Collagen-induced Arthritis Research Articles

Jinwu Jiangu capsule attenuates rheumatoid arthritis via the SLC7A11/GSH/GPX4 pathway in M1 macrophages.

JinWu JianGu capsule (JWJGC) is a Chinese herbal medicine that alleviates the clinical manifestations of rheumatoid arthritis (RA). However, the mechanism of action requires further investigation.. This study aimed to investigate the anti-inflammatory effects of JWJGC on RA via the regulation of reactive oxygen species (ROS) and ferroptosis. JWJGC was administered to rats with collagen-induced arthritis (CIA) via oral gavage for 28 days. In vitro, M1 macrophages were pre-treated with JWJGC-containing serum. After assessing joint swelling and physiologic, the M1/M2 macrophage ratio was detected in CIA rats. The levels of ROS markers were assessed in the serum and cell supernatants. Liquid chromatography-tandem mass spectrometry analyses were employed to check lipid metabolism, and changes in mitochondrial morphology during ferroptosis were detected by transmission electron microscopy. Western blotting, immunofluorescence, immunohistochemistry, and qRT-PCR were performed to validate these results. JWJGC ameliorated CIA by reducing ROS levels in rats. It also restored the balance of the M1/M2 macrophage ratio and reduced the levels of macrophage-related inflammatory markers. Additionally, JWJGC affected lipid metabolism to alleviate inflammation by downregulating lipids associated with ferroptosis. It attenuated ferroptosis by modulating glutathione (GSH)/ Glutathione peroxidase 4(GPX4) expression in CIA rats. In vitro, JWJGC targeted M1 macrophages via the solute carrier family 7a member 11 (SLC7A11)/GSH/GPX4 signaling pathway. This study showed that JWJGC improved RA, primarily through the integrated regulation of the SLC7A11/GSH/GPX4 pathway in M1 macrophages. These findings provide an innovative therapeutic basis for RA treatment and expanding the clinical applications of JWJGC.

Treatment with tofacitinib attenuates muscle loss through myogenin activation in the collagen-induced arthritis.

Sarcopenia is a muscle disease characterized by reduction of muscle strength and muscle mass. In RA, 25.9 to 43.3% of the patients present sarcopenia. The loss of muscle mass observed in RA patients occurs either by activation of catabolic pathways or by inhibition of anabolic pathways. Despite having a list of drugs capable of treating RA inflammation, their effect on muscle is unclear. Our objective was to evaluate the tofacitinib effect on the muscle mass of collagen-induced arthritis (CIA) mice. CIA was induced in male DBA/1J mice by subcutaneous injection of Type 2 Collagen plus Freund Adjuvant. Animals were randomized into 3 groups: CIA + tofacitinib; CIA + vehicle; and healthy controls. Treatment was administered twice a day, between days 18 and 45 after induction. Clinical score, edema, and body weight were evaluated during the experimental period. After euthanasia, tibiotarsal joints were collected for assessment of disease histopathological score, and tibialis anterior (TA) and gastrocnemius (GA) muscles were weighed to assess muscle mass. Muscle atrophy was evaluated by measurement of TA myofiber cross-sectional area (CSA). Protein expression was evaluated by western blot using GA homogenates. Serum inflammatory markers were evaluated by ELISA. Statistical analysis included ANOVA followed by Tukey's or with Kruskal-Wallis. The statistical difference was assumed for p < 0.05. Tofacitinib treatment decreased arthritis severity by reducing clinical score, and hind paw edema in comparison with the vehicle group. Tofacitinib showed weight gain, higher TA and GA weights, and increased CSA compared to the vehicle group. On day 45, Tofacitinib presented increased muscle strength compared to the vehicle group, however, no difference was found in muscle fatigue. Pax7 expression was unchanged, while MyoD expression showed an increasing trend, and myogenin expression was significantly increased in Tofacitinib compared to vehicle and control groups. The treatment didn't modify Murf-1 expression. Tofacitinib mice showed decreased serum levels of TNF and increased IL-6 serum levels. Tofacitinib attenuated muscle loss in arthritic mice, increased muscle weight and muscle CSA. Activation of satellite cell regeneration, based on the increased expression of myogenin, is a potential mechanism involved in tofacitinib action against muscle loss.

