Cells normally must use GAA to break down the carbohydrate glycogen to create energy. The 24 mice in the study were missing the GAA enzyme, causing massive amounts of glycogen to accumulate in their muscle cells. This accumulation disrupts the cells ™ architecture, disabling their ability to power efficient breathing, Mah said. Researchers painted the gene therapy gel onto the underside of the thin diaphragm muscle in the live study mice, then took tissue samples six weeks later.

Stain a section of muscle tissue and one can see the accumulated glycogen with a reagent that turns glycogen bright pink, Mah said. After the treatment, we no longer saw the accumulated glycogen no bright pink granules in the cells meaning that the cells were able to break down the stored glycogen. In addition, we were able to detect that the GAA enzyme itself was present in those cells.

Because the treated cells eliminated the excess stored glycogen, the diaphragm could work normally and breathing was repaired, the researchers said.

Other studies to address the adult and infantile form of Pompe ™s disease is in various stages of development, Mah said. Byrne, who has a long-standing interest in the ailment, is currently participating in second-stage clinical trials to develop an enzyme replacement therapy to administer by infusion. Other researchers are in the early stages of working to modify the outer protein shell of the delivery virus so that it could be injected into a vein and target a specific area or organ.

Jeffrey Chamberlain, a professor of neurology and director of the Muscular Dystrophy Cooperative Research Center at the University of Washington School of Medicine, said the findings could have important implications for a variety of neuromuscular disorders as well as for Pompe ™s disease.

The methods described by the Byrne lab are a new and exciting approach that have led to a significant level of gene delivery to this important muscle, Chamberlain said. Unfortunately, it is not a very accessible muscle, and it has proved quite difficult to deliver new genes to this muscle for the purpose of gene therapy interventions. In the short term, this work will help advance research into studying these diseases, and in the long term should help accelerate the ability to treat a variety of very serious diseases.