In 1993, researchers found one of the causes of familial amyotrophic lateral sclerosis (ALS). ALS is a neurodegenerative disorder which affects the motor neurons. Motor neurons are responsible for transmitting signals from the brain to the muscles. As the motor neurons die, muscle control is lost and paralysis can ensue. It ultimately causes respiratory failure and most people only live three to five years past diagnosis.
However, once researchers discovered one of the causes of ALS, they were able to take a new approach to research. In 1993, they discovered that mutations of the SOD1 protein are linked to familial ALS. And now, in 2018 they’ve found a way to silence that protein.
The Treatment
Researchers at the University of Massachusetts worked to use microRNA for RNA interference (RNAi) to stop SOD1 from producing within the motor neurons.
“These small non-coding RNAs pair to complementary sequences found on messenger RNA and destabilize them so the cell can’t turn these molecules into proteins.”
They tested their microRNA sequence on mouse models and it was successful in reducing SOD1 production in motor neurons by as much as 93%! That means that this type of treatment not only has potential, it has potential to be a one time therapy.
The experiment went exceptionally smoothly. Some of the concerns were that the treatment may cause liver toxicity, produce an immune reaction, or that the mircoRNA would target proteins that it wasn’t supposed to. But thankfully, the therapy caused no adverse side effects in the mice.
Who it Could Work For
Only 10% of ALS cases are familial (the other 90% are diagnosed with no identifiable risk factor). Of the familial cases, 20% are caused by a mutation to the SOD1 protein. However, there are over 180 different ways this protein can be mutated. Knowing this, researchers worked to find the commonalities between mutations. By targeting these commonalities, they hoped they would be able to develop a singular treatment that would work for a greater percentage of patients. Otherwise, they would have to uncover 180 different treatment options, each one requiring years of research, and its own clinical trial.
While this treatment is for SOD1 mutations specifically, their research is exciting news for the entire ALS community. It shows that this method of treatment has great potential. As we uncover what other types of mutations cause ALS, we can work to develop similar RNAi-based drugs to combat them. In the meantime, we are looking forward to seeing clinical trials develop for the SOD1 mutations.
You can read more about this research here, and stay tuned to hear about future clinical trials for familial ALS!
