Rat Model Of Rheumatoid Arthritis Research Articles

Myricetin reduces neutrophil extracellular trap release in a rat model of rheumatoid arthritis, which is associated with a decrease in disease severity.

Rheumatoid arthritis (RA) is a chronic disease characterized by joint inflammation and severe disability. However, there is a lack of safe and effective drugs for treating RA. In our previous study, we discovered that myricetin (MC) and celecoxib have a synergistic effect in the treatment of RA. We conducted in vitro and in vivo experiments to further investigate the effects and mechanisms of action of MC. Our findings demonstrated that MC treatment effectively reduced the release of neutrophil extracellular traps (NETs) and alleviated the inflammatory response in RA. Mechanistic studies showed that MC prevents the entry of PADI4 and MPO into the cell nucleus, thereby protecting DNA from decondensation. In a rat arthritis model, MC improved histological changes in ankle joints and suppressed NET-related signaling factors. In conclusion, MC protects the ankle joints against arthritis by inhibiting MPO and PADI4, thereby reducing NET release. The pharmacological mechanism of MC in RA involves the inhibition of NET release.

Evaluating the Efficacy of a Polyherbal Formulation in Ameliorating Arthritis Induced by Complete Freund’s Adjuvant

Background: This study investigates the antiarthritic potential of a polyherbal formulation (PHF) comprising extracts from Tinospora cordifolia, Rosa damescena, and Acacia leucoploea in a rat model of rheumatoid arthritis (RA). RA is a chronic autoimmune disorder with debilitating consequences. PHF's impact on joint inflammation, bone degradation, and cartilage preservation were evaluated. Methods: Arthritis was induced using complete Freund’s adjuvant (CFA), and animals were treated with PHF (200 and 400 mg/kg), prednisolone, or control treatments for 28 days. Parameters including body weight, paw volume, arthritis severity score, hematological parameters, serum markers (creatinine, ALP, total proteins), cytokine levels (IL-1β, IL-6, TNF-α, IL-10), and radiographic changes were assessed. Results: CFA-treated rats exhibited significant body weight loss, paw edema, increased arthritis severity scores, altered hematological parameters, and elevated serum markers compared to normal controls. PHF treatment at both doses mitigated body weight loss, reduced paw edema, and improved arthritis severity scores. Hematological changes induced by CFA were also attenuated by PHF treatment. Serum creatinine, ALP, and total protein levels, elevated in CFA-treated rats, were significantly improved by PHF. Furthermore, PHF modulated cytokine levels, decreasing IL-6, IL-1β, and TNF-α while increasing IL-10. Radiographic analysis displayed reduced joint damage in PHF-treated rats compared to CFA controls. Conclusion: This comprehensive investigation highlights PHF's potential to mitigate the inflammatory processes associated with RA, as evidenced by improved clinical, hematological, and biochemical parameters. The study underscores the promise of traditional botanical compounds in managing RA and suggests PHFs as novel therapeutic options. Further mechanistic studies are warranted to elucidate the exact pathways involved.

A dual dynamically cross-linked hydrogel promotes rheumatoid arthritis repair through ROS initiative regulation and microenvironment modulation-independent triptolide release

High oxidative stress and inflammatory cell infiltration are major causes of the persistent bone erosion and difficult tissue regeneration in rheumatoid arthritis (RA). Triptolide (TPL) has become a highly anticipated anti-rheumatic drug due to its excellent immunomodulatory and anti-inflammatory effects. However, the sudden drug accumulation caused by the binding of “stimulus-response” and “drug release” in a general smart delivery system is difficult to meet the shortcoming of extreme toxicity and the demand for long-term administration of TPL. Herein, we developed a dual dynamically cross-linked hydrogel (SPT@TPL), which demonstrated sensitive RA microenvironment regulation and microenvironment modulation-independent TPL release for 30 days. The abundant borate ester/tea polyphenol units in SPT@TPL possessed the capability to respond and regulate high reactive oxygen species (ROS) levels on-demand. Meanwhile, based on its dense dual crosslinked structure as well as the spontaneous healing behavior of numerous intermolecular hydrogen bonds formed after the breakage of borate ester, TPL could remain stable and slowly release under high ROS environments of RA, which dramatically reduced the risk of TPL exerting toxicity while maximized its long-term efficacy. Through the dual effects of ROS regulation and TPL sustained-release, SPT@TPL alleviated oxidative stress and reprogrammed macrophages into M2 phenotype, showing marked inhibition of inflammation and optimal regeneration of articular cartilage in RA rat model. In conclusion, this hydrogel platform with both microenvironment initiative regulation and TPL long-term sustained release provides a potential scheme for rheumatoid arthritis.

