Amyloid- β Causes Blood-Brain Barrier Leakage

Dysfunction of the blood-brain barrier, allowing molecules and cells not normally present in the central nervous system to enter, is one of the features of dementia. If nothing else, this causes inflammation in the brain as the immune system is roused to try to clear out the unwanted materials. Chronic inflammation in the immune cells of the central nervous system is an important part of the progression of neurodegenerative conditions, and in Alzheimer's disease shows up after the initial accumulation of amyloid-β. This sequence of events may be due in part to amyloid-β causing blood-brain barrier dysfunction, though there are certainly numerous other mechanisms to consider. Amyloid-β plaques, the protein aggregates that form in the brains of Alzheimer's patients, disrupt many brain functions and can kill neurons. They can also damage the blood-brain barrier - the normally tight border that prevents harmful molecules in the bloodstream from entering the brain. Researchers have now developed a tissue model that mimics the effects of amyloid-β on the blood-brain barrier, and used it to show that this damage can lead molecules such as thrombin, a clotting factor normally found in the bloodstream, to enter the brain and cause additional damage to Alzheimer's neurons. "We were able to show clearly in this model that the amyloid-β secreted by Alzheimer's disease cells can actually impair barrier function, and once that is impaired, factors are secreted into the brain ...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs