MicroRNA靶向Rac1与糖尿病心肌病心肌肥大的关系

MicroRNAs regulate negatively the expression of protein-coding genes through translational inhibition and RNA decay. Recently, microRNAs have been implicated in a wide range of biological processes, including cardiovascular development and pathophysiology and to be the potent therapeutic approach. However,the role of microRNAs in the cardiac hypertrophy in diabetes cardiomyopathy is still poorly understood. Our early experiments suggest that the expression of seventeen microRNAs changed significantly in cardiac hypertrophy induced by high glucose.Combined early bioinformatics analysis, we focused on miR-142-3p and miR-182 in the future investigation. Therefore,we hypothesis that myocardial cell hypertrophy was induced by high glucose through miR-142-3 p and/or miR-182 targeted Rac1 and related signaling pathway. To test this hypothesis, we will investigate the role of miR-142-3 p and/or miR-182 targeted Rac1 in cardiac hypertrophy induced by high glucose in cell model and animal model by RT-PCR, Western-blot, virus transfection, RNA interference and microbubble targeted gene transfection. From this new viewpoint, we are looking forward to provide the evidences for revealing the myocardial cell hypertrophy and new ideas in diabetic cardiomyopathy.

微小RNA作为转录后水平调控的关键因子，也参与了多种心脏疾病的病理过程，但其在糖尿病心肌病中的角色知之甚少。我们预实验提示17个miR在高糖致心肌细胞肥大中发生显著变化，结合生物信息学分析，我们聚焦在miR-142-3p和miR-182，并提出假设：高糖通过miR-142-3p和/或miR-182靶向Rac1并相关信号传导途径诱导心肌细胞肥大。为此本项目拟通过细胞、动物模型，采用RT-PCR、Western-blot、病毒载体转染、微泡携基因靶向转染、RNA干扰等技术，从分子、细胞、组织及动物整体水平探讨miR-142-3p和/或miR-182靶向Rac1在高糖致心肌细胞肥大中的重要作用及其机制。期待从miRs这个新视点为揭示高糖致心肌细胞肥大的发生机制提供依据，为深入研究糖尿病心肌病提供新思路。

本课题探讨参与调控Rac1基因的miRNAs，并进一步研究其在糖尿病心肌病中发挥的作用：通过利用生物信息学方法预测、通过动物模型体内实验及Pearson相关性分析，最终筛选得出Rac1的候选miRNA为miR-182；同时体外实验进一步验证心肌细胞中miR-182与Rac1表达呈负相关。MiR-182模拟物降低高糖诱导心肌细胞中Rac1的表达，减轻高糖诱导心肌细胞的肥大程度，降低心肌细胞肥大相关表型的表达。MiR-182可参与糖尿病心肌病的调控，miR-182模拟物能可减轻糖尿病小鼠心肌组织Rac1表达，改善糖尿病小鼠心脏收缩功能，这与其降低糖尿病小鼠心肌肥大及心肌纤维化程度，减轻糖尿病小鼠心肌超微结构损伤有关。从Rac1的上游miRNA调控机制的角度阐述糖尿病状态下心肌病变的机制，为Rac1基因和其上游靶向控制的miRNAs作为新的糖尿病心肌病分子标志物提供科学依据。