Collagen-induced Arthritis Animal Research Articles

Chronic β-adrenergic stress contributes to cardiomyopathy in rodents with collagen-induced arthritis.

Patients with rheumatoid arthritis (RA) have a much higher incidence of cardiac dysfunction, which contributes to the high mortality rate of RA despite anti-arthritic drug therapy. In this study, we investigated dynamic changes in cardiac function in classic animal models of RA and examined the potential effectors of RA-induced heart failure (HF). Collagen-induced arthritis (CIA) models were established in rats and mice. The cardiac function of CIA animals was dynamically monitored using echocardiography and haemodynamics. We showed that cardiac diastolic and systolic dysfunction occurred in CIA animals and persisted after joint inflammation and that serum proinflammatory cytokine (IL-1β, TNF-α) levels were decreased. We did not find evidence of atherosclerosis (AS) in arthritic animals even though cardiomyopathy was significant. We observed that an impaired cardiac β1AR-excitation contraction coupling signal was accompanied by sustained increases in blood epinephrine levels in CIA rats. Furthermore, serum epinephrine concentrations were positively correlated with the heart failure biomarker NT-proBNP in RA patients (r2 = +0.53, P < 0.0001). In CIA mice, treatment with the nonselective βAR blocker carvedilol (2.5 mg·kg-1·d-1, for 4 weeks) or the specific GRK2 inhibitor paroxetine (2.5 mg·kg-1·d-1, for 4 weeks) effectively rescued heart function. We conclude that chronic and persistent β-adrenergic stress in CIA animals is a significant contributor to cardiomyopathy, which may be a potential target for protecting RA patients against HF.

Ultrasound-Targeted Microbubble Destruction-Mediated Cell-Mimetic Nanodrugs for Treating Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease that mainly affects joints, and it can lead to disability and damage to vital organs if not diagnosed and treated in time. However, all current therapeutic agents for RA have limitations such as high dose, severe side effects, long-term use, and unsatisfactory therapeutic effects. The long-term use and dose escalation of methotrexate (MTX) may cause mild and severe side effects. To overcome the limitations, it is critical to target drug delivery to the inflamed joints. In this work, we constructed a folic acid-targeted and cell-mimetic nanodrug, MTX-loaded mesoporous silica composite nanoplatform (MMPRF), which can regulate drug release under ultrasound (US) and microbubble (MB) mediation. The targeted delivery and drug therapy were investigated through in vitro RAW264.7 cell experiments and in vivo collagen-induced arthritis animal experiments. The result showed that the targeting ability to the joints of MMPRF was strong and was more significant after US and MB mediation, which can potently reduce joint swelling, bone erosion, and inflammation in joints. This work indicated that the US- and MB-mediated MMPRF not only would be a promising method for synergistic targeted treatment of RA but also may show high potential for serving as a nanomedicine for many other biomedical fields.

Isochlorogenic Acid C Restrains Erk/JNK/NF-κB Signaling to Alleviate Inflammatory Response and Promote Cell Apoptosis

Isochlorogenic acid C (ICAC) is found in a variety of natural foods and medicinal plant materials. This study aims to validate the biological activity of isochlorogenic acid C in limiting inflammation by the Erk/JNK/NF-κB pathway. In this study, TNF-α-induced human fibroblast-like synoviocytes and collagen-induced arthritis animal models were used to perceive the potential anti-inflammation mechanism of ICAC. The role of isochlorogenic acid C was evaluated by observing the migration, invasion ability, and apoptotic activity of TNF-α-induced fibroblast-like synoviocytes cells in humans and analysing foot swelling, joint index, and histopathological changes in a collagen-induced RA animal model. The results reveal that ICAC inhibited the proliferation of human fibroblast-like synoviocytes and promoted their apoptosis. ICAC also blocked the nuclear transfer of NF-κB, Erk, and JNK. It was observed that ICAC significantly inhibited the degree of posterior foot swelling in CIA, reducing arthritis scores, bone tissue injury, and articular synovitis. ICAC may promote cell apoptosis and inhibit the hyperactivation of inflammatory cells to alleviate inflammation-induced synovial proliferation through the Erk/JNK/NF-κB pathway.

Zerumbone Protects Rats from Collagen-Induced Arthritis by Inhibiting Oxidative Outbursts and Inflammatory Cytokine Levels.

