Targeting TNF-α-induced expression of TTR and RAGE in rheumatoid arthritis: Apigenin's mediated therapeutic approach.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic inflammatory disease induced by TNF-α, which increases fibroblast-like synoviocytes inflammation, resulting in cartilage destruction. The current work sought to comprehend the pathophysiological importance of TNF-α stimulation on differential protein expression and their regulation by apigenin using in-vitro and in-vivo models of RA. METHODS: The human RA synovial fibroblast cells were stimulated with or without TNF-α (10 ng/ml) and treated with 40 µM apigenin. In-silico, in-vitro and in-vivo studies were performed to confirm the pathophysiological significance of apigenin on pro-inflammatory cytokines and on differential expression of TTR and RAGE proteins. RESULTS: TNF-α induced inflammatory response in synoviocytes revealed higher levels of IL-6, IL-1ß, and TNF-α cytokines and upregulated differential expression of TTR and RAGE. In-silico results demonstrated that apigenin has a binding affinity towards TNF-α, indicating its potential effect in the inflammatory process. Both in-vitro and in-vivo results obtained by Western Blot analysis suggested that apigenin reduced the level of p65 (p = 0.005), TTR (p = 0.002), and RAGE (p = 0.020). CONCLUSION: The findings of this study suggested that TNF-α promotes the differential expression of pro-inflammatory cytokines, TTR, and RAGE via NF-kB pathways activation. Anti-inflammatory effect of apigenin impedes TNF-α mediated dysregulation or expression associated with RA pathogenesis.

Aberrant pro-inflammatory responses of CD20+ T cells in experimental arthritis.

CD20+ T cells comprise a highly inflammatory subset implicated in autoimmunity, including rheumatoid arthritis (RA). We sought to characterize the CD20+ T cell subset in the murine collagen-induced arthritis (CIA) model of RA and investigate the phenotype and functional relevance of CD3+CD20+ T cells in the lymph nodes and arthritic joints using flow cytometry and immunohistochemistry. We demonstrate that CD3+CD4+CD20+ and CD3+CD8+CD20+ T cells are expanded in the draining lymph nodes of CIA mice, produce increased levels of pro-inflammatory cytokines and are less susceptible to regulation by regulatory T cells. Notably, CD3+CD4+CD20+ and CD3+CD8+CD20+ T cells are enriched with CXCR5+PD-1+ T follicular helper cells and CXCR5-PD-1+ peripheral T helper cells, subsets of T cells implicated in promoting B-cell responses and antibody production within pathologically inflamed non-lymphoid tissues in RA. Our findings suggest CD20+ T cells are associated with inflammatory responses and may exacerbate pathology by promoting inflammatory B-cell responses.

CP-25 enhances OAT1-mediated absorption of methotrexate in synoviocytes of collagen-induced arthritis rats.

Organic anion transporter 1 (OAT1) plays a major role in mediating the absorption, distribution and excretion of drugs and other xenobiotics in the human body. In this study we explored the OAT1 status in rheumatoid arthritis (RA) patients and arthritic animals and its role in regulating the anti-arthritic activity of methotrexate (MTX). We showed that OAT1 expression was significantly downregulated in synovial tissues from RA patients compared with that in the control patients. In collagen-induced arthritis (CIA) rats, synovial OAT1 expression was significantly decreased compared with the control rats. In synoviocytes isolated from CIA rats, PGE2 (0.003-1.75 µM) dose-dependently downregulated OAT1 expression, resulting in decreased absorption of MTX. Silencing OAT1 in synoviocytes caused a 43.7% reduction in the uptake of MTX. Furthermore, knockdown of OAT1 impaired MTX-induced inhibitory effects on the viability and migration of synoviocytes isolated from CIA rats. Moreover, injection of OAT1-shRNA into articular cavity of CIA rats significantly decreased synovial OAT1 expression and impaired the anti-arthritic action of MTX, while injection of lentivirus containing OAT1 sequences led to the opposite results. Interestingly, we found that paeoniflorin-6'-O-benzene sulfonate (CP-25) upregulated OAT1 expression both in vitro and in vivo and promoted MTX uptake by synoviocytes via regulating OAT1 expression and function. Taken together, OAT1 plays a major role in regulating MTX uptake by synoviocytes and the anti-arthritic activity of MTX. OAT1 is downregulated in RA and CIA rats, which can be improved by CP-25.

