Expression of vascular endothelial growth factor in bone marrow mesenchymal stem cells under hypoxic conditions / 中国组织工程研究

ABSTRACT

BACKGROUND:Whether transplanted bone marrow mesenchymal stem cells under hypoxic conditions can survive is crucial for the successful celltransplantation. Therefore, studies on the growth of bone marrow mesenchymal stem cells under hypoxic conditions in vitro can provide experimental evidence for in vivo celltransplantation. OBJECTIVE:To observe the expression of vascular endothelial growth factor in bone marrow mesenchymal stem cells under hypoxia. METHODS:Rat bone marrow mesenchymal stem cells were obtained and cultured, and observed under light microscopy. Passage 3 cells were cultured under normoxia (21%O2) and hypoxia (3%O2 hours. Then cellcounting kit-8 assay and flow cytometry were employed to detect cellproliferation in the two groups. Western blot assay was adopted to detect the expression of hypoxia-inducible factor-1αand vascular endothelial growth factor in the two groups. RESULTS AND CONCLUSION:(1)Rat bone marrow mesenchymal stem cells were obtained and cultured successful y, which were fusiform cells and had uniform shape under the light microscope. (2)The results of cellcounting kit-8 assay showed that the number of cells in the hypoxic group was higher than that in the normoxic group at each time point, and cellviability increased significantly at hours 36 and 48 (P<0.05). (3)The results of flow cytometry demonstrated that the proportion of cells in S phase and cellproliferation index in the hypoxic group were significantly increased, compared with the normoxic group (P<0.05). (4)Western blot results showed ), respectively, for 72 that there was a smal amount of the expression of hypoxia-inducible factor-1αand vascular endothelial growth factor in the normoxic group, but the expression of these two proteins in the hypoxic group was increased in a time-dependent manner (P<0.05). These findings suggest that hypoxia can induce proliferation of rat bone marrow mesenchymal stem cells cultured in vitro, and also raise hypoxia-inducible factor-1αand vascular endothelial growth factor expression in a time-dependent manner.