Understanding the dynamics: pathways involved in the pathogenesis of rheumatoid arthritis

Physiologically-based pharmacokinetic modeling to predict the exposure and provide dosage regimens of adalimumab in patients with juvenile idiopathic arthritis

BACKGROUND

Adalimumab has been approved for treating juvenile idiopathic arthritis (JIA). This study aimed to develop a physiologically-based pharmacokinetic (PBPK) model for adalimumab in JIA patients to optimize personalized treatment.

METHODS

A comprehensive literature search identified 13 clinical studies as the dataset for constructing and validating a PBPK model of adalimumab. Initially, a PBPK model for adalimumab in adults was constructed using PK-Sim and Mobi software. Subsequently, virtual pediatric populations were created by incorporating age-dependent parameters from the PK-Sim database, extending the model to JIA patients. Finally, based on the developed PBPK model for adalimumab in JIA patients, dosing regimens were evaluated for different age groups.

RESULTS

This study successfully developed and validated a PBPK model for adalimumab in both adult and pediatric populations. The model for adults accurately predicted 92.90% of the concentrations within 0.5-2 times the observed values, while the pediatric model predicted 90.62% of the concentrations within 0.5-2-fold range. For pediatric patients with JIA, age- and weight-based dosing is recommended to achieve trough concentrations comparable to those in adults.

CONCLUSION

A PBPK model for adalimumab in pediatric patients with JIA was developed, providing a basis for personalized dosing regimens in this population.

Exploring the Links Between Rheumatoid Arthritis and Pulpal-Periapical Diseases: Insights from Meta-Analysis and Two-Sample Mendelian Randomization

INTRODUCTION

Several clinical trials have investigated the relationship between rheumatoid arthritis (RA) and periapical periodontitis (AP), yielding inconsistent results. Our study aimed to synthesize clinical evidence through a meta-analysis and evaluate potential association using two-sample Mendelian randomization (TSM), which leverages genetic information for a more comprehensive perspective.

METHODS

A systematic literature search was executed across PubMed, Web of Science, Scopus, and gray literature sources until February 20, 2025. Studies comparing radiolucent periapical lesions in RA patients with controls were qualified for this meta-analysis. Genetic data from genome-wide association studies of European populations with RA were used to scrutinize the relationships with diseases of pulp and periapical tissues, particularly chronic periapical periodontitis and pulpitis, employing a TSMR approach. Our primary estimates used the radial inverse-variance weighted method complemented by a series of sensitivity analyses to ensure robustness. MR-Egger intercept, Cochran's Q statistical analysis, and I2 were used to assess the potential heterogeneity and pleiotropy.

RESULTS

The meta-analysis included 1,206 participants across 5 selected studies. No significant correlation was found between radiographically diagnosed AP and RA at the patient level (odds ratio [OR] = 1.56, 95% confidence interval [CI] = 0.91-2.67, P = .10). However, AP prevalence was 1.67 times higher in RA patients compared to healthy individuals at the tooth level (OR = 1.67, 95% CI = 1.18-2.35, P < .01). Genetically, RA was correlated with an elevated risk of diseases of pulp and periapical tissues (OR = 1.05; 95% CI = 1.03-1.07; P < .0000), chronic periapical periodontitis (OR = 1.05; 95% CI = 1.02-1.08; P = .0006) and pulpitis (OR = 1.01; 95% CI = 1.00-1.02; P = .0175), respectively.

CONCLUSIONS

Evidence from both the meta-analysis and the TSMR study moderately corroborates the associations between RA and pulpal-periapical diseases. Further research employing both human and animal models are recommended to confirm this link and elucidate potential underlying mechanisms.

Differential response of tissue engineered skeletal muscle from rheumatoid arthritis patients and healthy controls

Rheumatoid arthritis (RA) is a chronic inflammatory disease affecting articular joints and skeletal muscle. To assess the role of cytokines upon muscle strength in RA, we developed an in vitro tissue-engineered human skeletal muscle model (myobundle). Myobundles were generated using primary skeletal muscle cells from the vastus lateralis muscle of RA patients and age-matched healthy controls. RA myobundles were more sensitive to 5 ng/mL IFN-γ, exhibiting reduced contractile force and altered contraction kinetics. Addition of IL-6 with or without IFN-γ led to a small but significant increase in striated fibers. Gene sets involved in the response to hypoxia, MTOR1 signaling, and the unfolded protein response were enriched in IFN-γ-treated RA myobundles, but not IFN-γ-treated controls. Tofacitinib increased contractile force, myosin heavy chain, and PIM1 protein levels in RA myobundles treated with IFN-γ. Thus, in RA muscle, low levels of IFN-γ selectively increase gene pathways that reduce contractile force.

Roles of Immunity and Endogenous Retroelements in the Pathogenesis of Rheumatoid Arthritis and Treatment Strategies

Rheumatoid arthritis (RA) is a chronic, inflammatory, autoimmune disease that primarily affects the joints. RA usually results in synovial hyperplasia, expansion of "pannus" and destruction of cartilage. The etiology and pathogenesis of RA are not fully understood, but immunity has been shown to play an important role in the development of autoimmune diseases such as RA. In addition, endogenous retroelements, the remnants of ancient retroviruses in the human genome, are involved in cancer and/or immune disorders. As evidenced by increasing evidences that the aberrant expression of retroelements induces innate immunity, despite the fact that the expression of most retroelements has been epigenetically suppressed over a long period of evolution. With the continuous development of disease-modifying anti-rheumatic drugs (DMARDs), RA disease activity has been alleviated and improved. Unfortunately, some patients have a limited response to DMARDs, and the drugs also have the disadvantages of some side effects and high economic costs. This review summarizes the pathogenic mechanisms of RA and endogenous retroelements in autoimmunity, and concludes with a summary of treatments for RA, along with new therapeutic recommendations.

New Cardiovascular Risk Biomarkers in Rheumatoid Arthritis: Implications and Clinical Utility-A Narrative Review

Rheumatoid arthritis (RA) is a chronic autoimmune disease that not only causes joint inflammation but also significantly increases the risk of cardiovascular disease (CVD), leading to a higher morbidity and mortality. RA patients face an accelerated progression of atherosclerosis, attributed to both traditional cardiovascular risk factors and systemic inflammation. This review focuses on emerging biomarkers for cardiovascular risk assessment in RA, aiming to enhance early detection and treatment strategies. Specifically, we examine the roles of interleukin-32 (IL-32), Dickkopf-1 (DKK-1), galectin-3 (Gal-3), catestatin (CST), and fetuin-A (Fet-A) as potential markers for CVD in this patient population. IL-32, a proinflammatory cytokine, is elevated in RA patients and plays a significant role in inflammation and endothelial dysfunction, both of which contribute to atherosclerosis. DKK-1, a Wnt signaling pathway inhibitor, has been associated with both synovial inflammation and the development of atherosclerotic plaques. Elevated DKK-1 levels have been linked to an increased CV mortality and could serve as a marker for CVD progression in RA. Gal-3 is involved in immune modulation and fibrosis, with elevated levels in RA patients correlating with disease activity and cardiovascular outcomes. Catestatin, a peptide derived from chromogranin A, has protective anti-inflammatory and antioxidative properties, though its role in RA-related CVD remains under investigation. Finally, Fet-A, a glycoprotein involved in vascular calcification, shows potential as a biomarker for CV events in RA, though data on its role remain conflicting. These biomarkers provide deeper insights into the pathophysiology of RA and its cardiovascular comorbidities. Although some biomarkers show promise in improving CV risk stratification, further large-scale studies are required to validate their clinical utility. Currently, these biomarkers are in the research phase and are not yet implemented in standard care. Identifying and incorporating these biomarkers into routine clinical practice could lead to the better management of cardiovascular risk in RA patients, thus improving outcomes in this high-risk population. This review highlights the importance of continued research to establish reliable biomarkers that can aid in both diagnosis and the development of targeted therapies for cardiovascular complications in RA.

The Identification of Novel Therapeutic Biomarkers in Rheumatoid Arthritis: A Combined Bioinformatics and Integrated Multi-Omics Approach

Rheumatoid arthritis (RA) is a multifaceted autoimmune disease that is marked by a complex molecular profile influenced by an array of factors, including genetic, epigenetic, and environmental elements. Despite significant advancements in research, the precise etiology of RA remains elusive, presenting challenges in developing innovative therapeutic markers. This study takes an integrated multi-omics approach to uncover novel therapeutic markers for RA. By analyzing both transcriptomics and epigenomics datasets, we identified common gene candidates that span these two omics levels in patients diagnosed with RA. Remarkably, we discovered eighteen multi-evidence genes (MEGs) that are prevalent across transcriptomics and epigenomics, twelve of which have not been previously linked directly to RA. The bioinformatics analyses of the twelve novel MEGs revealed they are part of tightly interconnected protein-protein interaction networks directly related to RA-associated KEGG pathways and gene ontology terms. Furthermore, these novel MEGs exhibited direct interactions with miRNAs linked to RA, underscoring their critical role in the disease's pathogenicity. Overall, this comprehensive bioinformatics approach opens avenues for identifying new candidate markers for RA, empowering researchers to validate these markers efficiently through experimental studies. By advancing our understanding of RA, we can pave the way for more effective therapies and improved patient outcomes.

