title: Enhanced expression of insulin-like growth factor-binding proteins in human osteoarthritic cartilage detected by immunohistochemistry and in situ hybridization.
abstract: OBJECTIVE
  To determine the roles of insulin-like growth factor (IGF) and IGF-binding protein (IGFBP) in the pathogenesis of osteoarthritis (OA).
  
  
  METHODS
  Cartilage tissues were obtained from the femoral heads of patients with OA, and those from patients with femoral neck fractures were used as a control. The expression of IGFBP-3, -4, and -5 was examined using immunohistochemistry and in situ hybridization, and IGF-I and IGF-I receptors were also immunohistochemically detected. The percentages of positive chondrocytes were determined by counting the total number of chondrocytes over the area of the surface, middle, and deep zones of the cartilage.
  
  
  RESULTS
  There was a marked increase in the percentage of positive chondrocytes in all IGFBPs on protein and messenger RNA levels for OA compared to that of the control cartilage. Furthermore, enhanced expression of IGFBPs and the IGF-I/IGF-I receptor was positively correlated with the histologic score for cartilage lesions.
  
  
  CONCLUSIONS
  Up-regulation of IGFBPs as well as IGF-I and its receptor was observed for OA cartilage tissue, suggesting the involvement of IGFBPs in the pathogenesis of OA.
authors.affiliation: Department of Orthopedic Surgery, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan.
authors.forename: Hiotoshi
authors.initials: H
authors.lastname: Iwanaga
authors.forename: Tomoko
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Enomoto
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Okano
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Hishikawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Shindo
authors.forename: Takehiko
authors.initials: T
authors.lastname: Koji
mesh_terms: D000328:Adult; D000368:Aged; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology; D002452:Cell Count; D019902:Chondrocytes / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000032:analysis; D018974:Insulin-Like Growth Factor Binding Protein 4 / Q000032:analysis; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000032:analysis; D018969:Insulin-Like Growth Factor Binding Proteins / Q000032:analysis*; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D017526:Receptor, IGF Type 1 / Q000032:analysis; D013002:Somatomedins / Q000032:analysis*
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D018974:Insulin-Like Growth Factor Binding Protein 4; D018975:Insulin-Like Growth Factor Binding Protein 5; D018969:Insulin-Like Growth Factor Binding Proteins; D012333:RNA, Messenger; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1