Fig. 9

Administration of EXO isolated from TSG-6 siRNA knockdown MSCs did not suppress hyperoxia-induced inflammation and associated BPD pathology. a-c Histogram showing BALF total cell count (a), BALF absolute neutrophil count (b), total BALF protein (c), in RA, BPD and PBS-injected, MSC-CM EXO 25 wks-injected, scr siRNA EXO 25 wks and TSG-6 siRNA EXO 25 wks-injected BPD mice at PN14. d Representative images of lung histology (H&E staining) from the six experimental groups, RA (I), BPD (II), BPD + PBS (III), BPD + MSC-CM EXO 25 wks (IV), BPD + scr siRNA EXO 25 wks (V), BPD + TSG-6 siRNA EXO 25 wks (VI). Asterisks depict the increased alveolar simplification in the BPD, PBS and TSG-6 siRNA EXO 25 wks-injected BPD mice as compared to RA. ×200 magnification, Scale bar: 50 μm. e-f Histograms showing the mean chord length (e), alveolar area (f) in lungs of RA, BPD, PBS-injected, scr siRNA EXO 25 wks-injected and TSG-6 siRNA EXO 25 wks-injected BPD mice. g-h Histogram showing the RV to LV ratio (g) and Fulton’s index [RV/(LV + IVS)] (h), reflecting right ventricular hypertrophy at PN14. RA, BPD, BPD + PBS and BPD + MSC-CM EXO 25 wks samples used for comparison in this analysis are from Figs. 1, 2 and 3. All values are expressed as mean ± SEM; six experiments, N = 3–8 mice per group; one-way ANOVA with Tukey’s post hoc correction; *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001. BALF bronchoalveolar lavage fluid, BPD bronchopulmonary dysplasia, CM conditioned medium, EXO exosomes, IVS interventricular septa, LV left ventricular, MSC mesenchymal stem cell, PBS phosphate-buffered saline, RA room air, RV right ventricular, scr siRNA scrambled small interfering ribonucleic acid, TSG-6 tumor necrosis factor alpha-stimulated gene-6