Drp1调控的线粒体自噬在糖尿病肾病中的作用及机制研究

Diabetic kidney disease（DKD）is a main cause of end-stage renal disease，and tubular injury is one of the early pathological characteristics of DKD. Mitochondria is the most important organelle in energy metabolism，and cellular oxidative injury which is induced by reactive oxygen species（ROS）accumulation in mitochondria plays an important role in the pathogenesis of DKD. Therefore, the investigations of the function of mitochondria in tubular cell injury of DKD is one of the hot spots of current kidney disease research area. Cells continue to remove damaged or aging mitochondria through mitophagy. Drp1 is one of the main molecules that mediate mitochondrial fission and regulate the morphology of mitochondria. NLRP3 is a kind of receptor-NOD like receptor, which is the main component of inflammasome. We have shown earlier that the expression of Drp1 and NLRP3 was significantly decreased in renal tubular cells of DKD. But so far, the regulatory mechanism of mitophagy in DKD is still unclear. This paper takes the mitochondria as the starting point, to observe the expression of Drp1 in renal tubular cells from clinical and in vitro, and analyze its relationship with NLRP3 and mitophagy, the regulatory mechanism of the expression of Drp1. The aim of this study is to investigate the new mechanism of mitochondrial oxidative injury in tubular cells of DKD，provide a new theoretical basis for the prevention and control of the progression of DKD.

糖尿病肾病（DKD）是ESRD最主要的病因，而肾小管损伤是DKD早期的病理特征之一。线粒体是人体能量代谢最重要的细胞器，而线粒体产生大量的ROS蓄积导致细胞氧化损伤是DKD肾脏病理变化与发病机制的关键环节，故研究线粒体的功能是当前肾脏病研究领域的热点之一。细胞通过线粒体自噬作用不断清除受损或老化的线粒体，从而维持细胞稳态。Drp1是介导线粒体分裂、调控线粒体形态的主要分子之一。NLRP3炎症小体是一种识别受体-NOD样受体，是炎性小体的主要组分。迄今，线粒体自噬在DKD中的调控机制尚不清楚。本课题将以线粒体为着眼点，从临床、体外多个角度观察Drp1在肾小管上皮细胞中的表达，分析其与NLRP3及线粒体自噬的关系，研究Drp1表达可能的调控机制，揭示Drp1在糖尿病肾病小管损伤中的作用及分子机制，旨在阐明DKD小管细胞线粒体介导的氧化损伤新机制，为防治DKD进展提供新的理论依据。

糖尿病肾病（DKD）是ESRD最主要的病因，而肾小管损伤是DKD早期的病理特征之一。线粒体是人体能量代谢最重要的细胞器，而线粒体产生大量的ROS蓄积导致细胞氧化损伤是DKD肾脏病理变化与发病机制的关键环节。Drp1是介导线粒体分裂、调控线粒体形态的主要分子之一。NEAT1是LncRNA核富含丰富的转录本1。迄今，线粒体自噬在DKD中的调控机制尚不清楚。本课题将以线粒体为着眼点，从临床、体外多个角度观察Drp1在肾小管上皮细胞中的表达，分析其与临床指标及线粒体自噬的关系，并在细胞实验中进一步探讨NEAT1对线粒体自噬的调控。我们的研究发现DKD细胞模型中Drp1和NEAT1表达明显上调，而miR-150-5p水平表达下降。沉默DRP1和NEAT1后能显著降低高糖诱导HK2细胞产生的过量活性氧，激活线粒体自噬，保护高糖环境中的肾小管上皮细胞。抑制miR-150-5p加重DKD肾小管损伤。我们用双荧光素酶实验和和RNA免疫沉淀发现NEAT1通过吸附miR-150-5p增加DRP1表达。综上，DKD肾小管细胞NEAT1–miR-150-5p–DRP1轴通过调节线粒体自噬介导的线粒体损伤，为防治DKD进展提供新的理论依据。