CII)-induced Arthritis Research Articles

NAT10 promotes synovial aggression by increasing the stability and translation of N4-acetylated PTX3 mRNA in rheumatoid arthritis

ObjectiveRecent studies indicate that N-acetyltransferase 10 (NAT10)-mediated ac4C modification plays unique roles in tumour metastasis and immune infiltration. This study aimed to uncover the role of NAT10-mediated ac4C in fibroblast-like...

Optimal development of apoptotic cells-mimicking liposomes targeting macrophages

Macrophages are multifunctional innate immune cells that play indispensable roles in homeostasis, tissue repair, and immune regulation. However, dysregulated activation of macrophages is implicated in the pathogenesis of various human disorders, making them a potential target for treatment. Through the expression of pattern recognition and scavenger receptors, macrophages exhibit selective uptake of pathogens and apoptotic cells. Consequently, the utilization of drug carriers that mimic pathogenic or apoptotic signals shows potential for targeted delivery to macrophages. In this study, a series of mannosylated or/and phosphatidylserine (PS) -presenting liposomes were developed to target macrophages via the design of experiment (DoE) strategy and the trial-and-error (TaE) approach. The optimal molar ratio for the liposome formulation was DOPC: DSPS: Chol: PEG-PE = 20:60:20:2 based on the results of cellular uptake and cytotoxicity evaluation on RAW 264.7 and THP-1 in vitro. Results from in vivo distribution showed that, in the DSS-induced colitis model and collagen II-induced rheumatoid arthritis model, PS-presenting liposomes (PS-Lipo) showed the highest accumulation in intestine and paws respectively, which holds promising potential for macrophage target therapy since macrophages are abundant at inflammatory sites and contribute to the progression of corresponding diseases. Organs such as the heart, liver, spleen, lung, and kidney did not exhibit histological alterations such as inflammation or necrosis when exposed to PC-presenting liposomes (PC-Lipo) or PS-Lipo. In addition, liposomes demonstrated hemobiocompatibility and no toxicity to liver or kidney for circulation and did not induce metabolic injury in the animals. Thus, the well-designed PS-Lipo demonstrated the most potential for macrophage target therapy.

Fengshi Liuhe Decoction treatment for rheumatoid arthritis via the Fzd6/NF-κB signaling axis

To explore whether Fengshi Liuhe Decoction (FLD) alleviates rheumatoid arthritis (RA) via the Fzd6/NF-κB signaling axis. We used real-time quantitative PCR (qPCR) and western blotting (WB) to determine the genes of the frizzled (Fzd) protein 1- Fzd protein 10 that are significantly differentially expressed between normal rat fibroblast-like synoviocyte (FLS) and collagen II-induced arthritis (CIA) rat FLS. Next, we used enzyme-linked immunosorbent assay (ELISA) to evaluate the levels of inflammatory factors in cell culture supernatant to determine the ability of FLD to ameliorate RA. Finally, we employed WB to detect the key gene expression in protein levels of the Fzd6/NF-κB signaling axis among normal rat FLS, CIA rat FLS, and FLD-treated CIA rat FLS. Our results showed that Fzd6 expression was significantly higher in CIA rat FLS at both the mRNA and protein levels than in normal rat FLS. FLD was found to downregulate Fzd6 and inflammatory factors, including COX-2, IL-8, and TNF-α, at both the mRNA and protein levels. FLD was also found to downregulate the total protein levels of Fzd6 and the NF-κB signaling pathway key gene phosphorylation of p-p65/p65 and p-IκBα/IκBα. Moreover, FLD inhibited the nuclear translocation of NF-κB p65 in CIA rat FLS. FLD can alleviate inflammation of CIA rat FLS via the Fzd6/NF-κB signaling axis.

Ammodaucus Leucotrichus Seed Extract as a Potential Therapy in Animal Models of Rheumatoid Arthritis Induced by Complete Freund Adjuvant and Chicken Cartilage Collagen.

