Faculty Opinions Recommendation of FGF9 from Dermal γδ T Cells Induces Hair Follicle Neogenesis After Wounding
TLDR A substance called FGF9 from certain immune cells can trigger new hair growth during wound healing in mice, but humans may not have the same response due to fewer of these cells.
In a study conducted 10 years ago, researchers found that Fibroblast Growth Factor 9 (FGF9), secreted from γδ T cells, played a crucial role in inducing hair follicle neogenesis (new hair growth) in adult mice during wound healing. The study showed that FGF9 was significantly upregulated during late wound healing, and its overexpression resulted in an increase in wound-induced hair neogenesis (WIHN). The process involved FGF9 triggering Wnt expression in dermal fibroblasts, which then secreted additional FGF9, amplifying the Wnt activation and leading to hair follicle neogenesis. However, the study also noted that humans have a lower number and restricted location of resident γδ T cells in the dermis, suggesting a poor regenerative capacity of human skin. The findings suggested the potential clinical application of FGF9 for hair loss treatments.
