HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS REGISTER		Author Keyword(s) Vol Page [Advanced]

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this link to a friend Similar articles in this journal Similar articles in PubMed Add article to my folders Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Tardif, G Articles by Martel-Pelletier, J Search for Related Content PubMed PubMed Citation Articles by Tardif, G Articles by Martel-Pelletier, J

Differential regulation of the bone morphogenic protein antagonist chordin in human normal and osteoarthritic chondrocytes

¹ Osteoarthritis Research Unit, Hôpital Notre-Dame, Quebec, Canada
² Pavillon des Charmilles, Vimont, Quebec

Correspondence to:
Correspondence to:
Dr Johanne Martel-Pelletier
Osteoarthritis Research Unit, Hôpital Notre-Dame, Centre Hospitalier de l’Université de Montréal, 1560 Sherbrooke Street East, Montreal, Quebec, Canada H2L 4M1; jm{at}martelpelletier.ca

ABSTRACT
Objective: To investigate the distribution of the bone morphogenic protein (BMP) antagonist chordin in normal and osteoarthritic cartilage and synovial membranes, and its regulation in chondrocytes and synovial fibroblasts by inflammatory and growth factors.

Methods: Localisation of chordin in tissues was undertaken by immunohistochemistry and gene regulation was determined by real time polymerase chain reaction.

Results: In normal cartilage, chordin was found at low levels (mean (SD), 7.6 (1.3)%), mainly in the very superficial layers. In osteoarthritis, chordin was also found in the superficial layers (8.9 (1.1)%), though at a significantly higher level (24.7 (1.5)%) in the last two thirds of the cartilage. In contrast to normal cells, chordin mRNA and protein levels were significantly downregulated (p<0.01) in osteoarthritic chondrocytes by all the growth factors tested. Interferon stimulated chordin expression in normal but not in osteoarthritic chondrocytes (p<0.0002), while interleukin 1ß and tumour necrosis factor did not affect the expression level. However, no difference was found in either the distribution or regulation of chordin in normal and osteoarthritic synovial membranes or synovial fibroblasts.

Conclusions: The differential distribution and regulation of chordin in normal and osteoarthritic cartilage and chondrocytes suggests an involvement of this antagonist in the osteoarthritic process.

Abbreviations: Act.A, activin A; BMP, bone morphogenic protein; bFGF, basic fibroblast growth factor; EGF, epithelial growth factor; IFN, interferon ; IL1ß, interleukin 1ß; PDGF-BB, platelet derived growth factor BB; TGFß1, transforming growth factor ß1; TNF, tumour necrosis factor

Keywords: chordin; osteoarthritis; chondrocyte; synovial fibroblast