The involvement of HDAC3-mediated inhibition of microRNA cluster 17-92 in hyperoxia-mediated impairment of lung development in neonatal rats

BackgroundThe incidence of bronchopulmonary dysplasia (BPD), a chronic lung disease of newborns, has been paradoxically rising despite medical advances. Histone deacetylase 3 (HDAC3) has been reported to be a crucial regulator in alveologenesis. Hence, this study aims to investigate the mechanism of HDAC3 in the pulmonary angiogenesis and alveolarization of BPD. MethodsA hyperoxia-induced mouse model of BPD was constructed. The mean liner intercept (MLI) and alveolar volume were measured to evaluate the alveolarization in BPD mice. Immunofluorescence assay was performed to detect the microvessel density (MVD) of lung tissues. Next, the expression of HDAC3 and its enrichment in the promoter region of microRNA (miR)-17-92 cluster, as well as the enrichment of p65 in the placental growth factor (Pgf) promoter region were detected by Western blot analysis and chromatin immunoprecipitation (ChIP) assay. The effect of HDAC3 and p65 on the activity of miR-17-92 promoter and Pgf promoter were examined by dual-luciferase reporter gene assay, respectively. Finally, the role of HDAC3 in angiogenesis and alveolarization through miR-17 regulated EZH1-p65-Pgf axis was validated in BPD mouse models. ResultsHDAC3 was involved in the regulation of alveolarization and angiogenesis in BPD. Results demonstrated that the expression of the miR-17-92 cluster in BPD was regulated by HDAC3. miR-17 was related to the regulatory role of HDAC3 in regulating EZH1 expression and in lung fibroblasts of BPD. Besides, results showed that EZH1 could promote Pgf expression by recruiting p65 to regulate BPD. HDAC3 regulated the expression of EZH1 through miR-17 to promote the recruitment of p65 in the Pgf promoter region, thus enhancing the transcription and expression of Pgf. HDAC3 was demonstrated to regulate Pgf through the miR-17-EZH1-p65 axis to mediate angiogenesis and alveolarization of BPD mice. ConclusionAltogether, the present study revealed that HDAC3 could regulate the EZH1-p65-Pgf axis through miR-17 in the miR-17-92 cluster in the pulmonary angiogenesis and alveolarization of BPD mice.