title: Gro/TLE enables embryonic stem cell differentiation by repressing pluripotent gene expression.
abstract: Gro/TLE proteins (TLE1-4) are a family of transcriptional corepressors acting downstream of multiple signalling pathways. Several TLEs are expressed in a dynamic manner throughout embryonic development and at high levels in embryonic stem cells (ESCs). Here we find that Gro/TLE is not required in ESC for sustaining pluripotency and suppressing differentiation genes, but rather is important for the shutting down of the pluripotency network in differentiation. Consistent with this view, we found that one of the Gro/TLE family, TLE4 is expressed heterogeneously in ESCs in a population that corresponds to a Nanog low subset of ESC culture. TLE4 expression is also increased in response to LIF withdrawal and Fgf/Mek/Erk stimulation. To explore the role of Gro/TLE in more detail we generated an allelic series of knockout ESCs of two TLE genes expressed most dynamically in early differentiation, TLE3 and TLE4. Genetic reduction in TLE dose resulted in an increase in the expression of pluripotency markers and inhibition of ESC differentiation towards both epiblast and endoderm lineages. Overexpression of a drug inducible TLE4 could both rescue TLE3/TLE4 compound phenotypes and induce early expression of endoderm (Hhex-Venus) and neural (Sox1-GFP) reporter genes. Taken together, our results suggest that TLE activity is essential for early differentiation where it acts to suppress the pluripotency network, allowing for the initiation of lineage specific gene expression programs.
authors.affiliation: MRC Centre for Regenerative Medicine-Institute for Stem Cell Research, School of Biological Sciences, 5 Little France Drive, University of Edinburgh, Edinburgh EH16 4UU, UK.
authors.forename: Adam F
authors.initials: AF
authors.lastname: Laing
authors.affiliation: MRC Centre for Regenerative Medicine-Institute for Stem Cell Research, School of Biological Sciences, 5 Little France Drive, University of Edinburgh, Edinburgh EH16 4UU, UK.
authors.forename: Sally
authors.initials: S
authors.lastname: Lowell
authors.affiliation: MRC Centre for Regenerative Medicine-Institute for Stem Cell Research, School of Biological Sciences, 5 Little France Drive, University of Edinburgh, Edinburgh EH16 4UU, UK; The Danish Stem Cell Centre-DanStem, University of Copenhagen, 3B Blegdamsvej, DK-2200 Copenhagen, Denmark. Electronic address: joshua.brickman@sund.ku.dk.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Brickman
mesh_terms: D000483:Alleles; D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D056970:Co-Repressor Proteins / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology*; D004707:Endoderm / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D008957:Models, Genetic; D010641:Phenotype; D039904:Pluripotent Stem Cells / Q000166:cytology*; D012097:Repressor Proteins / Q000378:metabolism / Q000502:physiology*
chemical_list: D056970:Co-Repressor Proteins; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; C434946:Tle1 protein, mouse; C104849:Tle3 protein, mouse; C434949:Tle4 protein, mouse; D049452:Green Fluorescent Proteins
keywords: Differentiation; Embryonic stem cells; Gro/TLE; Pluripotency