OBJECTIVE Takeda G protein-coupled receptor 5(TGR5)is recognized as a promising target for type 2 diabetes and metabolic syndrome;its expression has been demonstrat⁃ed in the brain and is thought to be neuroprotec⁃tiv...OBJECTIVE Takeda G protein-coupled receptor 5(TGR5)is recognized as a promising target for type 2 diabetes and metabolic syndrome;its expression has been demonstrat⁃ed in the brain and is thought to be neuroprotec⁃tive.Here,we hypothesize that dysfunction of central TGR5 may contribute to the pathogene⁃sis of depression.METHODS In well-established chronic social defeat stress(CSDS)and chronic restraint stress(CRS)models of depression,we investigated the functional roles of TGR5 in CA3 pyramidal neurons(PyNs)and underlying mech⁃anisms of the neuronal circuit in depression(for in vivo studies,n=10;for in vitro studies,n=5-10)using fiber photometry;optogenetic,chemoge⁃netic,pharmacological,and molecular profiling techniques;and behavioral tests.RESULTS Both CSDS and CRS most significantly reduced TGR5 expression of hippocampal CA3 PyNs.Genetic overexpression of TGR5 in CA3 PyNs or intra-CA3 infusion of INT-777,a specific agonist,protected against CSDS and CRS,exerting sig⁃nificant antidepressant-like effects that were mediated via CA3 PyN activation.Conversely,genetic knockout or TGR5 knockdown in CA3 facilitated stress-induced depression-like behav⁃iors.Re-expression of TGR5 in CA3 PyNs rather than infusion of INT-777 significantly improved depression-like behaviors in Tgr5 knockout mice exposed to CSDS or CRS.Silencing and stimula⁃tion of CA3 PyNs→somatostatin-GABAergic(gamma-aminobutyric acidergic)neurons of the dorsolateral septum circuit bidirectionally regulat⁃ed depression-like behaviors,and blockade of this circuit abrogated the antidepressant-like effects from TGR5 activation of CA3 PyNs.CON⁃CLUSION TGR5 can regulate depression via CA3 PyNs→somatostatin-GABAergic neurons of dorsolateral septum transmission,suggesting that TGR5 could be a novel target for developing antidepressants.展开更多
OBJECTIVE To identify the mechanisms by which the formyl peptide receptor 2(FPR2)mediates both inflammatory and anti-inflammatory signaling in an agonist-dependent manner.METHODS Cells expressing FPR2 were incubated w...OBJECTIVE To identify the mechanisms by which the formyl peptide receptor 2(FPR2)mediates both inflammatory and anti-inflammatory signaling in an agonist-dependent manner.METHODS Cells expressing FPR2 were incubated with weak agonists,Aβ42 and Ac2-26,before stimulation with a strong agonist,WKYMVm.Calcium mobilization,c AMP inhibition and MAP kinase activation were measured.Intramolecular FRET were determined using FPR2 constructs with an ECFP attached to the C-terminus and a Fl As H binding motif embedded in the first or third intracellular loop(IL1 or IL3,respectively).RESULTS Aβ42 did not induce significant Ca^(2+) mobilization,but positively modulated WKYMVm-induced Ca^(2+) mobilization and c AMP reduction in a dose-variable manner within a narrow range of ligand concentrations.Treating FPR2-expressing cells with Ac2-26,a peptide with anti-inflammatory activity,negatively modulated WKYMVm-induced Ca^(2+) mobilization and c AMP reduction.Intramolecular FRET assay showed that stimulation of the receptor constructs with Aβ42 brought the C-terminal domain closer to IL1 but away from IL3.An opposite conformational change was induced by Ac2-26.The FPR2 conformation induced by Aβ42 corresponded to enhanced ERK phosphorylation and attenuated p38 MAPK phosphorylation,whereas Ac2-26 induced FPR2 conformational change corresponding to elevated p38 MAPK phosphorylation and reduced ERK phosphorylation.CONCLUSION Aβ42 and Ac2-26 induce different conformational changes in FPR2.These findings provide a structural basis for FPR2 mediation of inflammatory vs anti-inflammatory functions and identify a type of receptor modulation that differs from the classic positive and negative allosteric modulation.展开更多
