MELBOURNE, May 21 (UPI) -- Salamanders' ability to re-grow lost limbs could yield clues to future therapies for healing spinal cord injuries in humans, Australian researchers say.
Salamanders' immune systems are key to their remarkable ability to regenerate limbs and may be central to their ability to regenerate spinal cords, brain tissue and even parts of their hearts, scientists at the Australian Regenerative Medicine Institute at Monash University said.
When immune cells known as macrophages were systemically removed, salamanders lost their ability to regenerate a limb and instead formed scar tissue, they said.
"Now, we need to find out exactly how these macrophages are contributing to regeneration," lead researcher James Godwin said. "Down the road, this could lead to therapies that tweak the human immune system down a more regenerative pathway."
There are indications there is the capacity for regeneration in a range of animal species, but it has in most cases been turned off by evolution, Godwin said.
"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," he said.
When injured, salamanders can accomplish a complete functional restoration of any tissue, on any part of the body including organs. The regenerated tissue is scar free and almost perfectly replicates the injury site before damage occurred, the researchers said.
"We need to know exactly what salamanders do and how they do it well, so we can reverse-engineer that into human therapies," Godwin said.