Isolation and characterization of human epidermal stem cells

1. The keratinocytes in human epidermis are constantly turned over and replaced by a population of stem cells located in the basal epidermal layer. Until recently there were no markers allowing the isolation of viable epidermal stem cells, However, it has now been shown that epidermal stem cells can be isolated both in vitro and direct from the epidermis as they express high levels of functional beta(1) integrin family receptors for extracellular matrix proteins. 2. The evidence for integrins as stem cell markers and the insights that have been gained into stem cell behaviour are reviewed.