Pathogenetic insights from the treatment of rheumatoid arthritis

Identification the role of necroptosis in rheumatoid arthritis by WGCNA network

Rheumatoid arthritis (RA) is the predominant manifestation of inflammatory arthritis, distinguished by an increasing burden of morbidity and mortality. The intricate interplay of genes and signalling pathways involved in synovial inflammation in patients with RA remains inadequately comprehended. This study aimed to ascertain the role of necroptosis in RA, as along with their associations with immune cell infiltration. Differential expression analysis and weighted gene co-expression network analysis (WGCNA) were employed to identify central genes for RA. In this study, identified total of 28 differentially expressed genes (DEGs) were identified in RA. Utilising WGCNA, two co-expression modules were generated, with one module demonstrating the strongest correlation with RA. Through the integration of differential gene expression analysis, a total of 5 intersecting genes were discovered. These 5 hub genes, namely fused in sarcoma (FUS), transformer 2 beta homolog (TRA2B), eukaryotic translation elongation factor 2 (EEF2), cleavage and polyadenylation specific factor 6 (CPSF6) and signal transducer and activator of transcription 3 (STAT3) were found to possess significant diagnostic value as determined by receiver operating characteristic (ROC) curve analysis. The close association between the concentrations of various immune cells is anticipated to contribute to the diagnosis and treatment of RA. Furthermore, the infiltration of immune cells mentioned earlier is likely to exert a substantial influence on the initiation of this disease.

MiR-204/-211 double knockout exacerbates rheumatoid arthritis progression by promoting splenic inflammation

OBJECTIVE

Collagen-induced arthritis (CIA) model was induced in C57BL/6 wild-type (wt) and C57BL/6 miR-204/-211 double-knockout (dKO) mice to investigate the role of miR-204/-211 in suppressing splenic inflammation in rheumatoid arthritis (RA).

METHODS

Differences of miR-204/-211 and structure-specific recognition protein 1 (SSRP1) in the spleen of DBA/1J wt and CIA mice were detected via PCR and immunohistochemistry. CIA was induced in both C57BL/6 wt and C57BL/6 miR-204/-211 dKO mice, and the onset of CIA and disease severity were statistically analyzed. Immunohistochemistry staining of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and SSRP1 in spleen or knee joints was performed and analyzed. In CIA miR-204/-211 dKO mice, AAV-shSSRP1 was intra-articularly injected, with both the AAV-shRNA Ctrl and AAV-shRNA Ctrl CIA groups receiving the same dose of AAV-shRNA. Spleen sections were stained with hematoxylin and eosin (H&E).

RESULTS

Compared to wt mouse spleens, aberrant expression of miR-204/-211 and SSRP1 was observed in the spleens of CIA mice. Immunized dKO mice exhibited a higher incidence of CIA onset and a more exacerbated RA disease phenotype, characterized by increased spleen inflammation score and elevated levels of IL-1β, TNF-α, and SSRP1 expression. AAV-shSSRP1 injection in CIA dKO mice significantly reduced spleen inflammation scores, IL-1β and TNF-α expression levels, and down-regulated Ki-67 expression compared to CIA dKO mice.

CONCLUSION

Knockout of miR-204/-211 exacerbated the onset of CIA in C57BL/6 mice, while miR-204/-211 played a protective role against the progression of splenic inflammatory and proliferative progression in RA by targeting SSRP1.

Identification of novel biomarker hsa_circ_0003914 for rheumatoid arthritis from plasma exosomes

Rheumatoid arthritis (RA) is a complex autoimmune disease featuring invasive and infiltrative fibroblast-like synoviocytes (FLS) that lead to joint damage. While current RA pathological mechanisms remain incompletely defined, exosomes have been implicated as having the potential to drive disease progression due to their ability to deliver different types of biomolecules to tissues effected by RA. One potentially disease exacerbating molecule type found in exosomes are Circular RNAs (circRNAs), which are highly stable and have been previously implicated in RA pathogenesis. Here, we examine hsa_circ_0003914, a circRNA found in exosomes located in blood plasma, for a role in RA. Plasma exosomes were isolated and injected into collagen-induced arthritis (CIA) mice, followed by functional experiments to analyze the influence of exosomes on FLS formation. Sequencing revealed the presence of hsa_circ_0003914 in exosomes, so we examined its association with clinical markers in RA. Finally, the role for hsa_circ_0003914 in RA was directly confirmed through in vivo and in vitro experiments. We found that plasma exosomes isolated from RA patients could aggravate the disease of CIA mice, compared to exosomes isolated from healthy control patients. Hsa_circ_0003914 was highly enriched in the exosomes of RA patients. Mechanistically, Hsa_circ_0003914 promoted abnormal cell proliferation, migration, invasion and stimulated the secretion of inflammatory cytokines in FLSs through targeting NF-κB/p65 signaling pathway. Interestingly, knockdown of hsa_circ_0003914 rescued disease phenotypes in CIA mice. Taken together, these data implicate hsa_circ_0003914 as a potential therapeutic target for the prevention and management of RA.

Single-Cell Multi-Dimensional data analysis reveals the role of ARL4C in driving rheumatoid arthritis progression and Macrophage polarization dynamics

Rheumatoid arthritis (RA) is an enduring autoimmune inflammatory condition distinguished by continual joint inflammation, hyperplasia of the synovium, erosion of bone, and deterioration of cartilage.Fibroblast-like synoviocytes (FLSs) exhibiting "tumor-like" traits are central to this mechanism.ADP-ribosylation factor-like 4c (ARL4C) functions as a Ras-like small GTP-binding protein, significantly impacting tumor migration, invasion, and proliferation.However, it remains uncertain if ARL4C participates in the stimulation of RA FLSs exhibiting "tumor-like" features, thereby fostering the advancement of RA. In our investigation, we unveiled, for the inaugural instance, via the amalgamated scrutiny of single-cell RNA sequencing (scRNA-seq) and Bulk RNA sequencing (Bulk-seq) datasets, that activated fibroblast-like synoviocytes (FLSs) showcase high expression of ARL4C, and the ARL4C protein expression in FLSs derived from RA patients significantly surpasses that observed in individuals with osteoarthritis (OA) and traumatic injury (trauma).Silencing of the ARL4C gene markedly impeded the proliferation of RA FLSs by hindered the transition of cells from the G0/G1 phase to the S phase, and intensified cell apoptosis and diminished the migratory and invasive capabilities. Co-culture of ARL4C gene-silenced RA FLSs with monocytes/macrophages significantly inhibited the polarization of monocytes/macrophages toward M1 and the repolarization of M2 to M1.Furthermore, intra-articular injection of shARL4C significantly alleviated synovial inflammation and cartilage erosion in collagen-induced arthritis (CIA) rats. In conclusion, our discoveries propose that ARL4C assumes a central role in the synovial inflammation, cartilage degradation, and bone erosion associated with RA by triggering the PI3K/AKT and MAPK signaling pathways within RA FLSs.ARL4C holds promise as a prospective target for the development of pharmaceutical agents targeting FLSs, with the aim of addressing RA.

Therapeutic potential of probiotics in gut microbial homeostasis and Rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by inflammation and joint damage. Existing treatment options primarily focus on managing symptoms and slowing disease progression, often with side effects and limitations. The gut microbiome, a vast community of microorganisms present in the gastrointestinal tract, plays a crucial role in health and disease. Recent research suggests a bidirectional relationship between the gut microbiome and RA, highlighting its potential as a therapeutic option. This review focuses on the interaction between the gut microbiome and RA development, by discussing how dysbiosis, an imbalance in gut bacteria, can contribute to RA through multiple mechanisms such as molecular mimicry, leaky gut, and metabolic dysregulation. Probiotics, live microorganisms with health benefits, are emerging as promising tools for managing RA. They can prevent the negative effects of dysbiosis by displacing harmful bacteria, producing anti-inflammatory metabolites like short-chain fatty acids (SCFA), Directly influencing immune cells, and modifying host metabolism. animal and clinical studies demonstrate the potential of probiotics in improving RA symptoms and disease outcomes. However, further research is needed to optimize probiotic strains, dosages, and treatment protocols for personalized and effective management of RA. This review summarizes the current understanding of the gut microbiome and its role in RA and discusses future research directions. In addition to the established role of gut dysbiosis in RA, emerging strategies like fecal microbiota transplantation, prebiotics, and postbiotics offer exciting possibilities. However, individual variations in gut composition necessitate personalized treatment plans. Long-term effects and clear regulations need to be established. Future research focusing on metagenomic analysis, combination therapies, and mechanistic understanding will unlock the full potential of gut microbiome modulation for effective RA management.

Characteristics of T-Cell Receptor Repertoire for Differential Response to Methotrexate Treatment for Rheumatoid Arthritis

BACKGROUND

Methotrexate (MTX) serves as the initial treatment for rheumatoid arthritis (RA). However, a substantial proportion of RA patients, estimated between 30% and 50%, do not respond positively to MTX. While the T-cell receptor (TCR) is crucial for the immune response during RA, its role in differentiating MTX responsiveness has not been thoroughly investigated.

METHODS

This study used next-generation sequencing to analyze the TCR β-chain complementary determining region sequences in peripheral blood mononuclear cells obtained from RA patients before MTX treatment. This study aimed to compare the characteristics of the TCR repertoire between the MTX responder and non-responder groups.

RESULTS

The study identified a significant difference in the TRBV6-6 gene (p = .003) concerning MTX treatment response. Additionally, a significant difference was found in the number of "3" nucleotide deletions at the 5'Jdels site (p = .023) in the VDJ rearrangement.

CONCLUSION

These findings suggest distinct TCR repertoire characteristics between MTX responder and non-responder groups among RA patients. This discovery offers new insights into understanding the variable responses of RA patients to MTX therapy.

