内质网应激诱发冠状动脉痉挛的机制及相关生物标志物筛选

冠状动脉痉挛（coronary artery spasm, CAS）是导致心脏性猝死的重要因素。我们前期研究结果显示，MLCK/MLC2通路的激活可作为CAS致死的组织学依据；内质网应激调控MLCK/MLC2活性而诱发了CAS。但内质网应激通路有多条，它们在CAS发生中的作用及调控MLCK/MLC2通路的具体机制仍不明确；CAS发生时血液生物标志物还有待鉴定。本项目以冠心病大鼠为模型，结合血管平滑肌细胞，（1）进一步考察内质网应激引发CAS致心脏性猝死的时间-剂量-效应关系；（2）比较内质网应激UPR三条通路引发CAS的效应差异，并解析关键的UPR通路调控MLCK/MLC2活性的机制；（3）基于label-free蛋白质组学技术筛选CAS发生时血清中的差异蛋白，从中鉴定出与内质网应激相关的生物标志物。本项目将揭示CAS致心脏性猝死的全新机制，率先提出可用于死因鉴定和临床诊断的生化指标。

Coronary artery spasm (CAS) is a critical contributor to sudden cardiac death. Our previous studies have found that activation of MLCK/MLC2 pathway could serve as a tissue marker indicating CAS-induced deaths and endoplasmic reticulum stress (ER stress) mediates the activation of MLCK/MLC2 pathway and thereby inducing CAS. However, ER stress has several pathways. The role of each pathway in the induction of CAS remains unclear and whether there is any serum biomarker during CAS development remains to be elucidated. This project will utilize coronary atherosclerotic Sprague Dawley (SD) rat models as well as human vascular smooth muscle cells (hVSMCs), (1) to further investigate effects of ER stress activation on rat survival (to establish the time-dose-effect relationship); (2) to compare the effect difference between ER Stress UPR different pathways in inducing CAS and the detailed mechanisms of key ER stress pathway to activate MLCK/MLC2 pathway; (3) to screen the differential expressed proteins in the serum of CAS models to identify the ER stress-related biomarkers for CAS. Our project will delineate novel mechanisms of CAS-induced sudden deaths, and may provide valuable biomarkers for the forensic evaluation and clinical diagnosis of CAS.