title: Comparative proteomic characterization of articular cartilage tissue from normal donors and patients with osteoarthritis.
abstract: OBJECTIVE
  To identify potential molecular mediators and biomarkers for osteoarthritis (OA), through comparative proteomic analysis of articular cartilage tissue obtained from normal donors without OA (n = 7) and patients with OA (n = 7).
  
  
  METHODS
  The proteomic analyses comprised extraction of soluble proteins from cartilage, separation of the protein mixtures by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by in-gel digestion, and subsequent nano-liquid chromatography-tandem mass spectrometry analysis in conjunction with a database search for protein identification and semiquantitation.
  
  
  RESULTS
  A total of 814 distinct proteins were identified with high confidence from 14 samples; 420 of these proteins were detected with > or = 3 unique peptides in at least 4 samples from the same group. Using stringent criteria, 59 proteins were found to be differentially expressed in OA cartilage. Gene Ontology and Ingenuity pathway analysis tools were used to characterize these proteins into functional categories. One of the up-regulated proteins, HtrA1, a serine protease, was detected at high levels in cartilage.
  
  
  CONCLUSIONS
  Altered protein expression in the disease state is associated with many aspects of the pathogenesis of OA, such as increased proteolysis, lipid metabolism, immune response, and decreased signal transduction. To our knowledge, this is the first time that a large portion of these proteins and their expression patterns were identified in cartilage, thus providing new insights for finding novel pathologic mediators and biomarkers of OA.
authors.affiliation: Wyeth Research, Cambridge, Massachusetts 02140, USA.
authors.forename: Jiang
authors.initials: J
authors.lastname: Wu
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Amanda
authors.initials: A
authors.lastname: Bemis
authors.forename: Eunice
authors.initials: E
authors.lastname: Wang
authors.forename: Yongchang
authors.initials: Y
authors.lastname: Qiu
authors.forename: Elisabeth A
authors.initials: EA
authors.lastname: Morris
authors.forename: Carl R
authors.initials: CR
authors.lastname: Flannery
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism*; D002358:Cartilage, Articular / Q000378:metabolism* / Q000473:pathology; D002853:Chromatography, Liquid; D019295:Computational Biology; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism* / Q000473:pathology; D040901:Proteomics / Q000379:methods*; D012995:Solubility; D053719:Tandem Mass Spectrometry
chemical_list: D015415:Biomarkers