Clinical Arthritis Score Research Articles

Estrogen attenuates the spondyloarthritis manifestations of the SKG arthritis model

BackgroundAnkylosing spondylitis (AS) is a male-predominant disease, and radiographic evidence of damage is also more severe in males. Estrogen modulates immune-related processes such as T cell differentiation and cytokine production. This study aimed to evaluate the effect of estrogen on the disease activity of spondyloarthritis (SpA).MethodsThe effects of estrogen on the development of arthritis were evaluated by performing ovariectomy and 17β-estradiol (E2) pellet implantation in zymosan-treated SKG mice. Clinical arthritis scores were measured, and 18F-fluorodeoxyglucose (18F-FDG) small-animal positron emission tomography/computed tomography performed to quantify joint inflammation. The expression of inflammatory cytokines in joint tissue was measured.ResultsE2-treated mice showed remarkable suppression of arthritis clinically and little infiltration of inflammatory cells in the Achilles tendon and intervertebral disc. 18F-FDG uptake was significantly lower in E2-treated mice than in sham-operated (sham) and ovariectomized mice. Expression of TNF, interferon-γ, and IL-17A was significantly reduced in E2-treated mice, whereas expression of sclerostin and Dickkopf-1 was increased in E2-treated mice compared with sham and ovariectomized mice.ConclusionsEstrogen suppressed arthritis development in SKG mice, a model of SpA. Results of this study suggest that estrogen has an anti-inflammatory effect on the spondyloarthritis manifestations of the SKG arthritis model.

Protective effects of paeonol on inflammatory response in IL-1β-induced human fibroblast-like synoviocytes and rheumatoid arthritis progression via modulating NF-κB pathway.

Various investigations have demonstrated that human fibroblast-like synoviocytes rheumatoid arthritis (HFLS-RA) take part in the chronic inflammatory responses and RA progression. Inhibition of synovium activation and inflammatory processes may represent a therapeutic target to alleviate RA. Paeonol, a major natural product, has many biological and pharmacological activities. However, its protective effects against RA considering HFLS-RA have not been explored. In this study, anti-inflammatory effects of paeonol were detected in interleukin-1β (IL-1β)-treated HFLS-RA. Our results demonstrated that paeonol had no effect on cell survival and IL-1β-induced proliferation in HFLS-RA. Pretreatment with paeonol significantly suppressed the production of pro-inflammatory TNF-α, IL-6 and IL-1β, and the expressions of matrix metalloproteinase-1/-3 in vitro and in vivo. Mice treated with paeonol (10mg/kg) remarkablely attenuated arthritic symptoms based on clinical arthritis scores and histopathology in collagen-induced arthritis mice. Furthermore, the TLR4 expression and NF-κB p65 activation were inhibited by paeonol in vitro and in vivo. Our findings illustrated that paeonol had significantly suppressed inflammation effects in synovial tissues and RA progression. The potential mechanismmightbe based on the attenuation TLR4-NF-κB activation. These collective results indicated that paeonol might be a promising therapeutic agent for alleviating RA progress through inhibiting inflammations and NF-κB signalling pathway.

Platelet-rich plasma exhibits beneficial effects for rheumatoid arthritis mice by suppressing inflammatory factors

Platelet-rich plasma (PRP) is a multifunctional blood product containing highly concentrated platelets, and various cell growth factors which promote cell proliferation and differentiation. PRP exhibited benefits in injurious articular cartilage repair and the removal of inflammatory factors in clinical studies. Rheumatoid arthritis (RA) is an autoimmune disease manifesting primarily as inflammatory arthritis, which is associated with notable morbidity in humans. In the present study, the therapeutic effects and primary mechanism of PRP on a type II collagen‑induced arthritis (CIA) mouse model was investigated. Inflammatory factors interleukin (IL)‑6, IL‑8, IL‑17, IL‑1β, tumor necrosis factor (TNF)‑α and interferon (IFN)‑γ were analyzed in PRP and PBS‑treated groups. Vascular endothelial growth factor (VEGF), platelet‑derived growth factor (PDGF), insulin‑like growth factor (IGF)‑1 and transforming growth factor (TGF)‑β expression in peripheral whole blood was additionally analyzed. The therapeutic efficacy of PRP for RA mice was evaluated using clinical arthritis scores. The results of the present study demonstrated that treatment with PRP alleviated arthritis, and reduced humoral and cellular immune responses, leading to beneficial effects on histological parameters as observed using joint tissue histological staining. CIA mice treated with PRP exhibited downregulated expression of IL‑6, IL‑8, IL‑17A, IL‑1β, TNF‑α, receptor activator for nuclear factor‑κB and IFN‑γ in inflammatory tissue. In addition, VEGF, PDGF, IGF‑1 and TGF‑β expression in peripheral whole blood was increased following treatment with PRP. The serum concentration of anti‑collagen antibody was decreased in PRP‑treated CIA mice. In conclusion, CIA mice treated with PRP exhibited beneficial effects, including decreased joint inflammation, cartilage destruction and bone damage, and increased repair of joint tissue. The results of the present study suggested that PRP may be an effective therapeutic agent for RA.

