<Emphasis Type="Italic">Celastrus aculeatus</Emphasis>Merr. suppresses the induction and progression of autoimmune arthritis by modulating immune response to heat-shock protein 65

Complementary and alternative medicine products are increasingly being used for the treatment of autoimmune diseases. However, the mechanisms of action of these agents are not fully defined. Using the rat adjuvant arthritis (AA) model of human rheumatoid arthritis, we determined whether the ethanol extract of Celastrus aculeatus Merr. (Celastrus), a Chinese herb, can down-modulate the severity of AA, and also examined the Celastrus-induced changes in immune responses to the disease-related antigen mycobacterial heat-shock protein 65 (Bhsp65). AA was induced in the Lewis (LEW; RT.1^l) rat by immunization subcutaneously with heat-killed M. tuberculosis H37Ra (Mtb). Celastrus was fed to LEW rats by gavage daily, beginning either before Mtb challenge (preventive regimen) or after the onset of AA (therapeutic regimen). An additional group of rats was given methotrexate for comparison. All rats were graded regularly for the signs of arthritis. In parallel, the draining lymph node cells of Celastrus-treated rats were tested for proliferative and cytokine responses, whereas their sera were tested for the inflammatory mediator nitric oxide. Celastrus feeding suppressed both the induction as well as the progression of AA, and the latter effect was comparable to that of methotrexate. Celastrus treatment induced relative deviation of the cytokine response to anti-inflammatory type and enhanced the production of anti-Bhsp65 antibodies, which are known to be protective against AA. Celastrus feeding also reduced the levels of nitric oxide. On the basis of our results, we suggest further systematic exploration of Celastrus as an adjunct therapeutic modality for rheumatoid arthritis.     

The M20 IL-1 inhibitor prevents onset of adjuvant arthritis

Cytokines, specifically IL-1 and TNF, have been implicated as important mediators of joint destruction in rheumatoid arthritis (RA). Elevated levels of IL-1 in the joint fluid of patients with RA have been reported, as well as the presence of IL-1 inhibitory activity. We have reported the characterization of an inhibitor derived from a myelomonocytic cell line cloned in our laboratory which is specific for IL-1. This IL-1 inhibitor is protein in nature which specifically inhibits activityin vitro andin vivo. Previous studies showed that the inhibitor reduced acute inflammatory reactions associated with IL-1 (fever, leukocytosis, local foot pad swelling, lymph node enlargement and acute phase reactants). Thus it was of interest to study whether the M20 IL-1 inhibitor could modify adjuvant-induced chronic inflammation in rats, which is often used as a model for human RA. Administration of complete Freund's adjuvant (CFA) into Lewis rats, resulted in a severe adjuvant arthritis (AA) which reached peak severity after 14 days. Daily administration of IL-1 inhibitor, beginning after injection of CFA, abolished the appearance of AA. The parameters investigated were: joint swelling (the increase in diameter of joints), peri-articular erythema, limping of the rats and histological examination. The effect of the M20 IL-1 inhibitor was shown to be dose dependent and the IL-1 inhibitor alone had no adverse effects. These results indicate that the M20 IL-1 inhibitor may have a role in the treatment of AA and may be used to reduce pathological processes in joint inflammation.     

Local treatment with the selective IκB kinase β inhibitor NEMO-binding domain peptide ameliorates synovial inflammation

Nuclear factor (NF)-κB is a key regulator of synovial inflammation. We investigated the effect of local NF-κB inhibition in rat adjuvant arthritis (AA), using the specific IκB kinase (IKK)-β blocking NF-κB essential modulator-binding domain (NBD) peptide. The effects of the NBD peptide on human fibroblast-like synoviocytes (FLS) and macrophages, as well as rheumatoid arthritis (RA) whole-tissue biopsies, were also evaluated. First, we investigated the effects of the NBD peptide on RA FLS in vitro. Subsequently, NBD peptides were administered intra-articularly into the right ankle joint of rats at the onset of disease. The severity of arthritis was monitored over time, rats were sacrificed on day 20, and tissue specimens were collected for routine histology and x-rays of the ankle joints. Human macrophages or RA synovial tissues were cultured ex vivo in the presence or absence of NBD peptides, and cytokine production was measured in the supernatant by enzyme-linked immunosorbent assay. The NBD peptide blocked interleukin (IL)-1-β-induced IκBα phosphorylation and IL-6 production in RA FLS. Intra-articular injection of the NBD peptide led to significantly reduced severity of arthritis (p < 0.0001) and reduced radiological damage (p = 0.04). This was associated with decreased synovial cellularity and reduced expression of tumor necrosis factor (TNF)-α and IL-1-β in the synovium. Incubation of human macrophages with NBD peptides resulted in 50% inhibition of IL-1-β-induced TNF-α production in the supernatant (p < 0.01). In addition, the NBD peptide decreased TNF-α-induced IL-6 production by human RA synovial tissue biopsies by approximately 42% (p < 0.01). Specific NF-κB blockade using a small peptide inhibitor of IKK-β has anti-inflammatory effects in AA and human RA synovial tissue as well as in two important cell types in the pathogenesis of RA: macrophages and FLS. These results indicate that IKK-β-targeted NF-κB blockade using the NBD peptide could offer a new approach for the local treatment of arthritis.     

Enhanced intraarticular free radical reactions in adjuvant arthritis rats

One of the reasons of rheumatoid arthritis (RA) development is widely recognized the relation of free radical reactions in tissue injuries. The aim of this study was to evaluate the location where in vivo free radical reactions was enhanced in adjuvant arthritis (AA) model rats using in vivo electron spin resonance (ESR)/nitroxyl spin probe technique. The signal decay after intravenous injection of spin probe was enhanced in AA than that in control and suppressed by the pre-treatment of dexamethasone (DXT). Interestingly, the decay in joint cavity occurred prior to paw swelling of AA and suppressed by a simultaneous injection of free radical scavengers, indicating that the enhancement of free radical reactions in joint cavity of AA rats. This technique would be useful tool to determine the location of the enhanced free radical reactions and evaluate the activity of antioxidant medicine with non-invasive real-time measurement.     

Apoptosis and p53 expression in rat adjuvant arthritis

The kinetics of apoptosis and the apoptosis-regulating gene p53 in adjuvant arthritis (AA) were investigated to assess the value of the AA rat model for testing apoptosis-inducing therapies. Very few terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end-labeling (TUNEL)-positive cells were detected during the early phases of AA, but on day 23 (chronic arthritis) the percentage of TUNEL-positive cells was significantly increased. Expression of p53 in synovial tissue gradually increased from days 5-23, which was markedly higher than p53 levels in rheumatoid arthritis (RA) synovium. Significant apoptosis only occurs late in rat AA and is concordant with marked p53 overexpression, making it useful model for testing proapoptotic therapies, but rat AA is not the best model for p53 gene therapy because dramatic p53 overexpression occurs in the latter stages of the disease.     

Protective effect of betulinic acid on Freund's complete adjuvant‐induced arthritis in rats

The purpose of the experiment was to study the effects of betulinic acid (BA) on adjuvant‐induced arthritis in rats. The rat model of rheumatoid arthritis (AA) was established by Freund's complete adjuvant. Arthritis index, joint pathology, toe swelling, hemorheology, related cytokines and ROCK/NF‐κB signaling pathway were measured in rats. BA can significantly inhibit the arthritis index, improve joint pathology, reduce toe swelling, improve blood rheology, improve synovial cell apoptosis, and restore related cytokine negative regulation of ROCK/NF‐κB signaling pathways. BA has an obvious therapeutic effect on joint inflammation of toes in AA model rats, which may be due to the regulation of ROCK/NF‐κB signaling pathway.     

Exogenous tumour necrosis factor α induces suppression of autoimmune arthritis

Introduction  

Our previous studies showed that arthritic Lewis (LEW) rats produced the highest levels of tumour necrosis factor (TNF)α in the recovery phase of adjuvant arthritis (AA), suggesting a correlation between high TNFα levels and reduced severity of arthritis. To further explore this correlation, we compared the TNFα secretion profile of the AA-resistant Wistar Kyoto (WKY) rats with that of LEW rats, determined the effect of exogenous TNFα on the course of AA in LEW rats, and examined various mechanisms involved in TNFα-induced disease modulation.     

Independent associations of anti-cyclic citrullinated peptide antibodies and rheumatoid factor with radiographic severity of rheumatoid arthritis

Several recent publications have established a strong association between anti-cyclic citrullinated peptide antibody (anti-CCP)-positive rheumatoid arthritis (RA) and carriage of shared epitope (SE) alleles. Although anti-CCP have also been associated with more severe RA, the issue of whether this is independent of rheumatoid factor (RF) has not been addressed. To identify associations between RF, anti-CCP, SE status and radiological damage, we studied a large cross-sectional cohort with longstanding RA. Individuals (n = 872) enrolled in the study all fulfilled the American College of Rheumatology criteria for RA, had a minimum disease duration of 3 years, and at least one definite radiographic erosion was present in hands or feet. Radiographs were scored blind at study entry by a single musculoskeletal radiologist using a modified Larsen's score. Anti-CCP and RF levels were determined using enzyme-linked immunosorbent assay, and DRB1 typing was performed using polymerase chain reaction based methodology. Both anti-CCP and RF levels were strongly associated with radiographic severity (P < 0.0001). In subgroups stratified for both anti-CCP and RF status, evidence of independent associations of both antibodies with radiographic outcome was found (P < 0.0001). An association of SE alleles with radiographic severity was present only in RF-negative individuals. Anti-CCP positivity was associated with SE status with evidence of a gene-dose effect, most markedly in RF-negative individuals (P < 0.01). Anti-CCP and RF status are independent severity factors for RA, with SE alleles playing at most a secondary role. Our data support the view that previously described associations between SE and radiological severity, especially in RF-negative patients, may be indirect and due to an association with anti-CCP.     

Smoking–gender interaction and risk for rheumatoid arthritis

The present case–control study was conducted to investigate the relationship between smoking and rheumatoid arthritis, and to investigate formally the interaction between sex, smoking, and risk for developing rheumatoid arthritis. The study was performed in the Central District of Finland. Cases were patients with rheumatoid arthritis and the control group was a random sample of the general population. Logistic regression models were used to evaluate the effect of smoking on risk for rheumatoid arthritis, after adjusting for the effects of age, education, body mass index, and indices of general health and pain. Overall, 1095 patients with rheumatoid arthritis and 1530 control individuals were included. Patients were older, less well educated, more disabled, and had poorer levels of general health as compared with control individuals (all P < 0.01). Preliminary analyses revealed the presence of substantial statistical interaction between smoking and sex (P < 0.001). In separate multivariable analyses, past history of smoking was associated with increased risk for rheumatoid arthritis overall in men (odds ratio 2.0, 95% confidence interval 1.2–3.2) but not in women. Among men, this effect was seen only for rheumatoid factor-positive rheumatoid arthritis. There were significant interactions between smoking and age among women but not among men. We conclude that sex is a biologic effect modifier in the association between smoking and rheumatoid arthritis. The role of menopause in the etiology of rheumatoid arthritis merits further research.     

Serum cartilage oligomeric matrix protein (COMP) decreases in rheumatoid arthritis patients treated with infliximab or etanercept

Changes in serum cartilage oligomeric matrix protein (COMP) were studied during a 6-month period from initiation of treatment of rheumatoid arthritis patients with either infliximab or etanercept, to elucidate whether the favourable results of tissue protection reported in clinical trials are corroborated by changing levels of circulating COMP. Rheumatoid arthritis patients commencing treatment with infliximab (N = 32) or etanercept (N = 17) were monitored in accordance with a structured protocol. Only patients who were not receiving glucocorticoids or who were on a stable dose of oral prednisolone (<10 mg daily) were included. Serum COMP was measured by a sandwich immunoassay based on two monoclonal antibodies against human COMP in samples obtained at treatment initiation and at 3 and 6 months. Serum COMP decreased at 3 months in both infliximab- and etanercept-treated patients (P < 0.001 and <0.005, respectively) and remained low at 6 months. There was no significant correlation between changes in or concentrations of serum COMP and serum C-reactive protein at any time point. A decrease in serum COMP was seen both in ACR20 responders (patients meeting the American College of Rheumatology criteria for 20% improvement) and in nonresponders. The pattern of changes of serum COMP, a marker for cartilage turnover, in these patient groups supports the interpretation that infliximab and etanercept have a joint protective effect. Serum COMP has potential as a useful marker for evaluating tissue effects of novel treatment modalities in rheumatoid arthritis.     

Therapeutic effects of standardized Vitex negundo seeds extract on complete Freund's adjuvant induced arthritis in rats

The seeds of Vitex negundo L. (Verbenaceae) have been commonly used as a folk remedy for the treatment of rheumatism and joint inflammation in Traditional Chinese Medicine. This study aimed to evaluate the anti-arthritic activity of the extract of V. negundo seeds (EVNS) using Freund's complete adjuvant (CFA) induced arthritis (AA) in rat model. As a result, EVNS, with abundant phenylnaphthalene-type lignans, significantly inhibited the paw edema, decreased the arthritis score and spleen index, and reversed the weight loss of CFA-injected rats. Histopathological studies showed a marked decrease of synovial inflammatory infiltration and synovial lining hyperplasia in the joints of EVNS-treated animals. The remarkable decrement of serum inflammatory factors (TNF-α, IL-1β and IL-6) were observed in EVNS-treated rats, whereas, IL-10, an anti-inflammatory cytokine, was found to be significantly increased by EVNS. The expressions of COX-2 and 5-LOX in PBMC were also inhibited by administration of EVNS. Our results demonstrated that V. negundo seeds possessed potential therapeutic effect on adjuvant induced arthritis in rats by decreasing the levels of TNF-α, IL-1β and IL-6 and increasing that of IL-10 in serum as well as down-regulating the levels of COX-2 and 5-LOX, and therefore may be an effective cure for the treatment of human rheumatoid arthritis.     

Potent anti-angiogenic action of AGM-1470: comparison to the fumagillin parent.

The anti-angiogenic activity of AGM-1470, a new synthetic analog of fumagillin isolated from Aspergillus fumigatus, was extensively examined both in vitro and in vivo using four different types of assay and compared to that of the fumagillin parent. Locally administered AGM-1470 inhibited the angiogenesis in the chick embryo chorioallantoic membrane assay and the rat corneal assay. In the rat sponge implantation assay, systemically administered AGM-1470 inhibited angiogenesis induced by basic fibroblast growth factor. Furthermore, in the rat blood vessel organ culture assay, AGM-1470 (1-1,000 ng/ml) was found to selectively inhibit the capillary-like tube formation of endothelial cells with a minimal effect on the non-endothelial cell growth. AGM-1470 showed more potent anti-angiogenic activity and less toxicity than the fumagillin parent. Therefore, AGM-1470 is much better than the fumagillin parent as anti-angiogenic compound.     

Dual role of interleukin-17 in pannus growth and osteoclastogenesis in rheumatoid arthritis

Introduction  

In a murine model, interleukin (IL)-17 plays a critical role in the pathogenesis of arthritis. There are controversies, however, regarding whether IL-17 is a proinflammatory mediator in rheumatoid arthritis (RA). We previously established an ex vivo cellular model using synovial tissue (ST)-derived inflammatory cells, which reproduced pannus-like tissue growth and osteoclastic activity in vitro. Using this model, we investigated the effects of IL-17 on pannus growth and osteoclastogenesis in RA.     

Local treatment with the selective IkappaB kinase beta inhibitor NEMO-binding domain peptide ameliorates synovial inflammation

Nuclear factor (NF)-kappaB is a key regulator of synovial inflammation. We investigated the effect of local NF-kappaB inhibition in rat adjuvant arthritis (AA), using the specific IkappaB kinase (IKK)-beta blocking NF-kappaB essential modulator-binding domain (NBD) peptide. The effects of the NBD peptide on human fibroblast-like synoviocytes (FLS) and macrophages, as well as rheumatoid arthritis (RA) whole-tissue biopsies, were also evaluated. First, we investigated the effects of the NBD peptide on RA FLS in vitro. Subsequently, NBD peptides were administered intra-articularly into the right ankle joint of rats at the onset of disease. The severity of arthritis was monitored over time, rats were sacrificed on day 20, and tissue specimens were collected for routine histology and x-rays of the ankle joints. Human macrophages or RA synovial tissues were cultured ex vivo in the presence or absence of NBD peptides, and cytokine production was measured in the supernatant by enzyme-linked immunosorbent assay. The NBD peptide blocked interleukin (IL)-1-beta-induced IkappaB alpha phosphorylation and IL-6 production in RA FLS. Intra-articular injection of the NBD peptide led to significantly reduced severity of arthritis (p < 0.0001) and reduced radiological damage (p = 0.04). This was associated with decreased synovial cellularity and reduced expression of tumor necrosis factor (TNF)-alpha and IL-1-beta in the synovium. Incubation of human macrophages with NBD peptides resulted in 50% inhibition of IL-1-beta-induced TNF-alpha production in the supernatant (p < 0.01). In addition, the NBD peptide decreased TNF-alpha-induced IL-6 production by human RA synovial tissue biopsies by approximately 42% (p < 0.01). Specific NF-kappaB blockade using a small peptide inhibitor of IKK-beta has anti-inflammatory effects in AA and human RA synovial tissue as well as in two important cell types in the pathogenesis of RA: macrophages and FLS. These results indicate that IKK-beta-targeted NF-kappaB blockade using the NBD peptide could offer a new approach for the local treatment of arthritis.     

Association of a specific haplotype across the genes <Emphasis Type="Italic">MMP1</Emphasis> and <Emphasis Type="Italic">MMP3</Emphasis> with radiographic joint destruction in rheumatoid arthritis

The genetic background of rheumatoid arthritis (RA) is only partly understood, and several genes seem to be involved. The matrix metalloproteinases MMP1 (interstitial collagenase) and MMP3 (stromelysin 1) are thought to be important in destructive joint changes seen in RA. In the present study, functional relevant promoter polymorphisms of MMP1 and MMP3 were genotyped in 308 patients and in 110 controls, to test whether the polymorphisms contribute to the severity of the disease measured by radiographic progression of joint destruction. For comparison, the shared epitope of HLA DR4 and DR1 (SE) was determined by polymerase chain reaction. There was no association of MMP polymorphisms with susceptibility to RA. However, a strong linkage disequilibrium was observed between the 1G/2G (MMP1) and the 5A/6A (MMP3) polymorphisms (P << 10^-6; linkage disequilibrium index D' = 0.46). In factorial regression, the degree of radiographic joint destruction correlated significantly with the 1G-5A haplotype (P = 0.0001) and the interaction term 'estimated number of 1G-5A haplotypes × duration of disease' (P = 0.0007). This association was phasic, indicating that possession of the 1G-5A haplotype has a protective effect over a period of about 15 years of RA, but might be associated with a more pronounced radiographic progression later on. Similar results were also found with the 1G allele of MMP1 alone (P = 0.015) and with the interaction term 'estimated number of 1G alleles × duration of disease' (P = 0.014). The correlation of SE with the Ratingen score was comparable (0.044). The regression model of MMP haplotypes explained 35% of the variance of the radiographic score, whereas the SE explained 29%. The 1G-5A haplotype across the closely linked MMP1 and MMP3 gene loci is a newly described genetic factor strongly associated with the progression of joint damage in RA. Our findings suggest that there are haplotypes in a MMP cluster region that modify the joint destruction in RA in a phasic manner.     

Sulfuretin, a major flavonoid isolated from Rhus verniciflua, ameliorates experimental arthritis in mice

AimSulfuretin, a major flavonoid isolated from Rhus verniciflua, is known to have anti-inflammatory effects. However, the mechanisms underlying the anti-inflammatory effect of sulfuretin on rheumatoid arthritis have not been elucidated. In this study we investigated whether sulfuretin treatment modulates the severity of arthritis in an experimental model.Main methodsWe evaluated the effects of sulfuretin on tumor necrosis factor-α (TNF-α)-treated human rheumatoid fibroblast-like synoviocytes (FLS) in vitro and on collagen-induced arthritis (CIA) mice in vivo.Key findingsIn vitro experiments demonstrated that sulfuretin suppressed the chemokine production, matrix metalloproteinase secretion, and cell proliferation induced by tumor necrosis factor-α in rheumatoid FLS. In addition, sulfuretin inhibited the osteoclast differentiation induced by macrophage colony-stimulating factor and receptor activator of NF-κB ligand in bone marrow macrophages. In mice with CIA, early intervention with sulfuretin prevented joint destruction, as evidenced by a lower cumulative disease incidence and an absence of diverse disease features based on hind paw thickness, radiologic and histopathologic findings, and inflammatory cytokine levels. In mice with established arthritis, sulfuretin treatment significantly reduced synovial inflammation and joint destruction. The in vitro and in vivo protective effects of sulfuretin were mediated by inhibition of the NF-κB signaling pathway.SignificanceThese results suggest that using sulfuretin to block the NF-κB pathway in rheumatoid joints reduces both inflammatory responses and joint destruction. Therefore, sulfuretin may have therapeutic value in preventing or delaying the progression of rheumatoid arthritis.     

