RhoE双相调控Nrf2-ARE信号在糖尿病心肌病氧化应激中的作用及机制研究

氧化应激(OS)异常是糖尿病心肌病(DCM)的重要发病机制迄今未完全阐明。我们前期发现Rho GTP酶超家族成员RhoE在DCM心肌组织中表达下降并伴随P21上调；而P21可以通过非经典通路激活核因子E2相关因子2-抗氧化反应元件（Nrf2-ARE）这一调控OS的关键信号；有趣的是，RhoE基因敲除的DCM组织中存在Nrf2 mRNA上升和蛋白下降的不一致现象，同时其下游ARE基因较野生型DCM组明显反应不足。本项目假设DCM中RhoE表达下调且以激活和抑制的双相调节Nrf2-ARE信号的机制参与DCM的OS调节，从而介导DCM的发病。项目拟构建心肌细胞特异性RhoE正常、敲除及过表达大鼠，通过腹腔注射链脲佐菌素联合高脂饮食以构建Ⅱ型糖尿病模型，结合分子生物学技术，从体内和体外实验来综合分析RhoE不足在DCM中的作用及靶向干预Nrf2-ARE信号的价值。研究成果将提出DCM防治的新策略。

Oxidative stress (OS) abnormality is an important pathogenesis of diabetic cardiomyopathy (DCM) but has not been fully elucidated so far. We previously found that RhoE, a member of the Rho GTPase superfamily, has decreased expression in DCM heart tissues accompanied by upregulation of P21. While P21 can activate nuclear factor E2-related factor 2-antioxidative stress response element signaling (Nrf2-ARE), a key signaling regulating OS, through non-canonical mechanism; Interestingly, there is an inconsistency between the rise of Nrf2 mRNA levels and the decline of protein levels in the myocardium of RhoE knockout diabetic rats, and the downstream ARE genes such as HO-1, SOD3 and Nqo1 are also significantly inhibited than the control wild type (WT) DCM group. This project proposes that down-regulated RhoE in DCM biphasically regulated the Nrf2-ARE signaling in OS, thereby promoting the pathogenesis of DCM. The project intends to construct type 2 diabetes models through intraperitoneal injection of streptozotocin combination with high-fat diet to cardiomyocyte-specific RhoE over-expression, knockout and WT rats, combined with molecular biology techniques, to comprehensively analyze the functional role of RhoE deficiency and the value of targeted intervention of Nrf2-ARE signaling in DCM based on experiments in vivo and in vitro. The implementation results would propose new strategy for DCM treatment and prevention.