Therapeutic Dose of Zinc Aspartate and Zinc Citrate Attenuates Disease Activity Indices in Rheumatoid Arthritis.

Zinc aspartate and zinc citrate have been used as zinc supplements in different health conditions. Taking into consideration their anti-inflammatory, immunomodulatory, anti-oxidant and antimicrobial properties, the present study has been designed to analyse the effect of zinc aspartate and zinc citrate treatment at therapeutic dose level on disease severity index, haematological, serological, antimicrobial and radiological markers of rheumatoid arthritis in Wistar rats. Bactericidal potential of the two organic zinc compounds was analysed in vitro in clinically isolated Escherichia coli. Arthritis was induced in male Wistar rats by intradermal injection of an emulsion containing collagen type II and Complete Freund's Adjuvant (CFA) containing 1mgmL-1 Mycobacterium tuberculosis H37Ra. Zinc aspartate and zinc citrate were orally administered after the onset of the disease for 4weeks. Ameliorative effect of zinc aspartate and zinc citrate was evaluated by analysing indices of severity and disease activity markers of rheumatoid arthritis. The liver and kidney function tests were performed to evaluate any possible adverse effect of compounds. Antimicrobial activity of the zinc compounds was assessed in clinically isolated E. coli by MTT assay. Zinc aspartate and zinc citrate equivalent to a therapeutic dose of 50mg/day of elemental zinc attenuated the clinical characteristic of rheumatoid arthritis in the animal model of arthritis, collagen-induced arthritis (CIA). Both zinc salts also exhibited antimicrobial effects against E. coli. The selected dose of zinc aspartate and zinc citrate showed no adverse effects in treated rats. This study highlights the potentiality of zinc compounds as antiarthritic agents and also point to its preventive effects on microbial growth that has been observed in rheumatoid arthritis patients due to their increased sensitivity for bacterial infection.

Regulation of neutrophil associated RNASET2 expression in rheumatoid arthritis

Neutrophils (PMNs) are key players of innate immune responses through the release of cytoplasmic granule content and the formation of neutrophil extracellular traps (NETs). RNASET2 is an acidic ribonuclease, recently proposed as an alarmin signal associated with inflammatory responses. Here we show that, along the neutrophil maturation cascade, RNASET2 is expressed in segmented and mature PMNs. In human PMNs, RNASET2 colocalized with primary and tertiary granules and was found to be associated with NETs following PMA or Nigericin stimulation. Similarly, activation of PMNs by soluble immune complexes, a hallmark of several autoimmune diseases, also induced RNASET2-associated NETs. Genome-wide association studies recently identified RNASET2 among a cluster of genes associated with increased susceptibility to develop autoimmune diseases, including rheumatoid arthritis (RA). RNASET2 was found expressed by PMNs and macrophages infiltrating inflamed joints in a murine model of RA (K/BxN Serum-Transfer-Induced Arthritis, STIA), by immunostaining. Similar results were found in synovial biopsies of RA patients with active disease. In addition, we demonstrate that RNASET2 circulating levels correlated with the onset and the severity of disease in two mouse models of inflammatory arthritis, STIA and CIA (Collagen-Induced Arthritis) and in serum of RA patients. These results show that PMNs are an important source of RNASET2 and that its circulating levels are associated with RA development suggesting a role for RNASET2 in the pathogenesis of immune-mediated diseases.

GZMK Facilitates Experimental Rheumatoid Arthritis Progression by Interacting with CCL5 and Activating the ERK Signaling.

