If a newt loses an arm, it can grow it back. Humans cannot. Scientists have known that newts have the ability to regenerate damaged or missing limbs for 250 years, but still don’t know how they do this.
However, researchers at The Ottawa Hospital hope that by understanding the early stage of the newt’s regenerative process, called dedifferentiation, they can find the clue to enable healing of damaged human spines, eyes, or any other tissue.
“Newts can regenerate multiple structures. In the eye, they can regenerate the lens and the retina. They can regenerate limbs, tail, jaw, spinal cord, part of the heart,” said researcher Dr. Catherine Tsilfidis, senior scientist in the Regenerative Medicine Program of The Ottawa Hospital and associate professor at University of Ottawa. “The newt’s cells at the injury site have the ability to revert back to embryonic cells. They can then enter the cell cycle and divide and reform the structure that was lost. This reverting back to an embryonic cell type is something that human cells cannot do. Once they become muscle cells or nerve cells, they are committed for life.”
However, she said studying newts is not as easy as more common laboratory models, such as mice. It takes seven years for newts to reach sexual maturity, whereas mice are able to reproduce within two months, which makes studying generations of mice easier. More problematic for research is the newt’s genetic system. Its genome has not yet been sequenced because it is extremely complicated with some newt species having four times the amount of DNA that humans do.
“We’re trying to understand how we can potentially use the knowledge we gain in dedifferentiation in the newt and apply it to regeneration capability in humans,” said Dr. Tsilfidis. But, she adds, understanding the newt’s regenerative processes is difficult, and translating that to human cell structures is not straightforward, although the potential for human healing is limitless.