血管内皮细胞衰老是心血管疾病的独立危险因素，自噬是衰老相关极为重要的调节机制。我们前期研究显示，AngⅡ通过下调Bcl-2蛋白水平诱导HUVECs衰老。本项目拟进一步检测HUVECs在AngⅡ作用下，细胞自噬相关的形态学和分子生物学特征的变化，研究AngⅡ是否通过阻断正常的自噬途径诱导HUVECs衰老；检测HUVECs经自噬诱导剂Rapamycin预处理后，研究AngⅡ是否通过激活mTOR信号通路抑制HUVECs自噬；检测HUVECs在AngⅡ作用下，Bcl-2是否与自噬标志蛋白Beclin1结合导致游离Bcl-2含量降低，并且Beclin1是否通过其BH3结构域与Bcl-2结合，激活mTOR，抑制HUVECs自噬，最终导致细胞衰老。本课题将是我们前期研究结果的有益补充和完善。

Senescence of vascular endothelial cell is the independent risk factor for cardiovascular diseases, and autophagy is the most important regulatory mechanism correlated with senescence. Our studies have shown that AngⅡ（AngiotensinⅡ）induced the senescence of HUVECs（Human umbilical vein endothelial cells）by downregulating Bcl-2（B cell lymphoma/leukemia-2）, suggesting that Bcl-2 activity plays an important role in regulating vascular endothelial cell senescence lifespan in vitro. In this project, the morphological and molecular biological characteristics associated with autophagy in AngⅡ treated HUVECs will be examined to investigate whether AngⅡ induced the senescence of HUVECs by interfering with the normal autophagy. Next, HUVECs will be pretreated with Rapamycin to explore whether the negative role of AngⅡin autophagy is performed by activating mTOR（Mammalian target of rapamycin）. And, the probable interaction between Bcl-2 and Beclin1, which possibly results in the decrease of Bcl-2 will be examined in AngⅡ treated HUVECs, and whether the BH3 domain of Beclin1 is required for its binding to Bcl-2 will also be measured. In summary, we hope that this project is a beneficial supplement and improvement of our previous studies.