Dynamic O-GlcNAcylation coordinates ferritinophagy and mitophagy to activate ferroptosis

Ferroptosis is a regulated iron-dependent cell death characterized by the accumulation of lipid peroxidation. A myriad of facets linking amino acid, lipid, redox, and iron metabolisms were found to drive or to suppress the execution of Ferroptosis. However, how the cells decipher the diverse pro-ferroptotic stress to activate Ferroptosis remains elusive. Here, we report that protein O-GlcNAcylation, the primary nutrient sensor of glucose flux, orchestrates both ferritinophagy and Mitophagy for Ferroptosis. Following the treatment of Ferroptosis stimuli such as RSL3, a commonly used Ferroptosis inducer, there exists a biphasic change of protein O-GlcNAcylation to modulate Ferroptosis. Pharmacological or genetic inhibition of O-GlcNAcylation promoted ferritinophagy, resulting in the accumulation of labile iron towards mitochondria. Inhibition of O-GlcNAcylation resulted in mitochondria fragmentation and enhanced Mitophagy, providing an additional source of labile iron and rendering the cell more sensitive to Ferroptosis. Mechanistically, we found that de-O-GlcNAcylation of the ferritin heavy chain at S179 promoted its interaction with NCOA4, the ferritinophagy receptor, thereby accumulating labile iron for Ferroptosis. Our findings reveal a previously uncharacterized link of dynamic O-GlcNAcylation with iron metabolism and decision-making for Ferroptosis, thus offering potential therapeutic intervention for fighting disease.