Dentin matrix protein-1 promoted osteogenic differentiation of valvular interstitial cells via MAPK signal pathway during aortic valve calcification.

Valvular interstitial cells (VICs) are integral to the progression of calcific aortic valve disease (CAVD). Dentin matrix protein-1 (DMP-1), a member of the Sibling family protein, is implicated in the calcification process. This study aims to investigate the role and mechanisms of DMP-1 in the osteogenic differentiation of VICs. Between April 2018 and December 2018, aortic valve tissues were collected from 14 patients undergoing aortic valve replacement or heart transplantation. DMP-1 expression was quantified in calcified valves versus normal controls. An in vitro model of VICs' osteogenic differentiation was established to study the regulatory mechanism of DMP-1 on valvular calcification using immunoblot, immunohistochemistry, immunofluorescence, etc. The expression of DMP-1 was significantly increased in the calcified aortic valves patients (P < 0.01). DMP-1, both short and long arginine-glycine-aspartic acid (RGD) peptides, induced the osteogenic differentiation in VICs, an effect that was inhibited by an integrin αvβ3 antagonist (P < 0.05). Furthermore, the expression levels of RAF, RAS, MEK, and phosphorylated ERK1/2 were significantly elevated in VICs upon stimulation of DMP-1 (P < 0.05). DMP-1 is involved in the progression of valvular calcification and promotes the osteogenic differentiation of VICs via the integrin αvβ3 receptor. The combination of DMP-1 and integrin αvβ3 via its RGD domain activates the MAPK signaling pathway, leading to enhanced osteogenic gene expression in VICs. Clinical trial number: not applicable.