interacts_with DB01016?
Novel synthesis of various orthogonally protected Cα-methyllysine analogues and biological evaluation of a vapreotide analogue containing ( S ) -α-methyllysine . Prochiral malonic diesters containing a quaternary carbon center have been successfully transformed into a diverse set of (t)Boc-Fmoc-α(2,2)-methyllysine-OH analogues through chiral malonic half-ester intermediates obtained via enzymatic ( Pig Liver Esterase , PLE ) hydrolysis . The variety of chiral half-ester intermediates , which vary from 1 to 6 methylene units in the side chain , are achieved in moderate to high optical purity and in good yields . The PLE hydrolysis of malonic diesters with various side chain lengths appears to obey the Jones 's PLE model according to the stereochemical configurations of the resulting chiral half-esters . The established synthetic strategy allows the construction of both enantiomers of α(2,2)-methyllysine analogues , and a ( S ) -β(2,2)-methyllysine analogue from a common synthon by straightforward manipulation of protecting groups . Two different straightforward and cost effective synthetic strategies are described for the synthesis of α(2,2)-methyllysine analogues . The described strategies should find significant usefulness in preparing novel peptide libraries with unnatural lysine analogues . A DB04894 analogue incorporating ( S ) -α(2,2)-methyllysine was prepared . However , the DB04894 analogue with ( S ) -α-methyl-α-lysine is found to lose its specific binding to somatostatin receptor subtype 2 ( P30874 ) . DB01016 exerts an antitumor activity through reactive oxygen species-c-jun NH2-terminal kinase pathway in human gastric cancer cell line MGC-803 . DB01016 , a blocker of DB00171 -sensitive potassium ( K( DB00171 ) ) channels , can suppress progression of many cancers , but the involved mechanism is unclear . Herein we reported that MGC-803 cells expressed the K( DB00171 ) channels composed of Kir6.2 and Q09428 subunits . DB01016 induced cellular viability decline , coupled with cell apoptosis and reactive oxygen species ( ROS ) generation in MGC-803 cells . Meanwhile , glibenclamide increased NADPH oxidase catalytic subunit gp91(phox) expression and superoxide anion ( O2- ) generation , and caused mitochondrial respiration dysfunction in MGC-803 cells , suggesting that glibenclamide induced an increase of ROS derived from NADPH oxidase and mitochondria . DB01016 could also lead to loss of mitochondrial membrane potential , release of cytochrome c and apoptosis-inducing factor ( O95831 ) , and activation of c-jun NH2-terminal kinase ( JNK ) in MGC-803 cells . Pretreatment with antioxidant N-acetyl-l-cysteine ( Q9C000 ) prevented glibenclamide-induced JNK activation , apoptosis and cellular viability decline . Furthermore , glibenclamide greatly decreased the cellular viability , induced apoptosis and inhibited Akt activation in wild-type mouse embryonic fibroblast ( MEF ) cells but not in P45983 -/- or P45984 -/- MEF cells . Taken together , our study reveals that glibenclamide exerts an antitumor activity in MGC-803 cells by activating ROS-dependent , JNK-driven cell apoptosis . These findings provide insights into the use of glibenclamide in the treatment of human gastric cancer . Risk factors for coronary artery disease , circulating endothelial progenitor cells , and the role of P04035 inhibitors . Recent studies suggest that postnatal neovascularization relies not exclusively on sprouting of preexisting vessels ( " angiogenesis " ) , but also involves the contribution of bone marrow-derived circulating endothelial progenitor cells ( EPCs ) . EPCs can be isolated from peripheral blood or bone marrow mononuclear cells , P28906 (+) or CD133(+) hematopoietic progenitors . Infusion of EPCs was shown to promote postnatal neovascularization of ischemic tissue after myocardial infarction in animal models and initial clinical trials . Moreover , circulating endothelial precursor cells can home to denuded arteries after balloon injury and contribute to endothelial regeneration , thereby limiting the development of restenosis . Thus , circulating endothelial cells may exert an important function as endogenous repair mechanism to maintain the integrity of the endothelial monolayer and to promote ischemia-induced neovascularization . However , risk factors for coronary artery disease , such as diabetes , hypercholesterolemia , and hypertension are associated with impaired number and function of EPC in patients with coronary artery disease . Therapeutically , the reduction of EPC number and the decreased functional activity in patients with coronary artery disease was counteracted by 3-hydroxy-3-methylglutaryl coenzymeA ( HMG- DB01992 ) reductase inhibitors ( statins ) , vascular endothelial growth factor ( P15692 ) , estrogen , or exercise . At the molecular level , these factors are well established to activate the phosphatidyl-inositol-3-kinase ( PI3K ) -Akt-dependent activation of the endothelial nitric oxide synthase ( P29474 ) , suggesting that the PI3K-Akt- P29474 signaling pathway may be involved in the transduction of atheroprotective factors . Taken together , the balance of atheroprotective and proatherosclerotic factors may influence EPC levels and their functional capacity to improve neovascularization and endothelial regeneration . A protective role of hydrogen sulfide against oxidative stress in rat gastric mucosal epithelium . We investigated effect of hydrogen sulfide ( H(2)S ) on oxidative stress-caused cell death in gastric mucosal epithelial cells . In rat normal gastric epithelial RGM1 cells , NaHS , a H(2)S donor , at 1.5mM strongly suppressed hydrogen peroxide ( H(2)O(2) ) -caused cell death , while it slightly augmented the H(2)O(2) toxicity at 0.5-1mM . The protective effect of NaHS was abolished by inhibitors of MEK or JNK , but not of p38 Q96HU1 kinase . NaHS at 1.5mM actually phosphorylated P29323 and JNK in RGM1 cells . DB01016 , an DB00171 -sensitive K(+) ( K( DB00171 )(+) ) channel inhibitor , did not affect the protective effect of NaHS , although mRNAs for K( DB00171 )(+) channel subunits , Kir6.1 and Q09428 , were detected in RGM1 cells . In anesthetized rats , oral administration of NaHS protected against gastric mucosal lesion caused by ischemia-reperfusion . These results suggest that NaHS/H(2)S may protect gastric mucosal epithelial cells against oxidative stress through stimulation of Q96HU1 kinase pathways , a therapeutic dose range being very narrow . Molecular identification of the human O75899 : cell surface expression and coupling to adenylyl cyclase in the absence of Q9UBS5 . We have identified a gene encoding a GABAB receptor , the human O75899 , located on chromosome 9q22.1 , that is distinct from the recently reported rat Q9UBS5 . O75899 structurally resembles Q9UBS5 ( 35 % identity ) , having seven transmembrane domains and a large extracellular region , but differs in having a longer carboxy-terminal tail . O75899 is localized to the cell surface in transfected COS cells , and negatively couples to adenylyl cyclase in response to GABA , baclofen , and 3-aminopropyl(methyl)phosphinic acid in CHO cells lacking Q9UBS5 . DB00181 action is inhibited by the GABABR antagonist , 2-hydroxysaclofen . The human O75899 and Q9UBS5 genes are differentially expressed in the nervous system , with the greatest difference being detected in the striatum in which Q9UBS5 but not O75899 mRNA transcripts are detected . O75899 and Q9UBS5 mRNAs are also coexpressed in various brain regions such as the Purkinje cell layer of the cerebellum . Identification of a functional homomeric O75899 coupled to adenylyl cyclase suggests that the complexity of GABAB pharmacological data is at least in part due to the presence of more than one receptor and opens avenues for future research leading to an understanding of metabotropic GABA receptor signal transduction mechanisms . Regulation of hepatic lecithin:retinol acyltransferase activity by retinoic acid receptor-selective retinoids . The microsomal enzyme O95237 esterifies retinol and has been implicated in the hepatic storage of vitamin A . Previously , we showed that hepatic O95237 activity is negligible during vitamin A deficiency and that all-trans-retinoic acid ( all-trans-RA ) rapidly induces the activity of liver O95237 in retinoid-deficient rats . In the present studies , we have examined the ability of natural and synthetic retinoids to induce liver O95237 activity in retinoid-deficient rats . The natural retinoids retinol , all-trans-RA ( 100 microg ) , 9- DB00982 , or equal molar amounts of other retinoids were injected ip and O95237 specific activity was measured in liver homogenates 17-18 h later . In retinoid-deficient rats , liver O95237 activity was extremely low [ 0.13 +/- 0.03 pmol retinyl ester ( RE ) /min/mg liver protein , mean +/- SE ] . The natural retinoids retinol and all-trans-RA strongly induced O95237 activity ( 12.71 +/- 1.09 and 13.10 +/- 1.55 pmol RE/min/mg , respectively ) , whereas 9- DB00982 induced a lower level of O95237 activity ( 3.96 +/- 1.88 pmol RE/min/mg , P < 0.001 vs all-trans-RA ) . The retinoic acid receptor ( RAR ) -selective analog ( RAR pan-agonist ) all-trans-UAB8 and the P10276 -selective retinoid Am580 also strongly induced O95237 activity . In contrast , neither RXR-selective agonists nor retinoids having a retro structure were active . For retinoids with significant P10276 binding activity there was a strong direct correlation between receptor binding in vitro and