Adiponectin exerts a potent anti-arthritic effect and insulin resistance in collagen-induced arthritic rats.

Previous research has shown that adiponectin (AD) induces severe insulin resistance (IR) and exhibits pro-inflammatory effect, so it could serve as a useful risk biomarker in rheumatoid arthritis (RA). The present study aims to evaluate the effect of AD on IR and anti-arthritis in collagen-induced arthritic (CIA) rats. After immunization with bovine type II collagen (CII), Wistar rats were administered with AD (60μg/kg/day) or saline into the ankle joint cavity of the left hind leg for 15days. The severity of arthritis was clinically and histologically assessed. Arthritis score was recorded every other day for each paw. Paw volume was measured on alternate days to monitor the progression of the disease in the arthritic control group. Tumor necrosis factor (TNF)-α, interleukin (IL)-1, AD, insulin and fasting glucose were measured in sera. Histopathology of joint synovial tissues was also examined. Treatment with AD resulted in significantly delayed onset of arthritis as well as decreased clinical arthritis and histopathological severity scores. AD reduced both serum fasting glucose, TNF-α, IL-1 and IR. Histological analysis confirmed treatment with AD suppressed joint synovial inflammation and immunohistochemical expression of TNF-α compared to the CIA group. Surprisingly, adiponectin levels measured by enzyme-linked immunosorbent assay in serum were significantly increased in CIA rats compared to the normal group. Adiponectin might display anti-inflammatory effects. These results suggest that AD may be a potential immunosuppressant for the treatment of RA linked to metabolic disease.

Gambogic acid suppresses inflammation in rheumatoid arthritis rats via PI3K/Akt/mTOR signaling pathway.

Gamboge is the dried resin secreted by the Garciniamaingayi gambogic tree and is a substance that may be used to treat a variety of diseases, exhibits anti‑tumor and detoxification effects and prevents bleeding. The primary active constituent is gambogic acid. The present study aimed to investigate the anti‑inflammatory effects of gambogic acid in rheumatoid arthritis (RA) rats and to elucidate the mechanisms by which these effects occur. The swelling degree, the clinical arthritic scoring and pain threshold measurements were used to evaluate the effects of gambogic acid on RA. ELISA kits and western blot analysis were used to investigate inflammatory processes and the expression of RA‑associated proteins, respectively. The present results demonstrated that gambogic acid significantly inhibited the degree of right foot swelling, increased pain thresholds and reduced clinical arthritic scores of RA rats. Treatment with gambogic acid suppressed the activities of interleukin (IL)‑1β and IL‑6, promoted the protein expression of phosphorylated (p)‑Akt serine/threonine kinase (Akt), p‑mammalian target protein of rapamycin (mTOR) and inhibited hypoxia‑inducible factor‑1α and vascular endothelial growth factor expression in RA rats. The results of the present study therefore suggest that the anti‑inflammatory effects of gambogic acid in RA rats occur via regulation of the phosphoinositide 3‑kinase/Akt/mTOR signaling pathway.

