【摘要】 目的 探讨miR-126在大鼠心肌缺血再灌注(I/R)早期的表达及抗凋亡作用。方法 48只SD大鼠随机分为假手术(Sham)、I/R 2 h、I/R 4 h、I/R 6 h组,每组12只大鼠,比较各组缺血区心肌细胞凋亡蛋白水平及miR-126表达水平。构建重组腺病毒rAAV9-ZsGreen-pre-miR-126载体,24只SD大鼠随机分为:①I/R组:大鼠转染空白病毒后I/R 2 h;②I/R+miR-126组:大鼠转染rAAV9-ZsGreen-premiR-126后I/R 2 h,再次比较各组缺血区心肌细胞凋亡蛋白水平。结果 与Sham组相比,I/R 2 h、4 h、6 h组大鼠心肌缺血区miR-126表达进行性降低(P<0.05),非缺血区miR-126表达进行性升高(P<0.05);心肌凋亡蛋白BAX及CASPASE-3表达水平升高(P<0.05),抗凋亡蛋白BCL-2表达水平降低(P<0.05)。与I/R组相比,I/R+miR-126干预组心肌凋亡蛋白BAX及CASPASE-3表达水平明显减少,抗凋亡蛋白BCL-2表达水平增加(P<0.05)。结论 在I/R早期大鼠心肌缺血区miR-126表达随再灌注时间延长进行性下降,并伴随心肌细胞凋亡进展;过表达miR-126可减少I/R导致的心肌细胞凋亡,发挥保护心功能的作用。更多还原

【Abstract】 Objective To investigate the expression of microRNA-126(miR-126) and its protective effects in rat myocardium during early phase of ischemia-reperfusion.Methods 48 SD rats were randomly divided into Sham group(control group),I/R 2 h group,I/R 4 h group,I/R 6 h group(n=12).To compare the expression level of miR-126 and level of cell apoptosis between Sham group and the different I/R time point groups.rAAV9-ZsGreen-pre-miR-126 was successfully constructed and 24 SD rats were divided into two groups randomly(n=12):(1)I/R group:rats were treated with I/R after transfected with rAAV9-ZsGreen by coronary injection.(2)I/R+miR-126 group:rats were dealt with I/R after transfected with rAAV9-ZsGreen-pre-miR-126 by coronary injection.To compare again the expression level of miR-126 and level of cell apoptosis in the two groups.Results MiR-126 was down-regulated in the ischemic area after I/R compared with the Sham group at 2 h,4 h and 6 h,but it was up-regulated in the non-ischemic area(P<0.05).The level of CASPASE-3 and BAX was increased in the I/R group than the Sham group at 2 h,4 h and 6 h after I/R,but the level of BCL-2 was decreased when compared with the Sham group.After tranfected with rAAV9-ZsGreen-pre-miR-126,the level of CASPASE-3 and BAX were decreased in I/R+ miR-126 group by comparing with the I/R group,while the level of BCL-2 was increased when compared with the I/R group.Conclusion The expression of miR-126 was downregulated and cell apoptosis was increased in ischemic area at the early phase of I/R.Over-expression of miR-126 can inhibit cell apoptosis and protect cardiac function.更多还原