Not Just a Cell Marker: DPP4 Modulates Regeneration of Hair Follicles in Large Wounds

The study investigates the role of Dipeptidyl peptidase IV (DPP4), a molecule expressed on the surface of most mammalian skin fibroblasts, in the healing of large wounds and the regeneration of hair follicles. The research found that DPP4 is downregulated upon wounding, particularly at the beginning of the inflammatory phase and the activation of wound-induced hair follicle neogenesis (WIHN), a process that regenerates hair follicles in large wounds. The center of wounds showed fewer DPP4 positive cells compared to the wound margins, where WIHN typically does not occur. Inhibition of DPP4 around 9 days post-wounding increased the number of WIHN hair follicles and the expression of Wnt targets and ligands in the skin, suggesting that DPP4 may inhibit hair follicle regeneration.