Open AccessDual regulation of metalloproteinase expression in chondrocytes by Wnt‐1–inducible signaling pathway protein 3/CCN6
Author(s) -
Baker Natasha,
Sharpe Paul,
Culley Kirsty,
Otero Miguel,
Bevan Damon,
Newham Peter,
Barker Wendy,
Clements Kristen M.,
Langham Caroline J.,
Goldring Mary B.,
Gavrilović Jelena
Publication year - 2012
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.34411
Subject(s) - cartilage , wnt signaling pathway , signal transduction , small interfering rna , chemistry , gene silencing , cancer research , microbiology and biotechnology , rna , biology , gene , biochemistry , anatomy
Objective Wnt‐1–inducible signaling pathway protein 3 (WISP‐3)/CCN6 is mutated in progressive pseudorheumatoid dysplasia and may have effects on cartilage homeostasis. The aim of this study was to ascertain additional roles for WISP‐3/CCN6 by determining its expression in osteoarthritic (OA) cartilage and by investigating its effects on cartilage‐relevant metalloproteinase expression in immortalized (C‐28/I2) and primary chondrocytes. Methods Cartilage steady‐state levels of WISP‐3/CCN6 messenger RNA and protein production were determined by real‐time quantitative reverse transcription–polymerase chain reaction (RT‐PCR) and immunohistochemistry, respectively. WISP‐3/CCN6 was overexpressed in C‐28/I2 cells, and the resultant clones were analyzed by quantitative RT‐PCR. The stable clones were analyzed by RT‐PCR for metalloproteinase expression, and the signaling pathways involved were investigated using pharmacologic inhibition. The effects of WISP‐3/CCN6 on metalloproteinase expression in primary chondrocytes were investigated using a small interfering RNA approach. Results WISP‐3/CCN6 was highly expressed in OA cartilage compared with undamaged cartilage, at both the RNA and protein levels. WISP‐3/CCN6 overexpression in C‐28/I2 cells resulted in unexpected dual regulation of metalloproteinases; expression of the potent aggrecanase ADAMTS‐5 was down‐regulated 9‐fold, while expression of MMP‐10 was up‐regulated 14‐fold, and these responses were accentuated in the WISP‐3/CCN6 clones grown in suspension. MMP‐10 up‐regulation was dependent on several MAPKs, but WISP‐3/CCN6–mediated ADAMTS‐5 repression was independent of these pathways and was partially relieved by activation of β‐catenin signaling. WISP‐3/CCN6 also suppressed ADAMTS‐5 expression in C‐28/I2 cells treated with cytokines. In cytokine‐treated primary chondrocytes, gene silencing of WISP‐3/CCN6 resulted in enhanced ADAMTS‐5 expression, while MMP‐10 expression was suppressed. Conclusion WISP‐3/CCN6 was highly expressed in end‐stage OA cartilage, suggesting a role for this growth factor in cartilage homeostasis. WISP‐3/CCN6–induced repression of ADAMTS‐5 expression and regulation of MMP‐10 expression suggest complex and context‐dependent roles for WISP‐3/CCN6 in cartilage biology.