Combination of MTX and LEF attenuates inflammatory bone erosion by down-regulation of receptor activator of NF-kB ligand and interleukin-17 in type II collagen-induced arthritis rats

A chlorogenic acid-conjugated nanomicelle attenuates disease severity in experimental arthritis

Rheumatoid arthritis (RA) is a systemic immune disorder marked by synovitis, bone damage, and cartilage erosion, leading to increased socio-economic burdens and reduced quality of life. Despite its unknown cause, advancements in understanding its pathophysiology have facilitated novel therapeutic approaches. Current treatments, including disease-modifying anti-rheumatic drugs (DMARDs) and biologics, often result in low efficacy and unnecessary side effects. To address the limitations of these drugs, carrier-based drug delivery systems, such as nanomicelles, have emerged as a promising solution. In this study, nanomicelles were synthesised utilizing PLGA (poly(lactic-co-glycolic acid)) as a backbone; this backbone is conjugated with chlorogenic acid (CGA), which is known for suppressing inflammation, and incorporates methotrexate (MTX), a model drug that is established for RA treatment. The nanomicelles were extensively characterized in terms of size, charge, drug loading, and drug-release behaviour. The in vivo assessment of MTX-PLGA-b-CGA nanomicelles in a collagen-induced arthritis model demonstrated a remarkable reduction in joint swelling, cartilage erosion, and disease severity. Furthermore, histological findings confirmed cartilage integrity and reduced expression of key pro-inflammatory markers, including receptor activator of nuclear factor kappa beta ligand (RANKL) and tumor necrosis factor (TNF-α). The approach based on the MTX-PLGA-b-CGA nanomicelles presents a biocompatible and potentially effective therapeutic strategy for management of the severity and progression of RA, providing a hopeful alternative for RA treatment.

Association between disease-modifying antirheumatic drugs and bone turnover biomarkers

Rheumatoid arthritis (RA) has been linked to an increased risk of osteoporosis as well as fractures. Patients diagnosed with RA had a 25% increased risk of osteoporotic fracture, according to a recent population-based cohort study that compared them to people without RA. Several studies have found a correlation between osteoporosis and the presence of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1, and 6. These cytokines play a crucial part in the process of bone resorption by boosting osteoclast activation and encouraging osteoclast differentiation. Based on the correlation between RA, osteoporosis, and inflammation, it is possible that systemic immunosuppression with disease-modifying antirheumatic drugs (DMARDs) can help individuals with RA have a lower chance of developing osteoporosis and osteoporotic fractures. There is little information on how different DMARDs, biologic or non-biologic, affect RA patients' bone metabolism. In this study, we present an overview of the influence that targeted therapies, such as biologics, non-biologics, and small molecule inhibitors, have on bone homeostasis in RA patients.

Targeting fibroblast-like synoviocytes in rheumatoid arthritis

Fibroblast-like synoviocytes (FLS) are mesenchymal-derived cells that play an important role in the physiology of the synovium by producing certain components of the synovial fluid and articular cartilage. In rheumatoid arthritis (RA), however, fibroblasts become a key driver of synovial inflammation and joint damage. Because of this, there has been recent interest in FLS as a therapeutic target in RA to avoid side effects such as systemic immune suppression associated with many existing RA treatments. In this review, we describe how approved treatments for RA affect FLS signaling and function and discuss the effects of investigational FLS-targeted drugs for RA.

The effect of disease-modifying antirheumatic drugs (DMARDs) on bone homeostasis in rheumatoid arthritis (RA) patients

The autoimmune disease known as rheumatoid arthritis (RA) has been linked to the deterioration of bone. Bone erosion is a hallmark of RA and is linked to the severity of the disease as well as a poor functional result. Erosion of periarticular cortical bone is a common feature seen on plain radiographs of patients with RA. This characteristic feature is the result of excessive bone resorption and inadequate formation of bone. It has been determined that there is a complex interaction between the inflammatory condition seen in RA and bone destruction. Increased knowledge of the pathways and other mechanisms involved in osteoclastogenesis has resulted from advances in both animal and clinical investigations. Also, Biological and targeted medicines have modified RA's bone metabolism. Here, we provide a narrative overview of the literature on the pathomechanisms of bone structure involved in biological and targeted treatments for RA and also, the clinical implications of disease-modifying antirheumatic drugs (DMARDs) are discussed. In light of the fact that these newer treatments present patients with RA with new possibilities for disease improvement and symptom control, it is imperative that additional rigorous evidence be gathered to provide a clinical reference for both patients and their treating physicians.

