Human skin stem cells

The homeostasis of continuously renewing human epidermis relies on the presence of adult stem cells, residing in the basal layer. Epidermal stem cells have been enriched and functionally characterized, but the exact location remained elusive. The human hair follicle and its pigmentation unit also cyclically regenerate from stem cells. Contrary to epidermal stem cells, human hair follicle stem cells have been localized, enriched, functionally and biochemically characterized. Their specific gene expression pattern has been established. The melanocyte stem population has also been localized and characterized. Finally, the hair follicle was found to harbor a number of other multipotent cells, which designates this unique organ as an alternative source of stem cells for tissue regeneration.