MH_dev_227

Vitamin D analogues . The plethora of actions attributed to 1,25 ( OH ) 2D3 throughout the body have suggested potential therapeutic applications for the treatment of hyperproliferative diseases , immune dysfunction , endocrine disorders , and metabolic bone disease . However , the potent calcemic activity of the natural vitamin D hormone has precluded its use in most cases . New vitamin D analogues are under development that display greater specificity , in most cases , by retaining the therapeutic properties of 1,25 ( OH ) 2D3 , but with lower calcemic activity . Two analogues have been approved for use in patients : calcipotriol ( DB02300 MEN from Leo Pharmaceuticals , Copenhagen , Denmark ) for the treatment of psoriasis ; and 19 - nor -1,25 ( OH ) 2D2 ( DB00910 from Abbott Laboratories , Abbott Park , IL ) for secondary hyperparathyroidism . Many others analogues are currently being tested in preclinical and clinical trials for the treatment of various types of cancer and osteoporosis , and for immunosuppression . The selectivity of the analogues can be attributed to the combined interactions with four proteins : the vitamin D receptor ( P11473 REA ) , the serum vitamin D binding protein ( DBP ) , the vitamin D - 24 - hydroxylase and to a newly described membrane receptor . Low DBP affinity has been shown to be responsible for the reduced calcemic actions of calcipotriol and 22 - oxacalcitriol ( O75051 REA ) , which is being tested for secondary hyperparathyroidism . However , the low calcemic activity of other analogues , including 19 - nor -1,25 ( OH ) 2D2 , involves other , as yet undefined , mechanisms . Understanding of the molecular basis for the selectivity of the vitamin D analogues will allow the design of more effective and safer vitamin D compounds for the treatment of a wide range of clinical disorders .

Inhibition of the leukotriene synthetase of rat basophil leukemia cells by diethylcarbamazine , and synergism between diethylcarbamazine and piriprost , a P09917 REA inhibitor . DB00711 MEN inhibited the formation of sulfidopeptide leukotrienes in rat basophil leukemia ( RBL ) cells ( 50 % inhibitory concentration , EC50 , 3 mM ) . Similar concentrations also inhibited the formation of leukotriene C4 ( LTC 4 ) by LTC synthetase , a detergent-solubilized cell free particulate enzyme from RBL cells which is capable of coupling P09960 REA to glutathione . By contrast , the conversion of P09960 REA to LTC 4 using enzymes from rat liver was at least ten times less sensitive to this inhibitor . The EC50 for inhibition of the leukotriene C synthetase of RBL cells was directly proportional to the P09960 REA concentration in the incubations , ranging from 1.5 mM at 10 microM P09960 REA to over 40 mM at 500 microM P09960 REA . Kinetic analysis revealed that the inhibition of the leukotriene C synthetase reaction by diethylcarbamazine was competitive with respect to P09960 REA . In contrast to diethylcarbamazine , piriprost ( U -60,257 ; 6,9- deepoxy -6,9- ( phenylimino ) - delta 6,8- prostaglandin I1 ) , which inhibits the formation of sulfidopeptide leuktrienes in RBL cells at the P09917 REA step ( EC50 5 microM ) , did not inhibit the leukotriene synthetase of these cells . On the other hand , low concentrations of piriprost , which had no demonstrable inhibitory activity on leukotriene formation by themselves , markedly synergized the inhibitory activity of diethylcarbamazine . These results are consistent with the interpretation that both piriprost and diethylcarbamazine inhibit leukotriene formation but that they act on sequential steps in the biosynthetic pathway in such a manner as to synergistically interfere with the availability or utilization of P09960 REA in the leukotriene C synthetase reaction .

