The effects of glucose-induced metabolic injury on microglia activity and survival

Abstract

Glucose is the sole fuel for the brain in normal physiological conditions. Absence of glucose or its presence in high concentrations has been shown to be harmful to neurons. Microglia, the innate immune cells of the brain, are the first line of defense against changes in the CNS environment and their activity influences neuronal survival to a great extent. The effects of glucose-induced metabolic injury on microglia are unclear. Thus, the aim of this study was to investigate how hyperglycemia and hypoglycemia affect microglial phagocytotic activity, survival and secretory profile. Results showed that glucose concentration significantly affected microglia release of pro-inflammatory cytokines and growth factors. Microglia phagocytic activity was decreased at high and low glucose concentrations as compared to normal. Interestingly, microglia deprived of glucose showed better survival, exhibited increased ramification and a more quiescent phenotype where microglia released significantly less pro-inflammatory cytokines and growth factors as compared to controls