Insufficient sleep has been correlated to many physiological and psychoneurological disorders.Over the years,our understanding of the state of sleep has transcended from an inactive period of rest to a more active sta...Insufficient sleep has been correlated to many physiological and psychoneurological disorders.Over the years,our understanding of the state of sleep has transcended from an inactive period of rest to a more active state involving important cellular and molecular processes.In addition,during sleep,electrophysiological changes also occur in pathways in specific regions of the mammalian central nervous system(CNS).Activity mediated synaptic plasticity in the CNS can lead to long-term and sometimes permanent strengthening and/or weakening synaptic strength affecting neuronal network behaviour.Memory consolidation and learning that take place during sleep cycles,can be affected by changes in synaptic plasticity during sleep disturbances.G-protein coupled receptors(GPCRs),with their versatile structural and functional attributes,can regulate synaptic plasticity in CNS and hence,may be potentially affected in sleep deprived conditions.In this review,we aim to discuss important functional changes that can take place in the CNS during sleep and sleep deprivation and how changes in GPCRs can lead to potential problems with therapeutics with pharmacological interventions.展开更多
Anti-microbial peptides are essential for the intestinal innate immunity that protects the intestinal epithelia from attacks by foreign pathogens. Human β-defensin (HBD) is one of the pivotal anti-microbial peptides ...Anti-microbial peptides are essential for the intestinal innate immunity that protects the intestinal epithelia from attacks by foreign pathogens. Human β-defensin (HBD) is one of the pivotal anti-microbial peptides that are expressed in the colonic epithelia. This study investigated the effect and the signaling mechanism of inducible β-defensin HBD2 by an essential amino acid, isoleucine (Ile) in colonic epithelial cells. Here we examined the expression level of HBD2 on induction of Ile in epithelial cells, and checked this pathway. HBD2 mRNA was induced by co-incubation with IL-1α and Ile in Caco2 cells, but not by Ile alone. An inhibitor of either ERK or Gi, a subunit of G-proteins, reduced the induction of HBD2 mRNA by Ile. The treatment with Ile also increased the intracellular calcium ion concentration, thus suggesting that the GPCR and ERK signaling pathway mediate the effects of Ile. These results indicate that an essential amino acid, Ile, enhances the expression of an inducible β-defensin, namely HBD2, by IL-1α through the activation of GPCRs and ERK signaling pathway. The administration of Ile may therefore represent a possible option to safely treat intestinal inflammation.展开更多
The renal handling of Na^+ balance is a major determinant of the blood pressure(BP) level. The inability of the kidney to excrete the daily load of Na+ represents the primary cause of chronic hypertension. Among the d...The renal handling of Na^+ balance is a major determinant of the blood pressure(BP) level. The inability of the kidney to excrete the daily load of Na+ represents the primary cause of chronic hypertension. Among the different segments that constitute the nephron, those present in the distal part(i.e., the cortical thick ascending limb, the distal convoluted tubule, the connecting and collecting tubules) play a central role in the fine-tuning of renal Na^+ excretion and are the target of many different regulatory processes that modulate Na^+ retention more or less efficiently. G-protein coupled receptors(GPCRs) are crucially involved in this regulation and could represent efficient pharmacological targets to control BP levels. In this review, we describe both classical and novel GPCR-dependent regulatory systems that have been shown to modulate renal Na^+ absorption in the distal nephron. In addition to the multiplicity of the GPCR that regulate Na^+ excretion, this review also highlights the complexity of these different pathways, and the connections between them.展开更多
In the last few years, there have been important new insights into the structural biology of G-protein coupled receptors. It is now known that allosteric binding sites are involved in the affinity and selec- tivity of...In the last few years, there have been important new insights into the structural biology of G-protein coupled receptors. It is now known that allosteric binding sites are involved in the affinity and selec- tivity of ligands for G-protein coupled receptors, and that signaling by these receptors involves both G-protein dependent and independent pathways. The present review outlines the physiological and pharmacological implications of this perspective for the design of new drugs to treat disorders of the central nervous system. Specifically, new possibilities are explored in relation to allosteric and or- thosteric binding sites on dopamine receptors for the treatment of Parkinson＇s disease, and on muscarinic receptors for Alzheimer＇s disease. Future research can seek to identify ligands that can bind to more than one site on the same receptor, or simultaneously bind to two receptors and form a dimer. For example, the design of bivalent drugs that can reach homo/hetero-dimers of D2 dopa- mine receptor holds promise as a relevant therapeutic strategy for Parkinson＇s disease. Regarding the treatment of Alzheimer＇s disease, the design of dualsteric ligands for mono-oligomeric mus- carinic receptors could increase therapeutic effectiveness by generating potent compounds that could activate more than one signaling pathway.展开更多
