Hidden ability to regenerate was found in humans
Humans can regrow lost limbs like salamanders, said scientists at the MDI Biological Laboratory in Bar Harbor, Maine, USA. They made this conclusion by studying the body of the axolotl, according to Developmental Dynamics.
The axolotl, or Mexican salamander, is an almost extinct species in the wild. It is considered a “champion of regeneration” and is able to restore lost body parts: not only the legs and tail, but also the nervous system, eyes, spinal cord and heart.
Scientists decided to find out why this species tolerates injury differently than mice and other mammals (axolotls do not even leave scars after injury). They compared molecular signals after trauma in an axolotl with those of an adult mouse, which has a limited capacity for regeneration.
The study showed that the reason for the differences is in the immune cells of macrophages. In Mexican salamanders, they promoted tissue growth, and in mice, they caused scarring. When axolotls ran out of immune cells, they also began to develop scars.
The authors of the scientific work suggested that the mechanism of scar formation “blocks” regeneration in mammals and prevents them from regrowing limbs. Perhaps, if the brain pathways responsible for the formation of scars are blocked, this “superpower” can return.
“Our research shows that humans have untapped potential for regeneration,” said study author Dr. James Godwin.
Research has shown that the “response” of immune cells to injury depends on the signaling response of a class of proteins called toll-like receptors (TLRs). They help macrophages recognize a threat, be it infection or injury. In axolotls and mice, this reaction proceeded in different ways. The discovery of an alternative signaling pathway compatible with regeneration may ultimately restore the ability of mammals to grow new organs and tissues.
Scientists have previously found a sea creature capable of regenerating the entire body. This is an ascidian.
