TREM-1/SMC4/NEMO通路激活NLRP3炎症小体分子机制及其在脓毒性心肌病中作用

脓毒性心肌病（SCM）主要与炎症反应失调有关，具体机制尚不明确。我们临床及动物实验发现TREM-1加重脓毒症左室功能障碍，促进IL-1β、TNF-α、sTREM-1表达；TREM-1抑制剂LR12拮抗此效应。近期研究显示脂多糖上调心肌细胞表达TREM-1，TREM-1可激活NLRP3炎症小体及诱导细胞焦亡；心肌细胞存在TREM-1与TLR4协同作用及TREM-1与SMC4共定位；推测TREM-1可能通过SMC4/NEMO通路激活NLRP3炎症小体，但详细机制不明。本项目拟构建Trem-1或Smc4基因沉默细胞及基因敲除小鼠脓毒症模型，用免疫共沉淀、质谱分析、磷酸化蛋白组学、荧光共振能量转移等技术，探讨TREM-1经SCM4/NEMO通路激活NLRP3炎症小体的分子机制及其在SCM中作用。研究结果有助于阐明SCM发病机制，明确sTREM-1对SCM潜在预警价值，并为SCM防治提供新靶点。

Septic cardiomyopathy (SCM) is mainly related to the sepsis-induced inflammatory dysregulation, but its exact mechanism remains unclear. Our previous clinical and animal studies showed that TREM-1 exacerbated the left ventricular dysfunction and myocardial damage and reinforced IL-1β, TNF-α and sTREM-1 levels in septic mice, which was antagonized by TREM-1 inhibitor LR12. Recently, we found that TREM-1 expression was upregulated; TREM-1 activated NLRP3 inflammasome and induced pyroptosis; and the synergistic effect between TREM-1 and TLR4 and co-localization of TREM-1 and SMC4 were present in lipopolysaccharide (LPS)-treated cardiomyocytes. Therefore, TREM-1 might activate NLRP3 inflammasome through SCM4/NEMO pathway, while its detailed mechanism is unknown. This project intends to establish Trem-1 or Smc4 silencing septic cardiomyocytes and Trem-1-/- or Smc4-/- septic mice, and then investigate the molecular mechanism of NLRP3 inflammasome actived by TREM-1/SMC4/NEMO pathway and its role in SCM using co-immunoprecipitation, mass spectrometry, phosphorylated proteomics, fluorescence resonance energy transfer, and the like. These results will be helpful to elucidate the pathogenesis of SCM and determine the potential early-warning value of sTREM-1, which may provide a novel target for prevention and treatment of SCM.