Mechanism of endothelial cell shape change and cytoskeletal remodeling in response to fluid shear stress.
Mechanism of endothelial cell shape change and cytoskeletal remodeling in response to fluid shear stress.
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发表时间：
1996-04
影响因子：
4
通讯作者：
Adel M. Malek;S. Izumo
中科院分区：
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作者：
Adel M. Malek;S. Izumo
内皮细胞在流体剪切应力作用下，通过一种未知的机制发生细胞形态改变、排列和微丝网络重构。本研究探讨酪氨酸激酶（TK）活性、细胞内钙离子（[Ca ~（2+）]i）、机械敏感性通道和细胞骨架在牛主动脉内皮细胞（BAE）形态改变和肌动蛋白应力纤维诱导机制中的作用。我们报告，FSS诱导β-肌动蛋白mRNA的时间和幅度依赖性的方式。用quin 2-AM螯合细胞内钙释放和除草霉素A抑制TK活性的处理废除了BSS引起的BAE形状改变和肌动蛋白应力纤维诱导，而用白屈菜红碱抑制蛋白激酶C则没有效果。改变中间丝结构与丙烯酰胺不影响对齐或F-肌动蛋白诱导的FSS。检查BAE细胞骨架的作用揭示了微管（MT）的关键作用。MT中断与诺考达唑阻断FSS诱导的形态学变化和肌动蛋白应力纤维诱导。与此相反，MT与紫杉醇过度聚合衰减细胞形状的变化，但没有阻止肌动蛋白应力纤维诱导下流动。机械敏感通道被发现不参与FSS诱导的形状变化。用钡阻断剪切激活电流（IK.S）和用钆阻断牵张激活阳离子通道（伊萨）对剪切诱导的形态和细胞骨架变化没有影响。总之，FSS通过依赖于TK活性、细胞内钙离子和完整微管网络的机制对内皮形状和F-肌动蛋白网络产生深远影响，但不依赖于蛋白激酶C、中间丝和剪切和拉伸激活的机械敏感通道。
Endothelium exposed to fluid shear stress (FSS) undergoes cell shape change, alignment and microfilament network remodeling in the direction of flow by an unknown mechanism. In this study we explore the role of tyrosine kinase (TK) activity, intracellular calcium ([Ca2+]i), mechanosensitive channels and cytoskeleton in the mechanism of cell shape change and actin stress fiber induction in bovine aortic endothelium (BAE). We report that FSS induces beta-actin mRNA in a time- and magnitude-dependent fashion. Treatment with quin2-AM to chelate intracellular calcium release and herbimycin A to inhibit TK activity abolished BAE shape change and actin stress fiber induction by FSS, while inhibition of protein kinase C with chelerythrine had no effect. Altering intermediate filament structure with acrylamide did not affect alignment or F-actin induction by FSS. Examining the role of the BAE cytoskeleton revealed a critical role for microtubules (MT). MT disruption with nocodazole blocked both FSS-induced morphological change and actin stress fiber induction. In contrast, MT hyperpolymerization with taxol attenuated the cell shape change but did not prevent actin stress fiber induction under flow. Mechanosensitive channels were found not to be involved in the FSS-induced shape change. Blocking the shear-activated current (IK.S) with barium and the stretch-activated cation channels (ISA) with gadolinium had no effect on the shear-induced changes in morphology and cytoskeleton. In summary, FSS has a profound effect on endothelial shape and F-actin network by a mechanism which depends on TK activity, intracellular calcium, and an intact microtubule network, but is independent of protein kinase C, intermediate filaments and shear- and stretch-activated mechanosensitive channels.