Rheumatoid Arthritis: Michel BA

Michel BA. · No affiliation provided · Z Rheumatol. · Pubmed #11759229 No free full text.

This publication has no abstract.

Senolt L, Grigorian M, Lukanidin E, Michel BA, Gay RE, Gay S, Pavelka K, Neidhart M. · Center of Experimental Rheumatology, Univ Hosp Zürich, Gloriastrasse 25, CH-8091 Zürich, Switzerland. · Autoimmun Rev. · Pubmed #16431343 No free full text.

Abstract: S100A4 (Mts1) belongs to the S100 family of calcium binding proteins, which are involved in diverse biological regulatory activities. An association between S100A4 and tumor progression has been demonstrated in several studies. S100A4 binds to distinct intracellular target proteins and regulates specific functions involved in tumor progression such as cell motility, proliferation and apoptosis as well as remodelling of the extracellular matrix. Once released from the tumor or tumor-activated stromal cells, it may influence certain functions of target cells towards a more aggressive phenotype. Extracellular S100A4 has been demonstrated to contribute to angiogenesis and the increased production of matrix-degrading enzymes by both endothelial and tumor cells. Moreover, S100A4 might be responsible for TCRgammadelta T-cell mediated lysis and negative regulation of matrix mineralization. Increased expression of S100A4 mRNA has recently been found in proliferating rheumatoid arthritis synovial fibroblasts and synovial tissues from rheumatoid arthritis patients. Synovial hyperplasia in rheumatoid arthritis consists of inflammatory cells and activated synovial lining cells which contribute to the progressive destruction of the joints during the disease. Since several phenomena are similar between rheumatoid arthritis and malignant tumors it can be hypothesized that S100A4 contributes to the invasive and tumor-like behavior of rheumatoid arthritis synovium.

Forster A, Michel BA. · Rheumaklinik und Institut für Physikalische Medizin Universitätsspital Zürich Gloriastrasse 25 8091 Zürich, Switzerland. · Z Rheumatol. · Pubmed #11759231 No free full text.

Abstract: Recently, biologic agents have become available for the treatment of rheumatoid arthritis. Such agents, the so-called TNF blockers, selectively inhibit TNF alpha, a dominant proinflammatory cytokine. They allow good suppression of the disease activity in many patients. Even in nonresponders to conventional disease modifying antirheumatic drugs (DMARDs) a good response may be achieved. The anti-erosive effect appears to be excellent. Major advantages are the fast response and good overall safety. Constitutional symptoms often disappear rapidly, which may contribute substantially to the gain in quality of life. Efficacy and safety are maintained even in long-term use. Because of certain risks and high costs TNF-blocking agents should be reserved for patients who respond poorly to conventional DMARDs or do not tolerate them.

Seemayer CA, Distler O, Kuchen S, Müller-Ladner U, Michel BA, Neidhart M, Gay RE, Gay S. · WHO-Collaborating Center for Molecular Biology and Novel Therapeutic Strategies of Rheumatic Diseases, Department of Rheumatology, University Hospital Zürich, Gloriastrasse 25, 8091 Zürich, Switzerland. · Z Rheumatol. · Pubmed #11759230 No free full text.

Abstract: Rheumatoid arthritis (RA) is a chronic inflammatory disease, which is mainly characterized by synovial hyperplasia, pathological immune phenomena and progressive destruction of the affected joints. Various cell types are involved in the pathogenesis of RA including T cells, antigen presenting cells, and endothelial cells. Recent experimental evidence suggests that the CD40/CD154 system might play an important role in the development of RA. Our experimental approach focuses on RA synovial fibroblasts (RA-SF) that are able to destroy articular cartilage independent of inflammation. To elucidate the specific role of those cells in RA pathophysiology the following questions are currently addressed: 1. Which mechanisms do activate the RA-SF? 2. How do the activated RA-SF attach to the cartilage? 3. How do RA-SF destroy cartilage and bone? Which mechanisms do activate the RA-SF? The process of activation is poorly understood. It is unclear, how far the synovial hyperplasia of RA resembles tumor diseases. Along this line some contradictory results exist concerning the role of the tumor suppressor protein p53. Some investigations could show the expression of p53 in the synovial lining including p53 mutations in RA synovium and in RASF, while other research groups could not confirm these data. Our group has demonstrated that the tumor suppressor PTEN was less expressed in the synovial lining of RA than in normal synovium, but no PTEN mutations could be found in the RA-SF. In addition, the in vivo and in vitro expression of the anti-apoptotic molecule sentrin suggests a functional resistance of RA-SF to undergo apoptosis. Although it is still unclear, whether certain viruses or viral elements are involved in the pathogenesis of RA (cause, consequence or coincidence?), certain viruses could play a role in the pathogenesis of RA. The endogenous retroviral element L1 was found to be expressed in the synovial lining, at sites of invasion as well as in RA-SF grown in vitro. Moreover, the data indicate that after the initial activation of L1 downstream molecules such as the SAP kinase 4, the met-protoonocogene and the galectin-3 binding protein are upregulated. How do the activated RA-SF attach to the cartilage? It has been suggested that integrins mediate the attachment of RA-SF to fibronectin rich sites of cartilage. Intriguingly, other adhesion molecules such as the vascular cellular adhesion molecule-1 (VCAM) and CS-1, a splice variant of fibronectin, are synthesized by RA-SF. By binding to these adhesion molecules, lymphocytes that express the integrin VLA-4 could be stimulated and thereby maintain the inflammatory process. Osteopontin is an extracellular matrix protein, which is associated with matrix adhesion and metastasis in tumors. In RA synovium, osteopontin was detectable in the synovial lining and at sites of invasion. How do RA-SF destroy cartilage and bone? The destruction of cartilage and bone in RA is mediated by matrix metalloproteinases (MMPs) and cathepsins. MMPs exist as secreted and as membrane bound forms. In vitro models are being developed to simulate the invasive process of RA-SF. In an in vitro model developed in our laboratory, the treatment of RA-SF with anti-CD44 or anti-interleukin-1 (IL-1) minimized matrix degradation of RA-SF. On the other hand, co-culture of RA-SF and U937 cells as well as application of interleukin-1 beta (IL-1 beta) or tumor necrosis factor alpha (TNF alpha) increased the invasiveness of RA-SF. Gene transfer of bovine pancreas trypsin inhibitor (BPMI) or interleukin-10 (IL-10) reduced the invasion of RA-SF, while transduction of interleukin-1 receptor antagonist (IL-1Ra) was chondroprotective. Double gene transfer of IL-10 and IL-1Ra resulted in both inhibition of invasion and chondroprotection.