Inhibition of P42345 REA restores cisplatin sensitivity through down-regulation of growth and anti-apoptotic proteins . We show that cisplatin resistance in certain lung cancer cell lines can be reversed through inhibition of P42345 REA ( mammalian Target of DB00877 SUB ) . These cell lines appear to possess high levels of phospho - P42345 REA , phospho-AKT and other growth-related proteins , such as hTERT ( human telomerase reverse transcriptase ) , and P12004 REA D3 which decrease upon inhibition of P42345 REA . Interestingly in one cisplatin resistant cell line which expresses P10415 REA / BCLxL , treatment with P42345 REA inhibitor ( CCI - 779 ) results in decreased levels of these anti-apoptotic proteins and may contribute to increasing apoptosis . Moreover , continuous exposure to CCI - 779 was found to increase the expression of the multi-drug resistant P-gp 1 ( P-gycoprotein 1 ) efflux pump and therefore should be taken into consideration when designing clinical trials with this compound .

DB00877 SUB induces Q8NHJ6 ( high ) Q8N423 REA ( high ) dendritic cells promoting a new immunoregulatory pathway . Q8NHJ6 ( high ) Q8N423 REA ( high ) dendritic cells ( DCs ) may cause anergy in P01730 REA ( + ) CD45RO ( + ) CD25 ( + ) T cells transforming them into regulatory T cells ( Tregs ) . Here , we tested whether chronic exposure to rapamycin may modulate this immunoregulatory pathway in renal transplant recipients . Forty renal transplant patients with biopsy-proven chronic allograft nephropathy and receiving calcineurin inhibitors were randomly assigned to either calcineurin inhibitor dose reduction or withdrawal with rapamycin introduction . At conversion and 2 years thereafter , we measured the rapamycin effects on circulating DCs ( BDCA 1 / Q8WTT0 and Q8NHJ6 / Q8N423 REA expression ) , P01730 REA ( + ) / CD25 ( high ) / Foxp 3 ( + ) Tregs , CD8 ( + ) / P10747 REA ( - ) T cells , and the Th1 / Th2 balance in graft biopsies . In rapamycin-treated patients , peripheral Q8WTT0 ( + ) cells were significantly increased along with Q8NHJ6 / Q8N423 REA ( + ) DCs . The number of circulating P01730 REA ( + ) / CD25 ( high ) / Foxp 3 ( + ) / P16410 REA ( + ) Tregs , CD8 ( + ) P10747 REA ( - ) T cells , and P17693 REA serum levels were higher in the rapamycin-treated group . The number of Q8NHJ6 / Q8N423 REA ( + ) Q8WTT0 ( + ) DC was directly and significantly correlated with circulating Tregs and CD8 ( + ) P10747 REA ( - ) T cells . Q8NHJ6 / Q8N423 REA expression was increased in kidney biopsies at the end of the study period along with a significant bias toward a Th2 response within the graft only in the rapamycin-treated patients . Thus , rapamycin induces the upregulation of Q8NHJ6 and Q8N423 REA on the DC surface , and this effect is associated with an increase in the number of Tregs and expansion of the CD8 ( + ) P10747 REA ( - ) T cell population . This suggests that P42345 REA inhibition may promote a novel immunoregulatory pathway .

Microarray analyses of the effects of NF-kappaB or PI3K pathway inhibitors on the LPS-induced gene expression profile in RAW 264.7 cells : synergistic effects of rapamycin on LPS-induced P14780 REA - overexpression . Lipopolysaccharide ( LPS ) activates a broad range of signalling pathways including mainly NF-kappaB and the MAPK cascade , but recent evidence suggests that LPS stimulation also activates the PI3K pathway . To unravel the specific roles of both pathways in LPS signalling and gene expression profiling , we investigated the effects of different inhibitors of NF-kappaB ( BAY 11-7082 ) , PI3K ( wortmannin and LY294002 ) but also of P42345 REA ( rapamycin ) , a kinase acting downstream of PI3K / Akt , in LPS-stimulated RAW 264.7 macrophages , analyzing their effects on the LPS-induced gene expression profile using a low density DNA microarray designed to monitor the expression of pro-inflammatory genes . After statistical and hierarchical cluster analyses , we determined five clusters of genes differentially affected by the four inhibitors used . In the fifth cluster corresponding to genes upregulated by LPS and mainly affected by BAY 11-7082 , the gene encoding P14780 REA displayed a particular expression profile , since rapamycin drastically enhanced the LPS-induced upregulation at both the mRNA and protein levels . DB00877 SUB also enhanced the LPS-induced NF-kappaB transactivation as determined by a reporter assay , phosphorylation of the p38 and Erk 1/2 MAPKs , and counteracted Q07869 REA activity . These results suggest that P42345 REA could negatively regulate the effects of LPS on the NF-kappaB and MAPK pathways . We also performed real-time RT-PCR assays on mmp 9 expression using rosiglitazone ( agonist of PPARgamma ) , PD98059 ( inhibitor of Erk 1/2 ) and SB203580 ( inhibitor of p38 ( MAPK ) ) , that were able to counteract the rapamycin mediated overexpression of mmp 9 in response to LPS . Our results suggest a new pathway involving P42345 REA for regulating specifically mmp 9 in LPS-stimulated RAW 264.7 cells .

DB05311 MEN ( DX - 88 ) , a plasma kallikrein inhibitor for the treatment of hereditary angioedema and the prevention of blood loss in on-pump cardiothoracic surgery . BACKGROUND : P03952 REA plays a major role in the contact ( kallikrein-kinin ) cascade producing bradykinin . Bradykinin is a vasodilator , which increases vascular permeability , activates inflammation and produces pain . P03952 REA is also crosslinked to the coagulation system and the complement cascade . OBJECTIVE : DB05311 MEN ( DX - 88 ) is a potent and specific inhibitor of plasma kallikrein . DB05311 MEN is a recombinantly produced and engineered small protein based on the first Kunitz domain of human tissue factor pathway inhibitor . It was identified through phage display technology . METHODS : The search terms ' ecallantide ' , ' DX - 88 ' and ' hereditary angioedema ' were entered into Pubmed / Medline , ClinicalTrials and Google . RESULTS / CONCLUSION : At present , the drug is being studied for two major indications . First , the results for the treatment of hereditary angioedema are promising . Second , a prospective randomised multi-centre trial for the reduction of blood loss during on-pump cardiothoracic surgery will be terminated in October 2008 .

P42345 REA supports long-term self-renewal and suppresses mesoderm and endoderm activities of human embryonic stem cells . Despite the recent identification of the transcriptional regulatory circuitry involving P48431 REA , Q9H9S0 REA , and O75051 REA - 4 , the intracellular signaling networks that control pluripotency of human embryonic stem cells ( hESCs ) remain largely undefined . Here , we demonstrate an essential role for the serine / threonine protein kinase mammalian target of rapamycin ( P42345 REA ) in regulating hESC long-term undifferentiated growth . Inhibition of P42345 REA impairs pluripotency , prevents cell proliferation , and enhances mesoderm and endoderm activities in hESCs . At the molecular level , P42345 REA integrates signals from extrinsic pluripotency-supporting factors and represses the transcriptional activities of a subset of developmental and growth-inhibitory genes , as revealed by genome-wide microarray analyses . Repression of the developmental genes by P42345 REA is necessary for the maintenance of hESC pluripotency . These results uncover a novel signaling mechanism by which P42345 REA controls fate decisions in hESCs . Our findings may contribute to effective strategies for tissue repair and regeneration .

P10275 REA rediscovered : the new biology and targeting the androgen receptor therapeutically . Discoveries over the past decade suggest that castration-resistant prostate cancer ( CRPC ) is sensitive , but not resistant to , further manipulation of the androgen-androgen receptor ( AR ) axis . Several new therapies that target this axis have demonstrated clinical activity . In this article , preclinical and clinical findings occurring in the field of AR-targeted therapies are reviewed . Reviews of scientific and clinical development are divided into those occurring prereceptor ( androgen production and conversion ) and at the level of the receptor ( AR aberrations and therapies targeting AR directly ) . Intracrine androgen production and AR amplification , among others , are among the principal aberrancies driving CRPC growth . Phase III data with abiraterone acetate and phase II data with DB08899 MENMAX DB08899 MEN , along with other similar therapies , confirm for the clinician that the scientific findings related to persistent AR signaling in a castrate milieu can be harnessed to produce significant clinical benefit for patients with the disease . Studies aimed at optimizing the timing of their use and exploring the mechanisms of resistance to these therapies are under way . The clinical success of therapies that directly target androgen synthesis as well as the most common aberrancies of the AR confirm that prostate cancer retains dependence on AR signaling , even in the castrate state .

Differences in hepatotoxicity and gene expression profiles by anti-diabetic Q07869 REA gamma agonists on rat primary hepatocytes and human HepG 2 cells . Agonists of peroxisome proliferator-activated receptor gamma ( PPARgamma ) are a new class of oral drugs designed to treat insulin-resistant diabetes ( i . e . , type 2 diabetes ) . However , troglitazone , the first compound in the class approved by the US Food and Drug Administration ( FDA ) in 1997 was found to be hepatotoxic and was withdrawn from the market after reports of severe liver failure . The mechanism of Q07869 REA gamma agonist-induced hepatotoxicity remains unknown . In this study , we examined the hepatotoxic effects of five Q07869 REA gamma agonists ( ciglitazone , pioglitazone , rosiglitazone , troglitazone , and DB04971 MEN ) on rat primary hepatocytes and human HepG 2 cells . We also compared the gene expression profiles of rat primary hepatocytes after exposure to Q07869 REA gamma agonists by using the Rat Genome Survey Microarray system from Applied Biosystems in order to understand the mechanisms of hepatotoxicities induced by PPARgamma agonists . Consistent with the hepatotoxicity data , our results demonstrate that the gene expression profiles affected by troglitazone and ciglitazone can be clearly distinguished from those by pioglitazone and rosiglitazone . Genes that are differentially expressed between the more toxic troglitazone / ciglitazone group and the less toxic rosiglitazone / pioglitazone group are involved in necrotic , apoptotic , and cell proliferative pathways . The five compounds were also clustered based on a set of molecular descriptors . The clustering based on chemical structural information is in good agreement with the clustering of compounds based on cytotoxicity or gene expression data , indicating a strong relationship between chemical structure and biological endpoints . Our work suggests that microarray analysis together with toxicological observations can be used to rank drugs for hepatotoxicity and to evaluate the safety of new compounds .

Protective role of heme oxygenase 1 in the intestinal tissue injury in hemorrhagic shock in rats . Heme oxygenase ( HO ) 1 is inducible by a variety of oxidative stress and is thought to play an important role in the protection of tissues from oxidative injuries . Because hemorrhagic shock ( HS ) is an oxidative stress that results in tissue injury , we examined in this study the role of P09601 REA induction in intestinal tissue injuries in a rat model of HS . The levels of P09601 REA were significantly increased after HS both at transcriptional and protein levels in mucosal epithelial cells in the duodenum , jejunum , and colon , whereas their expression in the ileum was hardly detectable and not increased at all by the treatment . In contrast , HS-induced mucosal inflammation and apoptotic cell death in the duodenum , jejunum , and colon were far less than those observed in ileum as judged by the levels of expression of P01375 REA , P35228 REA , activated caspase 3 , and Bcl - 2 . Of note , inhibition of HO activity by DB04912 MEN resulted in an aggravation of HS-induced tissue inflammation and apoptotic cell death . These findings indicate that P09601 REA expression in the intestine is regulated in a highly site-specific manner after HS , and that P09601 REA induction plays a fundamental role in protecting mucosal cells of the intestine from oxidative damages induced by HS .

Androgens induce prostate cancer cell proliferation through mammalian target of rapamycin activation and post-transcriptional increases in cyclin D proteins . P10275 REA ( AR ) plays a central role in prostate cancer , with most tumors responding to androgen deprivation therapies , but the molecular basis for this androgen dependence has not been determined . Androgen [ 5alpha - dihydrotestosterone ( DB02901 ) ] stimulation of LNCaP prostate cancer cells , which have constitutive phosphatidylinositol 3 - kinase ( PI3K ) / Akt pathway activation due to P60484 REA loss , caused increased expression of cyclin D1 , D2 , and D3 proteins , retinoblastoma protein hyperphosphorylation , and cell cycle progression . However , cyclin D1 and D2 message levels were unchanged , indicating that the increases in cyclin D proteins were mediated by a post-transcriptional mechanism . This mechanism was identified as mammalian target of rapamycin ( P42345 REA ) activation . DB02901 treatment increased P42345 REA activity as assessed by phosphorylation of the downstream targets P08133 S6 kinase and Q13541 REA , and P42345 REA inhibition with rapamycin blocked the DB02901 - stimulated increase in cyclin D proteins . Significantly , DB02901 stimulation of P42345 REA was not mediated through activation of the PI3K / Akt or mitogen-activated protein kinase / p90 ribosomal S6 kinase pathways and subsequent tuberous sclerosis complex 2 / tuberin inactivation or by suppression of AMP-activated protein kinase . In contrast , P42345 REA activation by DB02901 was dependent on AR-stimulated mRNA synthesis . Oligonucleotide microarrays showed that DB02901 - stimulated rapid increases in multiple genes that regulate nutrient availability , including transporters for amino acids and other organic ions . These results indicate that a critical function of AR in P60484 REA - deficient prostate cancer cells is to support the pathologic activation of P42345 REA , possibly by increasing the expression of proteins that enhance nutrient availability and thereby prevent feedback inhibition of P42345 REA .

P22303 REA antagonist potentiated insulin action in fed but not fasted state . The glucose disposal effect of insulin is doubled in response to a meal . This meal-induced insulin sensitization results from insulin acting on the liver , in the presence of a permissive hepatic parasympathetic feeding signal and elevated hepatic glutathione ( DB00143 ) , to release hepatic insulin-sensitizing substance ( HISS ) , a hormone that acts selectively on skeletal muscle to stimulate insulin-mediated glucose uptake . Blockade of the parasympathetic feeding signal to the liver , either through surgical denervation or atropine-mediated antagonism of hepatic muscarinic receptors , eliminates the HISS response , resulting in HISS-dependent insulin resistance ( HDIR ) and decreasing the response to insulin by approximately 55 % in the fed state . P01308 REA action in Sprague-Dawley rats , as determined with a rapidly sampled , transient euglycemic clamp in response to insulin ( 50 mU / kg ) , is decreased in a dose-dependent manner by atropine . In this study , we have used the ED75 atropine-induced model of HDIR . After a submaximal dose of atropine , potentiation of the remaining parasympathetic effect with the acetylcholinesterase antagonist neostigmine significantly restored postprandial insulin sensitization in a dose-dependent manner with peak effect at 0.1 microg / kg / min . DB01400 MEN reversed the insulin resistance induced by partial fasting and partial muscarinic inhibition ( hepatic DB00143 levels are at fed levels ) , but not that induced by surgical hepatic denervation ( DB00143 normal , no nerve signal ) or 24 - h fasting ( low DB00143 ) . No potentiation of the response to insulin by neostigmine occurred in normal , fed rats . The data suggest the use of either direct or indirectly acting cholinergic agonists for the treatment of impaired postprandial insulin sensitization .

L-tryptophan-mediated enhancement of susceptibility to nonalcoholic fatty liver disease is dependent on the mammalian target of rapamycin . Nonalcoholic fatty liver disease is one of the most common liver diseases . L-tryptophan and its metabolite serotonin are involved in hepatic lipid metabolism and inflammation . However , it is unclear whether L-tryptophan promotes hepatic steatosis . To explore this issue , we examined the role of L-tryptophan in mouse hepatic steatosis by using a high fat and high fructose diet ( HFHFD ) model . L-tryptophan treatment in combination with an HFHFD exacerbated hepatic steatosis , expression of HNE-modified proteins , hydroxyproline content , and serum alanine aminotransaminase levels , whereas L-tryptophan alone did not result in these effects . We also found that L-tryptophan treatment increases serum serotonin levels . The introduction of adenoviral aromatic amino acid decarboxylase , which stimulates the serotonin synthesis from L-tryptophan , aggravated hepatic steatosis induced by the HFHFD . The fatty acid-induced accumulation of lipid was further increased by serotonin treatment in cultured hepatocytes . These results suggest that L-tryptophan increases the sensitivity to hepatic steatosis through serotonin production . Furthermore , L-tryptophan treatment , adenoviral P20711 REA introduction , and serotonin treatment induced phosphorylation of the mammalian target of rapamycin ( P42345 REA ) , and a potent P42345 REA inhibitor rapamycin attenuated hepatocyte lipid accumulation induced by fatty acid with serotonin . These results suggest the importance of P42345 REA activation for the exacerbation of hepatic steatosis . In conclusion , L-tryptophan exacerbates hepatic steatosis induced by HFHFD through serotonin-mediated activation of P42345 REA .

