Immune System Key to Salamander Regeneration Abilities

Salamanders can regrow limbs, spinal cords and parts of vital organs such as the brain and heart, and a new study points to the salamander's immune system as the key to their supernatural regeneration abilities.

The amphibians are remarkable healers, capable of regenerating completely functional, scar tissue-free replicas of almost any part of the body, including organs.

Seeking to better understand how salamanders can regenerate, researchers from the Australian Regenerative Medicine Institute at Monash University found that when immune cells known as macrophages were systematically removed, salamanders lost their ability to regenerate a limb and instead formed scar tissue.

The finding takes researchers one step closer to understanding the conditions necessary for regeneration, said lead researcher James Godwin.

"Previously, we thought that macrophages were negative for regeneration, and this research shows that that's not the case - if the macrophages are not present in the early phases of healing, regeneration does not occur," Godwin said. 

"Now, we need to find out exactly how these macrophages are contributing to regeneration. Down the road, this could lead to therapies that tweak the human immune system down a more regenerative pathway."

Godwin said he believes that studying the healing process of salamanders could lead to new treatments for a number of human conditions, including heart and liver disease, both of which are linked to scarring.

"Some of these regenerative pathways may still be open to us. We may be able to turn up the volume on some of these processes," Godwin said. 

"We need to know exactly what salamanders do and how they do it well, so we can reverse-engineer that into human therapies."

The research was published in the Proceedings of the National Academy of Sciences.