Rheumatoid arthritis (RA) is an immunocompromised disorder characterized by a marked increase in the synthesis of inflammatory molecules that stimulates the destruction of bones and cartilage. The conventional treatment modalities for RA are associated with adverse side effects and lack sensitivity, suggesting an immediate demand for alternate beneficial therapeutic remedies. The current study sought to understand more about zerumbone's anti-inflammatory properties in diagnosing collagen-induced arthritis (CIA) in experimental animals. The current study observed that zerumbone reduced clinical severity in CIA-induced animals compared to healthy animals. Zerumbone administration significantly decreased (p < 0.001) the concentration of SOD, CAT, GR, and GSH in treatment groups. Zerumbone administration drove down significantly (p < 0.001) the concentration of inflammatory cytokine molecules. Zerumbone was effective in bringing significant changes in levels of MPO, NO, LDH, MMP-8, and ELA. The therapeutic potential of zerumbone was found to be associated with reduced joint destruction and restored normal histology in the cartilage and tissue. Adsorption, distribution, metabolism, excretion, and toxicity studies were used to determine the druglike properties of zerumbone. ProTox-II studies revealed that zerumbone did not possess toxic properties like hepatotoxicity, immunotoxicity, carcinogenicity, mutagenicity, and cytotoxicity. Therefore, the present study evaluated the therapeutic properties of zerumbone in CIA animal models.

Wu-Teng-Gao External Treatment Improves Th17/Treg Balance in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) represents the consequence of an immune response of the body's immune system attacking healthy cells. This chronic inflammatory disorder has complicated pathogenesis. Traditional Chinese medicine (TCM) is well recognized as an effective therapy in treating RA and has been widely applied for centuries. Wu-Teng-Gao (WTG) is used as a representative natural herb formula in RA treatment in China, while its mechanisms are to be fully clarified. The present study attempted to explore mechanisms of WTG on RA treatment in a network pharmacological approach and verified using experiments in vitro. Following the establishment of a rat model of collagen-induced arthritis (CIA), WTG was applied externally on the metapedes of rats. HE staining was subsequently performed to visualize the pathological changes of synovium and bone. Simultaneously, flow cytometry was conducted to detect the cell ratio of T helper 17 (Th17) and Regulatory T cells (Treg) in splenic lymphocytes. Additionally, ELISA, qRT-PCR, and Western blot assays were adopted to determine expressions of RA-related factors in joints and serum. Results of network pharmacological analysis suggested that Th17 cell differentiation might serve as a potential signaling pathway of WTG therapy for RA. Animal experiments demonstrated that WTG ameliorated the articular inflammation and effectively inhibited the destruction of articular cartilage, and decreased Th17 and Treg cell ratios in CIA rats. Furthermore, WTG also greatly suppressed relevant levels of inflammatory cytokines (IL-17, TNF-α, IL-1, and IL-6) and RNAKL, whereas it elevated expressions of anti-inflammatory cytokines IL-10 and TGF-β. Our results confirmed that WTG might improve the imbalance of Th17/Treg cells in CIA animals through differentiation regulation, thus alleviating joint inflammation and bone destruction.

Therapeutic outcomes and biodistribution of gold nanoparticles in collagen-induced arthritis animal model

The role of gold nanoparticles (AuNPs) in the treatment of autoimmune diseases remains mysterious. Therefore, we investigated the effect of AuNPs on collagen-induced arthritis (CIA) and the impact of particle size on the tissue distribution of AuNPs. CIA model was set up in Wistar rats using bovine collagen type ІІ. CIA rats were then divided into five groups: CIA model (positive control), AuNPs treated- (sphere shape with size: 5, 25, and 75 nm), and methotrexate (MTX)-treated-rats. Untreated rats were run in parallel as normal control. At the end of the experiment, the radiographic assessment was done. Histopathological changes in the joints and vital organs were investigated. Liver- [aspartate transaminase (AST) and alanine transaminase (ALT)] and kidney- (creatinine) functions were measured. The gold bio-accumulation was measured quantitatively with inductively coupled plasma mass spectrometry (ICP-MS). Histopathological results revealed that AuNPs reduced the severity of arthritic symptoms in CIA rats. No histological changes were detected in vital organs. Importantly, AuNPs were deposited in all the examined organs, and the accumulation was size-dependent, with 75 nm demonstrated the least distributed one. Our results revealed that AuNPs decreased both liver and kidney functions as compared to normal controls. In conclusion, our data shed light on the therapeutic efficacy of AuNPs in experimental rheumatoid arthritis compared with a choice size (25 nm). Further investigations to investigate the immunological changes associated with AuNPs are in process.

The Use of Collagen-Induced Arthritis Animal Model on Studying Bone Metabolism.

CIA is a well-studied animal model of autoimmune arthritis. It resembles rheumatoid arthritis as far as histopathological changes and molecular pathogenesis are concerned. CIA is induced by immunization with collagen type II in susceptible strains. The purpose of this review is to assess the use of CIA animal model on bone metabolism and the potential therapeutic agents that could reverse this effect. A database search from their inception to 2019 was conducted to identify experimental animal studies pertinent to CIA model and bone examination. Studies including ovariectomy or without a direct comparison between control and CIA groups were excluded. Forty-eight articles were considered suitable for inclusion. Imaging techniques, biomechanical analysis, histopathological studies, and molecular biology techniques were employed. A decrease in bone mineral density in CII arthritic animals was established. Bone loss was either periarticular, generalized or both. Although trabecular bone loss was clear, the effect on cortical bone is yet to be determined. The proposed mechanism is an imbalance between bone formation and resorption as a result of osteoclast activation. The signal pathways implicated appear to be the RANKL/RANK/OPG and the Wnt pathway. Many therapeutic targets were investigated with promising results.

The Systemic Immune Response to Collagen-Induced Arthritis and the Impact of Bone Injury in Inflammatory Conditions.

Rheumatoid arthritis (RA) is a systemic disease that affects the osteoarticular system, associated with bone fragility and increased risk of fractures. Herein, we aimed to characterize the systemic impact of the rat collagen-induced arthritis (CIA) model and explore its combination with femoral bone defect (FD). The impact of CIA on endogenous mesenchymal stem/stromal cells (MSC) was also investigated. CIA induction led to enlarged, more proliferative, spleen and draining lymph nodes, with altered proportion of lymphoid populations. Upon FD, CIA animals increased the systemic myeloid cell proportions, and their expression of co-stimulatory molecules CD40 and CD86. Screening plasma cytokine/chemokine levels showed increased tumor necrosis factor-α (TNF-α), Interleukin (IL)-17, IL-4, IL-5, and IL-12 in CIA, and IL-2 and IL-6 increased in CIA and CIA+FD, while Fractalkine and Leptin were decreased in both groups. CIA-derived MSC showed lower metabolic activity and proliferation, and significantly increased osteogenic and chondrogenic differentiation markers. Exposure of control-MSC to TNF-α partially mimicked the CIA-MSC phenotype in vitro. In conclusion, inflammatory conditions of CIA led to alterations in systemic immune cell proportions, circulating mediators, and in endogenous MSC. CIA animals respond to FD, and the combined model can be used to study the mechanisms of bone repair in inflammatory conditions.

CXCR3 antagonist AMG487 suppresses rheumatoid arthritis pathogenesis and progression by shifting the Th17/Treg cell balance

Rheumatoid arthritis (RA) is an autoimmune disease that is characterized by uncontrolled joint inflammation and damage to bone and cartilage. Previous studies have shown that chemokine receptors have important roles in RA development, and that blocking these receptors effectively inhibits RA progression. Our study was undertaken to investigate the role of AMG487, a selective CXCR3 antagonist, in DBA/1J mice bearing collagen-induced arthritis (CIA). Following induction of CIA, animals were treated with 5 mg/kg AMG487 intraperitoneally every 48 h, starting from day 21 until day 41 and evaluated for clinical score, and histological hallmarks of arthritic inflammation. We further investigated the effect of AMG487 on Th1 (T-bet), Th17 (IL-17A, RORγt, STAT3), Th22 (IL-22), and T regulatory (Treg; Foxp3 and IL-10) cells in splenic CXCR3+ and CD4+ T cells using flow cytometry. We also assessed the effect of AMG487 on T-bet, RORγt, IL-17A, IL-22, Foxp3, and IL-10 at both mRNA and protein levels using RT-PCR and Western blot analyses of knee samples. The severity of clinical scores, and histological inflammatory damage decreased significantly in AMG487-treated compared with CIA control mice. Moreover, the percentage of Th1, Th17, and Th22 cells decreased significantly and that of Treg cells increased in AMG487-treated mice. We further observed that AMG487-treatment downregulated T-bet, IL-17A, RORγt, and IL-22, whereas it upregulated Foxp3 and IL-10 mRNA and protein levels. This study demonstrates the antiarthritic effects of AMG487 in CIA animal model and supports the development of CXCR3 antagonists as a novel strategy for the treatment of inflammatory and arthritic conditions.

SNR analysis of contrast-enhanced MR imaging for early detection of rheumatoid arthritis.

ObjectiveTo investigate whether signal to noise (SNR) analysis of contrast-enhanced MRI gives additional benefit for early disease detection by Magnetic Resonance Imaging (MRI) of experimental rheumatoid arthritis (RA) in a small animal model.MethodsWe applied contrast-enhanced MRI at 7T in DBA mice with or without collagen-induced arthritis (CIA). Clinical score, OMERACT RAMRIS analysis and analysis of signal to noise ratios (SNR) of regions of interest in RA bearing mice, methotrexate/methylprednisolone acetate treated RA and control animals were compared with respect to benefit for early diagnosis.ResultsWhile treated RA and control animals did not show signs of RA activity in any of the above-mentioned scoring methods at any time point analyzed, RA animals revealed characteristic signs of RA in RAMRIS at the same time point when RA was detected clinically through scoring of the paws. The MR-based SNR analysis detected signs of synovitis, the earliest indication of RA, not only in late clinical stages, but also at an early stage when little or no clinical signs of RA were present in CIA animals and RAMRIS did not allow a distinct early detection.ConclusionSNR analysis of contrast-enhanced MR imaging provides additional benefit for early arthritis detection in CIA mice.

Effect of Saururus chinensis leaves extract on type II collagen-induced arthritis mouse model

BackgroundSaururus chinensis leaves have been used as traditional medicine in Korea for pain, intoxication, edema, and furuncle. According to previous reports, these leaves exert renoprotective, neuroprotective, and antioxidant effects by attenuating inflammatory responses. However, the beneficial effect of Saururus chinensis leaves on arthritis has not been elucidated. Thus, we evaluated the water extract of Saururus chinensis leaves (SHW) using type II collagen-induced arthritis (CIA) mice models.MethodsQuantitative analysis of major components from SHW was performed by HPLC. Arthritis was induced by injection of type II collagen. Each group was orally administered SHW (100 mg/kg and 500 mg/kg). Methotrexate (MTX) was used as a positive control. Serum levels of interleukin-6, TNF-alpha, and type II collagen IgG in the animal models were measured using ELISA. Histological features were observed by H&E staining.ResultsQuantitative analysis of SHW showed the contents as 56.4 ± 0.52 mg/g of miquelianin, 7.75 ± 0.08 mg/g of quercetin 3-O-(2”-O-β -glucopyranosyl)-α-rhamnopyranoside, and 3.17 ± 0.02 mg/g of quercitrin. Treatment with 500 mg/kg SHW decreased the serum level of Interleukin-6 (IL-6), TNF-alpha, and collagen IgG in the CIA model. Moreover, SHW treatment diminished the swelling of hind limbs and monocyte infiltration in blood vessels in CIA animal models. The results indicate that SHW could decrease CIA-induced arthritis in vivo.ConclusionsThe results indicate that SHW could be used to improving arthritis by reducing inflammatory factors (IL-6 and TNF-alpha). However, further experiments are required to determine how SHW influences signal transduction in animal models.

Synergistic Effect of Tolerogenic Dendritic Cells and Etanercept on a Collagen-induced Arthritis Animal Model

Synergistic Effect of Tolerogenic Dendritic Cells and Etanercept on a Collagen-induced Arthritis Animal Model

Blocking of YY1 reduce neutrophil infiltration by inhibiting IL-8 production via the PI3K-Akt-mTOR signaling pathway in rheumatoid arthritis

