Researchers at the Marine Biological Laboratory have pin-pointed important gene “partners” in a type of salamander. When these genes are activated they enable the neural tube and associated nerve fibers to regenerate following severe spinal cord damage. This means that vertebrates like salamanders are atypical.
Instead of regenerating spinal cords, many vertebrates, like humans, only create scar tissues and are left with life-long damage. Symptoms of spinal cord injury can extend to loss of muscle function, sensation, or autonomic function. Injury can be complete injury, with a total loss of sensation together with muscle function; or it can be incomplete, where some nervous signals can continue to travel past the damaged areas of the cord.
What is of interest with the research is not simply the identification of the genes, but the fact the genes are present in humans. As to why the genes do not carry out the same effect, the findings suggest that the genes are activated differently.
The researchers identified that the c-Fos gene is up-regulated in specific cells found in the nervous system following a spinal cord injury. What is different in salamanders is that the gene is paired with one called gene JunB. However, in humans the pairing is with a different gene called c-Jun.
Studies showed that if salamanders are genetically modified so that the c-Fos pairing is with c-Jun instead of JunB, the ability to regenerate is lost. What the next stage of the research needs to look at, with human cells, is to see if the reverse is true. If it is, this would lead to a significant leap forward with biological and medical research.
Quoted by Phys.org, lead researcher Professor Karen Echeverri states that the salamanders are “the champions of regeneration in that they can regenerate multiple body parts. For example, if you make a lesion in the spinal cord, they can fully regenerate it and gain back both motor and sensory control.”
She adds that: “We wanted to understand what is different at a molecular level that drives them towards this pro-regenerative response instead of forming scar tissue.”
The new research has been published in the journal Nature Communications Biology. The research paper is titled “AP-1cFos/JunB/miR-200a regulate the pro-regenerative glial cell response during axolotl spinal cord regeneration.”
