Research Paper Volume 12, Issue 10 pp 9139—9150

Figure 1. IS stimulates the production of pro-inflammatory cytokines and promotes M1 macrophage polarization. (A) THP-1 cells were exposed to PMA (160 nM) for 48 h and then incubated in PMA-free medium for 24 h followed by the indicated concentrations of IS (0, 0.25, 0.5, 1, or 2 mM) for 24 and 48 h. The levels of TNFα, IL-6, and IL-1β were then analyzed by ELISA. (B) THP-1 cells were exposed to PMA (160 nM) for 48 h and then incubated in PMA-free medium for 24 h followed by the indicated concentrations of IS (0, 0.25, 0.5, 1, or 2 mM) for 24 h. Arginase1 and iNOS expression was analyzed by western blotting. (C) Arginase1 and iNOS expression was normalized to GAPDH. (D, E) Representative FACS plots for HLA-DR, a marker of M1 macrophages. Percentages of HLA-DR+ cells detected by FACS. (F, G) Representative FACS plots for CD206, a marker of M2 macrophages. Percentages of CD206+ cells detected by FACS. **P < 0.01 vs. IS-0 mM group.