the ability to induce hepatic O95237 activity in vivo ( r2 = 0.920 ) . These data implicate the RARs in the induction of hepatic O95237 and suggest a predominant role for P10276 -active ligands . Gene expression profiling in chronic myeloid leukemia patients treated with hydroxyurea . Using array technology that allows the simultaneous detection of gene expression of hundreds of genes , four patients with chronic myeloid leukemia ( CML ) were investigated at diagnosis and after starting administration of hydroxyurea . To detect the gene expression of peripheral blood mononuclears and granulocytes Human Cancer cDNA Array ( CLONTECH ) with 588 gene probes was used . Gene expression mononuclear and granulocyte profiles of patients at diagnosis were compared with the control profiles . The significant expression changes observed in most patients seemed to be important . Increased expression of c-jun N-terminal kinase 2 ( P45984 ) , integrin alpha E , P22894 , P14780 was detected in both fractions of most patients . In some samples P12004 , P51858 , MAPK p38 , P13987 increased expressions were found . Significant down-regulation of expression in patients was detected in genes P11802 inhibitor A , Q00577 , notch1 in mononuclears ; P52630 , P42229 , P10276 , Q8WXI8 -1 , junB , caspase 4 in granulocytes ; Q00534 , P35638 , P00533 -3 , cadherin 5 in both fractions . Expression profiles detected in patients at diagnosis did not differ markedly from those after one-week treatment with hydroxyurea . Only in a few genes were significant changes after hydroxyurea administration observed and inter-individual expression differences were rather common . P45984 phosphorylates endothelial nitric oxide synthase at serine 116 and regulates nitric oxide production . The c-Jun N-terminal kinases ( JNKs ) belonging to the mitogen-activated protein kinase ( MAPK ) superfamily play important roles in foam-cell formation , hypercholesterolemia-mediated endothelial dysfunction , and the development of obesity . Although decreased nitric oxide ( NO ) production via decreased phosphorylation of endothelial NO synthase at serine 1179 ( P29474 - DB00133 (1179) ) was reported to be partly involved in P45984 -derived endothelial dysfunction , P45984 seems likely to be indirectly involved in this signaling pathway . Here , using bovine aortic endothelial cells , we examined whether P45984 directly phosphorylated P29474 - DB00133 (116) , a putative substrate site for the MAPK superfamily , and this phosphorylation resulted in decreased NO release . JNK inhibitor SP60012 increased NO release in a time- and dose-dependent manner , which was accompanied by increased P29474 - DB00133 (116) phosphorylation . Purified P45984 directly phosphorylated P29474 - DB00133 (116)in vitro . Ectopic expression of dominant negative P45984 repressed P29474 - DB00133 (116) phosphorylation and increased NO production . Coimmunoprecipitation and confocal microscopy studies revealed a colocalization of P29474 and P45984 . However , all these observed effects were not manifested when P45983 probes were used . Overall , this study indicates that P45984 is a physiological kinase responsible for P29474 - DB00133 (116) phosphorylation and regulates NO production . Treatment with the glycogen synthase kinase-3beta inhibitor , TDZD-8 , affects transient cerebral ischemia/reperfusion injury in the rat hippocampus . The serine/threonine glycogen synthase kinase 3beta ( GSK-3beta ) is abundant in the central nervous system , particularly in the hippocampus , and plays a pivotal role in the pathophysiology of a number of diseases , including neurodegeneration . This study was designed to investigate the effects of GSK-3beta inhibition against I/R injury in the rat hippocampus . Transient cerebral ischemia ( 30 min ) followed by 1 h of reperfusion significantly increased generation of reactive oxygen species and modulated superoxide dismutase activity ; 24 h of reperfusion evoked apoptosis ( determined as mitochondrial cytochrome c release and Bcl-2 and caspase-9 expression ) , resulted in high plasma levels of P01375 and increased expression of cyclooxygenase-2 , inducible nitric oxide synthase , and intercellular adhesion molecule-1 . The selective GSK-3beta inhibitor , 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione ( TDZD-8 ) , was administered before and after ischemia or during reperfusion alone to assess its potential as prophylactic or therapeutic strategy . Prophylactic or therapeutic administration of TDZD-8 caused the phosphorylation ( DB00133 (9) ) and hence inactivation of GSK-3beta . Infarct volume and levels of P04271 protein , a marker of cerebral injury , were reduced by TDZD-8 . This was associated with a significant reduction in markers of