This study assessed the efficacy of an Ammodaucus leucotrichus seed extract to treat rheumatoid arthritis in rat models of this disease. Rheumatoid arthritis was induced in rats using two methods: immunization with 100 µL of Complete Freund Adjuvant (CFA) and immunization with 100 µL of a 3mg/ml solution of type II collagen (CII) from chicken cartilage. The therapeutic potential of the extract was assessed at different doses (150, 300, and 600mg/kg/day for 21 days in the CII-induced arthritis model and for 14 days in the CFA-induced arthritis model) and compared with methotrexate (MTX; 0.2mg/kg for the same periods), a commonly used drug for rheumatoid arthritis treatment in humans. In both models (CII-induced arthritis and CFA-induced arthritis), walking distance, step length, intra-step distance and footprint area were improved following treatment with the A. leucotrichus seed extract (all concentrations) and MTX compared with untreated animals. Both treatments increased the serum concentration of glutathione and reduced that of complement C3, malondialdehyde and myeloperoxidase. Radiographic data and histological analysis indicated that cartilage destruction was reduced already with the lowest dose of the extract (100mg/kg/dose) in both models. These results show the substantial antiarthritic potential of the A. leucotrichus seed extract, even at the lowest dose, suggesting that it may be a promising alternative therapy for rheumatoid arthritis and joint inflammation. They also emphasize its efficacy at various doses, providing impetus for more research on this extract as a potential therapeutic agent for arthritis.

A study of the molecular mechanism of action of Jiawei Guizhishaoyaozhimu Decoction during rheumatoid arthritis therapy based on basic of network pharmacology and experimental verification.

Rheumatoid arthritis (RA) is a chronic autoimmune disease, which primarily affects the joints. The aim of the present study was to predict the main active ingredients of Jiawei Guizhishaoyaozhimu Decoction (JWGZSYZMD) and potential targets of this treatment during RA therapy by using molecular docking and network pharmacology methods. In addition, another aim was to investigate the therapeutic effects and mechanism of JWGZSYZMD on joint inflammation in rat models of collagen Ⅱ-induced arthritis (CIA). JWGZSYZMD ingredients and targets and genes associated with RA first extracted from traditional Chinese medicine (TCM) Systems Pharmacology Database and Analysis Platform, Bioinformatics Analysis Tool of Molecular Mechanism-TCM and Genecards databases, which were then transferred to the STRING database to set up protein interaction networks. The crystal structures of target proteins were also downloaded from the Protein Data Bank before molecular docking of compounds onto the protein targets was performed using AutoDock Vina software. In addition, a drug compound target visualization network was constructed using Cytoscape 3.7.2 software, which was used to elucidate the main mechanism underlying the anti-RA effect of JWGZSYZMD. A CIA rat model was established and animals were divided into the control, CIA model, JWGZSYZMD treatment (low-, medium- and high-dose) and tripterygium glycoside groups. Compared with the rats in the CIA model group, the joint scores of the rats in the high-dose group of JWGZSYZMD were significantly lower after 21 days of treatment. The expression levels of IL-6, TNF-α, IL-1β and IL-17A in the synovial supernatant of the model rats were lower compared with those in the CIA group. Also, the expression of the aforementioned cytokines in the high-dose JWGZSYZMD group was significantly lower compared with those in the CIA model group. To conclude, using molecular docking combined with network pharmacology, the material basis and molecular mechanism underlying the effects of JWGZSYZMD during RA therapy were studied, which could potentially provide a reference for future clinical applications.

Lack of Syndecan-1 promotes the pathogenesis of experimental rheumatoid arthritis.

Syndecan-1 (Sdc-1), a transmembrane heparan sulfate protein, is implicated in several pathophysiological processes including rheumatoid arthritis (RA). The exact role of Syndican-1 in this autoimmune disease is still undetermined. This study explores the involvement level of Sdc-1 in the development of RA in a collagen II-induced arthritis mice model. RA was induced in two mice strains (wild-type BALB/c group and Sdc-1 knockout) by collagen II. Mice underwent regular clinical observations and scoring. After sacrifice, leg biopsies were taken from mice for histological examination, using a variety of stains. In addition, proteins were extracted, and molecular assessment of TNF-α was performed using the western blot technique. In the Sdc-1 knockout group, clinical scoring results showed a significantly more severe experimental RA; histology showed a significant increase in bone erosion, cartilage destruction, inflammation, and less granulated mast cells than the wild-type. In addition, molecular assessment of TNF-α showed more increase in expression in the Sdc-1 knockout models compared to the wild-type. Data suggest that lack of Sdc-1 enhances the inflammatory characteristics in RA. However, more molecular studies and investigations are needed to determine its exact role and possible mechanisms involved.

