title: Inhibition of transforming growth factor β signaling promotes epiblast formation in mouse embryos.
abstract: Early lineage segregation in preimplantation embryos and maintenance of pluripotency in embryonic stem cells (ESCs) are both regulated by specific signaling pathways. Small molecules have been shown to modulate these signaling pathways. We examined the influence of several small molecules and growth factors on second-lineage segregation of the inner cell mass toward hypoblast and epiblast lineage during mouse embryonic preimplantation development. We found that the second-lineage segregation is influenced by activation or inhibition of the transforming growth factor (TGF)β pathway. Inhibition of the TGFβ pathway from the two-cell, four-cell, and morula stages onward up to the blastocyst stage significantly increased the epiblast cell proliferation. The epiblast formed in the embryos in which TGFβ signaling was inhibited was fully functional as demonstrated by the potential of these epiblast cells to give rise to pluripotent ESCs. Conversely, activating the TGFβ pathway reduced epiblast formation. Inhibition of the glycogen synthase kinase (GSK)3 pathway and activation of bone morphogenetic protein 4 signaling reduced the formation of both epiblast and hypoblast cells. Activation of the protein kinase A pathway and of the Janus kinase/signal transducer and activator of transcription 3 pathway did not influence the second-lineage segregation in mouse embryos. The simultaneous inhibition of three pathways--TGFβ, GSK3β, and the fibroblast growth factor (FGF)/extracellular signal-regulated kinases (Erk)--significantly enhanced the proliferation of epiblast cells than that caused by inhibition of either TGFβ pathway alone or by combined inhibition of the GSK3β and FGF/Erk pathways only.
authors.affiliation: 1 Ghent Fertility and Stem Cell Team (G-FAST), Department for Reproductive Medicine, Ghent University Hospital , Ghent, Belgium .
authors.forename: Sabitri
authors.initials: S
authors.lastname: Ghimire
authors.forename: Björn
authors.initials: B
authors.lastname: Heindryckx
authors.forename: Margot
authors.initials: M
authors.lastname: Van der Jeught
authors.forename: Jitesh
authors.initials: J
authors.lastname: Neupane
authors.forename: Thomas
authors.initials: T
authors.lastname: O'Leary
authors.forename: Sylvie
authors.initials: S
authors.lastname: Lierman
authors.forename: Winnok H
authors.initials: WH
authors.lastname: De Vos
authors.forename: Susana
authors.initials: S
authors.lastname: Chuva de Sousa Lopes
authors.forename: Tom
authors.initials: T
authors.lastname: Deroo
authors.forename: Petra
authors.initials: P
authors.lastname: De Sutter
mesh_terms: D051700:Activating Transcription Factor 3 / Q000378:metabolism; D000818:Animals; D055415:Bone Morphogenetic Protein 4 / Q000378:metabolism; D019070:Cell Lineage; D049109:Cell Proliferation; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D005855:Germ Layers / Q000166:cytology* / Q000196:embryology / Q000378:metabolism; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D053612:Janus Kinases / Q000378:metabolism; D051379:Mice; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000378:metabolism*
chemical_list: D051700:Activating Transcription Factor 3; C525810:Bmp4 protein, mouse; D055415:Bone Morphogenetic Protein 4; D016212:Transforming Growth Factor beta; D053612:Janus Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D038362:Glycogen Synthase Kinase 3