CRT治疗心衰的线粒体蛋白质组的动态变化及调控

Cardiac resynchronization therapy (CRT) is a main treatment on drug-refractory heart failure, but in accordance with the standard guidelines recommend patient selection, there are still 30% of patients are non-responders. The reason of patients non response is not clear. Foreign animal models confirmed that the process of CRT therapy on heart failure is accompanied by changes in myocardial mitochondria, our previous study also found that mitochondria and ALDH2 expression were significantly increased after treatment of CRT. But how mitochondrial proteome expression profiling dynamically change before and after treatment of CRT? Is there difference in mitochondrial proteome expression in CRT group and invalid group? What is the function of these proteins? Whether these differences affect the CRT prognosis? What is the regulation of mitochondrial proteome expression by CRT? These are unknown. This study will describe the dynamic changes and control mechanism of mitochondrial proteome of CRT on heart failure by the animal model of rapid pacing-induced heart failure and CRT therapy of heart failure, explore the differences in mitochondrial proteome expression between CRT group and invalid group and its affect on CRT prognosis, look for the possible reasons of CRT non response at the molecular level, provide new ideas for clinicians to select new indicators to predict CRT efficacy and have greater clinical application potential.

心脏再同步化治疗（CRT）是药物难治性心衰的主要治疗方法，但按照指南推荐的标准选择病人，仍有30%患者对治疗无反应，CRT无反应的原因目前尚不清楚。国外动物模型研究证实CRT治疗心衰过程中伴随心肌线粒体的变化，我们前期的研究也发现CRT治疗后线粒体数量增加，ALDH2表达明显增加。但CRT治疗前后心肌线粒体蛋白质组表达谱如何动态变化？CRT有效组与无效组心肌线粒体蛋白质组表达有无差异？这些差异蛋白的功能是什么？这种差异是否对CRT预后有影响？CRT通过何种途径对其进行调控？这些都是未知的。本研究拟通过快速起搏诱发心衰及CRT治疗心衰的动物模型阐述CRT治疗心衰的心肌线粒体蛋白质组表达谱动态变化及调控机制，探讨CRT有效组与无效组心肌线粒体蛋白质组差异表达及其对CRT预后的影响，寻找CRT无反应在分子水平上的可能原因，为临床选择新的预测CRT疗效的指标提供新思路，具有较大的临床应用潜能。

心脏再同步化治疗（CRT）是药物难治性心衰的主要治疗方法，但仍有部分患者无应答，促使我们对CRT改善心功能的机制进行研究。通过消融左束支造成LBBB+右心室快速起搏建立心衰动物模型，CRT治疗组后期植入CRT。在此基础上，我们通过影像、病理、电镜、蛋白质组学、基因芯片从宏观到微观不同层面观察CRT治疗后的变化。我们重点锁定了能量代谢和纤维化这两个方面。我们采用8标iTraq联用液相色谱串级质谱的定量蛋白质组分析平台及生物信息分析，发现CRT治疗后相对心衰时所有与能量代谢相关的28个蛋白质除了ACSL1以外，全部下调。我们将定位在线粒体内的蛋白做了信号图，接下来行weston blot及血清Elisa验证。基因芯片发现心衰心肌组织中能量代谢相关酶类丙酮酸脱氢酶激酶4(PDK4)表达发生改变，在功能学层面进一步提示CRT对线粒体能量代谢的影响。我们测定了CRT治疗后线粒体基质钙离子浓度的变化情况，结果发现心衰犬线粒体基质钙离子浓度上调，而CRT则可减轻钙离子浓度的增加。在此基础上，我们进行了初步的基因芯片筛查，结果发现心衰犬心肌组织中线粒体内膜钙离子通道蛋白MCU、MICU2表达上调，而CRT在改善心衰症状的同时，可下调MCU表达水平（与蛋白质组学结果一致），上调MICU2表达水平（图6），最终影响线粒体基质内钙离子浓度的对应变化。.这些研究结果都提示CRT 与线粒体能量代谢密切相关。通过调节线粒体内膜上钙离子通道蛋白MCU、MICU2的表达，调控线粒体基质钙稳态，继而通过影响某些能量代谢相关酶类活性，如PDK4等，恢复衰竭心肌细胞能量供应，从而改善心脏功能。有待进一步研究去验证。