The Effect of the Ideal Food Pyramid on Gut Microbiota in Rheumatoid Arthritis Patients

BACKGROUND

The gut microbiota composition of rheumatoid arthritis (RA) patients differs from healthy people, and diet is among the powerful environmental determinants that can alter the microbiota. The purpose of this clinical research was to identify the effect of the Ideal Food Pyramid on gut microbiota in RA, as well as its impact on disease activity, biochemical findings and anthropometric measurements.

METHODS

Thirty patients diagnosed with RA that met the inclusion criteria were randomized into diet and control groups and followed for 12 weeks. The gut microbiota composition was indicated by 16SrRNA gene sequencing.

RESULTS

At the end of this study, Simpson, Shannon and Chao-1 indices were higher in the diet group (16) than in the control group (14), although not significantly (p > 0.05). In the diet group, at phylum levels, the abundance of Bacteroides decreased while the abundance of Firmicutes increased. At species level, Prevotella copri, Bacteroides fragilis, Prevotella stercorea, Bacteroides uniformis decreased, while Faecalibacterium prausnitzii, Roseburia faecis, Bacteroides ovatus, Akkermansia muciniphila, Coprococcus eutactus, Gemmiger formicilis, Ruminococcus bromii, and Bifidobacterium longum species increased in the diet group.

CONCLUSIONS

The Ideal Food Pyramid has been determined to have many clinical benefits for RA patients, especially for the gut microbiota.

ER O-glycosylation in synovial fibroblasts drives cartilage degradation

How arthritic synovial fibroblasts (SFs) activate cartilage ECM degradation remains unclear. GALNT enzymes initiate O-glycosylation in the Golgi; when relocated to the ER, their activity stimulates ECM degradation. Here, we show that in human rheumatoid and osteoarthritic synovial SFs, GALNTs are relocated to the ER. In an RA mouse model, GALNTs relocation occurs shortly before arthritis symptoms and abates as the animal recovers. An ER GALNTs inhibitor prevents cartilage ECM degradation in vitro and expression of this chimeric protein in SFs results in the protection of cartilage. One of the ER targets of GALNTs is the resident protein Calnexin, which is exported to the cell surface of arthritic SFs. Calnexin participates in matrix degradation by reducing ECM disulfide bonds. Anti-Calnexin antibodies block ECM degradation and protect animals from RA. In sum, ER O-glycosylation is a key switch in arthritic SFs and glycosylated surface Calnexin could be a therapeutic target.

Rheumatoid arthritis: a comprehensive overview of genetic markers, emerging therapies, and personalized medicine

Rheumatoid arthritis (RA) is a prevalent autoimmune disorder marked by chronic inflammatory arthritis and systemic effects. The etiology of RA is complex, involving genetic factors like HLA-DR4 and HLA-DR1, as well as environmental influences, particularly smoking, which heightens disease risk. Affecting approximately 1% of the global population, RA is associated with considerable morbidity and mortality, with its prevalence expected to increase due to demographic shifts, especially in certain regions. RA symptoms commonly manifest between ages 35 and 60 but can also affect children under 16 in cases of juvenile RA. Symptoms include prolonged joint stiffness, pain, fatigue, and, in advanced cases, joint deformities. Current treatment approaches involve disease-modifying antirheumatic drugs, biologics, and glucocorticoids to manage symptoms and slow disease progression, though these treatments often present limitations due to adverse effects and varied patient response. The identification of genetic markers, such as HLA-DRB1 and PTPN22, supports the growing emphasis on personalized treatment strategies that account for genetic and lifestyle factors. Non-pharmacological approaches - diet adjustments, physical activity, and stress management - are increasingly valued for their complementary role in RA management. Lifestyle interventions, including whole-food, plant-based diets and physical therapy, show promise in reducing inflammation and improving joint function. Technological advancements, like telemedicine, mobile health applications, and artificial intelligence, are enhancing RA diagnosis and treatment, making care more precise and accessible. Despite these advancements, RA remains incurable, necessitating continued research into novel therapeutic targets and approaches. A comprehensive, patient-centered approach that integrates lifestyle modifications, preventive strategies, and innovative treatments is essential for improving RA management and patient outcomes.

Therapy for the Rheumatoid Hand

Rheumatoid arthritis (RA) of the hand results in the progressive, inflammatory destruction of multiple tissue types resulting in significant functional deficit. Occupational therapy for the hand often plays a synergistic role in the improvement of health-related quality of life outcomes when employed alongside biological, disease-modifying antirheumatic drugs, and surgical regimens. Furthermore, postoperative therapeutic rehabilitation protocols in patients with RA have been shown to optimize surgical outcomes. While significant clinical data exist to support the role of occupational therapy in RA, further investigation is warranted to compare treatment protocols to further improve functional outcomes for the rheumatoid hand.

Pain in rheumatoid arthritis: Emerging role of high mobility group box 1 protein-HMGB1

Rheumatoid arthritis (RA) is a chronic inflammatory disease where pain, driven by both inflammatory and non-inflammatory processes, is a major concern for patients. This pain can persist even after joint inflammation subsides. High mobility group box-1 (HMGB1) is a non-histone-DNA binding protein located in the nucleus that plays a key role in processes such as DNA transcription, recombination, and replication. HMGB1 can be released into the extracellular space through both passive and active mechanisms. Extracellular HMGB1 contributes to synovial inflammation, bone degradation, and the production of cytokines in RA by binding to toll-like receptors (TLRs) and receptors for advanced glycation end products (RAGE). It also forms complexes with molecules like lipopolysaccharide (LPS) and IL-1β, amplifying inflammatory responses. Due to its central role in these processes, HMGB1 is considered a promising therapeutic target in RA. It also acts as a nociceptive molecule in mediating pain in diseases such as diabetes and bone cancer. In this review, we explore how HMGB1 contributes to chronic pain in RA, supported by both in vitro and in vivo models. We begin by providing an overview of the mechanisms of pain in RA, the structure of HMGB1, its release mechanisms, and the therapeutic potential of targeting HMGB1 in RA. Following this, we highlight its role in peripheral and central pain sensitization through direct activation of the TLR4/MAPK/NF-κB pathway, as well as indirectly through downstream mediators, underscoring its potential as a target for managing RA pain.

AMPD1 and MTHFR genes are not associated with calcium levels in rheumatoid arthritis patients with methotrexate therapy in Indonesia

Rheumatoid Arthritis (RA) is a chronic and progressive autoimmune disease that affects synovial tissues has greater risk of developing secondary osteoporosis (OP). In particular, polymorphisms in Adenosine Monophosphate Deaminase 1 (AMPD1) and Methylenetetrahydrofolate Reductase (MTHFR) affect the outcome of methotrexate (MTX) treatment in patients with RA. Therefore, this study aimed to determine the association of AMPD1 rs17602729, MTHFR C677T, and MTHFR A1298C polymorphisms with MTX activity in RA patients. A retrospective design was adopted to collect data from medical records and blood samples of 99 patients experiencing outpatient care at a referral hospital in Bandung. The inclusion criteria were patients diagnosed with RA, aged 18-59 years, and receiving MTX therapy for ≥ 6 months. DNA was isolated and then amplified using Polymerase Chain Reaction (PCR), and genotyping was performed with Sanger sequencing. The kinetic photometric method was used to measure the levels of calcium in the samples. The results showed that there is no significant association between the MTHFR C677T genotype variant or allele with calcium levels, as indicated by p-values of 0.177 and 0.174, respectively. The association between the MTHFR A1298C genotype variant or alleles with calcium levels was also not significant (p = 0.206 and p = 0.090, respectively). However, most patients had normal calcium levels (76 patients; 77.6%) with the MTHFR C677T genotype variant CC and the MTHFR A1298C genotype variant AA (84 patients; 84.9%). AMPD1 rs17602729 in all patients had a CC genotype with normal calcium levels. The results suggested that there was no significant association between the genetic variation of AMPD1 rs17602729, MTHFR C677T, and MTHFR A1298C with serum calcium levels in patients with RA receiving MTX therapy.

A Panoramic Review on the Management of Rheumatoid Arthritis through Herbalism

Arthritis is a chronic inflammatory condition that affects millions of individuals worldwide. The conventional treatment options for arthritis often come with limitations and potential side effects, leading to increased interest in herbal plants as alternative therapies. This article provides a comprehensive overview of the use of herbal plants in arthritis treatment, focusing on their traditional remedies, active components, mechanisms of action, and pharmaceutical approaches for enhancing their delivery. Various herbal plants, including turmeric, ginger, Boswellia, and willow bark, have shown anti-inflammatory and analgesic properties, making them valuable options for managing arthritis symptoms. The active components of these herbal plants, such as curcumin, gingerols, and boswellic acids, contribute to their therapeutic effects. To enhance the delivery of herbal medicines, pharmaceutical approaches like nanoparticle-based drug delivery systems, liposomes, polymeric nanoparticles, nanoemulsions, microneedles, and inhalation systems have been explored. These approaches aim to improve bioavailability, targeted delivery, and controlled release of herbal compounds. Safety considerations, including potential interactions with medications and the risk of allergic reactions, are also discussed. Future perspectives for this field involve conducting well-designed clinical studies, enhancing standardization and quality control measures, exploring novel drug delivery systems, and fostering collaborations between traditional medicine practitioners and healthcare professionals. Continued research and development in these areas will help unlock the full potential of herbal plants in arthritis treatment, offering personalized and effective care for affected individuals.

