nonalcoholic steatohepatitis (NASH) associated hepatocarcinogenesis, we compared the proteomes of human NASH-associated liver biopsies, resected hepatocellular carcinomas (HCCs) and HCCs of HCV+ patients with normal liver tissue of patients with gastrointestinal tumor metastasis, in formalin-fixed paraffin-embedded samples obtained after surgery in our hospital during the period from 2006 to 2011. In addition, proteome analysis of liver tumors in male STAM NASH-model mice was performed. Similar changes in the proteome spectrum such as overexpression of enzymes involved in lipid, cholesterol and bile acid biosynthesis and examples associated with suppression of fatty acid oxidation and catabolism, alcohol metabolism, mitochondrial function as well as low expression levels of cytokeratins 8 and 18 were observed in both human NASH biopsies and NASH HCCs, but not HCV+ HCCs. Alterations in downstream protein expression pointed to significant activation of transforming growth factor β, SMAD family member 3, β-catenin, Nrf2, SREBP-LXRα and nuclear receptor-interacting protein 1 (NRIP1), and inhibition of PPARs and p53 in human NASH biopsies and/or HCCs, suggesting their involvement in accumulation of lipids, development of fibrosis, oxidative stress, cell proliferation and suppression of apoptosis in NASH hepatocarcinogenesis. In STAM mice, PPARs inhibition was not obvious, while expression of cytokeratins 8 and 18 was elevated, indicative of essential differences between human and mouse NASH pathogenesis. PMID:28218651
Analysis of the effects of inter-individual variation in the distribution of plutonium in skeleton and liver.
Klein, W; Breustedt, B
One important parameter for biokinetic plutonium modelling is the ratio between the contents of plutonium in liver and skeleton. Autopsy data show a vast inter-individual variation in the partitioning between these organs. The capacity of recent biokinetic models for plutonium to reproduce these variations was studied. Autopsy data for plutonium amounts in liver and skeleton for both (238)Pu and (239)Pu isotopes can be merged into a single data set following several statistical tests. Simulations with different parameter values generate a mapping between the autopsy values and the model parameters. The observed partitioning distribution can be transformed into a distribution of transfer rates, which would result in the observed data. Besides, the variation in the partitioning between liver and skeleton leads via biliary pathway to a variation in the excretion ratio. This can be used to estimate an individual partitioning factor, which can be used in individual case assessments.
TGF β1 and PDGF AA override Collagen type I inhibition of proliferation in human liver connective tissue cells
Geremias, Alvaro T; Carvalho, Marcelo A; Borojevic, Radovan; Monteiro, Alvaro NA
Background A marked expansion of the connective tissue population and an abnormal deposition of extracellular matrix proteins are hallmarks of chronic and acute injuries to liver tissue. Liver connective tissue cells, also called stellate cells, derived from fibrotic liver have been thoroughly characterized and correspond phenotypically to myofibroblasts. They are thought to derive from fat-storing Ito cells in the perisinusoidal space and acquire a contractile phenotype when activated by tissue injury. In the last few years it has become evident that several peptide growth factors such as PDGF AA and TGF-β are involved in the development of fibrosis by modulating myofibroblast proliferation and collagen secretion. The fact that during the development of chronic fibrosis there is concomitant deposition of collagen, a known inhibitory factor, and sustained cell proliferation, raises the possibility that stellate cells from chronic liver fibrosis patients fail to respond to normal physiologic controls. Methods In this study we address whether cells from fibrotic liver patients respond to normal controls of proliferation. We compared cell proliferation of primary human liver connective tissue cells (LCTC) from patients with liver fibrosis and skin fibroblasts (SF) in the presence of collagens type I and IV; TGF-β, PDGF AA and combinations of collagen type I and TGF-β or PDGF AA. Results Our results indicate that despite displaying normal contact and collagen-induced inhibition of proliferation LCTC respond more vigorously to lower concentrations of PDGF AA. In addition, we show that collagen type I synergizes with growth factors to promote mitogenesis of LCTC but not SF. Conclusions The synergistic interaction of growth factors and extracellular matrix proteins may underlie the development of chronic liver fibrosis. PMID:15579200
Structural effects of simvastatin on liver rate tissue: Fourier transform infrared and Raman microspectroscopic studies
NASA Astrophysics Data System (ADS)
Garip, Sebnem; Bayari, Sevgi Haman; Severcan, Mete; Abbas, Sherif; Lednev, Igor K.; Severcan, Feride
Simvastatin is one of the most frequently prescribed statins because of its efficacy in the treatment of hypercholesterolemia, reducing cardiovascular risk and related mortality. Determination of its side effects on different tissues is mandatory to improve safe use of this drug. In the present study, the effects of simvastatin on molecular composition and structure of healthy rat livers were investigated by Fourier transform infrared and Raman imaging. Simvastatin-treated groups received 50 mg/kg/day simvastatin for 30 days. The ratio of the area and/or intensity of the bands assigned to lipids, proteins, and nucleic acids were calculated to get information about the drug-induced changes in tissues. Loss of unsaturation, accumulation of end products of lipid peroxidation, and alterations in lipid-to-protein ratio were observed in the treated group. Protein secondary structure studies revealed significant decrease in α-helix and increase in random coil, while native β-sheet decreases and aggregated β-sheet increases in treated group implying simvastatin-induced protein denaturation. Moreover, groups were successfully discriminated using principal component analysis. Consequently, high-dose simvastatin treatment induces hepatic lipid peroxidation and changes in molecular content and protein secondary structure, implying the risk of liver disorders in drug therapy.
Multifrequency time-harmonic elastography for the measurement of liver viscoelasticity in large tissue windows.
Tzschätzsch, Heiko; Ipek-Ugay, Selcan; Trong, Manh Nguyen; Guo, Jing; Eggers, Jonathan; Gentz, Enno; Fischer, Thomas; Schultz, Michael; Braun, Jürgen; Sack, Ingolf
Elastography of the liver for the non-invasive diagnosis of hepatic fibrosis is an established method. However, investigations of obese patients or patients with ascites are often limited by small and superficial elastographic windows. Therefore, multifrequency time-harmonic elastography (THE) based on time-resolved A-line ultrasound has recently been developed for measuring liver viscoelasticity in wide soft tissue windows and at greater depths. In this study, THE was integrated into a clinical B-mode scanner connected to a dedicated actuator bed driven by superimposed vibrations of 30- to 60-Hz frequencies. The resulting shear waves in the liver were captured along multiple profiles 7 to 14 cm in width and automatically processed for reconstruction of mean efficient shear wave speed and shear wave dispersion slope. This new modality was tested in healthy volunteers and 22 patients with clinically proven cirrhosis. Patients could be separated from controls by higher shear wave speeds (3.11 ± 0.64 m/s, 2.14-4.81 m/s, vs. 1.74 ± 0.10 m/s, 1.60-1.91 m/s) without significant degradation of data by high body mass index or ascites. Furthermore, the wave speed dispersion slope was significantly (p = 0.0025) lower in controls (5.2 ± 1.8 m/s/kHz) than in patients (39.1 ± 32.2 m/s/kHz). In conclusion, THE is useful for the diagnosis of cirrhosis in large tissue windows.
Microscale technologies for imaging endogenous gene expression in individual cells within 3D tissues
NASA Astrophysics Data System (ADS)
Ye, Ting; Luo, Zhen; Ma, Yunzhe; Gill, Harvinder Singh; Nitin, N.
The goal of this study was to develop an innovative approach to image gene expression in intact 3D tissues. Imaging gene expression of individual cells in 3D tissues is expected to have a significant impact on both clinical diagnostic applications and fundamental biological science and engineering applications in a laboratory setting. To achieve this goal, we have developed an integrated approach that combines: 1) microneedle-based minimally invasive intra-tissue delivery of oligonucleotide probes and Streptolysin O (SLO) or CPP; 2) SLO as a pore forming permeation enhancer to enable intracellular delivery of oligonucleotide probes and CPP peptides can also transport conjugated cargo in cells; and 3) fluorescence resonance energy transfer (FRET) pair of ON probes to improve specificity and sensitivity of RNA detection in tissue models. The results of this study demonstrate uniform coating and rapid release of ON probes from microneedles in a tissue environment. Microneedle assisted delivery of ON probes in 3D tissue does not result in cell damage and the ON probes are uniformly delivered in the tissue. The results also demonstrate the feasibility of FRET imaging of ON probes in 3D tissue and highlight the potential for imaging 28-s rRNA in individual living cells.
Human Liver Mitochondrial Cytochrome P450 2D6: Individual Variations and Implications in Drug Metabolism
Cook Sangar, Michelle L.; Anandatheerthavarada, Hindupur K.; Tang, Weigang; Prabu, Subbuswamy K.; Martin, Martha V.; Dostalek, Miroslav; Guengerich, F. Peter; Avadhani, Narayan G.
Summary Constitutively expressed human cytochrome P450 2D6 (CYP2D6) is responsible for the metabolism of approximately 25% of drugs in common clinical use. It is widely accepted that CYP2D6 is localized in the endoplasmic reticulum of cells; however, we have identified this enzyme in the mitochondria of human liver samples and found that extensive inter-individual variability exists in the level of the mitochondrial enzyme. Metabolic assays using 7-methoxy-4-aminomethylcoumarin as a substrate show that the human liver mitochondrial enzyme is capable of oxidizing this substrate and that the catalytic activity is supported by mitochondrial electron transfer proteins. Here we show that CYP2D6 contains an N-terminal chimeric signal that mediates its bimodal targeting to the endoplasmic reticulum (ER) and mitochondria. In vitro mitochondrial import studies using both N-terminal deletions and point mutations suggest that the mitochondrial targeting signal is localized between residues 23-33 and that the positively charged residues at positions 24, 25, 26, 28, and 32 are required for mitochondrial targeting. The importance of the positively charged residues was confirmed by transient transfection of a CYP2D6 mitochondrial targeting signal mutant in COS-7 cells. Both the mitochondria and the microsomes from a CYP2D6 stable expression cell line contain the enzyme and both fractions exhibit bufuralol 1′-hydroxylation activity, which is completely inhibited by CYP2D6 inhibitory antibody. Overall these results suggest that the targeting of CYP2D6 to mitochondria could be an important physiological process that has significance in xenobiotic metabolism. PMID:19438707
Analysis of acetylcholine, choline and butyrobetaine in human liver tissues by hydrophilic interaction liquid chromatography-tandem mass spectrometry.
Wang, Yuan; Wang, Tao; Shi, Xianzhe; Wan, Dafang; Zhang, Pingping; He, Xianghuo; Gao, Peng; Yang, Shengli; Gu, Jianren; Xu, Guowang
The strong polar quaternary ammoniums, acetylcholine (ACh), choline (Ch) and butyrobetaine (BB, (3-carboxypropyl)trimethylammonium), are believed playing important roles in liver metabolism. These metabolites are at low levels and are weakly retained on reversed-phase liquid chromatographic (RP-LC) columns. Several hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) methods have been reported to analyze these compounds from different samples. However, no application to human liver tissues has been published. In this study, HILIC-MS/MS method was developed to simultaneously determine these three metabolites in human liver tissues. They were simply extracted from tissue, separated on a HILIC column, and detected by tandem MS in the mode of multiple reaction monitoring (MRM). Further studies on the recovery and repeatability based on real samples indicated the method was accurate and reliable. This method was successfully applied to measure the levels of ACh, Ch and BB in 61 human liver tissue samples including normal, hepatocellular carcinoma (HCC) and matched non-cancerous liver tissues. By comparison of Ch and ACh contents in 29 HCC with their matched non-cancerous liver tissues, it was found that ACh content increased in 11/29 HCC cases and decreased in 13/29 cases. Furthermore, the ACh/Ch ratio increased in 16/29 HCC cases, while it decreased in 8/29 cases. These results strongly indicated that there exist different patterns of ACh content in cancer tissues among HCC patients, thus highlighting the understanding of ACh and its relevant signal pathways in hepatic carcinogenesis and HCC progression.
Comparative analysis of the liver tissue transcriptomes of Mongolian and Lanzhou fat-tailed sheep.
Cheng, X; Zhao, S G; Yue, Y; Liu, Z; Li, H W; Wu, J P
Research on gene regulation has been made possible with the help of RNA sequencing applications such as RNA-Seq technology for high-throughput sequencing platforms. Recent studies have explored the transcriptomes from different tissues of domestic animals using RNA-Seq technology, but little research has been done to study the transcriptomes of breeds of sheep having different adipose tissue deposition mechanisms, such as Mongolian and Lanzhou fat-tailed sheep. In this study, Mongolian and Lanzhou fat-tailed sheep were selected as experimental breeds, and six libraries (three libraries per breed) were constructed. A total of 286 Mb of high-quality reads was obtained, and three-quarters of the reads were mapped to the reference genome per library. In addition, there were 16,257, 16,186, 16,254, 16,827, 16,437, and 15,761 known reference genes in the six constructed libraries (LCL1, LCL2, LCL3, MCL1, MCL2, and MCL3, respectively). Seven genes were differentially expressed: four were upregulated and three were downregulated in liver tissue between the MCL and LCL groups; 65,303, 65,442, 63,426, 76,267, 69,853, and 57,439 potential cSNPs were detected in the six libraries, respectively, with the G/R substitution occurring most commonly. There were 24,239, 22,283, 22,457, 26,635, 27,093, and 18,700 alternate splicing (AS) events in the six libraries. Intron retention was the most common AS event, followed by alternative 3' splice sites. These results indicate that there are many differences in the liver transcriptomes of Mongolian and Lanzhou fat-tailed sheep breeds. Such results may provide fundamental information for further research on defining the sheep genome.
Similarities and Differences between Exome Sequences Found in a Variety of Tissues from the Same Individual
Gómez-Ramos, Alberto; Sanchez-Sanchez, Rafael; Muhaisen, Ashraf; Rábano, Alberto; Soriano, Eduardo; Avila, Jesús
DNA is the most stable nucleic acid and most important store of genetic information. DNA sequences are conserved in virtually all the cells of a multicellular organism. To analyze the sequences of various individuals with distinct pathological disorders, DNA is routinely isolated from blood, independently of the tissue that is the target of the disease. This approach has proven useful for the identification of familial diseases where mutations are present in parental germinal cells. With the capacity to compare DNA sequences from distinct tissues or cells, present technology can be used to study whether DNA sequences in tissues are invariant. Here we explored the presence of specific SNVs (Single Nucleotide Variations) in various tissues of the same individual. We tested for the presence of tissue-specific exonic SNVs, taking blood exome as a control. We analyzed the chromosomal location of these SNVs. The number of SNVs per chromosome was found not to depend on chromosome length, but mainly on the number of protein-coding genes per chromosome. Although similar but not identical patterns of chromosomal distribution of tissue-specific SNVs were found, clear differences were detected. This observation supports the notion that each tissue has a specific SNV exome signature. PMID:24984015
PI3K-Akt1 expression and its significance in liver tissues with chronic fluorosis.
Fan, Bin; Yu, Yanni; Zhang, Ying
This study was to explore the effect and significance of PI3K signal pathway on mechanism of liver injury in chronic fluorosis. We used 48 Sprague-Dawley rats which were randomly divided into 4 groups according to the body weight, 12 in each group, half of male and female. The control group was fed with the solid feed (the fluorine content was 1.5 mg/kg). The fluorosis animals were fed with the corn containing fluorine content of 17 mg/kg from the endemic fluorosis areas. Blocking agent LY294002 was injected in the blocking group and phosphate buffer solution was injected in the blocking control in the caudal vein with 10 mg/kg once every other day in the one week before the end of the experiment. The animals were drunk by tap water freely. The fluoride contents of urinary and skeletal were determined by the F-ion selective electrode method. The mRNA and protein expressions of PI3K, Akt1 in the liver tissues were determined by real-time polymerase chain reaction, and streptavidin-perosidase and Western blot, respectively. Results showed that fluoride contents of the urine and bone were increased in the fluorosis compared to those in the control. The expression of PI3K and Akt1 mRNA and proteins was significantly increased in fluorosis hepatocytes, and lower than that of the fluorosis in the blocking. The apoptosis and the intracellular calcium concentration were increased. Therefore, we conclude that PI3K-Akt signaling pathway may be one of the signaling pathways in the pathogenesis of liver injury caused by fluorosis.
PI3K-Akt1 expression and its significance in liver tissues with chronic fluorosis
Fan, Bin; Yu, Yanni; Zhang, Ying
This study was to explore the effect and significance of PI3K signal pathway on mechanism of liver injury in chronic fluorosis. We used 48 Sprague-Dawley rats which were randomly divided into 4 groups according to the body weight, 12 in each group, half of male and female. The control group was fed with the solid feed (the fluorine content was 1.5 mg/kg). The fluorosis animals were fed with the corn containing fluorine content of 17 mg/kg from the endemic fluorosis areas. Blocking agent LY294002 was injected in the blocking group and phosphate buffer solution was injected in the blocking control in the caudal vein with 10 mg/kg once every other day in the one week before the end of the experiment. The animals were drunk by tap water freely. The fluoride contents of urinary and skeletal were determined by the F-ion selective electrode method. The mRNA and protein expressions of PI3K, Akt1 in the liver tissues were determined by real-time polymerase chain reaction, and streptavidin-perosidase and Western blot, respectively. Results showed that fluoride contents of the urine and bone were increased in the fluorosis compared to those in the control. The expression of PI3K and Akt1 mRNA and proteins was significantly increased in fluorosis hepatocytes, and lower than that of the fluorosis in the blocking. The apoptosis and the intracellular calcium concentration were increased. Therefore, we conclude that PI3K-Akt signaling pathway may be one of the signaling pathways in the pathogenesis of liver injury caused by fluorosis. PMID:25973007
Mössbauer spectroscopic study of the forms of iron in normal human liver and spleen tissue
NASA Astrophysics Data System (ADS)
Chua-Anusorn, W.; Pierre, T. G. St.; Webb, J.; Macey, D. J.; Yansukon, P.; Pootrakul, P.
Mössbauer spectra of 12 normal human spleen and 12 normal human liver samples ( post mortem) from Australia and Thailand have been recorded at 78 K. The spectra show the presence of iron in the form of ferrihydrite, together with some deoxyhemoglobin and methemoglobin in some samples. The spectra were used in conjunction with elemental analysis to calculate the non-heme iron concentrations in the tissues. The mean non-heme iron concentration in the Thai livers was significantly less than that for the Australian samples. The goethite-like form of hemosiderin that has been observed in some pathological tissues was not detected.
Temperature distribution during RF ablation on ex vivo liver tissue: IR measurements and simulations
NASA Astrophysics Data System (ADS)
Macchi, Edoardo Gino; Gallati, Mario; Braschi, Giovanni; Cigada, Alfredo; Comolli, Lorenzo
Radiofrequency thermal ablation is the first therapeutic option for the minimally invasive treatment of liver tumors. This medical procedure employs the Joule heat produced by a RF electromagnetic field to kill tumor cells. The outcome of the procedure is strongly affected by the temperature distribution near the RF applicator, however the measurement of this distribution, even in ex vivo experiments, is not straightforward since most traditional local temperature measurement techniques are not well-suited, due to both electromagnetic interferences and the sensor heat sink effect. Given the importance of the temperature field knowledge, in this paper special care was devoted to its measurement employing both infrared thermal imaging and NTC thermistors. Several RF ablation tests on ex vivo porcine liver tissue were carried out measuring the space-time evolution of temperature during the procedure (with spatial resolution ≤1 mm) and producing useful data for the design and the calibration of a numerical model. Electro-thermal numerical simulations of the experimental tests were performed using a mathematical model suitable for the heating phase of the procedure (up to 95 °C). The simulations results allowed to check the physical consistency of the measured data and suggested that a constant thermal conductivity is satisfactory for modeling the temperature evolution during RF ablation.
Temperature distribution during RF ablation on ex vivo liver tissue: IR measurements and simulations
NASA Astrophysics Data System (ADS)
Macchi, Edoardo Gino; Gallati, Mario; Braschi, Giovanni; Cigada, Alfredo; Comolli, Lorenzo
Radiofrequency thermal ablation is the first therapeutic option for the minimally invasive treatment of liver tumors. This medical procedure employs the Joule heat produced by a RF electromagnetic field to kill tumor cells. The outcome of the procedure is strongly affected by the temperature distribution near the RF applicator, however the measurement of this distribution, even in ex vivo experiments, is not straightforward since most traditional local temperature measurement techniques are not well-suited, due to both electromagnetic interferences and the sensor heat sink effect. Given the importance of the temperature field knowledge, in this paper special care was devoted to its measurement employing both infrared thermal imaging and NTC thermistors. Several RF ablation tests on ex vivo porcine liver tissue were carried out measuring the space-time evolution of temperature during the procedure (with spatial resolution ≤1 mm) and producing useful data for the design and the calibration of a numerical model. Electro-thermal numerical simulations of the experimental tests were performed using a mathematical model suitable for the heating phase of the procedure (up to 95 °C). The simulations results allowed to check the physical consistency of the measured data and suggested that a constant thermal conductivity is satisfactory for modeling the temperature evolution during RF ablation.
Accumulation pattern of persistent organochlorine pesticides in liver tissues of various species of birds from India.
Dhananjayan, Venugopal
As part of a large study on assessing the impact of environmental contaminants in Indian avifauna, the presence of organochlorine pesticides (OCPs) in liver tissues of 16 species of birds collected from Ahmedabad, India during 2005-2007 was quantified. The higher concentrations of total organochlorine pesticides were detected in livers of shikra Accipiter badius (3.43 ± 0.99 μg/g wet wt) and the lower levels in white ibis Pseudibis papillosa (0.02 ± 0.01 μg/g wet wt). Marked differences in the concentrations of total OCPs occurred among species (p < 0.05). Concentrations of DDT and its metabolites, hexachlorocyclohexane (HCH) and isomers, dieldrin, and heptachlor epoxide were lower than the concentrations reported for various species of birds in India. Accumulation pattern of organochlorine pesticides in birds was, in general, in the order HCH > DDT > heptachlor epoxide > dieldrin. Among various pesticides analyzed, p,p'-DDE and β-HCH contributed maximum towards the total OCPs and study indicates the continuous use of lindane and DDT for agriculture and public health purpose, respectively. Although no serious threat is posed by any of the organochlorine pesticides detected in the present study species, continued monitoring is recommended.
Peripheral effects of the endocannabinoid system in energy homeostasis: adipose tissue, liver and skeletal muscle.
Silvestri, Cristoforo; Ligresti, Alessia; Di Marzo, Vincenzo
The endocannabinoid system (ECS) is composed of lipid signalling ligands, their G-protein coupled receptors and the enzymes involved in ligand generation and metabolism. Increasingly, the ECS is emerging as a critical agent of energy metabolism regulation through its ability to modulate caloric intake centrally as well as nutrient transport, cellular metabolism and energy storage peripherally. Visceral obesity has been associated with an upregulation of ECS activity in several systems and inhibition of the ECS, either pharmacologically or genetically, results in decreased energy intake and increased metabolic output. This review aims to summarize the recent advances that have been made regarding our understanding of the role the ECS plays in crucial peripheral systems pertaining to energy homeostasis: adipose tissues, the liver and skeletal muscle.
Multidetection of antibiotics in liver tissue by ultra-high-pressure-liquid-chromatography-tandem mass spectrometry.
Freitas, Andreia; Barbosa, Jorge; Ramos, Fernando
A multiresidue quantitative screening method covering 39 antibiotics from 7 different families by ultra-high-pressure-liquid-chromatography-tandem mass spectrometry (UHPLC-MS/MS) is described. Sulfonamides, trimethoprim, tetracyclines, macrolides, quinolones, penicillins and chloramphenicol are simultaneously detected in liver tissue. A simple sample treatment method consisting of extraction with a mixture of acetonitrile and ethylenediaminetetraacetic acid (EDTA) followed by solid-phase extraction (SPE) with a hydrophilic-lipophilic balanced (HLB) cartridge was developed. The methodology was validated, in accordance with Decision 2002/657/EC, by evaluating the following required parameters: decision limit (CCα), detection capability (CCβ), specificity, repeatability and reproducibility. The precision, in terms of the relative standard deviation, was under 22% for all of the compounds, and the recoveries were between 80% and 110%. The CCα and CCβ were determined according to the maximum residue limit (MRL) or the minimum required performance limit (MRPL), when established.
[Preparation of galactosylated hyaluronic acid/chitosan scaffold for liver tissue engineering].
Fan, Jinyong; Shang, Yi; Yang, Jun; Yuan, Yingjin
The purpose of this research is to construct a kind of 3D-Scaffold with galactose-carrying polysaccharide for improving the function of hepatocytes in vitro. Galactose moieties were covalently coupled with hyaluronic acid through ethylenediamine. Galactosylated hyaluronic acid/chitosan scaffolds were prepared by lyophilization. The characteristics of the scaffolds such as morphology, hydrophilicity, and mechanical properties were investigated. The results indicated that the porosity and the pore size of the scaffolds made in -20 degrees C were useful used for culturing hepatocytes. And, the incorporating of hyaluronic acid in chitosan network improved the hydrophilicity and mechanical properties of the scaffolds. Rat primary hepatocytes growing in the scaffolds observed by phase-contrast microscope showed the multicellular spheroid morphologies. Therefore, galactosylated hyaluronic acid/chitosan scaffolds could be used as a promising scaffold for liver tissue engineering.
Bioprinted 3D Primary Liver Tissues Allow Assessment of Organ-Level Response to Clinical Drug Induced Toxicity In Vitro
Funk, Juergen; Robbins, Justin B.; Crogan-Grundy, Candace; Presnell, Sharon C.; Singer, Thomas; Roth, Adrian B.
Modeling clinically relevant tissue responses using cell models poses a significant challenge for drug development, in particular for drug induced liver injury (DILI). This is mainly because existing liver models lack longevity and tissue-level complexity which limits their utility in predictive toxicology. In this study, we established and characterized novel bioprinted human liver tissue mimetics comprised of patient-derived hepatocytes and non-parenchymal cells in a defined architecture. Scaffold-free assembly of different cell types in an in vivo-relevant architecture allowed for histologic analysis that revealed distinct intercellular hepatocyte junctions, CD31+ endothelial networks, and desmin positive, smooth muscle actin negative quiescent stellates. Unlike what was seen in 2D hepatocyte cultures, the tissues maintained levels of ATP, Albumin as well as expression and drug-induced enzyme activity of Cytochrome P450s over 4 weeks in culture. To assess the ability of the 3D liver cultures to model tissue-level DILI, dose responses of Trovafloxacin, a drug whose hepatotoxic potential could not be assessed by standard pre-clinical models, were compared to the structurally related non-toxic drug Levofloxacin. Trovafloxacin induced significant, dose-dependent toxicity at clinically relevant doses (≤ 4uM). Interestingly, Trovafloxacin toxicity was observed without lipopolysaccharide stimulation and in the absence of resident macrophages in contrast to earlier reports. Together, these results demonstrate that 3D bioprinted liver tissues can both effectively model DILI and distinguish between highly related compounds with differential profile. Thus, the combination of patient-derived primary cells with bioprinting technology here for the first time demonstrates superior performance in terms of mimicking human drug response in a known target organ at the tissue level. PMID:27387377
Remodeling the Integration of Lipid Metabolism Between Liver and Adipose Tissue by Dietary Methionine Restriction in Rats
Hasek, Barbara E.; Boudreau, Anik; Shin, Jeho; Feng, Daorong; Hulver, Matthew; Van, Nancy T.; Laque, Amanda; Stewart, Laura K.; Stone, Kirsten P.; Wanders, Desiree; Ghosh, Sujoy; Pessin, Jeffrey E.; Gettys, Thomas W.
Dietary methionine restriction (MR) produces an integrated series of biochemical and physiological responses that improve biomarkers of metabolic health, limit fat accretion, and enhance insulin sensitivity. Using transcriptional profiling to guide tissue-specific evaluations of molecular responses to MR, we report that liver and adipose tissue are the primary targets of a transcriptional program that remodeled lipid metabolism in each tissue. The MR diet produced a coordinated downregulation of lipogenic genes in the liver, resulting in a corresponding reduction in the capacity of the liver to synthesize and export lipid. In contrast, the transcriptional response in white adipose tissue (WAT) involved a depot-specific induction of lipogenic and oxidative genes and a commensurate increase in capacity to synthesize and oxidize fatty acids. These responses were accompanied by a significant change in adipocyte morphology, with the MR diet reducing cell size and increasing mitochondrial density across all depots. The coordinated transcriptional remodeling of lipid metabolism between liver and WAT by dietary MR produced an overall reduction in circulating and tissue lipids and provides a potential mechanism for the increase in metabolic flexibility and enhanced insulin sensitivity produced by the diet. PMID:23801581
Saikokeishito Extract Exerts a Therapeutic Effect on α-Naphthylisothiocyanate-Induced Liver Injury in Rats through Attenuation of Enhanced Neutrophil Infiltration and Oxidative Stress in the Liver Tissue
Ohta, Yoshiji; Kongo-Nishimura, Mutsumi; Hayashi, Takahiro; Kitagawa, Akira; Matsura, Tatsuya; Yamada, Kazuo
We examined whether Saikokeishito extract (TJ-10), a traditional Japanese herbal medicine, exerts a therapeutic effect on α-naphthylisothiocyanate (ANIT)-induced liver injury in rats through attenuation of enhanced neutrophil infiltration and oxidative stress in the liver tissue. In rats treated once with ANIT (75 mg/kg, i.p.), liver injury with cholestasis occurred 24 h after treatment and progressed at 48 h. When ANIT-treated rats orally received TJ-10 (0.26, 1.3 or 2.6 g/kg) at 24 h after the treatment, progressive liver injury with cholestasis was significantly attenuated at 48 h after the treatment at the dose of 1.3 or 2.6 g/kg. At 24 h after ANIT treatment, increases in hepatic lipid peroxide and reduced glutathione contents and myeloperoxidase activity occurred with decreases in hepatic superoxide dismutase and glutathione reductase activities. At 48 h after ANIT treatment, these changes except for reduced glutathione were enhanced with decreases in catalase, Se-glutathione peroxidase, and glucose-6-phosphate dehydrogenase activities. TJ-10 (1.3 or 2.6 g/kg) post-administered to ANIT-treated rats attenuated these changes found at 48 h after the treatment significantly. These results indicate that TJ-10 exerts a therapeutic effect on ANIT-induced liver injury in rats possibly through attenuation of enhanced neutrophil infiltration and oxidative stress in the liver tissue. PMID:18437211
Perfluoroalkyl sulfonates and carboxylic acids in liver, muscle and adipose tissues of black-footed albatross (Phoebastria nigripes) from Midway Island, North Pacific Ocean.
Chu, Shaogang; Wang, Jun; Leong, Gladys; Woodward, Lee Ann; Letcher, Robert J; Li, Qing X
The Great Pacific Garbage Patch (GPGP) is a gyre of marine plastic debris in the North Pacific Ocean, and nearby is Midway Atoll which is a focal point for ecological damage. This study investigated 13 C4-C16 perfluorinated carboxylic acids (PFCAs), four (C4, C6, C8 and C10) perfluorinated sulfonates and perfluoro-4-ethylcyclohexane sulfonate [collectively perfluoroalkyl acids (PFAAs)] in black-footed albatross tissues (collected in 2011) from Midway Atoll. Of the 18 PFCAs and PFSAs monitored, most were detectable in the liver, muscle and adipose tissues. The concentrations of PFCAs and PFSAs were higher than those in most seabirds from the arctic environment, but lower than those in most of fish-eating water birds collected in the U.S. mainland. The concentrations of the PFAAs in the albatross livers were 7-fold higher than those in Laysan albatross liver samples from the same location reported in 1994. The concentration ranges of PFOS were 22.91-70.48, 3.01-6.59 and 0.53-8.35 ng g(-1) wet weight (ww), respectively, in the liver, muscle and adipose. In the liver samples PFOS was dominant, followed by longer chain PFUdA (8.04-18.70 ng g(-1) ww), PFTrDA, and then PFNA, PFDA and PFDoA. Short chain PFBA, PFPeA, PFBS and PFODA were below limit of quantification. C8-C13 PFCAs showed much higher composition compared to those found in other wildlife where PFOS typically predominated. The concentrations of PFUdA in all 8 individual albatross muscle samples were even higher than those of PFOS. This phenomenon may be attributable to GPGP as a pollution source as well as PFAA physicochemical properties.
Perfluoroalkyl Sulfonates and Carboxylic Acids in Liver, Muscle and Adipose Tissues of Black-Footed Albatross (Phoebastria nigripes) from Midway Island, North Pacific Ocean
Chu, Shaogang; Wang, Jun; Leong, Gladys; Woodward, Lee Ann; Letcher, Robert J.; Li, Qing X.
The Great Pacific Garbage Patch (GPGP) is a gyre of marine plastic debris in the North Pacific Ocean, and nearby is Midway Atoll which is a focal point for ecological damage. This study investigated 13 C4-C16 perfluorinated carboxylic acids (PFCAs), four (C4, C6, C8 and C10) perfluorinated sulfonates and perfluoro-4-ethylcyclohexane sulfonate [collectively perfluoroalkyl acids (PFAAs)] in black-footed albatross tissues (collected in 2011) from Midway Atoll. Of the 18 PFCAs and PFSAs monitored, most were detectable in the liver, muscle and adipose tissues. The concentrations of PFCAs and PFSAs were higher than those in most seabirds from the arctic environment, but lower than those in most of fish-eating water birds collected in the U.S. mainland. The concentrations of the PFAAs in the albatross livers were 7-fold higher than those in Laysan albatross liver samples from the same location reported in 1994. The concentration ranges of PFOS were 22.91-70.48, 3.01-6.59 and 0.53-8.35 ng g-1 wet weight (ww), respectively, in the liver, muscle and adipose. In the liver samples PFOS was dominant, followed by longer chain PFUdA (8.04-18.70 ng g-1 ww), PFTrDA, and then PFNA, PFDA and PFDoA. Short chain PFBA, PFPeA, PFBS and C16 PFODA were below limit of quantification. C8-C13 PFCAs showed much higher composition compared to those found in other wildlife where PFOS typically predominated. The concentrations of PFUdA in all 8 individual albatross muscle samples were even higher than those of PFOS. This phenomenon may be attributable to GPGP as a pollution source as well as PFAA physicochemical properties. PMID:26037817
Long-term Coexposure to Hexavalent Chromium and B[a]P Causes Tissue-Specific Differential Biological Effects in Liver and Gastrointestinal Tract of Mice
Sánchez-Martín, Francisco Javier; Fan, Yunxia; Carreira, Vinicius; Ovesen, Jerald L.; Vonhandorf, Andrew; Xia, Ying; Puga, Alvaro
Complex mixtures of environmental agents often cause mixture-specific health effects that cannot be accounted for by a single mechanism. To study the biological effects of exposure to a mixture of chromium-VI and benzo[a]pyrene (B[a]P), often found together in the environment, we exposed mice for 60 days to 0, 55, 550, or 5500 ppb Cr(VI) in drinking water followed by 90 days of coexposure to B[a]P at 0, 1.25, 12.5, or 125 mg/kg/day and examined liver and gastrointestinal (GI) tract for exposure effects. In the liver, the mixture caused more significant histopathology than expected from the sum of effects of the individual components, while in the GI tract, Cr(VI) alone caused significant enterocyte hypertrophy and increases in cell proliferation and DNA damage that were also observed in mice coexposed to B[a]P. Expression of genes involved in drug metabolism, tumor suppression, oxidative stress, and inflammation was altered in mixed exposures relative to control and to singly exposed mice. Drug metabolism and oxidative stress genes were upregulated and tumor suppressor and inflammation genes downregulated in the proximal GI tract, whereas most markers were upregulated in the distal GI tract and downregulated in the liver. Oral exposure to Cr(VI) and B[a]P mixtures appears to have tissue-specific differential consequences in liver and GI tract that cannot be predicted from the effects of each individual toxicant. Tissue specificity may be particularly critical in cases of extended exposure to mixtures of these agents, as may happen in the occupational setting or in areas where drinking water contains elevated levels of Cr(VI). PMID:25820237
Long-term Coexposure to Hexavalent Chromium and B[a]P Causes Tissue-Specific Differential Biological Effects in Liver and Gastrointestinal Tract of Mice.
Sánchez-Martín, Francisco Javier; Fan, Yunxia; Carreira, Vinicius; Ovesen, Jerald L; Vonhandorf, Andrew; Xia, Ying; Puga, Alvaro
Complex mixtures of environmental agents often cause mixture-specific health effects that cannot be accounted for by a single mechanism. To study the biological effects of exposure to a mixture of chromium-VI and benzo[a]pyrene (B[a]P), often found together in the environment, we exposed mice for 60 days to 0, 55, 550, or 5500 ppb Cr(VI) in drinking water followed by 90 days of coexposure to B[a]P at 0, 1.25, 12.5, or 125 mg/kg/day and examined liver and gastrointestinal (GI) tract for exposure effects. In the liver, the mixture caused more significant histopathology than expected from the sum of effects of the individual components, while in the GI tract, Cr(VI) alone caused significant enterocyte hypertrophy and increases in cell proliferation and DNA damage that were also observed in mice coexposed to B[a]P. Expression of genes involved in drug metabolism, tumor suppression, oxidative stress, and inflammation was altered in mixed exposures relative to control and to singly exposed mice. Drug metabolism and oxidative stress genes were upregulated and tumor suppressor and inflammation genes downregulated in the proximal GI tract, whereas most markers were upregulated in the distal GI tract and downregulated in the liver. Oral exposure to Cr(VI) and B[a]P mixtures appears to have tissue-specific differential consequences in liver and GI tract that cannot be predicted from the effects of each individual toxicant. Tissue specificity may be particularly critical in cases of extended exposure to mixtures of these agents, as may happen in the occupational setting or in areas where drinking water contains elevated levels of Cr(VI).
Liver extracellular matrix providing dual functions of two-dimensional substrate coating and three-dimensional injectable hydrogel platform for liver tissue engineering.
Lee, Jung Seung; Shin, Jisoo; Park, Hae-Min; Kim, Yun-Gon; Kim, Byung-Gee; Oh, Jong-Won; Cho, Seung-Woo
Decellularization of tissues or organs can provide an efficient strategy for preparing functional scaffolds for tissue engineering. Microstructures of native extracellular matrices and their biochemical compositions can be retained in the decellularized matrices, providing tissue-specific microenvironments for efficient tissue regeneration. Here, we report the versatility of liver extracellular matrix (LEM) that can be used for two-dimensional (2D) coating and three-dimensional (3D) hydrogel platforms for culture and transplantation of primary hepatocytes. Collagen type I (Col I) has typically been used for hepatocyte culture and transplantation. In this study, LEM was compared with Col I in terms of biophysical and mechanical characteristics and biological performance for enhancing cell viability, differentiation, and hepatic functions. Surface properties of LEM coating and mechanical properties and gelation kinetics of LEM hydrogel could be manipulated by adjusting the LEM concentration. In addition, LEM hydrogel exhibited improved elastic properties, rapid gelation, and volume maintenance compared to Col I hydrogel. LEM coating significantly improved hepatocyte functions such as albumin secretion and urea synthesis. More interestingly, LEM coating upregulated hepatic gene expression of human adipose-derived stem cells, indicating enhanced hepatic differentiation of these stem cells. The viability and hepatic functions of primary hepatocytes were also significantly improved in LEM hydrogel compared to Col I hydrogel both in vitro and in vivo. Albumin and hepatocyte transcription factor expression was upregulated in hepatocytes transplanted in LEM hydrogels. In conclusion, LEM can provide functional biomaterial platforms for diverse applications in liver tissue engineering by promoting survival and maturation of hepatocytes and hepatic commitment of stem cells. This study demonstrates the feasibility of decellularized matrix for both 2D coating and 3D hydrogel in
Nonlinear microscopy of lipid storage and fibrosis in muscle and liver tissues of mice fed high-fat diets
NASA Astrophysics Data System (ADS)
Brackmann, Christian; Gabrielsson, Britt; Svedberg, Fredrik; Holmäng, Agneta; Sandberg, Ann-Sofie; Enejder, Annika
Hallmarks of high-fat Western diet intake, such as excessive lipid accumulation in skeletal muscle and liver as well as liver fibrosis, are investigated in tissues from mice using nonlinear microscopy, second harmonic generation (SHG), and coherent anti-Stokes Raman scattering (CARS), supported by conventional analysis methods. Two aspects are presented; intake of standard chow versus Western diet, and a comparison between two high-fat Western diets of different polyunsaturated lipid content. CARS microscopy images of intramyocellular lipid droplets in muscle tissue show an increased amount for Western diet compared to standard diet samples. Even stronger diet impact is found for liver samples, where combined CARS and SHG microscopy visualize clear differences in lipid content and collagen fiber development, the latter indicating nonalcoholic fatty liver disease (NAFLD) and steatohepatitis induced at a relatively early stage for Western diet. Characteristic for NAFLD, the fibrous tissue-containing lipids accumulate in larger structures. This is also observed in CARS images of liver samples from two Western-type diets of different polyunsaturated lipid contents. In summary, nonlinear microscopy has strong potential (further promoted by technical advances toward clinical use) for detection and characterization of steatohepatitis already in its early stages.
Preparation, characterization, and evaluation of genipin crosslinked chitosan/gelatin three-dimensional scaffolds for liver tissue engineering applications.
Zhang, Yi; Wang, Qiang-Song; Yan, Kuo; Qi, Yun; Wang, Gui-Fang; Cui, Yuan-Lu
In liver tissue engineering, scaffolds with porous structure desgined to supply nutrient and oxygen exchange for three-dimensional (3-D) cells culture, and maintain liver functions. Meanwhile, genipin, as a natural crosslinker, is widely used to crosslink biomaterials in tissue engineering, with lower cytotoxicity and better biocompatibility. In present study, chitosan/gelatin 3-D scaffolds crosslinked by genipin, glutaraldehyde or 1-(3-dimethylaminopropyl)-3-ethyl-carbodimide hydrochloride (EDC) were prepared and characterized by Fourier-transform infrared (FT-IR) and scanning electron microscopy (SEM). The biocompatibility of chitosan/gelatin scaffolds corsslinked with different crosslinkers was investigated by cell viability, morphology and liver specific functions. The result showed that the 1% and 2% genipin crosslinked chitosan/gelatin scaffolds possess ideal porosity. The genipin crosslinked 3-D scaffolds possessed the best biocompatibility than that of the others, and maintained liver specific functions when HepG2 cells seeded on scaffolds. The cellular morphology of HepG2 cells seeded on scaffolds showed that cells could penetrate into the scaffolds and proliferate significantly. Therefore, genipin crosslinked chitosan/gelatin scaffolds could be a promising biomaterial used in liver tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1863-1870, 2016.
Cryo-chemical decellularization of the whole liver for mesenchymal stem cells-based functional hepatic tissue engineering.
Jiang, Wei-Cheng; Cheng, Yu-Hao; Yen, Meng-Hua; Chang, Yin; Yang, Vincent W; Lee, Oscar K
Liver transplantation is the ultimate treatment for severe hepatic failure to date. However, the limited supply of donor organs has severely hampered this treatment. So far, great potentials of using mesenchymal stem cells (MSCs) to replenish the hepatic cell population have been shown; nevertheless, there still is a lack of an optimal three-dimensional scaffold for generation of well-transplantable hepatic tissues. In this study, we utilized a cryo-chemical decellularization method which combines physical and chemical approach to generate acellular liver scaffolds (ALS) from the whole liver. The produced ALS provides a biomimetic three-dimensional environment to support hepatic differentiation of MSCs, evidenced by expression of hepatic-associated genes and marker protein, glycogen storage, albumin secretion, and urea production. It is also found that hepatic differentiation of MSCs within the ALS is much more efficient than two-dimensional culture in vitro. Importantly, the hepatic-like tissues (HLT) generated by repopulating ALS with MSCs are able to act as functional grafts and rescue lethal hepatic failure after transplantation in vivo. In summary, the cryo-chemical method used in this study is suitable for decellularization of liver and create acellular scaffolds that can support hepatic differentiation of MSCs and be used to fabricate functional tissue-engineered liver constructs.
Circulating tissue antigens. I. Tissue antigens in serum of patients with diseases involving injury of the liver and of other organs
Espinosa, E.
Circulating tissue antigens (CTA) were investigated in 143 patients with disorders involving injury of the liver and of other organs and in forty-eight normal subjects by immunodiffusion techniques using rabbit anti-human liver serum containing antibodies to a liver-specific antigen and to tissue antigens of wide organ distribution. Analysis of serum samples by double immunodiffusion showed up to three CTA in the following cases: fifteen out of eighteen, viral hepatitis (VH), two out of thirteen, other infectious diseases, two out of ten, alcoholic cirrhosis, seven out of twenty-one, congestive heart failure (CHF), four out of fourteen, myocardial infarction, ten out of twenty-one, trauma, two out of thirteen, carcinoma and three out of thirty-three, miscellaneous diseases. Forty-eight normal subjects showed no CTA. Immunoelectrophoresis of most of the positive cases showed two to three CTA, while a few cases showed four to six. Absorption tests with organ extracts demonstrated that in most patients, CTA were substances shared by several organs. However, in two cases of VH, in two cases of CHF with liver necrosis and in two cases of trauma to the liver, one of the CTA was shown to be liver specific. The CTA were susceptible to digestion by pronase and were found to be relatively thermolabile. Positive sera showed higher glutamic oxaloacetic transaminase and lactic dehydrogenase activities than the negative sera. These preliminary data suggest that further investigation on CTA in disease involving tissue injury and necrosis may be rewarding. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5 PMID:4219874
Lassa virus infection in experimentally infected marmosets: liver pathology and immunophenotypic alterations in target tissues.
Carrion, Ricardo; Brasky, Kathleen; Mansfield, Keith; Johnson, Curtis; Gonzales, Monica; Ticer, Anysha; Lukashevich, Igor; Tardif, Suzette; Patterson, Jean
Lassa virus causes thousands of deaths annually in western Africa and is considered a potential biological weapon. In an attempt to develop a small nonhuman primate model of Lassa fever, common marmosets were subcutaneously inoculated with Lassa virus strain Josiah. This inoculation resulted in a systemic disease with clinical and morphological features mirroring those in fatal human Lassa infection: fever, weight loss, high viremia and viral RNA load in tissues, elevated liver enzymes, and severe morbidity between days 15 and 20. The most prominent histopathology findings included multifocal hepatic necrosis with mild inflammation and hepatocyte proliferation, lymphoid depletion, and interstitial nephritis. Cellular aggregates in regions of hepatocellular necrosis were largely composed of HAM56-positive macrophages, devoid of CD3-positive and CD20-positive cells, and characterized by marked reductions in the intensity of HLA-DP, DQ, DR staining. A marked reduction in the major histocompatibility complex class II expression was also observed in the lymph nodes. Immunophenotypic alterations in spleen included reductions in overall numbers of CD20-positive and CD3-positive cells and the disruption of lymphoid follicular architecture. These findings identify the common marmoset as an appropriate model of human Lassa fever and present the first experimental evidence that replication of Lassa virus in tissues is associated with alterations that would be expected to impair adaptive immunity.
