Fig. 2

Microscopy images showing (a) EV distribution (red) in the lung parenchyma immediately after local instillation; (b) EV distribution (red) in the lung parenchyma 30 min after local instillation; EV uptake (red) by (c) MH-S (alveolar macrophages) × 200 and (d) primary lung fibroblast (× 400, scale bars represent 20 μm). e Flow cytometry representative results of EV uptake (Vybrant DiI staining) by MH-S (alveolar macrophages) after incubation for 24 h. f Flow cytometry representative results of EV uptake (Vybrant DiI staining) by lung primary fibroblasts after incubation for 24 h. Gray areas indicate negative controls. TNF-α (g) and TGF-β (h) concentration (per total amount of protein) in the conditioned medium of cultured macrophages stimulated with silica with or without addition of EVs; bars indicate means ± SEM, n = 4, *Significantly different from unstimulated group. **Significantly different from stimulated group without EVs, p < 0.05