Tetrachlorobenzoquinone exposure triggers ferroptosis contributing to its neurotoxicity

Halogenated quinones are representative metabolites of persistent organic pollutants. Tetrachlorobenzoquinone (TCBQ) is a reactive metabolite of the widely used fungicide hexachlorobenzene (HCB) and wood preservative pentachlorophenol (PCP). Our previous studies have demonstrated that TCBQ induced neuron-like cell apoptosis in a reactive oxygen species (ROS)-dependent manner. Here, we found that TCBQ caused lipid peroxidation and cellular morphological changes including shrinked mitochondrial size, suggesting the involvement of a recently uncovered form of programmed cell death (PCD), ferroptosis. Indeed, we then identified that ferroptosis is a novel PCD driven by TCBQ, which was correlated with a decrease in glutathione peroxidase 4 (GPX4) level and iron accumulation by altering iron metabolism. Notably, nuclear factor erythroid-derived 2-like 2 (Nrf2) is a negative regulator in modulating the outcomes of ferroptosis as an adaptive cellular defense response. Nrf2 activation enhanced iron storage capacity and GPX4 activity by elevating ferritin heavy chain 1 (FTH1) expression and glutathione (GSH) level, respectively. On the contrary, Nfe2l2 (Nrf2) deficiency enhanced PC12 cells susceptibility to ferroptosis. [Display omitted] •Ferroptosis is a novel form of programmed cell death (PCD) induced by TCBQ.•TCBQ exposure linked with a decrease in GPX4 level and iron accumulation.•Nrf2 activation alleviates TCBQ-induced ferroptosis.•Nrf2 suppresses ferroptosis by regulating iron metabolism and oxidative stress.