Expression and regulation of human beta-defensin-2 in osteoarthritic cartilage.

Abstract

Defensins are antibiotic peptides that are involved in host defence at epithelial and mesenchymal surfaces. Previous studies have shown the induction of human beta-defensin-3 (HBD-3) in osteoarthritic joints, suggesting that these molecules have functions in addition to their ability to kill microbes. The aim of this study was to investigate the production of a further human beta-defensin, named HBD-2, in osteoarthritis (OA) and to determine its regulation by inflammatory cytokines. Healthy and osteoarthritic cartilage was assessed for HBD-2 expression by RT-PCR, immunohistochemistry, and ELISA. C28/I2 chondrocytes, primary chondrocytes, and cartilage explants were cultured for in vitro studies. After 24 h of stimulation with tumour necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1) or IL-6, real-time RT-PCR and ELISA experiments were performed to evaluate the effect of these cytokines on the production of HBD-2. In contrast to healthy cartilage, HBD-2 expression was identified in most of the OA samples examined (eight of ten). Cytokines that are potentially involved in the pathogenesis of OA, namely TNF-alpha, IL-1, and IL-6, were transcriptional inducers of HBD-2 in cultured chondrocytes and cartilage explants in vitro, as measured by real-time RT-PCR and ELISA. These results illustrate the induction of HBD-2 in osteoarthritic cartilage and suggest that it is a further factor in the pathogenesis of OA. However, further studies are required to elucidate the role played by HBD-2 in osteoarthritic cartilage.

• Authors: D Varoga, F P Paulsen, S Kohrs, S Grohmann, S Lippross, R Mentlein, B N Tillmann, M B Goldring, L Besch, T Pufe
• Journal: The Journal of pathology (J Pathol) Vol. 209 Issue 2 Pg. 166-73 (Jun 2006) ISSN: 0022-3417 [Print] England
• PMID: 16622898 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright (c) 2006 Pathological Society of Great Britain and Ireland.

Chemical References

• Anti-Infective Agents
• DEFB4A protein, human
• Interleukin-1
• Interleukin-6
• RNA, Messenger
• Tumor Necrosis Factor-alpha
• beta-Defensins

Topics

• Adult
• Aged
• Anti-Infective Agents (analysis)
• Cartilage, Articular (chemistry)
• Cells, Cultured
• Chondrocytes (immunology, metabolism, microbiology)
• Enzyme-Linked Immunosorbent Assay (methods)
• Humans
• Immunohistochemistry (methods)
• Interleukin-1 (immunology)
• Interleukin-6 (immunology)
• Middle Aged
• Osteoarthritis (genetics, immunology, metabolism)
• Pseudomonas aeruginosa
• RNA, Messenger (analysis)
• Reverse Transcriptase Polymerase Chain Reaction (methods)
• Tumor Necrosis Factor-alpha (immunology)
• Up-Regulation (genetics)
• beta-Defensins (analysis, genetics)