Nail growth may hold key to limb regeneration

Washington: Researchers have shed light on how an amputated fingertip of mammals can regenerate.

NYU Langone Medical Center researchers used genetically engineered mice to document for the first time the biochemical chain of events that unfolds in the wake of a fingertip amputation.

The findings hold promise for amputees who may one day be able to benefit from therapies that help the body regenerate lost limbs.

Lead author Mayumi Ito, PhD, assistant professor of dermatology in the Ronald O. Perelman Department of Dermatology at NYU School of Medicine said that everyone knows that fingernails keep growing, but no one has an idea why it happens.

Ito and her team discovered an important clue in this process, a population of self-renewing stem cells in the nail matrix, a part of the nail bed rich in nerve endings and blood vessels that stimulate nail growth.

Moreover, the scientists found that the stem cells depend upon a family of proteins known as the "Wnt signaling network"- proteins playing a crucial role in hair and tissue regeneration-to regenerate bone in the fingertip.

Ito said that when they blocked the Wnt-signaling pathway in mice with amputated fingertips, the nail and bone did not regenerate back.

They also found that they could manipulate the Wnt pathway to stimulate regeneration in bone and tissue just beyond the fingertip.

Ito said that amputations of this magnitude normally don`t grow back.

The paper has been published in the journal Nature.