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E. Heideveld et al. Results
Glucocorticoid stimulation directs monocyte differentiation to CD16+CD163+CD169+CXCR4+CD206+ macrophages
We previously found that purified peripheral blood CD14+ monocytes cultured in EPO, SCF, lipids and dexam- ethasone differentiate within three days into CD163, CD169, CXCR4 and CD16-positive macrophages that, upon co-culture with CD34+ cells, significantly increase the erythroid yield.12 However, it remained unclear as to which growth factors were crucial to differentiate monocytes to
macrophages supporting erythropoiesis. Therefore, we examined which growth factors or supplements deter- mined this differentiation cue. Flow cytometry analysis showed that dexamethasone, exclusively, induces high expression of CD16 and CD163 in macrophages. The addi- tion of EPO, SCF or lipids does not contribute to this high expression (Figure 1A,B). CXCR4 expression was already upregulated in the absence of dexamethasone but was fur- ther increased upon stimulation with dexamethasone and lipids, whilst the expression of tissue residency marker CD169 was also upregulated but occurred in a dexametha- sone-independent manner (Figure 1C,D). Online
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Figure 2. Proteome analysis of CD14+ monocytes cultured in the presence or absence of dexamethasone revealed two distinct macrophage populations. (A) Principal component analysis of GC-macrophages (red) versus non-glucocorticoid stimulated cells (blue) of four donors (indicated A-D). (B) Volcano plot (false dis- covery rate 0.05 S0 0.4) showing P-values (-log) versus difference of cells cultured for three days in the presence or absence of dexamethasone. (C) Heatmap of dif- ferentially expressed proteins based on Z-scored label-free quantification values. (D) Interaction analysis based on STRING (all interactions) of upregulated (red) and downregulated (blue) proteins. (E) Enrichment analysis using BiNGO and enrichment mapper in GC-macrophages with upregulated (red) and downregulated (blue) processes.
haematologica | 2018; 103(3)