动脉粥样硬化中PPARγ19978;调c-Ski的机制及作用研究

项目名称： 动脉粥样硬化中PPARγ19978;调c-Ski的机制及作用研究

项目编号： No.81070229

项目类型： 面上项目

立项/批准年度： 2011

项目学科： 轻工业、手工业

项目作者： 李军

作者单位： 中国人民解放军第三军医大学

项目金额： 10万元

中文摘要： 动脉粥样硬化(AS)中，核受体PPARγ27963;化后可显著抑制血管平滑肌细胞（VSMC）增殖及胶原分泌，但具体机制尚待进一步阐明。基于前期研究发现c-Ski能有效抑制VSMC增殖及胶原分泌，而其在AS中表达显著下降，PPARγ27963;化则可显著上调其mRNA及蛋白水平表达，本项目通过报告基因检测、Super EMSA及ChIP实验明确了PPARγ23545;c-Ski基因5'调控区特异位点-864 ～ -852 bp的结合及对c-Ski从转录水平的调控，即证实c-Ski是PPARγ30340;又一靶基因。进而借助细胞增殖、胶原分泌及c-Ski过表达和RNAi等实验，证实PPARγ27963;化后可通过上调c-Ski显著抑制TGF-β35825;导的VSMC增殖及胶原分泌。此外，文献报道TGF-β22312;AS中具有促进和抑制VSMC增殖的双向作用，我们进一步研究发现c-Ski的存在是维持TGF-β25233;制VSMC增殖的关键因素之一；c-Ski表达水平的降低将促使TGF-β23545;VSMC增殖的作用从抑制转为促进。以上研究结果不仅为阐明PPARγ25239;AS的机制提供新的实验及理论依据，而且为基于c-Ski 的AS临床治疗提供了新的策略。

中文关键词： c-Ski；PPARγ65307;动脉粥样硬化；血管平滑肌细胞；表达调控

英文摘要： In the pathological courses of atherosclerosis, activation of peroxisome proliferators activated receptors γPPARγan significantly inhibit the proliferation of vascular smooth muscle cell (VSMC) and the secretion of collagen, but the mechanism of which need to be elucidated. It is reported that TGFβmad3 is one of important signaling in the development of AS. Our previous study has found that: (1) the level of c-Ski, one of the co-repressor of TGFβmad3 signal pathway, decreased markedly in the plaque of rat artery when compared with that of normal rat artery; (2) reconbinant c-Ski siganificantly inhibited the proliferation of rat VSMC and the secretion of collagen; (3) activation of PPARγgnaificantly up-regulated both mRNA and protein levels of c-Ski. Based on these resutls, in the present study,we confirmed the direct binding of PPARγo the 5'specific sequence of c-Ski(-864 ～ -852 bp) by reporter gene assay, Super EMSA and ChIP, which indicated that c-Ski is a new target gene of PPARγFurtherly, in vitro experiments, it was verified that the inhibitory effects of PPARγn VSMC proliferation and collagen secretion were large partly mediated by upregulaiton of c-Ski. In addtion, we also domonstrated that c-Ski dictated TGFβnhibitory effect on VSMC proliferation in vitro.This study may provid new experimental evidence for illustration of the anti-AS effect of PPARγnd further investigation for the theraputic strategy of AS targeted on PPARγ-Ski.

英文关键词： c-Ski；PPARγ65307;atherosclerosis；VSMC；gene expression regulation