Related Articles

Bone destruction is the most difficult target in the treatment of rheumatoid arthritis (RA). Here, we report that local overexpression of IL-4, introduced by a recombinant human type 5 adenovirus vector (Ad5E1mIL-4) prevents joint damage and bone erosion in the knees of mice with collagen arthritis (CIA). No difference was noted in the course of CIA in the injected knee joints between Ad5E1mIL-4 and the control vector, but radiographic analysis revealed impressive reduction of joint erosion and more compact bone structure in the Ad5E1mIL-4 group. Although severe inflammation persisted in treated mice, Ad5E1mIL-4 prevented bone erosion and diminished tartrate-resistant acid phosphatase (TRAP) activity, indicating that local IL-4 inhibits the formation of osteoclast-like cells. Messenger RNA levels of IL-17, IL-12, and cathepsin K in the synovial tissue were suppressed, as were IL-6 and IL-12 protein production. Osteoprotegerin ligand (OPGL) expression was markedly suppressed by local IL-4, but no loss of OPG expression was noted with Ad5E1mIL-4 treatment. Finally, in in vitro studies, bone samples of patients with arthritis revealed consistent suppression by IL-4 of type I collagen breakdown. IL-4 also enhanced synthesis of type I procollagen, suggesting that it promoted tissue repair. These findings may have significant implications for the prevention of bone erosion in arthritis.

Background: Therapeutic strategies to block tumour necrosis factor α (TNFα) activity in experimental autoimmune arthritis models and rheumatoid arthritis (RA) have proved highly successful, and provide sustained beneficial effects.

Objective: To examine whether TNFα inhibition has immunological activity beyond the reduction of inflammation in collagen induced arthritis (CIA), an established experimental model of RA.

Methods: Arthritic DBA/1 mice received single periarticular injections of retroviral constructs encoding human TNF receptor (TNF-R) into the affected arthritic paw, at the onset of arthritis. Severity of arthritis, antibodies to collagen type II (CII), and extent of pathological joint damage of arthritic paws were compared between TNF-R and media treated (control) animals 3, 7, 14, 21, and 49 days after disease onset.

Results: Severity of CIA was significantly decreased in TNF-R treated animals compared with controls, 14–34 days after disease onset. Joint destruction was reduced in TNF-R injected joints and in the uninjected contralateral and ipsilateral paws of TNF-R treated animals. Seven days after disease onset, TNF-R treated mice had lower levels of inflammatory Th1 driven IgG2a antibodies to CII (p<0.05) than controls. This altered the anticollagen IgG2a:IgG1 ratio towards Th2 driven IgG1.

Conclusions: Local TNF-R gene therapy in CIA appears to have systemic effects on the anti-CII antibodies. The overall influence of TNF-R gene therapy is that it inhibits the progression of CIA mainly by suppressing the inflammatory Th1 response rather than by stimulating a Th2 response. Therefore, periarticular TNF-R gene therapy may have excellent therapeutic potential in RA.

Objective

To determine the mechanism of action of IL-27 against rheumatoid arthritis (RA).

Methods

Adenovirus containing IL-27 transcript was constructed and was locally delivered into the ankles of collagen-induced arthritis (CIA) mice. Progression of arthritis was assessed in treated versus untreated mice by measuring ankle circumference and through histological analysis. IL-17 and its downstream targets as well as cytokines promoting TH-17 cell differentiation were quantified by ELISA in CIA ankles locally expressing adenoviral IL-27 versus controls. Ankles from both treatment groups were immunostained for neutrophil and monocyte migration. Last, vascularization was quantified by histology and by determining ankle hemoglobin levels.

Results

Our results demonstrate that ectopic expression of IL-27 in CIA ameliorates inflammation, lining hypertrophy, and bone erosion compared to the control group. Serum and joint IL-17 levels were significantly reduced in the IL-27 treatment group compared to controls. Two of the main cytokines which induce TH-17 cell differentiation and IL-17 downstream target molecules were greatly downregulated in CIA ankles receiving forced expression of IL-27. The control mice had higher levels of vascularization and monocyte trafficking compared to those mice ectopically expressing IL-27.

Conclusion

Our results suggest that increased IL-27 levels relieve arthritis in CIA ankles. This amelioration of arthritis involves a reduction in CIA serum and joint IL-17 levels and results in decreased IL-17-mediated monocyte recruitment and angiogenesis. Hence, IL-27 may be a therapeutic target in RA.

Background: Collagen induced arthritis (CIA) is an animal model of rheumatoid arthritis (RA) amenable to immunotherapy directed against tumour necrosis factor α (TNFα).

Objective: To evaluate whether local TNF receptor (TNF-R) gene therapy in DBA/1 mice exerts an influence beyond anti-inflammatory effects. Two measures of CIA pathogenesis were investigated—namely, immunity to collagen II (CII) 245–270 peptide (the major immunodominant epitope within bovine CII) and the preferential activation of T cell Vß8.2 variable region receptors in arthritic DBA/1 mice.

Methods: DBA/1 mice received single periarticular injections of media or retroviral vectors containing LacZ or human TNF-R into affected arthritic paws at disease onset. Disease severity was monitored, immune responses towards the immunodominant bovine CII 245–270 and subdominant CII 334–360 peptide epitopes were assessed by ELISA, and T cell Vß usage was analysed by real time polymerase chain reaction for the LacZ transduced, TNF-R, and viral-free media treated control animals. The therapeutic influence of TNF-R gene transduction was compared with other groups at different times after treatment.

Results: Reduced disease severity was seen 15–35 days after treatment, with a concomitant increase in immunity towards the subdominant CII 334–360 peptide epitope rather than the immunodominant CII 245–270 peptide in TNF-R treated animals. Early in the disease, TNF-R treated animals demonstrated a reduction of bias towards the otherwise predominant Vß8.2 T cell subset.

Conclusions: TNF-R gene therapy influences cellular immunity in CIA, leading to overall disease amelioration, thus suggesting that TNF inhibition may have therapeutic potential beyond the control of inflammation in RA.

Introduction

Endosomal toll-like receptors (TLRs) have recently emerged as potential contributors to the inflammation observed in human and rodent models of rheumatoid arthritis (RA). This study aims to evaluate the role of endosomal TLRs and in particular TLR7 in the murine collagen induced arthritis (CIA) model.

Methods

CIA was induced by injection of collagen in complete Freund's adjuvant. To investigate the effect of endosomal TLRs in the CIA model, mianserin was administered daily from the day of disease onset. The specific role of TLR7 was examined by inducing CIA in TLR7-deficient mice. Disease progression was assessed by measuring clinical score, paw swelling, serum anti-collagen antibodies histological parameters, cytokine production and the percentage of T regulatory (Treg) cells.

Results

Therapeutic administration of mianserin to arthritic animals demonstrated a highly protective effect on paw swelling and joint destruction. TLR7-/- mice developed a mild arthritis, where the clinical score and paw swelling were significantly compromised in comparison to the control group. The amelioration of arthritis by mianserin and TLR7 deficiency both corresponded with a reduction in IL-17 responses, histological and clinical scores, and paw swelling.

Conclusions

These data highlight the potential role for endosomal TLRs in the maintenance of inflammation in RA and support the concept of a role for TLR7 in experimental arthritis models. This study also illustrates the potential benefit that may be afforded by therapeutically inhibiting the endosomal TLRs in RA.

OBJECTIVE—To examine the effect of granulocyte-macrophage colony stimulating factor (GM-CSF) on disease progression in the collagen induced arthritis (CIA) model in mice.
METHODS—DBA/1 mice were primed for a suboptimal CIA response by intradermal injection of chick type II collagen without a secondary immunisation. Three weeks after immunisation the mice were given four to five consecutive daily intraperitoneal injections of recombinant murine GM-CSF (15 µg; 5 × 105 U), or vehicle, and arthritis development was monitored by clinical scoring of paws and calliper measurements of footpad swelling. At approximately six to eight weeks after immunisation mice were killed, their limbs removed and processed for histological analyses of joint pathology.
RESULTS—Control animals receiving a single immunisation with collagen exhibited a varied CIA response both in terms of incidence and severity. Mice treated with GM-CSF at 20 to 25 days after immunisation with collagen had a consistently greater incidence and more rapid onset of disease than the vehicle treated control mice, based on clinical assessment. GM-CSF treated mice showed higher average clinical scores and greater paw swelling than controls. Histological analyses of joints reflected the clinical scores with GM-CSF treated mice displaying more pronounced pathology (synovitis, pannus formation, cartilage and bone damage) than control mice.
CONCLUSION—GM-CSF is a potent accelerator of the pathological events leading to chronic inflammatory polyarthritis in murine CIA supporting the notion that GM-CSF may play a part in inflammatory polyarthritis, such as rheumatoid arthritis.



To evaluate the antioxidant activity of the glycosaminoglycans hyaluronic acid (HYA) and chondroitin-4-sulphate (C4S), we used a rat model of collagen-induced arthritis (CIA). Arthritis was induced in Lewis rats by multiple intradermal injections of 250 μl of emulsion containing bovine type II collagen in complete Freund's adjuvant at the base of the tail and into three to five other sites on the back. Rats were challenged again with the same antigen preparation 7 days later. Disease developed about 11 days after the second immunization. The effects of treatment in the rats were monitored by biochemical parameters and by macroscopic and histological evaluations in blood, synovial tissue and articular cartilage. Arthritis produced the following symptoms: severe periarticular erythema, edema and inflammation in the hindpaws; membrane peroxidation in the cartilage of the joints; endogenous antioxidant wasting; high tumour necrosis factor-α (TNF-α) plasma levels; and synovial neutrophil accumulation. Treatment with HYA and C4S, starting at the onset of arthritis for 10 days, limited the erosive action of the disease in the articular joints of knee and paw, reduced lipid peroxidation, restored the endogenous antioxidants reduced glutathione (GSH) and superoxide dismutase, decreased plasma TNF-α levels, and limited synovial neutrophil infiltration. These data confirm that erosive destruction of the joint cartilage in CIA is due at least in part to free radicals released by activated neutrophils and produced by other biochemical pathways. The beneficial effects obtained with the treatment suggest that HYA and C4S could be considered natural endogenous macromolecules to limit erosive damage in CIA or as a useful tool with which to study the involvement of free radicals in rheumatoid arthritis.