Administration of Recombinant TAPBPL Protein Ameliorates Collagen-Induced Arthritis in Mice.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease distinguished by synovial hyperplasia and a progressive destruction of joints. T cells are critical players in the pathogenesis of RA. We have previously identified a novel immune checkpoint molecule, TAPBPL, that inhibits T cell functions in vitro. As a model for human RA, we investigated the ability of the TAPBPL protein to ameliorate collagen type II (CII)-induced arthritis (CIA) in mice that were injected with recombinant TAPBPL or a control protein. The mice were analyzed for CIA development, immune cells, and their responses. We found that TAPBPL protein significantly decreased CIA incidence and reduced clinical and pathological arthritis scores, which were related to a lower number of activated CD4 T cells but a greater number of regulatory T cells (Tregs) in the spleen, and a reduction of Th1/Th17 inflammatory cytokines in the joints and serum. Importantly, TAPBPL protein inhibited CII-specific T cell growth and Th1 and Th17 cytokine expression and reduced the production of CII autoantibodies in the serum. Our results suggest that TAPBPL protein can ameliorate CIA in mice and has the potential to be used in the treatment of patients with RA.

Autoimmune diseases exhibit shared alterations in the gut microbiota.

Accumulating evidence from microbial studies have highlighted the modulatory roles of intestinal microbes in numerous human diseases, however, the shared microbial signatures across different diseases remain relatively unclear. To consolidate existing knowledge across multiple studies, we performed meta-analyses of 17 disease types, covering 34 case-control datasets of 16S rRNA sequencing data, to identify shared alterations among different diseases. Furthermore, the impact of a microbial species, Lactobacillussalivarius, was established in a dextran sodium sulphate-induced colitis model and a collagen type II-induced arthritis mouse model. Microbial alterations among autoimmune diseases were substantially more consistent compared with that of other diseases (cancer, metabolic disease and nervous system disease), with microbial signatures exhibiting notable discriminative power for disease prediction. Autoimmune diseases were characterized by the enrichment of Enterococcus, Veillonella, Streptococcus and Lactobacillus and the depletion of Ruminococcus, Gemmiger, Oscillibacter, Faecalibacterium, Lachnospiracea incertae sedis, Anaerostipes, Coprococcus, Alistipes, Roseburia, Bilophila, Barnesiella, Dorea, Ruminococcus2, Butyricicoccus, Phascolarctobacterium, Parabacteroides and Odoribacter, among others. Functional investigation of L. salivarius, whose genus was commonly enriched in numerous autoimmune diseases, demonstrated protective roles in two separate inflammatory mouse models. Our study highlights a strong link between autoimmune diseases and the gut microbiota, with notably consistent microbial alterations compared with that of other diseases, indicating that therapeutic strategies that target the gut microbiome may be transferable across different autoimmune diseases. Functional validation of L. salivarius highlighted that bacterial genera associated with disease may not always be antagonistic, but may represent protective or adaptive responses to disease.

Dopamine D2 receptor on CD4+ T cells is protective against inflammatory responses and signs in a mouse model of rheumatoid arthritis

