Vascular endothelial growth factor transfection induces human bone marrow mesenchymal stem cells differentiating into endothelial-like cells under hypoxia / 中国组织工程研究

BACKGROUND: It has been found that vascular endothelial growth factor can induce the differentiation of bone marrow mesenchymal stem cells into endothelial cells, but can the vascular endothelial growth factor gene promote the differentiation of bone marrow mesenchymal stem cells into vascular endothelial cells in the damaged organ under the hypoxic environment? OBJECTIVE: To observe whether human bone marrow mesenchymal stem cells induced by vascular endothelial growth factor could differentiate into vascular endothelial cells under hypoxia. METHODS: The third passage of human bone marrow mesenchymal stem cells were cultured in vitro. Cells in the control group were cultured with conventional culture medium, while those in experimental group were cultured with adenovirus vector containing vascular endothelial growth factor in 5% O2. After 2 weeks of culture, morphological observation and surface-related molecular detection were performed. The levels of vascular endothelial growth factor and endothelial nitric oxide synthase were detected by ELISA. The expression of endothelin and prostacyclin was detected by RT-PCR and western blot assay. RESULTS AND CONCLUSION: (1) The number of cells in the control group was more than that in the experimental group. The cells in the control group were crowded and arranged irregularly, showing a fiber-like growth, while those in the experimental group were mostly triangular or polygonal, exhibiting a colony-like growth. (2) CD31 was negative in the control group, while CD105 was positive and the positive rate was 99.7%, indicating that the cells still showed the phenotype of bone marrow mesenchymal stem cells. The positive rate ofCD31 was significantly increased to 30.33% in the experimental group and the positive rate of CD105 expression was decreased to 58.11%, indicating a typical phenotype of endothelial cells. (3) Compared with the control group, the expression of endothelin, vascular endothelial growth factor and endothelial nitric oxide synthase increased significantly in the experimental group (P < 0.05), and the expression of prostacyclin decreased significantly (P < 0.05). All these findings indicate that vascular endothelial growth factor can promote the differentiation of human bone marrow mesenchymal stem cells into vascular endothelial cells under hypoxia.

Kallikrein 1-transfected bone marrow mesenchymal stem cells：selection of the multiplicity of infection / 中国组织工程研究

BACKGROUND:Kalikrein 1 is an important component of the kalikrein-kinin system. Studies have shown that kalikrein can protect the cardiovascular system by promoting angiogenesis and inhibiting myocardial inflammation, but there is no report on its effect on inducing differentiation of stem cels. OBJECTIVE: To determine the transfection efficiency of kalikrein 1 adenoviral vector in rat bone mesenchymal stem cels. METHODS:Using adenovirus as a vector, the target gene kalikrein 1 was transfected into rat bone marrow mesenchymal stem cels. Fluorescence microscopy, MTT method and flow cytometry were used to investigate the effect of transfection and determine the optimal multiplicity of infection. RESULTS AND CONCLUSION:Adenovirus carrying kalikrein 1 was successfuly transfected into rat bone marrow mesenchymal stem cels. Results from flow cytometry showed that the transfection efficiency was associated with the multiplicity of infection. When the multiplicity of infection was 150, the transfection efficiency was 80.8%. MTT results showed that when the multiplicity of infection was 200, the cel growth was inhibited remarkably. These findings indicate that adenovirus-mediated kalikrein 1 can be successfuly transfected into rat bone marrow mesenchymal stem cels with the optimal multiplicity of infection=150.