Clinical manifestations and disease activity score of rheumatoid arthritis in southeast of Iran

Rheumatoid arthritis has a non-homogeneous pattern around the world. The current study aimed to describe the clinical manifestations and disease activity of rheumatoid arthritis patients in southeastern Iran. In this descriptive, cross-sectional study with convenience sampling, data regarding the demographics, painful joints, number of swollen and tender joints, ESR, disease activity, and therapeutic regimen of 500 patients with rheumatoid arthritis who referred to the Rheumatology Clinic of Ali Ebn Abitaleb Hospital between October 2012 and October 2013 was collected using a data form. After collection, the data was analyzed using SPSS version 16. Of the 500 studied cases, 437 cases (87.4%) were female and 63 cases (12.6%) were male. Average patient age was 48.78 ± 13.97 years, and the mean duration of the disease was 7.28 ± 7.14 years. The mean value of disease activity score-28 (DAS-28) was 3.54 ± 1.38. The DAS-28 in 30.25% of cases was below 2.6, while in 14.7% of cases it was greater than 5.1. The knee (49.6%) and the wrist (36.6%) were the most prevalent painful joints, and 375 patients complained of morning stiffness. The most frequent therapeutic regimens were prednisolone (81%), methotrexate (62.4%), hydroxychloroquine(60.8%), sulfasalazine (24%), and non-steroidal anti-inflammatory drugs (NSAIDs) (22.2%). Based on the results of this study, the mean value of DAS-28 of 3.54 ± 1.38 implies disease activity in most cases in southeastern Iran. This indicates that changing therapy regimens is necessary.

Metabolomics Approach to Explore the Effects of Rebamipide on Inflammatory Arthritis Using Ultra Performance Liquid Chromatography/Quadrupole Time-of-Flight Mass Spectrometry

Objective. Rebampide is a gastroprotective agent used to treat gastritis. It possesses anti-inflammatory and anti-arthritis effects, but the mechanisms of these effects are not well understood. The objective of this study was to explore mechanisms underlying the therapeutic effects of rebamipide in inflammatory arthritis. Methods. Collagen-induced arthritis (CIA) was induced in DBA/1J mice. DBA/1J mice were immunized with chicken type II collagen, then treated intraperitoneally with rebamipide (10 mg/kg or 30 mg/kg) or vehicle (10% carboxymethylcellulose solution) alone. Seven weeks later, plasma samples were collected. Plasma metabolic profiles were analyzed using ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry-based metabolomics study and metabolite biomarkers were identified through multivariate data analysis. Results. Low dose rebamipide treatment reduced the clinical arthritis score compared with vehicle treatment, whereas high dose rebamipide in CIA aggravated arthritis severity. Based on multivariate analysis, 17 metabolites were identified. The plasma levels of metabolites associated with fatty acids and phospholipid metabolism were significantly lower with rebamipide treatment than with vehicle. The levels of 15-deoxy-Δ12,14 prostaglandin J2 and thromboxane B3 decreased only in high dose-treated groups. Certain peptide molecules, including enterostatin (VPDPR) enterostatin and bradykinin dramatically increased in rebamipide- treated groups at both doses. Additionally, corticosterone increased in the low dose-treated group and decreased in the high dose-treated group. Conclusion. Metabolomics analysis revealed the anti-inflammatory effects of rebamipide and suggested the potential of the drug repositioning in metabolism- and lipid-associated diseases. (J Rheum Dis 2017;24:192-202)

Protective effect of taraxasterol against rheumatoid arthritis by the modulation of inflammatory responses in mice.

Taraxasterol is an effective component of dandelion that has anti-inflammatory effects in vivo and in vitro. The present study was performed to explore whether taraxasterol exhibits a protective effect against rheumatoid arthritis through the modulation of inflammatory responses in mice. Eight-week-old CCR9-deficient mice were injected with a collagen II monoclonal antibody cocktail to create a rheumatoid arthritis model. In the experimental group, arthritic model mice were treated with 10 mg/kg taraxasterol once per day for 5 days. Treatment with taraxasterol significantly increased the pain thresholds and reduced the clinical arthritic scores of the mice in the experimental group compared with those of the model group. Furthermore, treatment with taraxasterol significantly suppressed tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and nuclear factor-κB protein expression levels compared with those in the rheumatoid arthritis model mice. Taraxasterol treatment also significantly reduced nitric oxide, prostaglandin E2 and cyclooxygenase-2 levels compared with those in the rheumatoid arthritis model group. These observations indicate that the protective effect of taraxasterol against rheumatoid arthritis is mediated via the modulation of inflammatory responses in mice.

