title: The G3 domain of versican inhibits mesenchymal chondrogenesis via the epidermal growth factor-like motifs.
abstract: Versican is a highly expressed proteoglycan in zones of developing tissues. To investigate whether versican plays a role in cell differentiation, we studied its role in mesenchymal condensation and chondrogenesis. Here we report that a mini-versican gene product inhibits mesenchymal chondrogenesis but not condensation. The mini-versican-treated mesenchymal cultures form fewer, smaller cartilaginous nodules and produced lower levels of link protein and type II collagen. The versican G3 domain alone, but not G1, was sufficient to inhibit mesenchymal chondrogenesis. Deletion of two epidermal growth factor (EGF)-like motifs in the G3 domain abolished the effect of versican. The G3 domain of aggrecan, which does not contain an EGF-like motif, did not inhibit mesenchymal chondrogenesis. We also generated a chimera construct containing the two EGF-like motifs of versican and the G3 domain of aggrecan, and we observed that this chimera construct inhibited chondrogenesis to a lesser extent than did the full-length versican G3 construct. Direct transfection of mesenchymal cells with different constructs produced similar results. Furthermore, treatment with versican antisense oligonucleotides and transfection with a versican antisense construct promoted chondrogenesis. Taken together, our results strongly suggest that versican inhibits mesenchymal chondrogenesis via its EGF-like motifs.
authors.affiliation: Sunnybrook Health Science Centre and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto M4N 3M5, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: L
authors.initials: L
authors.lastname: Cao
authors.forename: C G
authors.initials: CG
authors.lastname: Kiani
authors.forename: B L
authors.initials: BL
authors.lastname: Yang
authors.forename: B B
authors.initials: BB
authors.lastname: Yang
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002642:Chick Embryo; D020219:Chondrogenesis; D011508:Chondroitin Sulfate Proteoglycans / Q000737:chemistry / Q000378:metabolism*; D017931:DNA Primers; D004815:Epidermal Growth Factor / Q000737:chemistry / Q000378:metabolism*; D037181:Lectins, C-Type; D008648:Mesoderm; D051379:Mice; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D053675:Versicans
chemical_list: D011508:Chondroitin Sulfate Proteoglycans; D017931:DNA Primers; D037181:Lectins, C-Type; D011994:Recombinant Proteins; C508323:Vcan protein, mouse; D053675:Versicans; D004815:Epidermal Growth Factor