Molecule Restores Motor Function in Mouse Study of Huntington’s Disease
Researchers of Huntington’s disease, a brain condition with no cure, said they restored motor skills in mice, pointing to a possible therapy for humans.
Infusing a brain molecule called GM1 into the laboratory animals eased motor impairment within days, scientists at the University of Alberta in Edmonton, Canada, said today in the Proceedings of the National Academy of Sciences of the U.S.
Huntington’s is a genetic disorder that causes cells in the brain to break down, potentially impeding movement and causing antisocial behavior, hallucinations and dementia. Doctors have no means to stop the disease, which generally begins from ages 30 to 50, according to the U.S. National Institutes of Health. It’s too early to know whether GM1 therapy would work in humans, said the senior study author, Simonetta Sipione.
“Although our data are encouraging, translating our findings to patients might still take quite some time,” said Sipione, an assistant professor in the university’s pharmacology department, in an e-mail yesterday. Clinical trials are needed to determine whether GM1 can delay or stop the effects of the disease, she said.
For the study, the researchers infused a synthetic form of GM1, made by closely held Seneb Biosciences Inc., of North Wales, Pennsylvania, into the brains of mice for 28 days. The animals had what scientists call a model of the disease in humans.
After 12 to 14 days, the mice saw motor skills return to normal, Sipione said. While the benefits appeared to last at least 14 days after treatment, the mice worsened and eventually returned to pre-treatment condition, according to the study. That may mean that if the treatment works in humans, GM1 would need to be taken for the entire course of the disease, Sipione said.
GM1, a molecule produced in the body, is a type of lipid and is part of the membrane that surrounds each cell. GM1 modulates communication between neurons in the brain and their response to their environment, Sipione said. Levels of GM1 in the body can be depressed by the disease.
Restoring GM1 may help neurons communicate and interpret signals from the environment, Sipione said. The treatment also may make a mutant protein called huntingtin less toxic.
“GM1 does not block the production of the toxic mutant huntingtin, but seems to make it less toxic and/or help neurons cope with it,” Sipione said.
Tests of GM1 in humans with the disease may begin in the next two years, according to the researchers. GM1 is already being tested in Parkinson’s disease and other neurodegenerative diseases, the scientists said.
“It’s a really promising strategy,” Jang-Ho Cha, an advisory-committee chairman for the Huntington’s Disease Society of America, and director of clinical research in neuroscience at Whitehouse Station, New Jersey-based Merck & Co., said today in a telephone interview. “Before you go forward you need to know how many different processes does GM1 hit.”
If GM1 affects a specific enzyme in the brain that works on the mutant protein huntingtin, a treatment might target that enzyme rather than GM1, he said.
The society is continuing a mission begun by Marjorie Guthrie, the widow of folk singer Woody Guthrie, who died of Huntington’s disease, according to the New York-based nonprofit group’s website.