The findings represent a culmination of years of work in the Fuchs lab on the science of hair and skin growth. This path of discovery has seen many hallmarks of progress, including the creation of transgenic mice with superthick hair growth, the identification of signals that are necessary to make hairs grow, and the earlier isolation and characterization of cells from a region of the hair follicle that researchers in the field thought might be the home of these stem cells.
Because they are so powerful, and so few in number, stem cells are used sparingly by the body and are tucked away in protected places. In the skin, cells suspected of having "stemness" because they divided infrequently were found by researchers to reside in a tiny bulge halfway up the side of a hair follicle shaft.
Earlier this year, researchers in the Fuchs lab reported in the journal Science a method to tag these "slow cycling" cells with a fluorescent marker and watched them travel out of the niche and move down to the bulb of the hair follicle to form new hair or move up to create new skin epidermis, lending more evidence to the idea that these were stem cells. But the researchers didn't know if hair and skin arose from one master cell -- a "multipotent" stem cell that can morph into a number of tissue types -- or from two populations of "unipotent" stem cells that are destined to be a single tissue.
"There has been increasing evidence that there are cells within this compartment that have the capacity to regenerate epidermis in wounding, and to regenerate hair follicles in the normal hair cycle, but it hasn't been clear whether this was due to the action of one stem cell or a bag of different cell
Contact: Lynn Love