Study co-author Dr. Lu Le, of the Harold C. Simmons Comprehensive Cancer Center at the University of Texas Southwestern in Dallas, and colleagues set out to investigate a disorder called neurofibromatosis type 1 (NF1), a genetic condition whereby tumors grow on nerves. Instead, the team ended up identifying the processes responsible for hair loss and graying, and reported their findings in the journal Genes and Development.
While hair loss and graying are considered by many as a normal part of aging, for some, the conditions can be highly distressing. Dr. Le and colleagues believe that their discovery could lead to new treatments for the conditions.
Findings may lead to surface treatments for hair loss and graying
Previous studies had already established that hair follicles contain stem cells that play a role in hair production, and that a protein called stem cell factor (SCF) is involved in hair pigmentation.
In their study, Dr. Le and team found that once stem cells move to the base of hair follicles, a protein called KROX20 – originally known for nerve development – is activated in skin cells that form hair shafts (progenitor cells). They found that when KROX20 is activated, the hair shaft-forming cells produce SCF.
In mice with skin cells that possessed both KROX20 and SCF, the researchers found that the skin cells communicated with melanocyte cells to form pigmented hairs. Melanocyte cells produce melanin, the pigment that gives color to the skin, hair, and eyes.
When the researchers deleted SCF in the mice, the researchers found that the rodents grew gray hairs, and these hairs turned white with age. When KROX20-producing cells were erased, the mice did not grow any hair.
Although studies in humans are required to confirm these findings, Dr. Le and colleagues believe that they show promise for the development of new therapies for baldness 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.
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.”