title: Transcriptional profiling of initial differentiation events in human embryonic stem cells.
abstract: Currently, there are no differentiation strategies for human embryonic stem cells (hESCs) that efficiently produce one specific cell type, possibly because of lack of understanding of the genes that control signaling events prior to overt differentiation. sed HepG2 cell conditioned medium (MEDII), which induces early differentiation in mouse ES cells while retaining pluripotent markers, to query gene expression in hESCs. Treatment of adherent hESCs with 50% MEDII medium effected differentiation to a cell type with gene expression similar to primitive streak stage cells of mouse embryos. MEDII treatment up-regulates TDGF1 (Cripto), a gene essential for anterior-posterior axis and mesoderm formation in mouse embryos and a key component of the TGFB1/NODAL signaling pathway. LEFTYA, an antagonist of NODAL/TDGF1 signaling expressed in anterior visceral endoderm, is down-regulated with MEDII treatment, as is FST, an inhibitor of mesoderm induction via the related INHBE1 pathway. In summary, the TGFB1/NODAL pathway is important for primitive-streak and mesoderm formation and in using MEDII, we present a means for generating an in vitro cell population that maintains pluripotent gene expression (POU5F1, NANOG) and SSEA-4 markers while regulating genes in the TGFB1/NODAL pathway, which may lead to more uniform formation of mesoderm in vitro.
authors.affiliation: Department of Biochemistry and Molecular Biology, The University of Georgia, Athens, GA 30602, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Calhoun
authors.forename: Raj R
authors.initials: RR
authors.lastname: Rao
authors.forename: Susanne
authors.initials: S
authors.lastname: Warrenfeltz
authors.forename: Romdhane
authors.initials: R
authors.lastname: Rekaya
authors.forename: Stephen
authors.initials: S
authors.lastname: Dalton
authors.forename: John
authors.initials: J
authors.lastname: McDonald
authors.forename: Steven L
authors.initials: SL
authors.lastname: Stice
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000737:chemistry*; D018929:Cell Culture Techniques / Q000379:methods*; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D003470:Culture Media / Q000378:metabolism; D017077:Culture Media, Conditioned / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D023822:Tissue Engineering / Q000379:methods*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D003470:Culture Media; D017077:Culture Media, Conditioned; D014157:Transcription Factors