G protein-coupled receptor kinase 2(GRK2),as a key Ser/Thr protein kinase,belong to the member of the G protein-coupled receptor kinase(GRK)family.The C-terminus of GRK2 including a plekstrin homology domain and the N...G protein-coupled receptor kinase 2(GRK2),as a key Ser/Thr protein kinase,belong to the member of the G protein-coupled receptor kinase(GRK)family.The C-terminus of GRK2 including a plekstrin homology domain and the N-terminus of GRK2 including the RGS homology domain with binding sites for several proteins and lipids such as G protein-coupled receptors(GPCRs),G protein,phospholipase C,phosphatidylinositol 4,5-bisphosphate,extracellular signal-regulated kinase,protein kinase A and Gβγ,which can regulate the activity of GRK2.GRK2 can regulate GPCR desensitization and internalization by phosphorylating the GPCR,promoting the affinity of binding to arrestins,and uncoupling the receptors from G proteins,which play an important role in maintaining the balance between the receptors and signal transduction.Previous studies have indicated that cardiac GRK2overexpression can promote the phosphorylation ofβ-adrenergic receptor(βAR)leading toβAR desensitization and internalization,which play a pivotal role in inducing heart failure(HF)-related dysfunction and myocyte death.GRK2,as a regulator of cell function,is overexpression in hypertension.Overexpression GRK2 can inhibit Akt/e NOS signaling pathway and decreased the production and activation of e NOS leading to endothelial dysfunction.Collagen-induced arthritis induces the upregulation of GRK2 expression in fibroblast-like synoviocytes.In this review,we mainly discussed the evidence for the association between GRK2 overexpression and various diseases,which suggests that GRK2 may be an effective drug target for preventing and treating heart failure,hypertension and inflammatory disease.展开更多
G蛋白偶联受体(G-prote in-coup led receptor,GPCR)是与G蛋白有信号连接的一大类受体家族,是人体内最大的膜受体蛋白家族,是一类具有7个跨膜螺旋的跨膜蛋白受体。GPCR的结构特征和在信号传导中的重要作用决定了其可以作为很好的药物靶...G蛋白偶联受体(G-prote in-coup led receptor,GPCR)是与G蛋白有信号连接的一大类受体家族,是人体内最大的膜受体蛋白家族,是一类具有7个跨膜螺旋的跨膜蛋白受体。GPCR的结构特征和在信号传导中的重要作用决定了其可以作为很好的药物靶标。目前世界药物市场上有三分之一的小分子药物是GPCR的激活剂(agon ist)或拮抗剂(antagon ist)。以其为靶点的药物在医药产业中占据显著地位。在当今前50种最畅销的上市药物中,20%属于G蛋白受体相关药物。近来的研究发现,大多数G蛋白偶联受体具有一个很重要的特性,就是具有固有活性(Constitutive ac-tivity),即无激动剂条件受体自发的维持激活并维持下游信号传导通路的活性。固有活性涉及受体、G蛋白及下游信号通路之间的关系。该文就G蛋白偶联受体固有活性概念、研究进展、反相激动剂与固有活性研究、固有活性与新药开发4个方面,进行以下论述。展开更多
G蛋白偶联受体(G protein coupled receptors,GPCR)是目前研究最广泛的药物靶标蛋白.超过30%的已上市药物以GPCR为靶点.这一重要的跨膜蛋白家族及其分子结构和功能一直是各大制药公司和学术界的研究热点.近年来,GPCR X射线衍射晶体学方...G蛋白偶联受体(G protein coupled receptors,GPCR)是目前研究最广泛的药物靶标蛋白.超过30%的已上市药物以GPCR为靶点.这一重要的跨膜蛋白家族及其分子结构和功能一直是各大制药公司和学术界的研究热点.近年来,GPCR X射线衍射晶体学方面取得了重大突破,已有30多个A类GPCR的高分辨率结构得到了解析.这为基于结构的药物设计和GPCR功能研究提供了结构依据,以及新的药物靶点和药物设计策略.利用这些结构,计算机模拟方法也在GPCR的结构和功能研究中得到了广泛应用,并在过去几年中取得了一些突破性的成果.这些研究进展深化了对GPCR的动态结构、配体识别和激活机制等方面的理解.简要回顾近年来对A类GPCR的结构和功能研究方面的最新进展,并特别对计算机辅助药物设计和分子模拟在这方面的应用进行重点讨论.展开更多
OBJECTIVE Aryl hydrocarbon receptor(Ahr)is thought to be a crucial factor that regulates immune responses,which may be involved in the pathogenesis of autoimmune inflammation including rheumatoid arthritis(RA).The res...OBJECTIVE Aryl hydrocarbon receptor(Ahr)is thought to be a crucial factor that regulates immune responses,which may be involved in the pathogenesis of autoimmune inflammation including rheumatoid arthritis(RA).The results of our group in recent years have shown that CP-25,a novel ester derivative of paeoniflorin,has a good effect on improving RA animal models.However,whether the anti-arthritis effect of CP-25 is related to Ahr remains unclear.METHODS CP-25 treatment ameliorated adjuvant-induced arthritis(AA),a mouse model of RA,by inhibiting Ahr-related activities in fibroblasts like synoviocytes(FLS).AA rats were treated with CP-25 or paroxetine from day 17 to 33 after immunization.RESULTS CP-25 alleviated arthritis symptoms and the pathological changes,decreased the expression of Ahr in the synovium and FLS of AA rats.Besides,treatment with CP-25 reduced the proliferation and migration of MH7A caused by Ahr activation.In addition,we also demonstrated that CP-25 down-regulated the co-expression and co-localization of Ahr and G protein-coupled receptor kinase 2(GRK2)in MH7A.CONCLUSION The data presented here demonstrated that CP-25 suppressed FLS dysfunction in rats with AA,which were associated with reduced Ahr activation and the interaction between Ahr and GRK2.展开更多
