title: Specific glycosaminoglycans modulate neural specification of mouse embryonic stem cells.
abstract: Mouse embryonic stem (mES) cells express a low sulfated form of heparan sulfate (HS). HS chains displayed by ES cells and their progeny become more complex and more sulfated during progression from pluripotency to neuroectodermal precursors. Sulfated epitopes are important for recognition and binding of a variety of ligands including members of the fibroblast growth factor (FGF) family. We demonstrated previously that mES cells lacking HS cannot undergo neural specification but this activity can be recovered by adding soluble heparin, a highly sulfated glycosaminoglycan (GAG). Therefore, we hypothesized that soluble GAGs might be used to support neural differentiation of HS competent cells and that the mechanisms underlying this activity might provide useful information about the signaling pathways critical for loss of pluripotency and early lineage commitment. In this study, we demonstrate that specific HS/heparin polysaccharides support formation of Sox1(+) neural progenitor cells from wild-type ES cells. This effect is dependent on sulfation pattern, concentration, and length of saccharide. Using a selective inhibitor of FGF signal transduction, we show that heparin modulates signaling events regulating exit from pluripotency and commitment to primitive ectoderm and subsequently neuroectoderm. Interestingly, we were also able to demonstrate that multiple receptor tyrosine kinases were influenced by HS in this system. This suggests roles for additional factors, possibly in cell proliferation or protection from apoptosis, during the process of neural specification. Therefore, we conclude that soluble GAGs or synthetic mimics could be considered as suitable low-cost factors for addition to ES cell differentiation regimes.
authors.affiliation: Stem Cell Glycobiology Group, School of Materials Science, University of Manchester, Manchester, United Kingdom.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Pickford
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Holley
authors.forename: Graham
authors.initials: G
authors.lastname: Rushton
authors.forename: Marios P
authors.initials: MP
authors.lastname: Stavridis
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Ward
authors.forename: Catherine L R
authors.initials: CL
authors.lastname: Merry
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000032:analysis / Q000096:biosynthesis; D005346:Fibroblast Growth Factors / Q000037:antagonists & inhibitors / Q000378:metabolism; D005434:Flow Cytometry; D055786:Gene Knockout Techniques; D006025:Glycosaminoglycans / Q000378:metabolism*; D019812:Heparan Sulfate Proteoglycans / Q000378:metabolism*; D051379:Mice; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics; D054258:Neural Plate / Q000196:embryology; D058953:Neural Stem Cells / Q000166:cytology* / Q000378:metabolism*; D034741:RNA, Small Interfering; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D055748:SOXB1 Transcription Factors / Q000096:biosynthesis; D015398:Signal Transduction; D000099065:Exostosin 2; D000099058:Exostosin 1
chemical_list: D006025:Glycosaminoglycans; D019812:Heparan Sulfate Proteoglycans; D034741:RNA, Small Interfering; D055748:SOXB1 Transcription Factors; C098693:Sox1 protein, mouse; D005346:Fibroblast Growth Factors; D017351:N-Acetylglucosaminyltransferases; D000099058:Exostosin 1; D000099065:Exostosin 2; D020794:Receptor Protein-Tyrosine Kinases; D048049:Extracellular Signal-Regulated MAP Kinases