自噬对大鼠缺血心肌微血管内皮细胞凋亡的影响

Effect of autophagy on apoptosis of ischemic myocardial microvascular endothelial cells in rats

目的探讨自噬对大鼠缺血心肌微血管内皮细胞(CMECs)凋亡的影响。方法构建24只雄性SD大鼠心肌梗死模型并培养CMECs后,随机均分为三组:QX组为模型对照,QX+雷帕霉素(RAPA)组培养液中加入RAPA,QX+3-甲基腺嘌呤(3-MA)组培养液中加入3-MA处理;另设空白对照组(ZC组,8只)。电镜下观察各组细胞自噬体形成情况,Western blot分析微管相关蛋白1轻链3(LC3)-Ⅱ/Ⅰ比值,流式细胞术检测细胞凋亡。结果与ZC组相比,QX组有自噬体形成,LC3-Ⅱ/Ⅰ比值升高,细胞总凋亡率增加(P<0.05);与QX组相比,QX+RAPA组自噬体数目增多,LC3-Ⅱ/Ⅰ比值升高,细胞总凋亡率减少(P<0.05);与QX组相比,QX+3-MA组自噬体数目减少,LC3-Ⅱ/Ⅰ比值降低,细胞总凋亡率增加(P<0.05)。结论缺血CMECs会发生自噬,细胞凋亡增加;RAPA能够增强缺血CMECs自噬,减少凋亡;3-MA抑制缺血CMECs自噬,进一步增加凋亡。

Objective To investigate the effect of autophagy on the apoptosis of the ischemic myocardial microvascular endothelial cells（CMECs）in rats.Methods The myocardial infarction models were established and the CMECs were cultured in 24 male SD rats,which were equally randomized into three groups of MC（model control）,T1（treated with rapamycin in the medium）,and T2（treated with 3-methyladenine）.Another 8rats were taken as blank controls（group BC）.The formation of autophagic body was observed under electron microscope,the expression of microtubuleassociated protein 1light chain 3（LC3）-Ⅱ/Ⅰ ratio was analyzed by Western blot and the cell apoptosis was detected by flow cytometry.Results Compared to group BC,the LC3-Ⅱ/Ⅰ ratio and cell apoptosis were higher in group MC,which appeared autophagic body formation（P〈0.05）.The number of autophagic body and LC3-Ⅱ/Ⅰratio were increased and the cell apoptosis was decreased in group T1 than those in group MC（P〈0.05）.The number of autophagic body and LC3-Ⅱ/Ⅰ ratio were lower and the cell apoptosis was higher in group T2 than those in group MC（P〈0.05）.Conclusion The autophagy and cell apoptosis are increased in the ischemic CMECs.Rapamycin can enhance the autophagy and reduce the apoptosis of CMECs,while 3-methyladenine can inhibit the autophagy of CMECs and increase the apoptosis.