Protective effect of higenamine ameliorates collagen-induced arthritis through heme oxygenase-1 and PI3K/Akt/Nrf-2 signaling pathways.

Existing in Ranunculaceae Aconitum and tomato, with the chemical name 1-phydroxybenzyl-1,2,3,4-tetrahy-droisoquinoline, higenamine is widely distributed in China. Higenamine's anti-inflammatory, antioxidant and anti-apoptotic effects have been identified in previous studies. The present study attempted to determine the protective effect of higenamine against collagen-induced arthritis through heme oxygenase-1 (HO-1) and PI3K/Akt/Nrf-2 signaling pathways. A type II collagen (CII)-induced arthritis (CIA) model was established and clinical arthritis scores were used to appraise the curative effect of higenamine. Inflammatory reactions, oxidative damage and caspase-3/9 activation were detected using specific ELISA kits. In addition, western blotting was used to evaluate the expression of HO-1, Akt and Nrf-2 protein in CII-induced CIA mice. In CII-induced CIA mice, the clinical arthritis scores, inflammatory reactions, oxidation damage and caspase-3/9 activation were increased and activated. The results demonstrated that treatment with higenamine significantly reduced the elevation of clinical arthritis scores (P<0.01), and suppressed the promotion of inflammatory reactions, oxidation damage and caspase-3/9 activation. Furthermore, higenamine significantly increased HO-1 protein expression (P<0.01) and upregulated the PI3K/Akt/Nrf-2 signal pathway in CII-induced CIA mice. Collectively, it is concluded that higenamine protects against CII-induced CIA through the induction of HO-1 and the upregulation of the PI3K/Akt/Nrf-2 signaling pathway. In conclusion, higenamine may be a beneficial drug for protecting against CIA.

Abstract # 1752 Time point of retrieval in behaviorally conditioned immunosuppression is important for the outcome of clinical symptoms in rheumatoid arthritis in rats

In an established paradigm of taste-immune conditioning in the rat, the novel taste saccharine (conditioned stimulus/CS) is combined with an i.p. injection of the immunosuppressive drug cyclosporine A (CsA; unconditioned stimulus/US). With this paradigm we analyzed in two experimental settings conditioned immunosuppressive effects on collagen type II induced arthritis as a model of chronic inflammatory autoimmune diseases. In both experiments, four different groups of rats were conditioned with three CS/US pairings starting nine days prior to induction of arthritis. During the first experiment animals were re-exposed to the CS at day 13 after immunization. Our data show that CS re-exposure led to a significant reduction of the clinical and histological arthritis score. This effect was accompanied by an inhibition of splenic CD3 stimulated T cell cytokine production. In the second experiment retrieval started one day after immunization before emergence of the first arthritis symptoms. Significant differences in the clinical score between conditioned animals and controls where only seen in the acute phase of the disease. These results essentially indicated that in conditioned immunosuppression the time point of retrieval is important for the beneficial outcome on inflammatory joint diseases. Moreover, in a third upcoming experiment, retrieval of the conditioned response will be initiated after the first symptoms occur, analyzing more clinically relevant aspects.

An antagonistic role for Fyn and Lyn kinases in autoimmune arthritis

Abstract Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder characterized by infiltration of innate immune cells into the synovial joints, whose etiology is unclear. While the Fcγ receptor (FcγR) aggregation on innate inflammatory cells by auto-antibodies is a critical stimulus, much of FcγR signaling remains unknown. Previous research from our lab has shown that FcγR-mediated innate immune cell activation is antagonistically controlled by the Src family kinases, Fyn and Lyn. Our current study investigates the Fyn/Lyn dichotomy in controlling the severity of the inflammatory arthritis using K/BxN model or RA. Our preliminary studies show that Lyn deletion exacerbates joint swelling and clinical arthritis scores, while Fyn deletion reduces plasma inflammatory cytokine levels. These data indicate an antagonistic role for Fyn and Lyn kinases in autoimmune arthritis and support further study of the mechanisms by which these Src family kinases regulate inflammation.

