Advancement in contemporary diagnostic and therapeutic approaches for rheumatoid arthritis

Luobitong Potentiates MTX's Anti-Rheumatoid Arthritis Activity via Targeting Multiple Inflammatory Pathways

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.

Iron, copper, zinc and magnesium on rheumatoid arthritis: a two-sample Mendelian randomization study

This study aimed to elucidate the causal genetic relationships between iron, copper, zinc, magnesium, and rheumatoid arthritis (RA). A two-sample Mendelian randomization (MR) analysis was conducted using the "TwoSampleMR" and "MendelianRandomization" packages in R. The random-effects inverse variance-weighted (IVW) method was used as the primary approach. We performed sensitivity analyses to test the reliability of the results. The random-effects IVW analysis revealed that there was no genetic causal relationship between iron (P = 0.429, odds ratio [OR] 95% confidence interval [CI] = 0.919 [0.746-1.133]), copper (P = 0.313, OR 95% CI = 0.973 [0.921-1.027]), zinc (P = 0.633, OR 95% CI = 0.978 [0.891-1.073]), or magnesium (P = 0.218, OR 95% CI = 0.792 [0.546-1.148]) and RA. Sensitivity analysis verified the reliability of the results. Therefore, there is no evidence to support a causal relationship between iron, copper, zinc, and magnesium intake at the genetic level and the development of RA.

Cold Air Plasma Inhibiting Tumor-Like Biological Behavior of Rheumatoid Arthritis Fibroblast-Like Synovial Cells via G2/M Cell Cycle Arrest

Background

Rheumatoid arthritis fibroblast-like synovial cells (RA-FLS) have become the core effector cells for the progression of rheumatoid arthritis due to their "tumor-like cell" characteristics, such as being able to break free from growth restrictions caused by contact inhibition, promoting angiogenesis, invading surrounding tissues, and leading to uncontrolled synovial growth. In recent years, cold air plasma (CAP) has been widely recognized for its clear anticancer effect. Inspired by this, this study investigated the inhibitory effect of CAP on the tumor-like biological behavior of RA-FLS through in vitro experiments.

Methods

Treatment of RA-FLS with CAP at different time doses (0s, 30s, 60s, 120s). 5-ethynyl-2'-deoxyuridine (EdU) proliferation assay was used to determine the cell viability. Analysis of cell migration and invasion was performed by wound-healing assay, transwell assay and immunofluorescent staining for f-actin, respectively. Flow cytometry technique was used for analysis of cell cycle and determination of reactive oxygen species (ROS). Hoechst staining was used for analysis of cell apoptosis. Protein expression was analyzed by Western blot analysis.

Results

Molecular and cellular level mechanisms have revealed that CAP blocks RA-FLS in the G2/M phase by increasing intracellular reactive oxygen species (ROS), leading to increased apoptosis and significantly reduced migration and invasion ability of RA-FLS.

Conclusion

Overall, CAP has significant anti proliferative, migratory, and invasive effects on RA-FLS. This study reveals a new targeted treatment strategy for RA.

Exosomes and exosomal miRNAs: A new avenue for the future treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic systemic autoimmune disease that involves mainly synovitis and joint injury and is one of the main causes of disability. The pathogenesis of rheumatoid arthritis is complicated, and the treatment cycle is long. The traditional methods of inhibiting inflammation and immunosuppression are no longer sufficient for treatment of the disease, so there is an urgent need to seek new treatments. The exocrine microenvironment is a kind of microvesicle with a lipid bilayer membrane structure that can be secreted by most cells in the body. This structure contains cell-specific proteins, lipids and nucleic acids that can transmit this information from one cell to another. To achieve cell-to-cell communication. Exocrine microRNAs can be contained in exocrine cells and can be selectively transferred to target receptor cells via exocrine signaling, thus regulating the physiological function of target cells. This article focuses on the pathological changes that occur during the development of rheumatoid arthritis and the biological regulation of exocrine and exocrine microRNAs in rheumatoid joints. Research on the roles of exocrine and exocrine microRNAs in regulating the inflammatory response, cell proliferation/apoptosis, autophagy, effects on fibroblast-like synoviocytes and immune regulation in rheumatoid arthritis was reviewed. In addition, the challenges faced by this new treatment are discussed.

Cayratia albifolia C.L.Li exerts anti-rheumatoid arthritis effect by inhibiting macrophage activation and neutrophil extracellular traps (NETs)

BACKGROUND

Cayratia albifolia C.L.Li (CAC), commonly known as "Jiao-Mei-Gu" in China, has been extensively utilized by the Dong minority for several millennia to effectively alleviate symptoms associated with autoimmune diseases. CAC extract is believed to possess significant anti-inflammatory properties within the context of Dong medicine. However, an in-depth understanding of the specific pharmaceutical effects and underlying mechanisms through which CAC extract acts against rheumatoid arthritis (RA) has yet to be established.

METHODS

Twenty-four Sprague-Dawley rats were divided into four groups, with six rats in each group. To induce the collagen-induced arthritis (CIA) model, the rats underwent a process of double immunization with collagen and adjuvant. CAC extract (100 mg/kg) was orally administered to rats. The anti-RA effects were evaluated in CIA rats by arthritis score, hind paw volume and histopathology analysis. Pull-down assay was conducted to identify the potential targets of CAC extract from RAW264.7 macrophage lysates. Moreover, mechanism studies of CAC extract were performed by immunofluorescence assays, real-time PCR and Western blot.

RESULTS

CAC extract was found to obviously down-regulate hind paw volume of CIA rats, with diminished inflammation response and damage. 177 targets were identified from CAC extract by MS-based pull-down assay. Bioinformatics analysis found that these targets were mainly enriched in macrophage activation and neutrophils extracellular traps (NETs). Additionally, we reported that CAC extract owned significant anti-inflammatory activity by regulating PI3K-Akt-mTOR signal pathway, and inhibited NETosis in response to PMA.

CONCLUSIONS

We clarified that CAC extract significantly attenuated RA by inactivating macrophage and reducing NETosis via a multi-targets regulation.

Can Combining Hyaluronic Acid and Physiotherapy in Knee Osteoarthritis Improve the Physicochemical Properties of Synovial Fluid?

Known as the degenerative disease of the knee with the highest prevalence, knee osteoarthritis (KOA) is characterized by a gradual destructive mechanism that, in severe cases, can provoke the need for total knee substitution. As the disease progresses, various enzymatic, immunological, and inflammatory processes abnormally degrade hyaluronic acid (HA), SF's main component, and affect the concentrations of specific proteins, with the final results seriously endangering synovial fluid (SF)'s rheological and tribological features and characteristics. No effective treatments have been found to stop the progression of KOA, but the injection of HA-based viscoelastic gels has been considered (alone or combined with physiotherapy (PT)) as an alternative to symptomatic therapies. In order to evaluate the effect of viscosupplementation and PT on the characteristics of SF, SF aspirated from groups treated for KOA (HA Kombihylan® and groups that received Kombihylan® and complex PT) was analyzed and compared from analytical, spectrophotometrical, and rheological perspectives. In the patients treated with PT, the SF extracted 6 weeks after viscosupplementation had a superior elastic modulus (G') and viscous moduli (G″), as well as a homogeneous distribution of proteins and polysaccharides. The viscosupplementation fluid improved the bioadhesive properties of the SF, and the use of the viscosupplementation fluid in conjunction with PT was found to be favorable for the distribution of macromolecules and phospholipids, contributing to the lubrication process and the treatment of OA-affected joints.

Potential clinical implications of molecular mimicry-induced autoimmunity

BACKGROUND

Molecular mimicry is hypothesized to be a mechanism by which autoimmune diseases are triggered. It refers to sequence or structural homology between foreign antigens and self-antigens, which can activate cross-reactive lymphocytes that attack host tissues. Elucidating the role of molecular mimicry in human autoimmunity could have important clinical implications.

OBJECTIVE

To review evidence for the role of molecular mimicry in major autoimmune diseases and discuss potential clinical implications.

METHODS

Comprehensive literature review of clinical trials, observational studies, animal models, and immunology studies on molecular mimicry in multiple sclerosis, type 1 diabetes, rheumatoid arthritis, lupus, Guillain-Barre syndrome, autoimmune myocarditis, and primary biliary cirrhosis published from 2000-2023.

RESULTS

Substantial indirect evidence supports molecular mimicry as a contributor to loss of self-tolerance in several autoimmune conditions. Proposed microbial triggers include Epstein-Barr virus, coxsackievirus, Campylobacter jejuni, and bacterial commensals. Key mechanisms involve cross-reactive T cells and autoantibodies induced by epitope homology between microbial and self-antigens. Perpetuation of autoimmunity involves epitope spreading, inflammatory mediators, and genetic factors.

