Arthritis Score Research Articles

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.

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.

Therapeutic potential of d-limonene in rheumatoid arthritis: Modulation of inflammatory, anti-inflammatory cytokines, and prostaglandin E2.

Rheumatoid arthritis (RA) is a persistent autoimmune disorder predominantly affecting the joint structures, eliciting inflammatory responses, and ultimately leading to degenerative changes without proper medical intervention. Ultimately, this can severely impair joint function and impact the patient's quality of life. Current treatment approaches include disease-modifying anti-rheumatic drugs, non-steroidal anti-inflammatory drug, corticosteroids, and biologic therapies for RA management. The current study contributes to the ongoing advancements in RA treatment. d-Limonene is a monocyclic monoterpene. It is present in essential oils of various aromatic plants, such as Lippia alba and Artemisia dracunculus, and in citrus fruits such as lemon and orange. It has reported anti-inflammatory and anti-nociceptive properties and was selected for the current study as a potential anti-arthritic candidate. It was administered at three dosages (25, 50, 100 mg/kg, b.w., p.o) in Complete Freund's adjuvant-induced arthritic rats over 28 days. The efficacy of the compound was compared to piroxicam, a widely used standard drug for treating RA. The anti-arthritic activity of the compound was assessed by measuring arthritic scoring and plethysmometry at both baseline and post-intervention stages. Additional confirmation of the investigation was sought by performing biochemical and hematological activities. Moreover, quantitative polymerase chain reaction was employed to determine the levels of messenger RNA expression for transcription factors such as tumor necrosis factor-α, interleukin (IL)-1β, nuclear factor-κB, matrix metalloproteinase-3, IL-6, and IL-4 in the blood. The levels of PGE2 were evaluated by enzyme-linked immunosorbent assay. The histopathological and radiographic studies were also carried out for further confirmation. The results of these findings supported our assertion regarding the anti-arthritic potential of the compound.

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.

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.

Metabolic effects of quercetin on inflammatory and autoimmune responses in rheumatoid arthritis are mediated through the inhibition of JAK1/STAT3/HIF-1α signaling

BackgroundRheumatoid arthritis, a chronic autoimmune disease, is characterized by synovial hyperplasia and cartilage erosion. Here, we investigated the potential mechanism of action of quercetin, the main component of flavonoids, in treating rheumatoid arthritis.ObjectTo examine the anti-arthritic effects of quercetin and elucidate the specific mechanisms that differentiate its metabolic effects on autoimmune and inflammatory responses at the synovial cell level.MethodsWe created a collagen-induced arthritis (CIA) model in Wistar rats, which were administered quercetin (50 or 100 mg/kg) continuously for four weeks via stomach perfusion. The arthritis score, histopathological staining, radiological assessment, and serum biochemical parameters were used to study the impact of quercetin on disease improvement. Additionally, immunofluorescence was employed to detect JAK1/STAT3/HIF-1α expression in rat joints. Moreover, the effects of quercetin (20, 40, and 80 µmol/L) on the properties and behavior of synovial fibroblasts were evaluated in an in vitro MH7A cell model using flow cytometry, CCK8, and transwell assays. Further, the mRNA expression levels of inflammatory cytokines IL1β, IL6, IL17, and TNFα were assessed by quantitative real-time PCR. Glucose, lactate, lactate dehydrogenase, pyruvate, pyruvate dehydrogenase, and adenosine triphosphate assay kits were employed to measure the metabolic effects of quercetin on synovial fibroblasts. Finally, immunoblotting was used to examine the impact of quercetin on the JAK1/STAT3/HIF-1α signaling pathway in synovial fibroblasts.ResultsIn vivo experiments confirmed the favorable effects of quercetin in CIA rats, including an improved arthritis score and reduced ankle bone destruction, in addition to a decrease in the pro-inflammatory cytokines IL-1β, IL-6, IL-17, and TNF-α in serum. Immunofluorescence verified that quercetin may ameliorate joint injury in rats with CIA by inhibiting JAK1/STAT3/HIF-1α signaling. Various in vitro experiments demonstrated that quercetin effectively inhibits IL-6-induced proliferation of MH7A cells and reduces their migratory and invasive behavior, while inducing apoptosis and reducing the expression of the pro-inflammatory cytokines IL1β, IL6, IL17, and TNFα at the mRNA level. Quercetin caused inhibition of glucose, lactate, lactate dehydrogenase, pyruvate, and adenosine triphosphate and increased pyruvate dehydrogenase expression in MH7A cells. It was further confirmed that quercetin may inhibit energy metabolism and inflammatory factor secretion in MH7A cells through JAK1/STAT3/HIF-1α signaling.ConclusionsQuercetin’s action on multiple target molecules and pathways makes it a promising treatment for cartilage injury in rheumatoid arthritis. By reducing joint inflammation, improving joint metabolic homeostasis, and decreasing immune system activation energy, quercetin inhibits the JAK1/STAT3/HIF-1α signaling pathway to improve disease status.