Visible to near-infrared refractive properties of freshly-excised human-liver tissues: marking hepatic malignancies
NASA Astrophysics Data System (ADS)
Giannios, Panagiotis; Toutouzas, Konstantinos G.; Matiatou, Maria; Stasinos, Konstantinos; Konstadoulakis, Manousos M.; Zografos, George C.; Moutzouris, Konstantinos
The refractive index is an optical constant that plays a significant role in the description of light-matter interactions. When it comes to biological media, refraction is understudied despite recent advances in the field of bio-optics. In the present article, we report on the measurement of the refractive properties of freshly excised healthy and cancerous human liver samples, by use of a prism-coupling technique covering the visible and near-infrared spectral range. Novel data on the wavelength-dependent complex refractive index of human liver tissues are presented. The magnitude of the real and imaginary part of the refractive index is correlated with hepatic pathology. Notably, the real index contrast is pointed out as a marker of discrimination between normal liver tissue and hepatic metastases. In view of the current progress in optical biosensor technologies, our findings may be exploited for the development of novel surgical and endoscopic tools.
Time course and mechanism of oxidative stress and tissue damage in rat liver subjected to in vivo ischemia-reperfusion.
González-Flecha, B; Cutrin, J C; Boveris, A
The time course of oxidative stress and tissue damage in zonal liver ischemia-reperfusion in rat liver in vivo was evaluated. After 180 min of ischemia, surface chemiluminescence decreased to zero, state 3 mitochondrial respiration decreased by 70-80%, and xanthine oxidase activity increased by 26% without change in the water content and in the activities of superoxide dismutase, catalase, and glutathione peroxidase. After reperfusion, marked increases in oxyradical production and tissue damage were detected. Mitochondrial oxygen uptake in state 3 and respiratory control as well as the activities of superoxide dismutase, catalase, and glutathione peroxidase and the level of nonenzymatic antioxidants (evaluated by the hydroperoxide-initiated chemiluminescence) were decreased. The severity of the post-reperfusion changes correlated with the time of ischemia. Morphologically, hepatocytes appeared swollen with zonal cord disarrangement which ranged from mild to severe for the tissue reperfused after 60-180 min of ischemia. Neutrophil infiltration was observed after 180 min of ischemia and 30 min of reperfusion. Mitochondria appear as the major source of hydrogen peroxide in control and in reperfused liver, as indicated by the almost complete inhibition of hydrogen peroxide production exerted by the uncoupler carbonylcyanide p-(trifluoromethoxy) phenylhydrazone. Additionally, inhibition of mitochondrial electron transfer by antimycin in liver slices reproduced the inhibition of state 3 mitochondrial respiration and the increase in hydrogen peroxide steady-state concentration found in reperfused liver. Increased rates of oxyradical production by inhibited mitochondria appear as the initial cause of oxidative stress and liver damage during early reperfusion in rat liver. Images PMID:8432855
Monitoring of temperature increase and tissue vaporization during laser interstitial thermotherapy of ex vivo swine liver by computed tomography.
Schena, E; Saccomandi, P; Giurazza, F; Del Vescovo, R; Mortato, L; Martino, M; Panzera, F; Di Matteo, F M; Beomonte Zobel, B; Silvestri, S
Laser interstitial thermotherapy (LITT) is a minimally invasive technique used to thermally destroy tumour cells. Being based on hyperthermia, LITT outcome depends on the temperature distribution inside the tissue. Recently, CT scan thermometry, based on the dependence of the CT number (HU) on tissue temperature (T) has been introduced during LITT; it is an attractive approach to monitor T because it overcomes the concerns related to the invasiveness. We performed LITT on nine ex vivo swine livers at three different laser powers, (P=1.5 W, P=3 W, P=5 W) with a constant treatment time t=200 s; HU is averaged on two ellipsoidal regions of interest (ROI) of 0.2 cm2, placed at two distances from the applicator (d=3.6 mm and d=8.7 mm); a reference ROI was placed away from the applicator (d=30 mm). The aim of this study is twofold: 1) to evaluate the effect of the T increase in terms of HU variation in ex vivo swine livers undergoing LITT; and 2) to estimate the P value for tissue vaporization. To the best of our knowledge, this is the first study focused on the HU variation in swine livers undergoing LITT at different P. The reported findings could be useful to assess the effect of LITT on the liver in terms of both T changes and tissue vaporization, with the aim to obtain an effective therapy.
Theoretical and observational analysis of individual ionizing particle effects in biological tissue
Nelson, A.C.
The microstructural damage to living tissue caused by heavy ion radiation was studied. Preliminary tests on rat corneal tissue, rat cerebellar tissue grown in culture, and rat retinal tissue indicated that the best assay for heavy ion damage is the rat cornea. The corneal tissue of the living rat was exposed to beams of carbon at 474 MeV/amu, neon at 8.5 MeV/amu, argon at 8.5 MeV/amu, silicon at 530 MeV/amu, iron at 500 MeV/amu, and iron at 600 MeV/amu. X-rays were also used on corneas to compare with the heavy ion irradiated corneas. Scanning electron microscopy revealed lesions with circular symmetry on the external plasma membranes of corneal epithelium which were irradiated with heavy ions, but similar lesions were not observed on the plasma membranes of x-ray irradiated or non-irradiated control samples. These data verify the special way in which heavy ions interact with matter: each ion interacts coulombically with electrons all along its trajectory to generate a track. The dose from heavy ion radiation is not distributed homogeneously on a tissue microstructural scale but is concentrated along the individual particle track. Even along a single particle track the dose is discontinuous except at the Bragg peak when the LET is maximum. Micrographs of heavy-ion-irradiated corneas demonstrated two significant correlations with the heavy ion beam: (1) the number of plasma membrane lesions per unit area was correlated with the particle fluence, and (2) the diameter of the lesions were linearly related to the energy loss or LET of the individual particle. These observations corroborate what has already been suggested theoretically about heavy ion tracks and what has been shown experimentally. But the new data indicate that particle tracks occur in biological tissues as well, and that a single heavy ion is responsible for each membrane lesion. (ERB)
Autologous adipose tissue-derived mesenchymal stem cells are involved in rat liver regeneration following repeat partial hepatectomy
Adipose tissue-derived mesenchymal stem cells (ADSCs) have been considered to be attractive and readily available adult mesenchymal stem cells, and they are becoming increasingly popular for use in regenerative cell therapy, as they are readily accessible through minimally invasive techniques. The present study investigated whether autologous ADSC transplantation promoted liver regeneration following a repeat partial hepatectomy in rats. The rats were divided into three groups as follows: 70% partial hepatectomy (PH) group; repeat PH (R-PH) group and R-PH/ADSC group, subjected to R-PH and treated with autologous ADSCs via portal vein injection. In each group, the rats were sacrificed at different time points postoperatively in order to evaluate the changes in liver function and to estimate the liver regenerative response. The expression of proliferating cell nuclear antigen (PCNA) labeling index in the liver was measured using immunohistochemistry. The expression levels of hepatocyte growth factor (HGF) mRNA were measured using reverse transcription polymerase chain reaction. The results showed that regeneration of the remaining liver following R-PH was significantly promoted by ADSC transplantation, as shown by a significant increase in liver to body weight ratio and the PCNA labeling index at 24 h post-hepatectomy. Additionally, ADSC transplantation markedly inhibited the elevation of serum levels of alanine aminotransferase, aspartate aminotransferase and total bilirubin, increased HGF content and also attenuated hepatic vacuolar degeneration 24 h postoperatively. Furthermore, the liver was found to almost fully recover from hepatocellular damage due to hepatectomy among the three groups at 168 h postoperatively. These results indicated that autologous ADSC transplantation enhanced the regenerative capacity of the remnant liver tissues in the early phase following R-PH. PMID:26783183
Tissue-specific bioaccumulation of human and veterinary antibiotics in bile, plasma, liver and muscle tissues of wild fish from a highly urbanized region.
Zhao, Jian-Liang; Liu, You-Sheng; Liu, Wang-Rong; Jiang, Yu-Xia; Su, Hao-Chang; Zhang, Qian-Qian; Chen, Xiao-Wen; Yang, Yuan-Yuan; Chen, Jun; Liu, Shuang-Shuang; Pan, Chang-Gui; Huang, Guo-Yong; Ying, Guang-Guo
We investigated the bioaccumulation of antibiotics in bile, plasma, liver and muscle tissues of wild fish from four rivers in the Pearl River Delta region. In total, 12 antibiotics were present in at least one type of fish tissues from nine wild fish species in the four rivers. The mean values of log bioaccumulation factors (log BAFs) for the detected antibiotics in fish bile, plasma, liver, and muscle tissues were at the range of 2.06-4.08, 1.85-3.47, 1.41-3.51, and 0.48-2.70, respectively. As the digestion tissues, fish bile, plasma, and liver showed strong bioaccumulation ability for some antibiotics, indicating a different bioaccumulation pattern from hydrophobic organic contaminants. Human health risk assessment based on potential fish consumption indicates that these antibiotics do not appear to pose an appreciable risk to human health. To the best of our knowledge, this is first report of bioaccumulation patterns of antibiotics in wild fish bile and plasma.
Comparative Analysis of the Relationship between Trichloroethylene Metabolism and Tissue-Specific Toxicity among Inbred Mouse Strains: Liver Effects
Yoo, Hong Sik; Bradford, Blair U.; Kosyk, Oksana; Shymonyak, Svitlana; Uehara, Takeki; Collins, Leonard B.; Bodnar, Wanda M.; Ball, Louise M.; Gold, Avram; Rusyn, Ivan
Trichloroethylene (TCE) is a widely used organic solvent. Although TCE is classified as carcinogenic to humans, substantial gaps remain in our understanding of inter-individual variability in TCE metabolism and toxicity, especially in the liver. We tested a hypothesis that amounts of oxidative metabolites of TCE in mouse liver are associated with liver-specific toxicity. Oral dosing with TCE was conducted in sub-acute (600 mg/kg/d; 5 days; 7 inbred mouse strains) and sub-chronic (100 or 400 mg/kg/d; 1, 2, or 4 weeks; 2 inbred mouse strains) designs. We evaluated the quantitative relationship between strain-, dose-, and time-dependent formation of TCE metabolites from cytochrome P450-mediated oxidation [trichloroacetic acid (TCA), dichloroacetic acid (DCA), and trichloroethanol] and glutathione conjugation [S-(1,2-dichlorovinyl)-L-cysteine and S-(1,2-dichlorovinyl)glutathione] in serum and liver, and various liver toxicity phenotypes. In sub-acute study, inter-strain variability in TCE metabolite amounts was observed in serum and liver. No induction of Cyp2e1 protein levels in liver was detected. Serum and liver levels of TCA and DCA were correlated with increased transcription of peroxisome proliferator-marker genes Cyp4a10 and Acox1, but not with degree of induction in hepatocellular proliferation. In sub-chronic study, serum and liver levels of oxidative metabolites gradually decreased over time despite continuous dosing. Liver protein levels of Cyp2e1, Adh and Aldh2 were unaffected by treatment with TCE. While the magnitude of induction of peroxisome proliferator-marker genes also declined, hepatocellular proliferation increased. This study offers a unique opportunity to provide a scientific data-driven rationale for some of the major assumptions in human health assessment of TCE. PMID:25424544
Insulin Signaling in Liver and Adipose Tissues in Periparturient Dairy Cows Supplemented with Dietary Nicotinic Acid
Kinoshita, Asako; Kenéz, Ákos; Locher, Lena; Meyer, Ulrich; Dänicke, Sven; Rehage, Jürgen; Huber, Korinna
The glucose homeostasis in dairy cattle is very well controlled, in line with the metabolic adaptation during the periparturient period. Former studies showed that nicotinic acid (NA) lowered plasma non-esterified fatty acids (NEFA) concentrations and increased insulin sensitivity in dairy cows. Thus, the purpose of this study was to investigate whether the expression of proteins involved in hepatic and adipose insulin signaling and protein expression of hepatic glucose transporter 2 (GLUT2) were affected by dietary NA and dietary concentrate intake in periparturient dairy cows. Twenty pluriparous German Holstein cows were fed with the same diet from about 21 days before the expected calving date (d-21) to calving. After calving, cows were randomly assigned in 4 groups and fed with diets different in concentrate proportion ("HC" with 60:40% or "LC" with 30:70% concentrate-to-roughage ratio) and supplemented with NA (24 g/day) (NA) or without (CON) until d21. Biopsy samples were taken from the liver, subcutaneous (SCAT) and retroperitoneal (RPAT) adipose tissues at d-21 and d21. Protein expression of insulin signaling molecules (insulin receptor (INSR), phosphatidylinositol-3-kinase (PI3K), protein kinase Cζ (PKCζ)) and hepatic GLUT2 was measured by Western Blotting. The ratio of protein expression at d21/at d-21 was calculated and statistically evaluated for the effects of time and diet. Cows in HC had significantly higher dietary energy intake than cows in LC. In RPAT a decrease in PI3K and PKCζ expression was found in all groups, irrespectively of diet. In the liver, the GLUT2 expression was significantly lower in cows in NA compared with cows in CON. In conclusion, insulin signaling might be decreased in RPAT over time without any effect of diet. NA was able to modulate hepatic GLUT2 expression, but its physiological role is unclear. PMID:26766039
Tissue contaminants and associated transcriptional response in trout liver from high elevation lakes of Washington
Moran, P.W.; Aluru, N.; Black, R.W.; Vijayan, M.M.
The consistent cold temperatures and large amount of precipitation in the Olympic and Cascade ranges of Washington State are thought to enhance atmospheric deposition of contaminants. However, little is known about contaminant levels in organisms residing in these remote high elevation lakes. We measured total mercury and 28 organochlorine compounds in trout collected from 14 remote lakes in the Olympic, Mt. Rainer, and North Cascades National Parks. Mercury was detected in trout from all lakes sampled (15 to 262 ??g/kg ww), while two organochlorines, total polychlorinated biphenyls (tPCB) and dichlorodiphenyldichloroethylene (DDE), were also detected in these fish tissues (<25 ??g/kg ww). In sediments, organochlorine levels were below detection, while median total and methyl mercury were 30.4 and 0.34 ??g/ kg dry weight (ww), respectively. Using fish from two lakes, representing different contaminant loading levels (Wilcox lake: high; Skymo lake: low), we examined transcriptional response in the liver using a custom-made low-density targeted rainbow trout cDNA microarray. We detected significant differences in liver transcriptional response, including significant changes in metabolic, endocrine, and immune-related genes, in fish collected from Wilcox Lake compared to Skymo Lake. Overall, our results suggest that local urban areas contribute to the observed contaminant patterns in these high elevation lakes, while the transcriptional changes point to a biological response associated with exposure to these contaminants in fish. Specifically, the gene expression pattern leads us to hypothesize a role for mercury in disrupting the metabolic and reproductive pathways in fish from high elevation lakes in western Washington. ?? 2007 American Chemical Society.
Tissue inhibitor of matrix metalloproteinase-1 expression in colorectal cancer liver metastases is associated with vascular structures.
Illemann, Martin; Eefsen, Rikke Helene Løvendahl; Bird, Nigel Charles; Majeed, Ali; Osterlind, Kell; Laerum, Ole Didrik; Alpízar-Alpízar, Warner; Lund, Ida Katrine; Høyer-Hansen, Gunilla
Metastatic growth by colorectal cancer cells in the liver requires the ability of the cancer cells to interact with the new microenvironment. This interaction results in three histological growth patterns of liver metastases: desmoplastic, pushing, and replacement. In primary colorectal cancer several proteases, involved in the degradation of extracellular matrix components, are up-regulated. In liver metastases, their expression is growth pattern dependent. Tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) is a strong prognostic marker in plasma from colorectal cancer patients, with significant higher levels in patients with metastatic disease. We therefore wanted to determine the expression pattern of TIMP-1 in primary colorectal cancers and their matching liver metastases. TIMP-1 mRNA was primarily seen in α-smooth-muscle actin (α-SMA)-positive cells. In all primary tumors and liver metastases with desmoplastic growth pattern, TIMP-1 mRNA was primarily found in α-SMA-positive myofibroblasts located at the invasive front. Some α-SMA-positive cells with TIMP-1 mRNA were located adjacent to CD34-positive endothelial cells, identifying them as pericytes. This indicates that TIMP-1 in primary tumors and liver metastases with desmoplastic growth pattern has dual functions; being an MMP-inhibitor at the cancer periphery and involved in tumor-induced angiogenesis in the pericytes. In the liver metastases with pushing or replacement growth patterns, TIMP-1 was primarily expressed by activated hepatic stellate cells at the metastasis/liver parenchyma interface. These cells were located adjacent to CD34-positive endothelial cells, suggesting a function in tumor-induced angiogenesis. We therefore conclude that TIMP-1 expression is growth pattern dependent in colorectal cancer liver metastases.
The in vivo effect of different bedding materials on the antioxidant levels of rat heart, lung and liver tissue.
Potgieter, F J; Wilke, P I; van Jaarsveld, H; Alberts, D W
Several experimental effects due to wood-derived bedding have been reported. Female Sprague Dawley rats were kept on pine shavings, eucalyptus pulp, vermiculite and in wire-bottomed cages without bedding for 14 days whereafter normal values for the antioxidants ascorbic acid and reduced glutathione (G-SH) in rat heart lung and liver tissue were determined and compared. Statistically significant differences were observed for lung G-SH between pine shavings and eucalyptus pulp (p < 0.0183), and heart G-SH between vermiculite and eucalyptus pulp (p < 0.0948). The highest levels of liver G-SH were obtained using pine shavings compared to vermiculite (p < 0.0001), eucalyptus pulp (p < 0.0002) and wire floor (p < 0.0001). Statistically significant differences in ascorbic acid concentrations could only be described between the wire-bottomed cages and eucalyptus pulp (p < 0.0333) for lung tissue and between pine shavings and eucalyptus pulp for liver tissue (p < 0.042). Although no statistically significant differences were observed in heart ascorbic acid levels between the different bedding applications, the concentration obtained using vermiculite was approximately 50% higher than that observed with the other materials. Pine shavings, eucalyptus pulp and wire floors demonstrated virtually the same heart tissue ascorbic acid levels. It was thus demonstrated that bedding material can alter the tissue antioxidant concentration of laboratory animals, limiting the comparison of this type of result between institutions to those using identical environmental conditions.
Long-term effects of evodiamine on expressions of lipogenesis and lipolysis genes in mouse adipose and liver tissues.
Jiang, D F; Li, W T; Yang, H L; Zhang, Z Z; Chen, D; Sun, C
Evodiamine, the major alkaloid component isolated from the fruit of dried, unripened Evodia rutaecarpa Bentham, affects the plasma levels of cholecystokinin and various biological events such as gastric emptying and gastrointestinal transit; these effects of evodiamine were previously investigated in male rats. In this study, we aimed to investigate the effects of evodiamine on average daily weight gain, rectal temperature, and expressions of genes involved in lipid metabolism in liver and adipose tissues. Evodiamine was added as a supplement, comprising 0.02, 0.04, and 0.06% of the diet fed to mice for 1, 2, 3, and 4 weeks. Results showed that average daily weight gain and rectal temperature decreased significantly over time in a dose-dependent manner. Evodiamine changed expressions of the peroxisome proliferator-activated receptor-g (PPARg) in mouse adipose and liver tissues in time- and dose-dependent manners. We found that evodiamine decreased mRNA expression of the sterol-regulatory element binding protein (SREBP-1c) and fatty acid synthase in adipose tissue. In addition, evodiamine increased expressions of hormone-sensitive lipase in both liver and adipose tissues. Interestingly, evodiamine increased the expression of triglyceride hydrolase only in adipose tissue. In conclusion, evodiamine could influence lipid metabolism through regulation of the expressions of its key genes, as well as reduce body heat and body weight.
Otali, Dennis; Stockard, Cecil R.; Oelschlager, Denise K.; Wan, Wen; Manne, Upender; Watts, Stephen A.; Grizzle, William E.
It is accepted that the aldehyde-based fixation of cells can affect the immunodetection of antigens; however, the effects of tissue processing on immunodetection have not been analyzed systematically. We therefore investigated the effects of aldehyde-based fixation and the individual steps of tissue processing on immunohistochemical detection of specific antigens. DU145 (prostate) and SKOV3 (ovarian) cancer cell lines were cultured as monolayers on microscope slides. The immunohistochemical detection of Ki67/MIB-1 and PCNA was evaluated after various times of fixation in 10% neutral-buffered formalin (NBF) plus after each of the individual cumulative steps of tissue processing. The effect of antigen retrieval (AR) was evaluated concomitantly as an additional variable. Our results indicate that, in addition to fixation, each of the different steps in tissue processing has effects on immunorecognition of the epitopes recognized by these antibodies. The extensive dehydration through ethanols to absolute ethanol had only modest effects except for the detection of Ki67/MIB-1 in SKOV-3 cells where the effect was stronger. In general, however, the establishment of a hydrophobic environment by xylene resulted in the greatest decrease in immunorecognition. Antigen retrieval was able to compensate for most, but not all of the losses in staining following fixation and exposure to xylene; however, AR gave very consistent results for most steps of tissue processing, suggesting that AR should also be used in staining for PCNA. The cellular variations that were noted indicate that the effects of fixation and other steps of tissue processing may depend upon how antigens are packaged by specific cells. PMID:19886759
[Changes of ultrastructure of the capillary endotheliocytes of ischemized and nonaffected muscular tissue after transplantation of human hemopoietic stem cells of fetal liver in experiment in vivo].
Saliutin, R V; Zadorozhna, T D; Medvets'kyĭ, E B; Driuk, M F; Petrenko, A Iu
In experiment was investigated ultrastructure of the capillaries endothelial cells and histological peculiarities of muscular tissue on various stages after transplantation of hemopoietic stem cells of fetal liver (HSCFL). There was proved, that in ischemic environment HSCFL stimulate processes of angiogenesis, and in the case of transplantation into intact muscular tissue they are differentiating into the tissue macrophages, not interfering with muscular tissue structure.
Gas-permeable membranes and co-culture with fibroblasts enable high-density hepatocyte culture as multilayered liver tissues.
Evenou, Fanny; Hamon, Morgan; Fujii, Teruo; Takeuchi, Shoji; Sakai, Yasuyuki
To engineer reliable in vitro liver tissue equivalents expressing differentiated hepatic functions at a high level and over a long period of time, it appears necessary to have liver cells organized into a three-dimensional (3D) multicellular structure closely resembling in vivo liver cytoarchitecture and promoting both homotypic and heterotypic cell-cell contacts. In addition, such high density 3D hepatocyte cultures should be adequately supplied with nutrients and particularly with oxygen since it is one of the most limiting nutrients in hepatocyte cultures. Here we propose a novel but simple hepatocyte culture system in a microplate-based format, enabling high density hepatocyte culture as a stable 3D-multilayer. Multilayered co-cultures of hepatocytes and 3T3 fibroblasts were engineered on collagen-conjugated thin polydimethylsiloxane (PDMS) membranes which were assembled on bottomless frames to enable oxygen diffusion through the membrane. To achieve high density multilayered co-cultures, primary rat hepatocytes were seeded in large excess what was rendered possible due to the removal of oxygen shortage generally encountered in microplate-based hepatocyte cultures. Hepatocyte/3T3 fibroblasts multilayered co-cultures were maintained for at least 1 week; the so-cultured cells were normoxic and sustained differentiated metabolic functions like albumin and urea synthesis at higher levels than hepatocytes monocultures. Such a microplate-based cell culture system appears suitable for engineering in vitro miniature liver tissues for implantation, bioartificial liver (BAL) development, or chemical/drug screening.
Expansion and hepatocytic differentiation of liver progenitor cells in vivo using a vascularized tissue engineering chamber in mice.
Forster, Natasha; Palmer, Jason A; Yeoh, George; Ong, Wei-Chen; Mitchell, Geraldine M; Slavin, John; Tirnitz-Parker, Janina; Morrison, Wayne A
Current cell-based treatment alternatives to organ transplantation for liver failure remain unsatisfactory. Hepatocytes have a strong tendency to dedifferentiate and apoptose when isolated and maintained in culture. In contrast, liver progenitor cells (LPCs) are robust, easy to culture and have been shown to replace damaged hepatocytes in liver disease. In this study we investigate whether isolated LPCs can survive and differentiate toward mature hepatocytes in vivo when implanted into a heterotopic mouse tissue engineering chamber model. Healthy Balb/c mice and those put on a choline-deficient ethionin-supplemented diet to induce chronic liver disease were implanted with a tissue engineering chamber based on the epigastric flow through pedicle model, containing either 1 × 10(6) LPCs suspended in Matrigel, or LPC-spheroids produced by preculture for 1 week in Matrigel. Four weeks after implantation the chamber contents were harvested. In all four groups, progenitor cells persisted in large numbers to 4 weeks and demonstrated evidence of considerable proliferation judged by Ki67-positive cells. Periodic acid Schiff staining demonstrated differentiation of some cells into mature hepatocytes. Constructs grown from LPC-spheroids demonstrated considerably greater LPC survival than those from LPCs that were grown as monolayers and implanted as dissociated cells. The combined use of LPC spheroids and the vascularized chamber model could be the basis for a viable alternative to current treatments for chronic liver failure.
v-Liver: Simulating Hepatic Tissue Lesions as Virtual Cellular Systems
The US EPA Virtual Liver (v-Liver) project is aimed at reducing the uncertainty in estimating the risk of toxic outcomes in humans by simulating the dose-dependent effects of environmental chemicals in silico. The v-Liver embodies an emerging field of research in computational ti...
Fasting for 21days leads to changes in adipose tissue and liver physiology in juvenile checkered garter snakes (Thamnophis marcianus).
Davis, Mary; Jessee, Renee; Close, Matthew; Fu, Xiangping; Settlage, Robert; Wang, Guoqing; Cline, Mark A; Gilbert, Elizabeth R
Snakes often undergo periods of prolonged fasting and, under certain conditions, can survive years without food. Despite this unique phenomenon, there are relatively few reports of the physiological adaptations to fasting in snakes. At post-prandial day 1 (fed) or 21 (fasting), brain, liver, and adipose tissues were collected from juvenile checkered garter snakes (Thamnophis marcianus). There was greater glycerol-3-phosphate dehydrogenase (G3PDH)-specific activity in the liver of fasted than fed snakes (P=0.01). The mRNA abundance of various fat metabolism-associated factors was measured in brain, liver, and adipose tissue. Lipoprotein lipase (LPL) mRNA was greater in fasted than fed snakes in the brain (P=0.04). Adipose triglyceride lipase (ATGL; P=0.006) mRNA was greater in the liver of fasted than fed snakes. In adipose tissue, expression of peroxisome proliferator-activated receptor (PPAR)γ (P=0.01), and fatty acid binding protein 4 (P=0.03) was greater in fed than fasted snakes. Analysis of adipocyte morphology revealed that cross-sectional area (P=0.095) and diameter (P=0.27) were not significantly different between fed and fasted snakes. Results suggest that mean adipocyte area can be preserved during fasting by dampening lipid biosynthesis while not changing rates of lipid hydrolysis. In the liver, however, extensive lipid remodeling may provide energy and lipoproteins to maintain lipid structural integrity during energy restriction. Because the duration of fasting was not sufficient to change adipocyte size, results suggest that the liver is important as a short-term provider of energy in the snake.
Development of a Multispectral Tissue Characterization System for Optimization of an Implantable Perfusion Status Monitor for Transplanted Liver
Baba, Justin S; Letzen, Brian S; Ericson, Milton Nance; Cote, Gerard L.; Xu, Weijian; Wilson, Mark A.
Optimizing wavelength selection for monitoring perfusion during liver transplant requires an in-depth characterization of liver optical properties. With these, the impact of liver absorption and scattering properties can be investigated to select optimal wavelengths for perfusion monitoring. To accomplish this, we are developing a single integrating-sphere-based using a unique spatially resolved diffuse reflectance system for optical properties determination for thick samples. We report early results using a monochromatic source implementation to measure the optical properties of well characterized tissue phantoms made from polystyrene spheres and Trypan blue. The presented results show the promise of using this unique system to measure the optical properties of the tissue phantoms. We are currently in the process of implementing an automated Levenberg Marquardt fitting algorithm to determine the peak location of the diffuse reflectance profile to ensure robust computation of sample optical properties. Future work will focus on the incorporation of multispectral capability to the technique to facilitate development of more realistic liver tissue phantoms.
Mesenchymal Stem Cells Increase Neo-Angiogenesis and Albumin Production in a Liver Tissue-Engineered Engraftment.
Carraro, Amedeo; Buggio, Maurizio; Gardin, Chiara; Tedeschi, Umberto; Ferroni, Letizia; Zavan, Padova-Barbara
The construction of a three-dimensional (3D) liver tissue is limited by many factors; one of them is the lack of vascularization inside the tissue-engineered construct. An engineered liver pocket-scaffold able to increase neo-angiogenesis in vivo could be a solution to overcome these limitations. In this work, a hyaluronan (HA)-based scaffold enriched with human mesenchymal stem cells (hMSCs) and rat hepatocytes was pre-conditioned in a bioreactor system, then implanted into the liver of rats. Angiogenesis and hepatocyte metabolic functions were monitored. The formation of a de novo vascular network within the HA-based scaffold, as well as an improvement in albumin production by the implanted hepatocytes, were detected. The presence of hMSCs in the HA-scaffold increased the concentration of growth factors promoting angiogenesis inside the graft. This event ensured a high blood vessel density, coupled with a support to metabolic functions of hepatocytes. All together, these results highlight the important role played by stem cells in liver tissue-engineered engraftment.
Distribution study of cisplatin in rat kidney and liver cancer tissues by using liquid chromatography electrospray ionization tandem mass spectrometry.
Bandu, Raju; Ahn, Hyun Soo; Lee, Joon Won; Kim, Yong Woo; Choi, Seon Hee; Kim, Hak Jin; Kim, Kwang Pyo
A sensitive and rapid liquid chromatography positive ion electrospray ionization tandem mass spectrometric (LC/ESI-MS/MS) method has been developed and validated for the quantitative determination and distribution of cisplatin (CP) in kidney and liver tissues after intravenous administration of drug to adult male Sprague Dawley rats. Oxaliplatin (OXP) was used as an internal standard. The tissue samples were homogenized and extracted using conventional liquid-liquid extraction method with phosphate buffer containing ethyl acetate and then subjected to LC-MS analysis. The chromatographic separation was achieved on an Agilent ZORBAX SB C-18 column (50 × 2.1 mm, 1.8 µm) using the mobile phase consisting of 0.1% formic acid in water (Solvent A) : methanol (Solvent B) (40 : 60; v/v) in an isocratic elution followed by detection with positive ion electrospray ionization tandem mass spectrometry using the transitions of m/z 301 > 265 for CP and m/z 398 > 310 for OXP in multiple reaction monitoring mode. The calibration curve was linear in the range of 5.0-7000 and 10.0-6000 ng/ml for kidney and liver tissue homogenates, respectively. The method revealed good performances in terms of within-batch, between-batch precision (1.31-5.70%) and accuracy (97.0-102.24%) for CP in both kidney and liver tissue homogenates including lower and upper limits of quantification. The recoveries from spiked control samples were >81.0% and >87.0 % for CP and OXP, respectively. Matrix effect was found to be negligible, and the stability data were within the acceptable limits. Further, the validated LC/ES-MS/MS method was successfully applied to investigate the distribution of CP in kidney and liver tissues after intravenous administration of CP to male Sprague Dawley rats. The results showed that the higher amount of CP was distributed in kidney followed by liver, which indicated that CP mainly accumulated in kidney tissues and renal excretion might be a primary and
Anti-oxidative responses of zebrafish (Danio rerio) gill, liver and brain tissues upon acute cold shock.
Wu, Su Mei; Liu, Jia-Hao; Shu, Li-Hsin; Chen, Ching Hsein
The present study seeks to detect oxidative damage and to compare anti-oxidative responses among liver, gills and brain of adult zebrafish that were cooled from 28 °C (control) to 12 °C (treatment) for 0-24 h. The lipid peroxidation of liver, gill and brain tissues significantly increased at 1h after transfer, but reactive oxygen species in the treatment group increased significantly after 24 h as compared to the control. The fish were found to develop a cascading anti-oxidative mechanism beginning with an increase in Cu/Zn-SOD levels, followed by increased CAT and GPx mRNA expressions in the three tissue types. Both smtB and mt2 mRNAs increased in the hepatic and brain tissues following 1h of cold stress, but only smtB exhibited a significant increase in the gills at 1 h and 6 h after transfer to 12 °C. Furthermore, cellular apoptosis in the brain was not evident after cold shock, but liver and gills showed cellular apoptosis at 1-3 h, with another peak in the liver at 6 h after cold shock. The results suggest that the cold shock induced oxidative stress, and the enzymatic (SOD, GPx and CAT) and non-enzymatic (mt-2 and smt-B) mRNA expressions all play a role in the resulting anti-oxidation within 1-6 h of cold shock. A functional comparison showed that the brain had the most powerful antioxidant defense system of the three tissue types since it had the highest smtB mRNA expression and a lower level of cell apoptosis than the liver and gills after exposure to cold stress.
High-frequency ultrasound for monitoring changes in liver tissue during preservation
NASA Astrophysics Data System (ADS)
Vlad, Roxana M.; Czarnota, Gregory J.; Giles, Anoja; Sherar, Michael D.; Hunt, John W.; Kolios, Michael C.
Currently the only method to assess liver preservation injury is based on liver appearance and donor medical history. Previous work has shown that high-frequency ultrasound could detect ischemic cell death due to changes in cell morphology. In this study, we use high-frequency ultrasound integrated backscatter to assess liver damage in experimental models of liver ischemia. Ultimately, our goal is to predict organ suitability for transplantation using high-frequency imaging and spectral analysis techniques. To examine the effects of liver ischemia at different temperatures, livers from Wistar rats were surgically excised, immersed in phosphate buffer saline and stored at 4 and 20 °C for 24 h. To mimic organ preservation, livers were excised, flushed with University of Wisconsin (UW) solution and stored at 4 °C for 24 h. Preservation injury was simulated by either not flushing livers with UW solution or, before scanning, allowing livers to reach room temperature. Ultrasound images and corresponding radiofrequency data were collected over the ischemic period. No significant increase in integrated backscatter (~2.5 dBr) was measured for the livers prepared using standard preservation conditions. For all other ischemia models, the integrated backscatter increased by 4-9 dBr demonstrating kinetics dependent on storage conditions. The results provide a possible framework for using high-frequency imaging to non-invasively assess liver preservation injury.
Genome-wide effects of acute progressive feed restriction in liver and white adipose tissue
Pohjanvirta, Raimo Boutros, Paul C.; Moffat, Ivy D.; Linden, Jere; Wendelin, Dominique; Okey, Allan B.
Acute progressive feed restriction (APFR) represents a specific form of caloric restriction in which feed availability is increasingly curtailed over a period of a few days to a few weeks. It is often used for control animals in toxicological and pharmacological studies on compounds causing body weight loss to equalize weight changes between experimental and control groups and thereby, intuitively, to also set their metabolic states to the same phase. However, scientific justification for this procedure is lacking. In the present study, we analyzed by microarrays the impact on hepatic gene expression in rats of two APFR regimens that caused identical diminution of body weight (19%) but differed slightly in duration (4 vs. 10 days). In addition, white adipose tissue (WAT) was also subjected to the transcriptomic analysis on day-4. The data revealed that the two regimens led to distinct patterns of differentially expressed genes in liver, albeit some major pathways of energy metabolism were similarly affected (particularly fatty acid and amino acid catabolism). The reason for the divergence appeared to be entrainment by the longer APFR protocol of peripheral oscillator genes, which resulted in derailment of circadian rhythms and consequent interaction of altered diurnal fluctuations with metabolic adjustments in gene expression activities. WAT proved to be highly unresponsive to the 4-day APFR as only 17 mRNA levels were influenced by the treatment. This study demonstrates that body weight is a poor proxy of metabolic state and that the customary protocols of feed restriction can lead to rhythm entrainment.
Autonomic nervous system-mediated effects of galanin-like peptide on lipid metabolism in liver and adipose tissue
Hirako, Satoshi; Wada, Nobuhiro; Kageyama, Haruaki; Takenoya, Fumiko; Izumida, Yoshihiko; Kim, Hyounju; Iizuka, Yuzuru; Matsumoto, Akiyo; Okabe, Mai; Kimura, Ai; Suzuki, Mamiko; Yamanaka, Satoru; Shioda, Seiji
Galanin-like peptide (GALP) is a neuropeptide involved in the regulation of feeding behavior and energy metabolism in mammals. While a weight loss effect of GALP has been reported, its effects on lipid metabolism have not been investigated. The aim of this study was to determine if GALP regulates lipid metabolism in liver and adipose tissue via an action on the sympathetic nervous system. The respiratory exchange ratio of mice administered GALP intracerebroventricularly was lower than that of saline-treated animals, and fatty acid oxidation-related gene mRNA levels were increased in the liver. Even though the respiratory exchange ratio was reduced by GALP, this change was not significant when mice were treated with the sympatholytic drug, guanethidine. Lipolysis-related gene mRNA levels were increased in the adipose tissue of GALP-treated mice compared with saline-treated animals. These results show that GALP stimulates fatty acid β-oxidation in liver and lipolysis in adipose tissue, and suggest that the anti-obesity effect of GALP may be due to anorexigenic actions and improvement of lipid metabolism in peripheral tissues via the sympathetic nervous system. PMID:26892462
The average baboon brain: MRI templates and tissue probability maps from 89 individuals.
Love, Scott A; Marie, Damien; Roth, Muriel; Lacoste, Romain; Nazarian, Bruno; Bertello, Alice; Coulon, Olivier; Anton, Jean-Luc; Meguerditchian, Adrien
The baboon (Papio) brain is a remarkable model for investigating the brain. The current work aimed at creating a population-average baboon (Papio anubis) brain template and its left/right hemisphere symmetric version from a large sample of T1-weighted magnetic resonance images collected from 89 individuals. Averaging the prior probability maps output during the segmentation of each individual also produced the first baboon brain tissue probability maps for gray matter, white matter and cerebrospinal fluid. The templates and the tissue probability maps were created using state-of-the-art, freely available software tools and are being made freely and publicly available: http://www.nitrc.org/projects/haiko89/ or http://lpc.univ-amu.fr/spip.php?article589. It is hoped that these images will aid neuroimaging research of the baboon by, for example, providing a modern, high quality normalization target and accompanying standardized coordinate system as well as probabilistic priors that can be used during tissue segmentation.
Osteopontin Deletion Prevents the Development of Obesity and Hepatic Steatosis via Impaired Adipose Tissue Matrix Remodeling and Reduced Inflammation and Fibrosis in Adipose Tissue and Liver in Mice
Lancha, Andoni; Rodríguez, Amaia; Catalán, Victoria; Becerril, Sara; Sáinz, Neira; Ramírez, Beatriz; Burrell, María A.; Salvador, Javier; Frühbeck, Gema; Gómez-Ambrosi, Javier
Osteopontin (OPN) is a multifunctional extracellular matrix (ECM) protein involved in multiple physiological processes. OPN expression is dramatically increased in visceral adipose tissue in obesity and the lack of OPN protects against the development of insulin resistance and inflammation in mice. We sought to unravel the potential mechanisms involved in the beneficial effects of the absence of OPN. We analyzed the effect of the lack of OPN in the development of obesity and hepatic steatosis induced by a high-fat diet (HFD) using OPN-KO mice. OPN expression was upregulated in epididymal white adipose tissue (EWAT) and liver in wild type (WT) mice with HFD. OPN-KO mice had higher insulin sensitivity, lower body weight and fat mass with reduced adipose tissue ECM remodeling and reduced adipocyte size than WT mice under a HFD. Reduced MMP2 and MMP9 activity was involved in the decreased ECM remodeling. Crown-like structure number in EWAT as well as F4/80-positive cells and Emr1 expression in EWAT and liver increased with HFD, while OPN-deficiency blunted the increase. Moreover, our data show for the first time that OPN-KO under a HFD mice display reduced fibrosis in adipose tissue and liver, as well as reduced oxidative stress in adipose tissue. Gene expression of collagens Col1a1, Col6a1 and Col6a3 in EWAT and liver, as well as the profibrotic cytokine Tgfb1 in EWAT were increased with HFD, while OPN-deficiency prevented this increase. OPN deficiency prevented hepatic steatosis via reduction in the expression of molecules involved in the onset of fat accumulation such as Pparg, Srebf1, Fasn, Mogat1, Dgat2 and Cidec. Furthermore, OPN-KO mice exhibited higher body temperature and improved BAT function. The present data reveal novel mechanisms of OPN in the development of obesity, pointing out the inhibition of OPN as a promising target for the treatment of obesity and fatty liver. PMID:24871103
Osteopontin deletion prevents the development of obesity and hepatic steatosis via impaired adipose tissue matrix remodeling and reduced inflammation and fibrosis in adipose tissue and liver in mice.
Lancha, Andoni; Rodríguez, Amaia; Catalán, Victoria; Becerril, Sara; Sáinz, Neira; Ramírez, Beatriz; Burrell, María A; Salvador, Javier; Frühbeck, Gema; Gómez-Ambrosi, Javier
Osteopontin (OPN) is a multifunctional extracellular matrix (ECM) protein involved in multiple physiological processes. OPN expression is dramatically increased in visceral adipose tissue in obesity and the lack of OPN protects against the development of insulin resistance and inflammation in mice. We sought to unravel the potential mechanisms involved in the beneficial effects of the absence of OPN. We analyzed the effect of the lack of OPN in the development of obesity and hepatic steatosis induced by a high-fat diet (HFD) using OPN-KO mice. OPN expression was upregulated in epididymal white adipose tissue (EWAT) and liver in wild type (WT) mice with HFD. OPN-KO mice had higher insulin sensitivity, lower body weight and fat mass with reduced adipose tissue ECM remodeling and reduced adipocyte size than WT mice under a HFD. Reduced MMP2 and MMP9 activity was involved in the decreased ECM remodeling. Crown-like structure number in EWAT as well as F4/80-positive cells and Emr1 expression in EWAT and liver increased with HFD, while OPN-deficiency blunted the increase. Moreover, our data show for the first time that OPN-KO under a HFD mice display reduced fibrosis in adipose tissue and liver, as well as reduced oxidative stress in adipose tissue. Gene expression of collagens Col1a1, Col6a1 and Col6a3 in EWAT and liver, as well as the profibrotic cytokine Tgfb1 in EWAT were increased with HFD, while OPN-deficiency prevented this increase. OPN deficiency prevented hepatic steatosis via reduction in the expression of molecules involved in the onset of fat accumulation such as Pparg, Srebf1, Fasn, Mogat1, Dgat2 and Cidec. Furthermore, OPN-KO mice exhibited higher body temperature and improved BAT function. The present data reveal novel mechanisms of OPN in the development of obesity, pointing out the inhibition of OPN as a promising target for the treatment of obesity and fatty liver.
Quantitative elemental analysis on aluminum accumulation by HVTEM-EDX in liver tissues of mice orally administered with aluminum chloride.
Kametani, Kiyokazu; Nagata, Tetsuji
Quantitative elemental analysis on Al was carried out by high-accelerating voltage transmission electron microscopy (HVTEM) equipped with energy-dispersive X-ray microanalysis (EDX) using an accelerating voltage at 300 kV with high permeability in 1-mum-thick samples obtained from mice administered with aluminum chloride solution for 3, 9, and 17 weeks. By light microscopic observation, no morphological changes were observed in the hepatocytes and macrophages in the liver tissues of mice that were administered with excess Al as compared with the normal control mice. In contrast, by electron microscopic observation, ultrastructural changes were observed in the lysosomes in the hepatocytes as well as the pinocytotic vesicles in the macrophages in the experimental animals. Therefore, the concentrations of Al detected in lysosomes in hepatocytes and pinocytotic vesicles in macrophages of livers of mice administered with Al were measured in relationship to those administration periods. Moreover, transitional changes of hepatocyte lysosome ratios by image analysis and the macrophage counts in the unit area increased in liver tissues of mice administered with Al as compared with normal control mice. From the results, it was demonstrated that hepatocyte lysosome ratio and macrophage count increased in liver tissues of treated mice during those short-term excessive Al administration periods. It was also clarified that the concentrations of Al in both hepatocytes and macrophages increased as observed by HVTEM-EDX. In conclusion, Al accumulated in hepatocytes and macrophages at 3 and 9 weeks administration, while the ultrastructural changes remained in the hepatocytes and macrophages. In contrast, Al concentration did not increase in the liver at 17 weeks administration.
Investigation for role of tissue factor and blood coagulation system in severe acute pancreatitis and associated liver injury.
Ou, Zhi-Bing; Miao, Chun-Mu; Ye, Ming-Xin; Xing, Ding-Pei; He, Kun; Li, Pei-Zhi; Zhu, Rong-Tao; Gong, Jian-Ping
This study aims to investigate the molecular mechanisms underlying the pathogenesis of severe acute pancreatitis (SAP) and SAP-associated liver injury, we performed an association analysis of the functions of tissue factor (TF) and blood coagulation system in both SAP patients and mouse SAP model. Our results showed that serum TF and tissue factor-microparticle (TF-MP) levels were highly up-regulated in both SAP patients and SAP mouse model, which was accompanied by the dysfunction of blood coagulation system. Besides, TF expression was also highly up-regulated in the Kupffer cells (KCs) of SAP mouse model. After inhibiting KCs in SAP mouse model, the amelioration of blood coagulation system functions was associated with the decrease in serum TF and TF-MPs levels, and the reduction of SAP-associated liver injury was associated with the decrease of TF expression in KCs. In conclusion, the dis-regulated TF expression and associated dysfunction of blood coagulation system are critical factors for the pathogenesis of SAP and SAP-associated liver injury. TF may serve as a potential and effective target for treating SAP and SAP-associated liver injury.
Correction of Negative Effect of Antenatal Hypoxia on Liver Tissue Homeostasis in Newborn Albino Rats with Opioid Peptides.
Pinaeva, O G; Sazonova, E N; Lebed'ko, O A; Timoshin, S S
We studied the possibility of correction of the negative effects of antenatal hypoxia on the liver tissue homeostasis in 7-day-old albino rats by administration of opioid peptides in a dose of 100 μg/kg on postnatal days 2-6. Administration of mixed μ/δ-opioid receptor agonist Dalargin neutralized deviations of gravimetric indicators, parameters of proliferative activity, and activity of the nucleolar apparatus of hepatocytes. Administration of the non-opiate Leu-enkephalin analogue did not normalize gravimetric parameters and nucleolar apparatus parameters, however, it significantly increased the pool of proliferating hepatocytes. Both peptides significantly reduced the intensity of free radical oxidation, improved antioxidant antiradical defense and resistance to peroxidation in the liver tissue of animals subjected to antenatal hypoxia.
Ultrasound-guided tissue fractionation by high intensity focused ultrasound in an in vivo porcine liver model
Khokhlova, Tatiana D.; Wang, Yak-Nam; Simon, Julianna C.; Cunitz, Bryan W.; Starr, Frank; Paun, Marla; Crum, Lawrence A.; Bailey, Michael R.; Khokhlova, Vera A.
The clinical use of high intensity focused ultrasound (HIFU) therapy for noninvasive tissue ablation has been recently gaining momentum. In HIFU, ultrasound energy from an extracorporeal source is focused within the body to ablate tissue at the focus while leaving the surrounding organs and tissues unaffected. Most HIFU therapies are designed to use heating effects resulting from the absorption of ultrasound by tissue to create a thermally coagulated treatment volume. Although this approach is often successful, it has its limitations, such as the heat sink effect caused by the presence of a large blood vessel near the treatment area or heating of the ribs in the transcostal applications. HIFU-induced bubbles provide an alternative means to destroy the target tissue by mechanical disruption or, at its extreme, local fractionation of tissue within the focal region. Here, we demonstrate the feasibility of a recently developed approach to HIFU-induced ultrasound-guided tissue fractionation in an in vivo pig model. In this approach, termed boiling histotripsy, a millimeter-sized boiling bubble is generated by ultrasound and further interacts with the ultrasound field to fractionate porcine liver tissue into subcellular debris without inducing further thermal effects. Tissue selectivity, demonstrated by boiling histotripsy, allows for the treatment of tissue immediately adjacent to major blood vessels and other connective tissue structures. Furthermore, boiling histotripsy would benefit the clinical applications, in which it is important to accelerate resorption or passage of the ablated tissue volume, diminish pressure on the surrounding organs that causes discomfort, or insert openings between tissues. PMID:24843132
Effects of carnosine, taurine, and betaine pretreatments on diethylnitrosamine-induced oxidative stress and tissue injury in rat liver.
Başaran-Küçükgergin, C; Bingül, I; Tekkeşin, M Soluk; Olgaç, V; Doğru-Abbasoğlu, S; Uysal, M
Several chemicals such as N-diethylnitrosamine (DEN) promote hepatocellular cancer in rodents and induce hepatocyte injury. DEN affects the initiation stage of carcinogenesis together with enhanced cell proliferation accompanied by hepatocellular necrosis. DEN-induced hepatocellular necrosis is reported to be related to enhanced generation of reactive oxygen species. Carnosine (CAR), taurine (TAU), and betaine (BET) are known to have powerful antioxidant properties. We aimed to investigate the effects of CAR, TAU, and BET pretreatments on DEN-induced oxidative stress and liver injury in male rats. Rats were given CAR (2 g L(-1) in drinking water), TAU (2.5% in chow), and BET (2.5% in chow) for 6 weeks and DEN (200 mg kg(-1) intraperitoneally) was given 2 days before the end of this period. Serum alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and γ-glutamyl transferase activities were determined and a histopathologic evaluation was performed on the liver tissue. Oxidative stress was detected in the liver by measuring malondialdehyde, diene conjugate, protein carbonyl and nitrotyrosine levels, glutathione and glutathione peroxidase levels, and superoxide dismutase and glutathione transferase activities. Pretreatments with CAR, TAU, and BET decreased liver prooxidant status without remarkable changes in antioxidant parameters in DEN-treated rats. Pretreatments with TAU and BET, but not CAR, were also found to be effective to reduce liver damage in DEN-treated rats. In conclusion, TAU, BET, and possibly CAR may have an ameliorating effect on DEN-induced hepatic injury by reducing oxidative stress in rats.
Whole-organ tissue engineering: decellularization and recellularization of three-dimensional matrix liver scaffolds.
Sabetkish, Shabnam; Kajbafzadeh, Abdol-Mohammad; Sabetkish, Nastaran; Khorramirouz, Reza; Akbarzadeh, Aram; Seyedian, Sanam Ladi; Pasalar, Parvin; Orangian, Saghar; Beigi, Reza Seyyed Hossein; Aryan, Zahra; Akbari, Hesam; Tavangar, Seyyed Mohammad
To report the results of whole liver decellularization by two different methods. To present the results of grafting rat and sheep decellularized liver matrix (DLM) into the normal rat liver and compare natural cell seeding process in homo/xenograft of DLM. To compare the results of in vitro whole liver recellularization with rats' neonatal green fluorescent protein (GFP)-positive hepatic cells with outcomes of in vivo recellularization process. Whole liver of 8 rats and 4 sheep were resected and cannulated via the hepatic vein and perfused with sodium dodecyl sulfate (SDS) or Triton + SDS. Several examinations were performed to compare the efficacy of these two decellularization procedures. In vivo recellularization of sheep and rat DLMs was performed following transplantation of multiple pieces of both scaffolds in the subhepatic area of four rats. To compare the efficacy of different scaffolds in autologous cell seeding, biopsies of homograft and xenograft were assessed 8 weeks postoperatively. Whole DLMs of 4 rats were also recellularized in vitro by perfusion of rat's fetal GFP-positive hepatic cells with pulsatile bioreactor. Histological evaluation and enzymatic assay were performed for both in vivo and in vitro recellularized samples. The results of this study demonstrated that the triton method was a promising decellularization approach for preserving the three-dimensional structure of liver. In vitro recellularized DLMs were more similar to natural ones compared with in vivo recellularized livers. However, homografts showed better characteristics with more organized structure compared with xenografts. In vitro recellularization of liver scaffolds with autologous cells represents an attractive prospective for regeneration of liver as one of the most compound organs. In vivo cell seeding on the scaffold of the same species may have more satisfactory outcomes when compared with the results of xenotransplantation. This study theoretically may pave the road for
Optical properties of normal and thermally coagulated chicken liver tissue measured ex-vivo with diffuse reflectance
NASA Astrophysics Data System (ADS)
Hafeez-Ullah; Atif, M.; Firdous, S.; Mehmood, M. S.; Hamza, M. Y.; Imran, M.; Hussain, G.; Ikram, M.
The purpose of the present study is to determine the optical properties of normal and thermally coagulated chicken liver at 720, 740, 770, 810, 825 and 840 nm wavelengths of laser irradiation. So, we were able to evaluate these optical properties (absorption and scattering coefficients) with ex-vivo study using Kubelka Munk Model (KMM) from the radial dependence of the diffuse reflectance with femtosecond pulsed laser in near IR region. These coefficients were significantly increased with coagulation. The penetration depths of the diffused light have been reported to a maximum value of 8.12 ± 0.36 mm in normal liver and 2.49 ± 0.17 mm in coagulated liver at 840 nm showing increasing behavior towards IR region. The Monte Carlo simulation was used to check the theoretical validation of measured optical properties of the tissue that showed a good match with our experimental results. We believe that these differences in optical properties will be helpful for the understanding arid optimal use of laser applications in medicine and differential diagnosis of tissues by using different optical methods. Especially for the investigation of biological tissue for photodynamic therapy (PDT), the knowledge of the specific optical properties and their thermo-induced changes is important.
Effects of grape seed polyphenols on oxidative damage in liver tissue of acutely and chronically exercised rats.
Belviranlı, Muaz; Gökbel, Hakkı; Okudan, Nilsel; Büyükbaş, Sadık
The objective of the present study was to investigate the effects of grape seed extract (GSE) supplementation on oxidative stress and antioxidant defense markers in liver tissue of acutely and chronically exercised rats. Rats were randomly assigned to six groups: Control (C), Control Chronic Exercise (CE), Control Acute Exercise (AE), GSE-supplemented Control (GC), GSE-supplemented Chronic Exercise(GCE) and GSE-supplemented Acute Exercise (GAE). Rats in the chronic exercise groups were subjected to a six-week treadmill running and in the acute exercise groups performed an exhaustive running. Rats in the GSE supplemented groups received GSE (100 mg.kg(-1) .day(-1) ) in drinking water for 6 weeks. Liver tissues of the rats were taken for the analysis of malondialdehyde (MDA), nitric oxide (NO) levels and total antioxidant activity (AOA) and xanthine oxidase (XO) activities. MDA levels decreased with GSE supplementation in control groups but increased in acute and chronic exercise groups compared to their non-supplemented control. NO levels increased with GSE supplementation. XO activities were higher in AE group compared to the CE group. AOA decreased with GSE supplementation. In conclusion, while acute exercise triggers oxidative stress, chronic exercise has protective role against oxidative stress. GSE has a limited antioxidant effect on exercise-induced oxidative stress in liver tissue.
Premalignant alteration assessment in liver-like tissue derived from embryonic stem cells by aristolochic acid I exposure
Li, Tong; Jin, Ke; Zhu, Dan-yan; Li, Lu; Mao, Zheng-rong; Wu, Bo-wen; Wang, Yi-fan; Pan, Zong-fu; Li, Lan-juan; Xiang, Chun-sheng; Su, Kun-kai; Lou, Yi-jia
The in vitro predictive evaluation of chemical carcinogenicity based on hepatic premalignance has so far not been established. Here, we report a novel approach to investigate the premalignant events triggered by human carcinogen aristolochic acid I (AAI) in the liver-like tissue derived from mouse embryonic stem cells. By AAI exposure, the liver-like tissue exhibited the paracrine interleukin-6 phenotypic characteristics. Hepatocytes expressed STAT3/p-STAT3, c-Myc and Lin28B in parallel. Some of them displayed the dedifferentiation characteristics, such as full of α-fetoprotein granules, increase in size, and nucleocytoplasmic shuttle of Oct4. When these cells were injected into mice, the xenografts mostly displayed the uniform area of hepatic-like tissue with malignant nuclei. The hepatic malignant markers, α-fetoprotein, cytokeratin 7 and cytokeratin 19, were co-expressed in albumin-positive areas, respectively. In conclusion, we established an approach to predict the hepatic premalignance triggered by carcinogen AAI. This premalignant assay system might aid to evaluate the effects of potential carcinogens in liver, and probably to screen the protecting against hepatocarcinogenic efficacy of pharmaceuticals in vitro. PMID:27713163
Tissue/fluid correlation study for the depletion of sulfadimethoxine in bovine kidney, liver, plasma, urine, and oral fluid.
Chiesa, O A; Li, H; Kijak, P J; Li, J X; Lancaster, V; Smith, M L; Heller, D N; Thomas, M H; Von Bredow, J
Sulfonamides are among the oldest, but still effective, antimicrobial veterinary medicines. In steers and dairy cows, the sulfonamides are effective in the treatment of respiratory disease and general infections. Sulfadimethoxine (SDM) has been approved by US Food and Drug Administration (FDA) for use in steers and dairy cows with a tolerance of 100 ng/g (ppb) in edible tissues and 10 ppb in milk. The detection of SDM residue above tolerance in the animal slaughtered for food process will result in the whole carcass being discarded. This report describes a comprehensive depletion study of SDM (and its main metabolite) in plasma, urine, oral fluid, kidney, and liver. In this study, nine steers were injected intravenously with the approved dose of SDM; the loading dose was 55 mg/kg, followed by 27.5 mg/kg dose at 24 h and again at 48 h. Fluids (blood, urine, and saliva) and tissue (liver and kidney) samples were collected at intervals after the last dose of SMD. The combination of laparoscopic serial sampling technique with the liquid chromatography/mass spectrometry method provided the data to establish the tissue/fluid correlation in the depletion of SMD. A strong correlation and linearity of the log-scale concentration over time in the depletion stage has been confirmed for kidney, liver, and plasma.
Neither bovine somatotropin nor growth hormone-releasing factor alters expression of thyroid hormone receptors in liver and mammary tissues.
Capuco, A V; Binelli, M; Tucker, H A
Physiological effects of thyroid hormones are mediated primarily by binding of triiodothyronine to specific nuclear receptors. Organ-specific changes in production of triiodothyronine from its prohormone, thyroxine, have been hypothesized to target the action of thyroid hormones on the mammary gland and play a role in mediating or augmenting a galactopoietic response to bovine somatotropin (bST). Additionally, tissue responsiveness to thyroid hormones may be altered by changes in the number or affinity of nuclear receptors for thyroid hormones. In the present study, effects of bST and bovine growth hormone-releasing factor (bGRF) on thyroid hormone receptors in liver and mammary gland were studied. Lactating Holstein cows received continuous infusions of bST or bGRF for 63 d or served as uninfused controls. Nuclei were isolated from harvested mammary and liver tissues and incubated with [(125)I]-triiodothyronine. Treatments did not alter the capacity or affinity of specific binding sites for triiodothyronine in liver or mammary nuclei. Evaluation of transcript abundance for thyroid hormone receptors showed that isoforms of thyroid hormone receptor or retinoid receptor (which may influence thyroid receptor action) expressed in the mammary gland were not altered by bST or bGRF treatment. Data do not support the hypothesis that administration of bST or bGRF alters sensitivity of mammary tissue by changing expression of thyroid hormone receptors.
Both liver-X receptor (LXR) isoforms control energy expenditure by regulating Brown Adipose Tissue activity
Korach-André, Marion; Archer, Amena; Barros, Rodrigo P.; Parini, Paolo; Gustafsson, Jan-Åke
Brown adipocytes are multilocular lipid storage cells that play a crucial role in nonshivering thermogenesis. Uncoupling protein 1 (UCP1) is a unique feature of brown fat cells that allows heat generation on sympathetic nervous system stimulation. As conventional transcriptional factors that are activated in various signaling pathways, liver-X receptors (LXRs) play important roles in many physiological processes. The role of LXRs in the regulation of energy homeostasis remains unclear, however. Female WT, LXRαβ−/−, LXRα−/−, and LXRβ−/− mice were fed with either a normal diet (ND) or a high-carbohydrate diet (HCD) supplemented with or without GW3965-LXR agonist. LXRαβ−/− mice exhibited higher energy expenditure (EE) as well as higher UCP1 expression in brown adipose tissue (BAT) compared with WT mice on the HCD. In addition, long-term treatment of WT mice with GW3965 showed lower EE at thermoneutrality (30 °C) and lower Ucp1 expression level in BAT. Furthermore, H&E staining of the BAT of LXRαβ−/− mice exhibited decreased lipid droplet size compared with WT mice on the HCD associated with a more intense UCP1-positive reaction. Quantification of triglyceride (TG) content in BAT showed lower TG accumulation in LXRβ−/− mice compared with WT mice. Surprisingly, GW3965 treatment increased TG content (twofold) in the BAT of WT and LXRα−/− mice but not in LXRβ−/− mice. Furthermore, glucose transporter (GLUT4) in the BAT of LXRα−/− and LXRβ−/− mice was sixfold and fourfold increased, respectively, compared with WT mice on the ND. These findings suggest that LXRα as well as LXRβ could play a crucial role in the regulation of energy homeostasis in female mice and may be a potential target for the treatment of obesity and energy regulation. PMID:21173252
Effect of dietary organic microminerals on starter pig performance, tissue mineral concentrations, and liver and plasma enzyme activities.
Martin, R E; Mahan, D C; Hill, G M; Link, J E; Jolliff, J S
Weanling pigs (n = 160) were used to evaluate dietary essential microminerals (Cu, Fe, Mn, Se, and Zn) on performance, tissue minerals, and liver and plasma enzymatic activities during a 35-d postweaning period. A randomized complete block design with 5 treatments and 8 replicates was used in this study. Organic microminerals were added to complex nursery diets at 0 (basal), 50, 100, or 150% of the requirements of microminerals listed by the 1998 NRC. A fifth treatment contained inorganic microminerals at 100% NRC and served as the positive control. Pigs were bled at intervals with hemoglobin (Hb), hematocrit (Hct), glutathione peroxidase, and ceruloplasmin activities determined. Six pigs at weaning and 1 pig per pen at d 35 were killed, and the liver, heart, loin, kidney, pancreas, and the frontal lobe of the brain were collected for micromineral analysis. The liver was frozen in liquid N for determination of enzymatic activities. The analyzed innate microminerals in the basal diet met the NRC requirement for Cu and Mn but not Fe, Se, and Zn. Performance was not affected from 0 to 10 d postweaning, but when microminerals were added to diets, ADG, ADFI, and G:F improved (P < 0.01) from 10 to 35 d and for the overall 35-d period. Pigs fed the basal diet exhibited parakeratosis-like skin lesions, whereas those fed the supplemental microminerals did not. This skin condition was corrected after a diet with the added microminerals was fed. When the basal diet was fed, Hb and Hct declined, but supplemental microminerals increased Hb and Hct values. Liver catalase activity increased (P < 0.01) when microminerals were fed. The Mn superoxide dismutase activity tended to decline quadratically (P = 0.06) when supplemental microminerals were fed above that of the basal diet. Liver plasma glutathione peroxidase activities were greater (P < 0.01) when dietary organic and inorganic micromineral were fed. Liver concentrations of microminerals increased linearly (P < 0.01) as
Selenium concentrations in serum of individuals with liver diseases (cirrhosis or hepatitis): relationship with some nutritional and biochemical markers.
Navarro-Alarcón, M; López-Ga de la Serrana, H; Pérez-Valero, V; López-Martínez, M C
Serum concentrations were measured in individuals (n = 50) with liver diseases (cirrhosis and hepatitis) by hydride generation atomic absorption spectrometry in a cross-sectional study. Mean serum selenium levels determined in patients with cirrhosis (n = 12) or with hepatitis (n = 38) were significantly lower (P<0.01) than those measured in control groups mainly due to a decreased liver function. Mean serum selenium concentrations were significantly lower in cirrhotic individuals when compared with patients with hepatitis (P<0.05). Therefore, the severity of the live injury is a factor conditioning the impairment in the selenium body status observed in individuals with hepatopathies. In hepatic patients serum total cholesterol levels showed a significant correlation with serum selenium concentrations (r=0.912, P<0.05) demonstrating the important role of selenium as an antioxidant agent; similarly, gamma-glutamic-transferase levels were significantly correlated with the serum selenium levels (r=-0.803, P<0.05) indicating that when the intensity of the hepatic injury increases (enhancement in serum GGT levels) concomitantly the serum selenium levels decrease significantly. No significant relationships between serum selenium levels and sex or age of patients were observed.
Isolation and characterization of extrachromosomal circular DNAs in mouse heart, brain and liver tissues at various ages
Flores, S.C.
Eucaryotic cells contains extrachromosomal circular (eccDNAs) which can be separated and distinguished from chromosomal DNA. Using alkaline denaturation-renaturation, exonuclease III digestion and density gradient centrifugations, covalently closed circular DNA (cc-cDNA) molecules were isolated from 1-, 8-, 16-, and 24-month C57BL/6 mouse heart, brain and liver organs. Restriction enzyme analyses and other enzymatic treatments established the covalently closed nature of the isolated molecules. Electron microscopic analyses of heart eccDNAs showed similar size distributions at all ages, but more discrete size classes and slightly larger circles were observed in 24-month heart eccDNA preparations. Heart contained more circles per cell than either liver or brain, which contained approximately the same amount of eccDNAs per genome. Furthermore, ({sup 3}H)-pBR322 recovery studies revealed no endogenous factors that might have affected the yields of eccDNAs from young and old tissues. To determine if there were any age-related or tissue-specific differences in repetitive sequences in eccDNAs, heart, brain and liver eccDNAs were probed with B1, B2, IAP, L1 and satellite sequences of the mouse genome. The hybridization results showed that these sequence families were differentially represented at all ages in eccDNAs. B2 sequences were the highest in heart, while satellite sequences were the highest in liver and brain. In heart, very little age-related change was observed in the quantity of repetitive sequences. Nevertheless, a tendency to decrease for B1 and B2 sequences at 24 months was observed. In liver, repetitive sequences decreased from 1 to 8 months of age, with very little change beyond that time point. Brain eccDNA repetitive sequences did not change significantly with age.
Analysis of multiple anticoagulant rodenticides in animal blood and liver tissue using principles of QuEChERS method.
Vudathala, Daljit; Cummings, Margaret; Murphy, Lisa
A quick and easy method for the analysis of anticoagulant rodenticides in blood or tissue using principles of dispersive solid-phase extraction (dSPE), commonly known as QuEChERS (short for quick, easy, cheap, effective, rugged, and safe), was developed. Briefly, a combination of magnesium sulfate, PSA, florisil, and basic alumina was used to cleanup blood samples. Further, to cleanup liver tissue samples, C(18) sorbent was included along with the previously mentioned. The samples were analyzed using high-performance liquid chromatography equipped with a reversed-phase C(18) column (150 x 4.6 mm, 5-microm particle size) and a UV and fluorescence detector. The mobile phase consisted of 0.03 M tetrabutylammonium hydroxide (TBA) adjusted to pH 7/methanol (1:1, v/v) as solvent A and methanol as solvent B in a gradient run. The method detection limit was as low as 10 ng/mL for brodifacoum and difenacoum in blood and 10 ng/g in liver; 50 ng/mL for bromadiolone, difethialone, and chlorphacinone in blood and similarly 50 ng/g in liver; and 100 ng/mL for coumafuryl, pindone, warfarin, and diphacinone in blood and 100 ng/g in liver samples. A number of clinical samples of both blood and liver were analyzed; the comparison of this modified QuEChERS and traditional solid-phase extraction data was found to be in close agreement. This method resulted in drastic reduction in processing time and solvent cost both in terms of consumption and disposal, thus making it an attractive alternative to the traditional solid-phase extraction.
How predictive quantitative modelling of tissue organisation can inform liver disease pathogenesis.
Drasdo, Dirk; Hoehme, Stefan; Hengstler, Jan G
From the more than 100 liver diseases described, many of those with high incidence rates manifest themselves by histopathological changes, such as hepatitis, alcoholic liver disease, fatty liver disease, fibrosis, and, in its later stages, cirrhosis, hepatocellular carcinoma, primary biliary cirrhosis and other disorders. Studies of disease pathogeneses are largely based on integrating -omics data pooled from cells at different locations with spatial information from stained liver structures in animal models. Even though this has led to significant insights, the complexity of interactions as well as the involvement of processes at many different time and length scales constrains the possibility to condense disease processes in illustrations, schemes and tables. The combination of modern imaging modalities with image processing and analysis, and mathematical models opens up a promising new approach towards a quantitative understanding of pathologies and of disease processes. This strategy is discussed for two examples, ammonia metabolism after drug-induced acute liver damage, and the recovery of liver mass as well as architecture during the subsequent regeneration process. This interdisciplinary approach permits integration of biological mechanisms and models of processes contributing to disease progression at various scales into mathematical models. These can be used to perform in silico simulations to promote unravelling the relation between architecture and function as below illustrated for liver regeneration, and bridging from the in vitro situation and animal models to humans. In the near future novel mechanisms will usually not be directly elucidated by modelling. However, models will falsify hypotheses and guide towards the most informative experimental design.
A study of metal concentrations and metallothionein binding capacity in liver, kidney and brain tissues of three Arctic seal species.
Sonne, Christian; Aspholm, Ole; Dietz, Rune; Andersen, Steen; Berntssen, Marc H G; Hylland, Ketil
Arctic seals are known to accumulate relatively high concentrations of potential toxic heavy metals in their vital organs, such as livers and kidneys, as well as in their central nervous system. We therefore decided to determine whether mercury, copper, cadmium and zinc levels in liver, kidney and brain tissues of three Arctic seal species were associated with the intracellular metal-binding protein metallothionein (MT) as a sign of toxic exposure. Samples from four ringed (Phoca hispida), five harp (P.groenlandica) and five hooded (Cystophora cristata) seals taken during field trips to Central West Greenland (Godhavn) and the Barents Sea in the spring of 1999 were used for the present study. In all three seal species concentrations of mercury, zinc and copper were highest in the liver, except for cadmium which was highest in the kidneys. Metal concentrations increased significantly in the order: ringed seal
Simultaneous determination of perfluorinated compounds and their potential precursors in mussel tissue and fish muscle tissue and liver samples by liquid chromatography-electrospray-tandem mass spectrometry.
Zabaleta, I; Bizkarguenaga, E; Prieto, A; Ortiz-Zarragoitia, M; Fernández, L A; Zuloaga, O
An analytical method for the simultaneous determination in fish liver and muscle tissue and mussel samples of 14 perfluorinated compounds (PFCs), including three perfluoroalkylsulfonates (PFSAs), seven perfluorocarboxylic acids (PFCAs), three perfluorophosphonic acids (PFPAs) and perfluorooctanesulfonamide (PFOSA), and 10 potential precursors, including four polyfluoroalkyl phosphates (PAPs), four fluorotelomer saturated acids (FTCAs) and two fluorotelomer unsaturated acids (FTUCAs), was developed in the present work. Different clean-up strategies by means of solid-phase extraction (SPE) using a mix-mode weak anion exchanger (WAX), reverse phase Envi-Carb or a combination of them was optimized and evaluated for the clean-up of focused ultrasonic solid-liquid (FUSLE) extracts before the analysis by liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS). Mix-mode WAX coupled in-line to Envi-Carb was finally selected since it rendered the cleanest extracts and minimum matrix effect. The FUSLE-SPE-LC-MS/MS methodology was validated in terms of recovery, precision and method detection limits (MDLs). Apparent recovery values in the 65-116%, 59-119% and 67-126% range and MDLs in the 0.1-2.7 ng/g, 0.1-3.8 ng/g and 0.2-3.1ng/g range were obtained for liver, mussel and fish muscle tissue samples, respectively. The method developed was applied to the analysis of grey mullet liver (Chelon labrosus) and mussel (Mytilus galloprovincialis) samples from the Basque Coast (North of Spain) and Yellowfin tuna muscle tissue (Thunnus albacares) samples from the Indian Ocean. To the best of our knowledge this is the first method that describes the simultaneous determination of 14 PFCs and 10 potential precursors in fish liver, fish muscle tissue and mussel samples. Besides, this is the first time that 8:2 monosubstituted polyfluorodecyl phosphate (8:2 monoPAP) and 8:2 disubstituted polyfluorodecyl phosphate (8:2 diPAP) were detected in mussel and tuna samples
Selective inhibition of cholesterol synthesis in liver versus extrahepatic tissues by HMG-CoA reductase inhibitors.
Parker, R A; Clark, R W; Sit, S Y; Lanier, T L; Grosso, R A; Wright, J J
Hepatic specificity of inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase may be achieved by efficient first-pass liver extraction resulting in low circulating drug levels, as with lovastatin, or by lower cellular uptake in peripheral tissues, seen with pravastatin. BMY-21950 and its lactone form BMY-22089, new synthetic inhibitors of HMG-CoA reductase, were compared with the major reference agent lovastatin and with the synthetic inhibitor fluindostatin in several in vitro and in vivo models of potency and tissue selectivity. The kinetic mechanism and the potency of BMY-21950 as a competitive inhibitor of isolated HMG-CoA reductase were comparable to the reference agents. The inhibitory potency (cholesterol synthesis assayed by 3H2O or [14C]acetate incorporation) of BMY-21950 in rat hepatocytes (IC50 = 21 nM) and dog liver slices (IC50 = 23 nM) equalled or exceeded the potencies of the reference agents. Hepatic cholesterol synthesis in vivo in rats was effectively inhibited by BMY-21950 and its lactone form BMY-22089 (ED50 = 0.1 mg/kg p.o.), but oral doses (20 mg/kg) that suppressed liver synthesis by 83-95% inhibited sterol synthesis by only 17-24% in the ileum. In contrast, equivalent doses of lovastatin markedly inhibited cholesterol synthesis in both organs. In tissue slices from rat ileum, cell dispersions from testes, adrenal, and spleen, and in bovine ocular lens epithelial cells, BMY-21950 inhibited sterol synthesis weakly in vitro with IC50 values 76- and 188-times higher than in hepatocytes; similar effects were seen for BMY-22089. However, the IC50 ratios (tissue/hepatocyte) for lovastatin and fluindostatin were near unity in these models. Thus, BMY-21950 and BMY-22089 are the first potent synthetic HMG-CoA reductase inhibitors that possess a very high degree of liver selectivity based upon differential inhibition sensitivities in tissues. This cellular uptake-based property of hepatic specificity of BMY-21950 and BMY-22089, also
Investigation of biochemical and histopathological effects of Mentha piperita Labiatae and Mentha spicata Labiatae on liver tissue in rats.
Akdogan, M; Ozguner, M; Aydin, G; Gokalp, O
The plant Mentha piperita, or peppermint, is commonly used in the treatment of loss of appetite, common cold, bronchitis, sinusitis, fever, nausea and vomiting, and indigestion as a herbal agent. In this study, we aimed to investigate biochemical and histological effects of M. piperita Labiatae, growing in the Yenisar Bademli town of Isparta city, and Mentha spicata Labiatae, growing in the Anamas high plateau of the Yenisar Bademli town, on the rat liver tissue. Forty-eight male Wistar albino rats weighing 200-250 g were used for this study. Rats were divided into four groups of 12 animals: Group I received no herbal tea (control group); Group II received 20 g/L M. piperita tea; Group III received 20 g/L M. spicata tea; and Group IV received 40 g/L M. spicata tea. Herbal teas were prepared daily and provided at all times to the rats during 30 days as drinking water. Liver function tests, including aspartate aminotransferase (AST/GOT) and alanine aminotransferase (ALT/GPT) activities were measured. To evaluate liver antioxidant defences, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and thiobarbituric acid reactive substance (TBARS) activities were determined in the homogenates of liver tissue. In addition, liver tissues were submitted for histopathologic examination. AST and ALT activities were increased in Group II, Group III and Group IV gradually when compared with the control group. The difference between Group II and the control group was not statistically significant (P > 0.016). Increases in AST and ALT activities of Group III and Group IV were statistically significant when compared with the control group. SOD, GSH-Px and CAT activities were increased in Group II when compared with the control group but the difference was not statistically significant (P > 0.016). However, SOD, GSH-Px activities and the TBARS level were significantly increased, and CAT activity was significantly decreased in Group III when compared with the
Berberine Ameliorates Hepatic Steatosis and Suppresses Liver and Adipose Tissue Inflammation in Mice with Diet-induced Obesity
Guo, Ting; Woo, Shih-Lung; Guo, Xin; Li, Honggui; Zheng, Juan; Botchlett, Rachel; Liu, Mengyang; Pei, Ya; Xu, Hang; Cai, Yuli; Zeng, Tianshu; Chen, Lulu; Li, Xiaodong; Li, Qifu; Xiao, Xiaoqiu; Huo, Yuqing; Wu, Chaodong
Increasing evidence demonstrates that berberine (BBR) is beneficial for obesity-associated non-alcoholic fatty liver disease (NAFLD). However, it remains to be elucidated how BBR improves aspects of NAFLD. Here we revealed an AMP-activated protein kinase (AMPK)-independent mechanism for BBR to suppress obesity-associated inflammation and improve hepatic steatosis. In C57BL/6J mice fed a high-fat diet (HFD), treatment with BBR decreased inflammation in both the liver and adipose tissue as indicated by reduction of the phosphorylation state of JNK1 and the mRNA levels of proinflammatory cytokines. BBR treatment also decreased hepatic steatosis, as well as the expression of acetyl-CoA carboxylase and fatty acid synthase. Interestingly, treatment with BBR did not significantly alter the phosphorylation state of AMPK in both the liver and adipose tissue of HFD-fed mice. Consistently, BBR treatment significantly decreased the phosphorylation state of JNK1 in both hepatoma H4IIE cells and mouse primary hepatocytes in both dose-dependent and time-dependent manners, which was independent of AMPK phosphorylation. BBR treatment also caused a decrease in palmitate-induced fat deposition in primary mouse hepatocytes. Taken together, these results suggest that BBR actions on improving aspects of NAFLD are largely attributable to BBR suppression of inflammation, which is independent of AMPK. PMID:26936230
Effect of Non-speckle Echo Signals on Tissue Characteristics for Liver Fibrosis using Probability Density Function of Ultrasonic B-mode image
NASA Astrophysics Data System (ADS)
Mori, Shohei; Hirata, Shinnosuke; Yamaguchi, Tadashi; Hachiya, Hiroyuki
To develop a quantitative diagnostic method for liver fibrosis using an ultrasound B-mode image, a probability imaging method of tissue characteristics based on a multi-Rayleigh model, which expresses a probability density function of echo signals from liver fibrosis, has been proposed. In this paper, an effect of non-speckle echo signals on tissue characteristics estimated from the multi-Rayleigh model was evaluated. Non-speckle signals were determined and removed using the modeling error of the multi-Rayleigh model. The correct tissue characteristics of fibrotic tissue could be estimated with the removal of non-speckle signals.
Cadmium and zinc in kidney, liver, muscle and mammary tissue from dairy cows in conventional and organic farming.
Olsson, I M; Jonsson, S; Oskarsson, A
Input of Cd to arable soils occurs mainly through atmospheric deposition and mineral fertilisers. Phosphate fertilisers are often contaminated with Cd. In organic farming the use of mineral fertilisers is restricted. The impact of conventional and organic farming on Cd and Zn levels in tissues from dairy cows was studied. Kidney, liver, muscle and mammary tissue samples were collected at slaughter from 67 cows, aged 30-95 months, in a project with conventional and organic production at the same farm. Samples were analysed by electrothermal atomic absorption spectrometry with a quality control programme. Significantly lower levels of Cd were found in cows from the organic system (n = 29) than from the conventional cows (n = 38) in kidney [330 +/- 100 (mean +/- s) micrograms kg-1 vs. 410 +/- 140], liver (33 +/- 15 vs. 44 +/- 19) and mammary tissue (0.38 +/- 0.14 vs. 0.59 +/- 0.37), while there were no differences in muscle (0.48 +/- 0.13 vs. 0.49 +/- 0.14). Organic cow kidneys had lower Zn levels than conventional cows (19 +/- 1.4 mg kg-1 vs. 20 +/- 2), whereas muscles had higher Zn levels than conventional cows (67 +/- 16 vs. 51 +/- 12). Cd and Zn in mammary tissue were positively related to age and milk production. There was a positive relationship between levels in kidney of Cd and metallothionein (MT) and a Cd/MT concentration ratio indicating protection from Cd-induced renal dysfunction. When older animals, that entered the project as milk-producing cows, were included the differences in kidney and liver Cd levels between the systems were no longer significant, while Cd in kidney became related to age- and production-related parameters. The change of significant relationships when older animals were included shows the importance of controlled conditions for environmental monitoring.
A Computational, Tissue-Realistic Model of Pressure Ulcer Formation in Individuals with Spinal Cord Injury.
Ziraldo, Cordelia; Solovyev, Alexey; Allegretti, Ana; Krishnan, Shilpa; Henzel, M Kristi; Sowa, Gwendolyn A; Brienza, David; An, Gary; Mi, Qi; Vodovotz, Yoram
People with spinal cord injury (SCI) are predisposed to pressure ulcers (PU). PU remain a significant burden in cost of care and quality of life despite improved mechanistic understanding and advanced interventions. An agent-based model (ABM) of ischemia/reperfusion-induced inflammation and PU (the PUABM) was created, calibrated to serial images of post-SCI PU, and used to investigate potential treatments in silico. Tissue-level features of the PUABM recapitulated visual patterns of ulcer formation in individuals with SCI. These morphological features, along with simulated cell counts and mediator concentrations, suggested that the influence of inflammatory dynamics caused simulations to be committed to "better" vs. "worse" outcomes by 4 days of simulated time and prior to ulcer formation. Sensitivity analysis of model parameters suggested that increasing oxygen availability would reduce PU incidence. Using the PUABM, in silico trials of anti-inflammatory treatments such as corticosteroids and a neutralizing antibody targeted at Damage-Associated Molecular Pattern molecules (DAMPs) suggested that, at best, early application at a sufficiently high dose could attenuate local inflammation and reduce pressure-associated tissue damage, but could not reduce PU incidence. The PUABM thus shows promise as an adjunct for mechanistic understanding, diagnosis, and design of therapies in the setting of PU.
Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.
Simó, Rafael; Hernández, Cristina; Sáez-López, Cristina; Soldevila, Berta; Puig-Domingo, Manel; Selva, David M
Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes) and in vivo (C57BL6/mice) experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels) in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not related to weight
The use of gas chromatography to analyze compositional changes of fatty acids in rat liver tissue during pregnancy.
Fisk, Helena L; West, Annette L; Childs, Caroline E; Burdge, Graham C; Calder, Philip C
Gas chromatography (GC) is a highly sensitive method used to identify and quantify the fatty acid content of lipids from tissues, cells, and plasma/serum, yielding results with high accuracy and high reproducibility. In metabolic and nutrition studies GC allows assessment of changes in fatty acid concentrations following interventions or during changes in physiological state such as pregnancy. Solid phase extraction (SPE) using aminopropyl silica cartridges allows separation of the major lipid classes including triacylglycerols, different phospholipids, and cholesteryl esters (CE). GC combined with SPE was used to analyze the changes in fatty acid composition of the CE fraction in the livers of virgin and pregnant rats that had been fed various high and low fat diets. There are significant diet/pregnancy interaction effects upon the omega-3 and omega-6 fatty acid content of liver CE, indicating that pregnant females have a different response to dietary manipulation than is seen among virgin females.
Residues of sulfadiazine and doxycycline in broiler liver and muscle tissue due to cross-contamination of feed.
Vandenberge, V; Delezie, E; Huyghebaert, G; Delahaut, P; Daeseleire, E; Croubels, S
Veterinary drugs, such as antimicrobial compounds, are widely used in poultry and may lead to the presence of residues in matrices of animal origin, such as muscle and liver tissue. In this study, broilers received an experimental feed containing sulfadiazine or doxycycline at cross-contamination levels of 2.5, 5 and 10% of the therapeutic dose in feed. Breast and thigh muscle and liver samples were collected during treatment and depletion period and analysed via liquid chromatography-tandem mass spectrometry (LC-MS/MS). Concentrations reached a plateau phase 3-5 days after the start of experimental feeding. A rapid depletion of residues was noted after withdrawal of the experimental feed. No significant differences in measured concentrations were observed between the various muscle types. Residue concentrations for some experimental groups; the 10% group of sulfadiazine and the 5 and 10% group of doxycycline, however, exceeded their corresponding maximum residue limits (MRLs).
Comparative analysis of the gap junction protein from rat heart and liver: is there a tissue specificity of gap junctions?
Gros, D B; Nicholson, B J; Revel, J P
Gap junctions have been isolated from both rat heart and liver, tissues where junctions are typical in appearance and physiology. The purity of the fractions obtained was monitored by electron microscopy (thin-sectioning and negative staining) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The myocardial gap junctions are comprised of a single polypeptide of Mr 28,000, apparently derived from a protein of Mr 30,000. Hepatic gap junctions are also comprised of a single native protein of Mr 28,000 as previously reported. Exhaustive trypsin digestion of the isolated junctions cleaves both of these proteins similarly, while leaving their characteristic junctional lattice structures intact. However, comparison of heart and liver junctional proteins by two-dimensional peptide mapping of tryptic and alpha-chymotryptic fragments, followed by high pressure liquid chromatography, reveals no homology between these proteins.
Structural and metabolic characterization of RNAs from rats with experimental Guerin tumor - I. Nucleotide composition of RNAs from the liver and tumor tissues of rats.
Ratkiewicz, A; Galasinski, W
The characteristics of the ribonucleic acids of Guerin tumor was the subject of this work. The effect of tumor development on the structure of the ribonucleic acids in the liver of tumor bearing rats was studied. Some differences of nucleotide compositions in RNAs isolated from subcellular fractions of liver of control and tumor bearing rats and of cancer tissue were observed. The nucleotide compositions of cancer nuclear RNA is distinctly different from liver RNA. The changes in primary structure of liver RNAs due by development of tumor in rats may be result of metabolic peculiarities of these RNAs.
Structural and metabolic characterization of RNAs from rats with experimental Guerin tumor - II. metabolic peculiarities of RNAs from the liver and tumor tissues of rats.
Ratkiewicz, A; Galasinski, W
Metabolic peculiarities of RNAs in the liver of the tumor bearing and in the tumor tissue were found. The synthesis of nuclear RNA in liver of tumor bearing rats is distinctly disordered in comparison to that of control rats. The level of 14C-orotic acid incorporation into RNA of cancer tissue is manifold lower than that into the liver RNA. The studies on turnover rate showed the metabolic heterogeneity of the nuclear RNAs. The part of them showed a short turnover, the other RNAs were degraded much slower.
Gene expression profiling and differentiation assessment in primary human hepatocyte cultures, established hepatoma cell lines, and human liver tissues
Olsavsky, Katy M.; Page, Jeanine L.; Johnson, Mary C.; Zarbl, Helmut; Strom, Stephen C.; Omiecinski, Curtis J. . E-mail: email@example.com
Frequently, primary hepatocytes are used as an in vitro model for the liver in vivo. However, the culture conditions reported vary considerably, with associated variability in performance. In this study, we characterized the differentiation character of primary human hepatocytes cultured using a highly defined, serum-free two-dimensional sandwich system, one that configures hepatocytes with collagen I as the substratum together with a dilute extracellular matrix (Matrigel{sup TM}) overlay combined with a defined serum-free medium containing nanomolar levels of dexamethasone. Gap junctional communication, indicated by immunochemical detection of connexin 32 protein, was markedly enhanced in hepatocytes cultured in the Matrigel sandwich configuration. Whole genome expression profiling enabled direct comparison of liver tissues to hepatocytes and to the hepatoma-derived cell lines, HepG2 and Huh7. PANTHER database analyses were used to identify biological processes that were comparatively over-represented among probe sets expressed in the in vitro systems. The robustness of the primary hepatocyte cultures was reflected by the extent of unchanged expression character when compared directly to liver, with more than 77% of the probe sets unchanged in each of the over-represented categories, representing such genes as C/EBP{alpha}, HNF4{alpha}, CYP2D6, and ABCB1. In contrast, HepG2 and Huh7 cells were unchanged from the liver tissues for fewer than 48% and 55% of these probe sets, respectively. Further, hierarchical clustering of the hepatocytes, but not the cell lines, shifted from donor-specific to treatment-specific when the probe sets were filtered to focus on phenobarbital-inducible genes, indicative of the highly differentiated nature of the hepatocytes when cultured in a highly defined two-dimensional sandwich system.
Enhanced liver progenitor cell survival and differentiation in vivo by spheroid implantation in a vascularized tissue engineering chamber.
Yap, Kiryu K; Dingle, Aaron M; Palmer, Jason A; Dhillon, Raminder S; Lokmic, Zerina; Penington, Anthony J; Yeoh, George C; Morrison, Wayne A; Mitchell, Geraldine M
Liver tissue engineering is hampered by poor implanted cell survival due to inadequate vascularization and cell-cell/cell-matrix interactions. Here, we use liver progenitor cell (LPC) spheroids to enhance cell-cell/cell-matrix interactions, with implantation into an angiogenic in vivo mouse chamber. Spheroids were generated in vitro in methylcellulose medium. Day 2 spheroids were optimal for implantation (22,407 +/-645 cells/spheroid), demonstrating maximal proliferation (Ki67 immunolabeling) and minimal apoptosis (caspase-3 immunolabelling). In vivo chambers established bilaterally on epigastric vessels of immunodeficient mice were implanted with equivalent numbers of LPCs as a cell suspension (200,000 cells), or spheroids (9 spheroids). At day 14, a trend of increased LPC survival was observed in spheroid-implanted chambers [pan-cytokeratin (panCK+) cells, p = 0.38, 2.4 fold increase)], with significantly increased differentiation [cytokeratin 18 (CK18+) cells, p < 0.002, 5.1 fold increase)] compared to cell suspension-implanted chambers. At day 45, both measures were significantly increased in spheroid-implanted chambers (panCK, p < 0.006, 16 fold increase) (CK18, p < 0.019, 6 fold increase). Hepatic acini/plates of CK18 + cells expressed hepatocyte nuclear factor 4-α and β-catenin, indicating ongoing hepatic differentiation. Spheroid cell-delivery significantly increased LPC survival and differentiation compared to conventional cell suspensions. This LPC spheroid/vascularized chamber model has clinical potential to generate three-dimensional vascularized liver tissue for liver replacement.
Tissue-resident Eomes(hi) T-bet(lo) CD56(bright) NK cells with reduced proinflammatory potential are enriched in the adult human liver.
Harmon, Cathal; Robinson, Mark W; Fahey, Ronan; Whelan, Sarah; Houlihan, Diarmaid D; Geoghegan, Justin; O'Farrelly, Cliona
The adult human liver is enriched with natural killer (NK) cells, accounting for 30-50% of hepatic lymphocytes, which include tissue-resident hepatic NK-cell subpopulations, distinct from peripheral blood NK cells. In murine liver, a subset of liver-resident hepatic NK cells have altered expression of the two highly related T-box transcription factors, T-bet and eomesodermin (Eomes). Here, we investigate the heterogeneity of T-bet and Eomes expression in NK cells from healthy adult human liver with a view to identifying human liver-resident populations. Hepatic NK cells were isolated from donor liver perfusates and biopsies obtained during orthotopic liver transplantation (N = 28). Hepatic CD56(bright) NK cells were Eomes(hi) T-bet(lo) , a phenotype virtually absent from peripheral blood. These NK cells express the chemokine receptor CXCR6 (chemokine (C-X-C motif) receptor 6), a marker of tissue residency, which is absent from hepatic CD56(dim) and blood NK cells. Compared to blood populations, these hepatic CD56(bright) NK cells have increased expression of activatory receptors (NKp44, NKp46, and NKG2D). They show reduced ability to produce IFN-γ but enhanced degranulation in response to challenge with target cells. This functionally distinct population of hepatic NK cells constitutes 20-30% of the total hepatic lymphocyte repertoire and represents a tissue-resident immune cell population adapted to the tolerogenic liver microenvironment.
Gene expression profile in the liver tissue of geese after overfeeding.
Zhu, L H; Meng, H; Duan, X J; Xu, G Q; Zhang, J; Gong, D Q
Geese form a fatty liver after feeding on a carbohydrate-rich diet, possibly as an evolutionary adaptation to accumulate reserves for migration. To gain insight into the gene-regulation processes of hepatic steatosis in geese, we examined the profile of transcriptional expression in goose fatty liver and control liver by suppression subtractive hybridization and measured the levels of serum biochemical variables. We found 107 genes whose expression was different between the treatment and control groups. The main functions of these genes are metabolic processes, including the metabolism of carbohydrates, amino acids, and lipids. Twenty-four genes were classified using the Kyoto Encyclopaedia of Genes and Genomes pathways. Twelve genes that related to metabolic and cellular processes were confirmed by quantitative RT-PCR. A specific positive effect of feeding was observed on the expression of genes involved mainly in unsaturated fatty acids and triglyceride synthesis, and a negative effect was observed on genes involved in β-oxidation, cholesterol metabolism, and glycolysis. The results could serve as an important reference for the development of goose breeding for fatty liver production and human liver disease research.