BackgroundDopamine is a neurotransmitter and has been found to regulate lymphocytes by acting on dopamine receptors (DRs). CD4+ T cells express all the five subtypes of DRs, D1R to D5R. Although CD4+ T cells have been involved in pathogenesis of rheumatoid arthritis (RA), roles of DRs expressed on these cells in RA are poorly understood. This study determined whether D2R expressed on CD4+ T cells regulates inflammatory responses and signs in collagen type II (CII)-induced arthritis (CIA), a mouse model of RA.MethodsDBA/1 mice and C57BL/6 mice with global D1r or D2r deficiency (D1r–/– or D2r–/–) or CD4+ T cell-specific D2r deletion (D2rfl/fl/CD4Cre) were used to prepare CIA model by intradermal injection of CII. D2R agonist sumanirole was intraperitoneally administered in CIA mice. CD4+ T cells obtained from CIA mice were exposed to sumanirole or/and D2R antagonist L-741,626 in vitro. Arthritic symptoms were assessed by clinical arthritis scores. Flow cytometric assay measured frequencies of CD4+ T cell subsets (Th1, Th2, Th17 and Treg cells). Expression of specific transcription factors for the CD4+ T cell subsets was tested by Western blot. Cytokine production was estimated by quantitative PCR and ELISA.ResultsCIA mice manifested a bias of CD4+ T cells towards Th1 and Th17 cells. D2r–/– CIA mice showed a stronger bias towards Th1 and Th17 phenotypes than CIA mice, while D1r–/– CIA mice did not show the changes. CD4+ T cell-specific D2r deletion exacerbated both the polarization towards Th1 and Th17 cells and the symptoms of arthritis. Sumanirole administration in CIA mice ameliorated the bias of CD4+ T cells towards Th1 and Th17 phenotypes as well as arthritic symptoms. Sumanirole treatment of in vitro CD4+ T cells obtained from CIA mice promoted the shift to Treg cells, and the effect of sumanirole was blocked by L-741,626.ConclusionsD2R expressed on CD4+ T cells is protective against imbalance between pro-inflammatory and anti-inflammatory T cells and arthritic symptoms in CIA.

Leocarpinolide B Attenuates Collagen Type II-Induced Arthritis by Inhibiting DNA Binding Activity of NF-κB.

Rheumatoid arthritis (RA) is a chronic autoimmune disease triggered by a cascading inflammatory response. Sigesbeckia Herba (SH) has long been utilized as a traditional remedy to alleviate symptoms associated with rheumatism. Our previous study found that leocarpinolide B (LB), a sesquiterpene lactone isolated from the whole plant of SH, possesses potent a anti-inflammatory effect on macrophages. This study was designed to evaluate the therapeutic effects of LB on RA, and further investigate the underlying mechanisms. In collagen type II-induced arthritic mice, LB was demonstrated to decrease the production of autoimmune antibodies in serum and inflammatory cytokines in the joint muscles and recover the decreased regulatory T lymphocytes in spleen. Moreover, LB significantly suppressed the inflammatory infiltration, formation of pannus and bone erosion in the paw joints. In vitro testing showed that LB inhibited the proliferation, migration, invasion, and secretion of inflammatory cytokines in IL-1β-induced human synovial SW982 cells. Network pharmacology and molecular docking suggested NF-κB p65 could be the potential target of LB on RA treatment, subsequent experimental investigation confirmed that LB directly interacted with NF-κB p65 and reduced the DNA binding activity of NF-κB in synovial cells. In conclusion, LB significantly attenuated the collagen type II-induced arthritis, which was at least involved in the inhibition of DNA binding activity of NF-κB through a direct binding to NF-κB p65. These findings suggest that LB could be a valuable lead compound for developing anti-RA drugs.

Effect of hydroalcoholic leaf extract of Cassia fistula L. on type II collagen-induced arthritis in rats

Objective: To explore the effect of Cassia fistula on collagen II-induced arthritis in rats. Methods: The effect of 250 and 500 mg/kg chloroform and hydroalcoholic extract of Cassia fistula leaf on collagen II-induced arthritis was investigated by evaluating paw volume, arthritis index, spleen index, and biochemical parameters. Histopathological analysis and docking study were also performed. Results: A dose-dependent reduction in paw volume, arthritic index, and spleen index was observed following oral administration of the chloroform and hydroalcoholic extracts. Treatment with Cassia fistula extracts reduced tumor necrosis factor-α, interleukin (IL)-1β, IL-6, prostaglandin E2, aspartate aminotransferase, alanine aminotransferase, total leucocyte count, and erythrocyte sedimentation rate while increasing IL-10 level. In addition, Cassia fistula extracts improved joint architecture, and prevented cartilage and bone destruction. Docking analysis demonstrated that the physcion, 1-octacosanol, 5,3',4'-trihydroxy-6-methoxy-7-O-α-L-rhamnopyranosyl-(1,2)-O-β-D-galactopyranoside and scopoletin may be responsible for the anti-arthritic effect of Cassia fistula. Conclusions: Cassia fistula suppresses the progression of collagen II-induced arthritis by lowering the inflammatory factors, decreasing paw volume and arthritic index, and alleviating joint architecture. However, further studies are required to confirm the bioactive molecule responsible for the anti-arthritic potential of Cassia fistula.

