Fig. 5: Control of macrophage reactivity by PGE₂-EP4 signaling.

a Upregulation of PTGER2 and PTGER4 expression upon THP-1 cell stimulation with PMA and LPS. Data represent mean ± SD (n = 3 per group). One-way ANOVA with Dunnett’s multiple comparison test. b PGE₂-mediated downregulation of c-Myc protein in M0-like THP1 macrophages in the EP4-dependent manner. THP-1 cells were differentiated into macrophages with PMA for 24 h, rested for 1 day, and then incubated with PGE₂ in the presence or absence of EP4 antagonist for 2 days (n = 3 per condition), and then subjected to Western blot analysis. Upper, representative Western blot. Lower, quantification of c-Myc protein levels. Matched one-way ANOVA. c Downregulation of c-Myc by PGE₂ in IFN-γ-induced M1-like macrophages. THP-1 cells differentiated to macrophages with PMA for 24 h were incubated with vehicle, 20 ng/ml each of IFN-γ or IL-4 in the presence or absence of 100 nM PGE₂ for 48 h (n = 3 per condition), and subjected to Western blot analysis. Upper, representative Western blot. Lower, relative quantification of c-Myc. Paired two-tailed t-test. b, c The results from one of three independent experiments are shown. a–c *P < 0.05. **P < 0.01, ***P < 0.001, ****P < 0.0001. d, e Reanalysis of published microarray dataset (GSE47189)⁴². n = 3 per condition. d GSEA of DEGs between PGE₂-treated and control hMDMs stimulated with vehicle, P3C or TNF-α for HALLMARK_MYC_TARGETS_V1 (upper) and MOOTHA_PGC (MsigDB) (lower). P-values were based on adaptive multilevel splitting Monte Carlo approach and adjusted by Benjamini–Hochberg procedure. e Heatmaps showing log₂ fold change of gene expression levels of OXPHOS (upper) and RP (lower) genes between PGE₂-stimulated and control hMDMs stimulated with vehicle, P3C, TNF-α or both P3C and TNF-α. Two-sided Wilcoxon Rank Sum test. Source data and exact P-values are provided as a Source Data file.