Langenegger T, Michel BA. · Department of Rheumatology, University Hospital Zurich, Switzerland. · Clin Orthop Relat Res. · Pubmed #10627714 No free full text.

Abstract: The general goals of drug treatment for patients with rheumatoid arthritis are to reduce morbidity and mortality. Because rheumatoid arthritis is a potentially devastating disease, a more aggressive treatment approach has emerged in the last decade. The modern treatment pyramid consists of nonsteroidal antiinflammatory drugs and glucocorticoids for symptomatic relief, and disease modifying antirheumatic drugs for reducing disease activity in the short term and joint damage in the long term. There is increasing evidence that a reduction of disease activity by disease modifying antirheumatic drugs alters the course of rheumatoid arthritis and that patients benefit from early installation of these compounds. The major problem with disease modifying antirheumatic drugs is their low efficacy to toxicity ratio, leading to marked reduction of the length of time a patient is taking a given drug. The new treatment strategies, including combination regimens and new drugs that are being investigated, promise better efficacy and tolerance in the near future. A step in this direction is the development of biologic agents targeting specific mechanisms in the immune response. Early results in clinical trials with antitumor necrosis factor-alpha monoclonal antibodies are encouraging.

Hermann F, Forster A, Chenevard R, Enseleit F, Hürlimann D, Corti R, Spieker LE, Frey D, Hermann M, Riesen W, Neidhart M, Michel BA, Hellermann JP, Gay RE, Lüscher TF, Gay S, Noll G, Ruschitzka F. · No affiliation provided · J Am Coll Cardiol. · Pubmed #15680730 No free full text.

This publication has no abstract.

Fransen J, Stucki G, Twisk J, Chamot AM, Gerster JC, Langenegger T, Seitz M, Michel BA, Anonymous00013. · Department of Rheumatology and Institute of Physical Medicine, University Hospital Zurich, Switzerland. · Ann Rheum Dis. · Pubmed #12810423 links to  free full text

Abstract: BACKGROUND: With the help of a measurement feedback system, the treatment strategy for individual patients with rheumatoid arthritis (RA) can be adjusted to achieve optimal control of disease activity. OBJECTIVE: To study whether a measurement feedback system is effective in reducing disease activity in patients with RA. METHODS: Forty eight rheumatologists and 264 patients participated in a controlled clinical trial. A three month control period was followed by a 12 month period, where feedback on disease activity, disability, and damage was provided to the rheumatologist. The primary outcome measure was the rheumatoid arthritis disease activity index (RADAI). RESULTS: The feedback system was used for 142/228 (62%) patients. Disease modifying antirheumatic drug changes occurred in 69/169 (41%) patients. In patients with high disease activity and feedback use (n=70), the RADAI decreased in the feedback period by -0.27 points per 30 days (p<0.05), as compared with the control period. Patients for whom the feedback system was used had a better outcome than non-users. CONCLUSION: Much more training on the use of a feedback system and outcome measures, as well as the inclusion of explicit treatment guidelines will be necessary to increase the clinical use of measurement feedback and, possibly, to reduce disease activity for a larger number of patients with RA.

Hürlimann D, Forster A, Noll G, Enseleit F, Chenevard R, Distler O, Béchir M, Spieker LE, Neidhart M, Michel BA, Gay RE, Lüscher TF, Gay S, Ruschitzka F. · Cardiology Department, University Hospital, Zürich, Switzerland. · Circulation. · Pubmed #12390945 links to  free full text

Abstract: BACKGROUND: Rheumatoid arthritis (RA) is associated with accelerated atherosclerosis and increased cardiovascular morbidity and mortality. Striking similarities exist in the inflammatory and immunologic response in RA and atherosclerosis. Indeed, adhesion molecules and cytokines, tumor necrosis factor (TNF)-alpha in particular, are key mediators of joint inflammation and of vascular dysfunction and progression of atherosclerotic vascular disease. Hence, the aim of the present study was to assess the effect of chronic antiinflammatory treatment with the anti-TNF-alpha antibody infliximab on disease activity and endothelial function in patients with active RA. METHODS AND RESULTS: Eleven RA patients (mean age 46+/-5 years; disease duration 9+/-2 years) with high disease activity despite treatment with stable doses of methotrexate (<or=25 mg/wk) and prednisone (<or=10 mg/d) were investigated. Clinical status and endothelium-dependent and -independent vasodilation of the brachial artery as assessed by high-resolution ultrasound were measured before and after 12 weeks of infliximab therapy. Flow-mediated vasodilation improved from 3.2+/-0.4% to 4.1+/-0.5% (P=0.018), whereas endothelium-independent vasodilation with nitroglycerin and baseline diameter remained unchanged (13.6+/-1.2% versus 12.8+/-1.4%, P=0.98, and 3.74+/-0.15 versus 3.66+/-0.11 mm, P=0.54, respectively). Disease activity score (DAS28) was significantly reduced, from 5.6+/-0.3 to 3.5+/-0.6 (P=0.002). Erythrocyte sedimentation rate and C-reactive protein were lowered from 34+/-7 to 19+/-5 mm/h (P=0.04) and from 38+/-11 to 15+/-10 mg/L (P=0.08), respectively. CONCLUSIONS: This is the first study to show that anti-TNF-alpha treatment improves endothelial function in RA. The data suggest that in RA, endothelial dysfunction is part of the disease process and is mediated by TNF-alpha.