Bacillus coagulans BACO-17 ameliorates in vitro and in vivo progression of Rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that causes persistent inflammation involving the joints, cartilage, and synovium. In individuals with RA, alterations in the composition of intestinal bacteria suggest the vital role of gut microbiota in immune dysfunction. Multiple therapies commonly used to treat RA can also alter the diversity of gut microbiota, further suggesting the modulation of gut microbiota as a prevention or treatment for RA. Therefore, a better understanding of the changes in the gut microbiota that accompany RA should facilitate the development of novel therapeutic approaches. In this study, B. coagulans BACO-17 not only significantly reduced paw swelling, arthritis scores, and hind paw and forepaw thicknesses but also protected articular cartilage and the synovium against RA degeneration, with a corresponding downregulation of TNF-α expression. The inhibition or even reversing of RA progression highlights B. coagulans BACO-17 as a novel therapeutic for RA worth investigating.

Bibliometric and visualization analysis of the application of inorganic nanomaterials to autoimmune diseases

Objective: To conduct bibliometric analysis of the application of inorganic nanomaterials to autoimmune diseases to characterize current research trends and to visualize past and emerging trends in this field in the past 15 years. Methods: The evolution and thematic trends of the application of inorganic nanomaterials to autoimmune diseases from January 1, 1985, to March 15, 2024, were analyzed by bibliometric analysis of data retrieved and extracted from the Web of Science Core Collection (WoSCC) database. A total of 734 relevant reports in the literature were evaluated according to specific characteristics such as year of publication, journal, institution, country/region, references, and keywords. VOSviewer was used to build co-authorship analysis, co-occurrence analysis, co-citation analysis, and network visualization. Some important subtopics identified by bibliometric characterization are further discussed and reviewed. Result: From 2009 to 2024, annual publications worldwide increased from 11 to 95, an increase of 764%. ACS Nano published the most papers (14) with the most citations (1372). China (230 papers, 4922 citations) and the Chinese Academy of Sciences (36 papers, 718 citations) are the most productive and influential country and institution, respectively. The first 100 keywords were co-clustered to form four clusters: (1) the application of inorganic nanomaterials in drug delivery, (2) the application of inorganic nano-biosensing to autoimmune diseases, (3) the use of inorganic nanomaterials for imaging applied to autoimmune diseases, and (4) the application of inorganic nanomaterials in the treatment of autoimmune diseases. Combination therapy, microvesicles, photothermal therapy (PTT), targeting, diagnostics, transdermal, microneedling, silver nanoparticles, psoriasis, and inflammatory cytokines are the latest high-frequency keywords, marking the emerging frontier of inorganic nanomaterials in the field of autoimmune diseases. Sub-topics were further discussed to help researchers determine the scope of research topics and plan research directions. Conclusion: Over the past 39 years, the application of inorganic nanotechnology to the field of autoimmune diseases shows extensive cooperation between countries and institutions, showing a continuous increase in the number of reports in the literature, and has clinical translation prospects. Future research should further improve the safety of inorganic nanomaterials, clarify the mechanism of action of nanomaterials, establish a standardized nanomaterial preparation and performance evaluation system, and ultimately achieve the goal of early detection and precise treatment of autoimmune diseases.

Synovial 5-Lipoxygenase-Derived Oxylipins Define a Lympho-Myeloid-Enriched Synovium

OBJECTIVE

Oxylipins are bioactive lipids derived from polyunsaturated fatty acids (PUFAs) that modulate inflammation and may remain overexpressed in refractory synovitis. In plasma, they could also be biomarkers of synovial pathology. The aim of this study is to determine if synovial oxylipins in inflamed joints correlate with plasma oxylipins and with synovial histologic patterns.

METHODS

Patients with established rheumatoid or psoriatic arthritis with active disease despite treatment were recruited, and paired synovial tissue (ST) and plasma were collected. Oxylipins were determined by liquid chromatography with tandem mass spectrometry and were classified into groups according to their PUFA precursor and enzyme. The expression of CD20, CD68, CD3, and CD138 was obtained to describe synovial histology. Cell-specific expression of oxylipin-related genes was identified by examining available synovial single-cell RNA sequencing data.

RESULTS

We included a total of 32 ST and 26 paired-plasma samples. A total of 71 oxylipins were identified in ST, but only 24 were identified in plasma. Only levels of 9,10-dihydroxyoctadecenoic acid and tetranor-Prostaglandin FM had a significant positive correlation between plasma and ST. Several oxylipins and oxylipin-related genes were differentially expressed among synovial phenotypes. Specifically, several 5-lipoxygenase (LOX)-derived oxylipins were statistically elevated in the lympho-myeloid phenotype and associated with B cell expression in rheumatoid arthritis samples.

CONCLUSION

The lack of correlation between ST and plasma oxylipins suggests that ST lipid profiling better characterizes active pathways in treated joints. Synovial 5-LOX-derived oxylipins were highly expressed in lympho-myeloid-enriched synovium. Combination therapy with 5-LOX inhibitors to improve refractory inflammation may be needed in patients with this histologic group.

Rheumatoid arthritis-recent advances in pathogenesis and the anti-inflammatory effect of plant-derived COX inhibitors

The majority of people with autoimmune disorders, including those with rheumatoid arthritis, osteoarthritis, and tendonitis report pain, stiffness, and inflammation as major contributors to their worse quality of life in terms of overall health. Of all the available treatment options, COX inhibitors are the ones that are utilized most frequently to ease the symptoms. Various signaling cascades have been reported to be involved in the pathogenesis of rheumatoid arthritis which includes JAK/STAT, MAPK, and NF-kB signaling pathways, and several allopathic inhibitors (tofacitinib and baricitinib) have been reported to target the components of these cascades and have received approval for RA treatment. However, the prolonged use of these COX inhibitors and other allopathic drugs can pose serious health challenges due to their significant side effects. Therefore, searching for a more effective and side effect-free treatment for rheumatoid arthritis has unveiled phytochemicals as both productive and promising. Their therapeutic ability helps develop potent and safe drugs targeting immune-inflammatory diseases including RA. Various scientific databases were used for searching articles such as NCBI, SpringerLink, BioMed Central, ResearchGate, Google Scholar, Scopus, Nature, Wiley Online Library, and ScienceDirect. This review lists various phytochemicals and discusses their potential molecular targets in RA treatment, as demonstrated by various in vitro, in vivo (pre-clinical), and clinical studies. Several pre-clinical and clinical studies suggest that various phytochemicals can be an alternative promising intervention for attenuating and managing inflammation-associated pathogenesis of rheumatoid arthritis.

Screening of Diagnostic Biomarkers and Immune Infiltration Characteristics Linking Rheumatoid Arthritis and Rosacea Based on Bioinformatics Analysis

Introduction

Both rheumatoid arthritis (RA) and rosacea represent common chronic systemic autoimmune conditions. Recent research indicates a heightened RA risk among individuals with rosacea. However, the molecular mechanisms linking these diseases remain largely unknown. This study aims to uncover shared molecular regulatory networks and immune cell infiltration patterns in both rosacea and RA.

Methods

The gene expression profiles of RA (GSE12021, GSE55457), and the rosacea gene expression profile (GSE6591), were downloaded from Gene Expression Omnibus (GEO) databases, and obtained to screen differentially expressed genes (DEGs) by using "limma" package in R software. Various analyses including GO, KEGG, protein-protein interaction (PPI) network, and weighted gene co-expression network analyses (WGCNA) were conducted to explore potential biological functions and signaling pathways. CIBERSORT was used to assess the abundance of immune cells. Pearson coefficients were used to calculate the correlations between overlapped genes and the leukocyte gene signature matrix. Flow cytometry (FCM) analysis confirmed the most abundant immune cells detected in rheumatoid arthritis and rosacea. Receiver operator characteristic (ROC) analysis, enzyme-linked immunosorbent assay (ELISA), and qRT-PCR were used to confirm biomarkers and functions.

Results

Two hundred seventy-seven co-expressed DEGs were identified from these datasets. Functional enrichment analysis indicated that these DEGs were associated with immune processes and chemokine-mediated signaling pathways. Fourteen and 17 hub genes overlapped between cytoHubba and WGCNA were identified in RA and rosacea, respectively. Macrophages and dendritic cells were RA and rosacea's most abundant immune cells, respectively. The ROC curves demonstrated potential diagnostic values of CXCL10 and CCL27, showing higher levels in the serum of patients with RA or rosacea, and suggesting possible regulation in the densities and functions of macrophages and dendritic cells from RA and rosacea, which were validated by FCM and qRT-PCR.

Conclusion

Importantly, our findings may contribute to the scientific basis for biomarkers and therapeutic targets for patients with RA and rosacea in the future.

Association between rheumatoid arthritis and serum vitamin C levels in Adults: Based on the National health and Nutrition Examination survey database

This study attempted to investigate relationship between rheumatoid arthritis and serum vitamin C levels using data from National Health and Nutrition Examination Survey (NHANES). The NHANES database aims to collect health, nutrition, biological, and behavioral data from a nationally representative sample of the population. This study utilizes NHANES data from three cycles: 2003-2004, 2005-2006, and 2017-2018, extracting data on the prevalence of rheumatoid arthritis and serum vitamin C levels. A generalized linear model is used to evaluate the association between the two. A total of 12,665 participants were included in the final analysis. Serum vitamin C levels were significantly higher in the non-rheumatoid arthritis group compared to the rheumatoid arthritis group (0.63 vs. 0.59, P = 0.042). Generalized linear model analysis showed that higher serum vitamin C levels were associated with a decreased risk of rheumatoid arthritis (OR = 0.62, 95 %CI: 0.40-0.98, P = 0.034). Stratified analysis revealed a significant interaction between non-hypertensive individuals and rheumatoid arthritis with serum vitamin C levels (P < 0.05). After adjusting for confounding factors, serum vitamin C levels remained significantly associated with rheumatoid arthritis in all models (P < 0.05). Restricted cubic spline results indicated that serum vitamin C levels above 0.95 mg/dL could help prevent rheumatoid arthritis. Increasing dietary vitamin C intake through supplementation was found to raise serum vitamin C levels. There was a significant association between rheumatoid arthritis and serum vitamin C levels, indicating that high levels of serum vitamin C may be a protective factor against rheumatoid arthritis.

