The expression of high molecular weight kininogen on human umbilical vein endothelial cells.
The expression of high molecular weight kininogen on human umbilical vein endothelial cells.
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DOI：
10.1016/s0021-9258(18)37596-3
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发表时间：
1988-11
期刊：
影响因子：
--
通讯作者：
Alvin H. Schmaier;A. Kuo;D. Lundberg;S. Murray;D. Cines
中科院分区：
文献类型：
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作者：
Alvin H. Schmaier;A. Kuo;D. Lundberg;S. Murray;D. Cines
高分子量激肽原（HMWK）作为激活血浆丝氨酸酶原的辅因子和组织半胱氨酸蛋白酶的抑制剂发挥作用。HMWK结合的细胞表面可以提供调节这些系统的位点。这些HMWK依赖性过程在血管损伤部位的定位可能取决于其与内皮细胞上特异性受体的结合。在培养中，传代的人脐静脉内皮细胞（HUVEC）将抗HMWK抗体结合至细胞表面，并含有171 +/- 75 ng HMWK/10（8）细胞。[35 S]蛋氨酸标记的HUVEC在培养物中合成一种120 kDa的蛋白质，使用抗激肽原抗体免疫分离，并且通过北方印迹在从HUVEC提取的RNA中检测到人HMWK的3500个核苷酸的信息。HUVEC还在其表面上表达HMWK的未占据结合位点。125 I-HMWK在需要Zn 2+的反应中特异性结合HUVEC。125 I-HMWK与HUVEC的结合在4 ℃下可饱和，但在23 ℃下不饱和。125 I-HMWK与HUVEC的结合亲和力与未标记的HMWK相同。激肽释放酶、因子XII、纤维蛋白原、纤连蛋白和凝血酶不抑制125 I-HMWK与HUVEC的结合。加入50倍摩尔过量的HMWK后，125 I-HMWK-HUVEC结合在60 min时保持完全可逆。HUVEC表达9.3 +/- 2.0 X 10（5）（平均值+/- S.E.）HMWK结合位点/细胞（Kd = 52 +/- 13 nM）。添加的和细胞结合的125 I-HMWK在十二烷基硫酸钠凝胶电泳上以120 kDa迁移，表明蛋白质在与HUVEC表面结合后保持不裂解。这些研究表明HUVEC合成HMWK，并且HUVEC表面存在HMWK的表达位点。通过合成和定位于细胞表面的HMWK，内皮细胞可能有助于激活血浆的接触丝氨酸酶原和调节组织半胱氨酸蛋白酶。
High molecular weight kininogen (HMWK) functions as a cofactor for activation of plasma serine zymogens and as an inhibitor of tissue cysteine proteases. Cell surfaces to which HMWK binds may provide sites for regulation of these systems. Localization of these HMWK-dependent processes at sites of vascular injury may depend on its binding to specific receptors on endothelial cells. In culture, passaged human umbilical vein endothelial cells (HUVEC) bind anti-HMWK antibody to the cell surface and contain 171 +/- 75 ng of HMWK/10(8) cells. [35S]Methionine-labeled HUVEC in culture synthesize a 120-kDa protein immunoisolated using an anti-kininogen antibody, and a 3500-nucleotide message for human HMWK was detected by Northern blot in RNA extracted from HUVEC. HUVEC also express unoccupied binding sites for HMWK on their surface. 125I-HMWK specifically binds to HUVEC in a reaction requiring Zn2+. 125I-HMWK binding to HUVEC is saturable at 4 degrees C but not at 23 degrees C. 125I-HMWK binds to HUVEC with equal affinity as unlabeled HMWK. Kallikrein, factor XII, fibrinogen, fibronectin, and thrombin do not inhibit 125I-HMWK binding to HUVEC. 125I-HMWK-HUVEC binding remains fully reversible at 60 min following the addition of a 50-fold molar excess HMWK. HUVEC express 9.3 +/- 2.0 X 10(5) (mean +/- S.E.) HMWK binding sites/cell (Kd = 52 +/- 13 nM). Both added and cell-bound 125I-HMWK migrate at 120 kDa on sodium dodecyl sulfate gel electrophoresis, suggesting that the protein remains uncleaved upon binding to the HUVEC surface. These studies indicate that HUVEC synthesize HMWK and the HUVEC surface has a site for its expression. By synthesizing and localizing HMWK to the cell surface, endothelial cells may contribute to the activation of plasma's contact serine zymogens and regulation of tissue cysteine proteases.