Complement component C1q induces endothelial cell adhesion and spreading through a docking/signaling partnership of C1q receptors and integrins
Complement component C1q induces endothelial cell adhesion and spreading through a docking/signaling partnership of C1q receptors and integrins
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DOI：
10.1016/s1567-5769(02)00270-9
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发表时间：
2003-03-01
影响因子：
5.6
通讯作者：
Peerschke, EIB
中科院分区：
文献类型：
--
作者：
Ghebrehiwet, B;Feng, XD;Peerschke, EIB
Clq与内皮细胞的相互作用引起多种生物学反应。尽管这些特异性反应被认为是由Clq与内皮细胞表面蛋白质的相互作用介导的，但参与者的分子身份尚未明确定义。在这项研究中，我们研究了两个Clq结合蛋白，cClq-R/CR和gClq-R/p33，Clq介导的粘附和人类皮肤微血管内皮细胞（HDMVEC）的蔓延的作用。当HDMVEC在用浓度范围为0至50 μ g/ml的Clq包被的微量滴定板威尔斯孔中培养时，观察到特异性和剂量依赖性的粘附和扩散。粘连和扩散的程度与胶原包被的威尔斯孔上观察到的粘连相似。此外，Clq的作用被多克隆抗cClq-R或mAb 60.11模拟，但不被同种型和物种匹配的对照IgG模拟。然而，更重要的是，当在30 mM肽GRRGDSP而不是GRRGESP存在下培养HDMVEC时，观察到对Clq包被的威尔斯孔的扩散而非粘附的100%抑制。此外，虽然抗β 1整联蛋白抗体阻断粘附和扩散，但抗α 5整联蛋白仅阻断扩散。由于早期的研究已经表明锌诱导gClq-R的C-末端中的疏水位点的暴露，包括对应于残基204- 218的推定的高分子量激肽原（HK）结合位点，我们还检查了锌对抗体与细胞表面gClq-R结合的影响。流式细胞术数据显示，当内皮细胞在50 μ M锌存在下孵育时，识别残基204-218的mAb 74.5.2的结合大大增强。总之，我们的数据显示：（a）Clq介导的内皮细胞粘附和扩散需要Clq受体和1整联蛋白以及可能的其他跨膜分子的合作，并且（B）锌可以诱导gClq-R的C-末端结构域中的疏水位点的暴露，从而允许mAb 74.5.2和HK的更有效结合。(C)2002 Elsevier Science B. V.保留所有权利。
The interaction of Clq with endothelial cells elicits a multiplicity of biologic responses. Although these specific responses are thought to be mediated by the interaction of Clq with proteins of the endothelial cell surface, the molecular identity of the participant(s) has not been clearly defined. In this study, we examined the role of two Clq-binding proteins, cClq-R/CR and gClq-R/p33, on Clq-mediated adhesion and spreading of human dermal microvascular endothelial cells (HDMVECs). A specific and dose-dependent adhesion and spreading was observed when HDMVECs were cultured in microtiter plate wells coated with concentrations of Clq ranging from 0 to 50 mug/ml. The extent of adhesion and spreading was similar to the adhesion seen on collagen-coated wells. Furthermore, the effect of Clq was mimicked by either polyclonal anti-cClq-R or mAb 60.11, but not with isotype- and species-matched control IgG. More importantly, however, a 100% inhibition of spreading but not adhesion to Clq-coated wells was observed when HDMVECs were cultured in the presence of 30 mM of the peptide GRRGDSP but not GRRGESP. Furthermore, while anti-beta1 integrin antibody blocked adhesion and spreading, antialpha5 integrin only blocked spreading. Since earlier studies have shown that zinc induces the exposure of hydrophobic sites in the C-terminus of gClq-R including the putative high-molecular weight kininogen (HK)-binding site corresponding to residues 204- 218, we also examined the effect of zinc on antibody binding to cell surface gClq-R. Flow cytometric data show that the binding of mAb 74.5.2, which recognizes residues 204-218, is greatly enhanced when endothelial cells were incubated in the presence of 50 muM zinc. In summary, our data show that: (a) Clq-mediated endothelial cell adhesion and spreading requires the cooperation of both Clq receptors and 1 integrins, and possibly other membrane-spanning molecules, and (b) zinc can induce the exposure of hydrophobic sites in the C-terminal domain of gClq-R allowing a more efficient binding of mAb 74.5.2 and HK. (C) 2002 Elsevier Science B.V. All rights reserved.