切应力条件下与血管平滑肌细胞联合培养的内皮细胞整合素β_1和F-actin的变化

Effects of Shear Stress on Integrin β_1 and F-actin in Endothelial Cells Co-cultured with Vascular Smooth Muscle Cells

目的 探讨与血管平滑肌细胞联合培养的内皮细胞力学信号转导的机制 ,研究切应力对联合培养的内皮细胞表面整合素 β1和F actin的影响。方法 应用免疫荧光双重标记、激光共聚焦扫描显微镜和计算机图象分析等技术 ,观察了在 2Pa层流切应力的作用下 ,与血管平滑肌细胞联合培养的内皮细胞表面整合素 β1的含量及细胞骨架F actin的变化 ,时相点分别取 1h、6h、12h和 2 4h。同时 ,以静态条件下联合培养的内皮细胞为对照组。结果 静态条件下联合培养的内皮细胞表面整合素 β1含量少 ,F actin含量亦少 ;在 2Pa层流切应力的作用下 ,随着时间延长 ,整合素 β1表达逐渐增多 ,并且有沿F actin分布的趋势 ,在 12h达到峰值 ,后又下降 ;F actin含量持续增加直至 2 4h。结论 结果提示整合素 β1作为重要的粘附分子 ,与细胞骨架F actin的相互协作 。

Objective To investigate the effects of shear stress on integrin β 1 and F-actin in endothelial cells (EC) co-cultured with vascular smooth muscle cells ( VSMC ) . Methods The double-immuno-fluoro-cytochemistry, laser confocal scanning microscopy and image analysis methods were used in the study. One group of EC was treated with shear stress 2Pa for 1h?6h?12h and 24h. The other group was maintained under static conditions as a control. Results It is showed that integrin β 1 distributed scattering in cytomembrane and stained faintly, and F-actin located in cytoplasm without polarity and stained faintly also showed in the control. After pretreating EC with shear stress for different time ,we found that incresing time exposed to shear stress increased the staining of F-actin and integrin β 1. Integrin β 1 enchanced gradually with a maximum at 12h then decreased and tended to realign in the direction of F-actin. F-actin kept on increasing staining until 24h and tended to polymerize into strong stress fiber around the cell periphery and realign in the direction of flow. Conclusion The results suggested that integrin β 1 as an important adhesion molecular interaction with F-actin may play a key role in the mechanotransduction of co-cultured vascular endothelial cells .