Hydrogen Sulfide Inhibits Ferritinophagy-Mediated Ferroptosis in the Hippocampus of Rotenone-Exposed Rats

Abstract

Our previous research has established that hydrogen sulfide (H2S) exerts an antagonistic effect against the hippocampal neurotoxicity induced by Rotenone (ROT). However, the underlying mechanisms are so far poorly understood. Substantial evidence corroborates the involvement of ferroptosis in ROT-induced neurotoxicity. To elucidate the protective mechanism of H2S against ROT-induced hippocampal neurotoxicity, this study explores its regulatory role in ferroptosis and its underlying mechanisms. We used Fluoro-Jade B staining to detect dead neurons. The levels of ferrous ions and glutathione (GSH) were measured by a kit. The ferroptosis-related proteins, including light-chain subunit (xCT), GSH peroxidase 4(GPX4), ferroptosis marker acyl-CoA synthetase long-chain family member 4(ACSL4), and ferritinophagy-related protein, including ferritin heavy chain 1 (FTH1), sequestosome 1 (p62), ferritinophagy markers autophagosome marker light-chain I/II (LC3I/II), and nuclear receptor coactivator 4 (NCOA4), were measured by Western blot. Our findings indicate that H2S reduces hippocampal neuron deaths in ROT-exposed rats. Meanwhile, H2S reverses the downregulations of xCT and GPX4, and the upregulations of ferrous ion and ACSL4 in the hippocampus induced by ROT. Furthermore, H2S reverses the upregulations of LC3I/II and NCOA4, and the downregulations of P62 and FTH1. Based on these findings, we concluded that the protective role of H2S against ROT-induced hippocampal neuronal death involves inhibiting ferroptosis triggered by ferritinophagy.

Keywords

• ferritinophagy
• ferroptosis
• hydrogen sulfide
• neurotoxicity
• rotenone