Resistant starch intake alleviates collagen-induced arthritis in mice by modulating gut microbiota and promoting concomitant propionate production.

Gut dysbiosis precedes clinic symptoms in rheumatoid arthritis (RA) and has been implicated in the initiation and persistence of RA. The early treatment of RA is critical to better clinical outcome especially for joint destruction. Although dietary interventions have been reported to be beneficial for RA patients, it is unclear to whether diet-induced gut microbiome changes can be a preventive strategy to RA development. Here, we investigated the effect of a high fiber diet (HFD) rich with resistant starch (RS) on collagen-induced arthritis (CIA) and gut microbial composition in mice. RS-HFD significantly reduced arthritis severity and bone erosion in CIA mice. The therapeutic effects of RS-HFD were correlated with splenic regulatory T cell (Treg) expansion and serum interleukin-10 (IL-10) increase. The increased abundance of Lactobacillus and Lachnoclostridium genera concomitant with CIA were eliminated in CIA mice fed the RS-HFD diet. Notably, RS-HFD also led to a predominance of Bacteroidetes, and increased abundances of Lachnospiraceae_NK4A136_group and Bacteroidales_S24-7_group genera in CIA mice. Accompanied with the gut microbiome changes, serum levels of the short-chain fatty acid (SCFA) acetate, propionate and isobutyrate detected by GC-TOFMS were also increased in CIA mice fed RS-HFD. While, addition of ß-acids from hops extract to the drinking water of mice fed RS-HFD significantly decreased serum propionate and completely eliminated RS-HFD-induced disease improvement, Treg cell increase and IL-10 production in CIA mice. Moreover, exogenous propionate added to drinking water replicated the protective role of RS-HFD in CIA including reduced bone damage. The direct effect of propionate on T cells in vitro was further explored as at least one mechanistic explanation for the dietary effects of microbial metabolites on immune regulation in experimental RA. Taken together, RS-HFD significantly reduced CIA and bone damage and altered gut microbial composition with concomitant increase in circulating propionate, indicating that RS-rich diet might be a promising therapy especially in the early stage of RA.

The therapeutic effects of edaravone on collagen-induced arthritis in rats.

Current research suggests that synovial phagocytic cells remove excessive amounts of free oxygen radicals (reactive oxygen species [ROS]), thereby preventing damage to synovial tissues. Moreover, ROS may affect the expression of growth arrest and DNA damage inducible α (GADD45A), thus further promoting the activation of synovial fibroblasts. Male adult rats were assessed for progression of collagen-induced arthritis (CIA) using a macroscopic arthritis scoring system of the hind paws and by measuring the changes in the rat's body weight, and activity level before and after diagnosis of CIA. Rats were intraperitoneally injected twice daily with edaravone at doses of 3, 6, and 9 mL/kg. Samples were taken at 2, 4, and 6 weeks, respectively. Edaravone was found to significantly reduce macroscopic arthritis and microscopic pathology scores in CIA rats. The concentration of endothelial nitric oxide synthase-6, glutathione, and heme oxygenase-1 in the serum of rats decreased, as was the production of ROS around the synovium and inflammatory factors. Moreover, ROS-1 increased the expression of the nuclear factor-κB (NF-κB) p65 protein by altering the expression level of GADD45A, causing aggravation of tissue damage. Edaravone also significantly improved the physiological condition of CIA rats, including appetite, weight changes, and loss of fur, as well as limb mobility. We believe that edaravone acts to reduce the expression of NF-ĸB p65 by clearing ROS, which causes reduced expression of GADD45A, and subsequently reduces the level of apoptosis and inflammatory response proteins, thereby reducing the symptoms of CIA. We, therefore, propose that edaravone is an effective option for clinical treatment of rheumatic arthritis.

Aryl hydrocarbon receptor suppresses the osteogenesis of mesenchymal stem cells in collagen-induced arthritic mice through the inhibition of ß-catenin.

The contributions of aryl hydrocarbon receptor (Ahr) to the pathogenesis of rheumatoid arthritis (RA), particularly bone loss, have not been clearly explored. The imbalance between osteoblasts and osteoclasts is a major reason for bone loss. The dysfunction of osteoblasts, which are derived from mesenchymal stem cells (MSCs), induced bone erosion occurs earlier and is characterized as more insidious. Here, we showed that the nuclear expression and translocation of Ahr were both significantly increased in MSCs from collagen-induced arthritis (CIA) mice. The enhanced Ahr suppressed the mRNA levels of osteoblastic markers including Alkaline phosphatase (Alp) and Runt-related transcription factor 2 (Runx2) in the differentiation of MSCs to osteoblasts in CIA. The 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD)-mediated activation of Ahr dose-dependently suppressed the expression of osteoblastic markers. In addition, the expression of ß-catenin was reduced in CIA MSCs compared with control, and the TCDD-mediated activation of the Ahr significantly inhibited ß-catenin expression. The Wnt3a-induced the activation of Wnt/ß-catenin pathway partly rescued the osteogenesis decline induced by TCDD. Taken together, these results indicate that activated Ahr plays a negative role in CIA MSCs osteogenesis, possibly by suppressing the expression of ß-catenin.

Herbal formula Xian-Fang-Huo-Ming-Yin regulates differentiation of lymphocytes and production of pro-inflammatory cytokines in collagen-induced arthritis mice.

BACKGROUND: Xian-Fang-Huo-Ming-Yin (XFHM), a traditional herbal formula, has been used to treat sores and carbuncles for hundreds of years in Asia. Nowadays, its clinical effects in treatment of rheumatoid arthritis (RA) have been validated. In this study, we want to study its possible molecular mechanisms of regulating the differentiation of lymphocytes and production of pro-inflammatory cytokines in collagen-induced arthritis (CIA) mice for RA treatment. METHODS: A high performance liquid chromatography-electrospray ionization/mass spectrometer (HPLC-ESI/MSn) system was used to analyze the constituents of XFHM granules. An arthritics mouse model was induced by collagen and leflunomide (LEF) was used as a positive control medicine. Pathological changes at the metatarsophalangeal joint were studied through Safranin O and immunohistochemical staining. The differentiation of T, B and NK cells was examined by flow cytometry and pro-inflammatory cytokines were assayed using an Inflammation Antibody Array assay. The expression of key molecules of the nuclear factor κB (NF-κB) and Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathways in spleen were studied by western-blot analysis. RESULTS: In our study. 21 different dominant chemical constituents were identified in XFHM. Treatment with XFHM suppressed the pathological changes in arthrosis of CIA. Additionally, XFHM down-regulated the proliferation and differentiation of CD3+ T cells and CD3-CD19+ B cells significantly. However, XFHM had no significant effect on CD3-NK1.1+ NK cells. Further study showed that the production of pro-inflammatory cytokines had been suppressed by inhibiting the activation of NF-κB and JAK/STAT signaling. CONCLUSIONS: XFHM can regulate and maintain the immunologic balance of lymphocytic immunity and inhibit the production of pro-inflammatory cytokines, thus suppressing the pathological changes of RA. Therefore, XFHM may be used as an application of traditional medicine against RA in modern complementary and alternative therapeutics.

Spectrum-Effect Relationships between Fingerprints of Caulophyllum robustum Maxim and Inhabited Pro-Inflammation Cytokine Effects.

