Undenatured type II collagen protects against collagen-induced arthritis by restoring gut-joint homeostasis and immunity.

Oral administration of harmless antigens can induce suppression of reactive immune responses, a process that capitalises on the ability of the gastrointestinal tract to tolerate exposure to food and commensal microbiome without triggering inflammatory responses. Repeating exposure to type II collagen induces oral tolerance and inhibits induction of arthritis, a chronic inflammatory joint condition. Although some mechanisms underlying oral tolerance are described, how dysregulation of gut immune networks impacts on inflammation of distant tissues like the joints is unclear. We used undenatured type II collagen in a prophylactic regime -7.33 mg/kg three times/week- to describe the mechanisms associated with protective oral immune-therapy (OIT) in gut and joint during experimental Collagen-Induced Arthritis (CIA). OIT reduced disease incidence to 50%, with reduced expression of IL-17 and IL-22 in the joints of asymptomatic mice. Moreover, whilst the gut tissue of arthritic mice shows substantial damage and activation of tissue-specific immune networks, oral administration of undenatured type II collagen protects against gut pathology in all mice, symptomatic and asymptomatic, rewiring IL-17/IL-22 networks. Furthermore, gut fucosylation and microbiome composition were also modulated. These results corroborate the relevance of the gut-joint axis in arthritis, showing novel regulatory mechanisms linked to therapeutic OIT in joint disease.

Injectable butyrate-prodrug micelles induce long-acting immune modulation and prevent autoimmune arthritis in mice.

Short chain fatty acid (SCFAs), such as butyrate, have shown promising therapeutic potential due to their immunomodulatory effects, particularly in maintaining immune homeostasis. However, the clinical application of SCFAs is limited by the need for frequent and high oral dosages. Rheumatoid arthritis (RA) is characterized by aberrant activation of peripheral T cells and myeloid cells. In this study, we aimed to deliver butyrate directly to the lymphatics using a polymeric micelle-based butyrate prodrug to induce long-lasting immunomodulatory effects. Notably, negatively charged micelles (Neg-ButM) demonstrated superior efficacy in targeting the lymphatics following subcutaneous (s.c.) administration and were retained in the draining lymph nodes, spleen, and liver for over one month. In the collagen antibody-induced arthritis (CAIA) mouse model of RA, only two s.c. injections of Neg-ButM successfully prevented disease onset and promoted tolerogenic phenotypes in T cells and myeloid cells, both locally and systemically. These results underscore the potential of this strategy in managing inflammatory autoimmune diseases by directly modulating immune responses via lymphatic delivery.

Administration of Liposomal-Based Pde3b Gene Therapy Protects Mice Against Collagen-Induced Rheumatoid Arthritis via Modulating Macrophage Polarization.

Background: Rheumatoid arthritis (RA) is a chronic and systemic autoimmune disease characterized by synovial inflammation and joint destruction. Despite progress in RA therapy, it remains difficult to achieve long-term remission in RA patients. Phosphodiesterase 3B (Pde3b) is a member of the phosphohydrolyase family that are involved in many signal transduction pathways. However, its role in RA is yet to be fully addressed. Methods: Studies were conducted in arthritic DBA/1 mice, a suitable mouse strain for collagen-induced rheumatoid arthritis (CIA), to dissect the role of Pde3b in RA pathogenesis. Next, RNAi-based therapy with Pde3b siRNA-loaded liposomes was assessed in a CIA model. To study the mechanism involved, we investigated the effect of Pde3b knockdown on macrophage polarization and related signaling pathway. Results: We demonstrated that mice with CIA exhibited upregulated Pde3b expression in macrophages. Notably, intravenous administration of liposomes loaded with Pde3b siRNA promoted the macrophage anti-inflammatory program and alleviated CIA in mice, as indicated by the reduced inflammatory response, synoviocyte infiltration, and bone and cartilage erosion. Mechanistic study revealed that depletion of Pde3b increased cAMP levels, by which it enhanced PKA-CREB-C/EBPß pathway to transcribe the expression of anti-inflammatory program-related genes. Conclusion: Our results support that Pde3b is involved in the pathogenesis of RA, and Pde3b siRNA-loaded liposomes might serve as a promising therapeutic approach against RA.

