Deficiency of Formyl Peptide Receptor 2 Retards Hair Regeneration by Modulating the Activation of Hair Follicle Stem Cells and Dermal Papilla Cells in Mice

The study investigated the role of Formyl Peptide Receptor 2 (FPR2) in hair regeneration using Fpr2 knockout (KO) mice. It was found that Fpr2 KO mice experienced excessive hair loss and had abnormal hair follicle structures compared to wild-type (WT) mice. The study revealed that FPR2 influenced hair regeneration by affecting the activity of hair follicle stem cells (HFSCs) and dermal papilla cells (DPCs). In Fpr2 KO mice, there was a significant decrease in Sonic hedgehog (Shh) and β-catenin levels, which are crucial for hair follicle regeneration, and an increase in bone morphogenetic protein (Bmp)2/4, which inhibits the anagen phase. The proliferation of HFSCs and DPCs was also significantly lower in Fpr2 KO mice. These findings demonstrated that FPR2 played a protective role in hair loss by modulating signaling molecules and promoting the proliferation of HFSCs and DPCs.