A protein active in immature pigment-producing skin cells could be responsible for hair colouring, according to US scientists. The findings about melanocyte stem cells (MSCs) may explain why hair turns grey and could provide insight into melanocyte-related diseases, such as melanoma.
Professor Mayumi Ito from New York University's Langone Medical Centre, who was involved in the study, said she and her team had successfully restored hair colour in mice. By manipulating the protein, called wnt, she thought it might be possible to stop hair turning grey.
Melanocyte cells produce melanin which causes pigmentation in eyes, skin and hair. Professor Ito and her team demonstrated how wnt drove melanocyte stem cells in mice to mature into pigment-producing melanocytes. The protein also regulated the coordination of MSCs and other skin stem cells to regenerate pigmented hair, the researchers said.
'We discovered wnt signalling is essential for coordinating actions of these two stem cell lineages and critical for hair pigmentation', said Professor Ito. She added: 'The methods behind communication between stem cells of hair and colour during hair replacement may give us important clues to regenerate organs containing many different types of cells'.
Previous studies have shown wnt may be responsible for producing new hair follicles, but its precise role in hair colouring was unclear. 'We have known for decades that hair follicle stem cells and pigment-producing melanocyte cells collaborate to produce coloured hair, but the underlying reasons were unknown', Professor Ito said.
The research could mean a lack of wnt in melanocyte stem cells is responsible for grey hair, providing a possible target for treatment. However, the researchers are yet to establish whether a fault in this process does turn people's hair grey.
The findings were published in the journal Cell.