Sevoflurane exposure induces neuronal cell ferroptosis initiated by increase of intracellular hydrogen peroxide in the developing brain via ER stress ATF3 activation

Abstract

Abstract Neuronal cell death has been well acknowledged as the primary pathological basis underlying developmental neurotoxicity following sevoflurane exposure, whereas the exact mechanism remains elusive. Ferroptosis is a programmed cell death featured by iron-dependent lipid peroxidation that is driven by hydrogen peroxide (H2O2) and ferrous iron through Fenton reaction, and participates in the pathogenesis of multiple neurological diseases. As stress response factor, activating transcription factor 3 (ATF3) can be activated by PERK/ATF4-mediated pathway during endoplasmic reticulum (ER) stress and followed by increased intracellular H2O2, which is involved in regulation of apoptosis, autophagy and ferroptosis. Here, we investigated whether ferroptosis and ATF3 activation are implicated in sevoflurane-triggered neuronal cell death in the developing brain. Results showed that sevoflurane exposure induced neuronal death as a result of iron-dependent lipid peroxidation damage secondary to H2O2 accumulation and ferrous iron increase, which was consistent with the criteria for ferroptosis. Furthermore, we observed that increases of iron and H2O2 induced by sevoflurane exposure were associated with the upregulation and nuclear translocation of ATF3 in response to ER stress. Knockdown of ATF3 expression alleviated iron-dependent lipid peroxidation, which prevented sevoflurane-triggered neuronal ferroptosis. Mechanistically, ATF3 promoted sevoflurane-induced H2O2 accumulation through activating NOX4 and suppressing catalase, GPX4 and SLC7A11. Additionally, we detected that increase of H2O2 was accompanied with upregulation of TFR and TF and downregulation of FPN which linked the iron overload to ferroptosis triggered by sevoflurane. Taken together, our results demonstrated ER stress-mediated ATF3 activation contributes to sevoflurane-induced neuronal ferroptosis via H2O2 accumulation and resultant iron overload.