Epidermal stem cells are a subpopulation of keratinocytes
Epidermal stem cells give rise to interfollicular epidermis, hair follicles and sebaceous gland.
Epidermal stem cells form clusters located in the upper hair follicle (bulge) and patches of basal keratinocytes at the tips of dermal papillae (between rete ridges)
This image is from a review article on epidermal stem cells written by Dr.Fiona Watt. Her research group is at Cancer Research UK, London Institute. Sweat glands (eccrine and apocrine) are derived from the epidermis during embryonic development but is is not known whether epidermal stem cells contribute to this differentiation pathway during postnatal life
Properties of Stem Cells
Not terminally differentiated
Can divide without limit (at least for the lifetime)
When a stem cell divides, each daughter cell has a choice: remain as a stem cell or embark on a course that commits to differentiation. Thus, stem cell population is self-maintained
Stem cells have often pluripotent differentiation potential. It is not yet known whether epidermal stem cells can give rise to other cell types such as blood cells. The picture below indicates the potential cell lineages that are derived from epidermal stem cells
Transit amplifying cells have limited proliferative potential and most likely limited differentiation potential as well. They divide rapidly a few times providing cells that are committed to terminal differentiation. Thus one stem cell division can give rise to several terminally differentiating cells.
Here is a recommended reading list on epidermal stem cells and other aspects on skin biology. Click here to download outline file of PowerPoint presentation on lecture material for stem cells and skin diseases.
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This page is maintained by Arto Maatta, last updated 15.04.2002