Pathogenesis of rheumatoid arthritis: targeting cytokines

Follicular CD8+ T cells promote immunoglobulin production and demyelination in multiple sclerosis and a murine model

Emerging evidence underscores the importance of CD8+ T cells in the pathogenesis of multiple sclerosis (MS), but the precise mechanisms remain ambiguous. This study intends to elucidate the involvement of a novel subset of follicular CD8+ T cells (CD8+CXCR5+ T) in MS and an experimental autoimmune encephalomyelitis (EAE) murine model. The expansion of CD8+CXCR5+ T cells was observed in both MS patients and EAE mice during the acute phase. In relapsing MS patients, higher frequencies of circulating CD8+CXCR5+ T cells were positively correlated with new gadolinium-enhancement lesions in the central nervous system (CNS). In EAE mice, frequencies of CD8+CXCR5+ T cells were also positively correlated with clinical scores. These cells were found to infiltrate into ectopic lymphoid-like structures in the spinal cords during the peak of the disease. Furthermore, CD8+CXCR5+ T cells, exhibiting high expression levels of ICOS, CD40L, IL-21, and IL-6, were shown to facilitate B cell activation and differentiation through a synergistic interaction between CD40L and IL-21. Transferring CD8+CXCR5+ T cells into naïve mice confirmed their ability to enhance the production of anti-MOG35-55 antibodies and contribute to the disease progression. Consequently, CD8+CXCR5+ T cells may play a role in CNS demyelination through heightening humoral immune responses.

Immune dysregulation and macrophage polarization in peri-implantitis

The term "peri-implantitis" (peri-implantitis) refers to an inflammatory lesion of the mucosa surrounding an endosseous implant and a progressive loss of the peri-implant bone that supports the implant. Recently, it has been suggested that the increased sensitivity of implants to infection and the quick elimination of supporting tissue after infection may be caused by a dysregulated peri-implant mucosal immune response. Macrophages are polarized in response to environmental signals and play multiple roles in peri-implantitis. In peri-implantitis lesion samples, recent investigations have discovered a considerable increase in M1 type macrophages, with M1 type macrophages contributing to the pro-inflammatory response brought on by bacteria, whereas M2 type macrophages contribute to inflammation remission and tissue repair. In an effort to better understand the pathogenesis of peri-implantitis and suggest potential immunomodulatory treatments for peri-implantitis in the direction of macrophage polarization patterns, this review summarizes the research findings related to macrophage polarization in peri-implantitis and compares them with periodontitis.

Dietary oleacein, a secoiridoid from extra virgin olive oil, prevents collagen-induced arthritis in mice

Olacein (OLA), one of the main secoiridoids derived from extra virgin olive oil (EVOO), has been shown to modulate oxidative and inflammatory responses in various pathological conditions; however, its potential benefit in joint disorders such as rheumatoid arthritis (RA) is unknown. Therefore, this study was designed to evaluate the preventive role of the effects of an OLA-supplemented diet in the murine model of collagen-induced arthritis (CIA), delving into the possible mechanisms and signaling pathways involved. Animals were fed an OLA-enriched preventive diet for 6 weeks prior to CIA induction and until the end of the experimental time course. On day 43 after the first immunization, mice were sacrificed: blood was collected, and paws were histologically and biochemically processed. Dietary OLA prevented collagen-induced rheumatic bone, joint and cartilage conditions. Circulating matrix metalloproteinase (MMP)-3 and proinflammatory cytokine (IL-6, IL-1β, TNF-α, IL-17) levels were significantly decreased in the joint, as well as MMP-9 and cathepsin-K (CatK) expression in secoiridoid-fed animals. In addition, dietary OLA was able to decrease COX-2, mPGES-1 and iNOS protein expressions and, also, PGE2 levels. The mechanisms possibly involved in these protective effects could be related to the activation of the Nrf-2/HO-1 axis and the inhibition of proinflammatory signaling pathways, including JAK-STAT, MAPKs and NF-κB, involved in the production of inflammatory and oxidative mediators. These results support the interest of OLA, as a nutraceutical intervention, in the management of RA.

Design and Evaluation of Continentalic Acid Encapsulated Transfersomal Gel and Profiling of its Anti-arthritis Activity

Rheumatoid arthritis restricts the physical ability of patients and increases the disease burden; therefore, research has always been focused on evaluating better therapeutic options. The present research aimed to design Continentalic acid (CA)-loaded transfersomes (CA-TF) embedded in Carbopol gel containing permeation enhancer (PE) for the treatment of rheumatoid arthritis. CA-TF was developed via a modified thin film hydration method and incorporated into Carbopol 934 gel containing Eucalyptus oil (EO) as PE. The fabricated CA-TF showed particle size of < 140 nm with spherical geometry, optimal encapsulation efficiency (EE), and sustained drug release pattern. CA-TF-gel along with PE (CA-TF-PE-gel) showed better ex vivo skin penetration than plain CA gel and CA-TF-gel without PE. In vivo evaluation supported improved therapeutic outcomes of CA-TF-PE-gel in terms of behavioral findings, arthritic index, and histological findings whereas biochemical assays and pro-inflammatory cytokines (TNF-α and IL-1β) showed a significant decrease in their levels. Furthermore, immunohistochemistry assay for Nrf2 and HO-1 signaling pathways showed significant improvement in the expression of the Nrf2, and HO-1 proteins to depict improvement in arthritic condition in the animal model. CA-TF-PE-gel significantly delivered CA to the diseased target site via a topical route with promising therapeutic outcomes displayed in the CFA-induced arthritic model.

Efficacy and safety of tofacitinib combined with methotrexate in the treatment of rheumatoid arthritis: A systematic review and meta-analysis

Objective

To evaluate the efficacy and safety of tofacitinib in combination with methotrexate (MTX) versus MTX monotherapy in patients with active rheumatoid arthritis (RA).

Methods

Trials were identified from four electronic databases: PubMed, Web of science, Cochrane Library and EMBASE from inception to April 2022. Two independent reviewers evaluated each database to scan the title, abstract and keywords of each record retrieved. Full articles were further assessed when the information suggested that the study was a randomized clinical trial (RCT) comparing tofacitinib combined with MTX vs. MTX monotherapy in patients with active RA. Data were extracted from the literature, and the methodological quality of the included literature were evaluated and screened by two reviewers independently. The results were analyzed using RevMan5.3 software. The full text of the studies and extracted data were reviewed independently according to PRISMA guidelines. The outcome indicators were ACR 20, ACR 50, ACR 70, Disease activity score 28 (DAS28), erythrocyte sedimentation Rate (ESR) and adverse events (AEs).

Results

Of 1152 studies yielded by the search, 4 were retained, totaling 1782 patients (1345 treated with tofacitinib combined with MTX vs 437 received MTX. In the trial of insufficient response to MTX treatment, tofacitinib combined with MTX had significant advantages compared with MTX monotherapy. Numerically higher ACR20, ACR50 and ACR70 response rates were observed in the tofacitinib combined with MTX groups versus MTX monotherapy. ACR20 (odds ratio (OR), 3.62; 95% CI, 2.84-4.61; P < 0.001), ACR50 (OR, 5.17; 95% CI, 3.62-7.38; P < 0.001), and ACR70 (OR, 8.44; 95% CI, 4.34-16.41; P < 0.001), DAS28 (ESR) < 2.6 (OR, 4.71, 95% CI, 2.06-10.77; P < 0.001). The probability of adverse events of tofacitinib combined with MTX was lower than that of MTX monotherapy (OR, 1.42; 95% CI, 1.08-1.88; P = 0.01). The number of cases discontinued due to lack of efficacy or adverse events was similar in both groups (OR, 0.93; 95% CI, 0.52-1.68). The probability of abnormal liver enzymes in the treatment of tofacitinib combined with MTX was significantly lower than that of MTX monotherapy (OR, 1.86; 95% CI, 1.35-2.56). However, there was no significant difference between the two groups in severe adverse reactions, neutropenia, anemia and cardiovascular disease.

Conclusions

In terms of ACR20/50/70 and DAS28 (ESR), tofacitinib combined with MTX demonstrated superiority to MTX monotherapy in the treatment of patients with refractory RA. Considering the hepatoprotective and observably therapeutic efficacy, tofacitinib combined with MTX could be effective in treating refractory RA. However, in terms of hepatoprotective, it requires further large-scale and high-quality clinical trials to confirm.

