Advances in research on animal models of rheumatoid arthritis

Gum acacia dietary fiber: Significance in immunomodulation, inflammatory diseases, and cancer

Gum arabic/acacia (GA), derived from Acacia trees, is a versatile natural product offering a broad spectrum of applications. Its rich content of soluble dietary fibers, coupled with a low caloric profile, renders GA a valuable dietary component associated with numerous health benefits. Furthermore, its fermentation by gut microbiota yields short-chain fatty acids, renowned for their positive impact on health. Immunomodulation, a crucially regulated mechanism in the body, serves to fend off pathogenic infections by releasing pro-inflammatory cytokines. However, prolonged synthesis of these cytokines can lead to chronic inflammation, tissue damage, and potentially contribute to the development of autoimmune diseases and cancer. Hence, there is an urgent need to identify plant-based biomolecules that can effectively reduce inflammation and inhibit inflammation-induced complications or disorders. In this context, edible biomolecules like GA are gaining prominence for their noteworthy immunomodulatory properties. Therefore, in the present review we have explored the role of GA in immunomodulation, inflammation, and inflammation-associated metabolic diseases, and cancer.

Decreased muscle strength in adjuvant-induced rheumatoid arthritis animal model: A relationship to behavioural assessments

Rheumatoid arthritis (RA) is an autoimmune disorder with unknown aetiology. Patients suffering from RA face persistent pain due to joint inflammation, and tissue destruction. Behavioural phenotyping is an approach to target the role of different behavioural traits associated with disease progression. The study aimed to assess behavioural patterns associated with decreased muscle strength in the adjuvant-induced rheumatoid arthritis animal model. The study was conducted on male Albino Wister rats (n = 30) [Control, Vehicle, and Disease groups]. After taking ethical approvals RA was induced by complete Freund's adjuvant (CFA) intradermally base of tail. The weight of animals, macroscopic analysis of inflammatory signs, and arthritic scores were measured weekly. Grip strength, ganglia-based movement, cataleptic activity, and motor-coordination-related behaviours were assessed among the groups. Radiographs and spleen index assay were performed followed by data analysis using one-way and two-way ANOVA (Analysis of Variance). A significant decrease in weight and an increase in arthritic scores among the diseased group was observed. Behavioural analyses confirmed that diseased animals had significantly decreased grip strength and increased cataleptic activity with less motor coordination. Radiographic images and spleen index assay confirmed the pattern of RA. Therefore, it can be suggested that the development of the disease animal model is an effective approach to identifying the disease progression and associated behavioural changes. Moreover, this prepared laboratory animal model may be utilised for pathway analyses to understand the key role of immune regulators and genetic insight into molecular pathways associated with acute and chronic phases of RA.

Morphofunctional analysis of fibroblast-like synoviocytes in human rheumatoid arthritis and mouse collagen-induced arthritis

BACKGROUND

Fibroblast-like synoviocytes (FLS) play a prominent role in rheumatoid synovitis and degradation of the extracellular matrix through the production of inflammatory cytokines and metalloproteinases (MMPs). Since animal models are frequently used for elucidating the disease mechanism and therapeutic development, it is relevant to study the ultrastructural characteristics and functional responses in human and mouse FLS. The objective of the study was to analyze ultrastructural characteristics, Interleukin-6 (IL-6) and Metalloproteinase-3 (MMP-3) production and the activation of intracellular pathways in Fibroblast like synoviocytes (FLS) cultures obtained from patients with rheumatoid arthritis (RA) and from mice with collagen-induced arthritis (CIA).

METHODS

FLSs were obtained from RA patients (RA-FLSs) (n = 8) and mice with CIA (CIA-FLSs) (n = 4). Morphology was assessed by transmission and scanning electron microscopy. IL-6 and MMP-3 production was measured by ELISA, and activation of intracellular signaling pathways (NF-κB and MAPK: p-ERK1/2, p-P38 and p-JNK) was measured by Western blotting in cultures of RA-FLSs and CIA-FLSs stimulated with tumor necrosis factor-alpha (TNF-α) and IL-1β.

RESULTS

RA-FLS and CIA-FLS cultures exhibited rich cytoplasm, rough endoplasmic reticula and prominent and well-developed Golgi complexes. Transmission electron microscopy demonstrated the presence of lamellar bodies, which are cytoplasmic structures related to surfactant production, in FLSs from both sources. Increased levels of pinocytosis and numbers of pinocytotic vesicles were observed in RA-FLSs (p < 0.05). Basal production of MMP-3 and IL-6 was present in RA-FLSs and CIA-FLSs. Regarding the production of MMP-3 and IL-6 and the activation of signaling pathways, the present study demonstrated a lower response to IL-1β by CIA-FLSs than by RA-FLSs.

CONCLUSION

This study provides a comprehensive understanding of the biology of RA-FLS and CIA-FLS. The differences and similarities in ultrastructural morphology and important inflammatory cytokines shown, contribute to future in vitro studies using RA-FLS and CIA-FLS, in addition, they indicate that the adoption of CIA-FLS for studies should take careful and be well designed, since they do not completely resemble human diseases.

Biosynthesis of Silver Nanoparticles Using Commiphora mukul Extract: Evaluation of Anti-Arthritic Activity in Adjuvant-Induced Arthritis Rat Model

Rheumatoid arthritis (RA) is a major global public health challenge, and novel therapies are required to combat it. Silver nanoparticles (AgNPs) have been employed as delivery vehicles of anti-inflammatory drugs for RA therapy, and it has been recently realized that AgNPs have anti-inflammatory action on their own. However, their conventional synthesis processes might result in cytotoxicity and environmental hazards. Instead, the use of natural products as a reducing and stabilizing agent in the biosynthesis of silver nanoparticles has arisen as an option to decrease the cytotoxic and environmental concerns associated with chemical synthesis of AgNPs. In this study, we challenged the efficacy of Commiphora mukul (guggul) aqueous extract as a reducing and/or capping agent for the biosynthesis of AgNPs. Guggul-mediated biosynthesized silver nanoparticles (G-AgNPs) were characterized via UV-vis spectroscopy, dynamic light scattering, and scanning electron microscopy. In addition, their anti-arthritic potential was evaluated in an adjuvant-induced arthritis (AIA) model. The fabricated NPs showed an absorption peak at 412 nm, corresponding to the typical surface plasmon resonance band of AgNPs. The synthesized G-AgNPs were nearly spherical, with a particle size of 337.6 ± 12.1 nm and a negative surface charge (−18.9 ± 1.8 mV). In AIA rat model, synthesized G-AgNPs exerted a potent anti-inflammatory action, as manifested by a remarkable reduction in paw volume (>40%) along with elicitation of a minimal arthritic score, compared to control rats. In addition, when compared to arthritic rats, treatment with G-AgNPs efficiently restored the activity of antioxidant enzyme, superoxide dismutase, and catalase, indicating the efficiency of synthesized G-AgNPs in alleviating the oxidative stress associated with RA. Finally, histological examination revealed comparatively lower inflammatory cells infiltration in ankle joint tissue upon treatment with G-AgNPs. Collectively, biosynthesized G-AgNPs might represent a plausible therapeutic option for the management of RA.

Curcumin-based nanotechnology approaches and therapeutics in restoration of autoimmune diseases

Autoimmune diseases usually arise as a result of an aberrant immune system attack on normal tissues of the body, which leads to a cascade of inflammatory reactions. The immune system employs different types of protective and anti-inflammatory cells for the regulation of this process. Curcumin is a known natural anti-inflammatory agent that inhibits pathological autoimmune processes by regulating inflammatory cytokines and their associated signaling pathways in immune cells. Due to the unstable nature of curcumin and its susceptibility to either degradation, or metabolism into other chemical entities (i.e., metabolites), encapsulation of this agent into various nanocarriers would appear to be an appropriate strategy for attaining greater beneficial effects from curcumin as it pertains to immunomodulation. Many studies have focused on the design and development of curcumin nanodelivery systems (micelles, dendrimers, and diverse nanocarriers) and are summarized in this review in order to obtain greater insight into novel drug delivery systems for curcumin and their suitability for the management of autoimmune diseases.