Synovial over-proliferation is a key event in the progression of rheumatoid arthritis (RA) disease. Ferroptosis may be essential for maintaining the balance between synovial proliferation and death. This study aimed to investigate the molecular mechanisms mediating the activation and ferroptosis of collagen-induced arthritis(CIA)-synovial fibroblasts (SFs). Differentially expressed genes (DEGs) in the synovial tissues of CIA rats and normal rats were screened through sequencing. The GSE115662 dataset from the GEO database was analyzed and screened for DEGs. The viability, proliferation, migration, invasion, cell cycle, and apoptosis of CIA-SFs were analyzed by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, flow cytometry, transwell migration, and invasion assays. The ferroptosis of CIA-SFs was assessed using matching reagent kits to detect indicators like reactive oxygen species, ferrous iron, malondialdehyde, glutathione, and superoxide dismutase. The interaction between Granzyme K (GZMK) and C-C motif chemokine 5 (CCL5) was determined by coimmunoprecipitation assay. We found abnormal GZMK expression in the GSE115662 database and mRNA sequencing data. GZMK was overexpressed in CIA-SFs, and GZMK promoted cell proliferation, migration, invasion, inflammation, and decreased cell apoptosis and ferroptosis in CIA-SFs. GZMK could interact with CCL5 to activate the ERK signaling. GZMK and CCL5 knockdown improved by reducing arthritis scores, redness and swelling of paws, and pathological changes in joint synovium of CIA rats. CCL5 overexpression reversed the effects of GZMK silencing on CIA-SFs cell proliferation, migration, invasion, apoptosis, and ferroptosis. We confirmed that GZMK accelerated experimental rheumatoid arthritis progression by interacting with CCL5 and activating the ERK signaling.

Sinulariolide Suppresses Inflammation of Fibroblast-Like Synoviocytes in Rheumatoid Arthritis and Mitigates Collagen-Induced Arthritis Symptoms in Mice.

Rheumatoid arthritis (RA) is a systemic inflammatory disease characterized by active polyarthritis, which leads to functional loss and joint deformities. Natural compounds derived from marine organisms are considered valuable immune-modulating agents. This study aimed to assess the anti-inflammatory effect of sinulariolide, a soft coral-derived compound, on RA fibroblast-like synoviocytes and its therapeutic efficacy against collagen-induced arthritis (CIA). To determine the effects of sinulariolide on tumor necrosis factor-alpha (TNF-α)-induced inflammation, MH7A cells pre-treated with 10 ng/mL TNF-α for 24h were treated with sinulariolide. The effect of sinulariolide on proinflammatory cytokine expressions at both the mRNA and protein levels in the MH7A cells was assessed using real-time-polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA). Further, we analyzed the effect of sinulariolide on the activation of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways using Western blotting and the TransAM NF-κB p65 kit. To comprehensively evaluate the potential application of sinulariolide in the treatment of inflammatory diseases, we used a well-established collagen-induced arthritis (CIA) mouse model. We examined the tissue sections of the ankle joints of the mice, assessed synovial hyperplasia, inflammatory cell infiltration, and cartilage damage, and used ELISA to analyze changes in cytokine expression in the hind paw tissues. MH7A cells treated with sinulariolide showed a notable reduction in the expression of proinflammatory cytokines, which could be due to decreased activation of the MAPK and NF-kB pathways. Additionally, sinulariolide-treated mice showed significantly reduced joint swelling and lower clinical arthritis scores than those in the normal and control groups. Significant reductions in synovial hyperplasia, inflammatory cell infiltration, and cartilage damage were observed in the tissue sections of the ankle joints of the mice treated with sinulariolide. Furthermore, the expression of inflammatory cytokines in the hind paw tissue of the mice treated with sinulariolide was significantly decreased. Sinulariolide inhibited the progression of inflammation in MH7A cells. Sinulariolide treatment significantly reduced clinical arthritis symptoms and histological inflammatory responses in mice with CIA. Sinulariolide may serve as a potential therapeutic agent for RA.

ITGA5+ synovial fibroblasts orchestrate proinflammatory niche formation by remodelling the local immune microenvironment in rheumatoid arthritis.

To investigate the phenotypic heterogeneity of tissue-resident synovial fibroblasts and their role in inflammatory response in rheumatoid arthritis (RA). We used single-cell and spatial transcriptomics to profile synovial cells and spatial gene expressions of synovial tissues to identify phenotypic changes in patients with osteoarthritis, RA in sustained remission and active state. Immunohistology, multiplex immunofluorescence and flow cytometry were used to identify synovial fibroblasts subsets. Deconvolution methods further validated our findings in two cohorts (PEAC and R4RA) with treatment response. Cell coculture was used to access the potential cell-cell interactions. Adoptive transfer of synovial cells in collagen-induced arthritis (CIA) mice and bulk RNA sequencing of synovial joints further validate the cellular functions. We identified a novel tissue-remodelling CD45-CD31-PDPN+ITGA5+ synovial fibroblast population with unique transcriptome of POSTN, COL3A1, CCL5 and TGFB1, and enriched in immunoregulatory pathways. This subset was upregulated in active and lympho-myeloid type of RA, associated with an increased risk of multidrug resistance. Transforming growth factor (TGF)-β1 might participate in the differentiation of this subset. Moreover, ITGA5+ synovial fibroblasts might occur in early stage of inflammation and induce the differentiation of CXCL13hiPD-1hi peripheral helper T cells (TPHs) from naïve CD4+ T cells, by secreting TGF-β1. Intra-articular injection of ITGA5+ synovial fibroblasts exacerbates RA development and upregulates TPHs in CIA mice. We demonstrate that ITGA5+ synovial fibroblasts might regulate the RA progression by inducing the differentiation of CXCL13hiPD-1hi TPHs and remodelling the proinflammatory microenvironments. Therapeutic modulation of this subpopulation could therefore be a potential treatment strategy for RA.

