NARFL Knockout Triggers Ferroptosis‐Driven Vascular Endothelial Dysfunction

Abstract Nuclear prelamin A recognition factor‐like (NARFL) is a core component of the cytosolic iron‐sulfur (Fe‐S) protein assembly (CIA) system. Yet, its role in vascular pathophysiology remains poorly defined. This study demonstrates that NARFL deficiency triggers ferroptosis, leading to severe vascular endothelial dysfunction across species. In zebrafish, narfl knockout causes embryonic lethality, accompanied by neurovascular defects, blood‐brain barrier disruption, and aberrant hemodynamics. Similarly, knockout of the murine ortholog (Ciao3) results in mid‐gestational embryonic lethality due to impaired vascular development and endothelial progenitor cell maturation. Mechanistically, NARFL deficiency disrupts CIA complex assembly, compromising Fe‐S cluster transfer to client apo‐proteins and leading to a functional shift of cytosolic aconitase (ACO) to iron regulatory protein 1 (IRP1), causing iron overload, heightened oxidative stress, and lipid peroxidation. Consequently, key anti‐ferroptotic defenses are suppressed, culminating in endothelial ferroptosis. This pathway is conserved in human endothelial cells, where NARFL deficiency recapitulates the ferroptotic phenotype and functional impairments, which are rescued by the ferroptosis inhibitor. Clinically, specific NARFL polymorphisms have been identified as conferring susceptibility to vascular endothelial disorders (pulmonary hypertension, epilepsy, and neurodegenerative diseases). The work unveils a novel CIA‐ferroptosis‐vascular axis, positioning NARFL as a critical guardian of endothelial health and a potential therapeutic target.