Sestrins 介导骨骼肌细胞自噬在有氧运动改善胰岛素抵抗中的作用机制

The Sestrins constitute a family of evolutionarily conserved stress-inducible proteins, and functions in cells protection by suppressing ROS accumulation. In our previous studies, we have shown that the interaction of AMPK and Sestrins is possibly participating in the regulation of exercise induced cellular autophagy activation and insulin resistance alleviation. Exercise activates cellular autophagy is one of the important mechanisms of exercise ameliorating insulin resistance. Based on our previous findings, this project will be focus on Sestrins/AMPK/mTOR signaling pathway, starting with exercise activates cellular autophagy, we will first screen the potential sites with mutation/modification, next we will clone it into expression plasmid vector to transfect cells. We will help elucidates the biological mechanisms of Sestrins/AMPK signaling in the process of aerobic exercise ameliorating insulin resistance by using both AMPK transgenic mice and in vitro cell culture models with gain of function and loss of function studies. Our study will provide intervention-based evidence to better understand the mechanism of Sestrin/AMPK/mTOR signaling in exercise improving insulin resistance mediated by autophagy. Together, these studies promise to elucidate a major new pathway controlling exercise ameliorating skeletal muscle insulin resistance. It has a direct impact on our ability to understand and provide new theoretical foundation of aerobic exercise improving cellular metabolism.

Sestrins 是新近发现的细胞应激诱导蛋白，在氧化应激状态下可清除细胞内 ROS 堆积而发挥细胞保护作用。我们前期研究发现骨骼肌细胞AMPK与 Sestrins 之间的相互作用可能参与了运动促进骨骼肌细胞自噬、改善组织代谢的过程。运动促进机体组织细胞自噬活性增强可能是运动改善IR的重要机制之一。本课题以此为基础，以 Sestrins/AMPK/mTOR 信号通路与细胞自噬活性关系为主线、以运动促进细胞自噬为切入点，利用AMPK基因敲除小鼠和离体骨骼肌细胞培养两个模型, 通过筛选突变位点并构建表达质粒，从功能增益和缺失正反两方面入手，对Sestrins/AMPK信号通路介导细胞自噬活性在有氧运动改善IR的作用机制展开深入研究，以揭示Sestrins与AMPK/mTOR信号通路之间相互作用关系及有氧运动调控细胞自噬的生物学机制。本研究将为丰富完善有氧运动改善细胞代谢的机制提供重要理论依据。

有氧运动能够改善机体能量代谢，改善胰岛素抵抗，但是其中的机制尚不完全清楚。最近的研究发现应激诱导蛋白 Sestrins (SESNs) 有可能在有氧运动调控机体能量代谢中发挥关键作用。本研究拟采用 AMPKα2-/-小鼠模型，探究 Sestrins 与细胞自噬的调控关系及其在有氧运动改善 IR 中的作用，并结合 C2C12 肌管细胞培养等试验方法，深入探究 Sestrins 与 AMPK/mTOR/S6K1 信号通路之间的调控关系及其在细胞自噬调控过程中的分子机制，解释骨骼肌细胞自噬在有氧运动改善骨骼肌能量代谢、增强胰岛素信号敏感性过程中的作用机制。采用 Sestrin2-/- 小鼠并且结合棕榈酸、JNK 抑制剂和激动剂干预肌管细胞等方法，探究 Sestrins 在有氧运动调控骨骼肌脂质代谢中的作用机制。Sestrins 作为新发现的细胞应激诱导蛋白，对其功能及作用机制的深入研究将为代谢性疾病药物治疗新作用靶点的开发提供重要的理论参考。