Perrault Cecile M, Brugues Agusti, Bazellieres Elsa, Ricco Pierre, Lacroix Damien, Trepat Xavier
Institute for In Silico Medicine, University of Sheffield, Sheffield, United Kingdom; Department of Mechanical Engineering, University of Sheffield, Sheffield, United Kingdom; Institute for Bioengineering of Catalonia, Barcelona, Spain.
Institute for Bioengineering of Catalonia, Barcelona, Spain.
Biophys J. 2015 Oct 20;109(8):1533-6. doi: 10.1016/j.bpj.2015.08.036.
Endothelial cells are constantly exposed to fluid shear stresses that regulate vascular morphogenesis, homeostasis, and disease. The mechanical responses of endothelial cells to relatively high shear flow such as that characteristic of arterial circulation has been extensively studied. Much less is known about the responses of endothelial cells to slow shear flow such as that characteristic of venous circulation, early angiogenesis, atherosclerosis, intracranial aneurysm, or interstitial flow. Here we used a novel, to our knowledge, microfluidic technique to measure traction forces exerted by confluent vascular endothelial cell monolayers under slow shear flow. We found that cells respond to flow with rapid and pronounced increases in traction forces and cell-cell stresses. These responses are reversible in time and do not involve reorientation of the cell body. Traction maps reveal that local cell responses to slow shear flow are highly heterogeneous in magnitude and sign. Our findings unveil a low-flow regime in which endothelial cell mechanics is acutely responsive to shear stress.
内皮细胞不断受到调节血管形态发生、内环境稳定和疾病的流体剪切应力影响。内皮细胞对相对较高剪切流（如动脉循环特征的剪切流）的机械反应已得到广泛研究。而对于内皮细胞对缓慢剪切流（如静脉循环、早期血管生成、动脉粥样硬化、颅内动脉瘤或间质流特征的剪切流）的反应，人们了解得要少得多。在此，据我们所知，我们使用了一种新型微流控技术来测量汇合的血管内皮细胞单层在缓慢剪切流下施加的牵引力。我们发现，细胞对流动的反应是牵引力和细胞间应力迅速且显著增加。这些反应在时间上是可逆的，并且不涉及细胞体的重新定向。牵引力图显示，局部细胞对缓慢剪切流的反应在大小和方向上具有高度异质性。我们的研究结果揭示了一种低流状态，其中内皮细胞力学对剪切应力具有敏锐的反应。
