NEDD4 suppresses ferroptosis in lung ischemia-reperfusion injury by ubiquitinating and degrading SLC1A5.

Lung ischemia-reperfusion injury (LIRI) is a critical complication in thoracic surgery and transplantation, driven partly by ferroptosis. While the E3 ubiquitin ligase neural precursor cell expressed, developmentally down-regulated 4 (NEDD4) mitigates ferroptosis in other organs, its role in pulmonary ferroptosis remains unexplored. We screened screened NEDD4 interactors in pulmonary epithelial cells through TurboID proximity proteomics. And functional validation was utilized, including murine LIRI models (WT/NEDD4-/-), hypoxia/reoxygenation (H/R) in vitro, Co-IP, ubiquitination assays, cycloheximide chase, and rescue experiments. The research indicated that NEDD4 expression was downregulated in murine LIRI and H/R-injured pulmonary epithelia. NEDD4 deficiency exacerbated LIRI-induced lung injury, apoptosis, inflammation, and ferroptosis. NEDD4 overexpression rescued H/R-induced ferroptosis by reducing ROS, lipid peroxidation, and iron overload. TurboID identified glutamine transporter solute carrier family 1 member 5 (SLC1A5) as a NEDD4-specific interactor. Mechanistically, NEDD4 ubiquitinated SLC1A5 primarily via K48-linked chains and promoted its proteasomal degradation in a manner dependent on NEDD4's catalytic activity. SLC1A5 overexpression reversed NEDD4-mediated protection against ferroptosis in vitro. In conclusion, NEDD4 attenuates ferroptosis in LIRI by ubiquitinating and degrading the pro-ferroptotic transporter SLC1A5. Targeting the NEDD4-SLC1A5 axis offers therapeutic potential for LIRI.