Scientists discover promising new drug target

Scientists at the University of Illinois say a protein fragment associated with Alzheimer's disease, called amyloid-beta protein, activates the AMPA receptor, embedded in the neurons of other cells. This activation eventually leads to cell death -- and could provide a meaningful target for drugs that fight the disease.

These bundles of amyloid-beta proteins, also known as amyloid plaques, are what's used to diagnose Alzheimer's, after death.

Research already has shown that these proteins can stimulate the AMPA receptor, and that when amyloid-beta binds to a neuron, that receptor opens a channel allowing calcium or sodium ions to enter the cell. This quick influx of ions causes a nerve impulse. Up to now, scientists did not know the mechanism by which amyloid-beta causes the AMPA receptor channel to open.

“If a mouse is exposed to amyloid-beta in the brain, it impairs neuron function, causing memory deficits and behavioral deficits,” Kevin Xiang, a professor of molecular and integrative physiology at Illinois says in a news release. "The question is how this peptide causes all these detrimental cellular effects.”

For their study, Xiang and colleagues focused on the beta-2 adrenergic receptor, a protein that, like the AMPA receptor, resides in the cell membrane. Neurotransmitters and hormones normally activate the beta-2 adrenergic receptor, but amyloid-beta also induces a cascade of events in the neuron by activating the beta-2 adrenergic receptor, the researchers found.

The story from United Press International.

The study abstract in the FASEB Journal.

The news release from the University of Illinois.