Humans Have Potential to Regrow Body Parts Just Like Salamanders, Say Scientists

A team of scientists from Maine believe that humans have an 'untapped' potential to regrow lost or injured body parts just like the salamanders. This behavior is characterized by a certain protein in amphibians that also exists in mammals.

The endangered axolotl, a neotenic salamander, also known as the Mexican walking fish, is considered as the 'champion' when it comes to regeneration. These amphibians can regrow almost any body part, including the brain.

Scientists from MDI Biological Laboratory in Bar Harbor, Maine found immune cells called macrophages in salamanders which promotes tissue cells growth.

Unlike the salamanders, mammals like mouse also have these cells but produced scarring instead. The researchers hope to understand how axolotl does not form a scar like the mouse and other mammals do when injured.

Scarring in Mammals Blocks Regeneration

Author Dr. James Godwin and his colleagues examined and compared cells of injured axolotl salamander to that of an adult mouse. The team initially hypothesized that the formation of scars among mammals is responsible for preventing tissue cells to regenerate.

The axolotl is known as one among the common models in regenerative medicine research because their nature and status of regeneration is incomparable.

Studying this rare animal could provide insight for researchers on how to block certain brain pathways that leads the human body to scar and might 'untap' their ability to regrow lost limbs and improve health in general.

"Scars typically creates a barrier to regeneration and solving the problem of scar formation could unlock that latent regenerative potential," Godwin explained.

Unlike humans, Axolotls don't scar which paves way for regeneration easily. They aren't exactly the same with other salamanders. They can regrow almost any body part such as brain, heart, jaws, limbs, lungs, ovaries, spinal cord, skin, tail and more.

Without Scarring, Quality of Life Would Improve for Many People

Basically, mammalian embryos have the ability to regenerate, just like human infants can regenerate heart tissue. Although this process had gone really slow for adult mammals, the genetic code for regeneration is retained.

This phenomenon sparks an idea for scientists that drugs could someday be developed to block scarring among humans and encourage regeneration in lost human tissues and organs due to disease or injury.

By comparing macrophages in the axolotl to those in the mouse, Godwin and his team hopes to find a certain pattern or aspect that helps promote regeneration among axolotl salamanders. Other studies confirmed that depleted macrophages in axolotl led them to scar, just like the mouse and other mammals.

Findings reveal that a class of proteins called toll-like receptors (TLRs) which allows macrophages to recognize infections were 'unexpectedly divergent' in the axolotl and the mouse. This indicates that regenerative medicine therapies could be possible for humans, although regrowing a lost limb would be unrealistic for now.

In the meantime, the team focuses on improving therapies for diseases in which scarring is more prevalent.