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Rheumatoid arthritis (RA) remains a formidable healthcare challenge due to its chronic nature and potential for irreversible joint damage. Methotrexate (MTX) is a cornerstone treatment for RA but carries significant risks of adverse effects with repeated administration, necessitating the exploration of alternative delivery methods. Injectable hydrogels loaded with MTX for intra-articular injection present a promising solution, allowing sustained drug release directly into affected joints. However, current hydrogel systems often lack extended therapeutic periods and the ability to self-regulate drug release according to disease state. Furthermore, RA is associated with excessive production of reactive oxygen species (ROS), which exacerbates inflammation and joint damage. Herein, we developed an advanced injectable hydrogel (MPDANPs/MTX HA-PEG gel) based on "bio-orthogonal chemistry", combining hyaluronic acid and polyethylene glycol (PEG) matrices co -loaded with mesoporous polydopamine nanoparticles (MPDANPs) and MTX. MPDANPs/MTX HA-PEG gel achieved prolonged, staged, and self-regulated MTX release, coupled with ROS scavenging capabilities for enhanced therapeutic efficacy. Due to its optimized MTX release behavior and significant ROS scavenging function, MPDANPs/MTX HA-PEG gel exhibited potent anti-inflammatory effects in collagen-induced arthritis (CIA) rats following a single intra-articular injection. Our findings highlight the potential of MPDANPs/MTX HA-PEG gel as a highly effective treatment strategy for RA, offering a promising avenue for improving patient outcomes. [Display omitted] • MPDANPs/MTX HA-PEG gel enabled prolonged, staged, and ROS-responsive MTX release. • Optimized MTX release behavior, combined with ROS scavenging capacities, contributed to efficient RA therapy. • Single intra-articular injection of MPDANPs/MTX HA-PEG gel showed significant anti-inflammatory effects in CIA rats. [ABSTRACT FROM AUTHOR]

Background: Morinda officinalis iridoid glycosides (MOIG) showed potential benefits in the treatment of rheumatoid arthritis (RA), but their exact mechanism has yet to be explored. Purpose: To evaluate the effects of MOIG on RA, and explore the potential targets and molecular mechanism of MOIG in RA. Methods: 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)-a 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-3ß (GSK-3ß). Results: 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-a-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-3ß, and inhibition of GSK-3ß attenuated the effects of MOIG on FLSs. Knockdown GSK-3ß 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-3ß. Conclusion: MOIG alleviates joint inflammation in RA through inhibition NF-κB and JAK2/STAT3 pathway via suppression of GSK-3ß in FLSs, which provides supports for MOIG as a promising therapeutic agent of RA. [ABSTRACT FROM AUTHOR]

Background: Rheumatoid 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. Object: To 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. Methods: We 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. Results: In 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. Conclusions: Quercetin'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. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a chronic condition characterized by inflammation and an abnormal immune response. N6-methyladenosine (m6A) methylation has altered nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing (NLRP) 3. This change is implicated in the regulation of cell pyroptosis and inflammation. WTAP has a crucial role in regulating NLRP3 m6A. In this work, we used a rat model of collagen-induced arthritis (CIA) to investigate the involvement of WTAP in the evolution of inflammation in RA. The purpose of silencing or overexpressing WTAP in RA-fibroblast-like synoviocytes (RA-FLSs) treated with TNF-α was to identify its impact on pyroptosis, NLRP3 inflammasome-related proteins, the secretion of pro-inflammatory cytokines and migration. Bioinformatics techniques were used to pinpoint the exact target controlled by WTAP. To assess WTAP and NLRP3's role in RA-FLSs, we used methylated RNA immunoprecipitation, LDH test, flow cytometry, RT-qPCR, Western blotting, and Transwell. Our results show that WTAP expression is upregulated in both RA rats and cell models. Cell pyroptosis, NLRP3-related pro-inflammatory cytokines, and migration were reduced in TNF-α-treated RA-FLSs when WTAP was knocked down, whereas overexpression of WTAP displayed the opposite effect in RA-FLSs. WTAP mediated m6A modification in the NLRP3 mRNA and enhanced its mRNA stability. These results suggested that WTAP promoted FLSs pyroptosis and related inflammatory response via NLRP3 and identified WTAP as a potential target for treating RA. [ABSTRACT FROM AUTHOR]