Ospelt C, Brentano F, Jüngel A, Rengel Y, Kolling C, Michel BA, Gay RE, Gay S. · Center of Experimental Rheumatology, University Hospital Zurich, and Zurich Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland. · Arthritis Rheum. · Pubmed #19180502 No free full text.

Abstract: OBJECTIVE: Since pattern-recognition receptors (PRRs), in particular Toll-like receptors (TLRs), were found to be overexpressed in the synovium of rheumatoid arthritis (RA) patients and to play a role in the production of disease-relevant molecules, we sought to determine the expression, regulation, and function of the PRR nucleotide-binding oligomerization domain 2 (NOD-2) in RA. METHODS: Expression of NOD-2 in synovial tissues was analyzed by immunohistochemistry. Expression and induction of NOD-2 in RA synovial fibroblasts (RASFs) were measured by conventional and real-time polymerase chain reaction (PCR) analyses. Levels of interleukin-6 (IL-6) and IL-8 were measured by enzyme-linked immunosorbent assay (ELISA) and expression of matrix metalloproteinases (MMPs) by ELISA and/or real-time PCR. NOD-2 expression was silenced with small interfering RNA. Western blotting with antibodies against phosphorylated and total p38, JNK, and ERK, as well as inhibitors of p38, JNK, and ERK was performed. Activation of NF-kappaB was measured by electrophoretic mobility shift assay. RESULTS: NOD-2 was expressed by fibroblasts and macrophages in the synovium of RA patients, predominantly at sites of invasion into articular cartilage. In cultured RASFs, no basal expression of messenger RNA for NOD-2 was detectable, but was induced by poly(I-C), lipopolysaccharide, and tumor necrosis factor alpha. After up-regulation of NOD-2 by TLR ligands, its ligand muramyl dipeptide (MDP) increased the expression of IL-6 and IL-8 via p38 and NF-kappaB. Stimulation with MDP further induced the expression of MMP-1, MMP-3, and MMP-13. CONCLUSION: Not only TLRs, but also the PRR NOD-2 is expressed in the synovium of RA patients, and activation of NOD-2 acts synergistically with TLRs in the production of proinflammatory and destructive mediators. Therefore, NOD-2 might contribute to the initiation and perpetuation of chronic, destructive inflammation in RA.

Ospelt C, Kurowska-Stolarska M, Neidhart M, Michel BA, Gay RE, Laufer S, Gay S. · Center of Experimental Rheumatology, University Hospital Zurich, Switzerland. · Ann Rheum Dis. · Pubmed #17666446 No free full text.

Abstract: OBJECTIVE: To find previously unknown properties of ML3000, a competitive inhibitor of the cyclooxygenase and the lipoxygenase (LO) pathway. METHODS: Gene expression of ML3000 treated and untreated rheumatoid arthritis synovial fibroblasts were measured with Affymetrix gene arrays. Downregulation of chemokine (C-X-C motif) ligands CXCL9, CXCL10 and CXCL11 was verified with Real-time polymerase chain reaction, CXCL10 protein levels were determined with ELISA. Rheumatoid arthritis synovial fibroblasts were treated with the cyclooxygenase inhibitor naproxen, the 5-LO inhibitor BWA4C and the 5-lipoxygenase-activating protein (FLAP) inhibitor MK886, and consecutive changes in CXCL10 protein levels measured. 5-LO expression was determined by polymerase chain reaction and Western blot. RESULTS: In synovial fibroblasts and monocyte-derived macrophages ML3000 inhibited the tumour necrosis factor induced expression of CXCL9, CXCL10 and CXCL11, which are all ligands of the chemokine receptor CXCR3. No effect was observed in monocytes. Whereas inhibition of the cyclooxygenase pathway or the FLAP protein showed no effect, blockade of 5-LO significantly downregulated CXCL10 protein levels. 5-LO mRNA was detected in monocytes and in monocyte-derived macrophages. All tested cell types expressed 5-LO protein. CONCLUSIONS: ML3000 effectively downregulates CXCR3 ligands. This study confirms that a thorough analysis of the impact of a drug on its target cells cannot only reveal unexpected properties of a substance, but also helps to understand the underlying molecular mechanisms. Accordingly, our data provide the basis for further clinical studies testing the application of ML3000 in diseases such as rheumatoid arthritis or multiple sclerosis.

Huber LC, Künzler P, Boyce SH, Michel BA, Gay RE, Ink BS, Gay S. · Center of Experimental Rheumatology, University Hospital Zurich, Gloriastrasse 25, CH-8091 Zurich, Switzerland. · Ann Rheum Dis. · Pubmed #17660218 No free full text.

