牛蒡子提取物通过PP2A调节糖尿病肾脏疾病炎症及细胞骨架的作用及机制研究

The incidence of diabetic kidney disease (DKD) is increasing rapidly, which is the primary cause of end-stage renal disease (ESRD). However, the treatment of DKD is limited, though intervention with ACEI/ARB drugs at the early stage, it still enters into the stage of ESRD. Traditional Chinese medicine treatment can effectively reduce DKD proteinuria, delay the progress of renal function, and has broad application prospects, but the mechanism is still unclear. The applicant screened Arctigenin(ATG), an extract of Arctium lappa L. from the effective prescription for early stage of DKD treatment. Previous studies showed that ATG could reduce proteinuria excretion and renal pathological damage in DKD animal models. And RNA sequence showed that ATG could down-regulate inflammatory signaling pathways, up-regulate cytoskeleton protein and adhesion signals. The team further screened protein phosphatase 2 (PP2A) which ATG had strong affinity and could activate their activity by means of drug affinity response target stability (DARTs) and Proteomics. On this basis, this project intends to confirm that ATG, through its main target PP2A, can achieve anti-inflammatory and cytoskeleton protection, increase adhesion and reduce migration of podocytes in high glucose environment, laying a solid foundation for the development of new drugs for early DKD.

糖尿病肾脏疾病（DKD）的发病率迅速上升，成为导致终末期肾脏病（ESRD）的首要原因。然而治疗DKD的手段有限，即使早期应用ACEI/ARB类药物仍进入ESRD阶段。中医药治疗能有效减少DKD蛋白尿、延缓肾功能进展，运用前景广阔，但作用机制仍不明确。申请人在治疗早期DKD有效经验方中筛选出君药牛蒡子的提取物牛蒡苷元（ATG），前期研究显示ATG可以减少DKD小鼠蛋白尿、减轻肾脏病理损伤。进一步对DKD小鼠的肾小球RNA测序，发现ATG可以下调炎症信号通路、上调细胞骨架蛋白及粘附等相关通路。课题组还通过药物亲和力响应目标稳定性技术结合蛋白质谱的方法，筛选出ATG与蛋白磷酸酶2（PP2A）有较强亲和力且能激活其活性。因此，本项目在此基础上拟证实ATG通过其主要作用靶点PP2A，实现高糖环境下对足细胞的抗炎及保护细胞骨架、增加粘附减少迁移的作用，为开发治疗早期DKD的新药打下坚实基础。

背景：糖尿病肾脏疾病（DKD）的发病率迅速上升，成为导致终末期肾脏病（ESRD）的首要原因，但其治疗策略有限且效果不尽理想。中医药治疗虽能有效减少DKD蛋白尿、延缓肾功能进展，但作用机制仍不明确。课题组在科室治疗早期DKD的经验效方中筛选君药牛蒡子的提取物牛蒡苷元（ATG），前期研究发现ATG与蛋白磷酸酶2（PP2A）有较强亲和力且能激活其活性。.主要研究内容：（1）证实高糖环境下 PP2A 通过去磷酸化p65和DBN1 介导足细胞的炎症和粘附；（2）通过体内体外实验证实ATG对高糖下足细胞的保护作用及其机制；（3）证实ATG通过PP2A缓解DKD的作用。.重要结果：（1）动物实验证实ATG可以减少DKD小鼠的尿蛋白排泄、改善肾脏病理损伤，并能减少肾组织p-p65和p-DBN1的表达；（2）细胞实验证实高糖环境下PP2A通过去磷酸化p65和drebrin减少足细胞的炎症和迁移。同时，ATG通过PP2A去磷酸化p65，减少高糖环境下足细胞的炎症反应；并能去磷酸化DBN1，增强高糖环境下足细胞的粘附作用，减少迁移，稳定细胞骨架蛋白；（3）利用足细胞特异性敲除PP2A小鼠建立DKD模型证实PP2A在DKD小鼠肾组织中的重要作用，且ATG通过PP2A发挥肾脏保护作用。