骨形态发生蛋白2与血管内皮生长因子在软骨内成骨过程中的基因表达

目的 检测并分析骨形态发生蛋白2(BMP-2)及血管内皮生长因子(VEGF)在骨发育基因表达谱及诱导成骨过程中表达规律及相互作用,为工程化BMP-2蛋白在骨科临床治疗中的运用提供依据.方法 应用基因芯片技术建立妊娠胎鼠肢芽发育成骨过程的基因表达谱,分析BMP-2与VEGF在发育成骨过程中的表达规律;检测VEGF mRNA在小鼠外源性工程化BMP-2蛋白体内诱导软骨内成骨过程中表达情况,结合组织学、免疫组织化学观察结果与基因表达谱分析结果,分析BMP-2与VEGF在软骨内成骨过程中的相互作用.结果 BMP-2及VEGF在发育成骨过程的基因表达谱中以及VEGF表达信号在外源性BMP-2诱导的体内软骨内成骨过程中,均呈现以诱导间质细胞向软骨细胞分化-肥大-吸收直至骨形成这一过程为轴线的时间-浓度表达关系.结论 BMP-2及VEGF在骨发育及诱导成骨过程中均存在协同促进作用,工程化BMP-2蛋白将在骨科临床治疗中得到更广泛的运用.

Assessment of the expression profile during the entochondrostosis of vascular endothelial growth factor in bone morphogenetic protein 2 induced osteogenesis

OBJECTIVES: To examine the gene expression profile of bone morphogenetic protein 2 (BMP-2) and vascular endothelial growth factor (VEGF) during entochondrostosis of mice and explore the expression rules and effects between BMP-2 and VEGF, and to detect the expression of VEGF in BMP-2 induced entochondrostosis in vivo. METHODS: cDNA microarray technique with 34,000 genes was used to analyze the gene expression profiles during entochondrostosis in the limbs of mice embryo from E10 to E14. Pathway analysis of BMP-2 and VEGF was performed with GCOS1.2 software. An experimental model of femoral muscular pouch in 20 mice was adopted. The expression of VEGF was examined by in situ hybridization method and immunohistochemical method in BMP-2 induced entochondrostosis in vivo. RESULTS: The expression signals of VEGF mRNA and VEGF appeared in cytoplasm during condensation of mesenchymal cell. As the mesenchymal cells differentiated into precartilage, the expression signals decreased in mesenchymal cells, but increased in chondrocytes and kept getting denser in the process of cartilage maturity. The peak expression of VEGF mRNA and VEGF in the experimental group appeared on the 14th day, accompanied by numerous hypertrophic chondrocytes. When mature cartilage calcified and new bone trabecula formed, the expression of VEGF mRNA and VEGF decreased in chondrocytes, but still expressed moderately in the osteoblasts and osteocytes. CONCLUSIONS: The finding reveals a complex pattern of gene coexpression of BMP-2 and VEGF during the critical period of entochondrostosis. It's feasible for the clinical application of BMP-2 in orthopedics.