The transcription factor Erg regulates expression of HDAC6 and multiple pathways involved in endothelial cell migration and angiogenesis
The transcription factor Erg regulates expression of HDAC6 and multiple pathways involved in endothelial cell migration and angiogenesis
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转录因子 Erg 调节 HDAC6 的表达以及参与内皮细胞迁移和血管生成的多种途径
DOI：
10.1016/j.vph.2011.08.120
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发表时间：
2012
影响因子：
4
通讯作者：
Birdsey G
中科院分区：
文献类型：
--
作者：
Birdsey G
血管生成是一个严格调控的过程，需要整合来自生长因子、粘附分子和其他细胞途径的信号。ETS转录因子Erg作为内皮基因表达的反式激活因子和阻遏因子，是血管生成和内皮细胞存活所必需的。在这里，我们表明，Erg参与调节内皮细胞（EC）迁移。在体外伤口试验中，抑制EC中Erg表达导致迁移减少，而Erg过度表达导致细胞迁移增加。Erg缺陷EC的转录组分析确定了约80个参与细胞迁移的基因作为新的候选Erg靶标。其中的命中是调节肌动蛋白和微管细胞骨架和小GT3途径。微阵列中最显著下调的基因之一是胞质组蛋白脱乙酰酶（HDAC）-6。HDAC 6的抑制导致其靶蛋白的超乙酰化，所述靶蛋白包括微管蛋白、corneumen和Hsp 90。我们表明，Erg调节内皮HDAC 6表达，并使用染色质免疫沉淀（ChIP），我们证明，Erg结合HDAC 6启动子。我们还表明，抑制Erg导致微管蛋白乙酰化的急剧增加，这可以通过HDAC 6的过度表达来挽救，表明这种酶介导Erg对细胞骨架的一些影响。为了研究细胞骨架动力学，我们进行了活细胞的ERG缺陷EC的成像与actin-RFP和记录图像的延时显微镜检查的receptecting细胞。对照组细胞表现出一个特征性的不对称形状与lamellae朝向迁移的方向; ERG缺陷的细胞表现出一个角的形状与皮质肌动蛋白和显着减少lamellipodia。使用记波仪的定量显示Erg抑制导致板状伪足形成的损失。在体内，抑制血管生成EC中的Erg表达导致HDAC 6表达减少，微管蛋白乙酰化增加。总之，这些结果表明，Erg是必需的内皮细胞迁移，调节HDAC 6的表达和微管蛋白乙酰化，并为动态运动的肌动蛋白丰富的板状伪足。这些途径对于细胞迁移和血管生成是必不可少的，并指出这种转录因子在内皮生物学中的新的关键功能。
Angiogenesis is a tightly regulated process that requires the integration of signals from growth factors, adhesion molecules and other cellular pathways. The ETS transcription factor Erg, which acts both as a trans-activator and a repressor of endothelial gene expression, is required for angiogenesis and endothelial survival. Here we demonstrate that Erg is involved in regulating endothelial cell (EC) migration. Inhibition of Erg expression in EC resulted in decreased migration in an in vitro wound assay, whilst Erg over-expression caused an increase in cell migration. Transcriptome profiling of Erg-deficient EC identified~ 80 genes involved in cell migration as novel candidate Erg targets. Amongst the hits are regulators of the actin and microtubule cytoskeleton and of the small GTPase pathways. One of the most significantly down-regulated genes in the microarray was the cytosolic histone deacetylase (HDAC)-6. Inhibition of HDAC6 causes hyperacetylation of its target proteins, which include tubulin, cortactin and Hsp90. We show that Erg regulates endothelial HDAC6 expression and using chromatin immunoprecipitation (ChIP) we demonstrate that Erg binds to the HDAC6 promoter. We also show that inhibition of Erg leads to a dramatic increase in tubulin acetylation, which can be rescued by over-expression of HDAC6, demonstrating that this enzyme mediates some of the effects that Erg exerts on the cytoskeleton. To study cytoskeletal dynamics we performed live-cell imaging of Erg-deficient EC by transfecting cells with actin-RFP and recording images by time-lapse microscopy. Control cells exhibited a characteristic asymmetrical shape with lamellae orientated towards the direction of migration; Erg-deficient cells exhibited an angular shape with cortical actin and markedly reduced lamellipodia. Quantification using kymographs showed that Erg inhibition results in loss of lamellipodia formation. In vivo, inhibition of Erg expression in angiogenic EC resulted in decreased HDAC6 expression with increased tubulin acetylation. In conclusion, these results indicate that Erg is required for endothelial cell migration, regulating HDAC6 expression and tubulin acetylation, and for the dynamic movement of actin-rich lamellipodia. These pathways are essential for cell migration and angiogenesis and point to a novel crucial function of this transcription factor in endothelial biology.