Fig. 6

miR-214 overexpression blocks the effect of the activated STAT3 pathway on alveolarization by inhibiting PlGF in neonatal rats with BPD. A The KEGG and GeneMANIA databases were used to predict the regulatory pathways downstream of PlGF. B Western blot analysis of the activation of the STAT3 pathway in BPD neonatal rats normalized to GAPDH. Neonatal rats with BPD were then treated with miR-214 NC + PlGF vector, miR-214 NC + PlGF, or miR-214 agomir + PlGF. C Western blot analysis of the expression of STAT3 and phosphorylated STAT3 in lung tissues of BPD neonatal rats, normalized to GAPDH. D Quantification of the levels of the inflammatory factors IL-1β, TNF-ɑ, and IL-6 by ELISA. E Quantification of the levels of ICAM-1 and Flt-1 by ELISA. F Giemsa staining of the number of macrophages. G H&E staining of the formation of pulmonary alveoli (× 400). H H&E staining of the number of alveoli and alveolar growth. Measurement data are summarized as the mean ± standard deviation. *p < 0.05 vs. BPD rats treated with miR-214 NC + PlGF vector. ^#p < 0.05 vs. BPD rats treated with miR-214 NC + PlGF. An independent sample t-test was used for comparisons between two groups. Comparisons between multiple groups were performed using one-way ANOVA, followed by Tukey's post hoc test for multiple comparisons. n = 3 for rats in each group