Ferritinophagy-mediated ferroptosis facilitates methotrexate-induced hepatotoxicity by high-mobility group box 1 (HMGB1)

Background and aim: Hepatotoxicity is a well-defined reaction to methotrexate (MTX), a drug commonly used for the treatment of rheumatoid arthritis and various tumours. We sought to elucidate the mechanism underlying MTX-induced hepatotoxicity and establish a potentially effective intervention strategy.

Methods: We administered MTX to liver cells and mice and assessed hepatotoxicity by cell viability assay and hepatic pathological changes. We determined Ferroptosis and ferritinophagy by detecting ferroptosis-related markers and autophagic degradation of ferritin heavy chain 1 (FTH1).

Results: We have shown that hepatocytes treated with MTX undergo Ferroptosis, and this process can be attenuated by Ferroptosis inhibitors. Interestingly, NCOA4-mediated ferritinophagy was found to be involved in MTX-induced Ferroptosis, which was demonstrated by the relief of Ferroptosis through the inhibition of Autophagy or knockdown of Ncoa4. Furthermore, MTX treatment resulted in the elevation of high-mobility group box 1 (HMGB1) expression. The depletion of Hmgb1 in hepatocytes considerably alleviated MTX-induced hepatotoxicity by limiting Autophagy and the subsequent autophagy-dependent Ferroptosis. It is noteworthy that glycyrrhizic acid (GA), a precise inhibitor of HMGB1, effectively suppressed Autophagy, Ferroptosis and hepatotoxicity caused by MTX.

Conclusion: Our study shows the significant roles of autophagy-dependent Ferroptosis and HMGB1 in MTX-induced hepatotoxicity. It emphasizes that the inhibition of ferritinophagy and HMGB1 may have potential as a therapeutic approach for preventing and treating MTX-induced liver injury.

HMGB1; autophagy; ferritinophagy; ferroptosis; methotrexate.