CD163 induction is a major effect of global glucocorticoid activity in monocytes. (A) iTRAQ MALDI-MS/MS analysis of the effects of glucocorticoid on the monocyte proteome. Monocytes were incubated for 36 hours with dexamethasone and then analyzed, as shown in Figure 1. A total of 1023 proteins were identified and relatively quantified (ratio of protein abundance for dexamethasone treated/control) based on at least 2 peptide matches. (B) Correlation plot of the 462 proteins identified in both independent experiments. Cyan dots represent ribosomal proteins; CD163 is shown in red. The prototypic M2 signature protein mannose receptor is highlighted in green. The complete list of up- and down-regulated proteins is given in supplemental Table 3. (C) Confirmation of CD163 up-regulation and increased Hb:Hp endocytosis in human monocytes after dexamethasone treatment. Monocytes were cultured on glass coverslips and stained with anti-CD163 monoclonal antibody (5C6FAT) and a secondary Alexa 568 goat anti-mouse antibody or incubated with 10 μg/mL Alexa594 Hb:Hp for 30 minutes. Images were acquired with a Zeiss epifluorescence microscope. Red indicates CD163 (right images) or internalized Hb:Hp (left images); blue shows DAPI (4′,6-diamidino-2-phenylindole)-stained nuclei.