AngII-ACE2-Ang-(1-7)在腹主动脉瘤发病和干预中的作用及其机制研究

To elucidate the effects and the underlying mechanisms of Ang-II-ACE2-Ang-(1-7) axis in the pathogenesis and intervention of the abdonimal aortic aneurysm (AAA), the present study was designed to first examine the effects of ACE2 gene overexpression, ACE2 gene silencing, Ang-(1-7)、Mas receptor gene silencing and ARB on cell apoptosis, collagen synthesis and degradation, oxidative stress, inflammatory response and downstream signaling pathways in vascular smooth muscle cells (VSMCs), in an attempt to clarify the different roles of ACE2, Ang-(1-7) and ARB in regulating VSMCs and their molecular mechanisms. Thereafter, AngII will be injected chronically into ApoE-/- by an implanted pump to produce an animal model of AAA, which will be used to examine the effects of CE2 gene overexpression, ACE2 gene knockout, chronic Ang-(1-7) infusion, Mas receptor gene knockout and oral ARB on the formation of AAA. The different effects of ACE2, Ang-(1-7) and ARB on the formation of AAA will be compared with the purpose to find out the key molecules in the Ang-II-ACE2-Ang-(1-7) axis for modulating the formation and progression of AAA. This project will result in a better understanding of the mechanisms underlying the pathogenesis of AAA, which may provide novel therapeutic targets for the prevention and treatment of this important disease.

为了阐明Ang-II-ACE2-Ang-(1-7)轴在腹主动脉瘤（AAA）发病和干预中的作用及其分子机制，本课题首先在AngII刺激的VSMCs中观察ACE2基因过表达、ACE2基因沉默、Ang-(1-7)、Mas受体基因沉默和ARB对细胞凋亡、胶原合成和降解、氧化应激和炎症反应以及下游信号通路的影响，明确ACE2、Ang-(1-7)和ARB 对VSMCs作用及其分子机制。然后，在高脂喂养的ApoE-/-小鼠中观察泵入AngII对AAA形成的影响，观察ACE2基因过表达、ACE2基因敲除、Ang-(1-7)泵入、Mas受体基因敲除、ARB灌胃对小鼠AAA形成的影响，同时对比ACE2、Ang-(1-7)和ARB三者作用的不同，寻找Ang-II-ACE2-Ang-(1-7)轴调控AAA的关键分子。本课题的实施将进一步阐明AAA的发生机制，为这一重大疾病的防治提供新的靶点。

为了阐明Ang-II-ACE2-Ang-(1-7)轴在腹主动脉瘤（AAA）发病和干预中的作用及其分子机制，本课题在体外观察了ACE2基因过表达、ACE2基因敲除和Ang-(1-7)对AngII介导的VSMCs凋亡、氧化应激、基质降解和炎症反应的影响以及下游信号通路的表达；在体内观察了ACE2和Ang-(1-7)对AAA形成的影响，从正反两个方面观察ACE2和Ang-(1-7)在AAA形成和进展中所起的作用；进一步明确了ACE2过表达和Ang-(1-7)对于AAA作用的分子机制及其差别，寻找Ang-II-ACE2-Ang-(1-7)轴调控AAA的关键分子机制。本课题在AngII刺激的血管平滑肌细胞（VSMCs）中观察了ACE2基因过表达、ACE2基因沉默、Ang-(1-7)、Mas受体基因沉默和ARB对AngII介导的细胞凋亡、氧化应激和炎症反应以及下游信号通路的影响，明确了ACE2、Ang-(1-7)和ARB 对VSMCs作用的分子机制的差异；在高脂喂养的ApoE-/-小鼠中观察了慢性泵入AngII对AAA形成的影响，观察了Ang-(1-7)泵入、Mas受体基因敲除、ARB灌胃对小鼠AAA形成的影响；从正反两个方面明确了ACE2和Ang-(1-7)在AAA发生和发展中所起的作用，同时对比了ACE2、Ang-(1-7)和ARB三者作用的不同，发现了Ang-II-ACE2-Ang-(1-7)轴调控AAA的关键分子机制。本课题的实施将进一步阐明AAA的发生机制，为这一重大疾病的防治提供新的靶点。通过本课题的研究，建立了ACE2基因过表达病毒载体，为体外和体内试验提供了基因治疗工具；建立了小鼠皮下埋藏式微量注射泵持续输注Ang-II和Ang-(1-7)以及ARB灌胃的方法学，以检验外源性Ang-II和Ang-(1-7)以及ARB在AAA中的作用；在体外实验中阐明了ACE2和Ang-(1-7)治疗AAA的分子机制，并在体内实验中检验了治疗效果。本课题的实施将进一步阐明AAA的发生机制，为这一重大疾病的防治提供新的靶点。