[Display omitted] Rheumatoid arthritis (RA) is an inflammatory autoimmune disease triggered by antigenic peptides with environmental and genetic risk factors. It has been shown that antigen-specific targeting could be a promising therapeutical strategy for RA by restoring immune tolerance to self-antigens without compromising normal immunity. Citrullination of antigens enhances antigenic properties and induces autoimmune responses. Here, we showed that citrullinated antigenic (citAg) vaccine ameliorated collagen-induced arthritis with decreased T-helper 1 (Th1) and Th17 cells, downregulated proinflammatory cytokines including interlukin-6 and tumor necrosis factor-α, and inhibited antigen recall responses. B cell receptor sequencing further revealed that citAg vaccine could dampen the dysregulated V(D)J recombination, restoring the immune repertoire. Taken together, the results demonstrated that citAg vaccine might have a therapeutic effect on RA. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a debilitating autoimmune disease characterized by chronic joint inflammation and cartilage damage. Current therapeutic strategies often result in side effects, necessitating the development of targeted and safer treatment options. This study introduces a novel nanotherapeutic system, 2-APB@DGP-MM, which utilizes macrophage membrane (MM)-encapsulated nanoparticles (NPs) for the targeted delivery of 2-Aminoethyl diphenylborinate (2-APB) to inflamed joints more effectively. The NPs are designed with a matrix metalloproteinase (MMP)-cleavable peptide, allowing for MMP-responsive drug release within RA microenvironment. Comprehensive in vitro and in vivo assays confirmed the successful synthesis and loading of 2-APB into the DSPE-GPLGVRGC-PEG (DGP) NPs, as well as their ability to repolarize macrophages from a pro-inflammatory M1 to an anti-inflammatory M2 phenotype. The NPs demonstrated high biocompatibility, low cytotoxicity, and enhanced cellular uptake. In a collagen-induced arthritis (CIA) mouse model, intra-articular injection of 2-APB@DGP-MM significantly reduced synovial inflammation and cartilage destruction. Histological analysis corroborated these findings, demonstrating marked improvements in joint structure and delayed disease progression. Above all, the 2-APB@DGP-MM nanotherapeutic system offers a promising and safe approach for RA treatment by modulating macrophage polarization and delivering effective agents to inflamed joints. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a chronic autoimmune disease accompanied by local and systemic bone loss. Fcgγs, especially FcgRIIa (hFcgγIIa), have been implicated in the pathogenesis of RA. However, the contribution of hFcγgIIa to bone loss has not been fully elucidated. In the present study, we demonstrated the doubleedged sword role of hFcgγIIa on osteoclast differentiation through investigations involving hFcgγIIa-transgenic (hFcgγIIa-Tg) mice. Our findings reveal that hFcgRIIa-Tg mice, previously shown to exhibit heightened susceptibility to collagen-induced arthritis (CIA), displayed increased osteoporosis during CIA or at advanced ages (40 weeks), accompanied by heightened in vivo osteoclast differentiation. Notably, bone marrow cells from hFcgγIIa-Tg mice exhibited enhanced efficiency in differentiating into osteoclasts and bone resorption in vitro compared to wild-type mice when stimulated with receptor activators of NF-kB ligand (RANKL). Additionally, hFcgγIIa-Tg mice exhibited augmented sensitivity to RANKL-induced bone loss in vivo, highlighting the osteoclastpromoting role of hFcgγIIa. Mechanistically, bone marrow cells from hFcgγIIa-Tg mice displayed heightened Syk self-activation, leading to mTOR-pS6 pathway activation, thereby promoting RANKL-driven osteoclast differentiation. Intriguingly, while hFcgRIIa crosslinking hindered RANKL-induced osteoclast differentiation, it activated the kinase cAbl, subsequently triggering STAT5 activation and inhibiting the expression of osteoclast-associated genes. This study provides novel insights into hFcgγIIa-mediated osteoclast biology, suggesting promising therapeutic targets for managing bone remodeling disorders. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that mainly affects the joints. Studies have shown that memory CD4+ T cells play an important role in the pathogenesis of RA. This study investigated the expression and function of CD305 on human memory CD4+ T cells and the effects of CD305 activating antibody on collagen-induced arthritis. The results showed that CD305 expression was significantly decreased on circulating memory CD4+ T cells from patients with RA and its mean fluorescence intensity (MFI) was negatively correlated with DAS28. Moreover, CD305 inhibited the activation of memory CD4+ T cells by down-regulating CD69 and CD25 and the production of IFN-γ, IL-4, and IL-17A induced by anti-CD3/CD28 antibodies. In addition, activation of CD305 inhibited the severity of disease in collagen-induced arthritis. In summary, CD305 reduction may mediate the excessive activation of memory CD4+ T cells and participate in the development of RA. It can be used as a predictive marker of disease activity and has potential medicinal value in the treatment of RA. • CD305 decreases prominently on circulating memory CD4+ T cells and is negatively correlated with DAS28 of patients with RA. • CD305 participates in the abnormal activation of memory CD4+ T cells in patients with RA. • CD305 inhibits secretion of IFN-γ, IL-4 and IL-17A by memory CD4+ T cells. • CD305 attenuates arthritis severity in Collagen-induced arthritis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Preliminary research by our group suggests that targeting fibroblast growth factor receptor 1 (FGFR1) may be an effective strategy for treating RA. OBJECTIVE: To investigate the effects of an FGFR1 inhibitor (PD173074) on bone destruction in rats with collagen-induced arthritis. METHODS: Twenty-five female Sprague-Dawley rats were randomly divided into five groups: normal control group, model group, methotrexate group, low- dose PD173074 group, and high-dose PD173074 group. Except for the normal control group, rat models of type II collagen-induced arthritis were made in each group. After successful modeling, rats were injected intraperitoneally with sterile PBS in the normal and model groups, 1.04 mg/kg methotrexate in the methotrexate group, and 5 and 20 mg/kg in the low-dose group and high-dose PD173074 groups, once a week. After 4 weeks of drug administration, clinical symptoms and joint swelling in rats were observed. Micro-CT was used for three-dimensional reconstruction and analysis of the ankle joints. Pathological changes in the ankle joints were observed. Periarticular angiogenesis and the expression of receptor activator of nuclear factor-κB ligand were detected. The expression levels of p-FGFR1, vascular endothelial growth factor A, and tartrate-resistant acid phosphatase in the synovial membrane were measured. Pathological changes in the liver, spleen, and kidney were observed and liver, spleen, and kidney indices were calculated. RESULTS AND CONCLUSION: PD173074 could alleviate clinical symptoms and joint swelling, delay bone loss, improve bone structure, reduce synovial invasion and cartilage bone erosion, reduce the number of periarticular osteoclasts, inhibit angiogenesis in synovial tissues, reduce the expression of receptor activator of nuclear factor-κB ligand, and inhibit the expression of FGFR1 phosphorylated protein, tartrate-resistant acid phosphatase and vascular endothelial growth factor A. Pathologic observation of the liver, spleen and kidney in rats showed no obvious toxic side effects after PD173074 treatment. To conclude, the FGFR1 inhibitor can delay the progression of joint inflammation and bone destruction and inhibit angiogenesis in the rat model of type II collagen-induced arthritis. The therapeutic effect of PD173074 has been preliminarily validated in the type II collagen-induced arthritis model and may act by inhibiting FGFR1 phosphorylation, which provides a direction for the search of new therapeutic targets for rheumatoid arthritis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rheumatoid arthritis is an inflammatory disease. Many studies have shown that wogonin has a good anti-inflammatory effect on rheumatoid arthritis, but its exact efficacy and specific mechanism of action remain to be clarified. OBJECTIVE: To investigate the mechanism of wogonin ameliorating joint inflammation by regulating endoplasmic reticulum stress pathway in rats with collagen- induced arthritis. METHODS: (1) At the animal level: Female Wistar rats were divided into healthy control group, arthritis model group and wogonin treatment group. Rat models of arthritis in the latter two groups were established by subcutaneous injection of bovine type II collagen and adjuvant. In the wogonin group, wogonin was given by gavage for 28 consecutive days after modeling. During this period, the rats in each group were weighed, and arthritis score and ankle swelling were measured every 7 days. After the experiment, the pathological changes of the joint were observed, the mRNA and protein levels of endoplasmic reticulum stress pathway GRP78 and CHOP were detected by qRT-PCR, western blot, and immunohistochemistry. (2) At the cellular level, cell counting kit-8 was used to detect the cytotoxic effect of wogonin on fibroblast-like synoviocytes from rats with collagen-induced arthritis. The fibroblast-like synoviocytes induced by thapsigargin were treated with different concentrations of wogonin. The levels of interleukin-1β and tumor necrosis factor-α in the cell supernatant were detected by ELISA, and the intracellular reactive oxygen species in each group were determined by DCFH-DA probe method. The mRNA and protein levels of GRP78, IRE1α, XBP1s and CHOP were detected by qRT-PCR and western blot, respectively. RESULTS AND CONCLUSION: Compared with the healthy control group, arthritis index score and ankle swelling degree in the arthritis model group were increased (P < 0.01), synovial hyperplasia, inflammatory cell infiltration, cartilage destruction and bone erosion were observed in pathological sections, and the mRNA and protein expressions of GRP78 and CHOP in the ankle were significantly increased (P < 0.01), which were mainly located in synovial tissue and articular surface. Compared with the arthritis model group, the arthritis index score and ankle swelling degree in the wogonin treatment group were decreased (P < 0.05), synovial hyperplasia and the number of inflammatory cells were decreased, cartilage destruction and bone erosion were alleviated, the mRNA and protein expression levels of GRP78 and CHOP in the ankle were decreased (P < 0.05), particularly in synovial tissue and on the articular surface. There was no significant difference in body mass among the three groups (P > 0.05). In the cell experiment, 200 μmol/L wogonin significantly reduced the survival rate of fibroblast-like synoviocytes (P < 0.01). Compared with the blank control group, the levels of interleukin-1β, tumor necrosis factor-α, content of reactive oxygen species, and mRNA and protein expression of GRP78, IRE1α, XBP1s, and CHOP in the thapsigargin group were significantly increased (P < 0.05); compared with the thapsigargin group, 50 and 100 μmol/L wogonin significantly reduced the levels of interleukin-1β and tumor necrosis factor-α in the cell supernatant (P < 0.05, P < 0.01), and 100 μmol/L wogonin significantly reduced the content of reactive oxygen species (P < 0.01) and down-regulated the mRNA and protein expression levels of GRP78, IRE1α, XBP1s and CHOP (all P < 0.05). These results suggest that wogonin can effectively alleviate joint inflammatory responses in rats with collagen-induced arthritis, and the endoplasmic reticulum stress pathway may be the key target of its intervention. [ABSTRACT FROM AUTHOR]

Abstract Rheumatoid arthritis (RA) is a chronic autoimmune disease marked by synovitis and cartilage destruction. The active compound, icariin (ICA), derived from the herb Epimedium, exhibits potent anti-inflammatory properties. However, its clinical utility is limited by its water insolubility, poor permeability, and low bioavailability. To address these challenges, we developed a multifunctional drug delivery system—adipose-derived stem cells-exosomes (ADSCs-EXO)-ICA to target active macrophages in synovial tissue and modulate macrophage polarization from M1 to M2. High-performance liquid chromatography analysis confirmed a 92.4 ± 0.008% loading efficiency for ADSCs-EXO-ICA. In vitro studies utilizing cellular immunofluorescence (IF) and flow cytometry demonstrated significant inhibition of M1 macrophage proliferation by ADSCs-EXO-ICA. Enzyme-linked immunosorbent assay, cellular transcriptomics, and real-time quantitative PCR indicated that ADSCs-EXO-ICA promotes an M1-to-M2 phenotypic transition by reducing glycolysis through the inhibition of the ERK/HIF-1α/GLUT1 pathway. In vivo, ADSCs-EXO-ICA effectively accumulated in the joints. Pharmacodynamic assessments revealed that ADSCs-EXO-ICA decreased cytokine levels and mitigated arthritis symptoms in collagen-induced arthritis (CIA) rats. Histological analysis and micro computed tomography confirmed that ADSCs-EXO-ICA markedly ameliorated synovitis and preserved cartilage. Further in vivo studies indicated that ADSCs-EXO-ICA suppresses arthritis by promoting an M1-to-M2 switch and suppressing glycolysis. Western blotting supported the therapeutic efficacy of ADSCs-EXO-ICA in RA, confirming its role in modulating macrophage function through energy metabolism regulation. Thus, this study not only introduces a drug delivery system that significantly enhances the anti-RA efficacy of ADSCs-EXO-ICA but also elucidates its mechanism of action in macrophage function inhibition. Graphical abstract

