Abstract
Introduction: Atherosclerosis represents the leading cause of cardiovascular mortality, with persistent inflammation driving residual risk despite lipid-lowering therapies. While Ninjurin-1 (Ninj1) has been implicated in inflammatory diseases, its endothelial-specific role in atherosclerosis remains unclear. Methods: We conducted integrated molecular, functional, and histological analyses to characterize Ninj1 expression and function in atherosclerosis. Endothelial Ninj1 silencing was performed to assess its effects on NF-κB signaling, CXCL-8 expression, and ox-LDL-induced endothelial dysfunction. In vivo, ApoE-/- mice were treated with the Ninj1 inhibitor mPN12 peptide to evaluate its impact on plaque formation and composition. Results: Ninj1 silencing in endothelial cells suppressed NF-κB signaling and its key inflammatory mediator CXCL-8, conferring protection against ox-LDL-induced endothelial dysfunction by enhancing proliferation and migration while reducing apoptosis (all p < 0.05). In ApoE-/- mice, pharmacological Ninj1 inhibition with mPN12 peptide significantly attenuated plaque development and lipid accumulation while preserving collagen content. Discussion: Our results provide the first evidence that endothelial Ninj1 functions as a novel activator of the NF-κB/CXCL-8 axis, establishing its causal role in atherosclerosis and highlighting its potential as a targeted anti-inflammatory therapy.