A model for shear stress-induced deformation of a flow sensor on the surface of vascular endothelial cells
A model for shear stress-induced deformation of a flow sensor on the surface of vascular endothelial cells
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DOI：
10.1006/jtbi.2001.2290
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发表时间：
2001-05-21
影响因子：
2
通讯作者：
Barakat, AI
中科院分区：
文献类型：
--
作者：
Barakat, AI
流体机械剪切应力eleventually体液，代谢和结构的反应，在血管内皮细胞（EC），然而，涉及剪切应力的传感和转导的机制仍然不完全清楚。除了响应剪切应力之外，EC区分不同类型的剪切应力并且对不同类型的剪切应力有不同的响应。最近的观察表明，内皮剪切应力传感可能会发生通过直接的相互作用的流动与细胞表面结构，作为主要行传感器。本文提出了一个数学模型的剪切应力引起的变形的行传感器上的EC表面。该传感器被建模为一个cytochronion耦合粘弹性结构，表现出标准的线性固体行为。由于EC对不同类型的流动的响应不同，因此已经研究了响应于稳定的、非反向脉动的和振荡的行的传感器的变形和所产生的速度。此外，各种模型参数，包括所施加的剪切应力的大小，表征粘弹性行为的常数，和脉动流频率（f）的变化的结果的灵敏度进行了研究。结果表明，在响应于突然施加的剪切应力，传感器表现出一定程度的瞬时变形，然后逐渐蠕变的长期响应。峰值变形随所施加的剪切应力的大小线性增加，并且对于对应于更硬的传感器的粘弹性常数减小。虽然对于低f值，传感器变形取决于f，但在临界阈值频率以上，变形变得与f无关。最后，峰值传感器变形是相当大的稳定和非反向脉动流比振荡行。如果传感器变形的程度与流量介导的内皮细胞信号的强度相关，那么我们的研究结果表明可能的机制，EC之间的稳定，非可逆脉动，振荡剪切应力区分。(C)北京：科学出版社.
Fluid mechanical shear stress elicits humoral, metabolic, and structural responses in vascular endothelial cells (ECs); however, the mechanisms involved in shear stress sensing and transduction remain incompletely understood. Beyond being responsive to shear stress, ECs distinguish among and respond differently to different types of shear stress. Recent observations suggest that endothelial shear stress sensing may occur through direct;interaction of the flow with cell-surface structures that act as primary Row sensors. This paper presents a mathematical model for the shear stress-induced deformation of a Row sensor on the EC surface. The sensor is modeled as a cytoskeleton-coupled viscoelastic structure exhibiting standard linear solid behavior. Since ECs respond differently to different types of flow, the deformation and resulting velocity of the sensor in response to steady, non-reversing pulsatile, and oscillatory Row have been studied. Furthermore, the sensitivity of the results to changes in various model parameters including the magnitude of applied shear stress, the constants that characterize the viscoelastic behavior, and the pulsatile flow frequency (f) has been investigated. The results have demonstrated that in response to a suddenly applied shear stress, the sensor exhibits a level of instantaneous deformation followed by gradual creeping to the long-term response. The peak deformation increases linearly with the magnitude of the applied shear stress and decreases for viscoelastic constants that correspond to stiffer sensors. While the sensor deformation depends on f for low f values, the deformation becomes f-independent above a critical threshold frequency. Finally, the peak sensor deformation is considerably larger for steady and non-reversing pulsatile flow than for oscillatory Row. If the extent of sensor deformation correlates with the intensity of flow-mediated endothelial signaling, then our results suggest possible mechanisms by which ECs distinguish among steady, nonreversing pulsatile, and oscillatory shear stress. (C) 2001 Academic Press.