Nerve Regeneration

An article on Sci-news.com states that the gene required for nerve regeneration has been identified. Researchers at Penn State University, led by Professor Melissa Rolls, have found that axons regrow themselves when cut or damaged and that the process by which the axons repair themselves is completely shut down a certain mutation is present within the gene.

The team began by looking at microtubule-remodeling proteins. Microtubules are structural components of cells that allow basic building blocks to be transported. It has been previously suggested that these microtubules might need to be rebuilt in order to repair the axons, hence why the team began by investigating the role of those remodeling proteins in axon regrowth. From these proteins, the team focused on a cut that sever the microtubules into small pieces. From this set, they identified a protein called spastin.

The disease gene that makes the spastin protein is called SPG4. According to Professor Rolls, "When one copy of this gene is disrupted, affected individuals develop hereditary spastic paraplegia (HSP), which is characterized by progressive lower-limb weakness and spasticity as the long-motor axons in the spinal cord degenerate. Thus, identifying a new neuronal function for spastin may help us to understand this disease."

The gene used the fruit fly to study the spastin gene. The results showed that in the flies with one or two mutant copies of the gene (as opposed to having two normal copies) had no regrowth within cut axons. Not only this, but the team also discovered that the spastin gene has no role in the development of axons that were being assembled for the first time. Furthermore, they found that the dendrites were unaffected and continued to repair themselves even if the axon itself was not repaired. The researchers are continuing to do studies to see if other disease genes also play a role in nerve cell regeneration.

This discovery has opened up a huge amount of possibilities in humans. Since the experiment was performed on fruit flies, it is not known if this same thing happens in humans. However, I am sure that new studies will be performed to see if we can control the way axons are repaired. This is great news for anyone who has had nerve cell damage because we may be able to find a way to stimulate regrowth and help those who suffer.