持续性压力促进成骨细胞分泌VEGF的机制

目的:探讨持续性压力促进成骨细胞分泌血管内皮生长因子(VEGF)的机制?方法:取1~2日龄SD大鼠颅盖骨进行成骨细胞原代培养,检测并鉴定成骨细胞?细胞培养至第3代,分为加压组和不加压组,每组再分成PD98059不预处理组和预处理组?加压组在密闭容器内采用压缩空气施以100 kPa的静压力,分别加压0.5?2.0?6.0 h,ELISA法检测培养液中VEGF浓度,RT-PCR检测VEGF mRNA的变化;Western blot 检测各组成骨细胞内磷酸化ERK1/2(pERK1/2)的水平?结果:持续性压力促进成骨细胞VEGF mRNA的表达和蛋白的分泌,同时也明显增加ERK1/2的磷酸化水平;而ERK1/2总蛋白的量却无明显变化?PD98059在显著抑制持续性加压所诱导的成骨细内ERK1/2磷酸化水平的同时,抑制了VEGF的表达及分泌?结论:持续性压力通过ERK1/2的激活调节成骨细胞VEGF的分泌?

The mechanism of vascular endothelial growth factor expression in osteoblasts induced by durative pressure

Objective:To investigate the mechanism of vascular endothelial growth factor(VEGF) expression in osteoblasts induced by durative pressure. Methods:Osteoblasts were isolated from the calvarias of neonatal(12 days old) Sprague-Dawley rats, cultured and identified according to published protocols. The cells were pretreated with or without PD98059 and cultured for 0.5, 2.0, 6.0 h under 100 kpa of pressure in sealed containers. The VEGF concentrations secreted into DMEM were detected by ELLSA. The mRNA levels of VEGF were evaluated by RT-PCR. The total ERK1/2 and the phosphorylation of ERK1/2 in osteoblasts were detected by Western blot. Results:The durative pressure increased the expression and secretion of VEGF, and meanwhile the phosphorylation of ERK1/2 in osteoblasts increased significantly. Pretreated the osteoblasts with PD98059 inhibited the phosphoryation of ERK1/2 and reduced the the expression and secretion of VEGF significantly. Conclusion:Durative pressure induces the expression of VEGF in osteoblasts by the activation of ERK1/2.