By Jessica Firger
What if there were a vaccine that could halt the progression of Alzheimer's-related dementia? Researchers at Université Laval, CHU de Québec say they may be close to developing a prophylactic treatment that could potentially stimulate the brain's natural defense against Alzheimer's disease.
Their study, partially funded by the pharmaceutical firm GlaxoSmithKline, was published in the early online edition of the Proceedings of the National Academy of Sciences. It is one of several the group of researchers have conducted to explore this innovative approach to combating Alzheimer's disease.
The vaccine works by stimulating the activity of microglial cells, the body's natural nervous system defenders, which are able to attack and prevent the proliferation of amyloid beta, the toxic plaque molecules that form in the brain and largely are responsible for the progression of Alzheimer's.
The researchers used mice with Alzheimer's disease to test the potential vaccine. Over a period of 12 weeks, the rodents were given weekly injections.Throughout the treatments, the scientists assessed their memory and cognitive abilities by observing whether the rodents were able to navigate through a water maze, one of the most widely used tests in the field of neuroscience. The mice that received the vaccine, and not the placebo, improved over time and were able to reach the other end of the maze.
"It's very similar to what you see in patients," says Serge Rivest, MD, PhD, professor at Université Laval's Faculty of Medicine, a researcher at the CHU de Québec research center, and the lead author of the study. "In patients, you do have some problems when you put them in an environment they're not familiar with."
If further studies bears out the mice study results, the researchers believe the vaccine could potentially be effective to both stop the progression of Alzheimer's disease and prevent it. Rivest speculates that such a vaccine may be most useful for individuals who are at risk for developing Alzheimer's. He says the type of biomarkers his vaccine targets can also be measured in the blood and accurately predict Alzheimer's risk.
One in eight Americans over the age of 65 has Alzheimer's disease, which is the sixth-leading cause of death in the United States, according to the Alzheimer's Association. Symptoms include memory loss, inability to recognize people or objects, and difficulty with motor skills and speech.
For years, scientists have worked to develop ways to slow the progression of the Alzheimer's. Cholinesterase inhibitors, the current class of drugs on the market, stop the breakdown of acetylcholine, a neurotransmitter that is believed to be important for cognition and memory. Drugs in this class include Aricept, Exelon, and Razadyne.
Rivest says other vaccines in research stage have been ineffective, and one was found to cause inflammation of the brain. The vaccine he and his team are developing activates immune cells, rather than targeting the proteins that cause dementia, which is how some Alzheimer's medications or vaccines work, he says.
"Alzheimer's Vaccine Shows Promise" originally appeared on Everyday Health.