直流电场对血管内皮细胞排列的影响及肌动蛋白在其中的作用

目的 研究外源性直流电场对血管内皮细胞(VEC)排列行为的作用及细胞骨架肌动蛋白的功能抑制对直流电场作用的影响.方法 取VEC,分为对照组、细胞松弛素B组和Y27632组,后两组分别接受肌动蛋白抑制剂细胞松弛素B和Y27632处理,3组细胞均暴露于场强为200mV/mm的直流电场中,用图像分析系统分别记录暴露于直流电场前及暴露4h和8h的细胞图像.对细胞排列方向性进行定量分析,采用免疫荧光染色及共聚焦显微镜观察细胞骨架肌动蛋白微丝的变化.结果 对照组细胞电场暴露前呈随机极向排列,而暴露于直流电场的细胞则呈一定极向定向排列,即细胞长轴与直流电场矢量方向垂直.细胞松弛素B和Y27632可抑制细胞的肌动蛋白微丝张力纤维形成,但均未减弱细胞在直流电场中的定向排列现象,且经Y27632处理的细胞在直流电场中的定向排列现象出现得更早.电场暴露前对照组细胞的肌动蛋白微丝骨架张力纤维亦呈随机极向排列,而暴露于直流电场中的细胞的肌动蛋白微丝及其张力纤维的排列方向则多与电场矢量方向相垂直.结论 直流电场可诱使VEC定向排列,但其作用不依赖于细胞骨架肌动蛋白微丝的聚合功能及张力纤维的形成.

Effects of direct current electric fields on vascular endothelial cell orientation and the influence of actin

Objective To investigate the effects of direct current electric fields on the orientation responses of vascular endothelial cells and the influence of the cytoskeleton filament actin on the orientation responses of cells in direct current electric fields. Methods Cultured vascular endothelial cells, with or without treatment with the actin inhibitors cytochalasin B or Y27632, were exposed to a direct current electric field of 200 mV/mm, and cell images were taken at 0, 4 and 8 hours during the exposure. Cells not exposed to the electric field were used as a control.Cell orientation was quantified using an image analyzer. Immunofluorescence staining of the cells for F-actin was observed through confocal microscopy. Results Cells in the control cultures oriented randomly with no predominant polarity. Cells exposed to the direct current electric field showed significant re-orientation to align their long axes perpondicular to the field vector. Neither cytochalasin B nor Y27632 reduced the re-orientation induced by the field, and earlier orientation response was observed in Y27632-treated cells. F-actin staining showed that the orientation of F-actin stress fibres was at random in control cells and perpendicular to the field vector in the field-exposed cells without any drug treatment. Although the formation of stress fibres was inhibited in the cytochalasin B-or Y27632-treated cells, the cells in the direct current electric fields kept their re-orientation responses, similar to the cells without any drug treatment. Conclusions A direct current electric field can induce vascular endothelial cells to re-orient, but the re-orientation response is independent of actin polymerization and actin stress fiber formation.