LncRNA T101406减轻急性心肌梗死后AMHCA诱导的免疫损伤机制研究

We found that both the plasma concentration of free LncRNA T101406 and anti-myocardiac myosin heavy chain antibodies(AMHCA) increased significantly in the acute myocardial infarction patients compared with that in the control group. In our former experiments conducted on cardiomyocytes, we have also found the expression of LncRNA T101406 up-regulated significantly on ischemic and anoxic conditions. After adding AMHCA, we observed its binding to the plasma membrane of cardiomyocytes, which triggered the cardiomyocyte apoptosis. Later we proved that the apoptosis induced by AMHCA could be alleviated by LncRNA T101406. We will further evaluate the diagnostic value of LncRNA T101406 in AMI through animal experiments, and eventually validate its diagnostic value in a large clinical sample consists of AMI patients. Furthermore,by employing various approcaches including metabonomics methods, we will attempt to reveal the binding site of AMHCA in the plasma membrane and the underlying mechanism as well as the exact signaling pathways. We will also evaluate the myocardial protection efficacy of LncRNA T101406 by comparing the differences of both clinical and pathological characteristics between LncRNA T101406 knocked out mice and WT mice. This study contributes to the elucidation of the myocardial protection efficacy of LncRNA T101406 in myocardial damage induced by the acute immune response secondary to AMI onset.

我们发现急性心肌梗死（AMI）病人与正常对照组相比，血浆LncRNA T101406和抗心肌肌球蛋白重链（AMHCA）显著增高。在前期心肌细胞实验中，我们也发现在缺血缺氧环境下，LncRNA T101406表达显著增加，加入AMHCA后，AMHCA能与心肌细胞结合并诱发凋亡；而且LncRNA T101406能缓解减轻AMHCA所致的细胞凋亡。我们将通过动物实验，判断LncRNA T101406在AMI中的诊断价值，并最终经过临床大样本检测，确定LncRNA T101406在AMI中的诊断价值；还将利用代谢组学等方法，揭示AMHCA与心肌细胞结合位点、作用机制及信号通路；并在LncRNA T101406敲除的AMI小鼠上验证，与未敲除的小鼠相比，临床指标和病理学指标的差别，来判断该LncRNA对心肌的保护作用。本课题有助于揭示LncRNA减轻AMI发生时急性免疫反应所致的心肌细胞损伤。

急性心肌心梗（Acute Myocardial Infarction, AMI）是心血管疾病中常见的急危重症，目前我国AMI的发病率也呈现逐年上升的趋势。尽管随着介入治疗技术的进步以及新型药物的应用，AMI患者的死亡率得到了很大改善，但是其远期预后仍然不是十分理想，还是有很多患者在日后不可避免的出现不良的心室重构，并最终导致心衰（Heart Failure, HF）。研究表明组织重塑会导致心脏纤维化，并且是心脏纤维化发展的结果。目前临床上的抗纤维化药物虽然会减缓疾病的进展，但是却不能逆转疾病。长非编码RNA （long noncoding RNA, lncRNA）是一类长度大于200个核苷酸且不编码蛋白质的转录本在过去被认为是基因组中的不具有功能的“垃圾”片段，直到近年来人们才开始意识到lncRNA可能在多种病理生理过程中发挥重要作用。然而，目前有关lncRNA 在心脏纤维化中的功能尚不十分明确。在我们这项研究中我们通过数据库得到了一些在心肌梗死小鼠中差异表达的lncRNA，接着通过结扎左前冠状动脉（left anterior descending coronary，LAD）的小鼠心梗模型验证了其表达。通过生物信息学分析推测其可能功能，发现该lncRNA Dnm3os可能与ECM的形成，纤维胶原酶的形成以及细胞外的组织重构有关。通过qPCR验证了该lncRNA的组织与细胞表达情况。单细胞数据进一步说明该lncRNA与心脏纤维化关系密切。通过在心脏成纤维细胞中敲低Dnm3os的表达，观察其对心脏成纤维细胞胶原蛋白等mRNA表达，增殖，迁移的影响，并送转录组测序进一步探索其下游机制，同时，我们也在心梗小鼠中干预Dnm3os的表达以观察其对MI还心脏纤维化以及HF的影响。结果表明该lncRNA可能与AMI后的纤维化相关，通过干预其在心脏成纤维细胞中的表明可能能够改善AMI患者的预后。