Targeting miR‐34a/Pdgfra interactions partially corrects alveologenesis in experimental bronchopulmonary dysplasia.

Bronchopulmonary dysplasia (BPD) is a common complication of preterm birth characterized by arrested lung alveolarization, which generates lungs that are incompetent for effective gas exchange. We report here deregulated expression of miR‐34a in a hyperoxia‐based mouse model of BPD, where miR‐34a expression was markedly increased in platelet‐derived growth factor receptor (PDGFR)α‐expressing myofibroblasts, a cell type critical for proper lung alveolarization. Global deletion of miR‐34a; and inducible, conditional deletion of miR‐34a in PDGFRα+ cells afforded partial protection to the developing lung against hyperoxia‐induced perturbations to lung architecture. Pdgfra mRNA was identified as the relevant miR‐34a target, and using a target site blocker in vivo, the miR‐34a/Pdgfra interaction was validated as a causal actor in arrested lung development. An antimiR directed against miR‐34a partially restored PDGFRα+ myofibroblast abundance and improved lung alveolarization in newborn mice in an experimental BPD model. We present here the first identification of a pathology‐relevant microRNA/mRNA target interaction in aberrant lung alveolarization and highlight the translational potential of targeting the miR‐34a/Pdgfra interaction to manage arrested lung development associated with preterm birth. Synopsis: The pathogenic mechanisms underlying stunted lung development associated with bronchopulmonary dysplasia (BPD) are unknown. In this study, the interaction between miR 34a and the Pdgfra 3′‐UTR was validated as both a causal factor and a potentially "druggable" target in BPD driven by oxygen toxicity. miR‐34a expression was increased by elevated oxygen levels in PDGFRα+ cells.PDGFRα expression was negatively regulated by miR‐34a in vitro and in vivo.Lung development was protected by genetic ablation of miR‐34a expression in PDGFRα+ cells in vivo.PDGFRα+ cell abundance was partially restored by neutralization of miR‐34a using LNA antimiRs in developing lungs.Disrupting the miR‐34a/Pdgfra mRNA interaction revealed a new pathogenic pathway that could be pharmacologically manipulated. The pathogenic mechanisms underlying stunted lung development associated with bronchopulmonary dysplasia (BPD) are unknown. In this study, the interaction between miR 34a and the Pdgfra 3′‐UTR was validated as both a causal factor and a potentially "druggable" target in BPD driven by oxygen toxicity. [ABSTRACT FROM AUTHOR]