Background: Fu-zi decoction (FZD) has a long history of application for treating Rheumatoid arthritis (RA) as a classic formulation. However, its underlying mechanisms have not been fully elucidated. This study aimed to decipher the potential mechanism of FZD in treating RA, with a specific focus on receptor activator of nuclear factor κB/receptor activator of nuclear factor κB ligand (RANK/RANKL) signaling pathway. Methods: The impact of FZD on RA was investigated in collagen-induced arthritis rats (CIA), and the underlying mechanism was investigated in an osteoclast differentiation cell model. In vivo, the antiarthritic effect of FZD at various doses (2.3, 4.6, 9.2 g/kg/day) was evaluated by arthritis index score, paw volume, toe thickness and histopathological examination of inflamed joints. Additionally, the ankle joint tissues were determined withmicro-CT and safranin O fast green staining to evaluate synovial hyperplasia and articular cartilage damage. In vitro, osteoclast differentiation and maturation were evaluated by TRAP staining in RANKL-induced bone marrow mononuclear cells. The levels of pro- and anti-inflammatory cytokines as well as RANKL and OPG were evaluated by ELISA kits. In addition, Western blotting was used to investigate the effect of FZD on RANK/RANKL pathway activation both in vivo and in vitro. Results: FZD significantly diminished the arthritis index score, paw volume, toe thickness and weigh loss in CIA rats, alleviated the pathological joint alterations. Consistent with in vivo results, FZD markedly inhibited RANKLinduced osteoclast differentiation by decreasing osteoclast numbers in a dose-dependent manner. Moreover, FZD decreased the levels of proinflammatory cytokines IL-6, IL-1β and TNF-α, while increasing antiinflammatory cytokine IL-10 level both in serum and culture supernatants. Treatment with FZD significantly reduced serum RANKL levels, increased OPG levels, and decreased the RANKL/OPG ratio. In both in vivo and in vitro settings, FZD downregulated the protein expressions of RANK, RANKL, and c-Fos, while elevating OPG levels, further decreasing the RANKL/OPG ratio. Conclusion: In conclusion, FZD exerts a therapeutic effect in CIA rats by inhibiting RANK/RANKL-mediated osteoclast differentiation, which suggested that FZD is a promising treatment for RA. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a chronic disease characterized by persistent synovitis and angiogenesis. Its clinical manifestations are synovial hyperplasia and progressive destruction of bone and cartilage, eventually leading to joint deformation and even disability. The healing effect of monomer stigmasterol, the main active ingredient of the Jinwujiangu recipe the Chinese Herbal Compound, on RA has been confirmed in several studies. Fibroblast-like synoviocytes (FLS) are related to the occurrence and development of RA. This study aims to investigate the effects of stigmasterol on FLS cell proliferation and apoptosis, as well as its impact on FLS cell cycle proteins and key genes in the Phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT) pathway, providing insights into the development of stigmasterol as an alternative therapeutic drug for RA. We administered 20 g/kg stigmasterol to rats continuously for 5 d to obtain stigmasterol-containing serum, and established rat models of osteoarthritis induced by ossein to obtain FLS. To explore the effects of stigmasterol on the viability, migration, proliferation and apoptosis of collagen-induced arthritis (CIA)-FLS cells, we selected 0% (control), 5% (low concentration), 10% (medium concentration) and 20% (high concentration) drug-containing serum to intervene cells and conducted Cell Counting Kit-8 (CCK- 8), Transwell, 5-ethynyl-2’ -deoxyuridine (EdU) staining and Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) experiments, respectively. The results showed that compared with the control group, low, medium, and high serum significantly inhibited the activity, migration, and proliferation of FLS cells, and promoted their apoptosis, and high serum had the best effect. In addition, we investigated the mechanism of stigmasterol inhibiting FLS proliferation and promoting its apoptosis by qPCR, Western blot, and immunofluorescence assays. The results showed that stigmasterol significantly inhibited the expression of Cyclin D1, cyclin-dependent kinase 4 (CDK4), and Retinoblastoma (Rb), and decreased the expression of key genes kinase insert domain-containing receptor (KDR), PI3K, AKT, phosphorylated PI3K (p-PI3K) and phosphorylated AKT (p-AKT) in the KDR-mediated PI3K/AKT signaling pathway, thus inhibiting the proliferation of FLS and promoting the apoptosis of FLS. It was suggested that stigmasterol may be a potential alternative drug for RA treatment. [ABSTRACT FROM AUTHOR]

Qianjinba is primarily cultivated in the southern regions of China and finds extensive use in traditional Chinese medicine (TCM) for conditions such as rheumatism, arthralgia, and gynecological ailments. It has been officially recognized as a protected variety of TCM by the state. The aim of this study was to investigate the therapeutic potential of Qianjinba polysaccharide (QJBDT) in treating rheumatoid arthritis (RA) in mice, along with a preliminary exploration of its mechanisms for inhibiting RA in these animals. Kunming mice (KM) were randomly divided into several groups, including a normal group, a model group (LPS group), low-dose, medium-dose, and high-dose QJBDT groups, as well as a positive control group (TGP group), each consisting of 10 mice. To induce inflammation and create an RA model, type II collagen was injected into the right hind foot joint. Following a 7-day modeling period, various concentrations of QJBDT and the positive control drug total glycoside of peony were administered via gavage once a day for 21 consecutive days. Throughout the study, we monitored and recorded the mice's weight, measured foot swelling, and assessed the arthritis index on a weekly basis. We also conducted pathological examinations of joint tissues and analyzed the signal pathway of p38 mitogen-activated protein kinase (MAPK) as well as the protein expression of nuclear factor NF-κB in the mice's right foot joint tissues. Additionally, we employed ELISA to detect the levels of interleukin-β (IL-β), IL-17, and tumor necrosis factor-α (TNF-α) in the mice's serum. The results of this study revealed that QJBDT effectively reduced the degree of foot swelling and the arthritis index in collagen-induced arthritis mice while improving their weight loss (P < 0.05). Furthermore, it alleviated the pathological damage observed in the mice's joints. Notably, the expression of transcription factors p38 and NF-κB proteins was down-regulated (P < 0.05), and the levels of inflammatory cytokines IL-β, IL-17, and TNF-α in the mice's serum were decreased (P < 0.05). In conclusion, this study demonstrated that polysaccharides could inhibit the expression of transcription factors p38 and NF-κB, reduce the production of inflammatory factors, and alleviate the progression of RA to a certain extent. [ABSTRACT FROM AUTHOR]

Summary: Rheumatoid arthritis (RA) is considered a multifactorial condition where interaction between the genetic and environmental factors lead to immune dysregulation causing autoreactivity. While among the various genetic factors, HLA‐DR4 and DQ8, have been reported to be the strongest risk factors, the role of various environmental factors has been unclear. Though events initiating autoreactivity remain unknown, a mucosal origin of RA has gained attention based on the recent observations with the gut dysbiosis in patients. However, causality of gut dysbiosis has been difficult to prove in humans. Mouse models, especially mice expressing RA‐susceptible and ‐resistant HLA class II genes have helped unravel the complex interactions between genetic factors and gut microbiome. This review describes the interactions between HLA genes and gut dysbiosis in sex‐biased preclinical autoreactivity and discusses the potential use of endogenous commensals as indicators of treatment efficacy as well as therapeutic tool to suppress pro‐inflammatory response in rheumatoid arthritis. [ABSTRACT FROM AUTHOR]

Rheumatoid Arthritis (RA) is a chronic autoimmune condition causing joint inflammation and damage. Despite treatment progress, effective topical therapies pose challenges. Animal models, like Collagen-Induced Arthritis (CIA) and Adjuvant-Induced Arthritis (AIA), mimic RA pathogenesis, aiding preclinical evaluation of topical treatments. By studying these models, experts can assess the efficacy, safety and pharmacokinetics of novel topical treatments, thereby accelerating their translation into clinical practice. Optimizing drug delivery, bioavailability and minimizing side effects are critical in formulation development. Animal studies refine parameters such as vehicle selection, drug concentration and application frequency for maximal therapeutic benefit. These models also deepen understanding of RA mechanisms, informing targeted topical therapy design against specific inflammatory mediators or immune cells. Lastly, animal models accelerate topical RA treatment development, providing vital data and mechanistic insights. Leveraging these models enhances formulation safety and efficacy, potentially improving patient outcomes. [ABSTRACT FROM AUTHOR]

Simple Summary: Auto-immune disorders, such as rheumatoid arthritis, are characterized by high levels of pro-inflammatory cytokines. Continued exposure to high levels of systemic inflammation has several other health consequences, including negative effects on organs such as the brain. These detrimental effects may result in mood and neurological disorders. However, the exact mechanisms through which inflammation can result in mood disturbances and neurological disorders are not well known and are difficult to study in humans. The collagen-induced arthritis (CIA) rat model has been used to mimic human autoimmune disorders and systemic inflammation. In this study, we used the CIA model to gain a better understanding of the role of inflammation on the processes that may be involved in mood and neurological disorders, by looking at several molecular markers in different brain regions. Our results showed that all the brain regions studied in the CIA rats had high levels of local inflammation, which may have resulted in cell death in these areas. We also showed that the markers associated with neuron health and neurotransmitters implicated in mood disturbances were dysregulated in some, but not all brain regions. These results suggest that inflammation induced by autoimmune disorders may result in neuroinflammation that could result in neurodegeneration. Background: The effects of collagen-induced arthritis (CIA), a model of systemic inflammation, on brain regional molecular markers associated with neurological disorders are uncertain. Objective: This study investigated the brain regional molecular changes in markers associated with inflammation and neuronal dysfunction in a CIA model. Methods: Fourteen male Sprague Dawley rats were divided into control (n = 5) or CIA (n = 9) groups. 10 weeks after CIA induction, brain tissue was collected. Brain regional mRNA expression of inflammatory markers (IL-1β and IL-6), apoptotic markers (BAX and Bcl2) and neurotrophic factors (BDNF, CREB and TrkB) was determined. Monoamine distribution and abundance in different brain regions were determine by mass spectrometry imaging (MSI). Results: Neuroinflammation was confirmed in the CIA group by increased IL-β mRNA expression, concurrent with an increased BAX/Bcl2 ratio. The mRNA expression of CREB was increased in the midbrain and hippocampus while BDNF was increased and TrkB was decreased across all brain regions in CIA compared to control animals. Serotonin was decreased in the midbrain and hippocampus while dopamine was decreased in the striatum of CIA rats, compared to controls. Conclusion: CIA resulted in neuroinflammation concurrent with an apoptotic state and aberrant expression of neurotrophic factors and monoamines in the brain, suggestive of neurodegeneration. [ABSTRACT FROM AUTHOR]

