Endothelial PAS domain protein 1 gene promotes angiogenesis through the transactivation of both vascular endothelial growth factor and its receptor, Flt-1
Endothelial PAS domain protein 1 gene promotes angiogenesis through the transactivation of both vascular endothelial growth factor and its receptor, Flt-1
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DOI：
10.1161/01.res.0000134920.10128.b4
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发表时间：
2004-07-23
影响因子：
20.1
通讯作者：
Nagai, R
中科院分区：
文献类型：
--
作者：
Takeda, N;Maemura, K;Nagai, R
内皮PAS结构域蛋白1（EPAS 1）是一种碱性螺旋环螺旋/PAS结构域转录因子，在血管内皮细胞中优先表达。EPAS 1与缺氧诱导因子-1 α（HIF-1 α）具有高度同源性，据报道可反式激活血管内皮生长因子（VEGF）、胎肝激酶-1（Flk-1）和Tie 2启动子。在本研究中，我们分析了EPAS 1在血管生成过程中的作用。利用基因芯片技术，我们在血管内皮细胞中寻找EPAS 1调控的靶基因。共有130个基因被EPAS 1上调，包括fms样酪氨酸激酶-1（Flt-1）。利用人Flt-1启动子和凝胶迁移率变动分析的报告基因分析表明，EPAS 1和芳香烃受体核转位蛋白的异源二聚体直接结合到Flt-1启动子上游的HIF-1结合位点并使其反式激活。因此认为EPAS 1在Flt-1基因的缺氧诱导中起重要作用。此外，使用小鼠伤口愈合模型，我们证明了腺病毒介导的EPAS 1基因的递送显著诱导了伤口部位VEGF、Flt-1、Flk-1和Tie 2 mRNA的表达，并促进了成熟的血管生成。新形成的血管中的壁细胞数量的比例在EPAS 1处理的伤口区域中显著高于VEGF处理的区域。总之，EPAS 1促进Flt-1基因表达并诱导VEGF、Flk-1和Tie 2的mRNA表达，从而导致体内成熟血管生成的增强。因此，EPAS 1可能通过调节VEGF、Flt-1、Flk-1和Tie 2的协调表达而有助于成熟血管的构建。
Endothelial PAS domain protein 1 (EPAS1) is a basic-helix-loop-helix/PAS domain transcription factor that is expressed preferentially in vascular endothelial cells. EPAS1 shares high homology with hypoxia-inducible factor-1alpha (HIF-1alpha) and is reported to transactivate vascular endothelial growth factor (VEGF), fetal liver kinase-1 (Flk-1), and Tie2 promoters. In this study, we analyzed the role of EPAS1 in the process of angiogenesis. Using microarray technology, we looked for target genes regulated by EPAS1 in vascular endothelial cells. A total of 130 genes were upregulated by EPAS1, including fms-like tyrosine kinase-1 (Flt-1). Reporter analysis using human Flt-1 promoter and gel mobility shift assays showed that the heterodimer of EPAS1 and aryl hydrocarbon receptor nuclear translocator binds directly to HIF-1-binding site upstream of Flt-1 promoter and transactivates it. Small interfering RNA targeted to EPAS1 but not HIF-1alpha attenuated desferrioxamine-induced Flt-1 mRNA expression, thus EPAS1 is thought to play an essential role in hypoxic induction of Flt-1 gene. Furthermore, using mouse wound healing models, we demonstrated that adenovirus-mediated delivery of EPAS1 gene significantly induced the expression of VEGF, Flt-1, Flk-1, and Tie2 mRNA at the wound site and promoted mature angiogenesis. The proportion of the number of mural cells in newly formed vessels was significantly higher in EPAS1-treated wound area than VEGF-treated area. In conclusion, EPAS1 promotes Flt-1 gene expression and induces mRNA expression of VEGF, Flk-1, and Tie2, leading to enhancement of mature angiogenesis in vivo. Thus, EPAS1 may contribute to the construction of mature vessels by modulating the coordinated expressions of VEGF, Flt-1, Flk-1, and Tie2.