Metabolic Characteristics and Pharmacokinetic Differences of QiweiTongbi Oral Liquid in Rheumatoid Arthritis Rats

Qiwei Tongbi oral liquid (QWTB), a classical traditional Chinese medicine (TCM) formula, is widely used to treat arthritis-related diseases in clinical practice. Currently, in vivo metabolic characteristics and pharmacokinetic studies are lacking. This study analyzed the prototype components of QWTB absorbed into the blood and their metabolic transformation process after intragastric administration and compared the differences in pharmacokinetic properties between healthy and rheumatoid arthritis model rats. In total, 17 prototype components and 21 related metabolites were identified in the plasma and urine of the treated rats. Metabolites were derived from sinomenine and magnolinine. Through systematic methodology verification, an accurate and stable detection method for sinomenine and magnolinine in plasma samples was established and applied to pharmacokinetic research of QWTB. At the three dose levels, the AUC_0-∞ of the two components showed a good positive correlation with the dose (R² > 0.9). Compared with healthy rats, the T_max , t_1/2z , and AUC of sinomenine were markedly increased, and C_max was decreased in rheumatoid arthritis model rats, indicating that the rate of absorption and elimination slowed, but the body exposure increased. However, there were no significant differences in the PK parameters of magnoline under healthy and pathological conditions. In summary, the main active ingredients of QWTB are sinomenine and magnolinine, which exhibit linear kinetic characteristics within a set dose range, and the rheumatoid arthritis pathological state is more conducive to the absorption and efficacy of sinomenine. The results of this study demonstrate the rationality of the clinical application of the QWTB.

Methotrexate-loaded nanoparticles ameliorate experimental model of autoimmune arthritis by regulating the balance of interleukin-17-producing T cells and regulatory T cells

Background

Rheumatoid arthritis (RA) is a progressive systemic autoimmune disease that is characterized by infiltration of inflammatory cells into the hyperplastic synovial tissue, resulting in subsequent destruction of adjacent articular cartilage and bone. Methotrexate (MTX), the first conventional disease-modifying antirheumatic drug (DMARD), could alleviate articular damage in RA and is implicated in humoral and cellular immune responses. However, MTX has several side effects, so efficient delivery of low-dose MTX is important.

Methods

To investigate the efficacy of MTX-loaded nanoparticles (MTX-NPs) against experimental model of RA, free MTX or MTX-NPs were administered as subcutaneous route to mice with collagen-induced arthritis (CIA) at 3 weeks after CII immunization. The levels of inflammatory factors in tissues were determined by immunohistochemistry, confocal microscopy, real-time PCR, and flow cytometry.

Results

MTX-NPs ameliorated arthritic severity and joint destruction in collagen-induced arthritis (CIA) mice compared to free MTX-treated CIA mice. The levels of inflammatory cytokines, including interleukin (IL)-1β, tumor necrosis factor-α, and vascular endothelial growth factor, were reduced in MTX-NPs-treated mice. Number of CD4 + IL-17 + cells decreased whereas the number of CD4 + CD25 + Foxp3 + cells increased in spleens from MTX- NPs-treated CIA mice compared to MTX-treated CIA mice. The frequency of CD19 + CD25 + Foxp3 + regulatory B cells increased in ex vivo splenocytes from MTX-loaded NPs-treated CIA mice compared to MTX-treated CIA mice.

Conclusion

The results suggest that MTX-loaded NPs have therapeutic potential for RA.

Berberine and its derivatives represent as the promising therapeutic agents for inflammatory disorders

Berberine, with the skeleton of quaternary ammonium, has been considered as the well-defined natural product in treating multiple diseases, including inflammation, acute and chronic infection, autoimmune diseases, and diabetes. However, due to the low bioavailability and systemic exposure, broad clinical applications of berberine have been largely impeded. Numerous studies have been conducted to further explore the therapeutic capacities of berberine in preclinical and clinical trials. Over the past, berberine and its derivatives have been shown to possess numerous pharmacological activities, as evidenced in intestinal, pulmonary, skin, and bone inflammatory disorders. In the present review, the pharmacological impact of berberine on inflammatory diseases are fully discussed, with indication that berberine and its potential derivatives represent promising natural therapeutic agents with anti-inflammatory properties.

The Effects of Crocin on Bone and Cartilage Diseases

Crocin, the main biologically active carotenoid of saffron, generally is derived from the dried trifid stigma of Crocus sativus L. Many studies have demonstrated that crocin has several therapeutic effects on biological systems through its anti-oxidant and anti-inflammatory properties. The wide range of crocin activities is believed to be because of its ability to anchor to many proteins, triggering some cellular pathways responsible for cell proliferation and differentiation. It also has therapeutic potentials in arthritis, osteoarthritis, rheumatoid arthritis, and articular pain probably due to its anti-inflammatory properties. Anti-apoptotic effects, as well as osteoclast inhibition effects of crocin, have suggested it as a natural substance to treat osteoporosis and degenerative disease of bone and cartilage. Different mechanisms underlying crocin effects on bone and cartilage repair have been investigated, but remain to be fully elucidated. The present review aims to undertake current knowledge on the effects of crocin on bone and cartilage degenerative diseases with an emphasis on its proliferative and differentiative properties in mesenchymal stem cells.

Restrained expression of canine glucocorticoid receptor splice variants α and P prognosticates fatal disease outcome in SIRS

Glucocorticoids play a central role in the inflammatory response and alleviate the symptoms in critically ill patients. The glucocorticoid action relies on the glucocorticoid receptor (GR) which translocates into the nucleus upon ligand-binding and regulates transcription of a battery of genes. Although the GR is encoded by a single gene, dozens of its splice variants have been described in diverse species. The GRα isoform encodes the full, functionally active protein that is composed of a transactivation, a DNA-binding, and a C-terminal ligand-binding domain. The second most highly expressed receptor variant, the GR-P, is formed by an intron retention that introduces an early stop codon and results in a probably dysfunctional protein with truncated ligand-binding domain. We described the canine ortholog of GR-P and showed that this splice variant is highly abundant in the peripheral blood of dogs. The level of cGRα and cGR-P transcripts are elevated in patients of SIRS and the survival rate is increased with elevated cGRα and cGR-P expression. The ratio of cGRα and cGR-P mRNA did not differ between the survivor and non-survivor patients; thus, the total GR expression is more pertinent than the relative expression of GR isoforms in assessment of the disease outcome.

Acid-Sensing Ion Channel-1a in Articular Chondrocytes and Synovial Fibroblasts: A Novel Therapeutic Target for Rheumatoid Arthritis

Acid-sensing ion channel 1a (ASIC1a) is a member of the extracellular H⁺-activated cation channel family. Emerging evidence has suggested that ASIC1a plays a crucial role in the pathogenesis of rheumatoid arthritis (RA). Specifically, ASIC1a could promote inflammation, synovial hyperplasia, articular cartilage, and bone destruction; these lead to the progression of RA, a chronic autoimmune disease characterized by chronic synovial inflammation and extra-articular lesions. In this review, we provided a brief overview of the molecular properties of ASIC1a, including the basic biological characteristics, tissue and cell distribution, channel blocker, and factors influencing the expression and function, and focused on the potential therapeutic targets of ASIC1a in RA and possible mechanisms of blocking ASIC1a to improve RA symptoms, such as regulation of apoptosis, autophagy, pyroptosis, and necroptosis of articular cartilage, and synovial inflammation and invasion of fibroblast-like cells in synovial tissue.

Indomethacin loaded dextran stearate polymeric micelles improve adjuvant-induced arthritis in rats: design and in vivo evaluation

BACKGROUND

Indomethacin is a non-steroidal anti-inflammatory drug (NSAID) that can effectively control the pain and inflammation caused by rheumatoid arthritis (RA), but its usage is limited due to severe adverse effects. For this reason, making more specific formulations of this drug can be considered. The aim of the present study was designing a novel nano-sized indomethacin delivery system.

