基于CXCL12甲基化介导CXCL12/CXCR4生物学轴调控PI3K-AKT信号通路研究清心饮抑制病毒性心肌炎心肌纤维化的分子机制

The main pathology of CVMC is MF, which can continue to develop to DCM, characterized by intractable heart failure with poor prognosis. Previous research has confirmed that Qingxinyin, which can nourish qi and yin and clear heart by removing stasis, can promote PI3K-AKT signaling pathway to significantly inhibit EndMT. However, the regulation mechanism of the gene and protein in the upstream of the pathway remains to be studied. Recent studies have found that CXCL12/CXCR4 biological axis can regulate PI3K-AKT pathway. Nevertheless, the abnormal methylation of CXCL12 gene can reduce the expression of CXCL12. We hypothesize that Qingxinyin may mediate the CXCL12/CXCR4 biological axis by interfering CXCL12 methylation, which then regulates the PI3K-AKT signaling pathway to suppress EndMT in CVMC. This project intends to establish a CVMC mouse model and a cell experiment platform to investigate the role of CXCL12 gene methylation mediated CXCL12/CXCR4 biological axis in the regulation of PI3K-AKT signaling pathway during the EndMT process of CVMC myocardial fibrosis, and further observe the intervention effect of Qingxinyin. The completion of the project will further elucidate the pathological mechanism of VMC myocardial fibrosis and the deep effect of Qingxinyin on the treatment of VMC, which is of great clinical significance.

CVMC的主要病理为MF，持续发展可致DCM，表现为顽固性心衰，预后极差。前期研究证实益气养阴、清心祛瘀的清心饮可促进PI3K-AKT信号通路传导明显抑制EndMT，但通路上游基因、蛋白等的调控机制尚待深入研究。晚近研究发现CXCL12/CXCR4生物学轴可调控PI3K-AKT通路传导，而CXCL12基因异常甲基化可下调CXCL12的表达水平。我们假说：清心饮可能通过干预CXCL12甲基化介导CXCL12/CXCR4生物学轴，进而调控PI3K-AKT信号通路来抑制CVMC中EndMT。本项目拟建立CVMC小鼠模型和细胞实验平台，探讨CVMC心肌纤维化EndMT过程中CXCL12基因甲基化介导CXCL12/CXCR4生物学轴对PI3K-AKT信号通路调控作用的同时，进一步观察清心饮的干预效应。项目完成将进一步阐明VMC心肌纤维化的病理机制以及清心饮治疗VMC的深层作用靶点，具有重要临床意义。

慢性病毒性心肌炎（chronic viral myocarditis，CVMC）可发展为扩张型心肌病（dilated cardiomyopathy，DCM），其主要病理表现为心肌纤维化。项目研究结果证实PI3K-AKT信号通路参与了VMC小鼠心肌纤维化过程，在细胞实验中发现PI3K-AKT信号通路活性与CVB3感染后CMVECs发生EndMT过程有关；清心饮干预可上调PI3K-AKT信号通路活性从而抑制心肌纤维化的进程；进一步研究还发现在CVB3感染CMVECs后的不同时段，均存在着CXCL12的甲基化,CXCL12/CXCR4生物轴参与了CVB3感染后CMVECs发生EndMT的过程，清心饮可显著下调CXCL12、CXCR4的mRNA和蛋白表达，提示清心饮的作用机制可能与抑制CXCL12/CXCR4生物轴有关。拮抗CXCL12/CXCR4生物轴，可以显著增强清心饮对CMVEC发生EndMT的抑制作用，说明CXCL12/CXCR4生物轴在清心饮抑制EndMT过程中发挥了重要作用。本项目研究结果为临床应用清心饮治疗VMC提供更详实的实验依据，且提示调控CXCL12/CXCR4生物轴有望成为MF新的治疗靶点。在临床实践中，我们积极采用以“伏邪理论”立法的专利复方中药清心饮治疗病毒性心肌炎，临床疗效显著；对急性病毒性心肌炎的磁共振影像诊断及与应激性心肌病等疾病的鉴别诊断也做了有益的探索。