Expression of CCL2 signaling pathway genes in patients with periodontitis and atherosclerosis.

Periodontitis and atherosclerosis are chronic inflammatory diseases characterized by leukocyte infiltration. We investigated the expression of CCL4, CCR5, c-Jun, c-Fos, NF-κB, and CCL2 as well as the possible mechanism involved in the regulation of CCL2 in human periodontitis tissues and atherosclerotic aorta based on previous research on the CCL4/CCR5/c-Jun and c-Fos/CCL2 pathway leading to CCL2 expression in collagen-induced arthritis (CIA) rat. Sixty-five volunteers were recruited and the condition of their gingiva and coronary arteries were assessed. The subjects were divided into four groups: healthy control, chronic periodontitis (CP), coronary artery diseases (CAD), and noncoronary artery diseases (non-CAD). Total RNA was isolated from gingiva in periodontitis patients and control populations and from the aorta in patients with and without CAD. PCR was used to examine CCL4, CCR5, c-Jun, c-Fos, NF-κB, and CCL2 levels. The production of CCL2 in the gingiva and aorta was analyzed by immunostaining. PCR revealed that CCL4, CCR5, and CCL2 mRNA levels were increased in CP patients' gingivae and aortas from coronary artery bypass grafting (CABG) patients. Marked c-Jun, c-Fos, and NF-κB gene productions were detected in CP patients' gingivae but did not show statistical differences between the CAD and non-CAD groups. Stronger immunoreactivity against CCL2 was observed in periodontitis gingiva and aorta from CABG patients. Our findings suggest that the CCL4/CCR5/c-Jun and c-Fos/CCL2 pathways may be involved in CCL2 expression in periodontitis. CCL4, CCR5, and CCL2 might act as possible nodes to link the presence of periodontitis and atherosclerosis.

Jinwu Jiangu Capsule Alleviates Rheumatoid Arthritis Symptoms by Regulating the ADCY10 and cAMP/RANKL Pathways.

Rheumatoid arthritis (RA) is a systemic autoimmune disease that primarily affects joints and damages other tissues, including the heart, kidneys, lungs, digestive system, eyes, skin and nervous system. Jinwu Jiangu Capsule (JWJG) is effective in tonifying kidneys, activating blood circulation, and dispelling wind and dampness. Meanwhile, it produces favorable clinical results in relieving joint pain and reducing inflammation. However, precise therapeutic effect and mechanisms of JWJG on RA remain unclear. The traditional Chinese medicine JWJG exhibits certain properties in anti-inflammation and pain relief for RA treatment. This study aimed to investigate the efficacy of JWJG and elucidate its underlying mechanisms in RA treatment. A collagen-induced arthritis (CIA) rat model was administered JWJG orally at varying doses for 28 days, alongside control and positive control groups treated with saline and leflunomide, respectively. Indicators including joint swelling, bone loss, histopathological changes, Th17/Treg lymphocyte differentiation, and inflammatory factor expression were assessed. RNA sequencing of synovial tissues identified JWJG-influenced genes and pathways. RASFs treated with ADCY10 lentivirus, PKA agonist, or AR plasmid underwent additional JWJG-containing serum or β-sitosterol treatment to monitor ADCY10, RANKL, and cAMP pathway alterations. JWJG administration significantly reduced joint swelling, bone loss, and inflammation, balanced Th17/Treg, and suppressed TNF-α, IL-1β, IL-6, and RANKL levels. In RASFs, JWJG downregulated ADCY10, cAMP, and phospho-PKA/CREB, thereby inhibiting osteoclast differentiation. Meanwhile, β-sitosterol decreased AR levels, which suppressed ADCY10 and RANKL expression. JWJG treatment could directly/indirectly inhibit ADCY10 reduced cAMP/RANKL, inflammation, and osteoclastogenesis, enhancing RA symptomatology comparable to leflunomide. It demonstrated superior regulation of Th17/Treg ratios and cytokine suppression, with potential to substantially improve RA patients' quality of life. JWJG inhibited ADCY10, decreased cAMP/RANKL, and impeded inflammation and osteoclastogenesis, with a notable improvement in RA symptoms comparable to leflunomide. It can be introduced as a potential new therapeutic strategy for preventing or even reversing bone damage and improving the quality of life for RA patients.

