中文摘要：

目的探讨microRNA-29a（miR-29a）对大鼠心肌细胞凋亡的调控作用。方法体外培养新生SD大鼠心肌细胞，合成人miR-29a的拟似物（mimic）。用LipofectamineRNAiMAX转染miR-29a的mimic进入心肌细胞．转染48h后用荧光定量PCR方法检测心肌细胞miR-29a的表达变化，流式细胞仪检测细胞凋亡水平变化，westemblot法检测凋亡相关蛋白Caspase-3和Caspase-9前体的表达变化。结果心肌细胞转染miR-29a的mimic48h后，心肌细胞中miR-29a的表迭水平较对照组明显升高（P〈0．05）；心肌细胞的凋亡水平也明显升高，凋亡相关蛋白Caspase-3和Caspase．9前体的含量则明显下降（P〈0．05）。结论在大鼠心肌细胞中过表达miR-29a能促进心肌细胞凋亡，其机制可能是通过Caspase．3和Caspase-9途径起作用。

英文摘要：

Aim To investigate the role of microRNA-29a （miR-29a） on apoptosis in rat cardiomyocytes. Methods In our study, newborn rats cardiomyocytes was isolated, cells were transfected with miR-29a mimic by lipo- fectamine RNAiMAX, and then real time RT-PCR was used to measure the level of miR-29a, flow cytometry （FCM） was used to detect the cells apoptosis, and western blot was used to detect the protein expressive level of Caspase-3 and Caspase-9. Results MiR-29a mimics could upregulate the level of miR-29a in rat cardiomyocytes after 48h of trans- fecting, accompanied with the increase of cellsapoptosis rate, and descent of the protein level of caspase-3 and caspase-9 in cardiomyocytes when compared to the control group （P 〈 0. 05）. Conclusion Our study demonstrated that the over- expression of miR-29a may regulate cells apoptosis of rat cardiomyocytes, and the mechanisms among it may be concerned with Caspase-3 and Caspase-9 pathway.