Osteoporosis can manifest in two ways in rheumatoid arthritis: generalized bone loss, which may result from immobility, the inflammatory process per se and/or treatments such as steroids; and periarticular demineralization, which is probably due to local release of inflammatory agents. Digital X-ray radiogrammetry (DXR) is an effective and sensitive modality for monitoring periarticular osteoporosis, which is among the earliest features of rheumatoid arthritis, preceding bone erosions. DXR is a promising technique, which can provide quantitative data that allow early diagnosis. During the course of rheumatoid arthritis it can be deployed in combination with established X-ray scoring methods to inform decisions regarding the optimal therapy to prevent joint destruction.

Introduction

We sought to investigate the capacity of interleukin (IL)-7 to enhance collagen-induced arthritis and to study by what mechanisms this is achieved.

Methods

Mice received multiple injections with IL-7 or phosphate-buffered saline (PBS) as a control. Arthritis severity and incidence were determined by visual examination of the paws. Joint destruction was determined by assessing radiographs and immunohistochemistry of the ankle joints. Total cellularity and numbers of T-cell and B-cell subsets were assessed, as well as ex vivo production of interferon-γ (IFN-γ), IL-17, and IL-4. Proinflammatory mediators were measured in serum with multianalyte profiling.

Results

IL-7 increased arthritis severity and radiology-assessed joint destruction. This was consistent with IL-7-increased intensity of cell infiltrates, bone erosions, and cartilage damage. Splenic CD19+ B cells and CD19+/GL7+ germinal center B cells, as well as CD4 and CD8 numbers, were increased by IL-7. IL-7 expanded memory T cells, associated with increased percentages of IFN-γ-, IL-4-, and IL-17-producing CD4+ T cells. On antigen restimulation of draining lymph node cells in vitro IL-7 treatment was found to increase IFN-γ and IL-17 production, whereas IL-4 was reduced. IL-7 also increased concentrations of proinflammatory mediators, indicative of T-cell activation (sCD40L), vascular activation (VCAM-1, VEGF), tissue destruction (fibroblast growth factor-basic (FGF-b), LIF), and chemotaxis (MIP-1γ, MIP-3β, lymphotactin, MDC, and MCP-5).

Conclusions

In arthritic mice, IL-7 causes expansion of T and B cells, associated with increased levels of proinflammatory mediators. IL-7 intensifies arthritis severity and joint destruction, accompanied by increased Th1 and Th17 activity. These data indicate that IL-7 could be an important mediator in arthritic conditions and that targeting IL-7 or its receptor represent novel therapeutic strategies.

Background

Rheumatoid arthritis (RA) is characterized by chronic poly-arthritis, synovial hyperplasia, erosive synovitis, progressive cartilage and bone destruction accompanied by a loss of body cell mass. This loss of cell mass, known as rheumatoid cachexia, predominates in the skeletal muscle and can in part be explained by a decreased physical activity. The murine collagen induced arthritis (CIA) model has been proven to be a useful model in RA research since it shares many immunological and pathological features with human RA. The present study explored the interactions between arthritis development, locomotion and muscle mass in the CIA model.

Methods

CIA was induced in male DBA/1 mice. Locomotion was registered at different time points by a camera and evaluated by a computerized tracing system. Arthritis severity was detected by the traditionally used semi-quantitative clinical scores. The muscle mass of the hind-legs was detected at the end of the study by weighing. A methotrexate (MTX) intervention group was included to study the applicability of the locomotion and muscle mass for testing effectiveness of interventions in more detail.

Results

There is a strong correlation between clinical arthritis and locomotion. The correlations between muscle mass and locomotion or clinical arthritis were less pronounced. MTX intervention resulted in an improvement of disease severity accompanied by an increase in locomotion and muscle mass.

Conclusion

The present data demonstrate that registration of locomotion followed by a computerized evaluation of the movements is a simple non invasive quantitative method to define disease severity and evaluate effectiveness of therapeutic agents in the CIA model.

Objective

The present study aimed to explore the hypothesis that bile salt-stimulated lipase (BSSL), in addition to being a key enzyme in dietary fat digestion during early infancy, plays an important role in inflammation, notably arthritis.

Methods

Collagen-induced arthritis (CIA) and pristane-induced arthritis (PIA) in rodents are commonly used experimental models that reproduce many of the pathogenic mechanisms of human rheumatoid arthritis, i.e. increased cellular infiltration, synovial hyperplasia, pannus formation, and erosion of cartilage and bone in the distal joints. We used the CIA model to compare the response in BSSL wild type (BSSL-WT) mice with BSSL-deficient ‘knock-out’ (BSSL-KO) and BSSL-heterozygous (BSSL-HET) littermates. We also investigated if intraperitoneal injection of BSSL-neutralizing antibodies affected the development or severity of CIA and PIA in mice and rats, respectively.