CONCLUSIONS

Molecular mimicry plausibly explains initial stages of autoimmune pathogenesis induced by infection or microbiota disturbances. Understanding mimicry antigens and pathways could enable improved prediction, monitoring, and antigen-specific immunotherapy for autoimmune disorders. However, definitive proof of causation in humans remains limited. Further research should focus on establishing clinical evidence and utility.

Comprehensive Analysis of N6-Methyladenosine RNA Methylation Regulators in the Diagnosis and Subtype Classification of Rheumatoid Arthritis

m6A modification is the most abundant mRNA modifications and plays an integral role in various biological processes in eukaryotes. However, the role of m6A regulators in rheumatoid arthritis remains unknown. To determine the expression of m6A RNA methylation regulators in rheumatoid arthritis and their possible functional and prognostic value. In this study, we performed differential analysis in the comprehensive gene expression database GSE93272 dataset between non-rheumatoid arthritis patients and rheumatoid arthritis patients to obtain 15 important m6A regulators. A random forest model and lasso regression were used to screen the five most important m6A regulators to predict the risk of developing rheumatoid arthritis. After further validation using in vitro qPCR experiments, a nomogram model was developed based on the four most important m6A regulators (ELAVL1, WTAP, YTHDF1, and ALKBH5). Immuno-infiltration analysis and consensus clustering analysis were then performed. An analysis of the decision curve showed that the nomogram model could be beneficial to patients. According to selected important m6A regulators, patients with rheumatoid arthritis were classified into two m6A models (ClusterA and ClusterB) via consensus approach. Activated B cells, CD56dim natural killer cells, immature B cells, monocytes, natural killer T cells, and T lymphocytes were associated with ClusterA in immune infiltration analysis. Importantly, immune infiltration in patients with high ELAVL1 expression was strikingly similar to ClusterA. m6A regulators play a non-negligible role in the development of rheumatoid arthritis. A study of m6A patterns may provide future therapeutic options for rheumatoid arthritis.

Profiling of differentially expressed circRNAs and functional prediction in peripheral blood mononuclear cells from patients with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disease associated with an increased risk of death, but its underlying mechanisms are not fully understood. Circular RNAs (circRNAs) have recently been implicated in various biological processes. The aim of this study was to investigate the key circRNAs related to RA.

METHODS

A microarray assay was used to identify the differentially expressed circRNAs (DEcircRNAs) in peripheral blood mononuclear cells (PBMCs) from patients with RA compared to patients with osteoarthritis (OA) and healthy controls. Then, quantitative real-time PCR was applied to verify the DEcircRNAs, and correlations between the levels of DEcircRNAs and laboratory indices were analysed. We also performed extensive bioinformatic analyses including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genome (KEGG) pathway and potential circRNA-miRNA-mRNA network analyses to predict the function of these DEcircRNAs.

RESULTS

A total of 35,342 and 6146 DEcircRNAs were detected in RA patients compared to controls and OA patients, respectively. Nine out of the DEcircRNAs in RA were validated by real-time PCR. There were correlations between the levels of DEcircRNAs and some of the laboratory indices. GO analyses revealed that these DEcircRNAs in RA were closely related to cellular protein metabolic processes, gene expression, the immune system, cell cycle, posttranslational protein modification and collagen formation. Functional annotation of host genes of these DEcircRNAs was implicated in several significantly enriched pathways, including metabolic pathways, ECM-receptor interaction, the PI3K-Akt signalling pathway, the AMPK signalling pathway, leukocyte transendothelial migration, platelet activation and the cAMP signalling pathway, which might be responsible for the pathophysiology of RA.

CONCLUSIONS

The findings of this study may help to elucidate the role of circRNAs in the specific mechanism underlying RA.Key messagesMicroarray assays showed that a total of 35,342 and 6146 DEcircRNAs were detected in RA patients compared to controls and OA patients, respectively.Nine out of the DEcircRNAs in RA were validated by real-time PCR, and the levels of the DEcircRNAs were related to some of the laboratory indices.GO analyses revealed that the DEcircRNAs in RA were closely related to cellular protein metabolic processes, gene expression, the immune system, etc.Functional annotation of host genes of the DEcircRNAs in RA was implicated in several significantly enriched pathways, including metabolic pathways, ECM-receptor interaction, the PI3K-Akt signalling pathway, etc.

Identification and Development of Synovial B-Cell-Related Genes Diagnostic Signature for Rheumatoid Arthritis

Background

The aim of the study was to investigate the landscape of B-cell-related gene expression profiling in rheumatoid arthritis (RA) synovium and explore the biological and clinical significance of these genes in RA.

Methods

Expression profiling of synovial biopsies from subjects with 152 RA patients, 22 osteoarthritis (OA) patients, and 28 healthy controls was downloaded from the Gene Expression Omnibus database. Single-sample gene set enrichment analysis (ssGSEA) was performed to evaluate the abundance of infiltrated immune cells, and the results were validated using immunohistochemical staining. GSEA was employed to decipher differences in B-cell-related biological pathways. B-cell-related differential expression genes (BRDEGs) were screened, and BRDEGs-based model was developed by machine learning algorithms and evaluated by an external validation set and clinical RA cohort, then biological functions were further analyzed.

Results

High levels of immune cell infiltration and B-cell-related pathway activation were revealed in RA synovium. BRDEGs were screened, and three key molecular markers consisting of FAS, GPR183, and TFRC were identified. The diagnosis model was established, and these gene markers have good discriminative ability for RA. Molecular pathological evaluation confirmed RA patients with high-risk scores presented higher levels of B-cell activation and RA characteristics. In addition, a competitive endogenous RNA network was established to elucidate the molecular mechanisms of the posttranscriptional network.

Conclusions

We described the B-cell-related molecular landscape of RA synovium and constructed a molecular diagnostic model in RA. The three genes FAS, GPR183, and TFRC may be potential targets for clinical diagnosis and immunoregulatory therapy of RA.

Discovery of WD-890: A novel allosteric TYK2 inhibitor for the treatment of multiple autoimmune diseases

Tyrosine kinase 2 (TYK2) as a member of Janus kinase (JAK) family, mainly mediates the signaling of type I interferons (IFN), interleukin-12 (IL-12) and interleukin-23 (IL-23), which has become an attractive target for treatment of immune and inflammatory diseases. However, the development of selective TYK2 inhibitors is challenging due to the high homology of the catalytic kinase domain among the JAK family members. Here, we report a novel and potent allosteric inhibitor, WD-890, which binds to the pseudokinase domain of TYK2 with high selectivity and inhibits its function. We accomplished a series of preclinical studies to demonstrate the therapeutic efficacy of WD-890 in four animal models: systemic lupus erythematosus (SLE), psoriasis, psoriatic arthritis (PsA), and inflammatory bowel disease (IBD). The pharmacokinetic and toxicology results further indicate that WD-890 has favorable absorption, distribution, metabolism, and excretion (ADME) properties and tolerable toxicity. In conclusion, our study shows that WD-890 could be a promising oral TYK2 inhibitor for future treatment of autoimmune diseases.

Comprehensive analysis of serum exosome-derived lncRNAs and mRNAs from patients with rheumatoid arthritis

BACKGROUND

Serum exosomes play important roles in intercellular communication and are promising biomarkers of several autoimmune diseases. However, the biological functions and potential clinical importance of long non-coding RNAs (lncRNAs) and mRNAs from serum exosomes in rheumatoid arthritis (RA) have not yet been studied.

METHODS

Serum exosomal lncRNAs and mRNAs were isolated from patients with RA and osteoarthritis (OA) and healthy controls. The differentially expressed lncRNAs (DE-lncRNAs) and mRNA profiles in the serum exosomes of patients with RA were analysed using high-throughput sequencing, and their functions were predicted using Gene Ontologyenrichment, Kyoto Encyclopedia of Genes and Genomes pathway, and gene set enrichment analysis. We constructed a DE-lncRNA-mRNA network and a protein-protein interaction network of differentially expressed mRNAs (DE-mRNAs) in RA using the Cytoscape software. The expression of several candidate a DE-lncRNAs and DE-mRNAs in the serum of patients with RA, patients with OA, and healthy controls was confirmed by qRT-PCR. We assessed the diagnostic ability of DE-lncRNAs and DE-mRNAs in patients with RA using receiver operating characteristic analysis. Furthermore, we analysed the characteristics of immune cell infiltration in RA by digital cytometry using the CIBERSORT algorithm and determined the correlation between immune cells and several DE-lncRNAs or DE-mRNAs in RA.

