title: Syndecan-1 expression is upregulated in degenerating articular cartilage in a transgenic mouse model for osteoarthritis.
abstract: OBJECTIVE
  Mice heterozygous for the Del1 transgene locus with a short deletion mutation in the type II collagen gene develop early-onset degenerative changes in the knee joints that progress to end-stage osteoarthritis by the age of 12-15 months. This study focuses on the expression and distribution of syndecan-1, a cell-surface heparan sulfate proteoglycan, during the development of osteoarthritic cartilage degeneration, to better understand its role in this disease.
  
  
  METHODS
  Northern analyses of total RNA extracted from knee joints of transgenic Del1 mice and their nontransgenic controls were used to monitor changes in syndecan-1 mRNA levels during development, growth, ageing, and cartilage degeneration. Immunohistochemistry was used to study the distribution of syndecan-1 in the knee joints at different stages of cartilage degeneration.
  
  
  RESULTS
  Syndecan-1 mRNA was present in knee joints throughout life, with the highest mRNA levels in ageing knee joints. In Del1 mice, a transient upregulation of syndecan-1 mRNA synthesis was observed at the age of 6 months coinciding with early stages of cartilage degeneration and a period of attempted repair. Immunostaining for syndecan-1 was most intense in chondrocytes of superficial and intermediate zones of articular cartilage adjacent to defect areas. Chondrocyte clusters also stained strongly for syndecan-1.
  
  
  CONCLUSIONS
  The present temporospatial expression data on upregulation of syndecan-1 in articular cartilage during early stages of cartilage degeneration suggest that this molecule is involved in the attempted repair of cartilage fibrillations. Combined with the known role of syndecan-1 during skeletal development and wound healing, this interesting finding warrants further validation.
authors.affiliation: Department of Medical Biochemistry, University of Turku, Finland. heli.salminen@utu.fi
authors.forename: H
authors.initials: H
authors.lastname: Salminen-Mankonen
authors.forename: A-M
authors.initials: AM
authors.lastname: Säämänen
authors.forename: M
authors.initials: M
authors.lastname: Jalkanen
authors.forename: E
authors.initials: E
authors.lastname: Vuorio
authors.forename: L
authors.initials: L
authors.lastname: Pirilä
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D002358:Cartilage, Articular / Q000378:metabolism*; D007150:Immunohistochemistry; D007719:Knee Joint / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D020370:Osteoarthritis, Knee / Q000235:genetics* / Q000378:metabolism; D011509:Proteoglycans / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D053668:Syndecan-1; D053667:Syndecans; D015854:Up-Regulation
chemical_list: D008562:Membrane Glycoproteins; D011509:Proteoglycans; D012333:RNA, Messenger; C508242:Sdc1 protein, mouse; D053668:Syndecan-1; D053667:Syndecans