Efficacy, safety and immunogenicity of the biosimilar etanercept compared to the reference formulation original etanercept in patients with rheumatoid arthritis: An open-label, randomized, comparative, multicenter study

BACKGROUND

The objective of this phase III clinical randomized trial was to establish the therapeutic equivalence of biosimilar etanercept (bio-etanercept) with original etanercept (O-etanercept) for patients diagnosed with rheumatoid arthritis.

METHODS

The study (NCT04079374) enrolled patients with moderate to high disease activity rheumatoid arthritis. Enrolled patients were randomized 1:1 into 2 treatment groups, 1 receiving bio-etanercept (study drug) and the other receiving O-etanercept (comparator) at a dose of 25mg twice weekly, for 24 weeks. The primary efficacy endpoint was the number of patients with an ACR20 response after 24 weeks of treatment. Safety (adverse reaction/adverse event) and immunogenicity of both drugs were evaluated.

RESULTS

Among 156 patients (79 in the bio-etanercept group and 77 in the O-etanercept group) who completed 24-week treatment and 4-week follow-up, 82.3% (65 patients) and 90.9% (70 patients) achieved an ACR20 response in the bio-etanercept and O-etanercept groups, respectively. There was no significant difference between the 2 groups (P = .16). No significant differences in the occurrence of adverse reactions/adverse events were found between the 2 groups regardless of severity (P = .63 for mild, P = .43 for moderate and P > .99 for severe). The development of antibodies in the bio-etanercept group was observed in 4 (5.1%; visit 6), 4 (5.0%; visit 9), and 3 (3.8%; visit 11) patients, and in 5 (6.4%), 5 (6.5%), and 3 (4.1%) patients in the O-etanercept group. The differences between the 2 groups were not significant (P > .99).

CONCLUSIONS

This study showed that bio-etanercept was equivalent to the reference formulation.

Coordinating Macrophage Targeting and Antioxidation by Injectable Nanocomposite Hydrogel for Enhanced Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA), an immune-mediated inflammatory disease, is characterized by a large number of infiltrated immune cells and abnormally elevated reactive oxygen species (ROS) in the joint. Various proinflammatory factors secreted by macrophages and the elevated ROS by inflammatory cells are deeply intertwined and together contribute to joint damage. Targeted and sustained anti-inflammation and antioxidation strategies are needed for RA treatment. To alleviate the oxidative stress and target the source of inflammatory cytokines, we developed a thermosensitive injectable hydrogel, Dex-DSLip/Cro@Gel, to coordinate the targeted anti-inflammatory and antioxidation effects. Within the injectable gel, dexamethasone (Dex)-loaded liposomes (Dex-DSLip), modified with dextran sulfate (DS), target macrophages via interaction with scavenger receptor A (SR-A). Simultaneously, crocin I (Cro) is loaded in the gel with a high loading capacity. The porous structure of Dex-DSLip/Cro@Gel successfully prolongs the retention time of both drugs and sustains the release of Dex and Cro. After intra-articular injection of Dex-DSLip/Cro@Gel in RA rats, the expression of inflammatory factors in the ankle joints was significantly reduced. Joint erythema and bone erosion were markedly alleviated. Through the synergistic effects of Dex and Cro, Dex-DSLip/Cro@Gel demonstrates targeted anti-inflammatory and antioxidation effects as well as mitigated bone erosion and long-term therapeutic effects for RA. This thermosensitive injectable nanocomposite hydrogel synergizes anti-inflammatory and antioxidation effects and targets the microenvironment in the joint, offering a new approach for RA treatment.

[ZIF-8@Pt Nanozyme Used for Scavenging Reactive Oxygen Species in the Treatment of Rheumatoid Arthritis]

Objective

To formulate a ZIF-8 nano mimetic enzyme conjugated with platinum metal (ZIF-8@Pt) that can scavenge reactive oxygen species (ROS) and to explore its potential applications in the treatment of rheumatoid arthritis (RA).

Methods

The ZIF-8@Pt nanozyme was created by in situ reduction. Characterization of the nanozyme was then performed and its ability to mimic enzymes was investigated. Cell experiments were conducted using RAW264.7 cells, which were divided into three groups, including the untreated group (UT), the positive control group receiving lipopolysaccharide (LPS), which was designated as the LPS group, and the ZIF-8@Pt group receiving ZIF-8@Pt and LPS treatment. The cell experiments were conducted to evaluate the anti-inflammatory properties of ZIF-8@Pt through scavenging intracellular ROS. On the other hand, a collagen-induced arthritis (CIA) model was induced in rats. Similar to the group designations in the cell experiments, the rats were assigned to three groups, including a healthy control group (the UT group), a positive control group receiving a local injection of PBS solution in the knee joint, which was referred to as the control group, and a treatment group receiving a local injection of ZIF-8@Pt solution in the knee joint, which was referred to as the ZIF-8@Pt group. General evaluation, imaging observation, assessment of inflammatory factors, and pathological evaluation were performed to assess the therapeutic efficacy of ZIF-8@Pt against RA.

Results

The in vitro experiment revealed significant difference in the levels of intracellular ROS and LPS-induced M1-type macrophage polarization between the LPS group and the ZIF-8@Pt group (P<0.05). The in vivo experiment showed that significant difference in the levels of inflammatory factors, including interleukin-1β (IL-1β), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), and arginase-1 (Arg-1) in the knee joints of the CIA rats between the LPS group and the ZIF-8@Pt group (P<0.05). Comparing the findings for the ZIF-8@Pt group and the control group, pathology assessment revealed that ZIF-8@Pt reduced local hypoxia and suppressed osteoclastic activity, neovascularization, and M1-type macrophage polarization (P<0.05).

Conclusion

The ZIF-8@Pt enzyme mimetic inhibits macrophage inflammatory polarization by ROS scavenging, thereby improving inflammation in RA. Furthermore, the ZIF-8@Pt nanozyme improves the hypoxic environment and inhibits angiogenesis and bone destruction, demonstrating promising therapeutic efficacy for RA.

Ferroptosis and endoplasmic reticulum stress in rheumatoid arthritis

Ferroptosis is an iron-dependent mode of cell death distinct from apoptosis and necrosis. Its mechanisms mainly involve disordered iron metabolism, lipid peroxide deposition, and an imbalance of the antioxidant system. The endoplasmic reticulum is an organelle responsible for protein folding, lipid metabolism, and Ca2+ regulation in cells. It can be induced to undergo endoplasmic reticulum stress in response to inflammation, oxidative stress, and hypoxia, thereby regulating intracellular environmental homeostasis through unfolded protein responses. It has been reported that ferroptosis and endoplasmic reticulum stress (ERS) have an interaction pathway and jointly regulate cell survival and death. Both have also been reported separately in rheumatoid arthritis (RA) mechanism studies. However, studies on the correlation between ferroptosis and ERS in RA have not been reported so far. Therefore, this paper reviews the current status of studies and the potential correlation between ferroptosis and ERS in RA, aiming to provide a research reference for developing treatments for RA.

Deciphering the role of ferroptosis in rheumatoid arthritis: Synovial transcriptome analysis and immune infiltration correlation

The pathogenesis of rheumatoid arthritis (RA) remains elusive. The initiation of joint degeneration is characterized by the loss of self-tolerance in peripheral joints. Ferroptosis, a form of regulated cell death, holds significant importance in the pathophysiology of inflammatory arthritis, primarily due to iron accumulation and the subsequent lipid peroxidation. The present study investigated the association between synovial lesions and ferroptosis-related genes using previously published data from rheumatoid patients. Transcriptome differential gene analysis was employed to identify ferroptosis-related differentially expressed genes (FRDEGs). To validate FRDEGs and screen hub genes, we used weighted gene co-expression network analysis (WGCNA) and receiver operating characteristic (ROC) curves. Subsequently, immune infiltration analysis and single cell analysis were conducted to investigate the relationship between various synovial tissues cells and FRDEGs. The findings were further confirmed through reverse transcription-quantitative polymerase chain reaction (RT-qPCR), immunohistochemical staining, and immunofluorescence techniques. Upon intersecting DEGs with ferroptosis-related genes, we identified a total of 104 FRDEGs. Through the construction of a protein-protein interaction (PPI) network, we pinpointed the top 20 most highly concentrated genes as hub genes. Subsequent analyses using ROC curve and WGCNA validated eight FRDEGs: TIMP1, JUN, EGFR, SREBF1, ADIPOQ, SCD, AR, and FABP4. Immuno-infiltration analyses revealed significant infiltration of immune cell in RA synovial tissues and their correlations with the FRDEGs. Notably, TIMP1 demonstrated a positive correlation with various immune cell populations. Single-cell sequencing date of RA synovial tissue revealed predominant expression of TIMP1 is in fibroblasts. RT-qPCR, immunohistochemistry, and immunofluorescence analyses confirmed significant upregulation of TIMP1 at both mRNA and protein levels in RA synovial tissues and fibroblast-like synoviocytes (FLS). The findings provide novel insights into pathophysiology of peripheral immune tolerance deficiency in RA. The dysregulation of TIMP1, a gene associated with ferroptosis, was significantly observed in RA patients, suggesting its potential as a promising biomarker and therapeutic target.

The role of anti-citrullinated protein antibody in pathogenesis of RA

Rheumatoid arthritis (RA) is a common autoimmune rheumatic disease that causes chronic synovitis, bone erosion, and joint destruction. The autoantigens in RA include a wide array of posttranslational modified proteins, such as citrullinated proteins catalyzed by peptidyl arginine deiminase4a. Pathogenic anti-citrullinated protein antibodies (ACPAs) directed against a variety of citrullinated epitopes are abundant both in plasma and synovial fluid of RA patients. ACPAs play an important role in the onset and progression of RA. Intensive and extensive studies are being conducted to unveil the mechanisms of RA pathogenesis and evaluate the efficacy of some investigative drugs. In this review, we focus on the formation and pathogenic function of ACPAs.

