title: Wnt/Tcf1 pathway restricts embryonic stem cell cycle through activation of the Ink4/Arf locus.
abstract: Understanding the mechanisms regulating cell cycle, proliferation and potency of pluripotent stem cells guarantees their safe use in the clinic. Embryonic stem cells (ESCs) present a fast cell cycle with a short G1 phase. This is due to the lack of expression of cell cycle inhibitors, which ultimately determines naïve pluripotency by holding back differentiation. The canonical Wnt/β-catenin pathway controls mESC pluripotency via the Wnt-effector Tcf3. However, if the activity of the Wnt/β-catenin controls the cell cycle of mESCs remains unknown. Here we show that the Wnt-effector Tcf1 is recruited to and triggers transcription of the Ink4/Arf tumor suppressor locus. Thereby, the activation of the Wnt pathway, a known mitogenic pathway in somatic tissues, restores G1 phase and drastically reduces proliferation of mESCs without perturbing pluripotency. Tcf1, but not Tcf3, is recruited to a palindromic motif enriched in the promoter of cell cycle repressor genes, such as p15Ink4b, p16Ink4a and p19Arf, which mediate the Wnt-dependent anti-proliferative effect in mESCs. Consistently, ablation of β-catenin or Tcf1 expression impairs Wnt-dependent cell cycle regulation. All together, here we showed that Wnt signaling controls mESC pluripotency and proliferation through non-overlapping functions of distinct Tcf factors.
authors.affiliation: KU Leuven Stem Cell Institute, Department of Development and Regeneration, Stem Cell Signalling laboratory, Herestraat 49, Onderwijs en Navorsing 4, Leuven, Belgium.
authors.forename: Anchel
authors.initials: A
authors.lastname: De Jaime-Soguero
authors.affiliation: Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, Spain.
authors.forename: Francesco
authors.identifier: 0000-0002-3097-3765
authors.initials: F
authors.lastname: Aulicino
authors.affiliation: Maastricht Centre for Systems Biology (MaCSBio), Maastricht University. Universiteitssingel 60, 6229 ER Maastricht, The Netherlands.
authors.forename: Gokhan
authors.identifier: 0000-0001-5602-6435
authors.initials: G
authors.lastname: Ertaylan
authors.affiliation: KU Leuven Stem Cell Institute, Department of Development and Regeneration, Stem Cell Signalling laboratory, Herestraat 49, Onderwijs en Navorsing 4, Leuven, Belgium.
authors.forename: Anna
authors.initials: A
authors.lastname: Griego
authors.affiliation: Istituto per l'Endocrinologia e l'Oncologia Sperimentale "Gaetano Salvatore", CNR, Napoli, Italy.
authors.forename: Aniello
authors.initials: A
authors.lastname: Cerrato
authors.affiliation: TWINCORE, Zentrum für Experimentelle und Klinische Infektionsforschung, Hannover, Germany.
authors.forename: Aravind
authors.identifier: 0000-0001-7714-9872
authors.initials: A
authors.lastname: Tallam
authors.affiliation: Luxembourg Centre for Systems Biomedicine (LCSB), University of Luxembourg, 7, Avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette, Luxembourg.
authors.forename: Antonio
authors.identifier: 0000-0002-9926-617X
authors.initials: A
authors.lastname: Del Sol
authors.affiliation: Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona, Spain.|Universitat Pompeu Fabra (UPF), Dr Aiguader 88, Barcelona, Spain.|ICREA, Pg. Lluís Companys 23, Barcelona, Spain.
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Cosma
authors.affiliation: KU Leuven Stem Cell Institute, Department of Development and Regeneration, Stem Cell Signalling laboratory, Herestraat 49, Onderwijs en Navorsing 4, Leuven, Belgium.
authors.forename: Frederic
authors.identifier: 0000-0002-7296-7611
authors.initials: F
authors.lastname: Lluis
mesh_terms: D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002453:Cell Cycle / Q000235:genetics*; D049109:Cell Proliferation / Q000235:genetics; D002478:Cells, Cultured; D050762:Cyclin-Dependent Kinase Inhibitor p15 / Q000235:genetics* / Q000378:metabolism; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D057809:HEK293 Cells; D051538:Hepatocyte Nuclear Factor 1-alpha / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D000066450:Mouse Embryonic Stem Cells / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D060449:Wnt Signaling Pathway / Q000235:genetics*
chemical_list: C417743:Cdkn2a protein, mouse; D050762:Cyclin-Dependent Kinase Inhibitor p15; D019941:Cyclin-Dependent Kinase Inhibitor p16; D051538:Hepatocyte Nuclear Factor 1-alpha; C496488:Hnf1a protein, mouse