MATERIALS AND METHODS

Indomethacin-loaded dextran stearate polymeric micelles were prepared by dialysis method. Particle size and zeta potential of micelles were measured by a zeta sizer instrument. Drug release from micelles was investigated in phosphate buffer medium pH 7.4 and then the best formulation regarding physical properties and drug release was selected for animal studies. Arthritis was induced by complete Freund's adjuvant injection in rats. Then, the animals were randomly assigned into the model, the indomethacin solution and the polymeric micelles groups. The clinical effects of polymeric micelle formulation were assessed by measuring arthritis index, animal paw edema and measuring biochemical parameters including myeloperoxidase (MPO) activity, lipid peroxidation (LPO), glutathione (GSH), total antioxidant capacity (TAC), TNF-α, IL-17 and IL-1β.

RESULTS

Paw edema was attenuated following the administration of indomethacin-loaded polymeric micelles. Based on the findings of the present study, the use of indomethacin-loaded polymeric micelles could improve inflammatory symptoms, decrease arthritis index and decrease the diameter of the paw in arthritic rats in a significant manner (p ≤ 0.05). In addition, the use of polymeric micelles like indomethacin solution significantly reduced (p ≤ 0.05) the activity of MPO, LPO, TNF-α, IL-17 and IL-1β, and made a significant increase (p ≤ 0.05) in glutathione and TAC content and ameliorated structural changes in the paw tissue compared to the control group.

CONCLUSION

Our findings demonstrated that indomethacin-loaded dextran stearate polymeric micelles can provide more effective therapeutic effects in control of inflammation in arthritis in rat.

Effects of intra-articular pulsed radiofrequency current administration on a rabbit model of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by synovial proliferation and inflammation. Intra-articular corticosteroid injections are commonly used for the treatment of arthritis affecting one or two joints. Although corticosteroid injections are fast-acting, repeated usage can result in severe adverse events. Recently, intra-articular pulsed radiofrequency (PRF) stimulation has been proposed to treat arthritis. The aim of the present study was to compare the effectiveness of intra-articular PRF with corticosteroid injection based on histopathological and motion analysis of an ovalbumin (OVA)-induced RA rabbit model. RA was induced in the right knee joint of 18 rabbits via OVA injection. The rabbits were randomly allocated into a PRF, an intra-articular corticosteroid injection or a sham PRF stimulation group. Movement was assessed in the rabbits before treatment, then at 2, 4 and 8 weeks after treatment using walking distance, fast walking time and mean walking speed. Histopathological evaluation of the distal femur and synovium was conducted 2, 4 and 8 weeks after treatment. Motion analysis demonstrated that changes in all movement variables showed significant group and time interaction as well as group effect among the three groups. The semiquantitative score based on the histopathological findings for the distal femoral condyle decreased 2 and 4 weeks after both the PRF and steroid groups, compared with the sham PRF group. Moreover, in the synovium, the semiquantitative histological score in the PRF and steroid groups tended to be lower compared with the sham PRF group, although this result was not statistically significant. Thus, intra-articular PRF stimulation may delay cartilage destruction and improve functional motion in RA.

IL-27 and autoimmune rheumatologic diseases: The good, the bad, and the ugly

The footprint of cytokines is evident in almost every biological process, such as development, as well as the pathogenesis of the different diseases, immune responses to pathogens, etc. These small proteins are categorized into different functional classes; for instance, they can play a pro-inflammatory or anti-inflammatory role in different situations, or they can confer a polarization to the immune system. Interleukin (IL)-27 is a member of the IL-12 family. Antigen-presenting cells are the primary source of IL-27 production, which exerts its effects by bindings to the IL-27 receptor expressed on the surface of target cells. Interaction of IL-27 and IL-27 receptor leads to activation of the JAK-STAT and p38 MAPK signaling pathways. Most studies focused on the inflammatory effects of this cytokine, but gradually anti-inflammatory effects were also revealed for this cytokine, which changed the traditional perception of the function of this cytokine. The functionality of IL-27 in the pathogenesis of rheumatic diseases has been attributed to a double-blade sword. Hence, novel therapeutic approaches have been devised targeting IL-12 family that has been accompanied with promising results. In this review, we focused on the inflammatory and anti-inflammatory properties of IL-27 in different autoimmune rheumatologic diseases and its plausible therapeutic potentials.

Gold-Coated Superparamagnetic Iron Oxide Nanoparticles Attenuate Collagen-Induced Arthritis after Magnetic Targeting

The aim of the study was to evaluate if gold-coated superparamagnetic iron oxide nanoparticles (AuSPION) magnetic-targeted to the arthritic articulation of collagen induced arthritis (CIA) rats are able to ameliorate rheumatoid arthritis without producing significant biological adverse effects in comparison to colloidal Au nanoparticles (AuC) and metotrexate (MTX). Male Wistar rats were divided into control; arthritic; AuSPION (150 μg kg^-1); AuC (150 μg kg^-1) and MTX (2.5 μg kg^-1). Treatments were administered thrice every other day by the intraperitoneal route 15 min after all groups had a neodymium magnet coupled to the right ankle joint (kept for 1 h). Paw edema and body weight were measured weekly. Joint sections were evaluated by Haematoxylin & Eosin and immunohistochemistry (TNF-α, IL-1β). Biomarkers of oxidative stress were used to evaluate toxicity. Among the evaluated treatments, AuSPION led to significant clinical improvements (decreased edema and infiltration by leukocytes as well as less positively immunostained cells for both TNF-α and IL-1β in synovium) accompanied by a lack of toxicity as indicated by redox state and genotoxicity assays. Our results clearly indicate that the magnetic targeting of AuSPION suppresses joint edema and inflammation, cytokine expression as well as the redox imbalance, thereby contributing to an amelioration of arthritis severity in CIA rats. The results demonstrate for the first time the potentiality of AuSPION administration under a magnetic field as an attractive alternative for future treatments of rheumatic diseases.

Theacrine alleviates chronic inflammation by enhancing TGF-β-mediated shifts via TGF-β/SMAD pathway in Freund's incomplete adjuvant-induced rats

Rheumatoid arthritis is a chronic and systemic autoimmune disease, which affects approximately 1% of the adult population worldwide. The present study investigated the therapeutic effect of theacrine (TC) on arthritis and its mechanisms in Freund's incomplete adjuvant (FIA)-induced SD rats. Rats were randomly divided into 5 groups: i) healthy control; ii) model; iii) positive control with methotrexate (MTX); iv) treatment with 12.5 mg/kg TC; and v) treatment with 25.0 mg/kg TC. The apparent scores, including changes in body weights, degree of paw swelling and arthritis indicators, were analyzed to evaluate the anti-chronic inflammatory effect of TC. The levels of interleukin (IL)-6 and transforming growth factor-β (TGF-β) in serum were measured by enzyme-linked immunosorbent assay. The protein and RNA expression levels of the critical factors in rats were measured to elucidate the mechanisms responsible for chronic inflammation and to verify molecular indexes of chronic inflammatory conditions. TC notably suppressed the severity of FIA-induced rat by attenuating the apparent scores, animal weight and inflammatory indexes in the 25 mg/kg TC group compared with the FIA rat model. Furthermore, TC significantly decreased the levels of IL-6 and increased the levels of TGF-β. Histopathological examinations indicated that TC rescued the synovial hyperplasia and inflammatory cell infiltration in joint tissues. In addition, TC enhanced TGF-β-mediated shifts in inflammatory marker expression in joint tissue. Overall, the present study demonstrated that TC exerted a superior anti-arthritic effect via the suppression of IL-6 and the activation of TGF-β by the TGF-β/SMAD pathway.

