Reactive Astrocytes in Neurodegenerative Conditions

Chronic, unresolved inflammation in brain tissue is a feature of age-related neurodegenerative conditions, and may even be the most important mechanism in these very complex conditions. The supporting cells of the brain, primarily microglia and astrocytes, become more active and inflammatory in later life. This overlaps with a rising count of senescent cells in these populations. Senescent cells produce an outsized contribution to inflammatory signaling, belying their relatively small numbers compared to non-senescent cells. Active microglia and astrocytes are largely not senescent, however. They are reacting to inflammatory signaling or molecular patterns resulting from cell dysfunction, stress, and death. Clearing senescent cells from the brain dampens inflammation and pathology in animal models of neurodegeneration. It seems plausible that finding ways to turn off the activation of microglia and astrocytes will be similarly beneficial. In the case of microglia, the entire population can be removed without harm, allowing new non-active microglia to emerge and repopulate the brain. Astrocytes present a harder challenge, however. Given that they make up a sizable fraction of all cell in the brain, clearance really isn't an option. Some form of adjustment or reprogramming of regulatory mechanisms is called for. Fortunately, it may be the case that astrocyte activation is a consequence of microglial activation: further studies of microglial clearance as an approach to th...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs