新型mTOR抑制分子Deptor在未成熟心肌保护中的作用及机制研究

婴幼儿手术日益增多，针对未成熟心肌保护的研究刻不容缓。自噬可以保护缺血再灌注引起的心肌细胞受损，课题组前期研究发现精胺可以抑制mTOR通路，从而诱导自噬，发挥对未成熟心肌细胞的保护作用，但mTOR下游机制不清。Deptor是目前发现唯一的PI3K/AKT/mTOR信号下游直接抑制因子，可以同时抑制mTORC1/2并诱导自噬。我们初步研究发现在体外模拟缺血再灌注损伤培养的未成熟心肌细胞中，Deptor表达明显下降，mTORC1/C2通路激活；上调Deptor表达可以抑制mTORC1/C2，促进自噬发生并减缓缺血缺氧引起的心肌细胞损伤。本研究拟在此基础上，通过CRISPR-Cas9和转基因动物等技术，在体内外心肌细胞损伤模型中验证Deptor在未成熟心肌损伤中的作用，明确自噬在这一过程中的作用，揭示mTOR调控未成熟心肌细胞发生自噬的机制。本研究结果可望为未成熟心肌保护提供新的治疗靶点。

The exploration of immature myocardial protection has become an urgent task following the development of cardiovascular surgery technology and more younger patients getting the opportunities to regain their health in recent years. Previous studies have found that autophagy can repair the ischemia damage cells. We have already investigated that Spermine could ameliorate ischemia/reperfusion injury in cardiomyocytes via regulation of autophagy and inhibition mTOR signal pathway. However, the specific mechanism of mTOR downstream is still unknown. Deptor is the only direct inhibitory factor for downstream of PI3K/AKT/mTOR signaling pathway, which could also inhibit both mTORC1 / C2 and induce autophagy. Our previous study indicated that in the ischemia/reperfusion injury of immature myocardial cells in vitro, the expression of Deptor significantly decreased and C2 / mTORC1 pathway was activated. Transfection with Deptor could protect the myocardial cells from ischemia-reperfusion injury via suppressing mTORC1 / C2 and promoting autophagy. Based on previous studies, this project wants to verify the hypothesis that Deptor could attenuate the ischemia/reperfusion injury in immature cardiomyocytes in vivo and in vitro. With the help of lentivirus transfection, transgenic animal and electron microscopy immunofluorescence techniques, we want to explore the role of autophagy in the protection of Deptor and the mechanism of mTOR in the regulation of autophagy. The purpose of our study is to find a new target to protect immature myocardium from ischemia injury.