Morinda officinalis iridoid glycosides, as an inhibitor of GSK-3β, alleviates rheumatoid arthritis through inhibition of NF-κB and JAK2/STAT3 pathway.

Morinda officinalis iridoid glycosides (MOIG) showed potential benefits in the treatment of rheumatoid arthritis (RA), but their exact mechanism has yet to be explored. To evaluate the effects of MOIG on RA, and explore the potential targets and molecular mechanism of MOIG in RA. The collagen-induced arthritis (CIA) rats were used to evaluate the effects of MOIG on RA. The proliferation, migration and invasion of fibroblast-like synoviocytes (FLSs) stimulated with or without tumor necrosis factor (TNF)-α were examined by CCK-8, wound healing and transwell assays, respectively. IF and WB were applied to investigate related mechanism in FLSs. The molecular docking, molecular dynamics simulation, CETSA and siRNA were used to analyze the interaction of MOIG with target. Finally, the adjuvant-induced arthritis (AA) mice model with gene knockdown was used to confirm the effect of MOIG on glycogen synthase kinase-3β (GSK-3β). MOIG significantly alleviated the paw swelling and synovial hyperplasia in CIA rats. Moreover, MOIG suppressed proliferation, migration and invasion, the secretion of inflammatory factors, and the expression of adhesion related proteins in TNF-α-stimulated FLSs. MOIG also inhibited the activation of Janus activating kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa-B (NF-κB) signaling pathway in FLSs. Interestingly, the plant metabolites in MOIG had a good affinity with GSK-3β, and inhibition of GSK-3β attenuated the effects of MOIG on FLSs. Knockdown GSK-3β gene could inhibit the paw swelling and inflammatory indicators, decrease the arthritis score and synovial hyperplasia, reduce the phosphorylation of p65 and STAT3 in AA mice, thereby suppressing the NF-κB and STAT3 signaling activation, and MOIG treatment had no significant effects on AA mice with si-GSK-3β. MOIG alleviates joint inflammation in RA through inhibition NF-κB and JAK2/STAT3 pathway via suppression of GSK-3β in FLSs, which provides supports for MOIG as a promising therapeutic agent of RA.

Wutou decoction attenuates rheumatoid arthritis in rats through SIRT1-mediated deacetylation of the HMGB1/NF-κB pathway

Ethnopharmacological relevanceIn traditional Chinese medicine (TCM), Wutou Decoction (WTD) has long been used to alleviate arthritis. Emerging studies have reported that WTD could improve the symptoms of rheumatoid arthritis (RA). However, the mechanism by which WTD is involved in the treatment of RA remains elusive, posing a challenge to the worldwide acceptance of WTD as an efficient RA therapy. Aim of the studyThis study investigated the antiarthritic efficacy of WTD in a collagen-induced arthritis (CIA) rat model and explored silent information regulator 1 (SIRT1)-mediated deacetylation of the high mobility group box 1 (HMGB1)/NF-κB pathway. Materials and methodsA rat CIA model was used to evaluate the antiarthritic activity of WTD. Clinical arthritis score assessment, left ankle thickness assessment, micro-CT, histopathological staining, immunofluorescence staining, and ELISA were conducted to elucidate the anti-inflammatory effects of WTD. The M1 macrophage polarization state, cell viability, and invasion were also determined to assess the effects of WTD on macrophage proliferation and invasion in vitro. Additionally, in vivo and in vitro HMGB1 nuclear translocation and NF-κB activation were analysed. Finally, deacetylase activity was assessed by Western blot, NAD+/NADH analysis, and co-immunoprecipitaion. ResultsWTD significantly alleviated arthritis in CIA rats and inhibited pathological changes in joint lesions while concurrently suppressing TNF-α, IL-6, and IL-1β release. Mechanistically, WTD suppressed M1 infiltration in ankle tissues and their invasion in vitro. Furthermore, WTD downregulated HMGB1/p65 nuclear translocation and acetylation, which may be associated with SIRT1 upregulation. ConclusionsOverall, WTD potentially alleviates RA through SIRT1-mediated downregulation of HMGB1 and NF-κB acetylation.

