The finding comes from the Johns Hopkins University lab of Catherine C. Thompson, PhD. Thompson and colleagues wondered exactly why mice lacking the Hairless gene are, well, hairless.
Their results point researchers toward a way to regenerate the hair follicles of men and women with alopecia.
A Tiny Organ
Hair follicles aren't normal skin cells. They're really tiny organs. And these tiny organs do one of the most amazing things any organ can do: they regenerate.
Hair cells grow hair, of course. But that's only one phase of their life cycle. Each follicle eventually withers down to a shadow of its former self. Then, somehow, stem cells inside the follicle come to life. The follicle regenerates and grows a new hair.
When something goes wrong with this process, hair thinning or baldness results. Researchers have a model for this: mice lacking the Hairless gene. At first, these mice grow normal-looking hair. But as their hair follicles cycle, the hairs fall out -- and don't grow back.
Thompson's team genetically engineered hairless mice to produce Hairless protein in specific cells within the hair follicle. The result: Mice that grew -- and kept growing -- thick fur.
The researchers showed that the Hairless gene only works when it gets the proper chemical signals at exactly the right time during the follicle cycle. Now researchers are one step closer to knowing what these signals are and when to give them.
Thompson and colleagues report their findings in the early online edition of Proceedings of the National Academy of Sciences.