AIM: To investigate the mechanism by which wogonin (WOG) induces ferroptosis in collagen-induced arthritis rat fibroblast-like synoviocytes (rat CIA-FLS cells) through the nuclear factor E2-related factor 2 (NRF2)/heme oxygenase-1 (HO-1) signaling pathway. METHODS: Rat CIA-FLS cells were divided into: control group, low, medium, and high dose of (25, 50 and 100 μmol/L) WOG group, ferroptosis inhibitor (LIP-1) group, LIP-1 + high dose WOG group, HO-1 agonist cobalt protoporphyrin (COPP) group, and COPP + high dose WOG group. CCK-8 assay was used for cell viability. Crystal violet staining was used for for cell morphology. The levels of oxidative stress markers glutathione (GSH), malondialdehyde (MDA), and superoxide dismutase (SOD) were measured. DCFH-DA fluorescent probe was used to detect the intracellular reactive oxygen species (ROS) content as well as Western blot to detect the protein expression levels of Kelch-like ECH-associated protein 1 (KEAP-1), NRF2 and HO-1. RESULTS: Compared with the normal control group, administration of WOG treatment resulted in a significant decrease in CIA-FLS cell viability (P< 0. 01, a significant increase in the level of oxidative stress (P<0. 01), a significant increase in the content of ROS (P< 0. 01), a significant decrease in the level of expression of NRF2 and HO-1 proteins (P<0. 01), and a significant increase in the level of KEAP-1 (P<0. 01) in the rat. Compared with the WOG group, the LIP-1-treated group showed a significant increase in cell viability (P<0. 01, a significant decrease in the level of oxidative stress (P<0. 01), and a significant decrease in the content of ROS (P<0. 01). Compared with the WOG group, the addition of COPP resulted in a significant increase in the protein expression levels of NRF2 and HO-1 (P<0. 01) and a significant decrease in KEAP-1 levels (P< 0.01). CONCLUSION: WOG can induce ferroptosis in rat CIA-FLS cells by promoting oxidative stress through the NRF2/HO-1 signaling pathway. [ABSTRACT FROM AUTHOR]

The characteristic features of the rheumatoid arthritis (RA) microenvironment are synovial inflammation and hyperplasia. Therefore, there is a growing interest in developing a suitable therapeutic strategy for RA that targets the synovial macrophages and fibroblast-like synoviocytes (FLSs). In this study, we used graphene oxide quantum dots (GOQDs) for loading anti-arthritic sinomenine hydrochloride (SIN). By combining with hyaluronic acid (HA)-inserted hybrid membrane (RFM), we successfully constructed a new nanodrug system named HA@RFM@GP@SIN NPs for target therapy of inflammatory articular lesions. Mechanistic studies showed that this nanomedicine system was effective against RA by facilitating the transition of M1 to M2 macrophages and inhibiting the abnormal proliferation of FLSs in vitro. In vivo therapeutic potential investigation demonstrated its effects on macrophage polarization and synovial hyperplasia, ultimately preventing cartilage destruction and bone erosion in the preclinical models of adjuvant-induced arthritis and collagen-induced arthritis in rats. Metabolomics indicated that the anti-arthritic effects of HA@RFM@GP@SIN NPs were mainly associated with the regulation of steroid hormone biosynthesis, ovarian steroidogenesis, tryptophan metabolism, and tyrosine metabolism. More notably, transcriptomic analyses revealed that HA@RFM@GP@SIN NPs suppressed the cell cycle pathway while inducing the cell apoptosis pathway. Furthermore, protein validation revealed that HA@RFM@GP@SIN NPs disrupted the excessive growth of RAFLS by interfering with the PI3K/Akt/SGK/FoxO signaling cascade, resulting in a decline in cyclin B1 expression and the arrest of the G2 phase. Additionally, considering the favorable biocompatibility and biosafety, these multifunctional nanoparticles offer a promising therapeutic approach for patients with RA. [ABSTRACT FROM AUTHOR]

[Display omitted] • PCSK9 exacerbates atrial structural remodeling and promotes AF in collagen-induced arthritis rats by enhancing M1 macrophages polarization. • The PCSK9 is increased in RA patients complicated with AF and the level of PCSK9 is independently associated with AF risk in RA patients. • Evolocumab (a monoclonal antibody of PCSK9) reduces AF susceptibility of rheumatoid arthritis rats. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is implicated in the pathogenesis and progression of autoimmune disease. Patients with rheumatoid arthritis (RA) are at high risk of developing atrial fibrillation (AF), while whether PCSK9 is involved in the onset of AF among RA patients remains unclear. To explore the role of PCSK9 in the occurrence of AF in RA patients and decipher the underlying mechanism. We established a rat model of collagen-induced arthritis (CIA) by immunization with type II collagen in Freund's incomplete adjuvant. Atrial electrophysiological test was used to evaluate AF susceptibility. We performed a clinical study to examine the correlation between PCSK9 level and AF, which recruited healthy control, RA patients and RA patients complicated with AF. Evolocumab (a monoclonal antibody of PCSK9) is administered via intraperitoneal injection in CIA rats to assess the role of PCSK9 in RA-related AF. LPS-RS (LPS inhibitor), clodronate liposomes (depletion of macrophages), and cell co-culture model were used to dissect the mechanism underlying PCSK9 promotes AF. AF inducibility and duration were higher in CIA rats, accompanied by elevated plasma and atrial PCSK9. Interestingly, compared with healthy control subjects, patients with RA showed an increase in PCSK9, and the PCSK9 is much higher in RA patients complicated with AF. The level of PCSK9 was independently associated with AF risk in RA patients. In the in vivo experiment, evolocumab reduced AF susceptibility, and ameliorated atrial structural remodeling of CIA rats. Mechanistically, augmented LPS in CIA rats led to an increase in PCSK9, which exacerbated fibrosis of cardiac fibroblasts and apoptosis of cardiac myocytes by enhancement of M1 macrophages polarization and inflammation, thereby contributing to AF. This study suggests that elevated PCSK9 causes atrial structural remodeling by enhancement of M1 macrophages polarization in atria, and evolocumab can effectively protects CIA rats from AF. [ABSTRACT FROM AUTHOR]

Background: Yishen-Tongbi Decoction (YSTB), a traditional Chinese prescription, has been used to improve syndromes of rheumatoid arthritis (RA) for many years. Previous research has shown that YSTB has anti-inflammatory and analgesic properties. However, the underlying molecular mechanism of the anti-RA effects of YSTB remains unclear. Purpose and study design: The purpose of this research was to investigate how YSTB affected mice with collagen-induced arthritis (CIA) and RAW264.7 cells induced with lipopolysaccharide (LPS). Results: The findings show that YSTB could significantly improve the clinical arthritic symptoms of CIA mice (mitigate paw swelling, arthritis score, thymus and spleen indices, augment body weight), downregulated expression of proinflammatory cytokines like tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), IL-6 and IL-17, while upregulated the level of anti-inflammatory like IL-10 and transforming growth factor-β (TGF-β). Meanwhile, YSTB inhibits bone erosion and reduces inflammatory cell infiltration, synovial proliferation, and joint destruction in CIA mice. In addition, we found that YSTB was able to suppress the LPS-induced inflammation of RAW264.7 cells, which was ascribed to the suppression of nitric oxide (NO) production and reactive oxygen species formation (ROS). YSTB also inhibited the production of inducible nitric oxide synthase and reduced the releases of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 in LPS-induced RAW264.7 cells. Furthermore, the phosphorylation expression of JAK2, JAK3, STAT3, p38, ERK and p65 protein could be suppressed by YSTB, while the expression of SOCS3 could be activated. Conclusion: Taken together, YSTB possesses anti-inflammatory and prevention bone destruction effects in RA disease by regulating the JAK/STAT3/SOCS3 signaling pathway. [ABSTRACT FROM AUTHOR]

The discovery of alternative medicines with fewer adverse effects is urgently needed for rheumatoid arthritis (RA). Sophoridine (SR), the naturally occurring quinolizidine alkaloid isolated from the leguminous sophora species, has been demonstrated to possess a wide range of pharmacological activities. However, the effect of SR on RA remains unknown. In this study, the collagen‐induced arthritis (CIA) rat model and tumor necrosis factor alpha (TNFα)‐induced fibroblast‐like synoviocytes (FLSs) were utilized to investigate the inhibitory effect of SR on RA. The anti‐arthritic effect of SR was evaluated using the CIA rat model in vivo and TNFα‐stimulated FLSs in vitro. Mechanistically, potential therapeutic targets and pathways of SR in RA were analyzed through drug target databases and disease databases, and validation was carried out through immunofluorescence, immunohistochemistry, and Western blot. The in vivo results revealed that SR treatment effectively ameliorated synovial inflammation and bone erosion in rats with CIA. The in vitro studies showed that SR could significantly suppress the proliferation and migration in TNFα‐induced arthritic FLSs. Mechanistically, SR treatment efficiently inhibited the activation of MAPKs (JNK and p38) and NF‐κB pathways in TNFα‐induced arthritic FLSs. These findings were further substantiated by Immunohistochemistry results in the CIA rat. SR exerts an anti‐arthritic effect in CIA rats through inhibition of the pathogenic characteristic of arthritic FLSs via suppressing NF‐κB and MAPKs (JNK and p38) signaling pathways. SR may have a great potential for development as a novel therapeutic agent for RA treatment. [ABSTRACT FROM AUTHOR]

Background: The LuoBiTong (LBT) capsule, a novel traditional Chinese medicine formulation, is currently in Phase III clinical trials. Preliminary preclinical and Phase II clinical studies suggest its efficacy and safety in treating rheumatoid arthritis (RA). However, the underlying mechanisms of its action remain to be elucidated.This research aims to explore the effects and mechanisms of LBT in conjunction with a maintenance dose of methotrexate (M-MTX) on RA. Methods: A Collagen-Induced Arthritis (CIA) mouse model was used to evaluate the anti-RA effects of LBT combined with M-MTX. Assessments included foot swelling, arthritis scoring, serum inflammatory factor analysis, and histopathological examination of the foot. These effects were compared with those of high-dose MTX (H-MTX). Network pharmacology was employed to construct a compound-target network for RA, based on drug composition, to predict its potential mechanism of action. Flow cytometry, Western Blot, and immunohistochemical analyses in animal models identified multiple inflammatory pathways targeted by LBT to augment the anti-RA effects of MTX. Results: The study revealed that LBT combined with M-MTX significantly alleviated CIA-induced arthritis without adverse effects. The combination of LBT and M-MTX showed similar or superior efficacy in regulating macrophage polarization, NF-κB, MAPK signaling pathways, and in the suppression of TH-17 expression in proinflammatory cells. These findings suggest that LBT may exert a multi-pathway therapeutic effect in RA treatment. The predicted pharmacological targets and mechanisms align well with this hypothesis. Conclusion: LBT, when combined with MTX, enhances the anti-RA effect by targeting multiple inflammatory pathways, demonstrating significant therapeutic potential. [ABSTRACT FROM AUTHOR]

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Background: Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects the body. Periploca forrestii was a miao ethnic drug in China that was used to treat arthritis for hundreds of years. But, the therapeutic mechanism is so far unknown. Therefore, the chemical component and effect of Periploca forrestii on arthritis in rats were studied using HPLC-QTOF MS, micro-CT, and other experiments in this paper. Method: Male Sprague-Dawley rats were used to assess the in vivo activity. HPLC QTOF-MS was used to analyze the chemical profile of the P. forrestii (PF). Bovine type II collagen and Complete Freund's Adjuvant were used to stimulate and construct the collagen-induced arthritis (CIA) model. Three dosages of PF (100 mg/kg, 200 mg/kg, 400 mg/kg) were used to evaluate in vivo activity. Methotrexate was used as the positive drug. H/E staining and micro-CT methods were used to monitor the pathological changes of CIA rats. ELISA method was used to assess the serum level of immune- and inflammationrelated cytokines. Immunohistochemical experiments were used to test the gene expression in JAK and Nf-B pathways. Results: 42 compounds were identified from PF. PF administration lowered the increased spleen index compared with that of control and MTX groups, and partially restored body weight, reduced paw swelling, and arthritis score compared with the model group. Macroscopic assessment indicated inflamed paw with significant swelling in the model group, while the extent of inflammation and swelling was attenuated by both MTX and PF. H/E staining experiments demonstrated that pathological changes of synovial cells and infiltration of inflammatory cells were observed in the model group. In contrast, the MTX and PF treatment partially reversed these pathological changes. Micro-CT examination showed severe injuries and scars caused by inflammation for the model group, and in the high-dosage group (400 mg/kg) the inflammationcaused injuries and scars were dramatically ameliorated. Mechanism study showed that PF restored Nf-B phosphorylation and JAK2 expression compared with the model group. Conclusion: P. forrestii possesses a potent effect on CIA rats. Nf-B and JAK2 pathways are involved in its protective effect on CIA. [ABSTRACT FROM AUTHOR]

Dietary supplementation with n-3 polyunsaturated fatty acids (PUFA) has been found to be beneficial in rodent rheumatoid arthritis models and human trials. However, the molecular targets of n-3 PUFAs and their beneficial effects on rheumatoid arthritis are under-researched. Free fatty acid receptor 4 (FFA4, also known as GPR120) is a receptor for n-3 PUFA. We aim to investigate whether FFA4 activation reduces collagen-induced rheumatoid arthritis (CIA) by using an FFA4 agonist, compound A (CpdA), in combination with DBA-1J Ffa4 gene wild-type (WT) and Ffa4 gene knock-out (KO) mice. CIA induced an increase in the arthritis score, foot edema, synovial hyperplasia, pannus formation, proteoglycan loss, cartilage damage, and bone erosion, whereas the administration of CpdA significantly suppressed those increases in Ffa4 WT mice but not Ffa4 gene KO mice. CIA increased mRNA expression levels of pro-inflammatory Th1/Th17 cytokines, whereas CpdA significantly suppressed those increases in Ffa4 WT mice but not Ffa4 gene KO mice. CIA induced an imbalance between Th1/Th17 and Treg cells, whereas CpdA rebalanced them in spleens from Ffa4 WT mice but not Ffa4 gene KO mice. In SW982 synovial cells, CpdA reduced the LPS-induced increase in pro-inflammatory cytokine levels. In summary, the present results suggest that the activation of FFA4 in immune and synovial cells could suppress the characteristics of rheumatoid arthritis and be an adjuvant therapy. [ABSTRACT FROM AUTHOR]

Introduction: Triptolide (TP), a natural product derived from the herbal medicine Tripterygium wilfordii, exhibits potent immunosuppressive activity. However, the mechanisms underlying its effects in rheumatoid arthritis remain incompletely understood. Methods: Collagen‐induced arthritis (CIA) model was induced in Sprague−Dawley rats by immunization with bovine type II collagen, and TP was administrated as treatment. The therapeutic effect of TP was evaluated based on paw swelling, histopathology, and serum levels of inflammatory factors. Exosomes isolated from rat serum were characterized by transmission electron microscopy, dynamic light scattering, and western blot analysis. Proteomic profiling of exosomes was analyzed by direct DIA quantitative proteomics analysis. Gene ontology and the Kyoto Encyclopedia of Genes and Genomes databases were employed for enrichment analysis related to molecular function, biological processes, and signaling pathways. Western blot analysis was used to analyze differentially expressed proteins. Results: TP treatment ameliorated arthritic phenotypes in CIA rats as evidenced by reduced arthritis score, paw swelling, pathological injury severity scores, and serum levels of inflammatory cytokines. The proteomic analysis revealed that TP treatment significantly inhibited complement and coagulation cascades, interleukin‐17 signaling pathway, and cholesterol metabolism, which were reactivated in CIA rats. Importantly, lipocalin 2 (LCN2) and myeloperoxidase (MPO) levels were markedly upregulated in the CIA group but suppressed upon TP administration. Furthermore, in synovial tissues, LCN2 and MPO expression levels were also elevated in the CIA group but decreased following TP treatment. Conclusion: Our findings demonstrate that TP alleviates CIA, possibly through modulation of exosomal LCN2 and MPO proteins. [ABSTRACT FROM AUTHOR]

Abstract Objectives Research has demonstrated that obesity may be associated with rheumatoid arthritis (RA). In addition, gut microbiota and its metabolites contribute to the occurrence and development of RA and obesity. However, the mechanism by which obesity affects RA remains unclear. In this study, we aimed to investigate whether gut microbiota and their metabolites alter the effects of high fat diet (HFD) on the severity of collagen-induced arthritis (CIA) in mice. Methods Briefly, mice were divided into normal group (N), CIA model group (C), HFD group (T), and HFD CIA group (CT). Hematoxylin and Eosin staining(HE) and Safranin O-fast green staining were conducted, and levels of blood lipid and inflammatory cytokines were measured. 16S rDNA sequencing technique and liquid chromatography-mass spectrometry (LC-MS)-based metabolomics were performed to explore changes in the microbiota structure to further reveal the pathomechanism of HFD on CIA. Results HFD aggravated the severity of CIA in mice. The CT group had the highest proportion of microbial abundance of Blautia, Oscillibacter, Ruminiclostridium-9, and Lachnospiraceae UCG 006 at the genus level, but had a lower proportion of Alistipes. Additionally, the fecal metabolic phenotype of the combined CT group shows significant changes, with differential metabolites enriched in 9 metabolic pathways, including primary bile acid biosynthesis, arginine biosynthesis, sphingolipid metabolism, purine metabolism, linoleic acid metabolism, oxytocin signaling pathway, aminoacyl-tRNA biosynthesis, the pentose phosphate pathway, and sphingolipid signaling pathway. Correlation analysis revealed that some of the altered gut microbiota genera were strongly correlated with changes in fecal metabolites, total cholesterol (TC), triglyceride (TG), and inflammatory cytokine levels. Conclusions This study shows that HFD may aggravate inflammatory reaction in CIA mice by altering the gut microbiota and metabolic pathways.

Abstract Background Rheumatoid arthritis (RA) is an autoimmune disease characterized by inflammatory reactions and tissue damage in the joints. Long-term drug use in clinical practice is often accompanied by adverse reactions. Extracorporeal photopheresis (ECP) is an immunomodulatory therapy with few side effects, offering a potential and safe therapeutic alternative for RA through the induction of immune tolerance. This study aimed to investigate the therapeutic effects of ECP on RA using a collagen-induced arthritis (CIA) murine model, as well as to explore its immunomodulatory effects in vivo. Additionally, particular attention was given to the significant role of monocytes during the ECP process. Methods A murine model of rheumatoid arthritis was established by administering two injections of bovine type II collagen to DBA/1J mice. ECP, ECP-MD (mononuclear cells were depleted during the ECP), MTX, and PBS treatment were applied to the CIA mice. During the treatment process, clinical scores and body weight changes of CIA mice were closely monitored. After six treatment sessions, micro-CT images of the hind paws from live mice were captured. Ankle joints and paws of the mice were collected and processed for histological evaluation. Spleen samples were collected to measure the Th17/Treg cells ratio, and serum samples were collected to assess cytokine and anti-type II collagen IgG levels. Monocytes and dendritic cells populations before and after ECP in vitro were detected by flow cytometry. Result ECP therapy significantly attenuated the progression of CIA, alleviated the severity of clinical symptoms in CIA mice and effectively suppressed synovial hyperplasia, inflammation, and cartilage damage. There was an expansion in the percentage of CD3 + CD4 + CD25 + FoxP3 + Tregs and a decrease in CD3 + CD4 + IL17A + Th17 cells in vivo. Furthermore, ECP reduced the serum levels of pro-inflammatory cytokines IL-6 (53.47 ± 7.074 pg/mL vs 5.142 ± 1.779 pg/mL, P

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial hyperplasia and cartilage/bone destruction with systemic comorbidities. Despite advances in understanding the aetiology of RA and novel biologic drugs, a substantial number of individuals with RA remain intolerant or resistant to these therapies. In this context, mesenchymal stem/stromal cell (MSC)-based therapy has emerged as an innovative therapeutic alternative to address unresolved treatment issues for patients with RA thanks to the immunomodulatory properties of these cells. The majority of preclinical studies in MSC-based therapy have been conducted using the well-known collagen-induced arthritis (CIA) mouse model however due to its low incidence, the mouse strain restriction and the prolonged induction phase of collagen-induced arthritis, alternative experimental models of RA have been developed such as K/BxN serum transfer-induced arthritis (STIA), which mimics many of human RA features. In this study, we evaluate whether the K/BxN STIA model could be used as an alternative model to study the immunomodulatory potential of MSC-based therapy. Unexpectedly, our data suggest that adiposederived MSC-based therapy is unsuitable for modulating the progression of K/BxN serum-transfer arthritis in mice despite the various experimental parameters tested. Based on the differences in the immune status and monocytic/macrophage balance among the different arthritic models, these results could help to identify the cellular targets of the MSCs and, most importantly to predict the RA patients that will respond positively to MSC-based therapy. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is an autoimmune disease. Early studies hold an opinion that gut microbiota is environmentally acquired and associated with RA susceptibility. However, accumulating evidence demonstrates that genetics also shape the gut microbiota. It is known that some strains of inbred laboratory mice are highly susceptible to collagen-induced arthritis (CIA), while the others are resistant to CIA. Here, we show that transplantation of fecal microbiota of CIA-resistant C57BL/6J mice to CIA-susceptible DBA/1J mice confer CIA resistance in DBA/1J mice. C57BL/6J mice and healthy human individuals have enriched B. fragilis than DBA/1J mice and RA patients. Transplantation of B. fragilis prevents CIA in DBA/1J mice. We identify that B. fragilis mainly produces propionate and C57BL/6J mice and healthy human individuals have higher level of propionate. Fibroblast-like synoviocytes (FLSs) in RA are activated to undergo tumor-like transformation. Propionate disrupts HDAC3-FOXK1 interaction to increase acetylation of FOXK1, resulting in reduced FOXK1 stability, blocked interferon signaling and deactivation of RA-FLSs. We treat CIA mice with propionate and show that propionate attenuates CIA. Moreover, a combination of propionate with anti-TNF etanercept synergistically relieves CIA. These results suggest that B. fragilis or propionate could be an alternative or complementary approach to the current therapies. [ABSTRACT FROM AUTHOR]

Background: Fufang Xiaohuoluo pill (FFXHL) is a commonly used prescription in clinical practice for treating rheumatoid arthritis in China, yet its specific mechanism remains unclear. This study aims to elucidate the pharmacological mechanisms of FFXHL using both in vivo and in vitro experiments. Methods: The collagen-induced arthritis (CIA) rat model was established to evaluate FFXHL's therapeutic impact. Parameters that include paw swelling, arthritis scores, and inflammatory markers were examined to assess the antiinflammatory and analgesic effects of FFXHL. Human fibroblast-like synoviocytes (MH7A cells) is activated by tumour necrosis factor-alpha (TNF-α) were used to explore the anti-inflammatory mechanism on FFXHL. Results: Our findings indicate that FFXHL effectively reduced paw swelling, joint pain, arthritis scores, and synovial pannus hyperplasia. It also lowered serum levels of TNF-α, interleukin-1β (IL1β), and interleukin-6 (IL-6). Immunohistochemical analysis revealed decreased expression of nuclear factor-kappa B (NF-κB) p65 in FFXHL-treated CIA rat joints. In vitro experiments demonstrated FFXHL's ability to decrease protein secretion of IL-1β and IL-6, suppress mRNAexpression of matrix metalloproteinases (MMP) -3, -9, and -13, reduce reactive oxygen species (ROS) levels, and inhibit NF-κB p65translocation in TNF-α stimulated MH7Acells. FFXHL also suppressed protein levels of extracellular signal-regulated kinase (ERK), c-Jun Nterminal kinase (JNK), p38 MAP kinase (p38), protein kinase B (Akt), p65, inhibitor of kappa B kinase α/β (IKKα/β), Toll-like receptor 4 (TLR4), and myeloid differentiation primary response 88 (MyD88) induced by TNF-α in MH7A cells. Conclusion: The findings imply that FFXHL exhibits significant anti-inflammatory and antiarthritic effects in both CIA rat models and TNF-α-induced MH7A cells. The potential mechanism involves the inactivation of TLR4/MyD88, mitogen-activated protein kinases (MAPKs), NF-κB, and Akt pathways by FFXHL. [ABSTRACT FROM AUTHOR]

Epstein–Barr virus (EBV) DNA is known to be shed upon reactivation of latent EBV. Based on our previous findings linking Toll-like receptor-9 (TLR9) to an EBV DNA-driven surge in IL-17A production, we aimed to examine the therapeutic potential of TLR9 inhibition in EBV DNA-exacerbated arthritis in a collagen-induced arthritis (CIA) mouse model. C57BL/6J mice were administered either collagen, EBV DNA + collagen, EBV DNA + collagen + TLR9 inhibitor, or only the TLR9 inhibitor. After 70 days, paw thicknesses, clinical scores, and gripping strength were recorded. Moreover, affected joints, footpads, and colons were histologically scored. Furthermore, the number of cells co-expressing IL-17A, IFN-γ, and FOXP3 in joint sections was determined by immunofluorescence assays. Significantly decreased paw thicknesses, clinical scores, and histological scores with a significantly increased gripping strength were observed in the group receiving EBV DNA + collagen + TLR9 inhibitor, compared to those receiving EBV DNA + collagen. Similarly, this group showed decreased IL-17A+ IFN-γ+, IL-17A+ FOXP3+, and IL-17A+ IFN-γ+ FOXP3+ foci counts in joints. We show that inhibiting TLR9 limits the exacerbation of arthritis induced by EBV DNA in a CIA mouse model, suggesting that TLR9 could be a potential therapeutic target for rheumatoid arthritis management in EBV-infected individuals. [ABSTRACT FROM AUTHOR]

