interacts_with DB00203?
Preliminary X-ray crystallographic studies of UDP-glucose-4-epimerase from Aspergillus nidulans . UDP-glucose-4-epimerase ( Q14376 ) from Aspergillus nidulans was overexpressed in Escherichia coli , purified via DB00117 -tag affinity chromatography and cocrystallized with DB03501 using the microbatch method . The crystals diffracted to 2.4 Å resolution using synchrotron radiation on the Canadian Light Source 08ID-1 beamline . Examination of the data with d* O95069 revealed nonmerohedral twinning , from which a single lattice was ultimately extracted for processing . The final space group was found to be P06681 , with unit-cell parameters a = 66.13 , b = 119.15 , c = 161.42 Å , β = 98.48° . An initial structure solution has been obtained via molecular replacement employing human Q14376 ( PDB entry 1hzj ) as a template model . Microarray analysis revealed different gene expression patterns in HepG2 cells treated with low and high concentrations of the extracts of Anacardium occidentale shoots . In this study , the effects of low and high concentrations of the Anacardium occidentale shoot extracts on gene expression in liver HepG2 cells were investigated . From MTT assays , the concentration of the shoot extracts that maintained 50 % cell viability ( IC(50) ) was 1.7 mg/ml . Cell viability was kept above 90 % at both 0.4 mg/ml and 0.6 mg/ml of the extracts . The three concentrations were subsequently used for the gene expression analysis using Affymetrix Human Genome 1.0 S.T arrays . The microarray data were validated using real-time qRT-PCR . A total of 246 , 696 and 4503 genes were significantly regulated ( P < 0.01 ) by at least 1.5-fold in response to 0.4 , 0.6 and 1.7 mg/ml of the extracts , respectively . Mutually regulated genes in response to the three concentrations included CDKN3 , LOC100289612 , P00374 , Q99986 , Q99741 , Q96GD4 and P78334 . Genes like Q07973 , P38398 , O14965 , P06493 , P24941 , P11802 and P06213 were significantly regulated at 0.6 mg/ml and 1.7 mg but not at 0.4 mg/ml . However , the expression of genes including O75473 , P17936 , P06400 , P14735 , P01130 , P55157 , P04114 , MTIX , P04179 and P08294 were exclusively regulated at the IC(50) concentration . In conclusion , low concentrations of the extracts were able to significantly regulate a sizable number of genes . The type of genes that were expressed was highly dependent on the concentration of the extracts used . DB00203 induces angiogenic response in human coronary arteriolar endothelial cells through the expression of thioredoxin , hemeoxygenase and vascular endothelial growth factor . This study was undertaken to investigate the effect of phosphodiesterase-5 ( O76074 ) inhibitor , sildenafil , on angiogenic response in human coronary arteriolar endothelial cells ( HCAEC ) . The cells exposed to sildenafil ( 1-20 microM ) demonstrated significantly accelerated tubular morphogenesis with the induction of thioredoxin-1 ( P10599 -1 ) , hemeoxygenase-1 ( P09601 ) and P15692 . DB00203 induced P15692 and angiopoietin specific receptors such as P35968 , Tie-1 and Tie-2 . This angiogenic response was repressed by tinprotoporphyrin IX ( SnPP ) , an inhibitor of P09601 enzyme activity . DB00203 below 1 muM has no angiogenic effect as evidenced by reduced tuborogenesis . DB00203 along with SnPP inhibited both P15692 and Q15389 ( Ang-1 ) protein expression . Therefore our results demonstrated for the first time that sildenafil is a very potent pro-angiogenic factor . DB00203 attenuates inflammation and oxidative stress in pelvic ganglia neurons after bilateral cavernosal nerve damage . Erectile dysfunction is a common complication for patients undergoing surgeries for prostate , bladder , and colorectal cancers , due to damage of the nerves associated with the major pelvic ganglia ( P29372 ) . Functional re-innervation of target organs depends on the capacity of the neurons to survive and switch towards a regenerative phenotype . O76074 inhibitors ( PDE5i ) have been successfully used in promoting the recovery of erectile function after cavernosal nerve damage ( BCNR ) by up-regulating the expression of neurotrophic factors in P29372 . However , little is known about the effects of PDE5i on markers of neuronal damage and oxidative stress after BCNR . This study aimed to investigate the changes in gene and protein expression profiles of inflammatory , anti-inflammatory cytokines and oxidative stress related-pathways in P29372 neurons after BCNR and subsequent treatment with sildenafil . Our results