An integrative transcriptome analysis framework for drug efficacy and similarity reveals drug-specific signatures of anti-TNF treatment in a mouse model of inflammatory polyarthritis

Anti-TNF agents have been in the first line of treatment of various inflammatory diseases such as Rheumatoid Arthritis and Crohn’s Disease, with a number of different biologics being currently in use. A detailed analysis of their effect at transcriptome level has nevertheless been lacking. We herein present a concise analysis of an extended transcriptomics profiling of four different anti-TNF biologics upon treatment of the established hTNFTg (Tg197) mouse model of spontaneous inflammatory polyarthritis. We implement a series of computational analyses that include clustering of differentially expressed genes, functional analysis and random forest classification. Taking advantage of our detailed sample structure, we devise metrics of treatment efficiency that take into account changes in gene expression compared to both the healthy and the diseased state. Our results suggest considerable variability in the capacity of different biologics to modulate gene expression that can be attributed to treatment-specific functional pathways and differential preferences to restore over- or under-expressed genes. Early intervention appears to manage inflammation in a more efficient way but is accompanied by increased effects on a number of genes that are seemingly unrelated to the disease. Administration at an early stage is also lacking in capacity to restore healthy expression levels of under-expressed genes. We record quantifiable differences among anti-TNF biologics in their efficiency to modulate over-expressed genes related to immune and inflammatory pathways. More importantly, we find a subset of the tested substances to have quantitative advantages in addressing deregulation of under-expressed genes involved in pathways related to known RA comorbidities. Our study shows the potential of transcriptomic analyses to identify comprehensive and distinct treatment-specific gene signatures combining disease-related and unrelated genes and proposes a generalized framework for the assessment of drug efficacy, the search of biosimilars and the evaluation of the efficacy of TNF small molecule inhibitors.

A number of anti-TNF drugs are being used in the treatment of inflammatory autoimmune diseases, such as Rheumatoid Arthritis and Crohn’s Disease. Despite their wide use there has been, to date, no detailed analysis of their effect on the affected tissues at a transcriptome level. In this work we applied four different anti-TNF drugs on an established mouse model of inflammatory polyarthritis and collected a large number of independent biological replicates from the synovial tissue of healthy, diseased and treated animals. We then applied a series of bioinformatics analyses in order to define the sets of genes, biological pathways and functions that are affected in the diseased animals and modulated by each of the different treatments. Our dataset allowed us to focus on previously overlooked aspects of gene regulation. We found that the majority of differentially expressed genes in disease are under-expressed and that they are also associated with functions related to Rheumatoid Arthritis comorbidities such as cardiovascular disease. We were also able to define gene and pathway subsets that are not changed in the disease but are, nonetheless, altered under various treatments and to use these subsets in drug classification and assessment. Through the application of machine learning approaches we created quantitative efficiency profiles for the tested drugs, which showed some to be more efficiently addressing changes in the inflammatory pathways, while others being quantitatively superior in restoring gene expression changes associated to disease comorbidities. We thus, propose a concise computational pipeline that may be used in the assessment of drug efficacy and biosimilarity and which may form the basis of evaluation protocols for small molecule TNF inhibitors.

Mimicking the Articular Joint with In Vitro Models

Treating joint diseases remains a significant clinical challenge. Conventional in vitro cultures and animal models have been helpful, but suffer from limited predictive power for the human response. Advanced models are therefore required to mimic the complex biological interactions within the human joint. However, the intricate structure of the joint microenvironment and the complex nature of joint diseases have challenged the development of in vitro models that can faithfully mimic the in vivo physiological and pathological environments. In this review, we discuss the current in vitro models of the joint and the progress achieved in the development of novel and potentially more predictive models, and highlight the application of new technologies to accurately emulate the articular joint.

Anti-oxidant and anti-inflammatory effects of cinnamaldehyde and eugenol on mononuclear cells of rheumatoid arthritis patients

Rheumatoid arthritis (RA) is an autoimmune disorder affecting joints and frequently characterized by initial local and later systemic inflammation. The present study was conducted with the aim to determine the anti-inflammatory and antioxidant effects of cinnamaldehyde and eugenol in the peripheral blood mononuclear cells (PBMC) of RA patients. PBMCs obtained from RA patients were treated with varying concentrations of cinnamaldehyde and eugenol. The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were monitored in the 24-h culture supernatant of PBMCs. Reactive oxygen species formation, biomolecular oxidation and the activities of antioxidant enzymes were also determined. FTIR analysis was done to determine structural alterations in the PBMCs. Molecular docking was performed to gain an insight into the binding mechanism of eugenol and cinnamaldehyde with pro-inflammatory cytokines. The levels of pro-inflammatory cytokines and markers of oxidative stress were found to be elevated in the PBMC culture of RA patients as compared to the healthy controls. Cinnamaldehyde and eugenol have significantly reduced the levels of cytokines. Reactive oxygen species formation, biomolecular oxidation and antioxidant defense response were also ameliorated by treating PBMCs with both the compounds. FTIR results further confirms cinnamaldehyde and eugenol mediated protection to biomolecules of PBMCs of RA patients. Molecular docking results indicates interaction of cinnamaldehyde and eugenol with key residues of TNF-α and IL-6. Cinnamaldehyde and eugenol were found to exert potent anti-inflammatory and anti-oxidant effects on the PBMC culture of RA patients. So, these compounds may be used as an adjunct in the management of RA.

Comparative anti-arthritic investigation of iridoid glycosides and crocetin derivatives from Gardenia jasminoides Ellis in Freund's complete adjuvant-induced arthritis in rats

BACKGROUND

Discovering novel compounds with higher activities is a key aim of natural products research. Gardenia jasminoides Ellis is a herb with anti-inflammatory properties. Iridoid glycosides (mainly geniposide) and crocetin derivatives (crocins) are the two major active constituents in this herb and are considered its active ingredients. However, which components are responsible for the anti-inflammatory properties of gardenia have remained to be investigated.

PURPOSE

Here, we prepared total iridoid glycocides (TIG) and total crocins (TC) from G. jasminoides Ellis, determined their main chemical constituents, and performed animal studies to evaluate their anti-adjuvant arthritis activities, thus, proposing a reasonable mechenism to explain the anti-inflammatory activities of the active components in this herbal remedy.

STUDY DESIGN

TIG and TC were prepared by using HPD-100 macroporous resin, and characterized by UHPLC-DAD-MS and UV-Vis spectrophotometer. Then, freund's complete adjuvant-injected rats underwent drug treatments with TIG (160 mg/kg) and TC (160 mg/kg) for 14 days, and their ankle diameters were measured. Moreover, X-ray radiographs of the adjuvant injected hind paws were evaluated. Finally, histopathological examinations of the ankle joints, spleens and thymus were carried out to evaluate inflammatory reactions, and immunohistochemical measurements were conducted to evaluate TNF-α and TGF-β1 expression in the ankle joint of the rats.

RESULTS

The chemical composition determination of the current study showed that TIG was mainly composed of geniposide and TC was a fraction predominantly with crocin-1, crocin-2 and crocin-3. Calculation of results showed that TIG and TC contained 58.2% total iridoid glycosides and 54.7% total crocins, respectively. Our study suggested TIG and TC treatments markedly decreased paw swelling and ankle diameters of AA rats (both p < 0.05). The radiological analysis showed that administration of TIG and TC ameliorated bone destruction, and reduced the radiological bone destruction scores (TIG p < 0.05, TC p>0.05). Moreover, data from histological assessment demonstrated considerable mitigation of inflammation in the joints (both p < 0.01), spleen and thymus of AA rats treated with TIG and TC. TNF-α and TGF-β1 protein expression according to immunohistochemistry staining also supported the anti-arthritis activities of TIG and TC (TNF-α: TIG p < 0.01 and TC p < 0.05, TGF-β1: TIG p < 0.01 and TC p>0.05).

CONCLUSION

In the current study, fractionation of gardenia prior to further in vivo investigation has for the first time provided reasonable explanation for the anti-inflammatory activity of this herbal remedy. Our study showed that both TIG and TC from gardenia have anti-inflammatory properties. Overall, these experimental findings suggest that gardenia could be regarded as a potential therapeutic target for arthritis. However, as geniposide has a higher content than crocins in this herbal drug, TIG (mainly geniposide) seems to be primarily responsible for the anti-inflammatory properties of gardenia. Taken together, this maiden attempt demonstrated that TIG (mainly geniposide) is more important in evaluating the anti-inflammatory activity of G. jasminoides Ellis.