Size-switchable polymer-based nanomedicines in the advanced therapy of rheumatoid arthritis.

Chronic inflammatory diseases such as rheumatoid arthritis represent a substantial socio-economic impact and have a high prevalence in the modern world. Nano-sized polymer therapeutics have shown suitable characteristics for becoming the next generation of anti-inflammatory nanomedicines. Here, we present biocompatible and stimuli-sensitive N-(2-hydroxypropyl)methacrylamide based polymer conjugates with the anti-inflammatory drug dexamethasone (DEX), which has been tailored for prolonged blood circulation, enhanced inflammatory site accumulation, site-specific drug release and subsequent elimination of the carrier via urine excretion. The hydrodynamic size of novel polymer-DEX nanomedicine was adjusted to prolong its blood circulation whilst maintaining the renal excretability of the polymer carrier after drug release in inflamed tissue. The therapeutic efficacy of the studied polymer nanomedicines was evaluated in a model of dissipated chronic arthritis, i.e. collagen II-induced arthritis, in mice. The pH-sensitive drug attachment enabled enhanced blood circulation with minimal systemic drug release, as well as rapid drug activation in affected joints. Importantly, unlike free DEX, the polymer nanomedicines were able to diminish joint inflammation and arthritis-induced bone damage - even at a reduced dosing regimen - as evaluated by micro computed tomography (micro-CT).

EFFECT OF COLLAGEN INDUCED ARTHRITIS ON ANTISTREPTOLYSIN TEST IN THE WHITE LABORATORY RAT

Rheumatoid arthritis (RA) is a serious health challenge as a disease with serious health consequences andthe potential to result in permanent disability. Most of the authors state that the reason for the occurrence of thedisease and its persistence is multifactorial, but above all it is a genetic predisposition as a result of the disruption ofthe control mechanisms of the immune system. The disease can occur at any age, but it is most common in patientsover sixty years of age who suffer from damage to the joints, resulting in impaired locomotion, reduced workcapacity, unproductive and poor quality of life. Animal models in RA disease research are useful for studying andevaluating the effect of potential antiarthritic drugs. The study of the disease in animal models provides usefulinformation about rheumatoid diseases and RA in humans because of the great similarity in their onset anddevelopment.Our research aimed to see how collagen type-II induced arthritis would cause an effect on the immune system andinter alia on ASTO in Wistar rats of both sexes, on the thirtieth and sixtieth days of immunization. ASTO is alsoused to diagnose RA secondary to streptococcal infections. Wistar rats, healthy seven-week-old male and femaleanimals, bred according to standard conditions for experimental animals at the laboratory animal farm at PMFSkopjewere used for the research. The experimental animals were divided into four groups; control group of maleanimals (n=20), control group of female animals (n=20), experimental group of male animals (n=30), which weretreated with collagen type-II and experimental group of female animals (n=30), which were also treated withcollagen. Analyzes of aliquots were performed on the thirtieth and sixtieth day of the test. We apply the highlypurified collagen type-II according to a defined protocol in the joint of the back right leg. We took blood for analysison the thirtieth and sixtieth day after immunization. The ASTO samples were tested on the computerized andthermostated Mini NEF TM Duinding Fait apparatus. The principle of the method is based on the fact thatpathogenic beta-hemolytic streptococci of group A produce streptolysin O, which stimulate the body to produceantistreptolysin. A titer greater than 1/200 is a positive value. From the studies that were done on the influence ofcollagen induced arthritis type-II on the value of ASTO in both sexes of animals, in both experimental periods, it canbe concluded that they are within the limits of normal values in all groups and in both sexes. All were <59,430IU/ml. In general, these studies of RA performed in animal models provide a good parallel for the course anddevelopment of RA in the human population.

