Signaling roles for astrocytic lipid metabolism in brain function

Astrocytes, the most abundant glial cell type in the central nervous system, have traditionally been viewed from the perspective of metabolic support, particularly supplying neurons with lactate via glycolysis. This view has focused heavily on glucose metabolism as the primary mode of sustaining neuronal function. However, recent research challenges this paradigm by positioning astrocytes as dynamic metabolic hubs that actively engage in lipid metabolism, especially mitochondrial fatty acid β-oxidation. Far from serving solely as an energy source, fatty acid ß-oxidation in astrocytes orchestrates reactive oxygen species-mediated signaling pathways that modulate neuron-glia communication and cognitive outcomes. This review integrates recent advances on astrocytic fatty acid ß-oxidation and ketogenesis, alongside other metabolic pathways converging on reactive oxygen species dynamics, including cholesterol metabolism and peroxisomal β-oxidation. In reframing astrocytic metabolism from energy provision to signaling, we propose new directions for understanding central nervous system function and dysfunction.