Modification of soluble common gamma chain function controls collagen-induced arthritis

Abstract IL-2Rγ (γc) is an essential subunit in γc cytokine signaling which is very important in development and homeostasis of immune cells. Recently, we showed that the soluble form of γc (sγc) is generated by alternative splicing and their production is enhanced in activated T cells. Moreover, we found that sγc inhibits γc cytokine signaling and enhances Th17 differentiation, consequently exacerbates an inflammation. Since Th17 cells are known to play pivotal roles in the pathogenesis of autoimmune rheumatoid arthritis (RA) disease, we have questioned whether sγc affects RA pathogenesis. Consistent with EAE model, we found that sγc overexpressing mice with collagen induced arthritis (CIA) displayed accelerated clinical score of arthritis compared to WT with CIA. In addition, serum level of sγc was significantly increased in CIA mice compared to WT, indicating that sγc may contribute to exacerbate the pathogenesis of RA. It is conceivable that a blockade of sγc function potentially improves autoimmune diseases. Although sγc dimerization is more functional than monomer, the dimerization mechanism of sγc is not fully understood. Using a mutant sγc form which cysteine (Cys) is replaced to alanine (Ala), we confirmed that the generation of sγc homodimer is elicited by disulfide bond. This result suggests that Cys is critical to form the dimer structure. To further study, we are designing sγc inhibitor to block sγc functions and then testing inhibitory effect in RA animal model.

Serotonin Is Involved in Autoimmune Arthritis through Th17 Immunity and Bone Resorption

Rheumatoid arthritis is a chronic disease that results in a disabling and painful condition as it progresses to destruction of the articular cartilage and ankylosis of the joints. Although the cause of the disease is still unknown, evidence argues that autoimmunity plays an important part. There are increasing but contradictory views regarding serotonin being associated with activation of immunoinflammatory pathways and the onset of autoimmune reactions. We studied serotonin's involvement during collagen-induced arthritis in wild-type and Tph1(-/-) mice, which have markedly reduced peripheral serotonin levels. In wild-type mice, induction of arthritis triggered a robust increase in serotonin content in the paws combined with less inflammation. In Tph1(-/-) mice with arthritis, a marked increase in the clinical and pathologic arthritis scores was noticed. Specifically, in Tph1(-/-) mice with arthritis, a significant increase in osteoclast differentiation and bone resorption was observed with an increase in IL-17 levels in the paws and in Th17 lymphocytes in the draining lymph nodes, whereas T-regulatory cells were dampened. Ex vivo serotonin and agonists of the 5-HT2A and 5-HT2B receptors restored IL-17 secretion from splenocytes and Th17 cell differentiation in Tph1(-/-) mice. These findings indicate that serotonin plays a fundamental role in arthritis through the regulation of the Th17/T-regulatory cell balance and osteoclastogenesis.

IL-1 receptor antagonist (IL-1Ra)-Fc ameliorate autoimmune arthritis by regulation of the Th17 cells/Treg balance and arthrogenic cytokine activation

IntroductionIL-1β signalling has a critical role in the pathogenesis of various types of inflammatory arthritis including rheumatoid arthritis (RA). We aimed to investigate the therapeutic effects of human IL-1 receptor antagonist with Fc fragment (hIL-1Ra-Fc) on autoimmune arthritis and to identify the possible mechanisms by which hIL-1RA-Fc exerts anti-arthritic effects in a murine model of RA and patients with rheumatoid arthritis. MethodsCollagen-induced arthritis (CIA) murine model was established in DBA/1J mice. The levels of various cytokines were determined by using enzyme-linked immunosorbent assay. The mouse joints were assessed for clinical arthritis score and histologic features. Th17 cells and Treg cells were stained by using antibodies specific for CD4, IL-17, CD25, and FoxP3. Osteoclastogenesis was determined by TRAP staining and real-time PCR. ResultshIL-1RA-Fc reduced the arthritis incidence, histological inflammation and cartilage score in the CIA model. The expression of proinflammatory cytokines, VEGF and RANK, was reduced in the affected joint of hIL-1Ra-Fc-treated mice. hIL-1Ra-Fc-treated mice showed decreased number of Th17 cells with increased number of Treg cells in spleens. hIL-1Ra-Fc reduced Th17 cell differentiation by inactivation of STAT3 signalling, and reciprocally induced Treg cell differentiation through STAT5 signalling. In addition, the expression of IL-17, TNF-α, RANKL, and VEGF was decreased, while Foxp3 gene expression was increased in PBMCs of RA patients after administration of hIL-1Ra-Fc. ConclusionThe anti-arthritis effects of hIL-1RA-Fc are associated with regulation of balance between Th17 cells and Treg cells and suppression of osteoclastogenesis and angiogenesis in the affected joints.

