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U Müller-Ladner

Publications and source records attributed to U Müller-Ladner.

At least 19 recordsLinked to original sources
PubMed1999

In vitro superfusion method to study nerve-immune cell interactions in human synovial membrane in long-standing rheumatoid arthritis or osteoarthritis.

Reports on patients with hemiparalysis indicate the importance of the nervous system for the pathophysiology of rheumatoid arthritis (RA) or osteoarthritis (OA). Norepinephrine (NE) and opioids seem to be more antiinflammatory neurotransmitters whereas substance P is proinflammatory. The study aimed to investigate the direct noradrenergic nerve-immune cell interaction in human synovial membrane. We used a recently developed superfusion technique with electrical stimulation of synovial membrane to elicit local NE from synovial membrane slices. The readout parameter of synovial immune cells was interleukin-6 (IL-6). IL-6 was spontaneously secreted from RA and OA synovial membranes. Electrical field stimulation intensively reduced IL-6 secretion. In patients with OA or RA, this electrically induced reduction of IL-6 secretion was not significantly changed by alpha- or beta-adrenergic antagonists. The study demonstrates that local endogenous NE seem to play a minor role, which may be due to a depletion of NE or loss of noradrenergic fibers during chronic RA and OA.

Aged↗
PubMed1999

[Analysis of gene expression patterns in rheumatoid synovial fibroblasts using RAP-PCR for differential display].

OBJECTIVE: Destruction of articular cartilage and bone by invading synovial fibroblasts is a typical histopathologic feature in rheumatoid arthritis (RA). However, little is known about specific up- or downregulation of genes leading to this aggressive phenotype. Thus, our aim was to identify genes, which are differentially expressed in RA synovial fibroblasts as compared to synovial fibroblasts derived from patients with osteoarthritis (OA) using RAP-PCR for differential display. METHODS: After extraction of total RNA, the first step of RAP-PCR was performed using various different arbitrary 10-12-base primers for first-strand cDNA synthesis. Second-strand synthesis was achieved by cycling at low stringency conditions for 35 cycles using different arbitrary 10-base primers, followed by electrophoretic separation and sequence analysis of the amplified fingerprint products. RESULTS: On average, approximately 70 different RNAs were obtained per primer, of which most were expressed both by RA and OA synovial fibroblasts. Using 26 different primer combinations, in total 12 cDNAs were differentially expressed between RA and OA synovial fibroblasts. In the RA group strong amplification of distinct PCR products suitable for sequencing could be observed. Sequence analysis identified these PCR products as highly homologous to various genes involved in regulation of cell cycle and metabolism. CONCLUSION: The data indicate that RAP-PCR is a suitable method to identify differentially expressed genes in rheumatoid synovial fibroblasts potentially involved in the specific pathophysiology of RA.

Arthritis, Rheumatoid↗
PubMed1999

Gene transfer of cytokine inhibitors into human synovial fibroblasts in the SCID mouse model.

OBJECTIVE: To investigate the effects of retrovirus-based gene delivery of inhibitory cytokines and cytokine inhibitors into human synovial fibroblasts in the SCID mouse model of rheumatoid arthritis (RA). METHODS: The MFG vector was used for gene delivery of tumor necrosis factor alpha receptor (TNFalphaR) p55, viral interleukin-10 (IL-10), and murine IL-10 into RA synovial fibroblasts. The effect on invasion of these cells into human articular cartilage and on perichondrocytic cartilage degradation was examined after 60 days of coimplantation into the SCID mouse. RESULTS: TNFalphaR p55 gene transfer showed only a limited effect on inhibition of RA synovial fibroblast invasiveness and cartilage degradation. In contrast, invasion of the RA synovial fibroblasts into the coimplanted cartilage was strongly inhibited by both viral and murine IL-10. Perichondrocytic cartilage degradation was not affected by either form of IL-10. CONCLUSION: The data show that cytokines can be successfully inserted into the genome of human RA synovial fibroblasts using a retroviral vector delivery system, and that the SCID mouse model of human RA is a valuable tool for examining the effects of gene transfer. In addition, inhibition of more than one cytokine pathway may be required to inhibit both synovial- and chondrocyte-mediated cartilage destruction in RA.

Animals↗
PubMed1999

Analysis of the p53 tumor suppressor gene in rheumatoid arthritis synovial fibroblasts.

