Amelioration of collagen-induced arthritis in rats by nanogold

OBJECTIVE: Angiogenesis plays a part in the pathogenesis of rheumatoid arthritis (RA), and nanogold inhibits the activity of an angiogenic factor, vascular endothelial growth factor (VEGF). We therefore investigated whether intraarticular delivery of nanogold ameliorates collagen-induced arthritis (CIA) in rats. METHODS: Binding of 13-nm nanogold to VEGF in human RA synovial fluid (SF) and its effects on RA SF-induced endothelial cell proliferation and migration were assessed. Nanogold was administered intraarticularly to rats with CIA before the onset of arthritis. Progression of CIA was monitored by measures of clinical, radiologic, and histologic changes. In addition, the microvessel density and extent of infiltrating macrophages as well as levels of tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta) in the ankle joints were determined. RESULTS: Nanogold bound to VEGF in RA SF, resulting in inhibition of RA SF-induced endothelial cell proliferation and migration. Significant reductions in ankle circumference, articular index scores, and radiographic scores were observed in the nanogold-treated rats with CIA compared with their control counterparts. In addition, the histologic score (of synovial hyperplasia, cartilage erosion, and leukocyte infiltration), microvessel density, macrophage infiltration, and levels of TNFalpha and IL-1beta were also significantly reduced in the ankle joints of nanogold-treated rats. CONCLUSION: Our results are the first to demonstrate that intraarticular administration of nanogold ameliorates the clinical course of CIA in rats. Nanogold exerted antiangiogenic activities and subsequently reduced macrophage infiltration and inflammation, which resulted in attenuation of arthritis. These results demonstrate proof of principle for the use of nanogold as a novel therapeutic agent for the treatment of RA.     

IL-32, a proinflammatory cytokine in rheumatoid arthritis

IL-32 is a recently discovered cytokine that induces TNFalpha, IL-1beta, IL-6, and chemokines. We investigated whether IL-32 is expressed in the synovia of patients with rheumatoid arthritis (RA) and studied associations with disease severity and the presence of other cytokines. Immunohistochemistry revealed that IL-32 is highly expressed in RA synovial tissue biopsies, whereas IL-32 was not observed in synovial tissues from patients with osteoarthritis. Moreover, in synovial biopsies from 29 RA patients with active disease, the level of IL-32 staining correlated with erythrocyte sedimentation rate, a marker of systemic inflammation (R = 0.63 and P < 0.0003). Synovial staining of IL-32 also correlated with indices of synovial inflammation (R = 0.80 and P < 0.0001) as well as synovial presence of TNFalpha (R = 0.68 and P < 0.004), IL-1beta (R = 0.79 and P < 0.0001), and IL-18 (R = 0.82 and P < 0.001). IL-32 was a potent inducer of prostaglandin E(2) release in mouse macrophages and human blood monocytes, an important property for inflammation. After the injection of human IL-32gamma into the knee joints of na?ve mice, joint swelling, with pronounced influx of inflammatory cells and cartilage damage, was observed. In TNFalpha-deficient mice, IL-32-driven joint swelling was absent and cell influx was markedly reduced, but loss of proteoglycan was unaffected, suggesting that IL-32 activity is, in part, TNFalpha-dependent. IL-32, strongly associated with TNFalpha, IL-1beta, and IL-18, appears to play a role in human RA and may be a novel target in autoimmune diseases.     

