Pathogenesis Of Rheumatoid Arthritis Research Articles

Machine learning and weighted gene co-expression network analysis identify a three-gene signature to diagnose rheumatoid arthritis.

Rheumatoid arthritis (RA) is a systemic immune-related disease characterized by synovial inflammation and destruction of joint cartilage. The pathogenesis of RA remains unclear, and diagnostic markers with high sensitivity and specificity are needed urgently. This study aims to identify potential biomarkers in the synovium for diagnosing RA and to investigate their association with immune infiltration. We downloaded four datasets containing 51 RA and 36 healthy synovium samples from the Gene Expression Omnibus database. Differentially expressed genes were identified using R. Then, various enrichment analyses were conducted. Subsequently, weighted gene co-expression network analysis (WGCNA), random forest (RF), support vector machine-recursive feature elimination (SVM-RFE), and least absolute shrinkage and selection operator (LASSO) were used to identify the hub genes for RA diagnosis. Receiver operating characteristic curves and nomogram models were used to validate the specificity and sensitivity of hub genes. Additionally, we analyzed the infiltration levels of 28 immune cells in the expression profile and their relationship with the hub genes using single-sample gene set enrichment analysis. Three hub genes, namely, ribonucleotide reductase regulatory subunit M2 (RRM2), DLG-associated protein 5 (DLGAP5), and kinesin family member 11 (KIF11), were identified through WGCNA, LASSO, SVM-RFE, and RF algorithms. These hub genes correlated strongly with T cells, natural killer cells, and macrophage cells as indicated by immune cell infiltration analysis. RRM2, DLGAP5, and KIF11 could serve as potential diagnostic indicators and treatment targets for RA. The infiltration of immune cells offers additional insights into the underlying mechanisms involved in the progression of RA.

The Role of α-Enolase on the Production of Interleukin (IL)-32 in Con A-Mediated Inflammation and Rheumatoid Arthritis (RA).

Interleukin (IL)-32 is produced by T lymphocytes, natural killer cells, monocytes, and epithelial cells. IL-32 induces the production of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, IL-1β, IL-6, and IL-8, and IL-32 expression is highly increased in rheumatoid arthritis (RA) patients. Enolase-1 (ENO1) is a glycolytic enzyme and the stimulation of ENO1 induces high levels of pro-inflammatory cytokines in concanavalin A (Con A)-activated peripheral blood mononuclear cells (PBMCs) and macrophages in RA patients. In addition, there are many reports that anti-ENO1 antibody is correlated with the disease progression of RA. It implies that ENO1 could regulate IL-32 production during inflammation related to the pathogenesis of RA. Therefore, we investigated the role of ENO1 in IL-32 production using Con A-activated PBMCs and RA PBMCs. IL-32 expression is increased by ENO1 stimulation using real-time PCR and ELISA. In addition, we confirmed that IL-32 production was decreased in Con A-activated PBMCs and RA PBMCs pre-treated with NF-κB or p38 MAPK pathway inhibitors. Taken together, these results suggest that ENO1 plays an important role in inflammation through the induction of IL-32 production by the activation of the NF-κB and p38 MAPK pathways.

The Role of Alarmins in the Pathogenesis of Rheumatoid Arthritis, Osteoarthritis, and Psoriasis.

Alarmins are immune-activating factors released after cellular injury or death. By secreting alarmins, cells can interact with immune cells and induce a variety of inflammatory responses. The broad family of alarmins involves several members, such as high-mobility group box 1, S100 proteins, interleukin-33, and heat shock proteins, among others. Studies have found that the concentrations and expression profiles of alarmins are altered in immune-mediated diseases. Furthermore, they are involved in the pathogenesis of inflammatory conditions. The aim of this narrative review is to present the current evidence on the role of alarmins in rheumatoid arthritis, osteoarthritis, and psoriasis. We discuss their potential involvement in mechanisms underlying the progression of these diseases and whether they could become therapeutic targets. Moreover, we summarize the impact of pharmacological agents used in the treatment of these diseases on the expression of alarmins.

