抗非酒精性脂肪性肝炎新型先导化合物发现及作用机制研究

Non-alcoholic steatohepathtitis (NASH) is characterized by inflammation induced by lipid ectopic accumulation (steatosis) in hepatocyte, its incidence has exceeded that of hepatitis B as the first leader of chronic liver disease. Currently there are still no approved drugs for NASH treatment. Hence, research and development of innovative anti-NASH drugs are very important. Studies have shown that mitochondrial oxidative stress caused by steatosis plays a pivotal role for NASH development. Our previous studies have found that hit compound R17 increased aerobic metabolism, reduced the triglyceride levels in hepatocytes, inhibited mitochondrial oxidative stress, decreased the levels of inflammatory factors. Similar results were verified in the obese mouse model. Thus the applicant propose a new strategy of anti-NASH drugs research based on promoting energy metabolism, inhibiting lipid ectopic accumulation and its mediated mitochondrial oxidative stress, protected hepatocytes viability beyond lipitoxicity from the starting. In this research, on the basis of our previous research results, we will design and synthesize a series of novel analogues of R17, reasonably construct the anti-NASH evaluation system, evaluate the activities of synthesized compounds and summarize the structure-activity relationship, identify the lead compounds, and further deeply study the molecular mechanism of lead compounds against NASH in vivo and in vitro. This project might provide a useful theoretical and experimental basis for the establishment of new therapy strategy and the development of new anti-NASH drugs.

非酒精性脂肪性肝炎（NASH）以肝细胞脂质过度沉积（脂肪变性）引发的肝脏炎症为主要特征，其发病率已超过乙型肝炎成为第一大类慢性肝病。目前仍没有直接治疗NASH的一线药物。因此，抗NASH创新药物研究意义重大。研究证明肝细胞脂肪变性诱导的线粒体氧化应激是NASH发病关键。申请人前期发现，化合物R17可促进肝细胞有氧代谢，降低脂质累积，抑制线粒体氧化应激，下调炎症因子水平，类似结果在肥胖小鼠模型上得到验证。为此，申请人提出通过促进能量代谢抑制脂质异位累积及其介导的线粒体氧化应激，保护肝细胞活性，进而从源头阻断脂质毒性，实现抗NASH的研究新策略。本项目拟设计合成新型R17类似物，并科学构建抗NASH评价体系，全面评价化合物活性并总结构效关系，深入研究代表性化合物的体内外抗NASH能力和分子作用机制，发现抗NASH先导化合物。为发展NASH治疗新策略和发现抗NASH新药提供理论和和实验依据。

非酒精性脂肪性肝炎（NASH）以肝细胞脂质过度沉积（脂肪变性）引发的肝细胞凋亡、引发炎症与纤维化等多重打击共存的慢性肝脏疾病，其发病率已超过乙型肝炎成为第一大类慢性肝病。目前NASH药物研究靶点稀缺且仍没有有效的直接治疗NASH的一线药物。因此，发现新的有效的NASH治疗靶点与NASH创新药物研究意义重大。. 肝细胞脂肪蓄积是NASH发生的起始诱导因素，减少冗余脂质是NASH治疗的先决条件。申请人前期研究发现化合物R17可促进肝细胞脂质氧化代谢，显著减少肝细胞脂质，并抑制线粒体氧化应激、炎症与纤维化。本项目通过化学合成策略设计合成80个化合物新型R17类似物（新化合物65个）；结合NASH病理机制构建了多种NASH细胞研究模型；采用NASH模型筛选评价化合物抗NASH活性、总结构效关系；深入研究优选化合物（SYSU-3d, IQN23, 6e等）的体内外抗NASH活性及其新作用机制。构效关系研究结果表明8α-位醛基是化合物维持降脂活性的必备基团，吲哚和喹唑啉片段的嘧啶环对保持降脂活性是关键，而D环则是非必备基团；其次，引入的侧链基团性质（以含N的刚性或半刚性环较好）与侧链长短（2-4个碳原子最佳）对降脂活性也有一定影响。机制研究发现该类化合物是一类HSF1激动剂，通过促进HSF1核转位并结合到线粒体再生因子PGC-1α启动子区域激活其表达，并激活AMPK通路，从而增强细胞线粒体含量与脂质氧化代谢能力。敲除HSF1或者PGC-1α则使该类化合物的肝保护作用消失；同时，敲除HSF1或者PGC-1α会增强细胞脂质毒性，促进肝细胞凋亡，表明激活HSF1/PGC-1α代谢轴可有效治疗NASH。以上研究结果提示，以HSF1为靶点发展新型HSF1激动剂是发展NASH治疗药物新的有效策略。. 本项目以先导化合物R17为基础，通过药物化学、化学生物学、细胞分子生物学等多学科方法发现了新的代谢调控靶点，为未来发展新的NASH治疗新策略和发现抗NASH新药提供理论和和实验依据。