Altered FGF expression profile in human scalp-derived fibroblasts upon WNT activation: implication of their role to provide folliculogenetic microenvironment

The study explored the role of human scalp-derived fibroblasts (sFBs) in hair follicle (HF) formation by analyzing their fibroblast growth factor (FGF) expression in response to WNT activation. It was found that WNT activation led to a downregulation of FGF7 and an upregulation of FGF9, which is known to positively regulate HF morphogenesis. This change in FGF expression was confirmed at the protein level and was shown to enhance hair morphogenesis and growth in vivo, as demonstrated in a mouse model where FGF9 increased the number and diameter of newly formed HFs. The findings suggested that sFBs could support HF formation by altering FGF expression in response to WNT signaling, highlighting the potential of targeting the WNT-FGF9 axis for HF regeneration. However, the study noted limitations such as the use of mouse models and the need for further investigation into the in vivo relevance of these findings.