Novel pyrrolyllactone and pyrrolyllactam indolinones as potent cyclin-dependent kinase 2 inhibitors . P12004 REA - dependent kinases ( CDKs ) are essential in the control of cell cycle progression . Inhibition of CDKs represents a new approach for pharmacological intervention in the treatment of a variety of proliferative diseases , especially cancer . Based on the crystal structure of P24941 REA in complex with an imidazole indolinone compound 1 ( DB03428 MEN ) , lead optimization through modeling , synthesis , and SAR studies has led to the discovery of a novel series of pyrrolyllactone and pyrrolyllactam indolinones as potent P24941 REA inhibitors .

Inducible raptor and rictor knockout mouse embryonic fibroblasts . The mammalian Target of DB00877 SUB ( P42345 REA ) kinase functions within two structurally and functionally distinct multiprotein complexes termed P42345 REA complex 1 ( mTORC 1 ) and mTORC 2 . The immunosuppressant and anticancer drug rapamycin is commonly used in basic research as a tool to study P42345 REA signaling . However , rapamycin inhibits only , and only incompletely , mTORC 1 , and no mTORC 2 - specific inhibitor is available . Hence , a full understanding of P42345 REA signaling in vivo , including the function of both complexes , requires genetic inhibition in addition to pharmacological inhibition . Taking advantage of the Cre / LoxP system , we generated inducible knockout mouse embryonic fibroblasts ( MEFs ) deficient for either the mTORC 1 - specific component raptor ( iRapKO ) or the mTORC 2 - specific component rictor ( iRicKO ) . Inducibility of the knockout was important because P42345 REA complex components are essential . Induction of either raptor or rictor knockout eliminated raptor or rictor expression , respectively , and impaired the corresponding P42345 REA signaling branch . The described knockout MEFs are a valuable tool to study the full function of the two P42345 REA complexes individually .

Activation of mTORC 1 in collecting ducts causes hyperkalemia . Mutation of TSC ( encoding tuberous sclerosis complex protein ) and activation of mammalian target of rapamycin ( P42345 REA ) have been implicated in the pathogenesis of several renal diseases , such as diabetic nephropathy and polycystic kidney disease . However , the role of P42345 REA in renal potassium excretion and hyperkalemia is not known . We showed that mice with collecting-duct ( CD ) - specific ablation of Q92574 REA ( CDTsc 1KO ) had greater P42345 REA complex 1 ( mTORC 1 ) activation in the CD and demonstrated features of pseudohypoaldosteronism , including hyperkalemia , hyperaldosteronism , and metabolic acidosis . mTORC 1 activation caused endoplasmic reticulum stress , columnar cell lesions , and dedifferentiation of CD cells with loss of aquaporin - 2 and epithelial-mesenchymal transition-like phenotypes . Of note , mTORC 1 activation also reduced the expression of serum - and glucocorticoid-inducible kinase 1 , a crucial regulator of potassium homeostasis in the kidney , and decreased the expression and / or activity of epithelial sodium channel-α , renal outer medullary potassium channel , and Na ( + ) , K ( + ) - ATPase in the CD , which probably contributed to the aldosterone resistance and hyperkalemia in these mice . DB00877 SUB restored these phenotypic changes . Overall , this study identifies a novel function of mTORC 1 in regulating potassium homeostasis and demonstrates that loss of Q92574 REA and activation of mTORC 1 results in dedifferentiation and dysfunction of the CD and causes hyperkalemia . The CDTsc 1KO mice provide a novel model for hyperkalemia induced exclusively by dysfunction of the CD .

