Abstract
The specific expression of Oct4 during early mouse development is required for the correct maintenance of pluripotent cells, and the regulatory control of the Oct4 expression is important. Wnt signaling could have multiple and/or complex effects on embryonic stem (ES) cells characteristics. Elucidation of the molecular mechanisms affecting Wnt signaling in ES cells could provide a better understanding of how these effects occur. The purpose of this study was to determine whether Oct4 was regulated by Wnt signaling in undifferentiated ES cells. Here, we report Oct4 as a novel target of β-catenin-mediated transcription. First, we observe that Wnt signaling pathway is activated in undifferentiated mouse ES cells. In 239T cells, Oct4 promoter was regulated by β-catenin. Through promoter mapping and chromatin immuno-precipitation assays, we found that Oct4 is a direct target of β-catenin/TCF-mediated transcription and the binding site at −875/−881 of Oct4 promoter is critical for b-catenin/TCF-dependent expression regulation. We further detect the expression of Oct4 in treatment with glycogen syntheses kinase (GSK)-3-specific inhibitor in mouse ES cells and HepG2 cells. We found that GSK-3-specific inhibitor can maintain the expression of Oct4 in ES cells and can enhance the expression of Oct4 in HepG2 cells. Our results suggest that Oct4 might be a novel target of β-catenin/TCF-mediated downstream gene in Wnt-activated cells.
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References
Cadigan KM, Nusse R (1997) Wnt signaling: a common theme in animal development. Genes Dev 11:3286–3305
Bafico A, Liu G, Yaniv A, Gazit A, Aaronson SA (2001) Novel mechanism of Wnt signaling inhibition mediated by Dickkopf-1 interaction with LRP6/Arrow. Nat Cell Biol 3:683–686
Aulehla A, Wehrle C, Brand-Saberi B, Kemler R, Gossler A, Kanzler B, Herrmann BG (2003) Wnt3a plays a major role in the segmentation clock controlling somatogenesis. Dev Cell 4:395–406
Aubert J, Dunstan H, Chambers I, Smith A (2002) Functional gene screening in embryonic stem cells implicates Wnt antagonism in neural differentiation. Nat Biotechnol 20:1240–1245
Sato N, Meijer L, Skaltsounis L, Greengard P, Brivanlou AH (2004) Maintenance of pluripotency in human and mouse embryonic stem cells through activation of Wnt signaling by a pharmacological GSK-3-specific inhibitor. Nat Med 10:55–63
Kielman MF, Rindapaa M, Gaspar C, van Poppel N, Breukel C, van Leeuwen S, Taketo MM, Roberts S, Smits R, Fodde R (2002) Apc modulates embryonic stem-cell differentiation by controlling the dosage of beta-catenin signaling. Nat Genet 32:594–605
Dravid G, Ye Z, Hammond H, Chen G, Pyle A, Donovan P, Yu X, Cheng L (2005) Defining the role of Wnt/beta-catenin signaling in the survival, proliferation, and self-renewal of human embryonic stem cells. Stem Cells 23:1489–1501
Scholer HR, Ruppert S, Suzuki N, Chowdhury K, Gruss P (1990) New type of POU domain in germ line-specific protein Oct-4. Nature 344:435–439
Brehm A, Ohbo K, Scholer HR (1997) The carboxy-terminal transactivation domain of Oct-4 acquires cell specificity through the POU domain. Mol Cell Biol 17:154–162
Scholer HR, Dressler GR, Balling R, Rohdewohld H, Gruss P (1990) Oct-4: a germline-specific transcription factor mapping to the mouse t-complex. EMBO J 9:2185–2195
Roose J, Clevers H (1999) TCF transcription factors: molecular switches in carcinogenesis. Biochim Biophys Acta 1424:M23–M37
