title: Lacrimal gland development and Fgf10-Fgfr2b signaling are controlled by 2-O- and 6-O-sulfated heparan sulfate.
abstract: Heparan sulfate, an extensively sulfated glycosaminoglycan abundant on cell surface proteoglycans, regulates intercellular signaling through its binding to various growth factors and receptors. In the lacrimal gland, branching morphogenesis depends on the interaction of heparan sulfate with Fgf10-Fgfr2b. To address if lacrimal gland development and FGF signaling depends on 2-O-sulfation of uronic acids and 6-O-sulfation of glucosamine residues, we genetically ablated heparan sulfate 2-O and 6-O sulfotransferases (Hs2st, Hs6st1, and Hs6st2) in developing lacrimal gland. Using a panel of phage display antibodies, we confirmed that these mutations disrupted 2-O and/or 6-O but not N-sulfation of heparan sulfate. The Hs6st mutants exhibited significant lacrimal gland hypoplasia and a strong genetic interaction with Fgf10, demonstrating the importance of heparan sulfate 6-O sulfation in lacrimal gland FGF signaling. Altering Hs2st caused a much less severe phenotype, but the Hs2st;Hs6st double mutants completely abolished lacrimal gland development, suggesting that both 2-O and 6-O sulfation of heparan sulfate contribute to FGF signaling. Combined Hs2st;Hs6st deficiency synergistically disrupted the formation of Fgf10-Fgfr2b-heparan sulfate complex on the cell surface and prevented lacrimal gland induction by Fgf10 in explant cultures. Importantly, the Hs2st;Hs6st double mutants abrogated FGF downstream ERK signaling. Therefore, Fgf10-Fgfr2b signaling during lacrimal gland development is sensitive to the content or arrangement of O-sulfate groups in heparan sulfate. To our knowledge, this is the first study to show that simultaneous deletion of Hs2st and Hs6st exhibits profound FGF signaling defects in mammalian development.
authors.affiliation: Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
authors.forename: Xiuxia
authors.initials: X
authors.lastname: Qu
authors.forename: Christian
authors.initials: C
authors.lastname: Carbe
authors.forename: Chenqi
authors.initials: C
authors.lastname: Tao
authors.forename: Andrea
authors.initials: A
authors.lastname: Powers
authors.forename: Roger
authors.initials: R
authors.lastname: Lawrence
authors.forename: Toin H
authors.initials: TH
authors.lastname: van Kuppevelt
authors.forename: Wellington V
authors.initials: WV
authors.lastname: Cardoso
authors.forename: Kay
authors.initials: K
authors.lastname: Grobe
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Esko
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D051526:Fibroblast Growth Factor 10 / Q000378:metabolism*; D005346:Fibroblast Growth Factors / Q000378:metabolism; D006025:Glycosaminoglycans / Q000737:chemistry; D006497:Heparan Sulfate / Q000737:chemistry*; D007150:Immunohistochemistry / Q000379:methods; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D007765:Lacrimal Apparatus / Q000196:embryology / Q000254:growth & development*; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation; D020794:Receptor Protein-Tyrosine Kinases / Q000737:chemistry; D051497:Receptor, Fibroblast Growth Factor, Type 2 / Q000737:chemistry*; D015398:Signal Transduction; D013455:Sulfur / Q000737:chemistry*
chemical_list: D051526:Fibroblast Growth Factor 10; D005346:Fibroblast Growth Factors; D006025:Glycosaminoglycans; D006497:Heparan Sulfate; D036341:Intercellular Signaling Peptides and Proteins; D020794:Receptor Protein-Tyrosine Kinases; D051497:Receptor, Fibroblast Growth Factor, Type 2; D013455:Sulfur; C496463:FGF10 protein, human