Created Muscle Tissue May Help Duchenne’s Patients
Posted on January 25, 2018
Researchers at Duke University have grown the first working human skeletal muscle using induced pluripotent stem cells.
This is not the school’s first attempt at engineering human muscle tissue. In 2015, Duke researchers grew the first functioning human muscle tissue using cells collected from muscle biopsies.
Their latest success is significant in that it allowed the scientists the ability to grow large numbers of cells that can be used in a variety of health applications, including treating people with rare muscle diseases such as Duchenne muscular dystrophy.
Duchenne muscular dystrophy is a rare muscle disorder. According to the National Organization for Rare Disorders, DMD affects approximately one in 3,500 male births globally.
Symptoms of DMD typically present before the age of 5 and include muscle weakness and atrophy of the muscles in the pelvic area and shoulder. The condition progress to the torso, forearms and other muscles of the body, and can leave some individuals disabled by the teenage years.
Some individuals with DMD also have trouble breathing and cardiomyopathy, a disease of the heart muscle that causes an abnormal heartbeat and shortness of breath.
The researchers chose to use pluripotent cells because of their ability to develop into other types of tissue. They used pluripotent stem cells taken from adult non-muscle tissue, skin or blood and reconditioned them to return to a basic state.
After reconditioning, the Duke researchers began to grow the cells, adding in Pax7, a molecule that signals the cells to develop into muscle. As the cells developed into adult muscle stem cells, the scientists stopped adding the Pax7, and supported the cells until fully developed.
Within two to four weeks of 3-D culture, the new muscle cells formed muscle fibers. These fibers reacted to signals and impulses like natural muscle tissue. Researchers also implanted the new muscle fibers into adult mice and observed that the new threads functioned and integrated into existing muscle tissue.
The new muscle tissue is not as strong as natural muscle tissue, or the tissue Duke created in 2015 using biopsied muscle tissue, but the results of the study show promise and potential.
The new muscle fibers do have a benefit compared to the tissue created in earlier attempts: The new muscle fibers form larger repositories of stem cells that can be used to repair any damage the muscle might suffer in the future.
The Duke researchers expect to continue to refine their research to advance new ways to treat and possibly prevent diseases like DMD.
This prospect interests Dr. Joel Singer, a New York physician who uses personal cell therapy to treat patients with muscular dystrophy.
“The ability to grow healthy muscle tissue to replace diseased tissue may mean regained strength and function for patients with musculoskeletal conditions such as muscular dystrophy, myasthenia Gravis and myositis,” Singer said.
Current treatments for muscular dystrophy target symptoms, but do not slow the progression of the disease. Conventional therapies include splints, crutches and steroid therapy.
“For many individuals, the conventional treatments for diseases that cause muscle atrophy only work for a short time, or not at all, leaving patients with diminished muscle function and potentially disability. Personal cell therapy can improve outcomes for patients who no longer respond to traditional treatment or cannot tolerate conventional therapies,” Singer said.
The personal cell therapy used by Singer to treat muscular dystrophy utilizes cells from the patient’s fat tissue. Singer collects the cells from patients through liposuction and returns them to areas of muscle atrophy.
Muscular dystrophy patients treated with this kind of regenerative medicine often experience increased motor function and strength.
Duke University. “Engineers grow functioning human muscle from skin cells: First functioning human muscle grown from induced pluripotent stem cells holds promise for cellular therapies, drug discovery and studying rare diseases.” ScienceDaily. ScienceDaily, 9 January 2018.