Musculoskeletal Organs-on-Chips: An Emerging Platform for Studying the Nanotechnology-Biology Interface

Nanotechnology-based approaches are promising for the treatment of musculoskeletal (MSK) disorders, which present significant clinical burdens and challenges, but their clinical translation requires a deep understanding of the complex interplay between nanotechnology and MSK biology. Organ-on-a-chip (OoC) systems have emerged as an innovative and versatile microphysiological platform to replicate the dynamics of tissue microenvironment for studying nanotechnology-biology interactions. This review first covers recent advances and applications of MSK OoCs and their ability to mimic the biophysical and biochemical stimuli encountered by MSK tissues. Next, by integrating nanotechnology into MSK OoCs, cellular responses and tissue behaviors may be investigated by precisely controlling and manipulating the nanoscale environment. Analysis of MSK disease mechanisms, particularly bone, joint, and muscle tissue degeneration, and drug screening and development of personalized medicine may be greatly facilitated using MSK OoCs. Finally, future challenges and directions are outlined for the field, including advanced sensing technologies, integration of immune-active components, and enhancement of biomimetic functionality. By highlighting the emerging applications of MSK OoCs, this review aims to advance the understanding of the intricate nanotechnology-MSK biology interface and its significance in MSK disease management, and the development of innovative and personalized therapeutic and interventional strategies.

Quantitative real-time PCR analysis of gut microbiota in rheumatoid arthritis patients compared to healthy controls

Rheumatoid arthritis (RA) is an autoimmune disorder with synovial inflammation of joints and extra articular manifestations. The results of recent researches consider the relationship between microbiota and the immune system as a double-edged sword. Considering that the relationship between the composition of intestinal microbiota and the immunological and clinical status of the body has been confirmed, it is very important to investigate the effect of each genus and species of bacteria on the state of the immune system. The current study was determined using 16S rRNA gene sequencing to explore the 4 selected gut microbiota from 25 people suffering from rheumatism (RA group) with a time interval of at least 3 years from the onset of the disease and 25 Healthy people by real time PCR. Gut dysbiosis in patients with rheumatoid arthritis (RA) is identified alongside key serological and clinical markers such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), immunofluorescence (IF), anti-cyclic citrullinated peptide (Anti-CCP), white blood cell count (WBC), mean corpuscular volume (MCV), aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), Platelet count (PLT), thyroid-stimulating hormone (TSH), creatinine (Cr), and hemoglobin (Hb). Additionally, data from individuals with incomplete or unverified records were excluded from the study to ensure accuracy and reliability. Bacteroides fragilis, Roseburia faecis and Fusobacterium nucleatum genera showed a much lower median in Rheumatoid arthritis patients in comparison with healthy people (P > 0.001, p = 0.002, P < 0.001 respectively). While the difference in the median of E. coli genera was not significant in the two studied groups (p = 0.31). In such a way that the change in the Gut normal flora homeostasis and the reduction of beneficial bacteria such as Bacteroides fragilis, Roseburia faecis, Fusobacterium nucleatum genera, may stimulate the immune system to initiate autoimmunity.

Angiopoietin-2, vascular endothelial growth factor family, and heparin binding endothelial growth factor are associated with subclinical atherosclerosis in rheumatoid arthritis

Introduction

Patients with RA are at a higher risk of developing CV diseases than the general population. The precise mechanisms are still unknown. We evaluated the associations between 8 plasma growth factors (GFs) (angiopoietin-2, EGF, HB-EGF, PLGF, TGF-α, VEGFa, VEGFc, and VEGFd) and subclinical arteriosclerosis in RA patients.

Materials and methods

A total of 199 patients with RA treated at the Hospital Universitari Sant Joan de Reus (Spain) between 2011 and 2015 were included in this cross-sectional study. Carotid intima media thickness (cIMT), carotid plaque presence (cPP) and pulse wave velocity (PWV) were measured. GFs were measured with Bio-Plex Pro Human Cancer Biomarker Panel 2 (Bio-Rad). Multivariate models and partial least square discriminant analysis (PLS-DA) were used for analysis (RStudio, version 4.0.1).

Results

Multivariate models showed that angiopoietin-2 was associated with cPP and PWV in the overall cohort (OR = 1.53 and β = 0.20, respectively). VEGFc (β = 0.29), VEGFa (β = 0.26) and HB-EGF (β = 0.22) were also associated with PWV. VEGFa (OR = 2.36), VEGFd (OR = 2.29), EGF (OR = 2.62), PLGF (OR = 2.54), and HB-EGF (OR = 2.24) were associated with cPP in men. According to PLS-DA, GFs were able to distinguish between patients with and without cPP in the overall cohort, male cohort, and female cohort. In women, angiopoietin-2 was associated with PWV (β = 0.18).

Conclusions

The selected GFs were closely related to atherosclerosis in patients with RA and are potential predictors of CV disease in patients with RA.

Exploration of Potential Anti-Inflammatory Cum Anti-Rheumatoid-Arthritis Phyto-Molecule Through Integrated Green Approach: Network Pharmacology, Molecular Docking, Molecular Dynamics, In-Vitro and Ex-Vivo Study

Rheumatoid arthritis (RA) and associated inflammatory complications are the most prevalent illnesses and can turn into fatal conditions if left untreated. Allopathic medicine is not satisfactory for curing RA. Scientific literature reports reveal that several phyto-compounds viz. flavonoids, saponins, and terpenoids, can heal joints and organs from auto-inflammatory rheumatoid arthritis and pain. Gene ontology, gene network analysis, molecular clustering, and literature review were used to optimise RA-specific highly expressed genes. In-silico molecular docking was performed to short-out potential phytomolecules (Neohesperidin dihydrochalcone (NHDC)) from 1000 datasets-library against RA and validate using MD simulation running at 100 ns. In-vitro anti-inflammatory assays of NHDC inhibited egg-albumin denaturation, IC50 of 47.739±0.51 μg/ml. The ex-vivo MTT assay with NHDC rendered 67.209 % inhibition at 100 μM against fd-FLS-cells. NHDC downregulated pro-inflammatory cytokine IL-17 A production by 61.11 % and 50 % at 300 and 200 μM, respectively. Thus, this Studies recommend that NHDC may be highlighted as a novel multi-target PADI4 and JAK3 inhibitor with better efficacy and minimal toxicity in RA warranted to In-Vivo and clinical investigation. The current findings have uncovered remarkable genes and signalling pathways linked to RA, which could enhance our existing comprehension of the molecular mechanisms that drive its development and progression.

Rheumatoid arthritis: a review of the key clinical features and ongoing challenges of the disease

Rheumatoid arthritis (RA) is an autoimmune inflammatory condition that primarily affects the joints and periarticular soft tissue. The development of joint swelling is traditionally regarded as the starting point of the disease. Emerging evidence indicates that RA patients often experience a preclinical stage characterized by immunological and inflammatory changes before developing the disease. The review discusses ongoing efforts to predict the transition from this preclinical phase to clinical RA and describes studies aimed at preventing the onset of RA in individuals at risk. Over the past two decades, there have been significant advancements in RA management and outcomes. An increasing number of patients can now achieve disease remission, and in some cases, this remission persists without ongoing treatment, which is effectively a cure. As new therapies and evolving scientific evidence emerge, recommendations for RA management are continuously evolving. Despite these improvements in the management of RA, many patients still do not respond to multiple conventional or more advanced therapies, including biologic and targeted synthetic disease modifying anti-rheumatic drugs, or experience disease flares when treatments are tapered or discontinued. This situation underscores the need for reliable biomarkers to guide therapy more effectively, improve personalized treatment approaches and monitoring strategies (i.e. precision medicine). In conclusion, this review provides a comprehensive overview of RA, covering new research on the 'pre-clinical' phase of the disease, as well as its epidemiology, pathogenesis, clinical manifestations, diagnosis, imaging, and management strategies. It highlights key clinical aspects of RA and addresses ongoing challenges in disease management, particularly in the areas of prevention and treatment.

Synovial Fluid Markers and Extracellular Vesicles in Rheumatoid Arthritis

In recent years, numerous potential prognostic biomarkers for rheumatoid arthritis (RA) have been investigated. Despite these advancements, clinical practice primarily relies on autoantibody tests-for rheumatoid factor (RF) and anti-citrullinated protein antibody (anti-CCP)-alongside inflammatory markers, such as the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Expanding the repertoire of diagnostic and therapeutic biomarkers is critical for improving clinical outcomes in RA. Emerging evidence highlights the significance of synovial fluid biomarkers, including aggrecan, matrix metalloproteinases, glucosyl-galactosyl-pyridinoline, hyaluronic acid, S100 proteins, calprotectin, and various cytokines, as well as immunological markers. Additionally, specific components of extracellular vesicles, such as non-coding RNAs, heat shock proteins, and lipids, are gaining attention. This review focuses on molecular markers found in synovial fluid and extracellular vesicles, excluding clinical and imaging biomarkers, and explores their potential applications in the diagnosis and management of RA.