AIM:To characterize the regeneration-associated stem cell-related phenotype of hepatocyte-derived growth factor receptor(HGFR)-expressing cells in active ulcerative colitis(UC).METHODS:On the whole 38 peripheral blood...AIM:To characterize the regeneration-associated stem cell-related phenotype of hepatocyte-derived growth factor receptor(HGFR)-expressing cells in active ulcerative colitis(UC).METHODS:On the whole 38 peripheral blood samples and 38 colonic biopsy samples from 18 patients with histologically proven active UC and 20 healthy control subjects were collected.After preparing tissue microarrays and blood smears HGFR,caudal type homeobox 2(CDX2),prominin-1(CD133) and Musashi-1conventional and double fluorescent immunolabelings were performed.Immunostained samples were digitalized using high-resolution Mirax Desk instrument,and analyzed with the Mirax TMA Module software.For semiquantitative counting of immunopositive lamina propria(LP) cells 5 fields of view were counted at magnification x 200 in each sample core,then mean ± SD were determined.In case of peripheral blood smears,30 fields of view with 100 μm diameter were evaluated in every sample and the number of immunopositive cells(mean ± SD) was determined.Using 337 nm UVA Laser MicroDissection system at least 5000 subepithelial cells from the lamina propria were collected.Gene expression analysis of HGFR,CDX2,CD133,leucine-rich repeat-containing G-protein coupled receptor 5(Lgr5),Musashi-1 and cytokeratin20(CK20) were performed in both laser-microdisscted samples and blood samples by using real time reverse transcription polymerase chain reaction(RT-PCR).RESULTS:By performing conventional and double fluorescent immunolabelings confirmed by RT-PCR,higher number of HGFR(blood:6.7 ± 1.22 vs 38.5 ±3.18;LP:2.25 ± 0.85 vs 9.22 ± 0.65;P < 0.05),CDX2(blood:0 vs 0.94 ± 0.64;LP:0.75 ± 0.55 vs 2.11± 0.75;P < 0.05),CD133(blood:1.1 ± 0.72 vs 8.3± 1.08;LP:11.1 ± 0.85 vs 26.28 ± 1.71;P < 0.05)and Musashi-1(blood and LP:0 vs scattered) positive cells were detected in blood and lamina propria of UC samples as compared to controls.HGFR/CDX2(blood:0 vs 1± 0.59;LP:0.8 ± 0.69 vs 2.06 ± 0.72,P < 0.05)and Musashi-1/CDX2(blood and LP:0 vs scattered) coexpressions were found in blood and lamina propria of UC samples.HGFR/CD133 and CD133/CDX2 coexpressions appeared only in UC lamina propria samples.CDX2,Lgr5 and Musashi-1 expressions in UC blood samples were not accompanied by CK20 mRNA expression.CONCLUSION:In active UC,a portion of circulating HGFR-expressing cells are committed to the epithelial lineage,and may participate in mucosal regeneration by undergoing mesenchymal-to-epithelial transition.展开更多
Fungal G-protein coupled receptors(GPCRs)play essential roles in sensing environmental cues including host signals.The study of GPCR in mediating fungus-insect interactions is still limited.Here we report the evolutio...Fungal G-protein coupled receptors(GPCRs)play essential roles in sensing environmental cues including host signals.The study of GPCR in mediating fungus-insect interactions is still limited.Here we report the evolution of GPCR genes encoded in the entomopathogenic Metarhizium species and found the expansion of Pth11-like GPCRs in the generalist species with a wide host range.By deletion of ten candidate genes MrGpr1–MrGpr10 selected from the six obtained subfamilies in the generalist M.robertsii,we found that each of them played a varied level of roles in mediating appressorium formation.In particular,deletion of MrGpr8 resulted in the failure of appressorium formation on different substrates and the loss of virulence during topical infection of insects but not during injection assays when compared with the wild-type(WT)strain.Further analysis revealed that disruption of MrGpr8 substantially impaired the nucleus translocation of the mitogen-activated protein kinase(MAPK)Mero-Fus3 but not the MAPK Mero-Slt2 during appressorium formation.We also found that the defect ofΔMrGpr8 could not be rescued with the addition of cyclic AMP for appressorium formation.Relative to the WT,differential expression of the selected genes have also been detected inΔMrGpr8.The results of this study may benefit the understanding of fungus-interactions mediated by GPCRs.展开更多
The G-protein coupled receptors(GPCRs)play fundamental roles in the human biololgy and drug discovery.GPCRs function as signalling molecules that transduce extracellular signals into cells.The signalling transduction ...The G-protein coupled receptors(GPCRs)play fundamental roles in the human biololgy and drug discovery.GPCRs function as signalling molecules that transduce extracellular signals into cells.The signalling transduction is generally triggered by interacting with ligands,including photons,ions,small organic compounds,peptides,proteins and lipids.In this review,we focus on interactions with diffusible ligands such as hormones and neurotransmitters.We discuss three aspects of the complexity of the GPCR-ligand interactions:functional selectivity of ligands,receptor subtype selectivity of ligands and orphan GPCRs.展开更多
Protein to protein interactions leading to homo/heteromerization of receptor is well documented in literature. These interactions leading to dimeric/oligomers formation of receptors are known to modulate their functio...Protein to protein interactions leading to homo/heteromerization of receptor is well documented in literature. These interactions leading to dimeric/oligomers formation of receptors are known to modulate their function, particularly in case of G-protein coupled receptors. The opioid receptor heteromers having changed pharmacological properties than the constituent protomers provides preferences for novel drug targets that could lead to potential analgesicactivity devoid of tolerance and physical dependence. Heterodimerization of opioid receptors appears to generate novel binding properties with improved specificity and lack of side effects. Further the molecules which can interact simultaneously to both the protomers of the heteromer, or to both the binding sites(orthosteric and allosteric) of a receptor protein could be potential therapeutic molecules. This review highlights the recent advancements in exploring the plausible role of heteromerization of opioid receptors in induction of tolerance free antinociception.展开更多