showed that BCNR in Fisher-344 rats promoted up-regulation of cytokines ( interleukin- 1 ( IL-1 ) β , P05231 , P22301 , transforming growth factor β 1 ( TGFβ1 ) , and oxidative stress factors ( DB02701 adenine dinucleotide phosphate ( NADPH ) oxidase , P05164 ( P05164 ) , inducible nitric oxide synthase ( P35228 ) , P01375 receptor superfamily member 5 ( P25942 ) that were normalized by sildenafil treatment given in the drinking water . In summary , PDE5i can attenuate the production of damaging factors and can up-regulate the expression of beneficial factors in the P29372 that may ameliorate neuropathic pain , promote neuroprotection , and favor nerve regeneration . Hsp27 regulates epithelial mesenchymal transition , metastasis , and circulating tumor cells in prostate cancer . Defining the mechanisms underlying metastatic progression of prostate cancer may lead to insights into how to decrease morbidity and mortality in this disease . An important determinant of metastasis is epithelial-to-mesenchymal transition ( EMT ) , and the mechanisms that control the process of EMT in cancer cells are still emerging . Here , we report that the molecular chaperone Hsp27 ( P04792 ) drives EMT in prostate cancer , whereas its attenuation reverses EMT and decreases cell migration , invasion , and matrix metalloproteinase activity . Mechanistically , silencing Hsp27 decreased P05231 -dependent P40763 phosphorylation , nuclear translocation , and P40763 binding to the Twist promoter , suggesting that Hsp27 is required for P05231 -mediated EMT via modulation of P40763 /Twist signaling . We observed a correlation between Hsp27 and Twist in patients with prostate cancer , with Hsp27 and Twist expression each elevated in high-grade prostate cancer tumors . Hsp27 inhibition by DB06094 , an antisense therapy currently in phase II trials , reduced tumor metastasis in a murine model of prostate cancer . More importantly , DB06094 treatment decreased the number of circulating tumor cells in patients with metastatic castration-resistant prostate cancer in a phase I clinical trial . Overall , this study defines Hsp27 as a critical regulator of P05231 -dependent and P05231 -independent EMT , validating this chaperone as a therapeutic target to treat metastatic prostate cancer . The P05230 -specific single-chain antibody scFv1C9 effectively inhibits breast cancer tumour growth and metastasis . Immunotherapy mediated by recombinant antibodies is an effective therapeutic strategy for a variety of cancers . In a previous study , we demonstrated that the fibroblast growth factor 1 ( P05230 ) -specific recombinant antibody scFv1C9 arrests the cell cycle at the G0/ P55008 transition by blocking the intracrine P05230 pathway in breast cancer cells . Here , we further show that the overexpression of scFv1C9 in MCF-7 and MDA-MB-231 breast cancer cells by lentiviral infection resulted in decreased tumourigenicity , tumour growth and lung metastasis through P05230 neutralization . We found that scFv1C9 resulted in the up-regulation of P38936 , which in turn inhibited the expression of P24941 and blocked cell cycle progression . To explore the potential role of scFv1C9 in vivo , we delivered the gene into solid tumours by electroporation , which resulted in significant inhibition of tumour growth . In tumour tissue sections , immunohistochemical staining of the cellular proliferation marker Ki-67 and the microvessel marker CD31 showed a reduction in the proliferative index and microvessel density , respectively , upon expression of scFv1C9 compared with the appropriate controls . Thus , our data indicate a central role for scFv1C9 in blocking the intracrine pathway of P05230 , therefore , scFv1C9 could be developed in an effective therapeutic for breast cancer . Phosphodiesterase-5 inhibitor sildenafil prevents neuroinflammation , lowers beta-amyloid levels and improves cognitive performance in P05067 / P49768 transgenic mice . Memory deficit is a marker of Alzheimer 's disease ( AD ) that has been highly associated with the dysfunction of cyclic GMP ( cGMP ) signaling and an ongoing inflammatory process . Phosphodiesterase-5 ( O76074 ) inhibitors prevent the breakdown of cGMP and are currently studied as a possible target for cognitive enhancement . However , it is still unknown whether inhibition of O76074 reversed β-amyloid peptide ( Aβ ) -induced neuroinflammation in P05067 / P49768 transgenic ( Tg P05067 / P49768 ) mice . The present study evaluated the cognitive behaviors , inflammatory mediators , and cGMP/PKG/pCREB signaling