Noninvasive, Multimodal Inflammatory Biomarker Discovery for Systemic Inflammation (NOVA Study): Protocol for a Cross-Sectional Study

BACKGROUND

Prolonged systemic inflammation is recognized as a major contributor to the development of various chronic inflammatory diseases. Daily measurements of inflammatory biomarkers can significantly improve disease monitoring of systemic inflammation, thus contributing to reducing the burden on patients and the health care system. There exists, however, no scalable, cost-efficient, and noninvasive biomarker for remote assessment of systemic inflammation. To this end, we propose a novel, multimodal, and noninvasive approach for measuring inflammatory biomarkers.

OBJECTIVE

This study aimed to evaluate the relationship between the levels of inflammatory biomarkers in serum (gold standard) and those measured noninvasively in urine, sweat, saliva, exhaled breath, stool, and core body temperature in patients with systemic inflammation.

METHODS

This study is a single-center, cross-sectional study and includes a total of 20 participants (10 patients with systemic inflammation and 10 control patients). Eligible participants provide serum, urine, sweat, saliva, exhaled breath, and stool samples for biomarker analyses. Core body temperature is measured using a sensor. The primary end point is the level of C-reactive protein (CRP). The secondary end points are interleukin (IL)-1β, IL-6, IL-8, IL-10, and tumor necrosis factor-α levels. The tertiary end points are fractional exhaled nitric oxide, calprotectin, and core body temperature. Samples will be collected in 2 batches, enabling preliminary analysis of the first batch (patients 1-5 from each group). The full analysis will include both batches. CRP and cytokine levels will be measured using enzyme-linked immunosorbent assay and electrochemiluminescence immunoassay. For statistical analysis, the Shapiro-Wilk test will be used to evaluate the normality of the distribution in each variable. We will perform the 2-tailed t test or Wilcoxon rank sum test to compare the levels of inflammatory biomarkers between patients with systemic inflammations and control patients. Pearson and Spearman correlation coefficients will assess the relationship between inflammatory biomarkers from noninvasive methods and serum biomarkers. Using all-subset regression analysis, we will determine the combination of noninvasive methods yielding the highest predictive accuracy for serum CRP levels. Participants' preferences for sampling methods will be assessed through a questionnaire.

RESULTS

The study received ethics approval from the independent research ethics committee of Canton Zurich on October 28, 2022. A total of 20 participants participated in the study measurements. Data collection started on February 22, 2023, and was completed on September 22, 2023. Participants were on average 52.8 (SD 14.4; range 24-82) years of age, and 70% (14/20) of them were women. The analysis results reporting findings are expected to be published in 2025.

CONCLUSIONS

This study aims to evaluate the feasibility of noninvasive, multimodal assessment of inflammatory biomarkers in patients with systemic inflammation. Promising results could lead to the creation of noninvasive and potentially digital biomarkers for systemic inflammation, enabling continuous monitoring and early diagnosis of inflammatory activity in a remote setting.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/62877.

The anti-rheumatoid arthritic activity of Artemisia ordosica Krasch. (traditional Chinese/Mongolian medicine) extract in collagen-induced arthritis in rats

OBJECTIVES

Rheumatoid arthritis (RA) seriously affects the daily life of people. The whole plant of Artemisia ordosica Krasch. (AOK) has been used in folk medicine. This study aimed to investigate the in vivo anti-RA effects of AOK extract (AOKE) on collagen-induced arthritis in rats.

METHODS

AOKE (400, 200, or 100 mg/kg) was administered orally to animals for 30 days. Body weight, paw swelling, arthritis index, thymus, and spleen indices, and pathological changes were assessed for effects of AOKE on RA. Furthermore, the inflammatory cytokines in rat serum were detected. In addition, the expressions of STAT3, Caspase-3, Galectin-3, and S100A9 in synovial tissue were researched using immunohistochemistry.

KEY FINDINGS

The AOKE significantly reduced the arthritis indices, paw swelling, spleen, and thymus indices. Meanwhile, AOKE (400 mg/kg) decreased the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-17A, and increased the level of IL-10 in rat serum. Histopathological examination showed that AOKE reduced inflammatory cell infiltration and cartilage erosion. Then, AOKE decreased the expressions of STAT3, Galectin-3, S100A9, and increased the expression of Caspase-3.

CONCLUSION

AOKE had interesting anti-RA activity in rats, which deserved further research for the development and clinical use of this medicinal resource.

Recent Progress in Microenvironment-Responsive Nanodrug Delivery Systems for the Targeted Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that often causes joint pain, swelling, and functional impairments. Drug therapy is the main strategy used to alleviate the symptoms of RA; however, drug therapy may have several adverse effects, such as nausea, vomiting, abdominal pain, diarrhea, gastric ulcers, intestinal bleeding, hypertension, hyperglycemia, infection, fatigue, and indigestion. Moreover, long-term excessive use of drugs may cause liver and kidney dysfunction, as well as thrombocytopenia. Nanodrug delivery systems (NDDSs) can deliver therapeutics to diseased sites with the controlled release of the payload in an abnormal microenvironment, which helps to reduce the side effects of the therapeutics. Abnormalities in the microenvironment, such as a decreased pH, increased expression of matrix metalloproteinases (MMPs), and increased concentrations of reactive oxygen species (ROS), are associated with the progression of RA but also provide an opportunity to achieve microenvironment-responsive therapeutic release at the RA site. Microenvironment-responsive NDDSs may overcome the abovementioned disadvantages of RA therapy. Herein, we comprehensively review recent progress in the development of microenvironment-responsive NDDSs for RA treatment, including pH-, ROS-, MMP-, and multiresponsive NDDSs. Furthermore, the pathological microenvironment is highlighted in detail.

Interleukin-35 protein inhibits osteoclastogenesis and attenuates collagen-induced arthritis in mice

Rheumatoid arthritis (RA) is a chronic autoimmune disease. Its pathological features include synovial inflammation, bone erosion, and joint structural damage. Our previous studies have shown that interleukin (IL)-35 is involved in the pathogenesis of bone loss in RA patients. In this study, we are further evaluating the efficacy of IL-35 on collagen-induced arthritis (CIA) in the mouse model. Male DBA/1J mice (n = 10) were initially immunized, 2 μg/mouse IL-35 was injected intraperitoneally every week for 3 weeks after the establishment of the CIA model. Clinical arthritis, histopathological analysis, and three-dimensional micro‑computed tomography (3D micro‑CT) were determined after the mice were anesthetized on the 42th day. In vitro, RANKL/M-CSF induced mouse preosteoclasts (RAW264.7 cells line) was subjected to antiarthritis mechanism study in the presence of IL-35. The results of clinical arthritis, histopathological analysis, and 3D micro‑CT, the expression of RANK/RANKL/OPG axis, inflammatory cytokines, and osteoclastogenesis-related makers demonstrated decreasing severity of synovitis and bone destruction in the ankle joints after IL-35 treatment. Furthermore, IL-35 attenuated inflammatory cytokine production and the expression of osteoclastogenesis-related makers in a mouse preosteoclasts cell line RAW264.7. The osteoclastogenesis-related makers were significantly reduced in IL-35 treated RAW264.7 cells line after blockage with the JAK/STAT1 signaling pathway. These results demonstrated that IL-35 protein could inhibits osteoclastogenesis and attenuates CIA in mice. We concluded that IL-35 can exhibit anti-osteoclastogenesis effects by reducing the expression of inflammatory cytokines and osteoclastogenesis-related makers, thus alleviating bone destruction in the ankle joint and could be a potential therapeutic target for RA.

Advancements in extracellular vesicle targeted therapies for rheumatoid arthritis: insights into cellular origins, current perspectives, and emerging challenges

Rheumatoid arthritis (RA) remains a challenging chronic autoimmune disorder characterized by persistent joint inflammation and damage. While modern regenerative strategies, encompassing cell/stem cell-based therapies, gene therapy, and tissue engineering, have advanced tissue repair efforts, a definitive cure for RA remains elusive. Consequently, there is growing interest in developing targeted therapies that directly address the underlying mechanisms driving RA pathogenesis, such as extracellular vesicles (EVs). These small membrane-bound particles can modulate immune responses within the inflammatory microenvironment of damaged cartilage. To launch the clinical potential of EVs, they can be isolated from various cell types through several techniques. EVs can carry various bioactive molecules and anti-inflammatory or pro-regenerative drugs, deliver them directly to the affected joints, and affect the behavior of injured cells, making them a compelling choice for targeted therapy and drug delivery in RA patients. However, there are still several challenges and limitations associated with EV-based therapy, including the absence of standardized protocols for EV isolation, characterization, and delivery. This review provides a comprehensive overview of the cellular sources of EVs in RA and delves into their therapeutic potential and the hurdles they must overcome.