Role of Tripartite Motif-Containing 3 Protein (TRIM3) in Rheumatoid Arthritis and Its Mechanism

Aim: To discuss TRIM3’s effects and relative mechanisms in RA development. Materials and methods: Using FLS as research object in our study. Present study divided into two steps, first step, discussing TRIM3 depressing effects in normal FLS cell; next, using IL-1β stimulating to make RA cell model, TRIM3 overexpression in RA model to observe cell biological activities. Measuring IL-6 and TNF-α levels by ELISA kit; evaluating cell proliferation by MTT and EdU assay; relative proteins including TRIM3, TAB2 and NF-κB(p65) proteins expression using WB method. Results: With TRIM3 knockdown, FLS cell proliferation were significantly increased with IL-6, TNF-α levels significantly up-regulation (P < 0.001, respectively). Meanwhile, TAB2 protein expression significantly depressing and NF-κB(p65) protein significantly increasing; those were similar as IL-1β stimulating RA cell model in FLS cell line. In RA cell model, transfection TRIM3 in FLS cell, the cell proliferation was significantly depressed with IL-1β, TNF-α levels depressing, and TAB2 protein expression significantly increasing and NF-κB(p65) protein significantly depressing. Conclusion: TRIM3 knockdown might be a result to RA development; with TRIM3 overexpression, RA induced FLS hyperproliferation significantly improved with TAB2 up-regulation and NF-κB(p65) down-regulation in vitro.

Application and pharmacological mechanism of methotrexate in rheumatoid arthritis

Methotrexate (MTX) has been used for the treatment of rheumatoid arthritis (RA) for about forty years and to date MTX remains the part of global standard of treatment for RA. The efficacy of MTX in RA is the result of multiple mechanisms of action. In order to summarize the possible pharmacological mechanisms of MTX in the treatment of RA, this review will elaborate on folate antagonism, promotion of adenosine accumulation, regulation of inflammatory signaling pathways, bone protection and maintenance of immune system function.

Effectiveness and safety of leflunomide compared with cyclophosphamide as induction therapy in Takayasu's arteritis: an observational study

Aims

The objective of this study was to investigate the outcomes of leflunomide (LEF) compared with those of cyclophosphamide (CYC) as induction against active Takayasu's arteritis (TA) in Chinese patients.

Methods

This was an observational study based on a prospective cohort that included TA patients diagnosed in large third-level first-class general hospitals in East China from January 2009 to September 2018. LEF- or CYC-induced active patients were enrolled for comparative effectiveness analysis. One-to-more paired cohorts of LEF versus CYC were derived by propensity-score matching (PSM). The primary outcome was complete remission (CR) at 9-month follow up, and secondary endpoints included partial remission (PR) and effectiveness rate (ER). Multivariable logistic regression was used to identify statistical significance.

Results

A total of 131 enrolled patients with at least 3-months treatment included 53 receiving a regimen of glucocorticoid (GC) and LEF and 78 receiving GC and CYC. Compared with the CYC group, the LEF group showed higher CR rate {LEF versus CYC: 84.6% [95% confidence interval (CI) 74.5-94.8%] versus 59.0% (47.8-70.1%); relative risk (RR) = 0.3 (0.1-0.6), p = 0.002} and lower daily GC dose [10.0 (5.0-12.5) versus 12.5 (10.0-15.0) mg, p = 0.043] at the end of the 9-month induction. In the matched analysis, the LEF group (n = 23) still indicated a higher CR rate than the CYC group (n = 54) after PSM [RR = 0.1 (0.0-0.6), p = 0.003]. Four LEF-treated patients had mild side effects, and one died unrelated to LEF.

