Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rode...Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.展开更多
BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progr...BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progression of gastric cancer(GC)is not yet clear.AIM To explore the role and underlying mechanisms of action of RGS4 in GC develop-ment.METHODS The prognostic significance of RGS4 in GC was analyzed using bioinformatics based public databases and verified by immunohistochemistry and quantitative polymerase chain reaction in 90 patients with GC.Function assays were employed to assess the carcinogenic impact of RGS4,and the mechanism of its possible influence was detected by western blot analysis.A nude mouse xenograft model was established to study the effects of RGS4 on GC growth in vitro.RESULTS RGS4 was highly expressed in GC tissues compared with matched adjacent normal tissues.Elevated RGS4 expression was correlated with increased tumor-node-metastasis stage,increased tumor grade as well as poorer overall survival in patients with GC.Cell experiments demonstrated that RGS4 knockdown suppressed GC cell proliferation,migration and invasion.Similarly,xenograft experiments confirmed that RGS4 silencing significantly inhibited tumor growth.Moreover,RGS4 knockdown resulted in reduced phosphorylation levels of focal adhesion kinase,phosphatidyl-inositol-3-kinase,and protein kinase B,decreased vimentin and N-cadherin,and elevated E-cadherin.CONCLUSION High RGS4 expression in GC indicates a worse prognosis and RGS4 is a prognostic marker.RGS4 influences tumor progression via the focal adhesion kinase/phosphatidyl-inositol-3-kinase/protein kinase B pathway and epithelial-mesenchymal transition.展开更多
目的:探讨G蛋白信号蛋白家族的调节因子17(regulator of G protein signaling 17,RGS17)在肾透明细胞癌患者中的临床意义和功能机制。方法:获得癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库中肾透明细胞癌(kidney renal clear c...目的:探讨G蛋白信号蛋白家族的调节因子17(regulator of G protein signaling 17,RGS17)在肾透明细胞癌患者中的临床意义和功能机制。方法:获得癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库中肾透明细胞癌(kidney renal clear cell carcinoma,KIRC)的RNAseq数据和相应的临床信息。利用R软件研究RGS17在KIRC中的表达差异及其与临床特征的关系。使用免疫组化及PCR进行验证。采用Kaplan-Meier(K-M)分析、受试者工作特征(receiver operating characteristic,ROC)曲线、单因素COX分析、多因素COX分析来评估患者的生存和预后,并构建nomogram模型。使用STRING进行RGS17相关基因的PPI网络构建,并进行GO及KEGG富集分析。并采用RT-qPCR、Western blot、CCK-8、Transwell和划痕实验等方法检测RGS17对ACHN细胞增殖迁移及cAMP信号通路的影响。结果:RGS17在KIRC中高表达,且RGS17的高表达与更高的T分期、临床分期、肿瘤转移显著相关。K-M生存分析显示,RGS17上调与KIRC患者总生存期、无疾病进展生存期下降密切相关。ROC曲线表明RGS17能较好的区分正常和KIRC患者,并在预测KIRC患者的预后方面具有一定的准确性。RGS17是KIRC独立预后因素。使用RGS17表达、临床分期、病理分级构建nomogram预后模型能较好预测1、3、5年生存率。RGS17敲低显著抑制ACHN细胞的增殖、迁移和侵袭能力。另外,RGS17敲低能够抑制cAMP信号通路的激活。结论:RGS17在肾透明细胞癌中具有促癌基因的作用,其可能通过激活cAMP信号通路促进肾透明细胞癌的进展。展开更多
