UBE3A通过调控磷酸化TRAF2参与CGA抑制心肌肥大的作用机制研究

心肌肥大是一种常见的慢性致死性心肌损伤疾病。本课题组前期研究发现绿原酸（CGA）能够有效地抑制异丙肾上腺素（Iso）诱导的心肌肥大，降低细胞内的氧自由基水平，抑制NF-kB向细胞核内转运，阻断NF-kB及其他炎症相关通路蛋白的激活。我们进一步筛选发现TRAF2和UBE3A基因可能参与该反应过程，但具体机理不明。本项目拟深入研究：1.在CGA预保护作用下，利用腺病毒和siRNA强制调控UBE3A，探讨UBE3A、TRAF2及其磷酸化与心肌肥大病程的相关性。2.通过MG132抑制蛋白酶复合体形成，分析磷酸化TRAF2在心肌肥大调控中的作用机制。3.借助碱基定点突变技术，使UBE3A催化泛素化功能失活，阐明其调控TRAF2的分子机制。该研究以期阐明CGA抑制磷酸化TRAF2激活炎症反应通路，进而阻断心肌肥大发生的分子机制，为以TRAF2为靶点治疗心肌肥大提供理论依据。

Cardiac hypertrophy is a chronic and progressive interstitial myocardial disease. In our previous study, we found that CGA could effectively inhibit cardiac hypertrophy induced by isoproterenol (Iso), reduce the level of intracellular ROS, prevent NF-κB from entering into nucleus, and blocks the activation of NF–κB and other proteins related inflammatory signaling pathways. Further study found that TRAF2 and UBE3A were both involved in the reaction process，but its functional mechanism is still unknown. This project intends to do some further study as follows. Firstly, the relevances among UBE3A, TRAF2 phosphorylation and cardiac hypertrophy will be investigated during CGA treatments or the changes of UBE3A. Secondly, the formation of proteasomes in cardiomyocytes will be blocked by MG132, and then we will study the regulatory mechanism of p-TRAF2 in the process of cardiac hypertrophy. Finally, based on the technique of PCR site-directed mutagenesis, we will reveal the roles of UBE3A regulating TRAF2 via inactivation of ubiquitin catalytic center. The goal of this study is to clarify the molecular mechanism of CGA inhibit cardiac hypertrophy by suppressing the activation of phosphorylated TRAF2 related inflammatory signaling pathways. It will also provide theoretical basis for the treatment of cardiac hypertrophy with TRAF2 as a new target.