Conclusion

LEF could be an alternative induction therapy against TA, showing good effectiveness and tolerance compared with CYC.

Synergistic enhancement and hepatoprotective effect of combination of total phenolic extracts of Citrus aurantium L. and methotrexate for treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune inflammatory disorder characterized by joint destruction and bone damage. Methotrexate (MTX) is recommended as the first-line disease-modifying agent for the treatment of RA. However, the clinical efficacy of MTX is limited due to its low response and side effects, especially hepatotoxicity. Total phenolic extracts of Citrus aurantium L. (TPE-CA) are rich in dietary bioactive flavonoids, which show beneficial effects on liver health and are regarded as therapeutic tools against inflammatory diseases. In this study, the efficacy of MTX, alone or in combination with TPE-CA, for the treatment of collagen-induced arthritis and protection against hepatic injury in rats was investigated. TPE-CA and MTX combination effectively reduced the inflammatory symptoms and joint damage by inhibiting the NF-κB pathway. Moreover, TPE-CA significantly ameliorated MTX-induced chronic hepatic injury by enhancing antioxidant enzymes activities, suppressing hepatic cytochrome P450 2E1 expression, and modulating the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 pathway. This combination regimen not only provided synergistic enhancement but also exhibited hepatoprotective effect against chemically induced chronic hepatotoxicity. This could be an alternative strategy to improve the low response of MTX in RA treatment.

Ultrasound-triggered perfluorocarbon-derived nanobombs for targeted therapies of rheumatoid arthritis

The targeted US-triggered PFC-based “nanobombs” with US used to treat the RA in this work would offer a new treatment strategy and have a great potential for the application in the areas of theranostic agent and nanomedicine treatment.

Leflunomide attenuates oxidative stress in fetal human lung endothelial cells via superoxide dismutase 2 and catalase

Hyperoxia-induced oxidative stress contributes to the pathogenesis of bronchopulmonary dysplasia (BPD), the most common respiratory morbidity of preterm infants. Importantly, the disease lack specific therapies and is associated with long-term cardio-pulmonary and neurodevelopmental morbidities, signifying the need to discover novel therapies and decrease the disease burden. We and others have demonstrated that leflunomide, a food and drug administration approved drug to treat humans with rheumatoid arthritis, increases the expression of the anti-oxidant enzymes, NAD(P)H quinone dehydrogenase 1 (NQO1), catalase, and superoxide dismutase (SOD). However, whether this drug can decrease oxidative stress in fetal human pulmonary arterial endothelial cells (HPAECs) is unknown. Therefore, we tested the hypothesis that leflunomide will decrease hyperoxia-induced oxidative stress by upregulating these anti-oxidant enzymes in HPAECs. Leflunomide decreased hydrogen peroxide (H₂O₂) levels and increased the mRNA and protein levels of catalase, NQO1, and SOD2 in HPAECs at basal conditions. Further, leflunomide-treated cells continued to have decreased H₂O₂ and increased SOD2 levels upon hyperoxia exposure. Leflunomide did not affect the expression of other anti-oxidant enzymes, including hemoxygenase-1 and SOD1. AhR-knockdown experiments suggested that leflunomide regulated NQO1 levels via AhR-dependent mechanisms and H₂O₂, catalase, and SOD2 levels via AhR-independent mechanisms. Collectively, the results support the hypothesis that leflunomide decreases oxidative stress in HPAECs via SOD2-and catalase-dependent, but AhR- and NQO1-independent mechanisms. Our findings indicate that leflunomide is a potential drug for the management of BPD in preterm infants.

