基于miR-214/PTEN通路探讨黄芪三七合剂防治糖尿病肾病足细胞损伤的作用机制

The key points of the progression of diabetic nephropathy (DN) are different types of podocyte injury, such as epithelial-mesenchymal transition , apoptosis and detachment and so on. It is urgent to treat DN with combination of different drugs according to different types of podocyte injury in order to delay the progression of the disease. Traditional Chinese medicine compound prescription is more suitable for solving this difficult problem because of its multiple actions and integral regulation. Our previous studies (NSFC81000305, 81573738) found that Astragaloside and Notoginsenoside R1, the effective components of Astragalus membranaceus and Panax notoginseng mixture which is a Yiqi Huoxue Compound, act on two different types of podocyte damage, which are apoptosis and detachment, respectively and synergistically protect podocyte, thus delaying the progression of DN. In view of the important role of miRNA in podocyte injury, we found that Astragalus membranaceus and Panax notoginseng mixture could inhibit the abnormal expression of miRNA-214 in DN mice by using miRNA chip. Therefore, this project uses the cell and animal models, chromatin immunoprecipitation, gene silencing or overexpression techniques to further clarify the mechanisms of Astragalus membranaceus and Panax notoginseng mixture in regulating the expression of miRNA-214 and its target gene PTEN, interfering the apoptosis, detachments and epithelial-mesenchymal transition of podocyte, and then provide new ideas and methods for the treatment of DN by using Chinese medicine compound prescription due to its advantages of multiple actions and integral regulation.

足细胞凋亡、脱落及转分化等多环节损伤是糖尿病肾病(DN)进展的关键，如何针对足细胞不同损伤环节，多靶点、联合用药，从而有效阻止DN进展，是目前迫切需要解决的难题。中药复方配伍以其多位点、整体调节的优势，特别适合解决这一难点。我们前期系列研究(NSFC81000305、81573738)发现益气活血复方黄芪三七合剂有效成分黄芪甲苷和三七皂苷R1可分别作用于足细胞凋亡及脱落两种不同损伤环节，协同保护足细胞，延缓DN进展。鉴于miRNA在足细胞凋亡及脱落等多环节损伤中的重要作用，我们通过miRNA芯片筛选发现黄芪三七合剂可抑制DN小鼠miRNA-214异常表达。因此，本项目采用细胞及动物模型，结合基因沉默和过表达、染色质免疫沉淀技术，进一步阐明黄芪三七合剂调节miRNA-214及其靶基因PTEN表达，多环节干预足细胞凋亡、脱落和转分化的机制，为中医方剂配伍多靶点、协同防治DN提供全新的思路。

足细胞凋亡、脱落及转分化等多环节损伤是糖尿病肾病(DN)进展的关键，如何针对足细胞不同损伤环节，多靶点、联合用药，从而有效阻止DN进展，是目前迫切需要解决的难题。本项目研究发现黄芪三七可改DN蛋白尿及足细胞损伤，且黄芪和三七具有协同作用，并阐明了黄芪三七合剂多环节干预足细胞凋亡、脱落和转分化的机制，从而为中药配伍多靶点、协同防治DN提供全新的思路。进一步研究发现黄芪有效成分黄芪皂苷II能改善DN动物模型蛋白尿、肾功能及肾脏病理损伤和足细胞超微结构损伤，为黄芪三七有效成分的深入研究提供了实验依据和研究基础。此外还发现三七及其有效成分三七总皂苷和三七皂苷Fc能改善足细胞凋亡，可能成为具有开发潜力的新型足细胞保护药物。还发现三七有效成分三七总皂苷可通过调节miRNA-214/ PTEN-PDK1-Akt-mTOR 信号通路表达，改善DN蛋白尿、肾脏病理损伤及足细胞损伤，从而为防治DN提供了新的思路和方法。本项目以miRNA 为切入点探讨了黄芪三七合剂不同有效成分配伍，多位点、整体调节miRNA 网络，进而发挥其复杂生物学效应的新机制，将为研究中药复方多环节、协同作用机理提供新的思路和方法。此外，足细胞损伤是多种肾小球疾病进展的共同发病机制，本项目从保护足细胞的视角，探讨黄芪三七合剂及其有效成分防治足细胞损伤的作用机制，将为临床防治以足细胞损伤为特征的肾小球疾病(包括DN)提供新途径。在该项目资助下，已发表SCI论文4篇，获得上海市科技进步奖二等奖1项，培养研究生6名。