George Cotsarelis, M.D. of the University of Pennsylvania Medical School has shown in mice stem cells in hair follicles can be labelled, extracted, and reimplanted to cause hair growth in the target implant area.
Stem cells plucked from the follicles of mice can grow new hair when implanted into another animal. The work represents a dramatic step forward that is sure to stimulate new research into treatments for human baldness.
Cotarelis' group and a different group at Rockefeller University headed by Elaine Fuchs each separaately developed means to label the stem cells around follicles so that they could be isolated from other cells around them. Then gene arrays were used to study which genes were on and off. That pattern of gene state ought to be useful for discovering the same cell type in humans.
After purifying a sufficient amount of these cells, both groups used gene chips to find which genes were switched on in the stem cells. For the first time, this provides a signature that researchers can use to identify the same cells in humans.
"We've shown for the first time these cells have the ability to generate hair when taken from one animal and put into another," Cotsarelis said in a telephone interview. "You can envision a process of isolating existing stem cells and re-implanting them in the areas where guys are bald."
One advantage of using your own adult stem cells for this purpose is that immune rejection problems are avoided.
"I think this or something like it will be available in the next five to 10 years," said George Cotsarelis
Many adult regenerative cells divide infrequently but have high proliferative capacity. We developed a strategy to fluorescently label slow-cycling cells in a cell type-specific fashion. We used this method to purify the label-retaining cells (LRCs) that mark the skin stem cell (SC) niche. We found that these cells rarely divide within their niche but change properties abruptly when stimulated to exit. We determined their transcriptional profile, which, when compared to progeny and other SCs, defines the niche. Many of the >100 messenger RNAs preferentially expressed in the niche encode surface receptors and secreted proteins, enabling LRCs to signal and respond to their environment.
|Share |||Randall Parker, 2004 March 15 02:53 AM Biotech Organ Replacement|