Scientists discover Alzheimer's gene allows toxins to leak into the brain

 Credit: University of Rochester Medical Center

Scientists discover Alzheimer's gene allows toxins to leak into the brain.

ScienceDaily — A well-known genetic risk factor for Alzheimer's disease triggers a cascade of signaling that ultimately results in leaky blood vessels in the brain, allowing toxic substances to pour into brain tissue in large amounts, scientists report May 16 in the journal Nature.

The results come from a team of scientists investigating why a gene called ApoE4 makes people more prone to developing Alzheimer's. People who carry two copies of the gene have roughly eight to 10 times the risk of getting Alzheimer's disease than people who do not.

A team of scientists from the University of Rochester, the University of Southern California, and other institutions found that ApoE4 works through cyclophilin A, a well-known bad actor in the cardiovascular system, causing inflammation in atherosclerosis and other conditions. The team found that cyclophilin A opens the gates to the brain assault seen in Alzheimer's.

"We are beginning to understand much more about how ApoE4 may be contributing to Alzheimer's disease," said Robert Bell, Ph.D., the post-doctoral associate at Rochester who is first author of the paper. "In the presence of ApoE4, increased cyclophilin A causes a breakdown of the cells lining the blood vessels in Alzheimer's disease in the same way it does in cardiovascular disease or abdominal aneurysm. This establishes a new vascular target to fight Alzheimer's disease."