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by synovial inflammation, causing substantial disability and reducing life quality. While macrophages are widely appreciated as a master regulator in the inflammatory response of RA, the precise mechanisms underlying the regulation of proliferation and inflammation in RA-derived fibroblast-like synoviocytes (RA-FLS) remain elusive. Here, we provide extensive evidence to demonstrate that macrophage contributes to RA microenvironment remodeling by extracellular vesicles (sEVs) and downstream miR-100-5p/ mammalian target of rapamycin (mTOR) axis. Results: We showed that bone marrow derived macrophage (BMDM) derived-sEVs (BMDM-sEVs) from collagen-induced arthritis (CIA) mice (cBMDM-sEVs) exhibited a notable increase in abundance compared with BMDM-sEVs from normal mice (nBMDM-sEVs). cBMDM-sEVs induced significant RA-FLS proliferation and potent inflammatory responses. Mechanistically, decreased levels of miR-100-5p were detected in cBMDM-sEVs compared with nBMDM-sEVs. miR-100-5p overexpression ameliorated RA-FLS proliferation and inflammation by targeting the mTOR pathway. Partial attenuation of the inflammatory effects induced by cBMDM-sEVs on RA-FLS was achieved through the introduction of an overexpression of miR-100-5p. Conclusions: Our work reveals the critical role of macrophages in exacerbating RA by facilitating the transfer of miR-100-5p-deficient sEVs to RA-FLS, and sheds light on novel disease mechanisms and provides potential therapeutic targets for RA interventions. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic and symmetric in-flammation. Our previous research revealed an imbalance in the gut flora of RA patients and showed that certain gut microbiota can accelerate RA progression by enhancing vitamin C degradation. However, it is unclear whether vitamin C supplementation could improve the gut microbiota to prevent the development of arthritis by interfering with the gut-joint axis. In this work, we aimed to evaluate the effects of vitamin C in regulating the gut microbiota and to elucidate its potential role in the onset and progression of RA in a mouse model, thus providing a basis for the development of new intervention strategies and treatments for RA. In this study, collagen-induced arthritis (CIA) mouse models, biochemical, histological and 16S rRNA microbiological methods were used to investigate the role and possible mechanism of vitamin C in rheumatoid arthritis. The results showed that treatment of CIA mice with vitamin C effectively rescued the gut mi-crobiota imbalance and suppressed the inflammatory response associated with RA, and effectively alleviated arthritis symptoms in mice in which levels of the pro-inflammatory cytokines IL-6 and TNF-α were specifi-cally reduced. In conclusion, our results demonstrate the potential of vitamin C as a potential therapeutic choice for RA. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a prevalent autoimmune disease characterized by excessive inflammation in the joints. Glucocorticoid drugs are used clinically to manage RA symptoms, while their dosage and duration need to be tightly controlled due to severe adverse effects. Using dexamethasone (DEX) as a model drug, we explored here whether peptide-guided delivery could increase the safety and therapeutic index of glucocorticoids for RA treatment. Using multiple murine RA models such as collagen-induced arthritis (CIA), we found that CRV, a macrophage-targeting peptide, can selectively home to the inflammatory synovium of RA joints upon intravenous injection. The expression of the CRV receptor, retinoid X receptor beta (RXRB), was also elevated in the inflammatory synovium, likely being the basis of CRV targeting. CRV-conjugated DEX increased the accumulation of DEX in the inflamed synovium but not in healthy organs of CIA mice. Therefore, CRV-DEX demonstrated a stronger efficacy to suppress synovial inflammation and alleviate cartilage/bone destruction. Meanwhile, CRV conjugation reduced immune-related adverse effects of DEX even after a long-term use. Last, we found that RXRB expression was significantly elevated in human patient samples, demonstrating the potential of clinical translation. Taken together, we provide a novel, peptide-targeted strategy to improve the therapeutic efficacy and safety of glucocorticoids for RA treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a chronic autoimmune disorder marked by persistent synovial inflammation and joint degradation, posing challenges in the development of effective treatments. Nuciferine, an alkaloid found in lotus leaf, has shown promising anti-inflammatory and anti-tumor effects, yet its efficacy in RA treatment remains unexplored. This study investigated the antiproliferative effects of nuciferine on the MH7A cell line, a human RA-derived fibroblast-like synoviocyte, revealing its ability to inhibit cell proliferation, promote apoptosis, induce apoptosis, and cause G 1 /S phase arrest. Additionally, nuciferine significantly reduced the migration and invasion capabilities of MH7A cells. The therapeutic potential of nuciferine was further evaluated in a collagen-induced arthritis (CIA) rat model, where it markedly alleviated joint swelling, synovial hyperplasia, cartilage injury, and inflammatory infiltration. Nuciferine also improved collagen-induced bone erosion, decreased pro-inflammatory cytokines and serum immunoglobulins (IgG, IgG1, IgG2a), and restored the balance between T helper (Th) 17 and regulatory T cells in the spleen of CIA rats. These results indicate that nuciferine may offer therapeutic advantages for RA by decreasing the proliferation and invasiveness of FLS cells and correcting the Th17/Treg cell imbalance in CIA rats. [ABSTRACT FROM AUTHOR]

Objective: Rheumatoid arthritis (RA) is a systemic autoimmune disease. Its pathogenesis has not yet been clarified, so it is urgent to explore therapeutic targets. Here, we clarified the role of HDAC6 in the mechanism of action of RA through mediating chaperone-mediated autophagy (CMA) to provide a clinical treatment of RA. Methods: We used rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) and collagen-induced arthritis mice (CIA mice) as models of RA and pharmacological inhibitors as well as genetic interference with adeno-associated viruses to reduce the expression of HDAC6. We explored the influence of CAY10603 on RA-FLS proliferation and inflammation, as well as the expression of proteins related to the CMA signaling pathway. CIA model was constructed using DBA/1J mice. Arthritis symptoms in CIA mice were evaluated, and the expression and localization of CMA-related proteins in mouse ankle joints were examined. Results: CAY10603 inhibited proliferation as well as the level of the molecular chaperone autophagy in RA-FLS. HDAC6 shRNA significantly reduced the clinical signs of arthritis in CIA mice, as did the expression of HDAC6 in the serum and ankle synovial tissues of CIA mice. Finally, it significantly inhibited the level of Hsc70 and LAMP-2A, which are involved in the CMA signaling pathway, in ankle joint tissues. Conclusion: Downregulation of HDAC6 may inhibit CMA and thereby ameliorate RA. [ABSTRACT FROM AUTHOR]

The positional cloning of single nucleotide polymorphisms (SNPs) of the neutrophil cytosolic factor 1 (Ncf1) gene, advocating that a low oxidative burst drives autoimmune disease, demands an understanding of the underlying molecular causes. A cellular target could be T cells, which have been shown to be regulated by reactive oxygen species (ROS). However, the pathways by which ROS mediate T cell signaling remain unclear. The adaptor molecule linker for activation of T cells (LAT) is essential for coupling T cell receptor-mediated antigen recognition to downstream responses, and it contains several cysteine residues that have previously been suggested to be involved in redox regulation. To address the possibility that ROS regulate T cell-dependent inflammation through LAT, we established a mouse strain with cysteine-to-serine mutations at positions 120 and 172 (LATSS). We found that redox regulation of LAT through C120 and C172 mediate its localization and phosphorylation. LATSS mice had reduced numbers of double-positive thymocytes and naïve peripheral T cells. Importantly, redox insensitivity of LAT enhanced T cell-dependent autoimmune inflammation in collagen-induced arthritis (CIA), a mouse model of rheumatoid arthritis (RA). This effect was reversed on an NCF1-mutated (NCF1m1j), ROS-deficient, background. Overall, our data show that LAT is redox-regulated, acts to repress T cell activation, and is targeted by ROS induced by NCF1 in antigen-presenting cells (APCs). [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is recognized as an autoimmune joint disease driven by T cell responses to self (or modified self or microbial mimic) antigens that trigger and aggravate the inflammatory condition. Newer treatments of RA employ monoclonal antibodies or recombinant receptors against cytokines or immune cell receptors as well as small-molecule Janus kinase (JAK) inhibitors to systemically ablate the cytokine or cellular responses that fuel inflammation. Unlike these treatments, a therapeutic vaccine, such as CEL-4000, helps balance adaptive immune homeostasis by promoting antigen-specific regulatory rather than inflammatory responses, and hence modulates the immunopathological course of RA. In this review, we discuss the current and proposed therapeutic products for RA, with an emphasis on antigen-specific therapeutic vaccine approaches to the treatment of the disease. As an example, we describe published results of the beneficial effects of CEL-4000 vaccine on animal models of RA. We also make a recommendation for the design of appropriate clinical studies for these newest therapeutic approaches, using the CEL-4000 vaccine as an example. Unlike vaccines that create or boost a new immune response, the clinical success of an immunomodulatory therapeutic vaccine for RA lies in its ability to redirect autoreactive pro-inflammatory memory T cells towards rebalancing the “runaway” immune/inflammatory responses that characterize the disease. Human trials of such a therapy will require alternative approaches in clinical trial design and implementation for determining safety, toxicity, and efficacy. These approaches include adaptive design (such as the Bayesian optimal design (BOIN), currently employed in oncological clinical studies), and the use of disease-related biomarkers as indicators of treatment success. [ABSTRACT FROM AUTHOR]

Inter-α-trypsin inhibitor heavy chain 4 (ITIH4) is a major protein in serum and reported to be upregulated at the onset of rheumatoid arthritis (RA). Its citrullinated form, cit-ITIH4, is specifically found in the serum and synovial fluid of patients with RA. However, the detailed function of ITIH4 in arthritis remains unknown. The aim of this study was to clarify the role of ITIH4 and cit-ITIH4 using experimental arthritis models. ITIH4 and cit-ITIH4 expression was examined in steady-state mice and two different arthritis models, and their pathological effects were examined in Itih4-deficient mice. In naïve C57BL/6 (WT) mice, ITIH4 was expressed as mRNA in the liver and the lung and was expressed as protein in serum and hepatocytes. In K/BxN serum transferred arthritis (K/BxN-STA) and collagen-induced arthritis (CIA), ITIH4 and cit-ITIH4 in sera were increased before the onset of arthritis, and cit-ITIH4 was further increased at the peak of arthritis. In Itih4-deficient mice, citrullinated proteins in serum and joints, especially 120 kDa protein, were clearly diminished; however, there was no significant difference in arthritis severity between WT and itih−/− mice either in the K/BxN-STA or CIA model. CIA mice also exhibited pulmonary lesions and itih4−/− mice tended to show enhanced inflammatory cell aggregation compared to WT mice. Neutrophils in the lungs of itih4−/− mice were significantly increased compared to WT mice. In summary, ITIH4 itself did not alter the severity of arthritis but may inhibit autoimmune inflammation via suppression of neutrophil recruitment. ITIH4 and cit-ITIH4 in sera of K/BxN-STA and CIA were increased before the onset of arthritis, and cit-ITIH4 was further increased at the peak of arthritis. CIA mice also exhibited pulmonary lesions and itih4−/− mice tended to show enhanced inflammatory cell aggregation compared to WT mice. Neutrophils in the lungs of itih4−/− mice were significantly increased compared to WT mice. Graphical Abstract [ABSTRACT FROM AUTHOR]