Moxibustion of Zusanli (ST36) and Shenshu (BL23) alleviates the inflammation of rheumatoid arthritis in rats through regulating macrophage migration inhibitory factor/glucocorticoids signaling.

To test the hypothesis that moxibustion may inhibit rheumatoid arthritis (RA) synovial inflammation by regulating the expression of macrophage migration inhibitory factor (MIF)/glucocorticoids (GCs). Fifty male Sprague-Dawley rats were randomly divided into five groups (n = 10 each): blank Control (CON) group, RA Model (RA) group, Moxibustion (MOX) group, MIF inhibitor (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1) group, and Moxibustion + MIF inhibitor ISO-1 (MOX + ISO-1) group. Rats in the ISO-1 group and ISO-1 + MOX group were intraperitoneally injected with the inhibitor ISO-1. The rats in the RA group, ISO-1 group, MOX group, and ISO-1 + MOX group were injected with Freund's complete adjuvant (FCA) in the right hind footpad to establish an experimental RA rat model. In the MOX group and MOX + ISO-1 group, rats were treated with Moxa. The thickness of the footpads of the rats in each group was measured at three-time points before, after modeling and after moxibustion treatment. The contents of serum MIF, corticosterone (CORT), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were detected by enzyme-linked immunosorbent assay; and the contents of synovial MIF were detected by Western blot. Hematoxylin-eosin (HE) staining method was used to observe the pathological changes of synovial tissue under a section light microscope, and pathological scoring was performed according to the grading standard of the degree of synovial tissue disease. Moxibustion was found to reduce the level of MIF and alleviate inflammation in RA rats in this study. In addition, after inhibiting the expression of MIF, the level of CORT increased, and the level of TNF-α decreased. Treating RA rats with inhibited MIF by moxibustion, the level of CORT was almost unchanged, but the level of TNF-α further decreased. The correlation analysis data suggested that MIF was positively related to the expression of TNF-α and negatively correlated with the expression of CORT. Reducing MIF to increase CORT and decrease TNF-α by moxibustion treatment in RA. MIF may be a factor for moxibustion to regulate the expression of CORT, but the expression of TNF-α is due to the incomplete regulation of the MIF. This study added to the body of evidence pointing to moxibustion's anti-inflammatory mechanism in the treatment of RA.

Preparation and anti-inflammatory effect of mercury sulphide nanoparticle-loaded hydrogels

We successfully prepared mercury sulphide nanoparticle hydrogels by physical encapsulation method. The successfully prepared mercuric sulphide nanoparticle hydrogel was a zinc folate hydrogel, which showed an obvious porous structure with interconnected and uniformly distributed pores and a pore size range of about 20 μm. The maximum drug loading of the hydrogels was 3%, and the in vitro cumulative release degree was in accordance with the first-order kinetic equation Mt = 149.529 (1 − e−0.026 t ). The particles in mercuric sulphide nanoparticle hydrogels significantly down-regulated the expression of the cell surface co-stimulatory molecule CD86 (p < .0001). Meanwhile, the inflammatory response was regulated through the NF-κB pathway in LPS-induced inflammatory cells. Later, it was observed that mercuric sulphide nanoparticle hydrogels could significantly counteract the inflammatory and immune models through a mouse ear swelling model, a rat foot-plantar swelling model and a rheumatoid arthritis model. This design targets the immunomodulatory, and anti-inflammatory effects through nanocomposite hydrogel technology. It reduces the drawbacks of low mercury utilisation and susceptibility to accumulation of toxicity. It aims to provide an experimental basis for the development of mercuric sulphide and the treatment of inflammatory and immune-related diseases. Highlights Mercury sulphide nanoparticle hydrogel has an optimal mercury sulphide nanoparticle content of 2%, is structurally homogeneous and stable, and does not exhibit significant liver or kidney toxicity. Mercuric sulphide nanoparticle hydrogel exerts anti-inflammatory effects in cells and rats, and regulates the expression of macrophage surface molecules and factors related to the NF-κB pathway. Mercuric sulphide nanoparticle hydrogel improves the condition of ankle synovial joints in a rat model of rheumatoid arthritis.

EIDD-1931 Treatment Tweaks CYP3A4 and CYP2C8 in Arthritic Rats to Expedite Drug Interaction: Implication in Oral Therapy of Molnupiravir.