Biochemical evaluation of possible protective effect of purslane extract in experimentally induced arthritis associated with obesity.

Arthritis, a prevalent inflammatory condition, is often linked to obesity as a contributing factor. This study aimed to assess the potential protective effects of purslane extract in male albino rats with induced arthritis and obesity. Fifty rats were randomly assigned to five groups: a control group, an induced arthritis-high-fat diet group, a high-dose purslane extract-supplemented group (300 mg/kg body weight) for 8 weeks, a low-dose purslane extract-supplemented group (150 mg/kg body weight) for 8 weeks, and a metformin-supplemented group. Arthritis was induced in the rats using Complete Freund's Adjuvant. Plasma biomarkers, including Total Cholesterol, Triglycerides, HDL-cholesterol, LDL-cholesterol, C Reactive Protein (CRP), Erythrocyte Sedimentation Rate (ESR), Rheumatoid Factor (RF), and Anti-CCP, were assessed in each group. The results revealed a significant improvement in these biomarkers in the high-dose purslane-supplemented group (300 mg/kg body weight) compared to the induced arthritis-high-fat-diet group. This suggests a potential protective role of purslane against arthritis associated with obesity, likely attributed to its lipolytic capacity and anti-inflammatory properties. These findings contribute to our understanding of the interplay between obesity, arthritis, and natural interventions, providing valuable insights for future therapeutic approaches.

Prevention of Collagen-Induced Arthritis by an Anti-Glycan Monoclonal Antibody Reactive with 6-Sulfo Sialyl Lewis x in DBA/1 Mice.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial tissue inflammation, substantially impacting the quality of life of patients. The interaction between L-selectin and its glycoprotein ligands modified with 6-sulfo sialyl Lewis x (6-sulfo sLex) is known to mediate lymphocyte homing to initiate immune responses. Thus, this process could be a potential therapeutic target for RA. Herein, we explored the preventive effects of an anti-6-sulfo sLex monoclonal antibody (mAb), SF1, on collagen-induced arthritis (CIA) in DBA/1 mice. Mice were administered SF1 from day 21 postfirst immunization with type II collagen (CII), and the effects of SF1 on both clinical and histopathological disease progression evoked by the second immunization were examined. SF1 significantly suppressed clinical features and histological levels associated with arthritis severity. Enzyme-linked immunosorbent assay consistently indicated that SF1 inhibited the production of CII-specific IgG2a. Based on the reverse transcription-quantitative PCR analysis, SF1 suppressed the expression of interferon-γ, a T helper 1 cytokine, as well as that of inflammatory cytokines, including tumor necrosis factor-α and interleukin-1ß, in draining lymph nodes. Collectively, these results indicate that SF1, an anti-sulfated glycan mAb, could be beneficial in preventing CIA in mice and may afford as a novel agent to treat RA.

A subset of type-II collagen-binding antibodies prevents experimental arthritis by inhibiting FCGR3 signaling in neutrophils.

Rheumatoid arthritis (RA) involves several classes of pathogenic autoantibodies, some of which react with type-II collagen (COL2) in articular cartilage. We previously described a subset of COL2 antibodies targeting the F4 epitope (ERGLKGHRGFT) that could be regulatory. Here, using phage display, we developed recombinant antibodies against this epitope and examined the underlying mechanism of action. One of these antibodies, R69-4, protected against cartilage antibody- and collagen-induced arthritis in mice, but not autoimmune disease models independent of arthritogenic autoantibodies. R69-4 was further shown to cross-react with a large range of proteins within the inflamed synovial fluid, such as the complement protein C1q. Complexed R69-4 inhibited neutrophil FCGR3 signaling, thereby impairing downstream IL-1ß secretion and neutrophil self-orchestrated recruitment. Likewise, human isotypes of R69-4 protected against arthritis with comparable efficiency. We conclude that R69-4 abrogates autoantibody-mediated arthritis mainly by hindering FCGR3 signaling, highlighting its potential clinical utility in acute RA.

Vaccines prevent reinduction of rheumatoid arthritis symptoms in collagen-induced arthritis mouse model.