OBJECTIVE: To determine whether mutations in the tumor suppressor gene p53 may contribute to the transformed-appearing phenotype of rheumatoid arthritis (RA) synovial fibroblasts. METHODS: We performed p53 gene mutation analysis using different molecular approaches. Synovial fibroblasts of 10 patients with RA were cultured and RNA and DNA were harvested after 3-5 passages in cell culture. Sequence analysis of all exons of the p53 gene was performed using 3 different techniques: 1) single-strand conformational polymorphism, 2) nonisotopic RNase cleavage assay, and 3) base excision sequence scanning T-scan, followed by sequence analysis of specific gene segments. RESULTS: Although p53 antigen could be detected by immunocytochemistry in numerous cultured fibroblasts, gel electrophoresis analysis of products obtained using all 3 methods and subsequent sequence analysis showed no specific mutation pattern in the genome of the synovial fibroblasts from patients in Germany, including the known "hot spots" within the p53 genome. However, p53 mutations were identified in different clones of 3 additional RA synovial fibroblast populations from the United States. Sequence analysis of the p53 promoter did not reveal mutational base changes. CONCLUSION: The findings of the study support the hypothesis that the majority of the mutations of the p53 gene observed in RA synovium are not derived from the genome of RA synovial fibroblasts, and that the variability of the mutation pattern reflects, in part, the heterogeneity of the disease.

Arthritis, Rheumatoid↗
PubMed1999

Anticytokines.

Explore the source record for details and available documents.

Animals↗
PubMed1999

MIA (melanoma inhibitory activity): a potential serum marker for rheumatoid arthritis.

OBJECTIVE: MIA (melanoma inhibitory activity) is correlated with metastasis in patients with malignant melanoma. As MIA is not only produced by melanoma cells, but also by differentiated chondrocytes, we examined whether serum levels of MIA are correlated with inflammation and/or joint destruction in rheumatic diseases. METHODS: MIA serum concentrations of patients with different rheumatic diseases were examined and compared with healthy individuals and malignant melanoma patients. In addition, MIA concentrations were correlated to inflammatory parameters and joint destruction. RESULTS: Increased MIA serum concentrations were found only in patients with rheumatic diseases associated with joint destruction, such as rheumatoid arthritis (RA), osteoarthritis, HLA B27-associated oligoarthritis, and psoriatic arthritis. Of these rheumatic diseases, a significant increase in MIA serum concentrations was seen only in patients with RA, associated with rheumatoid factor (RF) positivity and joint destruction. CONCLUSIONS: In addition to RF, MIA might therefore be useful in the differential diagnosis of RA vs non-destructive rheumatic diseases, and the presence of elevated levels of MIA in serum very likely reflects joint destruction in RA.

Arthritis, Rheumatoid↗
PubMed1999

Signaling and effector pathways.

There is increasing evidence that distinct signaling and effector pathways in the rheumatoid synovium result in a cascade of pathophysiologic events. These interactions, which finally lead to progressive joint destruction, are different from all other joint diseases in numerous aspects. As outlined in this review, molecular biology techniques allow detection of key pathways ranging from external stimuli to subcellular gene regulation mechanisms operative in various cells within the rheumatoid synovium. To alter these pathways, inhibitory factors need to be applied to these "hot zones" for an extended period, which can be achieved either by repeated drug administration or by local synthesis using genetically altered synovial cells. Both adenovirus and retroviral constructs, as well as ex vivo and in vivo strategies, can be used for gene transfer into these cells, and routine delivery of "protective" genes into the affected joints might be achieved within the next decade.

Arthritis, Rheumatoid↗
PubMed1998

[Surgical treatment of aseptic bone necroses of both knee joints in antiphospholipid antibody syndrome (APL) by synovectomy, arthrolysis and arthroplasty].

A 22 year old male patient with antiphospholipid-antibody syndrome (APL) developed severe bilateral avascular necrosis of both femoral condyles. Extensive synovectomy and arthrolysis in combination with an arthroplastic remodeling of both knee joints resulted in reduction of pain and joint effusion. Therefore, synovectomy and arthroplastic remodeling might be a promising therapy to extend the period of time to prosthetic joint replacement in young patients with APL.

Adult↗
PubMed1998

Molecular biology of cartilage and bone destruction.

Molecular biology has provided various new insights into the mechanisms operative in the pathogenesis of rheumatoid arthritis. Reflecting the unique character of rheumatoid synovium, advances have been achieved addressing the molecular changes taking place at the area of interaction between the aggressively growing synovium and the articular cartilage and bone. Key issues in the review period addressing this interaction were hyperplasia of rheumatoid arthritis synovium, mechanisms of activation and cell cycle regulation of synovial fibroblasts, pathways of synovial attachment to cartilage and bone, and the regulation of matrix-degrading enzymes.

