血清和糖皮质激素诱导的蛋白激酶1（SGK1)通过激活NLRP3炎症小体介导急性心肌梗死后心脏损伤的机制研究

项目名称： 血清和糖皮质激素诱导的蛋白激酶1（SGK1)通过激活NLRP3炎症小体介导急性心肌梗死后心脏损伤的机制研究

项目编号： No.81470431

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 医药、卫生

项目作者： 杨敏

作者单位： 中国医学科学院药物研究所

项目金额： 73万元

中文摘要： 近期发现炎症免疫反应的核心炎症小体是促进心血管重塑的重要机制，但是急性心梗后通过激活哪些关键分子活化NLRP3炎症小体进而介导心脏损伤仍不清楚。我们前期研究发现，心梗可激活心脏组织SGK1，敲除SGK1可减少梗死面积及NLRP3基因表达。据此我们假设：SGK1通过激活NLRP3炎症小体，释放大量炎症因子导致心梗后心脏损伤。本申请通过骨髓移植、Bio-plex悬液芯片、体内注射NLRP3干扰载体、流式细胞术结合病理等技术研究骨髓来源的巨噬细胞中SGK1 活化对NLRP3炎症小体及心梗的影响；采用分子克隆、荧光素酶活性检测、ChIP及EMSA等技术探索SGK1调控NLRP3表达的分子机制；进一步检测急性心梗病人SGK1及NLRP3炎症小体表达，并分析与心梗后心肌酶水平的相关性。本研究将阐明心梗激活SGK1调节NLRP3炎症小体介导心脏损伤的分子机制，为寻找和筛选新的药物靶点提供重要的科学依据。

中文关键词： 急性心肌梗死；炎症小体；NLRP3；SGK1

英文摘要： Recently, increasing evidence demonstrates that the inflammasome as central mediators of inflammatory immune response, could play an important role in development of cardiac remodeling. However, which intracellular signals activate the NLRP3 inflammasome contributing to postinfarction inflammatory response and cardiac adverse remodeling remains unclear. Our preliminary studies suggested that SGK1 expression was elevated after myocardial infarction (MI); SGK1-/- mice showed reduced infarct size and improved cardiac function compared with WT mice post-MI. Importantly, RNA-Seq data indicated that deficiency of SGK1 inhibited NLRP3 or IL-1β expression in the infarct myocardium after MI. Thus, we hypothesized that SGK1 might be fundamentally involved in activation of the NLRP3 inflammasome, trigger cytokines production contributing to adverse cardiac remodeling after infarction. The goals of this project are: 1) to determine the critical roles of bone marrow-derived SGK1 in postinfarct inflammatory response leading to cardiac injury; 2) to explore the mechanism by which SGK1 regulates the NLRP3 inflammasome; 3) to elucidate how SGK1 promotes postinfarct injury via the NLRP3 inflammasome. We will use WT and SGK1-/- mice undergoing permanent ligation of the left anterior coronary artery in combining with bone marrow transplant, Bio-plex assay and NLRP3shRNA injection in vivo. Moreover, to evaluate the effect of SGK1 on NLRP3 gene expression on the transcriptional level, the DNA binding activity of transcription factors will be investigated by dual-luciferase reporter assay, CHIP assay and EMSA assy. Furthermore, we will examine the expression levels of SGK1 and NLRP3 in periphery blood monocytes which from AMI patients or healthy people, and will further evaluate the relationship between SGK1 or NLRP3 and myocardial injury biomarkers. The proposed studies will provide new knowledge regarding the molecular mechanisms of how inflammatory response participates the pathogenesis of postinfarct injury, and provide the theoretical and experimental basis for intervention of adverse remodeling after MI.

英文关键词： acute myocardial infarction;inflammasome;NLRP3;SGK1