Oct4 was a novel target of Wnt signaling pathway
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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.
KeywordsOct4 β-Catenin Stem cell
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.
- 16.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 275:23387–23397PubMedCrossRefGoogle Scholar
- 18.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 25:3492–3505PubMedCrossRefGoogle Scholar