RESULTS

The profiles of serum exosomal lncRNAs and mRNAs in patients with RA were different from those in healthy controls and patients with OA. The functions of both DE-lncRNAs and DE-mRNAs in RA are associated with the immune response and cellular metabolic processes. The RT-PCR results show that NONHSAT193357.1, CCL5, and MPIG6B were downregulated in patients with RA. The combination of three DE-mRNAs, CCL5, MPIG6B, and PFKP, had an area under the curve of 0.845 for differentiating RA from OA. Digital cytometry using the CIBERSORT algorithm showed that the neutrophil counts were higher in patients with RA than those in healthy controls and patients with OA.

CONCLUSIONS

These findings help to elucidate the role of serum exosomal lncRNAs and mRNAs in the specific mechanisms underlying RA.

Effect of electroacupuncture at ST36 on the cerebral metabolic kinetics of rheumatoid arthritis rats

Electroacupuncture (EA) has been shown to enhance the recovery of symptoms in rheumatoid arthritis (RA); however, the underlying mechanism remains unclear. Both the pathogenesis of RA and the therapeutic effects of EA are closely associated with the metabolic activity of the brain. In this study, we investigated the effect of EA at the "Zusanli" acupoint (ST36) on a rat model of collagen-induced rheumatoid arthritis (CIA). The results demonstrated that EA effectively alleviated joint swelling, synovial hyperplasia, cartilage erosion, and bone destruction in CIA rats. Additionally, the metabolic kinetics study revealed a significant increase in the 13C enrichment of GABA2 and Glu4 in the midbrain of CIA rats treated with EA. Correlation network analysis showed that changes in Gln4 levels in the hippocampus were strongly associated with the severity of rheumatoid arthritis. Immunofluorescence staining of c-Fos in the midbrain's periaqueductal gray matter (PAG) and hippocampus demonstrated increased c-Fos expression in these regions following EA treatment. These findings suggest that GABAergic and glutamatergic neurons in the midbrain, along with astrocytes in the hippocampus, may play vital roles in the beneficial effects of EA on RA. Furthermore, the PAG and hippocampus brain regions hold potential as critical targets for future RA treatments. Overall, this study provides valuable insights into the specific mechanism of EA in treating RA by elucidating the perspective of cerebral metabolism.

The impact of exosomes derived from distinct sources on rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that can induce joint deformities and functional impairment, significantly impacting the overall well-being of individuals. Exosomes, which are cellularly secreted vesicles, possess favorable biological traits such as biocompatibility, stability, and minimal toxicity. Additionally, they contain nucleic acids, lipids, proteins, amino acids, and metabolites, serving as mediators in cellular communication and information exchange. Recent studies have demonstrated the association between exosomes and the pathogenesis of RA. Exosomes derived from mesenchymal stem cells, dendritic cells, and neutrophils exert influence on the biological functions of immune cells and joint cells, however, the precise mechanism remains largely unclarified. This comprehensive review systematically analyzes and summarizes the biological characteristics and functionalities of exosomes derived from diverse cellular sources, thus establishing a scientific foundation for the utilization of exosomes as diagnostic targets and therapeutic modalities in the context of RA.

Protective effect of fustin against adjuvant-induced arthritis through the restoration of proinflammatory response and oxidative stress

Rheumatoid arthritis causes irreparable damage to joints. The present research sought to check fustin's anti-arthritic efficacy against the complete Freund's adjuvant-induced arthritis paradigm in animals by altering the inflammatory response. In the rats, complete Freund's adjuvant was used to trigger arthritis and they received fustin at 50 and 100 mg/kg for 21 days. At regular intervals, the hind paw volume and arthritic score were assessed. After the trial period, hematological, antioxidant, pro-inflammatory cytokines, and other biochemical parameters were estimated. Fustin-treated rats showed the down-regulation of hind paw volume, arthritic score, and altered hematological parameters (TLC, DLC (neutrophil, lymphocyte, monocyte, eosinophil, basophil)). Furthermore, fustin significantly mitigates proinflammatory cytokine (reduced interleukin, tumor necrosis factor-a (TNF-α), IL-6, IL-1β), oxidative stress (attenuated malondialdehyde (MDA), catalase (CAT), glutathione (GSH), superoxide dismutase (SOD)), attenuated production of prostaglandin E2 and myeloperoxidase (MPO) and improved nuclear factor erythroid 2-related factor (Nrf2) action. Fustin led to the benefit in arthritis-prone animals elicited by complete Freund's adjuvant via pro-inflammatory cytokine.

Lariciresinol protects rats from complete Freund's adjuvant induced arthritis in rats via modulation of transforming growth factor-β and nuclear factor kappa B pathway: An in vivo and in silico study

Rheumatoid arthritis (RA) is a severe inflammatory auto-immune disorder affecting millions of people across the globe. The current therapeutic options are not adequate to address the complications of RA. Therefore, the present study was conducted to elucidate the protective effect of lariciresinol, a lignan, against Complete Freund's adjuvant (CFA)-induced arthritis in rats. The results of the study showed that lariciresinol improves paw swelling and arthritic scores in rats as compared to CFA rats. Lariciresinol also showed a significant reduction in rheumatoid factor, C-reactive protein, tumor necrosis factor-α, interleukin (IL)-17, and tissue inhibitor of metalloproteinases-3 level with a simultaneous increase in IL-4 level. The burden of oxidative stress was also reduced in CFA rats, as shown by reduced MDA levels and increased SOD and GPx after the administration of lariciresinol. In a Western blot analysis, lariciresinol showed a significant reduction of transforming growth factor-β and nuclear factor-κB (NF-κB) protein levels in CFA rats. To understand the binding characteristic of lariciresinol with NF-κB, molecular docking analysis was conducted, which showed Larciresinol interacted with the active site of NF-κB. Our study demonstrated the significant protective effect of lariciresinol against RA via multi-target action.

5-aminolevulinic acid-loaded dissolving microneedle array for photodynamic therapy of rheumatoid arthritis on rats

Photodynamic therapy (PDT) is a noninvasive technique that can be used to treat rheumatoid arthritis (RA) by irradiating photosensitizers with specific wavelengths of light to generate reactive oxygen species (ROS), thus leading to targeted cell necrosis. However, efficient delivery of photosensitizers with low side effects is a key issue. We developed a 5-aminolevulinic acid-loaded dissolving microneedle array (5-ALA@DMNA) that can locally and efficiently deliver photosensitizers for RA treatment by PDT. 5-ALA@DMNA was fabricated through a two-step molding process, which was characterized. The effects of 5-ALA-mediated PDT on RA fibroblast-like synoviocytes (RA-FLs) were investigated via in vitro experiments. Adjuvant arthritis rat models were established to evaluate the therapeutic effect of 5-ALA@DMNA-mediated PDT on RA. The results showed that 5-ALA@DMNA could penetrate the skin barrier and efficiently deliver photosensitizers. 5-ALA-mediated PDT can significantly inhibit the migration ability and selectively induce apoptosis of RA-FLs. Moreover, 5-ALA-mediated PDT had a significant therapeutic effect on rats with adjuvant arthritis, which may be related to the upregulation of interleukin (IL)- 4 and IL-10 and downregulation of TNF-α, IL-6, and IL-17. Thus, 5-ALA@DMNA-mediated PDT may be a potential therapy for RA.

Inhibition Ras/MEK/ERK pathway: An important mechanism of Baihu Jia Guizhi Decoction ameliorated rheumatoid arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Alleviating rheumatism by inhibiting synovitis is a routine treatment for rheumatoid arthritis (RA). Baihu Jia Guizhi Decoction (BHJGZ) is a classic prescription and has a long history of application for treating RA with a good anti-inflammatory action. However, the underlying molecular mechanisms have not been fully elucidated.

AIM OF THE STUDY

This work aimed to decipher the potential mechanism of BHJGZ against RA focusing on Ras/MEK/ERK pathway.

MATERIALS AND METHODS

Based on the prediction of network pharmacology, the inhibition action of BHJGZ on Ras/MEK/ERK pathway was firstly validated in vivo and in vitro. Moreover, the affinity with the ingredients of BHJGZ in serum and the targets of Ras/MEK/ERK pathway were evaluated. Finally, the efficacy of BHJGZ for relieving RA was assessed in AA rats.

