Mouse Study Uncovers the Roots of Gray Hair

THURSDAY, June 16 (HealthDay News) — The roots of gray hair may lie in a particular type of communication between hair follicles and melanocyte stem cells, the cells that make and store the pigments in skin and hair, a new study suggests.

Using mouse models, researchers at NYU Langone Medical Center found that Wnt signaling, already known to control many biological processes, may explain how these stem cells work together to produce hair color and generate hair growth.

“We have known for decades that hair follicle stem cells and pigment-producing melanocycte cells collaborate to produce colored hair, but the underlying reasons were unknown,” said Mayumi Ito, assistant professor of dermatology at NYU Langone in a news release from NYU. “We discovered Wnt signaling is essential for coordinated actions of these two stem cell lineages and critical for hair pigmentation.”

Researchers found the lack of Wnt activation in melanocyte stem cells leads to de-pigmented, or gray hair. They also showed that abnormal Wnt signaling in hair follicle stem cells prevents hair re-growth. The study’s authors concluded their findings could serve as a model for tissue regeneration.

“The human body has many types of stem cells that have the potential to regenerate other organs,” noted Ito. “The methods behind communication between stem cells of hair and color during hair replacement may give us important clues to regenerate complex organs containing many different types of cells.”

The researchers added the study, published in the June 11 issue of Cell, could help shed light on diseases in which melanocytes are either lost or grow uncontrollably as in melanoma.

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The U.S. Library of Congress has more on why hair turns gray.

– Mary Elizabeth Dallas

SOURCE: NYU Langone Medical Center, news release, June 14, 2011

Last Updated: June 16, 2011