Some of our animal cousins (and Deadpool) can regrow lost limbs. That’s a pretty neat trick that could benefit our wounded warriors and others. However, limb regeneration has been the stuff of science fiction and Marvel comics, but this past month, real scientific progress was made. Let me explain.
Regeneration: The Body’s Ability to Repair Its Own Tissues
In humans, self-repair happens every day. Our stem cells are constantly creating new cells to replace dying ones and coordinate self-repair for wounds and tissue injuries throughout our bodies. In the category of limb regeneration, however, we humans are actually quite low on the biological hierarchy compared to many other living organisms.
Some lizards, for example, can regenerate tails, deer can regenerate antlers, sea stars can regenerate entire limbs. An axolotl (an amphibian salamander) can regenerate not only its limbs and tail but also some organ parts, such as the heart and brain, and other body parts. Probably the most well-known (thanks to high-school biology) self-regenerator is the mighty little earthworm. If you cut an earthworm in half, not only will the front half (the head end) survive, but the earthworm will regrow its missing back half. Perhaps the organism that is the most advanced at regeneration is the flatworm. It can be cut into multiple segments with each segment retaining all the stem cells it needs to regrow a new head and become an entirely separate flatworm!
Humans simply can’t regrow organs or limbs and certainly not a new head, but we can investigate and learn a lot from other animals that can…
Science Takes Another Step Toward Advancing Human Limb Regeneration
In a new study, zebrafish, due to their ability to regenerate heart tissue, were investigated using a newly designed and advanced comparison database called RegenDbase. Researchers discovered genetic pathways containing certain noncoding RNA in cells that were once thought to serve no purpose and have no function but actually defined some of the regenerative capacity of the zebrafish.
So what does this have to do with humans? Knowing the genetic pathways that play a part in the regrowth of organs and limbs in these highly regenerative animals may one day advance the field of medicine and open doors to learn more about previously unexplored genetic pathways in humans that might lead to hidden regenerative capabilities. Further study may find mechanisms that can open up those regenerative pathways. Imagine the field of medicine in the year 2118—where a simple shot unlocks long dormant genes to allow a soldier to regrow a lost limb!
The upshot? We’re just beginning to scratch the surface of what’s possible in regenerative medicine. The super crazy and exciting stuff is yet to come!