Potential Treatment for Huntington’s Found
A team of scientists have found that a drug widely used to treat Alzheimer’s disease can successfully treat Huntington’s disease in a mouse model. The drug, memantine (Namenda®), acts on the electrical activity in the brain that is associated with Huntington’s.
Huntington’s disease is a progressive, hereditary condition caused by a mutated gene that creates dysfunctional, or misfolded, protein. The brain cells gradually degenerate, resulting in uncontrolled movement, loss of intellectual faculties, and emotional disturbances. The rate of progression varies from person to person. About 30,000 people in the United States have the disease.
Currently, there is only one drug approved by the Food and Drug Administration (FDA) for Huntington’s disease. Tetrabenazine was approved in 2008 and treats the involuntary writhing movements (Huntington’s chorea) characteristic of the condition. At this time there is no way to reverse or stop the progression of the disease.
The investigators at Burnham Institute for Medical Research, the University of British Columbia’s Centre for Molecular Medicine and Therapeutics, and the University of California, San Diego, discovered that normal synaptic activity in nerve cells (the electrical activity in the brain that facilitates communication among the cells) protects the brain from the mutated proteins associated with Huntington’s disease. In contrast, abnormal electrical activity in the brain enhances the mutated or misfolded proteins’ deadly impact.
The researchers also found that when they treated Huntington’s disease model mice with the Alzheimer’s drug memantine, they were able to preserve normal synaptic electrical activity and suppress the extra electrical activity in the brain. A reason why memantine may work in Huntington’s disease is that this neurodegenerative condition, like Alzheimer’s and Parkinson’s, involves protein misfolding.
According to one of the study’s authors, Stuart A. Lipton, MD, PhD, director of the Del E. Webb Center for Neuroscience, Aging and Stem Cell Research at Burnham and professor in the department of Neurosciences and attending neurologist at the University of California, San Diego, this study verifies that proper electrical activity protects the brain, “supporting the ‘use it or lose it theory’ of brain activity.” He also noted that their findings may explain why experts say that people who use their brain “by performing crossword puzzles and other games can stave off cognitive decline in diseases like Alzheimer’s.”
The study’s authors believe that their findings will facilitate new treatment opportunities for Huntington’s that will result in protective effects on nerve cells. They are also encouraged by the results of a small human clinical trial of memantine for Huntington’s disease, which recently showed positive effects. Larger, international studies are being planned.
Burnham Institute for Medical Research