Apoptosis↗
PubMed1998

Retroviral sequences in rheumatoid arthritis synovium.

There are several relationships between retroviruses and cellular transformation, as well as retroviruses being involved in the development of autoimmune diseases. Retroviruses have been discussed as etiologic agents modulating or triggering certain pathways in the pathogenesis of rheumatoid arthritis (RA). However, none of the currently known retroviruses has been identified as specific for RA. Due to the unique properties of retroviruses, distinct experimental approaches can be used to detect retroviral activity in cells and tissues. Current research in RA using state-of-the-art molecular biology techniques includes both the search for exogenous and endogenous retroviral gene sequences in synovium of patients with RA.

Animals↗
PubMed1998

Cysteine proteinase cathepsin K mRNA is expressed in synovium of patients with rheumatoid arthritis and is detected at sites of synovial bone destruction.

OBJECTIVE: Cysteine proteinases B and L have been shown to be involved in matrix degradation of joints in patients with rheumatoid arthritis (RA). Since the cysteine proteinase cathepsin K is assumed to play a pivotal role in osteoclast mediated bone resorption, we investigated the expression of cathepsin K in RA joints. METHODS: We studied 10 RA and 4 normal synovial specimens and 5 articular heads with RA lesions by in situ hybridization, applying specific riboprobes for cathepsin K, human collagen type I, and cathepsin B. Antibodies against monocyte/macrophage associated CD68 antigen were applied in immunohistochemistry. Reverse transcription-polymerase chain reaction (RT-PCR) and ribonuclease protection assay (RPA) were performed on 4 RA, 1 normal, and 1 immortalized normal fibroblast cultures. RESULTS: Cathepsin K mRNA expression was upregulated in RA synovium compared to normal synovium. Cathepsin K mRNA was expressed mainly by synovial fibroblasts. These data were confirmed by RT-PCR and RPA. In RA articular heads, cathepsin K mRNA was detected at sites where synovium attached and invaded underlying bone. The cells at these sites represented collagen type I and cathepsin B mRNA expressing fibroblasts as well as CD68+ macrophages and giant cells. In addition, a distinct expression of cathepsin K mRNA was also detected around lymphocytic infiltrates in RA synovium. CONCLUSION: The data indicate that cathepsin K is not only expressed by osteoclasts but also by synovial fibroblasts, and suggest that cathepsin K contributes to bone destruction mediated by RA synovial cells. The expression of cathepsin K around lymphocytic infiltrates suggests further to facilitate the movement of mononuclear cells through the perivascular interstitial matrix and thereby contribute to interstitial matrix turnover.

Adult↗
PubMed1997

Human IL-1Ra gene transfer into human synovial fibroblasts is chondroprotective.

Rheumatoid arthritis (RA) is characterized by progressive destruction of synovial cartilage. In vitro, degradation of cartilage is stimulated by IL-1, a proinflammatory cytokine, which is released from RA synovial fibroblasts (RA-SF). To determine whether gene therapy using the gene encoding the naturally occurring inhibitor of IL-1, IL-1 receptor antagonist (IL-1Ra) is feasible, IL-1 Ra-transduced RA-SF were coimplanted with normal human cartilage in SCID mice. The IL-1 Ra-transduced RA-SF continued to secrete IL-1Ra over a 60-day period. Cartilage that was coimplanted with RA-SF transduced with a marker gene exhibited progressive, chondrocyte-mediated cartilage degradation, whereas no such degradation was observed in cartilage that was coimplanted with RA-SF transduced with IL-1 Ra. Thus, gene therapy using a retrovirus-based gene delivery system appears to be a feasible approach to effectively modifying the local synovial environment.

Animals↗
PubMed1997

Tenosynovial nodulosis in a patient infected with human T cell lymphotropic virus I.

We describe a 45-year-old man who presented with multiple nodules along the tendons of the scapular region, the elbows, wrists, forearms, thighs, and ankles. The patient was a carrier of human T cell lymphotropic virus I (HTLV-I), which was probably transmitted from his mother; his mother also had polyarthritis. Histopathologically, the nodules consisted of numerous, small, fibrinoid masses. The synovium adjacent to the tendon sheath was hyperplastic, with fibrinoid necrosis mimicking rheumatoid synovium. However, synovitis was not present inside the adjacent joint. HTLV-I proviral DNA was detected in the cells of the nodule, in tenosynovial cells, and in peripheral blood lymphocytes, but not in skin fibroblasts. In situ reverse transcription assay showed a high quantity of tax/rex messenger RNA in the proliferating lining cells. Based on these features, we classified this case as an atypical manifestation of HTLV-I-associated arthropathy associated with fibrinoid nodules resulting from chronic tenosynovitis.

