Researchers from the University of Portsmouth have found a more effective way to treat Duchenne muscular dystrophy.
Duchenne muscular dystrophy is caused by a genetic mutation, affecting one in every 5,000 boys born. The affected gene is on the X chromosome resulting in girls carrying the mutant gene, but they only develop the condition in rare instances.
Previous research has illuminated that Duchenne muscular dystrophy starts in myofibres – cells involved in contraction – which make the bulk of any muscle. This has led researchers to focus on these cells and how to deliver therapeutics to them. Now, researchers from the University of Portsmouth have discovered that Duchenne muscular dystrophy begins earlier in cells destined to become muscle fibres, known as myoblasts.
The researchers published their findings in eLife.
What is Duchenne muscular dystrophy?
Duchenne muscular dystrophy affects the limb muscles before the arms. Early symptoms include delay in the ability to sit and stand independently, large calf muscles, trouble running, unusual gait when walking and using the Gower’s Manoeuvre to get off the floor.
The disease eventually affects all the muscles in the body, including the heart and breathing muscles. As a result, many people pass away from this disease under 30.
In the UK, approved treatments for Duchenne muscular dystrophy includes steroids, atualuren, heart treatments and bone protection treatments.
New discovery could change treatment routes
Senior author, Professor Darek Gorecki from the School of Pharmacy and Biological Sciences at the University of Portsmouth, said: “The findings are significant because they change the way we understand the disease. We discovered the functions of myoblasts are severely affected by the absence of dystrophin, and these cells are critically important for normal muscle growth but also regeneration.
“Because these myogenic cells malfunction, damaged muscle can’t be repaired effectively. And any repaired myofiber will eventually need to be replaced, which will not happen without myogenic cells, so it becomes a vicious circle.”
In 2021, the researchers published results of modelling Duchenne muscular dystrophy to understand its development. They discovered evidence of abnormalities before birth in the embryo. Most boys with Duchenne muscular dystrophy are typically diagnosed between two and five years old, and at this point, the damage is already significant. This elongated wait for a diagnosis may be preventing treatment interventions that could help slow or potentially stop disease progression.
“At the moment, we’re targeting the late stage of this disease by treating patients in their teens when muscle degeneration has already taken its toll”, added Professor Gorecki.
“Instead, if we try to correct cells that are at the beginning of the pathological process, we might be able to delay muscle degeneration and extend a patient’s lifespan. We can do this by identifying and treating DMD newborns and targeting myogenic cells.”
