Skeletal Muscle Cells
Understanding how skeletal muscle stem cells function may provide information leading to treatment of, not only muscle damage but also muscle wasting, often associated with cancer, HIV, cardiac cachexia, and rheumatoid arthritis. Claire Stewart, Ph.D., professor of cell and molecular biology, Manchester Metropolitan University, has been studying regulators of skeletal muscle degeneration and regeneration.
Initial challenges in working with these cells involved developing and establishing cultures. Dr. Stewart’s group developed specialized media to ensure performance of growth factor/cytokine studies. “Surprisingly, these are really great cells to work with—they grow and behave well in culture.”
Another hurdle is the construction of experiments. “We all have our favorite growth factors of choice alongside signaling molecules and cellular responses of choice, e.g., we are taking a linear approach to our studies. We need a multivariate approach that provides greater opportunity in that vaguely interconnected and simultaneous random observations are very often related.”
According to Dr. Stewart, this would provide unbiased insight into the mechanisms governing cell behavior. However, these studies are often viewed as fishing expeditions and usually not funded.
Recent research efforts have resulted in some exciting discoveries. The area Dr. Stewart calls “the most exciting work we’re doing at the moment,” involves cell memory and aging. Muscle biopsies were taken from controls and cancer patients to compare the number of stem cells. Results showed an age-related decline in muscle stem cells but no decline was seen in cancer patients.
“A 70-year-old cancer patient had the same number of muscle stem cells as a 40-year-old, but this wasn’t seen in the control population.” Dr. Stewart explained that it appears that biopsy tissues retain memory of their in vivo environment. “This has implications for all autologous stem cell research, making tissue sources and host environments key to autologous treatment.”
Additional efforts are being focused on multivariate analysis and development of muscle stem cell markers, 3-D cultures and regulation of cell fusion, improving computer tracking studies in injury, and establishing virtual muscle stem cell models.
There’s little doubt that ongoing stem cell research will continue to discover potential new therapies for a wide range of diseases as well as novel drug screening assays. Advanced Cell Technology recently filed an IND with the FDA to use embryonic stem cells to treat Stargardt’s macular dystrophy—a photoreceptor degenerative disease that leads to blindness. This will be the second U.S. company, providing the FDA approves, to test human embryonic stem cells in patients.