Caveolin-1/miR-21/ROS通路在剪切力诱导的血管内皮细胞自噬中的作用机制

Vascular homeostasis plays a pivotal role in cardiovascular diseases. There are various risk factors that can induce cardiovascular diseases. At the first step, vascular homeostasis will be disordered by risk factors. Then, the vascular homeostasis will induce cardiovascular occurring and developing. Thus, to study and explore the vascular homeostasis is one of the principle objectives in the field of occurrence mechanism of cardiovascular disease. Vascular endothelial cell is a crucial element among components of vascular homeostasis. The role of vascular endothelial cell that plays in occurrence of cardiovascular disease has received increasing attention in the worldwide. However, it is not clearly elucidated how endothelial cell maintains itself homeostasis effected by blood flow shear stress. . In pilot study, we found that autophagy was attenuated after caveolin-1 was knocked down or inhibited in endothelial cell. Meanwhile, the difference of miR-21 expression that induced by different shear stress was disappeared. The inhibited autophagy and the disappeared difference of miR-21 expression that induced by different shear stress were strongly associated with the changement of endothelial function that induced by shear stress. Because there is no evidence indicating that miR-21 directly relates to autophay, we predicated the target gene of miR-21 using data base of PicTar combined with miRanda, TargetScan, and miRBase. The predicated target gene of miR-21 was enriched using Integrated analysis of Cross-platform MicroArray and Pathway data (IncroMAP). The result revealed that reactive oxygen species (ROS) gene is the target gene of miR-21. . Thus, combined the results of the pilot study with the theory of autophagy and vascular homeostasis, we speculated that caveolin-1/miR-21/ROS pathway is one of the crucial regulatory mechanisms of autophagy induced by shear stress in endothelial cell. Flow shear stress modulates the expression of miR-21 through caveolin-1. Then, miR-21 targeted regulates ROS gene. And then, ROS is activated and initiates autophagy. Base on our previous study, we expect to further explore the regulatory mechanisms of shear stress to autophagy in endothelial cell using con-focal laser scanning fluorescent miscroscope, transmission electron miscroscope, etc. The results will provide new ideas and methods for Precision Medicine, target therapy, and gene therapy of cardiovascular diseases.

各种危险因素在诱导心血管病发生和发展时，首先引起血管稳态紊乱。因此，血管稳态是研究心血管病发生机制的重要方向之一。其中血管内皮细胞（EC）是血管稳态的重要组成部分，其如何在心血管病发生中发挥作用是国内外关注的重要环节。但是，EC在血流剪切力（SS）等因素作用下如何调控自身稳定尚未阐明。该研究在发现SS诱导EC发生自噬，Caveolin-1影响miR-21表达和EC自噬，以及软件预测ROS是miR-21靶基因等预实验基础上，结合自噬与血管稳态相关的理论，推测Caveolin-1/miR-21/ROS通路可能是SS诱导血管EC自噬的重要机制。重点研究SS是否通过Caveolin-1改变EC的miR-21表达，miR-21是否通过靶向调控ROS而启动自噬反应。预期结果的取得，有望率先揭示剪切力诱导血管EC发生自噬的关键机制，为心血管病的精准治疗、基因治疗、靶向治疗提供新的思路和依据。

内皮细胞（EC）功能稳定是维持血管结构和功能稳态的重要基石，其功能紊乱是各种心脑血管疾病发生与发展的共同的病理生理基础。阐明EC功能稳态的分子机制是是预防和治疗心脑血管疾病的重要环节。血流剪切力（SS）是血管EC直接承受的外界机械力，但在SS作用下，EC保持自身稳定并发挥生物学效应的分子机制尚未阐明。本研究是在前期提出SS通过Caveolin-1/miR-21/ROS（活性氧）通路诱导血管EC提高自噬反应水平维持EC及血管功能稳态的假说基础上开展的。研究结果显示，（1）无论流体SS升高还是下降，细胞内的ROS水平升高，并促进自噬相关基因表达以及自噬小体的形成。当Caveolin-1被siRNA阻断后，内皮细胞的microRNA表达谱发生改变，其中miR-21的差异性表达最为显著，细胞内的ROS水平下降，自噬反应水平降低。（2）激活或阻断miR-21可显著调控EC内的ROS相关基因的表达及EC内的ROS的浓度水平，并调控EC的自噬反应水平。（3）激活ROS活性可显著提高EC的自噬反应，而阻断ROS活性可显著降低EC的自噬反应。（4）提高或降低EC自噬反应水平，可显著改变EC和动脉血管的功能稳态。表明，EC膜上的Caveolin-1可以感知SS信号并传递给miR-21，miR-21又可调控EC内的ROS水平，激活或降低自噬反应，从而维持或破坏EC和动脉血管的功能稳态，Caveolin-1/miR-21/ROS通路诱导的自噬是SS调控EC和血管功能稳态的重要分子机制。依托本项目，在国内外知名学术期刊共发表学术论文24篇，其中SCI收录12篇，论文发表当年IF≥3分9篇，IF≥5分2篇；中文核心期刊13篇。培养硕士研究生4名，已顺利毕业并获得硕士学位2名，其中1名以此研究于2017年获得硕士研究生国家奖学金，另有2名硕士在读。