DPP4-regulated endothelial cell ferroptosis modulates atherosclerosis progression by ferritinophagy

BACKGROUND: Atherosclerosis (AS), the primary pathophysiological foundation of coronary artery disease (CAD), initiates through endothelial dysfunction that facilitates lipid deposition and plaque formation. Emerging evidence implicates dipeptidyl peptidase IV (DPP4) in vascular pathologies, yet its mechanistic role in AS-associated endothelial ferroptosis remains undefined. METHODS: mice under a high-fat diet; 4) Ox-LDL-induced endothelial injury models assessed DPP4-mediated ferroptosis mechanisms combining proteomics, cycloheximide chase assays, and pharmacological modulation of autophagy. RESULTS: Clinical samples analysis revealed a significant increase in plasma DPP4 levels in patients with severe coronary artery stenosis, with DPP4 enrichment observed at plaque. Animal studies demonstrated that DPP4 deficiency attenuated progression of AS and ferroptosis in murine models. Cellular experiments revealed ox-LDL upregulated DPP4 expression, concomitant with increased ferroptosis susceptibility and endothelial dysfunction. DPP4 inhibition preserved endothelial viability by blocking lipid peroxide accumulation. Mechanistically, mouse proteomics revealed that ferroptosis and autophagy pathways were associated with DPP4 in AS. DPP4 destabilized FTH1 via NCOA4-mediated ferritinophagy, proven by concordant rescue effects of chloroquine (autophagy inhibition) and saxagliptin (DPP4 inhibition) on FTH1 preservation. CONCLUSIONS: This study establishes endothelial DPP4 as a regulator of ferritinophagy-driven ferroptosis, inducing endothelial dysfunction in AS. Our findings propose targeting the DPP4-NCOA4-FTH1 axis as a promising strategy to preserve endothelial viability and halt early AS progression, with translational implications for repurposing DPP4 inhibitors in cardiovascular therapeutics.