EIDD-1931 is the active form of molnupiravir, an orally effective drug approved by the United States Food and Drug Administration (USFDA) against COVID-19. Pharmacokinetic alteration can cause untoward drug interaction (drug-drug/disease-drug), but hardly any information is known about this recently approved drug. Therefore, we first investigated the impact of the arthritis state on the oral pharmacokinetics of EIDD-1931 using a widely accepted complete Freund's adjuvant (CFA)-induced rat model of rheumatoid arthritis (RA) after ascertaining the disease occurrence by paw swelling measurement and X-ray examination. Comparative oral pharmacokinetic assessment of EIDD-1931 (normal state vs arthritis state) showed that overall plasma exposure was augmented (1.7-fold) with reduced clearance (0.54-fold), suggesting its likelihood of dose adjustment in arthritis conditions. In order to elucidate the effect of EIDD-1931 treatment at a therapeutic regime (normal state vs arthritis state) on USFDA-recommended panel of cytochrome P450 (CYP) enzymes (CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) for drug interaction using the same disease model, we monitored protein and mRNA expressions (rat homologs) in liver tissue by western blotting (WB) and real time-polymerase chain reaction (RT-PCR), respectively. Results reveal that EIDD-1931 treatment could strongly influence CYP3A4 and CYP2C8 among experimental proteins/mRNAs. Although CYP2C8 regulation upon EIDD-1931 treatment resembles similar behavior under the arthritis state, results dictate a potentially reverse phenomenon for CYP3A4. Moreover, the lack of any CYP inhibitory effect by EIDD-1931 in human/rat liver microsomes (HLM/RLM) helps to ascertain EIDD-1931 treatment-mediated disease-drug interaction and the possibility of drug-drug interaction with disease-modifying antirheumatic drugs (DMARDs) upon coadministration. As elevated proinflammatory cytokine levels are prevalent in RA and nuclear factor-kappa B (NF-kB) and nuclear receptors control CYP expressions, further studies should focus on understanding the regulation of affected CYPs to subside unexpected drug interaction.

Mechanism of aqueous extract of Strychni Semen in improving pain in rats with rheumatoid arthritis based on TLR4/TNF-α/MMP-9 signaling pathway

This study aims to explore the mechanism of aqueous extract of Strychni Semen(SA) in relieving pain in the rat model of rheumatoid arthritis(RA) via Toll-like receptor 4(TLR4)/tumor necrosis factor-α(TNF-α)/matrix metalloproteinase-9(MMP-9) signaling pathway. Firstly, the main chemical components of Strychni Semen were searched against TCMSP, TCMID, ETCM, and related literature, and the main targets of the chemical components were retrieved from TargetNet and SwissTargetPrediction. The main targets of RA and pain were searched against GeneCards, Online Mendelian Inheritance in Man(OMIM), and Therapeutic Target Database(TTD). Venny 2.1.0 was used to obtain the common targets shared by Strychni Semen, RA, and pain, and STRING and Cytoscape 3.6.1 were used to build the protein-protein interaction network. Then, molecular docking was carried out in AutoDock Vina. Finally, the rat model of type Ⅱ collagen-induced arthritis(CIA) was established. The up-down method and acetone method were employed to examine the mechanical pain threshold and cold pain threshold of rats, and the pain-relieving effect of SA on CIA rats was evaluated comprehensively. Hematoxylin-eosin(HE) staining was employed to evaluate the histopathological changes of joints in CIA rats. The expression levels of key target proteins was determined by immunohistochemistry and Western blot, and the mRNA levels of key targets were determined by real-time fluorescence quantitative polymerase chain reaction(real-time PCR). The results of network prediction showed that Strychni Semen may act on the TLR4/TNF-α/MMP-9 signaling pathway to exert the pain-relieving effect. The results of molecular docking showed that brucine, the main active component of SA, had strong binding ability to TLR4, TNF-α, and MMP-9. The results of animal experiments showed that SA improved the mechanical and cold pain sensitivity(P&lt;0.05, P&lt;0.01) and reduced the joint histopathological score of CIA rats(P&lt;0.01). In addition, medium and high doses of SA down-regulated the protein and mRNA levels of TNF-α, TLR4, and MMP-9(P&lt;0.05,P&lt;0.01). In conclusion, SA alleviated the mechanical pain sensitivity, cold pain sensitivity, and joint histopathological changes in CIA rats by inhibiting the over activation of TLR4/TNF-α/MMP-9 signaling pathway.

