Fig. 1

hUC MSC secretome treatment reverses pulmonary inflammation and alveolar-capillary leak associated with hyperoxia-induced lung injury in the BPD mouse model. a Schematic representation of BPD mouse model and secretome injection regime. The mice were kept in 100% oxygen from birth to PN4 followed by RA exposure till PN14. The mice were used for echocardiography and sacrificed for analysis at PN14. IP injections of hUC MSC-CM or hUC MSC-CM EXO were given at PN2 and PN4. 10 μg of MSC-CM and 2.5 μg of MSC-CM EXO (GA 25 wks and 30 wks), resuspended in 100 μl of PBS respectively, was injected into each neonatal mouse at PN2 and PN4. b-d Histogram showing BALF total cell count (b), BALF absolute neutrophil count (c), total BALF protein (d), in RA, BPD and vehicle (DMEM:F12 or PBS)-injected, MSC-CM or EXO 25 wks-injected, MSC-CM or EXO 30 wks-injected BPD mice at PN14. All values are expressed as mean ± standard error of the mean (SEM); eight experiments, N = 3–9 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, hUC human umbilical cord, i.p. intraperitoneal, MSC mesenchymal stem cell, PBS phosphate-buffered saline, PN postnatal, RA room air