Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association

Central role of Nix in the autophagic response to ochratoxin A.

PMID 24755393


Nephrotoxicity is the most prominent toxicological effects of ochratoxin A (OTA). We have previously shown that autophagy might be involved in OTA-induced early renal cytotoxicity, but the mechanisms of action are unknown. Since OTA is known to induce mitochondrial damage and Nix is a selective autophagy receptor for mitochondrial clearance, the objective of this study was to investigate whether Nix mediates autophagic response to OTA-induced renal cytotoxicity. Our results showed that OTA induced autophagic and mitophagic activitits. Nix shRNA HEK 293 cells were more sensitive than scrambled shRNA cells to OTA-induced cell death, and differentially affect the mRNA expression of SDHA, AIFM1, and Bad and protein expression of AIF, VDAC, SDHA and LONP1 after OTA treatment. In particular, up-regulation of the pro-apoptotic Bad and AIF after OTA treatment was prominent only in Nix shRNA cells, which might explain the higher ratio of cell death. These results might indicate that Nix plays a critical role in the cellular protection against OTA toxicity through autophagy and mitochondria.