【摘要】 利用内皮细胞流动小室方法对大鼠脑微血管内皮细胞在剪切力作用下细胞核内原癌基因c -fos蛋白的翻译水平的表达进行了初步研究 ,结果提示脑微血管内皮细胞在剪切力作用下 ,c -fos蛋白有明显的表达且显示了剪切力水平的非依赖性和作用时间的依赖性。流动剪切力诱导的c -fos的适度表达可以导致内皮细胞伸展、细胞骨架蛋白合成、细胞骨架重排等 ,以适应流动剪切力的作用。但过度的剪切力作用可以引起内皮细胞皱缩、损伤、脱落 ,这时的c-fos会有过度的表达。如何控制c -fos蛋白的表达量 ,可能是阻断内皮细胞损伤的可能途径之一。该工作为进一步开展剪切力对微血管内皮细胞信号转导机制的影响提供了实验数据。更多还原

【Abstract】 To study the effects of fluid shear stress on microvascular endothelial cell monolayers, we designed a flow chamber to investigate the c-fos protein changes after a period of shear stress applied. A coverslip carrying confluent rat brain microvascular endothelial cell monolayers was inserted into the device and the chamber gave parallel plate flow. The experiment proceeded with various perfusion rates. The perfusion medium was M199 with 20% calf serum and the viscosity was 0.75 mPa.s at 37℃. The shear stress effected on the monolayers were 0.14 and 0.28×10-5N/cm2 by a roller pump for a perfusion period of 1.5h, 2h and 3h. The whole device was brought to 37℃ with an air curtain incubator. After a period of perfusion, the coverslip was taken out and the c-fos protein was labeled by means of immunohistochemistry methods. After 0.14 and 0.28×10-5N/cm2 with 1.5h, 2h and 3h, MVEC were stained with c-fos immunohistochemistry kit. The cover slip was then processed by means of computer image analysis system to measure the density of MVEC monolayers. The c-fos protein was not observed in normal MVEC nucleus but was observed significantly in MVEC nucleus after shear stress applied. Those results suggested that fluid shear stress does lead to a cascade of downstream signaling events. The expression of c-fos protein showed the activation of ras-MEK-ERK1/2 pathway mediated by tyrosine kinase.更多还原