非酒精性脂肪性肝病（NAFLD）涉及的肝细胞自我保护机制尚未完全阐明，线粒体功能保护因素分析是重要着眼点。NS2TP能抑制非肝细胞线粒体损伤和细胞凋亡，还能与去乙酰化酶Sirt1结合。我们发现Sirt1沉默后NS2TP蛋白水平增高、高脂饮食诱导NAFLD小鼠肝组织NS2TP表达增多而Sirt1减少。因此提出“NS2TP保护脂肪变性肝细胞线粒体功能，NS2TP蛋白水平受Sirt1调控”假说。本项目拟利用NAFLD小鼠模型、体外细胞模型和HepG2细胞系，通过免疫荧光、电子显微镜、线粒体功能分析、流式细胞术、Western blot、免疫（共）沉淀和RNAi等技术，观察NS2TP在脂肪变性肝细胞线粒体中的表达和定位，分析NS2TP对脂肪变性肝细胞凋亡和线粒体功能的影响及机制，探讨Sirt1介导的NS2TP蛋白表达增高的机理。本项目将为阐释肝细胞自我保护机制和NAFLD发病机制研究提供新切入点。

The mechanism of self-protection in hepatocytes with NAFLD still needs to be clarified. It is a good starting point to analysis the factors of protecting mitochondrial function. NS2TP can inhibit mitochondrion damage and apoptosis, and bind with deacetylase Sirt1 as well. Our previous study showed that increased expression of NS2TP in liver tissues of mouse NAFLD models could be induced by high fatty diets, and levels of NS2TP increased when Sirt1 kept silence in HepG2 cell lines. Here we have a hypothesis that NS2TP should protect mitochondrion function in the steatosis stage and the protein level of NS2TP might be regulated by Sirt1. These experiments will performed on mouse NAFLD models of high fatty diet, steatosis cell models in vitro or hepatoma cell lines. And this project will be carried out by using immunofluorescence, electronmicroscope, mitochondrial function analysis, flow cytometry, Western blot, co-immunoprecipitation, immunoprecipitation and RNAi. This study is to explore the expression and sublocalization of NS2TP in adipose degeneration hepatocyte mitochondrion, analyze the effects and mechanisms of NS2TP on apoptosis and mitochondrial function, and further investigate the deeply mechanism of NS2TP regulated by Sirt1 at protein level. This project is expected to supply a further thinking for the self-protection function of hepatocyte, and also be a novel idea for the NAFLD research.