Our previous study revealed that Yin Yang 1(YY1) played an important part in promoting interleukin (IL)-6 production in rheumatoid arthritis (RA). However, whether YY1 has any role in regulation of IL-8 in RA remains unclear. YY1 and IL-8 expression in RA patients were analyzed by real-time polymerase chain reaction (PCR). Ingenuity pathway analysis (IPA) was used to analyze the signaling pathway involved in YY1-induced IL-8 production. The expression of YY1 and proteins involved in the pathway were detected by Western blot and enzyme-linked immunosorbent assay (ELISA). Migration of neutrophils was performed by chemotaxis assay. In this study, we found that high expression of IL-8 was positively associated with YY1 expression in RA. Blocking YY1 expression by YY1-short hairpin (sh)RNA lentivirus reduced IL-8 production. Mechanistically, we showed YY1 activated IL-8 production via the phosphatidylinositol-3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway. Further, using a co-culture system consisting of peripheral blood mononuclear cells (PBMC) and neutrophils, we found that migration of neutrophils would be inhibited by YY1 RNA interference. Finally, using the collagen-induced arthritis animal model, we showed that treatment with the YY1-shRNA lentivirus led to reduction of IL-8 levels and attenuation of inflammation and neutrophil infiltration in vivo. Our results reveal a role of YY1 involved in neutrophil infiltration in RA via the PI3K/Akt/mTOR/IL-8 signaling pathway. YY1 may be a new therapeutic target for treatment of RA.

Collagen-induced arthritis as an animal model of rheumatoid cachexia.

BackgroundRheumatoid arthritis is characterized by chronic polyarticular synovitis and presents systemic changes that impact quality of life, such as impaired muscle function, seen in up to 66% of the patients. This can progress to severely debilitating state known as rheumatoid cachexia—without loss of fat mass and body weight—for which there is little consensus in terms of diagnosis or treatment. This study aims to evaluate whether the collagen‐induced arthritis (CIA) animal model also develops clinical and functional features characteristic of rheumatoid cachexia.MethodsMale DBA1/J mice were randomly divided into 2 groups: healthy animals (CO, n = 11) and CIA animals (n = 13). The clinical score and edema size, animal weight and food intake, free exploratory locomotion, grip strength, and endurance exercise performance were tested 0, 18, 35, 45, 55, and 65 days after disease induction. After euthanasia, several organs, visceral and brown fat, and muscles were dissected and weighed. Muscles were used to assess myofiber diameter. Ankle joint was used to assess arthritis severity by histological score. Statistical analysis were performed using one‐way and two‐way analyses of variance followed by Tukey's and Bonferroni's test or t‐test of Pearson and statistical difference were assumed for a P value under 0.05.ResultsThe CIA had significantly higher arthritis scores and larger hind paw edema volumes than CO. The CIA had decreased endurance exercise performance total time (fatigue; 23, 22, 24, and 21% at 35, 45, 55, and 65 days, respectively), grip strength (27, 55, 63, 60, and 66% at 25, 35, 45, 55, and 65 days, respectively), free locomotion (43, 57, 59, and 66% at 35, 45, 55, and 65 days, respectively), and tibialis anterior and gastrocnemius muscle weight (25 and 24%, respectively) compared with CO. Sarcoplasmic ratios were also reduced in CIA (TA: 23 and GA: 22% less sarcoplasmic ratio), confirming the atrophy of skeletal muscle mass in these animals than in CO. Myofiber diameter was also reduced 45% in TA and 41% in GA in CIA when compared with the CO. Visceral and brown fat were lighter in CIA (54 and 39%, respectively) than CO group.ConclusionsThe CIA model is a valid experimental model for rheumatoid cachexia given that the clinical changes observed were similar to those described in patients with rheumatoid arthritis.

JN-2, a C-X-C motif chemokine receptor 3 antagonist, ameliorates arthritis progression in an animal model

Rheumatoid arthritis (RA) is a chronic autoimmune disease that is characterized by uncontrolled joint inflammation and destruction of bone and cartilage. Previous studies have shown that C-X-C motif chemokine 10 (CXCL10) has important roles in RA development and that blocking CXCL10 expression effectively inhibits arthritis progression in animal models. However, clinical study using anti-CXCL10 monoclonal antibody (MDX-1100) to block CXCL10 expression in patients with RA did not show significant effectiveness. Therefore, we turned our attention to C-X-C motif chemokine receptor 3 (CXCR3), which is a receptor for CXCL9, CXCL10, and CXCL11, to treat RA. In the present study, administration of JN-2, our newly developed CXCR3 antagonist, ameliorated the progression of arthritis in a collagen-induced arthritis animal model. JN-2 also inhibited CXCR3-induced cell migration and pro-inflammatory cytokine expression of bone marrow–derived macrophages and CD4+ T cells in vitro. In addition, we found that CXCL10 formed an auto-amplification loop through activation of NFκB. Furthermore, Phosphorylation of p65 at serine 536 played an important role in the auto-amplification of CXCL10. Overall, the present results demonstrated that JN-2 decreased inflammation by inhibiting CXCR3-enhanced cell migration and pro-inflammatory cytokine expression, which then ameliorated arthritis progression.