Memory deficit,which is often associated with aging and many psychiatric,neurological,and neurodegenerative diseases,has been a challenging issue for treatment.Up till now,all potential drug candidates have failed to ...Memory deficit,which is often associated with aging and many psychiatric,neurological,and neurodegenerative diseases,has been a challenging issue for treatment.Up till now,all potential drug candidates have failed to produce satisfa ctory effects.Therefore,in the search for a solution,we found that a treatment with the gene corresponding to the RGS14414protein in visual area V2,a brain area connected with brain circuits of the ventral stream and the medial temporal lobe,which is crucial for object recognition memory(ORM),can induce enhancement of ORM.In this study,we demonstrated that the same treatment with RGS14414in visual area V2,which is relatively unaffected in neurodegenerative diseases such as Alzheimer s disease,produced longlasting enhancement of ORM in young animals and prevent ORM deficits in rodent models of aging and Alzheimer’s disease.Furthermore,we found that the prevention of memory deficits was mediated through the upregulation of neuronal arbo rization and spine density,as well as an increase in brain-derived neurotrophic factor(BDNF).A knockdown of BDNF gene in RGS14414-treated aging rats and Alzheimer s disease model mice caused complete loss in the upregulation of neuronal structural plasticity and in the prevention of ORM deficits.These findings suggest that BDNF-mediated neuronal structural plasticity in area V2 is crucial in the prevention of memory deficits in RGS14414-treated rodent models of aging and Alzheimer’s disease.Therefore,our findings of RGS14414gene-mediated activation of neuronal circuits in visual area V2 have therapeutic relevance in the treatment of memory deficits.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
AIM: To identify kinases involved in phenotype regulation of vascular endothelial cells(VECs): Proproliferative G-protein signaling 5(RGS5)^(high)(typeⅠ) vs anti-proliferative RGS5^(low)(typeⅡ) VECs.METHODS: Proteom...AIM: To identify kinases involved in phenotype regulation of vascular endothelial cells(VECs): Proproliferative G-protein signaling 5(RGS5)^(high)(typeⅠ) vs anti-proliferative RGS5^(low)(typeⅡ) VECs.METHODS: Proteomic kinase assays were performed to identify the crucial kinase involved in the phenotype regulation of human VECs using typeⅠ VECs, which promotes the proliferation of human vascular smooth muscle cells(VSMCs), and typeⅡ VECs, which suppress the proliferation of human VSMCs. The assays were performed using multiple pairs of typeⅠ and typeⅡ VECs to obtain the least number of candidates. The involvement of the candidate kinases was verified by evaluating the effects of their specific inhibitors on the phenotype regulation of human VECs as well as the expression levels of regulator of RGS5, which is the causative gene for the "typeⅡ to typeⅠ" phenotype conversion of human VECs. RESULTS: p38α mitogen-activated protein kinase(p38α MAPK) was the only kinase that showed distinctive activities between typeⅠ and typeⅡ VECs: p38α MAPK activities were low and high in type-Ⅰand typeⅡ VECs, respectively. We found that an enforced expression of RGS5 indeed lowered p38α MAPK activitiesin typeⅡ VECs. Furthermore, treatments with a p38α MAPK inhibitor nullified the anti-proliferative potential in typeⅡ VECs. Interestingly, MAPK inhibitor treatments enhanced the induction of RGS5 gene. Thus, there is a vicious cycle between "RGS5 