G protein-coupled receptors(GPCRs)are the most widely targeted class for approved drugs but only a small portion(-15%)of GPCRs are currently targeted.Work in my laboratory has tested the hypothesis that individual cel...G protein-coupled receptors(GPCRs)are the most widely targeted class for approved drugs but only a small portion(-15%)of GPCRs are currently targeted.Work in my laboratory has tested the hypothesis that individual cell types express previously unrecognized GPCRs that regulate cell function and may be novel drug targets.A key focus has been our efforts to define differential expression(DE)of GPCRs on normal cells versus cells from patients with diseases:pulmonary arterial smooth muscle cells/pulmonary arterial hypertension,lung and cardiac fibroblasts/lung and cardiac fibrosis and pancreatic cells/pancreatic ductal adenocarcinoma(PDAC).To test our hypothesis,we have used unbiased(GPCRomic)approaches(Taqman GPCR arrays and RNA-seq),mining of publicly available datasets(the GTEX database for normal tissues and the Cancer Genome Atlas,TCGA)and studies of signaling and functional activity to validate newly detected GPCRs.The GPCRomic studies reveal that most cell types and tissues express>100 different GPCRs with limited prior data for many highly expressed GPCRs,numerous of which are"orphans"(which lack known physiologic agonists).Numerous GPCRs have DE and alter functionin diseased cells.For example,studies of PDAC tumors/cells and pancreatic cancer-associated fibroblasts(PCAFs)identify two GPCRs with high DE,respectively,in PDAC cells compared to normal pancreatic ductal epithelial cells and in PCAFs compared to normal pancreatic Fs/stellate cells.These two GPCRs:(1)are frequently,highly expressed in PDAC tumors compared to normal pancreas and(2)regulate functional activities that influence the malignant phenotype.Overall,the results indicate the utility of unbiased GPCRomic and data-mining approaches to identify previously unrecognized,functional GPCRs that may contribute to human disease and that may be novel,drug gable targets.展开更多
文摘OBJECTIVE Takeda G protein-coupled receptor 5(TGR5)is recognized as a promising target for type 2 diabetes and metabolic syndrome;its expression has been demonstrat⁃ed in the brain and is thought to be neuroprotec⁃tive.Here,we hypothesize that dysfunction of central TGR5 may contribute to the pathogene⁃sis of depression.METHODS In well-established chronic social defeat stress(CSDS)and chronic restraint stress(CRS)models of depression,we investigated the functional roles of TGR5 in CA3 pyramidal neurons(PyNs)and underlying mech⁃anisms of the neuronal circuit in depression(for in vivo studies,n=10;for in vitro studies,n=5-10)using fiber photometry;optogenetic,chemoge⁃netic,pharmacological,and molecular profiling techniques;and behavioral tests.RESULTS Both CSDS and CRS most significantly reduced TGR5 expression of hippocampal CA3 PyNs.Genetic overexpression of TGR5 in CA3 PyNs or intra-CA3 infusion of INT-777,a specific agonist,protected against CSDS and CRS,exerting sig⁃nificant antidepressant-like effects that were mediated via CA3 PyN activation.Conversely,genetic knockout or TGR5 knockdown in CA3 facilitated stress-induced depression-like behav⁃iors.Re-expression of TGR5 in CA3 PyNs rather than infusion of INT-777 significantly improved depression-like behaviors in Tgr5 knockout mice exposed to CSDS or CRS.Silencing and stimula⁃tion of CA3 PyNs→somatostatin-GABAergic(gamma-aminobutyric acidergic)neurons of the dorsolateral septum circuit bidirectionally regulat⁃ed depression-like behaviors,and blockade of this circuit abrogated the antidepressant-like effects from TGR5 activation of CA3 PyNs.CON⁃CLUSION TGR5 can regulate depression via CA3 PyNs→somatostatin-GABAergic neurons of dorsolateral septum transmission,suggesting that TGR5 could be a novel target for developing antidepressants.