The determinants of susceptibility/resistance to adjuvant arthritis in rats

Adjuvant arthritis (AA) serves as an excellent model for human rheumatoid arthritis. AA is readily inducible in certain rat strains, but not in others. Susceptibility/resistance to AA is determined by multiple factors. Among the genetic factors, both MHC and non-MHC genes contribute to arthritis susceptibility, and specific quantitative trait loci show association with the severity of the disease. Differential T-cell proliferative and cytokine responses, as well as antibody responses, to heat-shock proteins are evident when comparing AA-susceptible and AA-resistant rats. In addition, neuroendocrine factors and the housing environment can further modulate arthritis susceptibility/severity in particular rat strains.     

Treatment of adjuvant arthritis with granulocyte-colony stimulating factor and peptide derived from heat shock protein 65

Adjuvant arthritis in Lewis rats is induced by the subcutaneous injection of Mycobacterium tuberculosis in mineral oil, and the predominant T cell immune reactivity is against the heat shock protein 65 derived peptide 176-190. We treated Lewis rats with human recombinant G-CSF followed by (i.v) administration of peptide 176-190 after induction of adjuvant arthritis (AA), and observed decreased disease severity, joint destruction, new bone formation and joint ankylosis. Treatment with G-CSF alone was also effective, but to a lesser extent. In addition, we found that splenocytes from rats treated with G-CSF had reduced antigen presenting capacity compared with splenocytes from vehicle treated rats. Primed lymph node cells from G-CSF plus peptide treated rats showed a marked reduction in proliferation and secretion of IFN-gamma after stimulation with the heat shock protein peptide in vitro as compared to controls.     

Chemical Composition of Bawei Longzuan Granule and Its Anti‐Arthritic Activity on Collagen‐Induced Arthritis in Rats by Inhibiting Inflammatory Responses

Bawei Longzuan granule (BLG) is a representative Zhuang medicine preparation. The present work aims to characterize the chemical constituents of BLG and evaluate its anti‐arthritic activity. The major chemical constituents of BLG were tentatively identified by ultra‐performance liquid chromatography‐quadrupole time‐of‐flight mass spectrometry (UPLC‐Q‐TOF/MS), which revealed the presence of some alkaloids (e. g., magnoflorine, sinomenine and nitidine) and flavonoids (e. g., hesperidin, diosmin and sinensetin) that may be partly responsible for the anti‐arthritic effect of BLG. In addition, the collagen‐induced arthritis (CIA) model in rats was induced by intradermal injection of bovine collagen‐II in complete Freund's adjuvant at the base of tail. The CIA rats received oral administration of BLG (1.25, 2.5 and 5 g/kg) for 30 days. Then, various indicators were determined to evaluate its anti‐arthritic activity, including paw swelling, arthritic score, body weight, knee joint pathology, thymus index and spleen index. Additionally, the serum levels of tumor necrosis factor (TNF)‐α, interferon (IFN)‐γ, interleukin (IL)‐1β, IL‐6, IL‐4 and IL‐10 were measured to determine the underlying mechanisms. The results showed that BLG efficiently ameliorated the severity of arthritis in CIA rats by decreasing paw swelling and arthritis score and improving the histological lesions of knee joint. Moreover, the serum levels of several pro‐inflammatory cytokines (i. e., IL‐1β, TNF‐α, IL‐6 and IFN‐γ) were downregulated, whereas two anti‐inflammatory factors (i. e., IL‐4 and IL‐10) were upregulated after BLG administration. These results indicated that BLG possessed promising therapeutic effect on collagen‐induced arthritis by inhibiting inflammatory responses. BLG can be used as a complementary or alternative traditional medicine to treat rheumatoid arthritis.