title: Abrogation of E-cadherin-mediated cell-cell contact in mouse embryonic stem cells results in reversible LIF-independent self-renewal.
abstract: We have previously demonstrated that differentiation of embryonic stem (ES) cells is associated with downregulation of cell surface E-cadherin. In this study, we assessed the function of E-cadherin in mouse ES cell pluripotency and differentiation. We show that inhibition of E-cadherin-mediated cell-cell contact in ES cells using gene knockout (Ecad(-/-)), RNA interference (EcadRNAi), or a transhomodimerization-inhibiting peptide (CHAVC) results in cellular proliferation and maintenance of an undifferentiated phenotype in fetal bovine serum-supplemented medium in the absence of leukemia inhibitory factor (LIF). Re-expression of E-cadherin in Ecad(-/-), EcadRNAi, and CHAVC-treated ES cells restores cellular dependence to LIF supplementation. Although reversal of the LIF-independent phenotype in Ecad(-/-) ES cells is dependent on the beta-catenin binding domain of E-cadherin, we show that beta-catenin null (betacat(-/-)) ES cells also remain undifferentiated in the absence of LIF. This suggests that LIF-independent self-renewal of Ecad(-/-) ES cells is unlikely to be via beta-catenin signaling. Exposure of Ecad(-/-), EcadRNAi, and CHAVC-treated ES cells to the activin receptor-like kinase inhibitor SB431542 led to differentiation of the cells, which could be prevented by re-expression of E-cadherin. To confirm the role of transforming growth factor beta family signaling in the self-renewal of Ecad(-/-) ES cells, we show that these cells maintain an undifferentiated phenotype when cultured in serum-free medium supplemented with Activin A and Nodal, with fibroblast growth factor 2 required for cellular proliferation. We conclude that transhomodimerization of E-cadherin protein is required for LIF-dependent ES cell self-renewal and that multiple self-renewal signaling networks subsist in ES cells, with activity dependent upon the cellular context.
authors: Core Technology Facility, Faculty of Medical and Human Sciences, and The University of Manchester, Manchester, United Kingdom.
authors: Francesca
authors: F
authors: Soncin
authors: Lisa
authors: L
authors: Mohamet
authors: Dominik
authors: D
authors: Eckardt
authors: Sarah
authors: S
authors: Ritson
authors: Angela M
authors: AM
authors: Eastham
authors: Nicoletta
authors: N
authors: Bobola
authors: Angela
authors: A
authors: Russell
authors: Steve
authors: S
authors: Davies
authors: Rolf
authors: R
authors: Kemler
authors: Catherine L R
authors: CL
authors: Merry
authors: Christopher M
authors: CM
authors: Ward
mesh_terms: D028341:Activins / Q000494:pharmacology; D000818:Animals; D015820:Cadherins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D002417:Cattle; D002450:Cell Communication / Q000187:drug effects / Q000235:genetics; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D053605:Leukemia Inhibitory Factor / Q000494:pharmacology*; D051379:Mice; D055457:Nodal Protein / Q000494:pharmacology; D055503:Protein Multimerization / Q000235:genetics / Q000502:physiology; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism / Q000502:physiology
chemical_list: D015820:Cadherins; D053605:Leukemia Inhibitory Factor; D055457:Nodal Protein; C422405:activin A; D051176:beta Catenin; D016222:Fibroblast Growth Factor 2; D028341:Activins