induction" and "p38α MAPK inhibition", which can explain the unidirectional process in the stress-induced "typeⅡ to typeⅠ" conversions of human VECs. To understand the upstream signaling of RGS5, which is known as an inhibitory molecule against the G protein-coupled receptor(GPCR)-mediated signaling, we examined the effects of RGS5 overexpression on the signaling events from sphingosine-1-phosphate(S1P) to N-cadherin, because S1 P receptors belong to the GPCR family gene and N-cadherin, one of their downstream effectors, is reportedly involved in the regulation of VEC-VSMC interactions. We found that RGS5 specifically bound with S1P1. Moreover, N-cadherin localization at intercellular junctions in typeⅡ VECs was abolished by "RGS5 overexpression" and "p38α MAPK inhibition".CONCLUSION: p38α MAPK plays crucial roles in "type-Ⅰ vs type-Ⅱ" phenotype regulations of human VECs at the downstream of RGS5.展开更多
AIM: To integrally understand the effects of human vascular endothelial cells(VECs) on the proliferation of vascular smooth muscle cells(VSMCs).METHODS: Various kinds of human VECs of different origins were co-culture...AIM: To integrally understand the effects of human vascular endothelial cells(VECs) on the proliferation of vascular smooth muscle cells(VSMCs).METHODS: Various kinds of human VECs of different origins were co-cultured with human aortic smooth muscle cells, a representative of human VSMCs. To exclude the irrelevant effects due to growth competition between VECs and VSMCs, the proliferation of VECs had previously been arrested via a low-dose gamma rayirradiation. To discriminately analyze the proliferation of VSMCs from that of VECs, the former cells were labeled with red fluorescent dye while the latter cells were labeled with green fluorescent dye before performing coculture experiments. After 4 d, total cells were harvested and subjected to flow cytometric analyses. Decrements in red fluorescence intensities due to proliferationmediated dilutions were measured and mathematically processed using a specific software to quantitatively evaluate the proliferation of VSMCs. The findings obtained from the flow cytometry-based analyses were further validated by microscopic observations. RESULTS: Commercially available primary cultured human VECs exclusively promoted VSMC proliferation regardless of their tissue origins and we termed these pro-proliferative VECs as "typeⅠ". By contrast, VECs freshly generated from human bone marrow-derived endothelial progenitors cells or human pluripotent stem cells including embryonic stem cells and induced pluripotent stem cells suppressed VSMC proliferation and we termed these anti-proliferative VECs as "typeⅡ". Repetitive subcultures as well as oxidative stress induced "type Ⅱ VECs to typeⅠ" conversion along with an induction of Regulator of G-protein signaling 5(RGS5)Compatibly, anti-oxidant treatments suppressed both the subculture-dependent "typeⅡ to typeⅠ" conversion and an induction of RGS5 gene. Immunostaining studies of clinical specimens indicated that RGS5 protein expressions in endothelial layers were low in norma arteries but they were up-regulated in pathologica arteries including hypertension, atherosclerosis and autoimmune vasculitis in a dose-dependent manner Overexpression and knockdown of RGS5 caused that"typeⅡ to typeⅠ" and "typeⅠ to type Ⅱ" phenotype conversions of VECs, respectively. CONCLUSION: Human VECs are categorized into two types: pro-proliferative RGS5^(high) VECs(typeⅠ) and antiproliferative RGS5 ^(low) VECs(typeⅡ).展开更多