Deciphering farnesol's anti-arthritic and immunomodulatory potential by targeting multiple pathways: a combination of network pharmacology guided exploration and experimental verification.

Farnesol (FAR), a sesquiterpene alcohol, has documented FAR's anti-inflammatory and antioxidant activities. Current study was undertaken to assess the efficacy and mechanism of FAR in arthritis by employing network pharmacology and experimental models. Two experimental models comprising formaldehyde- and complete Freund's adjuvant (CFA)-induced arthritis evaluated the efficacy of FAR in treating arthritis. Various parameters were assessed. Then, a network pharmacology approach was applied to gain further insight into the potential mechanism and signaling pathways. FAR significantly reduced paw volume and the arthritic score and improved the hematological and biochemical changes. Radiographic and histological examination showed the anti-arthritic efficacy of FAR, which was associated with down-regulation of pro-inflammatory mediators and upregulation of anti-inflammatory mediators. Network pharmacology analysis revealed that FAR may exert its anti-arthritic effects by targeting specific genes associated with arthritis. Pathway analysis revealed the involvement of three key signaling pathways (IL-17 signaling, TNF signaling, and toll-like receptor signaling) in the development and progression of arthritis. The results pointed out the protective attributes of farnesol against formaldehyde and CFA-induced arthritis via modulation of multiple targets. This study provides a valuable reference for the development of a new treatment or complementary therapy for arthritis.

A Novel Etanercept-loaded Nano-emulsion for Targeted Treatment of Inflammatory Arthritis via Draining Lymph Node.

Rheumatoid arthritis (RA) is a systemic autoimmune disease (AD), and the global incidence rate is 0.5 ~ 1%. Existing medications might reduce symptoms, however, there is no known cure for this illness. Etanercept (EN) can competitively inhibit TNF-α binding to the TNF receptor on the cell surface to treat RA. However, subcutaneous injection of free EN predisposes to systemic distribution and induces immune system hypofunction. Draining lymph nodes (LNs) play a significant role in the onset, maintenance, and progression of RA as they are the primary sites of aberrant immune response and inflammatory cytokine production. The purpose of this study was to successfully treat RA with etanercept by encapsulating it in nanoemulsions (NEs/EN) and then delivering it specifically to draining LNs. The EN-loaded NEs were prepared by high-pressure homogenization method and modified with DSPE-mPEG2000 and Ca(OH)2. A novel nano-emulsion (NE) was constructed to deliver EN (NE/EN) to RA-draining LNs. To decrease aggregation and load EN, DSPE-mPEG2000 and Ca(OH)2 were successively decorated on the surface of the lipid injectable emulsions. The hydrodynamic diameter and morphology of NEs/EN were investigated by using a laser particle size analyzer and transmission electron microscopy, respectively. The in vivo fluorescence imaging system was used to study the in vivo LN targeting ability of the formulation. In the therapeutic experiment, NEs/EN was subcutaneously administrated to inhibit the development of the mouse arthritis model. Circular dichroism spectrum and L929 cell experiment confirmed that NEs encapsulation had no impact on the biological activity of EN. In vivo investigation on collagen-induced arthritis (CIA) mouse model showed that NEs/EN have good inguinal lymph node targeting capabilities, as well as, anti-inflammatory effect against RA. Compared with the free group, the paw thickness and arthritic score in NEs/EN group were significantly alleviated. Moreover, the concentration of pro-inflammatory cytokines TNF-α and IL-1β in NEs/EN-treated mice was lower than that in free EN. NEs/EN effectively improve the effectiveness of EN in the treatment of RA. Our work provides an experimental foundation for expanding the clinical application of EN.

Fumaric acid per se and in combination with methotrexate arrests inflammation via moderating inflammatory and oxidative stress biomarkers in arthritic rats

