Bone marrow-derived mesenchymal stem cells protect against lung injury in a mouse model of bronchopulmonary dysplasia.

ABSTRACT

The aim of the present study was to investigate the effect of bone marrow­derived mesenchymal stem cells (BMSCs) in the treatment of lung injury in a mouse model of bronchopulmonary dysplasia (BPD) and examine the underlying mechanisms. A mouse model of BPD was created using continuous exposure to high oxygen levels for 14 days. BMSCs were isolated, cultured and then labeled with green fluorescent protein. Cells (1x106) were subsequently injected intravenously 1 h prior to high oxygen treatment. Animals were randomly divided into three groups (n=5 in each) Control group, BPD model group and BMSC injection group. At two weeks post­treatment, the expression of transforming growth factor­ß1 (TGF­ß1), vascular endothelial growth factor (VEGF) and von Willebrand factor (vWF) was detected using immunohistochemical staining and immunofluorescence. Compared with the BPD model group, the body weight, airway structure and levels of TGF­ß1 and VEGF were significantly improved in the BMSC­treated group. Immunofluorescence observations indicated that BMSCs were able to differentiate into cells expressing vWF and VEGF, which are markers of vascular tissues. The present study demonstrated that intravenous injection of BMSCs significantly improved lung damage in a neonatal mouse model of BPD at 14 days following hyperoxia­induced injury. This provides novel information which may be used to guide further investigation into the use of stem cells in BPD.