PPARγ对TGFβ/smad信号通路阻遏子c-Ski的上调作用  

PPARγ up-regulates TGFβ/smad signal pathway repressor c-Ski

作　　者：李工博 李军[2] 曾益军[1] 钟丹[1] 吴庚泽[1] 付晓红[1] 何凤田[1] 戴双双[1] 

机构地区：[1]第三军医大学基础部生物化学与分子生物学教研室,重庆400038 [2]第三军医大学西南医院胸心外科,重庆400038

出　　处：《生理学报》2011年第1期62-68,共7页Acta Physiologica Sinica

基　　金：supported by the National Natural Science Foundation of China (No. 81070229);Natural Science Foundation Project of Chongqing Science and Technology Commission;China (No. CSTC 2009BB5139)

摘　　要：本文旨在研究过氧化物酶体增殖物激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)对动脉粥样硬化(atherosclerosis,AS)形成中关键信号通路TGFβ/smad途径的阻遏子c-Ski的调控作用,探讨PPARγ抗AS的分子机制。通过高脂饮食制作大鼠AS模型,检测AS斑块中c-Ski的mRNA及蛋白的表达变化;在体外培养的大鼠血管平滑肌细胞(vascular smooth musclecell,VSMC)中转染重组c-Ski质粒,并观察其对VSMC增殖及胶原分泌影响;采用real-timePCR和Western blot检测PPARγ激动剂和拮抗剂对c-Ski表达的调节,进而利用在线程序NUBIScan及荧光素酶报告基因检测明确PPARγ对c-Ski的调控机理。结果显示:AS大鼠动脉斑块中c-Skim RNA和蛋白表达显著降低;重组c-Ski转染显著抑制大鼠VSMC增殖及胶原分泌;PPARγ激动剂罗格列酮可明显上调大鼠VSMC中c-Ski表达,且这种上调可以被PPARγ拮抗剂GW9662所阻断。生物信息学分析表明c-Ski启动子区有可能的PPARγ结合位点,而罗格列酮也能显著上调转染了c-Ski的报告基因表达。以上结果表明c-Ski具有一定抗AS作用,其可能是PPARγ的又一靶基因,激活PPARγ可上调c-Ski而发挥抗AS作用。TGFβ/smad pathway is recognized as an important signal pathway to promote the pathogenesis of atherosclerosis（AS）.Peroxisome proliferator-activated receptor γ（PPARγ） activation is considered to be important in modulating AS.Herein,we investigated the regulation of PPARγ on c-Ski,the repressor of TGFβ/smad pathway,in rat AS model and cultured vascular smooth muscle cells（VSMCs）.c-Ski mRNA and protein expression were detected by real-time PCR and Western blot,respectively,in vivo and in vitro with treatment of PPARγ agonist rosiglitazone and antagonist GW9662.The proliferation and collagen secretion of VSMCs after c-Ski transfection were investigated.The underlying mechanism was further investigated by online program NUBIScan and luciferase reporter gene analysis.Results showed that both mRNA and protein expressions of c-Ski in the AS lesions was downregulated in vivo,while in cultured VSMCs,c-Ski transfection significantly suppressed the proliferation and collagen secretion of rat VSMCs.Rosiglitazone significantly up-regulated mRNA and protein levels of c-Ski in VSMCs,which could be blocked by GW9662.Online NUBIScan analysis suggested possible PPARγ binding sites in the promoter region of c-Ski.In addition,luciferase activity of c-Ski reporter gene was also increased obviously in the presence of rosiglitazone.These results indicate that c-Ski is one of the newly found target genes of PPARγ and thus involved in the anti-AS effect of PPARγ.

关 键 词：氧化物酶体增殖物激活受体γ c-Ski 动脉粥样硬化 血管平滑肌细胞 

分 类 号：R329[医药卫生—人体解剖和组织胚胎学]