in 15-month-old Tg P05067 / P49768 mice and age-matched wild-type ( WT ) mice that were treated with O76074 inhibitor sildenafil and the inhibitor of cGMP-dependent protein kinase Rp-8-Br-PET-cGMPS . In comparison with WT mice , Tg P05067 / P49768 mice were characterized by impaired cognitive ability , neuroinflammatory response , and down-regulated cGMP signaling . DB00203 reversed these memory deficits and cGMP/PKG/pCREB signaling dysfunction ; it also reduced both the soluble Aβ1-40 and Aβ1-42 levels in the hippocampus . These effects of sildenafil were prevented by intra-hippocampal infusion of the Rp-8-Br-PET-cGMPS . These results suggest that sildenafil could restore cognitive deficits in Tg P05067 / P49768 mice by the regulation of PKG/pCREB signaling , anti-inflammatory response and reduction of Aβ levels . OSU-03012 and Viagra Treatment Inhibits the Activity of Multiple Chaperone Proteins and Disrupts the Blood-Brain Barrier : Implications for Anti-Cancer Therapies . We examined the interaction between OSU-03012 ( also called AR-12 ) with phosphodiesterase 5 ( O76074 ) inhibitors to determine the role of the chaperone glucose-regulated protein ( P11021 ) / P11021 / P11021 in the cellular response . DB00203 ( Viagra ) interacted in a greater than additive fashion with OSU-03012 to kill stem-like GBM cells . Treatment of cells with OSU-03012/sildenafil : abolished the expression of multiple oncogenic growth factor receptors and plasma membrane drug efflux pumps and caused a rapid degradation of P11021 and other HSP70 and HSP90 family chaperone proteins . Decreased expression of plasma membrane receptors and drug efflux pumps was dependent upon enhanced Q9NZJ5 -eIF2α- P18848 - P35638 signaling and was blocked by P11021 over-expression . In vivo OSU-03012/sildenafil was more efficacious than treatment with celecoxib and sildenafil at killing tumor cells without damaging normal tissues and in parallel reduced expression of P08183 and Q9UNQ0 in the normal brain . The combination of OSU-03012/sildenafil synergized with low concentrations of sorafenib to kill tumor cells , and with lapatinib to kill P00533 over-expressing tumor cells . In multiplex assays on plasma and human tumor tissue from an OSU-03012/sildenafil treated mouse , we noted a profound reduction in uPA signaling and identified FGF and P23458 /2 as response biomarkers for potentially suppressing the killing response . Inhibition of FGFR signaling and to a lesser extent P23458 /2 signaling profoundly enhanced OSU-03012/sildenafil lethality . Sulfasalazine inhibits the growth of primary brain tumors independent of nuclear factor-kappaB . Nuclear factor-kappaB ( NF-kappaB ) is a pleiotropic transcription factor that generally enhances cellular resistance to apoptotic cell death . It has been shown to be constitutively active in some cancers and is being pursued as potential anticancer target . Sulfasalazine which is used clinically to treat Crohn 's disease has emerged as a potential inhibitor of NF-kappaB and has shown promising results in two pre-clinical studies to target primary brain tumors , gliomas . Once digested , sulfasalazine is cleaved into sulfapyridine and DB00244 ( DB00244 ; mesalamine ) by colonic bacteria , and the latter , too , is reported to suppress NF-kappaB activity . We now show that glioma cells obtained from patient biopsies or glioma cell lines do not show significant constitutive NF-kappaB activation , unless exposed to inflammatory cytokines . This does not change when gliomas are implanted into the cerebrum of severe combined immun-deficient mice . Nevertheless , sulfasalazine but not its cleaved form DB00244 caused a dose-dependent inhibition of glioma growth . This effect was entirely attributable to the inhibition of cystine uptake via the system x(c)(-) cystine-glutamate transporter . It could be mimicked by S-4-carboxy-phenylglycine ( S-4-CPG ) a more specific system x(c)(-) inhibitor , and lentiviral expression of a constitutively active form of O15111 b was unable to overcome the growth retarding effects of sulfasalazine or S-4-CPG . Both drugs inhibited cystine uptake causing a chronic depletion of intracellular DB00143 and consequently compromised cellular redox defense which stymied tumor growth . This data suggests that system x(c)(-) is a promising therapeutic target in gliomas and possibly other cancers and that it can be pharmacologically inhibited by Sulfasalazine , an FDA-approved drug . Activity , pharmacological inhibition and biological regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase in Trypanosoma brucei . Activity of hydroxymethylglutaryl-coenzyme A ( HMG- DB01992 ) reductase , the key enzyme in the biosynthesis of steroids and polyisoprenoids in mammalian cells , has been detected in both the bloodstream form and the culture-adapted procyclic form of Trypanosoma brucei ( 3.7 +/- 0.6 and 12.7 +/- 1.8 pmol mevalonate produced min-1 ( mg cell protein ) -1 , respectively ) . The enzyme activity is enriched 6-fold in microsomal fractions . Several competitive inhibitors of mammalian P04035 , including synvinolin ( simvastatin ) , inhibit the multiplication of both forms of trypanosome in vitro ( IC50 , approx. 