Results

In two consecutive studies, we found that BSSL-KO male mice, in contrast to BSSL-WT littermates, were significantly protected from developing arthritis. We also found that BSSL-HET mice were less prone to develop disease compared to BSSL-WT mice, but not as resistant as BSSL-KO mice, suggesting a gene-dose effect. Moreover, we found that BSSL-neutralizing antibody injection reduced both the incidence and severity of CIA and PIA in rodents.

Conclusion

Our data strongly support BSSL as a key player in the inflammatory process, at least in rodents. It also suggests the possibility that BSSL-neutralizing agents could serve as a therapeutic model to reduce the inflammatory response in humans.

It has been postulated that TNF has a pivotal role in a cytokine cascade that results in joint inflammation and destruction in rheumatoid arthritis (RA). To evaluate this, we examined the response of TNF-deficient (Tnf–/–) mice in two models of RA. Collagen-induced arthritis (CIA) was induced by injection of chick type II collagen (CII) in CFA. Tnf–/– mice had some reduction in the clinical parameters of CIA and, on histology, significantly more normal joints. However, severe disease was evident in 54% of arthritic Tnf–/– joints. Tnf–/– mice had impaired Ig class switching, but preserved T cell proliferative responses to CII and enhanced IFN-γ production. Interestingly, CII-immunized Tnf–/– mice developed lymphadenopathy and splenomegaly associated with increased memory CD4+ T cells and activated lymph node B cells. Acute inflammatory arthritis was also reduced in Tnf–/– mice, although again some mice exhibited severe disease. We conclude that TNF is important but not essential for inflammatory arthritis; in each model, severe arthritis could proceed even in the complete absence of TNF. These results call into doubt the concept that TNF is obligatory for chronic autoimmune and acute inflammatory arthritis and provide a rationale for further studies into TNF-independent cytokine pathways in arthritis.

Introduction

Dysregulated angiogenesis is implicated in the pathogenesis of rheumatoid arthritis (RA). To provide a more profound understanding of arthritis-associated angiogenesis, we evaluated the expression of angiogenesis-modulating genes at onset, peak and declining phases of collagen-induced arthritis (CIA), a well-established mouse model for RA.

Methods

CIA was induced in DBA/1 mice with type II collagen. Functional capillary density in synovial tissue of knee joints was determined by intravital fluorescence microscopy. To assess the ability of arthritic joint homogenates to induce angiogenesis, an endothelial chemotaxis assay and an in vivo matrigel plug assay were employed. The temporal expression profile of angiogenesis-related genes in arthritic paws was analysed by quantitative real-time RT-PCR using an angiogenesis focused array as well as gene specific PCR. Finally, we investigated the therapeutic effect of a monoclonal antibody specifically blocking the binding of VEGF to neuropilin (NRP)-1.

Results

Although arthritic paw homogenates displayed angiogenic activity in vitro and in vivo, and synovia of arthritic paws appeared highly vascularised on histological examination, the functional capillary density in arthritic knee synovia was significantly decreased, whereas capillary diameter was increased. Of the 84 genes analysed, 41 displayed a differential expression in arthritic paws as compared to control paws. Most significant alterations were seen at the peak of clinical arthritis. Increased mRNA expression could be observed for VEGF receptors (Flt-1, Flk-1, Nrp-1, Nrp-2), as well as for midkine, hepatocyte growth factor, insulin-like growth factor-1 and angiopoietin-1. Signalling through NRP-1 accounted in part for the chemotactic activity for endothelial cells observed in arthritic paw homogenates. Importantly, therapeutic administration of anti-NRP1B antibody significantly reduced disease severity and progression in CIA mice.

Conclusions

Our findings confirm that the arthritic synovium in murine CIA is a site of active angiogenesis, but an altered balance in the expression of angiogenic factors seems to favour the formation of non-functional and dilated capillaries. Furthermore, our results validate NRP-1 as a key player in the pathogenesis of CIA, and support the VEGF/VEGF receptor pathway as a potential therapeutic target in RA.

Destruction of cartilage and bone are hallmarks of human rheumatoid arthritis (RA), and controlling these erosive processes is the most challenging objective in the treatment of RA. Systemic interleukin-4 treatment of established murine collagen-induced arthritis suppressed disease activity and protected against cartilage and bone destruction. Reduced cartilage pathology was confirmed by both decreased serum cartilage oligomeric matrix protein (COMP) and histological examination. In addition, radiological analysis revealed that bone destruction was also partially prevented. Improved suppression of joint swelling was achieved when interleukin-4 treatment was combined with low-dose prednisolone treatment. Interestingly, synergistic reduction of both serum COMP and inflammatory parameters was noted when low-dose interleukin-4 was combined with prednisolone. Systemic treatment with interleukin-4 appeared to be a protective therapy for cartilage and bone in arthritis, and in combination with prednisolone at low dosages may offer an alternative therapy in RA.

