P2X7-NLRP3信号通路调控巨噬细胞表型转变在心梗后交感神经重构中的作用及分子机制

Sudden cardiac death and malignant ventricular arrhythmias after myocardial infarction (MI) is highly relevant with sympathetic neural remodeling, but the mechanism exploration is still at primary stage. Recent studies indicated macrophages as an important role in inflammation meditated sympathetic neural remodeling, but the molecular mechanism is unclear. Macrophages have the characters of diversity and plasticity, and exert different functions through phenotypic transition. P2X7-NLRP3 signaling is selectively highly expressed on macrophage and plays an important role in regulating macrophage function. We speculate that the activated P2X7 signaling after MI would regulate macrophage phenotype, which participates in the process of cardiac sympathetic nerve regeneration and subsequent cardiac electrical instability. In the present study, we intend to establish a co-culture system of macrophages and sympathetic neurons, bone marrow transplantation control group and MI model in P2X7R gene knockout and wild-type C57BL/6J and bone marrow transplanted mice. Based on our previous studies, we intend to investigate the role of P2X7 on inflammatory system post MI in vivo and in vitro, how P2X7 signaling pathway would regulate macrophage phenotype and the following sympathetic nerve regeneration. Furthermore, we try to develop a pathway of P2X7-NLRP3 signaling-macrophage -sympathetic nerve regeneration- cardiac electrical stability. The study will provide new therapeutic targets for cardiac arrhythmias and sudden cardiac death induced by cardiac autonomic nerve imbalance.

心肌梗死（MI）后猝死及室性心律失常与交感神经重构有关，相关分子机制研究仍处于初级阶段。近期研究发现巨噬细胞在炎症介导的交感神经重构中起重要作用，其分子机制尚不明确。巨噬细胞具有多样性及可塑性，可通过表型转变发挥不同的功能。高选择性表达在巨噬细胞的P2X7-NLRP3信号在炎症反应中起重要作用并影响巨噬细胞功能。 我们推测MI后被激活的P2X7受体可能通过诱导巨噬细胞表型转变，引发心脏交感神经过度增生，进而导致心电不稳定及心律失常。本课题拟在既往研究基础上，建立巨噬细胞交感神经元共培养模型、 P2X7R基因敲除及野生型C57BL/6J小鼠MI模型和骨髓移植后小鼠MI模型，从体外、体内二个层面探讨P2X7信号通路在MI后炎症体系中的作用，发现并构建P2X7-NLRP3信号-巨噬细胞-交感神经再生-心电稳定性的作用通路，为MI后自主神经失衡导致的心律失常及心脏性猝死的防治提供新的靶点。

心肌梗死后炎症致交感神经重构是室性心律失常发生及维持的主要原因之一，明确炎症关键细胞—巨噬细胞在交感神经再生中的作用及其导致心电不稳定的具体机制是防治室性心律失常的关键。本研究采用小分子化合物，选择与巨噬细胞的功能调控分子P2X7R与NLRP3炎症小体通路为研究靶点，探索其在心肌梗死后巨噬细胞调控心脏交感神经再生中的作用，并利用免疫荧光、RT-PCR、电刺激等技术，发现P2X7/NLRP3信号调控M1型巨噬细胞NGF产生，最终构建P2X7-NLRP3信号-巨噬细胞-交感神经再生-心电稳定性的作用通路，为MI后自主神经失衡导致的心律失常及心脏性猝死的防治提供新的靶点。课题组经过3年的研究，取得了预期的研究成果，已全面地完成了预期的考核指标。迄今为止，基于本项目发表SCI11篇。此外尚有3篇标注的成稿全英文论文正在国外SCI期刊投稿或修稿中 。在本项目研究成果的基础上，本课题组闫素华教授中标国家自然科学基金项目。课题实施期间，课题负责人闫素华获得山东省第一医科大学学术提升计划项目、科技进步二等奖。以本项目为依托，共培养博士后1名，博士研究生7名，硕士研究生3名。