BMP7 regulates lung fibroblast proliferation in newborn rats with bronchopulmonary dysplasia

The present study investigated the expression of bone morphogenetic protein (BMP) 7 in a newborn rat model of bronchopulmonary dysplasia (BPD) and the biological effects of BMP7 on newborn rat lung fibroblast (LF) cells. For this purpose, a total of 196 newborn rats were randomly and equally assigned to a model group and a control group. Lung tissue was collected at days 3, 7, 14 and 21 for histological analysis. The location and expression of BMP7 was examined by immunohistochemical staining and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis. A total of 38 full-term newborn rats on the day of birth were sacrificed and LF cells were isolated and treated with BMP7. The biological effects of BMP7 on LF cells were assessed by cell proliferation and cell cycle analysis. The findings demonstrated that abnormal alveolar development due to BPD was gradually intensified in the model group over time. Immunohistochemical staining revealed that the location of BMP7 in lung tissue was altered. Immunohistochemistry and RT-qPCR assays demonstrated a gradual decrease in BMP7 expression in the model group induced by hyperoxia. MTT assays demonstrated that BMP7 inhibited LF cells and the inhibitory effect was dose-dependent and time-dependent. Flow cytometry revealed that the inhibitory effect of BMP7 in LF cells was causing cell cycle arrest at the G(1) phase. The present study demonstrated that BMP7 may serve an important role in alveolar development in a BPD model. BMP7 may be involved in abnormal alveolar development through the regulation of LF proliferation.