SerpApi.Org
Though the two species seem wildly different, humans and mice do have a few key similarities and one of these features involves how both species’ hair grays as they age.
Humans and mice begin to develop gray hair later in life because, for unknown reasons, the melanocyte stem cell (McSC) system fails earlier than other adult stem cell populations.
Now, researchers from the NYU Grossman School of Medicine have discovered a potential reason behind this phenomenon, possibly explaining why hair turns gray later in life.
The study focused on mice to reveal information about human hair cells. The mice’s hair was physically aged by plucking and forced regrowth, in order to examine the effects on McSCs.
The team used recent 3D-intravital-imaging and scRNA-seq techniques to track cells in real time.
Study authors have discovered that hair color is determined by cells that move back and forth between compartments of the developing hair follicle.
However, as hair ages, sheds and then repeatedly grows back, increasing numbers of McSCs get stuck in the compartment called the hair follicle bulge.
A New Theory
“There, they remain, do not mature into the transit-amplifying state, and do not travel back to their original location in the germ compartment, where WNT proteins would have prodded them to regenerate into pigment cells,” shares NYU Langone.
The WNT pathway regulates many crucial aspects of cell fate determination, explains the National Library of Medicine.
“The WNTs are secreted glycoproteins and comprise a large family of 19 proteins in humans hinting to a daunting complexity of signaling regulation, function and biological output.”
Why these proteins are important has to do with a new theory proposed by the researchers.
Maybe WNT signaling could reverse hair graying.
“The newfound mechanisms raise the possibility that the same fixed positioning of melanocyte stem cells may exist in humans,” lead study investigator Qi Sun PhD, a post-doctoral fellow at NYU Langone Health, said.
“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 hair follicle compartments.”
‘Chameleon-like’
Earlier work by the same research team revealed that WNT signaling was necessary for McSCs to mature and produce pigment. When cells get stuck in the hair follicle bulge, they receive less WNT signaling, which could be contributing to how hair grays as it matures.
“It is the loss of chameleon-like function in melanocyte stem cells that may be responsible for graying and loss of hair color,” said study senior investigator Mayumi Ito, PhD, a professor in the Ronald O. Perelman Department of Dermatology and Department of Cell Biology at NYU Langone Health.
While the study has not yet determined exactly how to reverse this graying process, it reveals vital clues as to how this task can be undertaken.
The team plans to investigate means of restoring motility of McSCs or of physically moving them back to their germ compartment in which they can restore the ability to produce pigment.
Newsweek has reached out to study authors for comment via email.
Related Articles