Metabolic reprogramming of immune cells modulates their function and reduces the severity of autoimmune diseases. However, the long-term effects of the metabolically reprogrammed cells, specifically in the case of immune flare-ups, need to be examined. Herein, a re-induction rheumatoid arthritis (RA) mouse model was developed by injecting T-cells from RA mice into drug-treated mice to recapitulate the effects of T-cell-mediated inflammation and mimic immune flare-ups. Immune metabolic modulator paKG(PFK15 + bc2) microparticles (MPs) were shown to reduce clinical symptoms of RA in collagen-induced arthritis (CIA) mice. Upon re-induction, a significant delay in the reappearance of clinical symptoms in the paKG(PFK15 + bc2) microparticle treatment group was observed as compared to equal or higher doses of the clinically utilized U.S. Food and Drug Administration (FDA)-approved drug, Methotrexate (MTX). Furthermore, paKG(PFK15 + bc2) microparticle-treated mice were able to lower activated dendritic cells (DCs) and inflammatory T helper cell 1 (TH1) and increased activated, proliferating regulatory T-cells (Tregs) more effectively than MTX. The paKG(PFK15 + bc2) microparticles also led to a significant reduction in paw inflammation in mice as compared to MTX treatment. This study can pave the way for the development of flare-up mouse models and antigen-specific drug treatments.

Dasatinib, a selective tyrosine kinase inhibitor, prevents joint destruction in rheumatoid arthritis animal model.

AIM: We aimed to evaluate the preventive role of the tyrosine kinase inhibitor dasatinib in an animal model of rheumatoid arthritis (RA). METHODS: DBA/1J mice were injected with bovine type II collagen to induce arthritis (collagen-induced arthritis [CIA]). There were four experimental groups of mice, namely negative control (non-CIA), vehicle-treated CIA, dasatinib-pretreated CIA, and dasatinib-treated CIA. After collagen immunization, arthritis progression in the mice was clinically scored twice weekly for 5 weeks. Flow cytometry was used to evaluate in vitro CD4+ T-cell differentiation and ex vivo mast cell/CD4+ T-cell differentiation. Osteoclast formation was evaluated using tartrate-resistant acid phosphatase (TRAP) staining and by estimating the resorption pit area. RESULTS: We found that the clinical arthritis histological scores were lower in the dasatinib pretreatment group than in the vehicle and dasatinib post-treatment groups. Flow cytometry showed that FcεR1+ cells were downregulated and regulatory T cells were upregulated in splenocytes of the dasatinib pretreatment group compared with those in the vehicle group. Additionally, there was a decline in IL-17+ CD4+ T-cell differentiation and an increase in CD4+ CD24high Foxp3+ T-cell differentiation with in vitro dasatinib treatment of human CD4+ T cells. The number of TRAP+ osteoclasts and the area of the resorption were decreased in the bone marrow cells derived from dasatinib-pretreated mice compared with those derived from vehicle group. CONCLUSION: Dasatinib protected against arthritis in an animal model of RA by regulating the differentiation of regulatory T cells and IL-17+ CD4+ T cells and inhibiting osteoclastogenesis, indicating the therapeutic potential of dasatinib in the treatment of early RA.

Protective effect of lupeol on arthritis induced by type II collagen via the suppression of P13K/AKT signaling pathway in Sprague dawley rats.

To explore the therapeutic value of lupeol on collagen-induced arthritis (CIA) in rats, a rheumatoid arthritis model. Lupeol is well known pentacyclic triterpene found in various plant sources, which possess anti-inflammatory and antioxidant actions. The current study was assessed the anti-arthritic potential of lupeol and its molecular mechanisms as compared with indomethacin (Indo) in collagen-induced arthritis CIA rats. The rats were randomly alienated into five groups: Control, CIA alone, CIA + lupeol (10 mg/kg bw), CIA + Indomethacin (3 mg/kg bw), and lupeol (10 mg/kg bw) alone. The paw volume, biochemical, hematological parameters, inflammatory enzymes, and cytokines were measured. As well protein expression of apoptotic proteins, and histopathological of ankle joint were examined. Inflammatory markers, cytokines, histological changes, paw volume, and inflammation were intensely reduced and enhanced apoptosis by lupeol. Alterations in hematological parameters, rheumatoid factor, C-reactive protein, and ceruloplasmin in arthritis were reverted by lupeol. Protein expressions of Bcl-2, and P13K/Akt signaling were declined, whereas the Bax, caspssae-3, and caspase-9 were elevated. These results highlighted that lupeol suppresses P13K/Akt signaling and has a promising anti-arthritic potential for collagen-induced rheumatic arthritis treatment. Hence lupeol would be suggested as an alternative natural source with potent anti-inflammatory and apoptotic actions for chronic inflammatory disorders.