Experiences of Chinese Rheumatoid Arthritis Patients Who Chose Western Medicine, Traditional Chinese Medicine, and a Combination of Treatments: A Study Based on Interviews and Thematic Analysis

Background

This qualitative study, part of a prospective mixed-methods research, aimed to gain insights into the medical experiences and disease perceptions of Chinese patients living with rheumatoid arthritis (RA). Specifically, the study examined how RA patients' perceptions of their disease were influenced by the diagnosis and treatment they receive.

Methods

RA patients undergoing treatment were invited to participate in this qualitative study. Face-to-face semi-structured interviews were conducted among 18 patients, and the collected data were analyzed using thematic analysis.

Results

The 18 participants in this study had a mean (SD) age of 58, a median disease duration of 6.5 years, and a predominance of female subjects (17 out of 18). The qualitative analysis identified two themes with six sub-themes: 1. Patients' experiences of treatment: discovery of the disease, misdiagnosis and mistreatment, and patients' treatment choices; 2. Feelings about the disease: psychological impact, reflections on the disease, and expectations of treatment.

Conclusion

This study provides valuable perspectives and data to enhance the understanding of the relationship between patients' illness perceptions and their healthcare choices.

Building polarization into protein-inhibitor binding dynamics in rational drug design for rheumatoid arthritis

Standard force field-based simulations to accomplish structure-based evaluations of lead molecules is a powerful tool. Combining protein fragmentation into tractable sub-systems with continuum solvation method is envisaged to enable quantum mechanics-based electronic structure calculations of macromolecules in their realistic environment. This along with incorporation of many-body polarization effect in molecular dynamics simulations may augment an accurate description of electrostatics of protein-inhibitor systems for effective drug design. Rheumatoid arthritis (RA) is a complex autoimmune disorder plagued by the ceiling effect of current targeted therapies, encouraging identification of new druggable targets and corresponding drug design to tackle the refractory form of disease. In this study, polarization-inclusive force field approach has been used to model protein solvation and ligand binding for 'Mitogen-activated protein kinase' (MAP3K8), a regulatory node of notable pharmacological relevance in RA synovial biology. For MAP3K8 inhibitors belonging to different scaffold series, the calculations illustrated differential electrostatic contribution to their relative binding affinities and successfully explained examples from available structure-activity relationship studies. Results from this study exemplified i) the advantage of this approach in reliably ranking inhibitors having close nanomolar range activities for the same target; and ii) its prospective application in lead molecule identification aiding drug discovery efforts in RA.Communicated by Ramaswamy H. Sarma.

Crucial Roles of RSAD2/viperin in Immunomodulation, Mitochondrial Metabolism and Autoimmune Diseases

Autoimmune diseases are typically characterized by aberrant activation of immune system that leads to excessive inflammatory reactions and tissue damage. Nevertheless, precise targeted and efficient therapies are limited. Thus, studies into novel therapeutic targets for the management of autoimmune diseases are urgently needed. Radical S-adenosyl methionine domain-containing 2 (RSAD2) is an interferon-stimulated gene (ISG) renowned for the antiviral properties of the protein it encodes, named viperin. An increasing number of studies have underscored the new roles of RSAD2/viperin in immunomodulation and mitochondrial metabolism. Previous studies have shown that there is a complex interplay between RSAD2/vipeirn and mitochondria and that binding of the iron-sulfur (Fe-S) cluster is necessary for the involvement of viperin in mitochondrial metabolism. Viperin influences the proliferation and development of immune cells as well as inflammation via different signaling pathways. However, the function of RSAD2/viperin varies in different studies and a comprehensive overview of this emerging theme is lacking. This review will describe the characteristics of RSAD2/viperin, decipher its function in immunometabolic processes, and clarify the crosstalk between RSAD2/viperin and mitochondria. Furthermore, we emphasize the crucial roles of RSAD2 in autoimmune diseases and its potential application value.

GSK2334470 attenuates high salt-exacerbated rheumatoid arthritis progression by restoring Th17/Treg homeostasis

High salt (HS) consumption is a risk factor for multiple autoimmune disorders via disturbing immune homeostasis. Nevertheless, the exact mechanisms by which HS exacerbates rheumatoid arthritis (RA) pathogenesis remain poorly defined. Herein, we found that heightened phosphorylation of PDPK1 and SGK1 upon HS exposure attenuated FoxO1 expression to enhance the glycolytic capacity of CD4 T cells, resulting in strengthened Th17 but compromised Treg program. GSK2334470 (GSK), a dual PDPK1/SGK1 inhibitor, effectively mitigated the HS-induced enhancement in glycolytic capacity and the overproduction of IL-17A. Therefore, administration of GSK markedly alleviated HS-exacerbated RA progression in collagen-induced arthritis (CIA) model. Collectively, our data indicate that HS consumption subverts Th17/Treg homeostasis through the PDPK1-SGK1-FoxO1 signaling, while GSK could be a viable drug against RA progression in clinical settings.

Deep learning-based classification of erosion, synovitis and osteitis in hand MRI of patients with inflammatory arthritis

OBJECTIVES

To train, test and validate the performance of a convolutional neural network (CNN)-based approach for the automated assessment of bone erosions, osteitis and synovitis in hand MRI of patients with inflammatory arthritis.

METHODS

Hand MRIs (coronal T1-weighted, T2-weighted fat-suppressed, T1-weighted fat-suppressed contrast-enhanced) of rheumatoid arthritis (RA) and psoriatic arthritis (PsA) patients from the rheumatology department of the Erlangen University Hospital were assessed by two expert rheumatologists using the Outcome Measures in Rheumatology-validated RA MRI Scoring System and PsA MRI Scoring System scores and were used to train, validate and test CNNs to automatically score erosions, osteitis and synovitis. Scoring performance was compared with human annotations in terms of macro-area under the receiver operating characteristic curve (AUC) and balanced accuracy using fivefold cross-validation. Validation was performed on an independent dataset of MRIs from a second patient cohort.

RESULTS

In total, 211 MRIs from 112 patients (14 906 region of interests (ROIs)) were included for training/internal validation using cross-validation and 220 MRIs from 75 patients (11 040 ROIs) for external validation of the networks. The networks achieved high mean (SD) macro-AUC of 92%±1% for erosions, 91%±2% for osteitis and 85%±2% for synovitis. Compared with human annotation, CNNs achieved a high mean Spearman correlation for erosions (90±2%), osteitis (78±8%) and synovitis (69±7%), which remained consistent in the validation dataset.

CONCLUSIONS

We developed a CNN-based automated scoring system that allowed a rapid grading of erosions, osteitis and synovitis with good diagnostic accuracy and using less MRI sequences compared with conventional scoring. This CNN-based approach may help develop standardised cost-efficient and time-efficient assessments of hand MRIs for patients with arthritis.

Dynamic Release from Acetalated Dextran Nanoparticles for Precision Therapy of Inflammation

Polymer-based nanoparticles (NPs) that react to altered physiological characteristics have the potential to enhance the delivery of therapeutics to a specific area. These materials can utilize biochemical triggers, such as low pH, which is prone to happen locally in an inflammatory microenvironment due to increased cellular activity. This reduced pH is neutralized when inflammation subsides. For precise delivery of therapeutics to match this dynamic reaction, drug delivery systems (DDS) need to not only release the drug (ON) but also stop the release (OFF) autonomously. In this study, we use a systematic approach to optimize the composition of acetalated dextran (AcDex) NPs to start (ON) and stop (OFF) releasing model cargo, depending on local pH changes. By mixing ratios of AcDex polymers (mixed NPs), we achieved a highly sensitive material that was able to rapidly release cargo when going from pH 7.4 to pH 6.0. At the same time, the mix also offered a stable composition that enabled a rapid ON/OFF/ON/OFF switching within this narrow pH range in only 90 min. These mixed NPs were also sensitive to biological pH changes, with increased release in the presence of inflammatory cells compared to healthy cells. Such precise and controllable characteristics of a DDS position mixed NPs as a potential treatment platform to inhibit disease flare-ups, reducing both systemic and local side effects to offer a superior treatment option for inflammation compared to conventional systems.

Celastrol Regulates the Hsp90-NLRP3 Interaction to Alleviate Rheumatoid Arthritis

Previous studies have verified that celastrol (Cel) protects against rheumatoid arthritis (RA) by inhibiting the NLRP3 inflammasome signaling pathway, but the molecular mechanism by which Cel regulates NLRP3 has not been clarified. This study explored the specific mechanisms of Cel in vitro and in vivo. A type II collagen-induced arthritis (CIA) mouse model was used to study the antiarthritic activity of Cel; analysis of paw swelling, determination of the arthritis score, and pathological examinations were performed. The antiproliferative and antimigratory effects of Cel on TNF-α induced fibroblast-like synoviocytes (FLSs) were tested. Proinflammatory factors were evaluated using enzyme-linked immunosorbent assay (ELISA). The expression of NF-κB/NLRP3 pathway components was determined by western blotting and immunofluorescence staining in vitro and in vivo. The putative binding sites between Cel and Hsp90 were predicted through molecular docking, and the binding interactions were determined using the Octet RED96 system and coimmunoprecipitation. Cel decreased arthritis severity and reduced TNF-α-induced FLSs migration and proliferation. Additionally, Cel inhibited NF-κB/NLRP3 signaling pathway activation, reactive oxygen species (ROS) production, and proinflammatory cytokine secretion. Furthermore, Cel interacted directly with Hsp90 and blocked the interaction between Hsp90 and NLRP3 in FLSs. Our findings revealed that Cel regulates NLRP3 inflammasome signaling pathways both in vivo and in vitro. These effects are induced through FLSs inhibition of the proliferation and migration by blocking the interaction between Hsp90 and NLRP3.

