title: YKL-40 as a novel factor associated with inflammation and catabolic mechanisms in osteoarthritic joints.
abstract: YKL-40 is associated with tissue injury and inflammation, and consequently to diseases in which these mechanisms lead to tissue degradation, for example, asthma and rheumatoid arthritis. The purpose of the present study was to investigate if YKL-40 is also a significant factor in osteoarthritis (OA) by assessing associations of YKL-40 with mediators related to the pathogenesis of OA: cartilage destructing matrix metalloproteinases (MMPs) and proinflammatory cytokines interleukin-6 (IL-6) and interleukin-17 (IL-17). Cartilage, synovial fluid (SF), and plasma samples were obtained from 100 OA patients undergoing total knee replacement surgery. SF levels of YKL-40 (1027.9 ± 78.3 ng/mL) were considerably higher than plasma levels (67.2 ± 4.5 ng/mL) and correlated with YKL-40 released from cartilage samples obtained from the same patients (r = 0.37, P = 0.010), indicating that YKL-40 is produced by OA cartilage. Interestingly, YKL-40 concentrations in OA SF correlated positively with MMP-1 (r = 0.36, P = 0.014), MMP-3 (r = 0.46, P = 0.001), IL-6 (r = 0.57, P < 0.001), and IL-17 (r = 0.52, P = 0.010) levels. Moreover, IL-6 and IL-17 enhanced YKL-40 production in human primary chondrocyte cultures. The present study introduces YKL-40 as a cartilage-derived factor associated with mediators of inflammation and cartilage destruction involved in the pathogenesis of OA.
authors.affiliation: The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, 33014 Tampere, Finland.
authors.forename: Tuija
authors.initials: T
authors.lastname: Väänänen
authors.affiliation: The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, 33014 Tampere, Finland.
authors.forename: Anna
authors.initials: A
authors.lastname: Koskinen
authors.affiliation: The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, 33014 Tampere, Finland.
authors.forename: Erja-Leena
authors.identifier: 0000-0003-3076-7408
authors.initials: EL
authors.lastname: Paukkeri
authors.affiliation: The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, 33014 Tampere, Finland.
authors.forename: Mari
authors.initials: M
authors.lastname: Hämäläinen
authors.affiliation: The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, 33014 Tampere, Finland ; Coxa Hospital for Joint Replacement, P.O. Box 652, 33101 Tampere, Finland.
authors.forename: Teemu
authors.initials: T
authors.lastname: Moilanen
authors.affiliation: The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, 33014 Tampere, Finland.
authors.forename: Eeva
authors.identifier: 0000-0002-8577-0316
authors.initials: E
authors.lastname: Moilanen
authors.affiliation: The Immunopharmacology Research Group, University of Tampere School of Medicine and Tampere University Hospital, 33014 Tampere, Finland.
authors.forename: Katriina
authors.identifier: 0000-0003-0017-1291
authors.initials: K
authors.lastname: Vuolteenaho
mesh_terms: D054392:Adipokines / Q000378:metabolism*; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000378:metabolism*; D019645:Arthroplasty, Replacement, Knee; D002356:Cartilage / Q000378:metabolism; D002478:Cells, Cultured; D000071451:Chitinase-3-Like Protein 1; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006801:Humans; D007249:Inflammation / Q000378:metabolism*; D020381:Interleukin-17 / Q000378:metabolism / Q000494:pharmacology; D015850:Interleukin-6 / Q000378:metabolism / Q000494:pharmacology; D037102:Lectins / Q000378:metabolism*; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism*; D013582:Synovial Fluid / Q000378:metabolism
chemical_list: D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D020381:Interleukin-17; D015850:Interleukin-6; D037102:Lectins; D019278:Matrix Metalloproteinase 3; D020781:Matrix Metalloproteinase 1