Abstract: OBJECTIVE: Biologicals have revolutionised the treatment of rheumatoid arthritis (RA). However, progressive joint destruction can still be observed in many patients and the search for novel molecular therapies targeting specific signalling pathways is ongoing. In the present study, we investigated the effects of GW282974, a novel compound directed against tyrosine kinase activity with respect to the potential suppression of inflammation and destruction. METHODS: Synovial tissue specimens were obtained from RA patients undergoing surgical joint replacement. Rheumatoid arthritis synovial fibroblasts (RASFs) were stimulated with cytokines and GW282974 was added in different concentrations. Gene expression was checked by TaqMan PCR, using 18S as housekeeping gene. Protein analysis was quantified by ELISA. Cell growth and proliferation was measured using the "ViaLight" proliferation assay. RESULTS: EGF had no effect on the gene expression profile of RASFs when used as single stimulatory agent. In combination with pro-inflammatory mediators however, EGF showed a synergistic effect. The expression of matrix metalloproteinases, inflammatory cytokines and cyclooxygenase-2 on mRNA levels was strongly increased, whereas the addition of GW282974 abrogated these effects in a dose-dependent manner. These data could be confirmed on protein/lipid levels analysing the supernatants of RASFs by ELISA. Similarly, cell growth and proliferation of RASFs were inhibited by GW282974 in a dose- and time-dependent manner. By contrast, no cytotoxic effects were seen within the concentrations used. DISCUSSION: GW282974 appears to interfere with the inflammatory and the destructive pathways in RASFs and might therefore be used as novel therapeutic strategy for the treatment of RA.

Engler A, Aeschlimann A, Simmen BR, Michel BA, Gay RE, Gay S, Sprott H. · Center of Experimental Rheumatology, Department of Rheumatology and Institute of Physical Medicine, University Hospital, Gloriastrasse 25, Zurich, Switzerland. · Biochem Biophys Res Commun. · Pubmed #17560936 No free full text.

Abstract: The transient receptor potential vanilloid 1 (TRPV1) is a nonselective cation channel, which is mainly expressed by nociceptive neurons in dorsal root and trigeminal ganglia. However, there is increasing evidence that TRPV1 expression is not limited to primary afferent neurons but that the receptor is expressed in various cell types throughout the body. Here, we demonstrate the expression of TRPV1 in synovial fibroblasts (SF) from patients with symptomatic osteoarthritis (OA) and rheumatoid arthritis (RA). In addition, the mRNA expression of TRPV1 was shown in PBMCs from healthy controls and from OA patients. The presence of TRPV1 was confirmed at the protein level. Stimulation of cultured OA- and RA-SF with the TRPV1 agonist capsaicin led to increased expression of IL-6 mRNA as well as of IL-6 protein in the cell culture supernatants. IL-6 protein expression could be antagonized with capsazepine. Thus, we hypothesize that TRPV1 may play a role in non-neuronal mechanisms that might modulate nociception in symptomatic OA and RA patients.

Schmid S, Bossart W, Michel BA, Brühlmann P. · Department of Rheumatology and Physical Medicine, University Hospital of Zurich, Gloria-strasse 25, 8091 Zurich, Switzerland. · Rheumatol Int. · Pubmed #17401566 No free full text.

Abstract: To investigate the follow-up of the 17 patients during the period of 1995-2001 of the outpatient Clinic for Rheumatology at the University Hospital of Zurich with arthritis and the presence of parvovirus B19 DNA demonstrated by PCR in synovial biopsies. Seventeen patients of 163 with arthritis, which were routinely examined by needle arthroscopy during 1995-2001 with a positive parvovirus B19 DNA by PCR of synovial biopsy were reevaluated. Investigations included medical history, clinical examination and blood tests. Joint fluid was taken on patients with joint effusion. The observation period of the 17 patients (F:M = 11:6) was 2-8 years (Ø = 6.5 years). In 8 of 17 patients the arthritis could not be classified neither at entry nor during the follow up of the study. The arthritis could be diagnosed in six patients early in the onset of the disease and included three cases of lyme arthritis of the knee joint, two cases with arthritis following a gastrointestinal infection (one with Salmonella typhimurium--positive faecal test--and the other one with a culture negative agent), one patient probably had an infection-associated arthritis after a gastrointestinal infection with Entamöeba histolytica (Schirmer et al. in Rheumatol Int 18:37-38, 1998; Kasliwal in Am J Proctol Gastroenterol Colon Rectal Surg 32:12, 16, 28, 1981; Haslock and Wright in J R Coll Phys Lond 8:1554-162, 1974; Than-Saw et al. in Trop Geogr Med 44:355-358, 1992) with remission after antibiotic therapy. After a disease course of 9 months one patient could be classified as rheumatoid arthritis in the presence of anti-cyclic citrullinated antibodies but lack of rheumatoid factor. One patient with polyarthritis developed psoriasis of the skin 22 months later. From the nine patients with unclassified arthritis 4 (45%) got into complete remission with no symptoms or signs of joint inflammation after a disease course of 9-45 months, whereas 5 (55%) still demonstrate active non erosive arthritis (disease duration between 3 and 10 years). The presence of parvovirus B19 DNA in synovial tissue of patients with joint inflammation does not allow the diagnosis of parvovirus induced arthritis. If the arthritis remains unclassified and without erosions over time a virus associated aetiology may be assumed. However, no definitive diagnosis is possible even in the presence of parvovirus B19 DNA in synovial tissue.

