平行平板流室内不同血流状态下内皮细胞紧密连接的变化(英文)

Changes of tight junction of cultured endothelial cells under different flow condition in parallel plate flow chamber

目的研究不同血流状态下培养内皮细胞紧密连接的变化。方法设计一种新的平行平板流室模型,高速摄像微粒子示踪技术流体分析,培养内皮细胞进行7H6免疫荧光染色,F-肌动蛋白荧光染色和ZO-1双重免疫荧光染色,激光共聚焦显微镜观察。结果液体在入口与狭窄开始处中点的流速为249.8mm/sec,剪切应力为71.9dyn/cm2;进入狭窄段时的流速为316mm/sec,剪切应力为88.5dyn/cm2,上述区域液体为定常流。F-肌动蛋白纤维表达明显增加,呈束状,与液流方向一致,细胞变为细长。ZO-1和7H6则位于细胞周围呈现连续、线状环形分布。液体进入宽广区域后液体流速明显减慢并在两侧形成涡流甚至停滞,流速为54.4～119.6mm/sec,剪切应力为15.6～34.4dyn/cm2,F-肌动蛋白纤维分布和排列无方向性,细胞轮廓成不规则多边形,ZO-1和7H6在细胞周围呈点状分布。结论低剪切应力更易导致动脉硬化。

[Objective] To study the changes of tight junction of cultured endothelial cells under the different flow conditions. [Methods] A novel parallel plate flow chamber was designed, the flow analysis with microsphere tracing technique with high-speed vediocamera was done. Immunofluorescent staining of the cultured endothelial cells for 7H6 and the double immunofluoreseent staining for F-actin and ZO-1 were performed and observed with laser confocal microscope. [Results] The velocity and shear stress of the flow at the mid-point between the entrance and beginning of stenosis were 249.8 mm/sec and 71.9 dyn/cm^2, respectively. The ones at the stenosis were 316 mm/ see and 88.5 dyn/cm^2, respectively. The flow at above regions was steady laminar flow. The expression of F-actin was obvious, which was bundle-like in the same direction with flow, the cells became long. ZO-1 and 7H6 were lo- cated around the periphery of the cells, distributed with circular line. The velocity of the flow became significantly slow and formed a vortex and stagnation when it entered a broad area. The velocity and shear stress were 54.4-119.6 ram/see, 15.6-34.4 dyn/cm^2 respectively. The distribution and arrangement of F-actin fibers had no direction, the outlines of endothelial cells showed irregularly polygonal, ZO-1 and 7H6 were distributed with dots in the cell peripheries. [ Conclusion] Low shear stress induces readily atherosclerosis