Amelioration of collagen-induced arthritis in DBA/1J mice by recombinant TSG-6, a tumor necrosis factor/interleukin-1-inducible protein

OBJECTIVE: To examine the effect of recombinant TSG-6 on collagen-induced arthritis (CIA) in DBA/1J mice. TSG-6 is a tumor necrosis factor (TNF)/ interleukin-1 (IL-1)-inducible hyaluronan-binding protein produced by synovial cells and chondrocytes that is present in synovial fluids of patients with rheumatoid arthritis. METHODS: To determine the effect of TSG-6 on chronic inflammatory joint disease, we induced CIA in DBA/1J mice by immunization with bovine type II collagen. Animals were treated with 12 intraperitoneal doses of 200 microg of recombinant TSG-6, beginning 3 days before the expected onset of disease symptoms. Progression of arthritis was monitored by determining the disease incidence, arthritis index, and footpad swelling. Levels of IgG1, IgG2a, and IgG2b antibodies against bovine and murine type II collagen and serum concentrations of IL-6 were determined at various time points. Histologic examination of affected joints was performed approximately 20 days after the onset of arthritis. RESULTS: Treatment with recombinant TSG-6 protein had a potent ameliorative effect, manifested by decreases in the disease incidence, arthritis index, and footpad swelling. Histologic examination of affected joints in TSG-6-treated animals revealed little pannus formation and cartilage erosion, features which were conspicuous in control mice. Animals treated with recombinant TSG-6 developed significantly reduced levels of IgG1, IgG2a, and IgG2b antibodies against bovine and murine type II collagen. CONCLUSION: The antiinflammatory effect of the TNF/IL-1-inducible TSG-6 protein in murine CIA suggests a role for this protein as an endogenous regulator of the inflammatory process.     

Induction of suppurative arthritis in rabbits by Haemophilus endotoxin, tumor necrosis factor-alpha, and interleukin-1 beta

Because Haemophilus influenzae type b (Hib) is the principal cause of suppurative arthritis in young children and its lipooligosaccharide (LOS) is thought to be the main virulence factor, Hib endotoxin was evaluated for its ability to induce synovial inflammation in rabbits. Also, the role of the cytokines tumor necrosis factor-alpha (TNF alpha) and interleukin-1 beta (IL-1 beta) in mediating the synovial inflammatory process was studied. Intraarticular inoculation of 2 pg to 20 ng of Hib LOS produced a dose-dependent increase in concentrations of leukocytes and protein in synovial lavage fluid that was significantly modulated by concomitant administration of rabbit TNF alpha- and rabbit IL-1 beta-specific antibodies. Inoculation of joints with either 10(4) IU of rabbit TNF alpha or 10 ng recombinant rabbit IL-beta induced synovial inflammatory changes similar to those observed after LOS intraarticular challenge. These data provide evidence for the role of Hib LOS in inducing suppurative arthritis and for the critical participation of TNF alpha and IL-1 beta in the initial events of the synovial inflammatory response.     

Increased macrophage activation mediated through toll-like receptors in rheumatoid arthritis

OBJECTIVE: Macrophages are the major source of inflammation mediators that are important in the pathogenesis of rheumatoid arthritis (RA). This study was undertaken to analyze macrophages obtained from the joints of RA patients in order to characterize the expression of Toll-like receptor 2 (TLR-2) and TLR-4 and the responses to TLR ligation. METHODS: Cells were isolated from the synovial fluid (SF) of RA patients or patients with other forms of inflammatory arthritis. Cell surface TLR-2 and TLR-4 expression and intracellular tumor necrosis factor alpha (TNFalpha) and interleukin-8 (IL-8) expression by CD14+ macrophages were determined by flow cytometry. Peptidoglycan (PG) and lipopolysaccharide (LPS) were used as ligands for TLR-2 and TLR-4, respectively. RESULTS: The expression of TLR-2 and TLR-4 was increased on CD14+ macrophages from the joints of RA patients compared with that on control in vitro-differentiated macrophages or control peripheral blood monocytes. Neither TLR-2 expression nor TLR-4 expression differed between RA and other forms of inflammatory arthritis. However, PG- and LPS-induced TNFalpha expression and IL-8 expression were greater with RA SF macrophages than with those obtained from the joints of patients with other forms of inflammatory arthritis or with control macrophages. PG-induced TNFalpha expression and IL-8 expression were highly correlated with TLR-2 expression in normal macrophages, but not with that in macrophages obtained from joints of RA patients or patients with other forms of inflammatory arthritis. CONCLUSION: TLR-2 and TLR-4 ligation resulted in increased activation of RA synovial macrophages compared with those from patients with other forms of inflammatory arthritis or compared with control macrophages. Factors other than the level of TLR-2 and TLR-4 expression contributed to the increased activation of RA SF macrophages. These observations support the notion of a potential role for activation through TLR-2 and TLR-4 in the inflammation and joint destruction of RA.     