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.

Delivery of IL-35 by Lactococcus lactis Ameliorates Collagen-Induced Arthritis in Mice

IL-35, a relatively newly discovered cytokine belonging to the larger IL-12 family, shows unique anti-inflammatory properties, believed to be associated with dedicated receptors and signaling pathways. IL-35 plays a pivotal role in the development and the function of both regulatory B (Bregs) and T cells (Tregs). In order to further its therapeutic potential, a dairy Lactococcus lactis strain was engineered to express murine IL-35 (LL-IL35), and this recombinant strain was applied to suppress collagen-induced arthritis (CIA). Oral administration of LL-IL35 effectively reduced the incidence and disease severity of CIA. When administered therapeutically, LL-IL35 abruptly halted CIA progression with no increase in disease severity by reducing neutrophil influx into the joints. LL-IL35 treatment reduced IFN-γ and IL-17 3.7- and 8.5-fold, respectively, and increased IL-10 production compared to diseased mice. Foxp3+ and Foxp3- CD39+ CD4+ T cells were previously shown to be the Tregs responsible for conferring protection against CIA. Inquiry into their induction revealed that both CCR6+ and CCR6- Foxp3+or- CD39+ CD4+ T cells act as the source of the IL-10 induced by LL-IL35. Thus, this study demonstrates the feasibility and benefits of engineered probiotics for treating autoimmune diseases.

Mechanisms for Joint Pain in Rheumatoid Arthritis (RA): from Cytokines to Central Sensitization

PURPOSE OF REVIEW

Pain in rheumatoid arthritis (RA) may be due to different etiologies, ranging from peripheral inflammation to dysregulation of central nervous system (CNS) processing. This review evaluates relevant literature published on RA pain mechanisms in recent years.

RECENT FINDINGS

Despite successes of disease-modifying antirheumatic drugs (DMARDs), pain persists for many RA patients. Studies involving patient-reported outcomes, quantitative sensory testing, and neuroimaging indicate that, in addition to joint inflammation, abnormalities in CNS pain processing may contribute to pain. Some DMARDs (e.g., janus kinus inhibitors) may work via multiple pathways to decrease pain. Adjunctive treatments (e.g., antidepressants, antiepileptics) may also be useful in managing pain in RA patients with well-controlled disease. Both peripheral and central mechanisms play key roles in the expression of pain in RA. To effectively manage pain, physicians need accurate assessment tools to identify the pathways involved in each patient so that treatments may be appropriately targeted.

Dihydromyricetin relieves rheumatoid arthritis symptoms and suppresses expression of pro-inflammatory cytokines via the activation of Nrf2 pathway in rheumatoid arthritis model

Rheumatoid arthritis (RA) is a systemic inflammatory and autoimmune disease. In this research, we estimated the protective effects of Dihydromyricetin (DMY) on RA induced by Complete Freund's Adjuvant (CFA). We found that DMY effectively relieved rheumatoid arthritis symptoms, such as body weight change, paw swelling and rheumatoid arthritis scores. In addition, we also observed that DMY significantly lowered the immune organ indexes (including thymus and spleen) and exhibited the anti-inflammatory effect in CFA-induced rheumatoid arthritis. The results demonstrated that the increased expression levels of interleukin-1β (IL-1β), interleukin-6(IL-6), tumor necrosis factor-α (TNF-α) were significantly inhibited by DMY. Furthermore, the key inflammatory mediator, cyclooxygenase-2 (COX-2) was markedly lowered after treatment with DMY. A mechanistic study indicated that DMY could up-regulate the down-regulation levels of the mRNA and protein of Nrf2, HO-1 and NQO1. Moreover, the Nrf2 activation of DMY was abolished by Nrf2 inhibitor brusatol. Thus, DMY inhibits the expressions of pro-inflammatory cytokines via activating Nrf2 pathway in RA model, which suggests that DMY has potential for further investigation as a candidate anti-arthritic agent in future.

Antiarthritic Activity of Qi-Wu Rheumatism Granule (a Chinese Herbal Compound) on Complete Freund's Adjuvant-Induced Arthritis in Rats

Objective

The aim was to study the therapeutic effects and mechanisms of QWRG on adjuvant-induced RA in rats.

Methods

The RA rat models were manipulated and subsequently divided into five experimental groups: AIA, DEX, and QWRG groups. The paw volume, body weight, arthritic score, and mechanical nociceptive threshold were assessed. The serum levels of the RF, MDA, ALP, AST, ALT, IL-1β, IL-2, IL-16, and TNF-α were measured. The proliferative capacity of lymphocytes was evaluated, and the synovial tissue was histopathologically examined.

Results

The paw swelling and arthritic scores were relieved, and the variation of relative body weight and mechanical nociceptive threshold had improved in the AIA rats. The serum levels of RF, MDA, ALP, AST, and ALT were alleviated, and the inflammation and cartilage damage were effectively attenuated in the AIA rats. Simultaneously, the inflammation of the synovial cavity was alleviated, and the grading of synovitis reduced by inhibiting the expressions of IL-1β, TNF-α, and IL-16 in the serum and synovium tissue.

Conclusion

Our results suggested that the antiarthritic properties of QWRG may be due to immunodepression and downregulation of inflammatory cytokines, which may be a potential candidate for the treatment of RA.

Evaluation of destruction in a collagen-induced arthritis rat model: Bony spur formation

Over the past 40 years, the collagen-induced arthritis (CIA) animal model has been widely used as a model of rheumatoid arthritis (RA). However, no model is able to completely depict the characteristics of cartilage destruction to date. In the later stage of joint cartilage destruction, bony spurs form in RA. This bony spur formation is an important symptom in the pathological development of RA. In the present study, CIA was used to elucidate the pathological process of bony spur formation. Joint damage and spur formation in the animal model was detected by radiology and histology. Radiology identified bony spurs in the knee and foot joints, which worsened as the disease progressed. Furthermore, following observations of histological sections, fusion and damage of the articular cartilage, as well as a higher number of osteoclasts, were identified. Previous results have determined that bony spurs may be involved in another pathological process that occurs during the later stages of RA. Therefore, further studies investigating this symptom are required to improve the understanding of RA and facilitate the development of an appropriate treatment for RA.

Regulator of Calcineurin 3 Ameliorates Autoimmune Arthritis by Suppressing Th17 Cell Differentiation

Regulator of calcineurin 3 (RCAN3), an endogenous regulator of the calcineurin-nuclear factor of activated T cells (NFAT) signaling pathway, inhibits the phosphatase activity of calcineurin, the nuclear translocation of NFAT, and the NFAT downstream pathway. To investigate the effects of RCAN3 on T-cell regulatory function and the development and progression of inflammatory arthritis, we studied the effects of RCAN3 transfection on regulation of Th17 cell differentiation in a murine T-lymphoma cell line and primary splenic CD4⁺ T cells. Overexpression of RCAN3 suppressed Th17 cell differentiation through the down-regulation of RAR receptor orphan receptor γT mRNA and up-regulation of forkhead box P3 mRNA. In mice with collagen-induced arthritis, injection of an RCAN3-overexpression vector controlled arthritis development in vivo. Injection of RCAN3 reduced the formation of osteoclasts and expression of inflammatory cytokines in vivo. Antioxidants stimulated the expression of RCAN3 in vitro, and combination therapy with pcDNA-RCAN3 had a synergistic suppressive effect on the development of arthritis. These data suggest that RCAN3 may be an effective treatment for rheumatoid arthritis.

Anti-arthritic effect of berberine on adjuvant-induced rheumatoid arthritis in rats

BACKGROUND

Rheumatoid arthritis (RA) is a chronic and systemic autoimmune disease, which affects approximately 1% adult population in the worldwide.

AIM

The present study was to investigate the anti-arthritic effect of berberine and its involved mechanism in Freund's complete adjuvant (FCA) induced arthritis rats.

