Heparin-II domain of fibronectin is a vascular endothelial growth factor-binding domain - Enhancement of VEGF biological activity by a singular growth factor/matrix protein synergism
Heparin-II domain of fibronectin is a vascular endothelial growth factor-binding domain - Enhancement of VEGF biological activity by a singular growth factor/matrix protein synergism
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DOI：
10.1161/01.res.0000246849.17887.66
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发表时间：
2006-10-13
影响因子：
20.1
通讯作者：
Sobel, Michael
中科院分区：
文献类型：
--
作者：
Wijelath, Errol S.;Rahman, Salman;Sobel, Michael
我们描述了纤维连接蛋白(FN)和血管内皮生长因子(VEGF)之间的细胞外相互作用，这些相互作用影响整合素-生长因子受体串扰和细胞反应。在以前的工作中，我们发现血管内皮生长因子与纤维连接蛋白(FN)特异性结合，而不与玻璃体连接蛋白或胶原蛋白结合。在此，我们报道了血管内皮生长因子与纤维连接蛋白的肝素-II结构域结合，并且当物理连接时，纤维连接蛋白的细胞结合结构域和血管内皮生长因子结合结构域是促进血管内皮生长因子诱导的内皮细胞增殖、迁移和ERK激活的必要条件和充分条件。利用重组FN结构域，FN的C端肝素-II结构域(类型III重复13至14)被确定为关键的血管内皮生长因子结合位点。FnIII(13-14)上的肝素结合残基突变使血管内皮生长因子结合失效，与FnIII13-14上的肝素结合序列相对应的多肽抑制了血管内皮生长因子与Fn的结合。同时含有α(5)β(1)整合素结合域(III9~10)和VEGF结合域(III13~14)的FN片段显著促进了血管内皮细胞的迁移和增殖，并诱导了血管内皮生长因子受体和ERK的强烈磷酸化。无论是FN的细胞结合片段还是血管内皮生长因子结合片段都没有类似的促进血管内皮生长因子的作用。这些结果表明，血管内皮生长因子/纤维连接蛋白的协同作用机制是通过形成一种新型的血管内皮生长因子/纤维连接蛋白复合体来实现的，该复合体需要将细胞结合区和血管内皮生长因子结合区连接在一个分子单元中。这些数据还强调了FN C末端肝素结合域的一个新功能，该功能可能对血管生成和肿瘤生长具有重要意义。
We describe extracellular interactions between fibronectin (Fn) and vascular endothelial growth factor (VEGF) that influence integrin-growth factor receptor crosstalk and cellular responses. In previous work, we found that VEGF bound specifically to fibronectin (Fn) but not vitronectin or collagens. Herein we report that VEGF binds to the heparin-II domain of Fn and that the cell-binding and VEGF-binding domains of Fn, when physically linked, are necessary and sufficient to promote VEGF-induced endothelial cell proliferation, migration, and Erk activation. Using recombinant Fn domains, the C-terminal heparin-II domain of Fn (type III repeats 13 to 14) was identified as a key VEGF-binding site. Mutation of the heparin-binding residues on FnIII(13-14) abolished VEGF binding, and peptides corresponding to the heparin-binding sequences in FnIII13-14 inhibited VEGF binding to Fn. Fn fragments containing both the alpha(5)beta(1) integrin-binding domain (III 9 to 10) and the VEGF-binding domain (III13 to 14) significantly enhanced VEGF-induced EC migration and proliferation and induced strong phosphorylation of the VEGF receptor and Erk. Neither the cell-binding or VEGF-binding fragment of Fn alone had comparable VEGF-promoting effects. These results suggest that the mechanism of VEGF/Fn synergism is mediated extracellularly by the formation of a novel VEGF/Fn complex requiring both the cell-binding and VEGF-binding domains linked in a single molecular unit. These data also highlight a new function for the Fn C-terminal heparin-binding domain that may have important implications for angiogenesis and tumor growth.