Quantification of C4d deposition and hepatitis C virus RNA in tissue in cases of graft rejection and hepatitis C recurrence after liver transplantation
Song, Alice Tung Wan; de Mello, Evandro Sobroza; Alves, Venâncio Avancini Ferreira; Cavalheiro, Norma de Paula; Melo, Carlos Eduardo; Bonazzi, Patricia Rodrigues; Tengan, Fatima Mitiko; Freire, Maristela Pinheiro; Barone, Antonio Alci; D'Albuquerque, Luiz Augusto Carneiro; Abdala, Edson
Histology is the gold standard for diagnosing acute rejection and hepatitis C recurrence after liver transplantation. However, differential diagnosis between the two can be difficult. We evaluated the role of C4d staining and quantification of hepatitis C virus (HCV) RNA levels in liver tissue. This was a retrospective study of 98 liver biopsy samples divided into four groups by histological diagnosis: acute rejection in patients undergoing liver transplant for hepatitis C (RejHCV+), HCV recurrence in patients undergoing liver transplant for hepatitis C (HCVTx+), acute rejection in patients undergoing liver transplant for reasons other than hepatitis C and chronic hepatitis C not transplanted (HCVTx-). All samples were submitted for immunohistochemical staining for C4d and HCV RNA quantification. Immunoexpression of C4d was observed in the portal vessels and was highest in the HCVTx- group. There was no difference in C4d expression between the RejHCV+ and HCVTx+ groups. However, tissue HCV RNA levels were higher in the HCVTx+ group samples than in the RejHCV+ group samples. Additionally, there was a significant correlation between tissue and serum levels of HCV RNA. The quantification of HCV RNA in liver tissue might prove to be an efficient diagnostic test for the recurrence of HCV infection. PMID:25742264
Induced pluripotent stem cell-derived hepatocytes and endothelial cells in multi-component hydrogel fibers for liver tissue engineering.
Du, Chan; Narayanan, Karthikeyan; Leong, Meng Fatt; Wan, Andrew C A
Liver tissue engineering requires a suitable cell source, methodologies to assemble the cells within their niche microenvironments in a spatially defined manner, and vascularization of the construct in vivo for maintenance of hepatocyte viability and function. Recently, we have developed methods of encapsulating cells within separate domains in multi-component hydrogel fibers and methods of assembling fibers to form 3D-patterned tissue constructs. In the present work, we have combined these approaches to encapsulate hepatocytes and endothelial cells within their specific niches, and to assemble them into endothelialized liver tissue constructs. The hepatocytes and endothelial cells were obtained in parallel by differentiating human recombinant protein-induced human pluripotent stem cells, resulting in a construct which contained genetically identical endothelial and parenchymal elements. We were able to demonstrate that the presence of endothelial cells in the scaffold significantly improved hepatocyte function in vitro and facilitated vascularization of the scaffold when implanted in a mouse partial hepatectomy model. The in vivo studies further asserted that integration of the scaffold with host vasculature had occurred, as demonstrated by the presence of human albumin in the mouse serum.
Stabilin-1 expression defines a subset of macrophages that mediate tissue homeostasis and prevent fibrosis in chronic liver injury
Rantakari, Pia; Patten, Daniel A.; Valtonen, Joona; Karikoski, Marika; Gerke, Heidi; Dawes, Harriet; Laurila, Juha; Ohlmeier, Steffen; Elima, Kati; Hübscher, Stefan G.; Jalkanen, Sirpa; Adams, David H.; Salmi, Marko; Shetty, Shishir
Macrophages are key regulators of fibrosis development and resolution. Elucidating the mechanisms by which they mediate this process is crucial for establishing their therapeutic potential. Here, we use experimental models of liver fibrosis to show that deficiency of the scavenger receptor, stabilin-1, exacerbates fibrosis and delays resolution during the recovery phase. We detected a subset of stabilin-1+ macrophages that were induced at sites of cellular injury close to the hepatic scar in mouse models of liver fibrosis and in human liver disease. Stabilin-1 deficiency abrogated malondialdehyde-LDL (MDA-LDL) uptake by hepatic macrophages and was associated with excess collagen III deposition. Mechanistically, the lack of stabilin-1 led to elevated intrahepatic levels of the profibrogenic chemokine CCL3 and an increase in GFAP+ fibrogenic cells. Stabilin-1−/− macrophages demonstrated a proinflammatory phenotype during liver injury and the normal induction of Ly6Clo monocytes during resolution was absent in stabilin-1 knockouts leading to persistence of fibrosis. Human stabilin-1+ monocytes efficiently internalized MDA-LDL and this suppressed their ability to secrete CCL3, suggesting that loss of stabilin-1 removes a brake to CCL3 secretion. Experiments with cell-lineage–specific knockouts revealed that stabilin-1 expression in myeloid cells is required for the induction of this subset of macrophages and that increased fibrosis occurs in their absence. This study demonstrates a previously unidentified regulatory pathway in fibrogenesis in which a macrophage scavenger receptor protects against organ fibrosis by removing fibrogenic products of lipid peroxidation. Thus, stabilin-1+ macrophages shape the tissue microenvironment during liver injury and healing. PMID:27474165
Prediction of radiation-induced liver disease by Lyman normal-tissue complication probability model in three-dimensional conformal radiation therapy for primary liver carcinoma
Xu ZhiYong; Liang Shixiong; Zhu Ji; Zhu Xiaodong; Zhao Jiandong; Lu Haijie; Yang Yunli; Chen Long; Wang Anyu; Fu Xiaolong; Jiang Guoliang . E-mail: email@example.com
Purpose: To describe the probability of RILD by application of the Lyman-Kutcher-Burman normal-tissue complication (NTCP) model for primary liver carcinoma (PLC) treated with hypofractionated three-dimensional conformal radiotherapy (3D-CRT). Methods and Materials: A total of 109 PLC patients treated by 3D-CRT were followed for RILD. Of these patients, 93 were in liver cirrhosis of Child-Pugh Grade A, and 16 were in Child-Pugh Grade B. The Michigan NTCP model was used to predict the probability of RILD, and then the modified Lyman NTCP model was generated for Child-Pugh A and Child-Pugh B patients by maximum-likelihood analysis. Results: Of all patients, 17 developed RILD in which 8 were of Child-Pugh Grade A, and 9 were of Child-Pugh Grade B. The prediction of RILD by the Michigan model was underestimated for PLC patients. The modified n, m, TD{sub 5} (1) were 1.1, 0.28, and 40.5 Gy and 0.7, 0.43, and 23 Gy for patients with Child-Pugh A and B, respectively, which yielded better estimations of RILD probability. The hepatic tolerable doses (TD{sub 5}) would be MDTNL of 21 Gy and 6 Gy, respectively, for Child-Pugh A and B patients. Conclusions: The Michigan model was probably not fit to predict RILD in PLC patients. A modified Lyman NTCP model for RILD was recommended.
Cinnamon extract improves the body composition and attenuates lipogenic processes in the liver and adipose tissue of rats.
Lopes, Bruna P; Gaique, Thaiane G; Souza, Luana L; Paula, Gabriela S M; Kluck, George E G; Atella, Georgia C; Gomes, Anne Caroline C; Simas, Naomi K; Kuster, Ricardo M; Ortiga-Carvalho, Tania M; Pazos-Moura, Carmen C; Oliveira, Karen J
In models of metabolic disorders, cinnamon improves glucose and lipid metabolism. This study explores the effect of chronic supplementation with aqueous cinnamon extract (CE) on the lipid metabolism of rats. Male adult Wistar rats were separated into a control group (CTR) receiving water and a CE Group receiving aqueous cinnamon extract (400 mg of cinnamon per kg body mass per day) by gavage for 25 consecutive days. Cinnamon supplementation did not change the food intake or the serum lipid profile but promoted the following changes: lower body mass gain (P = 0.008), lower relative mass of white adipose tissue (WAT) compartments (P = 0.045) and higher protein content (percentage of the carcass) (P = 0.049). The CE group showed lower leptin mRNA expression in the WAT (P = 0.0017) and an important tendency for reduced serum leptin levels (P = 0.059). Cinnamon supplementation induced lower mRNA expression of SREBP1c (sterol regulatory element-binding protein 1c) in the WAT (P = 0.001) and liver (P = 0.013) and lower mRNA expression of SREBP2 (P = 0.002), HMGCoA reductase (3-hydroxy-3-methylglutaryl-CoA reductase) (P = 0.0003), ACAT1 (acetyl-CoA acetyltransferase 1) (P = 0.032) and DGAT2 (diacylglycerol O-acyltransferase 2) (P = 0.03) in the liver. These changes could be associated with the reduced esterified cholesterol and triacylglycerol content detected in this tissue. Our results suggest that chronic ingestion of aqueous cinnamon extract attenuates lipogenic processes, regulating the expression of key enzymes and transcriptional factors and their target genes, which are directly involved in lipogenesis. These molecular changes possibly promote adaptations that would prevent an increase in circulating cholesterol and triacylglycerol levels and prevent lipid accumulation in tissues, such as liver and WAT. Therefore, we speculate that cinnamon may also be useful for preventing or retarding the development of lipid disorders.
Effects of probiotic yogurt consumption on metabolic factors in individuals with nonalcoholic fatty liver disease.
Nabavi, S; Rafraf, M; Somi, M H; Homayouni-Rad, A; Asghari-Jafarabadi, M
The aim of this study was to investigate the effects of probiotic yogurt consumption on some metabolic factors in nonalcoholic fatty liver disease (NAFLD) patients. This double-blind, randomized, controlled clinical trial was conducted on 72 patients with NAFLD (33 males and 39 females) aged 23 to 63 yr. Subjects in the intervention group (n=36) consumed 300 g/d of probiotic yogurt containing Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 and those in the control group (n=36) consumed 300 g/d of conventional yogurt for 8 wk. Fasting blood samples, anthropometric measurements, and dietary records (24h/d for 3 d) were collected at baseline and at the end of the trial. Probiotic yogurt consumption resulted in reductions of 4.67, 5.42, 4.1, and 6.92% in serum levels of alanine aminotransferase, aspartate aminotransferase, total cholesterol, and low-density lipoprotein cholesterol, respectively, compared with control group. No significant changes were observed in levels of serum glucose, triglycerides, or high-density lipoprotein cholesterol in either group. Probiotic yogurt consumption improved hepatic enzymes, serum total cholesterol, and low-density lipoprotein cholesterol levels in studied subjects and might be useful in management of NAFLD risk factors.
Genetically engineering self-organization of human pluripotent stem cells into a liver bud-like tissue using Gata6.
Guye, Patrick; Ebrahimkhani, Mohammad R; Kipniss, Nathan; Velazquez, Jeremy J; Schoenfeld, Eldi; Kiani, Samira; Griffith, Linda G; Weiss, Ron
Human induced pluripotent stem cells (hiPSCs) have potential for personalized and regenerative medicine. While most of the methods using these cells have focused on deriving homogenous populations of specialized cells, there has been modest success in producing hiPSC-derived organotypic tissues or organoids. Here we present a novel approach for generating and then co-differentiating hiPSC-derived progenitors. With a genetically engineered pulse of GATA-binding protein 6 (GATA6) expression, we initiate rapid emergence of all three germ layers as a complex function of GATA6 expression levels and tissue context. Within 2 weeks we obtain a complex tissue that recapitulates early developmental processes and exhibits a liver bud-like phenotype, including haematopoietic and stromal cells as well as a neuronal niche. Collectively, our approach demonstrates derivation of complex tissues from hiPSCs using a single autologous hiPSCs as source and generates a range of stromal cells that co-develop with parenchymal cells to form tissues.
The Virtual Liver Project: Simulating Tissue Injury Through Molecular and Cellular Processes
Efficiently and humanely testing the safety of thousands of environmental chemicals is a challenge. The US EPA Virtual Liver Project (v-Liver™) is aimed at simulating the effects of environmental chemicals computationally in order to estimate the risk of toxic outcomes in humans...
The Virtual Liver Project: Modeling Tissue Response To Chemicals Through Multiscale Simulation
The US EPA Virtual Liver Project is aimed at simulating the risk of toxic effects from environmental chemicals in silico. The computational systems model of organ injury due to chronic chemical exposure is based on: (i) the dynamics of perturbed molecular pathways, (ii) their lin...
Diagnostic efficiency of Mueller-matrix polarization reconstruction system of the phase structure of liver tissue
NASA Astrophysics Data System (ADS)
Zabolotna, Natalia I.; Pavlov, Sergii V.; Radchenko, Kostiantyn O.; Stasenko, Vladyslav A.; Wójcik, Waldemar; Kussambayeva, Nazym
The application field of using the Mueller-matrix polarizing reconstruction system of phase structure of biological layer for optical-anisotropic parameters differentiation of histological sections of healthy and rat's liver with hepatitis were investigated. Comparison of system informativity with known systems on indexes of sensitivity, specificity and balanced accuracy were performed.
Organochlorine-induced histopathology in kidney and liver tissue from Arctic fox (Vulpes lagopus).
Sonne, Christian; Wolkers, Hans; Leifsson, Pall S; Jenssen, Bjørn Munro; Fuglei, Eva; Ahlstrøm, Oystein; Dietz, Rune; Kirkegaard, Maja; Muir, Derek C G; Jørgensen, Even
The effects of persistent organic pollutants on renal and liver morphology in farmed arctic fox (Vulpes lagopus) were studied under experimental conditions. Control animals received a diet containing pork (Sus scrofa) fat with low amounts of persistent organic pollutants, while the diet of the exposed animals contained whale blubber, 'naturally' contaminated with persistent organic pollutants. Polychlorinated biphenyls (PCB) and organochlorine pesticide (OCP) concentrations in the whale blubber were 488 and 395 ng/g wet weight, respectively. Animals were sacrificed and sampled when they were at their fattest (winter) as well as their lowest body weight (summer). The results show that PCB and OCP exposure causes renal (and probably also liver) lesions in arctic foxes. The prevalence of glomerular, tubular and interstitial lesions was significantly highest in the exposed group (chi-square: all p<0.05). The frequency of liver lesions (steatosis, intravascular granulocyte accumulations, interstitial cell infiltrations, lipid granulomas, portal fibrosis and bile duct hyperplasia) were also highest in the exposed group, although not significantly (chi-square: all p>0.05). The prevalence of lesions was not significantly different between lean (winter) and fat (summer) foxes for any of the lesions (chi-square: all p>0.05). We suggest that wild arctic foxes exposed to an environmental cocktail of persistent organic pollutants, such as PCBs and OCPs, in their natural diet are at risk for developing chronic kidney and liver damage. Whether such lesions may have an impact on age and health of the animals remains uncertain.
[Role of TT virus in pathogenesis of liver diseases--the prevalence of TTV in patients and healthy individuals].
Liwen, Izabela; Januszkiewicz-Lewandowska, Danuta; Nowak, Jerzy
Primarily TTV has been thought as an etiologic agent of post transfusion non-A to -G hepatitis. TTV can replicate in liver and bone marrow cells. The presence of TTV has been found in the serum of patients with acute as well as chronic hepatitis of known etiology. Patients with acute hepatitis A, B, C and hepatitis caused by EBV or CMV all have TTV viremia in a frequency up to 60%. In chronic viral hepatitis TTV was present in a wide range of 7-94.4%. Treatment of viral hepatitis patients with interferon alfa and rybawiryn leads to eradication of TTV viremia in 50% cases. TTV infection in hepatocellular carcinoma ranged from 8.1% up to 100% patients. In hepatitis of unknown etiology TTV infection was observed in 26% to 71% cases. In liver cirrhosis TTV infection has been evidenced in 10% to 66% patients. Some authors postulated that the frequency of TTV increased with the number of blood or blood products transfusions. Coinfection of TTV has been found in 34.9%-76% of HIV positive persons. The study of medical staff revealed no difference in TTV viremia with healthy individual control. TTV is widespread in healthy general population. Therefore based on so far published results the association between TTV infection and hepatitis is questionable.
The effect of N-acetylcysteine (NAC) on liver and renal tissue inducible nitric oxide synthase (iNOS) and tissue lipid peroxidation in obstructive jaundice stimulated by lipopolysaccharide (LPS).
Cağlikülekci, Mehmet; Pata, Cengiz; Apa, Duygu Dusmez; Dirlik, Musa; Tamer, Lulufer; Yaylak, Faik; Kanik, Arzu; Aydin, Suha
Morbidity and mortality rates are very high in obstructive jaundice when it is associated with sepsis and multiple organ failure. Nitric oxide (NO) formation and increased expression of inducible nitric oxide synthase (iNOS) also take place in obstructive jaundice (OJ). N-Acetylcysteine (NAC) has a beneficial effect by demonstrating anti-inflammatory activity such as inhibits cytokine expression/release, inhibiting the adhesion molecule expression and inhibiting nuclear factor kappa B (NFkappaB). The aim of this study was to investigate the effects of NAC on liver and renal tissue iNOS, and liver tissue lipid peroxidation in lipopolysaccharide (LPS) induced obstructive jaundice. We randomized 48 rats into six groups. Group A: Sham group; group B: OJ group; group C: OJ+NAC; group D: OJ+LPS (Escherichia coli LPS serotype L-2630, 100mg, Sigma) group E: OJ+NAC+LPS; group F: OJ+LPS+NAC. NAC was started subcutaneously 100mg/kg. LPS was injected intraperitoneally and then at the tenth day we sacrificed the rats. Liver malondialdehyde (MDA) increased and liver ATPase decreased in groups B-D when compared to group A. After the administration of NAC (groups C-E), liver MDA levels decreased, tissue ATPase levels increased as compared to other groups. The liver and renal tissue iNOS expression was increased in groups B, D, and F. After the administration of NAC (groups C-E) the liver and renal tissue iNOS expression were decreased. Our results indicated that NAC prevented the deleterious effects of LPS in OJ by reducing iNOS expression via lipid peroxidation in liver and renal tissue; if it was administrated before LPS. But NAC failed to prevent the iNOS expression and lipid peroxidation if there was established endotoxemia in OJ.
Chlorophyllin intervention reduces aflatoxin-DNA adducts in individuals at high risk for liver cancer.
Egner, P A; Wang, J B; Zhu, Y R; Zhang, B C; Wu, Y; Zhang, Q N; Qian, G S; Kuang, S Y; Gange, S J; Jacobson, L P; Helzlsouer, K J; Bailey, G S; Groopman, J D; Kensler, T W
Residents of Qidong, People's Republic of China, are at high risk for development of hepatocellular carcinoma, in part from consumption of foods contaminated with aflatoxins. Chlorophyllin, a mixture of semisynthetic, water-soluble derivatives of chlorophyll that is used as a food colorant and over-the-counter medicine, has been shown to be an effective inhibitor of aflatoxin hepatocarcinogenesis in animal models by blocking carcinogen bioavailability. In a randomized, double-blind, placebo-controlled chemoprevention trial, we tested whether chlorophyllin could alter the disposition of aflatoxin. One hundred and eighty healthy adults from Qidong were randomly assigned to ingest 100 mg of chlorophyllin or a placebo three times a day for 4 months. The primary endpoint was modulation of levels of aflatoxin-N(7)-guanine adducts in urine samples collected 3 months into the intervention measured by using sequential immunoaffinity chromatography and liquid chromatography-electrospray mass spectrometry. This aflatoxin-DNA adduct excretion product serves as a biomarker of the biologically effective dose of aflatoxin, and elevated levels are associated with increased risk of liver cancer. Adherence to the study protocol was outstanding, and no adverse events were reported. Aflatoxin-N(7)-guanine could be detected in 105 of 169 available samples. Chlorophyllin consumption at each meal led to an overall 55% reduction (P = 0.036) in median urinary levels of this aflatoxin biomarker compared with those taking placebo. Thus, prophylactic interventions with chlorophyllin or supplementation of diets with foods rich in chlorophylls may represent practical means to prevent the development of hepatocellular carcinoma or other environmentally induced cancers.
Flavin reductase: sequence of cDNA from bovine liver and tissue distribution.
Quandt, K S; Hultquist, D E
Flavin reductase catalyzes electron transfer from reduced pyridine nucleotides to methylene blue or riboflavin, and this catalysis is the basis of the therapeutic use of methylene blue or riboflavin in the treatment of methemoglobinemia. A cDNA for a mammalian flavin reductase has been isolated and sequenced. Degenerate oligonucleotides, with sequences based on amino acid sequences of peptides derived from bovine erythrocyte flavin reductase, were used as primers in PCR to selectively amplify a partial cDNA that encodes the bovine reductase. The template used in the PCR was first strand cDNA synthesized from bovine liver total RNA using oligo(dT) primers. A PCR product was used as a specific probe to screen a bovine liver cDNA library. The sequence determined from two overlapping clones contains an open reading frame of 621 nucleotides and encodes 206 amino acids. The amino acid sequence deduced from the bovine liver flavin reductase cDNA matches the amino acid sequences determined for erythrocyte reductase-derived peptides, and the predicted molecular mass of 22,001 Da for the liver reductase agrees well with the molecular mass of 21,994 Da determined for the erythrocyte reductase by electrospray mass spectrometry. The amino acid sequence at the N terminus of the reductase has homology to sequences of pyridine nucleotide-dependent enzymes, and the predicted secondary structure, beta alpha beta, resembles the common nucleotide-binding structural motif. RNA blot analysis indicates a single 1-kilobase reductase transcript in human heart, kidney, liver, lung, pancreas, placenta, and skeletal muscle. Images PMID:7937764
Mössbauer spectroscopic study of iron oxide deposits in liver tissue from the marine mammal Dugong dugong
NASA Astrophysics Data System (ADS)
Chua-Anusorn, W.; Pierre, T. G. St.; Black, G.; Webb, J.; Macey, D. J.; Parry, D.
A sample of liver from the marine mammal Dugong dugong was found to have an iron concentration of 137 000 Μg g-1 Fe dry weight. Histological examination of the tissue revealed dense extracellular deposits of iron-containing particles about 40 to 80 Μm in diameter. Mössbauer spectra of the sample at temperatures between 17 and 200 K show superparamagnetic behaviour with a mean superparamagnetic blocking temperature of about 67 K, with the sextet being extinguished between 160 and 200 K. The blocking temperature and spectral parameters are indicative of the goethite-like form of hemosiderin that has previously been reported in some iron-loaded thalassemic human tissues.
Effect of melatonin on element distribution in the liver tissue of diabetic rats subjected to forced exercise.
Bicer, M; Akil, M; Baltaci, A K; Mogulkoc, R; Sivrikaya, A; Akkus, H
The objective of the present study was to investigate the effects of melatonin supplementation on elements in the liver of diabetic rats subjected to acute swimming exercise. Eighty adult male rats were equally divided into eight groups. Group 1, general control. Group 2, melatonin-supplemented control. Group 3, melatonin-supplemented diabetic control. Group 4, swimming control. Group 5, melatonin-supplemented swimming. Group 6, melatonin-supplemented diabetic swimming. Group 7, diabetic swimming. Group 8, diabetic control. Liver tissue samples were analyzed for lead, cobalt, molybdenum, chrome, sulphur, magnesium, manganese, sodium, potassium, phosphorus, copper, iron, calcium, zinc, selenium. The highest cobalt, chrome values were found in the groups 7, 8 and the groups 5, 6 respectively. Groups 3 and 7 had the highest copper values. Iron and potassium values were higher in the groups 1 and 4. Group 6 had increased magnesium value, and groups 6, 7, 8 were found to have the highest manganese levels. The highest lead values were found in the groups 5 and 6. Group 6 had the highest selenium levels. The highest zinc levels were established in 1 and 2. Groups 1, 2, 5 and 6 were found to have the highest calcium values. The results of our study indicate that melatonin supplementation in diabetes and forced exercise significantly alters the element metabolism in the liver (Tab. 3,Ref. 33).
Primary mucosa-associated lymphoid tissue lymphoma of the liver: A report of two cases and review of the literature
Obiorah, Ifeyinwa E; Johnson, Lynt; Ozdemirli, Metin
Mucosa-associated lymphoid tissue (MALT) lymphoma of the liver is a very rare condition and thus the diagnosis may be challenging. The clinical presentation is usually variable, ranging from minimal clinical symptoms to severe end stage liver disease. In this paper, we describe the clinicopathologic findings in two cases of primary hepatic MALT lymphoma. One case is an 80-year-old female with no underlying chronic liver disease and the second case is a 30-year-old female with autoimmune hepatitis complicated by MALT lymphoma. In both specimens, there was diffuse infiltration of atypical B-lymphocytes that were positive for CD20 and CD79a, but negative for CD5, CD43 and CD10. There were occasional lymphoepithelial lesions involving the hepatocytes or bile ducts. Polymerase chain reaction analysis showed monoclonal immunoglobulin heavy chain gene rearrangement in both cases. The first case was treated with surgery but developed pulmonary recurrence a year after complete resection but went into remission following treatment with rituximab. A second recurrence occurred in the right parotid gland 7 years later, which was treated with idelalisib. The second case was effectively treated with rituximab. To our knowledge, the second case is the first reported case linked to autoimmune hepatitis. PMID:28217252
Tandem-base mutations occur in mouse liver and adipose tissue preferentially as G:C to T:A transversions and accumulate with age.
Buettner, V L; Hill, K A; Halangoda, A; Sommer, S S
Tandem-base mutations (TBM) are associated with ultraviolet light and other mutagens. Herein, we report an age- and tissue-specific difference in the frequency of spontaneous TBM in Big Blue transgenic mice. A total of 390 mutants from liver and adipose tissue contained 17 and 4 TBM, respectively, while no TBM were detected in 683 mutants from six other tissues. There was a proportional increase in the frequency of TBM in liver with age (29 days postconception to 25 months of age). Nine TBM (43%) were GG to TT transversions that preferentially occurred at specific sites. The remaining 12 mutants contained at least one transversion mutation each. We speculate that the increase of TBM in liver and adipose tissue with age is due to chronic mutagen exposure, perhaps derived from fat in the diet.
Effects of iron glycine chelate on growth, tissue mineral concentrations, fecal mineral excretion, and liver antioxidant enzyme activities in broilers.
Ma, W Q; Sun, H; Zhou, Y; Wu, J; Feng, J
The study was conducted to determine the effects of iron glycine chelate (Fe-Gly) on growth, tissue mineral concentrations, fecal mineral excretion, and liver antioxidant enzyme activities in broilers. A total of 360 1-day-old commercial broilers (Ross × Ross) were randomly allotted to six dietary treatments with six replications of ten chicks per replicate. Broilers were fed a control diet with no Fe supplementation, while five other treatments consisted of 40, 80, 120, and 160 mg Fe/kg diets from Fe-Gly, and 160 mg Fe/kg from ferrous sulfate, respectively. After a 42-day feeding trial, the results showed that 120 and 160 mg Fe/kg as Fe-Gly improved the average daily gain (P < 0.05) and average daily feed intake (P < 0.05) of broilers (4-6 weeks). Addition with 120 and 160 mg Fe/kg from Fe-Gly and 160 mg Fe/kg from FeSO(4) increased Fe concentration in serum (P < 0.05), liver (P < 0.05), breast muscle (P < 0.05), tibia (P < 0.05), and feces (P < 0.01) at 21 and 42 days. There were linear responses to the addition of Fe-Gly from 0 to 160 mg/kg Fe on Fe concentration in serum (21 days, P = 0.005; 42 days, P = 0.001), liver (P = 0.001), breast muscle (P = 0.001), tibia (P = 0.001), and feces (21 days, P = 0.011; 42 days, P = 0.032). Liver Cu/Zn superoxide dismutase activities of chicks were increased by the addition of 80, 120, and 160 mg Fe/kg as Fe-Gly to diets at 42 days. There were no differences in liver catalase activities of chicks among the treatments (P > 0.05). This study indicates that addition with Fe-Gly could improve growth performance and iron tissue storage and improves the antioxidant status of broiler chickens.
The identification and differentiation of secondary colorectal cancer in human liver tissue using X-ray fluorescence, coherent scatter spectroscopy, and multivariate analysis.
Darvish-Molla, Sahar; Al-Ebraheem, Alia; Farquharson, Michael J
Secondary colorectal liver cancer is the most widespread malignancy in patients with colorectal cancer. The aim of this study is to identify and differentiate between normal liver tissue and malignant secondary colorectal liver cancer tissue using X-ray scattering and X-ray fluorescence spectroscopy to investigate the best combination of data that can be used to enable classification of these two tissue types. X-ray fluorescence (XRF) and coherent scatter data were collected for 24 normal and 24 tumor matched pair tissue samples. The levels of 12 elements (P, S, K, Ca, Cr, Fe, Cu, Zn, As, Se, Br, and Rb) were measured in all samples. When comparisons were made between normal and tumor tissues, statistically significant differences were determined for K (p = 0.046), Ca (p = 0.040), Cr (p = 0.011), Fe, Cu, Zn, Br, and Rb (p < 0.01). However, for P, S, As, and Se, no statistically significant differences were found (p > 0.05). For the coherent scatter spectra collected, three peaks due to adipose, fibrous content, and water content of tissue were observed. The amplitude, full width half-maximum, and area under both fibrous content and water content peaks were found to be significantly higher in secondary colorectal liver tumors compared with surrounding normal liver tissue (p < 0.05). However, no significant differences were found for the adipose peak parameters (p > 0.05). Soft independent modeling of class analogy was performed using the XRF, coherent scatter, and elemental ratio data separately, and the accuracy of the classification of 20 unknown samples was found to be 50, 30, and 80%, respectively. Further analysis has shown that using a combination of the XRF and coherent scatter data in a single combined model gave improved normal and tumor liver tissue classification, with an accuracy that was found to be 85%.
Intra-Tissue Pressure Measurement in Ex Vivo Liver Undergoing Laser Ablation with Fiber-Optic Fabry-Perot Probe
Tosi, Daniele; Saccomandi, Paola; Schena, Emiliano; Duraibabu, Dinesh Babu; Poeggel, Sven; Leen, Gabriel; Lewis, Elfed
We report the first-ever intra-tissue pressure measurement performed during 1064 nm laser ablation (LA) of an ex vivo porcine liver. Pressure detection has been performed with a biocompatible, all-glass, temperature-insensitive Extrinsic Fabry-Perot Interferometry (EFPI) miniature probe; the proposed methodology mimics in-vivo treatment. Four experiments have been performed, positioning the probe at different positions from the laser applicator tip (from 0.5 mm to 5 mm). Pressure levels increase during ablation time, and decrease with distance from applicator tip: the recorded peak parenchymal pressure levels range from 1.9 kPa to 71.6 kPa. Different pressure evolutions have been recorded, as pressure rises earlier in proximity of the tip. The present study is the first investigation of parenchymal pressure detection in liver undergoing LA: the successful detection of intra-tissue pressure may be a key asset for improving LA, as pressure levels have been correlated to scattered recurrences of tumors by different studies. PMID:27092504
Intra-Tissue Pressure Measurement in Ex Vivo Liver Undergoing Laser Ablation with Fiber-Optic Fabry-Perot Probe.
Tosi, Daniele; Saccomandi, Paola; Schena, Emiliano; Duraibabu, Dinesh Babu; Poeggel, Sven; Leen, Gabriel; Lewis, Elfed
We report the first-ever intra-tissue pressure measurement performed during 1064 nm laser ablation (LA) of an ex vivo porcine liver. Pressure detection has been performed with a biocompatible, all-glass, temperature-insensitive Extrinsic Fabry-Perot Interferometry (EFPI) miniature probe; the proposed methodology mimics in-vivo treatment. Four experiments have been performed, positioning the probe at different positions from the laser applicator tip (from 0.5 mm to 5 mm). Pressure levels increase during ablation time, and decrease with distance from applicator tip: the recorded peak parenchymal pressure levels range from 1.9 kPa to 71.6 kPa. Different pressure evolutions have been recorded, as pressure rises earlier in proximity of the tip. The present study is the first investigation of parenchymal pressure detection in liver undergoing LA: the successful detection of intra-tissue pressure may be a key asset for improving LA, as pressure levels have been correlated to scattered recurrences of tumors by different studies.
Non-alcoholic fatty liver disease connections with fat-free tissues: A focus on bone and skeletal muscle
Poggiogalle, Eleonora; Donini, Lorenzo Maria; Lenzi, Andrea; Chiesa, Claudio; Pacifico, Lucia
The estimates of global incidence and prevalence of non-alcoholic fatty liver disease (NAFLD) are worrisome, due to the parallel burden of obesity and its metabolic complications. Indeed, excess adiposity and insulin resistance represent two of the major risk factors for NAFLD; interestingly, in the last years a growing body of evidence tended to support a novel mechanistic perspective, in which the liver is at the center of a complex interplay involving organs and systems, other than adipose tissue and glucose homeostasis. Bone and the skeletal muscle are fat- free tissues which appeared to be independently associated with NAFLD in several cross-sectional studies. The deterioration of bone mineral density and lean body mass, leading to osteoporosis and sarcopenia, respectively, are age-related processes. The prevalence of NAFLD also increases with age. Beyond physiological aging, the three conditions share some common underlying mechanisms, and their elucidations could be of paramount importance to design more effective treatment strategies for the management of NAFLD. In this review, we provide an overview on epidemiological data as well as on potential contributors to the connections of NAFLD with bone and skeletal muscle. PMID:28348479
The Hybrid Feature Selection Algorithm Based on Maximum Minimum Backward Selection Search Strategy for Liver Tissue Pathological Image Classification
We propose a novel feature selection algorithm for liver tissue pathological image classification. To improve the efficiency of feature selection, the same feature values of positive and negative samples are removed in rough selection. To obtain the optimal feature subset, a new heuristic search algorithm, which is called Maximum Minimum Backward Selection (MMBS), is proposed in precise selection. MMBS search strategy has the following advantages. (1) For the deficiency of Discernibility of Feature Subsets (DFS) evaluation criteria, which makes the class of small samples invalid for unbalanced samples, the Weighted Discernibility of Feature Subsets (WDFS) evaluation criteria are proposed as the evaluation strategy of MMBS, which is also available for unbalanced samples. (2) For the deficiency of Sequential Forward Selection (SFS) and Sequential Backward Selection (SBS), which can only add or only delete feature, MMBS decides whether to add the feature to feature subset according to WDFS criteria for each feature firstly; then it decides whether to remove the feature from feature subset according to SBS algorithm. In this way, the better feature subset can be obtained. The experiment results show that the proposed hybrid feature selection algorithm has good classification performance for liver tissue pathological image. PMID:27563344
Pomegranate vinegar attenuates adiposity in obese rats through coordinated control of AMPK signaling in the liver and adipose tissue
Background The effect of pomegranate vinegar (PV) on adiposity was investigated in high-fat diet (HF)-induced obese rats. Methods The rats were divided into 5 groups and treated with HF with PV or acetic acid (0, 6.5 or 13% w/w) for 16 weeks. Statistical analyses were performed by the Statistical Analysis Systems package, version 9.2. Results Compared to control, PV supplementation increased phosphorylation of AMP-activated protein kinase (AMPK), leading to changes in mRNA expressions: increases for hormone sensitive lipase and mitochondrial uncoupling protein 2 and decreases for sterol regulatory element binding protein-1c (SREBP-1c) and peroxisome proliferator-activated receptorγ (PPARγ) in adipose tissue; increases for PPARα and carnitinepalmitoyltransferase-1a (CPT-1a) and decrease for SREBP-1c in the liver. Concomitantly, PV reduced increases of body weight (p = 0.048), fat mass (p = 0.033), hepatic triglycerides (p = 0.005), and plasma triglycerides (p = 0.001). Conclusions These results suggest that PV attenuates adiposity through the coordinated control of AMPK, which leads to promotion of lipolysis in adipose tissue and stimulation of fatty acid oxidation in the liver. PMID:24180378
The Hybrid Feature Selection Algorithm Based on Maximum Minimum Backward Selection Search Strategy for Liver Tissue Pathological Image Classification.
Liu, Huiling; Jiang, Huiyan; Zheng, Ruiping
We propose a novel feature selection algorithm for liver tissue pathological image classification. To improve the efficiency of feature selection, the same feature values of positive and negative samples are removed in rough selection. To obtain the optimal feature subset, a new heuristic search algorithm, which is called Maximum Minimum Backward Selection (MMBS), is proposed in precise selection. MMBS search strategy has the following advantages. (1) For the deficiency of Discernibility of Feature Subsets (DFS) evaluation criteria, which makes the class of small samples invalid for unbalanced samples, the Weighted Discernibility of Feature Subsets (WDFS) evaluation criteria are proposed as the evaluation strategy of MMBS, which is also available for unbalanced samples. (2) For the deficiency of Sequential Forward Selection (SFS) and Sequential Backward Selection (SBS), which can only add or only delete feature, MMBS decides whether to add the feature to feature subset according to WDFS criteria for each feature firstly; then it decides whether to remove the feature from feature subset according to SBS algorithm. In this way, the better feature subset can be obtained. The experiment results show that the proposed hybrid feature selection algorithm has good classification performance for liver tissue pathological image.
Deep Sequencing Reveals Novel Genetic Variants in Children with Acute Liver Failure and Tissue Evidence of Impaired Energy Metabolism
Valencia, C. Alexander; Wang, Xinjian; Wang, Jin; Peters, Anna; Simmons, Julia R.; Moran, Molly C.; Mathur, Abhinav; Husami, Ammar; Qian, Yaping; Sheridan, Rachel; Bove, Kevin E.; Witte, David; Huang, Taosheng; Miethke, Alexander G.
Background & Aims The etiology of acute liver failure (ALF) remains elusive in almost half of affected children. We hypothesized that inherited mitochondrial and fatty acid oxidation disorders were occult etiological factors in patients with idiopathic ALF and impaired energy metabolism. Methods Twelve patients with elevated blood molar lactate/pyruvate ratio and indeterminate etiology were selected from a retrospective cohort of 74 subjects with ALF because their fixed and frozen liver samples were available for histological, ultrastructural, molecular and biochemical analysis. Results A customized next-generation sequencing panel for 26 genes associated with mitochondrial and fatty acid oxidation defects revealed mutations and sequence variants in five subjects. Variants involved the genes ACAD9, POLG, POLG2, DGUOK, and RRM2B; the latter not previously reported in subjects with ALF. The explanted livers of the patients with heterozygous, truncating insertion mutations in RRM2B showed patchy micro- and macrovesicular steatosis, decreased mitochondrial DNA (mtDNA) content <30% of controls, and reduced respiratory chain complex activity; both patients had good post-transplant outcome. One infant with severe lactic acidosis was found to carry two heterozygous variants in ACAD9, which was associated with isolated complex I deficiency and diffuse hypergranular hepatocytes. The two subjects with heterozygous variants of unknown clinical significance in POLG and DGUOK developed ALF following drug exposure. Their hepatocytes displayed abnormal mitochondria by electron microscopy. Conclusion Targeted next generation sequencing and correlation with histological, ultrastructural and functional studies on liver tissue in children with elevated lactate/pyruvate ratio expand the spectrum of genes associated with pediatric ALF. PMID:27483465
The sparse data extrapolation problem: strategies for soft-tissue correction for image-guided liver surgery
NASA Astrophysics Data System (ADS)
Miga, Michael I.; Dumpuri, Prashanth; Simpson, Amber L.; Weis, Jared A.; Jarnagin, William R.
The problem of extrapolating cost-effective relevant information from distinctly finite or sparse data, while balancing the competing goals between workflow and engineering design, and between application and accuracy is the 'sparse data extrapolation problem'. Within the context of open abdominal image-guided liver surgery, one realization of this problem is compensating for non-rigid organ deformations while maintaining workflow for the surgeon. More specifically, rigid organ-based surface registration between CT-rendered liver surfaces and laser-range scanned intraoperative partial surface counterparts resulted in an average closest-point residual 6.1 +/- 4.5 mm with maximumsigned distances ranging from -13.4 to 16.2 mm. Similar to the neurosurgical environment, there is a need to correct for soft tissue deformation to translate image-guided interventions to the abdomen (e.g. liver, kidney, pancreas, etc.). While intraoperative tomographic imaging is available, these approaches are less than optimal solutions to the sparse data extrapolation problem. In this paper, we compare and contrast three sparse data extrapolation methods to that of datarich interpolation for the correction of deformation within a liver phantom containing 43 subsurface targets. The findings indicate that the subtleties in the initial alignment pose following rigid registration can affect correction up to 5- 10%. The best deformation compensation achieved was approximately 54.5% (target registration error of 2.0 +/- 1.6 mm) while the data-rich interpolative method was 77.8% (target registration error of 0.6 +/- 0.5 mm).
Individual and family consent to organ and tissue donation: is the current position coherent?
Wilkinson, T M
The current position on the deceased's consent and the family's consent to organ and tissue donation from the dead is a double veto-each has the power to withhold and override the other's desire to donate. This paper raises, and to some extent answers, questions about the coherence of the double veto. It can be coherently defended in two ways: if it has the best effects and if the deceased has only negative rights of veto. Whether the double veto has better effects than other policies requires empirical investigation, which is not undertaken here. As for rights, the paper shows that it is entirely possible that individuals have a negative right of veto but no positive right to compel acceptance of their offers. Thus if intensivists and transplant teams turn down the deceased's offer, they do not thereby violate the deceased's right. This leaves it open whether non-rights based reasons-such as avoiding bad publicity or distress -require intensivists and transplant teams to turn down or accept the deceased's offer. This, however, is beyond the scope of this paper. The current position may or may not be wrong, but it is at least coherent.
Effect of pesticides on cell survival in liver and brain rat tissues.
Astiz, Mariana; de Alaniz, María J T; Marra, Carlos Alberto
Pesticides are the main environmental factor associated with the etiology of human neurodegenerative disorders such as Parkinson's disease. Our laboratory has previously demonstrated that the treatment of rats with low doses of dimethoate, zineb or glyphosate alone or in combination induces oxidative stress (OS) in liver and brain. The aim of the present work was to investigate if the pesticide-induced OS was able to affect brain and liver cell survival. The treatment of Wistar rats with the pesticides (i.p. 1/250 LD50, three times a week for 5 weeks) caused loss of mitochondrial transmembrane potential and cardiolipin content, especially in substantia nigra (SN), with a concomitant increase of fatty acid peroxidation. The activation of calpain apoptotic cascade (instead of the caspase-dependent pathway) would be responsible for the DNA fragmentation pattern observed. Thus, these results may contribute to understand the effect(s) of chronic and simultaneous exposure to pesticides on cell survival.
Prediction of Flunixin Tissue Residue Concentrations in Livers from Diseased Cattle.
Wu, H; Baynes, R E; Tell, L A; Riviere, J E
Flunixin, a widely used non-steroidal anti-inflammatory drug, was a leading cause of violative residues in cattle. The objective of this analysis was to explore how the changes in pharmacokinetic (PK) parameters that may be associated with diseased animals affect the predicted liver residue of flunixin in cattle. Monte Carlo simulations for liver residues of flunixin were performed using the PK model structure and relevant PK parameter estimates from a previously published population PK model for flunixin in cattle. The magnitude of a change in the PK parameter value that resulted in a violative residue issue in more than one percent of a cattle population was compared. In this regard, elimination clearance and volume of distribution affected withdrawal times. Pathophysiological factors that can change these parameters may contribute to the occurrence of violative residues of flunixin.
Prediction of flunixin tissue residue concentrations in livers from diseased cattle.
Wu, H; Baynes, R E; Tell, L A; Riviere, J E
Flunixin, a widely used non-steroidal anti-inflammatory drug, was a leading cause of violative residues in cattle. The objective of this analysis was to explore how the changes in pharmacokinetic (PK) parameters that may be associated with diseased animals affect the predicted liver residue of flunixin in cattle. Monte Carlo simulations for liver residues of flunixin were performed using the PK model structure and relevant PK parameter estimates from a previously published population PK model for flunixin in cattle. The magnitude of a change in the PK parameter value that resulted in a violative residue issue in more than one percent of a cattle population was compared. In this regard, elimination clearance and volume of distribution affected withdrawal times. Pathophysiological factors that can change these parameters may contribute to the occurrence of violative residues of flunixin.
Identification of N,N-dimethylamphetamine formed by methylation of methamphetamine in formalin-fixed liver tissue by multistage mass spectrometry.
Shakleya, Diaa M; Kraner, James C; Kaplan, James A; Gannett, Peter M; Callery, Patrick S
Methamphetamine is methylated in the presence of unbuffered formalin solutions within hours at room temperature. The product, N,N-dimethylamphetamine, is also found in human liver exposed to methamphetamine followed by incubation with formalin. In the present study, a direct mass spectrometric method was developed to identify N,N-dimethylamphetamine in human liver before and after treatment with formalin. Human liver samples were obtained from four deaths that were investigated by the West Virginia Office of Chief Medical Examiner. Full toxicological analysis was conducted on samples from the decedents and methamphetamine was among the positive findings in each case. The method used to expose liver tissue to formaldehyde involved treating a small piece of liver from each case with formalin solution (20% v/v) for 24 h at room temperature. The formalin treated tissues were homogenized and the resulting suspension was sonicated for 5 min, and then centrifuged. Supernatant aliquots were directly analyzed by electrospray ionization (ESI) mass spectrometry without chromatographic isolation. Positive ion multistage mass spectra recorded in MS, MS/MS and MS/MS/MS (MS3) modes were used to confirm the presence of N,N-dimethylamphetamine and methamphetamine in the mixture. Liver tissue not treated with formalin did not contain a detectable level of N,N-dimethylamphetamine. Decreases in methamphetamine concentrations in liver tissue resulting from treatment with formalin were measured using deuterium-labeled methamphetamine as internal standard. The method can be completed in less than 2 h on thawed tissue. The results suggest that the process of fixing tissues with formalin may lead to false negative findings for methamphetamine.
Estimating Functional Liver Reserve Following Hepatic Irradiation: Adaptive Normal Tissue Response Models
Stenmark, Matthew H.; Cao, Yue; Wang, Hesheng; Jackson, Andrew; Ben-Josef, Edgar; Ten Haken, Randall K.; Lawrence, Theodore S.; Feng, Mary
Purpose To estimate the limit of functional liver reserve for safe application of hepatic irradiation using changes in indocyanine green, an established assay of liver function. Materials and Methods From 2005–2011, 60 patients undergoing hepatic irradiation were enrolled in a prospective study assessing the plasma retention fraction of indocyanine green at 15-min (ICG-R15) prior to, during (at 60% of planned dose), and after radiotherapy (RT). The limit of functional liver reserve was estimated from the damage fraction of functional liver (DFL) post-RT [1−(ICG-R15pre-RT/ICG-R15post-RT)] where no toxicity was observed using a beta distribution function. Results Of 48 evaluable patients, 3 (6%) developed RILD, all within 2.5 months of completing RT. The mean ICG-R15 for non-RILD patients pre-RT, during-RT and 1-month post-RT was 20.3%(SE 2.6), 22.0%(3.0), and 27.5%(2.8), and for RILD patients was 6.3%(4.3), 10.8%(2.7), and 47.6%(8.8). RILD was observed at post-RT damage fractions of ≥78%. Both DFL assessed by during-RT ICG and MLD predicted for DFL post-RT (p<0.0001). Limiting the post-RT DFL to 50%, predicted a 99% probability of a true complication rate <15%. Conclusion The DFL as assessed by changes in ICG during treatment serves as an early indicator of a patient's tolerance to hepatic irradiation. PMID:24813090
MED13-dependent signaling from the heart confers leanness by enhancing metabolism in adipose tissue and liver.
Baskin, Kedryn K; Grueter, Chad E; Kusminski, Christine M; Holland, William L; Bookout, Angie L; Satapati, Santosh; Kong, Y Megan; Burgess, Shawn C; Malloy, Craig R; Scherer, Philipp E; Newgard, Christopher B; Bassel-Duby, Rhonda; Olson, Eric N
The heart requires a continuous supply of energy but has little capacity for energy storage and thus relies on exogenous metabolic sources. We previously showed that cardiac MED13 modulates systemic energy homeostasis in mice. Here, we sought to define the extra-cardiac tissue(s) that respond to cardiac MED13 signaling. We show that cardiac overexpression of MED13 in transgenic (MED13cTg) mice confers a lean phenotype that is associated with increased lipid uptake, beta-oxidation and mitochondrial content in white adipose tissue (WAT) and liver. Cardiac expression of MED13 decreases metabolic gene expression in the heart but enhances them in WAT. Although exhibiting increased energy expenditure in the fed state, MED13cTg mice metabolically adapt to fasting. Furthermore, MED13cTg hearts oxidize fuel that is readily available, rendering them more efficient in the fed state. Parabiosis experiments in which circulations of wild-type and MED13cTg mice are joined, reveal that circulating factor(s) in MED13cTg mice promote enhanced metabolism and leanness. These findings demonstrate that MED13 acts within the heart to promote systemic energy expenditure in extra-cardiac energy depots and point to an unexplored metabolic communication system between the heart and other tissues.
Paracetamol (acetaminophen) decreases hydrogen sulfide tissue concentration in brain but increases it in the heart, liver and kidney in mice.
Wiliński, Bogdan; Wiliński, Jerzy; Somogyi, Eugeniusz; Góralska, Marta; Piotrowska, Joanna
The biological action ofN-acetyl-p-aminophenol - paracetamol (acetaminophen) has been demonstrated to involve different mechanisms and is still not clear. Hydrogen sulfide (H2S) has been shown to play an important role in many physiological and pathological processes including nociception. The interaction between acetaminophen and endogenous H2S is unknown. Twenty four female CBA strain mice were administered intraperitoneal injections of N-acetyl-p-aminophenol solution: paracetemol in doses of 30 mg/kg b.w. per day (group D1, n = 8) or 100 mg/kg b.w. per day (group D2, n = 8).. The control group (n = 8) received physiological saline in portions of the same volume--0.2 ml. The measurements of tissue H2S concentration were performed with the Siegel spectrophotometric modified method. In the brain, the H2S tissue level decreased, but more significantly in the lower drug dose group. Conversely, there was a significant rise in the H2S tissue concentration in D1 and D2 groups in heart and kidney with the increase more pronounced in the group with the lower paracetamol dose. In the liver only the higher acetaminophen dose elicited a change in H2S concentration, increasing after administration of acetaminophen at 100 mg/kg. Our study demonstrates that paracetamol induces H2S tissue concentration changes in different mouse organs.
MED13-dependent signaling from the heart confers leanness by enhancing metabolism in adipose tissue and liver
Baskin, Kedryn K; Grueter, Chad E; Kusminski, Christine M; Holland, William L; Bookout, Angie L; Satapati, Santosh; Kong, Y Megan; Burgess, Shawn C; Malloy, Craig R; Scherer, Philipp E; Newgard, Christopher B; Bassel-Duby, Rhonda; Olson, Eric N
The heart requires a continuous supply of energy but has little capacity for energy storage and thus relies on exogenous metabolic sources. We previously showed that cardiac MED13 modulates systemic energy homeostasis in mice. Here, we sought to define the extra-cardiac tissue(s) that respond to cardiac MED13 signaling. We show that cardiac overexpression of MED13 in transgenic (MED13cTg) mice confers a lean phenotype that is associated with increased lipid uptake, beta-oxidation and mitochondrial content in white adipose tissue (WAT) and liver. Cardiac expression of MED13 decreases metabolic gene expression in the heart but enhances them in WAT. Although exhibiting increased energy expenditure in the fed state, MED13cTg mice metabolically adapt to fasting. Furthermore, MED13cTg hearts oxidize fuel that is readily available, rendering them more efficient in the fed state. Parabiosis experiments in which circulations of wild-type and MED13cTg mice are joined, reveal that circulating factor(s) in MED13cTg mice promote enhanced metabolism and leanness. These findings demonstrate that MED13 acts within the heart to promote systemic energy expenditure in extra-cardiac energy depots and point to an unexplored metabolic communication system between the heart and other tissues. See also: M Nakamura & J Sadoshima (December 2014) PMID:25422356
Differences in tissue distribution of iron from various clinically used intravenous iron complexes in fetal avian heart and liver.
Spicher, Karsten; Brendler-Schwaab, Susanne; Schlösser, Christoph; Catarinolo, Maria; Fütterer, Sören; Langguth, Peter; Enzmann, Harald
Nanomedicines are more complex than most pharmacologically active substances or medicines and have been considered as non-biological complex drugs. For nanomedicines pivotal pharmacokinetic properties cannot be assessed by plasma concentration data from standard bioequivalence studies. Using intravenous iron complexes (IICs) as model we show that fetal avian tissues can be used to study time dependent tissue concentrations in heart and liver. Clear differences were found between equimolar doses of sucrose, gluconate or carboxymaltose coated iron particles. The range in tissue iron concentrations observed with these clinically widely used IICs provides an orientation as to what should be acceptable for any new IICs. Moreover, sensitivity of the experimental model was high enough to detect a 20% difference in tissue iron concentration. For the authorization of generic products under Article 10 (1) of Directive 2001/83/EC a plasma concentration of an active substance in the range of 80%-125% versus the reference product is usually considered acceptable. Based on its high discriminatory sensitivity this method was used to support a positive marketing authorization decision for a generic nanomedicine product.
Malarial infection of female BWF1 lupus mice alters the redox state in kidney and liver tissues and confers protection against lupus nephritis.
Al-Quraishy, Saleh; Abdel-Maksoud, Mostafa A; El-Amir, Azza; Abdel-Ghaffar, Fathy A; Badr, Gamal
Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by an imbalanced redox state and increased apoptosis. Tropical infections, particularly malaria, may confer protection against SLE. Oxidative stress is a hallmark of SLE. We have measured changes in the levels of nitric oxide (NO), hydrogen peroxide (H2O2), malondialdehyde (MDA), and reduced glutathione (GSH) in both kidney and liver tissues of female BWF1 lupus mice, an experimental model of SLE, after infection with either live or gamma-irradiated malaria. We observed a decrease in NO, H2O2, and MDA levels in kidney tissues after infection of lupus mice with live malaria. Similarly, the levels of NO and H2O2 were significantly decreased in the liver tissues of lupus mice after infection with live malaria. Conversely, GSH levels were obviously increased in both kidney and liver tissues after infection of lupus mice with either live or gamma-irradiated malaria. Liver and kidney functions were significantly altered after infection of lupus mice with live malaria. We further investigated the ultrastructural changes and detected the number of apoptotic cells in kidney and liver tissues in situ by electron microscopy and TUNEL assays. Our data reveal that infection of lupus mice with malaria confers protection against lupus nephritis.
Source of metabolizable energy affects gene transcription in metabolic pathways in adipose and liver tissue of nonlactating, pregnant dairy cows.
Crookenden, M A; Mandok, K S; Grala, T M; Phyn, C V C; Kay, J K; Greenwood, S L; Roche, J R
The objective of this experiment was to determine if transcript abundance of genes involved in metabolic pathways in adipose and liver tissue could provide some explanation for the low efficiency with which ME in autumn pasture is used for BW gain. Nonlactating, pregnant (208 ± 19 d of gestation or approximately 75 d precalving) dairy cows (n = 90) were randomly allocated to either a control diet (i.e., offered fresh autumn pasture to maintenance requirements: 0.55 MJ ME/kg of measured metabolic BW [BW0.75] per day) or, in addition to the control diet, 1 of 2 supplement amounts (2.5 and 5.0 kg DM/d) of autumn pasture or 1 of 4 supplementary feeds (i.e., a control and 2 levels of feeding for each of 5 feeds: 11 groups of cows). Along with autumn pasture, evaluated feeds included spring pasture silage, maize silage, maize grain, and palm kernel expeller. Adipose and liver tissues were biopsied in wk 4 of the experiment and transcript abundance of genes involved in metabolic pathways associated with energy metabolism, lipolysis, and lipogenesis was determined. Additional feed, irrespective of type, increased BW gain (P < 0.01) and this effect was reflected in the expression of genes in adipose and liver tissue. However, autumn pasture had lower energy-use efficiency than the other feeds. Genes involved in both lipogenesis (ACACA, THRSP, GPAM, GPD1, and LPL) and lipolysis (PNPLA2) were upregulated (P < 0.05) in adipose tissue in response to increased ME intake/kilogram BW0.75. Hepatic expression of APOA1 decreased and that of APOB increased (P < 0.05) in cows offered maize grain and maize silage (i.e., starch-containing feeds). In comparison, pasture-fed cows demonstrated a degree of uncoupling of the somatotropic axis, with lower hepatic transcript abundance of both GHR1A and IGF-1 compared with cows offered any of the other 4 feeds. Changes to gene transcription indicate a possible molecular mechanism for the poor BW gain evident in ruminants consuming autumn
Inflammatory Kidney and Liver Tissue Response to Different Hydroxyethylstarch (HES) Preparations in a Rat Model of Early Sepsis
Schimmer, Ralph C.; Urner, Martin; Voigtsberger, Stefanie; Booy, Christa; Roth Z'Graggen, Birgit; Beck-Schimmer, Beatrice; Schläpfer, Martin
Background Tissue hypoperfusion and inflammation in sepsis can lead to organ failure including kidney and liver. In sepsis, mortality of acute kidney injury increases by more than 50%. Which type of volume replacement should be used is still an ongoing debate. We investigated the effect of different volume strategies on inflammatory mediators in kidney and liver in an early sepsis model. Material and Methods Adult male Wistar rats were subjected to sepsis by cecal ligation and puncture (CLP) and assigned to three fluid replenishment groups. Animals received 30mL/kg of Ringer's lactate (RL) for 2h, thereafter RL (75mL/kg), hydroxyethyl starch (HES) balanced (25mL/kg), containing malate and acetate, or HES saline (25mL/kg) for another 2h. Kidney and liver tissue was assessed for inflammation. In vitro rat endothelial cells were exposed to RL, HES balanced or HES saline for 2h, followed by stimulation with tumor necrosis factor-α (TNF-α) for another 4h. Alternatively, cells were exposed to malate, acetate or a mixture of malate and acetate, reflecting the according concentration of these substances in HES balanced. Pro-inflammatory cytokines were determined in cell supernatants. Results Cytokine mRNA in kidney and liver was increased in CLP animals treated with HES balanced compared to RL, but not after application of HES saline. MCP-1 was 3.5fold (95% CI: 1.3, 5.6) (p<0.01) and TNF-α 2.3fold (95% CI: 1.2, 3.3) (p<0.001) upregulated in the kidney. Corresponding results were seen in liver tissue. TNF-α-stimulated endothelial cells co-exposed to RL expressed 3529±1040pg/mL MCP-1 and 59±23pg/mL CINC-1 protein. These cytokines increased by 2358pg/mL (95% CI: 1511, 3204) (p<0.001) and 29pg/ml (95% CI: 14, 45) (p<0.01) respectively when exposed to HES balanced instead. However, no further upregulation was observed with HES saline. PBS supplemented with acetate increased MCP-1 by 1325pg/mL (95% CI: 741, 1909) (p<0.001) and CINC-1 by 24pg/mL (95% CI: 9, 38) (p<0
Melatonin increases intracellular calcium in the liver, muscle, white adipose tissues and pancreas of diabetic obese rats.
Agil, A; Elmahallawy, E K; Rodríguez-Ferrer, J M; Adem, A; Bastaki, S M; Al-Abbadi, I; Fino Solano, Y A; Navarro-Alarcón, M
Melatonin, a widespread substance with antioxidant and anti-inflammatory properties, has been found to act as an antidiabetic agent in animal models, regulating the release and action of insulin. However, the molecular bases of this antidiabetic action are unknown, limiting its application in humans. Several studies have recently shown that melatonin can modify calcium (Ca(2+)) in diabetic animals, and Ca(2+) has been reported to be involved in glucose homeostasis. The objective of the present study was to assess whether the antidiabetic effect of chronic melatonin at pharmacological doses is established via Ca(2+) regulation in different tissues in an animal model of obesity-related type 2 diabetes, using Zücker diabetic fatty (ZDF) rats and their lean littermates, Zücker lean (ZL) rats. After the treatments, flame atomic absorption spectrometry was used to determine Ca(2+) levels in the liver, muscle, main types of internal white adipose tissue, subcutaneous lumbar fat, pancreas, brain, and plasma. This study reports for the first time that chronic melatonin administration (10 mg per kg body weight per day for 6 weeks) increases Ca(2+) levels in muscle, liver, different adipose tissues, and pancreas in ZDF rats, although there were no significant changes in their brain or plasma Ca(2+) levels. We propose that this additional peripheral dual action mechanism underlies the improvement in insulin sensitivity and secretion previously documented in samples from the same animals. According to these results, indoleamine may be a potential candidate for the treatment of type 2 diabetes mellitus associated with obesity.
Assessment of individual organ doses in a realistic human phantom from neutron and gamma stimulated spectroscopy of the breast and liver
Belley, Matthew D.; Segars, William Paul; Kapadia, Anuj J.
Purpose: Understanding the radiation dose to a patient is essential when considering the use of an ionizing diagnostic imaging test for clinical diagnosis and screening. Using Monte Carlo simulations, the authors estimated the three-dimensional organ-dose distribution from neutron and gamma irradiation of the male liver, female liver, and female breasts for neutron- and gamma-stimulated spectroscopic imaging. Methods: Monte Carlo simulations were developed using the Geant4 GATE application and a voxelized XCAT human phantom. A male and a female whole body XCAT phantom was voxelized into 256 × 256 × 600 voxels (3.125 × 3.125 × 3.125 mm{sup 3}). A monoenergetic rectangular beam of 5.0 MeV neutrons or 7.0 MeV photons was made incident on a 2 cm thick slice of the phantom. The beam was rotated at eight different angles around the phantom ranging from 0° to 180°. Absorbed dose was calculated for each individual organ in the body and dose volume histograms were computed to analyze the absolute and relative doses in each organ. Results: The neutron irradiations of the liver showed the highest organ dose absorption in the liver, with appreciably lower doses in other proximal organs. The dose distribution within the irradiated slice exhibited substantial attenuation with increasing depth along the beam path, attenuating to ∼15% of the maximum value at the beam exit side. The gamma irradiation of the liver imparted the highest organ dose to the stomach wall. The dose distribution from the gammas showed a region of dose buildup at the beam entrance, followed by a relatively uniform dose distribution to all of the deep tissue structures, attenuating to ∼75% of the maximum value at the beam exit side. For the breast scans, both the neutron and gamma irradiation registered maximum organ doses in the breasts, with all other organs receiving less than 1% of the breast dose. Effective doses ranged from 0.22 to 0.37 mSv for the neutron scans and 41 to 66 mSv for the gamma
Assessment of individual organ doses in a realistic human phantom from neutron and gamma stimulated spectroscopy of the breast and liver
Belley, Matthew D.; Segars, William Paul; Kapadia, Anuj J.
Purpose: Understanding the radiation dose to a patient is essential when considering the use of an ionizing diagnostic imaging test for clinical diagnosis and screening. Using Monte Carlo simulations, the authors estimated the three-dimensional organ-dose distribution from neutron and gamma irradiation of the male liver, female liver, and female breasts for neutron- and gamma-stimulated spectroscopic imaging. Methods: Monte Carlo simulations were developed using the Geant4 GATE application and a voxelized XCAT human phantom. A male and a female whole body XCAT phantom was voxelized into 256 × 256 × 600 voxels (3.125 × 3.125 × 3.125 mm3). A monoenergetic rectangular beam of 5.0 MeV neutrons or 7.0 MeV photons was made incident on a 2 cm thick slice of the phantom. The beam was rotated at eight different angles around the phantom ranging from 0° to 180°. Absorbed dose was calculated for each individual organ in the body and dose volume histograms were computed to analyze the absolute and relative doses in each organ. Results: The neutron irradiations of the liver showed the highest organ dose absorption in the liver, with appreciably lower doses in other proximal organs. The dose distribution within the irradiated slice exhibited substantial attenuation with increasing depth along the beam path, attenuating to ∼15% of the maximum value at the beam exit side. The gamma irradiation of the liver imparted the highest organ dose to the stomach wall. The dose distribution from the gammas showed a region of dose buildup at the beam entrance, followed by a relatively uniform dose distribution to all of the deep tissue structures, attenuating to ∼75% of the maximum value at the beam exit side. For the breast scans, both the neutron and gamma irradiation registered maximum organ doses in the breasts, with all other organs receiving less than 1% of the breast dose. Effective doses ranged from 0.22 to 0.37 mSv for the neutron scans and 41 to 66 mSv for the gamma scans
FT-Raman study of deferoxamine and deferiprone exhibits potent amelioration of structural changes in the liver tissues of mice due to aluminum exposure
NASA Astrophysics Data System (ADS)
Sivakumar, S.; Khatiwada, Chandra Prasad; Sivasubramanian, J.; Raja, B.
The present study inform the alterations on major biochemical constituents such as lipids, proteins, nucleic acids and glycogen along with phosphodiester linkages, tryptophan bands, tyrosine doublet, disulfide bridge conformations, aliphatic hydrophobic residue, and salt bridges in liver tissues of mice using Fourier transform Raman spectroscopy. In amide I, amide II and amide III, the area value significant decrease due structural alteration in the protein, glycogen and triglycerides levels but chelating agents DFP and DFO upturned it. Morphology changes by aluminium induced alterations and recovery by chelating agents within liver tissues known by histopathological examination. Concentrations of trace elements were found by ICP-OES. FT-Raman study was revealed to be in agreement with biochemical studies and demonstrate that it can successfully specify the molecular alteration in liver tissues. The tyrosyl doublet ratio I899/I831 decreases more in aluminum intoxicated tissues but treatment with DFP and DFO + DFP brings back to nearer control value. This indicates more variation in the hydrogen bonding of the phenolic hydroxyl group due to aluminum poisoning. The decreased Raman intensity ratio (I3220/I3400) observed in the aluminum induced tissues suggests a decreased water domain size, which could be interpreted in terms of weaker hydrogen-bonded molecular species of water in the aluminum intoxicated liver tissues. Finally, FT-Raman spectroscopy might be a useful tool for obtained successfully to indicate the molecular level changes.
Intra-individual variability of mycophenolic acid concentration according to renal function in liver transplant recipients receiving mycophenolate monotherapy
Song, Gi-Won; Jung, Dong-Hwan; Park, Gil-Chun; Ahn, Chul-Soo; Moon, Deok-Bog; Ha, Tae-Yong; Kim, Ki-Hun; Lee, Sung-Gyu
Backgrounds/Aims Mycophenolate mofetil (MMF) has wide inter- and intra-individual variability of mycophenolic acid (MPA) after liver transplantation (LT). On this study, we aimed to analyse the intra-individual variability of MPA concentration in stable adult LT recipients receiving MMF monotherapy and develop a method to determine the target level in the situation of wide intra-individual variability. Methods This retrospective cross-sectional study included 30 LT recipients. All patients received MMF monotherapy at a dose of 500 mg twice daily for ≥2 years and were divided into two groups based on renal function. MPA concentration-associated values were presented as mean with standard deviation and coefficient of variation (CV). Results The normal renal function group (n=15) showed a mean 12-hour MPA concentration of 2.5±0.5 µg/ml (range, 1.8±0.5 to 3.6±0.7 µg/ml) and a mean CV of 20.4±7.7% (range, 8.7% to 39.4%). In the renal dysfunction group (n=15), the 12-hour MPA concentration fluctuated more widely with a mean value of 3.7±0.9 µg/ml (range, 2.8±0.8 to 5.1±1.2 µg/ml) and a mean CV of 24.5±4.9% (range, 17.1% to 37.5%). The 12-hour MPA concentration was significantly higher in the renal dysfunction group, as compared to the normal renal function group (p=0.001); whereas, the CV was not significantly different between the two groups (p=0.093). Conclusions We determined the inter- and intra-individual variability of 12-hour MPA concentration after LT. The results suggested that therapeutic drug monitoring of MPA is necessary due to the inter-individual and intra-individual variability of MMF pharmacokinetics, especially in LT recipients with renal dysfunction. PMID:28317040
Prevalence of Suspected Non-alcoholic Fatty Liver Disease in Hispanic/Latino Individuals Differs by Heritage
Kallwitz, Eric R.; Daviglus, Martha L.; Allison, Matthew A.; Emory, Kristen T.; Zhao, Lihui; Kuniholm, Mark H.; Chen, Jinsong; Gouskova, Natalia; Pirzada, Amber; Talavera, Gregory A.; Youngblood, Marston E.; Cotler, Scott J.
Background & Aims Non-alcoholic fatty liver disease (NAFLD) was shown to disproportionally affect Hispanic persons. We examined the prevalence of suspected NAFLD in Hispanic/Latino persons with diverse backgrounds. Methods We studied the prevalence of suspected NAFLD among 12,133 persons included in The Hispanic Community Health Study/Study of Latinos. We collected data on levels of aminotransferase, metabolic syndrome (defined by National Cholesterol Education Program-Adult Treatment Panel III guidelines), demographics, and health behaviors. Suspected NAFLD was defined based on increased level of aminotransferase in the absence of serologic evidence for common causes of liver disease or excessive alcohol consumption. In multivariate analyses, data were adjusted for metabolic syndrome, age, acculturation, diet, physical activity, sleep, and levels of education and income. Results In multivariate analysis, compared to persons of Mexican heritage, persons of Cuban (odds ratio [OR], 0.69; 95% confidence interval [CI], 0.57–0.85), Puerto Rican (OR, 0.67; 95% CI, 0.52–0.87), and Dominican backgrounds (OR, 0.71; 95% CI, 0.54–0.93) had lower rates of suspected NAFLD. Persons of Central American and South American heritage had a similar prevalence of suspected NAFLD compared to persons of Mexican heritage. NAFLD was less common in women than men (OR, 0.49; 95% CI, 0.40–0.60). Suspected NAFLD associated with the metabolic syndrome and all 5 of its components. Conclusion Based on an analysis of a large database of health in Latino populations, we found the prevalence of suspected NAFLD among Hispanic/Latino individuals to vary by region of heritage. PMID:25218670
[Effects of rumalon and arteparon correcting metabolism in the connective tissue on the functional state of the liver in toxic hepatitis].
Misiureva, S V; Zupanets, I A
Effects of the connective tissue metabolism correctors rumalon (a glycosaminoglycane peptide complex) and arteparon (glucosamine sulfate) on the cholepoietic and absorption-excretion functions of liver were studied on a model of toxic liver damage. Rumalon exhibits pronounced anticholelithiasis and cholagogic properties and improves the absorption-excretion liver function. Arteparon produced no cholagogic action, inhibited the elimination of bromosulfalein, and showed no anticholelithiasis activity. The difference in the pharmacological effects of two drugs is related to their structural distinctions and the differing characteristics of aglycons and anions entering into their compositions.
Dietary α-linolenic acid-rich flaxseed oil prevents against alcoholic hepatic steatosis via ameliorating lipid homeostasis at adipose tissue-liver axis in mice
Wang, Meng; Zhang, Xiao-Jing; Feng, Kun; He, Chengwei; Li, Peng; Hu, Yuan-Jia; Su, Huanxing; Wan, Jian-Bo
Low levels of n-3 polyunsaturated fatty acids (PUFAs) in serum and liver tissue biopsies are the common characteristics in patients with alcoholic liver disease. The α-linolenic acid (ALA) is a plant-derived n-3 PUFA and is rich in flaxseed oil. However, the impact of ALA on alcoholic fatty liver is largely unknown. In this study, we assessed the potential protective effects of ALA-rich flaxseed oil (FO) on ethanol-induced hepatic steatosis and observed that dietary FO supplementation effectively attenuated the ethanol-induced hepatic lipid accumulation in mice. Ethanol exposure stimulated adipose lipolysis but reduced fatty acid/lipid uptake, which were normalized by FO. Our investigations into the corresponding mechanisms demonstrated that the ameliorating effect of FO might be associated with the lower endoplasmic reticulum stress and normalized lipid metabolism in adipose tissue. In the liver, alcohol exposure stimulated hepatic fatty acid uptake and triglyceride synthesis, which were attenuated by FO. Additionally, dietary FO upregulated plasma adiponectin concentration, hepatic adiponectin receptor 2 expression, and the activation of hepatic adenosine monophosphate-activated protein kinase. Collectively, dietary FO protects against alcoholic hepatic steatosis by improving lipid homeostasis at the adipose tissue-liver axis, suggesting that dietary ALA-rich flaxseed oil might be a promising approach for prevention of alcoholic fatty liver. PMID:27220557
Bioprinting cell-laden matrigel for radioprotection study of liver by pro-drug conversion in a dual-tissue microfluidic chip.
Snyder, J E; Hamid, Q; Wang, C; Chang, R; Emami, K; Wu, H; Sun, W
The objective of this paper is to introduce a novel cell printing and microfluidic system to serve as a portable ground model for the study of drug conversion and radiation protection of living liver tissue analogs. The system is applied to study behavior in ground models of space stress, particularly radiation. A microfluidic environment is engineered by two cell types to prepare an improved higher fidelity in vitro micro-liver tissue analog. Cell-laden Matrigel printing and microfluidic chips were used to test radiation shielding to liver cells by the pro-drug amifostine. In this work, the sealed microfluidic chip regulates three variables of interest: radiation exposure, anti-radiation drug treatment and single- or dual-tissue culture environments. This application is intended to obtain a scientific understanding of the response of the multi-cellular biological system for long-term manned space exploration, disease models and biosensors.
Disrupted G{sub 1} to S phase clearance via cyclin signaling impairs liver tissue repair in thioacetamide-treated type 1 diabetic rats
Devi, Sachin S.; Mehendale, Harihara M. . E-mail: firstname.lastname@example.com
Previously we reported that a nonlethal dose of thioacetamide (TA, 300 mg/kg) causes 90% mortality in type 1 diabetic (DB) rats because of irreversible acute liver injury owing to inhibited hepatic tissue repair, primarily due to blockage of G{sub 0} to S phase progression of cell division cycle. On the other hand, DB rats receiving 30 mg TA/kg exhibited equal initial liver injury and delayed tissue repair compared to nondiabetic (NDB) rats receiving 300 mg TA/kg, resulting in a delay in recovery from liver injury and survival. The objective of the present study was to test the hypothesis that impaired cyclin-regulated progression of G{sub 1} to S phase of the cell cycle may explain inhibited liver tissue repair, hepatic failure, and death, contrasted with delayed liver tissue repair but survival observed in the DB rats receiving 300 in contrast to 30 mg TA/kg. In the TA-treated NDB rats sustained MAPKs and cyclin expression resulted in higher phosphorylation of retinoblastoma (pRb), explaining prompt tissue repair and survival. In contrast, DB rats receiving the same dose of TA (300 mg/kg) exhibited suppressed MAPKs and cyclin expression that led to inhibition of pRb, inhibited tissue repair, and death. On the other hand, DB rats receiving 30 mg TA/kg exhibited delayed up regulation of MAPK signaling that delayed the expression of CD1 and pRb, explaining delayed stimulation of tissue repair observed in this group. In conclusion, the hepatotoxicant TA has a dose-dependent adverse effect on cyclin-regulated pRb signaling: the lower dose causes a recoverable delay, whereas the higher dose inhibits it with corresponding effect on the ultimate outcomes on hepatic tissue repair; this dose-dependent adverse effect is substantially shifted to the left of the dose response curve in diabetes.
Effects of noradrenaline on potassium efflux, membrane potential and electrolyte levels in tissue slices prepared from guinea-pig liver
Haylett, D. G.; Jenkinson, D. H.
1. Some effects of noradrenaline on potassium efflux, electrolyte levels, membrane potential and current distribution in guinea-pig liver slices have been examined. 2. The slices (thickness ca. 300 μm) were prepared from the median lobe of the liver and incubated at 38° C in a mammalian Ringer fluid containing 2 mM pyruvate. After an initial recovery period, the ionic composition of the tissue remained stable for several hours. 3. The steady-state contents of sodium, potassium and chloride were 296, 266 and 272 m-equiv/kg dry tissue respectively. The inulin space was 29 ml./100 g wet tissue. 4. Most if not all of the tissue potassium was exchangeable. The rate constant for 42K efflux was 0·019 min-1. 5. Noradrenaline (1 μM) markedly increased the efflux of 42K and within 2 min caused tissue potassium to fall by 8%. At the same time the sodium content rose. 6. Traverses of the slices with micro-electrodes showed many negative-going deflexions of 30-40 mV in amplitude. The evidence suggests that these correspond to the membrane potentials of the parenchymal cells. 7. Noradrenaline (1 μM) caused a reversible hyperpolarization of about 10 mV. The response became larger on replacing external chloride by isethionate or methylsulphate, but was little affected by a reduction in external potassium. 8. After slices had been bathed in potassium and chloride-free solutions for several min, restoration of external potassium caused the membrane potential to increase by up to 10 mV. This hyperpolarization, but not that caused by noradrenaline, was abolished by ouabain. 9. Noradrenaline reduced the amplitude and quickened the time course of electrotonic potentials set up by current pulses from another microelectrode, suggesting that the membrane conductance had risen. 10. Although certain mechanisms based on electrogenic active transport processes with unusual properties have not been excluded, the present findings are more simply explained by supposing that noradrenaline
Effects of different types of hydroxyethyl starch (HES) on microcirculation perfusion and tissue oxygenation in patients undergoing liver surgery.
Cui, Yinghua; Sun, Bo; Wang, Changsong; Liu, Shujuan; Li, Peng; Shi, Jinghui; Li, Enyou
To compare the effects of hydroxyethyl starch (HES) 130/0.4 and HES 200/0.5, which have different molecular weights and degrees of substitution, on microcirculation perfusion and tissue oxygenation in patients undergoing liver surgery. Thirty patients with an American Society of Anesthesiologists status I/II who were scheduled for liver surgery were randomly divided into two groups: one received an intraoperative HES 130/0.4 infusion equal to the amount of blood loss (HES 130/0.4 group, n=15), and the other received HES 200/0.5 equal to the amount of blood loss (HES 200/0.5 group, n=15). Gastric mucosal perfusion and tissue oxygenation were monitored by measuring the gastric mucosal pH (pHi), which was determined using a carbon dioxide tonometer inserted through a nasogastric tube. Gastric mucosal pHi , hemodynamic parameters, body temperature, and blood gas parameters were recorded upon entering the operating room, before skin incision, one hour and two hours after skin incision, and at the end of surgery. The intraoperative pHi decreased in both groups of patients, but the decline in the HES 130/0.4 group was smaller than that of the HES 200/0.5 group. The pHi of the HES 130/0.4 group was significantly higher than that of the HES 200/0.5 group two hours after skin incision and at the end of surgery (P<0.05). A multivariate analysis showed that the type of colloid used intraoperatively was the only variant that affected pHi (F=0.626, P<0.05). Moreover, there were good correlation between pHi at the end of surgery and the length of postoperative hospital stay (r=-0.536, P<0.05) and the time intervals from surgery to the passage of flatus (r=-0.547, P<0.05). Compared with HES 200/0.5, the use of HES 130/0.4 (with a relatively lower molecular weight and lower degree of substitution) could significantly improve internal organ perfusion and tissue oxygenation in patients undergoing liver surgery with a relatively large amount of blood loss.
Computational reconstruction of tissue-specific metabolic models: application to human liver metabolism
Jerby, Livnat; Shlomi, Tomer; Ruppin, Eytan
The computational study of human metabolism has been advanced with the advent of the first generic (non-tissue specific) stoichiometric model of human metabolism. In this study, we present a new algorithm for rapid reconstruction of tissue-specific genome-scale models of human metabolism. The algorithm generates a tissue-specific model from the generic human model by integrating a variety of tissue-specific molecular data sources, including literature-based knowledge, transcriptomic, proteomic, metabolomic and phenotypic data. Applying the algorithm, we constructed the first genome-scale stoichiometric model of hepatic metabolism. The model is verified using standard cross-validation procedures, and through its ability to carry out hepatic metabolic functions. The model's flux predictions correlate with flux measurements across a variety of hormonal and dietary conditions, and improve upon the predictive performance obtained using the original, generic human model (prediction accuracy of 0.67 versus 0.46). Finally, the model better predicts biomarker changes in genetic metabolic disorders than the generic human model (accuracy of 0.67 versus 0.59). The approach presented can be used to construct other human tissue-specific models, and be applied to other organisms. PMID:20823844
Multi-omic profiles of human non-alcoholic fatty liver disease tissue highlight heterogenic phenotypes
Wruck, Wasco; Kashofer, Karl; Rehman, Samrina; Daskalaki, Andriani; Berg, Daniela; Gralka, Ewa; Jozefczuk, Justyna; Drews, Katharina; Pandey, Vikash; Regenbrecht, Christian; Wierling, Christoph; Turano, Paola; Korf, Ulrike; Zatloukal, Kurt; Lehrach, Hans; Westerhoff, Hans V.; Adjaye, James
Non-alcoholic fatty liver disease (NAFLD) is a consequence of sedentary life style and high fat diets with an estimated prevalence of about 30% in western countries. It is associated with insulin resistance, obesity, glucose intolerance and drug toxicity. Additionally, polymorphisms within, e.g., APOC3, PNPLA3, NCAN, TM6SF2 and PPP1R3B, correlate with NAFLD. Several studies have already investigated later stages of the disease. This study explores the early steatosis stage of NAFLD with the aim of identifying molecular mechanisms underlying the etiology of NAFLD. We analyzed liver biopsies and serum samples from patients with high- and low-grade steatosis (also pre-disease states) employing transcriptomics, ELISA-based serum protein analyses and metabolomics. Here, we provide a detailed description of the various related datasets produced in the course of this study. These datasets may help other researchers find new clues for the etiology of NAFLD and the mechanisms underlying its progression to more severe disease states. PMID:26646939
Trace level determination of trichloroethylene from liver, lung and kidney tissues by gas chromatography - magnetic sector mass spectrometry
Stacy D. Brown; S. Muralidhara; James V. Bruckner, Michael G. Bartlett
Trichloroethylene (TCE) is a common industrial chemical that has been heavily used as a metal degreaser and a solvent for the past 100 years. As a result of the extensive use and production of this compound, it has become prevalent in the environment, appearing at over 50% of the hazardous waste sites on the US EPA's National Priorities List (NPL). TCE exposure has been linked to neurological dysfunction as well as to several types of cancer in animals. This paper describes the development and validation of a gas chromatography-mass spectrometry (GC-MS) method for the quantitation of trace levels of TCE in its target tissues (i.e. liver, kidney and lungs). The limit of quantitation (5 ng/ml) is substantially lower than currently published methods for the analysis of TCE in tissues. The % RSD and % Error for the assay falls within the acceptable range (<15% for middle and high QC points and <20% for low QC points), and the recovery is high from all tissues (>79%).
Liver X receptor β controls thyroid hormone feedback in the brain and regulates browning of subcutaneous white adipose tissue
Miao, Yifei; Wu, Wanfu; Dai, Yubing; Maneix, Laure; Huang, Bo; Warner, Margaret; Gustafsson, Jan-Åke
The recent discovery of browning of white adipose tissue (WAT) has raised great research interest because of its significant potential in counteracting obesity and type 2 diabetes. Browning is the result of the induction in WAT of a newly discovered type of adipocyte, the beige cell. When mice are exposed to cold or several kinds of hormones or treatments with chemicals, specific depots of WAT undergo a browning process, characterized by highly activated mitochondria and increased heat production and energy expenditure. However, the mechanisms underlying browning are still poorly understood. Liver X receptors (LXRs) are one class of nuclear receptors, which play a vital role in regulating cholesterol, triglyceride, and glucose metabolism. Following our previous finding that LXRs serve as repressors of uncoupling protein-1 (UCP1) in classic brown adipose tissue in female mice, we found that LXRs, especially LXRβ, also repress the browning process of subcutaneous adipose tissue (SAT) in male rodents fed a normal diet. Depletion of LXRs activated thyroid-stimulating hormone (TSH)-releasing hormone (TRH)-positive neurons in the paraventricular nucleus area of the hypothalamus and thus stimulated secretion of TSH from the pituitary. Consequently, production of thyroid hormones in the thyroid gland and circulating thyroid hormone level were increased. Moreover, the activity of thyroid signaling in SAT was markedly increased. Together, our findings have uncovered the basis of increased energy expenditure in male LXR knockout mice and provided support for targeting LXRs in treatment of obesity. PMID:26504234
Tissue-specific metallothionein gene expression in liver and intestine by dexamethasone, interleukin-1. alpha. and elevated zinc status
Hempe, J.M.; Carlson, J.M.; Cousins, R.J. )
Intestinal metallothionein has been implicated in the regulation of zinc absorption. Glucocorticoids and cytokines mediate hepatic metallothionein gene expression but the effects of these hormones in the small intestine are unclear. In this experiment, rats were injected ip with dexamethasone (DEX), recombinant human interleukin-1{alpha} (ILK-1), or ZnSO{sub 4}. Data collected 0. 3, 6,9, or 12 hour post-injection showed tissue specific regulation of metallothionein gene expression. Liver metallothionein mRNA (determined by hybridization analysis) were increased by DEX, IL-1 and ZnSO{sub 4}. In contrast, the intestine was completely refractory to IL-1. DEX did not affect intestinal metallothionein but did enhance mucosal accumulation of {sup 65}Zn by ligated duodenal loops. Absorption of {sup 65}Zn was not affected by IL-1 or DEX but was inversely related to elevated intestinal metallothionein protein induced in response to ZnSO. Plasma zinc was depressed by DEX and IL-1 and elevated in rats injected with ZnSO{sub 4} but was not related to {sup 54}Zn absorption. Tissue-specific induction of metallothionein may constitute a mechanism for independently regulating both tissue zinc distribution and zinc absorption.
Autophagy in the CNS and Periphery Coordinate Lipophagy and Lipolysis in the Brown Adipose Tissue and Liver.
Martinez-Lopez, Nuria; Garcia-Macia, Marina; Sahu, Srabani; Athonvarangkul, Diana; Liebling, Emily; Merlo, Paola; Cecconi, Francesco; Schwartz, Gary J; Singh, Rajat
The integrative physiology of inter-organ communication in lipophagy regulation is not well understood. Lipophagy and the cytosolic lipases ATGL and HSL contribute to lipid droplet (LD) mobilization; however, whether autophagy proteins engage with lipases to promote lipid utilization remains unknown. Here, we show that cold induces autophagy in proopiomelanocortin (POMC) neurons and activates lipophagy in brown adipose tissue (BAT) and liver in mice. Targeted activation of autophagy in POMC neurons via intra-hypothalamic rapamycin is sufficient to trigger lipid utilization in room temperature-housed mice. Conversely, inhibiting autophagy in POMC neurons or in peripheral tissues or denervating BAT blocks lipid utilization. Unexpectedly, the autophagosome marker LC3 is mechanistically coupled to ATGL-mediated lipolysis. ATGL exhibits LC3-interacting region (LIR) motifs, and mutating a single LIR motif on ATGL displaces ATGL from LD and disrupts lipolysis. Thus, cold-induced activation of central autophagy activates lipophagy and cytosolic lipases in a complementary manner to mediate lipolysis in peripheral tissues.
Liver tissue engineering based on aggregate assembly: efficient formation of endothelialized rat hepatocyte aggregates and their immobilization with biodegradable fibres.
Pang, Y; Montagne, K; Shinohara, M; Komori, K; Sakai, Y
To realize long-term in vitro culture of hepatocytes at a high density while maintaining a high hepatic function for aggregate-based liver tissue engineering, we report here a novel culture method whereby endothelialized rat hepatocyte aggregates were formed using a PDMS microwell device and cultured in a perfusion bioreactor by introducing spacers between aggregates to improve oxygen and nutrient supply. Primary rat hepatocyte aggregates around 100 µm in diameter coated with human umbilical vein endothelial cells were spontaneously and quickly formed after 12 h of incubation, thanks to the continuous supply of oxygen by diffusion through the PDMS honeycomb microwell device. Then, the recovered endothelialized rat hepatocyte aggregates were mixed with biodegradable poly-l-lactic acid fibres in suspension and packed into a PDMS-based bioreactor. Perfusion culture of 7 days was successfully achieved with more than 73.8% cells retained in the bioreactor. As expected, the fibres acted as spacers between aggregates, which was evidenced from the enhanced albumin production and more spherical morphology compared with fibre-free packing. In summary, this study shows the advantages of using PDMS-based microwells to form heterotypic aggregates and also demonstrates the feasibility of spacing tissue elements for improving oxygen and nutrient supply to tissue engineering based on modular assembly.
Mechanical Model Analysis for Quantitative Evaluation of Liver Fibrosis Based on Ultrasound Tissue Elasticity Imaging
NASA Astrophysics Data System (ADS)
Shiina, Tsuyoshi; Maki, Tomonori; Yamakawa, Makoto; Mitake, Tsuyoshi; Kudo, Masatoshi; Fujimoto, Kenji
Precise evaluation of the stage of chronic hepatitis C with respect to fibrosis has become an important issue to prevent the occurrence of cirrhosis and to initiate appropriate therapeutic intervention such as viral eradication using interferon. Ultrasound tissue elasticity imaging, i.e., elastography can visualize tissue hardness/softness, and its clinical usefulness has been studied to detect and evaluate tumors. We have recently reported that the texture of elasticity image changes as fibrosis progresses. To evaluate fibrosis progression quantitatively on the basis of ultrasound tissue elasticity imaging, we introduced a mechanical model of fibrosis progression and simulated the process by which hepatic fibrosis affects elasticity images and compared the results with those clinical data analysis. As a result, it was confirmed that even in diffuse diseases like chronic hepatitis, the patterns of elasticity images are related to fibrous structural changes caused by hepatic disease and can be used to derive features for quantitative evaluation of fibrosis stage.
Establishment of a primary hepatocyte culture from the small Indian mongoose (Herpestes auropunctatus) and distribution of mercury in liver tissue.
Horai, Sawako; Yanagi, Kumiko; Kaname, Tadashi; Yamamoto, Masatatsu; Watanabe, Izumi; Ogura, Go; Abe, Shintaro; Tanabe, Shinsuke; Furukawa, Tatsuhiko
The present study established a primary hepatocyte culture for the small Indian mongoose (Herpestes auropunctatus). To determine the suitable medium for growing the primary hepatic cells of this species, we compared the condition of cells cultured in three media that are frequently used for mammalian cell culture: Dulbecco's Modified Eagle's Medium, RPMI-1640, and William's E. Of these, William's E medium was best suited for culturing the hepatic cells of this species. Using periodic acid-Schiff staining and ultrastructural observations, we demonstrated the cells collected from mongoose livers were hepatocytes. To evaluate the distribution of mercury (Hg) in the liver tissue, we carried out autometallography staining. Most of the Hg compounds were found in the central region of hepatic lobules. Smooth endoplasmic reticulum, which plays a role inxenobiotic metabolism, lipid/cholesterol metabolism, and the digestion and detoxification of lipophilic substances is grown in this area. This suggested that Hg colocalized with smooth endoplasmic reticulum. The results of the present study could be useful to identify the detoxification systems of wildlife with high Hg content in the body, and to evaluate the susceptibility of wildlife to Hg toxicity.
Biomarkers of oxidative stress and tissue damage released by muscle and liver after a single bout of swimming exercise.
Ramos, Dionizio; Martins, Eduarda Gabrielle; Viana-Gomes, Diego; Casimiro-Lopes, Gustavo; Salerno, Verônica P
Both acute exercise and excessive training can cause oxidative stress. The resulting increase in free radicals and the inadequate response from antioxidant systems can lead to a framework of cellular damage. An association between affected tissue and the biomarkers of oxidative stress that appear in plasma has not been clearly established. The aim of this study was to evaluate the source of oxidative stress biomarkers found in the plasma of untrained rats after a single bout of swimming exercise at 2 different intensities: low intensity (SBLIE) or high intensity (SBHIE). Immediately after the exercise, aspartate transaminase (AST), alanine transaminase (ALT), γ-glutamyltransferase (GGT), and lactate dehydrogenase (LDH) were measured in plasma to characterize cell damage. Oxidative stress was assessed using protein carbonylation (PC), total antioxidant capacity (TAC), and thiobarbituric acid reactive substances (TBARS) quantified by malondialdehyde concentration. SBHIE raised levels of plasma AST (93%) and ALT (17%), and both exercise regimens produced an increase in GGT (7%) and LDH (∼55%). Plasma levels of PC and TBARS were greater in the SBHIE group; there were no changes in TAC. SBLIE caused only a modest increase in TBARS. In muscle, there were no changes in TAC, PC, or TBARS, regardless of exercise intensity, In the liver, TAC and TBARS increased significantly in both the SBLIE and SBHIE groups. This indicates that the oxidative stress biomarkers measured in the plasma immediately after a single bout of swimming exercise were generated primarily in the liver, not in muscle.
Assessment of XAF1 as A Biomarker to Differentiate Hepatocellular Carcinoma from Nonneoplastic Liver Tissues
Lin, Ying
Objective XIAP-associated factor 1 (XAF1) expression has been shown to be related with apoptosis in hepatocellular carcinoma (HCC). However, the correlation of XAF1 expression with HCC tumor grade has not been intensively assessed. XIAP-associated factor-1 (XAF1) is an important apoptosis inducer in human HCC. The aim of this study is to determine the correlation between XAF1 expression and HCC histopathological grades. Methods The mRNA levels of XAF1 in 24 paired HCC-nonneoplastic specimens were quantified by real-time reverse transcription PCR (RT-PCR). Protein levels of XAF1 in 110 paired HCC-noncancer tissues were investigated by immunostaining specimens on a tissue microarray (TMA). Correlations between XAF1 mRNA levels or protein expression and clinicopathological features were assessed by statistical analysis. Results Both XAF1 mRNA and protein were significantly under-expressed in HCC tissues compared to their non-neoplastic counterparts. No significant relationship was found between XAF1 mRNA or protein expression and histological tumor grade. Conclusion All these data suggest that XAF1 is a potential biomarker for differentiating HCC with noncancerous tissues. PMID:23358741
Investigation into the Effects of Boron on Liver Tissue Protein Carbonyl, MDA, and Glutathione Levels in Endotoxemia.
