COLUMBUS, Ohio Reversing a protein deficiency through gene therapy can correct motor function, restore nerve signals and improve survival in mice that serve as a model for the lethal childhood disorder spinal muscular atrophy, new research shows.
This muscle-wasting disease results when a child's motor neurons nerve cells that send signals from the spinal cord to muscles produce insufficient amounts of what is called survival motor neuron protein, or SMN. This reduced protein in motor neurons specifically rather than in other cells throughout the body that contain the protein is caused by the absence of a single gene.
The researchers used an altered virus to deliver a portion of DNA that makes the SMN protein into the veins of newborn mice ranging in age from 1 to 10 days old. The SMN-laced viral vector injected into the youngest mice reached almost half of their motor neurons, resulting in improved muscle coordination, properly working electrical signals to the muscles and longer survival than in untreated mice, scientists said.
"We're replacing what we know is lost. And we have shown that when you put the protein in postnatally, it will rescue the genetic defect," said Arthur Burghes, professor of molecular and cellular biochemistry at Ohio State University and a senior co-author of the study. "This technique corrects the mice considerably more than any drug cocktails being studied as a potential treatment in humans."
Spinal muscular atrophy (SMA) is a genetic disorder that strikes about one in every 6,000 babies born in the United States, and leads to death in some affected children before age 2. According to the National Institutes of Health, there are many types of SMA, and life expectancy depends on how the disease affects breathing. There is no cure, but medicines and physical therapy help treat symptoms.
The research is published online in the journal Nature Biotechnology.
|Contact: Arthur Burghes|
Ohio State University