To test their theory, Blau and Mourkioti treated affected animals with two different antioxidants to neutralize the reactive oxygen species one provided in the animals' diet and another injected into the abdomen. In each of the two groups, the 10 treated animals exhibited improvements in heart function and life span when compared to 10 control animals.
"We began the treatment when the animals were 8 weeks old, before they had begun to develop cardiac symptoms of the disorder," Blau said. "But it may be that treatment even earlier would have an even more marked effect."
Although very encouraging, researchers caution that further studies are required to determine the effect of early antioxidant treatment on patients with Duchenne muscular dystrophy.
"The important thing is that we finally have a mouse model with which we can begin testing a number of potential therapies," Blau said. "Until now, no one really understood the cardiac basis of the disease, and clinicians have been prescribing nonspecific treatments. Now we can develop more specific drugs for patients that target the cause of their cardiac dysfunction."
The new mouse model may also be applicable to the study of other inherited conditions.
"Seeing this in the heart gave us new insight," said Blau. "It's possible that the effect of shortened telomeres may be relevant to diseases other than that caused by Duchenne muscular dystrophy. Many mouse models that now fail to recapitulate human diseases may be improved by similar shortening of telomeres."
|Contact: Krista Conger|
Stanford University Medical Center