Tumor necrosis factor-α regulates expression of vascular endothelial growth factor receptor-2 and of its co-receptor neuropilin-1 in human vascular endothelial cells
Tumor necrosis factor-α regulates expression of vascular endothelial growth factor receptor-2 and of its co-receptor neuropilin-1 in human vascular endothelial cells
复制标题
DOI：
10.1074/jbc.273.34.22128
复制
发表时间：
1998-08-21
影响因子：
4.8
通讯作者：
Bussolino, F
中科院分区：
文献类型：
--
作者：
Giraudo, E;Primo, L;Bussolino, F
肿瘤坏死因子 -α（TNF -α）调节内皮细胞中的基因表达，在体内具有血管生成作用。TNF -α在体外不激活内皮细胞的迁移和增殖，其血管生成活性是通过合成直接的血管生成诱导因子或蛋白酶而引发的。在此，我们表明TNF -α以剂量和时间依赖的方式上调人内皮细胞中血管内皮生长因子受体 - 2（VEGFR - 2）的表达和功能以及其共受体神经毡蛋白 - 1的表达。通过核连缀分析以及基于VEGFR - 2启动子的报告基因构建体的瞬时表达推断，该细胞因子增加了VEGFR - 2基因的转录。光辉霉素是一种核转录因子Sp1与启动子共有序列结合的抑制剂，它阻断了VEGFR - 2的激活，这表明受体的上调需要Sp1结合位点。TNF -α增加了VEGFR - 2蛋白的细胞量，并使高亲和力的¹²⁵I - VEGF - A₍₁₆₅₎结合能力增加了两倍，而不影响配体 - 受体相互作用的解离常数（Kd）。因此，TNF -α增强了由VEGF - A₍₁₆₅₎引发的迁移和伤口愈合。由于VEGFR - 2介导内皮细胞中的血管生成信号，我们的数据表明其上调是TNF -α具有血管生成作用的另一种机制，并且可能为TNF -α介导的病理情况下发生的新生血管形成机制提供见解。
Tumor necrosis factor-alpha (TNF-alpha) modulates gene expression in endothelial cells and is angiogenic in vivo, TNF-alpha does not activate in vitro migration and proliferation of endothelium, and its angiogenic activity is elicited by synthesis of direct angiogenic inducers or of proteases, Here, we show that TNF-alpha up-regulates in a dose- and time-dependent manner the expression and the function of vascular endothelial growth factor receptor-2 (VEGFR-2) as well as the expression of its coreceptor neuropilin-1 in human endothelium, As inferred by nuclear run-on assay and transient expression of VEGFR-2 promoter-based reporter gene construct, the cytokine increased the transcription of the VEGFR-2 gene. Mithramycin, an inhibitor of binding of nuclear transcription factor Spl to the promoter consensus sequence, blocked activation of VEGFR-2, suggesting that the up-regulation of the receptor required Spl binding sites. TNF-alpha increased the cellular amounts of VEGFR-2 protein and tripled the high affinity I-125-VEGF-A(165) capacity without affecting the K-d of ligand-receptor interaction. As a consequence, TNF-alpha enhanced the migration and the wound healing triggered by VEGF-A(165). Since VEGFR-2 mediates angiogenic signals in endothelium, our data indicate that its up-regulation is another mechanism by which TNF-alpha is angiogenic and may provide insight into the mechanism of neovascularization as occurs in TNF-alpha-mediated pathological settings.