A tale of two functions: C-reactive protein complement-ary structures and their role in rheumatoid arthritis

C-reactive protein (CRP) is an inflammatory biomarker with associated clinical utility in a wide number of inflammatory disorders, including rheumatoid arthritis (RA). The interaction of CRP with pro-inflammatory cytokines has been explored before, however its role in complement regulation is more subtle, where CRP is capable of both up and downregulating the complement cascade. CRP is produced in a pentameric form and can dissociate to a monomeric form in circulation which has significant implications for its ability to interact with receptors and binding partners. This dichotomy of CRP structure could have relevance in patients with RA who have significant dysfunction in their complement cascade and also widely varying CRP levels including at the time of flare. This review aims to bring together current knowledge of CRP in its various forms, its effects on complement function and how this could influence pathology in the context of RA.

Recent innovations in topical delivery for management of rheumatoid arthritis: A focus on combination drug delivery

Rheumatoid arthritis (RA) is an immune-mediated disease that necessitates a thorough understanding of its intricate pathophysiological mechanism for precise and effective therapeutic targeting. The European League Against Rheumatism (EULAR) has established guidelines for RA treatment, endorsing monotherapy or combination therapy with corticosteroids and synthetic disease-modifying antirheumatic drugs (sDMARDs). This review delves into clinical trials and research outcomes related to combination drug delivery, with an emphasis on the role of natural products in combination with synthetic drugs. Given the significant adverse effects associated with systemic administration, topical delivery has emerged as an alternative avenue for effective management of RA.

Systemic inflammation response index is associated with increased all-cause and cardiovascular mortality in US adults with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) stands as a persistent systemic inflammatory autoimmune condition. Despite this understanding, the precise impact of the systemic inflammation response index (SIRI) on the prognosis of RA patients remains elusive. This study aims to elucidate the correlation between the inflammatory biomarker SIRI and both all-cause mortality and cardiovascular mortality among RA patients.

METHODS

Utilizing data from the National Health and Nutrition Examination Survey (NHANES) spanning from 1999 to 2020, a retrospective analysis was conducted. Survival data were depicted through Kaplan-Meier survival curves, while the relationship between SIRI and all-cause or cardiovascular mortality in RA patients was scrutinized via multivariable Cox proportional hazards regression analysis and restricted cubic spline plots. Furthermore, subgroup analysis and mediation analysis were also performed.

RESULTS

This study encompassed 2656 RA patients with a comprehensive 20-year follow-up, during which 935 all-cause deaths and 273 deaths attributed to cardiovascular disease were recorded. We observed a nonlinear positive correlation between SIRI with both all-cause and cardiovascular mortality in RA patients. Notably, at a SIRI level of 1.12, the hazard ratio reached 1, indicating a shift from low to high mortality risk. Furthermore, mediation analysis revealed that 12.6% of the association between RA and mortality risk was mediated through SIRI. Subgroup analysis indicated a more pronounced association between SIRI and mortality in female patients or those with a high BMI.

CONCLUSION

This study underscores a non-linear positive correlation between the biomarker SIRI and both all-cause mortality and cardiovascular mortality in RA patients.

Preclinical evaluation of ELP-004 in mice

This study provides a detailed understanding of the preclinical pharmacokinetics and metabolism of ELP-004, an osteoclast inhibitor in development for the treatment of bone erosion. Current treatments for arthritis, including biological disease-modifying antirheumatic drugs, are not well-tolerated in a substantial subset of arthritis patients and are expensive; therefore, new treatments are needed. Pharmacokinetic parameters of ELP-004 were tested with intravenous, oral, and subcutaneous administration and found to be rapidly absorbed and distributed. We found that ELP-004 was non-mutagenic, did not induce chromosome aberrations, non-cardiotoxic, and had minimal off-target effects. Using in vitro hepatic systems, we found that ELP-004 is primarily metabolized by CYP1A2 and CYP2B6 and predicted metabolic pathways were identified. Finally, we show that ELP-004 inhibits osteoclast differentiation without suppressing overall T-cell function. These preclinical data will inform future development of an oral compound as well as in vivo efficacy studies in mice.

Research progress of T cell autophagy in autoimmune diseases

T cells, as a major lymphocyte population involved in the adaptive immune response, play an important immunomodulatory role in the early stages of autoimmune diseases. Autophagy is a cellular catabolism mediated by lysosomes. Autophagy maintains cell homeostasis by recycling degraded cytoplasmic components and damaged organelles. Autophagy has a protective effect on cells and plays an important role in regulating T cell development, activation, proliferation and differentiation. Autophagy mediates the participation of T cells in the acquired immune response and plays a key role in antigen processing as well as in the maintenance of T cell homeostasis. In autoimmune diseases, dysregulated autophagy of T cells largely influences the pathological changes. Therefore, it is of great significance to study how T cells play a role in the immune mechanism of autoimmune diseases through autophagy pathway to guide the clinical treatment of diseases.

Celastrol nano-emulsions selectively regulate apoptosis of synovial macrophage for alleviating rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune inflammation. Excessive proliferation and inadequate apoptosis of synovial macrophages are the crucial events of RA. Therefore, delivering therapeutic molecules to synovial macrophages specifically to tackle apoptotic insufficiency probably can be an efficient way to reduce joint inflammation and bone erosion. Based on the characteristics of dextran sulphate (DS) specifically binding scavenger receptor A (SR-A) on macrophage and celastrol (CLT) inducing apoptosis, we designed synovial macrophage-targeted nano-emulsions encapsulated with CLT (SR-CLTNEs) and explored their anti-RA effect. After intravenous injection, fluorescence-labelled SR-CLTNEs successfully targeted inflammatory joints and synovial macrophages in a mouse model of RA, with the macrophage targeting efficiency of SR-CLTNEs, CLTNEs and free DID was 20.53%, 13.93% and 9.8%, respectively. In vivo and in vitro studies showed that SR-CLTNEs effectively promoted the apoptosis of macrophages, reshaped the balance between apoptosis and proliferation, and ultimately treated RA in a high efficiency and low toxicity manner. Overall, our work demonstrates the efficacy of using SR-CLTNEs as a novel nanotherapeutic approach for RA therapy and the great translational potential of SR-CLTNEs.

JAK/STAT signaling in rheumatoid arthritis leukocytes is uncoupled from serum cytokines in a subset of patients

OBJECTIVE

Rheumatoid Arthritis (RA) is a systemic autoimmune disease involving pro-inflammatory cytokines that can be therapeutically targeted by antibodies or kinase inhibitors. Nevertheless, these drugs fail in a subset of patients independent of the abundance of the targeted cytokines. We aim to explore the cellular basis of this phenomenon by analyzing the relation of cytokine abundance and activation of downstream signaling pathways in RA.

METHODS

The study included 62 RA patients and 9 healthy controls (HC). Phosphorylation of STAT 1-6 in various immune cell subsets was determined ex vivo using a novel robust flow cytometry-based protocol. Serum concentrations of IL-6, IL-10, IL-12p70, IL-17 A, interferon gamma, and TNFα in the same samples were measured using highly sensitive single molecule array (SIMOA).

RESULTS

We found an increase in circulating cytokines in RA patients, while STAT activity was lower in RA patients compared to HC. Based on STAT activity we determined three endotypes in active RA patients (cDAI>10, n = 28): 1) those with active STAT5a/b signaling in T cells (n = 7/28), 2) those with a low STAT activity in all assessed cell types (n = 14/28), and 3) those with active STAT1 and STAT3 signaling mainly in myeloid cells (n = 7/28). Integrating intracellular STAT activation and cytokine analysis revealed diminished JAK/STAT signaling in a subset of patients (n = 8/20) despite elevated serum cytokine concentrations.

CONCLUSION

Diminished JAK/STAT signaling in active RA may partly explain unresponsiveness to therapy targeting cytokine signaling. Analysis of JAK/STAT phosphorylation may identify patients at risk for non-response to these therapies.

Treatment of Rheumatoid Arthritis Based on the Inherent Bioactivity of Black Phosphorus Nanosheets

Rheumatoid arthritis (RA) is an autoimmune disease that affects the living quality of patients, especially the elderly population. RA-related morbidity and mortality increase significantly with age, while current clinical drugs for RA are far from satisfactory and may have serious side effects. Therefore, the development of new drugs with higher biosafety and efficacy is demanding. Black phosphorus nanosheets (BPNSs) have been widely studied because of their excellent biocompatibility. Here, we focus on the inherent bioactivity of BPNSs, report the potential of BPNSs as a therapeutic drug for RA and elucidate the underlying therapeutic mechanism. We find that BPNSs inhibit autophagy at an early stage via the AMPK-mTOR pathway, switch the energy metabolic pathway to oxidative phosphorylation, increase intracellular ATP levels, suppress apoptosis, reduce inflammation and oxidative stress, and down-regulate senescence-associated secretory phenotype (SASP)-related genes in rheumatoid arthritis synovial fibroblasts (RA-SFs). Further, BPNSs induce the apoptosis of macrophages and promote their transition from the M1 to the M2 phenotype by regulating related cytokines. Significantly, the administration of BPNSs can alleviate key pathological features of RA in mice, revealing great therapeutic potential. This study provides a novel option for treating RA, with BPNSs emerging as a promising therapeutic candidate.

