Stem cells (p63+) in keratinocyte cultures from human adult skin

Epidermal stem cells (ESC) are responsible for maintaining skin cellular homeostasis, as they give rise to fast-dividing transit amplifying cells committed to terminal differentiation, while retaining their self-renewal capacity. However, no pure ESC cultures are available and no highly specific cytochemical marker was identified. We report here the experimental conditions allowing the selective enrichment in ESC, using cultured adult human keratinocytes. The main step was the selection of cells able to rapidly adhere to human collagen type IV in vitro. Thus, an increased proportion of putative ESC of about 65% was obtained, as demonstrated by p63 expression.