Prohibitin 2-mediated mitophagy attenuates renal tubular epithelial cells injury by regulating mitochondrial dysfunction and NLRP3 inflammasome activation

Accumulating evidence demonstrates that mitochondrial dysfunction and inflammasome activation play a critical role in the pathogenesis of renal tubular injury through the production of reactive oxygen species and cytokines. Prohibitin 2 (PHB2) is a newly identified intracellular receptor of mitophagy (a type of autophagy) that mediates selective removal of damaged mitochondria, and it could possibly play a renoprotective role in kidney disease. In this study, we confirmed that autophagy is activated in tubular epithelial cells treated with angiotensin II and that inhibition of autophagy results in tubular cell injury. Strikingly. PHB2 knockdown reduced the level of mitophagy and augmented cell death, while overexpression of PHB2 provided protection against pyrin domain-containing protein 3 (NLRP3)-induced inflammatory pathways through amelioration of mitochondrial dysfunction. Our research is the first to experimentally demonstrate the role of PHB2 in renal proximal tubular cells and thereby to provide a better understanding of how autophagy modulates inflammation in renal tubules. These data highlight PHB2 as a therapeutic target in the future treatment of CKD.