Rheumatoid arthritis treatment with zoledronic acid, a potentialinhibitorofGWAS-derived pharmacogenetics STAT3 and IL2 targets

Rheumatoid arthritis (RA) is an inflammatory condition that primarily affects the joints and progress to affect other vital organs. Variety of drugs are being recommended to control the disease progression that benefits patients to perform day-to-day activities. Few of these RA drugs have noticeable side effects; therefore, it's crucial to choose the appropriate drug for treating RA with an understanding of the disease's pathophysiology. Herein, we investigated the RA genes from GWAS data to construct protein-protein interaction (PPI) network and to define appropriate drug targets for RA. The predicted drug targets were screened with the known RA drugs based on molecular docking. Further, the molecular dynamics simulations were performed to comprehend the conformational changes and stability of the targets upon binding of the selected top ranked RA drug. As a result, our constructed protein network from GWAS data revealed, STAT3 and IL2 could be potential pharmacogenetics targets that interlink most of the RA genes encoding proteins. These interlinked proteins of both the targets showed involvement in cell signaling, immune response, and TNF signaling pathway. Among the 192 RA drugs investigated, zoledronic acid had the lowest binding energy that inhibit both STAT3 (-6.307 kcal/mol) and IL2 (-6.231 kcal/mol). Additionally, STAT3 and IL2 trajectories on zoledronic acid binding exhibit notable differences in MD simulations as compared to a drug-free environment. Also, the in vitro assessment with the zoledronic acid confirms the outcome of our computational study. Overall, our study identify zoledronic acid could be potential inhibitor against these targets, that will benefits patients with RA. Comparative efficiency assessments between the RA drugs through clinical trials are needed to validate our findings in the treatment of RA.

Hyaluronic acid-coated solid lipid nanoparticles enhance antirheumatic activity and reduce toxicity of methotrexate

Aim: Methotrexate (MTX) is used to treat rheumatoid arthritis (RA) but is associated with severe toxicity. To minimize these side effects of MTX, the study was undertaken to explore its delivery using solid lipid nanoparticles (SLNs). Materials & methods: MTX-loaded SLNs were synthesized and coated with hyaluronic acid (HA) for targeted drug delivery and evaluated for their safety and efficacy in a complete Freund's adjuvant (CFA) model. Results: HA-MTX-SLNs (230.0 ± 46.4 nm) with 78.75% entrapment were developed and showed sustained drug release with a significant reduction in toxicity and enhanced activity of the drug at the targeted site upon oral administration in CFA-induced rats. Conclusion: HA-MTX-SLNs can be considered as an efficient therapeutic agents for the treatment of RA.

Xanthorrhizol Ameliorates Oxidative Stress and Inflammation in Freund's Complete Adjuvant-Induced Rheumatoid Arthritis in Rats

Rheumatoid arthritis (RA) is an inflammatory disease and a common cause of disability. This study is aimed to ascertain the therapeutic potentials of the xanthorrhizol against Freund's complete adjuvant (FCA)-stimulated RA in rats. The RA was initiated in the rats via injecting FCA (0.1 ml) subcutaneously and then treated with xanthorrhizol (20 mg/kg) for 25 days. The hematological markers were investigated using the automated hematological analyzer. The organ index (spleen and thymus) and paw volume were inspected by standard methods. The ALP, SGOT, and SGPT activities were examined using kits. The levels of inflammatory biomarkers, i.e., IL-1β, IL-6, IL-10, and TNF-α, were inspected using assay kits. The status of MDA, SOD, CAT, GSH, COX-2, iNOS, and NF-κB was quantified using respective assay kits. The xanthorrhizol treatment appreciably improved the body weight and hematological parameters and reduced the arthritis score, organ index, and paw volume in the RA rats. The levels of RBCs and Hb were effectively improved, and activities of ALP, SGOT, and SGPT were decreased by the xanthorrhizol in the RA rats. The RA rats treated with 20 mg/kg of xanthorrhizol demonstrated the depleted IL-1β, IL-6, and TNF-α levels. The antioxidant markers SOD, CAT, and GSH were improved, and inflammatory biomarker levels such as COX-2, iNOS, and NF-κB were decreased by the xanthorrhizol in the RA rats. Overall, these outcomes witnessed that the xanthorrhizol effectively ameliorated the oxidative stress and inflammatory responses and attenuated the RA in rats. Hence, it could be a talented anti-arthritic medication to treat RA.

Suppression of NF-κB signaling by ECN in an arthritic model of inflammation

Background

The 7β-(3-ethyl-cis-crotonoyloxy)-1α-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (ECN), a sesquiterpenoid isolated from the Tussilago farfara Linneaus (Asteraceae), was evaluated against acute Carrageenan and chronic complete Freund’s adjuvant (CFA)-induced arthritis in mice.

Methods

Acute and chronic arthritis were induced by administering Carrageenan and CFA to the intraplantar surface of the mouse paw. Edema, mechanical allodynia, mechanical hyperalgesia, and thermal hyperalgesia were assessed in the paw. Similarly, histological and immunohistological parameters were assessed following arthritis induced by CFA. Antioxidants, inflammatory cytokines, and oxidative stress markers were also studied in all the treated groups.

Results

The ECN treatment significantly attenuated edema in the paw and elevated the nocifensive threshold following induction of this inflammatory model. Furthermore, ECN treatment markedly improved the arthritis index and distress symptoms, while attenuating the CFA-induced edema in the paw. ECN treatment also improved the histological parameters in the paw tissue compared to the control. At the same time, there was a significant reduction in edema and erosion in the ECN-treated group, as measured by radiographic analysis. Using the Comet’s assay, we showed that ECN treatment protected the DNA from chronic CFA-induced arthritis. Immunohistochemistry analysis showed a marked decrease in the expression level of p-JNK (phosphorylated C-Jun N-terminal kinase), NF-κB (Nuclear factor-kappa B), COX-2 (Cyclooxygenase-2), and TNF-α (Tumour necrosis factor-alpha) compared to the CFA-treated group. Biophysical analysis involving molecular docking, molecular dynamics simulations, and binding free energies of ECN were performed to explore the underlying mechanism.

Conclusion

ECN exhibited significant anti-inflammatory and anti-arthritic activity against Carrageenan and CFA-induced models.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03629-7.

Circulating CTRP5 in rheumatoid arthritis: an exploratory biomarker study

Background

Rheumatoid arthritis (RA) is an inflammatory disease that is characterized by the overproduction of cytokines. Among the newly discovered cytokines are the adipokines which are primarily produced by and released from the adipose tissue and some immune cells, as well as synovial cells. they are involved in various immune responses and inflammatory processes. However, there are controversial data regarding the pro-inflammatory or anti-inflammatory effects of adipokines in different conditions. C1q/TNF-related protein 5 (CTRP5) is a newly identified adipokine and adiponectin paralogous protein, which has been shown to be correlated with inflammatory diseases. Accordingly, the present study was designed to investigate the serum levels of CTRP5 in RA patients and evaluate any possible alterations in comparison to healthy individuals.

Methods

Serum CTRP-5 levels were measured in 46 patients and 22 healthy controls by ELISA. The demographic, laboratory, and clinical features of the patients were also evaluated in order to find any correlations.

Results

Serum levels of CTRP-5 were significantly (p < 0.0001) higher in patients with RA (14.88 ± 25.55) compared to healthy controls (4.262 ± 2.374). There was a significant correlation between serum CTRP-5 levels and triglyceride (TG) (r: − 0.3010, p: 0.0498), as well as erythrocyte sedimentation rate (ESR) (r: 0.3139, p: 0.0457), C-reactive protein (CRP) (r: 0.5140, p: 0.0008), and the number of white blood cells (WBC) (r: 0.3380, p: 0.0307), which are considered as the markers indicating the extent of inflammation. Moreover, CTRP-5 was found to be correlated with interstitial lung disease (ILD) (r: 0.3416, p: 0.0385), a comorbidity associated with RA disease.

Conclusion

This study demonstrated the increased level of circulating CTRP-5 in RA patients, which correlated with some inflammation-associated parameters and RA-associated comorbidities. Our observations suggest CTRP-5 as a putative inflammatory biomarker in RA, which may be useful besides the other disease-related markers.

