髙脂肥胖小鼠肝脏核受体的变化及调控作用研究

Obesity is a major health issue worldwide and has increased dramatically during recent decades. Visceral adipose tissue secretes free fatty acids (FFAs) and hormones, known as adipokines, and thus seems to play a major role in the development of nonalcoholic fatty liver disease (NAFLD), cirrhosis and even HCC. In the liver, by sensing lipid-soluble hormones and dietary lipids and governing expression of key liver metabolic genes, Nuclear receptor (NR) proteins direct a large array of key hepatic functions that include lipid and glucose metabolism，bile secretion and bile acid homeostasis. Derangements of nuclear receptor regulation and genetic variants may contribute to the pathogenesis and progression of liver diseases including cholestatic and fatty liver disease, drug hepatotoxicity, viral hepatitis, liver fibrosis, and cancer. We hypothesize that NRs' activities and their cellular signal should be altered in high fat diet (HFD) induced obesity (DIO) mice liver to regulate gene expression for metabolic adjustment or eliminate fatty acid surplus. However, little is known about their protein expression and DNA binding activity in the liver due to low abundance and lack of high-throughput methods for detection at the protein level. Fortunately, we have developed an NRRE-pulldown method for profiling DNA binding activity of the NR transcription factor superfamily. In this project, we will apply this powerful quantitative strategy to investigate the alterations of NR proteome in DIO mice liver. The change of NR pattern in DIO mice liver will be monitored and comprehensively compared by combining our NRRE-pulldown strategy with quantitative proteomics. A set of potential NR or coregulator candidates will be further validated by biological analysis. Our study will uncover the alteration of NRs and coregulators on protein level in a large-scale proteome aspect. The results will expend people's knowledge of the biological functions of NR superfamily of transcription factors in liver disorder of obese subjects, and provide potential drug targets for treatment of obesity associated liver diseases such as hepatic steatosis and NAFLD.

肥胖已成为严重威胁人类健康的代谢和营养失衡性疾病。腹部脂肪组织通过分泌自由脂肪酸、激素、炎性因子等参与非酒精性脂肪肝病（NAFLD）、肝硬化、肝癌等的发生发展过程。核受体是调节肝脏特异基因表达的重要转录因子超家族，参与肝脏生理病理过程，与肝炎、肝纤维化、脂肪肝等多种肝病的发生发展密切相关。但核受体超家族蛋白在肥胖症肝脏中的动态变化及其对肝脏病理生理的影响尚无报道，本课题拟采用NRRE-pulldown亲合富集联合质谱鉴定内源核受体蛋白的技术，通过引入质谱定量策略，检测核受体超家族蛋白在髙脂肥胖小鼠肝脏中的表达变化，建立差异核受体蛋白质组与肥胖症肝脏代谢活动的联系；对差异显著的核受体/辅调节蛋白进行深入功能研究，用生物学分析手段探讨其在肥胖症肝脏代谢中的调控作用。结果有望为系统了解核受体超家族蛋白在肥胖症肝脏中的调控作用提供理论依据，为肥胖相关代谢综合症的治疗提供新靶标。