Fig. 2

MSCs induced the M1 to M2 switch in lung tissue in the IPS mouse model. To investigate the effect of MSCs on M2 polarization in the IPS mouse model, the lungs were removed on Day 14 posttransplantation, and the tissue slides were analysed using immunofluorescence to identify the expression of the macrophage marker F4/80 (green) and the M2 marker CD206 (red). (A) CD206 was sharply downregulated in lung tissues in the IPS mouse model and upregulated after intervention with MSCs. Merged/high-power images revealed exclusively strong expression of CD206 in F4/80 + macrophages in the lung tissues of the MSC-treated group. Scale bar = 100 μm. (B) Flow cytometric analysis of gated F4/80 + cells from collagenase-digested cells in lung tissues. (C) Representative histograms and pooled data of the CD206 mean fluorescence intensity (MFI) showed that the infusion of MSCs increased the CD206 MFI of F4/80 + CD11b + macrophages. These results demonstrate that MSCs could regulate M2 polarization in lung tissue in the IPS mouse model. *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001; ns., no significant difference. The data are shown as the means ± SEMs