Circumstantial Insights into the Potential of Traditional Chinese Medicinal Plants as a Therapeutic Approach in Rheumatoid Arthritis

The advanced era has invited a plethora of chronic and autoimmune infirmities unmistakably dominated by rheumatoid arthritis, occurring because of the equivocal causes, including ecological factors, genetic variations, etc. Unfortunately, it is winning pretty much in every stratum of the society in undefined age group of the population. Engineered drugs are accessible for the treatment; however, they do experience adverse effects as the treatment requires a prolonged duration worsened by noncompliance. To overwhelm it, certain pharmacological and molecular pathways are explored in the wake of Chinese herbs that prompted the prevention of this deteriorating autoimmune disease. The alcoholic extracts and decoctions are procured from Chinese herbs, such as Paeonia lactiflora, Glycyrrhiza uralensis, Tripterygium wilfordii, etc., which have been proved to manifest constructive pharmacological actions. The activities that were exhibited by extracts are significantly innocuous, non- toxic and potent to fix the affliction in contrast with the chemosynthetic drugs. Therefore, these Chinese herbs bring forth the potent anti-inflammatory, immune suppressing, anti-nociceptive, anti-neovascularizing, free radical scavenging activities and various other benefits to withstand several pathological events that usually endure the infirmity. It can be abridged that Chinese herbs possess assorted and selective therapeutic properties with profound safety and viability to treat this rheumatic disorder. Thus, this review aims to shed a light naturally originated treatment that is pertinent to provide invulnerable therapy exonerating from adverse effects, by restraining the occurrences of joint deformities, production of auto-antibodies, and inflammation.

Biomarker identification and pathway analysis of rheumatoid arthritis based on metabolomics in combination with ingenuity pathway analysis

Rheumatoid arthritis (RA) is a common autoimmune and inflammatory disease worldwide, but understanding its pathogenesis is still limited. In this study, plasma untargeted metabolomics of a discovery cohort and targeted analysis of a verification cohort were performed by gas chromatograph mass spectrometry (GC/MS). Univariate and multivariate statistical analysis were utilized to reveal differential metabolites, followed by the construction of biomarker panel through random forest (RF) algorithm. The pathways involved in RA were enriched by differential metabolites using Ingenuity Pathway Analysis (IPA) suite. Untargeted metabolomics revealed eighteen significantly altered metabolites in RA. Among these metabolites, a three-metabolite marker panel consisting of L-cysteine, citric acid and L-glutamine was constructed, using random forest algorithm that could predict RA with high accuracy, sensitivity and specificity based on a multivariate exploratory receiver operator characteristic (ROC) curve analysis. The panel was further validated by support vector machine (SVM) and partial least squares discriminant analysis (PLS-DA) algorithms, and also verified with targeted metabolomics using a verification cohort. Additionally, the dysregulated taurine biosynthesis pathway in RA was revealed by an integrated analysis of metabolomics and transcriptomics. Our findings in this study not only provided a mechanism underlying RA pathogenesis, but also offered alternative therapeutic targets for RA.

Dietary Oleocanthal Supplementation Prevents Inflammation and Oxidative Stress in Collagen-Induced Arthritis in Mice

Oleocanthal (OLE), a characteristic and exclusive secoiridoid of Oleoaceae family, is mainly found in extra virgin olive oil (EVOO). Previous studies have reported its antioxidant, anti-inflammatory, antimicrobial, anticancer and neuroprotective effects. Since the pathogenesis of rheumatoid arthritis (RA) involves inflammatory and oxidative components, this study was designed to evaluate the preventive role of dietary OLE-supplemented effects in collagen-induced arthritis (CIA) murine model. Animals were fed with a preventive OLE-enriched dietary during 6 weeks previous to CIA induction and until the end of experiment time. At day 43 after first immunization, mice were sacrificed: blood was recollected and paws were histological and biochemically processed. Dietary OLE prevented bone, joint and cartilage rheumatic affections induced by collagen. Levels of circulatory matrix metalloproteinase (MMP)-3 and pro-inflammatory cytokines (IL-6, IL-1β, TNF-α, IL-17, IFN-γ) were significantly decreased in secoiridoid fed animals. Besides, dietary OLE was able to diminish COX-2, mPGES-1 and iNOS protein expressions and, also, PGE₂ levels. The mechanisms underlying these protective effects could be related to Nrf-2/HO-1 axis activation and the inhibition of relevant signaling pathways including JAK-STAT, MAPKs and NF-κB, thus controlling the production of inflammatory and oxidative mediators. Overall, our results exhibit preliminary evidences about OLE, as a novel dietary tool for the prevention of autoimmune and inflammatory disorders, such as RA.

Therapy of antigen-induced arthritis of the temporomandibular joint via platelet-rich plasma injections in domestic pigs

The aim of this animal study was to investigate the effect of platelet-rich plasma (PRP) injections into the temporomandibular joint (TMJ) to treat antigen-induced arthritis AIA. AIA was induced via the application of bovine serum albumin (BSA) into the TMJ. Clear histological signs and protein analysis results indicating inflammation of the TMJ were observed. Afterwards, two PRP injections were performed over an interval of 2 weeks. Concentration levels of the proinflammatory cytokines IL-1β (PRP: 33.7 ± 5.6 pg/mg, untreated: 50.0 ± 2.9 pg/mg; p = 0.04) and TNF-α (PRP: 20.7 ± 2.5 pg/mg, untreated: 31.4 ± 2.7 pg/mg; p = 0.03) were significantly decreased in the PRP-treated joints. A significant reduction in signs of histological inflammation, such as hyperplasia of the synovial membrane, leucocyte infiltration, cartilage surface alterations, and an increase in cartilage-specific glycosaminoglycan content, was observed. This animal study supports the understanding of the underlying effects of PRP treatment in the TMJ, and may enhance novel PRP therapies in the future.

Influence of β-D-mannuronic Acid, as a New Member of Non-steroidal Anti- Inflammatory Drugs Family, on the Expression Pattern of Chemokines and their Receptors in Rheumatoid Arthritis

BACKGROUND

Based on the encouraging results of phase III clinical trial of β-Dmannuronic acid (M2000) (as a new anti-inflammatory drug) in patients with RA, in this study, we aimed to evaluate the effects of this drug on the expression of chemokines and their receptors in PBMCs of RA patients.

METHODS

PBMCs of RA patients and healthy controls were separated and the patients' cells were treated with low, moderate and high doses (5, 25 and 50 μg/mL) of M2000 and optimum dose (1 μg/mL) of diclofenac, as a control in RPMI-1640 medium. Real-time PCR was used for evaluating the mRNA expression of CXCR3, CXCR4, CCR2, CCR5 and CCL2/MCP-1. Cell surface expression of CCR2 was investigated using flow cytometry.

RESULTS

CCR5 mRNA expression reduced significantly, after treatment of the patients' cells with all three doses of M2000 and optimum dose of diclofenac. CXCR3 mRNA expression was downregulated significantly followed by the treatment of these cells with moderate and high doses of M2000 and optimum dose of diclofenac. CXCR4 mRNA expression declined significantly after the treatment of these cells with moderate and high doses of M2000. CCL2 mRNA expression significantly reduced only followed by the treatment of these cells with a high dose of M2000, whereas, mRNA and cell surface expressions of CCR2 diminished significantly followed by the treatment of these cells with a high dose of M2000 and optimum dose of diclofenac.

CONCLUSION

According to our results, M2000 through the down-regulation of chemokines and their receptors may restrict the infiltration of immune cells into the synovium.

Rituximab as a treatment option in a patient with rheumatoid arthritis and a history of malignancy-intracranial chondrosarcoma/osteochondroma-case based review

When compared to general population, patients with rheumatoid arthritis are at higher risk of some malignancies (especially lymphomas and lung cancer). Genetic predisposition, chronic inflammatory stimuli and viral infections are some of the reasons untreated patients are at higher risk. Clinical studies and national/international registries collect the data about the malignancies with higher incidence (such as lung, skin and breast cancer) but on the other hand, malignancies with lower incidence (such as sarcomas) are rarely reported. We report a case of a 47-year-old male with a history of a malignant intracranial chondrosarcoma/osteochondroma who developed seropositive rheumatoid arthritis. Due to progression of erosions, the patient was initialy treated with conventional synthetic Disease-Modifying Antirheumatic Drugs (csDMARDs) and later on with rituximab. The patient's rheumatoid arthritis went and remained in remission on maintenance therapy with rituximab (every 6-8 months) and low-dose methotrexate with no relapse of malignant intracranial chondrosarcoma/osteochondroma. Rituximab should be considered as a treatment option in patients with rare and agressive malignancies, such as sarcomas.