Objective: Fibroblast-like synoviocytes (FLS) play a critical role on the exacerbation and deterioration of rheumatoid arthritis (RA). Aberrant activation of FLS pyroptosis signaling is responsible for the hyperplasia of synovium and destruction of cartilage of RA. This study investigated the screened traditional Chinese medicine berberine (BBR), an active alkaloid extracted from the Coptis chinensis plant, that regulates the pyroptosis of FLS and secretion of inflammatory factors in rheumatoid arthritis. Methods: First, BBR was screened using a high-throughput drug screening strategy, and its inhibitory effect on RA-FLS was verified by in vivo and in vitro experiments. Second, BBR was intraperitoneally administrated into the collagen-induced arthritis rat model, and the clinical scores, arthritis index, and joint HE staining were evaluated. Third, synovial tissues of CIA mice were collected, and the expression of NLRP3, cleaved-caspase-1, GSDMD-N, Mst1, and YAP was detected by Western blot. Results: The administration of BBR dramatically alleviated the severity of collagen-induced arthritis rat model with a decreased clinical score and inflammation reduction. In addition, BBR intervention significantly attenuates several pro-inflammatory cytokines (interleukin-1β, interleukin-6, interleukin-17, and interleukin-18). Moreover, BBR can reduce the pyroptosis response (caspase-1, NLR family pyrin domain containing 3, and gasdermin D) of the RA-FLS in vitro, activating the Hippo signaling pathway (Mammalian sterile 20-like kinase 1, yes-associated protein, and transcriptional enhanced associate domains) so as to inhibit the pro-inflammatory effect of RA-FLS. Conclusion: These results support the role of BBR in RA and may have therapeutic implications by directly repressing the activation, migration of RA-FLS, which contributing to the attenuation of the progress of CIA. Therefore, targeting PU.1 might be a potential therapeutic approach for RA. Besides, BBR inhibited RA-FLS pyroptosis by downregulating of NLRP3 inflammasomes (NLRP3, caspase-1) and eased the pro-inflammatory activities via activating the Hippo signaling pathway, thereby improving the symptom of CIA. Key Points • The administration of berberine (BBR) dramatically alleviated the severity of CIA model with a decreased clinic score and joint inflammation. • BBR inhibited the pyroptosis of RA-FLS by downregulating of NLRP3 inflammasomes and activating the Hippo signaling pathway, contributing to the suppression of RA progress. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study is to investigate whether fat mass and obesity-associated protein (FTO) and NOL1/NOP2/Sun domain family member 2 (NSUN2) mediated RNA methylation is associated with RA pathology. Methods: We studied the anti-rheumatoid arthritis (RA) mechanism mediated by FTO and NSUN2 in RA samples and collagen-induced arthritis (CIA) rats using real time qPCR (RT-qPCR), western blot, immunofluorescence, and other methods. Key findings: The expression of NSUN2 was significantly increased in both RA patients and CIA rats compared with normal controls. Knockdown of NSUN2 blocked the Wnt/β-catenin signaling pathway and inhibited RA pathological factors such as MMP3, fibronectin, and interleukins. FTO overexpression inhibited RA by inhibiting the expression of NSUN2, up-regulating the level of SFRP1 protein, and blocking the Wnt/β-catenin signaling pathway. NSUN2 overexpression interfered with the inhibitory effects of FTO on the Wnt/β-catenin signaling pathway and RA pathology, which further verified that FTO inhibited RA through the NSUN2/SFRP1/Wnt/β-catenin signal axis. Conclusions: FTO and NSUN2 are important factors of RA, and this work provides new potential diagnostic biomarkers and therapeutic targets for RA. We also reveal a gene expression regulation pattern of the interaction between m6A and m5C. revealing the pathogenesis of RA from the perspective of RNA methylation. FTO inhibits RA pathology through the NSUN2/SFRP1/Wnt/β-catenin signal axis. The expression of NSUN2 was significantly increased in RA compared with control. NSUN2 knockdown reduced the level of β-catenin in RA FLS, inhibited the entry of β-catenin into the nucleus of FLS, and down-regulated the expression of c-Myc and CCND1. Knockdown of NSUN2 inhibited the expression of RA related MMP3, fibronectin and interleukins. The expression of FTO is reduced in RA, and the FTO inhibited RA by inhibiting the expression of NSUN2, up-regulating the level of SFRP1 protein and blocking the Wnt/β-catenin pathway. [ABSTRACT FROM AUTHOR]

Objective: The collagen-induced arthritis (CIA) model is the most commonly studied autoimmune model of rheumatoidarthritis (RA). In this study, we investigated the usefulness of collagen type II emulsified in Freund's incompleteadjuvant (CII/IFA) as a suitable method for establishing RA in Lewis rats. The aim of the present study was to presenta straightforward and effective method for inducing CIA in rats.Materials and Methods: In this experimental study, animals were divided into two equal groups (n=5); control andCIA. Five rats were injected intradermally at the base of the tail with a 0.2 ml CII/IFA emulsion. On the seventh day,a 0.1 ml CII/IFA emulsion booster was injected. Arthritis symptoms that arose were evaluated at clinical, histological,radiological, and at protein expression levels to find out if the disease had been induced successfully.Results: Our finding showed a decreasing trend in the body weight during the RA induction period, while the arthritisscore and paw thickness were increased during this period. The results of the enzyme-linked immunosorbent assay(ELISA) for serum samples revealed that the levels of proinflammatory cytokines, interleukin (IL)-1β, IL-6, IL-17, andtumor necrosis factor (TNF)-α and anti-CII IgG were significantly increased in CIA rats compared to the control group.After CIA induction, the level of anti-inflammatory protein IL-10 was decreased significantly. Radiographic examinationof the hind paws showed soft tissue swelling, bone erosion, and osteophyte formation in CIA rats. Additionally, basedon histological evaluations, the hind paws of the CIA group showed pannus formation, synovial hyperplasia, and boneand cartilage destruction.Conclusion: It seems that CII/IFA treatment can be an appropriate and effective method to induce RA disease in Lewisrats. This well-established and well-characterized CIA model in female Lewis rats could be considered to study aspectsof RA and develop novel anti-arthritic agents.

Background: Recent therapeutic-plasmid DNA vaccine strategies for rheumatoid arthritis (RA) have significantly improved. Our pcDNA-CCOL2A1 vaccine is the most prominent and the first antigen-specific tolerising DNA vaccine with potent therapeutic and prophylactic effects compared with methotrexate (MTX), the current "gold standard" treatment for collagen-induced arthritis (CIA). This study developed a highly efficient, cost-effective, and easy-to-operate system for the lab-scale production of endotoxin-free supercoiled plasmids with high quality and high yield. Based on optimised fermentation culture, we obtained a high yield of pcDNA-CCOL2A1 vaccine by PEG/MgCl2 precipitation and TRION-114. We then established a method for quality control of the pcDNA-CCOL2A1 vaccine. Collagen-induced arthritis (CIA) model rats were subjected to intramuscular injection of the pcDNA-CCOL2A1 vaccine (300 μg/kg) to test its biological activity. Results: An average yield of 11.81 ± 1.03 mg purified supercoiled plasmid was obtained from 1 L of fermentation broth at 670.6 ± 57.42 mg/L, which was significantly higher than that obtained using anion exchange column chromatography and a commercial purification kit. Our supercoiled plasmid had high purity, biological activity, and yield, conforming to the international guidelines for DNA vaccines. Conclusion: The proposed innovative downstream process for the pcDNA-CCOL2A1 vaccine can not only provide a large-scale high-quality supercoiled plasmid DNA for preclinical research but also facilitate further pilot-scale and even industrial-scale production of pcDNA-CCOL2A1 vaccine. [ABSTRACT FROM AUTHOR]

Lignan-rich beans, nuts, and various seeds are the main foods with antioxidative and hormone-modulating activities. Although the role of lignans in mediating hormone-dependent cancers and cardiovascular diseases is well characterized, the function of lignans in anti-arthritic activity and its underlying mechanisms remain unknown. Three new lignan derivatives, (-)-nortrachelogenin, trachelogenin, and matairesinol, were extracted from Loranthus parasiticus. After establishing the collagen-induced arthritis (CIA) model by intradermal injection of collagen, rats were treated with three new lignan derivatives ((-)-nortrachelogenin: 37%; trachelogenin: 27%; matairesinol: 25.7%) at a concentration of 50 mg/kg and 100 mg/kg, or methotrexate at 0.3 mg/kg. Mixed lignan derivatives significantly attenuated the immune responses in the joints of CIA rats, leading to lower levels of proinflammatory cytokines (IL-6 and TNF-α) and higher levels of free androgen in the serum compared to the CIA model. The results of molecular docking using AutoDock Vina showed that the lignan derivative (-)-nortrachelogenin was the most effective compound for binding to sex hormone-binding globulin (SHBG), thus inhibiting the activity of NFκB in LPS-stimulated macrophages. In this study, (-)-nortrachelogenin was identified as a novel natural lignan derivative with previously unrecognized anti-inflammatory activity. Its molecular mechanism appears related to the regulation of the NFκB/SHBG pathway. Our findings suggest that further application of sex hormone-like compounds in the treatment of rheumatoid arthritis and the potential clinical applications of (-)-nortrachelogenin are promising. [ABSTRACT FROM AUTHOR]