BACE 1 gene may hold the key to Alzheimer's

Canadian scientists have found a specific gene which they believe may hold the key to the degenerative brain disorder Alzheimer's disease.

Lead researcher Weihong Song, a professor of psychiatry who holds a Canada Research Chair in Alzheimer's disease at the University of British Columbia in Vancouver, says the results of their study with mice found that lower oxygen levels (hypoxia) increased the activity of a specific gene.

The gene called BACE 1, encodes a protein that converts the precursor amyloid molecule to the more dangerous beta-amyloid form.

Professor Song says if blood to the brain is less oxygenated it may mean a build-up of the protein plaques that are so closely tied to Alzheimer's disease

In mice, hypoxia was found to increase amyloid plaque formation and memory loss.

The fact that lowered brain-oxygen levels, caused by reduced blood flow, increases the risk of Alzheimer's disease, is not a new theory and people who have suffered a stroke have a two or three times increased risk of dementia.

Other experts say however that the situation is far more complex and there is debate about whether the amyloid plaques cause the loss of mental function seen in Alzheimer's disease and they believe the study represents only a hypothesis rather than establishing an association.

But most are in agreement with Song that the health of the cardiovascular system is very important for the health of the brain, and the one promotes the health of the other.

Song says if blood flow to the brain can be improved, maybe the progression of Alzheimer's can be slowed down.

The study is published in the current issue of the Proceedings of the National Academy of Sciences.