The protective role of glucocerebrosidase/ceramide in rheumatoid arthritis.

OBJECTIVE: To clarify the role of glucocerebrosidase (GBA) and Ceramide (Cer) in rheumatoid arthritis (RA). METHODS: GBA-expressing lentivirus were constructed and injected into collagen-induced arthritis (CIA) mice, and compared with CIA mice injected with empty vector. The severity of arthritis and inflammatory mediators were evaluated. Fibroblast-like synoviocytes (FLS) from RA patients were transfected with GBA-expressing lentivirus, or pretreated with C6-Cer. The migration and invasion of FLS, the production of inflammatory cytokines, and the relevant signaling pathways were assessed. RESULTS: In CIA mice, GBA markedly improved arthritis compared to that in the CIA mice, with increased content of proteoglycan and integral cartilage surfaces and tidemarks. The circulating inflammatory mediators, including interleukin (IL)-1ß, IL-6, IL-18, and matrix metalloproteinase (MMP)-1, were significantly reduced in CIA mice with GBA overexpression compared to those in CIA mice. GBA and C6-Cer treatment inhibited migration and invasion of FLS, and suppressed production of inflammatory cytokines and activation of the MAPK pathways. CONCLUSION: GBA/Cer exhibited a protective role in CIA mice and RA FLS. These results highlight the potential of targeting GBA/Cer as a therapeutic strategy in RA and warrant further investigation.

Pharmacological exploration of anti-arthritic potential of terbutaline through in-vitro and in-vivo experimental models.

Terbutaline have been reported to have anti-inflammatory activity. Present study aimed to check the anti-arthritic activity of terbutaline. The drug was tested using in vitro models (bovine serum albumin denaturation, egg albumin denaturation and HRBC membrane stabilization) and in vivo (formaldehyde induced arthritis). Results of bovine serum albumin denaturation assay illustrated that terbutaline inhibited 89.54±0.46% denaturation at 6400µg/ml concentration. Terbutaline resulted in dose dependent impediment of protein denaturation in egg albumin denaturation assay with 74.40±0.72% inhibition at concentration of 6400µg/ml. Terbutaline also showed protection of HRBC membrane against hypotonic stress in a dose dependent manner, with maximum 76.45±0.62% prevention at 6400µg/ml concentration. Results of formaldehyde induced arthritis model showed that paw volume was significantly declined by terbutaline with maximum percentage inhibition at 10th day of study period which implies immune inhibitory potential of terbutaline. Findings of present study concluded that terbutaline has arthritis reducing potential possible through inhibitory effects on synthesis and release of inflammatory mediators as well as limiting the formation of autoantigen. Thus, terbutaline might be the potential candidate for use in treatment of arthritis.

TNF antagonist sensitizes synovial fibroblasts to ferroptotic cell death in collagen-induced arthritis mouse models.

Ferroptosis is a nonapoptotic cell death process that requires cellular iron and the accumulation of lipid peroxides. In progressive rheumatoid arthritis (RA), synovial fibroblasts proliferate abnormally in the presence of reactive oxygen species (ROS) and elevated lipid oxidation. Here we show, using a collagen-induced arthritis (CIA) mouse model, that imidazole ketone erastin (IKE), a ferroptosis inducer, decreases fibroblast numbers in the synovium. Data from single-cell RNA sequencing further identify two groups of fibroblasts that have distinct susceptibility to IKE-induced ferroptosis, with the ferroptosis-resistant fibroblasts associated with an increased TNF-related transcriptome. Mechanistically, TNF signaling promotes cystine uptake and biosynthesis of glutathione (GSH) to protect fibroblasts from ferroptosis. Lastly, low dose IKE together with etanercept, a TNF antagonist, induce ferroptosis in fibroblasts and attenuate arthritis progression in the CIA model. Our results thus imply that the combination of TNF inhibitors and ferroptosis inducers may serve as a potential candidate for RA therapy.

