The basis for the development of human hair is set up during pregnancy. About five million hair follicles develop during this time, just as many as in chimpanzees. The fact that the human species does not run about quite as hairy (at least not any more), is based on the circumstance of not every root sheath growing a hair. Just the more saddening if the relatively humble magnificence disappears either punctually or in the whole. Since scientists champion the thesis for decades now, that no new hair follicles grow after birth. And this means, loss of hair is irreversible – whether it is genetic or pathological.
This theory appears to be refuted now. Researchers of the University of Pennsylvania – School of Medicine recently proved in a mouse model, that a hair shaft grows within 45 days from those new hair follicles. Now the scientists hope to have come a bit closer to the target to develop new methods for treatment of hair loss and bald heads.
Sleeping Beauty and the Prince
Sleeping Beauty and her prince could have provided the scenario for that research result. In this case the prince has the proteins to wake Sleeping Beauty from her deep sleep. Indeed – hair follicles of mice were regenerated by “resurrection” of genes, which are only active during embryonic development. Professor George Cotsarelis and his team of Pennsylvania researchers found out that wound healing causes an embryonic state making skin receptive to instructions of the Wnt-signal way. The Wnts create a network of proteins normally provoking the development of hair follicles, but only during embryogenesis.
It showed that the influence of those molecules contributes to less scars remaining and a skin with a normal structure including hair follicles and sebaceous glands. The more Wnt-proteins the researchers put on the wound, the more hair follicles developed, thus suggesting that loss of hair and bald heads could be treated via the wound healing process with the motto – regenerate in lieu of repair.
Fortuity accelerates bald head's research
Rather by accident, the team of George Cotsarelis realized that the growth of hair can be promoted by wounds. The scientists brought scratches on mice to examine the part, stem cells from hair follicles play in wound healing. They were quite astonished to find hair growing right in the center of the wound. Taking a look at literature, the scientists found articles originating in the fifties telling the same story. But back in those days, the scientists did not pay any closer attention to their observation.
George Cotsarelis, who received last year's German Heinz-Maurer-Award for Dermatological Research, had hoped all along to be able to use stem cells from hair follicles as a super weapon against bald heads one day. For sure, those observations were a bang for the buck. But the discovery of the Wnt-protein proved to be just as important, since it makes significant contributions to the regeneration of hair follicles. Actually, the scientists from Pennsylvania are positive that some day, the treatment of hair loss might be possible without injury, for example by laser technology. In a few years we can expect clinical studies on this topic.