Hair follicle regeneration

It may soon be possible to grow new hair follicles thanks to stem cell research. Scientists have already isolated the stem cells responsible for hair follicle growth and regenerated hair follicles in mice. And whilst we’ve been advised it may be some time until a 100 percent guaranteed cure for baldness is created, the foundations for a new hair loss treatment is firmly established. 

In 2004, researchers at the University of Pennsylvania School of Medicine used sophisticated cell labeling techniques to track the death of the stem cells during normal hair growth and isolate them in adult mice. They transplanted an insoluble mixture of these cells into the skin of a different set of adult mice with no immune systems. The absence of an immune system prevented the mice from rejecting the stem cell transplant. Within four weeks, the transplanted cells made new hair follicles that produced new hair.

"Now that we can isolate stem cells involved in hair growth, we can develop targets for manipulating hair growth", says study principal investigator George Cotsarelis, MD, Director of the Penn Hair and Scalp Clinic and Assistant Professor of Dermatology.

"The cells that we have isolated not only make hair follicles, but also can make other skin cells," says Cotsarelis. "These stem cells are there for your lifetime and have a huge capacity to proliferate and regenerate."

Not only do the findings have implications for hair growth, but also for burn treatments. Hair cannot currently grow through scars because the hair follicle has been destroyed. The hair may possibly be replaced via a hair transplant but it would depend on the severity of the scar, says Leonora Doclis, senior trichologist of the Belgravia Centre.

“A scar is basically a barren land,” she says. “You can try to fertilise it but if there’s not enough blood supply, then there’s currently not a lot you can do.” A solution however may be on the horizon.

In 2007, researchers found that hair follicles in adult mice regenerate by re-awakening genes once active only in developing embryos. It was previously believed that adult mammal skin could not regenerate hair follicles. In fact, investigators generally believe that mammals had essentially no true regenerative qualities.

In this study, researchers found that wound healing in a mouse model created an “embryonic window” of opportunity. Inactive embryonic molecular pathways were awakened, sending stem cells to the area of injury. The regenerated hair follicles unexpectedly originated from non-hair-follicle stem cells.

Researchers found they could make skin regenerate instead of just repair by introducing more wnt proteins to the wound which allowed them to take advantage of the embryonic genes to promote hair-follicle growth. They also found that they could stop the production of hair follicles in healed skin by blocking wnt proteins.

“We’ve found that we can influence wound healing [and] allow the skin to heal in a way that has less scarring and includes all the normal structures of the skin, such as hair follicles and oil glands, rather than just a scar,” explains Cotsarelis.

Not only that, it was discovered that increased wnt signaling doubled the number of new hair follicles, suggesting hair-follicle regeneration can be manipulated which will lead to novel ways to treat hair loss and hair overgrowth.

These findings go beyond just a possible treatment for male and female pattern baldness. If researchers can effectively control hair growth, then they could potentially find cures for people with hair and scalp disorders, such as scarring alopecia where the skin scars, and hair overgrowth.

"Although these findings are promising, we advise hair loss sufferers not to put all their eggs in one basket and wait around for a solution like this to come about. Years of testing would be required before any such solution was available, and there is no guarantee that such a procedure would ever be possible for humans, whose genetics are far more complicated than mice," says Leonora Doclis.

More information on the EFFECTIVE HAIR LOSS TREATMENTS.

(Images courtesy of e3000 and Nictalopen on flickr)

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