Regulation of Trophoblast-Specific Factors by GATA2 and GATA3 in Bovine Trophoblast CT-1 Cells

Abstract

Abstract. 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. Key words: Bovine, GATA factors, Gene regulation, Trophoblast cells (J. Reprod. Dev. 57: [518][519][520][521][522][523][524][525] 2011) uring mammalian development, the first lineage decision is to establish the trophectoderm (TE) and inner cell mass (ICM). The outer TE layer attaches to and invades the maternal endometrium and eventually forms placental structures. It has been well established that caudal-type homeobox transcription factor 2 (Cdx2) serves as a lineage determining factor for the murine trophectoderm [1,2]. Quite recently, one of the GATA transcription factors, Gata3, was found to specify the trophectoderm lineage [3].In addition to these factors, there are numerous factors that are expressed in the trophoblasts during trophectoderm cell differentiation. These are E74-like factor 5 (Elf5), heart and neural crest derivatives expressed 1 (Hand1), a mammalian achaete scute-like homolog 2 (Ascl2), placental lactogens (PLs, CSHs) in many mammalian species, and interferon tau (IFNT) and trophoblast Kunitz domain proteins (TKDPs) in ruminant ungulates. Elf5 is necessary to maintain expression of the trophoblast stem cell genes Cdx2 and Eomes, and thereby reinforces trophoblast cell fate [4]. Hand1 and Ascl2, basic helix-loop-helix (bHLH) transcription factor genes, are essential for trophoblast proliferation and differentiation in mice [5,6]. CSHs belong to the growt...

Expression and Potential Role of GATA6 in Ruminant Trophoblasts during Peri-Implantation Periods

“…Recently, we found that GATA2 and GATA3 could also increase IFNT transcription in our transient transfection system [15,16]. During the peri-attachment period, changes in IFNT, GATA2, and GATA3 expression are similar, and the expression of these proteins declines following conceptus attachment to the uterine epithelium [15,16]. In our experiment, GATA6 expression increased after conceptus attachment to the uterine epithelium (Fig.…”

“…The numerous transcription factors found thus far as regulators of IFNT genes include ETS2 [30,31], activating protein 1 (AP-1; official symbol JUN) [32], CDX2 [24,27], homeobox protein distal-less 3 (DLX3) [33], and co-activators cAMP-response element binding protein (CREB)-binding protein (CREBBP) [34] and p300 [35]. Recently, we found that GATA2 and GATA3 could also increase IFNT transcription in our transient transfection system [15,16]. During the peri-attachment period, changes in IFNT, GATA2, and GATA3 expression are similar, and the expression of these proteins declines following conceptus attachment to the uterine epithelium [15,16].…”

“…Previously, we have shown that GATA2 and GATA3 are expressed in bovine conceptuses and regulate trophoblast-specific factors, including interferon tau (IFNT), a major cytokine involved in the maternal recognition of pregnancy in ruminants during the peri-attachment period [15,16]. We also reported that GATA1 was expressed in ovine conceptuses after attachment to uterine endo-metrial epithelial cells [17].…”

Bone morphogenetic protein 4 accelerates the establishment of bovine trophoblastic cell lines

“…Some elements, AP2, GATAs, PURA, and SPs, have been reported as activation factors for this gene, and CSH1 expression was closely related to the implantation process spatiotemporally (Limesand et al 2004, Jeckel et al 2009). GATA may play a regulatory role of CSH1 expression and differentiation of BNCs (Bai et al 2011). …”

Primary Bovine Extra-Embryonic Cultured Cells: A New Resource for the Study of In Vivo Peri-Implanting Phenotypes and Mesoderm Formation

“…The genes in the “Trophoblast Core” included many that have been reported in elongating trophoblasts (D12-D18: AKR1B1 , GATA2 , GATA3 , PAG2 , PCSK3 , TKDP [28]), trophoblast cell lines (bovine CT1, D10-11: GATA2 , GATA3 , PAG [29]), early trophectoderm (bovine D7 blastocysts: FABP5 , GATA2 , SLC15A1 [30]), or chorionic trophoblast stem cells ( PEG3 [31]). Most genes, however (41 out of 56), were new in the bovine trophoblast, including some involved in cell adhesion regulation and epithelial sheet morphogenesis.…”