Figure 3.

Regulation of macrophage metabolism by IL-33. In the pro-M1 setting, IL-33 drives glycolysis and decreases mitochondrial function; in the pro-M2 setting, IL-33 decreases glycolysis but increases OXPHOS. IL-33 alone directs macrophages toward a M2-like state, which mainly use OXPHOS to increase basal respiration and ATP production; in this context, UCP2-mediated uncoupling of the respiratory chain plays a critical role, which blocks the generation of ROS and allows sustained mitochondrial respiration and an intact TCA cycle. OXPHOS, oxidative phosphorylation; TCA, tricarboxylic acid; UCP2, uncoupling protein 2.