Fig. 6: HUC-MSCs modulated macrophage polarization via secretion of IL-6 in vitro.

a Relative gene expression levels of immunomodulatory factors involve in polarization modulatory effect of hUC-MSCs on macrophages. hUC-MSCs were cultured with primary BMDMs (M0) or with LPS- and IFN-γ-stimulated BMDMs (M1) for 24 h. Results are presented relative to those of hUC-MSCs cultured with M0, set as 1. b Quantitative RT-PCR analysis of IL-6 expression in hUC-MSCs. HUC-MSCs were cultured with M0 or M1 for 6, 12, 24 h, results are presented relative to those of hUC-MSCs cultured with M0, set as 1. c Quantitative RT-PCR analysis of IL-6 expression in hUC-MSCs (Con), hUC-MSCs transfected with scrambled siRNA (MSCs/scr siRNA), or hUC-MSCs with IL-6 siRNA (MSCs/IL-6 siRNA). HUC-MSCs were cultured with M0 or with M1. d Enzyme-linked immunosorbent assays (ELISA) of IL-6 in medium of hUC-MSCs cultured with M0 or M1, symbols are as in c. e Immunoblotting analysis of BMDMs in stimulation with LPS and IFN-γ cultured alone, cultured with hUC-MSCs transfected with scr siRNA, or with hUC-MSCs transfected with IL-6 siRNA. Relative protein level is quantified by ratio of iNOS to β-tubulin and that of Arg1 to β-tubulin, and separately shown in f and g. Values are means ± SD of three individual experiments, *p < 0.05, **p < 0.01. IL-6 interleukin 6, Ido indoleamine 2, 3-dioxygenase. Tsg6 TNF-α-induced protein 6, Pge2 prostaglandin E2