RESULTS

The Ras/MEK/ERK pathway was predicted by network pharmacology as one of important mechanisms of BHJGZ to treat RA. The high expression of Ras protein in synovitis of AA rats was significantly reduced by the treatment with BHJGZ, and the activation of Ras/MEK/ERK pathway in vivo and in vitro was also markedly inhibited (p < 0.05 or p < 0.01). Moreover, the level of p-ERK/ERK, IL-6 and TNF-α in vitro were further suppressed after Ras or MEK was inhibited by mirdametinib or lonafarnib respectively (p < 0.01). Furthermore, the results of molecular docking showed a good affinity and stable binding with the ingredients of BHJGZ in serum and multiple key proteins of the Ras/MEK/ERK pathway. Finally, paw swelling, paw circumference and pathological changes of joint synovitis were significantly reduced by BHJGZ in AA rats (p < 0.05).

CONCLUSION

The inhibition of Ras/MEK/ERK pathway is one of crucial mechanisms of BHJGZ for ameliorating synovitis of RA.

Validation of traditional claims of anti-arthritic efficacy of trans-Himalayan snow mountain garlic (Allium ampeloprasum L.) extract using adjuvant-induced arthritis rat model: A comparative evaluation with normal garlic (Allium sativum L.) and dexamethasone

ETHNOPHARMACOLOGICAL RELEVANCE

Snow Mountain Garlic (SMG) (Allium ampeloprasum L.) is a wild trans-Himalayan member of the genus Allium, valued for its anti-inflammatory and anti-arthritic properties in the mountain folk medicinal system (Sowa-Rigpa). Despite its age-old medicinal usage by traditional therapists and the native population for various ailments including rheumatism, there is no scientific validation of its phyto-pharmaceutical merits.

AIM OF THE STUDY

The present pre-clinical study compared the in-vivo anti-arthritic effects of SMG with reported efficacy doses of normal garlic (Allium sativum L.) extract and dexamethasone in a complete Freund's adjuvant (CFA)-induced arthritis rat model.

MATERIALS AND METHODS

The female Wistar rats were immunized by the subplannter injection of CFA into the right hind footpad. Aqueous extracts of SMG and normal garlic were administered orally at a dose of 250 mg/kg and 500 mg/kg for 28 days. Dexamethasone was used as positive control drug. Behavioral parameters including paw markers, arthritis index, joint stiffness, body weight change, etc. were measured. Also, the changes in histopathological indices, hematological profile, inflammatory mediators, and serum cytokines level was determined.

RESULTS

Treatment of rats with SMG extracts significantly (p < 0.001) prevented the reduction in body weight and hematological changes as well as ameliorated clinical symptoms such as arthritic index, joint stiffness, arthritis score, edema, hyperalgesia, and histopathological indices. This was associated with a significant reduction in the serum levels of RF, CRP, anti-CCP, and proinflammatory cytokines exhibiting strong anti-arthritic potential. SMG extracts could also significantly down regulate the NF-κB, COX-2, and iNOS expression in the ankle joint tissues.

CONCLUSIONS

The present study is the first attempt to validate the phyto-pharmaceutical efficacy of this folk garlic variety from the trans-Himalayan region. Overall, SMG extract showed remarkable preventive anti-inflammatory and anti-arthritic activities which were closely comparable to therapeutic effects of dexamethasone and at par or even better than normal garlic w.r.t. several study parameters.

Comparison of the effects of peficitinib and tofacitinib in the adjuvant-induced arthritis rat model

We investigated and compared the pharmacologic properties of two Janus kinase (JAK) inhibitors, peficitinib and tofacitinib, in an adjuvant-induced arthritis rat model. Repeated administration of peficitinib (3 - 30 mg/kg) or tofacitinib (1 - 10 mg/kg) exhibited a dose-related and significant attenuation of arthritis score, paw swelling, pain threshold, grip strength and histopathologic injuries in the model; peficitinib 10 mg/kg and tofacitinib 3 mg/kg demonstrated comparable efficacy. Equivalent C_max and AUC_0-12h values were observed with peficitinib 10 mg/kg and tofacitinib 3 mg/kg, suggesting that the two drugs may demonstrate comparable efficacy on arthritis-associated symptoms at comparable plasma concentration levels. However, peficitinib 10 mg/kg had greater efficacy than tofacitinib 3 mg/kg on some inflammation- and bone destruction-associated parameters in the paw fluid, including the production of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), receptor activator of nuclear factor kappa-B ligand, and matrix metalloproteinase-3, which are associated with arthritis exacerbation. Peficitinib 10 mg/kg also showed significantly greater inhibitory effects than tofacitinib 3 mg/kg on loss of bone mineral density and synovial thickening score, which might be a result of the VEGF and PDGF receptor kinase inhibitory effects of peficitinib, in addition to JAK inhibition. In conclusion, both tofacitinib and peficitinib potently improved arthritis and associated symptoms in adjuvant-induced arthritis rats; moreover, owing to possible differences in the mechanism of action of the two drugs, peficitinib may have exerted its effects through JAK inhibition and additional unique off-target properties.

SHIP1 is required for the formation of neutrophil extracellular traps in rheumatoid arthritis

Aberrant neutrophil extracellular traps (NETs) are involved in the pathogenesis of rheumatoid arthritis (RA). However, the specific pathway leading to NET formation in RA is poorly understood. Therefore, therapies targeting NETs are not available in RA. In this study, we demonstrated Src homology 2 domain-containing inositol phosphatase-1 (SHIP1) function as a hub to regulate NETosis through SHIP1/ p38 MAPK/TNF-α pathway both in vitro and ex vivo and inhibiting SHIP1 expression ameliorated RA symptoms in vivo. Neutrophils from RA patients showed enhanced NETosis as well as increased SHIP1, p38 mitogen-activated protein kinase (MAPK) family expression and tumor necrosis factor-α (TNF-α) expression. Inhibiting SHIP1 in neutrophils using small molecules counteracted the above-mentioned dysregulations and resulted in decrease in NETosis, p38 expression and TNF-α concentration. Consistent with this, SHIP1 agonist led to upregulated p38MAPK and NET formation. Moreover, inhibiting SHIP1 in vivo led to decreased NETosis and showed beneficial therapeutic effects in Collagen-induced arthritis (CIA) mice. Taken together, these results indicated that activation of SHIP1/MAPK/TNF-α pathway was necessary for upregulated NETosis in RA, which provided evidence for targeting SHIP1 in RA treatment.

Photoacoustic/ultrasonic dual-mode imaging for monitoring angiogenesis and synovial erosion in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by the formation of new vessels, synovial proliferation and destruction of articular cartilage. However, characteristic early diagnostic and therapeutic monitoring methods are still lacking. We report a study using a photoacoustic/ultrasound (PA/US) dual-mode imaging for RA disease. By establishing a collagen-induced (CIA) RA mouse model to classify disease states based on a subjective grading system, PA/US imaging allows real-time assessment of synovial erosion and vascular opacification within the knee joint in different disease states at high spatial resolution. The system also quantitatively monitors subcutaneous vascular physiology and morphology in the hind paw of mice, measuring the area and photoacoustic signal intensity of vascular proliferation and showing a positive correlation with disease grading. Compared to traditional subjective scoring of arthritis severity, the PA/US imaging is more sensitive i.e., vascular signals and synovial erosion can be observed early in the course of arthritis.

Synovial tissue metabolomics analysis of the therapeutic effects of stir-fried Xanthii Fructus on rheumatoid arthritis in rats

Rheumatoid arthritis (RA) is a rheumatic disease that easily causes synovial hyperplasia and joint damage. Comprehensive metabolomic profiling of synovial tissue can reveal local pathological changes during RA and identify metabolites as candidate biomarkers. Detecting metabolites in synovial tissue can more directly reflect the pathological state and disease activity associated with it. stir-fried Xanthii Fructus has demonstrated efficacy in treating RA, but its pharmacodynamic property and mechanism of action are unclear. In this study, the molecular composition of the extract of stir-fried Xanthium Fructus was determined through HPLC. The major components that exert anti-inflammatory and analgesic effects were speculated to be phenolic acids. Next, the effect of stir-fried Xanthii Fructus extracts in RA treatment was comprehensively evaluated using rat body weight, foot volume, inflammatory factors, and histopathological sections of the ankle joint as evaluation indicators. The results showed that the extract of stir-fried Xanthii Fructus could significantly reduce the inflammatory response and improve the degree of joint swelling and the imbalance between pro-inflammatory and anti-inflammatory in adjuvant arthritis rats. Finally, non-targeted metabolomics based on UPLC-Q-TOF/MS and multivariate statistical analysis were used to explore the changes of endogenous metabolites in synovium tissues and to search for potential biomarkers and related metabolic pathways in stir-fried Xanthii Fructus extract-treated AA rats. The results showed that stir-fried Xanthii Fructus mainly treated RA by regulating energy metabolism, hormone metabolism, amino acid metabolism and oxidative stress response in adjuvant arthritis rats. This study provides a theoretical basis for the mechanism of action of stir-fried Xanthii Fructus extract in treating RA.

