FTO-mediated GPX4 m6A modification in ferroptosis-induced DNA damage and inflammatory response during acute lung injury.

To investigate the role of Fat Mass and Obesity-associated Protein (FTO) in acute lung injury (ALI) and elucidate how it regulates ferroptosis via N6-methyladenosine (m6A) modification of glutathione peroxidase 4 (GPX4). ALI models were established in LPS‑stimulated BEAS‑2B cells and mice. FTO expression was modulated by siRNA, inhibitors, or adeno‑associated virus. Ferroptosis, apoptosis, inflammation and DNA damage were assessed by RIP‑qPCR, meRIP‑qPCR, Western blotting and TEM. GPX4 m6A site mutants were constructed. GPX4 mRNA/protein stability and translation were analyzed using actinomycin D and cycloheximide. Establish an LPS-induced ALI mouse model, perform adeno-associated viral knockdown of FTO in lung tissue, and validate in vivo using GPX4 inhibitors. FTO inhibition significantly attenuated LPS-induced ferroptosis, apoptosis, inflammatory responses, and mitochondrial damage. Mechanistically, FTO accelerates GPX4 protein degradation by reducing m6A modification of GPX4, thereby downregulating GPX4 protein expression in a post-transcriptional and post-translational manner. This leads to intracellular iron accumulation, ROS bursts, lipid peroxidation, and DNA damage. Mutating the m6A site in GPX4 or supplementing GPX4 protein effectively reverses the aforementioned damage. Silencing FTO in vivo significantly ameliorates pulmonary tissue pathology, impaired lung function, ferroptosis, and inflammatory responses in mice via a GPX4-dependent pathway, whereas GPX4 inhibition reverses this protective effect. FTO exacerbates ALI by mediating m6A modification of GPX4 and downregulates its protein expression, thereby driving ferroptosis and DNA damage. Targeting the FTO-GPX4 axis may offer novel therapeutic strategies for ALI.