lncRNA H19在巨噬细胞介导心肌梗死后交感神经重构中的作用及分子机制

Ventricular arrhythmia (VAs) following myocardial infarction (MI) is an important cause of death and disability, while sympathetic nerve remodeling is the core link. Previous studies and our previous study found that the macrophage phenotype varied post MI, and could mediate neural remodeling through the synthesis of nerve growth factor (NGF). Recently, we found M1 macrophages is the main source of NGF synthesis, however, the underlying mechanism remains to be further investigated. We found that the expression of lncRNA H19 in M1 type macrophages was significantly higher than that of M2, moreover, the inhibition of H19 significantly reduced the synthesis of M1 type macrophage NGF. Bioinformatics software and qRT-PCR analysis show that let-7a may be the main target miRNA for the role of H19 in MI, suggesting that H19 may play a role in miRNA sponge. We speculate that the H19-let-7a-NGF signaling pathway may be involved in the pathophysiological process of cardiac sympathetic remodeling after MI. The establishment of wild-type and H19 knock-out animal model and MI cell co culture model, applying gene over expression and silencing of molecular biology methods, the sympathetic nerve remodeling and arrhythmia susceptibility to effect, layer H19 validation on sympathetic nerve remodeling after MI for its molecular mechanism, in order to provide a new target for the prevention and treatment of ventricular arrhythmia after MI.

室性心律失常（VAs）是心肌梗死（MI）致死、致残的重要原因，交感神经重构是其发生机制之一。前期研究发现MI后巨噬细胞表型转变，合成神经生长因子（NGF）介导交感神经重构，M1型巨噬细胞是NGF合成的主要来源，其调控机制尚不明确。我们测序发现长链非编码RNA（lncRNA）H19在M1型巨噬细胞中显著表达，而抑制H19明显降低M1型巨噬细胞NGF的合成。生物信息学软件和qRT-PCR分析示let-7a可能为MI后H19作用的主要靶miRNA，H19可能通过miRNA海绵（sponge）发挥作用。我们推测，H19-let-7a-NGF信号通路可能参与MI后交感神经重构这一病理生理过程。本项目建立野生型和H19基因敲除动物MI模型及细胞共培养模型，采用基因过表达和沉默等方式，逐层验证H19在交感神经重构中的作用及其分子机制，以期为MI后室性心律失常的防治提供新的靶点和理论依据。

心肌梗死后炎症致交感神经重构是室性心律失常发生和发展的主要原因之一。巨噬细胞在交感神经再生致心电不稳中发挥重要作用。本研究选择H19-let-7a信号通路为研究研究靶点，采用病毒沉默与过表达技术，探索其在心肌梗死后调控心脏交感神经再生的作用，并利用RT-PCR、Western blotting、免疫荧光、双荧光素酶报告分析、电刺激等技术，发现H19-let-7a信号通路调控M1型巨噬细胞NGF产生，最终构建巨噬细胞-H19-let-7a-交感神经再生-心电不稳的作用通路，为自主神经失衡导致的心律失常及心源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，已全面完成预期的考核指标。迄今为止，基于本项目发表SCI论文6篇，中文核心1篇。在本研究成果的基础之上，课题负责人闫素华教授中标国家自然科学基金项目。以本项目为依托，共培养博士研究生生5名，硕士研究生9名。