Protein arginine methyltransferase 1 upregulates matrix metalloproteinase-2/9 expression via Zeste Homolog 2 to promote human rheumatoid arthritis fibroblast-like synovial cell survival and metastasis

OBJECTIVE

To explore the role of protein arginine methyltransferase 1 (PRMT1) in the development of rheumatoid arthritis (RA).

METHODS

Fibroblast-like synoviocytes (FLS) were isolated from synovial tissues, cultured and transfected with plasmid vector or short hairpin RNA (shRNA). The morphology and surface markers of FLS were investigated by light microscopy and flow cytometry. The expression levels of PRMT1, Zeste Homolog 2 (EZH2), matrix metalloproteinase-2 (MMP-2) and MMP-9 were detected by real-time polymerase chain reaction and Western blotting. Cell viability was tested by MTT assay, cell proliferation was assessed by EdU assay, cell invasion was evaluated by Transwell invasion test, cell migration was detected by wound healing assay, and cell apoptosis was detected by flow cytometry.

RESULTS

The expression of PRMT1 was elevated in RA synovial tissues compared with control tissues. FLS from control tissues showed a lower level of PRMT1 than FLS from RA tissues, and FLS from RA tissues had a stronger ability of cell survival and metastasis than those from control tissues. When silencing PRMT1 expression, FLS from RA tissues showed a decreased ability of cell survival and metastasis. Additionally, FLS from RA tissues expressed a higher level of MMP-2 and MMP-9. When silencing PRMT1 expression, the expression of MMP-2 and MMP-9 of FLS was suppressed. Furthermore, the effect of PRMT1 on FLS was mediated by EZH2.

CONCLUSION

We found that PRMT1 had an overall effect on FLS via EZH2, which contributed to the development of RA. Hence, PRMT1 and EZH2 provide potential targets for RA treatment.

Patient Goals for Living with Rheumatoid Arthritis: A Qualitative Study

Rheumatoid arthritis is highly individualized in terms of its flare ups and periods of remission. Each patient's unique experience requires a high level of personalization in terms of treatment making it necessary to understand what their goals for living are. This study explores patient perceptions on how the burden of RA shapes patients' goals for living and their preferences for symptom and side-effect management within the United States. Fifteen patients diagnosed with RA with varying lengths of diagnosis were interviewed. A thematic analysis was conducted to construct a conceptual framework. Emerging themes identified disease burdens as: (1) inability to perform essential needs, (2) negative feelings about disease, and (3) its influence on relationships. These burdens shaped desired goals for living which guided the symptom and side-effect priorities the patient wanted managed. Practitioners should consider patient goals and preferences in conjunction with disease progression when engaging in treatment decisions.

Identification of biomarkers associated with CD8+ T cells in rheumatoid arthritis and their pan-cancer analysis

Introduction

Rheumatoid arthritis (RA), a prevailing chronic progressive autoimmune disease, seriously affects the patient's quality of life. However, there is still a lack of precise treatment and management methods in clinical practice. Previous studies showed that CD8+ T cells take a lead in the progression of RA.

Methods

Genes closely related to CD8+T cells in RA were identified through multiple RA datasets, CIBERSORT, and WGCNA algorithms. Further machine learning analysis were performed to identify CD8+T cell-related genes most closely related to RA. In addition, the relationship between these three key genes and 33 cancer species was also explored in this study.

Results

In this study, 10 genes were identified to be closely related to CD8+T cells in RA. Machine learning analysis identified 3 CD8+T cell-related genes most closely related to RA: CD8A, GZMA, and PRF1.

Discussion

Our research aims to provide new ideas for the clinical treatment of RA.

Advancement in understanding the role of ferroptosis in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, systemic disease of unknown etiology. The primary manifestation of RA is inflammatory synovitis, which eventually leads to deformity and functional loss. Ferroptosis is a non-apoptosis form of cell death that depends on intracellular iron accumulation. This leads to an increase in reactive oxygen species (ROS) induced-lipid peroxidation. The underlying mechanisms of ferroptosis are System Xc- and Glutathione metabolism, regulation of glutathione peroxidase 4 activity, and ROS generation. Recent studies have shown an association between the pathogenesis of RA and ferroptosis, suggesting the involvement of ferroptosis in the onset and progression of RA. In this review, we have focused on the mechanism of ferroptosis and its association with RA pathogenesis. Further, we discuss the status of therapeutics targeting ferroptosis in the treatment of patients with RA. Targeting ferroptosis could be a potential therapeutic approach for RA treatment.

Repurposing of parenterally administered active substances used to treat pain both systemically and locally

Pain is a constant in our lives. The efficacy of drug therapy administered by the parenteral route is often limited either by the physicochemical characteristics of the drug itself or its adsorption-distribution-metabolism-excretion (ADME) mechanisms. One promising alternative is the design of innovative drug delivery systems that can improve the pharmacokinetics |(PK) and/or reduce the toxicity of traditionally used drugs. In this review, we discuss several products that have been approved by the main regulatory agencies (i.e., nano- and microsystems, implants, and oil-based solutions), highlighting the newest technologies that govern both locally and systemically the delivery of drugs. Finally, we also discuss the risk assessment of the scale-up process required, given the impact that this approach could have on drug manufacturing. Teaser: The management of pain by way of the parenteral route can be improved using complex drug delivery systems (e.g., micro- and nanosystems) which require high-level assessment and shorten the regulatory pathway.

Identification of Critical Biomarkers and Immune Infiltration in Rheumatoid Arthritis Based on WGCNA and LASSO Algorithm

Rheumatoid arthritis(RA) is the most common inflammatory arthritis, and a significant cause of morbidity and mortality. RA patients' synovial inflammation contains a variety of genes and signalling pathways that are poorly understood. It was the goal of this research to discover the major biomarkers related to the course of RA and how they connect to immune cell infiltration. The Gene Expression Omnibus was used to download gene microarray data. Differential expression analysis, weighted gene co-expression network analysis (WGCNA), and least absolute shrinkage and selection operator (LASSO) regression were used to identify hub markers for RA. Single-sample GSEA was used to examine the infiltration levels of 28 immune cells and their connection to hub gene markers. The hub genes' expression in RA-HFLS and HFLS cells was verified by RT-PCR. The CCK-8 assay was applied to determine the roles of hub genes in RA. In this study, we identified 21 differentially expressed genes (DEGs) in RA. WGCNA yielded two co-expression modules, one of which exhibited the strongest connection with RA. Using a combination of differential genes, a total of 6 intersecting genes was discovered. Six hub genes were identified as possible biomarkers for RA after a lasso analysis was performed on the data. Three hub genes, CKS2, CSTA, and LY96, were found to have high diagnostic value using ROC curve analysis. They were shown to be closely related to the concentrations of several immune cells. RT-PCR confirmed that the expressions of CKS2, CSTA and LY96 were distinctly upregulated in RA-HFLS cells compared with HFLS cells. More importantly, knockdown of CKS2 suppressed the proliferation of RA-HFLS cells. Overall, to help diagnose and treat RA, it's expected that CKS2, CSTA, and LY96 will be available, and the aforementioned infiltration of immune cells may have a significant impact on the onset and progression of the disease.

Anti-rheumatoid drugs advancements: New insights into the molecular treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is one of more than 100 types of arthritis. This chronic autoimmune disorder affects the lining of synovial joints in about 0.5% of people and may induce severe joints deformity and disability. RA impacts health life of people from all sexes and ages with more prevalence in elderly and women people. Significant improvement has been noted in the last two decades revealing the mechanisms of the development of RA, the improvement of the early diagnosis and the development of new treatment options. Non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and disease-modifying antirheumatic drugs (DMARDs) remain the most known treatments used against RA. However, not all patients respond well to these drugs and therefore, new solutions are of immense need to improve the disease outcomes. In the present review, we discuss and highlight the recent findings concerning the different classes of RA therapies including the conventional and modern drug therapies, as well as the recent emerging options including the phyto-cannabinoid and cell- and RNA-based therapies. A better understanding of their mechanisms and pathways might help find a specific target against inflammation, cartilage damage, and reduce side effects in arthritis.

Recent progress in therapeutic strategies and biomimetic nanomedicines for rheumatoid arthritis treatment

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune systemic disease in which inflammatory and immune cells accumulate in inflamed joints. Researchers aimed at the characteristics of RA to achieve the effect of treating RA through different therapeutic strategies, and have used various endogenous materials to design drug-loaded nanoparticles that can target RA by binding to cell adhesion molecules or chemokines. In some cases, the nanoparticles can respond to the characteristics of the microenvironment.

