Movement Can Be Restored With Gene Therapy After Spinal Cord Injury in Mice

 

Researchers report that gene therapy restored the mobility in mice with completely severed spinal cords. The mice were able to regain the ability to walk with walking patterns similar to mice who naturally regain walking ability after partial spinal cord injuries. The new gene therapy used techniques to repair spinal cord tissue and also direct the repairs so mobility could be restored. Partial damage in human and mouse spinal cords can cause initial paralysis, but it can be followed by recovery of motor functions, something that cannot happen in complete spinal cord injuries, where the patient remains paralyzed. To regain motor neuron function after an injury, specific axons need to regenerate and reconnect to their natural targets. The research team activated the neuron growth to regenerate its nerve fibers, used proteins that would support the growth of the neuron through scar tissue, and used guidance molecules to attract the regenerating nerve fibers to their natural targets. 

While studies done in animals do not always pan out to humans, the results of this study make it hopeful that we are closer to completing a solution for completely treating spinal cord injuries. While it's expected that gene therapy may need to be used with electrical stimulation of the spinal cord, it is exciting to think that with both these approaches there is a possibility that the regrown nerve fibers and the spinal cord below the injury could produce movement. 

https://www.usnews.com/news/health-news/articles/2023-09-27/in-mice-gene-therapy-helps-restore-movement-after-spinal-cord-injury 

https://www.uclahealth.org/news/scientists-regenerate-neurons-restore-walking-mice-after

Regenerative Mushrooms

               Hericium erinaceus, more commonly known as lion’s mane, is a mushroom with amazing medicinal qualities. It is a prized fungus held in high regard due to its unique flavor and healing abilities. A recent study tested the neuroregenerative effects lion’s mane would have on lab rats. In the experiment the peroneal nerve was crushed on both groups with only one group of rats receiving the aqueous extract from the fruiting bodies. One of the findings showed a relationship between the Akt and MAPK signaling path-ways, which both influence things such as mitosis, gene expression, cell survival, and cell migration just to name a few.

        They found that the rats that were given the extract had enhanced nerve regeneration and much better post trauma recovery. The treated group had much better leg function and better quality of life post treatment. Not only did the lion’s mane induce enhanced axonal regeneration but its neurotherapeutic effects were found to be comparable to mecobalamin. Further research must be done to find the exact pathways that Hericium erinaceus interacts with.

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.