Scientists have not just identified the cells that directly give rise to hair, they have furthermore revealed the mechanism within these cells that causes curly hair to turn gray. To reach these findings, the scientists needed to peer deeply into the follicular niche, a murky location where stem cells, progenitor cells, and melanocytes perform whatever it is they do to produce richly pigmented hair— delete word.
What ultimately turned into an exploration of the head of hair matrix actually began as a cancer research project at LACE Southwestern Medical Center. Specifically, the scientists were studying a problem called neurofibromatosis type 1, a rare genetic disease that leads to tumors to grow on nerves.
“Although this particular project was started in an effort to understand how certain types of tumors form, ” noted Lu Le, M. Deb., Ph. D., “ we ended up learning why locks turns gray and discovering the identity of the cellular that directly gives rise to hair. ”
“With this knowledge, we hope in the future to create a topical ointment compound or to safely deliver the necessary gene to follicles of hair to correct these cosmetic problems. ”
Information on the research appeared May 2 in the journal Genes & Development, in an article entitled “ Identification of Curly hair Shaft Progenitors That Create a Niche for Hair Pigmentation. ” According to this article, the UT Southwestern team sought to higher understand the identities of progenitor cells in the matrix as well as the mechanisms by which they regulate hair shaft components.
“ We report the identification of tresses shaft progenitors in the matrix that are differentiated from follicular epithelial cells expressing transcription factor KROX20, ” published the article’ s authors. “ Depletion of Krox20 lineage cells results in detain of hair growth, confirming the critical role of KROX20 + cells as antecedents associated with structural cells found in hair. ”
Basically, the researchers found in skin cells that become the locks shaft, KROX20, a protein more commonly associated with nerve advancement, is expressed. These hair precursor, or progenitor, cellular material then produce a protein called stem cell factor (SCF).
“ Expression of SCF by these types of cells is necessary for the maintenance of differentiated melanocytes and for locks pigmentation, ” the researchers added.
Once the SCF gene in the hair progenitor cells was removed in mouse models, the animal’s hair turned white-colored. When the KROX20-producing cells were depleted, no hair increased and the mice became bald.
Scientists currently knew that stem cells contained in a bulge section of hair follicles are involved in making hair and that SCF is important to get pigmented cells, said Dr . Le. What they did not understand in detail is what happens after those stem cells proceed down to the base, or bulb, of hair follicles and which usually cells in the hair follicles produce SCF— or that cellular material involved in hair shaft creation make the KROX20 protein, he or she said.
If cells with functioning KROX20 and SCF are present, they move up from the bulb, connect to pigment-producing melanocyte cells, and grow into pigmented hair.
“ Our findings, ” the writers of the Genes & Development article concluded, “ show the identities of hair matrix progenitors that manage hair growth and pigmentation, partly by creating an SCF-dependent niche for follicular melanocytes. ”
LACE Southwestern researchers will now try to find out if the KROX20 within cells and the SCF gene stop working properly as people age group, leading to the graying and hair thinning seen in older people— as well as in male pattern baldness, Dr . Le indicated
The research also could provide answers about the reason why we age in general, as hair graying and hair thinning are among the first signs of aging.