AREAS COVERED

This article reviews the recent advances in the treatment of RA from two aspects of therapeutic strategies and delivery strategies. Therapeutic strategies mainly include neutralization of inflammatory factors, promotion of inflammatory cell apoptosis, ROS scavenger, immunosuppression, and bone tissue repair. The drug delivery strategy is mainly described from two aspects: chemically functionalized biomimetic nanoparticles and endogenous nanoparticles.

EXPERT OPINION

Biomimetic NPs may be effective drug carriers for targeted RA treatment. NPs can reduce the clearance of mononuclear phagocytes, prolong the blood circulation time, and improve the targeting ability. With the deepening of research, more and more biomimetic NPs have entered the clinical trial stage. However, safe and scalable preparation methods are needed to improve their clinical applicability.

CKS2 and S100A12: Two Novel Diagnostic Biomarkers for Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic systematicness autoimmunity disease with joint inflammation. RA etiology is still unknown. Early and exact diagnosing is still hard to reach. In the paper, we purposed to discover novel diagnosis biological marker for RA. Two open, usable gene expression profiles of human RA as well as controlled specimens (dataset GSE17755 as well as GSE93272) were downloaded from the GEO database. Differentially expressed genes (DEGs) were screened between 331 RA and 88 control samples. Functional enrichment analysis was applied to explore the possible function of DEGs. Expression levels as well as diagnosis values of biological marker in RA were further verified in our cohort by the use of RT-PCR and ROC assays. We identified 13 DEGs between RA samples and control samples. 13 DEGs were remarkably abundant in NF-kappa B signal pathway. Among the 13 DEGs, CKS2, S100A12, LY96, and ANXA3 exhibited a strong diagnostic ability in screening RA specimens from normal specimens using all AUC > 0.8. Moreover, we confirmed that the expression of CKS2 and S100A12 was distinctly upregulated in RA specimens contrasted to normal specimens. Overall, serum CKS2 and S100A12 could be used as novel diagnosis biological markers for RA patients.

Mechanisms of bone pain: Progress in research from bench to bedside

The field of research on pain originating from various bone diseases is expanding rapidly, with new mechanisms and targets asserting both peripheral and central sites of action. The scope of research is broadening from bone biology to neuroscience, neuroendocrinology, and immunology. In particular, the roles of primary sensory neurons and non-neuronal cells in the peripheral tissues as important targets for bone pain treatment are under extensive investigation in both pre-clinical and clinical settings. An understanding of the peripheral mechanisms underlying pain conditions associated with various bone diseases will aid in the appropriate application and development of optimal strategies for not only managing bone pain symptoms but also improving bone repairing and remodeling, which potentially cures the underlying etiology for long-term functional recovery. In this review, we focus on advances in important preclinical studies of significant bone pain conditions in the past 5 years that indicated new peripheral neuronal and non-neuronal mechanisms, novel targets for potential clinical interventions, and future directions of research.

An updated review of the effects of eicosapentaenoic acid- and docosahexaenoic acid-derived resolvins on bone preservation

Resolvins are biosynthesized from omega-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in vivo by means of enzymatic activities, and these factors can attenuate inflammation and promote tissue regeneration. Inflammatory bone disorders can lead to bone loss and thereby be harmful to human health. The link between bone preservation and resolvins has been discussed in some experimental studies. Significant evidence has shown that resolvins benefit bone health and bone preservation by promoting the resolution of inflammation and directly regulating osteoclasts and osteoblasts. Therefore, this review highlights the role and beneficial impact of resolvins derived from EPA and DHA on inflammatory bone disorders, such as rheumatoid arthritis and periodontitis. In addition, the mechanisms by which resolvins exert their beneficial effects on bone preservation have also been summarized based on the available literature.

The Anti-Inflammatory Effect of Cabbage Leaves Explained by the Influence of bol-miRNA172a on FAN Expression

Recently, the possibility of cross-kingdom gene expression regulation by miRNAs from other species (“xenomiRs”), specifically from plants, has acquired scientific meaning. Based on the one of oldest methods for dealing with inflammation via the use of cabbage leaf compresses, we investigated the effects of Brassica oleracea derived miR172a on the potential human target gene encoding FAN (Factor Associated with Neutral Sphingomyelinase Activation) protein. In vitro experiments showed a decrease in FAN protein levels in both human and mouse cells transfected with bol-miRNA172a. As the FAN protein mediates inflammatory responses, the potential of miR172a to mitigate the inflammatory process was tested in a mouse model of rheumatoid arthritis. Animal studies showed the decreased oedema of inflamed paws in mouse with rheumatoid arthritis model induced after treatment with miR172a.

Integrative serum metabolomic analysis for preventive effects of Yaobitong capsule in adjuvant-induced rheumatoid arthritis rat based on RP/HILIC-UHPLC-Q-TOF MS

Yaobitong capsule (YBTC) has been used for the prevention and treatment of inflammation-related lumbago and leg pain. However, its intervention mechanism still remains unclear. This study was aimed to evaluate the control efficiency of YBTC on adjuvant-induced rheumatoid arthritis (RA) rats by metabonomic method and to explore its possible anti-arthritis mechanism. Taking into account the complexity of endogenous metabolites in serum samples, an integrated metabolomics method based on RP/HILIC-UHPLC-Q-TOF MS was developed, to overcome the limitations of a single chromatographic in this study. The results showed that 32 potential biomarkers of arthritis were identified, primarily related to amino acid metabolism, glucose metabolism, lipid metabolism and nucleotide metabolism. Further receiver operating characteristic analysis revealed that the area under the curve of two down-regulated metabolites (3-Hydroxy-hexadecanoic acid, 2-Oxoarginine) and one up-regulated metabolite (l-Glutamic acid) among 32 biomarkers were 0.906, 0.969 and 1.000, respectively, indicating that high predictive ability of this method for RA. In this study, an integrated serum metabolomics method based on high-resolution mass spectrometry was successfully established for the first time to study the intervention mechanism of YBTC in RA, providing evidence regarding the clinical application of YBTC and a new insight for the prevention of RA in the future.

Practical Implementation of Artificial Intelligence-Based Deep Learning and Cloud Computing on the Application of Traditional Medicine and Western Medicine in the Diagnosis and Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA), an autoimmune disease of unknown etiology, is a serious threat to the health of middle-aged and elderly people. Although western medicine, traditional medicine such as traditional Chinese medicine, Tibetan medicine and other ethnic medicine have shown certain advantages in the diagnosis and treatment of RA, there are still some practical shortcomings, such as delayed diagnosis, improper treatment scheme and unclear drug mechanism. At present, the applications of artificial intelligence (AI)-based deep learning and cloud computing has aroused wide attention in the medical and health field, especially in screening potential active ingredients, targets and action pathways of single drugs or prescriptions in traditional medicine and optimizing disease diagnosis and treatment models. Integrated information and analysis of RA patients based on AI and medical big data will unquestionably benefit more RA patients worldwide. In this review, we mainly elaborated the application status and prospect of AI-assisted deep learning and cloud computation-oriented western medicine and traditional medicine on the diagnosis and treatment of RA in different stages. It can be predicted that with the help of AI, more pharmacological mechanisms of effective ethnic drugs against RA will be elucidated and more accurate solutions will be provided for the treatment and diagnosis of RA in the future.

Mendelian randomization study on the causal effects of omega-3 fatty acids on rheumatoid arthritis

OBJECTIVES

To resolve the ongoing debate on the role of plasma omega-3 fatty acids in rheumatoid arthritis (RA), we attempted to identify the association between omega-3 intake and the risk of RA.

METHODS

We analyzed data from the largest genome-wide association study (GWAS) for omega-3 fatty acids (N = 114,999 of European ancestry) and RA (14,361 cases and 43,923 controls of European ancestry). Mendelian randomization-egger_intercept, MR-PRESSO, and Cochran's Q test were used to determine pleiotropy and heterogeneity. Egger, weighted median, inverse variance weighted (IVW), simple mode, and weighted mode were used to evaluate the causal association of plasma omega-3 levels on RA.

RESULTS

We found no significant pleiotropy, heterogeneity, and bias among the omega-3 genetic instrumental variables (IVs) in RA GWAS datasets. MR analysis demonstrated that as omega-3 levels genetically increased, the risk of MS increased using MR-egger (Beta = 0.137, p = 0.037; OR = 1.146, 95% CI: [1.014, 1.296]), weighted median (Beta = 0.162, p = 0.001; OR = 1.176, 95% CI: [1.070, 1.292]), IVW (Beta = 0.102, p = 0.025; OR = 1.108, 95% CI: [1.013, 1.211]), simple mode (Beta = 0.219, p = 0.149; OR = 1.245, 95% CI: [0.931, 1.665]), and weighted mode (Beta = 0.146, p = 0.006; OR = 1.157, 95% CI: [1.051, 1.274]).

