Genomes and Genes
Transcription Factors in Trophectoderm Differentiation
Principal Investigator: ROBERT MICHAEL ROBERTS
Abstract: The early production of human chorionic gonadotropin (hCG) by the trophoblast is essential to rescuing the corpus luteum and maintaining production of progesterone in early pregnancy. The major hypothesis behind the proposal is that three transcription factors, Oct-4, Ets-2, Dlx-3 and GATA-2, have a directive role in the initial differentiation of trophectoderm, as well as in the expression of key trophoblast-specific genes. We have noted that genes whose expressions are upregulated as trophectoderm first forms, including those for the hCG subunits and interferon-tau, are silenced by the transcription factor Oct-4, which has a role maintaining the inner cell mass in a totipotent state, and transactivated by Ets-2, Dlx-3 and GATA-2. There are four aims to this proposal. The first is to elucidate how the direct binding of Oct-4 to the CG-beta promoter results in silencing. We shall determine what domains of Oct-4 are involved, why the Oct-4 binding site differs so markedly from a consensus binding sequence, and identify which proteins interact with Oct-4 when it is associated with the promoter. Goal 2 is to understand how Oct-4 silences hCG-alpha. Here, we believe that the target is GATA-2 or a related GATA factor. One aim is to prove this hypothesis, but we shall also identify other transcription factors that bind Oct-4 in "early" human trophoblast cells, which could be additional Oct-4 targets, and the role of an Oct-4 binding site downstream of the alpha-ACT site where silencing is directed. Goal 3 is to determine whether 0ct-4 reverses the ability of Ets-2 to transactivate the hCG-alpha & hCG-beta gene promoters and how such an inhibition, if observed, is achieved. The final aim (Aim 4) is to understand the interrelationships between expression of Oct-4, Ets-2, Dlx-3 and GATA-2 and the differentiation of trophoblast from stem cell-like precursors. Two main model systems will be employed: i) HT-H teratocarcinoma cells, which convert spontaneously during culture from small, proliferating, floating precursors to larger, attached end-point cells that produce hCG; ii), human embryonic stem cells (HT 1) that can be directed towards trophoblast by addition of BMP-4 to the culture medium. Confirmatory experiments will also be carried out with choriocarcinoma cells, which appear to correspond to early precursor trophoblast, and cytotrophoblast from term placenta. Both these types of cell can be induced to differentiate to forms that produce abundant hCG. Together, these experiments will provide insight into why so many embryos are lost at about the time that the trophoblast is differentiating. The studies are expected to reveal mechanisms underpinning the transition of embryonic stem cells to trophectoderm, a developmental event that immediately precedes implantation and a time when expression of hCG begins.
Funding Period: 2003-07-01 - 2009-04-30
more information: NIH RePORT
- Comparison of extravillous trophoblast cells derived from human embryonic stem cells and from first trimester human placentasB P Telugu
University of Maryland, Animal and Avian Sciences, College Park, MD 20742, USA
Placenta 34:536-43. 2013..The goals of the present study were to further characterize the HLA-G(+) cells derived from BMP4-treated hESC, and determine their suitability as a model...
- Trophoblast stem cellsR Michael Roberts
Division of Animal Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
Biol Reprod 84:412-21. 2011..Recent derivation of TSC from blastocysts of the rhesus monkey suggests that isolation of the human equivalents may be possible and will reveal the extent to which mechanisms uncovered by using animal models are true in our own species...
- The promise of stem cell research in pigs and other ungulate speciesBhanu Prakash V L Telugu
Division of Animal Sciences, Christopher S Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
Stem Cell Rev 6:31-41. 2010....
- Induced pluripotent stem cells from swine (Sus scrofa): why they may prove to be importantR Michael Roberts
Division of Animal Sciences, University of Missouri, Columbia, MO, USA
Cell Cycle 8:3078-81. 2009....
- Progressive accumulation of epigenetic heterogeneity during human ES cell cultureBorko Tanasijevic
Center for Regenerative Biology, University of Connecticut, Storrs, CT 06269 4243, USA
Epigenetics 4:330-8. 2009..In addition, the results indicate that apparently normal cultures of hESCs may contain mixtures of cells with differing epigenetic states. Assays of epigenetic integrity are warranted as quality control measures for the culture of hESCs...