Salvianolic Acid B Suppresses Inflammatory Mediator Levels by Downregulating NF-κB in a Rat Model of Rheumatoid Arthritis

Background

Salvianolic acid B (SB) is a major active phyto-component of the plant Radix Salvia miltiorrhiza, which is traditionally used to treat joint pain and arthritis. The present study examined the anti-rheumatoid arthritis efficacy of SB on collagen-induced rheumatoid arthritis (CIA) in a rat model.

Material/Methods

Forty-eight rats were divided into 4 groups: Control rats treated with saline (Group I), rats subjected to CIA induction by intradermal injection of bovine collagen II type at the tail (Group II), and rats subjected to CIA and supplemented with either 20 or 40 mg/kg of SB for 28 days (group III or IV).

Results

Paw swelling, edema, arthritis score, thymus and spleen indexes, and neutrophil infiltration were significantly decreased (p<0.01) by treatment with 20 or 40 mg/kg of SB. The levels of inflammatory cytokines (interleukin-1β, -6, and -17, and TNF-α) and anti-collagen II-specific immunoglobulins (IgG₁ and IgG_2a) were markedly decreased (p<0.01), and those of antioxidant enzymes (SOD, CAT, and GSH) were significantly increased (p<0.01) in SB-treated rats. Administration with SB (20 or 40 mg/kg) resulted in lower phosphorylated IκB-α and NF-κB p65 protein levels and markedly downregulated IκB-α expression. Furthermore, CIA rats revealed the presence of highly diffused polymorphonuclear cells (PMNs) infiltration with eroded cartilage; however, these phenomena were considerably ameliorated by SB.

Conclusions

SB alleviates oxidative stress and inflammation in CIA rats, thus verifying its anti-rheumatoid arthritis property.

IL-22-producing CD4+T cells in the treatment response of rheumatoid arthritis to combination therapy with methotrexate and leflunomide

T cells are key players in immune-mediated rheumatoid arthritis (RA). We previously reported that interleukin (IL)-22+CD4+T helper (IL-22+ Th) cells and IL-22 critically control the pathogenesis of RA. Here we monitored circulating levels of different IL-22+ Th cell subsets and measured plasma levels of IL-22, IL-17, and interferon (IFN)-γ in 60 patients with active RA following 12-week combination methotrexate (MTX) and leflunomide (LEF) therapy (MTX+LEF) and 20 healthy individuals. We found the frequencies of circulating IFN-γ-IL-17-IL-22+ (Th22), IFN-γ-IL-17+ (total Th17), IFN-γ+IL-17-IL-22+ (IL-22+Th1) cells, and IFN-γ-IL-17+IL-22+ (IL-22+Th17) cells, as well as the plasma levels of IL-22, IL-17 and IFN-γ to be significantly reduced in RA patients that responded to treatment, but not in non-responders. Reductions in plasma IL-22 level significantly correlated with percentage of circulating Th22 cells and the decrease of plasma IL-22 level correlated with the reduction of DAS28 in responders. Our data suggests that circulating Th22 cells and plasma IL-22 level play a detrimental role in RA. The combination MTX+LEF therapy, by targeting Th22 cells and reducing IL-22 level, relieves the immune defects and ameliorates symptoms of RA. This study provides novel mechanistic understanding of the pathogenesis of RA, which may promote a design of better therapies for RA.

Possibilities for preventive treatment in rheumatoid arthritis? Lessons from experimental animal models of arthritis: a systematic literature review and meta-analysis

OBJECTIVE

Current research in rheumatoid arthritis focuses on preclinical disease phases as it is hypothesised that early preclinical treatment might prevent progression to full-blown disease. Since performance of studies in prearthritis phases in humans is challenging, animal models offer an opportunity to evaluate preventive treatments. We performed a systematic literature review and summarised treatment effects during different stages of arthritis development in animal models.

METHODS

Eight medical literature databases were systematically searched. Studies were selected if they reported effects of synthetic or biological disease-modifying antirheumatic drugs in animal models of arthritis (collagen-induced arthritis and adjuvant-induced arthritis) on arthritis severity, as measured with arthritis severity scores, paw swelling or paw volume. Quality was assessed using an 11-item checklist. Study characteristics were extracted and effect sizes obtained in high-quality studies were summarised in meta-analyses. Studies were categorised into three groups: prophylactic (prior to generation of autoantibody response), prearthritis (after induction of autoantibody response) and therapeutic intervention (after arthritis development).