CCR9+CD4+ T cells are associated with disease activity in patients with rheumatoid arthritis.

An increase in CD4+ T cells in the synovium is closely linked to the pathogenesis of rheumatoid arthritis (RA). We aimed to identify the possible causes of the elevated CD4+ T cell levels and to explore the factors influencing disease activity in RA. Fifty-five RA patients, including 28 with active RA (ARA), 27 with inactive RA, and 22 healthy controls, were recruited for this study. The proportion of CCR9+CD4+ T cells and the expression of chemokine receptor 9 (CCR9) on CD4+ T cells were analyzed by flow cytometry. Enzyme-linked immunosorbent assay and chemiluminescent immunoassay were used to evaluate interleukin (IL)-17A and IL-6 levels, respectively. The proportion of CCR9+CD4+ T cells and the expression of CCR9 on CD4+ T cells increased significantly in peripheral blood (PB) and synovial fluid (SF) in ARA compared to those in inactive RA. Furthermore, SF contained more CCR9+CD4+ T cells, IL-6, and IL-17A than PB in RA patients. Moreover, CD4+ T cells in the PB of patients with RA, especially ARA, expressed more CCR9 and secreted more IL-6 and IL-17A after activation. Here, we also demonstrated that both the percentage of CCR9+ cells in CD4+ T cells and the expression of CCR9 on circulating CD4+ T cells were positively correlated with erythrocyte sedimentation rate, hypersensitive C-reactive protein, rheumatoid factor, and anti-cyclic citrullinated peptide antibody. CCR9+CD4+ T cells are elevated in PB and SF, and are associated with disease activity in patients with RA.

Unveiling the Nexus: Cellular Metabolomics Unravels the Impact of Estrogen on Nicotinamide Metabolism in Mitigating Rheumatoid Arthritis Pathogenesis.

Rheumatoid arthritis (RA) is a metabolic joint disorder influenced by hormonal regulation, notably estrogen, which plays a cytoprotective role against inflammation. While estrogen's impact on RA pathogenesis has been studied, the altered metabolite expression under estrogen's influence remains unexplored. This study investigated the changes in the metabolome of synovial fibroblasts isolated from RA patients under 17β-estradiol (E2) using the liquid chromatography with tandem mass spectrometry (LC-MS/MS) approach followed by multivariate and biological pathway analysis along with in vitro validation. Results identified 3624 m/z, among which eight metabolites were significant (p < 0.05). Nicotinate and nicotinamide metabolism was found to be highly correlated with the treatment of E2, with metabolites NAD+ and 1-methynicotinamide (1-MNA) upregulated by E2 induction in RA-FLS. PharmMapper analysis identified potential gene targets of 1-MNA, which were further matched with RA gene targets, and thus, STAT1, MAPK14, MMP3, and MMP9 were concluded to be the common targets. E2 treatment affected the expression of these gene targets and ameliorated the development of oxidative stress associated with RA inflammation, which can be attributed to increased concentration of 1-MNA. Thus, an LC-MS/MS-based metabolomics study revealed the prominent role of estrogen in preventing inflammatory progression in RA by altering metabolite concentration, which can support its therapeutic capacity in remitting RA.

Functional Significance of miR-4693-5p in Targeting HIF1α and Its Link to Rheumatoid Arthritis Pathogenesis.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that causes joint inflammation and destruction with an unknown origin. Our study aims to elucidate the molecular mechanism behind HIF1α overexpression in RA. Dysregulated miRNA expressions are known to influence gene behavior, thereby enhancing cell proliferation, inflammation, and resistance to apoptosis, contributing to RA development. Our earlier finding indicated that exogenous miRNA similar to miR-4693-5p may modulate RA-related targets. However, the specific role of miR-4693-5p and its targets in RA remain unexplored. In this study, we found that miR-4693-5p was significantly reduced in PBMCs of RA patients, with evidence suggesting it targets the 3' UTR of HIF1α, thereby potentially contributing to its overexpression in RA. In vitro overexpression of miR-4693-5p leads to the knockdown of HIF1α, resulting in inhibited expression of Survivin to disrupt apoptosis resistance, inflammation suppression, and a reduction in the total cellular ROS response in SW982 and RAFLS cells. The results were validated using the CIA Rat model. In conclusion, this study provides a crucial foundation for understanding the functional role of miR-4693-5p. These findings improve our understanding and provide novel insights into the molecular mechanisms underlying RA pathogenesis.