Caulophyllum robustum Maxim (CRM) is a Chinese folk medicine with significant effect on treatment of rheumatoid arthritis (RA). This study was designed to explore the spectrum-effect relationships between high-performance liquid chromatography (HPLC) fingerprints and the anti-inflammatory effects of CRM. Seventeen common peaks were detected by fingerprint similarity evaluation software. Among them, 15 peaks were identified by Liquid Chromatography-Mass Spectrometry (LC-MS). Pharmacodynamics experiments were conducted in collagen-induced arthritis (CIA) mice to obtain the anti-inflammatory effects of different batches of CRM with four pro-inflammation cytokines (TNF-α, IL-ß, IL-6, and IL-17) as indicators. These cytokines were suppressed at different levels according to the different batches of CRM treatment. The spectrum-effect relationships between chemical fingerprints and the pro-inflammation effects of CRM were established by multiple linear regression (MLR) and gray relational analysis (GRA). The spectrum-effect relationships revealed that the alkaloids (N-methylcytisine, magnoflorine), saponins (leiyemudanoside C, leiyemudanoside D, leiyemudanoside G, leiyemudanoside B, cauloside H, leonticin D, cauloside G, cauloside D, cauloside B, cauloside C, and cauloside A), sapogenins (oleanolic acid), ß-sitosterols, and unknown compounds (X3, X17) together showed anti-inflammatory efficacy. The results also showed that the correlation between saponins and inflammatory factors was significantly closer than that of alkaloids, and saponins linked with less sugar may have higher inhibition effect on pro-inflammatory cytokines in CIA mice. This work provided a general model of the combination of HPLC and anti-inflammatory effects to study the spectrum-effect relationships of CRM, which can be used to discover the active substance and to control the quality of this treatment.

Therapeutic effect of ergotope peptides on CIA by down-regulation of inflammatory and Th1/Th17 responses and induction of regulatory T cells.

Rheumatoid arthritis (RA) is a systemic autoimmune disease that results in a chronic and inflammatory disorder. Dynamic balance of helper T cells (Th)1, Th17 and regulatory T cells (Treg) is broken in RA. Since there is no cure for RA at present, it's necessary to find a truly effective and convenient treatment. Several studies intended to induce ergotopic regulation to treat autoimmune diseases. This study was undertaken to find the potential ergotope peptides and investigate its effect in treating the animal model of RA and their underlying regulatory mechanisms. Firstly, we selected the functional ergotope peptides from 25 overlapping peptides derived from interlukin(IL)-2 receptor (IL-2R) α chain, and then used these peptides to treat collagen-induced arthritis (CIA). The study showed ergotope peptides as immunomodulatory factors with great benefits at the clinical and pathologic levels. This effect was associated with the inhibition of type II collagen (CII)-specific proliferation and autoantibody production as well as the induction of anti-ergotypic immune response, the down-regulation of both Th1 and Th17 cells and their related components, and the emergence of Treg cells that had suppressive actions on autoreactive T cells. We also proved that cytotoxic T lymphocyte associated antigen-4 (CTLA-4) and IL-10 are two important mediators which are critical to Treg suppressive function. The inhibition of Th1 and Th17 in established CIA could be attributed to ergotope induced Treg cells. Our findings reveal that ergotope peptides induce regulatory immune responses and restore immune tolerance, suggesting ergotope peptides treatment appears to be a novel approach to the therapy of RA patients and has a good application prospect with cheap, effective, convenient, wide-spectrum features.

Approaching the active conformation of 1,3-diaminopyrimidine based covalent inhibitors of Bruton's tyrosine kinase for treatment of Rheumatoid arthritis.

By applying conformational restrictions, we were able to discover highly potent 1,3-diaminopyrimidine based covalent inhibitors of BTK, such as 8a (IC50=3.76 nM), and providing useful information of its active conformation. We are developing these novel small molecule covalent inhibitors of BTK toward oral agents for Rheumatoid arthritis.

Novel peptide inhibitor of human tumor necrosis factor-α has antiarthritic activity.

