Inhibiting TNAP Attenuates the Aortic Valve Calcification and Reduces Oxidative Stress

Calcific aortic valve disease (CAVD) is a progressive condition driven by oxidative stress, chronic inflammation, and the osteogenic reprogramming of valvular interstitial cells, leading to hydroxyapatite crystallization. Because tissue non-specific alkaline phosphatase (TNAP) drives phosphate-mediated mineralization, this study evaluated the efficacy of novel TNAP inhibitors as a disease-modifying strategy. Using a vitamin D3-induced CAVD mouse model presenting human-like annular thickening and valvular calcification, we analyzed the therapeutic impact of these inhibitors. TNAP expression was highly elevated in diseased valves; however, inhibitor treatment significantly lowered TNAP levels and attenuated valvular calcification. Notably, the inhibitors suppressed lipid peroxidation and restored antioxidant capacity, significantly regulating GSH, SOD, and CAT levels while decreasing lipid oxidation markers (MDA, 4-HNE, MPO). Furthermore, pro-inflammatory cytokines (IL-1β, TNF-α) and apoptotic markers (cleaved Cas-3, cleaved PARP) were markedly decreased, accompanied by diminished fibrotic and osteogenic remodeling, while maintaining normal bone homeostasis. In conclusion, TNAP inhibition effectively reduces pathological valve calcification by suppressing interconnected oxidative, inflammatory, fibrotic, and osteogenic pathways, positioning it as a promising and safe therapeutic approach for CAVD.