Fluid shear stress stimulates incorporation of hyaluronan into endothelial cell glycocalyx
Fluid shear stress stimulates incorporation of hyaluronan into endothelial cell glycocalyx
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DOI：
10.1152/ajpheart.00592.2005
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发表时间：
2006-01-01
影响因子：
4.8
通讯作者：
Vink, H
中科院分区：
文献类型：
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作者：
Gouverneur, M;Spaan, JAE;Vink, H
血管内皮细胞通过内皮糖萼（一种糖蛋白、硫酸化蛋白聚糖和相关糖胺聚糖（GAG）的高度水合网状结构）而免受直接暴露于流动血液的影响。最近的数据表明，将未硫酸化的GAG透明质酸掺入内皮糖萼中对于维持其渗透性屏障性质是必不可少的，并且我们假设流体剪切应力是内皮透明质酸合成的重要刺激。为了评估剪切应力对糖萼合成及其GAG脱落到上清液中的影响，培养人脐静脉内皮细胞（即，用10 dyn/cm（2）的非脉动剪切力作用24 h，测定[~ 3 H]氨基葡萄糖和Na-2[S-35]O-4掺入糖胺聚糖的量。此外，通过ELISA测定糖萼和上清液中透明质酸的量。剪切应力不影响35 S的掺入，但显著增加了掺入内皮糖萼中的含葡糖胺的GAG的量[静态水平的168（SD 17）%，P < 0.01]，并脱落到上清液中[静态水平的231（SD 41）%，P > 0.01]。与这一发现相对应的是，剪切应力增加了糖萼中透明质酸的量[从26（SD 24）x 10 x 4到46（SD 29）x 10（-4）ng/细胞，静态与剪切应力，P < 0.05]和上清液中透明质酸的量[从28（SD 11）x 10（-4）到55（SD 16）x 10（-4）ng（.）单元格x 1（.）h（-1），静态与剪切应力，P < 0.05]。掺入糖萼中的透明质酸的量的增加通过剪切应力刺激的内皮细胞的糖萼内的透明质酸结合蛋白的三倍高水平来证实。总之，流体剪切应力刺激透明质酸在糖萼中的掺入，这可能有助于其对促炎性和促动脉粥样硬化刺激的血管保护作用。
Vascular endothelial cells are shielded from direct exposure to flowing blood by the endothelial glycocalyx, a highly hydrated mesh of glycoproteins, sulfated proteoglycans, and associated glycosaminoglycans (GAGs). Recent data indicate that the incorporation of the unsulfated GAG hyaluronan into the endothelial glycocalyx is essential to maintain its permeability barrier properties, and we hypothesized that fluid shear stress is an important stimulus for endothelial hyaluronan synthesis. To evaluate the effect of shear stress on glycocalyx synthesis and the shedding of its GAGs into the supernatant, cultured human umbilical vein endothelial cells (i.e., the stable cell line EC-RF24) were exposed to 10 dyn/cm(2) nonpulsatile shear stress for 24 h, and the incorporation of [3H] glucosamine and Na-2[S-35]O-4 into GAGs was determined. Furthermore, the amount of hyaluronan in the glycocalyx and in the supernatant was determined by ELISA. Shear stress did not affect the incorporation of 35S but significantly increased the amount of glucosamine-containing GAGs incorporated in the endothelial glycocalyx [168 (SD 17)% of static levels, P < 0.01] and shedded into the supernatant [ 231 ( SD 41)% of static levels, P > 0.01]. Correspondingly with this finding, shear stress increased the amount of hyaluronan in the glycocalyx [ from 26 ( SD 24) x 10 x 4 to 46 ( SD 29) x 10(-4) ng/cell, static vs. shear stress, P < 0.05] and in the supernatant [ from 28 ( SD 11) x 10(-4) to 55 ( SD 16) x 10(-4) ng(.)cell x 1 (.)h(-1), static vs. shear stress, P < 0.05]. The increase in the amount of hyaluronan incorporated in the glycocalyx was confirmed by a threefold higher level of hyaluronan binding protein within the glycocalyx of shear stress-stimulated endothelial cells. In conclusion, fluid shear stress stimulates incorporation of hyaluronan in the glycocalyx, which may contribute to its vasculoprotective effects against proinflammatory and pro-atherosclerotic stimuli.