MDA has awarded a research grant totaling $313,500 to Xander Wehrens, associate professor in the departments of molecular physiology & biophysics and medicine at Baylor College of Medicine in Houston, Texas. The new funds will help support Wehrens’ research into abnormal heart function in Duchenne muscular dystrophy (DMD).

In DMD, profound muscle weakness can affect the heart, manifesting as abnormal heart rhythm or heart failure that can lead to sudden cardiac death. Up to 90 percent of individuals affected by DMD experience some type of cardiac involvement and no effective therapy exists to prevent or treat it.

In previous studies, Wehrens and colleagues have demonstrated that deficiency of dystrophin (the protein missing in DMD) leads to abnormal calcium handling in heart muscle cells. More recent studies have revealed a connection between abnormal calcium fluxes and the activation of an otherwise inactive protein within the muscle cells called calmodulin-dependent kinase (or CaMKII).

Now, Wehrens' study team will explore biological factors affecting calcium-handling in heart muscle proteins and their connection to heart failure and abnormal heart rhythms in individuals with DMD. The group will focus on determining whether increased oxidative stress and/or enhanced activation of calmodulin-dependent kinase leads to abnormal calcium release channel function, arrhythmias and heart failure.

Findings from Wehrens' work are expected to set the stage for development of drugs specifically targeting the calcium-handling proteins in DMD and, potentially, in other forms of muscle disease associated with heart failure and abnormal heart rhythms.

"MDA funding over the past three years has allowed us to explore the role of various enzymes that activate calcium release channels in animal models of DMD," Wehrens said. "This has provided us deeper insight into the causes and processes of heart failure and abnormal heart rhythms in animal models the disease."

Funding for this MDA grant began February 1, 2011.