缺氧对成骨细胞VEGF和BMP-2表达的影响

Effects of Hypoxia on Expression of VEGF and BMP-2 on Osteoblast

目的 通过在缺氧条件下大鼠成骨细胞的培养 ,研究体外缺氧环境对成骨细胞血管内皮生长因子(VEGF)和骨形态发生蛋白 - 2 (BMP - 2 )表达的影响 ,为临床骨缺损和骨折治疗等方面提供理论依据。方法从新生SD大鼠颅骨中分离成骨细胞进行培养 ,建立成骨细胞缺氧模型。用免疫组化等方法测量缺氧组和对照组VEGF、BMP - 2的表达。用计算机图像分析系统测量阳性细胞的平均灰度值 ,进行统计学分析。结果 缺氧组VEGF免疫组化染色阳性细胞的平均灰度均低于对照组 ,并随缺氧时间的增加而更加明显 (P <0 0 1) ;BMP - 2阳性细胞的平均灰度在缺氧前 12h低于对照组 ,后逐渐升高 (P <0 0 1) ,即随着缺氧时间的延长VEGF的表达逐渐增加 ,而BMP - 2的表达逐渐减少。结论 体外条件下缺氧可以抑制成骨细胞的增殖 ,成骨细胞表达VEGF增强 ,但抑制BMP - 2的表达。

Objective This study was to investigate the expression of VEGF and BMP-2 after exposure of rat osteoblasts to anoxic stimuli in vitro. It will provide experimental basis for dealing with defect and fracture of bones. Methods The osteoblasts was obtained from the calvaria of the new born Sprague-Dawley rats,and they were cultured by the method of enzyme digestion in vitro. Establish the hypoxia model in osteoblast of the second generation,and separate the cell into two groups: normal group (contral) and anoxic group. Then the expression of growth factor VEGF and BMP-2 were studied by immunohistochemistry straining. Mean gray degree of the positive cell of staining section was measured by computer image processing software. Results The results of immunohistochemistry staining for VEGF, BMP-2 of the two groups were positive. The VEGF content of anoxic group is more than that of normal group. The VEGF average gray degree of the positive cell of stain section of anoxic group was lower than that of normal group. The average gray degree of anoxic group reduced greatly when the anoxic time was prolonged. The BMP-2 average gray degree of positive cell is lower than that of normal group when the cell was cultured for the first 12h, but it will increase as time goes on while the expression of BMP-2 decreased. Conclusions (1)Hypoxia can increase the expression of VEGF in osteoblast.(2)Hypoxia reduced the expression of BMP-2 in osteoblast.