Somewhere along the way, the purifying imperatives of evolution decided to dial back our bodies' ability to rapidly regenerate tissue. Nobody knows exactly why. It could be because cancer in mammals would grow like wildfire if it didn't. But this ancient property remains in fetuses and infants and diminishes significantly as we age.
Researchers say it may not have to. Dr. Hao Zhu of the Children's Medical Research Institute at UT Southwestern believes the gene Lin28a can be reactivated to enhance tissue regeneration after surgery, serious injury and to combat degenerative disease. "As we age, our tissues get worse and worse at regenerating. They get worse at coming back from injury," Zhu tells Unfair Park. "The curious thing is that the genetics behind this, the biology underlying that principle, is poorly understood. We believe some genes being turned off or on are responsible for that phenomenon."
By triggering Lin28a and the enhanced metabolic state of youth, we may be able to "trick adult tissue into thinking it's younger."
Over the last four years, Zhu has tested this hypothesis by over-expressing the gene in mice. Invariably, they healed faster than their normal counterparts. "We're just at the beginning to figure out what are potential drug targets to improve wound healing after surgery, and to improve degenerative diseases," Zhu says. "It's a rare situation where we can take an animal and improve healing after injury with just one gene."
The path toward human trials is a long one, he cautions. His lab's next goal is to identify whatever danger may lurk behind imbuing aging bodies with the regenerative capacity of youth. But the implications for how we heal -- possibly by simply flipping on a single gene -- represent a fascinating new discovery in a field seeking the solutions within us.