TRPM7 facilitates fibroblast-like synoviocyte proliferation, metastasis and inflammation through increasing IL-6 stability via the PKCα-HuR axis in rheumatoid arthritis

Transient receptor potential melastatin 7 (TRPM7) is a cation channel that plays a role in the progression of rheumatoid arthritis (RA), yet its involvement in synovial hyperplasia and inflammation has not been determined. We previously reported that TRPM7 affects the destruction of articular cartilage in RA. Herein, we further confirmed the involvement of TRPM7 in fibroblast-like synoviocyte (FLS) proliferation, metastasis and inflammation. We observed increased TRPM7 expression in FLSs derived from human RA patients. Pharmacological inhibition of TRPM7 protected primary RA-FLSs from proliferation, metastasis and inflammation. Furthermore, we found that TRPM7 contributes to RA-FLS proliferation, metastasis and inflammation by increasing the intracellular Ca2+ concentration. Mechanistically, the PKCα-HuR axis was demonstrated to respond to Ca2+ influx, leading to TRPM7-mediated RA-FLS proliferation, metastasis and inflammation. Moreover, HuR was shown to bind to IL-6 mRNA after nuclear translocation, which could be weakened by TRPM7 channel inhibition. Additionally, adeno-associated virus 9-mediated TRPM7 silencing is highly effective at alleviating synovial hyperplasia and inflammation in adjuvant-induced arthritis rats. In conclusion, our findings unveil a novel regulatory mechanism involved in the pathogenesis of RA and suggest that targeting TRPM7 might be a potential strategy for the prevention and treatment of RA.

Identification of PPARG as key gene to link coronary atherosclerosis disease and rheumatoid arthritis via microarray data analysis.

Inflammation is the common pathogenesis of coronary atherosclerosis disease (CAD) and rheumatoid arthritis (RA). Although it is established that RA increases the risk of CAD, the underlining mechanism remained indefinite. This study seeks to explore the molecular mechanisms of RA linked CAD and identify potential target gene for early prediction of CAD in RA patients. The study utilized five raw datasets: GSE55235, GSE55457, GSE12021 for RA patients, and GSE42148 and GSE20680 for CAD patients. Gene Set Enrichment Analysis (GSEA) was used to investigate common signaling pathways associated with RA and CAD. Then, weighted gene co-expression network analysis (WGCNA) was performed on RA and CAD training datasets to identify gene modules related to single-sample GSEA (ssGSEA) scores. Overlapping module genes and differentially expressed genes (DEGs) were considered as co-susceptible genes for both diseases. Three hub genes were screened using a protein-protein interaction (PPI) network analysis via Cytoscape plug-ins. The signaling pathways, immune infiltration, and transcription factors associated with these hub genes were analyzed to explore the underlying mechanism connecting both diseases. Immunohistochemistry and qRT-PCR were conducted to validate the expression of the key candidate gene, PPARG, in macrophages of synovial tissue and arterial walls from RA and CAD patients. The study found that Fc-gamma receptor-mediated endocytosis is a common signaling pathway for both RA and CAD. A total of 25 genes were screened by WGCNA and DEGs, which are involved in inflammation-related ligand-receptor interactions, cytoskeleton, and endocytosis signaling pathways. The principal component analysis(PCA) and support vector machine (SVM) and receiver-operator characteristic (ROC) analysis demonstrate that 25 DEGs can effectively distinguish RA and CAD groups from normal groups. Three hub genes TUBB2A, FKBP5, and PPARG were further identified by the Cytoscape software. Both FKBP5 and PPARG were downregulated in synovial tissue of RA and upregulated in the peripheral blood of CAD patients and differential mRNAexpreesion between normal and disease groups in both diseases were validated by qRT-PCR.Association of PPARG with monocyte was demonstrated across both training and validation datasets in CAD. PPARG expression is observed in control synovial epithelial cells and foamy macrophages of arterial walls, but was decreased in synovial epithelium of RA patients. Its expression in foamy macrophages of atherosclerotic vascular walls exhibits a positive correlation (r = 0.6276, p = 0.0002) with CD68. Our findings suggest that PPARG may serve as a potentially predictive marker for CAD in RA patients, which provides new insights into the molecular mechanism underling RA linked CAD.