The Lung in Rheumatoid Arthritis-Friend or Enemy?

Rheumatoid arthritis (RA) is a chronic autoimmune condition frequently found in rheumatological patients that sometimes raises diagnosis and management problems. The pathogenesis of the disease is complex and involves the activation of many cells and intracellular signaling pathways, ultimately leading to the activation of the innate and acquired immune system and producing extensive tissue damage. Along with joint involvement, RA can have numerous extra-articular manifestations (EAMs), among which lung damage, especially interstitial lung disease (ILD), negatively influences the evolution and survival of these patients. Although there are more and more RA-ILD cases, the pathogenesis is incompletely understood. In terms of genetic predisposition, external environmental factors act and subsequently determine the activation of immune system cells such as macrophages, neutrophils, B and T lymphocytes, fibroblasts, and dendritic cells. These, in turn, show the ability to secrete molecules with a proinflammatory role (cytokines, chemokines, growth factors) that will produce important visceral injuries, including pulmonary changes. Currently, there is new evidence that supports the initiation of the systemic immune response at the level of pulmonary mucosa where the citrullination process occurs, whereby the autoantibodies subsequently migrate from the lung to the synovial membrane. The aim of this paper is to provide current data regarding the pathogenesis of RA-associated ILD, starting from environmental triggers and reaching the cellular, humoral, and molecular changes involved in the onset of the disease.

Gut Subdoligranulum variabile ameliorates rheumatoid arthritis by promoting TSG-6 synthesis from joint cells

Background

A burgeoning body of evidence has substantiated the association between alterations in the composition of the gut microbiota and rheumatoid arthritis (RA). Nevertheless, our understanding of the intricate mechanisms underpinning this association is limited.

Methods

To investigate whether the gut microbiota influences the pathogenesis of RA through metabolism or immunity, we performed rigorous synthesis analyses using aggregated statistics from published genome-wide association studies (GWAS) using two-sample Mendelian randomization (MR) and mediated MR techniques, including two-step MR and multivariate MR analyses. Subsequently, we conducted in vitro cellular validation of the analyzed Microbial-Cytokine-RA pathway. We determined the optimal culture conditions through co-culture experiments involving concentration and time. Cell Counting Kit-8 (CCK-8) assays were employed to assess cellular viability, and enzyme-linked immunosorbent assays (ELISA) were performed to assess tumor necrosis factor-inducible gene 6 protein (TSG-6) and tumor necrosis factor-α (TNF-α) levels.

Results

Our univariable MR results confirmed 15 microbial traits, 7 metabolites and 2 cytokines that may be causally associated with RA (P FDR < 0.05). Mediation analysis revealed that microbial traits influence the risk of RA through metabolite or cytokine (proportion mediated: 7.75% - 58.22%). In vitro experiments demonstrated that TSG-6 was highly expressed in the Subdoligranulum variabile treatment group and was correlated with decreased RA severity (reduced TNF-α expression). Silencing the TSG-6 gene significantly increased TNF-α expression, regardless of treatment with S. variabile. Additionally, S. variabile-secreted exosomes exhibited the same effect.

Conclusion

The results of this study suggest that S. variabile has the potential to promote TSG-6 secretion, thereby reducing RA inflammation.

Vitamin C alleviates rheumatoid arthritis by modulating gut microbiota balance

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

Sinomenine treats rheumatoid arthritis by inhibiting MMP9 and inflammatory cytokines expression: bioinformatics analysis and experimental validation

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease marked by inflammatory cell infiltration and joint damage. The Chinese government has approved the prescription medication sinomenine (SIN), an effective anti-inflammation drug, for treating RA. This study evaluated the possible anti-inflammatory actions of SIN in RA based on bioinformatics analysis and experiments. Six microarray datasets were acquired from the gene expression omnibus (GEO) database. We used R software to identify differentially expressed genes (DEGs) and perform function evaluations. The CIBERSORT was used to calculate the abundance of 22 infiltrating immune cells. The weighted gene co-expression network analysis (WGCNA) was used to discover genes associated with M1 macrophages. Four public datasets were used to predict the genes of SIN. Following that, function enrichment analysis for hub genes was performed. The cytoHubba and least absolute shrinkage and selection operator (LASSO) were employed to select hub genes, and their diagnostic effectiveness was predicted using the receiver operator characteristic (ROC) curve. Molecular docking was undertaken to confirm the affinity between the SIN and hub gene. Furthermore, the therapeutic efficacy of SIN was validated in LPS-induced RAW264.7 cells line using Western blot and Enzyme-linked immunosorbent assay (ELISA). The matrix metalloproteinase 9 (MMP9) was identified as the hub M1 macrophages-related biomarker in RA using bioinformatic analysis and molecular docking. Our study indicated that MMP9 took part in IL-17 and TNF signaling pathways. Furthermore, we found that SIN suppresses the MMP9 protein overexpression and pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the LPS-induced RAW264.7 cell line. In conclusion, our work sheds new light on the pathophysiology of RA and identifies MMP9 as a possible RA key gene. In conclusion, the above findings demonstrate that SIN, from an emerging research perspective, might be a potential cost-effective anti-inflammatory medication for treating RA.

Dual drug nanoparticle synergistically induced apoptosis, suppressed inflammation, and protected autophagic response in rheumatoid arthritis fibroblast-like synoviocytes

Rheumatoid arthritis (RA) is a chronic immune-mediated joint inflammatory disorder associated with aberrant activation of fibroblast-like synoviocytes (FLS). Recently, FLS gained importance due to its crucial role in RA pathogenesis, and thus, targeting FLS is suggested as an attractive treatment strategy for RA. FLS-targeted approaches may be combined with disease-modifying antirheumatic drugs (DMARDs) and natural phytochemicals to improve efficacy in RA control and negate immunosuppression. In this study, we assessed the therapeutic effectiveness of DD NP HG in primary RA-FLS cells isolated from the synovial tissue of FCA-induced RA rats. We observed that DD NP HG had good biosafety for healthy FLS cells and, at higher concentrations, a mild inhibitory effect on RA-FLS. The combination therapy (DD NP HG) of MTX NP and PEITC NE in RA-FLS showed a higher rate of apoptosis with significantly reduced LPS-induced expression of pro-inflammatory cytokines (TNF-α, IL-17A, and IL-6) in arthritic FLS. Further, the gene expression studies showed that DD NP HG significantly down-regulated the mRNA expression of IL-1β, RANKL, NFATc1, DKK1, Bcl-xl, Mcl-1, Atg12, and ULK1, and up-regulated the mRNA expression of OPG, PUMA, NOXA and SQSTM1 in LPS-stimulated RA-FLS cells. Collectively, our results demonstrated that DD NP HG significantly inhibited the RA-FLS proliferation via inducing apoptosis, down-regulating pro-inflammatory cytokines, and further enhancing the expression of genes associated with bone destruction in RA pathogenesis. A nanotechnology approach is a promising strategy for the co-delivery of dual drugs to regulate the RA-FLS function and achieve synergistic treatment of RA.

Pathophysiology, diagnosis, and herbal medicine-based therapeutic implication of rheumatoid arthritis: an overview

Rheumatoid arthritis (RA) stands as an autoimmune disorder characterized by chronic joint inflammation, resulting in profound physiological alterations within the body. Affecting approximately 0.4-1.3% of the global population, this condition poses significant challenges as current therapeutic approaches primarily offer symptomatic relief, with the prospect of complete recovery remaining elusive. This review delves into the contemporary advancements in understanding the pathophysiology, diagnosis, and the therapeutic potential of herbal medicine in managing RA. Notably, early diagnosis during the initial stages emerges as the pivotal determinant for successful recovery post-treatment. Utilizing tools such as Magnetic Resonance Imaging (MRI), anti-citrullinated peptide antibody markers, and radiography proves crucial in pinpointing the diagnosis of RA with precision. Unveiling the intricate pathophysiological mechanisms of RA has paved the way for innovative therapeutic interventions, incorporating plant extracts and isolated phytoconstituents. In the realm of pharmacological therapy for RA, specific disease-modifying antirheumatic drugs have showcased commendable efficacy. However, this conventional approach is not without its drawbacks, as it is often associated with various side effects. The integration of methodological strategies, encompassing both pharmacological and plant-based herbal therapies, presents a promising avenue for achieving substantive recovery. This integrated approach not only addresses the symptoms but also strives to tackle the underlying causes of RA, fostering a more comprehensive and sustainable path towards healing.

Inflammatory macrophage reprogramming strategy of fucoidan microneedles-mediated ROS-responsive polymers for rheumatoid arthritis

During the pathogenesis of rheumatoid arthritis, inflammatory cells usually infiltrate synovial tissues, notably, M1-type macrophages, whose redox imbalance leads to the degradation of joint structures and deterioration of function. Natural active products play a vital role in immune modulation and antioxidants. In this study, we constructed a ROS-responsive nanoparticle called FTL@SIN, which consists of fucoidan (Fuc) and luteolin (Lut) connected by a ROS-responsive bond, Thioketal (TK), and encapsulated with an anti-rheumatic drug, Sinomenine (SIN), for synergistic anti-inflammatory effects. The FTL@SIN is then dispersed in high molecular weight Fuc-fabricated dissolvable microneedles (FTL@SIN MNs) for local administration. Therapy of FTL@SIN MNs afforded a significant decrease in macrophage inflammation while decreasing key pro-inflammatory cytokines and repolarizing M1 type to M2 type, thereby ameliorating synovial inflammation, and promoting cartilage repair. Additionally, our investigations have revealed that Fucoidan (Fuc) demonstrates synergistic effects, exhibiting superior mechanical strength and enhanced physical stability when compared to microneedles formulated solely with hyaluronic acid. This study combines nanomedicine with traditional Chinese medicine, a novel drug delivery strategy that presents a promising avenue for therapeutic intervention in rheumatoid arthritis.

