Terence Partridge, professor of integrative systemic biology and pediatrics at George Washington University and associate director of the Children’s Research Institute in Washington, D.C., was awarded an MDA research grant totaling $300,000 over a period of three years to investigate differences in muscle repair mechanisms in mice and humans, in the context of Duchenne muscular dystrophy (DMD).
When muscle is damaged, cells called satellite cells divide in order to replace the damaged muscle. This occurs in DMD, but eventually the satellite cell repair system is exhausted, leading to irreversible loss of muscle tissue. Mice also employ satellite cells, but the mouse system differs in some important ways from the human one, and these differences may have an impact on lessons that can be learned from using a mouse model of DMD (called the mdx mouse) to study repair in DMD.
Partridge will use the mdx mouse to investigate differences between satellite cell muscle building early and later in the mouse life cycle. “We now have ways of indelibly marking satellite cells during growth," Partridge says. "We can use this to ask whether the cells that are repairing the dystrophic muscle after two years of continuous repair are descended from the cells that were used for growth during the first three weeks of life, or whether they are recruited from other stem cell sources.
“At present, we do not know whether interventions designed to augment muscle regeneration that have been devised in the mdx mouse would be applicable to humans,” he says. “Design of effective strategies for rescuing or enhancing muscle repair in DMD requires that we learn which cells to use and how best to use them. We aim therefore to identify the significant participants and to characterize their relative roles in the formation, maintenance and repair of normal and chronically diseased muscle.”
Funding for this MDA grant began August 1, 2013.