G蛋白偶联受体(G protein-coupled receptors,GPCRs)是一类重要的细胞膜表面7次跨膜蛋白受体超家族,可将多种分子外刺激,包括激素、离子、有机分子和光转化为细胞内“效应器”,目前普遍认为GPCR通路是致癌信号传输的关键路径,G蛋白信号...G蛋白偶联受体(G protein-coupled receptors,GPCRs)是一类重要的细胞膜表面7次跨膜蛋白受体超家族,可将多种分子外刺激,包括激素、离子、有机分子和光转化为细胞内“效应器”,目前普遍认为GPCR通路是致癌信号传输的关键路径,G蛋白信号转导调节因子(regulators of G protein signaling,RGS)蛋白家族是调控GPCR通路的关键蛋白。RGS家族的许多分子在恶性肿瘤的发生和发展中具有重要作用,是癌症诊断、治疗和预后的重要靶点。文章综述了近年来RGS家族在肿瘤发生、发展中的重要作用,阐释了RGS在肿瘤微环境中的独特作用,总结了RGS作用于肿瘤的一般规律,最后介绍一些靶向RGS蛋白的治疗癌症的方法。展开更多
【目的】G蛋白信号调控因子(regulators of G-protein signaling,RGS)是G蛋白信号转导通路中的负调控因子,参与多个G蛋白信号通路介导的细胞内过程,目前对于胶孢炭疽菌相关RGS蛋白的生物学功能研究较少。【方法】本研究通过同源重组获得...【目的】G蛋白信号调控因子(regulators of G-protein signaling,RGS)是G蛋白信号转导通路中的负调控因子,参与多个G蛋白信号通路介导的细胞内过程,目前对于胶孢炭疽菌相关RGS蛋白的生物学功能研究较少。【方法】本研究通过同源重组获得CgRGS7基因的敲除突变体,并对其生物学功能进行初步分析。【结果】CgRGS7基因编码620个氨基酸,具有7个跨膜结构域和1个RGS功能域。CgRGS7敲除突变体与野生型菌株相比,表现为分生孢子产量降低且孢子呈多端萌发,附着胞形成率下降以及致病性减弱。【结论】CgRGS7参与调控胶孢炭疽菌分生孢子产量,同时影响芽管的形态发育、附着胞形成及致病性。展开更多
目的：探讨G-蛋白信号转导调节子4（regulator of G-protein signaling-4，RGS4）基因与精神分裂症及临床症状的遗传关联。方法：应用病例对照关联研究设计，采用聚合酶链式反应-限制性片断长度多态性（PCR-RFLP）和DNA测序方法，分析38...目的：探讨G-蛋白信号转导调节子4（regulator of G-protein signaling-4，RGS4）基因与精神分裂症及临床症状的遗传关联。方法：应用病例对照关联研究设计，采用聚合酶链式反应-限制性片断长度多态性（PCR-RFLP）和DNA测序方法，分析386例精神分裂症患者和390例正常对照者中RGS4基因4个单核苷酸多态性（SNP）位点与精神分裂症的关联。并采用阳性和阴性症状量表（PANSS）评估患者的临床症状，进一步分析PANSS因子分与RGS4多态性的关联。结果：RGS4基因的两个多态性位点rs12753561（T〉G，χ^2=8．970，P=0．002）和rs10759（C〉A，χ^2=13．773，F=0．002，P=0．002）与精神分裂症关联，由上述4个SNPs组成的多个单体型如AAGA（χ^2=11．120，P=0．0008，OR=0．52，95％CI=0．36—0．77）和GGGC（χ^2=10．096，P=0．001，OR=1．43，95％CI=1．15—1．79）均与精神分裂症关联。PANSS量表的阴性症状因子分与rs12753561（t=2．216，P=0．029）和rs10759（t=2．543，P=0．012）关联。结论：RGS4基因多态性与精神分裂症及阴性和一般精神病理症状显著关联。展开更多
G蛋白信号调控因子(regulators of G-protein signaling,RGS)是G蛋白的一类负调控因子,在植物病原真菌生长发育及致病过程中起着重要的作用,然而目前还未有关于胶孢炭疽菌(Colletotrichum gloeosporioides)RGS蛋白生物学功能的研究。试...G蛋白信号调控因子(regulators of G-protein signaling,RGS)是G蛋白的一类负调控因子,在植物病原真菌生长发育及致病过程中起着重要的作用,然而目前还未有关于胶孢炭疽菌(Colletotrichum gloeosporioides)RGS蛋白生物学功能的研究。试验利用PCR技术扩增了胶孢炭疽菌的CgRGS4基因,通过同源重组的方法获得CgRGS4基因的敲除突变体,通过表型分析初步确定了CgRGS4的生物学功能。结果表明,CgRGS4编码一个1 224个氨基酸的蛋白,包含RGS、PXA和PX功能域,该基因敲除突变体在营养相对贫瘠的条件下生长较野生型缓慢,对高渗透胁迫的耐受性增强,黑色素减少,对H_2O_2更加敏感,胞外漆酶及过氧化氢酶活性降低以及致病性减弱。由此可见,CgRGS4参与调控胶孢炭疽菌的营养生长、渗透压响应、氧化应激反应和致病性等多个过程。展开更多
基金supported by the National Institutes of Health,Nos.AA025919,AA025919-03S1,and AA025919-05S1(all to RAF).
文摘Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.
基金Supported by the Fundamental Research Program of Shanxi Province,No.202203021222418Research Program of Shanxi Provincial Health Commission,No.2023061+2 种基金Fundamental Research Cooperation Program of Beijing-Tianjin-Hebei Region of Natural Science Foundation of Tianjin,No.22JCZXJC00140Tianjin Major Science and Technology Project,No.21ZXJBSY00110Tianjin Health and Science and Technology Project,No.TJWJ2024ZK001.
