UT Southwestern Medical Center researchers have identified cells that stymie hair growth and also make hair turn gray as humans age. These findings could help identify possible treatments for balding and hair graying as further research is conducted.
Researchers found that a protein called KROX20, which is commonly associated with nerve development, is also responsible for “turning on” skill cells that become the hair shaft. This starts a cell chain process that eventually leads to the development of hair pigmentation protein. UT Southwestern reported that when it deleted the two genes in the proteins in this process in mouse models, “the animal’s hair turned white… When they deleted the KROX20-producing cells, no hair grew and the mice became bald.”
Dr. Lu Le, associate professor of dermatology at UT Southwestern’s Harold C. Simmons Comprehensive Cancer Center, says the discovery was made while conducting another study on neurofibromatosis Type 1, a rare genetic disease that causes tumors to 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,” Le said in a statement. “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.”
Le also said “they did not know in detail 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 [which] cells involved in hair shaft creation make the KROX20 protein.”
So far, it’s surmised that if cells with KROX20 and SCF are present, they move from the bulb, interact with pigment-producing cells, and grow pigmented hairs. However, without SCF, the hair turns gray, then white with age. And with KROX20-producing cells, no hair grows.
UT Southwestern conducted this study with support from the National Cancer Institute, Specialized Programs of Research Excellence grant, National Institutes of Health, the Dermatology Foundation, the Children’s Tumor Foundation, and the Burroughs Wellcome Fund.