DNA May Hold Clues for Treating Muscular Dystrophy
Posted on September 29, 2017
A discovery by University of Pennsylvania researchers may lead to new treatments for people with one form of muscular dystrophy.
A study by the Perelman School of Medicine has found that the stem cells in the muscles of people with Duchenne Muscular Dystrophy, or DMD, have shortened telomeres. DMD is the most common form of muscular dystrophy in the United States, and most patients only have a life expectancy into the mid-20s.
Telomeres are long chains of DNA located at the ends of chromosomes and serve as a protection for the chromosomes during cell division, the process in which cells reproduce or generate new tissue. Telomeres shorten during cell division, and their reduced length means death or inactivity for many cell types.
Researchers on the study found that telomeres in the muscle stem cells of teenage boys with DMD were abnormally short. Shortened telomeres mean that these cells cannot divide as many times as cells with telomeres of average length.
There is no cure for DMD or any other form of muscular dystrophy, and treatments for the condition are very limited. The Pennsylvania researchers on the project hope that their telomere discovery may lead to new treatments for the disease, like gene therapy and other treatments that can block telomeres from shortening prematurely.
More About MD
Muscular dystrophy is a group of more than 30 genetic disorders characterized by genetic mutations that interfere with the production of healthy muscle tissue. It causes muscle weakness and muscle loss that typically begins in the extremities.
Other symptoms include pain in the muscles, fatigue and loss of mobility for many individuals. Some forms of muscular dystrophy negatively impact the heart and cause difficulty breathing and swallowing.
The exact number of people affected by the condition is unknown, but there are fewer than 200,000 individuals diagnosed in the U.S. each year, according to the U.S. Centers for Disease Control and Prevention.
The condition impacts men and women equally, but some forms of the disease, like DMD, affect males in higher numbers. DMD affects one in every 1,500 men in the U.S., and symptoms are usually seen before the age of 5.
Helping Save Muscle
“When muscle cells stop dividing, growth stops and new muscle tissue can’t form,” said Dr. Joel Singer, M.D.
Singer is a New York physician who treats patients with muscular dystrophy using stem cell therapy.
“DMD causes the body to try to repair damaged muscle cells constantly, but because of shortened telomeres, the cells burn out faster trying to keep up with damage, and the body just cannot keep up,” Singer said.
To give patients with muscular dystrophy a boost in the repair process, Singer uses stem cells taken from the patient – but not from muscle. Instead, he uses stem cells taken from the adipose fat tissue.
“Adipose fat stem cells have the powerful ability to become different kinds of tissue and to divide over and over again,” Singer said.
Singer harvests stem cells from areas on the body with high concentrations of fat, like the thighs or abdomen. The collected stem cells are then deployed into the body to treat areas affected by the condition.
“Once the stem cells reach the affected area, they go to work immediately to restore damaged tissue,” Singer said.
Patients with muscular dystrophy often experience a reduction in pain and muscle fatigue, as well as increased mobility.
“Stem cell therapy can also slow the progression of the disease,” Singer said.
University of Pennsylvania School of Medicine. “Shortened telomeres linked to dysfunction in Duchenne muscular dystrophy, researchers find: New method reveals abnormally shortened telomeres in young DMD patients’ muscle stem cells.” ScienceDaily. ScienceDaily, 7 September 2017.