The Role of Semaphorins in the Pathogenesis of Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases. Inflammation of the synovial fluid propagates the pathological process of angiogenesis. Semaphorins play a crucial role in the context of endothelial cell function, and their pleiotropic nature has various effects on the further development of RA. This narrative review summarises the various roles of semaphorins in the pathology of RA and whether they could play a role in developing novel RA treatment options.

A bibliometric analysis of miRNAs in rheumatoid arthritis from 2001 to 2022: Research hotspots and trends.

MicroRNAs (miRNAs) are widely recognized in the pathogenesis of autoimmune disease. As a key regulatory factor, miRNAs have introduced new biomarkers for the early diagnosis of rheumatoid arthritis (RA) and provided a favorable research direction for the development of novel therapeutic targets. This study aimed to explore the hotspots of miRNA research related to RA published from different countries, organizations, and authors. From 2001 to 2022, publications on miRNA related to RA were identified in the Web of Science database. The total and annual number of publishments, citations, impact factor, H-index, productive authors, and involved journals were collected for quantitative and qualitative comparisons. A total of 29 countries/regions in the world have participated in the research of miRNAs and RA over the past two decades, and China (760, 53.18%) and the United States (233, 16.31%) account for the majority of the total publications. China dominated in total citation (17881) and H-index (62). A total of 507 academic journals have published articles in related fields, and Frontiers in Immunology published the most (53, 3.71%). Chih-hsin Tang of the China Medical University has published the most papers (16, 1.2%). Stanczyk (2008) published the most cited article Altered expression of miRNAs in synovial fibroblasts and synovial tissue in rheumatoid arthritis in Arthritis and Rheumatism, with 660 citations. Inflammation is the high-frequency keyword outside of RA and miRNAs, and related researches have mainly focused on miR-146a and miR-155. In the past two decades, extensive and continuous research has been conducted to investigate the role of miRNAs in RA, and miRNAs are widely recognized in the pathogenesis of RA. Related research has mainly focused on miR-146a and miR-155 that have shown promising results as key factors in RA experimental models. Focusing on clinical applications and translational research may be the future research direction and hotspot based on molecular biology basic research and mechanism exploration.

Current Prospects in Rheumatoid Arthritis: Pathophysiology, Genetics, and Treatments.

An autoimmune inflammatory disease, rheumatoid arthritis (RA), predominantly affects the synovium joint lining, augmenting disability, early mortality, and socioeconomic difficulty. Therefore, current updates on pharmacological therapies are crucial for developing drugs to treat the disease at each stage. This review attempts to compile a thorough analysis of current developments in our knowledge of RA pathogenesis and disease-modifying drugs, with the aim of providing insights for next-generation RA therapeutics. According to the literature, the most successful drugs for treatment techniques described so far in this include (cs) DMARDs (sub-class of DMARDs), tsDMARDS (targeted synthetic DMARDS), and bDMARDs (biological DMARDs). However, current pharmacologic therapy (consisting of biological, conventional, and creative views of small molecule anti-rheumatic drugs that treat the disease or DMARD) remains the cornerstone of rheumatoid arthritis treatment with which significant progress toward disease remission has been accomplished. The pathobiology of RA involves cytokine messengers such as B and T-cells, and an intricate interplay of pro-inflammatory cytokines responsible for activating and developing effector cells, in turn, accountable for local disease and systemic symptoms. Despite the fact that the cause of rheumatoid arthritis is not known, new treatments have been created as a result of better approaches towards the biology of the disease. As they target molecules directly implicated in the genesis of rheumatoid arthritis, these drugs may be more effective, targeted, and less harmful in the short and long term than standard therapies.

