Changes of vasodilator-stimulated phosphoprotein (VASP) and its phosphorylation in endothelial cells exposed to laminar flow.
Changes of vasodilator-stimulated phosphoprotein (VASP) and its phosphorylation in endothelial cells exposed to laminar flow.
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发表时间：
2003
影响因子：
2.1
通讯作者：
Lei Wei;S. Muller;J. Ouyang;J. Stoltz;Xiong Wang
中科院分区：
文献类型：
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作者：
Lei Wei;S. Muller;J. Ouyang;J. Stoltz;Xiong Wang
血管舒张刺激磷蛋白 (VASP) 是一种肌动蛋白丝相关蛋白，主要在内皮细胞 (EC) 的粘着斑和动态膜区域表达，可作为 cAMP 和 cGMP 依赖性蛋白激酶的底物。在这项工作中，我们研究了体外层流剪切应力对 VASP 的位置和表达及其与人脐带内皮细胞 (HUVEC) 肌动蛋白重组相关的磷酸化的影响。通过荧光双染观察VASP和微丝的分布。通过蛋白质印迹定量细胞中 VASP 表达水平。实验表明，在10 dyn/cm(2)的剪切应力作用下24 h后，除了细胞的伸长和定向外，在粗大的应力纤维上还发现了VASP斑点，特别是在其两端。 Western blot 数据显示，在相同的剪切应力下分别暴露 1 小时和 4 小时后，46 kD 非磷酸化形式 VASP 转化为 50 kD 磷酸化形式的比例分别高达 11.4% 和 8.9%。 15 dyn/cm(2) 的剪切应力与 10 dyn/cm(2) 的剪切应力在质量上具有相同的效果，但幅度较低。然而，2 dyn/cm(2) 的剪切应力对相同趋势的影响要慢得多且弱得多。这些结果表明，层流剪切应力可以诱导 VASP 易位和磷酸化，从而沿着 HUVEC 中的流动方向进行肌动蛋白丝重排。
Vasodilator-stimulated phosphoprotein (VASP), an actin filaments-associated protein expressed mainly in focal adhesions and dynamic membrane regions of endothelial cells (ECs), serves as a substrate for cAMP and cGMP-dependent protein kinases. In this work, we studied the effect of laminar shear stress in vitro on the location and expression of the VASP as well as its phosphorylation associated with actin reorganisation in human umbilical endothelial cells (HUVECs). The distributions of VASP and microfilaments were observed by a fluorescent double staining. The level of VASP expression in cells was quantified by western blot. Experiments showed that, after exposure to a shear stress of 10 dyn/cm(2) for 24 h, besides the elongation and orientation of the cells, and spots of VASP were found along thick stress fibres, particularly at their two extremities. Western blot data showed conversions up to 11.4% and 8.9% of the 46 kD non-phosphorylated form VASP to its 50 kD phosphorylated form after exposures of 1 h and 4 h respectively to the same shear stress. The shear stress of 15 dyn/cm(2) had qualitatively the same effect as that of 10 dyn/cm(2), but with a lower magnitude. However, the shear stress of 2 dyn/cm(2) had much slower and weaker effects on the same tendency. These results suggest that a laminar shear stress can induce VASP translocation and phosphorylation that proceed actin filaments rearrangement along with the flow direction in HUVECs.