The inhibition of tumor necrosis factor (TNF)-α trimer formation renders it inactive for binding to its receptors, thus mitigating the vicious cycle of inflammation. We designed a peptide (PIYLGGVFQ) that simulates a sequence strand of human TNFα monomer using a series of in silico methods, such as active site finding (Acsite), protein-protein interaction (PPI), docking studies (GOLD and Flex-X) followed by molecular dynamics (MD) simulation studies. The MD studies confirmed the intermolecular interaction of the peptide with the TNFα. Fluorescence-activated cell sorting and fluorescence microscopy revealed that the peptide effectively inhibited the binding of TNF to the cell surface receptors. The cell culture assays showed that the peptide significantly inhibited the TNFα-mediated cell death. In addition, the nuclear translocation of the nuclear factor kappa B (NFκB) was significantly suppressed in the peptide-treated A549 cells, as observed in immunofluorescence and gel mobility-shift assays. Furthermore, the peptide protected against joint damage in the collagen-induced arthritis (CIA) mouse model, as revealed in the micro focal-CT scans. In conclusion, this TNFα antagonist would be helpful for the prevention and repair of inflammatory bone destruction and subsequent loss in the mouse model of CIA as well as human rheumatoid arthritis (RA) patients. This calls upon further clinical investigation to utilize its potential effect as an antiarthritic drug.

Discovery of N-{5-[3-(3-hydroxypiperidin-1-yl)-1,2,4-oxadiazol-5-yl]-4-methyl-1,3-thiazol-2-yl}acetamide (TASP0415914) as an orally potent phosphoinositide 3-kinase γ inhibitor for the treatment of inflammatory diseases.

Class I phosphoinositide 3-kinases (PI3Ks), particularly PI3Kγ, have become attractive drug targets for inflammatory and autoimmune disorders such as rheumatoid arthritis. Herein, we describe the synthesis and the structure-activity relationships (SAR) of a series of 2-amino-5-oxadiazolyl thiazoles, culminating in the identification of 8j (TASP0415914), an orally potent inhibitor of phosphoinositide 3-kinase γ (PI3Kγ). TASP0415914 demonstrated good potency in a cell-based assay and, furthermore, exhibited in vivo efficacy in a collagen induced arthritis (CIA) model in mice after oral administration.

The newly engineered monoclonal antibody ON104, targeting the oxidized Macrophage Migration Inhibitory Factor (oxMIF), ameliorates clinical and histopathological signs of collagen-induced arthritis.

Macrophage Migration Inhibitory Factor (MIF) is a pleiotropic inflammatory cytokine that emerged as a pivotal regulator in the pathogenesis of several autoimmune diseases including rheumatoid arthritis (RA). MIF occurs in two immunologically distinct conformational isoforms, indicated as reduced (redMIF) and oxidized MIF (oxMIF) where the latter exerts disease-related activities. In this study we demonstrate the presence of circulating oxMIF in RA patients and investigate the in vivo effects of an oxMIF-neutralizing antibody in a murine model of RA. By advanced antibody engineering we generated the fully human anti-oxMIF antibody ON104 with abolished effector functions. The therapeutic potential of ON104 was tested in a model of Collagen-Induced Arthritis (CIA) in DBA/1j mice. At disease onset, the mice received ON104 twice a week for three weeks. Clinical symptoms were assessed daily, and histological examinations of the joints were performed at the end of the study. Antibody ON104, specifically targeting human and murine oxMIF, is highly affine and does not elicit effector functions in vitro. The treatment of CIA mice with ON104 profoundly modulated disease progression with marked amelioration of clinical signs of arthritis that was associated with reduced synovial and cartilage damage and reduced F4/80-positive macrophages in the joints. These data prove that oxMIF is a relevant target in a well-known model of human RA and its specific neutralization by the antibody ON104 ameliorates clinical and histological signs of the disease in the so-treated mice. Thus, ON104 represents a new and promising treatment option for RA and possibly other autoimmune diseases.