25-50 microM after 2-3 days ) . This growth inhibition is potentiated by agents interfering with the exogenous supply of cholesterol , such as antibodies blocking the low-density lipoprotein ( LDL ) receptor , or 5 microM chloroquine . Conversely , growth inhibition by synvinolin can be largely reverted either by 300 nM LDL or by products of the mevalonate pathway , such as 20 mM mevalonate and in procyclics by 100 microM squalene or cholesterol . In procyclics , low concentrations of synvinolin selectively inhibit the incorporation of [14C]acetate into sterols , but not into fatty acids . These results argue for a critical role in trypanosomes of a mevalonate pathway , that is involved in the biosynthesis of sterol and probably of other metabolites . The P04035 activity is decreased 2-fold in procyclics incubated with 4 mM mevalonate and increased 2-fold in the presence of 2.5 microM synvinolin . DB00641 also upregulates LDL binding up to 4-fold . These data suggest that P04035 and P01130 expression are regulated in T. brucei as in mammalian cells , to ensure sterol homeostasis . Alzheimer 's disease and modern lifestyle : what is the role of stress ? This Editorial highlights a study by Baglietto-Vargas et al. 2015 published in this issue of J. Neurochem . Stress is one of the environmental factors that can contribute to Alzheimer 's disease pathogenesis . However , the role of modern-life stress has not been investigated yet . The authors reveal that modern-life stress reduces the number of dendritic spines in the hippocampus of Alzheimer 's disease transgenic mice . The mechanism underlying such effect involves an increase in corticotropin-releasing hormone ( P06850 ) release that stimulates the amyloid precursor protein ( P05067 ) processing and fosters the generation of Amyloid-β , which negatively affects dendritic spines . Dimerization effect of sucrose octasulfate on rat P05230 . Fibroblast growth factors ( FGFs ) constitute a family of at least 23 structurally related heparin-binding proteins that are involved in regulation of cell growth , survival , differentiation and migration . DB01901 ( SOS ) , a chemical analogue of heparin , has been demonstrated to activate FGF signalling pathways . The structure of rat P05230 crystallized in the presence of SOS has been determined at 2.2 A resolution . SOS-mediated dimerization of P05230 was observed , which was further supported by gel-filtration experiments . The major contributors to the sulfate-binding sites in rat P05230 are Lys113 , Lys118 , Arg122 and Lys128 . An arginine at position 116 is a consensus residue in mammalian FGF molecules ; however , it is a serine in rat P05230 . This difference may be important for SOS-mediated P05230 dimerization in rat . Enhancement of auranofin-induced apoptosis in MCF-7 human breast cells by selenocystine , a synergistic inhibitor of thioredoxin reductase . P10599 system plays an important role in regulation of intracellular redox balance and various signaling pathways . P30044 ( TrxR ) is overexpressed in many cancer cells and has been identified as a potential target of anticancer drugs . DB00995 ( AF ) is potent TrxR inhibitor with novel in vitro and in vivo anticancer activities . Selenocystine ( SeC ) is a nutritionally available selenoamino acid with selective anticancer effects through induction of apoptosis . In the present study , we demonstrated the synergistic effects and the underlying molecular mechanisms of SeC in combination with AF on MCF-7 human breast cancer cells . The results showed that SeC and AF synergistically inhibited the cancer cell growth through induction of ROS-dependent apoptosis with the involvement of mitochondrial dysfunction . DNA damage-mediated p53 phosphorylation and down-regulation of phosphorylated AKT and P29323 also contributed to cell apoptosis . Moreover , we demonstrated the important role of TrxR activity in