Increased water temperature contributes to a chondrogenesis response in the eyes of spotted wolffish

Adult vertebrate cartilage is usually quiescent. Some vertebrates possess ocular scleral skeletons composed of cartilage or bone. The morphological characteristics of the spotted wolffish (Anarhichas minor) scleral skeleton have not been described. Here we assessed the scleral skeletons of cultured spotted wolffish, a globally threatened marine species. The healthy spotted wolffish we assessed had scleral skeletons with a low percentage of cells staining for the chondrogenesis marker sex-determining region Y-box (Sox) 9, but harboured a population of intraocular cells that co-express immunoglobulin M (IgM) and Sox9. Scleral skeletons of spotted wolffish with grossly observable eye abnormalities displayed a high degree of perochondrial activation as evidenced by cellular morphology and expression of proliferating cell nuclear antigen (PCNA) and phosphotyrosine. Cells staining for cluster of differentiation (CD) 45 and IgM accumulated around sites of active chondrogenesis, which contained cells that strongly expressed Sox9. The level of scleral chondrogenesis and the numbers of scleral cartilage PCNA positive cells increased with the temperature of the water in which spotted wolffish were cultured. Our results provide new knowledge of differing Sox9 spatial tissue expression patterns during chondrogenesis in normal control and ocular insult paradigms. Our work also provides evidence that spotted wolffish possess an inherent scleral chondrogenesis response that may be sensitive to temperature. This work also advances the fundamental knowledge of teleost ocular skeletal systems.

Combined ROS Sensitive Folate Receptor Targeted Micellar Formulations of Curcumin Effective Against Rheumatoid Arthritis in Rat Model

Introduction

Rheumatoid arthritis (RA) is an inflammatory immune-mediated disease that involves synovitis, cartilage destruction, and even joint damage. Traditional agents used for RA therapy remain unsatisfactory because of their low efficiency and obvious adverse effects. Therefore, we here established RA microenvironment-responsive targeted micelles that can respond to the increase in reactive oxygen species (ROS) levels in the joint and improve macrophage-specific targeting of loaded drugs.

Methods

We here prepared ROS-responsive folate-modified curcumin micelles (TK-FA-Cur-Ms) in which thioketal (TK) was used as a ROS-responsive linker for modifying polyethylene glycol 5000 (PEG5000) on the micellar surface. When micelles were in the ROS-overexpressing inflammatory microenvironment, the PEG5000 hydration layer was shed, and the targeting ligand FA was exposed, thereby enhancing cellular uptake by macrophages through active targeting. The targeting, ROS sensitivity and anti-inflammatory properties of the micelles were assessed in vitro. Collagen-induced arthritis (CIA) rats model was utilized to investigate the targeting, expression of serum inflammatory factors and histology change of the articular cartilage by micelles in vivo.

Results

TK-FA-Cur-Ms had a particle size of 90.07 ± 3.44 nm, which decreased to 78.87 ± 2.41 nm after incubation with H2O2. The micelles exhibited in vitro targeting of RAW264.7 cells and significantly inhibited inflammatory cytokine levels. Pharmacodynamic studies have revealed that TK-FA-Cur-Ms prolonged the drug circulation and exhibited augmented cartilage-protective and anti-inflammatory effects in vivo.

Conclusion

The unique ROS-responsive targeted micelles with targeting, ROS sensitivity and anti-inflammatory properties were successfully prepared and may offer an effective therapeutic strategy against RA.

Inflammasome Molecular Insights in Autoimmune Diseases

Autoimmune diseases (AIDs) emerge due to an irregular immune response towards self- and non-self-antigens. Inflammation commonly accompanies these conditions, with inflammatory factors and inflammasomes playing pivotal roles in their progression. Key concepts in molecular biology, inflammation, and molecular mimicry are crucial to understanding AID development. Exposure to foreign antigens can cause inflammation, potentially leading to AIDs through molecular mimicry triggered by cross-reactive epitopes. Molecular mimicry emerges as a key mechanism by which infectious or chemical agents trigger autoimmunity. In certain susceptible individuals, autoreactive T or B cells may be activated by a foreign antigen due to resemblances between foreign and self-peptides. Chronic inflammation, typically driven by abnormal immune responses, is strongly associated with AID pathogenesis. Inflammasomes, which are vital cytosolic multiprotein complexes assembled in response to infections and stress, are crucial to activating inflammatory processes in macrophages. Chronic inflammation, characterized by prolonged tissue injury and repair cycles, can significantly damage tissues, thereby increasing the risk of AIDs. Inhibiting inflammasomes, particularly in autoinflammatory disorders, has garnered significant interest, with pharmaceutical advancements targeting cytokines and inflammasomes showing promise in AID management.

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.

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 review of hyaluronic acid-based therapeutics for the treatment and management of arthritis

Hyaluronic acid (HA), a biodegradable, biocompatible and non-immunogenic therapeutic polymer is a key component of the cartilage extracellular matrix (ECM) and has been widely used to manage two major types of arthritis, osteoarthritis (OA) and rheumatoid arthritis (RA). OA joints are characterized by lower concentrations of depolymerized (low molecular weight) HA, resulting in reduced physiological viscoelasticity, while in RA, the associated immune cells are over-expressed with various cell surface receptors such as CD44. Due to HA's inherent viscoelastic property and its ability to target CD44, there has been a surge of interest in developing HA-based systems to deliver various bioactives (drugs and biologics) and manage arthritis. Considering therapeutic benefits of HA in arthritis management and potential advantages of novel delivery systems, bioactive delivery through HA-based systems is beginning to display improved outcomes over bioactive only treatment. The benefits include enhanced bioactive uptake due to receptor-mediated targeting, prolonged retention of bioactives in the synovium, reduced expressions of proinflammatory mediators, enhanced cartilage regeneration, reduced drug toxicity due to sustained release, and improved and cost-effective treatment. This review provides an underlying rationale to prepare and use HA-based bioactive delivery systems for arthritis applications. With special emphasis given to preclinical/clinical results, this article reviews various bioactive-loaded HA-based particulate carriers (organic and inorganic), gels, scaffolds and polymer-drug conjugates that have been reported to treat and manage OA and RA. Furthermore, the review identifies several key challenges and provides valuable suggestions to address them. Various developments, strategies and suggestions described in this review may guide the formulation scientists to optimize HA-based bioactive delivery systems as an effective approach to manage and treat arthritis effectively.

Occurrence of Bullous Pemphigoid in a Longstanding Case of Rheumatoid Arthritis in an Indian Patient: A Rare Association

Bullous pemphigoid is a subepidermal blistering disease that rarely involves the mucous membranes and possesses circulating antibodies against BP antigen II (BP180) and BP antigen I (BP230). Rheumatoid arthritis (RA) is a progressive inflammatory autoimmune disease that is characterized by joint inflammation and systemic involvement. The co-occurrence of RA, which is likewise linked to autoimmunity, with bullous pemphigoid may not be merely coincidental. A 55-year-old female, a known case of RA for 25 years, presented to us with multiple pruritic vesiculobullous lesions. After a thorough clinical and laboratory assessment, she was diagnosed with bullous pemphigoid. This emphasizes the significance of the simultaneous occurrence of autoimmune disorders and the need for vigilant and timely identification.

Effectiveness of Yoga in Modulating Markers of Immunity and Inflammation: A Systematic Review and Meta-Analysis

Chronic inflammation is central to the pathogenesis of many chronic inflammatory conditions. This review aims to analyze whether the practice of yoga, or yogic meditation and breathing, has any effect on the levels of inflammatory cytokines and other inflammatory markers in patients with various chronic inflammatory diseases such as rheumatoid arthritis, neoplastic disorders, and asthma, as well as in healthy subjects, compared to usual care or sham interventions. A comprehensive search of databases (PubMed, CENTRAL, Embase, and CINAHL) was performed. Randomized controlled trials (RCTs) that evaluated the effects of yoga as an intervention on inflammatory markers were analyzed. A total of 26 studies were included. Only two studies had a low risk of bias (RoB); 24 other studies had a high RoB. Most studies (n=24) reported a favorable outcome with yoga, irrespective of the type of yoga used, the condition studied, and the duration of the intervention. The commonly reported inflammatory markers included IL-6 (n=17), tumor necrosis factor-alpha (TNF-a) (n=13), and C-reactive protein (CRP) (n=10). Most studies showed a significant reduction in inflammatory markers in the yoga group (YG) compared to the control group (CG). Few studies also showed significant improvement in markers of cellular immunity (interferon gamma (IFN-g), IL-10, and transforming growth factor-beta (TGF-b); n=2 each) and improved mucosal defense (IgA, IL-6, and IL-2; n=2 each). A meta-analysis of IL-6, TNF-a, and CRP showed yoga had a favorable effect on the levels of these markers, but it was not statistically significant. Current evidence suggests that yoga can be a complementary intervention for various chronic inflammatory conditions. However, the quality of the evidence is poor, along with considerable heterogeneity. In the future, investigators should describe the intervention better, with a uniform assortment of outcome measures and treatment conditions, to generate high-quality evidence.

