The Impact of Viral Infection on Microglia and the Aging of the Brain

A growing school of thought sees persistent viral infection as an important contributing factor in age-related neurodegeneration. The widely varying burden of infection that is present in the population could help to explain the puzzling epidemiology of conditions such as Alzheimer's disease, in that only some of the people with evident risk factors in fact go on to develop dementia. A simplistic view of the role of viral infection, particularly by persistent herpesviruses, is that it produces chronic inflammation in brain tissue, and that inflammation contributes to the many forms of molecular pathology observed in neurodegenerative conditions. The immune system of the brain is distinct from that of the rest of the body, the two sides separated by the blood-brain barrier surrounding blood vessels in the central nervous system. In recent years, increasing attention has been given to the age-related dysfunction of innate immune cells in the brain, the microglia, and the contribution of that dysfunction to neurodegeneration. Microglia in older individuals are more inflammatory in general, and some become senescent, producing an outsized amount of pro-inflammatory signals. Studies in mice have shown that using senolytic drugs to clear senescent cells, including senescent microglia, from the brain can reverse neuroinflammation and pathology characteristic of neurodegenerative conditions. The interesting question is to what degree this inflammatory microglial dysfunction is...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs