Researchers in Scotland have made a breakthrough discovery which could reverse the damage caused by motor neurone disease (MND).
Scientists were able to repair the damage using motor neurons grown from stem cells, which helped to significantly reverse issues back to normal.
MND occurs when motor neurons, which send signals from the brain and spinal cord to the body’s muscles, stop working properly, meaning activities such as walking, speaking and swallowing gradually become more difficult. Weakness eventually leads to severe paralysis and breathing difficulties.
The disease affects more than 1,500 people in the UK each year, with around half of patients dying within two years of being diagnosed.
What did scientists find?
The research team, based at the Euan MacDonald Centre for MND Research at Edinburgh University, have shown for the first time that the axon, a nerve fibre which connects and sends electrical impulses from the nerve cells to the muscle, is shorter in cells affected by MND than in healthy ones.
The findings, published in the journal Acta Neuropathologica, also discovered that the movement of the mitochondria, which travel up and down the axons and are responsible for powering chemical reactions in all human cells, is impaired in people with MND.
However, this damage to nerve cells (or motor neurons) caused by the disease can be repaired by boosting the energy levels in the mitochondria. Once this is done, the axon then reverts to its normal length, which can sometimes reach up to one metre long.
Scientists achieved this result in the laboratory by using motor neurons grown from stem cells that were collected from people with a genetic mutation known to cause both MND and a form of dementia.
The lab-grown neurons were then exposed to a virus which charged a molecule vital to the healthy functioning of mitochondria, which then caused the issues to reverse back to normal.
Assessment of spinal cord tissue donated by MND sufferers who had died also revealed the same problems with the axon and mitochondria that were detected in the lab-grown stem stem cells.
Repurposing existing drugs for treatment
The research team believes they will be able to produce the same result from the lab in patients, by repurposing an existing drug.
A diabetes medication which is already licensed could be a promising candidate as it is known to increase mitochondrial activity.
However, thousands of potential compounds will need to be screened before one is recommended for clinical trials.
Dr Mehta, who carried out the study alongside Dr Bhuvaneish Selvaraj and Professor Siddharthan Chandran, said Scotland is well-placed to progress the findings into human clinical trials quickly thanks to the pioneering MND-SMART project launched last year.
The initiative is an adaptive clinical trial which brings together hundreds of patients across the UK with MND, enabling multiple possible treatments to be tested at once.
As such, this means as soon as researchers identify a drug that is likely to produce the mitochondrial boost required, it can be fast-tracked straight into large-scale clinical trials. This process can normally take between 10 and 15 years.