A responsive nanoplatform with molecular and structural imaging capacity for assisting accurate diagnosis of early rheumatoid arthritis

Accurate early diagnosis of rheumatoid arthritis (RA) and prompt implementation of appropriate treatment approaches are crucial. In the clinic, magnetic resonance imaging (MRI) has been recommended for implementation to aid in the precise and early diagnosis of RA. However, they are still limited by issues regarding specificity and their ability to capture comprehensive information about the pathological features. Herein, a responsive multifunctional nanoplatform with targeting capabilities (hMnO2-IR@BSA-PEG-FA) is constructed through integrating a RA microenvironment-responsive MRI contrast agent with activatable near-infrared (NIR) fluorescence imaging, aiming to simultaneously acquire comprehensive pathological features of RA from both structural and molecular imaging perspectives. Moreover, taking advantage of its targeting function to synovial microphages, hMnO2-IR@BSA-PEG-FA demonstrated a remarkable capability to accumulate effectively at the synovial tissue. Additionally, hMnO2 responded to the mild acidity and reactive oxygen species (ROS) in the RA microenvironment, leading to the controlled release of Mn2+ ions and IR780, which separately caused special MRI contrast enhancement of synovial tissues and sensitively demonstrated the presence of ROS and weakly acid microenvironment by NIR imaging. Consequently, hMnO2-IR@BSA-PEG-FA is expected to serve as a promising nanoplatform, offering valuable assistance in the precise diagnosis of early-stage RA by specially providing comprehensive information about the pathological features.

Advances in local drug delivery technologies for improved rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by an inflammatory microenvironment and cartilage erosion within the joint cavity. Currently, antirheumatic agents yield significant outcomes in RA treatment. However, their systemic administration is limited by inadequate drug retention in lesion areas and non-specific tissue distribution, reducing efficacy and increasing risks such as infection due to systemic immunosuppression. Development in local drug delivery technologies, such as nanostructure-based and scaffold-assisted delivery platforms, facilitate enhanced drug accumulation at the target site, controlled drug release, extended duration of the drug action, reduced both dosage and administration frequency, and ultimately improve therapeutic outcomes with minimized damage to healthy tissues. In this review, we introduced pathogenesis and clinically used therapeutic agents for RA, comprehensively summarized locally administered nanostructure-based and scaffold-assisted drug delivery systems, aiming at improving the therapeutic efficiency of RA by alleviating the inflammatory response, preventing bone erosion and promoting cartilage regeneration. In addition, the challenges and future prospects of local delivery for clinical translation in RA are discussed.

Intradermal acupuncture in the treatment of rheumatoid arthritis with liver and kidney deficiency syndrome - A sham-controlled, randomized, clinical trial

BACKGROUND AND PURPOSE

Rheumatoid arthritis (RA) is called "immortal cancer", and it affects the quality of life, disability rate and even the survival of patients. This study aimed to observe the clinical efficacy, and adverse reactions of intradermal acupuncture (IA) in the treatment of RA patients with liver and kidney deficiency syndrome.

MATERIALS AND METHODS

132 RA patients were split into an IA group and a sham IA group at a 1:1 ratio. Both groups were assessed before and after the intervention with the assessments: a traditional Chinese medicine (TCM) syndrome evaluation, the Health Assessment Questionnaire (HAQ), the Disease Activity Score 28 (DAS28) and serum C-reactive protein (CRP).

RESULTS

There was a statistically significant difference in TCM syndrome evaluation, HAQ, DAS28, and CRP between both groups before and after treatment (P < 0.01). The improvement of TCM syndrome evaluation (95% CI [1.14(0.38-1.89)]; P = 0.001), HAQ (95% CI [2.00(1.00-3.00)]; P = 0.003), and DAS28 (95% CI [0.11(0.02-0.20)]; P = 0.021) in the IA group was more obvious than that in the sham IA group (P < 0.05), except for CRP (95% CI [0.50(- 2.09 to 7.08)], P = 0.786). The difference in CRP outcome changes between the two groups was not statistically significant (P > 0.05). Both groups had comparable results in the implementation of RA in the upper and lower extremity acupoints and did not differ due to different sites (IA group: P = 0.852; sham IA group: P = 0.861). The comparison of effective rate of the upper limb as well as that of the lower limb was statistically significant (P = 0.001). Besides, patients reported no adverse effects.

CONCLUSION

The IA intervention was associated with a promising effect on the decrease in RA disease activity and delayed overall disease progression.

Treatment Patterns of Biologic Disease-Modifying Antirheumatic Drugs and Janus Kinase Inhibitors in Patients with Rheumatoid Arthritis in Japan: A Claims-Based Cohort Study

BACKGROUND

Reports on treatment patterns of biologic disease-modifying antirheumatic drugs (bDMARDs)/Janus kinase inhibitors (JAKi) for rheumatoid arthritis (RA) in clinical practice are still sparse in Japan, especially in combination with conventional synthetic DMARDs (csDMARDs).

OBJECTIVES

The aim of this study was to investigate treatment patterns of bDMARD/JAKi in the treatment of RA in real-world clinical practice in Japan.

METHOD

A retrospective cohort study was conducted using the Japanese Medical Data Vision health claims database. The inclusion criteria required a recorded diagnosis of RA, defined by ICD-10 codes, in patients aged 18 years and older on the index date. We analyzed 39,903 RA patients treated with DMARDs from 2008 to 2020.

RESULTS

Among analyzed subjects, 10,196 patients (25.6%) were prescribed bDMARDs/JAKi in combination with csDMARDs, and 3067 patients (7.7%) were prescribed these drugs without csDMARDs. Among the bDMARDs/JAKi, tumor necrosis factor inhibitors (TNFi) were the most commonly prescribed DMARD overall, and also the most common first-line therapy, accounting for 60.0% or 45.5% of patients prescribed these drugs in combination with or without csDMARDs, respectively. Switching, temporary discontinuation (restarting with the same agents), and discontinuation of bDMARDs/JAKi were observed in 3150 (30.9%), 1379 (13.5%), and 2025 (19.9%) patients with csDMARDs, and in 849 (27.7%), 513 (16.7%), and 833 (27.2%) patients without csDMARDs, respectively.

CONCLUSIONS

Real-world treatment trajectories of bDMARDs/JAKi with and without csDMARDs was analyzed in RA patients in Japan between 2008 and 2020. TNFi were the predominant first-line therapy, and likely to be switched to different classes. Understanding the current treatment patterns, including discontinuation, is important to find an optimal treatment strategy for RA patients.

Human MHC Class II and Invariant Chain Knock-in Mice Mimic Rheumatoid Arthritis with Allele Restriction in Immune Response and Arthritis Association

Transgenic mice expressing human major histocompatibility complex class II (MHCII) risk alleles are widely used in autoimmune disease research, but limitations arise due to non-physiologic expression. To address this, physiologically relevant mouse models are established via knock-in technology to explore the role of MHCII in diseases like rheumatoid arthritis. The gene sequences encoding the ectodomains are replaced with the human DRB1*04:01 and 04:02 alleles, DRA, and CD74 (invariant chain) in C57BL/6N mice. The collagen type II (Col2a1) gene is modified to mimic human COL2. Importantly, DRB1*04:01 knock-in mice display physiologic expression of human MHCII also on thymic epithelial cells, in contrast to DRB1*04:01 transgenic mice. Humanization of the invariant chain enhances MHCII expression on thymic epithelial cells, increases mature B cell numbers in spleen, and improves antigen presentation. To validate its functionality, the collagen-induced arthritis (CIA) model is used, where DRB1*04:01 expression led to a higher susceptibility to arthritis, as compared with mice expressing DRB1*04:02. In addition, the humanized T cell epitope on COL2 allows autoreactive T cell-mediated arthritis development. In conclusion, the humanized knock-in mouse faithfully expresses MHCII, confirming the DRB1*04:01 alleles role in rheumatoid arthritis and being also useful for studying MHCII-associated diseases.

Free Fatty Acid 4 Receptor Activation Attenuates Collagen-Induced Arthritis by Rebalancing Th1/Th17 and Treg Cells

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

Identification of FOXO1 as a geroprotector in human synovium through single-nucleus transcriptomic profiling

The synovium, a thin layer of tissue that is adjacent to the joints and secretes synovial fluid, undergoes changes in aging that contribute to intense shoulder pain and other joint diseases. However, the mechanism underlying human synovial aging remains poorly characterized. Here, we generated a comprehensive transcriptomic profile of synovial cells present in the subacromial synovium from young and aged individuals. By delineating aging-related transcriptomic changes across different cell types and their associated regulatory networks, we identified two subsets of mesenchymal stromal cells (MSCs) in human synovium, which are lining and sublining MSCs, and found that angiogenesis and fibrosis-associated genes were upregulated whereas genes associated with cell adhesion and cartilage development were downregulated in aged MSCs. Moreover, the specific cell-cell communications in aged synovium mirrors that of aging-related inflammation and tissue remodeling, including vascular hyperplasia and tissue fibrosis. In particular, we identified forkhead box O1 (FOXO1) as one of the major regulons for aging differentially expressed genes (DEGs) in synovial MSCs, and validated its downregulation in both lining and sublining MSC populations of the aged synovium. In human FOXO1-depleted MSCs derived from human embryonic stem cells, we recapitulated the senescent phenotype observed in the subacromial synovium of aged donors. These data indicate an important role of FOXO1 in the regulation of human synovial aging. Overall, our study improves our understanding of synovial aging during joint degeneration, thereby informing the development of novel intervention strategies aimed at rejuvenating the aged joint.