Lymphatic delivery of etanercept via nanotopography improves response to collagen-induced arthritis

BackgroundEvidence suggests lymphatic function mediates local rheumatoid arthritis (RA) flares. Yet biologics that target the immune system are dosed systemically via the subcutaneous (SC) administration route, thereby inefficiently reaching local lymphatic compartments. Nanotopography has previously been shown to disrupt tight cellular junctions, potentially enhancing local lymphatic delivery and potentially improving overall therapeutic efficacy.MethodWe first characterized nanotopography (SOFUSA™) delivery of an anti-TNF drug, etanercept, by comparing pharmacokinetic profiles to those obtained by conventional SC, intravenous (IV), and intradermal (ID) routes of administration, and assessed uptake of radiolabeled etanercept in draining lymph nodes (LNs) in single dosing studies. We then compared etanercept efficacy in a progressive rat model of collagen-induced arthritis (CIA), administered systemically via SC route of administration; via the regional lymphatics through ID delivery; or through a nanotopography (SOFUSA™) device at 10, 12, and 14 days post CIA induction. Measurements of hind limb swelling and near-infrared fluorescence (NIRF) imaging of afferent lymph pumping function and reflux were conducted on days 11, 13, and 18 post CIA induction and compared to untreated CIA animals. Univariate and multivariate analysis of variance were used to compare the group differences for percentage swelling and lymphatic contractile activity.ResultsEven though all three modes of administration delivered an equal amount of etanercept, SOFUSA™ delivery resulted in increased lymphatic pumping and significantly reduced swelling as compared to untreated, ID, and SC groups. Pharmacokinetic profiles in serum and LN uptake studies showed that using the nanotopography device resulted in the greatest uptake and retention in draining LNs.ConclusionsLocoregional lymphatic delivery of biologics that target the immune system may have more favorable pharmacodynamics than SC or IV administration. Nanotopography may provide a more efficient method for delivery of anti-TNF drugs to reverse impairment of lymphatic function and reduce swelling associated with RA flares.

Discovery of a new structural class of competitive hDHODH inhibitors with in vitro and in vivo anti-inflammatory, immunosuppressive effects

Human dihydroorotate dehydrogenase (hDHODH) is an inner mitochondrial membrane enzyme that involves in the fourth step of the biosynthesis of pyrimidine base. Inhibitors of hDHODH have been proven efficacy for the treatments of inflammation, rheumatoid arthritis, multiple sclerosis and cancer. In the present study, ascochlorin (ASC) and its derivatives, natural compounds from fungal metabolites, were discovered as hDHODH inhibitors by high-throughput screening. Enzyme kinetics studies showed that ASC competitively binds to hDHODH at the site of coenzyme Q substrate. In ex vivo study, ASC significantly inhibited the ConA-stimulated T lymphocytes proliferation and interleukin-2, interferon-γ production. Furthermore, ASC showed significant in vivo anti-inflammatory and immunosuppressive effects on the mice ears swelling, allogenic skin grafts and rat collagen-induced arthritis animal disease models. ASC significantly reduced ears edema level of mice, increased the survival time of allogenic skin implanted on the mice and attenuated arthritis severity of rat model. In conclusion, ASC was identified as a new structural class of hDHODH inhibitors with efficient anti-inflammatory, immunosuppressive activity, and may be a promising candidate for the development of new therapy in the treatment of autoimmune diseases.

Discovery of serum proteomic biomarkers for prediction of response to moxibustion treatment in rats with collagen-induced arthritis: an exploratory analysis.