G-protein coupled receptors(GPCRs)compromise the largest membrane protein superfamily which play vital roles in physiological and pathophysiological processes including energy homeostasis.Moreover,they also represent ...G-protein coupled receptors(GPCRs)compromise the largest membrane protein superfamily which play vital roles in physiological and pathophysiological processes including energy homeostasis.Moreover,they also represent the up-to-date most successful drug target.The gut hormone GPCRs,such as glucagon receptor and GLP-1 receptor,have been intensively studied for their roles in metabolism and respective drugs have developed for the treatment of metabolic diseases such as type 2 diabetes(T2D).Along with the advances of biomedical research,more GPCRs have been found to play important roles in the regulation of energy homeostasis from nutrient sensing,appetite control to glucose and fatty acid metabolism with various mechanisms.The investigation of their biological functions will not only improve our understanding of how our body keeps the balance of energy intake and expenditure,but also highlight the possible drug targets for the treatment of metabolic diseases.The present review summarizes GPCRs involved in the energy control with special emphasis on their pathophysiological roles in metabolic diseases and hopefully triggers more intensive and systematic investigations in the field so that a comprehensive network control of energy homeostasis will be revealed,and better drugs will be developed in the foreseeable future.展开更多
Hypothalamic neuropeptides named hypocretin/orexins which were identified in 1998 regulate critical functions such as wakefulness in the central nervous system.These past 20 years had revealed that orexins/receptors s...Hypothalamic neuropeptides named hypocretin/orexins which were identified in 1998 regulate critical functions such as wakefulness in the central nervous system.These past 20 years had revealed that orexins/receptors system was also present in the peripheral nervous system where they participated to the regulation of multiple functions including blood pressure regulation,intestinal motility,hormone secretion,lipolyze and reproduction functions.Associated to these peripheral functions,it was found that orexins and their receptors were involved in various diseases such as acute/chronic inflammation,metabolic syndrome and cancers.The present review suggests that orexins or the orexin neural circuitry represent potential therapeutic targets for the treatment of multiple pathologies related to inflammation including intestinal bowel disease,multiple sclerosis and septic shock,obesity and digestive cancers.展开更多
The dopamine hypothesis of how antipsychotic drugs exert their beneficial effect in psychotic illness has an interesting history that dates back to 1950.This hypothesis is not to be confused with the dopamine hypothes...The dopamine hypothesis of how antipsychotic drugs exert their beneficial effect in psychotic illness has an interesting history that dates back to 1950.This hypothesis is not to be confused with the dopamine hypothesis of schizophrenia;the aim of the latter is to explain the etiology of schizophrenia.The present review does not deal with schizophrenia but,rather,with the historical development of our current understanding of the dopamine-associated actions of the drugs that reduce the symptoms of psychosis.This historical review begins with the serendipitous discovery of chlorpromazine,a drug synthesized around a chemical core that initially served to produce man-made dyes.This molecular core subsequently contributed to the chemistry of antihistamines.It was with the aim of producing a superior antihistamine that chlorpromazine was synthesized;instead,it revolutionized the treatment of psychosis.The first hypothesis of how this drug worked was that it induced hypothermia,a cooling of the body that led to a tranquilization of the mind.The new,at the time,discoveries of the presence of chemical transmitters in the brain soon steered investigations away from a temperature-related hypothesis toward questioning how this drug,and other drugs with similar properties and effects,modulated endogenous neurotransmission.As a result,over the years,researchers from around the world have begun to progressively learn what antipsychotic drugs do in the brain.展开更多
AIMTo investigate the therapeutic potential of tesevatinib （TSV）, a unique multi-kinase inhibitor currently in Phase Ⅱ clinical trials for autosomal dominant polycystic kidney disease （ADPKD）, in well-defined rod...AIMTo investigate the therapeutic potential of tesevatinib （TSV）, a unique multi-kinase inhibitor currently in Phase Ⅱ clinical trials for autosomal dominant polycystic kidney disease （ADPKD）, in well-defined rodent models of autosomal recessive polycystic kidney disease （ARPKD）. METHODSWe administered TSV in daily doses of 7.5 and 15 mg/kg per day by I.P. to the well characterized bpk model of polycystic kidney disease starting at postnatal day（PN） 4 through PN21 to assess efficacy and toxicity in neonatal mice during postnatal development and still undergoing renal maturation. We administered TSV by oral gavage in the same doses to the orthologous PCK model （from PN30 to PN90） to assess effcacy and toxicity in animals where developmental processes are complete. The following parameters were assessed： Body weight, total kidney weight; kidney weight to body weight ratios; and morphometric determination of a cystic index and a measure of hepatic disease. Renal function was assessed by： Serum BUN; creatinine; and a 12 h urinary concentrating ability. Validation of reported targets including the level of angiogenesis and inhibition of angiogenesis （active VEGFR2/KDR） was assessed by Western analysis.RESULTSThis study demonstrates that： （1） in vivo pharmacological inhibition of multiple kinase cascades with TSV reduced phosphorylation of key mediators of cystogenesis： EGFR, ErbB2, c-Src and KDR; and （2） this reduction of kinase activity resulted in signifcant reduction of renal and biliary disease in both bpk and PCK models of ARPKD. The amelioration of disease by TSV was not associated with any apparent toxicity.CONCLUSIONThe data supports the hypothesis that this multi-kinase inhibitor TSV may provide an effective clinical therapy for human ARPKD.展开更多
