Aging epidermis is maintained by changes in transit-amplifying cell kinetics, not stem cell kinetics.
It has been assumed that the slow rate of healing in aging epidermis is due to slowing of the epidermal stem cell proliferative rate. In this issue, Charruyer et al. report that this may not be the case. Using a long-term repopulating model, they demonstrate that epidermal stem cell kinetics are maintained. Instead, it is the compensatory action of the transit-amplifying (TA) cells that changes in aging skin and thus bears responsibility for slowed wound healing.
Winter
Michael C
MC
Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA.
Bickenbach
Jackie R
JR
D000818:Animals; D002455:Cell Division / Q000502:physiology; D000078404:Epidermal Cells; D004817:Epidermis / Q000502:physiology*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000502:physiology; D015595:Skin Aging / Q000473:pathology* / Q000502:physiology*; D013234:Stem Cells / Q000166:cytology / Q000502:physiology