Combination of LMT-28 and Metformin Improves Beneficial Anti-Inflammatory Effect in Collagen-Induced Arthritis

OBJECTIVES

The interleukin-6 (IL-6)-mediated signaling pathway plays an essential role in the development of rheumatoid arthritis. LMT-28 suppresses the activation of the IL-6-mediated signaling by direct targeting of gp130. Although LMT-28 and metformin both possess anti-inflammatory activity, the beneficial effect of LMT-28 and metformin combination on a collagen-induced arthritis (CIA) model has not yet been investigated. This study aimed to investigate the anti-inflammatory effect and mechanism of a combination of LMT-28 and metformin in a CIA model.

METHODS

In MH7A cells, cell proliferation and the IL-6-mediated signaling pathway following administration of LMT-28 and metformin combination was analyzed through MTT assay and Western blotting. The level of T helper 17 (Th17) cell differentiation from CD4+ T cells was analyzed in mouse splenocytes and human peripheral blood mononuclear cells. Arthritis score, incidence rate, inflammatory cytokine, and T-cell subsets were measured in CIA mice following administration of LMT-28 and metformin combination.

RESULTS

Combination treatment with LMT-28 and metformin diminished proliferation of MH7A cells and IL-6-mediated gp130, STAT3, and ERK signaling more than in individual treatments. Furthermore, the differentiation of CD4+ T cells into Th17 cells was attenuated more by combination treatment with LMT-28 and metformin than individual treatments. The combination of LMT-28 and metformin ameliorated the arthritic score better than individual treatments. The combination significantly reduced tumor necrosis factor and IL-6 levels in the sera and had an anti-inflammatory effect on the distribution of Treg/Th17 cells in the lymph nodes.

CONCLUSION

Combination treatment with LMT-28 and metformin significantly ameliorates arthritic symptoms in CIA by suppressing Th17 differentiation and IL-6 signaling.

CXCR3 antagonist AMG487 inhibits glucocorticoid-induced tumor necrosis factor-receptor-related protein and inflammatory mediators in CD45 expressing cells in collagen-induced arthritis mouse model

Rheumatoid arthritis (RA) is an autoimmune disease classified by uncontrolled joint inflammation leading to the destruction of both cartilage and joints. Despite progress made in RA treatment in the past decade, new drugs with high efficacy and fewer long-term adverse effects are still needed; thus, safe anti-inflammatory therapies for RA are urgently needed. Previous results demonstrated that the CXCR3 antagonist is an extremely attractive therapeutic target for the treatment of several autoimmune diseases, suggesting that it might have an inhibitory effect on RA. In this study, we investigated the effect of AMG487, a selective CXCR3 antagonist, on collagen-induced arthritis (CIA) in mice and evaluated its potential therapeutic mechanism.Following induction of CIA, mice were treated with AMG487 (5 mg/kg, intraperitoneally), to investigate their protective effects against CIA. CD4, CD25, CCR6, IL-9, NF-κB, IL-6, IL-17A, IL-21, STAT6 and Foxp3 expressing GITR⁺ and CD45⁺ cells were measured in the spleen using flow cytometry to assess anti-inflammatory effects of AMG487. The mRNA and protein expression of GITR, CCR6, IL-9, and IL-21 were measured using quantitative real-time PCR and western blot analysis in knee tissue. AMG487 significantly alleviated joint inflammation by decreasing GITR⁺CD25⁺, GITR⁺CD45⁺, GITR⁺IL-9⁺, GITR⁺NF-κB⁺ CD45⁺CD4⁺, CD45⁺CCR6⁺, CD45⁺IL-6⁺ cells, CD45⁺IL-17A⁺, and CD45⁺IL-21⁺, and increasing GITR⁺Foxp3⁺ and GITR⁺STAT6⁺ cells. There was a significant decrease in mRNA and protein expression of GITR, CD4, CCR6, IL-6, IL-9, and IL-21 in knee tissue of CIA mice. This study demonstrates that AMG487 has a potential therapeutic effect on RA and could explore novel anti-inflammatory therapies for its treatment.

Efficient Delivery of Triptolide Plus a miR-30-5p Inhibitor Through the Use of Near Infrared Laser Responsive or CADY Modified MSNs for Efficacy in Rheumatoid Arthritis Therapeutics

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease for which treatment focuses on suppressing an overactive immune system and maintaining the physiological balance of synovial fibroblasts (SFs). We found that miR-30-5p was highly expressed in rheumatoid arthritis synovial fibroblasts (RASFs). Subsequently, we predicted that phosphatidylinositol 3-kinase regulatory subunit 2 (PIK3R2) might be a putative target of miR-30-5p. Recent studies have reported that PIK3R2 can maintain the physiological homeostasis of RASFs. Therefore, miR-30-5p inhibitor has the potential to be used in the treatment of RA, but low levels of miR-30-5p inhibitor internalization affect its application. Triptolide (TP) is an effective drug in the treatment of RA but induces severe toxicity and has a narrow therapeutic window. In this study, the cell internalization performance of miR-30-5p inhibitor was improved by loading it into cell membrane penetrating peptide (CADY)-modified mesoporous silica nanoparticles (MSNs), and the toxicity of TP was decreased by loading it into a controlled drug release system based on MSNs. The nanodrug carrier was constructed by filling a phase-change material (PCM) of 1-tetradecanol and drugs into MSNs that could be triggered by an NIR laser with thermo-chemo combination RA therapy. Our results show that the miR-30-5p inhibitor-loaded MSNs@CADY significantly inhibited RASF proliferation and increased apoptosis. In addition, MSNs@PCM@TP under 808 nm laser irradiation were effective in downregulating immune system activation in an RA rat model. Finally, the results of a pharmacodynamics study showed that the combination of MSNs@CADY@miR-30-5p inhibitor and MSNs@PCM@TP under 808 nm laser significantly increased the effectiveness of RA treatment. These findings provide a novel understanding of RA pathogenesis and a theoretical basis for RA treatment.

A directly GP130-targeting small molecule ameliorates collagen-induced arthritis (CIA) by inhibiting IL-6/GP130 signalling and Th17 differentiation

Rheumatoid arthritis is a chronic inflammatory disease associated with joint inflammation and destruction driven by T helper 17 (Th17) cells. Interleukin-6 (IL-6) is secreted by many cell types, including macrophages and synovial fibroblasts. It induces the differentiation and function of Th17 cells that can increase lymphocytic infiltration in the joint. LMT-28 can suppress IL-6 signalling through direct binding to glycoprotein-130 and alleviate inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease. The purpose of this study was to assess whether LMT-28 could potently inhibit Th17 differentiation and to determine the mechanism involved in the attenuating effect of LMT-28 on rheumatoid arthritis through the IL-6 signalling pathway. LMT-28 reduced the arthritis score and showed protective effects against bone and cartilage destruction in collagen-induced arthritis (CIA) mice. In mice with CIA, LMT-28 markedly decreased serum levels of IL-6, TNF and IL-1β compared to vehicle control. Moreover, LMT-28 attenuated Th17 cell activation in lymph nodes of CIA mice. We demonstrated that LMT-28 suppressed differentiation of Th17 in mouse splenocytes and human peripheral blood mononuclear cells (PBMCs). Additionally, LMT-28 inhibited phosphorylation of GP130, STAT3 and ERK induced by Hyper-IL-6 in human fibroblast-like synoviocytes (FLS). Collectively, these results suggest that LMT-28 can inhibit differentiated/activated-Th17 cells in rheumatoid arthritis by blocking activation of the STAT3 pathway. LMT-28 can attenuate rheumatoid arthritis by inhibiting differentiation/activation of Th17 cells and suppressing the proliferation and signalling activation of the IL-6/solubleIL-6 receptor complex stimulated FLS.

