Mitophagy Induced by Mitochondrial Function Damage in Chicken Kidney Exposed to Cr(VI).

Cr(VI) is a heavy metal environmental pollutant and carcinogen. Excessive Cr(VI) exposure injures kidneys. This study aimed to investigate mitophagy induced by mitochondrial function damage in chicken kidney exposed to Cr(VI). To explore the mechanism involved, we randomly divided 40 one-day-old Hy-line Brown cockerels into four groups, with each group exposed to different concentrations of Cr(VI), i.e., 0, 10, 30 and 50 mg kg-1, which were orally administered daily for 45 days. Excessive Cr(VI) increased tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and chemokine (C-X-C motif) ligand 1(CXCL1) expression and decreased Ca2+-adenosine triphosphatase (Ca2+-ATPase), Mg2+-ATPase and Na+/k+-ATPase activities in chicken kidney. Furthermore, Cr(VI) significantly increased reactive oxygen species (ROS) production and induced mitochondrial membrane potential (MMP) collapse and typical autophagosome formation. With the increase of Cr(VI) concentration, the Parkin translocation, value of LC3-II increased and decreased the content of p62/SQSTM1 and the translocase of outer mitochondrial membrane 20 (TOMM20). In summary, our findings explicated that mitochondrial function damage and mitophagy-related indicators were related to Cr(VI) concentration in chicken kidney.