Effects of FK506 on rat thymic epithelial cells ; immunohistochemical study . The effects of FK506 , a new immunosuppressive agent , on the rat thymus were investigated using the immunoperoxidase technique and flow cytofluorometry using monoclonal antibodies . Flow cytometric analysis of the thymus revealed that the proportion of cells labelled positively with OX7 ( P04216 REA ) , OX8 ( CD8 , T cytotoxic / suppressor cells ) and W3 / 25 ( P01730 REA , T helper cells and macrophages ) increased following treatment , with FK506 , 1 mg / kg body weight for 14 days . A marked reduction of the thymic medulla following treatment was clearly demonstrated by staining with OX18 ( MHC class I ) and OX6 ( MHC class II ) . Changes produced by FK506 were also observed in the cortical area of the thymus , being especially marked in the subcapsular area and around the blood vessels by staining with OX6 , P03952 REA - 1 ( alpha-cytokeratin ) , AB - 1040 ( type IV collagen ) , and AB - 1220 ( laminin ) . Eventually FK506 treatment resulted in patchy reduction of OX - 6 , P03952 REA - 1 , AB - 1040 and AB - 1220 positive area in the cortex . This evidence suggests that FK506 may impair the thymic microenvironment and subsequently disturb the thymocyte maturation .

[ ( 11 ) C ] 5 - HTP and microPET are not suitable for pharmacodynamic studies in the rodent brain . The PET tracer [ ( 11 ) C ] 5 - hydroxytryptophan ( [ ( 11 ) C ] 5 - HTP ) , which is converted to [ ( 11 ) C ] 5 - hydroxytryptamine ( [ ( 11 ) C ] 5 - HT ) by aromatic amino acid decarboxylase ( P20711 REA ) , is thought to measure 5 - HT synthesis rates . But can we measure these synthesis rates by kinetic modeling of [ ( 11 ) C ] 5 - HTP in rat ? Male rats were scanned with [ ( 11 ) C ] 5 - HTP ( 60 minutes ) after different treatments . Scans included arterial blood sampling and metabolite analysis . 5 - HT synthesis rates were calculated by a two-tissue compartment model ( 2TCM ) with irreversible tracer trapping or Patlak analysis . DB00190 MEN ( inhibitor peripheral P20711 REA ) dose-dependently increased [ ( 11 ) C ] 5 - HTP brain uptake , but did not influence 2TCM parameters . Therefore , 10 mg / kg carbidopa was applied in all subsequent study groups . These groups included treatment with NSD 1015 ( general P20711 REA inhibitor ) or p-chlorophenylalanine ( PCPA , inhibitor of tryptophan hydroxylase , P17752 REA ) . In addition , the effect of a low-tryptophan ( DB00150 ) diet was investigated . NSD 1015 or DB00150 depletion did not affect any model parameters , but PCPA reduced [ ( 11 ) C ] 5 - HTP uptake , and the k3 . This was unexpected as NSD 1015 directly inhibits the enzyme converting [ ( 11 ) C ] 5 - HTP to [ ( 11 ) C ] 5 - HT , suggesting that trapping of radioactivity does not distinguish between parent tracer and its metabolites . As different results have been acquired in monkeys and humans , [ ( 11 ) C ] 5 - HTP-PET may be suitable for measuring 5 - HT synthesis in primates , but not in rodents .

