Fig. 2

Mitochondrial energy metabolism in microglia. The high energy consumption of microglia to maintain immune functions is regulated by mitochondria. Under normal circumstances, microglia mainly use glucose oxidation for energy supply. First, after being transported into the cell, glucose is converted into pyruvate through the glycolytic pathway. Pyruvate is then converted into acetyl-CoA in the mitochondria, which participates in the TCA cycle and generates a small amount of energy. The subsequent ETC creates a chemical gradient by transferring electrons that powers the production of ATP. When being insulted by pathogenic factors (e.g., Aβ, p-Tau proteins, etc.) or in a state of stress, energy demands of microglia increase. Microglia exert metabolic flexibility to switch from OXPHOS to glycolysis for energy supply. In addition, microglia also use fatty acids and glutamine as alternative energy sources under some conditions