EMR2 is an EGF-like module containing mucin-like hormone receptor-2 precursor, a G-protein coupled receptor （G-PCR）. Mutation in EMR2 causes complicated disorders like polycystic kidney disease （PKD）. The structur...EMR2 is an EGF-like module containing mucin-like hormone receptor-2 precursor, a G-protein coupled receptor （G-PCR）. Mutation in EMR2 causes complicated disorders like polycystic kidney disease （PKD）. The structure of EMR2 shows that the fifth domain is comprised of EGF-TM7 helices. Functional assignment of EMR2 by support vector machine （SVM） revealed that along with transporter activity, several novel functions are predicted. A twenty amino acid sequence ＂MGGRVFLVFLAFCVWLTLPG＂ acts as the signal peptide responsible for post- translational transport. Eight amino acids are involved in N-glycosylation sites and two cleavage sites are LeuS17 and SerS18 in EMR2. The residue Arg241 is responsible for interaction with glycosaminoglycan and chondroitin sulfate. On the basis of structure, function and ligand binding sites, competitive EMR2 inhibitors designed may decrease the rate of human diseases like Usher＇s syndrome, bilateral frontoparietal polymicrogyria and PKD.展开更多
Target identification is a critical step following the discovery of small molecules that elicit a biological phenotype. G-protein coupled recaptors (GPCRs) are among the most important drug targets for the pharmaceuti...Target identification is a critical step following the discovery of small molecules that elicit a biological phenotype. G-protein coupled recaptors (GPCRs) are among the most important drug targets for the pharmaceutical industry. The present work seeks to provide an in silico model of known GPCR protein fishing technologies in order to rapidly fish out potential drug targets on the basis of amino acid sequences and seven transmembrane regions (TMs) of GPCRs. Some scoring matrices were trained on 22 groups of GPCRs in the GPCRDB database. These models were employed to predict the GPCR proteins in two groups of test sets. On average, the mean correct rate of each TM of 38 GPCRs from two test sets (ST23 and ST24) was found 62% and 57.5%, respectively, using training set 18 (SLD18);the mean hit rate of each TM of 38 GPCRs from ST23 and ST24 was found 68.1% and 64.7%, respectively. Based on the scoring matrices of PreMod, the mean correct rate of each TM of GPCRs from ST23 and ST24 was found 62% and 62.04%, respectively;the mean hit rate of each TM of GPCRs from ST23 and ST24 was found 67.7% and 68.0%, respecttively. The means of GPCRs in ST23 based on SLD18 is close to those based on PreMod;whereas the means of GPCRs in ST24 based on?SLD18 is less than those based on PreMod. Moreover, the accuracy (“2”) and validity (“2 + 1”) rates of prediction all seven TMs of 38 GPCRs by the scoring matrices of PreMod are more than those by SLD18, SLA14 and SLA3;whereas the hit rates (94.74% and 97.37%) by PreMod are less than those of?SLA3 but bigger than those of?SLD18 and SLA14, respectively. This is the reason that we choose PreMod to predict some potential drug targets. 22 GPCR proteins in the sense chain of chromosome 19 constructing validation set were predicted and validated by PreMod whose hit rate is up to 90.91%. Further evaluation is under investigation.展开更多
G protein-coupled receptors(GPCRs)are pivotal in mediating diverse physiological and pathological processes,rendering them promising targets for drug discovery.GPCRs account for about 40%of FDA-approved drugs,represen...G protein-coupled receptors(GPCRs)are pivotal in mediating diverse physiological and pathological processes,rendering them promising targets for drug discovery.GPCRs account for about 40%of FDA-approved drugs,representing the most successful drug targets.However,only approximately 15%of the 800 human GPCRs are targeted by market drugs,leaving numerous opportunities for drug discovery among the remaining receptors.Cell expression systems play crucial roles in the GPCR drug discovery field,including novel target identification,structural and functional characterization,potential ligand screening,signal pathway elucidation,and drug safety evaluation.Here,we discuss the principles,applications,and limitations of widely used cell expression systems in GPCR-targeted drug discovery,GPCR function investigation,signal pathway characterization,and pharmacological property studies.We also propose three strategies for constructing genome-wide pan-GPCR cell libraries,which will provide a powerful platform for GPCR ligand screening,and facilitate the study of GPCR mechanisms and drug safety evaluation,ultimately accelerating the process of GPCR-targeted drug discovery.展开更多
G-protein coupled receptors(GPCRs)are the largest family of druggable targets.In recent years,GPCR structural biology has made great advances,revealing the three-dimensional structures of many GPCRs and their interact...G-protein coupled receptors(GPCRs)are the largest family of druggable targets.In recent years,GPCR structural biology has made great advances,revealing the three-dimensional structures of many GPCRs and their interactions with ligands,proteins,and membrane components,which also have inspired a surge of structure-based drug discovery campaigns.This article provides a comprehensive summary of the currently available structural insights into the allosteric pockets of GPCRs and their regulatory mechanisms governing GPCR conformational changes.Furthermore,this article also presents several structure-inspired studies that utilize both orthosteric and allosteric modulation to discover small molecular modulators targeting GPCRs.The article emphasizes the promising potential of drug discovery targeting GPCR allosteric sites,while acknowledging the challenges arising from the limited structural information regarding the lipids and cholesterols in the membrane.Finally,the article discusses the future prospects of using large-scale or focused compound libraries to discover novel chemotypes,as well as the application of artificial intelligence(AI)in structure-based virtual screening(SBVS)against GPCRs.展开更多
基金Supported by Canadian Institutes of Health Research Grant,No.TGS-1092194-Year Fellowship from the University of British Columbia.
