Protein blocks Alzheimer's toxins in lab tests

A naturally occurring protein in the brain seems to curb the nerve damage of Alzheimer's disease, Canadian researchers have found.

The discovery could eventually help lead to a better treatment for the disease, which is the most common form of dementia and affects 10 per cent of people over 65 – about 290,000 Canadians.

The newly found protein blocks the creation of nerve toxins in Alzheimer's, a disease that slowly leads to memory impairment, behavioural changes and dementia.

Supervising author Prof. Paul Fraser and his team at the Centre for Research in Neurodegenerative Diseases at the University of Toronto describe the discovery in Thursday's issue of the journal Nature.

They found that when the protein is taken away, there is an increase in levels of the neurotoxin, called Abeta or beta-amyloid peptide.

"In the absence of this protein, we feel the disease would accelerate," Fraser told CBC Newsworld. "If we can understand how this prevents the toxic proteins, then we might be able to use it to create a treatment."

Treatment could have fewer side effects

Other attempts to create treatments for Alzheimer's weren't specific and resulted in inflammation in the brain, said Dr. Georges Levesque, chair of the biomedical review panel at the Alzheimer Society of Canada.

The main advantage of the newly discovered protein, known as TPM21, is it specifically targets Abeta – which suggests it could lead to a treatment that has fewer, less serious side-effects.

"This one is different because it can be mimicked by a small ligand [molecule] that can go directly in the brain," said Levesque, who is a professor of biochemistry and human genetics at Laval University in Quebec City.

The researchers plan to break the protein down into its components to try to find the most active part, although they don't know how the natural protein works.

A co-author of the study, Prof. Peter St George-Hyslop of the Centre for Research in Neurodegenerative Diseases, called the finding a "blueprint for the development of a drug to treat the disease."

If a potential drug is designed, it would need to be tested on mice and then in humans.

It's difficult to speculate when a drug could be on the market, but Levesque estimated five to 10 years at the earliest.

The study was supported by the Alzheimer Society of Ontario, the Canadian Institutes of Health Research and the Howard Hughes Medical Institute.