A New Way to Build Muscle
Posted on December 27, 2018
Scientists at the University of Texas Health Science Center at Houston have created a new line of stem cells to learn more about how stem cells differentiate into muscle tissue.
The goal of their research is to help individuals living with muscle disorders.
Researchers hope that their new strategy will help give more insight into how muscle disorders develop, ways to correct the genes involved in the development of muscle conditions and how cell therapy may help those conditions.
Although the human body is constantly replacing skeletal muscle cells that form new muscle tissue, those living with muscle disorders cannot make enough cells to fully replenish muscle tissue because their muscle stem cells fail and die.
Muscle disorders include conditions such as muscular dystrophy, myopathy and myotonic dystrophy. These conditions weaken the muscles and cause them to deteriorate over time.
Symptoms of muscle disorders include difficulty walking, moving and standing; falling; uneven gait; muscle pain and stiffness; walking on the toes; and calf pain. Some muscle conditions can cause learning disabilities and cognitive problems.
Day-to-day living for individuals with muscle disorders can be affected; mobility can be limited, or patients may be completely immobile. Some individuals with muscle disorders may require canes, walkers or wheelchairs to get around.
“Muscle disorders can completely change the quality of life for sufferers,” said Dr. Joel Singer, a New York personal cell physician.
Muscle disorders can progress very slowly for some individuals and very quickly for others.
“Some individuals live without major symptoms or changes in symptoms for long periods,” Singer said.
For those living with severe cases, their muscle disorder could eventually lead to more severe and life-threatening situations. Some muscle conditions can negatively affect the muscles involved in breathing as well as cardiac muscles, which can lead to death.
“When breathing or the ability to move blood through the body is interrupted, patients are at risk of death,” Singer said.
Muscle disorders affect more than 50,000 people in the United States.
There is no cure for muscle disorders, and conventional treatments include prescription drugs, physical therapy and surgery.
During the UTHealth study, researchers created a new line of human stem cells designed to build skeletal muscle. To monitor how the cells worked, the team used the CRISPR/Cas9 gene-editing method to add two different fluorescent proteins to the muscle genes PAX7 and MYF5.
Adding the proteins allowed them to observe the muscle stem cell activity in detail easily.
The muscle stem cells used in the project were taken from the skin of a patient and were reprogrammed to become stem cells with the ability to develop into muscle tissue.
Within two weeks, the researchers had progenitor skeletal muscle cells. The researchers believe that these cells have a lot of potential both in the laboratory and in humans.
The researchers also used the stem cells in a human tissue culture and a mouse model of Duchenne muscular dystrophy. DMD is an inherited genetic disorder marked by progressive muscle degeneration and muscle weakness.
DMD is caused by an absence of dystrophin, a protein that helps keep muscle cells together.
The researchers found that their created line of stem cells allowed for the faster development of muscle stem cells that resulted in improved muscle engraftment in the mouse model.
The UTHealth scientists will use their created muscle stem cells to study the pathology of muscular dystrophies and how they affect muscle tissue. They also hope to use them in testing medications for muscular dystrophy and examine the benefits of gene correction for those living with muscle disorders.
University of Texas Health Science Center at Houston. “Stem cell researchers develop promising technique to generate new muscle cells in lab.” ScienceDaily. ScienceDaily, 12 December 2018.