JPP 2006, 58: 359–366 © 2006 The Authors Received August 1, 2005 Accepted November 21, 2005 DOI 10.1211/jpp.58.3.0010 ISSN 0022-3573 359 Suppression of matrix metalloproteinase production from synovial fibroblasts by meloxicam in-vitro Kazuhito Asano, Misako Sakai, Takako Matsuda, Hironori Tanaka, Keigo Fujii and Tadashi Hisamitsu Abstract The aim of this study was to evaluate the influence of meloxicam on the production of both matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) from human synovial fibroblasts by TNF-a stimulation in-vitro. Synovial fibroblasts (2 × 10 4 cells/mL) derived from patients with osteoarthritis were stimulated with 20.0 ng mL -1 TNF-a in the presence of various concentra- tions of meloxicam. After 24 h, the culture supernatants were obtained and assayed for MMP-1, MMP-2, MMP-3, MMP-13, TIMP-1 and TIMP-2 by ELISA. mRNA expression for MMPs and TIMPs in 4- h-cultured cells were examined by real-time polymerase chain reaction. Transcriptional factor (NF-κ B and AP-1) activation in 2-h-cultured cells was also examined by ELISA. Meloxicam could suppress MMP production in a dose-dependent manner. The minimum concentration of the agent that showed significant suppression was 0.6 × 10 -6 M for MMP-1, MMP-2 and MMP-3, and 1.3 × 10 -6 M for MMP-13. The ability of synovial fibroblasts to produce TIMPs was also suppressed by meloxicam as in the case of MMP production. Addition of meloxicam into synovial fibroblast cultures inhibited dose- dependently mRNA expression for MMPs and TIMPs, which were increased by TNF-a stimulation, through the suppression of NF-kB and AP-1 activation. The suppressive effect of meloxicam on the production of MMPs and TIMPs may partly be involved in attenuation of the clinical conditions of osteoarthritis and rheumatoid arthritis. Osteoarthritis (OA) is characterized by loss of articular cartilage and secondary bone as well as changes to the synovium, including marginal osteophyte formation and synovitis (Alt- man 1997). The two main macromolecules of articular cartilage extracellular matrix are the large aggregating proteoglycans, aggrecan and type II collagen (Gendron et al 2003). Type II collagen fibrillar network forms the backbone of cartilage and provides it with stability and tensile strength, while the proteoglycan component is highly hydrated, absorbs loads and provides cartilage with compressive stiffness. Destruction of these components has been observed to occur in OA cartilage (Gendron et al 2003; Kafienah et al 2003). It has been shown that both biochemical and mechanical changes may contribute to the development of OA. Chondrocytes may respond to excessive loading by elaboration of deg- radative enzymes and inappropriate repair responses (Grodzinsky et al 2000; Jin et al 2000). Furthermore, a number of studies have also demonstrated that inflammatory cytokines, such as interleukin (IL)-1 and tumour necrosis factor (TNF), as well as functional changes of chondrocytes themselves, play potential roles in the process of deterioration by inducing expression of proteinases, such as those of the matrix metalloproteinase (MMP) family (Shinmei et al 1991; Westacott & Sharif 1996; Yuan et al 2001). MMPs are members of a unique family of zinc-binding endopeptidases that are responsible for degradation of colla- gen, elastin and other macromolecules of the extracellular matrix (Sadowski & Steinmeyer 2001; Kafienah et al 2003). As expected from their degradative nature, the uncontrolled expression of MMPs has been reported to be associated with many pathological conditions in articular cartilage of both rheumatoid arthritis and OA (Yamada et al 1996; Kafienah et al 2003), whereas their controlled expression is essential for normal tissue remodelling and wound healing (Nagase & Woessner 1999). Introduction Department of Physiology, School of Medicine, Showa University, Tokyo, Japan Kazuhito Asano, Misako Sakai, Takako Matsuda, Hironori Tanaka, Keigo Fujii, Tadashi Hisamitsu Correspondence: K. Asano, Department of Physiology, School of Medicine, Showa University, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan. E-mail: asanok@med. showa-u.ac.jp Funding: This study was supported in part by Nippon Boehringer Ingelheim Co. Ltd (Hyogo, Japan).