Hedgehog Stimulates Hair Follicle Neogenesis by Creating Inductive Dermis During Murine Skin Wound Healing

The study from 2018 investigated the role of the Sonic hedgehog (Shh) signaling pathway in hair follicle neogenesis (HFN) during the wound healing process in mice. It found that activation of the Shh pathway is essential for the formation of the dermal papilla, a key component in new hair follicle development. By genetically modifying mice to overexpress Shh or activate the Shh pathway in dermal cells, researchers were able to induce hair follicle formation in wound areas that would typically scar. The study suggests that fibrosis and regeneration are not mutually exclusive and that regenerative healing can be promoted by altering dermal signals. The number of mice used in the experiments varied, with specific numbers provided in the figure legends, ranging from 2 to 12 per condition. The findings indicate that the lack of regenerative cues, rather than an inherent inability of scarring cells to regenerate, is responsible for the absence of hair follicle morphogenesis after skin injury.