MicroRNA-31对血压波动引起的血管内皮损伤和重塑的作用及调控机制

Blood pressure variability is closely related to the occurrence of atherosclerosis, and involved into its development. However, the underlying molecular mechanisms are still little understood. Evidence shows that some microRNAs have abnormal expression in hypertension and atherosclerosis. Our previous study found that advanced glycation end products (AGE) signaling pathway was involved in the regulation of endothelial dysfunction and vascular remodeling in sinoaortic denervation (SAD) rats who is a classic model of arterial baroreflex (ABR) dysfunction leading to high level of blood pressure variability. But, the exact mechanism remains to be studied. The aim of present study was to investigate whether AGE signaling pathway regulated endothelial dysfunction by specific miRNA expression (miRNA-31) in SAD rats. By using Northern Blot, Western Blot and other molecular biology techniques, it would be identified that AGE regulated the expression of miRNA-31 in cultured endothelial cells and SAD model. Meanwhile, eNOS gene was confirmed as the target of miR-31, and its role was identified in vascular injury caused by blood pressure fluctuation. The results are expected to confirm that AGE regulates the expression of miRNA-31, thereby affects the level of eNOS, which plays an important role in the regulation of vascular endothelial function and vascular remodeling after injury caused by high blood pressure variability. Finally, it will provide experimental evidence for disease prevention and new intervention targets of atherosclerosis.

血压波动性与动脉粥样硬化的发生、发展具有密切关系，目前具体机制尚未阐明。研究显示，多种microRNAs在高血压和动脉粥样硬化中表达异常。我们前期研究发现在以去窦弓神经（SAD）作为血压波动引起的血管损伤模型中，发现晚期糖基化终产物（AGE）信号通路参与了血管内皮功能损伤和重塑的调控。本实验在预实验的基础上预进一步探讨AGE信号通路是否通过调节miRNA-31的表达发挥作用。在离体血管内皮细胞培养和整体SAD模型上，利用Northern Blot、Western Blot等分子生物学技术，明确AGE信号通路对miRNA-31的调控作用，确认miRNA-31靶基因，并确定其在血压波动引起的血管损伤和修复中作用。旨在阐明miRNA-31对eNOS表达的调控作用，对AGE/RAGE激活引起的血管内皮损伤以及血管重构的调控机制，并以其为靶点探索动脉粥样硬化性心血管疾病的干预策略和新治疗思路。

内皮功能损伤是动脉粥样硬化等血管疾病的起始因素，但其作用机制尚未阐明。微小RNA(miRNA) 广泛参与细胞增殖、凋亡、分化和代谢等生物学过程，在心血管领域也发挥重要作用。本项目主要：(1) 建立以血管紧张素2诱导的内皮细胞凋亡模型，确定了差异表达的miRNA，明确miR-31在血管紧张素2刺激后表达下调。（2）通过过表达和抑制miR-31的方法，发现过表达miR-31能够显著抑制血管紧张素2诱导的内皮细胞凋亡，而抑制miR-31则明显增加细胞凋亡水平。（3）通过生物信息学筛选及双荧光素酶报告基因系统验证以及western blot的方法明确了RASA1是miR-31的靶基因。(4)利用rescue等实验明确了miR-31通过抑制RASA1表达缓解血管紧张素2诱导的内皮细胞凋亡。（5）发现miR-217对高糖诱导的内皮细胞凋亡具有明显的促进作用，可能是通过抑制SIRT1表达实现的。（6）发现富氢水通过JNK、p38-MAPK和NF-κB信号通路缓解糖尿病诱导的心肌功能障碍。本项目执行期间共发表标注的论文9篇，其中SCI收录论文4篇，总影响因子11.65。申请国家专利3项，获批1项。赴美国宾夕法尼亚大学医学院心脏中心合作交流1次。参加国内学术交流会议11次，口头报告5次。