Enhanced production of monocyte chemoattractant protein-1 in rheumatoid arthritis. J. Clin. Invest

Department of Medicine, Northwestern University Medical School, Chicago, Illinois 60611.
Journal of Clinical Investigation (Impact Factor: 13.22). 10/1992; 90(3):772-9. DOI: 10.1172/JCI115950
Source: PubMed


Cells within the synovial tissue may recruit mononuclear phagocytes into the synovial fluid and tissues of arthritic patients. We investigated the production of the chemotactic cytokine monocyte chemoattractant protein-1 (MCP-1) using sera, synovial fluid, synovial tissue, as well as macrophages and fibroblasts isolated from synovial tissues from 80 arthritic patients. MCP1 levels were significantly higher (P < 0.05) in synovial fluid from RA patients (mean 25.5±8.1 ng/ml [SE]) compared to synovial fluid from osteoarthritis (OA) patients (0.92±0.08), or from patients with other arthritides (2.9±1.5). MCP-1 levels in RA sera (8.44±2.33) were significantly greater than MCP-1 in normal sera (0.16±0.06). The quantities of RA synovial fluid IL-8, which is chemotactic for neutrophils and lymphocytes, and MCP-1 were strongly positively correlated (P < 0.05). To examine the cellular source of MCP-1, RA synovial tissue macrophages and fibroblasts were isolated. Synovial tissue fibroblasts did not express MCP-1 mRNA, but could be induced to produce MCP-1 by stimulation with either IL-1β, tumor necrosis factor-alpha (TNF-α), or LPS. In contrast, unlike normal peripheral blood monocytes or alveolar macrophages, RA synovial tissue macrophages constitutively expressed MCP-1 mRNA and antigen. Immunohistochemical analysis of synovial tissue showed that a significantly greater percentage of RA macrophages (50±8%) as compared to either OA macrophages (5±2) or normal macrophages (1±0.3) reacted with anti-MCP-1 antibodies. In addition, the synovial lining layer reacted with MCP-1 in both RA and OA synovial tissues. In contrast, only a minority of synovial fibroblasts (18±8%) from RA synovium were positive for immunolocalization of MCP-1. These results suggest that synovial production of MCP-1 may play an important role in the recruitment of mononuclear phagocytes during inflammation associated with RA and that synovial tissue macrophages are the dominant source of this cytokine.

