Figure 5
Exosomal transfer of miR-126 from endothelial cells inhibits cell proliferation and cell transformation. (A) Representative fluorescence images of uptake of HUVEC-derived exosomes by A549 cells. A549 cells, cultured in exosome-depleted serum, were incubated with acridine orange (AO)-labelled HUVEC-derived exosomes (20 µg/ml) for 4 h and their internalization was visualised by fluorescent microscopy (magnification 400–600 x). Scale bar for all images equals 100 μm. (B) Gene expression of miR-126 targets insulin receptor substrate1 (IRS1), vascular endothelial growth factor (VEGF) -1, sex determining region Y-box 2 (SOX2), and EGF-like domain-containing protein 7 (EGFL7) after incubation of A549 cells with HUVEC-derived exosomes and miR-126-enriched exosomes derived from HUVECs grown under glucose deprivation (exo-HUVECmiR-126-enriched), with or without anti-miR. The level of miR-126 in HUVEC-derived exosomes (1) and miR-126-enriched HUVEC-derived exosomes (2) is shown in the insert. Cell proliferation (C) and colony-forming assay (D) in A549 cells after treatment with HUVEC-derived exosomes and miR-126-enriched HUVEC-derived exosomes. The data shown are mean values ± S.D. derived from three independent experiments. Representative images taken 3 months after treatment are shown (magnification 100 x). Comparisons among groups were determined by one-way ANOVA with Tukey post-hoc analysis. The symbol “*” indicates significant differences with p < 0.05.
