Patients with Pompe disease have a defect in a key enzyme that converts glycogen, a stored form of sugar, into glucose, the body's primary energy source. As a result, glycogen builds up in muscles throughout the body, including the heart, causing muscles to degenerate.
Using genetically altered mice in which the gene for the enzyme had been rendered nonfunctional, the researchers demonstrated they could introduce the functioning gene and correct glycogen buildup in heart and skeletal muscle. The findings suggest that such an approach should be considered as a potential gene therapy strategy for Pompe disease patients, the researchers report in a forthcoming issue of Molecular Therapy (now available online).
"Gene therapy in muscular dystrophies presents a unique challenge, because replacement of deficient, therapeutic proteins invokes an immune response that limits the efficacy of the treatment," said Duke medical geneticist Dwight Koeberl, M.D., senior author of the study. "By restricting the expression of introduced genes to muscle, the immune response can be prevented or attenuated."
The muscle-targeted gene therapy might therefore apply to other forms of muscular dystrophy, they added. Muscular dystrophies include many genetic diseases, all of which are characterized by progressive weakness and degeneration of the skeletal muscles which control movement.
The Muscular Dystrophy Association and Genzyme Corporation supported the research.
Source:Duke University Medical Center