Protein reverses Alzheimer's disease in mice

James Randerson, science correspondent
Tuesday July 24, 2007
The Guardian

Scientists have successfully tested a treatment in mice that stops the progression of Alzheimer's and even sends the disease into reverse.

It will be several years before the experimental treatment can be used on humans but one advantage is that it works at a very early stage. It is hoped the breakthrough could one day enable doctors to stop the disease in its tracks before patients suffer the worst effects.

The treatment is a protein, specifically designed for the job, based on the three-dimensional structure of two other proteins involved in the progression of the disease. It works by sticking to one of these proteins so that it cannot bind with the other - a step that triggers a succession of biochemical events that lead to the death of the nerve cell and ultimately to the patient's symptoms.

Most cases of Alzheimer's develop in those aged 65 or over - affecting about one in 20. But by 85 nearly half will have the disease. There are currently about 500,000 Alzheimer's patients in the UK.

Scientists studying the disease have established that Alzheimer's patients produce abnormally large quantities of the proteins amyloid - which forms the plaques in the brain typical of the disease - and ABAD. When amyloid and ABAD combine this triggers a cascade of changes leading to the death of the nerve cell.

The researchers worked out how to disrupt this interaction in mice which are genetically engineered to over-produce these proteins in the same way as Alzheimer's patients. They designed a "decoy" protein that would stick to the amyloid and prevent it from binding to ABAD. When they gave it to mice they found the animals did not develop the disease and changes that had already happened were reversed. The team report their work in the journal Molecular and Cellular Neuroscience.

"The work is now being continued to try and refine the inhibitor into a potential drug," said Frank Gunn-Moore, part of the team at St Andrew's University. "If it gets that far it will have to undergo several years of human tests before it could be used on patients."