百里香醌基于SIRT1/Lipin-1/LKB1调控酒精性脂肪蓄积及肝纤维化进程的分子机制研究

Alcoholic liver disease (ALD) refers to a broad spectrum of liver injuries, including alcoholic fatty liver, alcoholic hepatitis, and alcoholic cirrhosis. Excess fat accumulation in the liver could result from increased hepatic fattyacid synthesis and impaired hepatic fatty acid oxidation. Accumulation of fat in the hepatocyte results in hepatocyte ballooning and injury, and then activates hepatic stellate cells (HSCs), eventually leading to liver fibrosis. Thus, fataccumulation and HSCs activation are the two major events of ALD. Quiescent HSCsare related with silent mating type information regulation 2 homolog 1 (SIRT1) subtrate, peroxisome proliferator-activated receptor gamma (PPAR-γ), indicating that SIRT1 may be a critical targeting for ALD treatment. Previously, we found that thymoquinone upregulated SIRT1 expression in chronic-binge ethanol-induced mice fatty liver and in ethanol-stimulated HSCs as well. Thereby we hypothesis that thymoquinone may alleviate alcoholic fatty liver with fibrosis through SIRT1/Lipin-1/PPAR-γ and LKB1/AMPK signaling. Based on above, current study will focus onTQ regulates alcoholic fatty liver and alcoholic liver fibrosis via SIRT1/Lipin-1/LKB1 signaling in vivo and in vitro.

酒精性肝病(ALD)是长期大量饮酒所致的肝脏疾病，目前尚无特效治疗药物。肝脏内肝细胞脂肪过度蓄积-肝星状细胞活化是ALD发生发展的关键环节。经SIRT1-LKB1-AMPK介导的SREBP-1和PPARα异常是脂质稳态破坏的元凶，肝脏中SIRT1-Lipin-1信号是同时调控酒精性脂肪肝-肝纤维化进程，SIRT1为肝细胞脂肪蓄积‐肝星状细胞激活的多靶向调控网络提供新的干预靶标。由此提出，SIRT1/Lipin-1/LKB1是调控酒精致脂肪蓄积和肝纤维化的关键节点，基于SIRT1实现。我们发现百里香醌(TQ)上调小鼠酒精性脂肪肝和酒精刺激活化HSC的SIRT1。基于此，本研究拟从结合细胞和动物实验，明确SIRT1/Lipin-1/LKB1信号通路控制酒精性脂肪肝-肝纤维化进程的关键靶细胞及其关键位点，为ALD的防治提供新靶标与理论依据。

酒精性肝病诱发由简单的脂肪变性到脂肪性肝炎、肝纤维化以及肝癌。酒精性肝病治疗原则为戒酒、营养支持和药物治疗，严重酒精性肝硬化则可考虑肝移植治疗。目前临床西药治疗产生一定的副作用、中药缺乏统一的辨证分型治疗，导致临床疗效参差不齐、疗效重复性差。因此开发作用靶点明确、安全有效、无毒副作用的抗酒精性肝病药物仍是临床亟待解决的问题。长期酗酒会抑制肝脏中两种能够分解脂肪的蛋白质—AMPK和SIRT1的功能，SIRT1-Lipin-1-PPAR-γ和SIRT1-LKB1-AMPK信号轴在调控酒精性肝病中扮演重要角色。前期研究发现百里香醌（TQ）在体外肝形状细胞和体内动物实验上均表现出显著的调控肝纤维化作用，减少小鼠肝脏炎性浸润，降低肝纤维化蛋白表达，增强SIRT1-PPARγ信号通路表达。因此推断调节SIRT1-PPARγ信号通路可能是调控酒精性肝纤维化的重要靶点之一。本项目明确SIRT1是Lipin1/LKB1信号通路介导肝脏脂肪蓄积及肝纤维化不可或缺的关键上游节点，阐明百里香醌经由SIRT1-Lipin-1-PPARγ和SIRT1-LKB1-AMPK信号途径调控酒精性脂肪肝-酒精性肝纤维化进程。通过肝细胞和肝星状细胞共培养，阐明百里香醌调控酒精刺激后受损肝细胞、诱发肝星状细胞活化的机制，以及两者相互影响的相关性；采用SIRT1和LKB1单独/联合过表达或沉默时，明确TQ是同时调控SIRT1和LKB1作为干预下游信号转导研究的契机；采用SIRT1抑制剂与激动剂分析百里香醌基于SIRT1干预酒精性肝病治疗的分子作用机制，为探索抗酒精性肝病作用机理的研究方法可提供可行的思维，为将来的临床应用提供可靠的药理学依据，并可推进百里香醌的新药研发进程。本项目开展中发表SCI收录论文15篇，申请专利4项，培养硕士研究生6名，博士研究生5名。