METHODS AND MATERIALS

Rats were divided randomly into control, FCA, tripterysium glycosides, berberine (75 and 150mg/kg). The apparent indicators, including changes of body weights, paw swelling degrees and arthritis indexes, were analyzed to evaluate anti-arthritic effect of berberine. The levels of IL-6, IL-10, IL-17 and TGF-β in serum were measured by ELISA. Histopathological changes and immunohistochemical expression of anti-IL-10 and anti-IL-17 antibodies in ankle joint tissues were examined.

RESULTS

Berberine obviously suppressed the severity of RA rats by attenuating the apparent indicators as mentioned above. Meanwhile, berberine significantly decreased the levels of IL-6 and IL-17, and increased the levels of IL-10 and TGF-β. Histopathological examinations indicated that berberine attenuated the synovial hyperplasia and inflammatory cell infiltration in joint tissues. In addition, immunohistochemical results showed that the amount of anti-IL-10 antibody increased, while the amount of anti-IL-17 antibody decreased in ankle tissues of arthritis rats.

CONCLUSIONS

Our results showed that berberine exerted a superior anti-arthritic effect and the mechanism maybe involve the balance between Treg and Th17 cells.

Disease modifying anti-rheumatic activity of the alkaloid montanine on experimental arthritis and fibroblast-like synoviocytes

Montanine is an alkaloid isolated from Rhodophiala bifida bulb with potential anti-arthritic activity. In this context, we evaluated whether montanine has a disease modifying anti-rheumatic activity in two arthritis models and its effect in vitro on lymphocyte proliferation and on invasiveness of fibroblast-like synoviocytes (FLS). Antigen-induced arthritis (AIA) was performed in Balb/C mice with methylated bovine serum albumin, and nociception and leukocytes migration into the knee joint were evaluated. Collagen-induced arthritis (CIA) was performed in DBA/1J mice, and arthritis development and severity were assessed by clinical and histological scoring and articular nociception. Montanine was administered intraperitoneally twice a day. Lymphocyte proliferation stimulated by concanavalin A in 48h was performed with MTT assay, while FLS invasion in 24h was assayed in a Matrigel-coated transwell system. Administration of montanine decreased nociception (P<0.001) and leukocyte articular migration (P<0.001) in mice with AIA. In mice with CIA, treatment with montanine reduced severity of arthritis and joint damage assessed by clinical (P<0.001) and histological (P<0.05) scores and ameliorated articular nociception (P<0.05). In vitro, montanine inhibited lymphocyte proliferation stimulated with ConA (P<0.001) and decreased FLS invasion (P<0.05) by 54%, with an action independent of cytotoxicity. Our findings suggest that montanine can be further explored as an innovative pharmacological approach for autoimmune diseases such as arthritis.

Effects of Koumine on Adjuvant- and Collagen-Induced Arthritis in Rats

To examine the effect of koumine, a Gelsemium alkaloid, on two experimental models of rheumatoid arthritis (RA), rats with adjuvant-induced arthritis (AIA) and collagen-induced arthritis (CIA) were administered koumine (0.6, 3, or 15 mg/kg/day) or vehicle through gastric gavage (i.g.). Clinical evaluation was performed via measurements of hind paw volume, arthritis index (AI) score, mechanical withdrawal threshold, organ weight, and by radiographic and histological examinations. Levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and antitype II collagen (CII) antibody were also examined. In rats with AIA, koumine reduced the AI score and mechanical allodynia of the injected hind paw in a dose-dependent manner and significantly inhibited increase in thymus and liver weights. In rats with CIA, koumine inhibited increase in hind paw volume, AI score, and mechanical allodynia in a dose-dependent manner and reduced joint space narrowing. Furthermore, koumine also attenuated the increase in the expression of IL-1β and TNF-α, as well as the robust increase of serum anti-CII antibodies in response to immunization. These results suggested that koumine effectively attenuated arthritis progression in two rat models of RA and that this therapeutic effect may be associated with its immunoregulatory action.

Generation of Functional Cardiomyocytes from the Synoviocytes of Patients with Rheumatoid Arthritis via Induced Pluripotent Stem Cells

Cardiovascular disease is a leading cause of morbidity in rheumatoid arthritis (RA) patients. This study aimed to generate and characterise cardiomyocytes from induced pluripotent stem cells (iPSCs) of RA patients. Fibroblast-like synoviocytes (FLSs) from patients with RA and osteoarthritis (OA) were successfully reprogrammed into RA-iPSCs and OA-iPSCs, respectively. The pluripotency of iPSCs was confirmed by quantitative reverse transcription-polymerase chain reaction and immunofluorescence staining. Established iPSCs were differentiated into cardiomyocytes using a small molecule-based monolayer differentiation protocol. Within 12 days of cardiac differentiation from patient-specific and control-iPSCs, spontaneously beating cardiomyocytes (iPSC-CMs) were observed. All iPSC-CMs exhibited a reliable sarcomeric structure stained with antibodies against cardiac markers and similar expression profiles of cardiac-specific genes. Intracellular calcium signalling was recorded to compare calcium-handling properties among cardiomyocytes differentiated from the three groups of iPSCs. RA-iPSC-CMs had a lower amplitude and a shorter duration of calcium transients than the control groups. Peak tangential stress and the maximum contractile rate were also decreased in RA-iPSC-CMs, suggesting that contractility was reduced. This study demonstrates the successful generation of functional cardiomyocytes from pathogenic synovial cells in RA patients through iPSC reprogramming. Research using RA-iPSC-CMs might provide an opportunity to investigate the pathophysiology of cardiac involvement in RA.

Enhanced immunoregulation of mesenchymal stem cells by IL-10-producing type 1 regulatory T cells in collagen-induced arthritis

Mesenchymal stem cells (MSCs) possess immunomodulatory properties and have potential, however, there have been conflicting reports regarding their effects in rheumatoid arthritis (RA), which causes inflammation and destruction of the joints. Through a comparative analysis of regulatory T (Treg) and IL-10-producing type 1 regulatory T (Tr1) cells, we hypothesized that Tr1 cells enhance the immunoregulatory functions of MSCs, and that a combinatorial approach to cell therapy may exert synergistic immunomodulatory effects in an experimental animal model of rheumatoid arthritis (RA). A combination of MSCs and Tr1 cells prevented the development of destructive arthritis compared to single cell therapy. These therapeutic effects were associated with an increase in type II collagen (CII)-specific CD4+CD25+Foxp3+ Treg cells and inhibition of CII-specific CD4+IL-17+ T cells. We observed that Tr1 cells produce high levels of IL-10-dependent interferon (IFN)-β, which induces toll-like receptor (TLR) 3 expression in MSCs. Moreover, induction of indoleamine 2,3-dioxygenase (IDO) by TLR3 involved an autocrine IFN-β that was dependent on STAT1 signaling. Furthermore, we observed that production of IFN-β and IL-10 in Tr1 cells synergistically induces IDO in MSCs through the STAT1 pathway. These findings suggest co-administration of MSCs and Tr1 cells to be a novel therapeutic modality for clinical autoimmune diseases.

Pain in rheumatoid arthritis: models and mechanisms

Pain is one of the most challenging symptoms for patients with rheumatoid arthritis (RA). RA-related pain is frequently considered to be solely a consequence of inflammation in the joints; however, recent studies show that multiple mechanisms are involved. Indeed, RA pain may start even before the disease manifests, and frequently does not correlate with the degree of inflammation or pharmacological management. In this aspect, animal studies have the potential to provide new insights into the pathology that initiate and maintain pain in RA. The focus of this review is to describe the most commonly used animal models for studies of RA pathology, which have also been utilized in pain research, and to summarize findings providing potential clues to the mechanisms involved in the regulation of RA-induced pain.

Inhibition of GSK-3β Alleviates Collagen II-Induced Rheumatoid Arthritis in Rats

Background

Glycogen synthase kinase-3β (GSK-3β) inhibitor is a serine/threonine kinase with an inhibitory role in glycogen synthesis, which is essential in inflammatory and immunological diseases. The purpose of our study was to determine if TDZD-8 can alleviate collagen II-induced rheumatoid arthritis in rats.