Simiao pill attenuates collagen-induced arthritis and bleomycin-induced pulmonary fibrosis in mice by suppressing the JAK2/STAT3 and TGF-ß/Smad2/3 signalling pathway.

ETHNOPHAMACOLOGICAL RELEVANCE: Simiao Pill (SM) as a classic prescription of traditional Chinese medicine treatment of damp-heat arthralgia, the earliest from 'Cheng Fan Bian Du ', written by the Qing Dynasty doctor Zhang Bingcheng. Previous studies have shown that SM has obvious curative effect on rheumatoid arthritis, which provides a basis for the application of SM in rheumatoid arthritis related complications. AIM OF THE STUDY: Interstitial lung disease (ILD), as the most severe complication of rheumatoid arthritis (RA), lacks effective clinical treatments and a corresponding animal model. Simiao pill (SM) is a traditional Chinese medicine prescription extensively used as a complementary and alternative treatment for RA. However, the effect and mechanism of SM on RA-ILD have not yet been reported. This study aimed to investigate an appropriate animal model that can simulate RA-ILD, and the efficacy, safety, and mechanism of SM on RA-ILD. METHODS: Collagen-induced arthritis (CIA) and bleomycin-induced pulmonary fibrosis model were combined to construct the CIA-BLM model. After the intervention of SM, the protective effects of SM on RA-ILD were determined by detecting the CIA mouse arthritis index (AI), Spleen index, and the extent of pulmonary fibrosis. The joint inflammation and pulmonary fibrosis were detected by immunohistochemistry, H&E staining, safranin- O fast green Sirius red staining, trap staining, and Masson staining. Finally, the mechanism was verified by Western blot and immunohistochemistry. RESULTS: Our work showed that SM significantly reduced joint swelling, arthritis index, pulmonary fibrosis score, and spleen index in CIA mice. The pathological examination results indicated Si-Miao Pill suppressed inflammation, pulmonary fibrosis, bone erosion, and cartilage degradation of the ankle joint. Besides, SM up-regulated expressions of E-cadherin, whereas down-regulated expressions of α-SMA. Further studies confirmed that SM regulated JAK2/STAT3 and TGF-ß/SMAD2/3. CONCLUSION: SM can not only effectively improve joint inflammation by JAK2/STAT3 Pathway but also inhibit pulmonary fibrosis by TGF-ß/SMAD2/3. The fibrosis induced by CIA-BLM model was more stable and obvious than that induced by CIA model alone.

Therapeutic Efficacy of Mesenchymal Stem/Stromal Cell Small Extracellular Vesicles in Alleviating Arthritic Progression by Restoring Macrophage Balance.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by joint inflammation and damage, often associated with an imbalance in M1/M2 macrophages. Elevated levels of anti-inflammatory M2 macrophages have been linked to a therapeutic response in RA. We have previously demonstrated that mesenchymal stem/stromal cell small extracellular vesicles (MSC-sEVs) promote M2 polarization and hypothesized that MSC-sEVs could alleviate RA severity with a concomitant increase in M2 polarization. Here, we treated a mouse model of collagen-induced arthritis (CIA) with MSC-sEVs. Relative to vehicle-treated CIA mice, both low (1 µg) and high (10 µg) doses of MSC-sEVs were similarly efficacious but not as efficacious as Prednisolone, the positive control. MSC-sEV treatment resulted in statistically significant reductions in disease progression rate and disease severity as measured by arthritic index (AI), anti-CII antibodies, IL-6, and C5b-9 plasma levels. There were no statistically significant differences in the treatment outcome between low (1 µg) and high (10 µg) doses of MSC-sEVs. Furthermore, immunohistochemical analysis revealed that concomitant with the therapeutic efficacy, MSC-sEV treatment increased anti-inflammatory M2 macrophages and decreased pro-inflammatory M1 macrophages in the synovium. Consistent with increased M2 macrophages, histopathological examination also revealed reduced inflammation, pannus formation, cartilage damage, bone resorption, and periosteal new bone formation in the MSC-sEV-treated group compared to the vehicle group. These findings suggest that MSC-sEVs are potential biologic disease-modifying antirheumatic drugs (DMARDs) that can help slow or halt RA joint damage and preserve joint function.

