Chronic arsenic exposure induces ferroptosis via enhancing ferritinophagy in chicken livers

Abstract

Arsenic (As) is a well-known pollutant in the environment, whose contamination in groundwater is a serious threat to animals and humans. Ferroptosis, a form of cell death caused by iron-dependent lipid peroxidation, is involved in various pathological processes. Ferritinophagy is the selective autophagy of ferritin and a crucial step in the induction of ferroptosis. However, the mechanism of ferritinophagy in poultry livers exposed to As remains unexplored. In this study, we investigated whether As-induced chicken liver injury is related to ferritinophagy-mediated ferroptosis at the cellular and animal levels. Our results showed that As exposure via drinking water induced hepatotoxicity in chickens, characterized by abnormal liver morphology and elevated liver function markers. Our data suggested chronic As exposure led to mitochondrial dysfunction, oxidative stress, and impaired cellular processes in chicken livers and LMH cells. Our results also showed that As exposure activated the AMPK/mTOR/ULK1 signaling pathway and significantly changed the levels of ferroptosis and autophagy-related proteins in chicken livers and LMH cells. Moreover, As exposure induced iron overload and lipid peroxidation in chicken livers and LMH cells. Interestingly, pretreatment with ferrostatin-1, chloroquine (CQ), and deferiprone alleviated these aberrant effects. Using CQ, we found that As-induced ferroptosis is autophagy-dependent. Our findings further suggested chronic As exposure induced chicken liver injury by promoting ferritinophagy-mediated ferroptosis, as evidence by activated autophagy, decreased mRNA expression of FTH1, increased intracellular iron content, and alleviation of ferroptosis through pretreatment with CQ. In conclusion, ferritinophagy-mediated ferroptosis is one of the critical mechanisms of As-induced chicken liver injury. Inhibiting ferroptosis may provide new insights for preventing and treating liver injury induced by environmental As exposure in livestock and poultry.

Keywords: Arsenic; Autophagy; Ferritinophagy; Ferroptosis; Iron overload.