Anti-inflammatory, but not osteoprotective, effect of the TRAF6/CD40 inhibitor 6877002 in rodent models of local and systemic osteolysis.

NFκB plays a key role in inflammation and skeletal disorders. Previously, we reported that pharmacological inhibition of NFκB at the level of TRAF6 suppressed RANKL, CD40L and IL1ß-induced osteoclastogenesis and attenuated cancer-induced bone disease. TNFα is also known to regulate TRAF6/NFκB signalling, however the anti-inflammatory and osteoprotective effects associated with inhibition of the TNFα/TRAF6/NFκB axis have not been investigated. Here, we show that in vitro and ex vivo exposure to the verified small-molecule inhibitor of TRAF6, 6877002 prevented TNFα-induced NFκB activation, osteoclastogenesis and calvarial osteolysis, but it had no effects on TNFα-induced apoptosis or growth inhibition in osteoblasts. Additionally, 6877002 disrupted T-cells support for osteoclast formation and synoviocyte motility, without affecting the viability of osteoblasts in the presence of T-cells derived factors. Using the collagen-induced arthritis model, we show that oral and intraperitoneal administration of 6877002 in mice reduced joint inflammation and arthritis score. Unexpectedly, no difference in trabecular and cortical bone parameters were detected between vehicle and 6877002 treated mice, indicating lack of osteoprotection by 6877002 in the arthritis model described. Using two independent rodent models of osteolysis, we confirmed that 6877002 had no effect on trabecular and cortical bone loss in both osteoporotic rats or RANKL- treated mice. In contrast, the classic anti-osteolytic alendronate offered complete osteoprotection in RANKL- treated mice. In conclusion, TRAF6 inhibitors may be of value in the management of the inflammatory component of bone disorders, but may not offer protection against local or systemic bone loss, unless combined with anti-resorptive therapy such as bisphosphonates.

Non-lethal rodent malarial infection prevents collagen-induced arthritis in mice via anti-arthritic immunomodulation.

AIMS: Immunomodulatory effects of parasitic infections on the outcomes of allergic or autoimmune disorders have been addressed in many experimental studies. We examined the effects of Plasmodium yoelii 17X NL (Py) infection on collagen-induced arthritis (CIA). METHODS AND RESULTS: Male DBA/1J mice were immunized with bovine type II collagen (IIC). Py inoculation was induced at three different time points (1, 4 weeks after or 4 weeks before the immunization). Only the inoculation at 4 weeks after IIC immunization significantly inhibited arthritis development. Non-malarial anaemia induced by phenylhydrazine hydrochloride (PHZ) did not affect arthritis development. In the infected mice, anti-IIC IgG levels were transiently reduced. In addition, splenic production of pro-arthritic cytokines (IL-17 and TNF-α) and IFN-γ decreased, whereas IL-10 production increased. Flow cytometric analysis clarified that the main IL-10 producers in Py-infected mice had the CD4+ CD25- Foxp3- phenotype, presumably Tr1 cells. CONCLUSION: We demonstrated that experimental malarial infection alleviated autoimmune arthritis via immunomodulation, suggesting the importance of malaria in the hygiene hypothesis and the significance of searching for therapeutic immunomodulatory molecules from malarial parasites.

Inhibition of glycogen synthase kinase-3ß protects against collagen type II-induced arthritis associated with the inhibition of miR155/24 and inflammation and upregulation of apoptosis in rats.

MicroRNAs have been implicated in the pathogenesis of rheumatoid arthritis (RA) and their syntheses are modulated by glycogen synthase kinase-3ß (GSK-3ß). Therefore, we hypothesised that the GSK-3ß inhibitor, TDZD-8 can protect against collagen-induced arthritis (CIA) via downregulating miR155 and miR-24 expression. Rats were randomly allocated into four groups (n = 6) as follows: Control, Control + TDZD-8 (1 mg/kg), CIA, and CIA + TDZD-8. Rats were sacrificed after 6 weeks. We observed in the model group (CIA) significant (p<.05) increase in arthritis score and serum levels of RA biomarkers, which were significantly (p < .05) inhibited by TDZD-8. TDZD-8 also significantly (p<.05) inhibited CIA-induced synovial tissue levels of miR155, miR-24, and inflammation. In addition, a significant (p<.05) modulation of biomarkers of survival (Bcl-2) and apoptosis (cleaved caspase-3) by TDZD-8 was observed. Thus, TDZD-8 protects against CIA in rats for a period of 6 weeks, which is associated with the inhibition of miR155/24 and inflammation, and apoptosis augmentation.

