Yap蛋白通过糖酵解依赖的途径在心肌缺血再灌注损伤中发挥的作用及机制研究

Yap (Yes-associated protein) is an important component in Hippo signaling pathway, which is high evolutionarily conserved and regulates cell growth, proliferation and apoptosis. Previously research found that cardiac-specific Yap activation improves survival post myocardial infarction, and glycolysis, which is the major metabolic pathway to protect cardiomyocytes from hypoxic injury, could sustain Yap/Taz activity in kidney cancer cells. However, the role of Yap via glycolytic dependent pathway in myocardial ischemia reperfuion has not been investigation. Our preliminary data showed that low dosage of Poly(I:C) enhanced the glycolysis and promoted proliferation in H9C2 cells and enhanced the nuclear localization of Yap/Taz, and inhibited apoptosis signaling pathway. In addition, we found that treated with a hexokinase inhibitor (2-deoxy-D-glucose, 2-DG) abolished the cardioprotection and the nuclear localization of Yap/Taz of Poly (I:C). Based on our novel findings, we hypothesize that Yap via glycotic pathway plays a central role in the pathophysiologic mechanisms of myocardial I/R injury. To the best of our knowledge, there is no report of glycolysis regulated Yap on myocardial I/R injury. .To critically evaluate our hypothesis, we will determine the role of Yap via glycolytic dependent pathway in the pathogenesis of myocardial I/R injury using transfection of the myocardium with an adenovirus packing with VGLL4 (Adv-VGLL4) ,which inhibites the activity of Yap in the nucleus, one week before induction of myocardial I/R injury in mice, Poly(I:C), inhibitors of glycolysis and ligation of left anterior descending coronary artery (LAD). Myocardial morphologic changes and cardiac function will be measured post myocardial I/R injury. We will also examine the effect of Yap and glycolysis on apoptosis and proliferation using both in vivo myocardial I/R injury of mice and in vitro H9C2 H/R injury models. .These studies will illustrate the signaling molecular sensor that is critical for myocardial I/R injury. It may be possible to apply our finding in a practical fashion to identify new and novel therapeutic approaches to prevent or manage myocardial I/R injury.

Yap是Hippo信号通路中高度保守的信号分子，已有文献报道心肌特异性过表达Yap可增加心梗后存活率；而在肿瘤细胞中，糖酵解可以调控Yap的活性，促进细胞增殖。但Yap是否通过糖酵解依赖的途径在心肌缺血/再灌注（I/R）损伤中发挥作用尚不清楚。预实验发现：低剂量Poly(I:C)可以激活心肌细胞内糖酵解促进细胞增殖，增加Yap/Taz的核定位并抑制凋亡信号通路，而使用2-DG抑制糖酵解后可以取消Poly(I:C)的保护作用和对Yap/Taz核定位的影响。我们推测Yap可能以糖酵解依赖的途径在心肌I/R损伤的发病机制中起着重要作用。为此，本项目拟从整体动物与体外细胞两个方面，采用抑制Yap活性的Adv-VGLL4心肌局部转染方法、Poly(I:C)和糖酵解抑制剂，结合冠状动脉左前降支结扎术研究糖酵解及其调控的Yap在心肌I/R损伤中的整体功能作用和调控机制，为临床防治心肌I/R损伤提供线索。