RESULTS

Out of 1415 screened articles, 22 studies (including n=712 animals) were eligible of good quality and included in meta-analyses. Prophylactic (16 experiments, n=312 animals) and prearthritis treatment (9 experiments, n=156 animals) both were associated with a reduction of arthritis severity (p<0.001 and p=0.005, respectively). Stratified analyses for different antirheumatic drugs initiated in the prearthritis phase suggested higher efficacy of methotrexate than of anti-tumour necrosis factor.

CONCLUSIONS

Data of experimental studies in animal models of arthritis suggest that prophylactic and prearthritis treatment strategies are effective and hint at differences in efficacy between antirheumatic drugs.

Interleukin-6 enhances acid-induced apoptosis via upregulating acid-sensing ion channel 1a expression and function in rat articular chondrocytes

The inflammatory cytokine interleukin-6 (IL-6) is a causative agent of rheumatoid arthritis (RA), a chronic inflammatory disease complicated with degenerative arthritic cartilage. However, the precise mechanism of IL-6 on chondrocyte apoptosis is largely unclear. Acid-sensing ion channels (ASICs), a family of extracellular H(+)-activated cation channels, can be transiently activated by extracellular acid and play a pivotal role in acid-induced cell injury. In the present study, to investigate the role of IL-6 in regulating acid-induced articular chondrocyte apoptosis, primary rat articular chondrocytes were subjected to different treatments with or without IL-6 in the presence of acid. The results showed that the mRNA and protein expressions of ASIC1a were significantly increased in articular cartilage and chondrocytes of adjuvant arthritis (AA) rats. IL-6 could dramatically upregulate the level of ASIC1a in a time- and dose-dependent manner, and induce the activation of JAK2, STAT3, ERK, JNK and NF-κB in articular chondrocytes. Moreover, both the respective inhibitors of these signaling pathways and the specific antibody against IL-6 receptor (tocilizumab) could partially abrogate the ASIC1a upregulation induced by IL-6. Furthermore, IL-6 inhibited the cell viability and enhanced LDH release, [Ca(2+)]i elevation, and apoptosis in acid-induced articular chondrocytes, and these changes could be reversed by using psalmotoxin 1(PcTX1), which is the specific antagonist of ASIC1a. In addition, pretreatment with PcTX1 could inhibit the downregulated expression of Bcl-2 and the upregulated expression of Bax induced by IL-6 in acid-induced articular chondrocytes. Taken together, these results indicated that IL-6 could enhance acid-induced articular chondrocyte apoptosis, the mechanism of which might partially be involved with its ability of regulating the activation of ASIC1a-dependent JAK2/STAT3 and MAPK/NF-κB signaling pathways.

Therapeutic potential of interleukin-17 in inflammation and autoimmune diseases

INTRODUCTION

Interleukin-17 (IL-17) is a proinflammatory cytokine that mainly produced by T helper 17 (Th17) cells. In this article, we discussed the role of IL-17 in inflammation and autoimmune diseases, and the therapeutic strategies targeting IL-17.

AREAS COVERED

In this article, we discussed the proinflammatory cytokine IL-17 and IL-17 receptors signals, and their regulation. IL-17 expression was abnormal in the bacterium, virus and fungus infection, and its higher level caused the tissue inflammation. IL-17 was involved in the pathological process of autoimmune diseases, such as systemic sclerosis, rheumatoid arthritis, ankylosing spondylitis and systemic lupus erythematosus, and IL-17 has been put as a therapeutic target in the clinic.

EXPERT OPINION

IL-17/IL-17R signals and their application in inflammation process still need to be explored. Therapeutic strategies targeting IL-17 in autoimmune diseases ameliorated the inadequate response to anti-TNF-α therapy.