缺血性心律失常相关微小RNA在大鼠心脏的表达变化

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)、IP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.

Expression changes of microRNAs related to ischemic arrhythmia in rat heart

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 made 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 sham-operated 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.Conclusion 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.