急性心肌梗死大鼠缺血心肌中差异microRNA的表达谱分析

 目的：筛选急性心肌梗死（AMI）大鼠缺血心肌中差异表达的microRNAs（miRNAs）,预测其靶基因并分析其可能的生物学功能。方法：结扎冠状动脉左前降支建立雄性Wistar大鼠AMI模型,同时检测其心电图和颈总动脉血压变化,并用TTC法测定心肌梗死面积;假手术（sham）组除不结扎冠状动脉左前降支外,其它实验程序与AMI组相同。心肌缺血4 h后取梗死区心肌组织,提取总RNA进行microRNA芯片杂交检测,并用real-time PCR进行验证;生物信息学方法预测差异miRNAs的靶点并分析其生物学功能。结果：心电图、血压检测及病理切片证实AMI模型制备成功。Microarray检测结果表明,与sham组相比,获得11个与急性心肌梗死相关的miRNAs,其中6个miRNAs上调表达,5个miRNAs下调表达;已知3个miRNAs（rno-miR-181c、rno-miR-146b和rno-miR-208）参与了心血管功能的调节,8个miRNAs（rno-miR-672*、rno-miR-743b、rno-miR-128、rno-miR-138-1*、rno-miR-336、rno-miR-138-2*、rno-miR-325-3p和rno-miR-3572）是否与心血管功能有关尚不清楚,可能是心肌梗死相关的新的生物标志物。预测的miRNA靶基因中的一部分亦与心血管功能相关。结论：本研究获得的与AMI相关的差异miRNAs,可能是急性心肌梗死新的生物标志物和潜在的治疗靶点。

MicroRNA profile analysis of ischemic myocardial tissues from rats with acute myocardial infarction

AIM：To identify differentially expressed microRNAs (miRNAs) in ischemic myocardial tissues from the rats with acute myocardial infarction (AMI) by miRNA array technique, and to predict their targets and analyze their functions using bioinformatics. METHODS：The rat models of AMI (n=3) were prepared by ligaturing the left anterior descending coronary artery (LAD) of Wistar rats. Electrocardiogram and blood pressure were detected during the operation, and the myocardial infarct size was measured by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. Ischemic myocardial tissues were isolated from the infarct area 4 h after ischemia. The same procedure in sham group (n=3) was performed except for ligaturing LAD. Total RNA was extracted from ischemic and normal myocardial tissues. miRNA was isolated from total RNA, labeled with Cy3 and hybridized on miRNA array. Real-time PCR was applied to verify the reliability of miRNA array results. The targets of differentially expressed miRNAs were predicted and their functions were analyzed by bioinformatics. RESULTS：Rat model of AMI was successfully prepared and verified by electrocardiogram detection, blood pressure measurement and pathological observation. Compared with sham group, microarray screening showed that total 11 AMI-related miRNAs were selected, including 6 up-regulated and 5 down-regulated. Three of them (rno-miR-181c, rno-miR-146b and rno-miR-208) were related to the cardiovascular functions, while the functions of the others (rno-miR-672*, rno-miR-743b, rno-miR-128, rno-miR-138-1*, rno-miR-336, rno-miR-138-2*, rno-miR-325-3p and rno-miR-3572) were unknown and might be novel AMI-related biomarkers. Parts of the miRNA targets were also related to the cardiovascular functions. CONCLUSION：Differentially expressed miRNAs in AMI rats may serve as novel biomarkers for diagnosis of AMI and potential targets for treatment of AMI.