Regulation of Trophoblast-Specific Factors by GATA2 and GATA3 in Bovine Trophoblast CT-1 Cells
Regulation of Trophoblast-Specific Factors by GATA2 and GATA3 in Bovine Trophoblast CT-1 Cells
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DOI：
10.1262/jrd.10-186k
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发表时间：
2011-08-01
影响因子：
1.8
通讯作者：
Imakawa, Kazuhiko
中科院分区：
文献类型：
--
作者：
Bai, Hanako;Sakurai, Toshihiro;Imakawa, Kazuhiko
许多调控滋养层细胞发育过程的转录因子已经被确定，然而，滋养层细胞特异性基因表达的调控还没有明确的特征。虽然GATA3在小鼠滋养层发育中的新作用正在被证明，但我们检测了GATA转录因子对反刍动物中主要的滋养外胚层因子--受精卵干扰素tau(IFNT)的影响。本研究初步检测了滋养层细胞ASCL2、CDX2、CSH1、ELF5、HAND1、IFNT和TKDP1mRNAs的表达模式，发现ASCL2、CDX2、IFNT和TKDP1mRNAs在17、20和22天(0天=发情期)与GATA2和GATA3相似。染色质免疫沉淀(ChIP)分析表明，在牛滋养层细胞CT-1细胞中，内源性GATA2和GATA3占据了CSH1、IFNT和TKDP1基因上游区域以及CDX2基因内含子1的GATA结合位点。在牛CSH1、IFNT或CDX2基因内含子1区域的瞬时转基因分析中，GATA2的过表达诱导了这些滋养细胞特异性基因在牛非滋养层成纤维细胞EF细胞中的反式激活，而GATA3的过表达并不显著影响它们的反式激活。在CT-1细胞中，GATA2 siRNA下调内源性CDX2和IFNT的mRNAs表达，而GATA3 siRNA下调内源性ASCL2和CDX2mRNAs的表达。我们的结果表明，除了滋养外胚层的谱系特征外，GATA2和/或GATA3还参与了牛滋养层CT-1细胞滋养层特异性基因转录的调控。
Numerous transcription factors that regulate trophoblast developmental processes have been identified; however, the regulation of trophoblast-specific gene expression has not been definitively characterized. While a new role of Gata3 in trophoblast development was being demonstrated in mice, we examined effects of GATA transcription factors on conceptus interferon tau (IFNT), a major trophectoderm factor in ruminants. In this study, expression patterns of trophoblast ASCL2, CDX2, CSH1, ELF5, HAND1, IFNT, and TKDP1 mRNAs were initially examined, from which ASCL2, CDX2, IFNT, and TKDP1 mRNAs were found to be similar to those of GATA2 and GATA3 in days 17, 20, and 22 (day 0=day of estrus) bovine conceptuses. A chromatin immunoprecipitation (ChIP) assay revealed that endogenous GATA2 and GATA3 occupied GATA binding sites on the upstream regions of CSH1, IFNT, and TKDP1 genes and on the intron 1 region of CDX2 gene in bovine trophoblast CT-1 cells. In transient transfection analyses of the upstream region of bovine CSH1, and IFNT or the intron 1 region of CDX2 gene, over-expression of GATA2 induced transactivation of these trophoblast-specific genes in bovine non-trophoblast ear fibroblast EF cells, but over-expression of GATA3 did not substantially affect their transactivation. In CT-1 cells, endogenous CDX2 and IFNT mRNAs were down-regulated by GATA2 siRNA, while endogenous ASCL2 and CDX2 mRNAs were down-regulated by GATA3 siRNA. Our results indicate that in addition to trophectoderm lineage specification, GATA2 and/or GATA3 are involved in the regulation of trophoblast-specific gene transcription in bovine trophoblast CT-1 cells.