title: Syndecan-1 regulates BMP signaling and dorso-ventral patterning of the ectoderm during early Xenopus development.
abstract: Extracellular regulation of growth factor signaling is a key event for embryonic patterning. Heparan sulfate proteoglycans (HSPG) are among the molecules that regulate this signaling during embryonic development. Here we study the function of syndecan1 (Syn1), a cell-surface HSPG expressed in the non-neural ectoderm during early development of Xenopus embryos. Overexpression of Xenopus Syn1 (xSyn1) mRNA is sufficient to reduce BMP signaling, induce chordin expression and rescue dorso-ventral patterning in ventralized embryos. Experiments using chordin morpholinos established that xSyn1 mRNA can inhibit BMP signaling in the absence of chordin. Knockdown of xSyn1 resulted in a reduction of BMP signaling and expansion of the neural plate with the concomitant reduction of the non-neural ectoderm. Overexpression of xSyn1 mRNA in xSyn1 morphant embryos resulted in a biphasic effect, with BMP being inhibited at high concentrations and activated at low concentrations of xSyn1. Interestingly, the function of xSyn1 on dorso-ventral patterning and BMP signaling is specific for this HSPG. In summary, we report that xSyn1 regulates dorso-ventral patterning of the ectoderm through modulation of BMP signaling.
authors.affiliation: Center for Aging and Regeneration, Center for Cell Regulation and Pathology, MIFAB, Faculty of Biological Sciences, P. Universidad Católica de Chile, Alameda 340, Santiago, Chile.
authors.forename: Gonzalo H
authors.initials: GH
authors.lastname: Olivares
authors.forename: Héctor
authors.initials: H
authors.lastname: Carrasco
authors.forename: Francisco
authors.initials: F
authors.lastname: Aroca
authors.forename: Loreto
authors.initials: L
authors.lastname: Carvallo
authors.forename: Fabián
authors.initials: F
authors.lastname: Segovia
authors.forename: Juan
authors.initials: J
authors.lastname: Larraín
mesh_terms: D000818:Animals; D001483:Base Sequence; D019521:Body Patterning / Q000502:physiology*; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D017931:DNA Primers; D004475:Ectoderm / Q000196:embryology*; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering; D015398:Signal Transduction / Q000502:physiology*; D053668:Syndecan-1 / Q000235:genetics / Q000502:physiology*; D014982:Xenopus laevis / Q000196:embryology*
chemical_list: D019485:Bone Morphogenetic Proteins; D017931:DNA Primers; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D053668:Syndecan-1