Dr. Dimitrios Avramopoulos, an associate professor in Hopkins' Institute of Genetic Medicine and the Department of Psychiatry, and his colleagues measured levels of genes in 56 samples of human brain tissue. Of those, 30 were from confirmed cases of Alzheimer's; the remaining 26 had no signs of brain disease. Consistent with the risk of Alzheimer's with advancing age, Dr. Avramopoulos found that neuroglobin levels decreased as individuals age. The levels of neuroglobin were also found to be lower in women, who are at a slightly higher risk for Alzheimer's than men.

However, the researchers were surprised to find that neuroglobin was higher in the brain tissue from Alzheimer's patients than that of the control group. "An intriguing part of this study was the high levels of neuroglobin that we found in the Alzheimer's brain, which was exactly the opposite from what we expected," says Dr. Avramopoulos. He explains that previous studies have demonstrated that neuroglobin has a protective function; the brains of mice were shown to produce more neuroglobin in response to stress. Dr. Avramopoulos suggests that neuroglobin production increases as a reaction to the stress caused by Alzheimer's, but points out that in some people, that ramped up production is not adequate to effectively protect the brain from damage caused by the disease. "The older we get, the less neuroglobin this particular gene produces in our brains - unless something stimulates the gene to produce more," Dr. Avramopoulos says. "That something could be a stressor such as a lack of oxygen resulting from stoke or emphysema, for instance. And it looks like it also could be Alzheimer's disease. Further work on this gene will likely provide intervention targets for a multitude of very common conditions including Alzheimer's."

News Release: New evidence ties gene to Alzheimer's   www.eurekalert.org  May 6, 2009