Huber LC, Brock M, Hemmatazad H, Giger OT, Moritz F, Trenkmann M, Distler JH, Gay RE, Kolling C, Moch H, Michel BA, Gay S, Distler O, Jüngel A. · Center of Experimental Rheumatology, University Hospital Zurich, and Zurich Center of Integrative Human Physiology, Zurich, Switzerland. · Arthritis Rheum. · Pubmed #17393417 links to  free full text

Abstract: OBJECTIVE: Rheumatoid arthritis (RA) is a chronic inflammatory disorder of unknown origin. Histone deacetylase (HDA) activity is considered to play a major role in the transcriptional regulation of proinflammatory genes. We undertook this study to investigate the balance of histone acetylase and HDA activity in synovial tissue from RA patients compared with that from patients with osteoarthritis (OA) and normal controls. METHODS: Activity of histone acetylases and HDAs was measured in nuclear extracts of total synovial tissue samples, which were obtained from RA and OA patients undergoing surgical joint replacement, and compared with the activity in synovial tissues from patients without arthritis. Tissue expression of HDAs 1 and 2 was quantified by Western blotting. In addition, immunohistochemistry was performed for HDA-2. RESULTS: Mean+/-SEM HDA activity in synovial tissue samples derived from patients with RA was measured as 1.5+/-0.3 micromoles/microg, whereas the activity levels in OA (3.2+/-0.7 micromoles/microg) and normal (7.1+/-4.2 micromoles/microg) synovial tissue samples were significantly higher. Histone acetylase activity reached similar levels in RA and OA tissues and in normal tissues. The ratio of HDA activity to histone acetylase activity in RA synovial tissue was significantly reduced (12+/-2%) compared with that in OA synovial tissue (26+/-3%). The activity ratio in normal control samples was arbitrarily set at 100+/-40%. In addition, the tissue expression of HDA-1 and HDA-2 proteins was clearly lower in RA samples than in OA samples. CONCLUSION: The balance of histone acetylase/HDA activities is strongly shifted toward histone hyperacetylation in patients with RA. These results offer novel molecular insights into the pathogenesis of the disease that might be relevant to the development of future therapeutic approaches.

Senolt L, Grigorian M, Lukanidin E, Simmen B, Michel BA, Pavelka K, Gay RE, Gay S, Neidhart M. · Center for Experimental Rheumatology, University Hospital Zürich, Gloriastrasse 25, CH-8091 Zürich, Switzerland. · Ann Rheum Dis. · Pubmed #17105852 No free full text.

Abstract: The metastasis-associated protein S100A4 promotes the progression of cancer by regulating the remodelling of the extracellular matrix. The expression of S100A4 in vivo is shown and the functional role of S100A4 in the pathogenesis of osteoarthritis and rheumatoid arthritisis is explored. The expression of S100A4 in rheumatoid arthritis, osteoarthritis and normal synovial tissues was determined by immunohistochemistry. The expression of matrix metalloproteinase (MMP) mRNA was measured in rheumatoid arthritis and osteoarthritis synovial fibroblasts treated and untreated with S100A4 oligomer by real-time polymerase chain reaction. Levels of released MMPs were confirmed by ELISA in cell culture supernatants. S100A4 protein was expressed in rheumatoid arthritis and osteoarthritis synovial tissues, in contrast with normal synovium. S100A4 up regulated MMP-3 mRNA in rheumatoid arthritis synovial fluid, with a peak after 6 h. This resulted in release of MMP-3 protein. MMP-1, MMP-9 and MMP-13 mRNA were also up regulated in synovial fluid, but with different kinetics. MMP-14 mRNA showed no change. Thus, S100A4 protein is expressed in synovial tissues of patients with rheumatoid arthritis and osteoarthritis in contrast with healthy people. It induces the expression and release of MMP-3 and other MMPs from synovial fluid. The data suggest that S100A4-producing cells could be involved in the pathogenesis of osteoarthritis and rheumatoid arthritis, including pannus formation and joint destruction.

Jüngel A, Baresova V, Ospelt C, Simmen BR, Michel BA, Gay RE, Gay S, Seemayer CA, Neidhart M. · Centre of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, Gloriastrasse 25, CH 8091 Zurich, Switzerland. · Ann Rheum Dis. · Pubmed #16284094 links to  free full text

Abstract: BACKGROUND: Histone acetylation/deacetylation has a critical role in the regulation of transcription by altering the chromatin structure. OBJECTIVE: To analyse the effect of trichostatin A (TSA), a streptomyces metabolite which specifically inhibits mammalian histone deacetylases, on TRAIL-induced apoptosis of rheumatoid arthritis synovial fibroblasts (RASF). METHODS: Apoptotic cells were detected after co-treatment of RASF with TRAIL (200 ng/ml) and TSA (0.5, 1, and 2 micromol/l) by flow cytometry using propidium iodide/annexin-V-FITC staining. Cell proliferation was assessed using the MTS proliferation test. Induction of the cell cycle inhibitor p21Waf/Cip1 by TSA was analysed by western blot. Expression of the TRAIL receptor-2 (DR5) on the cell surface of RASF was analysed by flow cytometry. Levels of soluble TRAIL were measured in synovial fluid of patients with RA and osteoarthritis (OA) by ELISA. RESULTS: Co-treatment of the cells with TSA and TRAIL induced cell death in a synergistic and dose dependent manner, whereas TRAIL and TSA alone had no effect or only a modest effect. RASF express DR5 (TRAIL receptor 2), but treatment of the cells with TSA for 24 hours did not change the expression level of DR5, as it is shown for cancer cells. TSA induced cell cycle arrest in RASF through up regulation of p21Waf1/Cip1. Levels of soluble TRAIL were significantly higher in RA than in OA synovial fluids. CONCLUSION: Because TSA sensitises RASF for TRAIL-induced apoptosis, it is concluded that TSA discloses sensitive sites in the cascade of TRAIL signalling and may represent a new principle for the treatment of RA.

Neidhart M, Jüngel A, Ospelt C, Michel BA, Gay RE, Gay S. · University Hospital Zurich, Zurich, Switzerland. · Arthritis Rheum. · Pubmed #16200606 links to  free full text

This publication has no abstract.

