MiR-34a对人脐静脉内皮细胞端粒酶活性的影响  

Effects of MiR-34a on Telomerase Activity and Endothelial Cell Senescence

作　　者：陈宇[1] 贺淑君[2] 米雪楠[1] 杨淑均 李健[1] 惠汝太 张伟丽[1] 

机构地区：[1]阜外心血管病医院心血管疾病国家重点实验室,北京市100037 [2]北京市海淀区妇幼保健院,北京市100080

出　　处：《中国分子心脏病学杂志》2015年第4期1397-1401,共5页Molecular Cardiology of China

基　　金：阜外心血管病医院院所青年基金(2012-F03)

摘　　要：目的研究miR-34a对脐静脉内皮细胞端粒酶活性及细胞衰老的影响。方法原代培养人脐静脉内皮细胞(Human umbilical vein endothelial cells,HUVECs),通过传代培养,计算细胞群体倍增水平(Population doublings,PDL),得到年轻的内皮细胞(PDL8)及衰老细胞模型(PDL44),检测两组细胞SIRT1、h TERT、c-myc、p53及miR-34a表达水平的差异。并在PDL8细胞中过表达miR-34a,PDL44细胞中抑制miR-34a的表达,q PCR检测以上基因表达水平、TRAP-q PCR法检测端粒酶活性、SA-β-gal法显示细胞衰老状态的变化。结果 SIRT1、h TERT、c-myc基因在PDL44的HUVECs细胞中表达下调,p53及miR-34a表达上调。PDL8 HUVECs过表达miR-34a 48h后,SIRT1和h TERT表达分别下调43%和25%,TRAP-q PCR显示端粒酶活性降低21%,SA-β-gal法染色阳性细胞百分比由5.1%上升至8.7%;PDL44 HUVECs抑制miR-34a的表达,SIRT1和h TERT表达水平分别上调63%和30%,端粒酶活性上升20%,SA-β-gal法染色显示衰老细胞数量未见显著性变化。结论 Mi R-34a可以抑制内皮细胞SIRT1、h TERT基因表达及端粒酶活性,加速细胞衰老;抑制miR-34a可以上调SIRT1及h TERT表达,端粒酶活性升高;因此miR-34a可能通过抑制SIRT1表达和端粒酶活性的共同作用,参与内皮细胞衰老的调节。Objective To study the role of miR-34a in telomerase activity regulation and vascular endothelial cells senescence. Methods Human umbilical vein endothelial cells （HUVECs） were cultured in vitro and population-doubling levels （PDLs） were calculated during passages. PDL8 and PDL44 were respectively identified as young and senescent HUVECs, in which the differential expression of miR-34a, SIRT1, hTERT, p53 and c-myc were detected. MiR-34a mimics and inhibitor were separately transfected into PDL8 and PDL44 HUVECs, and then the telomerase activity, the cell senescence, the expression of SIRT1, hTERT and c-myc were assayed by TRAP-qPCR, SA-β- gal test and qPCR respectively. Results Compared with PDL8 HUVECs, miR-34a was increased by 36% （P=0.011） in PDL44 HUVECs, and the expression of SIRT1, hTERT, c-myc were decreased by 77% （P=0.042）, 46% （P=0.017） and 62% （P=0.034） respectively, p53 was increased by 69% （P=0.003）. Overexpression of miR-34a decreased SIRT1, hTERT and telomerase activity by 43%, 25% and 21% in PDL8 HUVECs. Inhibition of miR-34a in PDL44 HUVECs increased SIRT1, hTERT and telomerase activity by 63%, 30% and 20%. Conclusion Overexpression of miR-34a decreases hTERT expression and telomerase activity, while inhibition of miR-34a increases hTERT expression and telomerase activity, so miR-34a may regulate endothelial ceils senescence through the modulation of SIRT1 expression and telomerase activity corporately.

关 键 词：MIR-34A 人脐静脉内皮细胞 内皮细胞衰老 端粒酶活性 

分 类 号：R543.5[医药卫生—心血管疾病]