By closely studying certain fish, researchers from Inserm and the University of Montpellier have just gained a better understanding of how certain animals manage to repair themselves after an injury.
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| A zebrafish capable of regrowing its tail fin. - BARCROFT MEDIA / BARCROFT MEDIA via GETTYIMAGES |
Managing to regrow an eye, a leg or a part of one's body is the privilege of certain superheroes in the movies, but also of some animals.
The salamander, for example, is able to regrow a leg, a snout or a spinal cord in case of injury. The starfish can regrow a branch, and the zebrafish, a small tropical fish, also has the ability to regrow its tail fin in a few days, if it is severed. It is by studying this small black and white striped fish that a team from Inserm has just discovered some of the mysteries of this regeneration. This work is a world first.
This team has succeeded in better understanding the mechanism of this regeneration. Until now, research had already shown that in place of the severed fin, a so-called blastema appeared rapidly, a cluster of cells, capable of multiplying and diversifying, to form a fin tissue, identical to the one that had been cut. But we did not understand the process. The discovery is that for all this to be organized, "certain cells play the role of conductor", explains Farida Ddjouad, director of research at Inserm, a specialist in regenerative medicine. These neural crest cells summon other cells to build the new tissue, and send them instructions via molecules that have also been identified: these are neuregulin 1 (NRG1).
Immense prospects for medicine
This phenomenon could be reproduced in humans: 70% of our genes have a homologous gene in zebrafish. If we were able to create the same "construction site" in the human body, with cells conducting the orchestra and sending instruction molecules to others to create tissues, we could, for example, regenerate cartilage in people suffering from osteoarthritis, regenerate heart cells after a heart attack, and perhaps even slow down certain neurodegenerative diseases.
But before that, there are still other stages of research in animals, particularly mice. The zebrafish therefore gives us hope in the medium term. For possible applications in humans, we will have to wait at least ten years.