Balabanlı, Barbaros; Balaban, Tuba
Endotoxin has been known to cause the formation and damage of free radical. The importance of boron for human life is increasing each passing day, and its consuming fields are continuing to expand due to the advances in science and technology. Therefore, in our study, we intended to investigate into the effects of boron on liver tissue oxidative events. Eighteen male Wistar albino rats were randomly separated into three equal groups in the experiments; control group, boron + endotoxin group, and endotoxin group. Dissolved in distilled water, boric acid (100 mg/kg) was administered to boron + endotoxin group via gavage procedure for 28 days. Only distilled water was administered to control and endotoxin groups via gavage procedure for 28 days. Then 4 mg/kg endotoxin (LPS; Escherichia coli 0111:B4) was intraperitoneally (ip) administered to boron + endotoxin and endotoxin groups on the 28th day. Sterile saline was injected into control group on the 28th day (ip). Malondialdehyde (MDA), which is the end product of lipid peroxidation in liver tissues, protein carbonyl compounds (PC), which are protein oxidization markers, and glutathione (GSH) levels were measured spectrophotometrically. The results were compared with Mann-Whitney U test. When boron + endotoxin group is compared with endotoxin group, PC levels of endotoxin group showed a significant increase. When GSH levels are compared, GSH level in boron + endotoxin group decreased according to endotoxin group. Variations among all groups in MDA levels were found to be statistically insignificant. We are of the opinion that endotoxin affects the proteins by forming free radicals, and boron may also cause the structural and/or functional changes in proteins in order to protect proteins from oxidization.
Aldehyde dehydrogenases of the rat colon: comparison with other tissues of the alimentary tract and the liver.
Koivisto, T; Salaspuro, M
Intracolonic bacteria have previously been shown to produce substantial amounts of acetaldehyde during ethanol oxidation, and it has been suggested that this acetaldehyde might be associated with alcohol-related colonic disorders, as well as other alcohol-induced organ injuries. The capacity of colonic mucosa to remove this bacterial acetaldehyde by aldehyde dehydrogenase (ALDH) is, however, poorly known. We therefore measured ALDH activities and determined ALDH isoenzyme profiles from different subcellular fractions of rat colonic mucosa. For comparison, hepatic, gastric, and small intestinal samples were studied similarly. Alcohol dehydrogenase (ADH) activities were also measured from all of these tissues. Rat colonic mucosa was found to possess detectable amounts of ALDH activity with both micromolar and millimolar acetaldehyde concentrations and in all subcellular fractions. The ALDH activities of colonic mucosa were, however, generally low when compared with the liver and stomach, and they also tended to be lower than in small intestine. Mitochondrial low K(m) ALDH2 and cytosolic ALDH with low K(m) for acetaldehyde were expressed in the colonic mucosa, whereas some cytosolic high K(m) isoenzymes found in the small intestine and stomach were not detectable in colonic samples. Cytosolic ADH activity corresponded well to ALDH activity in different tissues: in colonic mucosa, it was approximately 6 times lower than in the liver and about one-half of gastric ADH activity. ALDH activity of the colonic mucosa should, thus, be sufficient for the removal of acetaldehyde produced by colonic mucosal ADH during ethanol oxidation. It may, however, be insufficient for the removal of the acetaldehyde produced by intracolonic bacteria. This may lead to the accumulation of acetaldehyde in the colon and colonic mucosa after ingestion of ethanol that might, at least after chronic heavy alcohol consumption, contribute to the development of alcohol-related colonic morbidity
Prepartal dietary energy alters transcriptional adaptations of the liver and subcutaneous adipose tissue of dairy cows during the transition period.
Selim, S; Salin, S; Taponen, J; Vanhatalo, A; Kokkonen, T; Elo, K T
Overfeeding during the dry period may predispose cows to increased insulin resistance (IR) with enhanced postpartum lipolysis. We studied gene expression in the liver and subcutaneous adipose tissue (SAT) of 16 Finnish Ayrshire dairy cows fed either a controlled energy diet [Con, 99 MJ/day metabolizable energy (ME)] during the last 6 wk of the dry period or high-energy diet (High, 141 MJ/day ME) for the first 3 wk and then gradually decreasing energy allowance during 3 wk to 99 MJ/day ME before the expected parturition. Tissue biopsies were collected at -10, 1, and 9 days, and blood samples at -10, 1, and 7 days relative to parturition. Overfed cows had greater dry matter, crude protein, and ME intakes and ME balance before parturition. Daily milk yield, live weight, and body condition score were not different between treatments. The High cows tended to have greater plasma insulin and lower glucagon/insulin ratio compared with Con cows. No differences in circulating glucose, glucagon, nonesterified fatty acids and β-hydroxybutyrate concentrations, and hepatic triglyceride contents were observed between treatments. Overfeeding compared with Con resulted in lower CPT1A and PCK1 and a tendency for lower G6PC and PC expression in the liver. The High group tended to have lower RETN expression in SAT than Con. No other effects of overfeeding on the expression of genes related to IR in SAT were observed. In conclusion, overfeeding energy prepartum may have compromised hepatic gluconeogenic capacity and slightly affected IR in SAT based on gene expression.
Preliminary assessment of facial soft tissue thickness utilizing three-dimensional computed tomography models of living individuals.
Parks, Connie L; Richard, Adam H; Monson, Keith L
Facial approximation is the technique of developing a representation of the face from the skull of an unknown individual. Facial approximation relies heavily on average craniofacial soft tissue depths. For more than a century, researchers have employed a broad array of tissue depth collection methodologies, a practice which has resulted in a lack of standardization in craniofacial soft tissue depth research. To combat such methodological inconsistencies, Stephan and Simpson 2008 [15] examined and synthesized a large number of previously published soft tissue depth studies. Their comprehensive meta-analysis produced a pooled dataset of averaged tissue depths and a simplified methodology, which the researchers suggest be utilized as a minimum standard protocol for future craniofacial soft tissue depth research. The authors of the present paper collected craniofacial soft tissue depths using three-dimensional models generated from computed tomography scans of living males and females of four self-identified ancestry groups from the United States ranging in age from 18 to 62 years. This paper assesses the differences between: (i) the pooled mean tissue depth values from the sample utilized in this paper and those published by Stephan 2012 [21] and (ii) the mean tissue depth values of two demographically similar subsets of the sample utilized in this paper and those published by Rhine and Moore 1984 [16]. Statistical test results indicate that the tissue depths collected from the sample evaluated in this paper are significantly and consistently larger than those published by Stephan 2012 [21]. Although a lack of published variance data by Rhine and Moore 1984 [16] precluded a direct statistical assessment, a substantive difference was also concluded. Further, the dataset presented in this study is representative of modern American adults and is, therefore, appropriate for use in constructing contemporary facial approximations.
Tissue Factor Activity in Lymphocyte Cultures from Normal Individuals and Patients with Hemophilia A
Rickles, Frederick R.; Hardin, John A.; Pitlick, Frances A.; Hoyer, Leon W.; Conrad, Marcel E.
The procoagulant material of lymphocytes has been characterized as tissue factor. Lymphocytes stimulated with phytohemagglutinin or the purified protein derivative of the tubercle bacillus developed procoagulant activity with incubation in tissue culture. While this material corrected the prolonged clotting time of factor VIII (AHF) deficient plasma, we have shown, utilizing a sensitive radioimmunoassay, that no AHF antigen was present in the cell cultures. Further, we have demonstrated this material to be tissue factor by coagulation techniques and immunological cross-reactivity. The published data regarding factor VIII synthesis is reviewed in light of these observations and comments are made regarding the role of the lymphocyte procoagulant. PMID:4634046
Trace elements in human cancerous and healthy tissues from the same individual: A comparative study by TXRF and EDXRF
NASA Astrophysics Data System (ADS)
Magalhães, T.; von Bohlen, A.; Carvalho, M. L.; Becker, M.
In this work we studied the elemental distribution of P, S, Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Ni, Se, Br, Rb, Sr, I and Pb in normal and cancerous tissues of the same individual along several contiguous thin sections (up to 10 μm thick) of each tissue. Samples of healthy and carcinoma tissues, of colon, breast and uterus on a total of 7 citizens from German population, were analysed directly by total-reflection X-ray fluorescence (TXRF). The tissues were also analysed by normal energy-dispersive X-ray fluorescence (EDXRF). An additional application was performed by studying, by the same processes, 10 carcinoma samples of 10 Portuguese citizens from: rectum, sigmoid, thyroid, kidney, larynx and lung, in order to find out a similar correlation pattern in the studied elements in carcinoma tissues. As major conclusion of this work a similar pattern for almost all the analysed tissues were obtained for all the studied samples: increased or constant levels of P, S, K, Ca, Fe and Cu, and decreased levels of Zn and Br were found in carcinoma tissues, when compared with the corresponding healthy ones. Some exceptions were found in some samples for a few numbers of elements. When comparing the results obtained for both techniques, the patterns were the same, however not always the results did coincide. This can be explained by considering that the analysed samples were not exactly the same and the differences can be explained by inhomogeneities.
Livers, guts and gills: mapping the decay profiles of soft tissues to understand authigenic mineral replacement.
NASA Astrophysics Data System (ADS)
Clements, Thomas; Purnell, Mark; Gabbott, Sarah
The hard mineralised parts of organisms such as shells, teeth and bones dominate the fossil record. There are, however, sites around the world where soft-tissues are preserved often through rapid replacement of original tissue by rapidly-precipitating authigenic minerals. These exceptionally well-preserved soft-bodied fossils are much more informative about the anatomy, physiology, ecology and behaviour of ancient organisms as well as providing a more inclusive picture of ecosystems and evolution throughout geological time. However, despite the wealth of information that soft-bodied fossils can provide they must first be correctly interpreted as the processes of both decay and preservation act to modify the carcass from its in vivo condition. Decay leads to alteration of the appearance and topology of anatomy, and ultimately to loss. Preservation is selective with some anatomical features being more likely to be captured than others. These problems are especially germane to the interpretation of deep-time and/or enigmatic fossils where no modern analogue exist for comparative anatomical analysis. It is therefore of vital importance to understand the processes carcasses undergo during the fossilisation process, , in order to interpret the anatomical remains of fossils and thus extract true evolutionary presence or absence of anatomy from absence due to taphonomic biases. We have designed a series of novel experiments to investigate, in real time, how decay processes affect the fossilisation potential of soft-tissues - especially of internal anatomy. Our data allow us to unravel both the timing and sequence of anatomical decay of different organs. At the same time through measuring Eh and pH in selected organs we can predict when anatomical features will fall in to the window of authigenic mineralization and thus potentially become preserved. We can also place constraints on which minerals will operate to capture tissues. Our findings are applied to the fossil record
Insulin Resistance in Adipose Tissue but Not in Liver Is Associated with Aortic Valve Calcification.
Jorge-Galarza, Esteban; Posadas-Romero, Carlos; Torres-Tamayo, Margarita; Medina-Urrutia, Aida X; Rodas-Díaz, Marco A; Posadas-Sánchez, Rosalinda; Vargas-Alarcón, Gilberto; González-Salazar, María Del Carmen; Cardoso-Saldaña, Guillermo C; Juárez-Rojas, Juan G
Background. Insulin resistance is involved in the pathogenesis of cardiovascular disease, but its relationship with cardiovascular calcification has yielded conflicting results. The purpose of the present study was to investigate the role of hepatic and adipose tissue insulin resistance on the presence of coronary artery (CAC > 0) and aortic valve calcification (AVC > 0). Methods. In 1201 subjects (52% women, 53.6 ± 9.3 years old) without familiar and personal history of coronary heart disease, CAC and AVC were assessed by multidetector-computed tomography. Cardiovascular risk factors were documented and lipid profile, inflammation markers, glucose, insulin, and free fatty acids were measured. Hepatic insulin resistance (HOMA-IR) and adipose tissue insulin resistance (Adipo-IR) indices were calculated. Results. There was a significant relationship between HOMA-IR and Adipo-IR indices (r = 0.758, p < 0.001). Participants in the highest quartiles of HOMA-IR and Adipo-IR indices had a more adverse cardiovascular profile and higher prevalence of CAC > 0 and AVC > 0. After full adjustment, subjects in the highest quartile of Adipo-IR index had higher odds of AVC > 0 (OR: 2.40; 95% CI: 1.30-4.43), as compared to those in the lowest quartile. Conclusions. Adipo-IR was independently associated with AVC > 0. This suggests that abnormal adipose tissue function favors insulin resistance that may promote the development and progression of AVC.
Insulin Resistance in Adipose Tissue but Not in Liver Is Associated with Aortic Valve Calcification
Jorge-Galarza, Esteban; Torres-Tamayo, Margarita; Rodas-Díaz, Marco A.; Posadas-Sánchez, Rosalinda; González-Salazar, María del Carmen; Cardoso-Saldaña, Guillermo C.
Background. Insulin resistance is involved in the pathogenesis of cardiovascular disease, but its relationship with cardiovascular calcification has yielded conflicting results. The purpose of the present study was to investigate the role of hepatic and adipose tissue insulin resistance on the presence of coronary artery (CAC > 0) and aortic valve calcification (AVC > 0). Methods. In 1201 subjects (52% women, 53.6 ± 9.3 years old) without familiar and personal history of coronary heart disease, CAC and AVC were assessed by multidetector-computed tomography. Cardiovascular risk factors were documented and lipid profile, inflammation markers, glucose, insulin, and free fatty acids were measured. Hepatic insulin resistance (HOMA-IR) and adipose tissue insulin resistance (Adipo-IR) indices were calculated. Results. There was a significant relationship between HOMA-IR and Adipo-IR indices (r = 0.758, p < 0.001). Participants in the highest quartiles of HOMA-IR and Adipo-IR indices had a more adverse cardiovascular profile and higher prevalence of CAC > 0 and AVC > 0. After full adjustment, subjects in the highest quartile of Adipo-IR index had higher odds of AVC > 0 (OR: 2.40; 95% CI: 1.30–4.43), as compared to those in the lowest quartile. Conclusions. Adipo-IR was independently associated with AVC > 0. This suggests that abnormal adipose tissue function favors insulin resistance that may promote the development and progression of AVC. PMID:28127113
Changes in collagen and albumin mRNA in liver tissue of mice infected with Schistosoma mansoni as determined by in situ hybridization
We have employed in situ hybridization to evaluate the molecular mechanisms responsible for hypoalbuminemia and increased liver collagen content in murine schistosomiasis. Results were compared using a simplified method of hybridizing isolated hepatocytes from Schistosoma mansoni-infected and normal mouse liver with mouse albumin (pmalb-2) and chick pro-alpha 2(l) collagen (pCg45) probes. Whereas hepatocytes from infected mice showed significantly less albumin mRNA than hepatocytes from control, there were more grains of procollagen mRNA in hepatocytes from infected as compared with control liver. Hybridization of infected liver tissue sections with the collagen probe showed more grains per field in granulomas than in liver regions, whereas with the albumin probe there was more hybridization in liver tissue than in granulomas. These results suggest that in murine schistosomiasis a reduction in albumin mRNA sequence content may be associated with decreased albumin synthesis and ultimately leads to hypoalbuminemia. In addition, although the granuloma seems to be the primary source of type I collagen synthesis, hepatocytes are also capable of synthesizing collagen, especially under fibrogenic stimulation. PMID:6619195
Distribution of inorganic mercury in liver and kidney of beluga and bowhead whales through autometallographic development of light microscopic tissue sections.
Woshner, Victoria M; Ohara, Todd M; Eurell, Jo Ann; Wallig, Matthew A; Bratton, Gerald R; Suydam, Robert S; Beasley, Val R
Inorganic mercury was localized through autometallography (AMG) in kidney and liver of free-ranging, subsistence-harvested beluga (Delphinapterus leucus: n = 20) and bowhead (Balaena mysticetrus: n = 5) whales. AMG granules were not evident in bowhead tissues, confirming nominal mercury (Hg) concentrations (range = 0.011 to 0.038 microg/g ww for total Hg). In belugas, total Hg ranged from 0.30 to 17.11 and from 0.33 to 82.47 microg/g ww in liver and kidney, respectively. AMG granules were restricted to cortical tubular epithelial cytoplasm in belugas with lower tissue burdens; whales with higher tissue burdens had granules throughout the uriniferous tubular epithelium. In liver, AMG granular densities differed between lobular zones, concentrating in stellate macrophages and bile cannalicular domains of hepatocytes. AMG granules aggregated in periportal regions in belugas with lower hepatic Hg concentrations, yet among whales with higher Hg, AMG granule deposition extended to pericentral and midzonal regions of liver lobules. Mean areas occupied by AMG granules correlated well with hepatic Hg concentrations and age. In beluga livers, AMG staining density was not associated with lipofuscin quantity (an index of oxidative damage). Occasionally, AMG granules and lipofuscin were colocalized, but more often were not, implying that Hg was not a prominent factor in hepatic lipofuscin deposition in belugas.
Inhibition of soluble epoxide hydrolase modulates inflammation and autophagy in obese adipose tissue and liver: role for omega-3 epoxides.
López-Vicario, Cristina; Alcaraz-Quiles, José; García-Alonso, Verónica; Rius, Bibiana; Hwang, Sung H; Titos, Esther; Lopategi, Aritz; Hammock, Bruce D; Arroyo, Vicente; Clària, Joan
Soluble epoxide hydrolase (sEH) is an emerging therapeutic target in a number of diseases that have inflammation as a common underlying cause. sEH limits tissue levels of cytochrome P450 (CYP) epoxides derived from omega-6 and omega-3 polyunsaturated fatty acids (PUFA) by converting these antiinflammatory mediators into their less active diols. Here, we explored the metabolic effects of a sEH inhibitor (t-TUCB) in fat-1 mice with transgenic expression of an omega-3 desaturase capable of enriching tissues with endogenous omega-3 PUFA. These mice exhibited increased CYP1A1, CYP2E1, and CYP2U1 expression and abundant levels of the omega-3-derived epoxides 17,18-epoxyeicosatetraenoic acid (17,18-EEQ) and 19,20-epoxydocosapentaenoic (19,20-EDP) in insulin-sensitive tissues, especially liver, as determined by LC-ESI-MS/MS. In obese fat-1 mice, t-TUCB raised hepatic 17,18-EEQ and 19,20-EDP levels and reinforced the omega-3-dependent reduction observed in tissue inflammation and lipid peroxidation. t-TUCB also produced a more intense antisteatotic action in obese fat-1 mice, as revealed by magnetic resonance spectroscopy. Notably, t-TUCB skewed macrophage polarization toward an antiinflammatory M2 phenotype and expanded the interscapular brown adipose tissue volume. Moreover, t-TUCB restored hepatic levels of Atg12-Atg5 and LC3-II conjugates and reduced p62 expression, indicating up-regulation of hepatic autophagy. t-TUCB consistently reduced endoplasmic reticulum stress demonstrated by the attenuation of IRE-1α and eIF2α phosphorylation. These actions were recapitulated in vitro in palmitate-primed hepatocytes and adipocytes incubated with 19,20-EDP or 17,18-EEQ. Relatively similar but less pronounced actions were observed with the omega-6 epoxide, 14,15-EET, and nonoxidized DHA. Together, these findings identify omega-3 epoxides as important regulators of inflammation and autophagy in insulin-sensitive tissues and postulate sEH as a druggable target in metabolic
Chitosan reduces plasma adipocytokines and lipid accumulation in liver and adipose tissues and ameliorates insulin resistance in diabetic rats.
Hsieh, Yu-Lin; Yao, Hsien-Tsung; Cheng, Ron-Shan; Chiang, Meng-Tsan
Chitosan is a natural product derived from chitin. To investigate the hypoglycemic and anti-obesity effects of chitosan, male Sprague-Dawley rats were divided into four groups: normal control, diabetic, and diabetic fed 5% or 7% chitosan. Diabetes was induced in rats by injecting streptozotocin/nicotinamide. After 10 weeks of feeding, the elevated plasma glucose, tumor necrosis factor-α, and interleukin-6 and lower adiponetin levels caused by diabetes were effectively reversed by chitosan treatment. In addition, 7% chitosan feeding also elevated plasma glucagon-like peptide-1 levels and lowered the insulin resistance index (homeostasis model assessment) in diabetic rats. Lower adipocyte granular intensities and higher lipolysis rates in adipose tissues were noted in the 7% chitosan group. Moreover, chitosan feeding reduced hepatic triglyceride and cholesterol contents and increased hepatic peroxisomal proliferator-activated receptor α expression in diabetic rats. Our results indicate that long-term administration of chitosan may reduce insulin resistance through suppression of lipid accumulation in liver and adipose tissues and amelioration of chronic inflammation in diabetic rats.
Human induced pluripotent stem cell-based microphysiological tissue models of myocardium and liver for drug development
Drug discovery and development to date has relied on animal models, which are useful but are often expensive, slow, and fail to mimic human physiology. The discovery of human induced pluripotent stem (iPS) cells has led to the emergence of a new paradigm of drug screening using human and disease-specific organ-like cultures in a dish. Although classical static culture systems are useful for initial screening and toxicity testing, they lack the organization of differentiated iPS cells into microphysiological, organ-like structures deemed necessary for high-content analysis of candidate drugs. One promising approach to produce these organ-like structures is the use of advanced microfluidic systems, which can simulate tissue structure and function at a micron level, and can provide high-throughput testing of different compounds for therapeutic and diagnostic applications. Here, we provide a brief outline on the different approaches, which have been used to engineer in vitro tissue constructs of iPS cell-based myocardium and liver functions on chip. Combining these techniques with iPS cell biology has the potential of reducing the dependence on animal studies for drug toxicity and efficacy screening. PMID:24565415
Study of laser-induced thermoelastic deformation of native and coagulated ex-vivo bovine liver tissues for estimating their optical and thermomechanical properties.
Soroushian, Behrouz; Whelan, William M; Kolios, Michael C
Several studies have explored the potential of optoacoustic imaging for monitoring thermal therapies, yet the origin of the contrast in the images is not well understood. A technique is required to measure the changes in the optical and thermomechanical properties of tissues upon coagulation to better understand this contrast. An interferometric method is presented for measuring simultaneously the optical and thermomechanical properties of native and coagulated ex-vivo bovine tissue samples based on analysis of the surface displacement of irradiated samples. Surface displacements are measured after irradiation by short laser pulses at 750 nm. A 51% decrease in the optical attenuation depth is observed for coagulated liver samples compared to native samples. No significant differences in the Grüneisen coefficient are measured in the native and coagulated tissue samples. A mean value of 0.12 for the Grüneisen coefficient is measured for both native and coagulated liver tissues. The displacement profiles exhibit consistent differences between the two tissue types. To assess the changes in the sample mechanical properties, the experimental data also are compared to numerical solutions of the equation for thermoelastic deformation. The results demonstrate that differences in the tissue expansion dynamics arise from higher values of elastic modulus for coagulated liver samples compared to native ones.
Reconstitution of hepatic tissue architectures from fetal liver cells obtained from a three-dimensional culture with a rotating wall vessel bioreactor.
Ishikawa, Momotaro; Sekine, Keisuke; Okamura, Ai; Zheng, Yun-wen; Ueno, Yasuharu; Koike, Naoto; Tanaka, Junzo; Taniguchi, Hideki
Reconstitution of tissue architecture in vitro is important because it enables researchers to investigate the interactions and mutual relationships between cells and cellular signals involved in the three-dimensional (3D) construction of tissues. To date, in vitro methods for producing tissues with highly ordered structure and high levels of function have met with limited success although a variety of 3D culture systems have been investigated. In this study, we reconstituted functional hepatic tissue including mature hepatocyte and blood vessel-like structures accompanied with bile duct-like structures from E15.5 fetal liver cells, which contained more hepatic stem/progenitor cells comparing with neonatal liver cells. The culture was performed in a simulated microgravity environment produced by a rotating wall vessel (RWV) bioreactor. The hepatocytes in the reconstituted 3D tissue were found to be capable of producing albumin and storing glycogen. Additionally, bile canaliculi between hepatocytes, characteristics of adult hepatocyte in vivo were also formed. Apart from this, bile duct structure secreting mucin was shown to form complicated tubular branches. Furthermore, gene expression analysis by semi-quantitative RT-PCR revealed the elevated levels of mature hepatocyte markers as well as genes with the hepatic function. With RWV culture system, we could produce functionally reconstituted liver tissue and this might be useful in pharmaceutical industry including drug screening and testing and other applications such as an alternative approach to experimental animals.
Rice Germosprout Extract Protects Erythrocytes from Hemolysis and the Aorta, Brain, Heart, and Liver Tissues from Oxidative Stress In Vitro
Hussain, Jakir; Islam, Saiful
Identifying dietary alternatives for artificial antioxidants capable of boosting antihemolytic and antioxidative defense has been an important endeavor in improving human health. In the present study, we studied antihemolytic and antioxidative effects of germosprout (i.e., the germ part along with sprouted stems plus roots) extract prepared from the pregerminated rice. The extract contained considerable amounts of antioxidant β-carotene (414 ± 12 ng/g of extract) and phytochemicals such as total polyphenols (12.0 ± 1.1 mg gallic acid equivalent/g of extract) and flavonoids (11.0 ± 1.4 mg catechin equivalent/g of extract). The antioxidant potential of the extract was assessed by its DPPH- (2,2-diphenyl-1-picrylhydrazyl-) free radical scavenging activity where we observed that germosprout extract had considerable antioxidative potentials. To evaluate antihemolytic effect of the extract, freshly prepared erythrocytes were incubated with either peroxynitrite or Fenton's reagent in the absence or presence of the extract. We observed that erythrocytes pretreated with the extract exhibited reduced degree of in vitro hemolysis. To support the proposition that germosprout extract could act as a good antioxidative agent, we also induced in vitro oxidative stress in erythrocyte membranes and in the aorta, brain, heart, and liver tissue homogenates in the presence of the extract. As expected, germosprout extract decreased oxidative stress almost to the same extent as that of vitamin E, as measured by lipid peroxide levels, in all the mentioned tissues. We conclude that rice germosprout extract could be a good natural source of antioxidants to reduce oxidative stress-induced hemolysis and damage of blood vessels and other tissues. PMID:27413391
Borate-aided anion exchange high-performance liquid chromatography of uridine diphosphate-sugars in brain, heart, adipose and liver tissues.
Oikari, Sanna; Venäläinen, Tuula; Tammi, Markku
In this paper we describe a method optimized for the purification of uridine diphosphate (UDP)-sugars from liver, adipose tissue, brain, and heart, with highly reproducible up to 85% recoveries. Rapid tissue homogenization in cold ethanol, lipid removal by butanol extraction, and purification with a graphitized carbon column resulted in isolation of picomolar quantities of the UDP-sugars from 10 to 30mg of tissue. The UDP-sugars were baseline separated from each other, and from all major nucleotides using a CarboPac PA1 anion exchange column eluted with a gradient of acetate and borate buffers. The extraction and purification protocol produced samples with few unidentified peaks. UDP-N-acetylglucosamine was a dominant UDP-sugar in all the rat tissues studied. However, brain and adipose tissue showed high UDP-glucose levels, equal to that of UDP-N-acetylglucosamine. The UDP-N-acetylglucosamine showed 2.3-2.7 times higher levels than UDP-N-acetylgalactosamine in all tissues, and about the same ratio was found between UDP-glucose and UDP-galactose in adipose tissue and brain (2.6 and 2.8, respectively). Interestingly, the UDP-glucose/UDP-galactose ratio was markedly lower in liver (1.1) and heart (1.7). The UDP-N-acetylglucosamine/UDP-glucuronic acid ratio was also constant, between 9.7 and 7.7, except in liver with the ratio as low as 1.8. The distinct UDP-glucose/galactose ratio, and the abundance of UDP-glucuronic acid may reflect the specific role of liver in glycogen synthesis, and metabolism of hormones and xenobiotics, respectively, using these UDP-sugars as substrates.
Angiotensin II Levels in Gingival Tissues from Healthy Individuals, Patients with Nifedipine Induced Gingival Overgrowth and Non Responders on Nifedipine
Balaji, Anitha; Balaji, Thodur Madapusi
Context The Renin Angiotensin system has been implicated in the pathogenesis of Drug Induced Gingival Overgrowth (DIGO), a fibrotic condition, caused by Phenytoin, Nifedipine and Cyclosporine. Aim This study quantified Angiotensin II levels in gingival tissue samples obtained from healthy individuals, patients on Nifedipine manifesting/not manifesting drug induced gingival overgrowth. Materials and Methods Gingival tissue samples were obtained from healthy individuals (n=24), patients on nifidipine manifesting gingival overgrowth (n= 18) and patients on nifidipine not manifesting gingival overgrowth (n=8). Angiotensin II levels were estimated in the samples using a commercially available ELISA kit. Results Angiotensin II levels were significantly elevated in patients on Nifedipine manifesting gingival overgrowth compared to the other 2 groups (p<0.01). Conclusion The results of the study give an insight into the role played by Angiotensin II in the pathogenesis of drug induced gingival overgrowth. PMID:26436057
Sunitinib-ibuprofen drug interaction affects the pharmacokinetics and tissue distribution of sunitinib to brain, liver, and kidney in male and female mice differently.
Lau, Christine Li Ling; Chan, Sook Tyng; Selvaratanam, Manimegahlai; Khoo, Hui Wen; Lim, Adeline Yi Ling; Modamio, Pilar; Mariño, Eduardo L; Segarra, Ignacio
Tyrosine kinase inhibitor sunitinib (used in GIST, advanced RCC, and pancreatic neuroendocrine tumors) undergoes CYP3A4 metabolism and is an ABCB1B and ABCG2 efflux transporters substrate. We assessed the pharmacokinetic interaction with ibuprofen (an NSAID used by patients with cancer) in Balb/c male and female mice. Mice (study group) were coadministered (30 min apart) 30 mg/kg of ibuprofen and 60 mg/kg of sunitinib PO and compared with the control groups, which received sunitinib alone (60 mg/kg, PO). Sunitinib concentration in plasma, brain, kidney, and liver was measured by HPLC as scheduled and noncompartmental pharmacokinetic parameters estimated. In female control mice, sunitinib AUC0→∞ decreased in plasma (P < 0.05), was higher in liver and brain (P < 0.001), and lower in kidney (P < 0.001) vs. male control mice. After ibuprofen coadministration, female mice showed lower AUC0→∞ in plasma (P < 0.01), brain, liver, and kidney (all P < 0.001). However, in male mice, AUC0→∞ remained unchanged in plasma, increased in liver and kidney, and decreased in brain (all P < 0.001). The tissue-to-plasma AUC0→∞ ratio was similar between male and female control mice, but changed after ibuprofen coadministration: Male mice showed 1.6-fold higher liver-to-plasma ratio (P < 0.001) while remained unchanged in female mice and in kidney (male and female mice) but decreased 55% in brain (P < 0.05). The tissue-to-plasma partial AUC ratio, the drug tissue targeting index, and the tissue-plasma hysteresis-like plots also showed sex-based ibuprofen-sunitinib drug interaction differences. The results illustrate the relevance of this DDI on sunitinib pharmacokinetics and tissue uptake. These may be due to gender-based P450 and efflux/transporters differences.
Epigenetic dysregulation of SHANK3 in brain tissues from individuals with autism spectrum disorders
Zhu, Li; Wang, Xiaoming; Li, Xin-Lei; Towers, Aaron; Cao, Xinyu; Wang, Ping; Bowman, Rachel; Yang, Hyuna; Goldstein, Jennifer; Li, Yi-Ju; Jiang, Yong-Hui
The molecular basis for the majority of cases of autism spectrum disorders (ASD) remains unknown. We tested the hypothesis that ASD have an epigenetic cause by performing DNA methylation profiling of five CpG islands (CGI-1 to CGI-5) in the SHANK3 gene in postmortem brain tissues from 54 ASD patients and 43 controls. We found significantly increased overall DNA methylation (epimutation) in three intragenic CGIs (CGI-2, CGI-3 and CGI-4). The increased methylation was clustered in the CGI-2 and CGI-4 in ∼15% of ASD brain tissues. SHANK3 has an extensive array of mRNA splice variants resulting from combinations of five intragenic promoters and alternative splicing of coding exons. Altered expression and alternative splicing of SHANK3 isoforms were observed in brain tissues with increased methylation of SHANK3 CGIs in ASD brain tissues. A DNA methylation inhibitor modified the methylation of CGIs and altered the isoform-specific expression of SHANK3 in cultured cells. This study is the first to find altered methylation patterns in SHANK3 in ASD brain samples. Our finding provides evidence to support an alternative approach to investigating the molecular basis of ASD. The ability to alter the epigenetic modification and expression of SHANK3 by environmental factors suggests that SHANK3 may be a valuable biomarker for dissecting the role of gene and environment interaction in the etiology of ASD. PMID:24186872
Effect of insulin on in vivo glucose utilization in individual tissues of anesthetized lactating rats
Burnol, A.F.; Ferre, P.; Leturque, A.; Girard, J.
Glucose utilization rate has been measured in skeletal muscles, white adipose tissue, and mammary gland of anesthetized nonlactating and lactating rats. During lactation, basal (1-TH) glucose utilization is decreased by 40% in periovarian white adipose tissue and by 65% in epitrochlearis and extensor digitorum longus but not in soleus muscle. This may be related to the lower blood glucose and plasma insulin concentrations observed during lactation. Basal glucose utilization rate in the mammary gland was, respectively, 18 +/- 2 and 350 +/- 50 g/min in nonlactating and lactating rats. During the euglycemic hyperinsulinemic clamp, a physiological increment in plasma insulin concentration induces a similar increase in glucose utilization rate in skeletal muscles and white adipose tissue in the two groups of rats. Furthermore this low increase in plasma insulin concentration does not alter mammary glucose utilization rate in nonlactating rats but induces the same increase as a maximal insulin concentration in lactating rats. These data show that the active mammary gland is the most insulin-sensitive tissue of the lactating rat that has been tested. The overall increase in insulin sensitivity and responsiveness that has been described in lactating rats can then mainly be attributed to the presence of the active mammary gland. Plasma insulin was determined by radioimmunoassay.
Expression of insulin-like growth factor system genes in liver and brain tissue during embryonic and post-hatch development of the turkey.
Richards, Mark P; Poch, Stephen M; McMurtry, John P
A molecular cloning strategy employing primer-directed reverse transcription polymerase chain reaction (RT-PCR) was devised to sequence 1300 bp of a turkey liver-derived cDNA corresponding to the complete coding region and the 5'- and 3'-untranslated regions of the insulin-like growth factor (IGF)-II mRNA transcript (GenBank accession no. ). The turkey IGF-II gene codes for a 187 amino acid precursor protein that includes a signal peptide, the mature IGF-II hormone, and a C-terminal extension peptide comprised of 24, 67 and 96 amino acids, respectively. Turkey IGF-II showed greater than 95% sequence identity at both the nucleotide and amino acid level with chicken IGF-II. Expression of IGF-I, IGF-II, IGF type-I receptor (IGF-IR), and IGF binding protein (IGFBP)-2 and -5 genes was quantified relative to an internal 18S rRNA standard by RT-PCR in liver and whole brain tissue on days 14, 16, 18, 20, 22, 24 and 26 of embryonic development, as well as at hatch (H, day 28) and at 3 weeks post-hatching (PH). Expression of liver IGF-I was low throughout embryonic development, but increased more than 8-fold by 3 weeks PH. In contrast, IGF-I was expressed in brain tissue at much higher levels than liver throughout development and this level of expression in brain increased gradually, reaching its highest point at 3 weeks PH. IGF-II was expressed at comparable levels in brain and liver tissue during embryonic development, except for transient increases in liver just prior to hatching (days 24 and 26) and at 3 weeks PH. Expression of IGF-IR declined in brain throughout development reaching its lowest level at 3 weeks PH. In liver, IGF-IR expression was lower than that of brain throughout development. An inverse relationship was observed for the expression of IGF-I and IGF-IR genes in brain, but not in liver, through 3 weeks PH. Expression of the IGFBP-2 gene increased in liver around the time of hatch (days 26-28) and declined by 3 weeks PH, whereas the level of expression of
Simple and Reliable Method to Quantify the Hepatitis B Viral Load and Replicative Capacity in Liver Tissue and Blood Leukocytes
Minosse, Claudia; Coen, Sabrina; Visco Comandini, Ubaldo; Lionetti, Raffaella; Montalbano, Marzia; Cerilli, Stefano; Vincenti, Donatella; Baiocchini, Andrea; Capobianchi, Maria R.; Menzo, Stefano
Background A functional cure of chronic hepatitis B (CHB) is feasible, but a clear view of the intrahepatic viral dynamics in each patient is needed. Intrahepatic covalently closed circular DNA (cccDNA) is the stable form of the viral genome in infected cells, and represents the ideal marker of parenchymal colonization. Its relationships with easily accessible peripheral parameters need to be elucidated in order to avoid invasive procedures in patients. Objectives The goal of this study was to design, set up, and validate a reliable and straightforward method for the quantification of the cccDNA and total DNA of the hepatitis B virus (HBV) in a variety of clinical samples. Patients and Methods Clinical samples from a cohort of CHB patients, including liver biopsies in some, were collected for the analysis of intracellular HBV molecular markers using novel molecular assays. Results A plasmid construct, including sequences from the HBV genome and from the human gene hTERT, was generated as an isomolar multi-standard for HBV quantitation and normalization to the cellular contents. The specificity of the real-time assay for the cccDNA was assessed using Dane particles isolated on a density gradient. A comparison of liver tissue from 6 untreated and 6 treated patients showed that the treatment deeply reduced the replicative capacity (total DNA/cccDNA), but had limited impact on the parenchymal colonization. The peripheral blood mononuclear cells (PBMCs) and granulocytes from the treated and untreated patients were also analyzed. Conclusions A straightforward method for the quantification of intracellular HBV molecular parameters in clinical samples was developed and validated. The widespread use of such versatile assays could better define the prognosis of CHB, and allow a more rational approach to time-limited tailored treatment strategies. PMID:27882060
The impact of individual cytochrome P450 enzymes on oxidative metabolism of benzo[a]pyrene in human livers.
Šulc, Miroslav; Indra, Radek; Moserová, Michaela; Schmeiser, Heinz H; Frei, Eva; Arlt, Volker M; Stiborová, Marie
Benzo[a]pyrene (BaP) is a human carcinogen that covalently binds to DNA after metabolic activation by cytochrome P450 (CYP) enzymes. In this study human recombinant CYPs (CYP1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C9, 2C19, 2E1, 3A4, and 3A5) were expressed in Supersomes™ together with their reductases, NADPH:CYP oxidoreductase, epoxide hydrolase and cytochrome b5 , to investigate BaP metabolism. Human CYPs produced up to eight BaP metabolites. Among these, BaP-7,8-dihydrodiol and BaP-9-ol, which are intermediates in BaP-derived DNA adduct formation, were mainly formed by CYP1A1 and 1B1, and to a lesser extent by CYP2C19 and 3A4. BaP-3-ol, a metabolite that is a 'detoxified' product of BaP, was formed by most human CYPs tested, although CYP1A1 and 1B1 produced it the most efficiently. Based on the amounts of the individual BaP metabolites formed by these CYPs and their expression levels in human liver, we determined their contributions to BaP metabolite formation in this organ. Our results indicate that hepatic CYP1A1 and CYP2C19 are most important in the activation of BaP to BaP-7,8-dihydrodiol, whereas CYP2C19, 3A4, and 1A1 are the major enzymes contributing to the formation of BaP-9-ol. BaP-3-ol is predominantly formed by hepatic CYP3A4, while CYP1A1 and 2C19 are less active.
PHBVHHx scaffolds loaded with umbilical cord-derived mesenchymal stem cells or hepatocyte-like cells differentiated from these cells for liver tissue engineering.
Su, Zhongchun; Li, Pengshan; Wu, Bogang; Ma, Huan; Wang, Yuechun; Liu, Gexiu; Zeng, Huilan; Li, Zhizhong; Wei, Xing
More attention has recently been focused on the treatment of various kinds of hepatic diseases based on cell-based therapies. In this study, mesenchymal stem cells were isolated from umbilical cord (UC-MSCs). Results confirmed that UC-MSCs could differentiate into adipocytes, osteoblasts and hepatocytes. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (PHBVHHx), a new member of polyhydroxyalkanoate (PHA) family, was produced by bacteria. Liver-injured mouse model was established by CCl4 injection. PHBVHHx scaffolds were transplanted into the liver-injured mice. Liver morphology on day 28 post-transplantation of scaffolds loaded with UC-MSCs or hepatocyte-like cells differentiated from UC-MSCs significantly improved and looked similar to the normal liver. Concentrations of albumin (ALB) significantly increased, and total bilirubin (TB) and alanine axminotransferase (ALT) significantly decreased on days 14 and 28 post-transplantation of scaffolds loaded with UC-MSCs or differentiated UC-MSCs. HE staining showed that on day 28 post-transplantation of scaffolds loaded with UC-MSCs or differentiated UC-MSCs, livers had similar tissue structure of normal livers. Masson staining showed that on day 28 post-transplantation of scaffolds loaded with UC-MSCs or differentiated UC-MSCs, livers had less blue staining for collagen deposition compared with the others. These results demonstrated that PHBVHHx scaffolds loaded with UC-MSCs or differentiated UC-MSCs had the similar effect on injured livers and significantly promoted the recovery of injured livers.
Metabolism of [1-14C]glyoxylate, [1-14C]-glycollate, [1-14C]glycine and [2-14C]-glycine by homogenates of kidney and liver tissue from hyperoxaluric and control subjects
Dean, Betty M.; Watts, R. W. E.; Westwick, Wendy J.
1. The metabolism of [1-14C]glyoxylate to carbon dioxide, glycine, oxalate, serine, formate and glycollate was investigated in hyperoxaluric and control subjects' kidney and liver tissue in vitro. 2. Only glycine and carbon dioxide became significantly labelled with 14C, and this was less in the hyperoxaluric patients' kidney tissue than in the control tissue. 3. Liver did not show this difference. 4. The metabolism of [1-14C]glycollate was also studied in the liver tissue; glyoxylate formation was demonstrated and the formation of 14CO2 from this substrate was likewise unimpaired in the hyperoxaluric patients' liver tissue in these experiments. 5. Glycine was not metabolized by human kidney, liver or blood cells under the conditions used. 6. These observations show that glyoxylate metabolism by the kidney is impaired in primary hyperoxaluria. PMID:5584012
Dielectric properties of human normal, malignant and cirrhotic liver tissue: in vivo and ex vivo measurements from 0.5 to 20 GHz using a precision open-ended coaxial probe.
O'Rourke, Ann P; Lazebnik, Mariya; Bertram, John M; Converse, Mark C; Hagness, Susan C; Webster, John G; Mahvi, David M
Hepatic malignancies have historically been treated with surgical resection. Due to the shortcomings of this technique, there is interest in other, less invasive, treatment modalities, such as microwave hepatic ablation. Crucial to the development of this technique is the accurate knowledge of the dielectric properties of human liver tissue at microwave frequencies. To this end, we characterized the dielectric properties of in vivo and ex vivo normal, malignant and cirrhotic human liver tissues from 0.5 to 20 GHz. Analysis of our data at 915 MHz and 2.45 GHz indicates that the dielectric properties of ex vivo malignant liver tissue are 19 to 30% higher than normal tissue. The differences in the dielectric properties of in vivo malignant and normal liver tissue are not statistically significant (with the exception of effective conductivity at 915 MHz, where malignant tissue properties are 16% higher than normal). Also, the dielectric properties of in vivo normal liver tissue at 915 MHz and 2.45 GHz are 16 to 43% higher than ex vivo. No statistically significant differences were found between the dielectric properties of in vivo and ex vivo malignant tissue (with the exception of effective conductivity at 915 MHz, where malignant tissue properties are 28% higher than normal). We report the one-pole Cole-Cole parameters for ex vivo normal, malignant and cirrhotic liver tissue in this frequency range. We observe that wideband dielectric properties of in vivo liver tissue are different from the wideband dielectric properties of ex vivo liver tissue, and that the in vivo data cannot be represented in terms of a Cole-Cole model. Further work is needed to uncover the mechanisms responsible for the observed wideband trends in the in vivo liver data.
Ethoxyresorufin O-deethylase (EROD) activity in the liver of dab (Limanda limanda L.) and flounder (Platichthys flesus L.) from the German Bight. EROD expression and tissue contamination
NASA Astrophysics Data System (ADS)
Westernhagen, H. v.; Krüner, G.; Broeg, K.
Ethoxyresorufin O-deethylase (EROD) activity was measured in the liver of dab (Limanda limanda) and flounder (Platichthys flesus) from the German Bight (southern North Sea) and compared with muscle and liver polychlorinated biphenyl (PCB) concentrations in an attempt to relate EROD activity to PCB body burden. In none of the different datasets (species-, tissue- or matrix-dependent) was a significant (P<0.05) correlation between PCB tissue contamination and EROD activity found. Yet EROD activity was significantly correlated with polycyclic aromatic hydrocarbons (PAH) levels (phenanthrene, fluoranthene, pyrene) in muscle tissue, indicating a possible dependence of EROD expression on other ubiquitous organic contaminants, thus making it a suitable biomarker for general pollution.
Doppler Tissue Evaluation of Atrial Conduction Properties in Patients With Non-alcoholic Fatty-liver Disease.
Ozveren, Olcay; Izgi, Cemil; Eroglu, Elif; Simsek, Mustafa Aytek; Turer, Ayca; Kucukdurmaz, Zekeriya; Cinar, Veysel; Degertekin, Muzaffer
Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in clinical practice, and there is an increasing trend in its prevalence in the general population. Recent studies have demonstrated increased risk of atrial fibrillation (AF) in NAFLD. However, information on the mechanism of increased risk of AF in NAFLD is lacking. Impaired atrial conduction is an important factor in the pathophysiology of AF. We aimed to investigate atrial conduction properties in patients with NAFLD by tissue Doppler echocardiography. Fifty-nine ultrasound diagnosed NAFLD patients without clinical diagnosis of hypertension, diabetes mellitus, or cardiac disease and 22 normal subjects as controls were included in this study. Atrial conduction properties were assessed by electromechanical delay (EMD) derived from Doppler tissue echocardiography examination and P-wave dispersion (PWD) calculated from the 12-lead electrocardiogram. Inter-atrial and intra-atrial EMD intervals were significantly longer in NAFLD patients than in controls (inter-atrial EMD, 31.9 ± 8.5 ms vs. 23.4 ± 4.6 ms,p= 0.0001, and intra-atrial EMD, 14.3 ± 5.2 vs. 10.2 ± 4.0 ms,p= 0.001). Similarly, PWD was significantly higher in NAFLD patients compared with controls (49.2 ± 6.3 ms vs. 43.3 ± 4.2 ms,p= 0.0001). Maximum left atrial volume was also significantly higher in the NAFLD group than in controls (51 ± 11 mL vs. 34 ± 9 mL,p< 0.0001). This study demonstrated that atrial conduction is impaired in patients with NAFLD. Also, in a patient population of NAFLD without any clinical diagnosis of cardiac disease, diabetes, or hypertension, left atrial volume was increased compared with controls. These findings suggest impaired atrial conduction as a factor in increased risk of AF in NAFLD.
