Fluid shear stress increases membrane fluidity in endothelial cells: a study with DCVJ fluorescence
Fluid shear stress increases membrane fluidity in endothelial cells: a study with DCVJ fluorescence
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DOI：
10.1152/ajpheart.2000.278.4.h1401
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发表时间：
2000-04-01
影响因子：
4.8
通讯作者：
Frangos, JA
中科院分区：
文献类型：
--
作者：
Haidekker, MA;L'Heureux, N;Frangos, JA
流体应激(FSS)是哺乳动物细胞代谢中普遍存在的一种刺激因子。虽然许多细胞内的信号转导途径已经被描述，但FSS的主要机械感受器仍然不清楚。一种假设是，细胞膜作为FSS的受体，导致膜流动性增加，进而导致异量滴定G蛋白的激活(13)。9-(二氰基)-朱利定(DCVJ)是一种结合到细胞膜上的荧光探针，它的量子产率随环境粘度的变化而变化。在平行板流动室中，DCVJ标记的人内皮细胞的融合层暴露于不同水平的FSS。随着FSS的增加，荧光强度降低，表明膜的流动性增加。FSS阶跃变化使荧光强度在5 S范围内呈近似线性下降，切变停止后恢复快且几乎完全恢复。切应力与膜流动性变化呈线性剂量-反应关系。在26dyn/cm(2)时，整个细胞单层的平均流动性增加了22%。这项研究为FSS与膜流动性之间的联系提供了证据，并提示膜是细胞重要的流动机械传感器。
Fluid sheer stress (FSS) has been shown to be an ubiquitous stimulator of mammalian cell metabolism. Although many of the intracellular signal transduction pathways have been characterized, the primary mechanoreceptor for FSS remains unknown. One hypothesis is that the cytoplasmic membrane acts as the receptor for FSS, leading to increased membrane fluidity, which in turn leads to the activation of heterotrimetric G proteins (13). 9-(Dicyanovinyl)-julolidine (DCVJ) is a fluorescent probe that integrates into the cell membrane and changes its quantum yield with the viscosity of the environment. In a parallel-plate flow chamber, confluent layers of DCVJ-labeled human endothelial cells were exposed to different levels of FSS. With increased FSS, a reduced fluorescence intensity was observed, indicating an increase of membrane fluidity. Step changes of FSS caused an approximately linear drop of fluorescence within 5 s, showing fast and almost full recovery after shear cessation. A linear dose-response relationship between shear stress and membrane fluidity changes was observed. The average fluidity increase over the entire cell monolayer was 22% at 26 dyn/cm(2). This study provides evidence for a link between FSS and membrane fluidity, and suggests that the membrane is an important flow mechanosensor of the cell.