Expansion of epidermal progenitors with high p63 phosphorylation during wound healing of mouse epidermis.

The transcription factor p63 plays an essential role in maintaining the proliferative potential of epidermal stem cells. We have shown recently that under homoeostatic conditions, phosphorylation of p63 increases during the early transition of stem cells to transit-amplifying cells in human epidermis. However, how p63 phosphorylation relates to the regenerative processes during wound healing remains unknown. In this study, we characterize epidermal cells that contribute to wound repair in mouse models using phosphorylated p63 as a marker for stem cell differentiation. Our studies reveal that epidermal progenitors with high p63 phosphorylation preferentially expand in response to wounding in both full-thickness wound and surface injury models. As phosphorylated p63 levels inversely correlate with the proliferative potential of epidermal progenitors, p63 phosphorylation may serve as a therapeutic target to modulate the function of these regenerative cells during wound healing.