Another new stem cell heard from…dermal stem cells, found by a research team in Toronto, Canada. Over several years of work, these cells have finally been identified as true stem cells (limited multipotent) that can produce a variety of other cells including skin, bone, cartilage, and neuron. It’s another advance in the fund of stem cells that can be found and nurtured from sources other than those associated with embryos and childbirth.
In this case, researchers isolated a type of cell in the dermis (the middle layer of skin) located most frequently around hair follicles. These cells, which are believed to be adult versions of cells generated during the embryonic phase of development, are found in all hair bearing mammals – hair being constantly regenerated is a clue that stem cells may be at work. Originally called “skin derived precursors,” or SKPs (skips) for short, they turned out to be derived from the neural crest cells of embryos – the ones that eventually form the brain and nervous system.
Freda Miller [HHMI international research scholar] and her colleagues first saw the cells several years ago in both rodents and people, but only now confirmed that the cells are stem cells. Like other stem cells, these cell scan self-renew and, under the right conditions, they can grow into the cell types that constitute the skin’s dermal layer, which lies under the surface epidermal layer. “We showed that these cells are, in fact, the real thing,” says Miller, a professor at the University of Toronto and a senior scientist in the department of developmental biology at the Hospital for Sick Children in Toronto. The dermal stem cells also appear to help form the basis for hair growth. The new work was published December 4, 2009, in the journal Cell Stem Cells.
The cells behavior both in wound healing and hair growth led the team to conclude that the SKPs are, in fact, dermal stem cells. Miller said the finding complements work by HHMI investigator Elaine Fuchs, who found epidermal stem cells, which help renew the top layer of skin. Combining the evidence from the two labs suggests a possible path to baldness treatments, Miller said—the dermal stem cells at the base of the hair follicle seem to be signaling the epidermal cells that form the shaft of the follicle to grow hair. But much about the signaling mechanism remains unknown.
[Source: Howard Hughes Medical Institute]
Part of the laboratory testing of the dermal skin cells was the (re)generation of hair in mice, which was successful, and suggests obvious uses of these stem cells in hair growing applications. However, the neural origin of the dermal stem cells also leads the researchers to believe that less cosmetic applications may be found for the nervous system and other internal organs.