MiR-139-5p通过调控Rho/ROCK信号通路参与高血压心肌重塑

MicroRNA，a class of small RNA Moleculars of 21～23 nucleotides, regulated the expression of target gene post-transcriptionally.The results of previous studies showned that miRNAs involved in the pathophysiological process of hypertensive myocardial remolding though different singal pathway.According to the previous results of our study, it raised intresting that miR-139-5p was aberrant expressed in the myocardium of 2K1C Hypertension model.Meanwhile, we found that miR-139-5p probably control the expression of ROCK2 as a target gene based on bioinformation analysis.Rho/ROCK singal pathway activated the process of cardiomyocytes apopsis by two ways: Caspase-dependent apoptotic pathway and mitochondrial apoptotic pathway regulated by Bcl-2 family. Therefore, our study aimed to reveal the molecular mechanism refers to miR-139-5p regulating Rho /ROCK singal pathway from molecular to cell to protein levels by steps, and then to explain the mechanism of miR-139-5p involved in the pathophysiological process of hypertensive myocardial remolding mediated by apoptosis pathway.The results of our study may provide a therapeutic strategy for the treatment of patients with left ventricular hypertrophy.

MicroRNA是一种大小约为21～23nt的单链小分子RNA，通过转录后调控，精细调节靶基因的表达。已有研究显示miRNAs参与了高血压心肌重塑的多条信号通路。在前期研究的基础上，miR-139-5p因其在心肌重塑动物模型心肌中的显著异常表达引起了我们的关注。生物信息学预测ROCK2可能是miR-139-5p的下游靶基因。激活的Rho /ROCK 信号通路通过Caspase 依赖的凋亡途径及Bcl-2家族调节的线粒体途径促进心肌细胞凋亡。本研究拟从分子-细胞-蛋白水平揭示miR-139-5p作用于Rho /ROCK 信号通路的分子机制，从而探讨miR-139-5p通过介导细胞凋亡信号通路参与高血压心肌重塑的病理生理学机制，为将来高血压心肌重塑的治疗策略提供依据。

MicroRNA是一种大小约为21～23nt的单链小分子RNA，通过转录后调控，精细调节靶基因的表达。已有研究显示miRNAs参与了高血压心肌重塑的多条信号通路，而细胞凋亡可能是引发心肌肥厚转变为病理性心肌重塑的重要诱因。在前期研究的基础上，miR-139因其在“双肾一夹”高血压大鼠心肌重塑动物模型中的显著异常表达引起了我们的关注。本课题通过构建“双肾一夹”高血压大鼠模型，采用Agilent大鼠miRNA芯片G2534A进行模型组及对照组心肌组织miRNA表达分析，发现心肌重塑心肌组织miR-139-5p的表达异常减低，miR-139-3p的表达明显升高，进一步实时荧光定量PCR方法，验证了上述 miRNA芯片的结果。体外实验：低氧诱导原代心肌细胞凋亡模型，发现miR-139-3p在实验组的表达显著上升，而miR-139-5p在实验组的表达水平显著降低，与上述动物模型miRNA芯片的结果相同。分离培养新生wistar大鼠原代心肌细胞，在心肌细胞中转染miR-139-5p模拟物（mimic），采用RT-PCR检测心肌细胞中miR-139-5p的表达，流式细胞术检测细胞的凋亡率。发现过表达miR-139-5p会促进凋亡的发生，可能是通过抑制wnt/β-catenin信号通路，降低了心脏的保护因子bcl-2的水平而发挥作用的。本课题发现miR-139通过介导细胞凋亡信号通路参与高血压心肌重塑的病理过程，可能为将来高血压心肌重塑的治疗策略提供依据。