Rutkauskaite E, Volkmer D, Shigeyama Y, Schedel J, Pap G, Müller-Ladner U, Meinecke I, Alexander D, Gay RE, Drynda S, Neumann W, Michel BA, Aicher WK, Gay S, Pap T. · Otto-von-Guericke-University, Magdeburg, Germany. · Arthritis Rheum. · Pubmed #15986375 links to  free full text

Abstract: OBJECTIVE: Membrane type 1 matrix metalloproteinase (MT1-MMP) is expressed prominently in rheumatoid arthritis synovial fibroblasts (RASFs), but the specific contribution of MT1-MMP to fibroblast-mediated destruction of articular cartilage is incompletely understood. This study used gene transfer of an antisense expression construct to assess the effects of MT1-MMP inhibition on the invasiveness of RASFs. METHODS: Retroviral gene transfer of a pLXIN vector-based antisense RNA expression construct (MT1-MMPalphaS) to MT1-MMP was used to stably transduce RASFs. Levels of MT1-MMP RNA and protein were determined by quantitative polymerase chain reaction, Western blotting, and immunocytochemistry in MT1-MMPalphaS-transduced RASFs as well as in control cells, with monitoring for 60 days. The effects of MT1-MMPalphaS on the invasiveness of RASFs were analyzed in the SCID mouse co-implantation model of RA. RESULTS: MT1-MMPalphaS-transduced RASFs produced high levels of antisense RNA that exceeded endogenous levels of MT1-MMP messenger RNA by 15-fold and resulted in a down-regulation of MT1-MMP at the protein level. Inhibition of MT1-MMP production was maintained for 60 days and significantly reduced the invasiveness of RASFs in the SCID mouse model. Whereas prominent invasion into cartilage by non-transduced and mock-transduced RASFs was observed (mean invasion scores 3.0 and 3.1, respectively), MT1-MMPalphaS-transduced cells showed only moderate invasiveness (mean invasion score 1.8; P < 0.05). CONCLUSION: The data demonstrate that an antisense RNA expression construct against MT1-MMP can be generated and expressed in RASFs for at least 60 days. Inhibition of MT1-MMP significantly reduces the cartilage degradation by RASFs.

Shen H, Aeschlimann A, Reisch N, Gay RE, Simmen BR, Michel BA, Gay S, Sprott H. · University Hospital Zurich, Zurich, Switzerland. · Arthritis Rheum. · Pubmed #15880345 links to  free full text

Abstract: OBJECTIVE: To investigate the expression and regulation of the kappa-opioid receptor (KOR) and the delta-opioid receptor (DOR) in fibroblast-like synoviocytes (FLS) from patients with osteoarthritis (OA) and rheumatoid arthritis (RA), and to explore the potential antiarthritic mechanisms of peripheral KORs. METHODS: FLS isolated from synovial tissues of 6 OA patients, 8 RA patients, and 2 healthy individuals were exposed to the selective KOR agonist U69593, the selective DOR agonist SNC 80, and kappa-opioid dynorphin A in the presence or absence of the KOR antagonist nor-binaltorphimine, the DOR antagonist naltrindole, and the proinflammatory cytokines tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta). The expression of KOR and DOR in OA and RA FLS was evaluated on the messenger RNA (mRNA) and protein levels with TaqMan real-time reverse transcriptase-polymerase chain reaction and immunofluorescence staining, respectively. KOR/DOR-mediated activation of ERK-1 and ERK-2 was investigated by Western blotting. RESULTS: We detected functional KOR and DOR in normal FLS and observed a reduction of both receptors in OA and RA FLS, which was more distinct in RA FLS. U69593 enhanced KOR mRNA expression in both OA and RA FLS in a KOR antagonist-reversible manner. However, the dose required for maximal enhancement in RA FLS was 10 times higher than that required in OA FLS. TNFalpha and IL-1beta both suppressed the expression of DOR and KOR mRNA in both OA and RA FLS. CONCLUSION: DOR and KOR are constitutively present in normal FLS and are suppressed under inflammatory conditions, such as RA and OA. Most interestingly, the KOR agonist U69593 may exert an antiarthritic effect via up-regulation of KOR in OA and RA FLS.

Distler JH, Jüngel A, Huber LC, Seemayer CA, Reich CF, Gay RE, Michel BA, Fontana A, Gay S, Pisetsky DS, Distler O. · Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, CH-8091 Zurich, Switzerland. · Proc Natl Acad Sci U S A. · Pubmed #15701693 links to  free full text

Abstract: Rheumatoid arthritis is a chronic inflammatory disease characterized by destruction of cartilage and bone that is mediated by synovial fibroblasts. To determine the mechanisms by which these cells are activated to produce matrix metalloproteinases (MMPs), the effects of microparticles were investigated. Microparticles are small membrane-bound vesicles whose release from immune cells is increased during activation and apoptosis. Because microparticles occur abundantly in the synovial fluid in rheumatoid arthritis, they could represent novel stimulatory agents. Microparticles derived from T cells and monocytes strongly induced the synthesis of MMP-1, MMP-3, MMP-9, and MMP-13 in fibroblasts. The induction was time-dependent, with effects primarily observed after 36 h; under these conditions, MMP-2, MMP-14, and tissue inhibitor of MMP-1 (TIMP-1), TIMP-2, and TIMP-3 were not induced. Microparticles also increased the synthesis of inflammatory mediators including IL-6, IL-8, monocyte chemoattractant protein 1 (MCP-1), and MCP-2. In Ikappa-B-transfected synovial fibroblasts, MMPs were less inducible by microparticles compared with wild-type fibroblasts. Blocking of TNFalpha and IL-1beta with antibodies against TNFalpha and with IL-1 receptor antagonist did not abrogate stimulation by microparticles. These data provide evidence for a novel mechanism by which vesicles derived from activated or apoptotic immune cells can promote the destructive activity of synovial fibroblasts in rheumatoid arthritis.

