基于PINK1/Parkin介导的线粒体自噬研究益气活血法干预糖尿病肾病肾小管上皮细胞的损伤机制

Mitochondrial injury of renal tubular epithelial cell (RTEC) plays an important role in diabetic kidney disease (DKD). PINK1/Parkin-mediated mitophagy is key pathway for mitochondrial quality control. Our previous study found that PINK1/Parkin signal pathway was upregulated in isolated mitochondria from kidney of type 2 diabetic mice model. However, the role of PINK1/Parkin-mediated mitophagy in DKD is unknown. The method of ‘Supplementing Qi and Activating Blood’ is a common and effective therapeutic method for DKD in Traditional Chinese Medicine, while its mechanism and target remain unclear. We hypothesize that in the context of diabetes, upregulated PINK1/Parkin-mediated mitophagy in RTEC will induce mitochondria loss, mitochondrial injury and finally result in DKD. Huangqi and Danshen, representative herbs of ‘Supplementing Qi and Activating Blood’, could delay DKD progression by regulating PINK1/Parkin-mediated mitophagy. This program is designed to investigate the role of PINK1/Parkin-mediated mitophagy in DKD and intervention mechanism of ‘Supplementing Qi and Activating Blood’ via in vivo and in vitro study. The meaning of this program lies on exploring mechanism of DKD in terms of mitochondrial homeostasis, developing new thought and targets for DKD treatment and supplying experimental evidence for the explanation of Qi-deficiency syndrome and Blood-stasis syndrome in DKD.

肾小管上皮细胞线粒体损伤在糖尿病肾病（DKD）中发挥了重要作用。PINK1/Parkin介导的线粒体自噬是线粒体质量调控的关键环节，我们的前期研究发现2型糖尿病小鼠肾脏线粒体PINK1/Parkin信号通路上调，而这种改变在DKD中的作用尚不清楚。益气活血法是中医治疗DKD的常用有效治法，而其作用机制及靶点仍不明确。我们假设糖尿病状态下肾小管上皮细胞PINK1/Parkin介导的线粒体自噬上调致使过多线粒体丢失引起线粒体损伤从而导致DKD发生发展；益气活血法代表药物黄芪、丹参可通过调节PINK1/Parkin介导的线粒体自噬改善线粒体损伤从而延缓DKD进展。本项目拟通过体内外实验探讨PINK1/Parkin介导的线粒体自噬在DKD中的作用及益气活血法干预机制。本项目将从线粒体稳态角度揭示DKD发病机制，为DKD治疗提供新思路及靶点，并为糖尿病肾病气虚、血瘀物质基础的现代科学诠释提供实验依据

糖尿病肾病（DKD）是我国慢性肾脏病（CKD）患者的第二位原发病且呈逐年增加趋势，是CKD患者死亡的独立危险因素。肾小管上皮细胞线粒体损伤在DKD进程中发挥了重要作用。PINK1/Parkin介导的线粒体自噬是线粒体质量调控的关键环节，是维持线粒体健康的重要调控机制，然而其在DKD中的作用有待阐明。益气活血法是中医治疗糖尿病肾病的常用、有效治法，然而其作用机制尚不明确。本项目中，我们首先在体外实验中研究了PINK1/Parkin介导的线粒体自噬在高糖诱导近端肾小管上皮细胞（NRK-52E）损伤中的作用。结果表明PINK1/Parkin介导的线粒体自噬激活是高糖诱导NRK-52E细胞凋亡的内在机制。黄芪的主要活性成分黄芪甲苷可下调PINK1/Parkin介导的线粒体自噬从而减轻高糖诱导的NRK-52E细胞凋亡。继而在体内实验中我们采用益气活血法代表药物黄芪-丹参药对水煎剂干预2型糖尿病db/db小鼠12周。结果表明黄芪-丹参药对水煎剂可延缓db/db小鼠肾病进展并下调PINK1/Parkin介导的线粒体自噬。此外，体内实验还发现黄芪的主要活性成分黄芪甲苷也可下调PINK1/Parkin介导的线粒体自噬，延缓2型糖尿病肾病进展。本项目从PINK1/Parkin介导的线粒体自噬角度揭示了DKD发病机制，为DKD治疗提供了新的思路及靶点，并为糖尿病肾病中医学“气虚”、“血瘀”物质基础的现代科学诠释提供了实验依据。