A team of researchers has identified and isolated the protein that allows zebrafish to regrow their spinal cord. Since zebrafish share most of their genes and proteins with humans, the discovery could further human medicine. The findings may eventually lead to better treatments for tissue repair, including spinal cord injuries. The details are in a paper that was just published in the journal Science.
Zebrafish (Danio rerio) have the remarkable ability to regenerate their spinal cord if it becomes damaged. The fish are also common models in scientific studies since they’re hardy, develop quickly, and their genomes have been fully sequenced. Their ability to regrow fins, spinal cords, heart cells, and other body parts has been of great interest to scientists.
Researchers from Duke University first identified the genes that became activated after the zebrafish suffered spinal cord injuries. The team discovered a gene of interest called CTGF. The gene coded for a protein called connective tissue growth factor a (ctgfa). The ctgfa protein was released when the spinal cord was regenerating. This specifically happened during the bridging process, where glial cells reconnect the spine at the point of injury. If the research team inactivated the CTGF gene, the zebrafish were unable to regenerate their spines. This shows that the gene is critical to their ability to regrow the spinal cord.
Zebrafish share many genes and proteins with humans, including CTGF. When the researchers dosed the fish with the human version of CTGF, they had no problems re-growing their spines. The zebrafish, which had been completely paralyzed, recovered completely. The authors believe that while CTGF is necessary for spinal cord repair, there are a lot of other factors involved that have yet to be discovered.
The team’s findings may eventually lead to tissue repair treatments in humans. The authors caution that the research is still in the early stages. The team will need to study the effects of CTGF in mammalian models, such as laboratory mice.
Mokalled et al. Injury-induced ctgfa directs glial bridging and spinal cord regeneration in zebrafish. Science (2016).