1α,25-Dihydroxyvitamin D3 Accelerates Skin Wound Re-Epithelialization by Promoting Epidermal Stem Cell Proliferation and Differentiation Through PI3K Activation: An In Vitro and In Vivo Study

This study demonstrates that 1α,25-Dihydroxyvitamin D3 (VD3) significantly accelerates skin wound re-epithelialization by promoting the proliferation and differentiation of epidermal stem cells (EpSCs) through the activation of the PI3K signaling pathway. Using a murine full-thickness skin defect model, VD3 was applied topically in varying doses, resulting in increased neo-epidermis length and improved proliferation and differentiation of K15+, K14+, and K10+ epidermal cells compared to controls. The findings were confirmed both in vivo and in vitro, with the PI3K pathway identified as a key mechanism, as its inhibition reduced the observed effects.