Pap T, Nawrath M, Heinrich J, Bosse M, Baier A, Hummel KM, Petrow P, Kuchen S, Michel BA, Gay RE, Müller-Ladner U, Moelling K, Gay S. · Center of Internal Medicine, University Hospital Magdeburg, Magdeburg, Germany. · Arthritis Rheum. · Pubmed #15457447 links to  free full text

Abstract: OBJECTIVE: To study the specific contribution of MAP kinase activator c-Raf-1 and one of its downstream transcription factors, c-Myc, to the growth and invasive behavior of rheumatoid arthritis synovial fibroblasts (RASFs). METHODS: RASFs were transduced with retroviral constructs expressing dominant-negative mutants of c-Raf-1 or c-Myc (DN c-Raf-1 or DN c-Myc, respectively) or with the mock vector. The expression of wild-type and mutant proteins was confirmed by Western blotting. Growth curves of RASFs were recorded, and apoptosis was measured by flow cytometry. Invasiveness of RASFs was assessed in the SCID mouse model of RA. Immunohistochemistry was used to study the effects of DN c-Raf-1 on phosphorylated c-Jun and matrix metalloproteinase 1 (MMP-1) in RASFs implanted into SCID mice. The phosphorylation of ERK and JNK in DN c-Raf-1- and mock-transduced RASFs was determined in vitro by Western blotting. The levels of MMPs in these cells were measured by quantitative polymerase chain reaction (PCR). RESULTS: Neither DN c-Raf-1 alone nor DN c-Myc alone significantly altered proliferation or apoptosis of RASFs, but both mutants together rapidly induced apoptosis. Inhibition of c-Raf-1 or c-Myc significantly reduced the invasiveness of RASFs in the SCID mouse model. DN c-Raf-1 decreased the phosphorylation of ERK and JNK in vitro and reduced the in vivo expression of phosphorylated c-Jun as well as the expression of disease-relevant MMPs. As determined by quantitative PCR, the inhibition was most pronounced for MMP-1 and MMP-3. CONCLUSION: The data demonstrate that Ras- and c-Myc-dependent signaling events cooperate to regulate the growth and invasiveness of RASFs. Targeting of both c-Raf-1 and c-Myc may constitute an interesting therapeutic approach in RA.

Schedel J, Distler O, Woenckhaus M, Gay RE, Simmen B, Michel BA, Müller-Ladner U, Gay S. · Department of Internal Medicine I, Division of Rheumatology and Clinical Immunology, University Hospital of Regensburg, D-93042 Regensburg, Germany. · Ann Rheum Dis. · Pubmed #15361372 links to  free full text

Abstract: OBJECTIVE: To investigate the expression of maspin in RA synovial tissue and compare it with the expression in osteoarthritis (OA) and normal synovial tissue (NS). METHODS: Using specific primers for maspin, a 237 bp fragment was amplified from cDNA obtained from cultured RA, OA, and normal synovial fibroblasts (SF) by RT-PCR. Additionally, mRNA expression levels were determined quantitatively by real time PCR. mRNA expression of maspin was investigated on snap frozen and paraffin embedded synovial tissue sections by in situ hybridisation. Immunohistochemistry was used to identify the cell type expressing maspin. SDS-PAGE and western blotting were performed to evaluate the protein expression in cultured SF. To confirm protein synthesis in situ, immunohistochemistry with specific anti-maspin antibodies was performed in synovial tissue sections of patients with RA. RESULTS: RT-PCR showed expression of maspin in all cDNA samples from cultured SF. Maspin mRNA was found to be decreased in RA SF twofold and 70-fold compared with OA SF and NS SF, respectively. Maspin mRNA was expressed in RA, OA, and normal synovial tissue. Importantly, maspin transcripts were also found at sites of invasion into cartilage and bone. At the protein level, maspin could be detected in RA and, less prominently, OA SF. In RA synovial tissue, maspin protein was detected in only a few synovial lining cells. CONCLUSION: Maspin is expressed intensively in RA SF at the mRNA level, but only slightly at the protein level, possibly owing to down regulation of maspin; this may contribute to the hyperplasia of synovial tissue in RA.

Neidhart M, Zaucke F, von Knoch R, Jüngel A, Michel BA, Gay RE, Gay S. · Centre for Experimental Rheumatology, University Hospital, Gloriastrasse 25, CH-8091 Zurich, Switzerland. · Ann Rheum Dis. · Pubmed #15345499 links to  free full text

Abstract: BACKGROUND: Galectin-3 is expressed in the synovial tissue of patients with rheumatoid arthritis (RA), particularly at sites of joint destruction. OBJECTIVE: To explore the possibilities that galectin-3 is induced either by proinflammatory cytokines or by adhesion to cartilage components. METHODS: Cell culture plates were coated with fibronectin, collagens I-VI, or cartilage oligomeric matrix protein (COMP), and the suspended cells were then added. The medium was changed after 1 hour at 37 degrees C. Adherent cells were further incubated for 18 hours in the presence or absence of tumour necrosis factor alpha (TNF alpha) or interleukin 1 beta. Cells were pretreated with murine IgG1, anti-CD29, -CD51, -CD61 (integrins), or -CD3 monoclonal antibodies and transferred to culture plates coated with COMP. Adherent cells were counted by light microscopy. The expression of intracellular galectin-3, or cell surface CD29, CD51, and CD61 was determined by flow cytometry before and after adhesion. RESULTS: Four times more RA synovial fibroblasts (SF) than osteoarthritis SF adhered to COMP. RA SF presented more cell surface integrins, and monoclonal antibodies against CD51 inhibited the adhesion to COMP by 80%. TNF alpha reduced the expression of CD61 and the adhesion to COMP, but did not reverse the adhesion once it had taken place. The adhesion of RA SF to COMP was found to increase the intracellular level of galectin-3. In contrast, intracellular galectin-3 decreased after exposure to TNF alpha. CONCLUSION: The increase of galectin-3 occurs after adhesion to COMP, and the alpha V beta 3 receptor (CD51/CD61) has a pivotal role in this process.