oxidative stress , apoptosis , and the inflammatory response resulting from cerebral I/R . These beneficial effects were associated with a reduction of I/R-induced activation of the mitogen-activated protein kinases P45983 /2 and p38 and nuclear factor-kappaB . The present study demonstrates that TDZD-8 protects the brain against I/R injury by inhibiting GSK-3beta activity . Collectively , our data may contribute to focus the role of GSK-3beta in cerebral I/R . DB11320 Promotes the Release of P05231 via the P35367 /p38 and NF-κB Pathways in Nasal Fibroblasts . PURPOSE : Based on the close relationship between histamine and interleukin 6 ( P05231 ) , we hypothesized that histamine may regulate the production of cytokines , such as P05231 , during allergic inflammation . Here , we examined the role of histamine in P05231 production and histamine receptor activity in nasal fibroblasts , along with the mechanisms underlying these effects . METHODS : Experiments were performed using nasal fibroblasts from 8 normal patients . RT-PCR was used to identify the major histamine receptors expressed in nasal fibroblasts . Fibroblasts were then treated with histamine with or without histamine-receptor antagonists , and monitored for P05231 production using an ELISA . Four potential downstream signaling molecules , p38 , extracellular signal-regulated kinase ( P29323 ) , c-Jun N-terminal kinase ( JNK ) , and NF-κB , were evaluated by Western blot , and a luciferase reporter assay . RESULTS : Elevated expression was seen for all histamine receptors , with P05231 protein levels increasing significantly following histamine stimulation . Among the histamine-receptor specific antagonists , only the P35367 antagonist significantly decreased P05231 production in histamine-stimulated nasal fibroblasts . DB11320 increased the expression level of phosphorylated p38 ( pp38 ) , pERK , and pJNK , as well as NF-κB induction . The P35367 antagonist actively suppressed pp38 and NF-κB expression in histamine-induced nasal fibroblasts , but not pERK and pJNK . The p38 inhibitor strongly attenuated P05231 production in histamine-stimulated nasal fibroblasts . CONCLUSIONS : The data presented here suggest that antihistamines may be involved in the regulation of cytokines , such as P05231 , due to the role of histamine as an inflammatory mediator in nasal fibroblasts . Combination of DB05210 and gefitinib induces apoptosis of triple-negative breast cancer cells through the PI3K/AKT- P42345 pathway . To investigate the apoptotic mechanism of triple-negative breast cancer ( TNBC ) cells induced by gefitinib and PI3K inhibitor DB05210 . MDA-MB-231 , MDA-MB-436 , and MCF-7 cells were incubated with 0.1 μmol/l gefitinib , 1 μmol/l gefitinib , 10 μmol/l gefitinib , 1 μmol/l DB05210 , 0.1 μmol/l gefitinib+1 μmol/l DB05210 , 1 μmol/l gefitinib+1 μmol/l DB05210 , and 10 μmol/l gefitinib+1 μmol/l DB05210 . Then , cell viability and survival were determined using an 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide ( MTT ) assay and Hoechst staining . The apoptosis-related factors and phosphoinositide-3-kinase/protein kinase B , the mammalian target of rapamycin ( PI3K/AKT- P42345 ) signaling pathway-related factors were detected by western blot . For TNBC cells , cell viability or survival was not significantly inhibited by gefitinib or DB05210 alone ; however , marked cell apoptosis was noted in the gefitinib and DB05210 combination groups , and this effect was dose dependent . Also , the expressions of apoptosis markers , such as cleaved caspase-3 , Bcl-2/Bax , were altered by the gefitinib and DB05210 combination . Moreover , phosphorylated AKT ( p-AKT ) and 70 kDa ribosomal protein S6-kinase ( p-p70S6K ) were also inhibited by the gefitinib and DB05210 combination , which may be responsible for the apoptosis . Gefitinib combined with DB05210 could induce cell apoptosis in TNBC cells and this effect was mediated through the P00533 -PI3K-AKT- P42345 -p70S6K pathway . Our studies have set the stage for future clinical trials of TNBC therapy by the combination of gefitinib and DB05210 . Prolonged treatment with bicalutamide induces androgen receptor overexpression and androgen hypersensitivity . BACKGROUND : Various hormone refractory prostate cancer cell models have been established with androgen depletion and have helped to clarify the mechanism for the transition into androgen-depletion independent status . However , the mechanism of bicalutamide resistance remains unclear because few cell models have been generated . METHODS : We generated a bicalutamide-resistant subline , LNCaP- O43633 , from LNCaP after prolonged treatment with bicalutamide . Androgen and/or bicalutamide responsiveness for proliferation and prostate-specific antigen ( PSA ) secretion were examined in vitro and in vivo . DB00624 and dihydrotestosterone ( DB02901 ) levels in xenografted tumors were analyzed by liquid chromatography-tandem mass spectrometry . P10275 ( AR ) gene mutation and amplification and AR and pAR(210) expression were determined . RESULTS : LNCaP- O43633 did not grow in an androgen-depleted medium and proliferation was stimulated in a tenfold lower concentration of androgen than that of LNCaP . LNCaP- O43633 grew in castrated male mice , and the DB02901 level in grafted LNCaP- O43633 tumors was 7.7-fold lower than in LNCaP tumors . DB01128 stimulated LNCaP- O43633 proliferation and PSA secretion in vitro and the antitumor activity of bicalutamide against LNCaP- O43633 was weaker than that of LNCaP in vivo . Additional AR mutation and AR gene amplification were not detected in LNCaP- O43633 , but AR and pAR(210) expression and PSA secretion in LNCaP- O43633 were higher than in LNCaP . CONCLUSIONS : DB01128 -resistant LNCaP- O43633 exhibited AR overexpression and hypersensitivity to low levels of androgen . Our data suggests that AR overexpression is a significant mechanism of bicalutamide resistance similar to resistance from chronic androgen depletion . In addition , pAR(210) overexpression could be a potential mechanism for hypersensitivity to low androgen in LNCaP- O43633 . Lack of glibenclamide response in a case of permanent neonatal diabetes caused by incomplete inactivation of glucokinase . BACKGROUND : Hypoglycaemic drugs that close the KATP channel have been tested in patients with permanent neonatal diabetes due to glucokinase mutations ( PNDM-GCK ) . From the results obtained , it has been suggested that this treatment may be beneficial in patients carrying GCK mutations with mild kinetic defects . The aim of this study was to evaluate the kinetic analysis of glucokinase activity as a predictive factor for response to sulphonylureas in PNDM-GCK . METHODS : The clinical characteristics of two siblings with PNDM born to non-consanguineous parents are described . Mutation analysis of Q14654 , P01308 and GCK genes was done by sequencing . A comprehensive functional characterisation of GCK mutation was undertaken . DB01016 treatment was assayed for 16 weeks in one child . Response to treatment was evaluated by means of fasting glycaemia , C-peptide and HbA1c levels . RESULTS : Compound heterozygous GCK mutations ( p.Ile19Asn and p.Ser441Trp ) were identified . Functional analysis of GCK(p.Ile19Asn) indicated that this mutant retained more than 70 % of wild-type catalytic activity in vitro , with a slight increase of thermolability . This mutation did not impair the interaction with the glucokinase regulatory protein , and the enzymatic activity of the GCK(p.Ile19Asn) mutant is restored to wild-type levels in the presence of GCK allosteric activator LY2121260 . However , glibenclamide treatment of the patient on a reduced dose of insulin did not reduce HbA1c levels , and C-peptide increased only very slightly . CONCLUSION : Hypoglycaemic drugs acting on the KATP channel might not be useful in the treatment of PNDM-GCK , even in patients carrying GCK mutations with mild kinetic defects . Could treatment with arundic acid ( DB05343 ) increase vulnerability for depression ? Arundic acid ( DB05343 ) is believed to be neuroprotective because of its actions on glia cells ; i.e. , its inhibitory effects on the synthesis of a calcium-binding protein P04271 . DB05343 is undergoing clinical trials for the treatment of patients with stroke and Alzheimer 's disease . Recent clinical studies point to a pervasive comorbidity of depression with stroke and Alzheimer 's disease . Previously , P04271 has been implicated in the pathobiological mechanisms of depression . Preclinical studies have shown that antidepressant treatment significantly increases brain P04271 . Here we hypothesize that available data that link P04271 with depression , along with the proposed inhibitory action of DB05343 on P04271 synthesis , indicate that this compound could increase vulnerability for depression in patients at risk for this disorder , and we propose that evaluation of patients with stroke and Alzheimer 's disease for the presence of depression should be routine in clinical trials employing DB05343 . Although it may be open for discussion whether the neuroprotective effects of DB05343 are exclusively due to its inhibition of P04271 synthesis , the latter action of DB05343 warrants studies of the effects of this drug in the pathobiology of depression . P01308 secretory defects and impaired islet architecture in pancreatic beta-cell-specific P40763 knockout mice . Normal islet formation and function depends on the action of various growth factors operating in pre- and postnatal