Therapeutic effect of cortistatin on experimental arthritis by downregulating inflammatory and Th1 responses

BACKGROUND: Rheumatoid arthritis is a chronic autoimmune disease of unknown aetiology characterised by chronic inflammation in the joints and subsequent destruction of the cartilage and bone. Aim: To propose a new strategy for the treatment of arthritis based on the administration of cortistatin, a newly discovered neuropeptide with anti-inflammatory actions. METHODS: DBA/1J mice with collagen-induced arthritis were treated with cortistatin after the onset of disease, and the clinical score and joint histopathology were evaluated. Inflammatory response was determined by measuring the levels of various inflammatory mediators (cytokines and chemokines) in joints and serum. T helper cell type 1 (Th1)-mediated autoreactive response was evaluated by determining the proliferative response and cytokine profile of draining lymph node cells stimulated with collagen and by assaying the content of serum autoantibodies. RESULTS: Cortistatin treatment significantly reduced the severity of established collagen-induced arthritis, completely abrogating joint swelling and destruction of cartilage and bone. The therapeutic effect of cortistatin was associated with a striking reduction in the two deleterious components of the disease-that is, the Th1-driven autoimmune and inflammatory responses. Cortistatin downregulated the production of various inflammatory cytokines and chemokines, decreased the antigen-specific Th1-cell expansion, and induced the production of regulatory cytokines, such as interleukin 10 and transforming growth factor beta1. Cortistatin exerted its effects on synovial cells through both somatostatin and ghrelin receptors, showing a higher effect than both peptides protecting against experimental arthritis. CONCLUSION: This work provides a powerful rationale for the assessment of the efficacy of cortistatin as a novel therapeutic approach to the treatment of rheumatoid arthritis.     

类风湿关节炎滑膜中高迁移率族蛋白1的表达

目的探讨高迁移率族蛋白1（HMGB1）与类风湿关节炎（RA）发生和发展的关系.方法采用免疫组织化学方法观察25例RA和3例未累及关节的创伤患者滑膜中HMGB1的表达规律与分布特点及与血清急性时相反应蛋白的关系.结果22例RA滑膜HMGB1标记阳性,RA滑膜中滑膜上皮细胞和血管内皮细胞呈阳性反应，其中以巨噬细胞样滑膜细胞为多，另有部分成纤维细胞样滑膜细胞。RA滑膜中HMGB1细胞内分布以细胞质中表达较多,细胞核中无表达或表达较少,与正常滑膜中行HMGB1主要在细胞核中表达有明显的不同.RA滑膜上皮细胞HMGB1标记阳性细胞百分比与RA患者血清C反应蛋白无显著相关（rs=0.372,Rs0.05=0.381）.结论RA滑膜中核外HMGB1的出现,作为晚期炎症因子参与了RA的疾病过程,可能在RA组织损伤的病理过程中起重要作用.     

Increased macrophage activation mediated through toll‐like receptors in rheumatoid arthritis

Objective

Macrophages are the major source of inflammation mediators that are important in the pathogenesis of rheumatoid arthritis (RA). This study was undertaken to analyze macrophages obtained from the joints of RA patients in order to characterize the expression of Toll‐like receptor 2 (TLR‐2) and TLR‐4 and the responses to TLR ligation.

