Scientists find skin cells at the root of balding, gray hair

May 8, 2017 by Carol Marie Cropper
Strand of human hair at 200x magnification. Credit: Jan Homann/Wikipedia

UT Southwestern Medical Center researchers have identified the cells that directly give rise to hair as well as the mechanism that causes hair to turn gray – findings that could one day help identify possible treatments for balding and hair graying.

"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 or to safely deliver the necessary gene to hair follicles to correct these cosmetic problems."

The researchers found that a protein called KROX20, more commonly associated with nerve development, in this case turns on in skin that become the hair shaft. These hair precursor, or progenitor, cells then produce a protein called stem cell factor (SCF) that the researchers showed is essential for hair pigmentation.

When they deleted the SCF gene in the hair progenitor cells in mouse models, the animal's hair turned white. When they deleted the KROX20-producing cells, no hair grew and the mice became bald, according to the study.

The findings are published online in Genes & Development.

Dr. Le, who holds the Thomas L. Shields, M.D. Professorship in Dermatology, said he and his researchers serendipitously uncovered this explanation for balding and hair graying while studying a disorder called Neurofibromatosis Type 1, a rare genetic disease that causes tumors to grow on nerves.

Scientists already knew that stem cells contained in a bulge area of hair follicles are involved in making hair and that SCF is important for pigmented cells, said Dr. Le, a member of the Hamon Center for Regenerative Science and Medicine.

What they did not know in detail is what happens after those stem cells move down to the base, or bulb, of hair follicles and which cells in the hair follicles produce SCF – or that cells involved in hair shaft creation make the KROX20 protein, he said.

If cells with functioning KROX20 and SCF are present, they move up from the bulb, interact with pigment-producing melanocyte cells, and grow into pigmented hairs.

But without SCF, the hair in mouse models was gray, and then turned white with age, according to the study. Without KROX20-producing cells, no hair grew, the study said.

UT Southwestern researchers will now try to find out if the KROX20 in cells and the SCF gene stop working properly as people age, leading to the graying and hair thinning seen in older people – as well as in male pattern baldness, Dr. Le said.

The research also could provide answers about why we age in general as hair graying and loss are among the first signs of aging.

Explore further: New research provides clues on why hair turns gray

More information: Chung-Ping Liao et al. Identification of hair shaft progenitors that create a niche for hair pigmentation, Genes & Development (2017). DOI: 10.1101/gad.298703.117

Related Stories

New research provides clues on why hair turns gray

June 14, 2011
A new study by researchers at NYU Langone Medical Center has shown that, for the first time, Wnt signaling, already known to control many biological processes, between hair follicles and melanocyte stem cells can dictate ...

New research clarifies how stem cells get activated to produce new hair

March 3, 2016
Adult stem cells provide the body with a reservoir from which damaged or used up tissues can be replenished. In organs like the intestines and skin, which need constant rejuvenating, these stem cells are dividing frequently. ...

Recommended for you

Association found between abnormal cerebral connectivity and variability in the PPARG gene in developing preterm infants

December 12, 2017
(Medical Xpress)—A team of researchers with King's College London and the National Institute for Health Research Biomedical Research Centre, both in the U.K., has found what they describe as a strong association between ...

Large genetic study links tendency to undervalue future rewards with ADHD, obesity

December 11, 2017
Researchers at University of California San Diego School of Medicine have found a genetic signature for delay discounting—the tendency to undervalue future rewards—that overlaps with attention-deficit/hyperactivity disorder ...

Gene variants identified that may influence sexual orientation in men and boys

December 8, 2017
(Medical Xpress)—A large team of researchers from several institutions in the U.S. and one each from Australia and the U.K. has found two gene variants that appear to be more prevalent in gay men than straight men, adding ...

Disease caused by reduction of most abundant cellular protein identified

December 8, 2017
An international team of scientists and doctors has identified a new disease that results in low levels of a common protein found inside our cells.

Study finds genetic mutation causes 'vicious cycle' in most common form of amyotrophic lateral sclerosis

December 8, 2017
University of Michigan-led research brings scientists one step closer to understanding the development of neurodegenerative disorders such as ALS.

Mutations in neurons accumulate as we age: The process may explain normal cognitive decline and neurodegeneration

December 7, 2017
Scientists have wondered whether somatic (non-inherited) mutations play a role in aging and brain degeneration, but until recently there was no good technology to test this idea. A study published online today in Science, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.