基金supported by National Natural Science Foundation of China(31470856 to RDY)the Science and Technology Development Fund of Macao(FDCT 072/2015/A2)the University of Macao(SRG2015-00047-ICMS-QRCM)
文摘OBJECTIVE To identify the mechanisms by which the formyl peptide receptor 2(FPR2)mediates both inflammatory and anti-inflammatory signaling in an agonist-dependent manner.METHODS Cells expressing FPR2 were incubated with weak agonists,Aβ42 and Ac2-26,before stimulation with a strong agonist,WKYMVm.Calcium mobilization,c AMP inhibition and MAP kinase activation were measured.Intramolecular FRET were determined using FPR2 constructs with an ECFP attached to the C-terminus and a Fl As H binding motif embedded in the first or third intracellular loop(IL1 or IL3,respectively).RESULTS Aβ42 did not induce significant Ca^(2+) mobilization,but positively modulated WKYMVm-induced Ca^(2+) mobilization and c AMP reduction in a dose-variable manner within a narrow range of ligand concentrations.Treating FPR2-expressing cells with Ac2-26,a peptide with anti-inflammatory activity,negatively modulated WKYMVm-induced Ca^(2+) mobilization and c AMP reduction.Intramolecular FRET assay showed that stimulation of the receptor constructs with Aβ42 brought the C-terminal domain closer to IL1 but away from IL3.An opposite conformational change was induced by Ac2-26.The FPR2 conformation induced by Aβ42 corresponded to enhanced ERK phosphorylation and attenuated p38 MAPK phosphorylation,whereas Ac2-26 induced FPR2 conformational change corresponding to elevated p38 MAPK phosphorylation and reduced ERK phosphorylation.CONCLUSION Aβ42 and Ac2-26 induce different conformational changes in FPR2.These findings provide a structural basis for FPR2 mediation of inflammatory vs anti-inflammatory functions and identify a type of receptor modulation that differs from the classic positive and negative allosteric modulation.
基金supported by National Natural Science Foundation of China(8150212381330081)+1 种基金Natural Science Foundation of Anhui Province(1308085QH130)Provincial Natural Science Research Foundation of Anhui Province(KJ2014A119)
文摘G protein-coupled receptor kinase 2(GRK2),as a key Ser/Thr protein kinase,belong to the member of the G protein-coupled receptor kinase(GRK)family.The C-terminus of GRK2 including a plekstrin homology domain and the N-terminus of GRK2 including the RGS homology domain with binding sites for several proteins and lipids such as G protein-coupled receptors(GPCRs),G protein,phospholipase C,phosphatidylinositol 4,5-bisphosphate,extracellular signal-regulated kinase,protein kinase A and Gβγ,which can regulate the activity of GRK2.GRK2 can regulate GPCR desensitization and internalization by phosphorylating the GPCR,promoting the affinity of binding to arrestins,and uncoupling the receptors from G proteins,which play an important role in maintaining the balance between the receptors and signal transduction.Previous studies have indicated that cardiac GRK2overexpression can promote the phosphorylation ofβ-adrenergic receptor(βAR)leading toβAR desensitization and internalization,which play a pivotal role in inducing heart failure(HF)-related dysfunction and myocyte death.GRK2,as a regulator of cell function,is overexpression in hypertension.Overexpression GRK2 can inhibit Akt/e NOS signaling pathway and decreased the production and activation of e NOS leading to endothelial dysfunction.Collagen-induced arthritis induces the upregulation of GRK2 expression in fibroblast-like synoviocytes.In this review,we mainly discussed the evidence for the association between GRK2 overexpression and various diseases,which suggests that GRK2 may be an effective drug target for preventing and treating heart failure,hypertension and inflammatory disease.
