Coagulation factor Va binds to human umbilical vein endothelial cells and accelerates protein C activation.
Coagulation factor Va binds to human umbilical vein endothelial cells and accelerates protein C activation.
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凝血因子Va与人脐静脉内皮细胞结合并加速蛋白C激活。
DOI：
10.1172/jci111405
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Majerus,PW
中科院分区：
文献类型：
--
作者：
Maruyama,I;Salem,HH;Majerus,PW
在体外，凝血酶激活蛋白C的速度被两个不同的辅助因子显著加速：(A)内皮细胞表面蛋白，血栓调节蛋白，和(B)人凝血因子Va。我们最近报道，因子Va的活性包含在78,000-D轻链中。在这项研究中，我们研究了因子Va及其轻链在培养内皮细胞存在的情况下对蛋白C激活的影响。凝血酶催化的蛋白C在人脐静脉内皮细胞上的激活被凝血因子Va增强。因子Va刺激这些细胞上蛋白C激活的能力在50 nM的因子Va时达到饱和，并在几种蛋白C浓度下观察到。分离的凝血因子Va轻链在浓度高达50 nM时也促进内皮细胞蛋白C的激活，但较高的浓度抑制了这一反应。因子Va或其轻链对蛋白C激活的影响也显示在小鼠血管瘤细胞系上，但不在人成纤维细胞或人无色素性黑色素瘤细胞系上。山羊抗血栓调节蛋白抗体可部分抑制蛋白C对内皮细胞的激活，进一步加入兔抗因子V(Va)多克隆抗体可产生额外的抑制作用。在没有凝血因子V活性的添加人血清的培养液中生长的内皮细胞含有细胞表面因子V(Va)(约15,000个分子/细胞)，通过与针对因子V(Va)的单抗免疫球蛋白结合来测量。通过使用125I-因子Va的直接结合研究，这些细胞还额外结合了每个细胞6,000-10,000个分子因子Va。我们认为血栓调节蛋白和凝血因子Va协同作用调节内皮细胞表面蛋白C的激活。
In vitro the rate of protein C activation by thrombin is significantly accelerated by two distinct cofactors (a) the endothelial cell surface protein, thrombomodulin, and (b) human coagulation Factor Va. We have recently reported that the activity of Factor Va is contained in the 78,000-D light chain. In this study we have investigated the effects of Factor Va and its light chain on the activation of protein C in the presence of cultured endothelial cells. Thrombin-catalyzed protein C activation on human umbilical vein endothelial cells was enhanced by Factor Va. The ability of Factor Va to stimulate protein C activation on these cells was saturated at 50 nM Factor Va and was observed at several protein C concentrations. Isolated Factor Va light chain in concentrations up to 50 nM also accelerated protein C activation on endothelial cells, but higher concentrations inhibited the reaction. The effects of Factor Va or its light chain on protein C activation were also shown on a mouse hemangioma cell line but not on human fibroblasts nor on a human amelanotic melanoma cell line. Protein C activation on endothelial cells was partially inhibited by a goat anti-thrombomodulin antibody and further addition of a polyclonal rabbit anti-Factor V(Va) antibody resulted in additional inhibition. Endothelial cells grown in medium supplemented with human serum, devoid of Factor V coagulant activity, contained cell surface Factor V(Va) (approximately 15,000 molecules/cell) as measured by the binding of a monoclonal IgG directed against Factor V(Va). These cells also bound an additional 6,000-10,000 molecules Factor Va per cell as determined by direct binding studies using 125I-Factor Va. We suggest that thrombomodulin and Factor Va act in concert to regulate protein C activation on the surface of endothelial cells.Images