文摘Insufficient sleep has been correlated to many physiological and psychoneurological disorders.Over the years,our understanding of the state of sleep has transcended from an inactive period of rest to a more active state involving important cellular and molecular processes.In addition,during sleep,electrophysiological changes also occur in pathways in specific regions of the mammalian central nervous system(CNS).Activity mediated synaptic plasticity in the CNS can lead to long-term and sometimes permanent strengthening and/or weakening synaptic strength affecting neuronal network behaviour.Memory consolidation and learning that take place during sleep cycles,can be affected by changes in synaptic plasticity during sleep disturbances.G-protein coupled receptors(GPCRs),with their versatile structural and functional attributes,can regulate synaptic plasticity in CNS and hence,may be potentially affected in sleep deprived conditions.In this review,we aim to discuss important functional changes that can take place in the CNS during sleep and sleep deprivation and how changes in GPCRs can lead to potential problems with therapeutics with pharmacological interventions.
文摘Anti-microbial peptides are essential for the intestinal innate immunity that protects the intestinal epithelia from attacks by foreign pathogens. Human β-defensin (HBD) is one of the pivotal anti-microbial peptides that are expressed in the colonic epithelia. This study investigated the effect and the signaling mechanism of inducible β-defensin HBD2 by an essential amino acid, isoleucine (Ile) in colonic epithelial cells. Here we examined the expression level of HBD2 on induction of Ile in epithelial cells, and checked this pathway. HBD2 mRNA was induced by co-incubation with IL-1α and Ile in Caco2 cells, but not by Ile alone. An inhibitor of either ERK or Gi, a subunit of G-proteins, reduced the induction of HBD2 mRNA by Ile. The treatment with Ile also increased the intracellular calcium ion concentration, thus suggesting that the GPCR and ERK signaling pathway mediate the effects of Ile. These results indicate that an essential amino acid, Ile, enhances the expression of an inducible β-defensin, namely HBD2, by IL-1α through the activation of GPCRs and ERK signaling pathway. The administration of Ile may therefore represent a possible option to safely treat intestinal inflammation.
文摘The renal handling of Na^+ balance is a major determinant of the blood pressure(BP) level. The inability of the kidney to excrete the daily load of Na+ represents the primary cause of chronic hypertension. Among the different segments that constitute the nephron, those present in the distal part(i.e., the cortical thick ascending limb, the distal convoluted tubule, the connecting and collecting tubules) play a central role in the fine-tuning of renal Na^+ excretion and are the target of many different regulatory processes that modulate Na^+ retention more or less efficiently. G-protein coupled receptors(GPCRs) are crucially involved in this regulation and could represent efficient pharmacological targets to control BP levels. In this review, we describe both classical and novel GPCR-dependent regulatory systems that have been shown to modulate renal Na^+ absorption in the distal nephron. In addition to the multiplicity of the GPCR that regulate Na^+ excretion, this review also highlights the complexity of these different pathways, and the connections between them.
基金supported by SIP-IPN,CONACYT (CB-168116)FIS/IMSS (FIS/IMSS/PROT/G11-2/1013)
文摘In the last few years, there have been important new insights into the structural biology of G-protein coupled receptors. It is now known that allosteric binding sites are involved in the affinity and selec- tivity of ligands for G-protein coupled receptors, and that signaling by these receptors involves both G-protein dependent and independent pathways. The present review outlines the physiological and pharmacological implications of this perspective for the design of new drugs to treat disorders of the central nervous system. Specifically, new possibilities are explored in relation to allosteric and or- thosteric binding sites on dopamine receptors for the treatment of Parkinson＇s disease, and on muscarinic receptors for Alzheimer＇s disease. Future research can seek to identify ligands that can bind to more than one site on the same receptor, or simultaneously bind to two receptors and form a dimer. For example, the design of bivalent drugs that can reach homo/hetero-dimers of D2 dopa- mine receptor holds promise as a relevant therapeutic strategy for Parkinson＇s disease. Regarding the treatment of Alzheimer＇s disease, the design of dualsteric ligands for mono-oligomeric mus- carinic receptors could increase therapeutic effectiveness by generating potent compounds that could activate more than one signaling pathway.
