Epidermal stem cells are resistant to cellular aging.
The epidermis of the skin, acting as the primary physical barrier between self and environment, is a dynamic tissue whose maintenance is critical to the survival of an organism. Like most other tissues and organs, the epidermis is maintained and repaired by a population of resident somatic stem cells. The epidermal stem cells reside in the proliferative basal cell layer and are believed to persist for the lifetime of an individual. Acting through intermediaries known as transit amplifying cells, epidermal stem cells ensure that the enormous numbers of keratinocytes required for epidermal homeostasis to be maintained are generated. This continual demand for new cell production must be met over the entire lifetime of an individual. Breakdown of the epidermal barrier would have catastrophic consequences. This leads us to question whether or not epidermal stem cells represent a unique population of cells which, by necessity, might be resistant to cellular aging. We hypothesized that the full physiologic functional capacity of epidermal stem cells is maintained over an entire lifetime. Using murine skin epidermis as our model system, we compared several properties of young and old adult epidermal stem cells. We found that, over an average mouse's lifetime, there was no measurable loss in the physiologic functional capacity of epidermal stem cells, leading us to conclude that murine epidermal stem cells resist cellular aging.
Stern
Matthew M
MM
Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine, IA 52242, USA.
Bickenbach
Jackie R
JR
D053687:Adult Stem Cells / Q000502:physiology*; D000818:Animals; D002454:Cell Differentiation; D016922:Cellular Senescence / Q000502:physiology*; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism; D020869:Gene Expression Profiling; D049452:Green Fluorescent Proteins; D015603:Keratinocytes / Q000166:cytology* / Q000378:metabolism; D007633:Keratins; D051379:Mice; D008810:Mice, Inbred C57BL; D039902:Multipotent Stem Cells / Q000502:physiology; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress; D013482:Superoxide Dismutase / Q000378:metabolism; D016615:Telomere / Q000648:ultrastructure
D049452:Green Fluorescent Proteins; D007633:Keratins; D013482:Superoxide Dismutase