The Situation of Chemokine Ligands and Receptors Gene Expression, Following the Oral Administration of Drug Mannuronic Acid in Rheumatoid Arthritis Patients

BACKGROUND

Regarding the leukocytes infiltration into the synovium of Rheumatoid Arthritis (RA) patients is mostly mediated by chemokine ligands and receptors, and following the efficient and motivating results of international Phase III clinical trial of β-D-Mannuronic acid (M2000) patented EP067919 (2017), as a novel anti-inflammatory drug, in patients with RA, the present research was designed.

OBJECTIVES

This study aimed to assess the oral administration effects of this new drug on gene expression of some chemokine receptors and ligands, including CXCR4, CXCR3, CCR2, CCR5 and CCL2/MCP-1 in PBMCs of patients with active form of RA.

METHODS

Twelve patients suffering from RA, with inadequate response to conventional drugs were selected (Clinical trial identifier IRCT2017100213739N10) and 1000mg/day of M2000 was orally administrated to them for 12 weeks. The mRNA expression of target molecules was then evaluated in PBMCs of the patients before and after treatment with M2000 using real-time PCR and was compared to healthy controls. Patents related to this study were also reviewed.

RESULTS

The results showed that M2000 was able to significantly down-regulate the mRNA expression of CXCR4, CCR2 and CCL2/MCP-1 in the PBMCs of the RA patients. It should be noted that the gene expression situation of the target molecules was in coordinate with the clinical and paraclinical assessments in the patients.

CONCLUSION

Taken together, the results of this investigation revealed the part of molecular and immunological mechanisms of drug Mannuronic acid (M2000) in the treatment of RA, based on chemokine ligands and receptors mediated processes.

A selective CB2 agonist protects against the inflammatory response and joint destruction in collagen-induced arthritis mice

Rheumatoid arthritis (RA) is a chronic, inflammatory, synovitis-dominated systemic disease with unknown etiology. RA is characterized by the involvement of multiple affected joints, symmetry, and invasive arthritis of the limbs, which can lead to joint deformity, cartilage destruction, and loss of function. Cannabinoid receptor 2 (CB₂) has potent immunomodulatory and anti-inflammatory effects and is predominantly expressed in non-neuronal tissues. In the current study, the role of CB₂ in the process of inflammatory bone erosion in RA was examined. The selective agonist or high-affinity ligand of CB₂ (4-quinolone-3-carboxamides CB2 agonist, 4Q3C CB₂ agonist, 4Q3C) significantly reduced the severity of arthritis, decreased histopathological findings, and markedly reduced bone erosion in collagen-induced arthritis (CIA) mice. In addition, 4Q3C prevented an increase in the nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) ratio and inhibited the formation of osteoclasts in CIA mice. Furthermore, the expression of tumor necrosis factor-alpha, interleukin-1β, cyclooxygenase-2, and inducible nitric oxide synthase was lower in 4Q3C-treated CIA mice than in control CIA mice. Micro-computed tomography corroborated the finding that 4Q3C reduced joint destruction. These data clearly indicate that the CB₂-selective agonist, 4Q3C, may have anti-inflammatory and anti-osteoclastogenesis effects in RA and may be considered to be a novel treatment for RA.

Crude extract from Libidibia ferrea (Mart. ex. Tul.) L.P. Queiroz leaves decreased intra articular inflammation induced by zymosan in rats

Background

Libidibia ferrea (L. ferrea) has been used in folk medicine to treat several conditions and to prevent cancer. This study performed a chromatographic analysis of the crude aqueous extract of Libidibia ferrea (Mart. ex. Tul.) L.P. Queiroz (LfAE) leaves and evaluated its in vivo antioxidant and anti-inflammatory potential.

Methods

Polyphenols present in LfAE were characterized by high performance liquid chromatography (HPLC). Anti-inflammatory activity was studied in an experimental model of zymosan-induced intra-articular inflammation, conducted in Wistar rats treated with LfAE at the doses of 100, 200 and 300 mg/kg by gavage. Synovial fluid was collected for global leukocyte count, for spectrocopical UV/VIS analysis of myeloperoxidase (MPO) activity, total glutathione and malondialdehyde (MDA), and for quantification of inflammatory cytokines IL1-β and TNF-α by enzyme-linked immunosorbent assay. Synovial membrane was collected for histological analysis. The level of statistical significance was p < 0.05.

Results

HPLC detected concentrations of 1.56 (0.77) %m/m for ellagic acid and 1.20 (1.38) %m/m for gallic acid in LfAE leaves. Treatment with LfAE at all doses significantly decreased the leukocyte influx into the synovial fluid (p < 0.001) and myeloperoxidase activity (p < 0.001), an important marker of neutrophils. LfAE at doses of 100 (p < 0.05), 200 and 300 mg/kg (p < 0.001) also reduced the levels of MDA. LfAE at doses of 200 and 300 mg/kg significantly decreased the levels of IL-1β (p < 0.05) and TNF-α (p < 0.001). All doses of LfAE resulted in increased levels of total glutathione (p < 0.001). Histopathological findings confirmed a reduction of the inflammatory infiltrate in the rats treated with LfAE at a dose of 200 mg/kg (p < 0.05).

Conclusion

LfAE has an important anti-oxidant and anti-inflammatory effect on intra-articular inflammation.

The effects of total glucosides of paeony (TGP) and paeoniflorin (Pae) on inflammatory-immune responses in rheumatoid arthritis (RA)

Rheumatoid arthritis (RA) is a chronic inflammatory and systemic autoimmune disease with an unknown aetiology. Accumulative studies suggest that the pathogenesis of RA involves the excessive activation of synoviocytes and immune cells, increasing the secretion of inflammatory mediators and cytokines in synoviocytes, causing dysfunctional E-prostanoid (EP)-G-protein-cyclic adenosine monophosphate (cAMP) and mitogen-associated-protein kinase (MAPK) signalling in synoviocytes. Total glucosides of paeony (TGP) extracted from the roots of Paeonia lactiflora Pall, was approved by the China Food and Drug Administration as an anti-inflammatory and immuno-modulator drug in 1998. Paeoniflorin (Pae), a water-soluble monoterpene glucoside,is the main effective component of TGP. TGP and Pae produce anti-inflammatory and immuno-regulatory effects by suppressing immune cells and synoviocytes activation, decreasing inflammatory substance production and restoring abnormal signalling in synoviocytes. In this review, the regulation of the inflammatory-immune responses and the therapeutic mechanism between RA and TGP and Pae are discussed in detail. The aim of this review was to provide novel insights into the treatment of RA.

Immunomodulatory Effects of CP-25 on Splenic T Cells of Rats with Adjuvant Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease in which T cells play an important role. Paeoniflorin-6-oxy-benzenesulfonate (CP-25) shows a strong anti-inflammatory and immunomodulatory effect in the joint of adjuvant arthritis (AA) rats, but the role of the spleen function is still unclear. The aim of this study was to research how CP-25 regulated spleen function of AA rats. Male Sprague-Dawley rats were administered with CP-25 (50 mg/kg) orally from day 17 to 29 after immunization. The spleen histopathological changes were analyzed by hematoxylin-eosin staining. G protein-coupled receptor kinases (GRKs) and prostaglandin receptor subtypes (EPs) were screened by Western blot and immunohistochemistry. The co-expression of GRK2 and EP2 as well as GRK2 and EP4 was measured by immunofluorescence and co-immunoprecipitation. The expression of GRK2 and EP4 in splenic T cells was further detected by immunofluorescence. CP-25 was found to relieve the secondary paw swelling, attenuate histopathologic changes, and downregulate GRK2, EP2 and EP4 expression in AA rats. Additionally, CP-25 not only downregulated the co-expression of GRK2 and EP4 but also downregulated GRK2, EP4 expression in splenic T cells of AA rats. From these results, we can infer that CP-25 play an anti-inflammatory and immune function by affecting the function of the splenic T cells.

[Advances in macrophage function and its anti-inflammatory and proresolving activity and role in periodontitis development]

Macrophage plays an important role in human innate immune system. It has powerful functions, such as recognition, phagocytosis, and bacteria and foreign body removal. Periodontitis, which is a chronic infectious disease characterized by gum inflammation and bone loss, is a major cause of tooth loss in adults. Several studies demonstrated that periodontal tissue destruction is caused by the host immune response defending against infections. As an important part of host immune response, macrophage is also involved in periodontitis pathogenesis. Recently, anti-inflammatory and proresolving activities of macrophage was discovered. Thus, the complex function of macrophage in the occurrence, development, and resolution of inflammation and its potential role in periodontitis were reviewed.