To examine the possible impact of moxibustion on the serum proteome of the collagen-induced arthritis (CIA) rat model. Thirty-six male Sprague-Dawley rats were included in this experiment. The CIA animal model was prepared by injection of type II bovine collagen in Freund's adjuvant on the first and seventh day. The 36 rats were randomly divided into two groups: the untreated CIA group (control), and the CIA plus treatment with moxibustion (CIA+moxi) group. Moxibustion was administered daily at ST36 and BL23 for 7, 14 or 21 days (n=12 rats each). Arthritis score was used to assess the severity of arthritis. At the end of each 7 day treatment, blood samples from the control group and the CIA+moxi group were collected. After removal of high abundance proteins from serum samples, two-dimensional gel combined with matrix-assisted laser desorption ionisation time-of-flight MS/MS (MALDI-TOF-MS/MS) techniques were performed to examine serum protein expression patterns of the CIA rat model with and without moxibustion treatment. In addition, the relevant proteins were further analysed with the use of bioinformatics analysis. Moxibustion significantly decreased arthritis severity in the rats in the CIA+moxi group, when compared with the rats in the CIA group 35 days after the first immunisation (p=0.001). Seventeen protein spots which changed >1.33 or <0.77 at p<0.05 using Bonferonni correction for multiple testing were found to be common to all three comparisons, and these proteins were used for classification of functions using the Gene Ontology method. Consequently, with the use of the Ingenuity Pathway Analysis, the top canonical pathways and a predicted proteomic network related to the moxibustion effect of CIA were established. Using the proteomics technique, we have identified novel candidate proteins that may be involved in the mechanisms of action underlying the beneficial effects of moxibustion in rats with CIA. Our findings suggest that immune responses and metabolic processes may be involved in mediating the effects of moxibustion. Moreover, periodxiredoxin I (PRDX1) and inositol 1,4,5-triphosphate receptor (IP3R) may be potential targets.

Nimesulide improves the symptomatic and disease modifying effects of leflunomide in collagen induced arthritis.

Nimesulide is a COX-2 inhibitor used for symptomatic relief of rheumatoid arthritis. Leflunomide is an anti-pyrimidine used to manage the progression of rheumatoid arthritis. Herein we studied the influence of nimesulide and leflunomide combination in terms of disease symptoms and progression using collagen-induced arthritis model in mice, as a model for rheumatoid arthritis. Collagen induced arthritis was induced by immunization with type II collagen. Assessment of joint stiffness and articular hyperalgesia were evaluated using a locomotor activity cage and the Hargreaves method, respectively. Disease progression was assessed via arthritic index scoring, X-ray imaging, myeloperoxidase enzyme activity and histopathologic examination. Nimesulide induced only transient symptomatic alleviation on the top of decreased leucocytic infiltration compared to arthritis group. However, nimesulide alone failed to induce any significant improvement in the radiological or pathological disease progression. Leflunomide alone moderately alleviates the symptoms of arthritis and moderately retarded the radiological and pathological disease progression. Combination of nimesulide and leflunomide significantly improved symptomatic (analgesia and joint stiffness) and arthritic disease progression (radiological, pathological and Myeloperoxidase enzyme activity) in collagen induced arthritis animal model.

Muscle wasting in collagen-induced arthritis and disuse atrophy

The mechanisms of muscle wasting and decreased mobility have a major functional effect in rheumatoid arthritis, but they have been poorly studied. The objective of our study is to describe muscular involvement and the pathways in an experimental model of arthritis compared to the pathways in disuse atrophy. Female Wistar rats were separated into three groups: control (CO), collagen-induced arthritis (CIA), and immobilized (IM). Spontaneous locomotion and weight were evaluated weekly. The gastrocnemius muscle was evaluated by histology and immunoblotting to measure the expression of myostatin (a negative regulator), LC3 (autophagy), MuRF-1 (proteasome-mediated proteolysis), MyoD, and myogenin (satellite-cell activation). The significance level was set at P < 0.05, and histological analysis of joints confirmed the severity of the arthropathy. There was a significant difference in spontaneous locomotion in the CIA group. Animal body weight, gastrocnemius muscle weight, and relative muscle weight decreased 20%, 30%, and 20%, respectively, in the CIA rats. Inflammatory infiltration and swelling were present in the gastrocnemius muscles of the CIA rats. The mean cross-sectional area was reduced by 30% in the CIA group and by 60% in the IM group. The expressions of myostatin and LC3 between the groups were similar. There was increased expression of MuRF-1 in the IM (1.9-fold) and CIA (3.1-fold) groups and of myogenin in the muscles of the CIA animals (1.7-fold), while MyoD expression was decreased in the IM (20%) rats. This study demonstrated that the development of experimental arthritis is associated with decreased mobility, body weight, and muscle loss. Both IM and CIA animal models presented muscle atrophy, but while proteolysis and the regeneration pathways were activated in the CIA model, there was no activation of regeneration in the IM model. We can assume that muscle atrophy in experimental arthritis is associated with the disease itself and not simply with decreased mobility.