循环微囊泡miR-155靶向S1PR1/STAT3通路调节Th17细胞在风湿性心脏病中的作用

Circulating microvesicles-mediated miR-155 involve in regulating a variety of pathophysiological processes in the body. Our previous studies have shown that Th17 cells effectors increased in the cardiac valves and blood of RHD rats. Circulating microvesicles-mediated miRNAs from RHD rats also increased. After interfering Th17 cells with microvesicles from RHD rats in vitro, as a result the S1PR1 protein was downregulated and pSTAT3 protein was upregulated in these Th17 cells.Existing researches have shown S1PR1/STAT3 signal pathway was closely related to Th17 cell differentiation. So we speculate that circulating microvesicles-mediated miR-155 may downregulates S1PR1 genes and activates STAT3 signal pathway, so as to promote Th17 cell differentiation in the development of RHD. In this study, miR-155 mimics and inhibitors will be transfered into microvesicles ,which will be used to intervene the Lewis rats and induce Th17 cells differentiation in vitro. And validation of target genes, lentiviral vector transfection to rats and cells, flow cytometry, western blot will be used in this research to clarify that the role of circulating microvesicles mediated miR-155 targeting S1PR1/STAT3 signal pathway to regulate Th17 cells in rheumatic heart disease,so as to lay new theoretical foundations and intervention targets for the prevention and treatment of RHD.

循环微囊泡中miRNA参与调控机体多种病理生理过程。我们前期研究发现：风湿性心脏病（RHD）大鼠心瓣膜及血液Th17细胞效应因子升高，且循环微囊泡中miR-155表达升高，用RHD大鼠微囊泡干预体外培养的Th17细胞，细胞S1PR1蛋白表达水平下调，而pSTAT3蛋白表达水平上调。已有研究表明S1PR1/STAT3通路与Th17细胞分化密切相关。我们推测，微囊泡中miR-155可能通过下调S1PR1基因，激活STAT3信号，促进Th17细胞分化，参与RHD发生发展。本课题拟将miR-155模拟物或抑制物导入微囊泡中，用其干预Lewis大鼠及体外诱导分化的Th17细胞，并采用靶基因验证、慢病毒载体转染大鼠及细胞、免疫印迹及流式细胞等技术，阐明循环微囊泡中miR-155靶向S1PR1/STAT3通路调节Th17细胞在风湿性心脏病中的作用，为防治RHD提供新的理论依据及干预靶点。

循环微囊泡中miRNA参与调控机体多种病理生理过程。课题组前期研究表明：风湿性心脏病（RHD）大鼠心瓣膜及血液Th17细胞效应因子升高，且循环微囊泡中miR-155表达升高，用RHD大鼠微囊泡干预体外培养的Th17细胞，细胞S1PR1蛋白表达水平下调，而pSTAT3蛋白表达水平上调。已有研究表明S1PR1/STAT3通路与Th17细胞分化密切相关。因此推测，微囊泡中miR-155可能通过下调S1PR1基因，激活STAT3信号，促进Th17细胞分化，参与RHD发生发展。项目主要研究内容：建立RHD大鼠模型，确认该大鼠心脏瓣膜出现炎性损伤及纤维化；通过以腺相关病毒载体干预大鼠miR-155、S1PR1及STAT3的表达，探索miR-155和S1PR1/STAT3信号通路在RHD大鼠瓣膜损伤过程中的作用。经开展研究，本课题组证实了循环外囊泡miR-155参与RHD大鼠瓣膜炎性损伤及异常纤维化，抑制miR-155可减轻心脏瓣膜损伤；miR-155主要通过靶向调控S1PR1/STAT3信号通路，介导Th17细胞释放炎症因子加重心脏瓣膜损伤；S1PR1过表达或抑制STAT3表达也可减轻瓣膜损伤。项目结论：循环外囊泡miR-155主要通过靶向抑制S1PR1，诱导STAT3磷酸化，促进Th17细胞相关炎症因子的释放，参与RHD瓣膜损伤。这为防治RHD提供新的理论依据及干预靶点。