Distinct Developmental Ground States of Epiblast Stem Cell Lines Determine Different Pluripotency Features

• Published in: Stem cells (Dayton, Ohio) Vol. 29; no. 10; pp. 1496 - 1503
• Main Authors: Bernemann, Christof, Greber, Boris, Ko, Kinarm, Sterneckert, Jared, Han, Dong Wook, Araúzo‐Bravo, Marcos J., Schöler, Hans R.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-10-2011
• Subjects: Animals; Cell biology; Cell Culture Techniques; Cell Differentiation; Cell Line; Culture Media, Conditioned; Developmental biology; Embryonic Stem Cells - cytology; Embryonic Stem Cells - metabolism; Epiblast stem cells; Fetal Proteins - genetics; Fetal Proteins - metabolism; Gastrulation; Gene Expression Regulation; Gene Expression Regulation, Developmental; Germ Layers - cytology; Germ Layers - embryology; Germ Layers - growth & development; Immunohistochemistry; Mice; Mice, SCID; Octamer Transcription Factor-3 - genetics; Octamer Transcription Factor-3 - metabolism; Oligonucleotide Array Sequence Analysis; Pluripotency; Pluripotent Stem Cells - cytology; Polymerase Chain Reaction - methods; RNA Interference; SOXB1 Transcription Factors - genetics; SOXB1 Transcription Factors - metabolism; T-Box Domain Proteins - genetics; T-Box Domain Proteins - metabolism; Teratoma - metabolism; Teratoma - pathology; Transfection
• ISSN: 1066-5099; 1549-4918
• DOI: 10.1002/stem.709

Epiblast stem cells (EpiSCs) are pluripotent stem cells derived from mouse postimplantation embryos at embryonic day (E) 5.5–E7.5 at the onset of gastrulation, which makes them a valuable tool for studying mammalian postimplantation development in vitro. EpiSCs can also be reprogrammed into a mouse embryonic stem cell (mESC)‐like state. Some reports have shown that the reversion of EpiSCs requires transcription factor overexpression, whereas others have suggested that use of stringent mESC culture conditions alone is sufficient for the reversion of EpiSCs. To clarify these discrepancies, we systematically compared a panel of independent EpiSC lines. We found that—regardless of the embryonic day of derivation—the different EpiSC lines shared a number of defining characteristics such as the ability to form teratomas. However, despite use of standard EpiSC culture conditions, some lines exhibited elevated expression of genes associated with mesendodermal differentiation. Pluripotency (Oct4) and mesodermal (Brachyury) marker genes were coexpressed in this subset of lines. Interestingly, the expression of mesendodermal marker genes was negatively correlated with the cells' ability to efficiently undergo neural induction. Moreover, these mesodermal marker gene‐expressing cell lines could not be efficiently reverted to an mESC‐like state by using stringent mESC culture conditions. Conversely, Brachyury overexpression diminished the reversion efficiency in otherwise Brachyury‐negative lines. Overall, our data suggest that different EpiSC lines may undergo self‐renewal into distinct developmental states, a finding with important implications for functional readouts such as reversion of EpiSCs to an mESC‐like state as well as directed differentiation. STEM CELLS 2011;29:1496–1503