MicroRNA-214 Prevents Pulmonary Angiogenesis and Alveolarization in Rat Models with Bronchopulmonary Dysplasia via PlGF-Dependent STAT3 Signaling Pathway

Background: In recent years, the roles of microRNAs (miRNAs) in pulmonary diseases have been widely studied and researched. However, the molecular mechanism by which miR-214 affects bronchopulmonary dysplasia (BPD) remains elusive and merits further exploration. Hence, this study aims to clarify the function of miR-214 in pulmonary angiogenesis and alveolarization in preterm infants with BPD. Methods: BPD neonatal rat model was induced by hyperoxia, and pulmonary epithelial cells were isolated from rats and exposed to hyperoxia. Gain- or loss-of-function experiments were performed in BPD neonatal rats and hyperoxic pulmonary epithelial cells. MiR-214 and PlGF expression in BPD neonatal rats, and eNOS, Bcl-2, c-myc, Survivin, α-SMA and E-cadherin expression in hyperoxic pulmonary epithelial cells were detected using RT-qPCR and western blot analysis. The interaction between PlGF and miR-214 was identified using dual luciferase reporter gene assay and RIP assay. ELISA was adopted to assess IL-1β, TNF-a, IL-6, ICAM-1 and Flt-1 expression in rats. Results: Decreased miR-214 expression and elevated PlGF expression were evident in the lung tissues of neonatal rats with BPD. PlGF was a target of miR-214, and miR-214 downregulated PlGF to inactivate the STAT3 signaling pathway. miR-214 overexpression or PlGF silencing decreased apoptosis of hyperoxic pulmonary epithelial cells and declined pulmonary angiogenesis and alveolarization in BPD neonatal rats. Conclusions: Collectively, miR-214 can protects against pulmonary angiogenesis and alveolarization in preterm infants with BPD by suppressing PlGF and blocking STAT3 signaling pathway.