Is amyloid oligomers the cause of Alzheimer's disease?
In experiments on a mouse model of Alzheimer's disease, Mount Sinai School of Medicine researchers working under the guidance of Professor Sam Gandy confirmed a relatively recent assumption that beta-amyloid oligomers, and not the infamous amyloid plaques, cause this disease. The results of their work were published on April 14 in the preliminary on-line version of the journal Annals of Neurology in the article "Days-to-criterion as an indicator of toxicity associated with human Alzheimer amyloid-β oligomers".The accumulation of amyloid plaques in brain tissues was described more than 100 years ago and since then they have attracted a lot of attention of specialists studying the pathogenesis of Alzheimer's disease. However, until now, experts have not come to a single conclusion as to whether these plaques are toxic, inert or perform a protective function.
The results of a number of studies indicate that the main cause of brain dysfunction in Alzheimer's disease is not amyloid plaques, but small clots of beta-amyloid (oligomers) freely moving through the brain tissue. To test this hypothesis, the authors developed a line of mice in whose brains beta-amyloid forms exclusively oligomers.
Such mice, in whose brain under no circumstances does the accumulation of amyloid plaques occur, show all the typical symptoms of the disease, usually developing in the presence of both forms of beta-amyloid in the brain. Moreover, the addition of a gene converting oligomers into plaques to the genome of mice prevented the development of symptoms of Alzheimer's disease.
The authors believe that the data they have obtained will help in the development of methods for visualization and neutralization of oligomers. They also note the particular importance of these data in the light of the results of clinical trials of the immunopreparation Bapineuzumab published in March, the introduction of which eliminates up to 25% of amyloid plaques, without having a visible therapeutic effect.
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of The Mount Sinai Medical Center: Alzheimer's Memory Problems Originate with Protein Clamps Floating in the Brain, Not Amyloid Plaques.
04.05.2010