A Breakdown in Metabolic Reprogramming Causes Microglia Dysfunction in Alzheimer's Disease

• DOI: 10.1016/j.cmet.2019.06.005
• Publication Date: 2019-06-27T14:44:27Z
• Authors: Sung Hoon Baik; Seokjo Kang; Woochan Lee; Hayoung Choi; Sunwoo Chung; Jong-Il Kim; Inhee Mook-Jung
• Keywords: Inflammation; Male; Mice, Inbred ICR; 0303 health sciences; Amyloid beta-Peptides; Mice, Transgenic; Hypoxia-Inducible Factor 1, alpha Subunit; Oxidative Phosphorylation; Recombinant Proteins; Cell Line; 3. Good health; Disease Models, Animal; Interferon-gamma; Mice; 03 medical and health sciences; Gene Expression Regulation; Phagocytosis; Alzheimer Disease; Animals; Cytokines; Female; Microglia; Glycolysis

Reactive microglia are a major pathological feature of Alzheimer's disease (AD). However, the exact role of microglia in AD pathogenesis is still unclear. Here, using metabolic profiling, we found that exposure to amyloid-β triggers acute microglial inflammation accompanied by metabolic reprogramming from oxidative phosphorylation to glycolysis. It was dependent on the mTOR-HIF-1α pathway. However, once activated, microglia reached a chronic tolerant phase as a result of broad defects in energy metabolisms and subsequently diminished immune responses, including cytokine secretion and phagocytosis. Using genome-wide RNA sequencing and multiphoton microscopy techniques, we further identified metabolically defective microglia in 5XFAD mice, an AD mouse model. Finally, we showed that metabolic boosting with recombinant interferon-γ treatment reversed the defective glycolytic metabolism and inflammatory functions of microglia, thereby mitigating the AD pathology of 5XFAD mice. Collectively, metabolic reprogramming is crucial for microglial functions in AD, and modulating metabolism might be a new therapeutic strategy for AD.