Phosphorylation of PFKL regulates metabolic reprogramming in macrophages following pattern recognition receptor activation

Abstract

Innate immune responses are linked to key metabolic pathways, yet the proximal signaling events that connect these systems remain poorly understood. Here we show that phosphofructokinase 1, liver type (PFKL), a rate-limiting enzyme of glycolysis, is phosphorylated at Ser775 in macrophages following several innate stimuli. This phosphorylation increases the catalytic activity of PFKL, as shown by biochemical assays and glycolysis monitoring in cells expressing phosphorylation-defective PFKL variants. Using a genetic mouse model in which PFKL Ser775 phosphorylation cannot take place, we observe that upon activation, glycolysis in macrophages is lower than in the same cell population of wild-type animals. Consistent with their higher glycolytic activity, wild-type cells have higher levels of HIF1α and IL-1β than Pfkl^S775A/S775A after LPS treatment. In an in vivo inflammation model, Pfkl^S775A/S775A mice show reduced levels of MCP-1 and IL-1β. Our study thus identifies a molecular link between innate immune activation and early induction of glycolysis.

Pro-inflammatory signals trigger innate immune pathways with consequential metabolic remodeling. Here authors show that a rate-limiting enzymes of glycolysis, PFKL, is directly regulated by innate stimuli via phosphorylation at Ser775, which modification in turn influences pro-inflammatory cytokine production.