Introduction:

Rheumatoid arthritis (RA) is associated with an increased production of a range of cytokines including tumour necrosis factor (TNF)-α and interleukin (IL)-1, which display potent proinflammatory actions that are thought to contribute to the pathogenesis of the disease. Although TNF-α seems to be the major cytokine in the inflammatory process, IL-1 is the key mediator with regard to cartilage and bone destruction. Apart from direct blockade of IL-1/TNF, regulation can be exerted at the level of modulatory cytokines such as IL-4 and IL-10. IL-4 is a pleiotropic T-cell derived cytokine that can exert either suppressive or stimulatory effects on different cell types, and was originally identified as a B-cell growth factor and regulator of humoral immune pathways. IL-4 is produced by activated CD4+ T cells and it promotes the maturation of Th2 cells. IL-4 stimulates proliferation, differentiation and activation of several cell types, including fibroblasts, endothelial cells and epithelial cells. IL-4 is also known to be a potent anti-inflammatory cytokine that acts by inhibiting the synthesis of proinflammatory cytokines such as IL-1, TNF-α, IL-6, IL-8 and IL-12 by macrophages and monocytes. Moreover, IL-4 stimulates the synthesis of several cytokine inhibitors such as interleukin-1 receptor antagonist (IL-1Ra), soluble IL-1-receptor type II and TNF receptors IL-4 suppresses metalloproteinase production and stimulates tissue inhibitor of metalloproteinase-1 production in human mononuclear phagocytes and cartilage explants, indicating a protective effect of IL-4 towards extracellular matrix degradation. Furthermore, IL-4 inhibits both osteoclast activity and survival, and thereby blocks bone resorption in vitro. Of great importance is that IL-4 could not be detected in synovial fluid or in tissues. This absence of IL-4 in the joint probably contributes to the disturbance in the Th1/Th2 balance in chronic RA.

Collagen-induced arthritis (CIA) is a widely used model of arthritis that displays several features of human RA. Recently it was demonstrated that the onset of CIA is under stringent control of IL-4 and IL-10. Furthermore, it was demonstrated that exposure to IL-4 during the immunization stage reduced onset and severity of CIA. However, after cessation of IL-4 treatment disease expression increased to control values.

Aims:

Because it was reported that IL-4 suppresses several proinflammatory cytokines and matrix degrading enzymes and upregulates inhibitors of both cytokines and catabolic enzymes, we investigated the tissue protective effect of systemic IL-4 treatment using established murine CIA as a model. Potential synergy of low dosages of anti-inflammatory glucocorticosteroids and IL-4 was also evaluated.

Methods:

DBA-1J/Bom mice were immunized with bovine type II collagen and boosted at day 21. Mice with established CIA were selected at day 28 after immunization and treated for days with IL-4, prednisolone, or combinations of prednisolone and IL-4. Arthritis score was monitored visually. Joint pathology was evaluated by histology, radiology and serum cartilage oligomeric matrix protein (COMP). In addition, serum levels of IL-1Ra and anticollagen antibodies were determined.

Results:

Treatment of established CIA with IL-4 (1 μg/day) resulted in suppression of disease activity as depicted in Figure 1. Of great interest is that, although 1 μg/day IL-4 had only a moderate effect on the inflammatory component of the disease activity, it strongly reduced cartilage pathology, as determined by histological examination (Fig. 1). Moreover, serum COMP levels were significantly reduced, confirming decreased cartilage involvement. In addition, both histological and radiological analysis showed that bone destruction was prevented (Fig. 1). Systemic IL-4 administration increased serum IL-1Ra levels and reduced anticollagen type II antibody levels. Treatment with low-dose IL-4 (0.1 μg/day) was ineffective in suppressing disease score, serum COMP or joint destruction. Synergistic suppression of both arthritis severity and COMP levels was noted when low-dose IL-4 was combined with prednisolone (0.05 mg/kg/day), however, which in itself was not effective.

Discussion:

In the present study, we demonstrate that systemic IL-4 treatment ameliorates disease progression of established CIA. Although clinical disease progression was only arrested and not reversed, clear protection against cartilage and bone destruction was noted. This is in accord with findings in both human RA and animal models of RA that show that inflammation and tissue destruction sometimes are uncoupled processes. Of great importance is that, although inflammation was still present, strong reduction in serum COMP was found after exposure to IL-4. This indicated that serum COMP levels reflected cartilage damage, although a limited contribution of the inflamed synovium cannot be excluded.

Increased serum IL-1Ra level (twofold) was found after systemic treatment with IL-4, but it is not likely that this could explain the suppression of CIA. We and others have reported that high dosages of IL-1Ra are needed for marked suppression of CIA. As reported previously, lower dosages of IL-4 did not reduce clinical disease severity of established CIA. Of importance is that combined treatment of low dosages of IL-4 and IL-10 appeared to have more potent anti-inflammatory effects, and markedly protected against cartilage destruction. Improved anti-inflammatory effect was achieved with IL-4/prednisolone treatment. In addition, synergistic effects were found for the reduction of cartilage and bone destruction. This indicates that systemic IL-4/prednisolone treatment may provide a cartilage and bone protective therapy for human RA.

Objective

To assess the efficacy of human placental extract (HPE) in an animal model of rheumatoid arthritis (RA).