Effect of M3 muscarinic acetylcholine receptor deficiency on collagen antibody-induced arthritis.

BackgroundThere is increasing evidence that the non-neuronal cholinergic system might be of importance for the pathology of rheumatoid arthritis. The role of M3 muscarinic acetylcholine receptor (M3R) in this regard has, however, not been investigated to date. Thus, in the present study we analyzed if M3R deficiency might have a protective effect on experimentally induced arthritis.MethodsCollagen antibody-induced arthritis (CAIA) was evoked in M3R-deficient (M3R−/−) mice and wild-type (WT) littermates. Severity of arthritis was assessed by scoring of paw swelling. The joints of arthritic and nonarthritic animals were analyzed for histopathological changes regarding synovial tissue, cartilage degradation and bone destruction. Further, gene expression analysis of respective markers was performed. Systemic and local inflammatory response was determined by flow cytometry and immunohistochemistry for leukocytes as well as mRNA and protein measurements for pro-inflammatory cytokines and chemokines.ResultsIn arthritic M3R−/− mice the number of leukocytes, specifically neutrophils, was enhanced even though clinical arthritis score was not significantly different between WT and M3R−/− mice with CAIA. In M3R−/− mice, levels of neutrophil chemoattractant chemokine C-X-C-motif ligand 2 (CXCL2) as well as the pro-inflammatory cytokine interleukin-6 were already strongly increased in mice with low arthritis score, whereas WT mice only showed prominent expression of these markers when reaching high arthritis scores. Furthermore, arthritic M3R−/− mice displayed a stronger degradation of collagen II in the articular cartilage and, most strikingly, histopathological evaluation revealed more severe bone destruction in arthritic mice with M3R deficiency compared to WT littermates. Moreover, in M3R−/− mice, gene expression of markers for bone degradation (matrix metalloproteinase 13, cathepsin K and receptor activator of nuclear factor-κB ligand) was already increased in mice with low arthritis score.ConclusionsTaken together, the present study shows that while M3R−/− mice were not protected from CAIA, they had a tendency toward a higher inflammatory response after arthritis induction than WT mice. Further, arthritis-induced joint destruction was significantly stronger in mice with M3R deficiency, indicating that stimulation of M3R might have protective effects on arthritis.

Anthocyanin Extracted from Black Soybean Seed Coats Prevents Autoimmune Arthritis by Suppressing the Development of Th17 Cells and Synthesis of Proinflammatory Cytokines by Such Cells, via Inhibition of NF-κB.

IntroductionOxidative stress plays a role in the pathogenesis of rheumatoid arthritis (RA). Anthocyanin is a plant antioxidant. We investigated the therapeutic effects of anthocyanin extracted from black soybean seed coats (AEBS) in a murine model of collagen-induced arthritis (CIA) and human peripheral blood mononuclear cells (PBMCs) and explored possible mechanisms by which AEBS might exert anti-arthritic effects.Material and MethodsCIA was induced in DBA/1J mice. Cytokine levels were measured via enzyme-linked immunosorbent assays. Joints were assessed in terms of arthritis incidence, clinical arthritis scores, and histological features. The extent of oxidative stress in affected joints was determined by measuring the levels of nitrotyrosine and inducible nitric oxide synthase. NF-κB activity was assayed by measuring the ratio of phosphorylated IκB to total IκB via Western blotting. Th17 cells were stained with antibodies against CD4, IL-17, and STAT3. Osteoclast formation was assessed via TRAP staining and measurement of osteoclast-specific mRNA levels.ResultsIn the CIA model, AEBS decreased the incidence of arthritis, histological inflammation, cartilage scores, and oxidative stress. AEBS reduced the levels of proinflammatory cytokines in affected joints of CIA mice and suppressed NF-κB signaling. AEBS decreased Th17 cell numbers in spleen of CIA mice. Additionally, AEBS repressed differentiation of Th17 cells and expression of Th17-associated genes in vitro, in both splenocytes of naïve DBA/1J mice and human PBMCs. In vitro, the numbers of both human and mouse tartrate-resistant acid phosphatase+ (TRAP) multinucleated cells fell, in a dose-dependent manner, upon addition of AEBS.ConclusionsThe anti-arthritic effects of AEBS were associated with decreases in Th17 cell numbers, and the levels of proinflammatory cytokines synthesized by such cells, mediated via suppression of NF-κB signaling. Additionally, AEBS suppressed osteoclastogenesis and reduced oxidative stress levels.