基金Cell Analysis Laboratory, 2nd Department of Internal Medicine, and the 1st Department of Pathology and Experimental Oncology, Semmelweis University for their technical support
文摘AIM:To characterize the regeneration-associated stem cell-related phenotype of hepatocyte-derived growth factor receptor(HGFR)-expressing cells in active ulcerative colitis(UC).METHODS:On the whole 38 peripheral blood samples and 38 colonic biopsy samples from 18 patients with histologically proven active UC and 20 healthy control subjects were collected.After preparing tissue microarrays and blood smears HGFR,caudal type homeobox 2(CDX2),prominin-1(CD133) and Musashi-1conventional and double fluorescent immunolabelings were performed.Immunostained samples were digitalized using high-resolution Mirax Desk instrument,and analyzed with the Mirax TMA Module software.For semiquantitative counting of immunopositive lamina propria(LP) cells 5 fields of view were counted at magnification x 200 in each sample core,then mean ± SD were determined.In case of peripheral blood smears,30 fields of view with 100 μm diameter were evaluated in every sample and the number of immunopositive cells(mean ± SD) was determined.Using 337 nm UVA Laser MicroDissection system at least 5000 subepithelial cells from the lamina propria were collected.Gene expression analysis of HGFR,CDX2,CD133,leucine-rich repeat-containing G-protein coupled receptor 5(Lgr5),Musashi-1 and cytokeratin20(CK20) were performed in both laser-microdisscted samples and blood samples by using real time reverse transcription polymerase chain reaction(RT-PCR).RESULTS:By performing conventional and double fluorescent immunolabelings confirmed by RT-PCR,higher number of HGFR(blood:6.7 ± 1.22 vs 38.5 ±3.18;LP:2.25 ± 0.85 vs 9.22 ± 0.65;P < 0.05),CDX2(blood:0 vs 0.94 ± 0.64;LP:0.75 ± 0.55 vs 2.11± 0.75;P < 0.05),CD133(blood:1.1 ± 0.72 vs 8.3± 1.08;LP:11.1 ± 0.85 vs 26.28 ± 1.71;P < 0.05)and Musashi-1(blood and LP:0 vs scattered) positive cells were detected in blood and lamina propria of UC samples as compared to controls.HGFR/CDX2(blood:0 vs 1± 0.59;LP:0.8 ± 0.69 vs 2.06 ± 0.72,P < 0.05)and Musashi-1/CDX2(blood and LP:0 vs scattered) coexpressions were found in blood and lamina propria of UC samples.HGFR/CD133 and CD133/CDX2 coexpressions appeared only in UC lamina propria samples.CDX2,Lgr5 and Musashi-1 expressions in UC blood samples were not accompanied by CK20 mRNA expression.CONCLUSION:In active UC,a portion of circulating HGFR-expressing cells are committed to the epithelial lineage,and may participate in mucosal regeneration by undergoing mesenchymal-to-epithelial transition.
基金the National Key Research and Development Programs of China(2017YFD0200400 and 2017YFD0201202)the National Natural Science Foundation of China(31501699).
文摘Fungal G-protein coupled receptors(GPCRs)play essential roles in sensing environmental cues including host signals.The study of GPCR in mediating fungus-insect interactions is still limited.Here we report the evolution of GPCR genes encoded in the entomopathogenic Metarhizium species and found the expansion of Pth11-like GPCRs in the generalist species with a wide host range.By deletion of ten candidate genes MrGpr1–MrGpr10 selected from the six obtained subfamilies in the generalist M.robertsii,we found that each of them played a varied level of roles in mediating appressorium formation.In particular,deletion of MrGpr8 resulted in the failure of appressorium formation on different substrates and the loss of virulence during topical infection of insects but not during injection assays when compared with the wild-type(WT)strain.Further analysis revealed that disruption of MrGpr8 substantially impaired the nucleus translocation of the mitogen-activated protein kinase(MAPK)Mero-Fus3 but not the MAPK Mero-Slt2 during appressorium formation.We also found that the defect ofΔMrGpr8 could not be rescued with the addition of cyclic AMP for appressorium formation.Relative to the WT,differential expression of the selected genes have also been detected inΔMrGpr8.The results of this study may benefit the understanding of fungus-interactions mediated by GPCRs.
基金supported in part bythe National Institutes of Health(GM67168 to Dr.Yong Duan)computing resources at the National Supercomputing Center TeraGrid(MCB100132 to Dr.Ting Wang and MCA06N028 to Dr.Yong Duan)
文摘The G-protein coupled receptors(GPCRs)play fundamental roles in the human biololgy and drug discovery.GPCRs function as signalling molecules that transduce extracellular signals into cells.The signalling transduction is generally triggered by interacting with ligands,including photons,ions,small organic compounds,peptides,proteins and lipids.In this review,we focus on interactions with diffusible ligands such as hormones and neurotransmitters.We discuss three aspects of the complexity of the GPCR-ligand interactions:functional selectivity of ligands,receptor subtype selectivity of ligands and orphan GPCRs.
基金Supported by Council of Scientific and Industrial Research
文摘Protein to protein interactions leading to homo/heteromerization of receptor is well documented in literature. These interactions leading to dimeric/oligomers formation of receptors are known to modulate their function, particularly in case of G-protein coupled receptors. The opioid receptor heteromers having changed pharmacological properties than the constituent protomers provides preferences for novel drug targets that could lead to potential analgesicactivity devoid of tolerance and physical dependence. Heterodimerization of opioid receptors appears to generate novel binding properties with improved specificity and lack of side effects. Further the molecules which can interact simultaneously to both the protomers of the heteromer, or to both the binding sites(orthosteric and allosteric) of a receptor protein could be potential therapeutic molecules. This review highlights the recent advancements in exploring the plausible role of heteromerization of opioid receptors in induction of tolerance free antinociception.