the synergistic action of SeC and AF . Taken together , our results suggest the strategy to use SeC and AF in combination could be a highly efficient way to achieve anticancer synergism by targeting TrxR . Roxithromycin is an inhibitor of human coronary artery smooth muscle cells proliferation : a potential ability to prevent coronary heart disease . Roxithromycin ( RXM ) , a macrolide antibiotic , is used in clinical trials to address secondary prevention of coronary heart disease . However , the effects of RXM on human coronary artery smooth muscle cells ( CASMC ) proliferation remain unclear . Human CASMC were stimulated with growth medium containing 5 % fetal bovine serum and growth factors . RXM at 1 or 10 microg/ml , which are relevant to the therapeutic plasma levels , significantly suppressed mitogen-induced CASMC proliferation , assessed by WST-1 assay and cell counting . Flow cytometry analysis demonstrated that RXM suppressed mitogen-induced P55008 to S progression on cell cycle . Western blot showed that RXM inhibited phosphorylation of retinoblastoma gene products , reduced protein levels of cyclin D1 and A , and restored downregulation of cyclin-dependent kinase ( CDK ) inhibitor p27kip1 . The activities of P11802 and P24941 were suppressed by RXM without affecting their protein levels . When transfected with both O15111 alpha and beta constructs as nuclear factor-kappa B ( NF-kappaB ) activator , CASMC entered S phase at 24 h , and RXM inhibited it . Electrophoretic mobility shift assay and immunostaining of NF-kappaB p65 demonstrated that RXM inhibited mitogen-induced NF-kappaB activation . These results indicate that RXM is an inhibitor of human CASMC proliferation through modulating cell cycle regulatory proteins and inhibiting NF-kappaB signaling pathway . Disrupted coordinate regulation of farnesoid X receptor target genes in a patient with cerebrotendinous xanthomatosis . Cerebrotendinous xanthomatosis ( CTX ) , sterol 27-hydroxylase ( Q02318 ) deficiency , is associated with markedly reduced chenodeoxycholic acid ( DB06777 ) , the most powerful activating ligand for farnesoid X receptor ( Q96RI1 ) . We investigated the effects of reduced DB06777 on Q96RI1 target genes in humans . Liver specimens from an untreated CTX patient and 10 control subjects were studied . In the patient , hepatic DB06777 concentration was markedly reduced but the bile alcohol level exceeded DB06777 levels in control subjects ( 73.5 vs. 37.8 +/- 6.2 nmol/g liver ) . DB04540 7alpha-hydroxylase ( P22680 ) and Na+/taurocholate-cotransporting polypeptide ( Q14973 ) were upregulated 84- and 8-fold , respectively . However , small heterodimer partner ( Q15466 ) and bile salt export pump were normally expressed . Marked P22680 induction with normal Q15466 expression was not explained by the regulation of liver X receptor alpha ( LXRalpha ) or pregnane X receptor . However , another nuclear receptor , hepatocyte nuclear factor 4alpha ( HNF4alpha ) , was induced 2.9-fold in CTX , which was associated with enhanced mRNA levels of HNF4alpha target genes , P22680 , 7alpha-hydroxy-4-cholesten-3-one 12alpha-hydroxylase , Q02318 , and Q14973 . In conclusion , the coordinate regulation of Q96RI1 target genes was lost in CTX . The mechanism of the disruption may be explained by a normally stimulated Q96RI1 pathway attributable to markedly increased bile alcohols with activation of HNF4alpha caused by reduced bile acids in CTX liver . Inhibition of neuronal nitric oxide reduces anxiety-like responses to pair housing . Many psychological disorders are characterized by anxiety and alterations in social interactions . Recent studies demonstrate that the chemical messenger nitric oxide ( NO ) can regulate both anxiety and social behaviours . We tested whether an enzyme that produces NO in the brain , neuronal nitric oxide synthase ( P29475 ) , serves as an interface between social interactions and anxiety-like behaviour . Several investigators have observed that mice increase anxiety-like responses in the elevated plus-maze after pair housing . P29475 gene deletion and DB01997 were used to inhibit the production of neuronal NO . Similar to previous studies , pair housing reduced open arm exploration in the elevated plus-maze . Pair housing also increased corticotropin-releasing hormone ( P06850 ) immunoreactive cells in the paraventricular nucleus ( PVN ) of the hypothalamus . Inhibition of NO production increased open arm exploration in pair-housed mice but decreased open arm exploration in individually housed mice . These results suggest that the effect of P29475 inhibition on anxiety-like responses is context dependent and that behavioural responses to social housing are altered after P29475 inhibition . This research suggests that NO may play an important role in mediating the effect social interactions have on anxiety . P30532 gene D398N polymorphism in Japanese lung adenocarcinoma . BACKGROUND : Recently , to identify genetic factors that modify lung cancer risk , P30532 non-synonymous variant amino acid position 398 ( D398N ) was identified . The site was a highly conserved in the second cellular loop of the nicotinic acetylcholine receptor subunit protein . MATERIALS AND METHODS : We have investigated P30532 gene polymorphism status in 302 surgically treated lung adenocarcinoma cases from Nagoya City University Hospital . The presence or absence of P30532 polymorphism was analyzed by direct sequences . P00533 mutations status was already investigated and reported . RESULTS : We detected nine cases ( 2.98 % ) of P30532 polymorphism ( D398N ) in our cohort . Total P00533 mutations were present in 129 patients ( 42.7 % ) . The polymorphism statuses were not correlated with gender ( women ; 2.1 % versus men ; 3.7 % , P = 0.5119 ) , smoking status ( never smoker ; 2.0 % versus smoker ; 4.0 % , P = 0.3339 ) , pathological stages ( stage I ; 2.6 % versus stage II-IV ; 3.8 % , P = 0.7246 ) , and P00533 mutation status of the lung adenocarcinomas ( mutation ; 2.3 % versus wild type ; 3.7 % , P = 0.7373 ) . In this analysis , P30532 polymorphism ( D398N ) patients had significantly worse prognosis ( 5/9 were dead ; mean survival = 27.1 mo ) than the patients with P30532 wild type ( 74/293 were dead ; mean survival = 113.9 mo ) ( log-rank test ; P = 0.0146 ) . CONCLUSION : Although P30532 polymorphism is rare from Japanese lung cancer , polymorphism status might be correlated with shorter survival . Partial agonists of the α3β4* neuronal nicotinic acetylcholine receptor reduce ethanol consumption and seeking in rats . DB00898 use disorders ( AUDs ) impact millions of individuals and there remain few effective treatment strategies . Despite evidence that neuronal nicotinic acetylcholine receptors ( nAChRs ) have a role in AUDs , it has not been established which subtypes of the nAChR are involved . Recent human genetic association studies have implicated the gene cluster P32297 - P30532 - P30926 encoding the α3 , α5 , and β4 subunits of the nAChR in susceptibility to develop nicotine and alcohol dependence ; however , their role in ethanol-mediated behaviors is unknown due to the lack of suitable and selective research tools . To determine the role of the α3 , and β4 subunits of the nAChR in ethanol self-administration , we developed and characterized high-affinity partial agonists at α3β4 nAChRs , CP-601932 , and PF-4575180 . Both CP-601932 and PF-4575180 selectively decrease ethanol but not sucrose consumption and operant self-administration following long-term exposure . We show that the functional potencies of CP-601932 and PF-4575180 at α3β4 nAChRs correlate with their unbound rat brain concentrations , suggesting that the effects on ethanol self-administration are mediated via interaction with α3β4 nAChRs . Also varenicline , an approved smoking cessation aid previously shown to decrease ethanol consumption and seeking in rats and mice , reduces ethanol intake at unbound brain concentrations that allow functional interactions with α3β4 nAChRs . Furthermore , the selective α4β2(*) nAChR antagonist , DHβE , did not reduce ethanol intake . Together , these data provide further support for the human genetic association studies , implicating P32297 and P30926 genes in ethanol-mediated behaviors . CP-601932 has been shown to be safe in humans and may represent a potential novel treatment for AUDs . Differential expression of cholesterol hydroxylases in Alzheimer 's disease . DB04540 is eliminated from neurons by oxidization , which generates oxysterols . DB04540 oxidation is mediated by the enzymes cholesterol 24-hydroxylase ( Q9Y6A2 ) and cholesterol 27-hydroxylase ( Q02318 ) . Immunocytochemical studies show that Q9Y6A2 and Q02318 are expressed in neurons and some astrocytes in the normal brain , and Q02318 is present in oligodendrocytes . In Alzheimer 's disease ( AD ) , Q9Y6A2 shows prominent expression in astrocytes and around amyloid plaques , whereas Q02318 expression decreases in neurons and is not apparent around amyloid plaques but increases in oligodendrocytes . Although previous studies have examined