MDA has awarded a grant totaling $375,000 over three years to Michael Rudnicki, director of the Regenerative Medicine Program at Ottawa Hospital Research Institute and a professor in the department of medicine at the University of Ottawa, Canada. This funding will support Rudnicki's continuing studies on the function of muscle satellite cells in mice with a disease resembling human Duchenne muscular dystrophy (DMD).

DMD is caused by any of a number of mutations in the gene for the muscle protein dystrophin that result in a complete absence of the dystrophin protein in the skeletal muscles and heart. The closely related disease Becker muscular dystrophy (BMD) is due to mutations in the dystrophin gene that result in dystrophin protein that's only partially functional.

Muscle satellite cells are required for the growth and repair of skeletal muscles. In previous studies, Rudnicki and his colleagues have found that there is a subset of muscle satellite cells that function as "satellite stem cells," giving rise to the satellite cells that then become muscle.

They've also found that satellite stem cells do not function properly in dystrophin-deficient mice; and that a protein called WNT7a stimulates proliferation of satellite stem cells and benefits normal and dystrophic muscle.

In this new set of experiments, Rudnicki's team will investigate the nature of the defect in satellite stem cells in dystrophin-deficient mice and the mechanism through which WNT7a treatment increases the numbers of these cells.

The researchers also will investigate the possibility of using WNT7a as a treatment for DMD or BMD, through experiments in dystrophin-deficient mice.

Rudnicki, who has received MDA support for several years, says, "MDA funding has been critical in allowing my lab to investigate the fundamental mechanisms that regulate the function of muscle stem cells."

Funding for this MDA grant began August 1, 2011.