Stem cells in hair follicles point to general model of organ regeneration

Most people consider hair as a purely cosmetic part of their lives. To others, it may help uncover one of nature’s best-kept secrets: the body’s ability to regenerate organs. Now, new research from Rockefeller University gets to the root of the problem, revealing that a structure at the base of each strand of hair, the **hair follicle**, uses a two-step mechanism to activate its **stem cells** and order them to divide. The mechanism provides insights into how repositories of stem cells may be organized in other body tissues for the purpose of supporting **organ regeneration**. For a new round of hair growth to begin, stem cells in the hair follicle must receive a signal to divide. In response to this signal, the hair follicle regenerates first by growing downward through the skin’s middle layer, the dermis, and then producing the specialized cells that form the hair. After a period during which the hair grows longer, stem cells stop dividing, and the hair follicle gradually retracts again. There is then a period of rest and the cycle repeats. More "newswire.rockefeller.edu":[ http://newswire.rockefeller.edu/?page=engine&id=881]

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