Method

We used (i) KRN C57BL/6 TCR transgenic x NOD mice (KBx/N) serum transfer arthritis and (ii) collagen-induced arthritis (CIA) mice to evaluate the effi cacy of HPE (1 ul or 100 ul, intra-peritoneal, three times per week) on RA. Incidence, severity of arthritis, and hind-paw thickness were quantifi ed. Joint destruction was analyzed using modifi ed mammographic imaging. Histopathological analysis for inflammation, cartilage, and osteoclasts was performed using Hematoxylin-eosin (H-E), safranin-O, and tartrate-resistant acidic phosphatase (TRAP). ELISAs were used for detection of various cytokines in serum and joint tissue.

Results

There were no significant differences in incidence of arthritis, clinical scores of arthritis, and hind-paw thickness between HPE-treated and vehicle-treated groups for up to 2 weeks in the KBx/N serum transfer arthritis model. Histopathological analysis also showed no differences 2 weeks after treatment. Levels of TNF-α, IL-1β, IL-6, IL-10, and RANKL in serum and joint tissues were similar in all groups. Furthermore, there were no differences in clinical, radiological, and histological parameters between HPE-treated and vehicle-treated group for 3 weeks in the CIA model.

Conclusion

Systemic treatment with HPE has no beneficial effects on arthritis in animal models of RA. Therefore, indiscreet use of HPE in RA should be forbidden.

The anti-inflammatory activity of licorice (LE) and roated licorice (rLE) extracts determined in the murine phorbol ester-induced acute inflammation model and collagen-induced arthritis (CIA) model of human rheumatoid arthritis. rLE possessed greater activity than LE in inhibiting phorbol ester-induced ear edema. Oral administration of LE or rLE reduced clinical arthritis score, paw swelling, and histopathological changes in a murine CIA. LE and rLE decreased the levels of proinflammatory cytokines in serum and matrix metalloproteinase-3 expression in the joints. Cell proliferation and cytokine secretion in response to type II collagen or lipopolysaccharide stimulation were suppressed in spleen cells from LE or rLE-treated CIA mice. Furthermore, LE and rLE treatment prevented oxidative damages in liver and kidney tissues of CIA mice. Taken together, LE and rLE have benefits in protecting against both acute inflammation and chronic inflammatory conditions including rheumatoid arthritis. rLE may inhibit the acute inflammation more potently than LE.

Background: Periarticular osteoporosis is an early finding in the hands of patients with rheumatoid arthritis (RA), due to release of bone resorbing cytokines from the inflamed synovium. There has been disagreement as to whether periarticular bone loss occurs in psoriatic arthritis (PsA). Bone mineral density (BMD) can now be measured accurately using dual energy x ray absorptiometry (DEXA). Recently, DEXA has been used to measure periarticular BMD at predefined regions of interest (ROIs) around the joints.

Objectives: Firstly, to compare periarticular BMD around the finger joints of patients with early RA or PsA. Secondly, to determine whether periarticular bone loss is related to joint inflammation and radiological erosions in RA and PsA.

Methods: Seventeen patients with RA and 15 with PsA were recruited, all with disease duration of less than five years. All finger joints were examined by one person for swelling, or tenderness, or both. Hand radiographs were scored for the presence of erosions. Periarticular BMD was measured at 10 predetermined ROIs using a Hologic QDA-4500A fan-beam densitometer.

Results: Patients with PsA were less likely to be positive for rheumatoid factor (RF) (13% v 94%) and more likely to be men (60% v 23%) than patients with RA. There were no other clinical differences between patients with RA or PsA. Patients with RA had significantly lower BMD at each of the ROIs than those with PsA (p<0.05). However, these differences disappeared after adjusting for age and sex. Among patients with RA, those with a higher total number of swollen and/or tender hand joints had significantly lower periarticular BMD at the metocarpophalangeal (MCP) and proximal interphalangeal (PIP) joints. No such association was found for patients with PsA.

Conclusions: In early disease, periarticular bone loss occurred both in patients with RA and those with PsA. Among patients with RA, periarticular osteoporosis was related to measures of joint inflammation. There was no association between joint inflammation and periarticular bone loss in patients with PsA, which lends support to the hypothesis that the primary site of inflammation in PsA is extrasynovial.

Introduction

The mechanism by which intra-articular injection of hyaluronan (HA) ameliorates joint pathology is unknown. Animal studies have shown that HA can reduce synovial activation, periarticular fibrosis and cartilage erosion; however, its specific effects on the different cell types involved remain unclear. We have used the TTR (TGFbeta1 injection and Treadmill Running) model of murine osteoarthritis (OA), which exhibits many OA-like changes, including synovial activation, to examine in vivo tissue-specific effects of intra-articular HA.

Methods

The kinetics of clearance of fluorotagged HA from joints was examined with whole-body imaging. Naïve and treated knee joints were examined macroscopically for cartilage erosion, meniscal damage and fibrosis. Quantitative histopathology was done with Safranin O for cartilage and with Hematoxylin & Eosin for synovium. Gene expression in joint tissues for Acan, Col1a1, Col2a1, Col3a1, Col5a1, Col10a1, Adamts5 and Mmp13 was done by quantitative PCR. The abundance and distribution of aggrecan, collagen types I, II, III, V and X, ADAMTS5 and MMP13 were examined by immunohistochemistry.

