Fig. 3

Exosomes derived from epithelial cells transfer miR-17-5p to fibroblast, which promotes myofibroblast differentiation. Control (epithelial cells transfected negative control), miR-17-5p (epithelial cells transfected mimic), Anti-miR-17-5p (epithelial cells transfected inhibitor), U6 or GAPDH was used as an internal control for qRT-PCR. a A transwell co-culture cell model with transfected epithelial cells (top well) and fibroblasts (bottom well). A 0.4-μm porous membrane is between the 2 wells, allowing the transmission of exosomes, but inhibiting direct contact between cells. b A co-culture assay to study the miRNA cargo from epithelial cells to fibroblasts. The epithelial cells were transfected with a Cy3-labeled miR-17-5p (red) and then treated with PBS or GW4869. Nuclei were counterstained with DAPI (blue). Scale bar: 50 μm. c The expression level of miR-17-5p in fibroblasts after 48 h co-culturing with epithelial cells transfected with miR-17-5p or anti-miR-17-5p. Immunostaining (d) and (e) Immunoblotting detection of collagen type I and α-SMA expression in fibroblast after 48 h co-culturing with epithelial cells. Scale bars, 100 μm. Sirius Red total collagen assay (f), collagen contraction assay (g, h) and transwell migration assay (i, j) were determined for fibroblast. n = 3–5 technical replicates, representative of two or three assays. Scale bars, 100 μm. Statistics: mean ± SEM, one-way ANOVA, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.000 1