EROD induction in microsomes and primary hepatocyte cultures prepared from individual double-crested cormorant embryo livers
Davis, J.A.; Fry, D.M.; Wilson, B.W.
Double-crested cormorants (Phalacrocorax auritus) are being studied as a high trophic level indicator species for toxic contamination in San Francisco Bay and other locations on the California coast. In 1993, median ethoxyresorufin-o-deethylase (EROD) activities in embryo liver microsomes sampled from San Francisco Bay colonies were 4.2-fold and 2.3-fold higher than two coastal locations. In 1994 cormorant embryo livers from these same locations were again analyzed for liver microsomal EROD activity. In addition, basal and maximal EROD activity were measured in primary hepatocyte cultures from portions of the same livers used for microsomal EROD analysis to determine whether factors other than contaminant burdens in the egg contribute to the observed differences in activity. Differences in basal activity and induction capacity among the populations are discussed in the context of the hypothesis that polluted habitats select for increased metabolic capacity in affected populations.
Comparative study of the iron cores in human liver ferritin, its pharmaceutical models and ferritin in chicken liver and spleen tissues using Mössbauer spectroscopy with a high velocity resolution.
Alenkina, I V; Oshtrakh, M I; Klepova, Yu V; Dubiel, S M; Sadovnikov, N V; Semionkin, V A
Application of Mössbauer spectroscopy with a high velocity resolution (4096 channels) for comparative analysis of iron cores in a human liver ferritin and its pharmaceutically important models Imferon, Maltofer(®) and Ferrum Lek as well as in iron storage proteins in chicken liver and spleen tissues allowed to reveal small variations in the (57)Fe hyperfine parameters related to differences in the iron core structure. Moreover, it was shown that the best fit of Mössbauer spectra of these samples required different number of components. The latter may indicate that the real iron core structure is more complex than that following from a simple core-shell model. The effect of different living conditions and age on the iron core in chicken liver was also considered.
Mesodermal cell displacements during avian gastrulation are due to both individual cell-autonomous and convective tissue movements.
Zamir, Evan A; Czirók, András; Cui, Cheng; Little, Charles D; Rongish, Brenda J
Gastrulation is a fundamental process in early development that results in the formation of three primary germ layers. During avian gastrulation, presumptive mesodermal cells in the dorsal epiblast ingress through a furrow called the primitive streak (PS), and subsequently move away from the PS and form adult tissues. The biophysical mechanisms driving mesodermal cell movements during gastrulation in amniotes, notably warm-blooded embryos, are not understood. Until now, a major challenge has been distinguishing local individual cell-autonomous (active) displacements from convective displacements caused by large-scale (bulk) morphogenetic tissue movements. To address this problem, we used multiscale, time-lapse microscopy and a particle image velocimetry method for computing tissue displacement fields. Immunolabeled fibronectin was used as an in situ marker for quantifying tissue displacements. By imaging fluorescently labeled mesodermal cells and surrounding extracellular matrix simultaneously, we were able to separate directly the active and passive components of cell displacement during gastrulation. Our results reveal the following: (i) Convective tissue motion contributes significantly to total cell displacement and must be subtracted to measure true cell-autonomous displacement; (ii) Cell-autonomous displacement decreases gradually after regression from the PS; and (iii) There is an increasing cranial-to-caudal (head-to-tail) cell-autonomous motility gradient, with caudal cells actively moving away from the PS faster than cranial cells. These studies show that, in some regions of the embryo, total mesodermal cell displacements are mostly due to convective tissue movements; thus, the data have profound implications for understanding cell guidance mechanisms and tissue morphogenesis in warm-blooded embryos.
Top-Down and Bottom-Up Identification of Proteins by Liquid Extraction Surface Analysis Mass Spectrometry of Healthy and Diseased Human Liver Tissue
NASA Astrophysics Data System (ADS)
Sarsby, Joscelyn; Martin, Nicholas J.; Lalor, Patricia F.; Bunch, Josephine; Cooper, Helen J.
Liquid extraction surface analysis mass spectrometry (LESA MS) has the potential to become a useful tool in the spatially-resolved profiling of proteins in substrates. Here, the approach has been applied to the analysis of thin tissue sections from human liver. The aim was to determine whether LESA MS was a suitable approach for the detection of protein biomarkers of nonalcoholic liver disease (nonalcoholic steatohepatitis, NASH), with a view to the eventual development of LESA MS for imaging NASH pathology. Two approaches were considered. In the first, endogenous proteins were extracted from liver tissue sections by LESA, subjected to automated trypsin digestion, and the resulting peptide mixture was analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) (bottom-up approach). In the second (top-down approach), endogenous proteins were extracted by LESA, and analyzed intact. Selected protein ions were subjected to collision-induced dissociation (CID) and/or electron transfer dissociation (ETD) mass spectrometry. The bottom-up approach resulted in the identification of over 500 proteins; however identification of key protein biomarkers, liver fatty acid binding protein (FABP1), and its variant (Thr→Ala, position 94), was unreliable and irreproducible. Top-down LESA MS analysis of healthy and diseased liver tissue revealed peaks corresponding to multiple (~15-25) proteins. MS/MS of four of these proteins identified them as FABP1, its variant, α-hemoglobin, and 10 kDa heat shock protein. The reliable identification of FABP1 and its variant by top-down LESA MS suggests that the approach may be suitable for imaging NASH pathology in sections from liver biopsies.
Effects of various extremely low frequency magnetic fields on the free radical processes, natural antioxidant system and respiratory burst system activities in the heart and liver tissues.
Canseven, Ayse Gulnihal; Coskun, Sule; Seyhan, Nesrin
Magnetic fields (MFs) can affect biological systems by increasing the release of free radicals that are able to alter cell defense systems and breakdown tissue homeostasis. In the present study, the effects of extremely low frequency (ELF) electromagnetic fields (EMF) were investigated on free radical levels, natural antioxidant systems and respiratory burst system activities in heart and liver tissues of guinea pigs exposed to 50 Hz MFs of 1, 2 and 3 mT for 4 h/day and 8 h/day for 5 days by measuring malondialdehyde (MDA), nitric oxide (NO), glutathione (GSH) levels and myeloperoxidase (MPO) activity. A total of sixty-two male guinea pigs, 10-12 weeks old were studied in seven groups as control and exposure groups: Group I (control), II (1 mT, 4 h/day), III (1 mT, 8 h/day), IV (2 mT, 4 h/day), V (2 mT, 8 h/day), VI (3 mT, 4 h/day), and VII (3 mT, 8 h/day). Controls were kept under the same conditions without any exposure to MF. MDA levels increased in liver in groups II and IV, but decreased in group VII for both liver and heart tissues. NOx levels declined in heart in groups II and III and in liver in groups III, V, and VI, but increased in liver in group VII. GSH levels increased in heart in groups II, IV, V, and in liver in groups V and VI and VI, but decreased in groups II and IV in liver. MPO activity decreased in liver in groups III, IV, VI and VII with respect to controls and in heart tissues in groups II, III and IV; however, there was a significant increase MPO activity in heart in group VII. From the results, it can be concluded that the intensity and exposure duration of MFs are among the effective conditions on the formation of free radicals and behaviour of antioxidant enzymes.
Macro- and microelements in the rat liver, kidneys, and brain tissues; sex differences and effect of blood removal by perfusion in vivo.
Orct, Tatjana; Jurasović, Jasna; Micek, Vedran; Karaica, Dean; Sabolić, Ivan
Concentrations of macro- and microelements in animal organs indicate the animal health status and represent reference data for animal experiments. Their levels in blood and tissues could be different between sexes, and could be different with and without blood in tissues. To test these hypotheses, in adult female and male rats the concentrations of various elements were measured in whole blood, blood plasma, and tissues from blood-containing (nonperfused) and blood-free liver, kidneys, and brain (perfused in vivo with an elements-free buffer). In these samples, 6 macroelements (Na, Mg, P, S, K, Ca) and 14 microelements (Fe, Mn, Co, Cu, Zn, Se, I, As, Cd, Hg, Pb, Li, B, Sr) were determined by inductively coupled plasma mass spectrometry following nitric acid digestion. In blood and plasma, female- or male-dominant sex differences were observed for 6 and 5 elements, respectively. In nonperfused organs, sex differences were observed for 3 (liver, brain) or 9 (kidneys) elements, whereas in perfused organs, similar differences were detected for 9 elements in the liver, 5 in the kidneys, and none in the brain. In females, perfused organs had significantly lower concentrations of 4, 5, and 2, and higher concentrations of 10, 4, and 7 elements, respectively, in the liver, kidneys, and brain. In males, perfusion caused lower concentrations of 4, 7, and 2, and higher concentrations of 1, 1, and 7 elements, respectively, in the liver, kidneys, and brain. Therefore, the residual blood in organs can significantly influence tissue concentrations of various elements and their sex-dependency.
Exotic herbivores on a shared native host: tissue quality after individual, simultaneous, and sequential attack.
Gómez, Sara; Orians, Colin M; Preisser, Evan L
Plants in nature are often attacked by multiple enemies whose effect on the plant cannot always be predicted based on the outcome of individual attacks. We investigated how two invasive herbivores, the hemlock woolly adelgid (Adelges tsugae) (HWA) and the elongate hemlock scale (Fiorinia externa) (EHS), alter host plant quality (measured as amino acid concentration and composition) when feeding individually or jointly on eastern hemlock (Tsuga canadensis), an important long-lived forest tree that is in severe decline. The joint herbivore treatments included both simultaneous and sequential infestations by the two herbivores. We expected resource depletion over time, particularly in response to feeding by HWA. In contrast, HWA dramatically increased the concentration and altered the composition of individual free amino acids. Compared to control trees, HWA increased total amino acid concentration by 330% after 1 year of infestation. Conversely, EHS had a negligible effect when feeding individually. Interestingly, there was a marginally significant HWA × EHS interaction that suggests the potential for EHS presence to reduce the impact of HWA on foliage quality when the two species co-occur. We suggest indirect effects of water stress as a possible physiological mechanism for our results. Understanding how species interactions change the physiology of a shared host is crucial to making more accurate predictions about host mortality and subsequent changes in affected communities and ecosystems, and to help design appropriate management plans.
Bio-inspired fabrication of fibroin cryogels from the muga silkworm Antheraea assamensis for liver tissue engineering.
Kundu, Banani; Kundu, S C
Conventional scaffold fabrication techniques result in narrow pore architectures causing a limited interconnectivity and use of porogens, which affects the bio- or cyto-compatibility. To ameliorate this, cryogels are immensely explored due to their macro-porous nature, ease in fabrication, using ice crystals as porogens, the shape property, easy reproducibility and cost-effective fabrication technique. Cryogels in the present study are prepared from nonmulberry Indian muga silk gland protein fibroin of Antheraea assamensis using two different fabrication temperatures (-20 and -80 °C). Anionic surfactant sodium dodecyl sulfate is used to solubilize fibroin, which in turn facilitates gelation by accelerating the ß-sheet formation. Ethanol is employed to stabilize the 3D network and induces bimodal porosity. The gels thus formed demonstrate increased ß-sheet content (FTIR) and a considerable effect of pre-freezing temperatures on 3D micro-architectures. The cryogels are capable of absorbing large amounts of water and withstanding mechanical compression without structure deformation. Further, cell impregnated cryogels well support the viability of human hepatocarcinoma cells (live/dead assay). The formation of cellular aggregates (confocal laser and scanning electron microscope), derivation in metabolic activity and proliferation rate are obtained in constructs fabricated at different temperatures. In summary, the present work reveals promising insights in the development of a biomimetic functional template for biomedical therapeutics and liver tissue engineering.
Sequential Exposure to Obesogenic Factors in Females Rats: From Physiological Changes to Lipid Metabolism in Liver and Mesenteric Adipose Tissue
Novelle, Marta G.; Vázquez, María J.; Peinado, Juan R.; Martinello, Kátia D.; López, Miguel; Luckman, Simon M.; Tena-Sempere, Manuel; Malagón, María M.; Nogueiras, Rubén; Diéguez, Carlos
During their lifetime, females are subjected to different nutritional and hormonal factors that could increase the risk of obesity and associated comorbidities. From early postnatal periods until the postmenopausal phase, exposure to over nutrition, high-energy diet and oestrogen deficiency, are considered as significant obesity risk factors in women. In this study, we assessed how key transitional life events and exposure to different nutrition influence energy homeostasis in a rat model. Specifically, we assessed the sequential exposure to postnatal over nutrition, high-fat diet (HFD) after weaning, followed later by ovariectomy (OVX; as a model of menopause). Each obesity risk factor increased significantly body weight (BW) and adiposity, with additive effects after sequential exposure. Increased energy intake in both HFD and/or OVX groups, and decreased locomotor activity and energy expenditure after OVX can explain these metabolic changes. Our study also documents decreased lipogenic pathway in mesenteric adipose tissue after HFD and/or OVX, independent of previous postnatal programming, yet only HFD evoked this effect in liver. In addition, we report an increase in the expression of the hepatic PEPCK depending on previous metabolic status. Overall, our results identify the impact of different risk factors, which will help in understanding the development of obesity in females. PMID:28387334
Hepatic and nonhepatic sterol synthesis and tissue distribution following administration of a liver selective HMG-CoA reductase inhibitor, CI-981: comparison with selected HMG-CoA reductase inhibitors.
Bocan, T M; Ferguson, E; McNally, W; Uhlendorf, P D; Bak Mueller, S; Dehart, P; Sliskovic, D R; Roth, B D; Krause, B R; Newton, R S
Since cholesterol biosynthesis is an integral part of cellular metabolism, several HMG-CoA reductase inhibitors were systematically analyzed in in vitro, ex vivo and in vivo sterol synthesis assays using [14C]acetate incorporation into digitonin precipitable sterols as a marker of cholesterol synthesis. Tissue distribution of radiolabeled CI-981 and lovastatin was also performed. In vitro, CI-981 and PD134967-15 were equipotent in liver, spleen, testis and adrenal, lovastatin was more potent in extrahepatic tissues than liver and BMY21950, pravastatin and PD135023-15 were more potent in liver than peripheral tissues. In ex vivo assays, all inhibitors except lovastatin preferentially inhibited liver sterol synthesis; however, pravastatin and BMY22089 were strikingly less potent in the liver. CI-981 inhibited sterol synthesis in vivo in the liver, spleen and adrenal while not affecting the testis, kidney, muscle and brain. Lovastatin inhibited sterol synthesis to a greater extent than CI-981 in the spleen, adrenal and kidney while pravastatin and BMY22089 primarily affected liver and kidney. The tissue distribution of radiolabeled CI-981 and lovastatin support the changes observed in tissue sterol synthesis. Thus, we conclude that a spectrum of liver selective HMG-CoA reductase inhibitors exist and that categorizing agents as liver selective is highly dependent upon method of analysis.
Prevalence and Outcomes of Hepatitis B Coinfection and Associated Liver Disease Among Antiretroviral Therapy-Naive Individuals in a Rural Tanzanian Human Immunodeficiency Virus Cohort
Ramírez-Mena, Adrià; Glass, Tracy R.; Winter, Annja; Kimera, Namvua; Ntamatungiro, Alex; Hatz, Christoph; Tanner, Marcel; Battegay, Manuel; Furrer, Hansjakob; Wandeler, Gilles; Letang, Emilio
Background. We evaluated the prevalence of chronic hepatitis B virus (HBV) infection and liver fibrosis/cirrhosis in human immunodeficiency virus (HIV)-infected individuals enrolled in a rural Tanzanian prospective cohort and assessed hepatic fibrosis progression 12–24 months after antiretroviral treatment (ART) initiation. Methods. All ART-naive HIV-infected adults ≥15-year-old enrolled in the Kilombero and Ulanga Antiretroviral Cohort who started ART between 2005 and 2015 were included. Pre-ART factors associated with significant liver fibrosis (aspartate aminotransferase-to-platelet ratio index [APRI] >1.5) and cirrhosis (APRI > 2.0) were identified using logistic regression. Results. Of 3097 individuals screened, 227 (7.3%; 95% CI, 6.4–8.2) were hepatitis B surface antigen (HBsAg) positive. Before ART initiation, 9.1% individuals had significant liver fibrosis and 5.3% had cirrhosis. Human immunodeficiency virus/HBV-coinfected individuals were more likely to have an APRI score indicating significant fibrosis (14.2% vs 8.7%, P = .03) and cirrhosis (9.2% vs 4.9%, P = .03) than HBV-uninfected patients. CD4 cell count <200 cell/μL and alcohol consumption were independently associated with pre-ART APRI score, indicating significant fibrosis and cirrhosis in multivariable analyses. Among individuals with elevated APRI measurements pre- and 12–24 months post-ART initiation, 53 of 57 (93.0%) of HIV-monoinfected and 4 of 5 (80.0%) of HIV/HBV-coinfected had a regression to APRI < 1.5. Conclusions. Hepatic fibrosis and cirrhosis were common in our cohort, especially among HIV/HBV-coinfected individuals. The APRI improved in most patients. Pre-ART HBsAg screening and early onset of tenofovir-based ART for HIV/HBV-coinfection should be prioritized in sub-Saharan Africa. PMID:27704017
The impact of individual cytochrome P450 enzymes on oxidative metabolism of benzo[a]pyrene in human livers
Šulc, Miroslav; Indra, Radek; Moserová, Michaela; Schmeiser, Heinz H.; Frei, Eva; Arlt, Volker M.; White, P.
Benzo[a]pyrene (BaP) is a human carcinogen that covalently binds to DNA after metabolic activation by cytochrome P450 (CYP) enzymes. In this study human recombinant CYPs (CYP1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C9, 2C19, 2E1, 3A4, and 3A5) were expressed in Supersomes™ together with their reductases, NADPH:CYP oxidoreductase, epoxide hydrolase and cytochrome b5, to investigate BaP metabolism. Human CYPs produced up to eight BaP metabolites. Among these, BaP‐7,8‐dihydrodiol and BaP‐9‐ol, which are intermediates in BaP‐derived DNA adduct formation, were mainly formed by CYP1A1 and 1B1, and to a lesser extent by CYP2C19 and 3A4. BaP‐3‐ol, a metabolite that is a 'detoxified' product of BaP, was formed by most human CYPs tested, although CYP1A1 and 1B1 produced it the most efficiently. Based on the amounts of the individual BaP metabolites formed by these CYPs and their expression levels in human liver, we determined their contributions to BaP metabolite formation in this organ. Our results indicate that hepatic CYP1A1 and CYP2C19 are most important in the activation of BaP to BaP‐7,8‐dihydrodiol, whereas CYP2C19, 3A4, and 1A1 are the major enzymes contributing to the formation of BaP‐9‐ol. BaP‐3‐ol is predominantly formed by hepatic CYP3A4, while CYP1A1 and 2C19 are less active. Environ. Mol. Mutagen. 57:229–235, 2016. © 2016 The Authors. Environmental and Molecular Mutagenesis Published by Wiley Periodicals, Inc. PMID:26919089
A descriptive study to provide evidence of the teratogenic and cellular effects of sibutramine and ephedrine on cardiac- and liver-tissue of chick embryos.
Oberholzer, Hester Magdalena; Van Der Schoor, Ciska; Taute, Helena; Bester, Megan Jean
Exposure to drugs during pregnancy is a major concern, as some teratogenic compounds can influence normal foetal development. Although the use of drugs during pregnancy should generally be avoided, exposure of the developing foetus to teratogens may occur unknowingly since these compounds may be hidden in products that are being marketed as "all natural." The aim of the current study was to investigate the possible teratogenic and cellular effects of sibutramine-a serotonin-norepinephrine reuptake inhibitor used in the treatment of obesity-on the heart and liver tissue of chick embryos. Ephedrine was used as a positive control. The chick embryo model was chosen because it has been used in studying developmental and experimental biology and teratology with great success. The embryos were exposed to three different concentrations of sibutramine and ephedrine respectively. The results obtained revealed that both compounds exhibited embryotoxicity when compared to the control groups. Liver and heart tissue of the exposed embryos was severely affected by these compounds in a dose-related manner. Morphology similar to that of muscle dystrophy was observed in the heart, where the muscle tissue was infiltrated by adipose and connective tissue. Severe liver steatosis was also noted. A more in-depth investigation into the molecular pathways involved might provide more information on the exact mechanism of toxicity of these products influencing embryonic development.
Identifying Novel Targets for Treatment of Liver Fibrosis: What Can We Learn from Injured Tissues which Heal Without a Scar?
Pritchard, Michele T.; McCracken, Jennifer M.
The liver is unique in that it is able to regenerate. This regeneration occurs without formation of a scar in the case of non-iterative hepatic injury. However, when the liver is exposed to chronic liver injury, the purely regenerative process fails and excessive extracellular matrix proteins are deposited in place of normal liver parenchyma. While much has been discovered in the past three decades, insights into fibrotic mechanisms have not yet lead to effective therapies; liver transplant remains the only cure for advanced liver disease. In an effort to broaden the collection of possible therapeutic targets, this review will compare and contrast the liver wound healing response to that found in two types of wound healing: scarless wound healing of fetal skin and oral mucosa and scar-forming wound healing found in adult skin. This review will examine wound healing in the liver and the skin in relation to the role of humoral and cellular factors, as well as the extracellular matrix, in this process. While several therapeutic targets are similar between fibrotic liver and adult skin wound healing, others are unique and represent novel areas for hepatic anti-fibrotic research. In particular, investigations into the role of hyaluronan in liver fibrosis and fibrosis resolution are warranted. PMID:26302807
Non-Invasive Quantification of White and Brown Adipose Tissues and Liver Fat Content by Computed Tomography in Mice
Lubura, Marko; Hesse, Deike; Neumann, Nancy; Scherneck, Stephan; Wiedmer, Petra; Schürmann, Annette
Objectives Obesity and its distribution pattern are important factors for the prediction of the onset of diabetes in humans. Since several mouse models are suitable to study the pathophysiology of type 2 diabetes the aim was to validate a novel computed tomograph model (Aloka-Hitachi LCT-200) for the quantification of visceral, subcutaneous, brown and intrahepatic fat depots in mice. Methods Different lean and obese mouse models (C57BL/6, B6.V-Lepob, NZO) were used to determine the most adequate scanning parameters for the detection of the different fat depots. The data were compared with those obtained after preparation and weighing the fat depots. Liver fat content was determined by biochemical analysis. Results The correlations between weights of fat tissues on scale and weights determined by CT were significant for subcutaneous (r2 = 0.995), visceral (r2 = 0.990) and total white adipose tissue (r2 = 0.992). Moreover, scans in the abdominal region, between lumbar vertebrae L4 to L5 correlated with whole-body fat distribution allowing experimenters to reduce scanning time and animal exposure to radiation and anesthesia. Test-retest reliability and measurements conducted by different experimenters showed a high reproducibility in the obtained results. Intrahepatic fat content estimated by CT was linearly related to biochemical analysis (r2 = 0.915). Furthermore, brown fat mass correlated well with weighted brown fat depots (r2 = 0.952). In addition, short-term cold-expose (4°C, 4 hours) led to alterations in brown adipose tissue attributed to a reduction in triglyceride content that can be visualized as an increase in Hounsfield units by CT imaging. Conclusion The 3D imaging of fat by CT provides reliable results in the quantification of total, visceral, subcutaneous, brown and intrahepatic fat in mice. This non-invasive method allows the conduction of longitudinal studies of obesity in mice and therefore enables experimenters to investigate
PEPCK-C reexpression in the liver counters neonatal hypoglycemia in Pck1 (del/del) mice, unmasking role in non-gluconeogenic tissues.
Semakova, Jana; Hyroššová, Petra; Méndez-Lucas, Andrés; Cutz, Ernest; Bermudez, Jordi; Burgess, Shawn; Alcántara, Soledad; Perales, José C
Whole body cytosolic phosphoenolpyruvate carboxykinase knockout (PEPCK-C KO) mice die early after birth with profound hypoglycemia therefore masking the role of PEPCK-C in adult, non-gluconeogenic tissues where it is expressed. To investigate whether PEPCK-C deletion in the liver was critically responsible for the hypoglycemic phenotype, we reexpress this enzyme in the liver of PEPCK-C KO pups by early postnatal administration of PEPCK-C-expressing adenovirus. This maneuver was sufficient to partially rescue hypoglycemia and allow the pups to survive and identifies the liver as a critical organ, and hypoglycemia as the critical pathomechanism, leading to early postnatal death in the whole-body PEPCK-C knockout mice. Pathology assessment of survivors also suggest a possible role for PEPCK-C in lung maturation and muscle metabolism.
Altered gut and adipose tissue hormones in overweight and obese individuals: cause or consequence?
Lean, M E J; Malkova, D
The aim of this article is to review the research into the main peripheral appetite signals altered in human obesity, together with their modifications after body weight loss with diet and exercise and after bariatric surgery, which may be relevant to strategies for obesity treatment. Body weight homeostasis involves the gut-brain axis, a complex and highly coordinated system of peripheral appetite hormones and centrally mediated neuronal regulation. The list of peripheral anorexigenic and orexigenic physiological factors in both animals and humans is intimidating and expanding, but anorexigenic glucagon-like peptide 1 (GLP-1), cholecystokinin (CCK), peptide YY (PYY) and orexigenic ghrelin from the gastrointestinal tract, pancreatic polypeptide (PP) from the pancreas and anorexigenic leptin from adiposites remain the most widely studied hormones. Homeostatic control of food intake occurs in humans, although its relative importance for eating behaviour is uncertain, compared with social and environmental influences. There are perturbations in the gut-brain axis in obese compared with lean individuals, as well as in weight-reduced obese individuals. Fasting and postprandial levels of gut hormones change when obese individuals lose weight, either with surgical or with dietary and/or exercise interventions. Diet-induced weight loss results in long-term changes in appetite gut hormones, postulated to favour increased appetite and weight regain while exercise programmes modify responses in a direction expected to enhance satiety and permit weight loss and/or maintenance. Sustained weight loss achieved by bariatric surgery may in part be mediated via favourable changes to gut hormones. Future work will be necessary to fully elucidate the role of each element of the axis, and whether modifying these signals can reduce the risk of obesity.
Altered gut and adipose tissue hormones in overweight and obese individuals: cause or consequence?
Lean, M E J; Malkova, D
The aim of this article is to review the research into the main peripheral appetite signals altered in human obesity, together with their modifications after body weight loss with diet and exercise and after bariatric surgery, which may be relevant to strategies for obesity treatment. Body weight homeostasis involves the gut–brain axis, a complex and highly coordinated system of peripheral appetite hormones and centrally mediated neuronal regulation. The list of peripheral anorexigenic and orexigenic physiological factors in both animals and humans is intimidating and expanding, but anorexigenic glucagon-like peptide 1 (GLP-1), cholecystokinin (CCK), peptide YY (PYY) and orexigenic ghrelin from the gastrointestinal tract, pancreatic polypeptide (PP) from the pancreas and anorexigenic leptin from adiposites remain the most widely studied hormones. Homeostatic control of food intake occurs in humans, although its relative importance for eating behaviour is uncertain, compared with social and environmental influences. There are perturbations in the gut–brain axis in obese compared with lean individuals, as well as in weight-reduced obese individuals. Fasting and postprandial levels of gut hormones change when obese individuals lose weight, either with surgical or with dietary and/or exercise interventions. Diet-induced weight loss results in long-term changes in appetite gut hormones, postulated to favour increased appetite and weight regain while exercise programmes modify responses in a direction expected to enhance satiety and permit weight loss and/or maintenance. Sustained weight loss achieved by bariatric surgery may in part be mediated via favourable changes to gut hormones. Future work will be necessary to fully elucidate the role of each element of the axis, and whether modifying these signals can reduce the risk of obesity. PMID:26499438
Blood cell oxidative stress precedes hemolysis in whole blood-liver slice co-cultures of rat, dog, and human tissues
Vickers, Alison E.M.; Sinclair, John R.; Fisher, Robyn L.; Morris, Stephen R.; Way, William
A novel in vitro model to investigate time-dependent and concentration-dependent responses in blood cells and hemolytic events is studied for rat, dog, and human tissues. Whole blood is co-cultured with a precision-cut liver slice. Methimazole (MMI) was selected as a reference compound, since metabolism of its imidazole thione moiety is linked with hematologic disorders and hepatotoxicity. An oxidative stress response occurred in all three species, marked by a decline in blood GSH levels by 24 h that progressed, and preceded hemolysis, which occurred at high MMI concentrations in the presence of a liver slice with rat (>= 1000 muM at 48 h) and human tissues (>= 1000 muM at 48 h, >= 750 muM at 72 h) but not dog. Human blood-only cultures exhibited a decline of GSH levels but minimal to no hemolysis. The up-regulation of liver genes for heme degradation (Hmox1 and Prdx1), iron cellular transport (Slc40a1), and GSH synthesis and utilization (mGST1 and Gclc) were early markers of the oxidative stress response. The up-regulation of the Kupffer cell lectin Lgals3 gene expression indicated a response to damaged red blood cells, and Hp (haptoglobin) up-regulation is indicative of increased hemoglobin uptake. Up-regulation of liver IL-6 and IL-8 gene expression suggested an activation of an inflammatory response by liver endothelial cells. In summary, MMI exposure led to an oxidative stress response in blood cells, and an up-regulation of liver genes involved with oxidative stress and heme homeostasis, which was clearly separate and preceded frank hemolysis.
Dietary Omega-3 Polyunsaturated Fatty Acids Alter Fatty Acid Composition of Lipids and CYP2E1 Expression in Rat Liver Tissue.
Maksymchuk, Oksana; Shysh, Angela; Chashchyn, Mykola; Moibenko, Olexyi
Omega-3 polyunsaturated fatty acids (PUFAs) are used for the treatment and prevention of numerous pathologies in humans. As recently found, PUFAs play significantly protective roles in liver, cardiovascular system and kidney. They also are widely used in total parenteral nutrition. We evaluated the effect of omega-3 PUFA consumption on liver fatty acid composition and the expression of CYP2E1, one of the key enzymes in detoxification and prooxidant systems of liver cells. To estimate the oxidative stress in liver tissue, the antioxidant status and the level of lipid peroxidation were determined in a rodent model. Animals were divided into two groups: control (n = 10) and experimental (n = 10). Epadol-containing omega-3 PUFA fish oil capsules were administered to Wistar rats within 4 weeks (0.1 mL/100 g b.w./day). The consumption of omega-3 PUFAs resulted in changes of fatty acid composition of liver tissue. A significant increase was detected in the α-linolenic, eicosapentaenoic and docosahexaenoic acid content (5.1-, 16-, and 1.3-fold, respectively, p < 0.05), while the content of linoleic and arachidonic acid was reduced (1.7- and 3.2-fold, respectively, p < 0.05). This caused significant increases in the omega-3:omega-6 ratio. Consumption of omega-3 PUFAs led to a 3-fold (p < 0.05) increase in CYP2E1 content, which could entail enhanced Nrf2 expression levels and increases in the HO-1 content in rat liver. The alteration in CYP2E1 expression did not have an impact on the level of lipid peroxidation and on the prooxidant/antioxidant balance.
Individualized Radical Radiotherapy of Non-Small-Cell Lung Cancer Based on Normal Tissue Dose Constraints: A Feasibility Study
Baardwijk, Angela van Bosmans, Geert; Boersma, Liesbeth; Wanders, Stofferinus; Dekker, Andre; Dingemans, Anne Marie C.; Bootsma, Gerben; Geraedts, Wiel; Pitz, Cordula; Simons, Jean; Lambin, Philippe; Ruysscher, Dirk de
Purpose: Local recurrence is a major problem after (chemo-)radiation for non-small-cell lung cancer. We hypothesized that for each individual patient, the highest therapeutic ratio could be achieved by increasing total tumor dose (TTD) to the limits of normal tissues, delivered within 5 weeks. We report first results of a prospective feasibility trial. Methods and Materials: Twenty-eight patients with medically inoperable or locally advanced non-small-cell lung cancer, World Health Organization performance score of 0-1, and reasonable lung function (forced expiratory volume in 1 second > 50%) were analyzed. All patients underwent irradiation using an individualized prescribed TTD based on normal tissue dose constraints (mean lung dose, 19 Gy; maximal spinal cord dose, 54 Gy) up to a maximal TTD of 79.2 Gy in 1.8-Gy fractions twice daily. No concurrent chemoradiation was administered. Toxicity was scored using the Common Terminology Criteria for Adverse Events criteria. An {sup 18}F-fluoro-2-deoxy-glucose-positron emission tomography-computed tomography scan was performed to evaluate (metabolic) response 3 months after treatment. Results: Mean delivered dose was 63.0 {+-} 9.8 Gy. The TTD was most often limited by the mean lung dose (32.1%) or spinal cord (28.6%). Acute toxicity generally was mild; only 1 patient experienced Grade 3 cough and 1 patient experienced Grade 3 dysphagia. One patient (3.6%) died of pneumonitis. For late toxicity, 2 patients (7.7%) had Grade 3 cough or dyspnea; none had severe dysphagia. Complete metabolic response was obtained in 44% (11 of 26 patients). With a median follow-up of 13 months, median overall survival was 19.6 months, with a 1-year survival rate of 57.1%. Conclusions: Individualized maximal tolerable dose irradiation based on normal tissue dose constraints is feasible, and initial results are promising.
Persistent liver lesions in rats after a single oral dose of polybrominated biphenyls (firemaster FF-1) and concomitant PBB tissue levels.
Kimbrough, R D; Burse, V W; Liddle, J A
In a preliminary study, 12 male and 12 female weanling Sherman strain rats were given a single dose of 1000 mg polybrominated biphenyls (PBBs) FireMaster FF1 Lot 7042 kg/body weight as a 5% solution in corn oil. Three male and three female weanling rats were given corn oil. One day after dosing PBB blood levels ranged from 78 to 162 ppm and 42 days later they ranged from 1.1 to 2.99 ppm. The liver was the only organ with pathological changes. In a long-term recovery study groups of 20 male and female rats, 2 months old, were given 0 or 1000 mg PBBs/kg body weight as a single dose in peanut oil. Five rats per group killed 2, 6, 10, and 14 months after dosing had pronounced liver pathology, including hepatic porphyria in the female rats and neoplastic nodules also mainly in female rats. Chemical analyses of blood, liver, and adipose tissue for PPBs 10 and 14 months after dosing gave the following mean results. Blood levels in females were 2.9 and 2.92 ppm, respectively, and males 0.94 and 1.34 ppm, respectively. Adipose tissue levels in females were 1202 and 783 ppm and in males 713 and 866 ppm, respectively. The liver levels in females were 37 and 22 ppm and in males 60 and 63 ppm, respectively.
Comparing individual-based approaches to modelling the self-organization of multicellular tissues
The coordinated behaviour of populations of cells plays a central role in tissue growth and renewal. Cells react to their microenvironment by modulating processes such as movement, growth and proliferation, and signalling. Alongside experimental studies, computational models offer a useful means by which to investigate these processes. To this end a variety of cell-based modelling approaches have been developed, ranging from lattice-based cellular automata to lattice-free models that treat cells as point-like particles or extended shapes. However, it remains unclear how these approaches compare when applied to the same biological problem, and what differences in behaviour are due to different model assumptions and abstractions. Here, we exploit the availability of an implementation of five popular cell-based modelling approaches within a consistent computational framework, Chaste (http://www.cs.ox.ac.uk/chaste). This framework allows one to easily change constitutive assumptions within these models. In each case we provide full details of all technical aspects of our model implementations. We compare model implementations using four case studies, chosen to reflect the key cellular processes of proliferation, adhesion, and short- and long-range signalling. These case studies demonstrate the applicability of each model and provide a guide for model usage. PMID:28192427
Internet-Based Image Analysis Quantifies Contractile Behavior of Individual Fibroblasts inside Model Tissue
Vanni, Steven; Lagerholm, B. Christoffer; Otey, Carol; Taylor, D. Lansing; Lanni, Frederick
In a cell-populated collagen gel, intrinsic fiber structure visible in differential interference contrast images can provide markers for an in situ strain gauge to quantify cell-gel mechanics, while optical sections of fluorescent protein distribution capture cytoskeletal kinematics. Mechanics quantification can be derived automatically from timelapse differential interference contrast images using a Deformation Quantification and Analysis software package accessible online at http://dqa.web.cmu.edu. In our studies, fibroblast contractile machinery was observed to function entirely within pseudopods, while GFP-alpha-actinin concentrated in pseudopod tips and cortex. Complex strain patterns around individual cells showed instances of both elastic and inelastic strain transmission, suggesting a role in observed long-range alignment of cells. PMID:12668480
BAR502, a dual FXR and GPBAR1 agonist, promotes browning of white adipose tissue and reverses liver steatosis and fibrosis
Carino, Adriana; Cipriani, Sabrina; Marchianò, Silvia; Biagioli, Michele; Santorelli, Chiara; Donini, Annibale; Zampella, Angela; Monti, Maria Chiara; Fiorucci, Stefano
Non-alcoholic steatohepatitis (NASH) is a highly prevalent chronic liver disease. Here, we have investigated whether BAR502, a non-bile acid, steroidal dual ligand for FXR and GPBAR1, reverses steato-hepatitis in mice fed a high fat diet (HFD) and fructose. After 9 week, mice on HFD gained ≈30% of b.w (P < 0.01 versus naïve) and were insulin resistant. These overweighting and insulin resistant mice were randomized to receive HFD or HFD in combination with BAR502. After 18 weeks, HFD mice developed NASH like features with severe steato-hepatitis and fibrosis, increased hepatic content of triacylglycerol and cholesterol and expression of SREPB1c, FAS, ApoC2, PPARα and γ, α-SMA, α1 collagen and MCP1 mRNAs. Treatment with BAR502 caused a ≈10% reduction of b.w., increased insulin sensitivity and circulating levels of HDL, while reduced steatosis, inflammatory and fibrosis scores and liver expression of SREPB1c, FAS, PPARγ, CD36 and CYP7A1 mRNA. BAR502 increased the expression of SHP and ABCG5 in the liver and SHP, FGF15 and GLP1 in intestine. BAR502 promoted the browning of epWAT and reduced liver fibrosis induced by CCl4. In summary, BAR502, a dual FXR and GPBAR1 agonist, protects against liver damage caused by HFD by promoting the browning of adipose tissue. PMID:28202906
Distribution of sterol carrier protein/sub 2/ (SCP/sub 2/) in rat tissues and evidence for slow turnover in liver and adrenal cortex
Kharroubi, A., Chanderbhan, R.; Fiskum, G.; Noland, B.J.; Scallen, T.J.; Vahouny, G.V.
Sterol carrier protein/sub 2/ (SCP/sub 2/) has been implicated in the regulation of the terminal stages of hepatic cholesterol biosynthesis, and in sterol utilization for adrenal steroid hormone and hepatic bile acid synthesis. In the present studies, a highly sensitive radioimmunoassay, using (/sup 125/I) SCP/sub 2/, has been developed. Highest levels of SCP/sub 2/ were found in rat liver with progressively lower levels in intestinal mucosa, adrenal, kidney, lung and testis. SCP/sub 2/ levels were low or absent in heart, brain, skeletal muscle and serum. Liver SCP/sub 2/ was largely (44%) associated with the microsomal fraction, while in adrenal, 46% was associated with mitochondria, a distribution which is consistent with the proposed roles for SCP/sub 2/ in these tissues. Levels of SCP/sub 2/ in AS 30D hepatoma cells were only 5% of those in normal liver. In liver there was no indication of diurnal rhythm of SCP/sub 2/ in the cytosol and only slight variation of the microsomal SCP/sub 2/ levels. Fasting has only slight effects on SCP/sub 2/ concentration of rat liver microsomes and cytosol. Neither ACTH nor cycloheximide treatment of rats had a significant effect on SCP/sub 2/ distribution in the adrenal. In general, these findings indicate that SCP/sub 2/ has a low turn-over rate.
Nutritional Strategies for the Individualized Treatment of Non-Alcoholic Fatty Liver Disease (NAFLD) Based on the Nutrient-Induced Insulin Output Ratio (NIOR)
Stachowska, Ewa; Ryterska, Karina; Maciejewska, Dominika; Banaszczak, Marcin; Milkiewicz, Piotr; Milkiewicz, Małgorzata; Gutowska, Izabela; Ossowski, Piotr; Kaczorowska, Małgorzata; Jamioł-Milc, Dominika; Sabinicz, Anna; Napierała, Małgorzata; Wądołowska, Lidia; Raszeja-Wyszomirska, Joanna
Nutrients play a fundamental role as regulators of the activity of enzymes involved in liver metabolism. In the general population, the action of nutrients may be affected by gene polymorphisms. Therefore, individualization of a diet for individuals with fatty liver seems to be a fundamental step in nutritional strategies. In this study, we tested the nutrient-induced insulin output ratio (NIOR), which is used to identify the correlation between the variants of genes and insulin resistance. We enrolled 171 patients, Caucasian men (n = 104) and women (n = 67), diagnosed with non-alcoholic fatty liver disease (NAFLD). From the pool of genes sensitive to nutrient content, we selected genes characterized by a strong response to the NIOR. The polymorphisms included Adrenergic receptor (b3AR), Tumor necrosis factor (TNFα), Apolipoprotein C (Apo C III). Uncoupling Protein type I (UCP-1), Peroxisome proliferator activated receptor γ2 (PPAR-2) and Apolipoprotein E (APOEs). We performed three dietary interventions: a diet consistent with the results of genotyping (NIOR (+)); typical dietary recommendations for NAFLD (Cust (+)), and a diet opposite to the genotyping results (NIOR (−) and Cust (−)). We administered the diet for six months. The most beneficial changes were observed among fat-sensitive patients who were treated with the NIOR (+) diet. These changes included improvements in body mass and insulin sensitivity and normalization of blood lipids. In people sensitive to fat, the NIOR seems to be a useful tool for determining specific strategies for the treatment of NAFLD. PMID:27455252
Fabrication of individual alginate-TCP scaffolds for bone tissue engineering by means of powder printing.
Castilho, Miguel; Rodrigues, Jorge; Pires, Inês; Gouveia, Barbara; Pereira, Manuel; Moseke, Claus; Groll, Jürgen; Ewald, Andrea; Vorndran, Elke
The development of polymer-calcium phosphate composite scaffolds with tailored architectures and properties has great potential for bone regeneration. Herein, we aimed to improve the functional performance of brittle ceramic scaffolds by developing a promising biopolymer-ceramic network. For this purpose, two strategies, namely, direct printing of a powder composition consisting of a 60:40 mixture of α/β-tricalcium phosphate (TCP) powder and alginate powder or vacuum infiltration of printed TCP scaffolds with an alginate solution, were tracked. Results of structural characterization revealed that the scaffolds printed with 2.5 wt% alginate-modified TCP powders presented a uniformly distributed and interfusing alginate TCP network. Mechanical results indicated a significant increase in strength, energy to failure and reliability of powder-modified scaffolds with an alginate content in the educts of 2.5 wt% when compared to pure TCP, as well as to TCP scaffolds containing 5 wt% or 7.5 wt% in the educts, in both dry and wet states. Culture of human osteoblast cells on these scaffolds also demonstrated a great improvement of cell proliferation and cell viability. While in the case of powder-mixed alginate TCP scaffolds, isolated alginate gels were formed between the calcium phosphate crystals, the vacuum-infiltration strategy resulted in the covering of the surface and internal pores of the TCP scaffold with a thin alginate film. Furthermore, the prediction of the scaffolds' critical fracture conditions under more complex stress states by the applied Mohr fracture criterion confirmed the potential of the powder-modified scaffolds with 2.5 wt% alginate in the educts as structural biomaterial for bone tissue engineering.
The Analysis of Phenylbutazone and Its Active Metabolite, Oxyphenbutazone, in Equine Tissues (Muscle, Kidney, and Liver), Urine, and Serum by LC-MS/MS.
Boison, Joe O; Dowling, Patricia; Matus, Johanna L; Kinar, Jana; Johnson, Ron
This study reports the use of two validated LC with tandem MS (MS/MS) methods to study the residue depletion profile ofphenylbutazone (PBZ) and its metabolite oxyphenbutazone (OXPBZ) from equine serum, urine, and muscle, kidney, and liver tissues. One LC-MS/MS method, with an LOQ of 1.0 ng/mL for PBZ and 2.0 ng/mL for OXPBZ, was used for the analysis of the two drugs in the biological fluids (equine urine and serum); the other LC-MS/MS method, with an LOQ of 0.5 ng/g for PBZ and OXPBZ, was used for the analysis of the drugs in the equine tissue samples. PBZ was administered intravenously to two horses dosed with 8.8 mg/kg PBZ once daily for 4 days and sacrificed humanely at a slaughter plant 7 days after the last drug administration. Urine, serum, and kidney, liver, and muscle tissues were collected from the two horses and shipped on ice to the laboratory and stored at −20°C until analysis. The concentrations of PBZ and OXPBZ residues in the biological fluid and tissue samples collected at slaughter were measured with the two validated LC-MS/MS methods using deuterated internal standards. The results demonstrate that the validated methods are fit for studying the depletion kinetics of PBZ residues in equine tissues and biological fluids.
Comparative biochemical characterization of the monoacylglycerol lipase inhibitor KML29 in brain, spinal cord, liver, spleen, fat and muscle tissue.
Pasquarelli, Noemi; Porazik, Christoph; Hanselmann, Johannes; Weydt, Patrick; Ferger, Boris; Witting, Anke
Monoacylglycerol lipase (MAGL) is part of the endocannabinoid and the prostaglandin signaling system. MAGL degrades the endocannabinoid 2-arachidonoylglycerol (2-AG) into glycerol and arachidonic acid. MAGL-induced arachidonic acid is the primary source for prostaglandin synthesis in the brain. 2-AG mainly induces neuroprotective and anti-inflammatory effects, whereas prostaglandins are related to pro-inflammatory effects inducing neurotoxicity. Therefore, inhibition of MAGL represents a promising target for neurological diseases characterized by inflammation. However, as 2-AG is an agonist for the cannabinoid receptor 1 (CB1), inhibition of MAGL might be associated with unwanted cannabimimetic effects. Here, we show that oral administration of KML29, a highly selective inhibitor of MAGL, induced large and dose-dependent changes in 2-AG levels in vivo in brain and spinal cord of mice. Of note, MAGL inhibition by KML29 induced a decrease in prostaglandin levels in brain and most peripheral tissues but not in the spinal cord. MAGL expression was highest in fat, liver and brain, whereas the cytosolic phospholipase A2 (cPLA2), a further enzyme responsible for arachidonic acid production, was highly expressed in spinal cord, muscle and spleen. In addition, high doses (10 mg/kg) of KML29 induced some cannabimimetic effects in vivo in the tetrad test, including hypothermia, analgesia and hypomotility without induction of cataleptic behavior. In summary, inhibition of MAGL by KML29 represents a promising strategy for targeting the cannabinoid and prostaglandin system of the brain with only a moderate induction of cannabimimetic effects.
