title: Heparan sulfate facilitates FGF and BMP signaling to drive mesoderm differentiation of mouse embryonic stem cells.
abstract: Heparan sulfate (HS) has been implicated in regulating cell fate decisions during differentiation of embryonic stem cells (ESCs) into advanced cell types. However, the necessity and the underlying molecular mechanisms of HS in early cell lineage differentiation are still largely unknown. In this study, we examined the potential of EXT1(-/-) mouse ESCs (mESCs), that are deficient in HS, to differentiate into primary germ layer cells. We observed that EXT1(-/-) mESCs lost their differentiation competence and failed to differentiate into Pax6(+)-neural precursor cells and mesodermal cells. More detailed analyses highlighted the importance of HS for the induction of Brachyury(+) pan-mesoderm as well as normal gene expression associated with the dorso-ventral patterning of mesoderm. Examination of developmental cell signaling revealed that EXT1 ablation diminished FGF and BMP but not Wnt signaling. Furthermore, restoration of FGF and BMP signaling each partially rescued mesoderm differentiation defects. We further show that BMP4 is more prone to degradation in EXT1(-/-) mESCs culture medium compared with that of wild type cells. Therefore, our data reveal that HS stabilizes BMP ligand and thereby maintains the BMP signaling output required for normal mesoderm differentiation. In summary, our study demonstrates that HS is required for ESC pluripotency, in particular lineage specification into mesoderm through facilitation of FGF and BMP signaling.
authors.affiliation: Complex Carbohydrate Research Center and Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Kraushaar
authors.forename: Sumit
authors.initials: S
authors.lastname: Rai
authors.forename: Eduard
authors.initials: E
authors.lastname: Condac
authors.forename: Alison
authors.initials: A
authors.lastname: Nairn
authors.forename: Siyuan
authors.initials: S
authors.lastname: Zhang
authors.forename: Yu
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Kelley
authors.initials: K
authors.lastname: Moremen
authors.forename: Stephen
authors.initials: S
authors.lastname: Dalton
authors.forename: Lianchun
authors.initials: L
authors.lastname: Wang
mesh_terms: D000818:Animals; D000925:Anticoagulants / Q000494:pharmacology; D055415:Bone Morphogenetic Protein 4 / Q000378:metabolism* / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D019070:Cell Lineage / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003470:Culture Media / Q000494:pharmacology; D004475:Ectoderm / Q000166:cytology / Q000187:drug effects; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects; D005326:Fetal Proteins / Q000235:genetics / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism* / Q000494:pharmacology; D006493:Heparin / Q000494:pharmacology; D006497:Heparan Sulfate / Q000378:metabolism* / Q000494:pharmacology; D008648:Mesoderm / Q000166:cytology / Q000187:drug effects; D051379:Mice; D008817:Mice, Mutant Strains; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics / Q000378:metabolism; D054258:Neural Plate / Q000166:cytology / Q000187:drug effects; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism; D060449:Wnt Signaling Pathway / Q000187:drug effects / Q000502:physiology*; D000098908:Brachyury Protein; D000099058:Exostosin 1
chemical_list: D000925:Anticoagulants; D055415:Bone Morphogenetic Protein 4; D003470:Culture Media; D005326:Fetal Proteins; D016222:Fibroblast Growth Factor 2; D006493:Heparin; D006497:Heparan Sulfate; D017351:N-Acetylglucosaminyltransferases; D012333:RNA, Messenger; D020825:T-Box Domain Proteins; D000098908:Brachyury Protein; D000099058:Exostosin 1; C525810:Bmp4 protein, mouse