Involvement of the rapamycin-sensitive pathway in the insulin regulation of muscle protein synthesis in streptozotocin-diabetic rats . P01308 REA resistance in 3 - day streptozotocin ( Q11206 REA ) - treated rats was manifested by the lack of antiproteolytic action of insulin as well as by a reduction of its stimulatory effect on protein synthesis ( - 60 % compared with the control group ) in epitrochlearis muscle incubated in vitro . In the present study , we have investigated the diabetes-associated alterations in the insulin signalling cascade , especially the phosphatidylinositol - 3 kinase ( P19957 REA kinase ) / P08133 S6 kinase ( P08133 ( S6K ) ) pathway , in rat skeletal muscle . LY 294002 , a specific inhibitor of P19957 REA kinase , markedly decreased the basal rate of protein synthesis and completely prevented insulin-mediated stimulation of this process both in control and diabetic rats . Thus , P19957 REA kinase is required for insulin-stimulated muscle protein synthesis in diabetic rats as in the controls . DB00877 SUB , an inhibitor of mammalian target of rapamycin ( P42345 REA ) , had no effect on the basal rate of protein synthesis in either of the experimental groups . In control rats , the stimulatory action of insulin on muscle protein synthesis was diminished by 36 % in the presence of rapamycin , whereas in diabetic muscles this reduction amounted to 68 % . The rapamycin-sensitive pathway makes a relatively greater contribution to the stimulatory effect of insulin on muscle protein synthesis in diabetic rats compared with the controls , due presumably to the preferential decrease in the rapamycin-insensitive component of protein synthesis . Neither basal nor insulin-stimulated P08133 ( S6K ) activity , a signalling element lying downstream of P42345 REA , were modified by Q11206 REA - diabetes .

ROS-mediated autophagy induced by dysregulation of lipid metabolism plays a protective role in colorectal cancer cells treated with gambogic acid . Gambogic acid ( GA ) , the main active component of gamboge resin , has potent antitumor activity both in vivo and in vitro . However , the underlying molecular mechanisms remain unclear . In this study , we found that GA could initiate autophagy in colorectal cancer cells , and inhibition of the autophagy process accelerated the effect of proliferative inhibition and apoptotic cell death induced by GA , implying a protective role of autophagy . Two-dimensional electrophoresis-based proteomics showed that GA treatment altered the expression of multiple proteins involved in redox signaling and lipid metabolism . Functional studies revealed that GA-induced dysregulation of lipid metabolism could activate P09917 REA ( 5 - P28300 REA ) , resulting in intracellular ROS accumulation , followed by inhibition of Akt - P42345 REA signaling and autophagy initiation . Finally , results using a xenograft model suggested ROS-induced autophagy protect against the antitumor effect of GA . Taken together , these data showed new biological activities of GA against colorectal cancer underlying the protective role of ROS-induced autophagy . This study will provide valuable insights for future studies regarding the anticancer mechanisms of GA .

DB00877 SUB antagonizes P01375 REA induction of P19320 REA on endothelial cells by inhibiting mTORC 2 . Recruitment of circulating leukocytes into inflamed tissues depends on adhesion molecules expressed by endothelial cells ( ECs ) . Here we report that rapamycin pretreatment reduced the ability of P01375 REA - treated ECs to capture T cells under conditions of venular flow . This functional change was caused by inhibition of P01375 REA - induced expression of vascular cell adhesion molecule - 1 ( P19320 REA ) and could be mimicked by knockdown of mammalian target of rapamycin ( P42345 REA ) or rictor , but not raptor , implicating mTORC 2 as the target of rapamycin for this effect . Mechanistically , mTORC 2 acts through Akt to repress Raf 1 - Q02750 REA / 2 - P27361 REA / 2 signaling , and inhibition of mTORC 2 consequently results in hyperactivation of P27361 REA / 2 . Increased P27361 REA / 2 activity antagonizes P19320 REA expression by repressing P01375 REA induction of the transcription factor P10914 REA . Preventing activation of P27361 REA / 2 reduced the ability of rapamycin to inhibit P01375 REA - induced P19320 REA expression . In vivo , rapamycin inhibited mTORC 2 activity and potentiated activation of P27361 REA / 2 . These changes correlated with reduced endothelial expression of P01375 REA - induced P19320 REA , which was restored via pharmacological inhibition of P27361 REA / 2 . Functionally , rapamycin reduced infiltration of leukocytes into renal glomeruli , an effect which was partially reversed by inhibition of P27361 REA / 2 . These data demonstrate a novel mechanism by which rapamycin modulates the ability of vascular endothelium to mediate inflammation and identifies endothelial mTORC 2 as a potential therapeutic target .