The Association between Genetics and Response to Treatment with Biologics in Patients with Psoriasis, Psoriatic Arthritis, Rheumatoid Arthritis, and Inflammatory Bowel Diseases: A Systematic Review and Meta-Analysis

Genetic biomarkers could potentially lower the risk of treatment failure in chronic inflammatory diseases (CID) like psoriasis, psoriatic arthritis (PsA), rheumatoid arthritis (RA), and inflammatory bowel disease (IBD). We performed a systematic review and meta-analysis assessing the association between single nucleotide polymorphisms (SNPs) and response to biologics. Odds ratio (OR) with 95% confidence interval (CI) meta-analyses were performed. In total, 185 studies examining 62,774 individuals were included. For the diseases combined, the minor allele of MYD88 (rs7744) was associated with good response to TNFi (OR: 1.24 [1.02-1.51], 6 studies, 3158 patients with psoriasis or RA) and the minor alleles of NLRP3 (rs4612666) (OR: 0.71 [0.58-0.87], 5 studies, 3819 patients with RA or IBD), TNF-308 (rs1800629) (OR: 0.71 [0.55-0.92], 25 studies, 4341 patients with psoriasis, RA, or IBD), FCGR3A (rs396991) (OR: 0.77 [0.65-0.93], 18 studies, 2562 patients with psoriasis, PsA, RA, or IBD), and TNF-238 (rs361525) (OR: 0.57 [0.34-0.96]), 7 studies, 818 patients with psoriasis, RA, or IBD) were associated with poor response to TNFi together or infliximab alone. Genetic variants in TNFα, NLRP3, MYD88, and FcRγ genes are associated with response to TNFi across several inflammatory diseases. Most other genetic variants associated with response were observed in a few studies, and further validation is needed.

Therapeutic effect of Periploca forrestii on collagen-induced arthritis in rats through JAK2/Nf-κB pathway

Background

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects the body. Periploca forrestii was a miao ethnic drug in China that was used to treat arthritis for hundreds of years. But, the therapeutic mechanism is so far unknown. Therefore, the chemical component and effect of Periploca forrestii on arthritis in rats were studied using HPLC-QTOF MS, micro-CT, and other experiments in this paper.

Method

Male Sprague-Dawley rats were used to assess the in vivo activity. HPLC QTOF-MS was used to analyze the chemical profile of the P. forrestii (PF). Bovine type II collagen and Complete Freund's Adjuvant were used to stimulate and construct the collagen-induced arthritis (CIA) model. Three dosages of PF (100 mg/kg, 200 mg/kg, 400 mg/kg) were used to evaluate in vivo activity. Methotrexate was used as the positive drug. H/E staining and micro-CT methods were used to monitor the pathological changes of CIA rats. ELISA method was used to assess the serum level of immune- and inflammation-related cytokines. Immunohistochemical experiments were used to test the gene expression in JAK and Nf-κB pathways.

Results

42 compounds were identified from PF. PF administration lowered the increased spleen index compared with that of control and MTX groups, and partially restored body weight, reduced paw swelling, and arthritis score compared with the model group. Macroscopic assessment indicated inflamed paw with significant swelling in the model group, while the extent of inflammation and swelling was attenuated by both MTX and PF. H/E staining experiments demonstrated that pathological changes of synovial cells and infiltration of inflammatory cells were observed in the model group. In contrast, the MTX and PF treatment partially reversed these pathological changes. Micro-CT examination showed severe injuries and scars caused by inflammation for the model group, and in the high-dosage group (400 mg/kg) the inflammation-caused injuries and scars were dramatically ameliorated. Mechanism study showed that PF restored Nf-κB phosphorylation and JAK2 expression compared with the model group.

Conclusion

P. forrestii possesses a potent effect on CIA rats. Nf-κB and JAK2 pathways are involved in its protective effect on CIA.

Assessing the effects of distinct biologic therapies on rheumatoid arthritis pain by nociceptive, neuropathic and nociplastic pain components: a randomised feasibility study

BACKGROUND

Pain management is a major unmet need in people with rheumatoid arthritis (RA). Although many patients are treated with disease modifying anti-rheumatic drugs (DMARDS), including biologic therapies, many people with RA continue to experience significant pain. We aimed to determine whether performing a comprehensive pain evaluation is feasible in people with active RA receiving conventional DMARDs and biologic therapies.

METHODS

The BIORA-PAIN feasibility study was an open-label, randomised trial, which recruited participants suitable for treatment with biologic therapy. The primary feasibility outcomes were recruitment, randomisation and retention of eligible participants. All participants underwent pain assessment for nociceptive, neuropathic and nociplastic pain during the 12-month study period, with quarterly assessments for VAS (Visual Analogue Scale) pain, painDETECT and QST (quantitative sensory testing). This trial was registered in clinicaltrials.gov NCT04255134.

RESULTS

During the study period, 93 participants were screened of whom 25 were eligible: 13 were randomised to adalimumab and 12 to abatacept. Participant recruitment was lower than expected due to the COVID-19 pandemic. Pain assessments were practical in the clinical trial setting. An improvement was observed for VAS pain from baseline over 12 months, with a mean (SEM) of 3.7 (0.82) in the abatacept group and 2.3 (1.1) in the adalimumab group. There was a reduction in painDETECT and improvement in QST measures in both treatment groups during the study. Participant feedback included that some of the questionnaire-based pain assessments were lengthy and overlapped in their content. Adverse events were similar in both groups. There was one death due to COVID-19.

CONCLUSIONS

This first-ever feasibility study of a randomised controlled trial assessing distinct modalities of pain in RA met its progression criteria. This study demonstrates that it is feasible to recruit and assess participants with active RA for specific modalities of pain, including nociceptive, neuropathic and nociplastic elements. Our data suggests that it is possible to stratify people for RA based on pain features. The differences in pain outcomes between abatacept and adalimumab treated groups warrant further investigation.

TRIAL REGISTRATION

NCT04255134, Registered on Feb 5, 2020.

Abelmoschus manihot (L.) medik. seeds alleviate rheumatoid arthritis by modulating JAK2/STAT3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Abelmoschus manihot (L.) Medik. Seeds (AMS, སོ་མ་ར་ཛ།), a Tibetan classical herbal in China, are rich in flavonoids and phenolic glycosides compounds, such as quercetin and its derivatives. Moreover, it has been found to possess anti-rheumatoid arthritis (RA) effects. Nonetheless, its anti-RA mechanism is yet unknown.

AIM OF THE STUDY

This research aimed to examine the active ingredients of AMS as well as potential pharmacological mechanisms in AMS on RA.

MATERIALS AND METHODS

The ultra-performance liquid chromatography-electrospray ionization-tandem multistage mass spectrometry (UPLC-ESI-IT-MSn) technique was used to determine the primary chemical components of AMS that were responsible for the therapeutic effects on RA. In addition, 36 male Wistar rats weighing between 200 and 220 g were classified at random into six groups [normal control group, collagen-induced arthritis (CIA) group, methotrexate group (positive control, 1.05 mg/kg), AMS group (157.5 mg/kg, 315 mg/kg, 630 mg/kg)]. CIA rats were given AMS extract by intragastric administration for 28 days, and their ankles were photographed to observe the degree of swelling. Further, the arthritis score, paws swelling, and body weight changes of CIA rats were determined to observe whether AMS has any effect on RA, and synovial and cartilage tissue injuries were identified by histopathology. Besides, the levels of IL-10, TNF-α, IL-1β, INF-γ, etc. in serum were estimated by ELISA. Western blot experiments were implemented to identify the expression levels of protein involved in the JAK2/STAT3 signaling pathway in the CIA rats' synovial tissues. Moreover, the mechanisms and targets of active ingredient therapy of AMS for RA were predicted using network pharmacology and then verified using molecular docking.

RESULT

In the present study, 12 compounds were detected by UPLC-ESI-IT-MSn, such as quercetin and its derivative which could be potential active ingredients that contribute to the anti-RA properties of AMS. Our in vivo studies on CIA rats revealed that an AMS-H dose of 630 mg/kg significantly improved joint damage while decreasing the arthritic index and paw swelling. Furthermore, AMS inhibited the INF-γ, IL-6, IL-17, IL-1β, and TNF-α, levels while upregulating the expression of anti-inflammatory cytokines IL-10 and IL-4 in serum. Besides, AMS inhibited the protein Bcl-2/Bax, STAT3, and JAK2 levels, and promoted the expression of Caspase3, SOCS1, and SOCS3 in the JAK2/STAT3 pathway. Additionally, the JAK/STAT signaling pathway was found to perform a remarkable function in the AMS therapy of RA as evidenced by enrichment in GO terms and KEGG pathways. Meanwhile, data from molecular docking experiments indicated that the core targets of PIK3CA, JAK2, and SRC bound stably to the active ingredients of mimuone, 4'-methoxy-bavachromanol, and quercetin.

CONCLUSION

According to these findings, the AMS could improve joint inflammation in CIA rats, and its underlying mechanism could be linked to the regulation of the JAK2/STAT3 pathway. Therefore, AMS might become a promising agent for alleviating inflammation in RA patients.

ECM-mimetic, NSAIDs loaded thermo-responsive, immunomodulatory hydrogel for rheumatoid arthritis treatment

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease, and it leads to irreversible inflammation in intra-articular joints. Current treatment approaches for RA include non-steroidal anti-inflammatory drugs (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs), corticosteroids, and biological agents. To overcome the drug-associated toxicity of conventional therapy and transdermal tissue barrier, an injectable NSAID-loaded hydrogel system was developed and explored its efficacy.

RESULTS

The surface morphology and porosity of the hydrogels indicate that they mimic the natural ECM, which is greatly beneficial for tissue healing. Further, NSAIDs, i.e., diclofenac sodium, were loaded into the hydrogel, and the in vitro drug release pattern was found to be burst release for 24 h and subsequently sustainable release of 50% drug up to 10 days. The DPPH assay revealed that the hydrogels have good radical scavenging activity. The biocompatibility study carried out by MTT assay proved good biocompatibility and anti-inflammatory activity of the hydrogels was carried out by gene expression study in RAW 264.7 cells, which indicate the downregulation of several key inflammatory genes such as COX-2, TNF-α & 18s.

