血管内皮细胞来源的TET2对心室重构的作用和机制研究

病理性心脏重构将导致心脏结构和功能恶化，并与临床不良预后密切相关，但目前缺乏有效的治疗手段。在心脏重构时，内皮间充质转化（EndMT）会加重心脏功能恶化，但关于EndMT在心脏重构中的作用和潜在分子机制尚未完全阐明。本项目前期研究发现抑制心脏DNA甲基化可以阻止心脏纤维化进而预防心力衰竭发生，而内皮细胞DNA甲基化调节关键酶TET2在心脏重构发挥主要作用。TET2功能减退后，内皮细胞TGFβ信号通路激活，内皮细胞发生明显的EndMT转分化。拟在此项目中通过构建内皮细胞特异性TET2基因敲除小鼠明确TET2对心脏重构的作用，通过荧光小鼠遗传谱系追踪明确内皮细胞转分化方向。并用甲基化DNA测序、生物信息学手段筛选TET2的潜在作用靶点。最后通过逆转实验证实TET2可通过调控其潜在靶点调控EndMT的发生发展，明确以TET2为中心的EndMT调控网络，为未来心脏重构治疗提供新靶点。

Pathological cardiac remodeling leads to the deterioration of cardiac structure and function, and contributes to the clinical poor prognosis. However, there is still no effective treatment. During cardiac remodeling, endothelial-to-mesenchymal transition (EndMT) occurs, which can aggravate the deterioration of cardiac function. But its role and underlying molecular mechanism in cardiac remodeling have not been fully elucidated. In the previous study of this project, it was found that cardiac fibrosis and even heart failure can be prevented when cardiac DNA methylation is restrained. The tet methylcytosine dioxygenase 2 (TET2) enzyme is an important DNA demethylase. Tet2 expressed in endothelial cells take a significant part in cardiac remodeling. The TGF β signal pathway of endothelial cells was activated, and the endothelial cells had obvious EndMT transdifferentiation after the decrease of TET2 function. In this project, we propose to determine the effects of TET2 on cardiac remodeling by constructing endothelial cell specific TET2 knockout mice, and to track the direction of endothelial cell transdifferentiation by genealogical tracing. The potential targets of TET2 will be screened by DNA methylation sequencing and bioinformatics. Finally, It will be confirmed that TET2 can regulate the occurrence and development of EndMT by regulating its potential targets via reverse experiments. The regulatory network of EndMT centered on TET2 can provide new targets for future cardiac reconstruction therapies.