Methods

Cells were isolated from the synovial fluid (SF) of RA patients or patients with other forms of inflammatory arthritis. Cell surface TLR‐2 and TLR‐4 expression and intracellular tumor necrosis factor α (TNFα) and interleukin‐8 (IL‐8) expression by CD14+ macrophages were determined by flow cytometry. Peptidoglycan (PG) and lipopolysaccharide (LPS) were used as ligands for TLR‐2 and TLR‐4, respectively.

Results

The expression of TLR‐2 and TLR‐4 was increased on CD14+ macrophages from the joints of RA patients compared with that on control in vitro–differentiated macrophages or control peripheral blood monocytes. Neither TLR‐2 expression nor TLR‐4 expression differed between RA and other forms of inflammatory arthritis. However, PG‐ and LPS‐induced TNFα expression and IL‐8 expression were greater with RA SF macrophages than with those obtained from the joints of patients with other forms of inflammatory arthritis or with control macrophages. PG‐induced TNFα expression and IL‐8 expression were highly correlated with TLR‐2 expression in normal macrophages, but not with that in macrophages obtained from joints of RA patients or patients with other forms of inflammatory arthritis.

Conclusion

TLR‐2 and TLR‐4 ligation resulted in increased activation of RA synovial macrophages compared with those from patients with other forms of inflammatory arthritis or compared with control macrophages. Factors other than the level of TLR‐2 and TLR‐4 expression contributed to the increased activation of RA SF macrophages. These observations support the notion of a potential role for activation through TLR‐2 and TLR‐4 in the inflammation and joint destruction of RA.

     

Arguments for interleukin 1 as a target in chronic arthritis

Tumour necrosis factor (TNF) and interleukin 1 (IL1) are considered as master cytokines in chronic, destructive arthritis. Therapeutic approaches in rheumatic arthritis (RA) patients so far mainly focused on TNF. Although TNF is a major inflammatory mediator in RA and a potent inducer of IL1, anti-TNF treatment is not effective in all patients, nor does it fully control the arthritic process in affected joints of good responders. Analysis of cytokine patterns in early synovial biopsy specimens of RA patients reveals prominent TNF staining in 50% of the patients, whereas IL1b staining was evident in 100%. This argues that TNF independent IL1 production occurs in some of the patients. Studies in a range of experimental arthritis models in mice make it clear that TNF is involved in early joint swelling. However, TNF alone is not arthritogenic nor destructive and exerts its arthritogenic potential through IL1 induction. Intriguingly, TNF independent IL1 production is found in many models. Its relevance is further underlined by the greater efficacy of anti-IL1 treatment as compared with anti-TNF treatment and the total lack of chronic, erosive arthritis in IL1b deficient mice. IL1b is not necessarily involved in early joint swelling, but is a crucial mediator in chronic arthritis and cartilage erosion in all models studied so far. This makes ILb an attractive target in chronic, destructive arthritis.     

Th17 Cells in Immunopathogenesis and treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by the sequestration of various leukocyte subpopulations within both the developing pannus and synovial space. The chronic nature of this disease results in inflammation of multiple joints, with subsequent destruction of the joint cartilage and erosion of bone. Identification of T helper (Th)17 cells led to breaking the dichotomy of the Th1/Th2 axis in immunopathogenesis of autoimmune diseases such as RA, and its experimental model, collagen‐induced arthritis (CIA). Th17 cells produce cytokines, including interleukin (IL)‐17, IL‐6, IL‐21, IL‐22 and tumor necrosis factor (TNF)‐α, with pro‐inflammatory effects, which appear to have a role in immunopathogenesis of RA. Regarding the wide ranging production of pro‐inflammatory cytokines and chemokines by Th17 cells, it is expected that Th17 cell could be a potent pathogenic factor in disease immunopathophysiology. Thus the identification of effector mechanisms used by Th17 cells in induction of disease lesions may open new prospects for designing a new therapeutic strategy for treatment of RA.     