Biological activity of a small molecule indole analog, 1-[(1H-indol-3-yl)methylene]-2-phenylhydrazine (HMPH), in chronic inflammation

A synthetic small molecule, 1-[(1H-indol-3-yl)methylene]-2-phenylhydrazine (HMPH) was conveniently synthesised by a one-step reaction, purified and characterised by chromatographic and spectroscopic methods. HMPH scavenged free radicals and inhibited lipopolysaccharide (LPS)-induced ROS generation and NO release in RAW-264.7 cells without signs of any detectable cytotoxicity. HMPH inhibited lipid peroxidation (LPO) with IC50 of 135 ± 9 as against 58 ± 8 μM for α-tocopherol. Further, HMPH (>50 μM) significantly reduced the LPS-induced TNF-α release in mouse peritoneal macrophages and in human peripheral blood mononuclear cells (PBMCs). HMPH did not show any visible signs of toxicity in rats up to 400 mg/kg/intraperitoneal and 2000 mg/kg/oral. HMPH at 25 and 50 mg/kg attenuated neutrophil infiltration in air-pouch lavage and bronchoalveolar lavage (BAL) in rat models. HMPH also reduced myeloperoxidase (MPO), nitrite and TNF-α in air-pouch lavage in addition to MPO in plasma. HMPH reduced acute paw-inflammation in carrageenan-induced paw-edema. HMPH consistently decreased both ipsilateral and contralateral paw inflammation, minimised the clinical scores of arthritis, prevented body weight (B.wt.) loss, attenuated serum C-reactive protein (C-RP) and rheumatoid factors (RF) in rat model of adjuvant-induced arthritis. Histopathology and radio-graphical reports show that HMPH reduced bone erosion in both ipsilateral and contralateral paw joints. Failure to inhibit COX suggests that effectiveness of HMPH in both acute and chronic inflammation is mediated by a multimodal mechanism involving modulation of immunity, attenuating TNF-α, protecting bone attrition and reducing oxidative stress.

Hyperleptinemia suppresses aggravation of arthritis of collagen-antibody-induced arthritis in mice

BackgroundLeptin is an adipocytokine produced by adipocytes and controlling body weight. It is unclear whether leptin works as a proinflammatory or an anti-inflammatory cytokine. We investigated the effects of hyperleptinemia on leptin transgenic (LepTg) mice in terms of cartilage destruction, bone destruction, joint synovitis, and serum cytokine levels by using a mouse model of collagen-antibody-induced arthritis (CAIA). MethodsCAIA was induced for female age-matched 6- to 8-week-old C57BL/6J control mice and LepTg mice. Mice were injected intraperitoneally with 5mg of a combination of monoclonal antibody specific for type II collagen on day 0 and 12.5mg of lipopolysaccharide (LPS) on day 3. Clinical evaluation of arthritis was monitored for 14days, and hind paws were examined clinically and histologically. Serum cytokine levels of interleukin (IL)-1β, IL-6, IL-10, and IL-17 and tumor necrosis factor alpha (TNF-α) were also analyzed on days 0 and 5. Moreover, THP-1 cells, which are human monocytic cell line derived from an acute monocytic leukemia patient, were cultured and differentiated into macrophages. The effects of leptin on messenger RNA (mRNA) expression of IL-6 were examined by real-time quantitative polymerase chain reaction (RT-PCR). ResultsSerum leptin concentrations were approximately ninefold higher in LepTg mice (62.0±20.7ng/ml) than in control mice (7.2±0.5ng/ml). Severity of clinical paw swelling, arthritis score, synovial hyperplasia, and cartilage damage were suppressed in LepTg mice with CAIA. Although serum cytokine levels of IL-1β, IL-17, and IL-10 and TNF-α showed no significant changes in two mice, serum levels of IL-6 in LepTg mice were suppressed at day 5. Moreover, in vitro study showed that IL-6 elevation following LPS exposure in THP-1 cells was suppressed with high leptin concentrations. ConclusionOur finding suggests that hyperleptinemia suppress IL-6 responses and progression of joint inflammation. Leptin may play an anti-inflammatory role under hyperleptinemia.