Isoliquiritigenin inhibits apoptosis and ameliorates oxidative stress in rheumatoid arthritis chondrocytes through the Nrf2/HO-1-mediated pathway

Rheumatoid arthritis (RA) is a chronic inflammatory condition known for its irreversible destructive impact on the joints. Chondrocytes play a pivotal role in the production and maintenance of the cartilage matrix. However, the presence of inflammatory cytokines can hinder chondrocyte proliferation and promote apoptosis. Isoliquiritigenin (ISL), a flavonoid, potentially exerts protective effects against various inflammatory diseases. However, its specific role in regulating the nuclear factor E2-associated factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway in chondrocytes in RA remains unclear. To investigate this, this study used human chondrocytes and Sprague-Dawley rats to construct in vitro and in vivo RA models, respectively. The study findings reveal that cytokines markedly induced oxidative stress, the activation of matrix metalloproteinases, and apoptosis both in vitro and in vivo. Notably, ISL treatment significantly mitigated these effects. Moreover, Nrf2 or HO-1 inhibitors reversed the protective effects of ISL, attenuated the expression of Nrf2/HO-1 and peroxisome proliferator-activated receptor gamma-coactivator-1α, and promoted chondrocyte apoptosis. This finding indicates that ISL primarily targets the Nrf2/HO-1 pathway in RA chondrocytes. Moreover, ISL treatment led to improved behavior scores, reduced paw thickness, and mitigated joint damage as well as ameliorated oxidative stress in skeletal muscles in an RA rat model. In conclusion, this study highlights the pivotal role of the Nrf2/HO-1 pathway in the protective effects of ISL and demonstrates the potential of ISL as a treatment option for RA.

Prolonged administration of total glucosides of paeony improves intestinal immune imbalance and epithelial barrier damage in collagen-induced arthritis rats based on metabolomics-network pharmacology integrated analysis.

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by synovial inflammation and joint damage with complex pathological mechanisms. In recent years, many studies have shown that the dysregulation of intestinal mucosal immunity and the damage of the epithelial barrier are closely related to the occurrence of RA. Total glucosides of paeony (TGP) have been used clinically for the treatment of RA in China for decades, while the pharmacological mechanism is still uncertain. The purpose of this study was to investigate the regulatory effect and mechanism of TGP on intestinal immunity and epithelial barrier in RA model rats. The results showed that TGP alleviated immune hyperfunction by regulating the ratio of CD3+, CD4+ and CD8+ in different lymphocyte synthesis sites of the small intestine, including Peyer's patches (PPs), intraepithelial lymphocytes (IELs), and lamina propria lymphocytes (LPLs). Specially, TGP first exhibited immunomodulatory effects on sites close to the intestinal lumen (IELs and LPLs), and then on PPs far away from the intestinal lumen as the administration time prolonged. Meanwhile, TGP restores the intestinal epithelial barrier by upregulating the ratio of villi height (V)/crypt depth (C) and expression of tight junction proteins (ZO-1, occludin). Finally, the integrated analysis of metabolomics-network pharmacology was also used to explore the possible regulation mechanism of TGP on the intestinal tract. Metabolomics analysis revealed that TGP reversed the intestinal metabolic profile disturbance in CIA rats, and identified 32 biomarkers and 163 corresponding targets; network pharmacology analysis identified 111 potential targets for TGP to treat RA. By intersecting the results of the two, three key targets such as ADA, PNP and TYR were determined. Pharmacological verification experiments showed that the levels of ADA and PNP in the small intestine of CIA rats were significantly increased, while TGP significantly decreased their ADA and PNP levels. In conclusion, purine metabolism may play an important role in the process of TGP improving RA-induced intestinal immune imbalance and impaired epithelial barrier.

