Chemical link in Alzheimer's study

Alzheimer's symptoms such as memory loss could be prevented by targeting a chemical that dismantles brain connections, research suggests Wednesday. Scientists have already started work searching for a drug that will block the mechanism, discovered in mice. The study, published in the Journal of Neuroscience, was funded by the charity Alzheimer's Research UK and the Biotechnology and Biological Sciences Research Council (BBSRC). If successful, a treatment that effectively protects against the effects of Alzheimer's could be available in the next 10 years. It has long been known that the disease is linked to a build-up of toxic amyloid-beta protein in the brain. Researchers at University College London have now found that amyloid-beta stimulates production of another protein, Dkk1, which is largely responsible for Alzheimer's symptoms. Dkk1 destroys synapses, connections between neurons, in an area of the brain vital to learning and memory. Studying samples of mouse brain in the laboratory, the scientists found they could neutralise Dkk1 with a specific antibody. Neurons exposed to the antibody remained healthy with no synaptic disintegration. In practical terms, it is unlikely that a vaccine-type treatment could tackle Alzheimer's the same way. But study leader Dr Patricia Salinas said now that Dkk1's role was known, there was a chance of developing drugs to target it. "These novel findings raise the possibility that targeting this secreted Dkk1 protein could offer an effective treatment to protect synapses against the toxic effect of amyloid-beta," she said. "Importantly, these results raise the hope for a treatment and perhaps the prevention of cognitive decline early in Alzheimer's disease." Her team is now working with a biotech company to develop molecules that can block Dkk1. A major obstacle is overcoming the "blood-brain barrier" - a natural "firewall" that prevents damaging substances entering the brain. Alzheimer's is the most common form of dementia, which affects around 750, 000 people in the UK and costs the economy an estimated 23 billion pounds per year.