SIRT1-FOXO3 Pathway reprograms fatty acid metabolism to Mitigate Ferroptosis and Fibrosis

Targeting ferroptosis with reductive agents has emerged as a promising strategy to mitigate fibrotic diseases in various pathological conditions. However, while the NAD+/NADH redox pair plays a crucial role in biological processes, its connection to ferroptosis beyond FSP1 remains poorly understood. To explore underappreciated NAD+/NADH-dependent factors in the ferroptosis cascade, we conducted a compound screening of 138 NAD+ enzyme modulatory molecules and identified Sirtuin-1 (SIRT1) activators as critical regulators of ferroptosis. SIRT1 activators, such as SRT1720, broadly inhibit ferroptosis by reducing lipid peroxidation without affecting labile iron levels. Moreover, SRT1720 effectively alleviates pulmonary and liver fibrosis in mouse models. Using ChIP-seq and validation assays, we demonstrated that FOXO3 binds to gene loci involved in fatty acid elongation and arachidonic acid metabolism in ferroptosis. SRT1720 disrupts this binding, thereby restraining fatty acid metabolism and limiting lipid peroxides production. Our findings establish the SIRT1-FOXO3 axis as a key inhibitory pathway against ferroptosis and highlight its therapeutic potential for ferroptosis-associated diseases, including fibrosis. Overall design: RNA-seq data of CTL, RSL3 and RSL3+SRT in MEFs