Nail stem cells underneath the fingernails maybe the key for humans to have the ability of salamanders to regenerate a chopped off limb. A new study documented how scientists worked on mice and found a way to grow an incompletely amputated digit.
The study titled "Wnt activation in nail epithelium couples nail growth to digit regeneration" that documented the methods used by experts from New York University was published Wednesday on Nature.
For now, the study was able to tap the regenerative powers in mammals but not yet the full capacity of how amphibians orchestrate regrowth of their limbs.
The regeneration of the finger will depend on how much of the said regrowth cells, called Wnt, remain. In case the amputation happens where the cells crucial for regrowth were also slashed off, there will be zero chance for regrowth, otherwise it is very much possible.
"I was amazed by the similarities. It suggests that we partly retain the regeneration mechanisms that operate in amphibians," said Mayumi Ito, lead author of the study in an interview with Nature.
There have been documented cases where young patients partially amputated their fingertips in various accidents and have phenomenally regrown the tips of their digits according to a report on NPR.
The study conducted by Ito and her team aimed to explore how this regrowth occurs. During the experiment, the researchers labeled the cells underneath the nails of the mice and traced which ones are responsible for self-renewal and growth. The Wnt proteins carry the signals that tell the body to regrow the nails and may also be responsible for the regrowth of the cut off tips of the toe.
The researchers also tried removing the nerves and the stem cells beneath the nails of the mice. In both cases, the mice did not regrow its nails and toe tips.
When amputation occurs, the stem cells are activated and a protein referred to as FGF2 is used by the nerves to stimulate growth of the mesenchymal cells and eventually bone, muscles and tendons.
The results of the study give rise to the possibilities that humans have the same capabilities, too. If indeed humans have the same cells, this may lead to better treatment for amputees in the future.
In a related story published on Popular Science, a patient by the name of Deep Kulkami was able to regenerate her finger tips using Matrisem, a powder formulated from the bladder of pigs. The powder stimulates the healing process and attracts stem cells that promote regrowth of the fingertip. Just like in the Ito's study, it might have worked because Kulkami retained portions of the necessary cells under the finger nail to promote regrowth.