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.

Macrophage re-programming by JAK inhibitors relies on MAFB

Monocyte-derived macrophages play a key pathogenic role in inflammatory diseases. In the case of rheumatoid arthritis (RA), the presence of specific synovial tissue-infiltrating macrophage subsets is associated with either active disease or inflammation resolution. JAK inhibitors (JAKi) are the first targeted synthetic disease-modifying antirheumatic drugs (tsDMARD) approved for treatment of RA with comparable efficacy to biologics. However, the effects of JAKi on macrophage specification and differentiation are currently unknown. We have analyzed the transcriptional and functional effects of JAKi on human peripheral blood monocyte subsets from RA patients and on the differentiation of monocyte-derived macrophages promoted by granulocyte-macrophage colony-stimulating factor (GM-CSF), a factor that drives the development and pathogenesis of RA. We now report that JAKi Upadacitinib restores the balance of peripheral blood monocyte subsets in RA patients and skewed macrophages towards the acquisition of an anti-inflammatory transcriptional and functional profile in a dose-dependent manner. Upadacitinib-treated macrophages showed a strong positive enrichment of the genes that define synovial macrophages associated to homeostasis/inflammation resolution. Specifically, Upadacitinib-treated macrophages exhibited significantly elevated expression of MAFB and MAFB-regulated genes, elevated inhibitory phosphorylation of GSK3β, and higher phagocytic activity and showed an anti-inflammatory cytokine profile upon activation by pathogenic stimuli. These outcomes were also shared by macrophages exposed to other JAKi (baricitinib, tofacitinib), but not in the presence of the TYK2 inhibitor deucravacitinib. As a whole, our results indicate that JAKi promote macrophage re-programming towards the acquisition of a more anti-inflammatory/pro-resolution profile, an effect that correlates with the ability of JAKi to enhance MAFB expression.

Postmenopausal Hormone, Hematology and Immune Modulation in Rheumatoid Arthritis Patients

Background: There is a significant hormonal shift in Postmenopausal women with low levels of estrogen and progesterone. These changes may cause the pathogenesis of autoimmune diseases, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), which exhibit a higher prevalence in women. It is crucial to determine the pathophysiology and treatment strategies and to understand the hematological, hormonal, and immunological differences in postmenopausal women with RA and SLE. This study determined the hematological, hormonal, and immunological parameters in postmenopausal RA and SLE patients. Methods: 75 postmenopausal women (aged 52-65 years) were recruited in this study, comprising 25 with RA, 25 with SLE, and 25 with healthy controls. Blood samples were collected for complete blood count (CBC), erythrocyte sedimentation rate (ESR), and serum hormone and immunoglobulin assays. Statistical analyses were conducted using Fisher's test, t-test, and ANOVA, with significance at p &lt; 0.05. Results: In postmenopausal RA and SLE patients, significant blood parameter differences were observed versus controls. RA showed elevated WBC count (18.189±0.782) and PLT (373.778±14.644), lower RBC (4.009±0.149) and Hb (11.705±0.328). SLE had lower WBC (3.016±0.595), RBC (4.293±0.112), and Hb (12.270±0.312), and higher RDW (18.830±1.719) and lower MPV (8.327±0.314). Hormonal differences included higher FSH and lower LH, estrogen, and testosterone in both groups, while RA exhibited decreased cortisol and increased progesterone, and both diseases showed elevated rheumatoid factor (RF), ESR, and immunoglobulin E (IgE). Conclusion: Postmenopausal women with RA and SLE showed distinct hematological, hormonal, and immunological profiles compared to healthy controls. This study demonstrated the complex interplay between hormonal changes and autoimmune diseases, warranting further investigation into their underlying mechanisms and potential implications for treatment strategies.

