调控脂联素和瘦素的吡咯并嘧啶类衍生物的优化合成、构-效关系及其在肥胖型非酒精性脂肪肝中作用研究

Nonalcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease and the incidence seems to be rising as the obesity epidemic continues. Currently, no recommended conventional medicines are used in clinic. Adipocytokines such as adiponectin and leptin play key roles in the development and progression of NAFLD. However, the exploration of small-molecule drugs targeting to adiponectin and leptin for the treatment of NAFLD is blank both in China and abroad. Previously, Pyrrolo[3,2-d]pyrimidine-2,4-dione derivative SKLB058 with an oral bioavailability of 30.5% was found to regulate the expression of adiponectin and leptin in 3T3-L1 adipocyte, reduce the fat deposition in the liver tissue of NAFLD and obese mice and further improve the level of blood glucose, lipid and insulin resistance, etc. Therefore, this project is planned to design and synthesize a library of 500 compounds based on pyrrolo[3,2-d]pyrimidine-2,4-dione and SKLB058 as lead, optimize the synthetic method and process, and evaluate them by the screening of adiponectin and leptin secretion in adipocyte for the study of structure-activity relationship. Furthermore, we investigate in vivo efficacy, pharmacokinetics, and toxicology of these candidate compounds to obtain a novel, safe and potent drug candidate for the treatment of obesity-related NAFLD. So, there are potential application and development prospect and important social and economic significance if the study is successfully done.

非酒精性脂肪肝（NAFLD）的发病率随着肥胖患者的增多而逐年上升，目前临床上尚无推荐的常规治疗药物。脂肪因子脂联素和瘦素在NAFLD发生发展中起关键作用，而基于调控脂联素和瘦素而治疗NAFLD的小分子药物研究在国内外鲜有报道。前期研究发现吡咯并[2,3-d]嘧啶二酮衍生物SKLB058，口服生物利用度为30.5%，能调控3T3-L1脂肪细胞中脂联素和瘦素分泌，减少NAFLD和肥胖动物模型中肝脏脂肪沉积并缓解血脂、血糖、胰岛素抵抗等代谢指标。本项目将以吡咯并[2,3-d]嘧啶-2,4-二酮结构为基础，SKLB058为先导化合物，拟设计并合成一个含500小分子化合物库，优化合成路线与工艺，完成体外脂联素和瘦素筛选，建立具有指导意义的构-效关系。同时针对候选化合物，进行体内药效学、药代动力学和初步毒理的评价，筛选出新型安全有效的治疗肥胖相关的NAFLD药物候选分子。

本项目针对非酒精性脂肪肝（NAFLD）的发病率随着肥胖患者的增多而逐年上升，目前临床上尚无推荐的常规治疗药物的现状，以脂肪因子脂联素和瘦素在NAFLD发生发展中起关键作用为基础，合成系列吡咯并嘧啶酮衍生物，其中化合物WCH016对脂肪酸结合蛋白4（FABP4）有良好的结合活性，并在体外发现其可以有效的抑制FABP4的表达。体外HepG2肝癌细胞葡萄糖消耗试验、3T3-L1脂肪细胞调控脂联素和瘦素实验及体内DIO小鼠模型共同证实了WCH016不仅能够改善肥胖病症如降低体重、肝重、附睾脂肪重量以及胰岛素抵抗，并且没有引起低血糖症状，此外，化合物8g生物利用度较好（60.5%）。组织病理切片苏木素伊红染色实验表明，WCH016在体内毒性实验，体内NAFLD动物模型以及DIO模型实验中，毒性都很低，是一个安全有效的，可用于口服的降低血脂和血糖的潜在化合物。Western blotting结果也证明，WCH016可以上调Adiponectin的表达、下调leptin的表达，同时调节AMPK分子通路。以上结果说明，化合物WCH016可用于非酒精性脂肪肝的治疗。项目执行期间相关成果发表论文3篇，并申请国内专利1项。