Results

Injected HA showed a half-life of less than 2 h in the murine knee joint. At the tissue level, HA protected against neovascularization and fibrosis of the meniscus/synovium and maintained articular cartilage integrity in wild-type but not in Cd44 knockout mice. HA injection enhanced the expression of chondrogenic genes and proteins and blocked that of fibrogenic/degradative genes and proteins in cartilage/subchondral bone, whereas it blocked activation of both groups in meniscus/synovium. In all locations it reduced the expression/protein for Mmp13 and blocked Adamts5 expression but not its protein abundance in the synovial lining.

Conclusions

The injection of HA, 24 h after TGFbeta1 injection, inhibited the cascade of OA-like joint changes seen after treadmill use in the TTR model of OA. In terms of mechanism, tissue protection by HA injection was abrogated by Cd44 ablation, suggesting that interaction of the injected HA with CD44 is central to its protective effects on joint tissue remodeling and degeneration in OA progression.

Background

Cia5a is a locus on rat chromosome 10 that regulates disease severity and joint damage in two models of rheumatoid arthritis, collagen- and pristane-induced arthritis (PIA). In this study, we aimed to identify cellular and molecular processes regulated by Cia5a using microarray-based gene expression analysis of synovial tissues from MHC identical DA (severe erosive disease) and DA.F344(Cia5a) congenics (mild non-erosive disease) rats.

Results

Synovial tissues from six DA and eight DA.F344(Cia5a) rats were analyzed 21 days after the induction of PIA using the Illumina RatRef-12 BeadChip (21,922 genes) and selected data confirmed with qPCR. There was a significantly increased expression of pro-inflammatory mediators such as Il1b (5-fold), Il18 (3.9-fold), Cxcl1 (10-fold), Cxcl13 (7.5-fold) and Ccl7 (7.9-fold), and proteases like Mmp3 (23-fold), Mmp9 (32-fold), Mmp14 (4.4-fold) and cathepsins in synovial tissues from DA, with reciprocally reduced levels in congenics. mRNA levels of 47 members of the Spleen Tyrosine Kinase (Syk) pathway were significantly increased in DA synovial tissues compared with DA.F344(Cia5a), and included Syk (5.4-fold), Syk-activating receptors and interacting proteins, and genes regulated by Syk such as NFkB, and NAPDH oxidase complex genes. Nuclear receptors (NR) such as Rxrg, Pparg and Rev-erba were increased in the protected congenics, and so was the anti-inflammatory NR-target gene Scd1 (54-fold increase). Tnn (72-fold decrease) was the gene most significantly increased in DA.

Conclusions

Analyses of gene expression in synovial tissues revealed that the arthritis severity locus Cia5a regulates the expression of key mediators of inflammation and joint damage, as well as the expression of members of the Syk pathway. This expression pattern correlates with disease severity and joint damage and along with the gene accounting for Cia5a could become a useful biomarker to identify patients at increased risk for severe and erosive disease. The identification of the gene accounting for Cia5a has the potential to generate a new and important target for therapy and prognosis.

Avian retrovirus MH2 contains two oncogenes, v-mil and v-myc. We have previously shown that a spontaneous mutant of MH2 (PA200-MH2), expressing only the v-mil oncogene, is able to induce proliferation of quiescent neuroretina cells. In this study, we investigated the transforming and tumorigenic properties of v-mil. PA200 induced fibrosarcomas in about 60% of the injected chickens, whereas inoculation of MH2 resulted mainly in the appearance of kidney carcinomas. Analysis of several parameters of transformation showed that PA200, in contrast to MH2, induced only limited in vitro transformation of fibroblasts and neuroretina cells. These results suggest that v-myc is the major transforming and tumorigenic gene in MH2-infected cells. This low in vitro transforming capacity differentiates v-mil not only from other avian oncogenes, but also from the homologous murine v-raf gene.

Images

Previous studies showed that polymerized-type I collagen (polymerized collagen) exhibits potent immunoregulatory properties. This work evaluated the effect of intramuscular administration of polymerized collagen in early and established collagen-induced arthritis (CIA) in mice and analyzed changes in Th subsets following therapy. Incidence of CIA was of 100% in mice challenged with type II collagen. Clinimorphometric analysis showed a downregulation of inflammation after administration of all treatments (P < 0.05). Histological analysis showed that the CIA-mice group had extensive bone erosion, pannus and severe focal inflammatory infiltrates. In contrast, there was a remarkable reduction in the severity of arthritis in mice under polymerized collagen, methotrexate or methotrexate/polymerized collagen treatment. Polymerized Collagen but not methotrexate induced tissue joint regeneration. Polymerized Collagen and methotrexate/polymerized collagen but not methotrexate alone induces downregulation of CD4+/IL17A+ T cells and upregulation of Tregs and CD4+/IFN-γ+ T cells. Thus, Polymerized Collagen could be an effective therapeutic agent in early and established rheumatoid arthritis by exerting downregulation of autoimmune inflammation.

