miRNA-21表达对大鼠心肌梗死交界区MHC-α mRNA的影响

Effect of miR-21 on MHC-α mRNA expression on junctional zone post acute myocardial

目的:观察大鼠心肌梗死后心室重构过程中miR-21的动态表达变化对MHC-αmRNA的影响。方法:建立大鼠急性心肌梗死模型,随机分为心肌梗死14d组、28d组(8只),另设对照组(8只)。提取梗死交界区心肌组织的RNA及miRNA,应用荧光定量PCR法检测miR-21,RT-PCR方法检测MHC-α、MHC-βmRNA的表达。免疫组织化学方法检测MHC-α、MHC-β的蛋白表达。结果:心肌梗死交界区组织中14d组和28d组miR-21的表达逐渐增加。与对照组相比,14d组miR-21的表达增加34%(P<0.01),28d组miR-21的表达增加89%(P<0.01)。MHC-αmRNA表达随着心肌梗死时间延长而逐渐降低。与对照组比较,14d组MHC-αmRNA的表达下降44%(P<0.01),28d组MHC-αmRNA的表达下降68%(P<0.01)。MHC-βmRNA表达随着心肌梗死时间延长而逐渐增加。与对照组比较,14d组MHC-βmRNA的表达增加2.16倍(P<0.01),28d组MHC-αmRNA的表达增加3.62倍(P<0.01)。MHC-α、MHC-βmRNA的蛋白表达情况与其基因表达基本一致。结论:miR-21在大鼠心肌梗死后交界区组织中的表达上调,MHC-α的表达下调,可能与心肌梗死后的心室重构调控有关。

Objective：To detect the effect of miR-21 on MHC-α mRNA expression in myocardium post acute myocardium infarction in rat. Method： Rats underwent left descending coronary ligation or sham surgery. Rats with MI were assigned in two groups （n= 8）. Real-time PCR was used to detect the expressions of miR-21, MHC-α and MHC-α mRNA. MHC-a and MHC-β protein was tested by IHC, in myocardium. Result：The expression level of miR-21 in myocardium was up-regulated in the 14th and 28th day post MI. Compared to sham group, the expression level of miR-21 in myocardium was increased by 34% （P〈0.01） in the 14th day and by 89% （P〈0.01） in the 28th day post MI. The expression levels of MHC-α, MHC-β mRNA were altered in the progress of ventricular remodeling post MI in rat. The expression level of MHC-α mRNA in myocardium was decreased by 44% （P〈0.01） in the 14th day and by 68% （P〈0.01） in the 28th day post MI. The expression level of MHC-β mRNA in myocardium was increased by 2.16 fold （P〈0.01） in the 14th day and by 3. 62 fold （P〈0. 01） in the 28th day post MI. Conclusion：The expression levels of miR-21 and MHC-α were altered in the progress of ventricular remodeling post MI in rat. miR-21 might be involved in ventricular remodeling post MI.