摘要
目的探讨microRNA-34a(miR-34a)在大鼠心肌梗死后的心肌细胞凋亡过程中的作用。方法建立大鼠心肌梗死模型,检测缺血区心肌组织miR-34a、bcl-2、bax和cleaved-caspase-3的表达。在体外培养大鼠心肌细胞株H9C2,构建低氧无血清损伤模型(1%O_2,94%N_2,5%CO_2),并将H9C2细胞转染miR-34a inhibitor下调miR-34a水平,观察细胞凋亡情况。同时H9C2细胞转染miR-34a mimics,观察miR-34a对细胞凋亡的影响。荧光实时定量PCR检测miR-34a的表达,Western Blot检测bcl-2、bax和cleaved-caspase-3的表达。结果心肌梗死组大鼠和低氧无血清培养饥饿诱导的H9C2细胞中miR-34a表达均增多,bcl-2/bax比值下降,心肌梗死模型组大鼠cleaved-caspase-3表达增加,差异均有统计学意义(P<0.05);转染miR-34a mimics的H9C2细胞bcl-2/bax比值下降(P<0.05);转染miR-34a inhibitor能抑制低氧无血清损伤所致的心肌细胞bcl-2/bax下降(P<0.05)。结论 miR-34a在大鼠心肌梗死后的心肌细胞中表达增加,可能具有促进心肌细胞凋亡的作用。
Objective To investigate the role of microRNA-34a(miR-34a)in myocyte apoptosis of rats after myocardial infarction.Methods MiR-34a,bcl-2,bax and cleaved-caspase-3in ischemic cardiac tissues were tested after a rat model of myocardial infarction was established.H9C2cell line of rat cardiomyocytes was cultured in serum-free medium and hypoxia environment(1%O2,94%N2,5%CO2).Myocyte apoptosis was tested after transfected with miR-34a inhibitor to down regulate miR-34a or transfected with miR-34a mimics.Real time PCR was preformed to analyze the expression of miR-34a.The expressions of bcl-2,bax and cleaved-caspase-3were detected by western blot.Results The expression of miR-34a increased and bcl-2/bax decreased in both rats with myocardial infarction and H9C2cells cultured in serum-free medium and hypoxia environment(P<0.05).The expression of cleaved-caspase-3was significantly higher in rats with myocardial infarction than without myocardial infarction(P<0.05).Transfection of miR-34a mimics decreased bcl-2/bax of H9C2cells(P<0.05).Transfection of miR-34a inhibitor inhibited down-regulation of bcl-2/bax cultured in serum-free medium and hypoxia environment.Conclusion Increased expression of miR-34a in rat cardiomyocytes after myocardial infarction may promote myocyte apoptosis.
作者
潘嘉林
潘嘉西
石哲伟
王永光
张敏学
PAN Jialin;PAN Jiaxi;SHI Zhewei(Department of Vasculocardiology, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China)
出处
《心电与循环》
2017年第5期312-316,346,共6页
Journal of Electrocardiology and Circulation
基金
浙江省自然科学基金(LY13H020004)