IL-38 and IL-36 Target Autophagy for Regulating Synoviocyte Proliferation, Migration, and Invasion in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease leading to severe joint damage and disability. Fibroblast-like synoviocytes (FLSs) mostly contribute to the joint inflammation and destruction in RA through distinct mechanisms. However, little is known about newly discovered interleukin- (IL-) 36 and IL-38 involving in the pathology of RA. Here, we assessed the effect of IL-36 and IL-38 on RA-FLS function using IL-36 and IL-38 overexpression plasmids. We found that IL-36 inhibited synoviocytes proliferation while IL-38 showed an opposite influence. Furthermore, IL-36 and IL-38 significantly sequestered or accelerated RA-FLS migration and invasion capacity, respectively. Mechanically, IL-36 and IL-38 targeted autophagy for RA-FLS modulation. Using autophagy inhibitor 3-MA and inducer compound rapamycin, we found that autophagy negatively regulated the survival, migration, and invasion of synovial cells. Based on these results, IL-38 in combination with autophagy inhibitor 3-MA treatment demonstrated the strongest blockage of the above three activities of RA-FLS, and IL-38 overexpression reversed rapamycin-inhibited cell proliferation, migration, and invasion. Moreover, injection of IL-36 can improve the symptoms of RA in a rat model of RA. Taken together, we conclude that IL-38 and IL-36 target autophagy for regulating synoviocyte proliferation, migration, and invasion in RA.

Suppression of inflammatory arthritis by the parasitic worm product ES-62 is associated with epigenetic changes in synovial fibroblasts.

ES-62 is the major secreted protein of the parasitic filarial nematode, Acanthocheilonema viteae. The molecule exists as a large tetramer (MW, ~240kD), which possesses immunomodulatory properties by virtue of multiple phosphorylcholine (PC) moieties attached to N-type glycans. By suppressing inflammatory immune responses, ES-62 can prevent disease development in certain mouse models of allergic and autoimmune conditions, including joint pathology in collagen-induced arthritis (CIA), a model of rheumatoid arthritis (RA). Such protection is associated with functional suppression of "pathogenic" hyper-responsive synovial fibroblasts (SFs), which exhibit an aggressive inflammatory and bone-damaging phenotype induced by their epigenetic rewiring in response to the inflammatory microenvironment of the arthritic joint. Critically, exposure to ES-62 in vivo induces a stably-imprinted CIA-SF phenotype that exhibits functional responses more typical of healthy, Naïve-SFs. Consistent with this, ES-62 "rewiring" of SFs away from the hyper-responsive phenotype is associated with suppression of ERK activation, STAT3 activation and miR-155 upregulation, signals widely associated with SF pathogenesis. Surprisingly however, DNA methylome analysis of Naïve-, CIA- and ES-62-CIA-SF cohorts reveals that rather than simply preventing pathogenic rewiring of SFs, ES-62 induces further changes in DNA methylation under the inflammatory conditions pertaining in the inflamed joint, including targeting genes associated with ciliogenesis, to programme a novel "resolving" CIA-SF phenotype. In addition to introducing a previously unsuspected aspect of ES-62's mechanism of action, such unique behaviour signposts the potential for developing DNA methylation signatures predictive of pathogenesis and its resolution and hence, candidate mechanisms by which novel therapeutic interventions could prevent SFs from perpetuating joint inflammation and destruction in RA. Pertinent to these translational aspects of ES-62-behavior, small molecule analogues (SMAs) based on ES-62's active PC-moieties mimic the rewiring of SFs as well as the protection against joint disease in CIA afforded by the parasitic worm product.

Pterostilbene Coupled with Physical Exercise Effectively Mitigates Collagen-Induced Articular Synovial by Correcting the PI3K/Akt/NF-κB Signal Pathway.