Celastrol inhibits rheumatoid arthritis by inducing autophagy via inhibition of the PI3K/AKT/mTOR signaling pathway

ObjectiveRheumatoid arthritis (RA) is a chronic autoimmune inflammatory disorder of the synovial joints. Celastrol (Cel) is a quinone-methylated triterpenoid extracted from Tripterygium wilfordii Hook F (TwHF) that has been proven to be effective in treating RA. However, the underlying molecular mechanism of celastrol in the treatment of RA remains unknown. This study explored the protective effect of celastrol against RA and the specific mechanisms of celastrol in vitro and in vivo. MethodsA chicken type II collagen (CII)-induced arthritis (CIA) mouse model was used to explore the anti-arthritic effects of celastrol, and paw swelling degree, the poly-arthritis index score and serum cytokine levels were determined. Pathological morphology was observed using hematoxylin and eosin (H&E) staining. The influences of celastrol on the proliferation of tumor necrosis factor-α (TNF-α)-induced fibroblast-like synoviocytes (FLSs) were tested by Cell Counting Kit-8 (CCK-8) assays and5-ethynyl-2′-deoxyuridine (EdU) staining assays. The level of autophagy was detected by transmission electron microscopy (TEM). Furthermore, the PI3K/AKT/mTOR pathway and the status of autophagy in the CIA model and FLSs were also detected by western blot and immunofluorescence staining. ResultsThe results showed that celastrol decreased arthritis severity and inhibited TNF-α-induced FLSs proliferation. Additionally, celastrol decreased the secretion of pro-inflammatory cytokines. Moreover, celastrol increased autophagosome levels and LC3B protein expression in TNF-α-treated FLSs. Furthermore, celastrol increased the protein expression of LC3-II and Beclin-1 and decreased the phosphorylation degree of mTOR and AKT. ConclusionIn conclusion, our findings confirmed that celastrol ameliorates RA via the up-regulation of autophagy by inhibiting the PI3K/AKT/mTOR axis.

Menthone inhibits type-I interferon signaling by promoting Tyk2 ubiquitination to relieve local inflammation of rheumatoid arthritis

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease. RA development is mediated by the abnormal activation of multiple signaling pathways. Recent studies have revealed that type-I interferon (IFN-I) signaling plays an essential role in the occurrence and development of RA. However, how to target IFN-I signaling to develop anti-rheumatoid arthritis drugs remains largely unexplored. Here, our study showed that IFN-I signaling was over-activated in articular synovial cells from collagen II-induced arthritis (CIA) mice. Interestingly, we found that a small molecule compound, menthone, strongly inhibited the activation of the IFN-I signaling pathway. Further studies revealed that menthone promoted K48-linked polyubiquitination of Tyk2, thus lowering the protein level and stability of Tyk2. Importantly, menthone administration in the local articulus of CIA mice significantly attenuated the local inflammation in CIA mice. This study could promote our understanding of rheumatoid arthritis, and also suggests a potential strategy to develop anti-RA drugs.

Guar gum nanoparticles ameliorate inflammatory damage in a preclinical mouse model of collagen II-induced arthritis

Introduction: Rheumatoid arthritis (RA) is a bone disorder causing inflammation of synovial lining followed by production of proinflammatory cytokines at the same site. The synovial hyperplasia is also mediated by the infiltration of lymphocytes, macrophages and other inflammatory cells. The available drugs for RA shows temporary recovery and some are associated with side effects. Here we have used surface functionalized guar gum nanoparticles (GN) to ameliorate disease pathology using collagen II (CII) induced arthritis model in C57BL/6 mice. Methods: The systemic as well as the bone damage was assessed by the total count, differential count, clonogenic potential, flow cytometry and histological studies. The migration of inflammatory cells was assessed by flow cytometry of cells from the bone marrow, blood, spleen and the synovial tissue. The joint inflammation was assessed both by visible presentation in terms of thickness and corroborated with the H&E staining of the knee joint sections. Results: Synovitis was observed in the diseased group while GN controlled the synovial inflammation. Post sacrifice, the total number of cells and the immune cells were increased significantly in the diseased group and decreased on GN treatment. The clonogenic potential of cells was also restored on GN administration. The elevated level of NO was also decreased by GN administration. The expression of proinflammatory cytokines and the signaling molecules were also restored on GN treatment. Conclusion: The results provide insights to understand the therapeutic effect of GN in CII induced arthritis for translational outcomes. Through this study we investigated the signaling mechanism involved in the pathology of disease to examine the role of GN in preventing the disease progression.

