Now That We Understand Where Gray Hair Comes From, Can We Reverse It?

There’s an entire industry surrounding the practice of getting rid of gray hair, yet a new study is poised to set the market on its head (pun intended). A group of researchers from the University of Texas Southwestern Medical Center have identified the cells that provoke gray hair. Their findings could possibly lead to medical innovations that would reverse the growth of grays and whites. 

KROX20 is a protein that is usually associated with nerve development; however, the researchers discovered how it’s ignited in skin cells that evolve into the hair shaft. These cells produce stem cell factor (SCF), and when both KROX20 and SCF move from the bulb to connect with the pigment-producing melanocyte cells, then gray hair grows.

The researchers found that when they removed the SCF gene on mice, their fur turned white. But, when they deleted the cells that produce KROX20, the mice stopped growing hair and eventually turned bald. The researchers stumbled upon this analysis when studying Neurofibromatosis Type 1, a rare condition that causes tumors to grow in the skin and brain, and usually triggers skin pigmentation.

It has already been established that SCF is a component of pigmented cells, and that stem cells located in the biggest part of the hair follicles are essential to the hair-growing process. However, what the study uncovered is that the cells that take part in hair shaft development also make the KROX20. Study leader, Lu Q. Le, MD, says that the next step is to find out if KROX20 and SCF stop working when hair goes gray or causes hair thinning.

“In baldness, it appears that the epithelial stem cells in the bulge are still there. However, the hair shaft progenitor cells (which differentiated from the epithelial stem cells that are in the bulge) that directly give rise to hair--the KROX20-producing cells--are gone,” Dr. Le told Dermatology Times. “This gives us hope that we can figure out a way to activate the differentiation of epithelial stem cells in the bulge into KROX20-producing cells in order to make hair again.”