Identification of HHT-9041P1: A novel potent and selective JAK1 inhibitor in a rat model of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic systemic disease associated with long-term disability and premature mortality. If left untreated, it can seriously affect patients’ quality of life. The JAK-STAT signal transduction process is known to affect the occurrence and development of RA, and small molecule JAK inhibitors, such as tofacitinib, have been identified as treatments for RA. However, tofacitinib is a non-selective JAK inhibitor that was found to be associated with dose-limiting tolerability and safety issues, such as anemia in phase 2 dose-ranging studies. Therefore, we developed a selective JAK1 inhibitor, HHT-9041P1, to overcome target-related adverse reactions. We used enzyme and cytokine potency assays in vitro as well as the collagen-induced arthritis (CIA) model in vivo to explore the efficacy and mechanism. In vitro, HHT-9041P1 was diluted (0.017 nM–1 mM) in DMSO) and mixed with JAK1, JAK2, JAK3 or TYK2 kinases for use in the respective assays for inhibitory activity and selectivity evaluation. Fresh human PBMCs were activated and incubated with 100 ng/mL cytokine IL-6 or 20 ng/mL GM-CSF for use in the investigation of the immune mechanism. In vivo, HHT-9041P1 (1 mg/kg, 3 mg/kg and 10 mg/kg) was administered by oral gavage twice daily to CIA model Lewis rats from Day 8 to Day 29 for paw swelling and arthritis score evaluation. At the end of the experiment, the rats were sacrificed before collection of the hind ankle joint, spleen and blood for analysis of inflammation, arthritis phenotypes, inflammatory cytokine expression and Th1 cell proportions. As expected, HHT-9041P1 showed 10-fold greater selectivity for JAK1 over JAK2, and 23-fold greater selectivity over JAK3 in cellular assays. The high selectivity of HHT-9041P1 was also validated by in vivo safety studies. HHT-9041P1 demonstrated significant efficacy in a rat model of collagen-induced arthritis (CIA) and was associated with reduced helper T Cell 1 (Th1) cell differentiation. HHT-9041P1 also exhibited excellent pharmacokinetics properties. Thus, HHT-9041P1 was identified as a candidate for clinical development with many options for the treatment of RA.

Enhanced intra-articular therapy for rheumatoid arthritis using click-crosslinked hyaluronic acid hydrogels loaded with toll-like receptor antagonizing peptides

Rheumatoid arthritis (RA) is a chronic inflammatory disorder that results in the deterioration of joint cartilage and bone. Toll-like receptor 4 (TLR4) has been pinpointed as a key factor in RA-related inflammation. While Toll-like receptor antagonizing peptide 2 (TAP2) holds potential as an anti-inflammatory agent, its in vivo degradation rate hinders its efficacy. We engineered depots of TAP2 encapsulated in click-crosslinked hyaluronic acid (TAP2+Cx-HA) for intra-articular administration, aiming to enhance the effectiveness of TAP2 as an anti-inflammatory agent within the joint cavity. Our data demonstrated that FI-TAP2+Cx-HA achieves a longer retention time in the joint cavity compared to FI-TAP2 alone. Mechanistically, we found that TAP2 interacts with TLR4 on the cell membranes of inflammatory cells, thereby inhibiting the nuclear translocation of NF-κB and maintaining it in an inactive cytoplasmic state. In a rat model of RA, the TAP2+Cx-HA formulation effectively downregulated the inflammatory cytokines TNF-α and IL-6, while upregulating the anti-inflammatory cytokine IL-10 and the therapeutic protein 14-3-3ζ. This led to a more rapid restoration of cartilage thickness, increased deposition of glycosaminoglycans, and new bone tissue formation in the regenerated cartilage, in comparison to a single TAP2 treatment after a six-week period. Our results suggest that TAP2+Cx-HA could serve as a potent intra-articular treatment for RA, offering both symptomatic relief and promoting cartilage regeneration. This innovative delivery system holds significant promise for improving the management of RA and other inflammatory joint conditions. Statement of significanceIn this study, we developed a therapy by creating toll-like receptor 4 (TLR4)-antagonizing peptide (TAP2)-loaded click-crosslinked hyaluronic acid (TAP2+Cx-HA) depots for direct intra-articular injection. Our study demonstrates that FI-TAP2+Cx-HA exhibits a more than threefold longer lifetime in the joint cavity compared to FI-TAP2 alone. Furthermore, we found that TAP2 binds to TLR4 and masks the nuclear localization signals of NF-κB, leading to its sequestration in an inactive state in the cytoplasm. In a rat model of RA, TAP2+Cx-HA effectively suppresses inflammatory molecules, specifically TNF–α and IL-6, while upregulating the anti-inflammatory cytokine IL-10 and the therapeutic protein 14-3-3ζ. This resulted in faster regeneration of cartilage thickness, increased glycosaminoglycan deposits in the regenerated cartilage, and a twofold increase in new bone tissue formation compared to a single TAP2 treatment.