CONCLUSION

In summary, the proposed ECM-mimetic, thermo-sensitive in situ hydrogels may be utilized for intra-articular inflammation modulation and can be beneficial by reducing the frequency of medication and providing optimum lubrication at intra-articular joints.

Discovery of novel diaryl substituted isoquinolin-1(2H)-one derivatives as hypoxia-inducible factor-1 signaling inhibitors for the treatment of rheumatoid arthritis

Since synovial hypoxic microenvironment significantly promotes the pathological progress of rheumatoid arthritis (RA), hypoxia-inducible factor 1 (HIF-1) has been emerged as a promising target for the development of novel therapeutic agents for RA treatment. In this study, we designed and synthesized a series of diaryl substituted isoquinolin-1(2H)-one derivatives as HIF-1 signaling inhibitors using scaffold-hopping strategy. By modifying the substituents on N-atom and 6-position of isoquinolin-1-one, we discovered compound 17q with the most potent activities against HIF-1 (IC50 = 0.55 μM) in a hypoxia-reactive element (HRE) luciferase reporter assay. Further pharmacological studies revealed that 17q concentration-dependently blocked hypoxia-induced HIF-1α protein accumulation, reduced inflammation response, inhibited cellular invasiveness and promoted VHL-dependent HIF-1α degradation in human RA synovial cell line. Moreover, 17q improved the pathological injury of ankle joints, decreased angiogenesis and attenuated inflammation response in the adjuvant-induced arthritis (AIA) rat model, indicating the promising therapeutic potential of compound 17q as an effective HIF-1 inhibitor for RA therapy.

A reconfigurable integrated smart device for real-time monitoring and synergistic treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a global autoimmune disease that requires long-term management. Ambulatory monitoring and treatment of RA favors remission and rehabilitation. Here, we developed a wearable reconfigurable integrated smart device (ISD) for real-time inflammatory monitoring and synergistic therapy of RA. The device establishes an electrical-coupling and substance delivery interfaces with the skin through template-free conductive polymer microneedles that exhibit high capacitance, low impedance, and appropriate mechanical properties. The reconfigurable electronics drive the microneedle-skin interfaces to monitor tissue impedance and on-demand drug delivery. Studies in vitro demonstrated the anti-inflammatory effect of electrical stimulation on macrophages and revealed the molecular mechanism. In a rodent model, impedance sensing was validated to hint inflammation condition and facilitate diagnosis through machine learning model. The outcome of subsequent synergistic therapy showed notable relief of symptoms, elimination of synovial inflammation, and avoidance of bone destruction.

Lymphocyte subset phenotyping for the prediction of progression to inflammatory arthritis in anti-citrullinated-peptide antibody-positive at-risk individuals

OBJECTIVES

Inflammatory arthritis (IA) is considered the last stage of a disease continuum, where features of systemic autoimmunity can appear years before clinical synovitis. Time to progression to IA varies considerably between at-risk individuals, therefore the identification of biomarkers predictive of progression is of major importance. We previously reported on the value of three CD4+T cell subsets as biomarkers of progression. Here, we aim to establish the value of 18 lymphocyte subsets (LS) for predicting progression to IA.

METHODS

Participants were recruited based on a new musculoskeletal complaint and being positive for anti-citrullinated-peptide antibody. Progression (over 10 years) was defined as the development of clinical synovitis. LS analysis was performed for lymphocyte lineages, naive/memory subsets, inflammation-related cells (IRC) and regulatory cells (Treg/B-reg). Modelling used logistic/Cox regressions.

RESULTS

Of 210 patients included, 93 (44%) progressed to IA, 41/93 (44%) within 12 months (rapid progressors). A total of 5/18 LS were associated with progression [Treg/CD4-naïve/IRC (adjusted P < 0.0001), CD8 (P = 0.021), B-reg (P = 0.015)] and three trends (NK-cells/memory-B-cells/plasmablasts). Unsupervised hierarchical clustering using these eight subsets segregated three clusters of patients, one cluster being enriched [63/109(58%)] and one poor [10/45(22%)] in progressors. Combining all clinical and LS variables, forward logistic regression predicted progression with accuracy = 85.7% and AUC = 0.911, selecting smoking/rheumatoid-factor/HLA-shared-epitope/tender-joint-count-78 and Treg/CD4-naive/CD8/NK-cells/B-reg/plasmablasts. To predict rapid progression, a Cox regression was performed resulting in a model combining smoking/rheumatoid factor and IRC/CD4-naive/Treg/NK-cells/CD8+T cells (AUC = 0.794).

CONCLUSION

Overall, progression was predicted by specific LS, suggesting potential triggers for events leading to the development of IA, while rapid progression was associated with a different set of subsets.

Mechanistic insight on the role of iRhom2-TNF-α-BAFF signaling pathway in various autoimmune disorders

iRhom2 is a crucial cofactor involved in upregulation of TNF receptors (TNFRs) and the pro-inflammatory cytokine tumor necrosis factor (TNF-) from the cell surface by ADAM17. Tumor necrosis factor- α converting enzyme (TACE) is another name given to ADAM17. Many membrane attached biologically active molecules are cleaved by this enzyme which includes TNFRs and the pro-inflammatory cytokine tumor necrosis factor- α. The TNF receptors are of two types TNFR1 and TNFR2. iRhom2 belongs to the pseudo-protease class of rhomboid family, its abundance is observed in the immune cells. Biological activity of ADAM17 is affected in multiple levels by the iRhom2. ADAM17 is trafficked into the Golgi apparatus by the action of iRhom2, where it gets matured proteolytically and is stimulated to perform its function on the cell surface. This process of activation of ADAM17 results in the protection of the organism from the cascade of inflammatory reactions, as this activation blocks the TNF- α mediated secretion responsible for inflammatory responses produced. Present paper illustrates about the iRhom2-TNF-α-BAFF signaling pathway and its correlation with several autoimmune disorders such as Rheumatoid Arthritis, Systemic Lupus Erythematosus, Hemophilia Arthropathy, Alzheimer's disease and Tylosis with esophageal cancer etc.

Extracellular microRNAs induce dendritic cell-dependent joint inflammation and potentiate osteoclast differentiation via TLR7/8 engagement

OBJECTIVES

Monocyte-derived dendritic cells (DCs) are key players in the induction of inflammation, autoreactive T cell activation and loss of tolerance in rheumatoid arthritis (RA), but the precise mechanisms underlying their activation remain elusive. Here, we hypothesized that extracellular microRNAs released in RA synovial fluids may represent a novel, physiological stimulus triggering unwanted immune response via TLR8-expressing DC stimulation.

METHODS

Human monocyte-derived DCs were stimulated with a mixture of GU-rich miRNAs upregulated in RA tissues and released in synovial fluids (Ex-miRNAs). Activation of DCs was assessed in terms of NF-κB activation by Western blot, cytokine production by ELISA, T cell proliferation and polarization by allogeneic mixed lymphocyte reaction. DC differentiation into osteoclasts was evaluated in terms of tartrate-resistant acid phosphatase production and formation of resorption pits in dentine slices. Induction of joint inflammation in vivo was evaluated using a murine model of DC-induced arthritis. TLR7/8 involvement was assessed by specific inhibitors.

RESULTS

Ex-miRNAs activate DCs to secrete TNFα, induce joint inflammation, start an early autoimmune response and potentiate the differentiation of DCs into aggressive osteoclasts.

CONCLUSIONS

This work represents a proof of concept that the pool of extracellular miRNAs overexpressed in RA joints can act as a physiological activator of inflammation via the stimulation of TLR8 expressed by human DCs, which in turn exert arthritogenic functions. In this scenario, pharmacological inhibition of TLR8 might offer a new therapeutic option to reduce inflammation and osteoclast-mediated bone destruction in RA.

Integrative Analyses of Bulk and Single-Cell RNA Seq Identified the Shared Genes in Acute Respiratory Distress Syndrome and Rheumatoid Arthritis

Acute respiratory distress syndrome (ARDS), a progressive status of acute lung injury (ALI), is primarily caused by an immune-mediated inflammatory disorder, which can be an acute pulmonary complication of rheumatoid arthritis (RA). As a chronic inflammatory disease regulated by the immune system, RA is closely associated with the occurrence and progression of respiratory diseases. However, it remains elusive whether there are shared genes between the molecular mechanisms underlying RA and ARDS. The objective of this study is to identify potential shared genes for further clinical drug discovery through integrated analysis of bulk RNA sequencing datasets obtained from the Gene Expression Omnibus database, employing differentially expressed genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA). The hub genes were identified through the intersection of common DEGs and WGCNA-derived genes. The Random Forest (RF) and least absolute shrinkage and selection operator (LASSO) algorithms were subsequently employed to identify key shared target genes associated with two diseases. Additionally, RA immune infiltration analysis and COVID-19 single-cell transcriptome analysis revealed the correlation between these key genes and immune cells. A total of 59 shared genes were identified from the intersection of DEGs and gene clusters obtained through WGCNA, which analyzed the integrated gene matrix of ALI/ARDS and RA. The RF and LASSO algorithms were employed to screen for target genes specific to ALI/ARDS and RA, respectively. The final set of overlapping genes (FCMR, ADAM28, HK3, GRB10, UBE2J1, HPSE, DDX24, BATF, and CST7) all exhibited a strong predictive effect with an area under the curve (AUC) value greater than 0.8. Then, the immune infiltration analysis revealed a strong correlation between UBE2J1 and plasma cells in RA. Furthermore, scRNA-seq analysis demonstrated differential expression of these nine target genes primarily in T cells and NK cells, with CST7 showing a significant positive correlation specifically with NK cells. Beyond that, transcriptome sequencing was conducted on lung tissue collected from ALI mice, confirming the substantial differential expression of FCMR, HK3, UBE2J1, and BATF. This study provides unprecedented evidence linking the pathophysiological mechanisms of ALI/ARDS and RA to immune regulation, which offers novel understanding for future clinical treatment and experimental research.