Objective: Fumaric acid is a dicarboxylic acid that belongs to the phenolic class enriched in fruits and vegetables that are traditionally used for the treatment of various ailments. The research was planned to find out the anti-inflammatory and anti-arthritic activities of fumaric acid using in-vitro and in-vivo assays. Moreover, safety study was also done. Materials and methods: The 0.1 ml complete Freund’s adjuvant was injected in left hind paw in all Wistar rats except normal rats at day 1 to induced arthritis. The treatment with fumaric acid at 10, 20, 40, and fumaric acid 40 mg/kg together with methotrexate (MTX) was administered to immunized rats at 8th day via oral gavage and continued till 28th day though, MTX was administered as standard control. Results: The fumaric acid notably (p < 0.0001) lessened the paw edema and arthritic scoring, reinstated body and immune organ weight, and oxidation status in treated rats. Fumaric acid notably restored altered C-reactive protein, rheumatoid factor, liver function tests, ESR, WBCs, RBCs and Hb levels in treated rats. The fumaric acid in combination noticeably (p < 0.01–0.0001) suppressed the expression of TNF- α, IL-6, IL-1β, NF-kβ, and COX-2, and over expressed IL-4, and IL-10 in contrast to other treated groups. Fumaric acid had presented a dose-dependent antioxidant, anti-inflammatory and anti-arthritic activities while notable activity exhibited by fumaric acid in combination with MTX. The fumaric acid exhibited non-significant clinical signs of toxicity and mortality in acute toxicity study. The LD50 was more than 2000 mg/kg. Conclusion: Fumaric acid in combination can be used as disease-modifying anti-rheumatic drug but it will need extensive pre-clinical and clinical studies.

Aberrant overexpression of the autoantigen protein vimentin promotes Th17 cell differentiation and autoimmune arthritis via activation of STAT3 signaling

Vimentin contributes to the positioning and function of organelles, cell migration, adhesion, and division. However, secreted vimentin accumulates on the cell surface (Mor-Vaknin et al., 2003; Ramos et al., 2020 [1,2]) where it acts as a coreceptor for viral infection and as an autoantigen in inflammatory and autoimmune diseases. The roles of vimentin in Th17 cells were examined in mice with knockdown of vimentin. We also examined whether STAT3 is required for vimentin expression.Vimentin expression was significantly increased in Th17 cells through STAT3 activation, and vimentin+ IL-17+ T cells were markedly increased in the joint and spleen tissues of CIA mice. The arthritis score and expression levels of proinflammatory cytokines were significantly decreased in CIA mice treated with vimentin shRNA vector.In this study, we demonstrated that vimentin is significantly expressed in Th17 cells through STAT3 activation. Our results provide new insights into the role of vimentin in Th17 cells and the complex pathogenesis of RA.

Low dose methotrexate impaired T cell transmigration through down-regulating CXCR4 expression in rheumatoid arthritis (RA)

BackgroundCXC chemokine CXCL12 is involved in the pathological development of rheumatoid arthritis (RA) through abnormal migration of peripheral immune cells in the joint. Although low dose methotrexate (MTX) is clinically used to treat RA patients, CXCL12 signaling responses to MTX-mediated treatments is still not well understood.MethodsIn this study, we examined the expression of CXCR4 (cognatic receptor for CXCL12) in peripheral T cells from RA patients and arthritis mice models received from low dose MTX therapies. The effects of low dose MTX on CXCR4 were further determined via both in vitro CD3+ T cells and Cxcr4 conditional knockout (CKO) arthritis mice models.ResultsOur clinical data shows that low dose MTX treatment was clinically associated with down-regulated expression of chemokine receptor CXCR4 on patient peripheral T cells. In vitro, low dose MTX significantly decreased cell transmigration through down-regulated CXCR4’s expression in CD3+ T cells. Consistently, CD3+ T cells treated with low dose MTX demonstrated an increased genomic hypermethylation across the promoter region of Cxcr4 gene. Furthermore, our preclinical studies showed that low dose MTX-mediated downregulation of CXCR4 significantly improved the pathological development in mouse arthritis models. Conditional disruption of the Cxcr4 gene in peripheral immune cells potentially alleviated inflammation of joints and lung tissue in the arthritis mice, though genetic modification itself overall did not change their clinical scores of arthritis, except for a significant improvement on day 45 in CXCR4 CKO arthritis mice models during the recovery phase.ConclusionOur findings suggest that the effect of low dose MTX treatment could serve to eliminate inflammation in RA patients through impairment of immune cell transmigration mediated by CXCR4.