- Derivation of induced pluripotent stem cells from pig somatic cellsToshihiko Ezashi
Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA
Proc Natl Acad Sci U S A 106:10993-8. 2009..Such cell lines derived from individual animals could provide a means for testing the safety and efficacy of stem cell-derived tissue grafts when returned to the same pigs at a later age...
- Effects of fgf2 and oxygen in the bmp4-driven differentiation of trophoblast from human embryonic stem cellsPadmalaya Das
Department of Animal Sciences, University of Missouri Columbia, Christopher S Bond Life Sciences Center, 65211, USA
Stem Cell Res 1:61-74. 2007..In conclusion, BMP4 induced conversion of hESC exclusively towards trophoblast; FGF2 slowed differentiation, while O(2) accelerated this process and promoted syncytiotrophoblast formation...
- Identification of oxygen-sensitive transcriptional programs in human embryonic stem cellsSuzanne D Westfall
Department of Animal Sciences, University of Missouri, Columbia, Missouri 65211 7310, USA
Stem Cells Dev 17:869-81. 2008..The data are consistent with the hypothesis that 4% O(2) favors the molecular mechanisms required for the maintenance of pluripotency...
- The role of homeobox protein distal-less 3 and its interaction with ETS2 in regulating bovine interferon-tau gene expression-synergistic transcriptional activation with ETS2Toshihiko Ezashi
Department of Animal Sciences, University of Missouri, Columbia, Missouri 65211, USA
Biol Reprod 79:115-24. 2008..Together, these results suggest that DLX3 has a central role in controlling IFNT gene expression by associating with ETS2 on the IFNT promoter...
- Human embryonic stem cells as models for trophoblast differentiationL C Schulz
Division of Animal Sciences, University of Missouri Columbia, Columbia, MO 65211, USA
Placenta 29:S10-6. 2008..Immunohistochemical observations performed on whole colonies combined with microarray analysis of mRNA can be employed to track developmental transitions as they occur over time and in two-dimensional space as the cells respond to BMP4...
- Combinatorial roles of protein kinase A, Ets2, and 3',5'-cyclic-adenosine monophosphate response element-binding protein-binding protein/p300 in the transcriptional control of interferon-tau expression in a trophoblast cell linePadmalaya Das
Christopher S Bond Life Sciences Center, University of Missouri Columbia, 1201 East Rollins Street, Columbia, MO 65211 7310, USA
Mol Endocrinol 22:331-43. 2008..The up-regulation of IFNT in the elongating bovine conceptus is likely due to the combinatorial effects of PKA, Ets2, and CBP/p300 and triggered via growth factors released from maternal endometrium...
- Ets-2 and C/EBP-beta are important mediators of ovine trophoblast Kunitz domain protein-1 gene expression in trophoblastAnindita Chakrabarty
Departments of Veterinary Pathobiology, University of Missouri Columbia, Columbia, MO 65211, USA
BMC Mol Biol 8:14. 2007..Our goal here has been to determine whether the ovine (ov) Tkdp-1 and IFNT genes possess a similar transcriptional code...
- Cdx2 gene expression and trophectoderm lineage specification in mouse embryosKaushik Deb
Department of Animal Sciences, Columbia, MO 65211, USA
Science 311:992-6. 2006..The asymmetrical distribution of Cdx2 gene products in the oocyte and embryo defines the lineage to trophectoderm...
- Low O2 tensions and the prevention of differentiation of hES cellsToshihiko Ezashi
Department of Animal Sciences, University of Missouri, Columbia, MO 65211, USA
Proc Natl Acad Sci U S A 102:4783-8. 2005..In addition, hES cell growth under hypoxia provided enhanced formation of embryoid bodies. Hypoxic culture would appear to be necessary to maintain full pluripotency of hES cells...
- Coordinate regulation of basal and cyclic 5'-adenosine monophosphate (cAMP)-activated expression of human chorionic gonadotropin-alpha by Ets-2 and cAMP-responsive element binding proteinDebjani Ghosh
Department of Animal Sciences, University of Missouri, Columbia, Missouri 65211 7310, USA
Mol Endocrinol 19:1049-66. 2005..We propose that regulation of hCGalpha by Ets-2 and CREB enables coordinated expression of hCGalpha with its partner hCGbeta subunit...