the effects of synthetic oxysterols on the processing of amyloid precursor protein ( P05067 ) , the actions of the naturally occurring oxysterols have yet to be examined . To understand the role of cholesterol oxidation in AD , we compared the effects of 24(S)- and 27-hydroxycholesterol on the processing of P05067 and analyzed the cell-specific expression patterns of the two cholesterol hydroxylases in the human brain . Both oxysterols inhibited production of Abeta in neurons , but 24(S)-hydroxycholesterol was approximately 1000-fold more potent than 27-hydroxycholesterol . The IC(50) of 24(S)-hydroxycholesterol for inhibiting Abeta secretion was approximately 1 nm . Both oxysterols induced O95477 expression with IC(50) values similar to that for inhibition of A beta secretion , suggesting the involvement of liver X receptor . Oxysterols also inhibited protein kinase C activity and P05067 secretion following stimulation of protein kinase C . The selective expression of Q9Y6A2 around neuritic plaques and the potent inhibition of P05067 processing in neurons by 24(S)-hydroxycholesterol suggests that Q9Y6A2 affects the pathophysiology of AD and provides insight into how polymorphisms in the Q9Y6A2 gene might influence the pathophysiology of this prevalent disease . DB00203 inhibits calcineurin/ Q13469 -mediated cyclin A expression in pulmonary artery smooth muscle cells . AIMS : To examine whether calcineurin/NFAT signaling pathway leads to proliferation of pulmonary artery smooth muscle cells ( PASMCs ) by regulating cell cycle proteins and whether the phosphodiesterase-5 ( O76074 ) inhibitor sildenafil affects calcineurin/NFAT-induced cell proliferation . MAIN METHODS : A [(3)H]thymidine incorporation assay was used to examine DNA synthesis ( cell proliferation ) ; cyclin A and Q13469 expressions were determined by Western blot . P24941 ( P24941 ) activity was measured with an in vitro kinase activity assay , and calcineurin and NFAT activity were evaluated using a calcineurin assay kit and a luciferase activity assay , respectively . A chemical inhibitor or siRNA transfection was used to inhibit calcineurin/NFAT signaling pathway . KEY FINDINGS : Serotonin dose-dependently stimulated cyclin A expression in PASMCs . This effect was accompanied by dose-dependent increases in P24941 activity and the rate of DNA synthesis . At the same time , PASMCs treated with serotonin showed dose-dependent activation of calcineurin/NFAT signaling pathway . Inhibition of calcineurin activity by cyclosporine A or loss of Q13469 protein by siRNA transfection abolished serotonin-induced cyclin A expression and consequent P24941 activation and DNA synthesis . We further found that pretreatment of cells with sildenafil suppressed serotonin-triggered activation of calcineurin/ Q13469 signaling pathway and resultant cyclin A expression , P24941 activation and cell proliferation , while the presence of DT-3 [ a specific protein kinase G ( PKG ) peptide inhibitor ] reversed the effects of sildenafil on PASMCs . SIGNIFICANCE : Our study suggests that enhanced PKG activity suppresses calcineurin/ Q13469 cascade-mediated cyclin A expression , P24941 activation and PASMC proliferation to contribute to the overall effects of sildenafil in the treatment of pulmonary hypertension . Significance of water molecules in the inhibition of cylin-dependent kinase 2 and 5 complexes . Interest in P24941 and Q00535 has stemmed mainly from their association with cancer and neuronal migration or differentiation related diseases and the need to design selective inhibitors for these kinases . In the present paper , eight Molecular Dynamics ( MD ) simulations are carried out to examine the importance of structure and dynamics of water in the active site of both P24941 and Q00535 complexes with roscovitine and indirubin analogues . Together with previous results , the current work shows a highly conserved water-involved hydrogen bonding ( HB ) network in both P24941 - and Q00535 -indirubin combinations to complete information from the X-ray crystallography . The simulations suggest the importance of such a network for combining the inhibitor to the host protein as well as the significance of using an activated CDK as a template when designing new inhibitors . Different binding patterns of roscovitine in P24941 and Q00535 are detected during the simulations because of the different binding conformations of the group on the P06681 side chain , which might offer a clue toward finding highly selective inhibitors with regards to P24941 and Q00535 .