文摘BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progression of gastric cancer(GC)is not yet clear.AIM To explore the role and underlying mechanisms of action of RGS4 in GC develop-ment.METHODS The prognostic significance of RGS4 in GC was analyzed using bioinformatics based public databases and verified by immunohistochemistry and quantitative polymerase chain reaction in 90 patients with GC.Function assays were employed to assess the carcinogenic impact of RGS4,and the mechanism of its possible influence was detected by western blot analysis.A nude mouse xenograft model was established to study the effects of RGS4 on GC growth in vitro.RESULTS RGS4 was highly expressed in GC tissues compared with matched adjacent normal tissues.Elevated RGS4 expression was correlated with increased tumor-node-metastasis stage,increased tumor grade as well as poorer overall survival in patients with GC.Cell experiments demonstrated that RGS4 knockdown suppressed GC cell proliferation,migration and invasion.Similarly,xenograft experiments confirmed that RGS4 silencing significantly inhibited tumor growth.Moreover,RGS4 knockdown resulted in reduced phosphorylation levels of focal adhesion kinase,phosphatidyl-inositol-3-kinase,and protein kinase B,decreased vimentin and N-cadherin,and elevated E-cadherin.CONCLUSION High RGS4 expression in GC indicates a worse prognosis and RGS4 is a prognostic marker.RGS4 influences tumor progression via the focal adhesion kinase/phosphatidyl-inositol-3-kinase/protein kinase B pathway and epithelial-mesenchymal transition.
文摘目的:探讨G蛋白信号蛋白家族的调节因子17(regulator of G protein signaling 17,RGS17)在肾透明细胞癌患者中的临床意义和功能机制。方法:获得癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库中肾透明细胞癌(kidney renal clear cell carcinoma,KIRC)的RNAseq数据和相应的临床信息。利用R软件研究RGS17在KIRC中的表达差异及其与临床特征的关系。使用免疫组化及PCR进行验证。采用Kaplan-Meier(K-M)分析、受试者工作特征(receiver operating characteristic,ROC)曲线、单因素COX分析、多因素COX分析来评估患者的生存和预后,并构建nomogram模型。使用STRING进行RGS17相关基因的PPI网络构建,并进行GO及KEGG富集分析。并采用RT-qPCR、Western blot、CCK-8、Transwell和划痕实验等方法检测RGS17对ACHN细胞增殖迁移及cAMP信号通路的影响。结果:RGS17在KIRC中高表达,且RGS17的高表达与更高的T分期、临床分期、肿瘤转移显著相关。K-M生存分析显示,RGS17上调与KIRC患者总生存期、无疾病进展生存期下降密切相关。ROC曲线表明RGS17能较好的区分正常和KIRC患者,并在预测KIRC患者的预后方面具有一定的准确性。RGS17是KIRC独立预后因素。使用RGS17表达、临床分期、病理分级构建nomogram预后模型能较好预测1、3、5年生存率。RGS17敲低显著抑制ACHN细胞的增殖、迁移和侵袭能力。另外,RGS17敲低能够抑制cAMP信号通路的激活。结论:RGS17在肾透明细胞癌中具有促癌基因的作用,其可能通过激活cAMP信号通路促进肾透明细胞癌的进展。
基金supported by grants from the Ministerio de Economia y Competitividad(BFU2013-43458-R)Junta de Andalucia(P12-CTS-1694 and Proyexcel-00422)to ZUK。
文摘Memory deficit,which is often associated with aging and many psychiatric,neurological,and neurodegenerative diseases,has been a challenging issue for treatment.Up till now,all potential drug candidates have failed to produce satisfa ctory effects.Therefore,in the search for a solution,we found that a treatment with the gene corresponding to the RGS14414protein in visual area V2,a brain area connected with brain circuits of the ventral stream and the medial temporal lobe,which is crucial for object recognition memory(ORM),can induce enhancement of ORM.In this study,we demonstrated that the same treatment with RGS14414in visual area V2,which is relatively unaffected in neurodegenerative diseases such as Alzheimer s disease,produced longlasting enhancement of ORM in young animals and prevent ORM deficits in rodent models of aging and Alzheimer’s disease.Furthermore,we found that the prevention of memory deficits was mediated through the upregulation of neuronal arbo rization and spine density,as well as an increase in brain-derived neurotrophic factor(BDNF).A knockdown of BDNF gene in RGS14414-treated aging rats and Alzheimer s disease model mice caused complete loss in the upregulation of neuronal structural plasticity and in the prevention of ORM deficits.These findings suggest that BDNF-mediated neuronal structural plasticity in area V2 is crucial in the prevention of memory deficits in RGS14414-treated rodent models of aging and Alzheimer’s disease.Therefore,our findings of RGS14414gene-mediated activation of neuronal circuits in visual area V2 have therapeutic relevance in the treatment of memory deficits.