Comprehensive Co-Inhibitory Receptor (Co-IR) Expression on T Cells and Soluble Proteins in Rheumatoid Arthritis

Co-inhibitory receptors (Co-IRs) are essential in controlling the progression of immunopathology in rheumatoid arthritis (RA) by limiting T cell activation. The objective of this investigation was to determine the phenotypic expression of Co-IR T cells and to assess the levels of serum soluble PD-1, PDL-2, and TIM3 in Taiwanese RA patients.

METHODS

Co-IRs T cells were immunophenotyped employing multicolor flow cytometry, and ELISA was utilized for measuring soluble PD-1, PDL-2, and TIM3. Correlations have been detected across the percentage of T cells expressing Co-IRs (MFI) and different indicators in the blood, including ESR, high-sensitivity CRP (hsCRP), 28 joint disease activity scores (DAS28), and soluble PD-1/PDL-2/TIM3.

RESULTS

In RA patients, we recognized elevated levels of PD-1 (CD279), CTLA-4, and TIGIT in CD4+ T cells; TIGIT, HLA-DR, TIM3, and LAG3 in CD8+ T cells; and CD8+CD279+TIM3+, CD8+HLA-DR+CD38+ T cells. The following tests were revealed to be correlated with hsCRP: CD4/CD279 MFI, CD4/CD279%, CD4/TIM3%, CD8/TIM3%, CD8/TIM3 MFI, CD8/LAG3%, and CD8+HLA-DR+CD38+%. CD8/LAG3 and CD8/TIM3 MFIs are linked to ESR. DAS28-ESR and DAS28-CRP exhibited relationships with CD4/CD127 MFI, CD8/CD279%, and CD8/CD127 MFI, respectively. CD4+CD279+TIM3+% was correlated with DAS28-ESR (p = 0.0084, N = 46), DAS28-CRP (p = 0.007, N = 47), and hsCRP (p = 0.002, N = 56), respectively. In the serum of patients with RA, levels of soluble PD-1, PDL-2, and Tim3 were extremely elevated. CD4+ TIM3+% (p = 0.0089, N = 46) and CD8+ TIM3+% (p = 0.0305, N = 46) were correlated with sTIM3 levels; sPD1 levels were correlated with CD4+CD279+% (p < 0.0001, N = 31) and CD3+CD279+% (p = 0.0084, N = 30).

CONCLUSIONS

Co-IR expressions on CD4+ and CD8+ T cells, as well as soluble PD-1, PDL-2, and TIM3 levels, could function as indicators of disease activity and potentially play crucial roles in the pathogenesis of RA.

Identification and Verification of Novel Biomarkers Involving Rheumatoid Arthritis with Multimachine Learning Algorithms: An In Silicon and In Vivo Study

Background

Rheumatoid arthritis (RA) remains one of the most prevalent chronic joint diseases. However, due to the heterogeneity among RA patients, there are still no robust diagnostic and therapeutic biomarkers for the diagnosis and treatment of RA.

Methods

We retrieved RA-related and pan-cancer information datasets from the Gene Expression Omnibus and The Cancer Genome Atlas databases, respectively. Six gene expression profiles and corresponding clinical information of GSE12021, GSE29746, GSE55235, GSE55457, GSE77298, and GSE89408 were adopted to perform differential expression gene analysis, enrichment, and immune component difference analyses of RA. Four machine learning algorithms, including LASSO, RF, XGBoost, and SVM, were used to identify RA-related biomarkers. Unsupervised cluster analysis was also used to decipher the heterogeneity of RA. A four-signature-based nomogram was constructed and verified to specifically diagnose RA and osteoarthritis (OA) from normal tissues. Consequently, RA-HFLS cell was utilized to investigate the biological role of CRTAM in RA. In addition, comparisons of diagnostic efficacy and biological roles among CRTAM and other classic biomarkers of RA were also performed.

Results

Immune and stromal components were highly enriched in RA. Chemokine- and Th cell-related signatures were significantly activated in RA tissues. Four promising and novel biomarkers, including CRTAM, PTTG1IP, ITGB2, and MMP13, were identified and verified, which could be treated as novel treatment and diagnostic targets for RA. Nomograms based on the four signatures might aid in distinguishing and diagnosing RA, which reached a satisfactory performance in both training (AUC = 0.894) and testing (AUC = 0.843) cohorts. Two distinct subtypes of RA patients were identified, which further verified that these four signatures might be involved in the immune infiltration process. Furthermore, knockdown of CRTAM could significantly suppress the proliferation and invasion ability of RA cell line and thus could be treated as a novel therapeutic target. CRTAM owned a great diagnostic performance for RA than previous biomarkers including MMP3, S100A8, S100A9, IL6, COMP, LAG3, and ENTPD1. Mechanically, CRTAM could also be involved in the progression through immune dysfunction, fatty acid metabolism, and genomic instability across several cancer subtypes.

Conclusion

CRTAM, PTTG1IP, ITGB2, and MMP13 were highly expressed in RA tissues and might function as pivotal diagnostic and treatment targets by deteriorating the immune dysfunction state. In addition, CRTAM might fuel cancer progression through immune signals, especially among RA patients.

Galantamine mitigates testicular injury and disturbed spermatogenesis in adjuvant arthritic rats via modulating apoptosis, inflammatory signals, and IL-6/JAK/STAT3/SOCS3 signaling

Rheumatoid arthritis (RA) affects the joints and the endocrine system via persistent immune system activation. RA patients have a higher frequency of testicular dysfunction, impotence, and decreased libido. This investigation aimed to evaluate the efficacy of galantamine (GAL) on testicular injury secondary to RA. Rats were allocated into four groups: control, GAL (2 mg/kg/day, p.o), CFA (0.3 mg/kg, s.c), and CFA + GAL. Testicular injury indicators, such as testosterone level, sperm count, and gonadosomatic index, were evaluated. Inflammatory indicators, such as interleukin-6 (IL-6), p-Nuclear factor kappa B (NF-κB p65), and anti-inflammatory cytokine interleukin-10 (IL-10), were assessed. Cleaved caspase-3 expression was immunohistochemically investigated. Protein expressions of Janus kinase (JAK), signal transducers and activators of transcription (STAT3), and Suppressors of Cytokine Signaling 3 (SOCS3) were examined by Western blot analysis. Results show that serum testosterone, sperm count, and gonadosomatic index were increased significantly by GAL. Additionally, GAL significantly diminished testicular IL-6 while improved IL-10 expression relative to CFA group. Furthermore, GAL attenuated testicular histopathological abnormalities by CFA and downregulated cleaved caspase-3 and NF-κB p65 expressions. It also downregulated JAK/STAT3 cascade with SOCS3 upregulation. In conclusion, GAL has potential protective effects on testicular damage secondary to RA via counteracting testicular inflammation, apoptosis, and inhibiting IL-6/JAK/STAT3/SOCS3 signaling.

Mechanistic evaluation of antiarthritic and anti-inflammatory effect of campesterol ester derivatives in complete Freund's adjuvant-induced arthritic rats

Background: Current therapies for RA have limitations and side effects, leading to a growing need for safer treatment options. Natural compounds from plants are gaining attention for their therapeutic benefits and fewer side effects. One such compound is the campesterol derivative, a steroid derivative occurring in plants. Studies have shown that this derivative has anti-inflammatory properties and can impact the expression of pro-inflammatory factors. The primary objective of this study was to explore and assess the potential therapeutic effects of Campesterol Ester Derivatives (CED) utilizing a rat model of arthritis induced by Complete Freund's Adjuvant (CFA). Method: The rats were divided into specific experimental groups and treated with either CED or piroxicam (as a positive control) for a duration of 28 days. We determined the effects of CED on various parameters including paw edema, thermal hyperalgesia, and mechanical allodynia at different time points. Furthermore, serum levels of inflammatory cytokines, oxidative stress markers and histological analyses were performed. Additionally, mRNA expression levels of inflammatory markers, both pro-inflammatory (such as TNF-α, NF-κB, IL-6, COX-1, COX-2, and IL-4) and anti-inflammatory were analyzed. Results: In the arthritic rat model, CED exhibited significant anti-inflammatory effects and resulted in a notable reduction in paw edema levels compared to the control group. Histopathological examination of the treated rats' paws confirmed a decrease in inflammation and tissue damage, including reduced pannus formation and bone erosion. Importantly, there were no observable signs of damage to the liver and kidneys following CED treatment, indicating its safety profile and potential for organ protection. At the molecular level, CED treatment downregulated mRNA expression levels of pro-inflammatory markers, indicating its ability to suppress inflammation. Conversely, certain anti-inflammatory markers were upregulated following CED treatment, suggesting a positive influence on the immune response. The positive effects of CED were not limited to joint inflammation; it also showed systemic benefits by positively influencing hematological and biochemical parameters. Conclusion: CED demonstrated promising therapeutic potential as an anti-inflammatory intervention for arthritis in the experimental rat model. Its ability to reduce inflammation, protect tissues, and improve organ function indicates its multifaceted benefits.

