Hair Follicle and Interfollicular Epidermal Stem Cells Make Varying Contributions to Wound Regeneration

The document summarizes a study that explored the roles of hair follicle (HF) and interfollicular epidermal (IFE) stem cells in wound regeneration. The study utilized genetic fate mapping in mice to track the contributions of different keratinocyte lineages over time. Initially, HF and IFE cells contributed almost equally to the regenerating basal epithelium, but by day 50, HF-derived cells became more dominant, making up 65-69% of the cells, with bulge-derived cells (a specific HF population) increasing to 19.5-26.4%. The study also found that suppressing Notch signaling allowed IFE-derived cells to out-compete HF-derived cells, indicating that Notch plays a role in cell differentiation and competitive dynamics during wound healing. The results suggest that the dynamics of cell contribution to wound healing are influenced by non-genetic factors and that both HF and IFE stem cells are important for the regeneration process, with HF-derived cells, particularly those from the bulge, becoming more significant in the long term.