Nijenhuis Nadja, Mizuno Daisuke, Schmidt Christoph F, Vink Hans, Spaan Jos A E
Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Biomacromolecules. 2008 Sep;9(9):2390-8. doi: 10.1021/bm800381z. Epub 2008 Aug 14.
The endothelial glycocalyx (EG) is a complex biopolymer network produced by vascular endothelial cells that forms a layer with multiple functions at the luminal side of blood vessels. The EG acts as an anti-adhesive protection layer, as a molecular sieve, as a chemical sensor site, and as a mechanotransducer of fluid shear stress to the underlying cell layer. A major component involved in these processes is the highly hydrated glycosaminoglycan (GAG) hyaluronan (HA). Here we used laser interferometry to measure the broadband mechanical response of reconstituted HA solutions at close to physiological conditions. HA showed rheological behavior consistent with that of a flexible polymer. The elastic behavior observed for entangled HA networks showed reptational relaxation with a large distribution of time scales, which disappeared quickly (15 min) with the addition of hyaluronidase (HAase). We conclude that the broadband mechanical probing of model systems (HA solutions) provides quantitative data that are crucial to understand the mechanical response of the EG in vivo and its role in mechanosensing.
内皮糖萼(EG)是一种由血管内皮细胞产生的复杂生物聚合物网络,在血管腔侧形成具有多种功能的一层结构。EG作为抗黏附保护层、分子筛、化学传感位点以及将流体剪切应力传递至下层细胞层的机械转导器。参与这些过程的一个主要成分是高度水合的糖胺聚糖(GAG)透明质酸(HA)。在此,我们使用激光干涉测量法在接近生理条件下测量了重组HA溶液的宽带力学响应。HA表现出与柔性聚合物一致的流变行为。对于缠结的HA网络观察到的弹性行为显示出具有大时间尺度分布的链段松弛,加入透明质酸酶(HAase)后这种松弛迅速消失(15分钟)。我们得出结论,对模型系统(HA溶液)的宽带力学探测提供了定量数据,这些数据对于理解体内EG的力学响应及其在机械传感中的作用至关重要。