The Effect of Triptolide Combined With Crocin on Arthritis in Mice: From Side Effect Attenuation to Therapy.

Clinical use of triptolide (TP) is restricted due to severe toxicity. This study assessed the protective effect of crocin (CR) as a natural antioxidant against TP-induced toxicity in bovine collagen type II-induced arthritis (CIA) in mice. The mice in the CIA model group showed macroscopic signs of severe arthritis. The anti-arthritis effects in the control, TP + CR, and TP groups were evaluated through assessment of foot volume, arthritis score, and proinflammatory cytokines, and collagen antibody assay. Crocin reduced TP-induced toxicity, as evidenced by evaluation of survival rate, body weight, visceral index, hepatic and renal functions, histopathologic analyses, and antioxidant enzyme activities. Transcriptome sequencing resulted in identification of 76 differentially expressed genes (DEGs) associated with hepatotoxicity between the TP and TP + CR groups. Of these, Three DEGs (Cyp1a2,Gsta4, and Gstp1) were validated using quantitative real-time PCR analysis. In conclusion, CR protected CIA mice from TP-induced toxicity through modulation of the cytochrome P450 and glutathione metabolism pathways.

A Natural Plant Ingredient, Menthone, Regulates T Cell Subtypes and Lowers Pro-inflammatory Cytokines of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease with nearly 1.6 billion patients worldwide and an incidence of 0.5-1%. In recent years, basic and clinical studies have revealed that immune cell responses and corresponding secretion of inflammatory factors are important in the control of RA development. Our study found that a natural plant ingredient, menthone, could be used as a potential antirheumatism compound. In vivo observations demonstrated that menthone alleviates collagen II-induced arthritis (CIA) in mice. Furthermore, we found that menthone regulates the number of Th1 and Th17 cells in CIA mice. Importantly, menthone significantly inhibits the release of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, in CIA mice. Our study suggests a potential component for the development of drugs to treat rheumatoid arthritis.

Knockout of SLAMF8 attenuates collagen-induced rheumatoid arthritis in mice through inhibiting TLR4/NF-κB signaling pathway

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by synovial hyperplasia, cartilage damage, and ultimate bone destruction. The signaling lymphocytic activation molecule family member 8 (SLAMF8) is a cell surface receptor expressed on various immune cells. This study aimed to investigate the role of SLAMF8 in the pathogenesis of RA. The SLAMF8 gene was identified as a differentially expressed gene in RA by analyzing the Gene Expression Omnibus database and synovial tissue samples collected from RA patients. Upregulation of SLAMF8 was associated with increased disease activity and inflammation in RA. Mice with collagen type II-induced arthritis (CIA) showed highly expressed SLAMF8, severe paw swelling, elevated inflammatory cytokine production, and excessive accumulation of immune cells. However, knockout of SLAMF8 alleviated collagen type II immunization-induced synovial hyperplasia and joint arthritis in mice. The in-vitro and in-vivo study showed that genetic deletion of SLAMF8 significantly inhibited upregulation of Toll-like receptor 4 (TLR4) and activation of the nuclear factor kappa B (NF-κB) pathway in fibroblast-like synoviocytes and bone marrow-derived macrophages derived from WT and SLAMF8 knockout mice under lipopolysaccharide stimulation. In conclusion, SLAMF8 was aberrantly expressed in RA patient and played an indispensable role in initiating inflammation and maintaining the pro-inflammatory environment in the inflamed joint. Targeted inhibition of SLAMF8 attenuated the severity of RA via blocking the TLR4/NF-κB signaling pathway. These data suggested that SLAMF8 may be a potential target for the treatment of RA.

Suppression of Nitrosative Stress and Inflammation of the Knee Joint Synovium in Collagen Type II-Induced Rheumatoid Arthritis by the Inhibition of Glycogen Synthase Kinase-3ß

Suppression of Nitrosative Stress and Inflammation of the Knee Joint Synovium in Collagen Type II-Induced Rheumatoid Arthritis by the Inhibition of Glycogen Synthase Kinase-3ß