Ferroptosis Induces gut microbiota and metabolic dysbiosis in Collagen-Induced arthritis mice via PAD4 enzyme

Ferroptosis Induces gut microbiota and metabolic dysbiosis in Collagen-Induced arthritis mice via PAD4 enzyme

IL-10 is not required for the alleviation of collagen-induced arthritis by non-lethal malarial infection in mice

IL-10 is not required for the alleviation of collagen-induced arthritis by non-lethal malarial infection in mice

Polysaccharides from Gaultheria leucocarpa var. yunnanensis (DBZP) alleviates rheumatoid arthritis through ameliorating gut microbiota

Gaultheria leucocarpa var. yunnanensis (Dianbaizhu) is a traditional Chinese herb for rheumatoid arthritis (RA). However, its macromolecular components have always been overlooked. This study aimed to investigate the chemical composition and effect on improving RA of polysaccharides from Dianbaizhu (DBZP). The results showed the yield of DBZP was 4.07 % ± 0.03 %, and it was composed of Mannose (6.63 %), ribose (1.33 %), rhamnose (4.53 %), glucuronic acid (2.95 %), galacturonic acid (32.29 %), glucose (13.78 %), galactose (22.97 %), xylose (3.94 %) and arabinose (11.59 %), with a large molecular weight distribution range. DBZP treatment could reduce the paws thickness and arthritis scores of collagen-induced arthritis (CIA) mice, and improve inflammatory cell infiltration, synovial hyperplasia, bone erosion, and deterioration. The abundance of several specific bacteria, such as Lactobacillus, Bacteroides, Alistipes, Mucispirillum, and Candidatus_Saccharimonas, and some metabolites in feces or urine, such as 11beta-hydroxytestosterone, pregnanediol 3-O-glucuronide, p-cresol sulfate and several amino acids and peptides, was also altered. The process of DBZP alleviating RA through gut microbiota involves affecting the digestion and metabolism of carbohydrates and protein, altering sex hormones levels, and regulating intestinal immune function, such as the differentiation and signaling of Th17 cells. These findings suggest that DBZP possesses a protective effect on CIA in mice via modulating gut microbiota.

Low Iron Diet Improves Clinical Arthritis in the Mouse Model of Collagen-Induced Arthritis.