Carrier State↗
PubMed1997

Decrease of interleukin 6 during the first 12 months is a prognostic marker for clinical outcome during 36 months treatment with disease-modifying anti-rheumatic drugs.

The aim of this study was to determine prognostic markers for the outcome after 36 months of therapy with disease-modifying anti-rheumatic drugs (DMARDs) in patients with rheumatoid arthritis (RA) and to study serial cytokine serum levels. During 36 months, 20 patients receiving DMARDs (nine patients gold sodium thiomalate and 11 patients methotrexate, no comparison undertaken) were followed for clinical and laboratory data. Investigation at baseline, 12, 24 and 36 months, included clinical, radiological and laboratory parameters such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), and interleukin (IL)-1 beta, IL-6, tumor necrosis factor alpha (TNF-alpha), IL-1 receptor antagonist (IL-1RA) and IL-2. During the 3 yr of therapy, the patients showed significant clinical improvement and decline of ESR, CRP, and serum levels of IL-6 and IL-2. The decrease in IL-6 serum levels during the first year of therapy correlated significantly with the decrease, after 36 months, in the number of inflamed joints (r = 0.7608, P < 0.005), Lansbury index (r = 0.6642, P < 0.005) and morning stiffness (r = -0.6561, P < 0.005). In contrast to IL-6 or IL-2, TNF-alpha and IL-1RA did not vary significantly during the 3 yr of therapy. During 36 months of therapy, patients treated with DMARD showed significant improvement of clinical parameters and a trend for delayed progression of radiographic damage. The decrease in IL-6 concentration in serum during the first 12 months was the best prognostic marker for the clinical outcome after 36 months of DMARD therapy.

Aged↗
PubMed1997

Cellular pathways of joint destruction.

In the past year, evaluation of cellular pathways of rheumatoid synovial fibroblasts has been the focus of several laboratories investigating the molecular and cellular mechanisms operating in the pathogenesis of rheumatoid arthritis. Major topics that have been reported on include the adhesion and interaction of synovial fibroblasts with cartilaginous matrix and other synovial cells, intracellular signaling, and activation of gene transcription. Novel approaches to inhibiting cartilage destruction have also been described. In the latter case, thorough multicenter characterization of the interleukin-1/interleukin-1 receptor antagonist pathways resulted in the first gene therapy trials in animals and humans.

Arthritis, Rheumatoid↗
PubMed1997

Alternatively spliced CS-1 fibronectin isoform and its receptor VLA-4 in rheumatoid arthritis synovium.

OBJECTIVE: Extracellular matrix components and cell adhesion molecules play a role in the pathogenesis of rheumatoid arthritis (RA). Interaction between the integrin very late antigen-4 (VLA-4) and the connecting segment-1 (CS-1) fibronectin (FN) isoform may contribute to lymphocyte interaction in RA synovium. We examined both mRNA and protein expression of CS-1 FN in inflamed synovium, and VLA-4 expression in synovial tissue and on cultured fibroblast-like synoviocytes from patients with RA. METHODS: Snap frozen synovial tissue specimens of 10 patients with RA and 4 patients with osteoarthritis were examined for expression of CS-1 FN mRNA and protein by in situ hybridization and immunohistochemistry. VLA-4 expression of synovial fibroblasts and in synovial tissue was evaluated by flow cytometry and immunohistochemistry. RESULTS: CS-1 FN mRNA was detected in RA lining layer synoviocytes, around terminal vessels, and in endothelial cells. Double labeling revealed that most lining synoviocytes expressing CS-1 FN mRNA were CD68 negative. VLA-4 was found in RA synovial fibroblasts, sublining mononuclear cells, and lymphoid aggregates. CONCLUSION: Our findings suggest that expression of CS-1 FN may partially correlate with cell proliferation in the RA lining layer. VLA-4 was found in RA synovial lining, as well as on cultured synovial fibroblasts. Thus, VLA-4/CS-1 FN interaction may facilitate lymphocyte interaction and synovial proliferation in RA.

Anti-Allergic Agents↗