热休克蛋白90巯基亚硝基化修饰在动脉粥样硬化内皮损伤中的作用研究

内皮损伤是动脉粥样硬化（AS）的重要始动因素,其发病机制未全阐明。热休克蛋白90(Hsp90) 作为分子伴侣参与众多蛋白的成熟与激活。研究表明Hsp90可发生巯基亚硝基化修饰,但该修饰是否参与AS内皮损伤尚不明确。预实验结果显示oxLDL可增加内皮细胞Hsp90巯基亚硝基化修饰及诱导型一氧化氮合酶（iNOS）水平，串联质谱技术检测修饰位点可能为半胱氨酸529（Cys529），Cys529位点突变后，oxLDL增加Hsp90巯基亚硝基化水平及降低Hsp90与AHA1结合的作用消失。因此，本项目拟在离体细胞及整体动物水平，联合特定半胱氨酸位点突变，验证科学假说：致AS内皮损伤因素可通过影响iNOS水平调节Hsp90半胱氨酸位点的巯基亚硝基化修饰，改变其与AHA1、Cdc37的结合来调控相关信号通路，参与AS内皮损伤。可望揭示AS新机制，为内皮损伤相关疾病的防治提供新的干预靶点和思路。

Vascular endothelial dysfunction is a significant initiating factor of atherosclerosis (AS). Chaperone protein Hsp90 participates in the maturation and activation of many proteins. Hsp90 is modified by S-nitrosylation but whether it participates in atherosclerosis induced endothelial injury remains unknown. Prior experiments have showed that oxLDL increased the level of Hsp90 S-nitrosylation and iNOS in endothelial cells, the potential modification site of which identified to be cysteine 529 combining a tandem affinity purification approach and mass spectrometry. Mutation of Cys529 reversed the effect of oxLDL on the increasing of Hsp90 S-nitrosylation and binding of Hsp90 to AHA1. Therefore, combining site-directed cysteine mutagenesis, we aim to test the hypothesis that AS-related damaging factors regulate Hsp90 S-nitrosylation by affecting the level of iNOS, and Hsp90 S-nitrosylation influence its binding to AHA1 and Cdc37 resulting in signaling pathway alternation in vivo and vitro. This research would hopefully uncover the novel mechanism of atherosclerosis and provide new targets for preventing vascular endothelial cell injuring-related diseases.