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Available from: Marie Burdick, Oct 01, 2015
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    • "Interestingly, it has already been shown that this chemokine is produced by osteoblasts and, in response to RANKL, might be expressed by osteoclast precursors, acting as a recruiter of monocytes and other osteoclast precursors [83]–[86]. MCP-1 expression has already been detected at sites of tooth eruption, bone metastasis and Rheumatoid Arthritis, being regulated by inflammatory cytokines such as TNF-α and Interleukin (IL)-1b and hormones, such as PTH [84], [85], [87]–[90]. Therefore, augmented MCP-1 related to LN activity may help to explain the increase in osteoclast activity and bone resorption detected in our patients. "
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    ABSTRACT: Introduction Bone loss in Lupus Nephritis (LN) patients is common and multifactorial. The aim of this study was to evaluate the bone status of newly diagnosed LN patients and their correlation with inflammatory factors involved in LN physiopathology. Methods We studied 15 pre-menopausal patients with ≤2 months of diagnosed SLE and LN. Patients with prior kidney or bone disease were excluded. In addition to biochemical evaluation (including 25-hydroxyvitamin D3 [25(OH)D] and Monocyte Chemotactic Protein (MCP1) dosage), we performed bone biopsies followed by osteoblast culture, histomorphometric and immunohistochemistry analysis. Results LN patients presented a mean age of 29.5±10 years, a proteinuria of 4.7±2.9 g/day and an estimated glomerular filtration rate (GFR) of 37(31–87) ml/min/1,73 m2. They were on glucocorticoid therapy for 34±12 days. All patients presented vitamin D insufficiency (9.9±4.4 ng/ml, range 4–20). Urinary MCP1 correlated negatively with 25(OH)D (r = −0.53, p = 0.003) and positively with serum deoxypyridinoline (r = 0.53, p = 0.004). Osteoblasts isolated from LN bone biopsies presented a significantly higher expression of MCP-1 when compared to controls (32.0.±9.1 vs. 22.9±5.3 mean fluorescence intensities, p = 0.01). LN patients presented a significantly reduced osteoid volume, osteoid thickness, osteoid surface, mineralization surface and bone formation rate, associated with an increased eroded surface and osteoclast surface. Patient’s bone specimens demonstrated a reduced immunostaining for osteoprotegerin (0.61±0.82 vs. 1.08±0.50%, p = 0.003), and an increased expression of Receptor Activator of NF-κB ligand (RANKL) (1.76±0.92 vs. 0.41±0.28%, p<0.001) when compared to controls. Discussion Newly diagnosed LN patients presented a significant disturbance in bone metabolism, characterized by an impaired bone formation and mineralization, associated with an increase in resorption parameters. Glucocorticoid use, vitamin D insufficiency and inflammation might be involved in the physiopathology of bone metabolism disturbance.
    PLoS ONE 09/2014; 9(9):e106728. DOI:10.1371/journal.pone.0106728 · 3.23 Impact Factor
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    • "One of potential therapy in RA is targeting chemokines and a randomized clinical trial with an anti-CCL2/MCP-1 monoclonal antibody in RA patients has been reported previously [23]. MCP-1 plays a key role in leukocyte migration and recruitment of mononuclear phagocytes during inflammation in the joint and previous study indicated that there is overproduction of CCL-2/MCP-1 in RA patient’s synovium [24]. To further elucidate the anti-inflammatory effects of 5-LOX inhibitors in the rheumatoid arthritis, human synovial fibroblasts were pretreated with 5-LOX inhibitors NDGA (10 µM) and MK-886 (5 µM) for 1 hr and then treated with TNF-α (10 ng/ml) for another 6 hr. "
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    ABSTRACT: The lipoxygenase isoform of 5-lipoxygenase (5-LOX) is reported to be overexpressed in human rheumatoid arthritis synovial tissue and involved in the progress of inflammatory arthritis. However, the detailed mechanism of how 5-lipoxygenase regulates the inflammatory response in arthritis synovial tissue is still unclear. The aim of this study was to investigate the involvement of lipoxygenase pathways in TNF-α-induced production of cytokines and chemokines. Human synovial fibroblasts from rheumatoid patients were used in this study. 5-LOX inhibitors and shRNA were used to examine the involvement of 5-LOX in TNF-α-induced cytokines and chemokines expression. The signaling pathways were examined by Western Blotting or immunofluorescence staining. The effect of 5-LOX inhibitor on TNF-α-induced chemokine expression and paw edema was also explored in vivo in C57BL/6 mice. Treatment with 5-LOX inhibitors significantly decreased TNF-α-induced pro-inflammatory mediators including interleukin-6 (IL-6) and monocyte chemo-attractant protein-1 (MCP-1) in human synovial fibroblasts. Knockdown of 5-LOX using shRNA exerted similar inhibitory effects. The abrogation of NF-κB activation was involved in the antagonizing effects of these inhibitors. Furthermore, 5-LOX inhibitor decreased TNF-α-induced up-regulation of serum MCP-1 level and paw edema in mouse model. Our results provide the evidence that the administration of 5-LOX inhibitors is able to ameliorate TNF-α-induced cytokine/chemokine release and paw edema, indicating that 5-LOX inhibitors may be developed for therapeutic treatment of inflammatory arthritis.
    PLoS ONE 09/2014; 9(9):e107890. DOI:10.1371/journal.pone.0107890 · 3.23 Impact Factor
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    • "It was previously shown that MCP-1 is produced during arthritis in human and in animal models (20, 21). We used an air pouch model as a tool to evaluate the role of myeloid cells in MCP-1 production during arthritis. "
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    ABSTRACT: Monocyte chemoattractant protein-1 (MCP-1)/CCL2 is a chemokine regulating the recruitment of monocytes into sites of inflammation and cancer. MCP-1 can be produced by a variety of cell types, such as macrophages, neutrophils, fibroblasts, endothelial cells, and epithelial cells. Notably, macrophages produce high levels of MCP-1 in response to proinflammatory stimuli in vitro, leading to the hypothesis that macrophages are the major source of MCP-1 during inflammatory responses in vivo. In stark contrast to the hypothesis, however, there was no significant reduction in MCP-1 protein or the number of infiltrating macrophages in the peritoneal inflammatory exudates of myeloid cell-specific MCP-1-deficient mice in response to i.p injection of thioglycollate or zymosan A. Furthermore, injection of LPS into skin air pouch also had no effect on local MCP-1 production in myeloid-specific MCP-1-deficient mice. Finally, myeloid-specific MCP-1-deficiency did not reduce MCP-1 mRNA expression or macrophage infiltration in LPS-induced lung injury. These results indicate that non-myeloid cells, in response to a variety of stimulants, play a previously unappreciated role in innate immune responses as the primary source of MCP-1.
    Frontiers in Immunology 01/2014; 4:482. DOI:10.3389/fimmu.2013.00482
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