The selectins, along with very late antigen-4 and CD44, have been implicated in mediating leukocyte rolling interactions that lead to joint recruitment and inflammation during the pathogenesis of rheumatoid arthritis. Previously, we showed that P-selectin deficiency in mice resulted in accelerated onset of joint inflammation in the murine collagen-immunized arthritis model. Here, we report that mice deficient either in E-selectin or in E-selectin and P-selectin (E/P-selectin mutant) also exhibit accelerated development of arthritis compared with wild type mice in the CIA model, suggesting that these adhesion molecules perform overlapping functions in regulating joint disease. Analyses of cytokine and chemokine expression in joint tissue from E/P-selectin mutant mice before the onset of joint swelling revealed significantly higher joint levels of macrophage inflammatory protein-1α and IL-1β compared to wild-type mice. IL-1β remained significantly increased in E/P-selectin mutant joint tissue during the early and chronic phases of arthritis. Overall, these data illustrate the novel finding that E-selectin and P-selectin expression can significantly influence cytokine and chemokine production in joint tissue, and suggest that these adhesion molecules play important regulatory roles in the development of arthritis in E/P-selectin mutant mice.

Neovascularization is observed in a spectrum of diseases such as solid tumors, diabetic retinopathy, and rheumatoid arthritis. It is also evident in rat collage-induced arthritis (CIA), an animal model with histologic, clinical, and radiographic manifestations resembling rheumatoid arthritis. To evaluate the effects of angioinhibition in CIA, Louvain rats were immunized with type II collagen to induce arthritis and then administered an angiogenesis inhibitor, AGM-1470, in an attempt to either prevent arthritis or suppress established disease. Using clinical and radiographic criteria, AGM-1470 prevented CIA and significantly suppressed established disease without evidence of immunosuppression. Histologic sections from control ankle joints manifested pannus and neovascularization, which were absent in experimental animals. This is the first study to investigate this novel agent in an autoimmune disease, and additional evaluation of this promising compound in other diseases that are potentially angiogenesis dependent, such as rheumatoid arthritis, might be warranted.

Adjuvant arthritis (AA) in rats is susceptible to cell-mediated passive transfer. Collagen-induced arthritis (CIA) in rats is susceptible to passive transfer with antibody to type II collagen. We report here the development of strikingly severe arthritis in Lewis rats as the result of synergy between passively transferred antibody to type II collagen from rats with CIA and concanavalin A (Con A)-stimulated lymph node or spleen cells from syngeneic rats with AA. Similar synergy was seen in rats with AA given anticollagen antibody, in rats with CIA given Con A- stimulated adjuvant spleen cells, and in rats actively immunized with CII and complete Freund's adjuvant. The synergistic process caused a very severe polyarthritis, characterized by marked swelling and erythema in all the joints of the distal extremities, with histologic and radiographic evidence of early, extensive erosion of articular cartilage. Synergy was apparent if the lymphoid cells from AA rats were given up to 1 mo after a single injection of anticollagen antibody. No synergy was seen when normal rat immunoglobulin or anti-ovalbumin antibody was substituted for anticollagen antibody, when Con A- stimulated lymphoid cells from normal rats or donors with CIA were used, or when Con A-stimulated AA lymphoid cells were irradiated before transfer. Synergy between separate immune effector mechanisms may represent a general phenomenon in the pathogenesis of inflammatory joint disease.

Background

A genomewide scan in a DA×ACI F2 intercross studied for collagen‐induced arthritis (CIA) identified the severity quantitative trait locus Cia25 on rat chromosome 12. Cia25 co‐localises with loci regulating several forms of autoimmune diseases in rats, mice and humans, suggesting a common gene.

Objective

To characterise the effects of Cia25 on severity of arthritis in congenic rats.

Methods

DA.ACI(Cia25) congenic rats were constructed according to a genotype‐guided strategy, and tested for pristane‐induced arthritis (PIA) and CIA, induced with rat type II collagen (CII). A well‐established scoring system previously shown to correlate with histological damage, including cartilage and bone erosions, synovial hyperplasia and synovial inflammation, was used.

Results

The introgression of ACI alleles at Cia25 into DA background, as in DA.ACI(Cia25) rats, was enough to significantly reduce arthritis severity by 60% in PIA and by 40% in CIA, both in males and females compared with DA rats of the same sex. Levels of IgG anti‐CII in male DA.ACI(Cia25) rats were 83% lower than in male DA. Levels of anti‐CII in females were not affected by the congenic interval.

Conclusions

Cia25 contains a gene that regulates disease severity in two distinct models of autoimmune arthritis. Although both genders were protected in arthritis studies, only male congenic rats had a dramatic reduction in levels of anti‐CII, suggesting the possibility of a second arthritis gene in this interval that operates via the regulation of autoantibodies in a sex‐specific manner. The identification of the gene(s) accounting for Cia25 is expected to generate novel prognostic biomarkers and targets for therapy.