Fig. 4.

Treatment with mMSCs-Exo reversed radiation-induced EMT in MLE-12 cells via miR-466f-3p. A MiRNA microassay data of irradiated MLE-12 cells pretreated with or without mMSCs-Exo were shown in the Heatmap. B qRT-PCR analysis of miRNAs expression in mMSCs-Exo. Cel-miR-39-3p was used as an internal control. C qRT-PCR analysis of miR-466f-3p expression in MLE-12 cells with or without radiation and mMSCs cells. U6 was used as an internal control. D qRT-PCR analysis of miR-466f-3p expression in irradiated MLE-12 cells cocultured with mMSCs, mMSCs-Exo, or GW4869. U6 was used as an internal control. E qRT-PCR analysis of miR-466f-3p in scramble and miR-466f-3p-inhibiting exosomes. Cel-miR-39-3p was used as an internal control. F qRT-PCR analysis of miR-466f-3p in irradiated MLE-12 cells pretreated with scramble or miR-466f-3p-inhibiting exosomes (mMSCs-Exo/si-466f-3p). U6 was used as an internal control. G, H Western Blot analysis (G) and densitometric quantification (H) of E-cadherin, Vimentin, and GAPDH (for normalization) in irradiated MLE-12 cells pretreated with scramble or miR-466f-3p-inhibiting exosomes. I Representative images of transmission electron microscopy for irradiated MLE-12 cells pretreated with scramble or mMSCs-Exo/si-466f-3p. Zoom-in images were shown to closely observe cellular junctions. Scale bars = 2 μm. MLE-12/IR: MLE-12 cells exposed to 8 Gy radiation. J H&E and Masson staining in lung tissues from the mouse model of RILI treated with scramble or mMSCs-Exo/si-466f-3p at 8 w post-irradiation, n = 4 mice per group. Scale bars = 200 μm. K Biochemical assay for Hydroxyproline content in lung sections from different groups at 8 w post-irradiation, shown as microgram of Hyp per milligram of wet weight (μg/mg). L ELISA assay for proinflammatory cytokine IL-1β and IL-6 in serum from different groups at 8 w post-irradiation. Data are presented as the mean ± SD. from three independent experiments, * p < 0.05