title: Inhibition of glycosaminoglycan incorporation influences collagen network formation during cartilage matrix production.
abstract: To understand cartilage degenerative diseases and improve repair procedures, we investigate the influence of glycosaminoglycans (GAGs) on cartilage matrix biochemistry and functionality. Bovine articular chondrocytes were cultured in alginate beads with(out) para-nitrophenyl-beta-d-xyloside (PNPX) to inhibit GAG incorporation into newly formed proteoglycans. As expected, GAG deposition in alginate beads decreased with increasing PNPX concentration. Next to GAGs, collagen deposition and cross-linking also decreased. In the presence of PNPX, GAGs and collagen were deposited further away from the chondrocyte than in the control and increased amounts were found in the culture medium. These changes resulted in decreased functional properties of the construct. We conclude that in our culture system, intact proteoglycans play a role in deposition of collagen and thus the formation of a functional matrix. The effect of less proteoglycans on the collagen network could explain why cartilage repair is ineffective in osteoarthritis and help us with development of new therapies.
authors.affiliation: Erasmus MC, University Medical Centre Rotterdam, Department of Orthopaedics, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.
authors.forename: Yvonne M
authors.initials: YM
authors.lastname: Bastiaansen-Jenniskens
authors.forename: Wendy
authors.initials: W
authors.lastname: Koevoet
authors.forename: Kaspar M B
authors.initials: KM
authors.lastname: Jansen
authors.forename: Jan A N
authors.initials: JA
authors.lastname: Verhaar
authors.forename: Jeroen
authors.initials: J
authors.lastname: DeGroot
authors.forename: Gerjo J V M
authors.initials: GJ
authors.lastname: VanOsch
mesh_terms: D000464:Alginates / Q000737:chemistry; D000818:Animals; D002356:Cartilage / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure*; D002417:Cattle; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D003094:Collagen / Q000378:metabolism / Q000648:ultrastructure*; D024043:Collagen Type II / Q000235:genetics; D015870:Gene Expression; D020723:Glucuronic Acid / Q000737:chemistry; D006025:Glycosaminoglycans / Q000378:metabolism*; D006027:Glycosides / Q000737:chemistry / Q000494:pharmacology; D006603:Hexuronic Acids / Q000737:chemistry; D055758:SOX9 Transcription Factor / Q000235:genetics; D046509:Tissue Culture Techniques
chemical_list: D000464:Alginates; D024043:Collagen Type II; D006025:Glycosaminoglycans; D006027:Glycosides; D006603:Hexuronic Acids; D055758:SOX9 Transcription Factor; C008646:4-nitrophenyl beta-D-xyloside; D020723:Glucuronic Acid; D003094:Collagen