缺血性心律失常相关微小RNA在大鼠心脏的表达变化

Expression changes of microRNAs related to ischemic arrhythmia in rat heart

目的筛查缺血预适应大鼠心脏微小RNA(microRNA,或miRNA)的表达变化,寻找与缺血性心律失常相关的微小RNA。方法SD大鼠随即分为假手术组和缺血预适应组(IP),每组3只。应用手术套管法建立在体大鼠心肌缺血预适应模型(5min缺血、5min再灌,三个循环)。建模4h后取材提取RNA,应用微小RNA芯片技术检测IP组非缺血再灌注区(a)I、P组缺血再灌注区(b)和假手术组(c)心肌组织小RNA的表达情况。结果同假手术组相比,缺血再灌区心肌有4个miRNA上调,5个miRNA下调;缺血预适应组非缺血再灌区有23个miRNA上调,包括三个肌肉特异表达的miRNA(mir-1、mir-133和mir-206),另有9个miRNA表达下调。结论在心肌缺血预适应过程中,心肌微小RNA的表达发生明显变化,这些微小RNA可能对缺血预适应介导的抗心律失常起重要调节作用,为缺血性心律失常机制研究提供了新思路。

Objective To investigate the expression profile of microRNAs undergoing ischemic preconditioning in rats. Methods SD rats were randomly divided into sham-operated group and ischemic preconditioning（IP） group with 3 rats in each group. Ischemic preconditioning model was wade by 3 cycles of 5min ischemia intermitted with 5min reperfusion. Samples were collected 4hs after operation. The expression profile of microRNAs in ischemic reperfusion area of left ventricle of IP rats, non-ischemic area of IP rats and left ventricle of shamoperated rats was screened using microRNA microarray chip. Results Compared with sham-operated rats, 4 miRNAs in ischemic reperfusion area were upregulated which included the cardiac muscle specific microRNA （miR-1） ,and 5 were downregulated. The expression change was more significant in nonischemic area of IP rats in comparision with sham-operated rats with 23 microRNAs upregulated and 9 downregulated. Condusion The expression profile of microRNA is changed in classical ischemic preconditioned hearts, which ＂implies that those changed microRNAs may play an important role in ischemic preconditioning induced antiarrhythmic effects.