Scientists who have been studying hair follicles in mice have finally come across a reason behind why and how Gray Hair Occurs. This discovery could one day lead to some potential new ways to either stop or even reverse the process.
On a basic level, everybody knows that the hair starts turning Gray Hair when specialized pigment-producing cells called as the melanocytes are in short supply. But looking at it in depth, we still haven’t found why and how exactly it happens, or if there could be a way to stop or prevent it from happening.
What are the findings of the new study?
This new study has recently been able to uncover and add a few extra details to the process. It has also challenged the previous ideas about how melanocytes develop.
These melanocytes are derived from the melanocyte stem cells (McSCs) that are present in the Gray Hair follicle. The latest research has been focusing on these particular stem cells.
It has been observed that, as a person ages, the precursors to the pigment-producing cells seem to get stuck in a region called as the follicle bulge. This causes it to stop developing into the melanocytes in enough numbers to fill the growing strands of Gray Hair.
In a test conducted on mice, after the scientists forced the aging process, it was observed that the number of hair follicles with McSCs stuck in the follicle bulge had increased from 15% to almost half the amount.
Those cells were no longer able to regenerate or mature into the cells that could make the pigment and remained stuck as McSCs instead.
“Our study adds to our basic understanding of how melanocyte stem cells work to colour hair,” says dermatologist Qi Sun from New York University. “The new-found mechanisms raise the possibility that the same fixed positioning of melanocyte stem cells may exist in humans.”
“If so, it presents a potential pathway for reversing or preventing the graying of human hair by helping jammed cells to move again between developing Gray Hair follicle compartments.”
Adding to our basic knowledge
In this study, the researchers further found that unlike other stem cell types, the McSCs have the ability to switch between a pure stem cell state and a state known as the transit-amplifying (TA) state. The TA is sort of a halfway state between a stem cell and a full melanocyte cell.
It was found that the TA state is an important state for the McSC health, which leads to the continuous production of hair colour. But, the team has also found that switching to the TA state depends on factors like signals from specific locations. These locations are those where the cells get cut off from when they are stuck in the follicle bulges.
Even if the findings of this study are remarkable, it still needs to be observed in human hair follicles, but there might be a chance that the same mechanisms are at play in humans. Furthermore, the study could also offer humans a way of treating Gray Hair and make sure that it doesn’t lose its colour.
“These results identify a new model whereby dedifferentiation is integral to homeostatic stem cell maintenance and suggest that modulating McSC mobility may represent a new approach for the prevention of Gray Hair,” write the researchers in their published paper.
In conclusion, the MsSCs are able to move around in different states unlike the other stem cells. And it has been found that this mobility and plasticity is important to continue the production of melanin through melanocytes.
“These findings suggest that melanocyte stem cell motility and reversible differentiation are key to keeping hair healthy and colored.”
The research has been published in Nature.