α-ketoglutarate orchestrates macrophage activation through metabolic and epigenetic reprogramming.
Pu-Ste LiuHaiping WangXiaoyun LiTung ChaoTony TeavStefan ChristenGiusy Di ConzaWan-Chen ChengChih-Hung ChouMagdalena VavakovaCharlotte MuretKoen DebackereMassimiliano MazzoneHsien-Da HuangSarah-Maria FendtJulijana IvanisevicPing-Chih HoPublished in: Nature immunology (2017)
Glutamine metabolism provides synergistic support for macrophage activation and elicitation of desirable immune responses; however, the underlying mechanisms regulated by glutamine metabolism to orchestrate macrophage activation remain unclear. Here we show that the production of α-ketoglutarate (αKG) via glutaminolysis is important for alternative (M2) activation of macrophages, including engagement of fatty acid oxidation (FAO) and Jmjd3-dependent epigenetic reprogramming of M2 genes. This M2-promoting mechanism is further modulated by a high αKG/succinate ratio, whereas a low ratio strengthens the proinflammatory phenotype in classically activated (M1) macrophages. As such, αKG contributes to endotoxin tolerance after M1 activation. This study reveals new mechanistic regulations by which glutamine metabolism tailors the immune responses of macrophages through metabolic and epigenetic reprogramming.