Evidence For Autophagy to be Important to Microglial Dysfunction in the Aged Brain

A number of lines of evidence implicate senescent microglia in the development of neurodegenerative conditions. Microglia are innate immune cells of the central nervous system, analogous to macrophages elsewhere in the body. Microglia appear to become more inflammatory with age, but this isn't just an amplification of inflammatory signaling that arises due to age-related dysfunctions such as mislocalization of mitochondrial DNA. Some microglia become senescent, and like other types of senescent cell, they energetically produce inflammatory signaling. Clearing such cells from the brain has produced benefits in animal models of neurodegeneration, but it remains to be seen as to whether that works well in humans. The materials here summarize the work of researchers who suggest that failing autophagy is an important cause of microglial senescence in the aging brain. Autophagy is a collection of cell maintenance processes responsible for recycling damaged and worn proteins and cell components, sending them to a lysosome for disassembly by enzymes. It is well known that autophagy falters with advancing age, though a full accounting of why this is the case remains to be established. Inefficient autophagy leads to a greater burden of dysfunction in a cell, and, in principle, more cells tipped over the edge into a state of senescence. The one caution here is that researchers essentially disabled autophagy rather than dialing it back to a lesser degree of efficiency. This...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs