title: Altered aggrecan synthesis and collagen expression profiles in chondrocytes from patients with Kashin-Beck disease and osteoarthritis.
abstract: OBJECTIVE
  To investigate cell morphology, aggrecan expression, and type I, II, III and X collagen expression in chondrocytes from adults with Kashin-Beck disease or osteoarthritis (OA).
  
  
  METHODS
  Samples of knee articular cartilage were taken during surgery; cartilage samples  obtained from fresh cadavers without arthritic disease were used as controls. Samples were digested with collagenase; isolated chondrocytes were cultured in monolayers. Aggrecan was detected by toluidine blue staining; collagen and aggrecan protein levels were evaluated by immuno cytochemistry  and immuno fluorescence staining.
  
  
  RESULTS
  Samples were obtained from six participants per group. Aggrecan and type II collagen levels in chondrocytes from patients were significantly lower than those from controls, but levels of type I, III and X collagen were enhanced in patients compared  with controls. Production of type III and X collagen was higher in chondrocytes from patients with Kashin-Beck disease than in those from OA patients.
  
  
  CONCLUSIONS
  Biochemical and morphological mechanisms underlying Kashin-Beck disease and OA include enhanced dedifferentiation  and hypertrophy of chondrocytes, increased type I, III and X collagen levels, and suppressed type II collagen and aggrecan production compared with control samples.
authors.affiliation: Department of Orthopaedic Surgery, Second Affiliated Hospital of Xi'an Jiaotong University, and Institute of Endemic Diseases, Faculty of Public Health, College of Meidicne, Ministry of Education, Xi'an Jiaotong University, Xi'an, Shanxi Province, China.
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Gao
authors.forename: X
authors.initials: X
authors.lastname: Guo
authors.forename: C
authors.initials: C
authors.lastname: Duan
authors.forename: W
authors.initials: W
authors.lastname: Ma
authors.forename: P
authors.initials: P
authors.lastname: Xu
authors.forename: W
authors.initials: W
authors.lastname: Wang
authors.forename: J C
authors.initials: JC
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D053674:Aggrecans / Q000096:biosynthesis*; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology; D016022:Case-Control Studies; D019902:Chondrocytes / Q000378:metabolism*; D005260:Female; D024022:Fibrillar Collagens / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D057767:Kashin-Beck Disease / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000378:metabolism* / Q000473:pathology
chemical_list: C508319:ACAN protein, human; D053674:Aggrecans; D024022:Fibrillar Collagens