Knockdown expression and hepatic deficiency reveal anatheroprotective role for SR-BI in liver and peripheral tissues
Huby, Thierry; Doucet, Chantal; Dachet, Christiane; Ouzilleau,Betty; Ueda, Yukihiko; Afzal, Veena; Rubin, Edward; Chapman, M. John; Lesnik, Philippe
Scavenger receptor SR-BI has been implicated inHDL-dependent atheroprotective mechanisms. We report the generation of anSR-BI conditional knockout mouse model in which SR-BI gene targeting byloxP site insertion produced a hypomorphic allele (hypomSR-BI).Attenuated SR-BI expression in hypomSR-BI mice resulted in 2-foldelevation in plasma total cholesterol (TC) levels. Cre-mediated SR-BIgene inactivation of the hypomorphic SR-BI allele in hepatocytes(hypomSR-BI-KOliver) was associated with high plasma TC concentrations,increased plasma free cholesterol/TC (FC/TC) ratio, and alipoprotein-cholesterol profile typical of SR-BI-/- mice. Plasma TClevels were increased 2-fold in hypomSR-BI and control mice fed anatherogenic diet, whereas hypomSR-BI-KOliver and SR-BI-/- mice developedsevere hypercholesterolemia due to accumulation of FC-rich, VLDL-sizedparticles. Atherosclerosis in hypomSR-BI mice was enhanced (2.5-fold)compared with that in controls, but to a much lower degree than inhypomSR-BI-KOliver (32-fold) and SR-BI-/- (48-fold) mice. The lattermodels did not differ in either plasma lipid levels or in the capacity ofVLDL-sized lipoproteins to induce macrophage cholesterol loading.However, reduced atherosclerosis in hypomSR-BI-KOliver mice wasassociated with decreased lesional macrophage content as compared withthat in SR-BI-/- mice. These data imply that, in addition to its majoratheroprotective role in liver, SR-BI may exert an antiatherogenic rolein extrahepatic tissues.
Fasciola hepatica: Histological changes in the somatic and reproductive tissues of liver fluke following closantel treatment of experimentally-infected sheep.
Scarcella, S; Hanna, R E B; Brennan, G P; Solana, H; Fairweather, I
Lambs infected with the Cullompton isolate of Fasciola hepatica were treated orally or subcutaneously with 10mg/kg of closantel at 16 weeks post-infection. Adult flukes were recovered from the liver of individual animals at 12h, 24h, or 36h post-treatment. The flukes were processed for histological analysis. In general, degenerative changes in the reproductive and somatic tissues were progressive, and were most marked in flukes exposed to closantel in vivo for 36h. However, flukes from a 12h subcutaneously-treated lamb showed marked deterioration of the testis, possibly because a portion of the dose has been delivered intravenously. Fewer intact eggs were seen in the uterus of flukes exposed to closantel for longer times (whether administered subcutaneously or orally to the host). The most conspicuous closantel-induced effect in flukes from treated hosts was progressive damage to the tegumental syncytium. While the flukes from 24h-treated hosts showed relatively minor damage to limited areas of the syncytium, towards the posterior end, the flukes from 36h-treated hosts (and flukes from the lamb that putatively received intravenous dosage) had lost large areas of the surface syncytium from the posterior end and dorsal surface, although the syncytium over the anterior end and the anterior ventral surface was largely spared. In areas where the syncytium had sloughed, the underlying structures such as the vitelline follicles, gut profiles and testis profiles, showed marked degeneration and breakdown. Other changes included cell depletion and early stage apoptosis in the testis, ovary and vitelline follicles. This study establishes a model for histological changes in closantel-sensitive F. hepatica exposed to closantel in vivo. Histopathological studies could be complementary to the efficacy controlled test for for closantel resistance in fluke populations.
Liver Disease and Pulmonary Hypertension
Liver Disease Pulmonary & PH Hypertension Did you know that if you have liver disease, you are at risk for pulmonary hypertension? ... tissue diseases (scleroderma and lupus for example), chronic liver disease, congenital heart disease, or HIV infec- tion. ...
The effect of Prometheus device on laboratory markers of inflammation and tissue regeneration in acute liver failure management.
Rocen, M; Kieslichova, E; Merta, D; Uchytilova, E; Pavlova, Y; Cap, J; Trunecka, P
Prometheus, based on modified fractionated plasma separation and adsorption (FPSA) method, is used in the therapy of acute liver failure as a bridge to liver transplantation. As the therapeutic effect of Prometheus is caused not only by the elimination of terminal metabolites, the aim of the study was to identify the effect of FPSA on the levels of cytokines and markers of inflammation and liver regeneration. Previous studies assessing cytokine levels involved mostly acute-on-chronic liver failure patients. Data concerning markers of inflammation and liver regeneration are not published yet. Eleven patients (three males, eight females) with acute liver failure were investigated. These patients underwent 37 therapeutic sessions on Prometheus device. Before and after each treatment, the plasma levels of selected cytokines, tumor necrosis factor alpha (TNFα), C-reactive protein (CRP), procalcitonin (PCT), hepatocyte growth factor (HGF), and α(1) fetoprotein, were measured, and the kinetics of their plasma concentrations was evaluated. Before the therapy, elevated levels of interleukin (IL)-6, IL-8, IL-10, TNFα, CRP, and PCT were detected. The level of TNFα, CRP, PCT, and α(1) fetoprotein decreased significantly during the therapy. In contrast, an increase of HGF was detected. The decline of IL-6, IL-8, and IL-10 concentrations was not significant. Our results show that Prometheus is highly effective in clearing inflammatory mediators responsible for systemic inflammatory response syndrome and affects the serum levels of inflammatory and regeneration markers important for management of acute liver failure.
Unraveling the Molecular Signatures of Oxidative Phosphorylation to Cope with the Nutritionally Changing Metabolic Capabilities of Liver and Muscle Tissues in Farmed Fish
Bermejo-Nogales, Azucena; Calduch-Giner, Josep Alvar; Pérez-Sánchez, Jaume
Mitochondrial oxidative phosphorylation provides over 90% of the energy produced by aerobic organisms, therefore the regulation of mitochondrial activity is a major issue for coping with the changing environment and energy needs. In fish, there is a large body of evidence of adaptive changes in enzymatic activities of the OXPHOS pathway, but less is known at the transcriptional level and the first aim of the present study was to define the molecular identity of the actively transcribed subunits of the mitochondrial respiratory chain of a livestock animal, using gilthead sea bream as a model of farmed fish with a high added value for European aquaculture. Extensive BLAST searches in our transcriptomic database (www.nutrigroup-iats.org/seabreamdb) yielded 97 new sequences with a high coverage of catalytic, regulatory and assembly factors of Complex I to V. This was the basis for the development of a PCR array for the simultaneous profiling of 88 selected genes. This new genomic resource allowed the differential gene expression of liver and muscle tissues in a model of 10 fasting days. A consistent down-regulated response involving 72 genes was made by the liver, whereas an up-regulated response with 29 and 10 differentially expressed genes was found in white skeletal muscle and heart, respectively. This differential regulation was mostly mediated by nuclear-encoded genes (skeletal muscle) or both mitochondrial- and nuclear-encoded genes (liver, heart), which is indicative of a complex and differential regulation of mitochondrial and nuclear genomes, according to the changes in the lipogenic activity of liver and the oxidative capacity of glycolytic and highly oxidative muscle tissues. These insights contribute to the identification of the most responsive elements of OXPHOS in each tissue, which is of relevance for the appropriate gene targeting of nutritional and/or environmental metabolic disturbances in livestock animals. PMID:25875231
A high expression of heme oxygenase-1 in the liver of LEC rats at the stage of hepatoma: the possible implication of induction in uninvolved tissue.
Matsumoto, A; Hanayama, R; Nakamura, M; Suzuki, K; Fujii, J; Tatsumi, H; Taniguchi, N
We have examined changes in the expression of heme oxygenase-1 (HO-1), an inducible isoform and HO-2, a constitutive isoform, in the liver of Long-Evans with a Cinnamon-like color (LEC) rat, a mutant strain which spontaneously develops acute hepatitis and hepatoma. HO-1 expression was highly enhanced in the LEC rat livers with jaundice, and then decreased slightly, but overall remained at a higher level than in the Long-Evans with Agouti color (LEA) control rats, as judged by Northern blotting analysis of the whole liver extract. The high expression of HO-1 in the LEC rat liver was, however, not due to the actual cancer lesion but, rather, due to the surrounding uninvolved tissues including hepatocytes. Immunohistochemical analysis also supported this conclusion. Among normal tissues, the expression of HO-1 but not HO-2 was high in only the spleen of both LEC and LEA rats. The high expression observed in the stage of acute hepatitis and hepatoma stages in the LEC rat is probably due to the oxidative stress caused by the accumulation of free copper and free iron levels which has been reported earlier by our group (Suzuki et al., Carcinogenesis, 1993, 14, 1881-1884 and Koizumi et al., Free Radical Research, in press) as well as by free heme levels. The inflammatory cytokines produced by the surrounding tissue at the hepatoma stage would also be expected to play a role in the induction mechanism. The physiological relevance of HO-1 induction might be an adaptive response to oxidative stress and vasodilatory effect of carbon monoxide on sinusoidal circulation.
A comparison of whole genome gene expression profiles of HepaRG cells and HepG2 cells to primary human hepatocytes and human liver tissues.
Hart, Steven N; Li, Ye; Nakamoto, Kaori; Subileau, Eva-anne; Steen, David; Zhong, Xiao-bo
HepaRG cells, derived from a female hepatocarcinoma patient, are capable of differentiating into biliary epithelial cells and hepatocytes. More importantly, differentiated HepaRG cells are able to maintain activities of many xenobiotic-metabolizing enzymes, and expression of the metabolizing enzyme genes can be induced by xenobiotics. The ability of these cells to express and induce xenobiotic-metabolizing enzymes is in stark contrast to the frequently used HepG2 cells. The previous studies have mainly focused on a set of selected genes; therefore, it is of significant interest to know the extent of similarity of gene expression at whole genome levels in HepaRG cells and HepG2 cells compared with primary human hepatocytes and human liver tissues. To accomplish this objective, we used Affymetrix (Santa Clara, CA) U133 Plus 2.0 arrays to characterize the whole genome gene expression profiles in triplicate biological samples from HepG2 cells, HepaRG cells (undifferentiated and differentiated cells), freshly isolated primary human hepatocytes, and frozen liver tissues. After using similarity matrix, principal components, and hierarchical clustering methods, we found that HepaRG cells globally transcribe genes at levels more similar to human primary hepatocytes and human liver tissues than HepG2 cells. In particular, many genes encoding drug-processing proteins are transcribed at a more similar level in HepaRG cells than in HepG2 cells compared with primary human hepatocytes and liver samples. The transcriptomic similarity of HepaRG with primary human hepatocytes is encouraging for use of HepaRG cells in the study of xenobiotic metabolism, hepatotoxicology, and hepatocyte differentiation.
A fish protein hydrolysate alters fatty acid composition in liver and adipose tissue and increases plasma carnitine levels in a mouse model of chronic inflammation
Background There is growing evidence that fish protein hydrolysate (FPH) diets affect mitochondrial fatty acid metabolism in animals. The aim of the study was to determine if FPH could influence fatty acid metabolism and inflammation in transgene mice expressing human tumor necrosis factor alpha (hTNFα). Methods hTNFα mice (C57BL/6 hTNFα) were given a high-fat (23%, w/w) diet containing 20% casein (control group) or 15% FPH and 5% casein (FPH group) for two weeks. After an overnight fast, blood, adipose tissue, and liver samples were collected. Gene expression and enzyme activity was analysed in liver, fatty acid composition was analyzed in liver and ovarian white adipose tissue, and inflammatory parameters, carnitine, and acylcarnitines were analyzed in plasma. Results The n-3/n-6 fatty acid ratio was higher in mice fed the FPH diet than in mice fed the control diet in both adipose tissue and liver, and the FPH diet affected the gene expression of ∆6 and ∆9 desaturases. Mice fed this diet also demonstrated lower hepatic activity of fatty acid synthase. Concomitantly, a lower plasma INF-γ level was observed. Plasma carnitine and the carnitine precursor γ-butyrobetaine was higher in the FPH-group compared to control, as was plasma short-chained and medium-chained acylcarnitine esters. The higher level of plasma acetylcarnitine may reflect a stimulated mitochondrial and peroxisomal β-oxidation of fatty acids, as the hepatic activities of peroxisomal acyl-CoA oxidase 1 and mitochondrial carnitine palmitoyltransferase-II were higher in the FPH-fed mice. Conclusions The FPH diet was shown to influence hepatic fatty acid metabolism and fatty acid composition. This indicates that effects on fatty acid metabolism are important for the bioactivity of protein hydrolysates of marine origin. PMID:24098955
Induction by mercury compounds of metallothioneins in mouse tissues: inorganic mercury accumulation is not a dominant factor for metallothionein induction in the liver.
Yasutake, Akira; Nakamura, Masaaki
Among the naturally occurring three mercury species, metallic mercury (Hg(0)), inorganic mercury (Hg(II)) and methylmercury (MeHg), Hg(II) is well documented to induce metallothionein (MT) in tissues of injected animals. Although Hg(0) and MeHg are considered to be inert in terms of directly inducing MT, MT can be induced by them after in vivo conversion to Hg(II) in an animal body. In the present study we examined accumulations of inorganic mercury and MT inductions in mouse tissues (brain, liver and kidney) up to 72 hr after treatment by one of three mercury compounds of sub-lethal doses. Exposure to mercury compounds caused significant mercury accumulations in mouse tissues examined, except for the Hg(II)-treated mouse brain. Although MeHg caused the highest total mercury accumulation in all tissues among mercury compounds, the rates of inorganic mercury were less than 10% through the experimental period. MT inductions that depended on the inorganic mercury accumulation were observed in kidney and brain. However, MT induction in the liver could not be accounted for by the inorganic mercury accumulation, but by plasma IL6 levels, marked elevation of which was observed in Hg(II) or MeHg-treated mouse. The present study demonstrated that MT was induced in mouse tissues after each of three mercury compounds, Hg(0), Hg(II) and MeHg, but the induction processes were different among tissues. The induction would occur directly through accumulation of inorganic mercury in brain and kidney, whereas the hepatic MT might be induced secondarily through mercury-induced elevation in the plasma cytokines, rather than through mercury accumulation in the tissue.
A dynamic multi-organ-chip for long-term cultivation and substance testing proven by 3D human liver and skin tissue co-culture.
Wagner, Ilka; Materne, Eva-Maria; Brincker, Sven; Süssbier, Ute; Frädrich, Caroline; Busek, Mathias; Sonntag, Frank; Sakharov, Dmitry A; Trushkin, Evgeny V; Tonevitsky, Alexander G; Lauster, Roland; Marx, Uwe
Current in vitro and animal tests for drug development are failing to emulate the systemic organ complexity of the human body and, therefore, to accurately predict drug toxicity. In this study, we present a multi-organ-chip capable of maintaining 3D tissues derived from cell lines, primary cells and biopsies of various human organs. We designed a multi-organ-chip with co-cultures of human artificial liver microtissues and skin biopsies, each a (1)/100,000 of the biomass of their original human organ counterparts, and have successfully proven its long-term performance. The system supports two different culture modes: i) tissue exposed to the fluid flow, or ii) tissue shielded from the underlying fluid flow by standard Transwell® cultures. Crosstalk between the two tissues was observed in 14-day co-cultures exposed to fluid flow. Applying the same culture mode, liver microtissues showed sensitivity at different molecular levels to the toxic substance troglitazone during a 6-day exposure. Finally, an astonishingly stable long-term performance of the Transwell®-based co-cultures could be observed over a 28-day period. This mode facilitates exposure of skin at the air-liquid interface. Thus, we provide here a potential new tool for systemic substance testing.
Triton WR1339, an inhibitor of lipoprotein lipase, decreases vitamin E concentration in some tissues of rats by inhibiting its transport to liver.
Abe, Chisato; Ikeda, Saiko; Uchida, Tomono; Yamashita, Kanae; Ichikawa, Tomio
The aim of this experiment was to clarify the contribution of the alpha-tocopherol transfer activity of lipoprotein lipase (LPL) to vitamin E transport to tissues in vivo. We studied the effect of Triton WR1339, which prevents the catabolism of triacylglycerol-rich lipoproteins by LPL on vitamin E distribution in rats. Vitamin E-deficient rats fed a vitamin E-free diet for 4 wk were injected with Triton WR1339 and administered by oral gavage an emulsion containing 10 mg of alpha-tocopherol, 10 mg of gamma-tocopherol, or 29.5 mg of a tocotrienol mixture with 200 mg of sodium taurocholate, 200 mg of triolein, and 50 mg of albumin. alpha-Tocopherol was detected in the serum and other tissues of the vitamin E-deficient rats, but gamma-tocopherol, alpha- and gamma-tocotrienol were not detected. Triton WR1339 injection elevated (P<0.05) the serum alpha-tocopherol concentration and inhibited (P<0.05) the elevation of alpha-tocopherol concentration in the liver, adrenal gland, and spleen due to the oral administration of alpha-tocopherol. Neither alpha-tocopherol administration nor Triton WR1339 injection affected (P>or=0.05) the alpha-tocopherol concentration in the perirenal adipose tissue, epididymal fat, and soleus muscle despite a high expression of LPL in the adipose tissue and muscle. These data show that alpha-tocopherol transfer activity of LPL in adipose tissue and muscle is not important for alpha-tocopherol transport to the tissue after alpha-tocopherol intake or that the amount transferred is small relative to the tissue concentration. Furthermore, Triton WR1339 injection tended to elevate the serum gamma-tocopherol (P=0.071) and alpha-tocotrienol (P=0.053) concentrations and lowered them (P<0.05) in the liver and adrenal gland of rats administered gamma-tocopherol or alpha-tocotrienol. These data suggest that lipolysis of triacylglycerol-rich chylomicron by LPL is necessary for postprandial vitamin E transport to the liver and subsequent transport to the
Tissue-specific and minor inter-individual variation in imprinting of IGF2R is a common feature of Bos taurus Concepti and not correlated with fetal weight.
Bebbere, Daniela; Bauersachs, Stefan; Fürst, Rainer W; Reichenbach, Horst-Dieter; Reichenbach, Myriam; Medugorac, Ivica; Ulbrich, Susanne E; Wolf, Eckhard; Ledda, Sergio; Hiendleder, Stefan
The insulin-like growth factor 2 receptor (IGF2R) is essential for prenatal growth regulation and shows gene dosage effects on fetal weight that can be affected by in-vitro embryo culture. Imprinted maternal expression of murine Igf2r is well documented for all fetal tissues excluding brain, but polymorphic imprinting and biallelic expression were reported for IGF2R in human. These differences have been attributed to evolutionary changes correlated with specific reproductive strategies. However, data from species suitable for testing this hypothesis are lacking. The domestic cow (Bos taurus) carries a single conceptus with a similar gestation length as human. We identified 12 heterozygous concepti informative for imprinting studies among 68 Bos taurus fetuses at Day 80 of gestation (28% term) and found predominantly maternal IGF2R expression in all fetal tissues but brain, which escapes imprinting. Inter-individual variation in allelic expression bias, i.e. expression of the repressed paternal allele relative to the maternal allele, ranged from 4.6-8.9% in heart, 4.3-10.2% in kidney, 6.1-11.2% in liver, 4.6-15.8% in lung and 3.2-12.2% in skeletal muscle. Allelic bias for mesodermal tissues (heart, skeletal muscle) differed significantly (P<0.05) from endodermal tissues (liver, lung). The placenta showed partial imprinting with allelic bias of 22.9-34.7% and differed significantly (P<0.001) from all other tissues. Four informative fetuses were generated by in-vitro fertilization (IVF) with embryo culture and two individuals displayed fetal overgrowth. However, there was no evidence for changes in imprinting or DNA methylation after IVF, or correlations between allelic bias and fetal weight. In conclusion, imprinting of Bos taurus IGF2R is similar to mouse except in placenta, which could indicate an effect of reproductive strategy. Common minor inter-individual variation in allelic bias and absence of imprinting abnormalities in IVF fetuses suggest changes in IGF2R
The Responses of Tissues from the Brain, Heart, Kidney, and Liver to Resuscitation following Prolonged Cardiac Arrest by Examining Mitochondrial Respiration in Rats.
Kim, Junhwan; Villarroel, José Paul Perales; Zhang, Wei; Yin, Tai; Shinozaki, Koichiro; Hong, Angela; Lampe, Joshua W; Becker, Lance B
Cardiac arrest induces whole-body ischemia, which causes damage to multiple organs. Understanding how each organ responds to ischemia/reperfusion is important to develop better resuscitation strategies. Because direct measurement of organ function is not practicable in most animal models, we attempt to use mitochondrial respiration to test efficacy of resuscitation on the brain, heart, kidney, and liver following prolonged cardiac arrest. Male Sprague-Dawley rats are subjected to asphyxia-induced cardiac arrest for 30 min or 45 min, or 30 min cardiac arrest followed by 60 min cardiopulmonary bypass resuscitation. Mitochondria are isolated from brain, heart, kidney, and liver tissues and examined for respiration activity. Following cardiac arrest, a time-dependent decrease in state-3 respiration is observed in mitochondria from all four tissues. Following 60 min resuscitation, the respiration activity of brain mitochondria varies greatly in different animals. The activity after resuscitation remains the same in heart mitochondria and significantly increases in kidney and liver mitochondria. The result shows that inhibition of state-3 respiration is a good marker to evaluate the efficacy of resuscitation for each organ. The resulting state-3 respiration of brain and heart mitochondria following resuscitation reenforces the need for developing better strategies to resuscitate these critical organs following prolonged cardiac arrest.
Obesogenic memory can confer long-term increases in adipose tissue but not liver inflammation and insulin resistance after weight loss
Schmitz, J.; Evers, N.; Awazawa, M.; Nicholls, H.T.; Brönneke, H.S.; Dietrich, A.; Mauer, J.; Blüher, M.; Brüning, J.C.
Objective Obesity represents a major risk factor for the development of type 2 diabetes mellitus, atherosclerosis and certain cancer entities. Treatment of obesity is hindered by the long-term maintenance of initially reduced body weight, and it remains unclear whether all pathologies associated with obesity are fully reversible even upon successfully maintained weight loss. Methods We compared high fat diet-fed, weight reduced and lean mice in terms of body weight development, adipose tissue and liver insulin sensitivity as well as inflammatory gene expression. Moreover, we assessed similar parameters in a human cohort before and after bariatric surgery. Results Compared to lean animals, mice that demonstrated successful weight reduction showed increased weight gain following exposure to ad libitum control diet. However, pair-feeding weight-reduced mice with lean controls efficiently stabilized body weight, indicating that hyperphagia was the predominant cause for the observed weight regain. Additionally, whereas glucose tolerance improved rapidly after weight loss, systemic insulin resistance was retained and ameliorated only upon prolonged pair-feeding. Weight loss enhanced insulin action and resolved pro-inflammatory gene expression exclusively in the liver, whereas visceral adipose tissue displayed no significant improvement of metabolic and inflammatory parameters compared to obese mice. Similarly, bariatric surgery in humans (n = 55) resulted in massive weight reduction, improved hepatic inflammation and systemic glucose homeostasis, while adipose tissue inflammation remained unaffected and adipocyte-autonomous insulin action only exhibit minor improvements in a subgroup of patients (42%). Conclusions These results demonstrate that although sustained weight loss improves systemic glucose homeostasis, primarily through improved inflammation and insulin action in liver, a remarkable obesogenic memory can confer long-term increases in adipose tissue
Effects of Liver Fibrosis Progression on Tissue Relaxation Times in Different Mouse Models Assessed by Ultrahigh Field Magnetic Resonance Imaging
Müller, Andreas; Hochrath, Katrin; Stroeder, Jonas; Hittatiya, Kanishka; Schneider, Günther; Lammert, Frank; Buecker, Arno
Recently, clinical studies demonstrated that magnetic resonance relaxometry with determination of relaxation times T1 and T2⁎ may aid in staging and management of liver fibrosis in patients suffering from viral hepatitis and steatohepatitis. In the present study we investigated T1 and T2⁎ in different models of liver fibrosis to compare alternate pathophysiologies in their effects on relaxation times and to further develop noninvasive quantification methods of liver fibrosis. MRI was performed with a fast spin echo sequence for measurement of T1 and a multigradient echo sequence for determination of T2⁎. Toxic liver fibrosis was induced by injections of carbon tetrachloride (1.4 mL CCl4 per kg bodyweight and week, for 3 or 6 weeks) in BALB/cJ mice. Chronic sclerosing cholangitis was mimicked using the ATP-binding cassette transporter B4 knockout (Abcb4 −/−) mouse model. Untreated BALB/cJ mice served as controls. To assess hepatic fibrosis, we ascertained collagen contents and fibrosis scores after Sirius red staining. T1 and T2⁎ correlate differently to disease severity and etiology of liver fibrosis. T2⁎ shows significant decrease correlating with fibrosis in CCl4 treated animals, while demonstrating significant increase with disease severity in Abcb4 −/− mice. Measurements of T1 and T2⁎ may therefore facilitate discrimination between different stages and causes of liver fibrosis. PMID:28194423
Effects of Liver Fibrosis Progression on Tissue Relaxation Times in Different Mouse Models Assessed by Ultrahigh Field Magnetic Resonance Imaging.
Müller, Andreas; Hochrath, Katrin; Stroeder, Jonas; Hittatiya, Kanishka; Schneider, Günther; Lammert, Frank; Buecker, Arno; Fries, Peter
Recently, clinical studies demonstrated that magnetic resonance relaxometry with determination of relaxation times T1 and T2(⁎) may aid in staging and management of liver fibrosis in patients suffering from viral hepatitis and steatohepatitis. In the present study we investigated T1 and T2(⁎) in different models of liver fibrosis to compare alternate pathophysiologies in their effects on relaxation times and to further develop noninvasive quantification methods of liver fibrosis. MRI was performed with a fast spin echo sequence for measurement of T1 and a multigradient echo sequence for determination of T2(⁎). Toxic liver fibrosis was induced by injections of carbon tetrachloride (1.4 mL CCl4 per kg bodyweight and week, for 3 or 6 weeks) in BALB/cJ mice. Chronic sclerosing cholangitis was mimicked using the ATP-binding cassette transporter B4 knockout (Abcb4 (-/-)) mouse model. Untreated BALB/cJ mice served as controls. To assess hepatic fibrosis, we ascertained collagen contents and fibrosis scores after Sirius red staining. T1 and T2(⁎) correlate differently to disease severity and etiology of liver fibrosis. T2(⁎) shows significant decrease correlating with fibrosis in CCl4 treated animals, while demonstrating significant increase with disease severity in Abcb4 (-/-) mice. Measurements of T1 and T2(⁎) may therefore facilitate discrimination between different stages and causes of liver fibrosis.
Metastases to the liver; Metastatic liver cancer; Liver cancer - metastatic; Colorectal cancer - liver metastases; Colon cancer - liver metastases; Esophageal cancer - liver metastases; Lung cancer - liver metastases; Melanoma - liver metastases
Rectification of impaired adipose tissue methylation status and lipolytic response contributes to hepatoprotective effect of betaine in a mouse model of alcoholic liver disease
Dou, Xiaobing; Xia, Yongliang; Chen, Jing; Qian, Ying; Li, Songtao; Zhang, Ximei; Song, Zhenyuan
Background and Purpose Overactive lipolysis in adipose tissue contributes to the pathogenesis of alcoholic liver disease (ALD); however, the mechanisms involved have not been elucidated. We previously reported that chronic alcohol consumption produces a hypomethylation state in adipose tissue. In this study we investigated the role of hypomethylation in adipose tissue in alcohol-induced lipolysis and whether its correction contributes to the well-established hepatoprotective effect of betaine in ALD. Experimental Approach Male C57BL/6 mice were divided into four groups and started on one of four treatments for 5 weeks: isocaloric pair-fed (PF), alcohol-fed (AF), PF supplemented with betaine (BT/AF) and AF supplemented with betaine (BT/AF). Betaine, 0.5% (w v−1), was added to the liquid diet. Both primary adipocytes and mature 3T3-L1 adipocytes were exposed to demethylation reagents and their lipolytic responses determined. Key Results Betaine alleviated alcohol-induced pathological changes in the liver and rectified the impaired methylation status in adipose tissue, concomitant with attenuating lipolysis. In adipocytes, inducing hypomethylation activated lipolysis through a mechanism involving suppression of protein phosphatase 2A (PP2A), due to hypomethylation of its catalytic subunit, leading to increased activation of hormone-sensitive lipase (HSL). In line with in vitro observations, reduced PP2A catalytic subunit methylation and activity, and enhanced HSL activation, were observed in adipose tissue of alcohol-fed mice. Betaine attenuated this alcohol-induced PP2A suppression and HSL activation. Conclusions and Implications In adipose tissue, a hypomethylation state contributes to its alcohol-induced dysfunction and an improvement in its function may contribute to the hepatoprotective effects of betaine in ALD. PMID:24819676
Application of Focused Ultrasound-Assisted Extraction for the Quantification of Persistent Organic Pollutions in Liver Tissue of Giant Toad (Rhinella marina).
Flores-Ramírez, R; Espinosa-Reyes, G; Cilia-López, V G; González-Mille, D J; Rodríguez-Aguilar, M; Díaz de León-Martínez, L; Díaz-Barriga, F
A simple and rapid focused ultrasound extraction method was developed for the determination of Persistent Organic Pollutants (POPs) in liver tissue obtained of giant toad (Rhinella marina) using a gas chromatography coupled to a mass detector with electron impact ionization. The performed method for POPs, was validated in fortified matrix, showing linearity from the LOQ up to 100 ng/mL; LODs and LOQs for each compound were between 1.7 and 4.8 and 3.5-7.5 ng/mL, respectively. Recovery rates were among 79%-116% for POPs determined. Finally, the method was applied in liver samples of giant toads found in a malarial area in Mexico. The sensitivity of the proposed method was good enough to ensure reliable determination of target analytes at concentration levels commonly found in this kind of samples.
Exon-skipping and mRNA decay in human liver tissue: molecular consequences of pathogenic bile salt export pump mutations
Dröge, Carola; Schaal, Heiner; Engelmann, Guido; Wenning, Daniel; Häussinger, Dieter; Kubitz, Ralf
The bile salt export pump BSEP mediates bile formation. Over 150 BSEP mutations are associated with progressive familial intrahepatic cholestasis type 2 (PFIC-2), with few characterised specifically. We examined liver tissues from two PFIC-2 patients compound heterozygous for the splice-site mutation c.150 + 3A > C and either c.2783_2787dup5 resulting in a frameshift with a premature termination codon (child 1) or p.R832C (child 2). Splicing was analysed with a minigene system and mRNA sequencing from patients' livers. Protein expression was shown by immunofluorescence. Using the minigene, c.150 + 3A > C causes complete skipping of exon 3. In liver tissue of child 1, c.2783_2787dup5 was found on DNA but not on mRNA level, implying nonsense-mediated mRNA decay (NMD) when c.2783_2787dup5 is present. Still, BSEP protein as well as mRNA with and without exon 3 were detectable and can be assigned to the c.150 + 3A > C allele. Correctly spliced transcripts despite c.150 + 3A > C were also confirmed in liver of child 2. In conclusion, we provide evidence (1) for effective NMD due to a BSEP frameshift mutation and (2) partial exon-skipping due to c.150 + 3A > C. The results illustrate that the extent of exon-skipping depends on the genomic and cellular context and that regulation of splicing may have therapeutic potential. PMID:27114171
Exon-skipping and mRNA decay in human liver tissue: molecular consequences of pathogenic bile salt export pump mutations.
Dröge, Carola; Schaal, Heiner; Engelmann, Guido; Wenning, Daniel; Häussinger, Dieter; Kubitz, Ralf
The bile salt export pump BSEP mediates bile formation. Over 150 BSEP mutations are associated with progressive familial intrahepatic cholestasis type 2 (PFIC-2), with few characterised specifically. We examined liver tissues from two PFIC-2 patients compound heterozygous for the splice-site mutation c.150 + 3A > C and either c.2783_2787dup5 resulting in a frameshift with a premature termination codon (child 1) or p.R832C (child 2). Splicing was analysed with a minigene system and mRNA sequencing from patients' livers. Protein expression was shown by immunofluorescence. Using the minigene, c.150 + 3A > C causes complete skipping of exon 3. In liver tissue of child 1, c.2783_2787dup5 was found on DNA but not on mRNA level, implying nonsense-mediated mRNA decay (NMD) when c.2783_2787dup5 is present. Still, BSEP protein as well as mRNA with and without exon 3 were detectable and can be assigned to the c.150 + 3A > C allele. Correctly spliced transcripts despite c.150 + 3A > C were also confirmed in liver of child 2. In conclusion, we provide evidence (1) for effective NMD due to a BSEP frameshift mutation and (2) partial exon-skipping due to c.150 + 3A > C. The results illustrate that the extent of exon-skipping depends on the genomic and cellular context and that regulation of splicing may have therapeutic potential.
Altered vitamin D status in liver tissue and blood plasma from Greenland sledge dogs (Canis familiaris) dietary exposed to organohalogen contaminated minke whale (Balaenoptera acuterostrata) blubber.
Sonne, Christian; Kirkegaard, Maja; Jakobsen, Jette; Jenssen, Bjørn Munro; Letcher, Robert J; Dietz, Rune
This study compared vitamin D3 (vitD3) and 25-OH vitamin D3 (25OHD3) status in Greenland sledge dogs (Canis familiaris) given either minke whale (Balaenoptera acuterostrata) blubber high in organohalogen contaminants (OHCs) or clean porcine (Suis scrofa) fat for up to 636 days. A group of six exposed and six control sister bitches (maternal generation) and their three exposed and four control pups, respectively, were daily fed 112g whale blubber (193µg ∑PCB/day) or porcine fat (0.17µg ∑PCB/day). Mean level of ∑PCB in adipose tissue of exposed bitches and their pups was 3106 and 2670ng/g lw, respectively, which was significantly higher than the mean concentration of 53ng/g lw for all controls (p<0.001). The vitamin analyses showed that 25OHD3 in liver of maternal exposed bitches were significantly lower than in controls (p=0.004) while vitD3 was significantly highest in liver of exposed pups (p<0.003). Regarding blood plasma concentrations, exposed F generation pups had significantly higher concentrations of 25OHD3 than controls (p=0.009). Correlation analyses showed that blood 25OHD3 decreased significantly with increased adipose tissue concentrations of ∑PCB in exposed dogs (R(2)=0.64, p=0.005) and a similar trend was found for liver 25OHD3 (R(2)=0.32, p=0.08). The results indicate that the homeostasis and metabolism of vitamin D compounds may respond differently to the dietary composition of fatty acids and OHC exposure. It is unknown if the lower level of 25OHD3 in the liver of exposed dogs would have any negative effects on immunity and reproduction and more focus should be conducted on this compound in Arctic wildlife.
Microengineered cell and tissue systems for drug screening and toxicology applications: Evolution of in-vitro liver technologies
Usta, O. B.; McCarty, W. J.; Bale, S.; Hegde, M.; Jindal, R.; Bhushan, A.; Golberg, I.; Yarmush, M. L.
The liver performs many key functions, the most prominent of which is serving as the metabolic hub of the body. For this reason, the liver is the focal point of many investigations aimed at understanding an organism's toxicological response to endogenous and exogenous challenges. Because so many drug failures have involved direct liver toxicity or other organ toxicity from liver generated metabolites, the pharmaceutical industry has constantly sought superior, predictive in-vitro models that can more quickly and efficiently identify problematic drug candidates before they incur major development costs, and certainly before they are released to the public. In this broad review, we present a survey and critical comparison of in-vitro liver technologies along a broad spectrum, but focus on the current renewed push to develop "organs-on-a-chip". One prominent set of conclusions from this review is that while a large body of recent work has steered the field towards an ever more comprehensive understanding of what is needed, the field remains in great need of several key advances, including establishment of standard characterization methods, enhanced technologies that mimic the in-vivo cellular environment, and better computational approaches to bridge the gap between the in-vitro and in-vivo results. PMID:26167518
Microengineered cell and tissue systems for drug screening and toxicology applications: Evolution of in-vitro liver technologies.
Usta, O B; McCarty, W J; Bale, S; Hegde, M; Jindal, R; Bhushan, A; Golberg, I; Yarmush, M L
The liver performs many key functions, the most prominent of which is serving as the metabolic hub of the body. For this reason, the liver is the focal point of many investigations aimed at understanding an organism's toxicological response to endogenous and exogenous challenges. Because so many drug failures have involved direct liver toxicity or other organ toxicity from liver generated metabolites, the pharmaceutical industry has constantly sought superior, predictive in-vitro models that can more quickly and efficiently identify problematic drug candidates before they incur major development costs, and certainly before they are released to the public. In this broad review, we present a survey and critical comparison of in-vitro liver technologies along a broad spectrum, but focus on the current renewed push to develop "organs-on-a-chip". One prominent set of conclusions from this review is that while a large body of recent work has steered the field towards an ever more comprehensive understanding of what is needed, the field remains in great need of several key advances, including establishment of standard characterization methods, enhanced technologies that mimic the in-vivo cellular environment, and better computational approaches to bridge the gap between the in-vitro and in-vivo results.
Trypanosoma cruzi infection and benznidazole therapy independently stimulate oxidative status and structural pathological remodeling of the liver tissue in mice.
Novaes, Rômulo Dias; Santos, Eliziária C; Cupertino, Marli C; Bastos, Daniel S S; Oliveira, Jerusa M; Carvalho, Thaís V; Neves, Mariana M; Oliveira, Leandro L; Talvani, André
This study used a murine model of Chagas disease to investigate the isolated and combined impact of Trypanosoma cruzi infection and benznidazole (BZ) therapy on liver structure and function. Male C57BL/6 mice were challenged with T. cruzi and BZ for 15 days. Serum levels of cytokines and hepatic enzymes, liver oxidative stress, morphology, collagen, and glycogen content were monitored. Separately, T. cruzi infection and BZ treatment resulted in a pro-oxidant status and hepatic reactive damage. Concurrently, both T. cruzi infection and BZ treatment induced upregulation of antioxidant enzymes and pathological reorganization of the liver parenchyma and stroma. T. cruzi infection increased serum levels of Th1 cytokines, which were reduced by BZ in both infected and non-infected animals. BZ also induced functional organ damage, increasing serum levels of liver enzymes. When combined, T. cruzi infection and BZ therapy elicited intense hepatic reactive damage that was not compensated by antioxidant enzymatic reaction, subsequently culminating in more severe morphofunctional hepatic injury. Taken together, these findings indicate that during specific treatment of Chagas disease, hepatic pathology may be a result of an interaction between BZ metabolism and specific mechanisms activated during the natural course of T. cruzi infection, rather than an isolated toxic effect of BZ on liver structure and function.
The impacts of liver cirrhosis on head and neck cancer patients undergoing microsurgical free tissue transfer: an evaluation of flap outcome and flap-related complications.
Kao, Huang-Kai; Chang, Kai-Ping; Ching, Wei-Cheng; Tsao, Chung-Kan; Cheng, Ming-Huei; Wei, Fu-Chan
Several authors have cited liver cirrhosis as a risk factor for surgery but no study performed statistical correlation between flap outcome and severity of liver cirrhosis in patients with head and neck cancer. We performed a retrospective analysis of 3108 patients who underwent free tissue transfer after head and neck cancer ablation between January 2000 and December 2008. Liver cirrhosis was identified in 62 patients. Forty-two patients (67.7%) were classified as having Child's class A cirrhosis, seventeen (27.4%) as having class B, and three (4.9%) as having class C cirrhosis. The overall complete flap survival rate was 90.3% (56/62). The flap-related complications of patients with Child's class A, B, and C were 38.1% (16/42), 47.1% (8/17), and 100% (3/3), respectively and showed no significant difference between these three groups (p=0.2758). The rate of postoperative neck hematoma was 14.5%; the risk of postoperative neck hematoma was significantly higher in patients with more advanced liver cirrhosis (p=0.0003). The recipient-site complications of patients with Child's class A cirrhosis, Child's class B, and Child's class C cirrhosis were 35.7%, 41.1%, and 66.6%, respectively, with no significant difference among the three groups. The statistical analysis demonstrated that diabetes mellitus is significantly associated with a negative prognosis for free flap reconstruction (p=0.0364). The flap survival rate and patency of microvascular anastomosis have no association with liver cirrhosis. To achieve a superior surgical outcome, preoperative optimization and a multidisciplinary team responsible for the evaluation and treatment of head and neck cancer patients with cirrhosis are necessary.
A case of idiopathic portal hypertension associated with nodular regenerative hyperplasia-like nodule of the liver and mixed connective tissue disease.
Hayano, Shunsuke; Naganuma, Atsushi; Okano, Yudai; Suzuki, Yuhei; Shiina, Keisuke; Yoshida, Haruka; Hayashi, Eri; Uehara, Sanae; Hoshino, Takashi; Miyamae, Naomi; Kudo, Tomohiro; Ishihara, Hiroshi; Ogawa, Akira; Sato, Ken; Kakizaki, Satoru
A 51-year-old woman was diagnosed with mixed connective tissue disease (MCTD) in 2011. She underwent treatment with prednisolone. Her hepatobiliary enzyme level increased, and multiple nodules were found in both liver lobes in abdominal imaging studies. Ultrasonography revealed large and small hyperechoic lesions with indistinct or well-defined borders. No findings of classic hepatocellular carcinoma or liver cirrhosis were observed on contrast-enhanced computed tomography, but some nodules showed an enhanced effect of the central lesion that was characteristic of focal nodular hyperplasia (FNH) in an arterial phase. On gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging, slightly high-intensity nodules, 10-40mm in size, were observed on T1- and T2-weighted images. The nodules showed highest intensities in the hepatocyte phase and were enhanced with the uptake of Gd-EOB-DTPA as compared with the background liver. FNH was suspected based on the imaging findings, but we performed a liver tumor biopsy for differential diagnosis of the malignant lesion. Based on the immunohistopathological examination results, the final diagnosis was idiopathic portal hypertension associated with nodular regenerative hyperplasia (NRH)-like nodule of the liver. Benign nodular hepatocellular lesions are caused by abnormal hepatic circulation and were previously known as anomalous portal tract syndrome. Our case of atypical NRH with large nodules may be included in this disease entity. Here, we report a rare case of MCTD with NRH-like nodules and idiopathic portal hypertension with a review of literature.
Liver Fibrosis in HCV Monoinfected and HIV/HCV Coinfected Patients: Dysregulation of Matrix Metalloproteinases (MMPs) and Their Tissue Inhibitors TIMPs and Effect of HCV Protease Inhibitors.
Latronico, Tiziana; Mascia, Claudia; Pati, Ilaria; Zuccala, Paola; Mengoni, Fabio; Marocco, Raffaella; Tieghi, Tiziana; Belvisi, Valeria; Lichtner, Miriam; Vullo, Vincenzo; Mastroianni, Claudio Maria; Liuzzi, Grazia Maria
An imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) may contribute to liver fibrosis in patients with hepatitis C (HCV) infection. We measured the circulating levels of different MMPs and TIMPs in HCV monoinfected and HIV/HCV coinfected patients and evaluated the potential for anti-HCV therapy to modulate MMP and TIMP levels in HCV subjects. We analyzed 83 plasma samples from 16 HCV monoinfected patients undergoing dual or triple anti-HCV therapy, 15 HIV/HCV coinfected patients with undetectable HIV load, and 10 healthy donors (HD). Levels of MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, MMP-10, TIMP-1, and TIMP-2 were measured by a SearchLight Multiplex Immunoassay Kit. MMP-2 and MMP-9 were the highest expressed MMPs among all the analyzed samples and their levels significantly increased in HCV monoinfected and HIV/HCV coinfected subjects compared to HD. TIMP-1 levels were significantly higher in HCV and HIV/HCV subjects compared to HD and were correlated with liver stiffness. These findings raise the possibility of using circulating TIMP-1 as a non-invasive marker of liver fibrosis in HCV infection. A longitudinal study demonstrated that MMP-9 levels significantly decreased (40% reduction from baseline) in patients receiving dual as well as triple direct-acting antivirals (DAA) anti-HCV therapy, which had no effect on MMP-2, TIMP-1, and TIMP-2. As the dysregulation of MMP-2 and MMP-9 may reflect inflammatory processes in the liver, the decrease of MMP-9 following HCV protease inhibitor treatment suggests a positive effect on the reduction of liver inflammation.
T1-Weighted MR imaging of liver tumor by gadolinium-encapsulated glycol chitosan nanoparticles without non-specific toxicity in normal tissues
NASA Astrophysics Data System (ADS)
Na, Jin Hee; Lee, Sangmin; Koo, Heebeom; Han, Hyounkoo; Lee, Kyung Eun; Han, Seung Jin; Choi, Seung Hong; Kim, Hyuncheol; Lee, Seulki; Kwon, Ick Chan; Choi, Kuiwon; Kim, Kwangmeyung
Herein, we have synthesized Gd(iii)-encapsulated glycol chitosan nanoparticles (Gd(iii)-CNPs) for tumor-targeted T1-weighted magnetic resonance (MR) imaging. The T1 contrast agent, Gd(iii), was successfully encapsulated into 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-modified CNPs to form stable Gd(iii)-encapsulated CNPs (Gd(iii)-CNPs) with an average particle size of approximately 280 nm. The stable nanoparticle structure of Gd(iii)-CNPs is beneficial for liver tumor accumulation by the enhanced permeation and retention (EPR) effect. Moreover, the amine groups on the surface of Gd(iii)-CNPs could be protonated and could induce fast cellular uptake at acidic pH in tumor tissue. To assay the tumor-targeting ability of Cy5.5-labeled Gd(iii)-CNPs, near-infrared fluorescence (NIRF) imaging and MR imaging were used in a liver tumor model as well as a subcutaneous tumor model. Cy5.5-labeled Gd(iii)-CNPs generated highly intense fluorescence and T1 MR signals in tumor tissues after intravenous injection, while DOTAREM®, the commercialized control MR contrast agent, showed very low tumor-targeting efficiency on MR images. Furthermore, damaged tissues were found in the livers and kidneys of mice injected with DOTAREM®, but there were no obvious adverse effects with Gd(iii)-CNPs. Taken together, these results demonstrate the superiority of Gd(iii)-CNPs as a tumor-targeting T1 MR agent.Herein, we have synthesized Gd(iii)-encapsulated glycol chitosan nanoparticles (Gd(iii)-CNPs) for tumor-targeted T1-weighted magnetic resonance (MR) imaging. The T1 contrast agent, Gd(iii), was succes