流体切应力梯度对血管内皮细胞排列和形状的影响

目的研究不同梯度切应力作用下,血管内皮细胞(endothelial cells,ECs)排列和形状变化,旨在了解流体切应力梯度对ECs形态的影响,为进一步探讨其功能变化提供实验基础。方法建立可对体外培养ECs施加梯度切应力的流动腔装置,并应用该装置对人脐静脉ECs加载了大小在15dyn/cm2～6.6dyn/cm2(1dyn=10-5N)范围、梯度分别为1.5dyn/cm2和3dyn/cm2的切应力,加载时间均为6h。比较这两种不同切应力梯度对ECs的细胞方向角、细胞宽长比和细胞形态指数的影响。结果在不同切应力梯度作用下,ECs的细胞方向角分布散乱,细胞无排列规律。与3dyn/cm2相比,1.5dyn/cm2切应力梯度下ECs的宽长比和细胞形态指数明显减少,趋向于拉伸状态。结论在不同切应力梯度作用下,ECs均排列紊乱,无规律可循。然而,在相对较小的切应力梯度作用下,细胞容易被拉伸,细胞形状趋向于伸长,而较大切应力梯度作用下,细胞形状则趋向于圆形。

Effect of flow shear stress gradient on the arrangement and shape of endothelial cells

Objective The effect of different flow shear stress gradient on the changes of arrangement and shape of endothelial cells was evaluated in order to investigate the effect of shear stress gradient on ECs morphology and function. Method A flow chamber system with gradient shear stress was established, in which the range of shear stress is from 15 dyn/cm2 to 6.6 dyn/cm2(1 dyn=10-5 N), and the shear stress gradient is 1.5 dyn/cm2 and 3 dyn/cm2 respectively. After ECs were subjected to the gradient shear stress for 6 hours, cell angle, cell width length ratio, as well as cell shape index of ECs under the different shear stress gradient were examined. Results The cell angles of ECs were straggling under both 1.5 dyn/cm2 and 3 dyn/cm2 shear stress gradient. The cell width length ratio and cell shape index of ECs were decreased under 1.5 dyn/cm2 shear stress gradient compared with that of 3 dyn/cm2 shear stress gradient. Conclusions The ECs show random orientation under the different shear stress gradient. The ECs are trending to stretch and elongate shape under smaller shear stress gradient, and to approach cycloid under larger shear stress gradient.