Histological synovitis score in juvenile idiopathic arthritis and other pediatric synovial inflammatory conditions

ObjectiveThe Krenn’s scoring is a system for histopathological grading of synovial inflammation, and in adults, useful in etiological grouping. The score has only rarely been used in pediatric samples. We aimed to assess the performance of the score in juvenile idiopathic arthritis and other pediatric synovial inflammatory processes in categorization of the disease and in finding characteristic pathological features. DesignWe collected an unselected series of pediatric (age < 16 years) routine synovial biopsy samples to represent normal synovium and inflammatory conditions. The final diagnosis based on clinical follow-up was determined and classified as normal synovium, and different groups according to etiology. Total of 142 patients were analyzed. According to the score, case was classified to normal, low- or high-grade synovitis. ResultsThe synovitis scores in clinically normal synovium were low with 48 % of cases with scores of low-grade synovitis. In structural joint disorders scores varied from normal to low grade synovitis with occasional cases of high grade synovitis. In transient/reactive arthritis scores showed increase, majority clustering to low grade synovitis. In JIA and in bacterial synovitis the scores were higher than in the other groups high grade synovitis being the dominant grade. Extended oligoarthritis showed higher score than persistent oligoarthritis. ROC analysis indicated that JIA could be differentiated from other conditions. ConclusionsThe Krenn’s synovitis score is useful in the etiological classification of pediatric synovial samples, high Krenn’s score suggesting JIA. Observed differences between the subcategories of oligoarthritis may be useful in subclassifying these types of JIA.

Effects of exogenous deoxyribonuclease I in collagen antibody-induced arthritis

BackgroundRheumatoid arthritis (RA) is associated with a high concentration of extracellular DNA (ecDNA). This could be a consequence of the inflammation, but the ecDNA could also be involved in the unknown etiopathogenesis of RA. Clearance of ecDNA is hypothesized to prevent the development of RA. This study aimed to analyze the effects of exogenous deoxyribonuclease I (DNase I) administration in an animal model of RA.MethodsThe collagen antibody-induced arthritis (CAIA) model of RA was induced in adult female DBA/1J mice. CAIA mice were treated with saline or DNase I (10 mg/kg) every 12 h for the whole duration of the experiment. Arthritic scores were assessed. Paw volume and temperature were assessed using a plethysmometer and a thermal camera, respectively. Plasma ecDNA and its subcellular origin were analyzed using fluorometry and real-time PCR. DNase activity was quantified with single radial enzyme diffusion method.ResultsThe CAIA model was successfully induced as proved by a higher volume, temperature and the overall arthritis score in comparison to controls. The administration of DNase I resulted in a nearly two-fold increase in serum DNase activity. Still, it did affect neither plasma ecDNA, nor the arthritis score or other measures of joint inflammation.ConclusionOur results suggest that exogenous DNase I does not prevent the development of CAIA in mice. Whether this is true for other animal models of arthritis or clinical RA requires further research. EcDNA does not seem to be involved in the pathogenesis of CAIA. Additional studies are also needed to elucidate the role of ecDNA in the development of RA, focusing especially on its origin and inhibition of ecDNA release.

Hyaluronic acid-coated polypeptide nanogel enhances specific distribution and therapy of tacrolimus in rheumatoid arthritis

Rheumatoid arthritis (RA) involves chronic inflammation, oxidative stress, and complex immune cell interactions, leading to joint destruction. Traditional treatments are often limited by off-target effects and systemic toxicity. This study introduces a novel therapeutic approach using hyaluronic acid (HA)-conjugated, redox-responsive polyamino acid nanogels (HA-NG) to deliver tacrolimus (TAC) specifically to inflamed joints. The nanogels’ disulfide bonds enable controlled TAC release in response to high intracellular glutathione (GSH) levels in activated macrophages, prevalent in RA-affected tissues. In vitro results demonstrated that HA-NG/TAC significantly reduced TAC toxicity to normal macrophages and showed high biocompatibility. In vivo, HA-NG/TAC accumulated more in inflamed joints compared to non-targeted NG/TAC, enhancing therapeutic efficacy and minimizing side effects. Therapeutic evaluation in collagen-induced arthritis (CIA) mice revealed HA-NG/TAC substantially reduced paw swelling, arthritis scores, synovial inflammation, and bone erosion while suppressing pro-inflammatory cytokine levels. These findings suggest that HA-NG/TAC represents a promising targeted drug delivery system for RA, offering potential for more effective and safer clinical applications.