Interleukin 1 beta in synovial fluid is related to local disease activity in rheumatoid arthritis

Summary Interleukin 1 beta (IL-1 beta) is a polypeptide with pro-inflammatory and immunopotentiating effects in vivo and in vitro. With relevance to rheumatoid arthritis (RA) IL-1 augments release of prostanoids, proteinases and oxygen metabolites and is a potent inducer of bone and cartilage resorption. Although high levels of IL-1 have been found in rheumatoid synovial fluids, intra-individual variation in IL-1 production has made it difficult to correlate these levels with disease activity. To overcome this problem we have studied patients with symmetrical and asymmetrical knee joint inflammation. Local disease activity was documented using Ritchie score and joint circumference; IL-1 beta levels were quantitated in synovial fluid by ELISA. In patients with symmetrical joint involvement almost identical levels of IL-1 beta were detected in the right and left knee joints. In contrast, in patients exhibiting asymmetrical knee joint involvement, IL-1 beta levels in the inflamed joints were significantly higher than in the contralateral joints. The study provides further evidence for the role of IL-1 in the pathogenesis of rheumatoid inflammation.     

High serum and synovial fluid granulocyte colony stimulating factor (G-CSF) concentrations in patients with rheumatoid arthritis

OBJECTIVE: To determine the relationship between serum G-CSF, RA disease activity and the levels of inflammatory cytokines. METHODS: Sixty-one patients (5 men and 56 women; mean age; 56.1 +/- 11.4 [+/- SD] years, range, 22-70 years) who were selected at random and met the American College of Rheumatology criteria for RA were examined. Granulocyte-colony stimulating factor (G-CSF) levels in sera and synovial fluid were measured by solid-phase radioimmunoassay (RIA). We also measured various indices of RA disease activity and serum levels of IL-1 beta, IL-6 and TNF-alpha by ELISA. RESULTS: The morning stiffness, number of tender or swollen joints, ESR, Lansbury index and serum G-CSF levels in patients with active RA were significantly higher than the corresponding levels in patients with inactive RA. Serum G-CSF levels correlated significantly with morning stiffness, the number of tender or swollen joints and the Lansbury index. However, there was no correlation between serum G-CSF and ESR. High levels of IL-1 beta, IL-6 and TNF-alpha were detected in RA patients. The number of tender or swollen joints, ESR, Lansbury index, and IL-1 beta were significantly higher in G-CSF-positive RA patients than in G-CSF-negative RA patients. CONCLUSION: Our results suggest that G-CSF produced by synovial cells stimulated by inflammatory cytokines might contribute to inflammatory arthritis in RA patients.     

TNF-induced structural joint damage is mediated by IL-1

Blocking TNF effectively inhibits inflammation and structural damage in human rheumatoid arthritis (RA). However, so far it is unclear whether the effect of TNF is a direct one or indirect on up-regulation of other mediators. IL-1 may be one of these candidates because it has a central role in animal models of arthritis, and inhibition of IL-1 is used as a therapy of human RA. We removed the effects of IL-1 from a TNF-mediated inflammatory joint disease by crossing IL-1alpha and beta-deficient mice (IL-1-/-) with arthritic human TNF-transgenic (hTNFtg) mice. Development of synovial inflammation was almost unaffected on IL-1 deficiency, but bone erosion and osteoclast formation were significantly reduced in IL-1-/-hTNFtg mice, compared with hTNFtg mice based on an intrinsic differentiation defect of IL-1-deficient monocytes. Most dramatically, however, cartilage damage was absent in IL-1-/-hTNFtg mice. Chimera studies revealed that protection of cartilage is based on the loss of IL-1 on hematopoietic, but not mesenchymal, cells, leading to decreased expression of ADAMTS-5 and MMP-3. These data show that TNF-mediated cartilage damage is completely and TNF-mediated bone damage is partially dependent on IL-1, suggesting that IL-1 is a crucial mediator for inflammatory cartilage and bone degradation.