Man alopecia baldness or hair loss - Close up head two hands isolated
May 11, 2017

Scientists discover what causes grey hair and baldness

Research conducted at UT Southwestern Medical Center has led to hope that scientists could one day "deliver the necessary gene to hair follicles" to put an end to baldness and graying hair.

Experts accidentally discovered the cause of balding and gray hair while studying a disorder known as Neurofibromatosis Type 1, a rare genetic disease in which tumors grow on nerves.

“Although this project was started in an effort to understand how certain kinds of tumors form, we ended up learning why hair turns gray and discovering the identity of the cell that directly gives rise to hair,” said Dr. Lu Le, Associate Professor of Dermatology with the Harold C. Simmons Comprehensive Cancer Center at UT Southwestern.

“With this knowledge, we hope in the future to create a topical compound to safely deliver the necessary gene to hair follicles to correct these cosmetic problems.”

The researchers discovered a protein that's usually associated with nerve development, called KROX20. The protein was found to turn on in skin cells that are a hair precursor, or progenitor, eventually becoming the hair shaft.

The cells produce a protein known as stem cell factor (SCF), which was found to be essential in hair pigmentation.

Deleting the SCF gene in hair progenitor cells of mice, the researchers found, led to white hair. Deleted KROX20-producing cells meant that hair did not grow at all, leading to baldness in the mice.

The end of gray hair and baldness?

Dr. Le, a member of the Hamon Center for Regenerative Science and Medicine, explained that scientists are already aware of the fact that stem cells contained in a bulge area of hair follicles contribute to making hair. It's also known that SCF is important for pigmented cells.

What is newly revealed, however, is what happens once those stem cells move down to the base, or bulb, of hair follicles, and which cells in the hair follicles produce SCF.

Also a new finding is that cells involved in creating hair shafts are responsible for making the KROX20 protein.

Cells that do contain functioning KROX20 and SCF are able to move up from the bulb, interact with melanocyte cells that make pigment, before developing into pigmented hairs.

The next step for the experts is to investigate whether KROX20 and the SCF gene cease to work efficiently as people get older, resulting in the gray and thinning hair that almost everyone experiences with age, along with the baldness most men face.

The hope is that the accidental discovery could one day make cosmetic concerns like gray hair and baldness things of the past.

Graying hair is not a terrible affliction, of course. Dying gray patches (or the whole head) is easy enough if people choose to do so, and many men may choose not to do so because the George Clooney, "silver fox" look is seen as being attractive.

Baldness is not a terrible affliction either, but it is harder to change should someone want to. The only options are very expensive hair replacement treatment, or a wig.

These days, most men would rather just embrace their baldness than wear a wig, but if they could reverse or prevent their baldness by other means, they may take action.

The findings from UT Southwestern could even tell us something more broadly about the ageing process in general, since baldness and gray hair are such common signs of ageing.

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