Figure 4

Exosomes derived from AMSCs pre-activated with pro-inflammatory cytokines induce an anti-inflammatory M2 phenotype reverting M1 differentiation. (A) Representative phase contrast microscopic images (20x magnification) of monocytes differentiated into macrophages in presence of GM-CSF alone (CTRL) or in combination with exosomes isolated from the supernatants of unstimulated (EXO UNSTIM) or cytokines-activated (EXO IFNγ/TNFα 10, 20 and 40 ng/ml) AMSCs. The green circles evidence cells with elongated, spindle-like morphology, a typical feature of M2 macrophages. Flow cytometry analysis of cell surface molecules CD163 (B) CD206 (C) and CD80 (D) on macrophages. The levels of expression are presented as median fluorescent intensity (MFI) fold change respect untreated cells. Columns, mean; bars, SD, * significant difference from unstimulated cells, P < 0.05.