Mitochondria as a Form of Intracellular Signaling Important in the Aging Brain

Researchers in the field of neurodegeneration here provide evidence for supporting cells in the brain, specifically microglia, to use their own mitochondria as a form of signaling. Mitochondria are the power plants of the cell, responsible for packaging chemical energy store molecules. Their function declines with age for a range of poorly understood reasons, and this is important in numerous age-related conditions, particularly those in energy hungry tissues such as the brain. The researchers here report that microglia eject both whole and fragmentary mitochondria that other cells react to. Where the microglia are stressed, these ejected mitochondria are more often fragmentary, and are harmful to the surrounding environment.

This is all quite fascinating, given (a) past work on the ability of cells to take up mitochondria from their surroundings or pass mitochondria between one another, and (b) the growing body of evidence showing that senescent microglia are important in the progression of numerous age-related neurodegenerative conditions. Senescent cells, of course, cause harm to their surroundings via active signaling, consisting of secreted molecules and extracellular vesicles - and perhaps also mitochondria.

Researchers report that when microglia spat out damaged mitochondria, these cast-offs inflamed astrocytes, which in turn expelled their own mitochondrial fragments. Jetsam from either cell sickened neurons as well, limiting their energy production. C...

Source: Fight Aging! - October 2, 2019 Category: Research Authors: Reason Tags: Daily News Source Type: blogs