持续性压力促进成骨细胞分泌VEGF的机制

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

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。

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.