Can nerve cells regenerate after an injury

Healing Injured Nerves: New Approaches


Injuries to nerve fibers in the brain, spinal cord and optic nerves usually result in functional losses because the nerve fibers are unable to regenerate. A team from the Department of Cell Physiology at the Ruhr University Bochum (RUB) led by Prof. Dr. Dietmar Fischer has deciphered new mechanisms that enable the regeneration of such fibers.

This could open up new therapeutic approaches for brain, optic nerve and spinal cord injuries. The researchers report these results in the journal Nature Communications Biology.

The brain, spinal cord and optic nerves are summarized under the term central nervous system. The nerve fibers, so-called axons, can no longer grow back after injury, so damage is permanent. “You can partially restore the regenerative capacity of nerve cells in the central nervous system by eliminating the inhibitory protein PTEN,” explains Dietmar Fischer. “However, such a so-called knockout triggers many different reactions in the cells at the same time, which often lead to cancer.” For this reason, direct inhibition of this protein is unsuitable for therapeutic approaches in humans. The originally postulated mechanism underlying the renewed ability to regenerate after PTEN knockout could not be confirmed by further studies, so the researchers looked for alternative explanations.

In their investigation of this still unclear mechanism, the Bochum scientists were able to show for the first time that the PTEN knockout strongly inhibits an enzyme called glycogen synthase kinase-3, or GSK3 for short. This enzyme, in turn, blocks another protein called collapsin response mediator protein-2, CRMP2. This means that the PTEN knockout prevents CRMP2 from being inhibited by GSK3. "If we prevent this second step directly, that is, by preventing the inhibition of CRMP2, we can also achieve the regeneration-promoting effect more specifically," explains Dietmar Fischer. As far as is known, the activation of CRMP2 itself is not carcinogenic.

“Even though we have only shown these effects in genetically modified mice and using gene therapy approaches, these findings open up various possibilities for developing new drug approaches,” explains the neuropharmacologist. Further research at his chair deals with these options.

Source: Ruhr-University Bochum