Ferroptosis as a novel therapeutic target for Friedreich's ataxia

M. Grazia Cotticelli, Shujuan Xia, Daniel Lin, Taehee Lee, Leila Terrab, Peter Wipf, Donna Huryn and Robert Wilson
Journal of Pharmacology and Experimental Therapeutics January 11, 2019, jpet.118.252759; DOI:10.1124/jpet.118.252759

Ferropotosis is a recently identified pathway of regulated, iron-dependent cell death, which is biochemically distinct from apoptosis. We evaluated whether there is evidence for ferroptotic pathway activation in cellular models of FRDA. We found that primary patient-derived fibroblasts, murine fibroblasts with FRDA-associated mutations, and murine fibroblasts in which a repeat expansion had been introduced (KIKO) were more sensitive than normal control cells to erastin, a known ferroptosis inducer. We also found that the ferroptosis inhibitors SRS11-92 and Fer-1, used at 500 nM, were efficacious in protecting human and mouse cellular models of FRDA treated with ferric ammonium citrate (FAC) and an inhibitor of glutathione synthesis (BSO), whereas caspase-3 inhibitors failed to show significant biological activity. Cells treated with FAC and BSO consistently showed decreased glutathione-dependent peroxidase activity and increased lipid peroxidation, both hallmarks of ferroptosis. Finally, the ferroptosis inhibitor SRS11-92 decreased the cell death associated with frataxin knockdown in healthy human fibroblasts. Taken together, these data suggest that ferroptosis inhibitors may have therapeutic potential in FRDA.