Vaccine slows progression of skeletal muscle disorder
Study in mice shows reduced levels of beta amyloid
A potential vaccine for Alzheimer's disease also has been shown in mice to slow the weakening of muscles associated with inclusion body myositis, a disorder that affects the elderly.
The finding brings new hope for IBM patients with weakness, inflammation or atrophy of muscles in their fingers, wrists, forearms or quadriceps. There is no cure for IBM, nor is there an effective treatment, according to the National Institutes of Health.
"The immunization wasn't a complete fix, but it significantly slowed the deterioration of motor function in our IBM mice," said Frank LaFerla, director of UC Irvine's Institute for Brain Aging & Dementia. "I hope our discovery leads to clinical trials and, eventually, a vaccine for people suffering from or at risk for IBM."
Study results appear Wednesday, May 13, in The Journal of Neuroscience.
LaFerla and assistant project scientist Masashi Kitazawa tested the vaccine on 1-year-old mice with high levels of a protein called beta amyloid in their skeletal muscle tissue - a characteristic feature of IBM.
After three months of treatment, the mice were producing antibodies against beta amyloid and had less of the protein in their muscles. Levels of oligomeric beta amyloid - a more toxic form - also were reduced.
"It appears the antibodies helped remove beta amyloid or blocked its accumulation in muscle cells so they could stay healthy longer," Kitazawa said.
Immunotherapy approaches such as vaccination are being extensively studied for Alzheimer's in humans. In that disease, beta amyloid accumulates in the brain and leads to the creation of senile plaques, one of two signature Alzheimer's lesions. Although immunotherapy has shown some benefit in human clinical trials, there are significant safety concerns. For example, about 6 percent of people develop encephalitis, or brain inflammation.
LaFerla thinks it's unlikely IBM patients would develop encephalitis: "With IBM, brain integrity is not compromised like it is with Alzheimer's. We should be cautious, but there's little reason to assume IBM patients would have the same problem."
UCI scientists Vitaly Vasilevko and David Cribbs also worked on this study, supported by the NIH.
About the University of California, Irvine: Founded in 1965, UCI is a top-ranked university dedicated to research, scholarship and community service. Led by Chancellor Michael Drake since 2005, UCI is among the fastest-growing University of California campuses, with more than 27,000 undergraduate and graduate students, 1,100 faculty and 9,200 staff. The top employer in dynamic Orange County, UCI contributes an annual economic impact of $4.2 billion. For more UCI news, visit http://today.uci.edu/.
News Radio: UCI maintains on campus an ISDN line for conducting interviews with its faculty and experts. Use of this line is available for a fee to radio news programs/stations that wish to interview UCI faculty and experts. Use of the ISDN line is subject to availability and approval by the university.