Microglial cells, known as the maintenance workers of the central nervous system (CNS), are responsible for protecting the brain by clearing pathogens and pruning damaged neurons. However, as these cells age, their efficiency in performing these tasks diminishes. Understanding the underlying mechanism of microglial cell aging is crucial in preventing and treating brain dysfunction.
A team of researchers led by Bo Peng and Yanxia Rao from Fudan University conducted a study to investigate how microglial cells change as they age and how this aging process directly affects the brain. The study involved profiling the microglial transcriptomes of male and female mice at different stages of their lifespan. The researchers discovered “unexpected sex differences” in the aging process of microglia.
The team established a model to study aged microglial cells in a non-aged brain, and their findings revealed that aged-like microglia contribute to cognitive decline even in young mice. They also identified age-dependent microglia (ADEM) genes that correlate with the aging process in both female and male mice. Furthermore, the researchers found that aged microglia are less responsive compared to young microglia when exposed to an immune-triggering substance.
To explore the independent functions of aged-like microglia, the researchers used a process called 3-round depletion-repopulation (3xDR) to remove most microglial cells from the brain and allow the remaining cells to rapidly repopulate. The results showed that aged-like microglia contribute to cognitive decline and impairment of myelin, the material that coats nerve cells and facilitates quick communication across fibers.
The study raises the need for further research to determine if the microglial features observed in mice are relevant to humans. Nevertheless, the data generated from this study provides valuable insights into microglial cell aging and is publicly available at MicrogliAtlas.
Source: Microglial Cell Aging Contributes to Brain Dysfunction, Study Finds. (No URL provided)
