Another Muscular Dystrophy Mystery Solved; MU Scientists Inch Closer to a Therapy for Patients

Approximately 250,000 people in the United States suffer from muscular dystrophy, which occurs when damaged muscle tissue is replaced with fibrous, bony or fatty tissue and loses function. Three years ago, University of Missouri scientists found a molecular compound that is vital to curing the disease, but they didn’t know how to make the compound bind to the muscle cells. In a new study, published in the Proceedings of the National Academies of Science, MU School of Medicine scientists Yi Lai and Dongsheng Duan have discovered the missing pieces to this puzzle that could ultimately lead to a therapy and, potentially, a longer lifespan for patients suffering from the disease.

Duchenne muscular dystrophy (DMD), predominantly affecting males, is the most common type of muscular dystrophy. Patients with Duchenne muscular dystrophy have a gene mutation that disrupts the production of dystrophin, a protein essential for muscle cell survival and function. Absence of dystrophin starts a chain reaction that eventually leads to muscle cell degeneration and death. While dystrophin is vital for muscle development, the protein also needs several “helpers” to maintain the muscle tissue. One of these “helper” molecular compounds is nNOS, which produces nitric oxide that can keep muscle cells healthy after exercise.

“Dystrophin not only helps build muscle cells, it’s also a key factor to attracting nNOS to the muscles cells and helping nNOS bind to the cell and help repair it following activity,” said Lai, a research assistant professor in the Department of Molecular Microbiology and Immunology. “Prior to this discovery, we didn’t know how dystrophin made nNOS bind to the cells. What we found was that dystrophin has a special ‘claw’ that is used to grab nNOS and bring it close to the muscle cell. Now that we have that key, we hope to begin the process of developing a therapy for patients.”