Background: In response to inflammation, the absorption of nutritional iron is restricted. Since the pathophysiological significance of the presence and uptake of iron in chronic inflammation is still unknown, we tested the effect of a low iron diet on the clinical course of arthritis in the mouse model of collagen-induced arthritis (CIA). Methods: Six- to eight-week-old male DBA/1 mice were fed either a normal (51 mg/kg) or a low iron diet (5 mg/kg) starting four weeks before the first immunization. From day 4 after the second collagen booster made on day 25, the development of arthritis was regularly monitored until the end of the experiment (day 34), using a standard clinical arthritis score. Concentrations of mouse anti-bovine and anti-mouse collagen type 2 IgG antibodies were measured by ELISA; blood cell counts were performed and mediators of inflammation, tissue matrix degradation, oxygenation and oxidative stress were measured in the mouse sera of both diet groups at the end of the experiment by bead-based multiplex assay. Fe2+, Fe3+, oxidized and reduced glutathione (GSH and GSSG) and malondialdehyde (MDA) were quantified in whole paw tissue by ELISA. Quantitative PCR was performed in the tissues for glutathione peroxidase 4 and other key regulator genes of iron metabolism and ferroptosis. We used nonparametric tests to compare cross-sectional data. Nonlinear regression models were used for longitudinal data of the arthritis scores. Results: Mice fed a low iron diet showed a significantly less severe course of arthritis compared to mice fed a normal iron diet (p < 0.001). The immune response against bovine and mouse type 2 collagen did not differ between the two diet groups. Mice fed a low iron diet exhibited significantly lower serum levels of tissue inhibitor of metalloproteinase-1 (TIMP-1), a central regulator of inflammation and tissue matrix degradation (p < 0.05). In addition, a low iron diet led to a significant reduction in red blood cell indices, indicating restricted iron uptake and latent iron deficiency, but had no effect on hemoglobin concentrations or red blood cell counts. There were no differences between the dietary groups in Fe2+ or Fe3+ content in the paws. Based on calculation of the GSH/GSSG ratio and high MDA levels, high oxidative stress and lipid peroxidation were likewise detected in the paws of both diet groups of mice. Consequently, no differences associated with gene expression of key regulators of iron metabolism and ferroptosis could be detected between the paws of both diet groups. Conclusions: Restricted dietary iron intake alleviates immune-mediated inflammation in CIA without causing anemia. This finding suggests a promising option for dietary treatment of arthritis in inflammation. The underlying mechanism causing reduced arthritis may be linked to the complex regulatory network of TIMP-1 and appears to be independent from the local iron levels, oxidative stress and ferroptosis in the synovial tissues.

Gingival mesenchymal stem cells derived from patients with rheumatoid arthritis treat experimental arthritis

AbstractA therapeutic strategy using mesenchymal stem cells (MSCs) has been accepted as a novel therapy for treating rheumatoid arthritis (RA). Human gingiva‐derived MSCs (GMSCs) are superior in regulating immune responses. Autologous MSCs are the optimal candidate to avoid the potential risks of allogenic MSCs. However, whether autologous GMSCs from RA patients are therapeutic remains unknown. In this study, we compared the therapeutic efficacy of GMSCs derived from patients with RA (RA‐GMSCs) and that from health donors (H‐GMSCs) in vivo and in vitro. Then, we utilized RNA‐sequencing, the molecular and cellular assays to determine the immunomodulatory molecules that contribute to the therapeutic effect of RA‐GMSCs on both collagen‐induced arthritis (CIA) and humanized synovitis models. We demonstrated that GMSCs derived from patients with RA (RA‐GMSCs) and health donors (H‐GMSCs) shared a similar expression of immunomodulatory molecules. Moreover, RA‐GMSCs were as effective as H‐GMSCs in suppressing T‐cell proliferation, proinflammatory cytokines secretion, as well as osteoclast differentiation in vitro. In addition, RA‐GMSCs had a robust therapeutic effect on the CIA model. Importantly, RA GMSCs can survive for at least 24 days in a CIA mouse model and can be distributed in the spleen, lymph nodes, and joints. Specifically, RA‐GMSCs decreased the frequency of Th1 and Th17 cells whereas enhanced Treg cells, reducing the joint histopathological scores of lymphocytes, osteoclasts, and cartilages. Moreover, RA‐GMSCs were also effective in suppressing inflamed synoviocyte proliferation, migration, and invasion in vitro, and cartilage invasion in a humanized synovitis model in vivo. Our study implies that manipulation of RA‐GMSCs is therapeutic in CIA mice and humanized synovitis models and may have therapeutic potential in RA patients using autologous GMSCs in the future.

A Novel Subset of Regulatory T Cells Induced by B Cells Alleviate the Severity of Immunological Diseases.

Regulatory T (Treg) cells are crucial for maintaining immune tolerance by suppressing response to self-antigens and harmless antigens to prevent autoimmune diseases and uncontrolled immune responses. Therefore, using Treg cells is considered a therapeutic strategy treating inflammatory diseases. Based on their origin, Treg cells are classified into thymus-derived, peripherally induced, and in vitro induced Treg cells. Our group discovered a novel Treg cell subset, namely, Treg-of-B (Treg/B) cells, generated by culturing CD4+CD25- T cells with B cells, including Peyer's patch B cells, splenic B cells and peritoneal B1a cells, for 3days. Treg/B cells express CD44, OX40 (CD134), cytotoxic T-lymphocyte-associated antigen-4 (CD152), glucocorticoid-induced tumor necrosis factor receptor family-related protein (CD357), interleukin-10 receptor, lymphocyte activation gene-3 (CD223), inducible co-stimulator (CD278), programmed-death 1 (CD279), tumor necrosis factor receptor II, and high levels of IL-10, but not forkhead box protein P3, similar to type 1 Treg (Tr1) cells. However, unlike Tr1 cells, Treg/B cells do not express CD103, CD226, and latency-associated peptide. Treg/B cells have been applied for the treatment of some murine models of inflammatory diseases, including allergic asthma, inflammatory bowel disease, collagen-induced arthritis, gout, psoriasis and primary biliary cholangitis. This review summarizes the current knowledge of Treg/B cells.

Chronic stress-mediated dysregulations in inflammatory, immune and oxidative circuitry impairs the therapeutic response of methotrexate in experimental autoimmune disease models.

Chronic stress is significantly implicated in the worsening of autoimmune disorders, contributing to elevated inflammation and diminished therapeutic efficacy. Here, in this study, we investigated the detrimental impact of an 8-week chronic unpredictable stress (CUS) protocol on the progression of arthritis and psoriasis using collagen-induced arthritis (CIA) and imiquimod (IMQ)-induced psoriasis rat models, respectively. Our objective was to elucidate how prolonged stress exacerbates disease severity and impairs the effectiveness of treatment drug. Following the induction of CIA and IMQ, rats were subjected to an 8-week CUS paradigm designed to simulate chronic stress conditions. Moreover, after 5 weeks of CUS, methotrexate (MTX; 2 mg/kg, administered once weekly for 3 weeks, intraperitoneally) was introduced as a therapeutic intervention. The severity of CUS-induced effects and the therapeutic impairment of MTX in arthritis and psoriasis rats were assessed through pathological examination of joint and epidermal tissues, respectively. Additionally, we measured various pro-inflammatory cytokine levels, including NF-κB (nuclear factor kappa B), IFN-γ (interferon-gamma), TNF-α (tumour necrosis factor alpha), IL (interleukin)-1β, IL-6, IL-17 and IL-23 using enzyme-linked immunosorbent assay (ELISA), analysed immune cells through complete haematological profiling and evaluated oxidative stress markers. Our findings revealed that CUS significantly aggravated the pathological features of both arthritis and psoriasis. Prolonged stress exposure led to heightened inflammatory responses, increased oxidative stress and more severe tissue damage. Moreover, the therapeutic efficacy of MTX was notably reduced in stressed rats compared to non-stressed, underscoring the detrimental effects of chronic stress on treatment outcomes. Taken together, our results emphasize the importance of considering chronic stress as a critical factor in the management of autoimmune diseases.

Propionibacterium freudenreichii MJ2-derived extracellular vesicles inhibit RANKL-induced osteoclastogenesis and improve collagen-induced rheumatoid arthritis

Rheumatoid arthritis causes excessive bone loss by stimulating osteoclast differentiation. Extracellular vesicles are valuable disease markers, conveyors of distant cell-to-cell communication, and carriers for drug delivery. The aim of this study was to investigate the anti-osteoclastogenic effects of extracellular vesicles derived from dairy Propionibacterium freudenreichii MJ2 (PFEVs) and the improvement effect of PFEVs on collagen-induced arthritis (CIA) animal model. PFEVs were observed by scanning electron microscopy, transmission electron microscopy, nanoparticle tracking analysis, and LC–MS/MS. The inhibitory activity of PFEVs against receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclast differentiation was investigated in RAW 264.7 cells. PFEVs significantly decreased the expression levels of genes and proteins related to osteoclast differentiation. PFEVs decreased RANK–RANKL binding. In a CIA mouse model, PFEVs treatment significantly reduced arthritis scores and collagen-specific immunoglobulins. PFEVs treatment also reduced pro-inflammatory cytokines and increased anti-inflammatory cytokines. The anti-inflammatory effects were confirmed by H&E staining, and PFEVs treatment inhibited osteoclastogenesis in the CIA mouse model. In conclusion, PFEVs inhibited osteoclast differentiation by inhibiting RANK–RANKL signaling, thereby decreasing the expression of osteoclast differentiation-related genes. PFEVs also improved collagen-induced arthritis by inhibiting inflammation and osteoclastogenesis.

