曲美他嗪通过抑制MicroRNA-423-5p凋亡信号通路保护H2O2引起的心肌缺血再灌注损伤

摘要

目的 探讨曲美他嗪通过microRNA-423-5p(miR-423-5 p)凋亡信号通路对H2O2引起的缺血再灌注损伤保护作用的分子生物学机制.方法 培养小鼠心肌细胞,先以CCK-8和TUNEL检测对比观察H2 O2对心肌细胞活性及凋亡的影响,同时以RT-q-PCR定量检测各组心肌细胞内miR-423-5p表达的情况.再通过质粒转染细胞上调和下调miR-423-5p的表达,观察心肌细胞的活性及凋亡情况.最后在H2O2诱导组中加入不同浓度曲美他嗪,检测miR-423-5p和下游通道的表达以及细胞活性和凋亡情况.结果 以H2O2处理小鼠心肌细胞会上调miR-423-5p的表达,同时降低心肌细胞的活性并引起凋亡(P＜0.01).以质粒转染心肌细胞提高miR-423-5p表达可以降低心肌细胞活性并引发凋亡;降低miR-423-5p表达则可以减轻H2O2引起的细胞活性降低及凋亡效应(p＜0.01).在H2O2处理组中加入曲美他嗪可以下调miR-423-5p的表达,同时减轻心肌细胞活性降低及凋亡比例(p＜0.01).结论 H2O2通过上调心肌细胞中的miR-423-5p表达诱导心肌细胞活性降低并引起凋亡,曲美他嗪通过抑制该miR的表达从而减少H2O2对心肌细胞活性的损伤并减少凋亡.%Objective To investigate the molecular biological mechanism of the protective effect of trimetazidine against H2O2induced apoptosis in ischemic reperfusion injuries.Methods Mouse cardiomyocytes were cultured.The effect of H2O2on cardiomyocytic activity and apoptosis was observed by detection of CCK-8 and TUNEL.Meanwhile,the expression of microRNA-423-5p (miR-423-5p) in myocardiocytes following exposure to H2O2 was determined by using RT-q-PCR analysis.Further,up-or down-regulation of miR-423-5p were carried out through plasmid transfection to cells to observe the cardiomyocytic activity and apoptosis.Finally,expression of miR-423-5p and downstream as well as cardiomyocytic activity and apoptosis in the H2O2 induce group after addition of various concentrations of trimetazidine.Results H2O2 increased the expressions of miR-423-Sp,decreased myocardiocytic activity and induced cell apoptosis (P ＜ 0.01).The plasmid transfection to myocardiocytes increased the expression of microRNA-423-5p that decreased myocardiocytic activity and induced cell apoptosis.However,the decreased expressions of miR-423-5p could reduce the effect of H2O2(P ＜ 0.01).Trimetazidine could decrease the expression of miR-423-5p and relieve the H2O2-induced decrease of myocardiocytic activity and apoptosis (P ＜ 0.01).Conclusion H2O2 induces the myocardial cell activity and apoptosis through up-regulating the expression of microRNA-423-5p.Trimetazidine targets microRNA-423-5p signal pathway to protect cardiomyocytes from H2O2-induced apoptosis in ischemic reperfusion injuries.