development ; however , the specific physiological function of each factor is largely unknown . Loss-of-function analyses in mice have provided little information so far , perhaps due to functional redundancies of the growth factors acting on the pancreas . The present study focuses on the role of the transcription factor P40763 in insulin-producing cells . P40763 is one of the potential downstream mediators for multiple growth factors acting on the pancreatic beta-cells , including betacellulin , hepatocyte growth factor , growth hormone , and heparin-binding P01133 -like growth factor . To elucidate its role in the beta-cells , the P40763 gene was disrupted in insulin-producing cells in mice ( P40763 -insKO ) , using a cre-mediated gene recombination approach . Unexpectedly , P40763 -insKO mice exhibited an increase in appetite and obesity at 8 weeks of age or older . The mice showed partial leptin resistance , suggesting that expression of the RIP ( rat insulin promoter ) -cre transgene in hypothalamus partially inhibited the appetite-regulating system . Intraperitoneal glucose tolerance tests , performed in non-obese 5-week-old mice , showed that the P40763 -insKO mice were glucose intolerant . Islet perifusion experiments further revealed a deficiency in early-phase insulin secretion . Whereas islet insulin content or islet mass was not affected , expression levels of P11168 , Q09428 , and P15692 were significantly reduced in P40763 -insKO islets . Interestingly , P40763 -insKO mice displayed impaired islet morphology : alpha-cells were frequently seen in central regions of islets . Our present observations demonstrate a unique role of P40763 in maintaining glucose-mediated early-phase insulin secretion and normal islet morphology . Endothelial nitric oxide synthase is essential for the P04035 inhibitor cerivastatin to promote collateral growth in response to ischemia . HMG- DB01992 ( 3-hydroxy-3-methylglutaryl-coenzyme A ) reductase inhibitors , or statins , are prescribed widely to lower cholesterol . Accumulating evidence indicates that statins have various effects on vascular cells , which are independent of their lipid-lowering effect . Here , we tested the hypothesis that statins may augment collateral flow to ischemic tissues . We induced hind-limb ischemia in wild-type mice and treated them with either saline or cerivastatin . DB00439 enhanced the blood flow recovery dramatically as determined by Laser Doppler imaging . The mice treated with saline displayed frequent autoamputation of the ischemic toe , which was prevented completely by cerivastatin . Anti-CD31 immunostaining revealed that cerivastatin significantly increased the capillary density . Endothelial nitric oxide synthase ( P29474 ) activity was enhanced markedly in the mice treated with cerivastatin . The angiogenic effect of cerivastatin was abrogated in P29474 deficient ( P29474 -/- ) mice . These results indicate that P29474 is essential for cerivastatin to promote collateral growth in response to ischemia . Inhibition of DB00171 -sensitive K+ channels by substituted benzo[c]quinolizinium P13569 activators . The substituted benzo[c]quinolizinium compounds MPB-07 and MPB-91 are novel activators of the cystic fibrosis transmembrane conductance regulator ( P13569 ) chloride channel . High homologies between P13569 and the sulfonylurea receptor ( Q09428 ) , which associates with the potassium channel Kir6.2 to form the DB00171 -sensitive K(+) ( K( DB00171 ) ) channel , prompted us to examine possible effects of these compounds on K( DB00171 ) channels using electrophysiological recordings and binding assays . Activity of recombinant K( DB00171 ) channels expressed in Xenopus oocytes was recorded in the inside-out configuration of the patch-clamp technique . Channels were practically unaffected by MPB-07 but were fully blocked by MPB-91 with half-inhibition achieved at approximately 20 microM MPB-91 . These effects were similar on channels formed by Kir6.2 , and either the Q09428 or SUR2A isoforms were independent of the presence of nucleotides . They were not influenced by Q09428 mutations known to interfere with its nucleotide-binding capacity . MPB-91 , but not MPB-07 , was able to displace binding of glibenclamide to P29320 cells expressing recombinant Q09428 /Kir6.2 channels . DB01016 binding to native channels from pancreatic MIN6 cells was also displaced by MPB-91 . A Kir6.2 mutant able to form channels without Q09428 was also blocked by MPB-91 , but not by MPB-07 . These observations demonstrate that neither MPB-07 nor MPB-91 interact with Q09428 , in spite of its high homology with P13569 , and that MPB-91 blocks K( DB00171 ) channels by binding to the Kir6.2 subunit . Thus , caution should be exercised when planning to