CONCLUSIONS

Our analysis suggested a causal association between genetically increased plasma omega-3 levels and the increased risk of RA in populations with European ancestry. Thus, to reduce the risk of RA, those of European descent should reduce omega-3 intake. Key Points • No significant pleiotropy or heterogeneity among the omega-3 genetic IVs in RA GWAS datasets. • Genetically increased plasma omega-3 levels enhanced the risk of RA in European lineages.

Yaobitong capsules reshape and rebalance the gut microbiota and metabolites of arthritic rats: An integrated study of microbiome and fecal metabolomics analysis

Yaobitong capsule (YBTC), a Chinese medicine compound preparation, has been demonstrated to affect multiple pathways associated with inflammation and exhibit potential anti-arthritis effect. In this study, an integrated omic approach based on UHPLC-Q-TOF MS and 16S rRNA sequencing analyses was proposed to reveal the anti-arthritis effect and possible mechanism of YBTC. The AIA rat model showed that YBTC significantly alleviated the typical symptoms of AIA rats such as weight, spleen index and pro-inflammatory cytokines. Fecal metabolomics results identified 41 differential metabolites, which mainly referred to tryptophan, bile acid and fatty acid metabolism. The gut microbiota played a crucially important role in anti-inflammatory immunity, 16S rRNA results indicated that YBTC changed the community structure and alleviated the microecological imbalance caused by rheumatoid arthritis (RA). Further ROC curve analysis demonstrated that it was reliable to identify RA by using 5 metabolites and 3 microorganisms (AUC > 0.83). In summary, it was the first time that the preventive effect of YBTC in RA was confirmed. The secretion of the microbiota-mediated metabolites was significantly improved by YBTC, through its callback effect on the disturbed gut microbiota. Thus, we have indicated a potential novel strategy for the prevention of RA via evaluation of intervention effects of YBTC on AIA rat model.

"Platelet-rich plasma holds promise in management of rheumatoid arthritis"-systematic review

The treatment of rheumatoid arthritis (RA) has been closely evolving with an understanding of disease pathogenesis with disease modifying anti-rheumatoid drugs (DMARDS) and Biologic DMARDS being the main stay. platelet rich plasma (PRP) has been the center of research in many specialties in the past decade. Its ability to stop and reverse inflammation have attracted researchers to try PRP in RA. A systematic review of studies on PRP in RA is lacking. The study protocol was prospectively registered in PROSPERO. Detailed search of Cochrane, Scopus, Medline, Embase, and Web of science databases were made to identify the relevant articles till Sep 2020 following Cochrane and PRISMA guidelines. Number of subjects, Animal model used, cell lines used for the study, method of induction of arthritis, PRP dose, concentration used, frequency of administration and clinical, histologic, and molecular changes from baseline following PRP use were extracted and analysed. Eight studies were included for the review. Four of these were in-vitro studies. Two were exclusive animal studies. One study analysed the effects of PRP in RA in both animal models (mice) and Hela cell lines. One study was a report of a series of patients of resistant RA treated with PRP. In the in vitro studies while platelets increase the migration and invasion of RA-FLS, they suppressed the inflammation on the whole. Available animal studies and the Human study have shown encouraging results. There has been no evidence of exacerbation of inflammation in these studies. The quantity and quality of literature on the effects of PRP in treating joint pathologies in RA is limited. Preclinical studies show decrease in disease activity with good safety profile. Invitro studies show suppression of inflammation. Thus, the available literature is encouraging towards the use of PRP in RA. Larger trials and molecular studies to understand the exact role of platelets in disease pathogenesis and treatment mechanisms are needed to decide the future course of PRP in RA.

Anti-arthritic effect of chicken embryo tissue hydrolyzate against adjuvant arthritis in rats (X-ray microtomographic and histopathological analysis)

Finding new, safe strategies to prevent and control rheumatoid arthritis is an urgent task. Bioactive peptides and peptide-rich protein hydrolyzate represent a new trend in the development of functional foods and nutraceuticals. The resulting tissue hydrolyzate of the chicken embryo (CETH) has been evaluated for acute toxicity and tested against chronic arthritis induced by Freund's full adjuvant (modified Mycobacterium butyricum) in rats. The antiarthritic effect of CETH was studied on the 28th day of the experiment after 2 weeks of oral administration of CETH at doses of 60 and 120 mg/kg body weight. Arthritis was evaluated on the last day of the experiment on the injected animal paw using X-ray computerized microtomography and histopathology analysis methods. The CETH effect was compared with the non-steroidal anti-inflammatory drug diclofenac sodium (5 mg/kg). Oral administration of CETH was accompanied by effective dose-dependent correction of morphological changes caused by the adjuvant injection. CETH had relatively high recovery effects in terms of parameters for reducing inflammation, inhibition of osteolysis, reduction in the inflammatory reaction of periarticular tissues, and cartilage degeneration. This study presents for the first time that CETH may be a powerful potential nutraceutical agent or bioactive component in the treatment of rheumatoid arthritis.

Myrtenal and β-caryophyllene oxide screened from Liquidambaris Fructus suppress NLRP3 inflammasome components in rheumatoid arthritis

Background

Liquidambaris Fructus (LF) is the infructescence of Liquidambar formosana. In Traditional Chinese Medicine, LF has been used to treat joint pain, a common symptom of arthritis and rheumatism; however, a lack of pharmacological evidence has limited its applications in modern clinics. Therefore, this study aims to explore the protective effect of LF on rheumatoid arthritis (RA) and to identify its active ingredients.

Methods

Rats with adjuvant-induced arthritis (AIA) were divided into 4 groups and administered petroleum ether extract of LF (PEL), ethyl acetate extract of LF (EEL), water extract of LF (WEL), or piroxicam (PIR) respectively for 3 weeks. Two additional groups were used as normal control (NC) and model control (MC) and administered distilled water as a placebo. The clinical scores for arthritis, bone surface, synovial inflammation and cartilage erosion were used to evaluate the therapeutic efficacy of each treatment. The serum IL-1β and TNF-α level and the expression of NLRP3, IL-1β and caspase-1 p20 in the synovial tissue of AIA rats were evaluated by ELISA and Western blot. The active ingredients of LF were investigated using network pharmacology and molecular docking methods, and their inhibition of NLRP3 inflammasome activation was verified in the human rheumatoid arthritis fibroblast-like synovial cells (RA-FLS) model.

Results

PEL could alleviate paw swelling, bone and joint destruction, synovial inflammation and cartilage erosion in the AIA rats, with significantly superior efficacy to that of EEL and WEL. PEL reduced IL-1β and TNF-α serum levels, and attenuated the upregulation of NLRP3, IL-1β and caspase-1 p20 expression in the synovial tissue of AIA rats. Network pharmacology and molecular docking results indicated that myrtenal and β-caryophyllene oxide were the main two active ingredients of PEL, and these two compounds showed significant inhibition on TNF-α, NLRP3, IL-1β and caspase-1 p20 expression in RA-FLS.

Conclusions

Myrtenal and β-caryophyllene oxide screened from PEL could suppress the activation of NLRP3 inflammasome, thereby alleviating RA symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03410-2.

Integrated serum pharmacochemistry and network pharmacological analysis used to explore possible anti-rheumatoid arthritis mechanisms of the Shentong-Zhuyu decoction

ETHNOPHARMACOLOGICAL RELEVANCE

Shentong-Zhuyu decoction (STZYD) has been recognized by the Chinese National Administration of Traditional Chinese Medicine (TCM) as a classic TCM formula. Use of STZYD has shown a satisfactory clinical therapeutic outcome for rheumatoid arthritis (RA); despite this, its bioactive chemical composition and relevant mechanism(s) of this action have not been clearly elucidated.

AIM OF THE STUDY

To explore the bioactive chemical composition of STZYD used for RA treatment and its possible mechanism(s) of action.

MATERIALS AND METHODS

Serum pharmacochemistry mediated by the UPLC-Q-Exactive MS/MS method was employed to identify the absorbed phytochemical compounds in serum derived from STZYD, which were commonly considered as the potential bioactive compounds. And then, these components were used to construct a compound-target network for RA using a network pharmacology approach, to predict the possible biological targets of STZYD along with potential signaling pathways. Afterwards, we established a Complete Freund's adjuvant (CFA)-induced RA rat model, and observed the anti-RA effect of STZYD by a series of indexes, including foot swelling, ankle diameter, arthritis score, morphological and radiographic analysis, serum inflammatory factors, and histopathological analysis of synovial tissues. Particularly, the predicted pathway by the combination of serum pharmacochemistry and network pharmacology was further validated using RT-qPCR, Western blot, and immunohistochemical analyses in animal experiment.

