A different approach
Usually, curing a disease born of a genetic defect lies in fixing the problematic gene, like in the case of Duchenne muscular dystrophy. However, researchers from the Ecole Polytechnique Fédérale de Lausanne (EPFL) suggest a different approach. In a study published in Science Translational Medicine, a team led by Johan Auwerx discovered that a vitamin called nicotinamide riboside is highly effective in large doses for halting the progress of the disease in animals.
Considered as one of the most severe and common forms of muscular dystrophy, Duchenne affects one out of every 3,500 children. It's caused by a genetic mutation that disables the production of dystrophin, a protein required to keep muscles intact. The deformed cells mechanically cause inflammation that gradually destroy muscles.
It leads to progressive general paralysis, and eventually death, due to respiratory failure. Children with this disease end up in a wheelchair by the age of 12.
Auwerx and his team focused on the second cycle in the progression of Duchenne, where initial inflammation causes a certain gene to consume large amounts of NAD+ — an essential component serving as fuel for the mitochondria. NAD+ shortage in mitochondria weakens muscles and aggravate inflammation that further destroys muscles
Clinical tests within 2 years
The researchers considered preventing this second cycle from occurring by sustaining the mitochondria through nicotinamide riboside, the vitamin precursor of NAD+. The approach was tested on C. elegans worms and on mice genetically modified to have the disease.
The results were promising. After administering large doses of the vitamin, the worms did not have any of the symptoms of Duchenne's second cycle. The mice, while demonstrating muscular inflammation at lower levels, showed reduced effects of muscular damage.
"We have good reason to think that humans will also respond to this treatment and that we'll be able to reduce inflammation," explains Auwerx. While the water-soluble vitamin nicotinamide riboside is commercially available, clinical tests for viability on humans are expected within 2 years.