Studies have revealed that a novel anti-inflammatory mediator─maresin-1 (MaR1)─can reduce the level of inflammatory factors. There is evidence that physical exercise (PE) promotes the biosynthesis of MaR1, leading to the prevention of rheumatoid arthritis (RA). Previously, we have proven that resveratrol can mitigate the formation of RA. Pterostilbene (Pte) is an analogue of resveratrol, but it is around four times more bioavailable. Hence, we hypothesize that Pte could be more effective in preventing RA, in particular, when accompanied by moderate PE. Based on this hypothesis, we explored the preventive effect of Pte combined with PE on a bovine type II collagen (BIIC)-stimulated rat RA model and its underlying molecular mechanism. Compared with the BIIC-stimulated group, the serum content of MaR1 with continuous intervention of Pte plus PE for 8 weeks was significantly increased to 46.3 pg/mL from 7.2 pg/mL in BIIC-treated alone. Besides, the variation in the relative expression levels of p-NF-κB and p-Akt was reversed with the administration of Pte plus PE. More importantly, the in vitro results confirmed that the treatment of Pte plus MaR1 inhibited proliferation and apoptosis and promoted the autophagy of the interleukin (IL)-1ß-stimulated primary rat synovial cells through the PI3K/Akt/NF-κB signal pathway. Collectively, the oral administration of Pte plus moderate PE helped to ameliorate the pathological process of RA by correcting the PI3K/Akt/NF-κB signal pathway.

Apelin Promotes Endothelial Progenitor Cell Angiogenesis in Rheumatoid Arthritis Disease via the miR-525-5p/Angiopoietin-1 Pathway.

Angiogenesis is a critical process in the formation of new capillaries and a key participant in rheumatoid arthritis (RA) pathogenesis. The adipokine apelin (APLN) plays critical roles in several cellular functions, including angiogenesis. We report that APLN treatment of RA synovial fibroblasts (RASFs) increased angiopoietin-1 (Ang1) expression. Ang1 antibody abolished endothelial progenitor cell (EPC) tube formation and migration in conditioned medium from APLN-treated RASFs. We also found significantly higher levels of APLN and Ang1 expression in synovial fluid from RA patients compared with those with osteoarthritis. APLN facilitated Ang1-dependent EPC angiogenesis by inhibiting miR-525-5p synthesis via phospholipase C gamma (PLCγ) and protein kinase C alpha (PKCα) signaling. Importantly, infection with APLN shRNA mitigated EPC angiogenesis, articular swelling, and cartilage erosion in ankle joints of mice with collagen-induced arthritis. APLN is therefore a novel therapeutic target for RA.

Bioactive compounds and therapeutic role of Brassica oleracea L. seeds in rheumatoid arthritis rats via regulating inflammatory signalling pathways and antagonizing interleukin-1 receptor action.

CONTEXT: Rheumatoid arthritis (RA) is a chronic, progressive autoimmune disease characterized by aggressive and systematic polyarthritis. OBJECTIVE: The present study aimed to isolate and identify the phenolic constituents in Brassica oleracea L. (Brassicaceae) seeds methanolic extract and evaluates its effect against rheumatoid arthritis in rats referring to the new therapy; interleukin-1 receptor antagonist (IL-1RA). MATERIALS AND METHODS: The GC/MS profiling of the plant was determined. Arthritis induction was done using complete Freund's adjuvant. Arthritis severity was assessed by percentage of edema and arthritis index. IL-1 receptor type I gene expression, interleukin-1ß (IL-1ß), oxidative stress markers, protein content, inflammatory mediators, prostaglandin-E2 (PGE2), genetic abnormalities and the histopathological features of ankle joint were evaluated. RESULTS: For the first time twelve phenolic compounds had been isolated from the seeds extract. Treatment with extract and IL-1RA improved the tested parameters by variable degrees. CONCLUSIONS: RA is an irreversible disease, where its severity increases with the time of induction. Brassica oleracea L. seeds extract is considered as a promising anti-arthritis agent. IL-1 RA may be considered as an unusual therapeutic agent for RA disease. More studies are needed to consider the seeds extract as a nutraceutical agent and to recommend IL-1RA as a new RA drug.