RESULTS

Totally, 38 compounds derived from STZYD have been identified by serum sample analysis. Based on it, 387 genes related to these identified compounds in STZYD and 3807 genes related to RA were collected by network pharmacology. Critically, KEGG analysis indicated that the PI3K/AKT signaling pathway was recommended as one of the main pathway related to anti-RA effect of STZYD. Experimentally, STZYD significantly alleviated CFA-induced arthritis without any visible side-effects. Compared to the RA model group without any treatment, the treatment of STZYD significantly reduced the expression of both mRNA and protein targets in the PI3K/AKT signaling pathway. Furthermore, this result was also corroborated by immunohistochemistry analysis. All these studies could effectively corroborate the predicted result as above, suggested that the feasibility of this integrated strategy.

CONCLUSION

This study provided a useful strategy to identify bioactive compounds and the potential mechanisms for TCM formula by integrating serum pharmacochemistry and network pharmacology.

Hsa_circ_0044235 regulates the pyroptosis of rheumatoid arthritis via MiR-135b-5p-SIRT1 axis

Studies have found that cell pyroptosis is involved in the occurrence and development of rheumatoid arthritis (RA). Hsa_circ_0044235 has been found to be significantly low-expressed in RA patients. The purpose of this research was to reveal the regulatory mechanism of hsa_circ_0044235 in the pyroptosis pathway of RA. Serum expressions of hsa_circ_0044235 and SIRT were detected by RT-qPCR, and the relationship of the two genes was analyzed by Pearson. Next, a collagen-induced arthritis (CIA) mouse model was constructed to examine the effect of hsa_circ_0044235 on knee joint injury. The number of apoptotic cells and the level of inflammatory cytokines in synovial tissue were detected by TUNEL and ELISA. Fibroblast-like synoviocytes (FLSs) were extracted as in vitro study subject. Functional assays including flow cytometry and immunofluorescence staining, molecular experiments including RT-qPCR, Western blot and dual luciferase assay, and bioinformatics analysis were performed to analyze the mechanism of hsa_circ_0044235 in pyroptosis in FLSs. Hsa_circ_0044235 and SIRT1 expressions were suppressed in RA patients and the two were positively correlated. Overexpressed hsa_circ_0044235 attenuated joint inflammation, cell apoptosis, and joint damage, reduced foot pad thickness, clinical case scores, inhibited the NLRP3-mediated pyroptosis pathway but promoted SIRT1 expression in CIA mice. Overexpressed hsa_circ_0044235 inhibited caspase-1 content and the NLRP3-mediated pyroptosis pathway. Moreover, hsa_circ_0044235 promoted SIRT1 expression by sponging miR-135b-5p in FLSs. Additionally, the effect of overexpressed hsa_circ_0044235 on FLSs was reversed by miR-135b-5p mimic and siSIRT1, while the effect of siSIRT1 was reversed by miR-135b-5p inhibitor. Hsa_circ_0044235 regulated NLRP3-mediated pyroptosis through miR-135b-5p-SIRT1 axis to regulate the development of RA.

KDM4B Overexpression Promotes the Growth, Migration, and Invasion of Rheumatoid Arthritis Fibroblast-Like Synoviocytes by Activating STAT3 Pathway

In rheumatoid arthritis (RA), fibroblast-like synoviocytes (FLS) present a unique aggressive phenotype and have a passive response to the inflammatory microenvironment, which are critical for the disease’s progression. KDM4B, as a histone demethylase, functions as an oncogenic factor in many cancers and is implicated in osteoclastogenesis as well as pro-inflammatory cytokine release in inflammatory diseases. However, the effects of KDM4B on RA FLS have not been reported. To investigate this issue, our study determined the expression of KDM4B in RA FLS using RT-qPCR and western blot. The effects of KDM4B on RA FLS viability, apoptosis, migration, and invasion were detected by MTT, flow cytometry, transwell migration, and invasion assays. Furthermore, the interaction of KDM4B with STAT3 signaling was studied by western blot, MTT, flow cytometry, transwell migration, and invasion assays. The experimental results showed that KDM4B expression was upregulated in RA synovial tissues and FLS as compared to healthy control tissues and normal FLS. Knockdown of KDM4B obviously suppressed RA FLS viability, migration and invasion, and induced apoptosis. In addition, knockdown of KDM4B in RA FLS decreased the expression of p-STAT3 and MMP-9 but increased cleaved caspase-3 expression compared with the control group. Moreover, KDM4B overexpression could promote cell growth, migration and invasion, and suppress apoptosis in RA FLS by activating STAT3 signaling. Therefore, these findings provide new insight for understanding the pathogenesis of RA and indicate that KDM4B may have a potential to be an effective therapeutic target for RA.

Triggers of Cardiovascular Diseases in Rheumatoid Arthritis

The risk of cardiovascular disease (CVD) in patients with rheumatoid arthritis (RA) is higher than that in patients without RA, and it is even higher than that in patients with diabetes. Autoimmune-mediated inflammation is observed in patients with RA, resulting in endothelial dysfunction, oxidative stress and activation, and vascular migration of white blood cells. Traditionally, RA-associated CVD was assumed to be mediated by disease-related inflammation, resulting in atherosclerosis (AS). However, this concept has been challenged because treatment with anti-rheumatic drugs, such as methotrexate or proinflammatory cytokine antagonists, such as tumor necrosis factor-alpha (TNF-α) inhibitors, did not reduce the risk of CVD in patients with RA. Current cardiovascular guidelines recommend screening and treatment of CVD risk factors in patients with RA but without clear biomarkers and treatment goals. There is no scientific basis for establishing therapeutic targets for cardiovascular risk factors in RA. Numerous studies have shown that the mechanism of early cardiac dysfunction in patients with RA may occur prior to AS. Therefore, it is crucial to explore the related mechanisms to prevent early cardiac dysfunction in patients with RA.

Function and Role of Regulatory T Cells in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic and heterogeneous autoimmune disease with symmetrical polyarthritis as its critical clinical manifestation. The basic cause of autoimmune diseases is the loss of tolerance to self or harmless antigens. The loss or functional deficiency of key immune cells, regulatory T (Treg) cells, has been confirmed in human autoimmune diseases. The pathogenesis of RA is complex, and the dysfunction of Tregs is one of the proposed mechanisms underlying the breakdown of self-tolerance leading to the progression of RA. Treg cells are a vital component of peripheral immune tolerance, and the transcription factor Foxp3 plays a major immunosuppressive role. Clinical treatment for RA mainly utilizes drugs to alleviate the progression of disease and relieve disease activity, and the ideal treatment strategy should be to re-induce self-tolerance before obvious tissue injury. Treg cells are one of the ideal options. This review will introduce the classification, mechanism of action, and characteristics of Treg cells in RA, which provides insights into clinical RA treatment.

Anti-rheumatic effect of quercetin and recent developments in nano formulation

Quercetin is a potential anti-rheumatoid drug. Nano formulation strategies could improve its solubility and efficacy.

Effects of intra-articular pulsed radiofrequency current administration on a rabbit model of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by synovial proliferation and inflammation. Intra-articular corticosteroid injections are commonly used for the treatment of arthritis affecting one or two joints. Although corticosteroid injections are fast-acting, repeated usage can result in severe adverse events. Recently, intra-articular pulsed radiofrequency (PRF) stimulation has been proposed to treat arthritis. The aim of the present study was to compare the effectiveness of intra-articular PRF with corticosteroid injection based on histopathological and motion analysis of an ovalbumin (OVA)-induced RA rabbit model. RA was induced in the right knee joint of 18 rabbits via OVA injection. The rabbits were randomly allocated into a PRF, an intra-articular corticosteroid injection or a sham PRF stimulation group. Movement was assessed in the rabbits before treatment, then at 2, 4 and 8 weeks after treatment using walking distance, fast walking time and mean walking speed. Histopathological evaluation of the distal femur and synovium was conducted 2, 4 and 8 weeks after treatment. Motion analysis demonstrated that changes in all movement variables showed significant group and time interaction as well as group effect among the three groups. The semiquantitative score based on the histopathological findings for the distal femoral condyle decreased 2 and 4 weeks after both the PRF and steroid groups, compared with the sham PRF group. Moreover, in the synovium, the semiquantitative histological score in the PRF and steroid groups tended to be lower compared with the sham PRF group, although this result was not statistically significant. Thus, intra-articular PRF stimulation may delay cartilage destruction and improve functional motion in RA.