文摘G-protein coupled receptors(GPCRs)compromise the largest membrane protein superfamily which play vital roles in physiological and pathophysiological processes including energy homeostasis.Moreover,they also represent the up-to-date most successful drug target.The gut hormone GPCRs,such as glucagon receptor and GLP-1 receptor,have been intensively studied for their roles in metabolism and respective drugs have developed for the treatment of metabolic diseases such as type 2 diabetes(T2D).Along with the advances of biomedical research,more GPCRs have been found to play important roles in the regulation of energy homeostasis from nutrient sensing,appetite control to glucose and fatty acid metabolism with various mechanisms.The investigation of their biological functions will not only improve our understanding of how our body keeps the balance of energy intake and expenditure,but also highlight the possible drug targets for the treatment of metabolic diseases.The present review summarizes GPCRs involved in the energy control with special emphasis on their pathophysiological roles in metabolic diseases and hopefully triggers more intensive and systematic investigations in the field so that a comprehensive network control of energy homeostasis will be revealed,and better drugs will be developed in the foreseeable future.
基金INSERM U1149/The Inflammation Research Center,Inserm Transfert,The Institut National du Cancer,No.2013-213Ligue Nationale Contre le Cancer,No.R16020HH,GB/MA/CD/EP-12062and AgroParisTech(INRAE and UniversitéParis-Saclay).
文摘Hypothalamic neuropeptides named hypocretin/orexins which were identified in 1998 regulate critical functions such as wakefulness in the central nervous system.These past 20 years had revealed that orexins/receptors system was also present in the peripheral nervous system where they participated to the regulation of multiple functions including blood pressure regulation,intestinal motility,hormone secretion,lipolyze and reproduction functions.Associated to these peripheral functions,it was found that orexins and their receptors were involved in various diseases such as acute/chronic inflammation,metabolic syndrome and cancers.The present review suggests that orexins or the orexin neural circuitry represent potential therapeutic targets for the treatment of multiple pathologies related to inflammation including intestinal bowel disease,multiple sclerosis and septic shock,obesity and digestive cancers.
文摘The dopamine hypothesis of how antipsychotic drugs exert their beneficial effect in psychotic illness has an interesting history that dates back to 1950.This hypothesis is not to be confused with the dopamine hypothesis of schizophrenia;the aim of the latter is to explain the etiology of schizophrenia.The present review does not deal with schizophrenia but,rather,with the historical development of our current understanding of the dopamine-associated actions of the drugs that reduce the symptoms of psychosis.This historical review begins with the serendipitous discovery of chlorpromazine,a drug synthesized around a chemical core that initially served to produce man-made dyes.This molecular core subsequently contributed to the chemistry of antihistamines.It was with the aim of producing a superior antihistamine that chlorpromazine was synthesized;instead,it revolutionized the treatment of psychosis.The first hypothesis of how this drug worked was that it induced hypothermia,a cooling of the body that led to a tranquilization of the mind.The new,at the time,discoveries of the presence of chemical transmitters in the brain soon steered investigations away from a temperature-related hypothesis toward questioning how this drug,and other drugs with similar properties and effects,modulated endogenous neurotransmission.As a result,over the years,researchers from around the world have begun to progressively learn what antipsychotic drugs do in the brain.
基金Supported by The PKD research program is provided by the Children’s Research Institute,the Lillian Goldman Charitable Trust,Ellsworth FamilyChildren’s Foundation of Children’s Hospital and Health System of Wisconsin
文摘AIMTo investigate the therapeutic potential of tesevatinib （TSV）, a unique multi-kinase inhibitor currently in Phase Ⅱ clinical trials for autosomal dominant polycystic kidney disease （ADPKD）, in well-defined rodent models of autosomal recessive polycystic kidney disease （ARPKD）. METHODSWe administered TSV in daily doses of 7.5 and 15 mg/kg per day by I.P. to the well characterized bpk model of polycystic kidney disease starting at postnatal day（PN） 4 through PN21 to assess efficacy and toxicity in neonatal mice during postnatal development and still undergoing renal maturation. We administered TSV by oral gavage in the same doses to the orthologous PCK model （from PN30 to PN90） to assess effcacy and toxicity in animals where developmental processes are complete. The following parameters were assessed： Body weight, total kidney weight; kidney weight to body weight ratios; and morphometric determination of a cystic index and a measure of hepatic disease. Renal function was assessed by： Serum BUN; creatinine; and a 12 h urinary concentrating ability. Validation of reported targets including the level of angiogenesis and inhibition of angiogenesis （active VEGFR2/KDR） was assessed by Western analysis.RESULTSThis study demonstrates that： （1） in vivo pharmacological inhibition of multiple kinase cascades with TSV reduced phosphorylation of key mediators of cystogenesis： EGFR, ErbB2, c-Src and KDR; and （2） this reduction of kinase activity resulted in signifcant reduction of renal and biliary disease in both bpk and PCK models of ARPKD. The amelioration of disease by TSV was not associated with any apparent toxicity.CONCLUSIONThe data supports the hypothesis that this multi-kinase inhibitor TSV may provide an effective clinical therapy for human ARPKD.
