Dermal CD271⁺ cells are closely associated with regeneration of the dermis in the wound healing process

Stem cells have recently been shown to play important roles in wound healing. The aim of this study was to investigate the role of dermal CD271⁺ cells in wound healing. Full-thickness wounds were produced on the backs of 5-year-old and 24-week-old mice, and timecourse of wound closure, CD271 cell counts, and gene + expression levels were compared. Delayed wound healing was observed in 24-week-old mice. The peak of CD271⁺ cell increase was delayed in 24-week-old mice, and gene expression levels of growth factors in wounded tissue were significantly increased in 5-year-old mice. Dermal CD271⁺ cells purified by fluorescenceactivated cell sorting (FACS) expressed higher growth factors than CD271^– cells, suggesting that CD271⁺ cells play important roles by producing growth factors. This study also investigated dermal CD271⁺ cells in patients with chronic skin ulcers. Dermal CD271⁺ cells in patients were significantly reduced compared with in healthy controls. Thus, dermal CD271⁺ cells are closely associated with wound healing.