Blocking prokineticin receptors attenuates synovitis and joint destruction in collagen-induced arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory disease mediated by an interdependent network of proinflammatory molecules such as chemokines. Prokineticin 2 (PK2) is a chemokine-like peptide that modulates nociceptive threshold and immuno-inflammatory processes via two G-protein-linked receptors, prokineticin receptor 1 and 2 (PKR1 and PKR2). In the present study, we investigated the effects of the prokineticin receptor antagonist PC1 on arthritic pain and the inflammatory response in type II collagen-induced arthritis (CIA) in mice. We demonstrated that PC1, administered subcutaneously from day 25 to day 35 after CIA, improved clinical signs of arthritis such as paw edema, pain, and impaired locomotor activity. In CIA mice, PC1 was also able to lower plasma malondialdehyde (MDA) levels, suggesting a role in reducing oxidative damage, as well as joint expression levels of PK2, PKRs, TNFα, IL-1ß, CD4, CD8, and NF-kB. These results suggest that blocking PKRs may be a successful strategy to control arthritic pain and pathology development. KEY MESSAGES: PK2/PKRs expression levels strongly increase in the synovium of RA mice. PC1 treatment shows anti-arthritic activity and reduces arthritis-induced pain. PC1 treatment significantly lowers synovial PK2/PKRs levels. PC1 treatment lowers plasma MDA levels and synovial levels of TNFα and IL -1ß PC1 treatment is a viable therapeutic option for RA.

C-Terminal Region of Caveolin-3 Contains a Stretch of Amino Acid Residues Capable of Diminishing Symptoms of Experimental Autoimmune Encephalomyelitis but Not Rheumatoid Arthritis Modeled in Rats.

A short synthetic peptide from the C-terminal part of the caveolin-3 structure was tested for experimental autoimmune encephalomyelitis (EAE) treatment in rats. The structure-function similarity established between the novel synthetic peptide of pCav3 and the well-known immunomodulator immunocortin determined pCav3's ability to reduce EAE symptoms in Dark Agouti (DA) rats injected with pCav3 (500 µg/kg). pCav3 was found to interfere with the proliferation of lymphocytes extracted from the LNs of DA rats primed with homogenate injection, with IC50 = 0.42 µM (2.35 mcg/mL). pCav3 affected EAE in a very similar manner as immunocortin. The high degree of homology between the amino acid sequences of pCav3 and immunocortin corresponded well with the therapeutic activities of both peptides, as demonstrated on EAE. The latter peptide, possessing a homologous structure to pCav3, was also tested on EAE to explore whether there were structural restrictions between these peptides implied by the MHC-involved cell machinery. Consequently, immunocortin was further examined with a different autoimmune disease model, collagen-induced arthritis (CIA), established in Sprague-Dawley rats. CIA was established using an intentionally different genetic platform than EAE. Based on the results, it was concluded that the effectiveness of pCav3 and immunocortin peptides in EAE rat model was almost identical, but differed in the rat model of rheumatoid arthritis; thus, efficacy may be sensitive to the MHC type of animals used to establish the autoimmune disease model.

Pharmacology and molecular docking study of cartilage protection of Chinese herbal medicine Fufang Shatai Heji (STHJ) by inhibiting the expression of MMPs in collagen-induced arthritis mice.