Huang HC, Klein PS (2004) The Frizzled family: receptors for multiple signal transduction pathways. Genome Biol 5:234
Aberle H, Bauer A, Stappert J, Kispert A, Kemler R (1997) Beta-catenin is a target for the ubiquitin-proteasome pathway. EMBO J 16:3797–3804
Kang DE, Soriano S, Xia X, Eberhart CG, De Strooper B, Zheng H, Koo EH (2002) Presenilin couples the paired phosphorylation of beta-catenin independent of axin: implications for beta-catenin activation in tumorigenesis. Cell 110:751–762
Nichols J, Zevnik B, Anastassiadis K, Niwa H, Klewe-Nebenius D, Chambers I, Scholer HR, Smith A (1998) Formation of pluripotent stem cells in the mammalian embryo depends on the POU transcription factor Oct4. Cell 95:379–391
Ambrosetti DC, Scholer HR, Dailey L, Basilico C (2000) Modulation of the activity of multiple transcriptional activation domains by the DNA binding domains mediates the synergistic action of Sox2 and Oct-3 on the fibroblast growth factor-4 enhancer. J Biol Chem 275:23387–23397
Yuan H, Corbi N, Basilico C, Dailey L (1995) Developmental-specific activity of the FGF-4 enhancer requires the synergistic action of Sox2 and Oct-3. Genes Dev 9:2635–2645
Gu P, Goodwin B, Chung AC, Xu X, Wheeler DA, Price RR, Galardi C, Peng L, Latour AM, Koller BH, Gossen J, Kliewer SA, Cooney AJ (2005) Orphan nuclear receptor LRH-1 is required to maintain Oct4 expression at the epiblast stage of embryonic development. Mol Cell Biol 25:3492–3505
Chew JL, Loh YH, Zhang W, Chen X, Tam WL, Yeap LS, Li P, Ang YS, Lim B, Robson P, Ng HH (2005) Reciprocal transcriptional regulation of Pou5f1 and Sox2 via the Oct4/Sox2 complex in embryonic stem cells. Mol Cell Biol 25:6031–6046
Boyer LA, Lee TI, Cole MF, Johnstone SE, Levine SS, Zucker JP, Guenther MG, Kumar RM, Murray HL, Jenner RG, Gifford DK, Melton DA, Jaenisch R, Young RA (2005) Core transcriptional regulatory circuitry in human embryonic stem cells. Cell 122:947–956
Garcia-Castro MI, Marcelle C, Bronner-Fraser M (2002) Ectodermal Wnt function as a neural crest inducer. Science 297:848–851
Niwa H, Miyazaki J, Smith AG (2000) Quantitative expression of Oct-3/4 defines differentiation, dedifferentiation or self-renewal of ES cells. Nat Genet 24:372–376
Pesce M, Scholer HR (2001) Oct-4: gatekeeper in the beginnings of mammalian development. Stem Cells 19:271–278
Botquin V, Hess H, Fuhrmann G, Anastassiadis C, Gross MK, Vriend G, Scholer HR (1998) New POU dimer configuration mediates antagonistic control of an osteopontin preimplantation enhancer by Oct-4 and Sox-2. Genes Dev 12:2073–2090
Nishimoto M, Fukushima A, Okuda A, Muramatsu M (1999) The gene for the embryonic stem cell coactivator UTF1 carries a regulatory element which selectively interacts with a complex composed of Oct-3/4 and Sox-2. Mol Cell Biol 19:5453–5465
Avilion AA, Nicolis SK, Pevny LH, Perez L, Vivian N, Lovell-Badge R (2003) Multipotent cell lineages in early mouse development depend on SOX2 function. Genes Dev 17:126–140
Chambers I, Colby D, Robertson M, Nichols J, Lee S, Tweedie S, Smith A (2003) Functional expression cloning of Nanog, a pluripotency sustaining factor in embryonic stem cells. Cell 113:643–655
Acknowledgments
This study was supported by The National Natural Science Foundation of China (NSFC no. 30900859). Many thanks to Johnson K. Chan, who helped edit this article.