Antiarthritic and Anti-inflammatory Activity of Different Types of Milk in Complete Freund’s Adjuvant-induced Arthritis in Male Adult Rats

Background: Rheumatoid arthritis (RA) is a chronic, immune-inflammatory disease that could be managed by an attenuation in dietary habits. With the increase in research that links the effect of nutrition linked to RA. Purpose: Our study aimed to determine the possible therapeutic effect of different types of milk in rat models experimentally induced with RA using 40 ml milk (camel (CM), goat (GM), sheep (SHM), cow (CWM), almond (AM), and soy milk (SM)). Methods: Forty adult male Wistar Albino rats were divided into eight groups (five rats each) as follows: (Control group): nonarthritic, (RA): rheumatoid arthritis, (RA+CM): RA having CM, (RA+GM): RA having GM, (RA+SHM): RA having SHM, (RA+CWM): RA having CWM, (RA+AM): RA is having AM, and (RA+SM): RA has SM. Results: It has been observed that in the RA group and milk-treated groups, but not in the RA+CM group, the arthritis score changed significantly ( p ≤ 0.05) in comparison with the control group. CM and GM showed promising effects in downregulating various arthritis effector players including anticitrullinated peptide antibodies, C-reactive protein, prostaglandin E2, and other inflammatory mediators, which may be attributed to their lowest ω-6/ω-3 polyunsaturated fatty acid ratios. Conclusion: A possible benefit of this research is the potential development of new functional foods that promote health, prevent disease, and potentially enable the milk to be used as a therapeutic agent for RA.

Evaluation of CD4+ CD25+/high CD127low/- Regulatory T-Cells in Different Stages of Psoriatic Arthritis Patients.

Psoriatic arthritis (PsA) is a systemic auto-immune condition characterized by diverse and distinctive inflammation, affecting both musculoskeletal and extra-articular systems. This study aims to investigate the role of regulatory T-cells (Tregs), specifically the CD4+CD25+/high CD127-/low subset, in PsA pathogenesis, and their potential as biomarkers and therapeutic targets. In a case-control study involving 40 PsA patients and 25 healthy individuals, CD4+ CD25+/high CD127-/low Tregs were analyzed in peripheral blood mononuclear cells (PBMCs) using flow cytometry. Disease activity was assessed using the Disease Activity in Psoriatic Arthritis (DAPSA) score. We observed a significant positive correlation between Treg levels and the DAPSA score (P = 0.02) in non-treated PsA patients. Additionally, patient age showed a significant positive correlation with erythrocyte sedimentation rate in the same group (P = 0.04), emphasizing the potential influence of Tregs on disease activity and age-related effects on inflammatory markers in PsA. While not revealing significant differences in Treg populations, our research underscores the importance of considering specific Treg subsets in PsA. These subsets may respond differently to disease micro-environments and treatments, affecting disease progression. This study contributes to the broader comprehension of immune dysregulation in auto-immune diseases and suggests that further investigation into Treg subsets' function and count is warranted. Such insights may lead to more tailored therapeutic approaches for PsA patients.

Mediterranean diet and exercise are associated with better disease control in psoriatic arthritis.

Psoriatic arthritis (PsA) is associated with obesity and other related comorbidities, which impose an additional burden on disease activity and response to treatment. We investigated the impact of Mediterranean diet, and exercise on the presentation and severity of PsA. Three hundred fifty-five patients with PsA (n = 279) and psoriasis (PsO) (n = 76) were included in a cross-sectional study. Demographic and clinical characteristics and dietary and exercise patterns were recorded. Patients were grouped into (i) high, moderate, and low Mediterranean diet adherence and (ii) high, medium, and low activity level. Levels of diet and exercise were correlated with disease activity indices. PsA patients had more comorbidities than their PsO counterparts (42.7% vs. 26.3%, p = .038). The majority showed a low exercise pattern (total = 71.3%, PsA = 72.4%, PsO = 67.1%). Approximately half (total = 44.2%, PsA = 43.4%, PsO = 47.4%) did not follow a Mediterranean diet. Disease Activity in Psoriatic Arthritis Score (DAPSA) (p = .004), tender (p = .003) and swollen (p = .015) joint counts, erythrocyte sedimentation rate (ESR) (p = .001), and Psoriasis Area and Severity Index (PASI) (p = .015) had an inverse correlation with exercise. Higher Mediterranean diet adherence was associated with reduced ESR (p = .056), PASI (p = .011), and body surface area (BSA) (p = .009) indices. After adjusting for body mass index (BMI), exercise retained its positive correlation with PsA disease activity, but diet showed significant correlation only with enthesitis (p = 0.015). Uptake of a Mediterranean diet and exercise have positive effects on PsA activity, independently of BMI. These findings support lifestyle recommendations to supplement conventional treatment for improvement in disease outcomes. Key points • Diet and lifestyle are important influencers of health-related outcomes in PsA. • In this cross-sectional study of 355 patients with psoriatic disease, we found that Med Diet and exercise improve outcomes in PsA independently of weight loss. • Our results suggest that diet and lifestyle modifications should supplement conventional medical treatments.