TMAO通过AP-1/Fdxr途径调控线粒体能量代谢促进心肌缺血再灌注损伤的作用及机制研究

研究表明高TMAO血症人群发生急性心肌梗死后心肌损伤更为严重，但TMAO是否促进心肌缺血再灌注损伤（MIRI）目前尚未明确。我们预实验发现：TMAO增加小鼠缺血再灌注后心肌坏死面积，并加重心肌细胞线粒体能量代谢障碍。文献指出线粒体能量代谢障碍是促进MIRI的重要机制；RNA-seq结果显示TMAO下调线粒体功能蛋白Fdxr并上调转录因子AP-1；生信分析表明AP-1可能为Fdxr的上游负调控因子。因此提出假说：TMAO上调AP-1阻遏Fdxr转录，介导线粒体能量代谢障碍，促进MIRI。本项目拟在细胞和动物MIRI模型中：①明确TMAO促进MIRI；②验证TMAO通过加重线粒体能量代谢障碍促进MIRI；③通过敲低和过表达Fdxr、ChIP-qPCR及AP-1基因敲除等方法，阐明TMAO通过上调AP-1阻遏Fdxr转录，调控线粒体能量代谢。本研究有望为减轻高TMAO血症人群MIRI提供新策略。

It is reported that patients with high level of plamse trimetlylamine oxide (TMAO) have more serious myocardial injury after acute myocardia infaction. However, it is not clear whether TMAO aggravates myocardial ischamia/reperfusion injury (MIRI). Our pre-experiment showed that TMAO increased mouse myocardial infarct sizes after ischamia/reperfusion. Besides, TMAO also impaired energy metabolism in mitochondria during myocardial ischamia/reperfusion. According to the result of RNA-seq and computational analysis, we found that TMAO might impaire mitochondrial energy metabolism by a AP-1/Fdxr pathway. Therefore, we hypothesis that TMAO impaires energy metabolism and aggravates MIRI by a AP-1/Fdxr pathway. To verify this hypothesis, we plan to perform further in vitro and in vivo experiments:①demonstrating that TMAO aggravates MIRI in both in-vitro and in-vivo myocardial ischamia/reperfusion modles;②demonstrating that TMAO aggravates MIRI by impairing mitochondrial energy metabolism;③through knocking down and overexpressing Fdxr, knocking out AP-1, ChiP-qPCR and other methods to demonstrate that TMAO impaires energy metabolism in a Fdxr/AP-1-dependent manner. The successful completion of our research will be helpeful to develop a new strategy to alleviate MIRI in patients with high level of plamse TMAO.