Role of transcriptional corepressor ETO2 in erythroid cells
Role of transcriptional corepressor ETO2 in erythroid cells
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DOI：
10.1016/j.exphem.2012.10.015
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发表时间：
2013-03-01
影响因子：
2.6
通讯作者：
Harigae, Hideo
中科院分区：
文献类型：
--
作者：
Fujiwara, Tohru;Alqadi, Yarob Wael;Harigae, Hideo
转录辅阻遏物ETO 2是含有造血主要调节因子的蛋白质复合物的组分，包括加塔-1、SCL/TAL 1、LMO 2和LDB 1。为了阐明ETO 2在红系分化过程中的作用，包括ETO 2对加塔-1靶标的影响，我们使用ETO 2过表达的K562细胞进行基因表达谱分析。分析表明，在ETO 2过表达细胞中，分别有667和598个基因上调和下调（超过两倍）。ETO 2抑制基因包括那些编码原型红细胞蛋白的基因。为了测试多少百分比的ETO 2抑制基因可以是K562细胞中加塔-1的直接靶基因，我们将微阵列结果与ChIP-seq图谱（n = 5，749）合并，证明23.1%的ETO 2抑制基因在其基因座中含有显著的加塔-1。然而，在ETO 2抑制基因中，PU.1靶基因没有显著富集。ETO 2-阻遏基因的基因本体分析显示显着富集的基因相关的“氧转运蛋白”，相应的珠蛋白基因。定量染色质免疫沉淀和ETO 2敲低分析证实，ETO 2直接调节珠蛋白基因在K562细胞。接下来，我们评估了ETO 2在人原代成红细胞中的作用，所述人原代成红细胞来源于脐带血CD 34阳性细胞。在从CD 34阳性细胞分化成红系细胞的离体模型中，ETO 2蛋白水平在第2-4天达到峰值，并且在分化的后期几乎降低。此外，短发夹RNA介导的敲低和逆转录病毒载体介导的原代成红细胞中ETO 2的过表达表明ETO 2显著抑制HBB、HBA和ALAS 2表达。总之，ETO 2调节对红系分化至关重要的加塔-1靶基因，红系分化期间ETO 2水平的降低将有助于这些靶基因的激活。(C)2013 ISEH -血液学和干细胞学会。爱思唯尔公司出版
Transcriptional corepressor ETO2 is a component of a protein complex containing master regulators of hematopoiesis, including GATA-1, SCL/TAL1, LMO2, and LDB1. To elucidate the role of ETO2 during erythroid differentiation, including the effects of ETO2 on GATA-1 targets, we performed gene expression profiling using K562 cells overexpressed with ETO2. The analysis demonstrated that 667 and 598 genes were upregulated and downregulated (more than twofold), respectively, in ETO2-overexpressing cells. ETO2-repressed genes included those encoding prototypical erythroid proteins. To test what percentages of ETO2-repressed genes could be direct target genes of GATA-1 in K562 cells, we merged the microarray results with ChIP-seq profile (n = 5,749), demonstrating that 23.1% of ETO2-repressed genes contained significant GATA-1 in their loci. However, there was no significant enrichment of PU.1 target genes among ETO2-repressed genes. Gene ontology analysis among ETO2-repressed genes revealed significant enrichment of genes related to "oxygen transporter," corresponding to globin genes. Quantitative chromatin immunoprecipitation and ETO2 knockdown analyses confirmed that ETO2 directly regulates globin genes in K562 cells. Next, we evaluated the role of ETO2 in human primary erythroblasts, derived from cord blood CD34-positive cells. In an ex vivo model of erythroid differentiation from CD34-positive cells, ETO2 protein level peaked at day 2-4 and almost diminished at the later stage of differentiation. Furthermore, short hairpin RNA mediated knockdown and retroviral vector mediated overexpression of ETO2 in primary erythroblasts suggested that ETO2 significantly represses HBB, HBA, and ALAS2 expression. In summary, ETO2 regulates GATA-1 target genes critical for erythroid differentiation, and the decrease of ETO2 levels during erythroid differentiation would contribute to the activation of these targets. (C) 2013 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc.