title: Type II collagen synthesis in the articular cartilage of a rabbit model of osteoarthritis: expression of type II collagen C-propeptide and mRNA especially during early-stage osteoarthritis.
abstract: BACKGROUND
  The aim of this study was to observe time course changes in type II collagen synthesis in various regions of articular cartilage affected with osteoarthritis (OA) by examining the expression of type II collagen C-propeptide (pCOL II-C) and mRNA in a rabbit OA model.
  
  
  METHODS
  Osteoarthritis was experimentally induced by partial lateral meniscectomy in the knees of Japanese white rabbits. The cartilage of the animals was then examined histologically over time. The degenerative area of articular cartilage was divided into three areas, according to the degree of degeneration. The ability to synthesize type II collagen was estimated by the immunohistological staining of pCOL II-C and the in situ hybridization of mRNA in type II collagen.
  
  
  RESULTS
  The positive rate of pCOL II-C immunostaining in chondrocytes was highest in the central-degenerative region 1 week after surgery, and the highest rate in the para-degenerative region was observed 2 and 4 weeks after surgery. The percentage of pCOL II-C positive cells increased as the histological degeneration score increased to moderate degeneration and then decreased with further progression of the severity of cartilage degeneration. Examination by in situ hybridization revealed that the regions marked by strong pCOL II-C mRNA expression were similar to those indicated by the immunohistology results.
  
  
  CONCLUSIONS
  These results suggest that the type II collagen-synthesizing potential of chondrocytes is highest in moderately degenerated areas of OA articular cartilage. Cartilage repair continues to be seen even as OA advances, although the reaction varies depending on the stage of OA.
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Hiraku
authors.initials: H
authors.lastname: Hotta
authors.forename: Harumoto
authors.initials: H
authors.lastname: Yamada
authors.forename: Hironari
authors.initials: H
authors.lastname: Takaishi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Abe
authors.forename: Hideo
authors.initials: H
authors.lastname: Morioka
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kikuchi
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Fujikawa
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D019902:Chondrocytes / Q000378:metabolism / Q000648:ultrastructure; D024043:Collagen Type II / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D010003:Osteoarthritis / Q000378:metabolism* / Q000473:pathology; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D011347:Procollagen / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D011817:Rabbits
chemical_list: D024043:Collagen Type II; D010446:Peptide Fragments; D011347:Procollagen; D012333:RNA, Messenger; C093212:procollagen type II carboxy-terminal peptide