Fig. 6

N-EV and H-EV treatment promote macrophage M2 polarization by delivering miR-21-5p that targets PTEN. a, western blot analysis of PTEN protein expression level in induced macrophages. H/i-miR-EV, monocytes were induced with the presence of EV secreted by miR-21-5p-inhibited, hypoxia pre-challenged MSCs; H-EV + i-miR, monocytes were transfected with miR-21-5p inhibitor-expressing vector before induction with the presence of H-EV. Macrophages induced without MSC-EV were used as negative control (NC). b, c, flow cytometry determining the percentage of CD163⁺CD206⁺ cells among total CD68⁺ cells after induction. N-EV + O/E PTEN or H-EV + O/E PTEN, monocytes were transfected with PTEN overexpressing vector before N-EV or H-EV treatment, respectively. d–f, western blot detecting Akt and STAT3 protein expression as well as their activating phosphorylation (p-Ser473 for Akt and p-tyr705 for STAT3) in macrophages after induction. g–i, ELISA evaluating IL-10, TGF-β and VEGF-α in macrophage culture medium after induction. Macrophages induced with the presence of N-EV were used as negative control in b–i. Tukey’s test was used for statistical analysis. *, p < 0.05; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001