Therapeutic effects of matrine derivate MASM in mice with collagen-induced arthritis and on fibroblast-like synoviocytes

MASM is a matrine derivate that exhibits a number of pharmacological effects, including immunosuppressive activity and anti-inflammatory properties. In this study, the mechanisms underlying the therapeutic efficacy of MASM in the treatment of rheumatoid arthritis were investigated using DBA/1 mice with collagen-induced arthritis (CIA) and fibroblast-like synoviocytes derived from rheumatoid arthritis patients (RA-FLS). We demonstrated that MASM markedly attenuated the severity of arthritis in CIA mice. The therapeutic effects were associated with ameliorated joint swelling and reduced bone erosion and destruction. Furthermore, the administration of MASM suppressed the expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6). In vitro, MASM inhibited the expression of pro-inflammatory cytokines (TNF-α, IL-6, IL-8) and matrix metalloproteinases (MMP-1, MMP-3 and MMP-13) by inhibiting both the phosphorylation of MAPKs and the activation of NF-κB in IL-1β-stimulated RA-FLS. Additionally, MASM could induce apoptosis of RA-FLS via mitochondrial and Akt signaling pathways in human RA-FLS. These findings suggest that MASM could attenuate arthritis severity in CIA mice at least partially by blocking the phosphorylation of MAPKs and the activation of NF-κB and by inducing apoptosis in RA-FLS. MASM could be a potent therapeutic agent for the treatment of RA.

Effective transdermal delivery of methotrexate through nanostructured lipid carriers in an experimentally induced arthritis model

Rheumatoid arthritis (RA), an autoimmune and inflammatory pathology, is resulted due to the disruption of immune-homeostasis and failure of host immune-surveillance mechanism leading to cartilage degradation and bone erosion. Orally and parenterally administered methotrexate (MTX) have had adverse systemic complications in RA therapeutics. Therefore, transdermal application of MTX is recommended for the treatment of RA [1]. Present study is designed to develop MTX loaded nanostructured lipid carriers and chemical enhancer co-incorporated hydrogel (gel-(MTX-NLCs+CE)) for an efficient transdermal delivery of MTX in a Freund's adjuvants induced experimental animal model of RA. A gel-(MTX-NLCs+CE) was formulated and evaluated for its biocompatibility in hyper keratinocytes (HaCaT) and human monocytic cells (U937). Further, systemic and local inflammation was assessed by the estimation of pro-inflammatory cytokines & joint-destructive enzymes (TNF-α, IL-6, MMP-1 & IL-1β,; iNOS & COX-2) in the serum and synovial fluid, respectively in an experimentally induced RA animal model. Prepared formulations were also evaluated with respect to arthritis index, arthritis score and histopathology of paw and ankle bones. The biocompatibility study of formulation on U937 and HaCaT is suggestive of safe and greater therapeutic efficacy of the developed formulations. Our results show that transcutaneous ability of MTX loaded nanostructured lipid carries (NLCs) and chemical enhancer (CE) co-incorporated hydrogel significantly (p<0.001) decreases the inflammation in RA animal model. In conclusion, developed NLCs-based gel formulation loaded with MTX opens new avenues for developing novel therapeutic modality for RA patients with the acceptably minimum adverse effects.

Lack of tumor necrosis factor alpha gene polymorphism -857c/t (rs1799724) association in Pakistani rheumatoid arthritis patients

BACKGROUND

Rheumatoid arthritis (RA) is a common systemic autoimmune disease, influenced greatly by the pro-inflammatory cytokine tumor necrosis factor- alpha (TNF-α). Single nucleotide polymorphisms (SNPs) in regulatory regions of the TNF-α gene play a significant role in disease development and pathogenesis. The aim of this study was to investigate the association of TNF-α -857C/T (rs1799724) SNP with RA activity or severity in our Pakistani study group.

METHODS

The study included 134 (116 women, 18 men) patients with RA and 134 ethnically matched healthy controls (108 women, 26 men). Each patient's disease activity was measured by Disease Activity Score of 28 joints. The genotypes were determined in all included individuals following allele-specific polymerase chain reaction along with the prerequisite internal amplification controls. Statistical analysis including chi-square/Fischer exact test and one-way analysis of variance; nonparametric Kruskal-Wallis test was employed using Graphpad Prism 6 software for association study.

RESULTS

The prevalence of TNF-α -857C/T (rs1799724) polymorphism was not differentially distributed between RA patients and controls in either allele frequency, with odds ratio (95% CI) of 0.9661 (0.6714-1.390) and P-value of 0.8527, or genotype frequency with χ² of 0.5015 and P-value of 0.7782. Moreover, no correlation was found when genotype frequency distribution was analyzed with disease severity (P = 0.6321 and Kruskal-Wallis statistics of 1.098).

CONCLUSION

The study demonstrated -857C/T (rs1799724) polymorphism may not have influenced RA susceptibility in our study group. However, investigations of genetic variability influence on disease outcome in large prospective cohorts are required, so the complicated interconnection of genetic and environmental elements can be emulated for better understanding.

Triptolide Modulates TREM-1 Signal Pathway to Inhibit the Inflammatory Response in Rheumatoid Arthritis

Triptolide (TP), an active component isolated from Tripterygiumwilfordii Hook F, has therapeutic potential against rheumatoid arthritis (RA). However, the underlying molecular mechanism has not been fully elucidated. The aim of this study is to investigate the mechanisms of TP acting on RA by combining bioinformatics analysis with experiment validation. The human protein targets of TP and the human genes of RA were found in the PubChem database and NCBI, respectively. These two dataset were then imported into Ingenuity Pathway Analysis (IPA) software online, and then the molecular network of TP on RA could be set up and analyzed. After that, both in vitro and in vivo experiments were done to further verify the prediction. The results indicated that the main canonical signal pathways of TP protein targets networks were mainly centered on cytokine and cellular immune signaling, and triggering receptors expressed on myeloid cells (TREM)-1 signaling was searched to be the top one shared signaling pathway and involved in the cytokine and cellular immune signaling. Further in vitro experiments indicated that TP not only remarkably lowered the levels of TREM-1 and DNAX-associated protein (DAP)12, but also significantly suppressed the activation of janus activating kinase (JAK)2 and signal transducers and activators of transcription (STAT)3. The expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 in lipopolysaccharides (LPS)-stimulated U937 cells also decreased after treatment with TP. Furthermore, TREM-1 knockdown was able to interfere with the inhibition effects of TP on these cytokines production. In vivo experiments showed that TP not only significantly inhibited the TREM-1 mRNA and DAP12 mRNA expression, and activation of JAK2 and STAT3 in ankle of rats with collagen-induced arthritis (CIA), but also remarkably decreased production of TNF-α, IL-1β and IL-6 in serum and joint. These findings demonstrated that TP could modulate the TREM1 signal pathway to inhibit the inflammatory response in RA.

Nanostructured lipid carrier mediates effective delivery of methotrexate to induce apoptosis of rheumatoid arthritis via NF-κB and FOXO1

Present study was designed to develop novel nano-structured lipid carriers (NLCs) formulated by lipid mixture and chemical permeation enhancer-based hydrogel for an effective transdermal delivery of methotrexate (MTX). The prepared NLCs were optimized with different preparative variables such as particle size <200 nm, poly-dispersity index (PDI) <0.2, and entrapment efficiency ∼85%. The drug incorporated into NLCs-gel base showed excellent spread ability without any grittiness during rheological behavior and texture profile analysis. The in vitro release showed biphasic release pattern with initial fast release of drug (>50%) in 8h followed by sustained release (up to 85%) by the end of 48thh. NLCs showed greater uptake in human hyper-proliferative keratinocyte cell line (HaCaT). NLCs showed increased expression of inflammatory mediators as well asapoptosis in U937 monocytic cells. The greater expression of pro-apoptotic gene Bim regulated by NF-κB-IkB and FOXO1 is supported by fold regulations calculated for various apoptotic and pro-inflammatory biomarkers carried out by RT-PCR. The immunocytochemistry to detect IL-6 expression and immunofluorescence assay suggested that induced apoptosis occurs in experimentally induced in vitro arthritis model treated with NLCs-MTX. We saw reduced inflammation and triggered apoptosis through NF-κB & FOXO1 pathways induced by MTX loaded NLCs in rheumatoid arthritic cells. In addition, formulated NLCs exhibit better skin permeation with higher permeation flux & enhancement ratio as shown by confocal laser scanning microscopy (CLSM). Moreover, histopathological examinations of skin are suggestive of safety potential of NLCs.