use MPB compounds in cystic fibrosis therapy , specially MPB-91 which could nonetheless find interesting applications as the precursor of a new class of K channel blockers . Complex formation with the Type B gamma-aminobutyric acid receptor affects the expression and signal transduction of the extracellular calcium-sensing receptor . Studies with P29320 -293 cells and neurons . We co-immunoprecipitated the Ca(2+)-sensing receptor ( CaR ) and type B gamma-aminobutyric acid receptor ( GABA-B-R ) from human embryonic kidney ( P29320 ) -293 cells expressing these receptors and from brain lysates where both receptors are present . CaRs extensively co-localized with the two subunits of the GABA-B-R ( Q96GN5 and R2 ) in P29320 -293 cell membranes and intracellular organelles . Coexpressing CaRs and GABA-B-R1s in P29320 -293 cells suppressed the total cellular and cell surface expression of CaRs and inhibited phospholipase C activation in response to high extracellular [ Ca(2+) ] ( [Ca(2+)](e) ) . In contrast , coexpressing CaRs and GABA-B-R2s enhanced CaR expression and signaling responses to raising [Ca(2+)](e) . The latter effects of the O75899 on the CaR were blunted by coexpressing the Q9UBS5 . Coexpressing the CaR with Q9UBS5 or R2 enhanced the total cellular and cell surface expression of the Q9UBS5 or R2 , respectively . Studies with truncated CaRs indicated that the N-terminal extracellular domain of the CaR participated in the interaction of the CaR with the Q9UBS5 and R2 . In cultured mouse hippocampal neurons , CaRs co-localized with the Q9UBS5 and R2 . CaRs and GABA-B-R1s also co-immunoprecipitated from brain lysates . The expression of the CaR was increased in lysates from Q9UBS5 knock-out mouse brains and in cultured hippocampal neurons with their Q9UBS5 genes deleted in vitro . Thus , CaRs and GABA-B-R subunits can form heteromeric complexes in cells , and their interactions affect cell surface expression and signaling of CaR , which may contribute to extracellular Ca(2+)-dependent receptor activation in target tissues . Rainbow trout somatostatin receptor subtypes SSTR1A , SSTR1B , and P30874 differentially activate the extracellular signal-regulated kinase and phosphatidylinositol 3-kinase signaling pathways in transfected cells . Previously , we reported that extracellular signal-regulated kinase ( P29323 ) and protein kinase B ( Akt ) , a downstream target of phosphatidylinositol 3-kinase ( PI3K ) , mediated somatostatin ( SS ) inhibition of P10912 , IGF1 , and IGF1 receptor expression . In this study , we used Chinese hamster ovary- P04264 cells that stably transfected individually with trout SS receptors ( SSTR1A , SSTR1B , and P30874 ) to elucidate receptor-effector pathway linkages . SS induced P29323 and Akt activation in a time- and concentration-related manner in all SSTR-expressing cells ; however , the PI3K/Akt pathway was activated to a greater extent through SSTR1A than through either SSTR1B or P30874 , whereas the P29323 pathway was activated to a greater extent though P30874 than through either SSTR1A or SSTR1B . Although the P29323 pathway inhibitor U0126 had no effect on Akt activation , the PI3K inhibitor LY294002 reduced P29323 activation to near control levels in all SSTR-expressing cell lines , suggesting some cross talk between the pathways , possibly at the level of c-Raf , the phosphorylation of which also was induced by SS via each SSTR . Pertussis toxin ( PTX ) completely abolished SS-induced activation of P29323 and Akt in SSTR1A- , SSTR1B- , and P30874 -expressing cells , suggesting that these receptors link to the P29323 and PI3K/Akt pathways via PTX-sensitive G-proteins . SS-induced activation of Elk1 , Stat3 , and C/EBPβ also was mediated by each of the trout SSTRs . These findings establish important receptor-effector pathway linkages for fish SSTRs and provide insight into the molecular mechanisms by which SSs may elicit diverse physiological effects in target cells . P10275 antagonism and an insulin sensitizer block the advancement of vaginal opening by high-fat diet in mice . Reduced hypothalamic sensitivity to steroid negative feedback may contribute to the onset of puberty . In high fat-fed rodents , the timing of vaginal opening ( VO ) is advanced , suggesting that puberty begins earlier . Because obesity can increase androgens , which interfere with normal steroid feedback in adult females , we hypothesized that androgens reduce hypothalamic sensitivity to negative feedback during puberty and that blocking androgen action would prevent advanced VO in high fat-fed mice . Age at VO was examined in mice fed high-fat or low-fat diets from weaning and treated with the androgen receptor antagonist flutamide or vehicle ( controls ) . VO was advanced in high-fat