title: Co-culture of mechanically injured cartilage with joint capsule tissue alters chondrocyte expression patterns and increases ADAMTS5 production.
abstract: We studied changes in chondrocyte gene expression, aggrecan degradation, and aggrecanase production and activity in normal and mechanically injured cartilage co-cultured with joint capsule tissue. Chondrocyte expression of 21 genes was measured at 1, 2, 4, 6, 12, and 24h after treatment; clustering analysis enabled identification of co-expression profiles. Aggrecan fragments retained in cartilage and released to medium and loss of cartilage sGAG were quantified. Increased expression of MMP-13 and ADAMTS4 clustered with effects of co-culture, while increased expression of ADAMTS5, MMP-3, TGF-beta, c-fos, c-jun clustered with cartilage injury. ADAMTS5 protein within cartilage (immunohistochemistry) increased following injury and with co-culture. Cartilage sGAG decreased over 16-days, most severely following injury plus co-culture. Cartilage aggrecan was cleaved at aggrecanase sites in the interglobular and C-terminal domains, resulting in loss of the G3 domain, especially after injury plus co-culture. Together, these results support the hypothesis that interactions between injured cartilage and other joint tissues are important in matrix catabolism after joint injury.
authors.affiliation: Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Lee
authors.forename: J B
authors.initials: JB
authors.lastname: Fitzgerald
authors.forename: M A
authors.initials: MA
authors.lastname: DiMicco
authors.forename: D M
authors.initials: DM
authors.lastname: Cheng
authors.forename: C R
authors.initials: CR
authors.lastname: Flannery
authors.forename: J D
authors.initials: JD
authors.lastname: Sandy
authors.forename: A H
authors.initials: AH
authors.lastname: Plaas
authors.forename: A J
authors.initials: AJ
authors.lastname: Grodzinsky
mesh_terms: D051722:ADAM Proteins / Q000096:biosynthesis*; D053674:Aggrecans / Q000378:metabolism; D000818:Animals; D002356:Cartilage / Q000293:injuries* / Q000378:metabolism* / Q000473:pathology; D002417:Cattle; D019902:Chondrocytes / Q000378:metabolism* / Q000473:pathology; D018920:Coculture Techniques; D010450:Endopeptidases / Q000378:metabolism; D005786:Gene Expression Regulation; D017746:Joint Capsule / Q000378:metabolism* / Q000473:pathology; D053509:Matrix Metalloproteinase 13 / Q000096:biosynthesis; D017434:Protein Structure, Tertiary; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000096:biosynthesis
chemical_list: D053674:Aggrecans; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D016212:Transforming Growth Factor beta; D010450:Endopeptidases; D051722:ADAM Proteins; D053509:Matrix Metalloproteinase 13; C083641:aggrecanase