Deficiency of Thrombospondin-4 in Mice Does Not Affect Skeletal Growth or Bone Mass Acquisition, but Causes a Transient Reduction of Articular Cartilage Thickness

Although articular cartilage degeneration represents a major public health problem, the underlying molecular mechanisms are still poorly characterized. We have previously utilized genome-wide expression analysis to identify specific markers of porcine articular cartilage, one of them being Thrombospondin-4 (Thbs4). In the present study we analyzed Thbs4 expression in mice, thereby confirming its predominant expression in articular cartilage, but also identifying expression in other tissues, including bone. To study the role of Thbs4 in skeletal development and integrity we took advantage of a Thbs4-deficient mouse model that was analyzed by undecalcified bone histology. We found that Thbs4-deficient mice do not display phenotypic differences towards wildtype littermates in terms of skeletal growth or bone mass acquisition. Since Thbs4 has previously been found over-expressed in bones of Phex-deficient Hyp mice, we additionally generated Thbs4-deficient Hyp mice, but failed to detect phenotypic differences towards Hyp littermates. With respect to articular cartilage we found that Thbs4-deficient mice display transient thinning of articular cartilage, suggesting a protective role of Thbs4 for joint integrity. Gene expression analysis using porcine primary cells revealed that Thbs4 is not expressed by synovial fibroblasts and that it represents the only member of the Thbs gene family with specific expression in articular, but not in growth plate chondrocytes. In an attempt to identify specific molecular effects of Thbs4 we treated porcine articular chondrocytes with human THBS4 in the absence or presence of conditioned medium from porcine synovial fibroblasts. Here we did not observe a significant influence of THBS4 on proliferation, metabolic activity, apoptosis or gene expression, suggesting that it does not act as a signaling molecule. Taken together, our data demonstrate that Thbs4 is highly expressed in articular chondrocytes, where its presence in the extracellular matrix is required for articular cartilage integrity.

IL-27-induced modulation of autoimmunity and its therapeutic potential

Interleukin-27 (IL-27) is a new member of the IL-12 family. It is produced by activated antigen-presenting cells and plays an important role in the regulation of CD4+ T cell differentiation and immune response. IL-27 activates multiple signaling cascades, including the JAK-STAT and p38 MAPK pathways. Several studies have revealed that IL-27 promotes the differentiation of Th1 and Tr1, but inhibits Th2, Th17, and Treg cells. However, a few studies have shown an opposite effect on certain T cell subsets, such as Treg. IL-27 displays both pro- and anti- inflammatory activities in different autoimmune diseases. Here, we have discussed the role of IL-27 in rheumatoid arthritis, multiple sclerosis, colitis, lupus, psoriasis, type 1 diabetes, and uveitis. Most of this information is derived from experimental models of these autoimmune diseases. The mechanistic basis of the dual role of IL-27 in inflammation and autoimmunity is still not fully defined. In general, the pro-/anti-inflammatory activity of IL-27 is influenced by the underlying immune effector pathways, the phase of the disease, the presence or absence of counter-regulatory cytokines/T cell subsets, and the tissue/cell type under study. Despite a spectrum of outcomes in various autoimmune diseases, mostly anti-inflammatory and immunomodulatory effects of IL-27 have been observed in this category of diseases. Accordingly, IL-27 represents a novel, promising target/agent for the treatment of autoimmune diseases.

Therapeutic potential of IL-15 in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, destructive inflammatory autoimmune disease. Cytokine-mediated immunity has been found to play an important role in the pathogenesis of autoimmune diseases including RA. Recently, much attention has been paid on the role of IL-15, which is a member of the 4 α-helix bundle cytokine family. IL-15 was detected in serum and synovial fluid from RA patients and arthritis mice models. Moreover, administration of IL-15 leads to the development of severe inflammatory arthritis, suggesting that IL-15 may be therapeutically relevant in RA. Therefore, targeting IL-15 may be significantly important and valuable. In this article, we discuss the biological features and effects of IL-15 and summarize recent advances on the pathological roles of IL-15 in RA and treatment for RA.

Anti-Arthritic Effect of Chebulanin on Collagen-Induced Arthritis in Mice

Rheumatoid arthritis is a chronic degenerative autoimmune disease characterized by persistent inflammation of synovial membranes, which leads to cartilage destruction and bone erosion. To date, there are no effective therapies to slow the progress of this degenerative condition. Here, we evaluate the anti-arthritic effect of chebulanin, an abundant anti-inflammatory agent isolated from Terminalia chebula, in collagen induced arthritis in DBA/1 mice by intragastric administration. Arthritic severity was scored by performing histopathological evaluation of the joints and measuring the expression of inflammatory cytokines and relative enzymes by immunohistochemical staining. In parallel, bone destruction and erosion were confirmed by micro-CT. Our data revealed that chebulanin significantly improved the severity of arthritis. Specifically, the histopathological characteristics of the tissues were improved and expression of TNF-α, IL-6, MMP-3 and COX-2 in the paws and joints of the treated mice decreased in a dose-dependent manner compared with control mice. Furthermore, micro-CT analysis revealed that chebulanin induced a dose-dependent reduction in cartilage destruction and bone erosion. Taken together, our findings suggest that chebulanin suppresses the expression of inflammatory mediators and prevents cartilage destruction and bone erosion in mice. Therefore, chebulanin is a strong therapeutic alternative for the treatment of RA.

Macrophage subsets and osteoimmunology: tuning of the immunological recognition and effector systems that maintain alveolar bone

Chronic and aggressive periodontal diseases are characterized by the failure to resolve local inflammation against periodontopathogenic bacteria in the subgingival biofilm. Alveolar bone resorption is associated with altered innate and adaptive immune responses to periodontal pathogens. Macrophage-derived cytokines, chemokines and growth factors, present in both destructive and reparative phases of periodontitis, are elevated in numerous animal and human studies. Macrophage polarization to either a predominantly pro-inflammatory or anti-inflammatory phenotype may be a critical target for monitoring disease activity, modulating immune responses to subgingival biofilms in patients at risk and reducing alveolar bone loss.

Etanercept ameliorates inflammation and pain in a novel mono-arthritic multi-flare model of streptococcal cell wall induced arthritis

Background

The impact of anti-TNF, corticosteroid and analgesic therapy on inflammation and pain was evaluated in a novel mono-arthritic multi-flare rat Streptococcal Cell Wall (SCW) model using Etanercept, Dexamethasone and Buprenorphine.

Methods

Multiple flares of arthritis were induced with an intra-articular injection of SCW in the hind ankle on day 1, followed by intravenous challenges on days 21 and 42. Inflammation and pain were monitored in the hind paws. Cytokine profiling, cell phenotyping, bioluminescence imaging and histopathological evaluation were also performed.

Results

Local injection of SCW caused a rapid onset of inflammation and pain in the injected ankle which resolved within 4 days (Flare 1). Intravenous injection 20 days after sensitization resulted in an increase in ankle diameter and pain, which partially resolved in 8 days (Flare 2). The subsequent intra-venous injection in the same animals 14 days after resulted in a more chronic disease with inflammation and pain persisting over a period of 10 days (Flare 3). In Flare 2, therapeutic administration of Dexamethasone inhibited paw swelling (95%; P<0.001) and pain (55%; P<0.05). Therapeutic administration of Buprenorphine inhibited pain (80%; P<0.001) without affecting paw swelling (0%). Prophylactic administration of Etanercept in Flare 2 inhibited paw swelling (≥60%; P<0.001) and pain by ≥30%. Expression of IL-1β, IL-6, MCP-1 and CINC was reduced by >50% (P<0.001). Treatment with Etanercept in Flare 3 inhibited paw swelling by 60% (P<0.001) and pain by 25%. Prior treatment with Etanercept in Flare 2 followed by re-administration in Flare 3 led to a complete loss in the efficacy of Etanercept. Systemic exposure of Etanercept corroborated with lack of efficacy. Dexamethasone inhibited inflammation and pain in both Flares 2 and 3 (P<0.001).