Material/Methods

Twenty collagen II-induced rheumatoid arthritis rats were treated with selective GSK-3β inhibitor. The effects of GSK-3β inhibition on collagen II-induced rheumatoid arthritis in the rats were evaluated by paw edema, histological examination of arthritic synovium, radiographic examination of knee joint, and the level of inflammation mediators such as prostaglandin E2, 5-hydroxytryptamin, and histamine. The level of cytokines such as IL-6, IL-12, IL-10, and TNF-α, was examined by Elisa.

Results

GSK-3β inhibitor significantly reduced the development of rheumatoid arthritis in rats. The levels of inflammation mediators such as prostaglandin E2, 5-hydroxytryptamin, and histamine were decreased in the TDZD-8 group. Serum levels of IL-6, IL-12, and TNF-α were significantly reduced in the TDZD-8 group compared with the RA group.

Conclusions

Treatment with GSK-3β inhibitor suppressed inflammatory response in RA rats. These findings suggest that the inhibition of GSK-3β can be an effective treatment for RA.

JAK1-STAT3 blockade by JAK inhibitor SHR0302 attenuates inflammatory responses of adjuvant-induced arthritis rats and decreases Th17 and total B cells

OBJECTIVE

To investigate the effects of JAK inhibitor (SHR0302) on adjuvant-induced arthritis (AA) rats and the partial mechanisms focused on T, B lymphocyte subsets through JAK1-STAT3 pathway, including Th17, Treg, total B cells and memory B cells.

METHODS

Animals were divided randomly into normal control, AA, SHR0302 (0.3,1.0, 3.0mg/kg) and MTX. The effects of SHR0302 on AA rats by evaluating arthritis index, arthritis global assessment and paw swelling degree, histopathology of joint and spleen. We examined the proliferation of T, B and FLS. Th17, Treg, total B and memory B cell proportion was measured by flow cytometry. Cytokines TNF-α, IL-1β, IL-10, IL-17 and antibody IgG1, IgG2a levels in serum were measured by Elisa. The expression of p-JAK1 and p-STAT3 was measured by western blot.

RESULTS

SHR0302 suppressed the severity of AA rats by attenuating the arthritis index, arthritis global assessment and paw swelling degree, and alleviated histopathology of spleen and joint of AA rats. SHR0302 can inhibit the proliferation of T, B and FLS, and down-regulated cytokines TNF-α, IL-1β, IL-17 and antibody IgG1, IgG2a levels, and suppressed the proportion of Th17 and total B, and inhibited JAK1-STAT3 phosphorylation. There was no significant effect on Treg function and memory B cell proportion.

CONCLUSION

SHR0302 may attenuate the severity of AA rats, partially through reducing Th17 function and total B cell proportion by inhibiting JAK1-STAT3 phosphorylation.

The treatment of rheumatoid arthritis using Chinese medicinal plants: From pharmacology to potential molecular mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Rheumatoid arthritis (RA) is a common worldwide public health problem. Traditional Chinese Medicine (TCM) achieved some results to some extent in the treatment of rheumatoid arthritis (RA). Especially in China, TCM formulas are used in the clinic because of their advantages. Some of these TCM formulas have been used for thousands of years in ancient China, they pays much attention to strengthening healthy qi, cleaning heat, and wet, activating blood, etc. So TCM in anti-RA drug is considered as a simple and effective method. In addition, TCM are also traditionally used as extracts and many Chinese herbs which are considered to be effective for RA. With the advancement of technologies and research methods, researchers have devoted themselves to exploring new therapeutic materials from troves of TCM. The components of TCM are identified and purified, which include alkaloids, coumarins, flavonoids, saponins and so on. However, little or no review works are found in the research literature on the anti-RA drugs from TCM. The present review aims to provide systematically reorganized information on the ethnopharmacology, phytochemistry and pharmacology of TCM used traditionally against RA. The information recorded in this review will provide new directions for researchers in the future.

MATERIALS AND METHODS

Relevant scientific literatures were collected from Chinese traditional books and Chinese Pharmacopoeia. Several important pharmacology data, clinical observations, animal experiments on effects of anti-RA drugs from TCM and their mechanisms were extracted from a library and electric search (Pubmed, PubChem Compound, Science Direct, Spring Link, Elsevier, Web of Science, CNKI, Wan Fang, Bai du, The Plant List, etc.). We collected information published between 2002 and 2015 on Chinese medicine in the treatment of RA. Information was also acquired from local classic herbal literature, conference papers, government reports, and PhD and MSc dissertations.

RESULTS

This review mainly introduces the current research on anti-RA TCM formulas, extracts and compounds from TCM, pharmacological data and potential mechanisms (inhibit osteoclast proliferation, suppress fibroblast-like synoviocytes (FLSs) growth, decrease the expression of inflammatory cytokines, blocking signal pathways, etc.).

CONCLUSIONS

TCM, as a multi-component and multi-target approach, which is a perfect match with the holistic concept of systems biology, is applicable in the treatment of RA. The synergistic connections of Chinese herbs and mechanisms of related active compounds on RA increase the trust for TCM. TCM as alternative remedies for RA not only has an important position in the world market, but also has an irreplaceable role in the treatment of RA in future.

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.

Therapeutic Effect of Saponin Rich Fraction of Achyranthes aspera Linn. on Adjuvant-Induced Arthritis in Sprague-Dawley Rats

Objective. Achyranthes aspera Linn. (AA) is used in folklore for the treatment of various inflammatory ailments and arthritis like conditions. Anti-inflammatory activity of saponin rich (SR) fraction of AA has been previously reported. The objective of this study was to assess the antiarthritic effect of SR fraction of Achyranthes aspera in adjuvant-induced arthritic rats. Methods. Arthritis was assessed by arthritis score, paw volume, changes in tibiotarsal joint thickness, hyperalgesic parameters, and spleen and thymus index. Haematological, serum, biochemical, and inflammatory cytokine and in vivo antioxidant parameters were measured on the last day of the study. Results. SR fraction significantly suppressed paw swelling and arthritic score and improved the pain threshold in motility and stair climbing tests. There was a reversal in the levels of altered parameters, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and antioxidant parameters like superoxide dismutase, catalase, glutathione, malondialdehyde, and nitric oxide. SR fraction significantly decreased plasma levels of tumor necrosis factor-alpha and interleukin-6. Moreover, histopathology revealed a significant reduction in synovial hyperplasia, inflammatory cell infiltration, and bone destruction in the joints. Conclusion. These observations explain the therapeutic benefit of SR fraction of AA in suppressing the progression of adjuvant-induced arthritis in rats.

99mTc-NTP 15-5 Imaging for Cartilage Involvement in Experimental Rheumatoid Arthritis: Comparison with Routinely Used Molecular Imaging Methods and Sensitivity to Chronic Nonsteroidal Antiinflammatory Drug Treatment

This study determined, using the intraarticular complete Freund adjuvant arthritis mice model, whether the radiotracer (99m)Tc-N-(triethylammonium)-3-propyl-[15]ane-N5 ((99m)Tc-NTP 15-5) targeting proteoglycans has a pathophysiologic validity for in vivo imaging of rheumatoid arthritis (RA) and its response to chronic nonsteroidal antiinflammatory drugs.

METHODS

We investigated the time course of cartilage remodeling by (99m)Tc-NTP 15-5 scintigraphy, bone damages by (99m)Tc-hydroxymethylene diphosphonate imaging, inflammation by (18)F-FDG PET, and joint proteoglycan content and pain behavior in animals, without and with meloxicam treatment. Paw circumference, thermal pain behavior, and histology as well as proteoglycan content of the whole joint were determined.

