Amyloid- β Causes Pericyte Dysfunction and Reduced Blood Flow in the Aging Brain

The brain is an energy-hungry organ, and the supply of oxygen and nutrients to brain tissue is vital to its function. This is one of the reasons why cardiovascular disease contributes to neurodegeneration. Researchers know that cells that wrap small blood vessels in the brain, called pericytes, tend to become dysfunctional or die in later life, another of the cellular casualties of the damage of aging. This causes greater constriction of the blood vessels, reducing the blood flow to tissues. Researchers here provide evidence for this to be a consequence of the aggregation of amyloid-β, characteristic of the early stages of Alzheimer's disease. This is an intriguing addition to what is known of the issues caused by protein aggregation in neurodegenerative conditions. A new study looked at the role of pericytes, cells wrapped around capillaries that have the ability to contract and regulate blood flow. Researchers examined capillaries in Alzheimer's-affected human brain tissue and in mice bred to develop Alzheimer's pathology, and found that they were squeezed by pericytes. They also applied amyloid beta protein (which accumulates in the brains of people with Alzheimer's) to slices of healthy brain tissue, and found that the capillaries were squeezed as a result. They calculated that the constriction was severe enough to halve blood flow, which is comparable to the decrease in blood flow found in parts of the brain affected by Alzheimer's. "Our study has, for t...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs