Nifedipine Protects Against DAHP-Induced Endothelial Dysfunction via Caveolin-1 Phosphorylation in EAhy926 Endothelial cells

Background: Endothelial dysfunction is a key factor in cardiovascular disease, driven by cellular aging and oxidative stress. Tyrosine kinase signaling has been linked to this process, and inhibiting it could be a potential treatment option. We investigate the ability of nifedipine to counteract DAHP-induced endothelial senescence and oxidative stress by modulating Caveolin-1 phosphorylation, thereby restoring endothelial homeostasis. Methods: Human EA.hy926 endothelial cells were exposed to 2,4-diamino-6-hydroxypyrimidine (DAHP) to induce oxidative stress and cellular senescence. The protective effects of nifedipine were evaluated by assessing caveolin-1 phosphorylation, the expression of senescence-associated markers (p21 and p53), telomerase activity, nicotinamide adenine dinucleotide (NAD⁺) levels, and tetrahydrobiopterin (BH₄) and dihydrobiopterin (BH₂) metabolism. Endothelial function was further assessed using wound healing assays. Results: Exposure of EA.hy926 endothelial cells to DAHP significantly increased caveolin-1 tyrosine phosphorylation, disrupted biopterin metabolism (BH₄ and BH₂), and upregulated the senescence-associated markers p21 and p53. DAHP also promoted cellular senescence by reducing NAD⁺ levels and telomerase activity, leading to impaired endothelial function, as demonstrated by reduced wound healing and cell migration. In contrast, nifedipine treatment markedly attenuated these deleterious effects by normalizing caveolin-1 tyrosine phosphorylation, restoring NAD⁺ levels, telomerase activity, and BH₄/BH₂ homeostasis. Furthermore, nifedipine downregulated the expression of p21 and p53 and improved endothelial proliferative and migratory capacities, thereby mitigating DAHP-induced endothelial senescence and dysfunction. Conclusion: Our findings reveal a novel mechanism by which nifedipine attenuates DAHP-induced endothelial injury by suppressing caveolin-1 phosphorylation, reducing endothelial senescence, and restoring endothelial function. Beyond its established antihypertensive effects, nifedipine may offer additional vasculoprotective benefits by preserving endothelial integrity and mitigating vascular aging, highlighting its potential as a therapeutic strategy for preventing endothelial dysfunction and promoting vascular health.