Transforming Growth Factor-β Signaling-Mediated Wound Healing Is Required for Hair Follicle Neogenesis

The study investigates the role of Transforming growth factor-β (TGF-β) signaling in wound healing and its necessity for hair follicle neogenesis (HFN) in mice. It was found that TGF-β signaling is crucial for collagen deposition in the wound dermis, which is essential for initiating HFN. The research showed that macrophages are key in sending TGF-β signals to fibroblasts, and the absence of TGF-β1 secretion from macrophages impairs HFN. Conditional knockout of TGF-β receptor 2 in fibroblasts before re-epithelialization inhibited HFN, but not after. Additionally, knocking out collagen type I, a downstream component of TGF-β signaling, also inhibited HFN. However, activating the Sonic hedgehog pathway could rescue HFN, highlighting its potential as a therapeutic target for hair regeneration.