August 8, 2012
Underlying Causes Of Impaired Brain Function In Muscular Dystrophy Revealed
The molecular missteps that disrupt brain function in the most common form of adult-onset muscular dystrophy have been revealed in a new study published by Cell Press. Myotonic dystrophy is marked by progressive muscle wasting and weakness, as well as excessive daytime sleepiness, memory problems, and mental retardation. A new mouse model reported in the August 9 issue of the journal Neuron reproduces key cognitive and behavioral symptoms of this disease and could be used to develop drug treatments, which are currently lacking.
"The new animal model reproduces important aspects of myotonic dystrophy brain disease, so this model may be useful to develop biomarkers and test future drug therapies," says senior study author Maurice Swanson of the University of Florida.
In the new study, Swanson and his team focused on a related protein called MBNL2, which is found in the brain. They developed a new mouse model that lacked a functional Mbnl2 gene. These animals experienced an increase in the amount of rapid eye movement sleep as well as learning and memory deficits, similar to human patients.
The researchers also found extensive evidence of toxic RNAs in the hippocampus, as well as signs that fetal proteins were being produced in the brains of adult mutants. This pattern was also evident in the autopsied brain tissue of humans who had myotonic dystrophy. "This study should accelerate our understanding of how myotonic dystrophy mutations impact brain development and function," Swanson says.
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