ABSTRACT
Objective To explore the influence of vascular endothelial growth factor(VEGF) gene-transfected bone marrow mesenchymal stem cells (MSCs) on pulmonary alveolar structure and microvascular in rats with bronchopulmonary dysplasia.Methods Bone marrow MSCs were isolated from SD rats by way of density gradient centrifugation,purified,and transfected with pcDNA3.1 (-)/VEGF164 and blank plasmid pcDNA3.1 respectively using the liposome mediated method.After placing newborn SD rats in the oxygen box of 950 mL/L for 14 days,they were randomly divided into the transfected group(MSCs/VEGF group),the control group(MSCs group),and the blank group(serumfree medium group),with 10 rats in each group respectively,and they were injected respectively with 1 × 105 MSCs transfected by VEGF,MSCs and the same amount of simple serum-free medium by airway.After transplantation for 1 week and 4 weeks,lung tissue was observed by means of hematoxylin eosin staining to study lung structure and radial alveolar counts(RAC),and VEGF protein expression and angiogenesis densities were evaluated by immunohistochemistry,and finally VEGF164 protein was detected using Western blot.Results After transplantation for 1 week,4 weeks,the RAC,VEGF expression,vascular density by immunohistochemistry in transfected group were significantly more than those in the control group and the blank group(all P ＜0.05).After transplantation for 1 week,4 weeks,the VEGF164 protein level in transfected group was significantly more than that in the control group and the blank group (all P ＜0.05).Conclusions Eukaryotic expression vector pcDNA3.1 (-)/VEGF164 can effectively be expressed in MSCs.Transplantation of vascular endothelial growth factor gene by means of transfected MSCs brings better improvement in pulmonary alveolar structure and microvascular regeneration.VEGF is closely related to lung development in newborn rats.