文摘G蛋白偶联受体(G protein coupled receptors,GPCR)是目前研究最广泛的药物靶标蛋白.超过30%的已上市药物以GPCR为靶点.这一重要的跨膜蛋白家族及其分子结构和功能一直是各大制药公司和学术界的研究热点.近年来,GPCR X射线衍射晶体学方面取得了重大突破,已有30多个A类GPCR的高分辨率结构得到了解析.这为基于结构的药物设计和GPCR功能研究提供了结构依据,以及新的药物靶点和药物设计策略.利用这些结构,计算机模拟方法也在GPCR的结构和功能研究中得到了广泛应用,并在过去几年中取得了一些突破性的成果.这些研究进展深化了对GPCR的动态结构、配体识别和激活机制等方面的理解.简要回顾近年来对A类GPCR的结构和功能研究方面的最新进展,并特别对计算机辅助药物设计和分子模拟在这方面的应用进行重点讨论.
基金National Nature Science Foundation of China(81573443,82173824,81973332)Anhui Province Natural Science Fund(170808J10)+1 种基金Anhui Provincial Natural Science Foundation(2108085MH320)and Collaborative Innovation Project of Key Scientific Research Platform in Anhui Universities(GXXT-2020-065)。
文摘OBJECTIVE Aryl hydrocarbon receptor(Ahr)is thought to be a crucial factor that regulates immune responses,which may be involved in the pathogenesis of autoimmune inflammation including rheumatoid arthritis(RA).The results of our group in recent years have shown that CP-25,a novel ester derivative of paeoniflorin,has a good effect on improving RA animal models.However,whether the anti-arthritis effect of CP-25 is related to Ahr remains unclear.METHODS CP-25 treatment ameliorated adjuvant-induced arthritis(AA),a mouse model of RA,by inhibiting Ahr-related activities in fibroblasts like synoviocytes(FLS).AA rats were treated with CP-25 or paroxetine from day 17 to 33 after immunization.RESULTS CP-25 alleviated arthritis symptoms and the pathological changes,decreased the expression of Ahr in the synovium and FLS of AA rats.Besides,treatment with CP-25 reduced the proliferation and migration of MH7A caused by Ahr activation.In addition,we also demonstrated that CP-25 down-regulated the co-expression and co-localization of Ahr and G protein-coupled receptor kinase 2(GRK2)in MH7A.CONCLUSION The data presented here demonstrated that CP-25 suppressed FLS dysfunction in rats with AA,which were associated with reduced Ahr activation and the interaction between Ahr and GRK2.
基金supported by NIH grants(R21CA202608,R21AG053568)Dept of Defense Grant(W81XWH-14-1-0372)+1 种基金Bristol Myers Squibb,Padres Pedal the Cause PTC2017an ASPET-David Lehr Research Award
文摘G protein-coupled receptors(GPCRs)are the most widely targeted class for approved drugs but only a small portion(-15%)of GPCRs are currently targeted.Work in my laboratory has tested the hypothesis that individual cell types express previously unrecognized GPCRs that regulate cell function and may be novel drug targets.A key focus has been our efforts to define differential expression(DE)of GPCRs on normal cells versus cells from patients with diseases:pulmonary arterial smooth muscle cells/pulmonary arterial hypertension,lung and cardiac fibroblasts/lung and cardiac fibrosis and pancreatic cells/pancreatic ductal adenocarcinoma(PDAC).To test our hypothesis,we have used unbiased(GPCRomic)approaches(Taqman GPCR arrays and RNA-seq),mining of publicly available datasets(the GTEX database for normal tissues and the Cancer Genome Atlas,TCGA)and studies of signaling and functional activity to validate newly detected GPCRs.The GPCRomic studies reveal that most cell types and tissues express>100 different GPCRs with limited prior data for many highly expressed GPCRs,numerous of which are"orphans"(which lack known physiologic agonists).Numerous GPCRs have DE and alter functionin diseased cells.For example,studies of PDAC tumors/cells and pancreatic cancer-associated fibroblasts(PCAFs)identify two GPCRs with high DE,respectively,in PDAC cells compared to normal pancreatic ductal epithelial cells and in PCAFs compared to normal pancreatic Fs/stellate cells.These two GPCRs:(1)are frequently,highly expressed in PDAC tumors compared to normal pancreas and(2)regulate functional activities that influence the malignant phenotype.Overall,the results indicate the utility of unbiased GPCRomic and data-mining approaches to identify previously unrecognized,functional GPCRs that may contribute to human disease and that may be novel,drug gable targets.
