Fig. 1: Glycogen is synthesized in inflammatory macrophages.

a–c Intracellular glycogen levels in untreated, IFN-γ/LPS (20 ng mL⁻¹ IFN-γ plus 100 ng mL⁻¹ LPS) or IL-4 (10 ng mL⁻¹) treated BMDMs were detected and observed by PAS staining (scale bar, 20 μm) (a), colorimetric assay (b) and TEM (scale bar, 0.5 μm) (c). The arrows point to intracellular glycogen deposits. d, e Pgm1, Ugp2, and Gys1 expression in untreated, IFN-γ/LPS or IL-4 treated BMDMs were determined by real-time PCR (d) and western blot (e). f Overview of three glucose metabolic pathways: glycogen metabolism (left), glycolysis (middle) and PPP (right) and the inhibitors (GPI/6AN) are shown. g–i BMDMs differentiated in normal ¹²C-glucose were stimulated with IFN-γ/LPS or IL-4 for 6 h and switched to ¹³C-glucose for 6 h, LC-MS/MS was performed for m + 6-labeled G6P/G1P (g), m + 6-labeled UDPG (h) and m + 3-labeled G6P/G1P (i). j, k Pck1, Fbp1, and G6pase expression in untreated, IFN-γ/LPS or IL-4 treated BMDMs were determined by real-time PCR (j) and western blot (k). l Consumption of glucose in untreated, IFN-γ/LPS or IL-4 treated BMDMs were measured by enzymatic methods. m Relative mRNA expression of Slc2a1/2 and Hk1/2/3 in untreated, IFN-γ/LPS or IL-4 treated BMDMs were determined by real-time PCR. n, o Hk1/2/3, Pgm1 or Gys1 siRNA transfected BMDMs were stimulated with IFN-γ/LPS for 36 h. Intracellular glycogen levels were detected by colorimetric assay. Unless otherwise specified, n = 3 biologically independent experiments were performed. Data are presented as mean ± SEM. P values were calculated using one-way ANOVA, ****p < 0.0001.