RESULTS

(99m)Tc-NTP 15-5 showed specific tracer accumulation within RA joints, with a significant increase in scintigraphic ratio observed in RA versus shams from day 3 to day 28. (18)F-FDG evidenced uptake in RA joints from day 15 to day 29. Animals treated with meloxicam (5 mg/kg) exhibited a dose-dependent decrease in both (99m)Tc-NTP 15-5 and (18)F-FDG uptake ratios versus saline-treated animals. (99m)Tc-hydroxymethylene diphosphonate bone scans were only positive at day 14 in RA versus shams, with a significant effect of meloxicam. An increase in proteoglycans of RA joint and thermal pain behavior were observed and were dose-dependently reduced by meloxicam.

CONCLUSION

These experimental results bring data in favor of the (99m)Tc-NTP 15-5 radiotracer for assessing, in vivo, cartilage remodeling in RA that could be used to monitor therapy.

Rheumatoid arthritis vaccine therapies: perspectives and lessons from therapeutic ligand epitope antigen presentation system vaccines for models of rheumatoid arthritis

The current status of therapeutic vaccines for autoimmune diseases is reviewed with rheumatoid arthritis as the focus. Therapeutic vaccines for autoimmune diseases must regulate or subdue responses to common self-antigens. Ideally, such a vaccine would initiate an antigen-specific modulation of the T-cell immune response that drives the inflammatory disease. Appropriate animal models and types of T helper cells and signature cytokine responses that drive autoimmune disease are also discussed. Interpretation of these animal models must be done cautiously because the means of initiation, autoantigens, and even the signature cytokine and T helper cell (Th1 or Th17) responses that are involved in the disease may differ significantly from those in humans. We describe ligand epitope antigen presentation system vaccine modulation of T-cell autoimmune responses as a strategy for the design of therapeutic vaccines for rheumatoid arthritis, which may also be effective in other autoimmune conditions.

Milk-based nutraceutical for treating autoimmune arthritis via the stimulation of IL-10- and TGF-β-producing CD39+ regulatory T cells

Autoimmune diseases arise from the loss of tolerance to self, and because the etiologies of such diseases are largely unknown, symptomatic treatments rely on anti-inflammatory and analgesic agents. Tolerogenic treatments that can reverse disease are preferred, but again, often thwarted by not knowing the responsible auto-antigens (auto-Ags). Hence, a viable alternative to stimulating regulatory T cells (Tregs) is to induce bystander tolerance. Colonization factor antigen I (CFA/I) has been shown to evoke bystander immunity and to hasten Ag-specific Treg development independent of auto-Ag. To translate in treating human autoimmune diseases, the food-based Lactococcus was engineered to express CFA/I fimbriae, and Lactococcus-CFA/I fermented milk fed to arthritic mice proved highly efficacious. Protection occurred via CD39⁺ Tregs producing TGF-β and IL-10 to potently suppress TNF-α production and neutrophil influx into the joints. Thus, these data demonstrate the feasibility of oral nutraceuticals for treating arthritis, and potency of protection against arthritis was improved relative to that obtained with Salmonella-CFA/I.

Anti-inflammation effect of methyl salicylate 2-O-β-D-lactoside on adjuvant induced-arthritis rats and lipopolysaccharide (LPS)-treated murine macrophages RAW264.7 cells

Methyl salicylate 2-O-β-D-lactoside (MSL) is a derivative of natural salicylate isolated from Gaultheria yunnanensis (Franch.) Rehder, which is widely used for treating rheumatoid arthritis (RA), swelling and pain. The aim of the present study was to investigate the effect of MSL on the progression of adjuvant-induced arthritis (AIA) in rat in vivo and explore the anti-inflammatory effects and mechanism of MSL in lipopolysaccharide (LPS)-treated murine macrophages RAW264.7 cells in vitro. Our results showed that MSL significantly inhibited the arthritis progression in AIA rats, decreasing the right hind paw swelling and ankle diameter, attenuating histopathological changes and suppressing the plasma levels of TNF-α and IL-1β in AIA rats. Besides, MSL had potent anti-inflammatory effects on the LPS-activated RAW264.7. MSL dose-dependently inhibited the activity of COX-1, and COX-2. Moreover, MSL prominently inhibited LPS-induced activation of MAPK in RAW264.7 cells by blocking phosphorylation of p38 and ERK. Our study suggests that MSL may be effective in the treatment of inflammatory diseases by inhibiting the pro-inflammatory cytokine production and regulating the MAPK signal pathway.

Immunomodulation in human and experimental arthritis: including vitamin D, helminths and heat-shock proteins

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that is mainly directed to the joints, affecting the synovial membrane, the cartilage and also the bone. This disease affects 1% to 2% of the world population and is associated with significant morbidity and increased mortality. RA experimental models have allowed a great deal of information to be translated to the corresponding human disease. This review summarizes some of the most relevant findings targeting immunomodulation in arthritis. Some general guidelines to choose an adequate experimental model and also our experience with arthritis are supplied.

The interrelationship between leukotriene B4 and leukotriene-A4-hydrolase in collagen/adjuvant-induced arthritis in rats

This study aimed to check the involvement of lipid mediator leukotriene (LT) B4 and the activity of LTA4 hydrolase (LTA4H) in the development of arthritis induced in rats by collagen and adjuvant (CIA). High-performance liquid chromatography (HPLC) and enzyme immunoassay (EIA) were used for measurements of LTB4 and LTA4H in plasma, synovial fluid (SF), soluble (SO), and solubilized membrane-bound fraction (MB) from synovial tissue (ST) and peripheral blood mononuclear cells (PBMCs) of CIA-arthritic and CIA-resistant. EIA process is simple, clean, and rapid and offered advantages over HPLC, showing that in SF and MB-PBMCs of CIA-arthritic and CIA-resistant, and in MB-ST of CIA-resistant, LTB4 and LTA4H were altered in parallel and were positively related. In the plasma and SO-ST and SO-PBMCs of CIA-arthritic and CIA-resistant, and in MB-ST of CIA-arthritic, this pattern was not found. The primordial role played by LTA4H in the biosynthesis of LTB4 was confirmed together with the existence of alternative steps that regulate LTB4 without participation of LTA4H. The involvement of compartmentalized and coupled changes of LTB4 and LTA4H in the resistance and development of arthritis in CIA model was demonstrated for the first time.

Oral Escherichia coli colonization factor antigen I fimbriae ameliorate arthritis via IL-35, not IL-27

A Salmonella therapeutic expressing enterotoxigenic Escherichia coli colonization factor Ag I (CFA/I) fimbriae protects against collagen-induced arthritis (CIA) by eliciting two regulatory T cell (Treg) subsets: TGF-β-producing Foxp3(-)CD39(+)CD4(+) T cells and IL-10-producing Foxp3(+)CD39(+)CD4(+) T cells. However, it is unclear whether CFA/I fimbriae alone are protective and whether other regulatory cytokines are involved, especially in the context for the EBI3-sharing cytokines, Treg-derived IL-35 and APC-derived IL-27, both capable of suppressing Th17 cells and regulating autoimmune diseases. Subsequent evaluation revealed that a single oral dose of purified, soluble CFA/I fimbriae protected against CIA as effectively as did Salmonella-CFA/I and found that Foxp3(+)CD39(+)CD4(+) T cells were the source of secreted IL-35, whereas IL-27 production by CD11c(+) cells was inhibited. Inquiring into their relevance, CFA/I fimbriae-treated IL-27R-deficient (WSX-1(-/-)) mice were equally protected against CIA as were wild-type mice, suggesting a limited role for IL-27. In contrast, CFA/I fimbriae-mediated protection was abated in EBI3(-/-) mice, accompanied by the loss of TGF-β- and IL-10-producing Tregs. Adoptive transfer of C57BL/6 CD39(+)CD4(+) T cells to EBI3(-/-) mice with concurrent CFA/I plus IL-35 treatment effectively stimulated Tregs suppressing proinflammatory collagen II-specific Th cells. In contrast, recipients cotransferred with C57BL/6 and EBI3(-/-) CD39(+)CD4(+) T cells and treated with CFA/I plus IL-35 were not protected, implicating the importance of endogenous IL-35 for conferring CFA/I-mediated protection. Thus, CFA/I fimbriae stimulate IL-35 required for the coinduction of TGF-β and IL-10.