In the future scientists may be able to alter people’s skin and hair colour, thanks to a stem cell study that has located the mechanism that controls both.

The study, by scientists at NYU Langone Medical Center, describes how the control of skin and hair cells, known as melanocyte stem cells, is regulated by cell-to-cell signalling reactions.

These reactions are part of the endothelin receptor type B (EdnrB) and the Wnt signalling pathways.

By stimulating the EdnrB pathway, wounded skin in normally white mice became dark upon healing, and by blocking Wnt signalling and stopping melanocyte stem cells from developing into normally functioning melanocytes, mice developed unpigmented grayish fur.

“Our study results show that EdnrB signaling plays a critical role in growth and regeneration of certain pigmented skin and hair cells and that this pathway is dependent on a functioning Wnt pathway,” says study senior investigator and cell biologist Mayumi Ito, PhD

If the mechanism that controls skin colour was targeted, then the researchers believe that the technique could be used to repigment cells damaged by vitiligo, a disfiguring illness marked by the loss of skin pigmentation that leaves its sufferers with a blotchy, white complexion.

The same technique could also recolour greyed hair cells for people who can’t or won’t use cosmetic dyes, and to correct discoloration around scars.

The study’s co-lead investigator and postdoctoral fellow Dr Wendy Lee, said the mechanism’s involvement in the determination of hair colour was “clearly evident” in the mice when she first examined them.

The team was then able to achieve a 15-fold increase in pigment production within two months, producing a phenomenon called “hyperpigmentation” in the mice.

Ito says her team plans to further investigate how signalling pathways interact with EdnrB and melanocyte stem cells and hope to find other ways to activate these pathways.

The researchers’ full findings are available in the journal Cell Reports.