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.
基金Supported by A Grant-in-Aid from the Ministry of HealthLabour and Welfare of Japan+2 种基金No.KHD1017by that from JSTPRESTO
文摘AIM: To identify kinases involved in phenotype regulation of vascular endothelial cells(VECs): Proproliferative G-protein signaling 5(RGS5)^(high)(typeⅠ) vs anti-proliferative RGS5^(low)(typeⅡ) VECs.METHODS: Proteomic kinase assays were performed to identify the crucial kinase involved in the phenotype regulation of human VECs using typeⅠ VECs, which promotes the proliferation of human vascular smooth muscle cells(VSMCs), and typeⅡ VECs, which suppress the proliferation of human VSMCs. The assays were performed using multiple pairs of typeⅠ and typeⅡ VECs to obtain the least number of candidates. The involvement of the candidate kinases was verified by evaluating the effects of their specific inhibitors on the phenotype regulation of human VECs as well as the expression levels of regulator of RGS5, which is the causative gene for the "typeⅡ to typeⅠ" phenotype conversion of human VECs. RESULTS: p38α mitogen-activated protein kinase(p38α MAPK) was the only kinase that showed distinctive activities between typeⅠ and typeⅡ VECs: p38α MAPK activities were low and high in type-Ⅰand typeⅡ VECs, respectively. We found that an enforced expression of RGS5 indeed lowered p38α MAPK activitiesin typeⅡ VECs. Furthermore, treatments with a p38α MAPK inhibitor nullified the anti-proliferative potential in typeⅡ VECs. Interestingly, MAPK inhibitor treatments enhanced the induction of RGS5 gene. Thus, there is a vicious cycle between "RGS5 induction" and "p38α MAPK inhibition", which can explain the unidirectional process in the stress-induced "typeⅡ to typeⅠ" conversions of human VECs. To understand the upstream signaling of RGS5, which is known as an inhibitory molecule against the G protein-coupled receptor(GPCR)-mediated signaling, we examined the effects of RGS5 overexpression on the signaling events from sphingosine-1-phosphate(S1P) to N-cadherin, because S1 P receptors belong to the GPCR family gene and N-cadherin, one of their downstream effectors, is reportedly involved in the regulation of VEC-VSMC interactions. We found that RGS5 specifically bound with S1P1. Moreover, N-cadherin localization at intercellular junctions in typeⅡ VECs was abolished by "RGS5 overexpression" and "p38α MAPK inhibition".CONCLUSION: p38α MAPK plays crucial roles in "type-Ⅰ vs type-Ⅱ" phenotype regulations of human VECs at the downstream of RGS5.
基金Supported by A Grant-in-Aid from the Ministry of HealthLabour and Welfare of Japan(KHD1017)a Grant-in-Aid from JST and PRESTO
文摘AIM: To integrally understand the effects of human vascular endothelial cells(VECs) on the proliferation of vascular smooth muscle cells(VSMCs).METHODS: Various kinds of human VECs of different origins were co-cultured with human aortic smooth muscle cells, a representative of human VSMCs. To exclude the irrelevant effects due to growth competition between VECs and VSMCs, the proliferation of VECs had previously been arrested via a low-dose gamma rayirradiation. To discriminately analyze the proliferation of VSMCs from that of VECs, the former cells were labeled with red fluorescent dye while the latter cells were labeled with green fluorescent dye before performing coculture experiments. After 4 d, total cells were harvested and subjected to flow cytometric analyses. Decrements in red fluorescence intensities due to proliferationmediated dilutions were measured and mathematically processed using a specific software to quantitatively evaluate the proliferation of VSMCs. The findings obtained from the flow cytometry-based analyses were further validated by microscopic observations. RESULTS: Commercially available primary cultured human VECs exclusively promoted VSMC proliferation regardless of their tissue origins and we termed these pro-proliferative VECs as "typeⅠ". By contrast, VECs freshly generated from human bone marrow-derived endothelial progenitors cells or human pluripotent stem cells including embryonic stem cells and induced pluripotent stem cells suppressed VSMC proliferation and we termed these anti-proliferative VECs as "typeⅡ". Repetitive subcultures as well as oxidative stress induced "type Ⅱ VECs to typeⅠ" conversion along with an induction of Regulator of G-protein signaling 5(RGS5)Compatibly, anti-oxidant treatments suppressed both the subculture-dependent "typeⅡ to typeⅠ" conversion and an induction of RGS5 gene. Immunostaining studies of clinical specimens indicated that RGS5 protein expressions in endothelial layers were low in norma arteries but they were up-regulated in pathologica arteries including hypertension, atherosclerosis and autoimmune vasculitis in a dose-dependent manner Overexpression and knockdown of RGS5 caused that"typeⅡ to typeⅠ" and "typeⅠ to type Ⅱ" phenotype conversions of VECs, respectively. CONCLUSION: Human VECs are categorized into two types: pro-proliferative RGS5^(high) VECs(typeⅠ) and antiproliferative RGS5 ^(low) VECs(typeⅡ).