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

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

Emodin alleviates joint inflammation and bone erosion in rats with collagen-induced arthritis by inhibiting ferroptosis and degrading matrix metalloproteinases

To investigate the osteoprotective mechanism of emodin in light of the ferroptosis signaling pathway in a rat model of rheumatoid arthritis. SD rat models of collagen-induced arthritis (CIA) were treated with methotrexate or low or high doses of emodin, and the changes in arthritis scores and toe volume were recorded. model of CIA rats. Malondialdehyde (MDA) content in the joint cartilage was determined, and ankle joint tissue pathologies were observed using caffein solid green staining and hematoxylin-spermine red staining. MMP3 and MMP13 expressions in the ankle joint tissues were detected using immunohistochemistry, and Western blotting was used to detect the protein expressions of ACSL4, SLC7A11, GPX4, and FTH1. Compared with the normal control rats, the CIA rats showed significantly increased arthritis score index with obvious toe swelling (P<0.05), rough cartilage surface, and loss and irregular aligment of chondrocytes. The rat models also showed significantly increased MDA and ACSL4 contents, lowered SLC7A11, GPX4, and FTH1 contents (P<0.05), and decreased expressions of MMP3 and MMP13 in the ankle joint (P<0.05). The rat models treated with either methotrexate or emodin (40 and 80 mg/kg) had significantly reduced arthritis score index and toe swelling with smooth cartilage surface and neat arrangement of the chondrocytes. The treatments with methotrexate and emodin both decreased the contents of MDA and ACSL4 and increased the contents of SLC7A11, GPX4, and FTH1 in the joint tissues (P<0.05). Emodin can effectively control joint inflammation and improve joint bone erosion in CIA rats possibly by inhibiting the ferroptosis signaling pathways and reducing the expressions of MMP3 and MMP13.

Evaluating the effect of ursodeoxycholic acid (UDCA) in comparison with dexamethasone and diclofenac in a rat model of rheumatoid arthritis.

Ursodeoxycholic acid (UDCA) is known for its major effects on the liver, but its impact on autoimmune diseases is not well understood. This study aimed to assess the effectiveness of UDCA in controlling rheumatoid arthritis (RA) in an in vivo setting. Experimental RA was induced in rats using Freund's complete adjuvant, and the effects of UDCA (50,100 mg/kg) were compared to those of dexamethasone and diclofenac by measuring changes in paw size, IL-17, pro-inflammatory cytokines, oxidative stress (GSH, MDA), and radiological changes. The administration of UDCA resulted in decreased cartilage damage, reduced paw edema, and a decrease in the release of pro-inflammatory cytokines and oxidative stress. Additionally, X-ray joint alterations were observed in the UDCA-treated group compared to the dexamethasone and diclofenac groups. These results suggest that UDCA has anti-rheumatoid arthritis properties due to its ability to minimize oxidative stress and inflammation in arthritis-affected rats.

Moxibustion enables protective effects on rheumatoid arthritis-induced myocardial injury transforming growth factor beta1 signaling and metabolic reprogramming.

To examine the effects of moxibustion on myocardial injury and myocardial metabolomics in rats with rheumatoid arthritis (RA) based on the transforming growth factor beta1 (TGF-β1)/Smads signaling pathway. One hundred rats were treated with saline [normal control (NC) group] or complete Freund's adjuvant (CFA) by right plantar injection for the RA model group, and the latter were randomly divided into 4 groups. Tripterygium wilfordii polyglycoside tablets (, TPT) have anti-inflammatory and are widely used in the clinical treatment of RA, therefore serving as a positive control group. Three days post injection rats were given TPT tablet (TPT group), acupuncture therapy (APT group), and moxibustion treatment (MOX group) for 15 consecutive days, while NC group and model group were equally grasped and fixed and received normal saline. Rat joint swelling scores and arthritis index (AI) were evaluated in each group before the CFA challenge, therapy and after receiving therapy. Myocardial ultrastructure was observed by electron microscope. Enzyme-linked immunosorbent assay was used to detect cardiac troponin I (cTnI) levels in rat myocardial tissue. Quantitative reverse transcription polymerase chain reaction and Western blotting analysis were used to measure the mRNA and protein levels of TGF-β signaling molecules including TGF-β1, Smad2, Smad3, Smad4, and Smad7. Myocardial metabolomics was analyzed using gas chromatography-mass spectrometer. Compared with model group, RA model rats receiving TPT, acupuncture, or moxibustion therapy all showed reduced joint swelling scores and AI (all P < 0.01) and improved myocardial damage, whereas rats treated with moxibustion were found to be more marked. Consistently, the expressions of cTnI, TGF-β1, Smad2, Smad3, and Smad4 were found to be elevated in model rat group in contrast to NC rats and were significantly downregulated in TPT, APT and MOX group when compared with model group, while the levels of Smad7 showed the opposite result (all P < 0.01). Moreover, the dissection of metabolomics suggested a novel metabolite biomarker panel including D-Xylulose 5-phosphate, dihydroxyacetone phosphate, arachidonic acid, etc was defined and implicated in amino acid, glucose, and fatty acid metabolic processes as revealed by principal component analysis and partial least squares discriminant analysis. Moxibustion prevents RA-induced inflammatory response and offers potent therapeutic effects on myocardial dysfunctions. The protective effects might be associated with its role in TGF-β1 inactivation and metabolic reprogramming.