基金supported by the project "Establishment of Biomedical Informatics Center at RMRIRMS,Patan" by ICMR (Govt. of India),New Delhi
文摘EMR2 is an EGF-like module containing mucin-like hormone receptor-2 precursor, a G-protein coupled receptor （G-PCR）. Mutation in EMR2 causes complicated disorders like polycystic kidney disease （PKD）. The structure of EMR2 shows that the fifth domain is comprised of EGF-TM7 helices. Functional assignment of EMR2 by support vector machine （SVM） revealed that along with transporter activity, several novel functions are predicted. A twenty amino acid sequence ＂MGGRVFLVFLAFCVWLTLPG＂ acts as the signal peptide responsible for post- translational transport. Eight amino acids are involved in N-glycosylation sites and two cleavage sites are LeuS17 and SerS18 in EMR2. The residue Arg241 is responsible for interaction with glycosaminoglycan and chondroitin sulfate. On the basis of structure, function and ligand binding sites, competitive EMR2 inhibitors designed may decrease the rate of human diseases like Usher＇s syndrome, bilateral frontoparietal polymicrogyria and PKD.
文摘Target identification is a critical step following the discovery of small molecules that elicit a biological phenotype. G-protein coupled recaptors (GPCRs) are among the most important drug targets for the pharmaceutical industry. The present work seeks to provide an in silico model of known GPCR protein fishing technologies in order to rapidly fish out potential drug targets on the basis of amino acid sequences and seven transmembrane regions (TMs) of GPCRs. Some scoring matrices were trained on 22 groups of GPCRs in the GPCRDB database. These models were employed to predict the GPCR proteins in two groups of test sets. On average, the mean correct rate of each TM of 38 GPCRs from two test sets (ST23 and ST24) was found 62% and 57.5%, respectively, using training set 18 (SLD18);the mean hit rate of each TM of 38 GPCRs from ST23 and ST24 was found 68.1% and 64.7%, respectively. Based on the scoring matrices of PreMod, the mean correct rate of each TM of GPCRs from ST23 and ST24 was found 62% and 62.04%, respectively;the mean hit rate of each TM of GPCRs from ST23 and ST24 was found 67.7% and 68.0%, respecttively. The means of GPCRs in ST23 based on SLD18 is close to those based on PreMod;whereas the means of GPCRs in ST24 based on?SLD18 is less than those based on PreMod. Moreover, the accuracy (“2”) and validity (“2 + 1”) rates of prediction all seven TMs of 38 GPCRs by the scoring matrices of PreMod are more than those by SLD18, SLA14 and SLA3;whereas the hit rates (94.74% and 97.37%) by PreMod are less than those of?SLA3 but bigger than those of?SLD18 and SLA14, respectively. This is the reason that we choose PreMod to predict some potential drug targets. 22 GPCR proteins in the sense chain of chromosome 19 constructing validation set were predicted and validated by PreMod whose hit rate is up to 90.91%. Further evaluation is under investigation.
基金supported by introducing the talented person scientific research starts funds subsidization project of Chengdu University of Traditional Chinese Medicine(030040019,030040017,China).
文摘G protein-coupled receptors(GPCRs)are pivotal in mediating diverse physiological and pathological processes,rendering them promising targets for drug discovery.GPCRs account for about 40%of FDA-approved drugs,representing the most successful drug targets.However,only approximately 15%of the 800 human GPCRs are targeted by market drugs,leaving numerous opportunities for drug discovery among the remaining receptors.Cell expression systems play crucial roles in the GPCR drug discovery field,including novel target identification,structural and functional characterization,potential ligand screening,signal pathway elucidation,and drug safety evaluation.Here,we discuss the principles,applications,and limitations of widely used cell expression systems in GPCR-targeted drug discovery,GPCR function investigation,signal pathway characterization,and pharmacological property studies.We also propose three strategies for constructing genome-wide pan-GPCR cell libraries,which will provide a powerful platform for GPCR ligand screening,and facilitate the study of GPCR mechanisms and drug safety evaluation,ultimately accelerating the process of GPCR-targeted drug discovery.
基金This work is supported by Beijing Municipal Science&Technology Commission(Z201100005320012 to N.H.)and Tsinghua University.
文摘G-protein coupled receptors(GPCRs)are the largest family of druggable targets.In recent years,GPCR structural biology has made great advances,revealing the three-dimensional structures of many GPCRs and their interactions with ligands,proteins,and membrane components,which also have inspired a surge of structure-based drug discovery campaigns.This article provides a comprehensive summary of the currently available structural insights into the allosteric pockets of GPCRs and their regulatory mechanisms governing GPCR conformational changes.Furthermore,this article also presents several structure-inspired studies that utilize both orthosteric and allosteric modulation to discover small molecular modulators targeting GPCRs.The article emphasizes the promising potential of drug discovery targeting GPCR allosteric sites,while acknowledging the challenges arising from the limited structural information regarding the lipids and cholesterols in the membrane.Finally,the article discusses the future prospects of using large-scale or focused compound libraries to discover novel chemotypes,as well as the application of artificial intelligence(AI)in structure-based virtual screening(SBVS)against GPCRs.