The Lnc-ENST00000602558/IGF1 axis as a predictor of response to treatment with tripterygium glycosides in rheumatoid arthritis patients

AIMS

Growing clinical evidence suggests that not all patients with rheumatoid arthritis (RA) benefit to the same extent by treatment with tripterygium glycoside (TG), which highlights the need to identify RA-related genes that can be used to predict drug responses. In addition, single genes as markers of RA are not sufficiently accurate for use as predictors. Therefore, there is a need to identify paired expression genes that can serve as biomarkers for predicting the therapeutic effects of TG tablets in RA.

METHODS

A total of 17 pairs of co-expressed genes were identified as candidates for predicting an RA patient's response to TG therapy, and genes involved in the Lnc-ENST00000602558/GF1 axis were selected for that purpose. A partial-least-squares (PLS)-based model was constructed based on the expression levels of Lnc-ENST00000602558/IGF1 in peripheral blood. The model showed high efficiency for predicting an RA patient's response to TG tablets.

RESULTS

Our data confirmed that genes co-expressed in the Lnc-ENST00000602558/IGF1 axis mediate the efficacy of TG in RA treatment, reduce tumor necrosis factor-α induced IGF1 expression, and decrease the inflammatory response of MH7a cells.

CONCLUSION

We found that genes expressed in the Lnc-ENST00000602558/IGF1 axis may be useful for identifying RA patients who will not respond to TG treatment. Our findings provide a rationale for the individualized treatment of RA in clinical settings.

Functional Ingredients Associated with the Prevention and Suppression of Locomotive Syndrome: A Review

In 2007, the Japanese Orthopaedic Association proposed the concept of locomotive syndrome, a comprehensive description of conditions involving the functional decline of the locomotor system. Locomotive syndrome includes bone-related diseases such as osteoporosis, joint cartilage and disc-related diseases such as osteoarthritis and lumbar spondylosis, and sarcopenia and locomotive syndrome-related diseases. If left untreated, these diseases are likely to reduce mobility, necessitating nursing care. To prevent the progression of locomotive syndrome, a daily exercise routine and well-balanced diet are important, in addition to recognizing one's own decline in mobility. Therefore, research on the effectiveness of functional ingredients in the prevention and suppression of locomotive syndrome progression is ongoing. In this review, we summarize the latest reports on the effectiveness of five functional ingredients, namely, epigallocatechin gallate, resveratrol, curcumin, ellagic acid, and carnosic acid, in the treatment of osteoarthritis, osteoporosis, and rheumatoid arthritis, which are considered representative diseases of the locomotive syndrome.

Comprehensive multi-omics analysis reveals the core role of glycerophospholipid metabolism in rheumatoid arthritis development

OBJECTIVES

Rheumatoid arthritis (RA) is a chronic autoimmune disease with complex causes and recurrent attacks that can easily develop into chronic arthritis and eventually lead to joint deformity. Our study aims to elucidate potential mechanism among control, new-onset RA (NORA) and chronic RA (CRA) with multi-omics analysis.

METHODS

A total of 113 RA patients and 75 controls were included in our study. Plasma and stool samples were obtained for 16S rRNA sequencing, internally transcribed spacer (ITS) sequencing and metabolomics analysis. And PBMCs were obtained for RNA sequencing. We used three models, logistic regression, least absolute shrinkage and selection operator (LASSO), and random forest, respectively, to distinguish NORA from CRA, and finally we validated model performance using an external cohort of 26 subjects.

RESULTS

Our results demonstrated intestinal flora disturbance in RA development, with significantly increased abundance of Escherichia-Shigella and Proteobacteria in NORA. We also found that the diversity was significantly reduced in CRA compared to NORA through fungi analysis. Moreover, we identified 29 differential metabolites between NORA and CRA. Pathway enrichment analysis revealed significant dysregulation of glycerophospholipid metabolism and phenylalanine metabolism pathways in RA patients. Next, we identified 40 differentially expressed genes between NORA and CRA, which acetylcholinesterase (ACHE) was the core gene and significantly enriched in glycerophospholipid metabolism pathway. Correlation analysis showed a strong negatively correlation between glycerophosphocholine and inflammatory characteristics. Additionally, we applied three approaches to develop disease classifier models that were based on plasma metabolites and gut microbiota, which effectively distinguished between new-onset and chronic RA patients in both discovery cohort and external validation cohort.

CONCLUSIONS

These findings revealed that glycerophospholipid metabolism plays a crucial role in the development and progression of RA, providing new ideas for early clinical diagnosis and optimizing treatment strategies.

The Impact of UFP-512 in Mice with Osteoarthritis Pain: The Role of Hydrogen Sulfide

The pain-relieving properties of opioids in inflammatory and neuropathic pain are heightened by hydrogen sulfide (H2S). However, whether allodynia and functional and/or emotional impairments related to osteoarthritis (OA) could be reduced by activating δ-opioid receptors (DOR) and the plausible influence of H2S on these actions has not been completely established. In female C57BL/6J mice with OA pain generated via monosodium acetate (MIA), we analyze: (i) the effects of UFP-512 (a DOR agonist), given alone and co-administered with two H2S donors, on the symptoms of allodynia, loss of grip strength (GS), and anxiodepressive-like comportment; (ii) the reversion of UFP-512 actions with naltrindole (a DOR antagonist), and (iii) the impact of UFP-512 on the expression of phosphorylated NF-kB inhibitor alpha (p-IKBα) and the antioxidant enzymes superoxide dismutase 1 (SOD-1) and glutathione sulfur transferase M1 (GSTM1); and the effects of H2S on DOR levels in the dorsal root ganglia (DRG), amygdala (AMG), and hippocampus (HIP) of MIA-injected animals. Results showed that systemic and local administration of UFP-512 dose-dependently diminished the allodynia and loss of GS caused by MIA, whose effects were potentiated by H2S and reversed by naltrindole. UFP-512 also inhibited anxiodepressive-like behaviors, normalized the overexpression of p-IKBα in DRG and HIP, and enhanced the expression of SOD-1 and GSTM1 in DRG, HIP, and/or AMG. Moreover, the increased expression of DOR triggered by H2S might support the improved analgesic actions of UFP-512 co-administered with H2S donors. This study proposes the use of DOR agonists, alone or combined with H2S donors, as a new treatment for OA pain.

Association between rheumatoid arthritis and pulpal-periapical pathology: a systematic review

OBJECTIVES

Rheumatoid arthritis (RA) is a debilitating disease where numerous pro-inflammatory cytokines have a proven role in its pathology. These cytokines are also involved in the pathogenesis of apical periodontitis (AP) where they have a pro-inflammatory role and induce bone resorption. Patients with RA may therefore be more prone to develop pulpal-periapical pathology (PPP). This study systematically reviewed the existing literature evaluating the association between RA and PPP.

MATERIALS AND METHODS

Studies including human participants with both RA and PPP were included. The search was performed in PubMed, Web of Science, and The Cochrane Library databases using keywords and Medical Subject Headings (MeSH) search terms. The risk of bias was assessed using Newcastle-Ottawa Quality Assessment Scale. The following parameters were extracted and analyzed by the reviewers; author, journal, year, design of the study, diagnostic criteria for periapical pathology, the association between rheumatoid arthritis and periapical pathology, and the evidence level.

RESULTS

The search identified 142 records. Inclusion criteria were as follows; studies in the English language, including human participants only, including patients with RA and PPP, cohort studies, cross-sectional studies, clinical trials, and case-control studies. According to the inclusion criteria, 5 studies were included in this systematic review. Three of the five studies reported significant association between RA and PPP.

CONCLUSIONS

Existing evidence suggests there may be an association between RA and PPP.

CLINICAL RELEVANCE

Clinicians should be aware that RA patients can be more prone to develop PPP which may result in a reduced quality of life.

Rheumatoid arthritis

Rheumatoid arthritis is a chronic, systemic, autoimmune inflammatory disease that mainly affects the joints and periarticular soft tissues. In this Seminar, we provide an overview of the main aspects of rheumatoid arthritis. Epidemiology and advances in the understanding of rheumatoid arthritis pathogenesis will be reviewed. We will discuss the clinical manifestations of rheumatoid arthritis, classification criteria, and the value of imaging in the diagnosis of the disease. The advent of new medications and the accumulated scientific evidence demand continuous updating regarding the diagnosis and management, including therapy, of rheumatoid arthritis. An increasing number of patients are now able to reach disease remission. This major improvement in the outcome of patients with rheumatoid arthritis has been determined by a combination of different factors (eg, early diagnosis, window of opportunity, treat-to-target strategy, advent of targeted disease-modifying antirheumatic drugs, and combination therapy). We will discuss the updated recommendations of the two most influential societies for rheumatology worldwide (ie, the American College of Rheumatology and European Alliance of Associations for Rheumatology) for the management of rheumatoid arthritis. Furthermore, controversies (ie, the role of glucocorticoids in the management of rheumatoid arthritis and safety profile of Janus kinase inhibitors) and outstanding research questions, including precision medicine approach, prevention, and cure of rheumatoid arthritis will be highlighted.