Targeting VEGF-A with a vaccine decreases inflammation and joint destruction in experimental arthritis.

Inflammation and angiogenesis are two tightly linked processes in arthritis, and therapeutic targeting of pro-angiogenic factors may contribute to control joint inflammation and synovitis progression. In this work, we explored whether vaccination against vascular endothelial growth factor (VEGF) ameliorates collagen-induced arthritis (CIA). Anti-VEGF vaccines were heterocomplexes consisting of the entire VEGF cytokine (or a VEGF-derived peptide) linked to the carrier protein keyhole limpet hemocyanin (KLH). Two kinds of vaccines were separately tested in two independent experiments of CIA. In the first, we tested a kinoid of the murine cytokine VEGF (VEGF-K), obtained by conjugating VEGF-A to KLH. For the second, we selected two VEGF-A-derived peptide sequences to produce heterocomplexes (Vpep1-K and Vpep2-K). DBA/1 mice were immunized with either VEGF-K, Vpep1-K, or Vpep2-K, before CIA induction. Clinical and histological scores of arthritis, anti-VEGF, anti-Vpep Ab titers, and anti-VEGF Abs neutralizing capacity were determined. Both VEGF-K and Vpep1-K significantly ameliorated clinical arthritis scores and reduced synovial inflammation and joint destruction at histology. VEGF-K significantly reduced synovial vascularization. None of the vaccines reduced anti-collagen Ab response in mice. Both VEGF-K and Vpep1-K induced persistently high titers of anti-VEGF Abs capable of inhibiting VEGF-A bioactivity. Vaccination against the pro-angiogenic factor VEGF-A leads to the production of anti-VEGF polyclonal Abs and has a significant anti-inflammatory effect in CIA. Restraining Ab response to a single peptide sequence (Vpep1) with a peptide vaccine effectively protects immunized mice from joint inflammation and destruction.

Pyrroloquinoline Quinone Decelerates Rheumatoid Arthritis Progression by Inhibiting Inflammatory Responses and Joint Destruction via Modulating NF-κB and MAPK Pathways

Pyrroloquinoline quinone (PQQ) is a naturally occurring redox cofactor that acts as an essential nutrient and antioxidant and has been reported to exert potent immunosuppressive effects. However, the therapeutically potential of PQQ on rheumatoid arthritis (RA) has not been explored. In the present study, the anti-inflammatory effects of PQQ were investigated in interleukin (IL)-1β-treated SW982 cells, a RA-like fibroblast-like synoviocytes (FLSs) injury model. Our observations showed that pretreatment with PQQ significantly inhibited the expression of matrix metalloproteinase (MMP)-1 and MMP-3 and suppressed the production of proinflammatory mediators such as TNF-α and IL-6 in IL-1β-treated SW982 cells. The nuclear translocation of nuclear factor kappa B (NF-κB) and the phosphorylation level of p65, p38, and JNK MAP kinase pathways were also inhibited by PQQ in IL-1β-stimulated SW982 cells. To further confirm the therapeutic effects of PQQ on RA in vivo, a collagen-induced arthritis (CIA) model was used. Mice treated with PQQ demonstrated marked attenuation of arthritic symptoms based on histopathology and clinical arthritis scores. These results collectively suggested that PQQ might be a promising therapeutic agent for alleviating the progress of RA.