Fig. 7

TSG-6 treatment decreases proinflammatory cytokines and cell death in lungs of the BPD mouse model. a IL-6 levels measured using ELISA in lung tissue of RA, BPD, MSC-CM EXO 25 wks- and MSC-CM EXO 30 wks-injected BPD mice at PN14. b IL-6 levels measured using ELISA in lung tissue of RA, BPD and TSG-6-injected BPD mice at PN14. c-e Pro-inflammatory cytokines levels in the lung tissues of RA, BPD and BPD mice injected with PBS, MSC-CM EXO 25 wks and TSG-6. Histogram showing relative expression of IL-6 (c), TNF-α (d) and IL-1β (e) as determined using real-time PCR. f Representative TUNEL immunofluorescence images of lung from the four experimental groups, RA (I), BPD (II), BPD + PBS (III), BPD + TSG-6 (IV). TUNEL-positive cells are labeled with FITC (green). The nuclei are counterstained with DAPI. Arrows depict TUNEL-positive dead cells in the field. Scale bar: 50 μm. (g) Histogram depicting the quantitative analysis of TUNEL-positive cells in the lungs of RA, BPD, PBS-injected and TSG-6-injected BPD mice. TUNEL-positive cells are expressed as a percentage, as described in Additional file 1: Methods. All values are expressed as mean ± SEM; 3–4 experiments, N = 3–5 mice per group; one-way ANOVA with Tukey’s post hoc correction; *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001. BPD bronchopulmonary dysplasia, CM conditioned medium, DAPI 4,6-diamidino-2-phenylindole, EXO exosomes, IL-6 interleukin-6, IL-1β interleukin 1 beta, MSC mesenchymal stem cell, PBS phosphate-buffered saline, RA room air, TNF-α tumor necrosis factor alpha, TSG-6 tumor necrosis factor alpha-stimulated gene-6, TUNEL terminal deoxynucleotidyl transferase dUTP nick-end labeling