Fig. 1.

Modulation of H1R, H2R and the H4R mRNA expressions during the differentiation process of M2 macrophages. Regulation of CD68 and CD163 expressions by histamine or histamine receptor agonists during the differentiation process of M2 macrophages. a Primary human monocytes were obtained from PBMCs after 2 h adherence. Monocytes were differentiated into M2 macrophages with M-CSF (10 ng/mL) only or with histamine and different HR agonists (10 µM). Expressions of CD68 and CD163 were measured after different time periods as indicated. The mRNA expressions of the (b) H1R, (c) H2R, and (d) H4R in monocytes obtained by adherence were measured at day 0 (day 0) and in fully differentiated M2 macrophages after a differentiation period of 10 days (day 10), analysed by quantitative PCR and calculated by the [delta] [delta] Ct method, the target/reference (Tgt/Ref) ratios are indicated. Expressions of CD68 and CD163 were analysed by flow cytometry. e The expression of CD68 was measured at different days of the differentiation process as indicated on non-stimulated cells. Expressions of CD68 in (f) histamine, (g) 2-pyridylethylamine (H1R agonist), (h) amthamine (H2R agonist) and (i) in ST-1006 treated cells are shown (only non-stimulated samples with MFI < 450 were included). j The expression of CD163 was measured at different days of the differentiation process as indicated on non-stimulated cells. Expressions of CD163 in (k) histamine, (l) 2-pyridylethylamine (H1R agonist), (m) amthamine (H2R agonist) and in (n) ST-1006 treated cells are shown. Significant differences, as determined by the Wilcoxon signed rank test are indicated as follows: * p < 0.05; ** p < 0.01; *** p < 0.001; medians are shown in the graphs. ns, non-stimulated; Hist, histamine; MFI, mean fluorescence intensity.