title: SIP1 mediates cell-fate decisions between neuroectoderm and mesendoderm in human pluripotent stem cells.
abstract: Human embryonic stem cells (hESCs) rely on fibroblast growth factor and Activin-Nodal signaling to maintain their pluripotency. However, Activin-Nodal signaling is also known to induce mesendoderm differentiation. The mechanisms by which Activin-Nodal signaling can achieve these contradictory functions remain unknown. Here, we demonstrate that Smad-interacting protein 1 (SIP1) limits the mesendoderm-inducing effects of Activin-Nodal signaling without inhibiting the pluripotency-maintaining effects exerted by SMAD2/3. In turn, Activin-Nodal signaling cooperates with NANOG, OCT4, and SOX2 to control the expression of SIP1 in hESCs, thereby limiting the neuroectoderm-promoting effects of SIP1. Similar results were obtained with mouse epiblast stem cells, implying that these mechanisms are evolutionarily conserved and may operate in vivo during mammalian development. Overall, our results reveal the mechanisms by which Activin-Nodal signaling acts through SIP1 to regulate the cell-fate decision between neuroectoderm and mesendoderm in the progression from pluripotency to primary germ layer differentiation.
authors.affiliation: Laboratory for Regenerative Medicine, West Forvie Building, Robinson Way, University of Cambridge, Cambridge, CB2 0SZ, UK.
authors.forename: Zhenzhi
authors.initials: Z
authors.lastname: Chng
authors.forename: Adrian
authors.initials: A
authors.lastname: Teo
authors.forename: Roger A
authors.initials: RA
authors.lastname: Pedersen
authors.forename: Ludovic
authors.initials: L
authors.lastname: Vallier
mesh_terms: D028341:Activins / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D004707:Endoderm / Q000166:cytology* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008648:Mesoderm / Q000166:cytology* / Q000378:metabolism*; D051379:Mice; D000071317:Nanog Homeobox Protein; D054258:Neural Plate / Q000166:cytology* / Q000378:metabolism*; D055457:Nodal Protein / Q000378:metabolism; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism*; D016601:RNA-Binding Proteins; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D018398:Homeodomain Proteins; D047908:Intracellular Signaling Peptides and Proteins; C486780:NANOG protein, human; C526007:NODAL protein, human; D000071317:Nanog Homeobox Protein; D055457:Nodal Protein; D050814:Octamer Transcription Factor-3; C494173:POU5F1 protein, human; D016601:RNA-Binding Proteins; C411545:SNIP1 protein, human; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors; D028341:Activins