Schedel J, Seemayer CA, Pap T, Neidhart M, Kuchen S, Michel BA, Gay RE, Müller-Ladner U, Gay S, Zacharias W. · Center of Experimental Rheumatology and WHO Collaborating Center for Molecular Biology and Novel Therapeutic Strategies for Rheumatic Diseases, Department of Rheumatology, University Hospital of Zurich, Zurich, Switzerland. · Gene Ther. · Pubmed #15164093 No free full text.

Abstract: The present study was undertaken to examine whether ribozymes cleaving specifically cathepsin L (CL) mRNA are able to decrease the synthesis of CL protease in rheumatoid arthritis synovial fibroblasts (RA-SF) and thereby reduce the invasiveness into cartilage both in vitro and in the SCID mouse coimplantation model of RA. Two different ribozymes that cleave CL mRNA specifically at positions 533 (RzCL533) and 790 (RzCL790) were generated. Using retroviral gene transfer, RA-SF were transduced with the ribozyme constructs or the empty vector. To examine the effect of the ribozymes on the mRNA level, quantitative analysis for CL mRNA was performed using real-time PCR. For evaluation on the protein level, ELISA using specific anti-CL antibodies was performed. In addition, transduced RA-SF were examined in vitro in a three-dimensional destruction assay evaluating their ability to degrade extracellular matrix produced by human chondrocytes. Matrix destruction was monitored by the release of soluble glycosaminoglycans (sGAG). Using the in vivo SCID mouse coimplantation model of RA, RzCL533-transduced RA-SF and control cells were coimplanted with human cartilage for 60 days. After being killed, invasion of RA-SF into the cartilage was evaluated by using a semiquantitative score. Transduction of RA-SF with RzCL533 and RzCL790 ribozymes decreased significantly the expression of CL mRNA to 44% (range 25-62%) and 20% (range 1-43%), respectively, when compared to mock-transduced cells. The protein concentration of CL in the cell culture supernatants of transduced RA-SF was decreased from 16.0 ng/ml in the mock constructs to 4.1 and 8.2 ng/ml (mean), respectively. Using the in vitro cartilage destruction assay, the release of sGAG decreased to 46 and 60%, respectively, after 14 days when compared to mock-transduced cells. In the SCID mouse coimplantation model of RA, RzCL533-transduced RA-SF revealed a significant lower cartilage invasion when compared to mock and untransduced cells. Using retroviral gene transfer, ribozymes cleaving CL mRNA inhibit specifically the synthesis of this matrix-degrading enzyme and reduce cartilage destruction in in vitro and in vivo models. Our study therefore suggests that ribozymes targeting CL could be a novel and efficient tool to inhibit joint destruction in RA.

Jüngel A, Distler JH, Kurowska-Stolarska M, Seemayer CA, Seibl R, Forster A, Michel BA, Gay RE, Emmrich F, Gay S, Distler O. · Center of Experimental Rheumatology, Department of Rheumatology, University Hospital Zurich, Gloriastrasse 25, CH-8091 Zurich, Switzerland. · Arthritis Rheum. · Pubmed #15146416 links to  free full text

Abstract: OBJECTIVE: To determine the role and expression of the cytokine/receptor pair interleukin-21 (IL-21)/IL-21 receptor (IL-21R) in rheumatoid arthritis (RA). METHODS: The expression of IL-21R and IL-21 was analyzed by TaqMan real-time polymerase chain reaction (PCR) and in situ hybridization of synovial biopsy samples from patients with RA and osteoarthritis (OA). Double labeling by immunohistochemistry after in situ hybridization was performed with anti-CD68 antibodies. The expression of IL-21R at the protein level was confirmed by Western blotting. Stimulation experiments were performed with recombinant IL-1beta, tumor necrosis factor alpha (TNFalpha), platelet-derived growth factor (PDGF), and transforming growth factor beta (TGFbeta). The role of IL-21R in cartilage destruction was analyzed in the SCID mouse coimplantation model of RA. RESULTS: IL-21R was found in total RNA extracts and in synovial biopsy samples from RA patients, whereas no expression or only minimal expression was seen in samples from OA patients. Double labeling indicated that both synovial macrophages and synovial fibroblasts expressed IL-21R. Western blotting with anti-IL-21R antibodies confirmed the expression of IL-21R protein in RA synovial fibroblasts (RASFs). Of note, IL-21 was not detectable by real-time PCR and in situ hybridization in the same samples in vivo as in vitro. The level of expression of IL-21R messenger RNA (mRNA) was not altered by stimulation with IL-1beta, TNFalpha, PDGF, or TGFbeta. Interestingly, in the SCID mouse coimplantation model, RASFs did not maintain their expression of IL-21R at sites of invasion into the cartilage. Similarly, IL-21R mRNA was not expressed at sites of invasion into cartilage and bone in RA synovium. CONCLUSION: Our data demonstrate that IL-21R is expressed in RA synovium by RASFs and synovial macrophages. IL-21R is associated with the activated phenotype of RASFs independently of the major proinflammatory cytokines IL-1beta and TNFalpha, but correlates negatively with the destruction of articular cartilage and bone.