Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, The Second Xiangya Hospital at Central South University, Changsha, Hunan, China.
Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, The Second Xiangya Hospital at Central South University, Changsha, Hunan, China.
Redox Biol. 2021 Jan;38:101767. doi: 10.1016/j.redox.2020.101767. Epub 2020 Oct 23.
Sepsis is the major cause of acute kidney injury (AKI) associated with high mortality rates. Mitochondrial dysfunction contributes to the pathophysiology of septic AKI. Mitophagy is an important mitochondrial quality control mechanism that selectively eliminates damaged mitochondria, but its role and regulation in septic AKI remain largely unknown. Here, we demonstrate the induction of mitophagy in mouse models of septic AKI induced by lipopolysaccharide (LPS) treatment or by cecal ligation and puncture. Mitophagy was also induced in cultured proximal tubular epithelial cells exposed to LPS. Induction of mitophagy under these experimental setting was suppressed by pink1 or park2 knockout, indicating the role of the PINK1/PARK2 pathway of mitophagy in septic AKI. In addition, sepsis induced more severe kidney injury and cell apoptosis in pink1 or park2 knockout mice than in wild-type mice, suggesting a beneficial role of mitophagy in septic AKI. Furthermore, in cultured renal tubular cells treated with LPS, knockdown of pink1 or park2 inhibited mitochondrial accumulation of the autophagy adaptor optineurin (OPTN) and silencing Optn inhibited LPS-induced mitophagy. Taken together, these findings suggest that the PINK1/PARK2 pathway of mitophagy plays an important role in mitochondrial quality control, tubular cell survival, and renal function in septic AKI.
脓毒症是与高死亡率相关的急性肾损伤(AKI)的主要原因。线粒体功能障碍导致脓毒症 AKI 的病理生理学改变。自噬是一种重要的线粒体质量控制机制,可选择性地消除受损的线粒体,但自噬在脓毒症 AKI 中的作用和调节仍知之甚少。在这里,我们在脂多糖(LPS)处理或盲肠结扎穿孔诱导的脓毒症 AKI 小鼠模型中证明了自噬的诱导。LPS 暴露于培养的近端肾小管上皮细胞中也诱导了自噬。在这些实验条件下,自噬的诱导被 pink1 或 park2 敲除抑制,表明自噬的 PINK1/PARK2 途径在脓毒症 AKI 中的作用。此外,与野生型小鼠相比,pink1 或 park2 敲除小鼠在脓毒症中诱导更严重的肾损伤和细胞凋亡,表明自噬在脓毒症 AKI 中具有有益作用。此外,在 LPS 处理的肾小管细胞培养物中,pink1 或 park2 的敲低抑制了自噬衔接蛋白 optineurin(OPTN)在线粒体中的积累,沉默 Optn 抑制了 LPS 诱导的自噬。总之,这些发现表明,自噬的 PINK1/PARK2 途径在脓毒症 AKI 中的线粒体质量控制、管状细胞存活和肾功能中发挥重要作用。