文摘G蛋白偶联受体(G protein-coupled receptors,GPCRs)是一类重要的细胞膜表面7次跨膜蛋白受体超家族,可将多种分子外刺激,包括激素、离子、有机分子和光转化为细胞内“效应器”,目前普遍认为GPCR通路是致癌信号传输的关键路径,G蛋白信号转导调节因子(regulators of G protein signaling,RGS)蛋白家族是调控GPCR通路的关键蛋白。RGS家族的许多分子在恶性肿瘤的发生和发展中具有重要作用,是癌症诊断、治疗和预后的重要靶点。文章综述了近年来RGS家族在肿瘤发生、发展中的重要作用,阐释了RGS在肿瘤微环境中的独特作用,总结了RGS作用于肿瘤的一般规律,最后介绍一些靶向RGS蛋白的治疗癌症的方法。
文摘【目的】G蛋白信号调控因子(regulators of G-protein signaling,RGS)是G蛋白信号转导通路中的负调控因子,参与多个G蛋白信号通路介导的细胞内过程,目前对于胶孢炭疽菌相关RGS蛋白的生物学功能研究较少。【方法】本研究通过同源重组获得CgRGS7基因的敲除突变体,并对其生物学功能进行初步分析。【结果】CgRGS7基因编码620个氨基酸,具有7个跨膜结构域和1个RGS功能域。CgRGS7敲除突变体与野生型菌株相比,表现为分生孢子产量降低且孢子呈多端萌发,附着胞形成率下降以及致病性减弱。【结论】CgRGS7参与调控胶孢炭疽菌分生孢子产量,同时影响芽管的形态发育、附着胞形成及致病性。
文摘目的：探讨G-蛋白信号转导调节子4（regulator of G-protein signaling-4，RGS4）基因与精神分裂症及临床症状的遗传关联。方法：应用病例对照关联研究设计，采用聚合酶链式反应-限制性片断长度多态性（PCR-RFLP）和DNA测序方法，分析386例精神分裂症患者和390例正常对照者中RGS4基因4个单核苷酸多态性（SNP）位点与精神分裂症的关联。并采用阳性和阴性症状量表（PANSS）评估患者的临床症状，进一步分析PANSS因子分与RGS4多态性的关联。结果：RGS4基因的两个多态性位点rs12753561（T〉G，χ^2=8．970，P=0．002）和rs10759（C〉A，χ^2=13．773，F=0．002，P=0．002）与精神分裂症关联，由上述4个SNPs组成的多个单体型如AAGA（χ^2=11．120，P=0．0008，OR=0．52，95％CI=0．36—0．77）和GGGC（χ^2=10．096，P=0．001，OR=1．43，95％CI=1．15—1．79）均与精神分裂症关联。PANSS量表的阴性症状因子分与rs12753561（t=2．216，P=0．029）和rs10759（t=2．543，P=0．012）关联。结论：RGS4基因多态性与精神分裂症及阴性和一般精神病理症状显著关联。