BACKGROUND: This study aims to explore whether Fufang Shatai Heji (STHJ), as a mixture collected by a decoction of a variety of Chinese herbal medicines for immune system diseases, can improve the cartilage destruction of rheumatoid arthritis (RA). METHODS: The therapeutic effects of STHJ were studied using collagen induced arthritis (CIA) mice. The improvement effect of STHJ on synovitis and cartilage damage caused by arthritis was studied by joint pathological analysis. The inhibitory effect of STHJ on related degradation enzymes in cartilage was studied by immunohistochemistry and real-time polymerase chain reaction (PCR). The specific targets of STHJ were predicted by molecular docking. RESULTS: After successfully inducing CIA, the paws of the mice showed significant swelling, and athological analysis of the ankle and knee joints also showed significant cartilage destruction and synovial hyperplasia. However, synovial hyperplasia and cartilage destruction were markedly alleviated after administration of STHJ. And after STHJ treatment, the expression of ADAMTS-4, ADAMTS-5, MMP-9 and MMP-13, in the cartilage layer of CIA mice was significantly inhibited. Through molecular docking assays, we proved that acteoside in STHJ could directly bind to the Glu111, Phe110 residues in MMP-9 and glycyrrhizic acid in STHJ bind to the Glu382, Asn433 residues in MMP-13. CONCLUSIONS: Our results suggested that STHJ may alleviate synovial hyperplasia and cartilage destruction in CIA mice and protect cartilage by inhibiting the expression of MMP-9 and other enzymes.

Angiotensin AT2 Receptor Stimulation Alleviates Collagen-Induced Arthritis by Upregulation of Regulatory T Cell Numbers.

The angiotensin AT2 receptor (AT2R) is a main receptor of the protective arm of the renin-angiotensin system and exerts for instance anti-inflammatory effects. The impact of AT2R stimulation on autoimmune diseases such as rheumatoid arthritis (RA) is not yet known. We investigated the therapeutic potential of AT2R-stimulation with the selective non-peptide AT2R agonist Compound 21 (C21) in collagen-induced arthritis (CIA), an animal model for inflammatory arthritis. Arthritis was induced by immunization of DBA/1J mice with collagen type II (CII). Prophylactic and therapeutic C21 treatment alleviates arthritis severity and incidence in CIA. Joint histology revealed significantly less infiltrates of IL-1 beta and IL-17A expressing cells and a well-preserved articular cartilage in C21- treated mice. In CIA, the number of CD4+CD25+FoxP3+ regulatory T (Treg) cells significantly increased upon C21 treatment compared to vehicle. T cell differentiation experiments demonstrated increased expression of FoxP3 mRNA, whereas IL-17A, STAT3 and IFN-gamma mRNA expression were reduced upon C21 treatment. In accordance with the mRNA data, C21 upregulated the percentage of CD4+FoxP3+ cells in Treg polarizing cultures compared to medium-treated controls, whereas the percentage of CD4+IL-17A+ and CD4+IFN-gamma+ T cells was suppressed. To conclude, C21 exerts beneficial effects on T cell-mediated experimental arthritis. We found that C21-induced AT2R-stimulation promotes the expansion of CD4+ regulatory T cells and suppresses IL-17A production. Thus, AT2R-stimulation may represent an attractive treatment strategy for arthritis.

Ninjin'yoeito suppressed the onset of arthritis, pain, and muscle atrophy in rheumatoid arthritis model mice.

Rheumatoid arthritis is one of the most common diseases in orthopedic surgery. The main symptoms are joint pain and systemic symptoms. In recent years, rheumatoid arthritis is known to cause sarcopenia. Ninjin'yoeito (NYT), a traditional Japanese medicine, has been prescribed for patients with post-illness or post-operative weakness, fatigue, loss of appetite, rash, cold limbs, and anemia. In addition to its traditional use, NYT has been prescribed for treating frailty in gastrointestinal, respiratory, and urinary functions. Further, NYT is known to be effective in suppressing muscle atrophy in the prior literature. The present study aimed to investigate whether NYT suppresses various symptoms of the Collagen-induced arthritis (CIA) model. Long-term administration of NYT inhibited the increases in arthritis scores, decreases pain threshold, and muscle atrophy in the CIA model. In addition, NYT inhibited the elevation of the plasma IL-6 level. These results suggest that NYT may have therapeutic effects on symptoms, muscle atrophy and increase in plasma IL-6 level caused by rheumatoid arthritis.