Environment and arthritis.

The present narrative review explores the multifactorial aetiology of rheumatoid arthritis (RA) and other immunemediated inflammatory disorders (IMIDs), emphasising the significant role of various environmental factors in disease development and exacerbation. Key modifiable environmental factors such as cigarette smoking and air pollution are identified as major contributors to RA. We will also focus on the influence of weather, seasonality, and particularly vitamin D levels, on RA activity, suggesting potential for seasonal management and supplementation to mitigate disease severity. The emerging role of diet and the gut microbiome in RA pathogenesis and progression is discussed as well, with dietary interventions and specific nutrients like omega-3 fatty acids offering protective benefits against inflammation. Despite the mounting evidence around these factors, further research is needed, to better understand the clinical impacts on RA, including well-designed randomised clinical trials.

Revealing the changes in signaling pathways caused by tofacitinib in patients with rheumatoid arthritis through RNA sequencing and the correlation with clinical parameters.

The current study is to accelerate the understanding of how tofacitinib works in patients with rheumatoid arthritis (RA) due to the lack of relevant information. We selected ten patients with active RA and obtained the expression profile for their peripheral blood mononuclear cells before and after the tofacitinib treatment by RNA sequencing. The gene set enrichment analysis was conducted, and the significantly enriched gene sets were identified. The hub gene highly correlated with clinical parameters in the gene set was selected. We constructed the weighted gene co-expression network, linked modules with clinical indicators, and screened hub genes. The expression of representative hub genes was validated by real-time quantitative PCR (qPCR). Gene set interferon (IFN) α and IFN β signaling was the most significantly down-regulated after tofacitinib treatment. In this gene set, genes Oas2 and Oasl showed a significant positive correlation with morning stiffness. In co-expression network, gene Vgll3 from the violet module with the highest correlation coefficient, was positively correlated with morning stiffness. Among them, Oasl and Vgll3 have shown significant down-regulation in qPCR validation. Our results highlighted the role of type I IFN, mainly including IFN α and IFN β, in the pathogenesis of RA and action for tofacitinib, and provided a new entry point for further elucidating the mechanism of morning stiffness. Key Points • Gene set IFN α and IFN β signaling was the most significantly down-regulated after tofacitinib treatment in RA patients. • Gene Oasl and Vgll3 were correlated with morning stiffness and significantly down-regulated due to the action of tofacitinib. • Type I IFN system was highlighted in the action of tofacitinib.

Infectious and Commensal Bacteria in Rheumatoid Arthritis-Role in the Outset and Progression of the Disease.

Rheumatoid arthritis (RA) is a chronic, autoimmune disease with a complex outset. Besides the genetic susceptibility in its pathogenesis, various environmental factors also participate. Of these, in recent years, there have been increasing reports of the involvement of bacteria in the disease's outset and development, especially gut microbiota and oral pathogens. Most recent reports about bacteria participation in RA pathogenesis focus on Prevotella copri and Porphyromonas gingivalis. There are also reports about the involvement of respiratory and urinary tract pathogens. The exact mechanisms leading to RA development used by bacteria are not well known; however, some mechanisms by which bacteria can interact with the immune system are known and can potentially lead to RA development. The aim of this study is to provide a comprehensive review of the potential bacteria participating in RA development and the mechanism involved in that process.

Exploring the significance of microbiota metabolites in rheumatoid arthritis: uncovering their contribution from disease development to biomarker potential.