vs. low-fat controls , and flutamide blocked this advancement . VO was also delayed in low fat-fed flutamide-treated females , suggesting involvement of androgens in the timing of normal puberty . We next investigated if high-fat diet-induced insulin resistance contributes to early VO , as elevated insulin can stimulate androgen production . VO was examined in mice on either diet treated with the insulin sensitizer metformin . Metformin blocked high-fat advancement of VO but did not alter the timing of VO in low fat-fed mice . P01308 was elevated in high fat-fed females that had undergone VO compared with age-matched low fat-fed or metformin-treated animals on either diet that had not undergone VO . Together , these data suggest a model in which metabolic changes induced by high-fat diet , including transient increased circulating insulin , act in part by increasing androgen action to influence the timing of puberty in females . Pharmacological profile of astemizole-derived compounds at the histamine H1 and H4 receptor -- H1/H4 receptor selectivity . DB00637 , a P35367 antagonist shows high affinity to the histamine H1 receptor but only a moderate affinity to the histamine H4 receptor . This study aims to modify the astemizole to keep high affinity to the histamine H1 receptor and to increase affinity to the histamine H4 receptor . Therefore , 13 astemizole-derived compounds and astemizole-JNJ7777120-derived hybrid compounds were synthesized and pharmacologically characterized at the histamine H1 and H4 receptors . The new compounds show affinity to the histamine H1 receptor in the pK i range from 5.3 to 8.8 , whereas the affinity of these compounds to the histamine H4 receptor was surprisingly rather low ( pK i from 4.4 to 5.6 ) . Three representative compounds were docked into the histamine H1 receptor and molecular dynamic studies were performed to explain the binding mode and the experimental results on a molecular level . Furthermore , taking into account the binding mode of compounds with high affinity to the histamine H4 receptor , a H1/H4-pharmacophore hypothesis was developed . DB01016 -induced apoptosis is specifically enhanced by expression of the sulfonylurea receptor isoform Q09428 but not by expression of SUR2B or the mutant Q09428 (M1289T) . Q09428 ( Q09428 ) is the regulatory subunit of the pancreatic DB00171 -sensitive K+ channel ( K( DB00171 ) channel ) , which is essential for triggering insulin secretion via membrane depolarization . Sulfonylureas , such as glibenclamide and tolbutamide , act as K( DB00171 ) channel blockers and are widely used in diabetes treatment . These antidiabetic substances are known to induce apoptosis in pancreatic beta-cells or beta-cell lines under certain conditions . However , the precise molecular mechanisms of this sulfonylurea-induced apoptosis are still unidentified . To investigate the role of Q09428 in apoptosis induction , we tested the effect of glibenclamide on recombinant human embryonic kidney 293 cells expressing either Q09428 , the smooth muscular isoform SUR2B , or the mutant Q09428 (M1289T) at which a single amino acid in transmembrane helix 17 ( TM17 ) was exchanged by the corresponding amino acid of SUR2 . By analyzing cell detachment , nuclear condensation , DNA fragmentation , and caspase-3-like activity , we observed a Q09428 -specific enhancement of glibenclamide-induced apoptosis that was not seen in SUR2B , Q09428 (M1289T) , or control cells . Coexpression with the pore-forming Kir6.2 subunit did not significantly alter the apoptotic effect of glibenclamide on Q09428 cells . In conclusion , expression of Q09428 , but not of SUR2B or Q09428 (M1289T) , renders cells more susceptible to glibenclamide-induced apoptosis . Therefore , Q09428 as a pancreatic protein could be involved in specific variation of beta-cell mass and might also contribute to the regulation of insulin secretion at this level . According to our results , TM17 is essentially involved in Q09428 -mediated apoptosis . This effect does not require the presence of functional Kir6.2-containing K( DB00171 ) channels , which points to additional , so far unknown functions of Q09428 . C. elegans vulval development as a model system to study the cancer biology of P00533 signaling . Molecular genetic studies of C. elegans vulval development have helped to define an evolutionarily conserved signaling pathway from an P01133 -like ligand through P01133 -receptor , Ras and Q96HU1 kinase to the nucleus . Further studies have identified novel positive regulators such as Q8IVT5 -1 and Q09428 -8/ Q5T124 -2 and negative regulators such as cbl/SLI-1 . The many negative regulatory proteins might serve to prevent inappropriate signaling , and thus are analogous to tumor suppressor genes .