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

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.

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。

冠状动脉痉挛（coronary artery spasm, CAS）是导致心脏性猝死的重要因素。CAS的发病机制还有待研究，且司法鉴定及临床医学中关于CAS的诊断标志物还极其缺乏。本项目基于内质网应激通路，（1）考察内质网应激对CAS的剂量调控关系；（2）鉴定内质网应激调控CAS的关键UPR通路；（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分子标志物及其它潜在诊断标志物。我们发现，内质网应激抑制剂对CAS的调控并不呈线性关系，UPR通路中以IRE1及PERK通路对CAS发挥更关键作用，在CAS发生时血清中的3个内质网应激相关分泌蛋白（LMAN2、CAPN-1及VCP）可作为稳定的诊断标志物。此外，我们还鉴定了2个与内质网应激无关的血液指标（SELENBP1及VCL）也有望作为临床和法医学对CAS的诊断标志物。以上5个血液标志物诊断CAS的效能均显著优于传统心肌损伤标志物（CK-MB及cTnI）。因此，本项目揭示了CAS发病的新机制，率先提出了可用于死因鉴定和临床诊断的多个生化指标。