Katharina Buczek
This process is extremely unique– since other stem cells primarily just mature linearly until death.
Yet, MsSCs’ maturity levels are even more complicated than just that. As an individual gets older, and their hair sheds and grows back in a cyclical fashion, more McSCs will actually get stuck in the hair follicle bulge– a specific compartment.
While in the follicle bulge, McSCs will not receive any signals to mature. Plus, the cells are not sent to a different compartment that can send signals.
So, while the jammed cells do allow an individual’s hair to continue growing, the strands do not receive pigmentation– which results in gray locks.
The researchers confirmed this finding using a mouse model. They physically plucked strands of hair from mice for two whole years until they eventually produced mice that had salt-and-pepper-colored hair.
Afterward, they determined that the number of McSCs stuck in the follicle bulge had grown from 15% to almost 50%.
However, among the younger hairs that had not been plucked, the team found that McSCs continued traveling throughout different compartments– which allowed them to receive protein signals and consistently produce brown pigment.
Now, it is important to note that McSCs are not the only determining factor for when hair begins to gray.
“Some people think sun exposure can damage their melanocytes more or less. And hormones can play into it as well,” explained Dr. Jenna Lester, a professor from the University of California, San Francisco.
However, the recent discovery concerning McSCs may present new opportunities to prevent graying by actually moving the cells to their proper location.
On top of that, the finding may help us get one step closer to curing a lot more than a few silver strands– including cancer.