Total triterpenes of Euphorbium alleviates rheumatoid arthritis via Nrf2/HO-1/GPX4 pathway

This study aims to investigate the effect and mechanism of total triterpenes of Euphorbium in treating rheumatoid arthritis(RA). The rat model of RA was established with Freund's complete adjuvant(FCA). Male rats were randomly assigned into control, model, Tripterygium glycosides(7.5 mg·kg~(-1)), and low-, medium-, and high-dose total triterpenes of Euphorbium(32, 64, and 128 mg·kg~(-1), respectively) groups, with 10 rats in each group. In other groups except the control group, 0.2 mL FCA was injected into the right hind toe. Rats in the intervention groups were administrated with corresponding drugs by gavage, and the control group and the model group with the same volume of 0.5% CMC-Na solution once a day. During the treatment period, the swelling degree of the hind paw was measured and the arthritis was scored until day 30. At the end of drug administration, the pathological changes of the joint tissue were observed by hematoxylin-eosin staining. The content of malondialdehyde(MDA), glutathione(GSH), and Fe~(2+) and the activity of superoxide dismutase(SOD) in the joint tissue were measured by biochemical colorimetry. RT-PCR was performed to determine the mRNA levels of nuclear factor erythroid 2-related factor 2(Nrf2), glutathione peroxidase 4(GPX4), and acyl-CoA synthetase long chain family member 4(ACSL4) in the joint tissue. Western blot was employed to determine the protein levels of Nrf2, Kelch-like ECH-associated protein 1(Keap1), heme oxygenase-1(HO-1), NAD(P)H quinone oxidoreductase 1(NQO1), SOD2, GPX4, and ACSL4 in the joint tissue. The results showed that the treatment with Tripterygium glycosides(7.5 mg·kg~(-1)) and total triterpenes of Euphorbium(32, 64, and 128 mg·kg~(-1)) alleviated the swelling degree of bilateral hind limbs, decreased the arthritis score, reduced joint tissue lesions and the content of MDA and Fe~(2+) in the joint tissue, and increased GSH content and SOD activity. Furthermore, the interventions up-regulated the protein and mRNA levels of Nrf2 and GPX4, down-regulated the protein and mRNA levels of ACSL4, and up-regulated the protein levels of Keap1, NQO1, HO-1, and SOD2 in the Nrf2/HO-1/GPX4. In summary, the total triterpenes of Euphorbium can treat RA by inhibiting lipid peroxidation and abnormal ferroptosis, which may involve the Nrf2/HO-1/GPX4 signaling pathway.

Integrated bioinformatics analysis and experimental validation reveals hub genes of rheumatoid arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by systemic inflammation, especially synovitis, leading to joint damage. It is important to explore potential biomarkers and therapeutic targets to improve the clinical treatment of RA. However, the potential underlying mechanisms of action of available treatments for RA have not yet been fully elucidated. The present study investigated the potential biomarkers of RA and identified specific targets for therapeutic intervention. A comprehensive analysis was performed using mRNA files downloaded from the Gene Expression Omnibus. Differences in gene expression were analyzed and compared between the normal and RA groups. In addition, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed on differentially expressed genes (DEGs). A protein-protein interaction network, Molecular Complex Detection and cytoHubba network were evaluated to identify hub genes. Finally, using an experimental RA rat model induced by Freund's complete adjuvant (FCA), the expression of potential biomarkers or target genes in RA were verified through reverse transcription-quantitative PCR. The results of the mRNA dataset processing revealed 195 DEGs in patients with RA when compared with the healthy controls. Moreover, 10 hub genes were identified in patients with RA and four candidate mRNAs were identified, as follows: Discs large homolog-associated protein 5 (DLGAP5), kinesin family member 20A (KIF20A), maternal embryonic leucine zipper kinase (MELK) and nuclear division cycle 80 (NDC80). Finally, the bioinformatics analysis results were validated by quantifying the expression of the DLGAP5, KIF20A, MELK and NDC80 genes in the FCA-induced experimental RA rat model. The findings of the present study suggested that the treatment of RA may be successful through the inhibition of DLGAP5, KIF20A, MELK and NDC80 expression. Therefore, the targeting of these genes may result in more effective treatments for patients with RA.

