title: Gata4 blocks somatic cell reprogramming by directly repressing Nanog.
abstract: Somatic cells can be reprogrammed to induced pluripotent stem (iPS) cells by ectopic expression of the four factors Oct4, Klf4, Sox2, and Myc. Here, we investigated the role of Gata4 in the reprogramming process and present evidence for a negative role of this family of transcription factors in the induction of pluripotency. Coexpression of Gata4 with Oct4, Klf4, and Sox2 with or without Myc in mouse embryonic fibroblasts greatly impaired reprogramming and endogenous Nanog expression. The lack of Nanog upregulation was associated with a blockade in the transition from the initiation phase of reprogramming to the full pluripotent state characteristic of iPS cells. Addition of Nanog to the reprogramming cocktail blocked the deleterious effects observed with Gata4 expression. Downregulation of endogenous Gata4 by short hairpin RNAs during reprogramming both accelerated and increased the efficiency of the process and augmented the mRNA levels of endogenous Nanog. Using comparative genomics, we identified a consensus binding site for Gata factors in an evolutionary conserved region located 9 kb upstream of the Nanog gene. Using chromatin immunoprecipitation, gel retardation, and luciferase assays, we found that Gata4 bound to this region and inhibited Nanog transcription in mouse embryonic stem cells. Overall, our results describe for first time the negative effect of Gata4 in the reprogramming of somatic cells and highlight the role of Gata factors in the transcriptional networks that control cell lineage choices in the early embryo.
authors.affiliation: Unidad de Hepatología Experimental, CIBERehd, Instituto de Investigación Sanitaria La Fe, Valencia, Spain.
authors.forename: Felipe
authors.initials: F
authors.lastname: Serrano
authors.forename: Carles F
authors.initials: CF
authors.lastname: Calatayud
authors.forename: Marina
authors.initials: M
authors.lastname: Blazquez
authors.forename: Josema
authors.initials: J
authors.lastname: Torres
authors.forename: Jose V
authors.initials: JV
authors.lastname: Castell
authors.forename: Roque
authors.initials: R
authors.lastname: Bort
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D002460:Cell Line; D065150:Cellular Reprogramming; D047369:Chromatin Immunoprecipitation; D015536:Down-Regulation; D024202:Electrophoretic Mobility Shift Assay; D053595:Embryonic Stem Cells / Q000378:metabolism*; D050991:GATA4 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D051542:Hepatocyte Nuclear Factor 3-beta / Q000378:metabolism; D018398:Homeodomain Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism; D051379:Mice; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3 / Q000378:metabolism; D039904:Pluripotent Stem Cells / Q000378:metabolism*; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering; D055748:SOXB1 Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: C496503:Foxa2 protein, mouse; D050991:GATA4 Transcription Factor; C484171:Gata4 protein, mouse; D018398:Homeodomain Proteins; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; C489428:Myc protein, mouse; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D055748:SOXB1 Transcription Factors; C527783:Sox2 protein, mouse; D051542:Hepatocyte Nuclear Factor 3-beta