MsrB1-regulated GAPDH oxidation plays programmatic roles in shaping metabolic and inflammatory signatures during macrophage activation

초록

Classically activated pro-inflammatory macrophages are generated from naive macrophages by pro-inflammatory cues that dynamically reprogram their fuel metabolism toward glycolysis. This increases their intracellular reactive oxygen species (ROS) levels, which then activate the transcription and release of proinflammatory mediators. Our study on mice that lack methionine sulfoxide reductase (Msr)-B1 shows that the resulting partial loss of protein methionine reduction in pro-inflammatory macrophages creates a unique metabolic signature characterized by altered fuel utilization, including glucose and pyruvate. This change also associates with hyper-inflammation that is at least partly due to sustained oxidation of an exposed methionine residue (M44) on glyceraldehyde 3-phosphate dehydrogenase (GAPDH), thereby inducing GAPDH aggregation, inflammasome activation, and subsequent increased interleukin (IL)-1b secretion. Since MsrB1-knockout mice exhibit increased susceptibility to lipopolysaccharide (LPS)-induced sepsis, the MsrB1-GAPDH axis may be a key molecular mechanism by which protein redox homeostasis controls the metabolic profile of macrophages and thereby regulates their functions.

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