title: Aggrecanase- and matrix metalloproteinase-mediated aggrecan degradation is associated with different molecular characteristics of aggrecan and separated in time ex vivo.
abstract: Aggrecan is one of the first proteins to be depleted from articular cartilage in early osteoarthritis. We investigated the molecular differences between matrix metalloproteinase (MMP)- and aggrecanase-mediated aggrecan degradation, as a consequence of their distinct time-dependent degradation profiles. Cartilage degradation was induced by cytokine stimulation in bovine articular cartilage explants and quantified by a dye-binding assay and immunoassays. The size of degradation fragments was analysed by Western blot. Cytokine stimulation resulted in the early release of aggrecanase-mediated aggrecan degradation fragments. In contrast, MMP-mediated aggrecan degradation began only at day 16 and continued to day 21. Western blot analysis showed that glycosylated high-molecular-weight (374)ARGSVI fragments appeared at day 7, in contrast to deglycosylated low-molecular-weight (342)FFGVG fragments which were detected at day 21. Aggrecan degradation may be divided into two different pools, a high-molecular-weight aggrecanase-mediated pool, and a low-molecular-weight MMP-mediated pool. This may have implications for the development of intervention strategies for OA.
authors.affiliation: Nordic Bioscience A/S, Herlev, Denmark.
authors.forename: Suzi Hoegh
authors.initials: SH
authors.lastname: Madsen
authors.forename: Eren Ufuk
authors.initials: EU
authors.lastname: Sumer
authors.forename: Anne-Christine
authors.initials: AC
authors.lastname: Bay-Jensen
authors.forename: Bodil-Cecilie
authors.initials: BC
authors.lastname: Sondergaard
authors.forename: Per
authors.initials: P
authors.lastname: Qvist
authors.forename: Morten Asser
authors.initials: MA
authors.lastname: Karsdal
mesh_terms: D051722:ADAM Proteins / Q000378:metabolism; D000071121:ADAMTS4 Protein; D053674:Aggrecans / Q000378:metabolism*; D000818:Animals; D015415:Biomarkers / Q000097:blood*; D015153:Blotting, Western / Q000379:methods; D002356:Cartilage / Q000378:metabolism; D002417:Cattle; D016207:Cytokines / Q000378:metabolism*; D010450:Endopeptidases / Q000097:blood*; D006025:Glycosaminoglycans / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D020782:Matrix Metalloproteinases / Q000097:blood*; D023421:Models, Animal; D008954:Models, Biological; D010003:Osteoarthritis / Q000097:blood / Q000175:diagnosis*; D011348:Procollagen N-Endopeptidase / Q000378:metabolism
chemical_list: D053674:Aggrecans; D015415:Biomarkers; D016207:Cytokines; D006025:Glycosaminoglycans; D010450:Endopeptidases; D051722:ADAM Proteins; D020782:Matrix Metalloproteinases; D011348:Procollagen N-Endopeptidase; D020780:Matrix Metalloproteinase 9; D000071121:ADAMTS4 Protein; C083641:aggrecanase