Conclusions

We established a novel multi-flare SCW arthritis model enabling drug intervention in different stages of disease. We show for the first time the evaluation of inflammation and pain simultaneously in this model. Etanercept and Dexamethasone inhibited inflammation, pain and proinflammatory cytokines in this model. Taken together, this model facilitates the assessment of anti-rheumatic agents targeting inflammation and pain in the multiple flare paradigm and offers a powerful tool for drug discovery.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-409) contains supplementary material, which is available to authorized users.

Certolizumab pegol (CDP870) for rheumatoid arthritis in adults

BACKGROUND

Tumour necrosis factor (TNF)-alpha inhibitors are beneficial for the treatment of rheumatoid arthritis (RA) in terms of reducing the risk of joint damage, improving physical function and improving quality of life. This Cochrane review is an update of a review of the treatment of RA with certolizumab pegol that was first published in 2011.

OBJECTIVES

To assess the clinical benefits and harms of certolizumab pegol (CDP870) in patients with RA who have not responded well to conventional disease-modifying anti-rheumatic drugs (DMARDs).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2014, Issue 5), MEDLINE, EMBASE, Scopus, TOXLINE, Web of Knowledge; websites of the US Food and Drug Administration (FDA) and European Medicines Evaluation Agency (EMEA); reference lists of articles; and searched http/clinicaltrials.gov. The searches were updated from 2009 (date of last search for the original review) to 5 June 2014.

SELECTION CRITERIA

Randomised controlled trials that compared certolizumab pegol with any other agent including placebo or methotrexate (MTX) in adult patients with active RA despite current or prior treatment with conventional disease-modifying anti-rheumatic drugs (DMARDs), such as MTX.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed search results, trial quality and extracted data. Disagreements were resolved by discussion or referral to a third author.

MAIN RESULTS

Eleven trials were included in this update. Ten (4324 patients) were included in the pooled analysis for benefits, five more than previously, and 10 (3711 patients) in the pooled analysis for harms, four more trials (1930 patients) than previously. The duration of follow-up varied from 12 to 52 weeks and the range of doses of certolizumab pegol varied from 50 to 400 mg given subcutaneously (sc). In phase III trials, the control was placebo plus MTX in five trials and placebo in four trials. The risk of bias of the included studies was assessed as low but there may have been a risk of attrition bias.Statistically significant improvements were observed at 24 weeks with the approved dose of 200 mg certolizumab pegol every other week, in 1) American College of Rheumatology (ACR) 50% improvement: 27% absolute improvement (95% CI 20% to 33%), NNT of 4 (95% CI 3 to 8), risk ratio (RR) 3.80 (95% CI 2.42 to 5.95); 2) the Health Assessment Questionnaire (HAQ): -12% absolute improvement (95% CI -9% to -14%), NNT of 6 (95% CI 5 to 8), mean difference (MD) - 0.35 (95% CI -0.43 to -0.26) (scale 0 to 3); 3) Disease Activity Score (DAS) remission improvement: absolute improvement 11% (95% CI 8% to 15%), NNT of 9 (95% CI 4 to 20), RR 8.47 (95% CI 4.15-17.28); and 4) radiological changes: erosion score (ES) absolute improvement -0.29% (95% CI -0.42% to -0.17%), NNT of 6 (95% CI 4 to 10), MD -0.67 (95% CI -0.96 to -0.38) (scale 0 to 230). Serious adverse events were statistically significantly more frequent for certolizumab pegol (200 mg every other week) with an absolute rate difference of 4% (95% CI 2% to 6%), NNTH of 32 (95% CI 17 to 88), Peto odds ratio (OR) 1.77 (95% CI 1.27 to 2.46). There was a statistically significant increase in all withdrawals in the placebo groups (for all doses and all follow-ups) with an absolute rate difference of -34% (95% CI -18% to -50%), NNTH of 4 (95% CI 3 to 5), NNTH of 4 (95% CI 3 to 5), RR 0.42 (95% CI 0.36 to 0.50); and there was a statistically significant increase in all withdrawals due to adverse events in the certolizumab groups (for all doses and all follow-up) with an absolute rate difference of 2% (95% CI 1% to 3%), NNTH of 55 (95% CI 27 to 238), Peto OR 1.66 (95% CI 1.15 to 2.37).The risk of bias was low and the quality of evidence was downgraded to moderate because of high rates of dropouts (> 20%) in most of the trials. We did not find any problems with inconsistency, indirectness, imprecision or publication bias.

AUTHORS' CONCLUSIONS

The results and conclusions did not change from the previous review. There is moderate-level evidence from randomised controlled trials that certolizumab pegol alone or combined with methotrexate is beneficial in the treatment of RA. Adverse events were more frequent with active treatment. We found a potential risk of serious adverse events.

Resistin in inflammatory and degenerative rheumatologic diseases. Relationship between resistin and rheumatoid arthritis disease progression

AIMS OF THE STUDY

To assess and compare resistin levels in the serum and synovial fluid of patients with rheumatoid arthritis (RA; an inflammatory rheumatologic disease) and osteoarthritis (OA; a degenerative rheumatologic disease) and to study the relationship between resistin levels and prognostic factors of RA disease progression.

PATIENTS AND METHODS

This study included a total of 50 patients: 25 with RA and 25 with OA. Full case history was documented for all patients and all underwent a thorough clinical examination and laboratory testing. Body mass index (BMI) values were also calculated. Radiographs were made of OA patients' knees and RA patients' hands. Disease Activity Score 28 (DAS28) was calculated for RA patients. Serum and synovial fluid samples were obtained from the effused knees of all patients and tested for resistin level.

RESULTS

Serum resistin levels were higher in RA patients than in those with OA (p < 0.01). Synovial fluid resistin levels were also higher in RA than OA patients (p < 0.001). While serum resistin levels correlated with Larsen score and total leukocyte count (TLC), synovial fluid resistin levels correlated with rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) levels in addition to Larsen score and TLC.

CONCLUSION

Resistin levels were found to be higher in the serum and synovial fluid of RA patients than in those with OA. This may suggest a role for resistin in inflammatory rheumatologic diseases. The observed statistically significant correlation between synovial fluid resistin levels and RF, ACPA and Larsen score may suggest that high synovial fluid resistin levels can be considered a poor prognostic factor for RA progression. However, further studies employing a larger cohort of patients are needed to confirm the relevance of resistin as a prognostic marker in RA patients.

(E)-3-(3,4-Dimethoxyphenyl)-1-(5-hydroxy-2,2-dimethyl-2H-chromen-6-yl)prop-2-en-1-one ameliorates the collagen-arthritis via blocking ERK/JNK and NF-κB signaling pathway

Our previous report has shown a natural pyranochalcones-derived compound, (E)-3-(3,4-Dimethoxyphenyl)-1-(5-hydroxy-2,2-dimethyl-2H-chromen-6-yl)prop-2-en-1-one (5b), that exerted protection against carrageenan-induced hind paw edema and adjuvant-induced arthritis. In this study, collagen-induced arthritis (CIA) model was used to further examine the anti-arthritic effects of 5b in vivo; the underlying molecular mechanisms of action were also investigated using a murine monocytic cell line, RAW264.7 cells. Here we showed that oral administration of 5b (20mg/kg) significantly suppressed the progression of arthritis. Improvement in disease severity was accompanied by inhibition of CD68-positive cells in knee joint and reduced pro-inflammatory cytokines TNF-α, IL-1β and IL-6 in serum. In vitro, 5b suppressed expressions of iNOS, cyclooxygenase-2 (COX-2), TNF-α, IL-6 and IL-1β as well as productions of nitric oxide (NO) and prostaglandin E2 (PGE2) in lipopolysaccharide (LPS)-treated macrophages. This compound also significantly suppressed LPS-induced NF-κB activation, including phosphorylation of I-κB, degradation of I-κB, and nuclear translocation of p65 and p50. Treatment with 5b also blocked LPS-induced expression of TLR4 remarkably, suppressed degradation of IRAKs and phosphorylations of JNK and ERK, but had little effect to p38 kinase activation. These findings indicated that 5b might be a therapeutic agent for rheumatoid arthritis, and exerted an anti-inflammatory effect mainly through mediating TLR4, NF-κB and ERK/JNK signaling pathways in monocytes.