In vivo application of magnetic molecularly imprinted polymer in rheumatoid arthritis rat model

A magnetic molecularly imprinted polymer (MMIP) was synthesised and tested for an in vivo rheumatoid arthritis (RA) rat model. Magnetite coated with mesoporous silica (Fe2O3@mSi) was used as core for surface imprinting, dopamine was used as monomer and methotrexate (MTX) was loaded directly during polymerisation. The amount of MTX loaded on MMIPs reached 201.165 ± 0.315 µmol/g. Characterisation of the polymers was done via SEM, TEM, and FTIR. The pharmacological effect of the selected MMIP was evaluated in a Complete Freund’s Adjuvant (CFA) induced arthritis rat model where a 3D magnet bearing construct was designed for targeted delivery of MMIPs. The parameters evaluated were the change in paw edoema, paw diameter, gait score, and animal’s weight. Results revealed a tendency of MMIP to significantly improve the measured parameters which was confirmed with histopathological findings. In conclusion, the improvement in the arthritic signs associated with MMIP treatment compared to free MTX, indicated successful targeting of MMIPs to the site of inflammation.

Carbon Quantum Dots Derived from Herbal Medicine as Therapeutic Nanoagents for Rheumatoid Arthritis with Ultrahigh Lubrication and Anti-inflammation.

As a typical chronic inflammatory joint disease with swelling and pain syndromes, rheumatoid arthritis (RA) is closely related to articular lubrication deficiency and excessive proinflammatory cytokines in its progression and pathogenesis. Herein, inspired by the dual effects of joint lubrication improvement and anti-inflammation to treat RA, two novel potential therapeutic nanoagents have been developed rationally by employing herbal medicine-derived carbon quantum dots (CQDs), i.e., safflower (Carthamus tinctorius L.) CQDs and Angelica sinensis CQDs, yielding ultrahigh lubrication and anti-inflammation bioefficacy. In vitro experimental results show that the two nanoagents display excellent friction reduction due to their good water solubility and spherical structure. Using RA rat models, it is indicated that the nanoagents significantly relieved swelling symptoms and inhibited the expression of related inflammatory cytokines, including IL-1, IL-6, and TNF-α, indicating their extraordinary anti-inflammation bioefficacy. Thus, combining the lubricating and anti-inflammation bioefficacy of CQDs derived from herbal medicine is an attractive strategy to develop new nanoagents for RA treatment.

Exploring the molecular mechanisms of the involvement of GZMB-Caspase-3-GSDME pathway in the progression of rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease with an unclear pathogenesis. Granzyme B (GZMB) has been reported as a potential therapeutic target for RA treatment, but its mechanism remains unclear. This study aimed to explore the molecular mechanism of the GZMB-Caspase-3-GSDME pathway in the progression of RA. An SD rat model of RA was constructed, and Western blot analysis was used to verify the high expression of the GZMB gene in RA rats. Functional validation was then performed on two common RA cells, HFLS-RA cells and MH7A cells, by inhibiting the GZMB gene with the GZMB siRNA virus. Cell proliferation function was measured by CCK8 and EDU assays; cell pyroptosis markers were detected by the LDH assay; inflammation factor levels were measured by ELISA; and the expression of GZMB and pathway-related genes and proteins was measured by Western blot. After GZMB silencing, cell proliferation was decreased compared to the control group, and the inflammation factors IL-1b and IL-18, as well as the pyroptosis markers LDH, IL-1b, and IL-18, were all reduced. The GZMB-related proteins GZMB, caspase-3, and Gasdermin E (GSDME) were also decreased. Therefore, GZMB silencing reduces pyroptosis by inhibiting caspase-3 and Gasdermin E decomposition. In summary, GZMB silencing inhibits the activation of caspase-3 and Gasdermin E, thereby delaying inflammation in RA. The GZMB gene may be a potential therapeutic target for RA.