Rheumatoid arthritis (RA) is a multifaceted autoimmune disorder characterized by chronic inflammation and joint destruction. Recent research has elucidated the intricate interplay between gut microbiota and RA pathogenesis, underscoring the role of microbiota-derived metabolites as pivotal contributors to disease development and progression. The human gut microbiota, comprising a vast array of microorganisms and their metabolic byproducts, plays a crucial role in maintaining immune homeostasis. Dysbiosis of this microbial community has been linked to numerous autoimmune disorders, including RA. Microbiota-derived metabolites, such as short-chain fatty acids (SCFAs), tryptophan derivatives, Trimethylamine-N-oxide (TMAO), bile acids, peptidoglycan, and lipopolysaccharide (LPS), exhibit immunomodulatory properties that can either exacerbate or ameliorate inflammation in RA. Mechanistically, these metabolites influence immune cell differentiation, cytokine production, and gut barrier integrity, collectively shaping the autoimmune milieu. This review highlights recent advances in understanding the intricate crosstalk between microbiota metabolites and RA pathogenesis and also discusses the potential of specific metabolites to trigger or suppress autoimmunity, shedding light on their molecular interactions with immune cells and signaling pathways. Additionally, this review explores the translational aspects of microbiota metabolites as diagnostic and prognostic tools in RA. Furthermore, the challenges and prospects of translating these findings into clinical practice are critically examined.

MicroRNA-150 Deletion Reduces the Occurrence and Severity of Rheumatoid Arthritis by Inhibiting IL-17.

Understanding the effects of epigenetic factors on the pathogenesis of rheumatoid arthritis (RA) is important for the early diagnosis and therapeutic intervention of this disease. MicroRNA-150 (miR-150) exerts an important influence on the development and function of lymphocytes. However, the role of miR-150 in the pathogenesis of RA remains unclear. To explore the role of miR-150 in the pathogenesis of RA and the related immune mechanism. In this study, we used miR-150 knock-out (miR-150KO) and created animal models of RA. Flow cytometry, immunohistochemistry, and real-time RT-PCR were employed to assess the frequency of T cell subsets and cytokines expression. Compared to wild-type (WT) mice, the onset of RA was postponed and the incidence of RA was reduced in miR-150KO mice. The expression of IL-4 and IFN-γ significantly increased while the expression of IL-17 decreased significantly in NKT and CD4+ T cells of KO mice compared to that of WT mice after RA induction. In addition, the expression of IL-4 and IFN-γ increased while the expression of IL-17 decreased significantly in the joint tissues of KO mice compared to that of WT mice. Furthermore, the mRNA expression of TNF-α and IL-17 decreased significantly in the synovial fluid cells of KO mice compared to that of the WT mice after RA induction. MiR-150 deficiency decreases the expression of IL-17 in T cells and joint tissues, and alleviates the occurrence and progression of RA in mice.

Implementing analytical quality by design in reversed phase-high performance liquid chromatography for simultaneous estimation of teriflunomide and quercetin: Applicability in dual drug loaded topical microemulsion

The current study reports the development of a novel, robust, and sensitive reversed-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous estimation of teriflunomide (TFD) and quercetin (QCN) in dual drug-loaded microemulsion. TFD and QCN have been reported to exhibit anti-inflammatory effects by targeting various inflammatory mediators involved in the pathogenesis of rheumatoid arthritis (RA). This analytical method employs a risk-based approach and follows the principles of analytical quality by design (AQbD). The study involved preliminary screening trials and systematic risk analysis to identify critical method attributes, that significantly impact the critical quality attributes (CQAs). For the optimization of method,a face centered central composite design was utilized, and 16 experimental runs were performed using design expert software version 7.0.0. Chromatographic conditions were carefully optimized using AQbD, falling within the design space and consisting of ammonium acetate buffer (pH 3.5) and acetonitrile (60:40, % v/v) with a flow rate of 1.0 mL/min. An analytical Hibar Lichospher 100 RP-18e column (250 × 4.6 mm, 5 µm) was employed, with detection wavelength of 280 nm and 367 nm for TFD and QCN, respectively. The optimized method underwent validation according to ICH guidelines and demonstrating applicability for evaluating topical microemulsion.