Inflammation-Responsive Polyion Complex Vesicles for Autoimmune Disease Therapy via Cell-Free DNA Scavenging and Inflammatory Microenvironment Modulation.

Cell-free DNA (cfDNA) scavenging represents a promising anti-inflammatory modality for autoimmune disease (AID) treatment. However, it remains challenging for existing systems to achieve inflammation-targeted cfDNA scavenging and the management of cfDNA-unrelated inflammatory pathways. Herein, inflammation-responsive polyion complex vesicles (PICsomes) are developed, bridging inflammation-instructed cfDNA scavenging, and methotrexate (MTX) delivery for AID management. A positively charged, PEGylated polypeptide with guanidine side chains (PEG-PG) is developed, which self-assembles with a negatively charged, cis-aconitic anhydride-modified poly-L-lysine (PC) to form the PICsomes and encapsulate MTX disodium salt. The neutrally charged PICsomes feature prolonged blood circulation after systemic administration, allowing for passive accumulation to the inflamed tissues. In the slightly acidic inflammatory microenvironment, PC transforms from negatively charged to positively charged, thereby disintegrating the PICsomes and liberating the PEG-PG and MTX. Consequently, PEG-PG-mediated cfDNA scavenging and MTX-mediated immunosuppression cooperate to inhibit inflammation and ameliorate the inflammatory microenvironment, promoting tissue repair in AID mouse models including collagen-induced arthritis and 2,4,6-trinitrobenzenesulfonic acid-induced colitis.

Evaluation of the Anti-Inflammatory/Immunomodulatory Effect of Teucrium montanum L. Extract in Collagen-Induced Arthritis in Rats.

The anti-inflammatory/immunomodulatory effects of Teucrium montanum L. (TM), a plant distributed in the Mediterranean region, have been insufficiently examined. The effects of the TM ethanol extract were tested in a rat collagen-induced arthritis (CIA) model of rheumatoid arthritis. LC-MS was used for the phytochemical analysis of the TM extract. Dark Agouti rats were immunized with bovine type II collagen (CII) in incomplete Freund's adjuvant for CIA, and treated with 100 or 200 mg/kg of TM extract daily via oral administration. Clinical and histopathological evaluations and a flow cytometric analysis of the phenotypic and functional characteristics of splenocytes and draining lymph node cells were performed. The cytokines in the paw tissue culture supernatants and anti-CII antibodies in serum were determined by ELISA. The TM extract, with the dominant components verbascoside and luteolin 7-O-rutinoside, reduced the arthritic score and ankle joint inflammation in CIA rats, promoted the antioxidant profile in serum, and lowered pro-inflammatory TNF-α, IL-6 and IL-1β production. It suppressed the activation status of CD11b+ cells by lowering CD86, MHCII and TLR-4 expression, and promoted the Th17/T regulatory cell (Tregs) balance towards Tregs. A lower frequency of B cells was accompanied by a lower level of anti-CII antibodies in treated rats. These findings imply the favorable effect of TM extract on the clinical presentation of CIA, suggesting its anti-inflammatory/immunomodulatory action and potential therapeutic effect.

MiR-147-3p in pathogenic CD4 T cells controls chemokine receptor expression for the development of experimental autoimmune diseases

Incomplete Freund's adjuvant (IFA) has long been used to trigger autoimmune diseases in animal models, such as experimental autoimmune encephalitis and collagen-induced arthritis. However, the molecular mechanisms that control CD4 T cell effector functions and lead to the development of autoimmune diseases are not well understood. A self-antigen and heat-killed Mycobacterium tuberculosis emulsified in IFA augmented the activation of CD4 T cells, leading to the differentiation of pathogenic CD4 T cells in the draining lymph nodes. In contrast, IFA emulsification did not elicit Foxp3+ regulatory T cell expansion. We found that pathogenic Th1 cells expressed miR-147-3p, which targets multiple genes to affect T cell function. Finally, miR-147-3p expressed in CXCR6+SLAMF6– Th1 cells was required for the onset of neurological symptoms through the control of CXCR3 expression. Our findings demonstrate that miR-147-3p expressed in pathogenic CD4 T cells regulates the migratory potential in peripheral tissues and impacts the development of autoimmune diseases.