The key to regrowing limbs could be stem cells underneath your fingernails
The thoughts of regrowing limbs or even healing instantly is just crazy talk, unless you’re either Wolverine or that cheerleader girl from Heroes. Now a new study led by NYU’s stem cell biologist Dr. Mayumi Ito has discovered the key to regrowing tissue and bone could have been underneath our fingernails all this time.
The study looked into the curious case of Deepa Kulkarni, who lost part of her finger in an unfortunate door-slamming incident but was able to regrow the tip of her finger thanks to a seemingly magic powder made of ground-up pig bladders called MatriStem.
Scientists long theorized that the MatriStem acted as cellular scaffolding that attracted stem cells from the bone marrow or the small bit of the nail that Deepa retained on her partially severed finger.
Dr. Ito's study confirmed the fingernail theory when she discovered a new group of stem cells in our fingernails called Wnts (pronounced "wints”). If you’ve ever wondered why your nails never stop growing, it’s because of there’s a network of self-renewing stem cells in the nail matrix called the Wnt signaling network. These Wnts don’t just promote the growth of fingernails, but also flesh and even bone.
The NYU Langone Medical Center scientists confirmed her findings by replicating the same finger-clipping scenario with mice. Amazingly, the scientists also rerouted the Wnt pathways to other areas of the body to stimulate the regeneration of bone and tissue beyond the fingertip.
“Amputations of this magnitude ordinarily do not grow back,” said Dr. Mayumi in a release.
The implications for this research could be huge. Potentially this discovery could help an estimated 1.7 million people in the US who live with amputations, as well as the millions missing limbs from around the world.
The team’s next step is to explore the molecular mechanisms that control how the Wnt signaling pathway interacts with the nail stem cells to influence bone and nail growth. You can also read more about this amazing nail regeneration in a paper published in Nature.