Vitamin A Regulates Dermal Papilla Cell Proliferation and Apoptosis Under Heat Stress via IGF1 and Wnt10b Signaling

The study demonstrates that Vitamin A (VA) at 0.4 mg/L significantly enhances rabbit dermal papilla cell (DPC) proliferation and reduces apoptosis under heat stress (HS) by modulating the IGF1 and Wnt10b/β-catenin signaling pathways. VA treatment decreased the proportion of DPCs in the G0/G1 phase and reduced the expression of caspase 3, HSP70, and miR-195, while activating IGF1 and Wnt10b/β-catenin pathways. Overexpression of miR-195–5p negated VA's positive effects, indicating its role in regulating IGF1 expression. Blocking Wnt10b and β-catenin signaling also attenuated VA's benefits. These findings suggest that VA could be a potential therapeutic agent for promoting hair follicle development and mitigating hair loss under environmental heat stress.