Augmenter of liver regeneration reduces mitochondria-derived ROS and NLRP3 inflammasome activation through PINK1/Parkin-mediated mitophagy in ischemia-reperfusion-induced renal tubular injury

Ischemia–reperfusion (IR) injury is one of the main causes of acute kidney disease (AKI). Several studies have shown that mitochondrial damage, which leads to increased production of reactive oxygen species (ROS), plays a vital role in the pathogenesis of IR-induced AKI. Increased ROS production can cause oxidative damage and activate the inflammasome in renal tubular cells, ultimately resulting in apoptosis or necrosis. Mitophagy is a type of selective autophagy that plays a protective role in AKI by regulating the quality of mitochondria and reducing the production of ROS. We previously reported that the augmenter of liver regeneration (ALR) exhibits antiapoptotic and antioxidant functions, although the precise mechanisms of action need to be studied further. In the current study, ALR was overexpressed and an in vitro model of IR injury was constructed. The overexpression of ALR reduced the production of mitochondria-derived ROS (mtROS), the activation of the NLRP3 inflammasome, and the rate of apoptosis. Moreover, this suppression of mtROS production and inflammasome activation was mediated through the PTEN-induced kinase 1 (PINK1)/Parkin pathway of mitophagy. These results suggest that ALR can alleviate IR-induced apoptosis via the PINK1/Parkin mitophagy pathway to reduce the production of mtROS and limit the activation of the NLRP3 inflammasome.