Zebrafish May Help Humans to One Day Regrow Limbs
Prosthetics may someday be objects collecting dust in a museum. Researchers hope to one day break open genetic elements (the genome/complete DNA) to regenerate limbs and other body parts. Salamanders, starfish and zebrafish already have this ability. Can humans be next?
Kenneth D. Poss is senior author of the new study and a professor of cell biology at Duke University School of Medicine and his team surmises that by going into human genetic’s past, before evolution, there was a common ancestor with the ability to regrow body parts. If that dormant biology could be awakened, it may be possible to regenerate body parts as well.
We want to know how regeneration happens, with the ultimate goal of helping humans realize their full regenerative potential.
This study’s focus in on discovering “tissue regeneration enhancer elements” (TREEs), the specific gene that signal when a tissue is being repaired or has completed repair. It is not on actual tissue or cell regeneration.
By studying zebrafish, a species capable of regenerating fins and hearts, researchers were able to identify the genetic elements responsible for regeneration. When damaged, a gene called “leptin b” was activated and the repairs began.
We want to find more of these types of elements so we can understand what turns on and ultimately controls the program of regeneration. There may be strong elements that boost expression of the gene much higher than others, or elements that activate genes in a specific cell type that is injured. Having that level of specifity may one day enable us to change a poorly regenerative tissue to a better one with near-surgical precision.
This was taken a step further using mice. Brian L. Black, a collaborator and professor at the University of California in San Francisco has successfully activated this ability in mice. He borrowed the genes from zebrafish to create transgenic mice. He discovered that the TREEs triggered the regeneration of paws and hearts in the mice.
Poss suggests that the genome editing technologies of today may make it possible to one day allow humans and other mammals to repair and regenerate damaged or missing body parts.
We are just at the beginning of this work, but now we have an encouraging proof of concept that these elements posses all the sequences necessary to work with mammalian machinery after an injury …Our study points to a way that we could potentially awaken the genes responsible for regeneration that we carry within us.
So far, the only organ in the human body that can regrow cells and regenerate itself is the liver. Perhaps, one day soon, other organs and limbs can be regenerated as well.