Rheumatoid arthritis

Amino Acids Fueling Fibroblast-Like Synoviocyte Activation and Arthritis By Regulating Chemokine Expression and Leukocyte Migration

OBJECTIVE

We analyzed the impact of amino acid (AA) availability on the inflammatory response in arthritis.

METHODS

We stimulated rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLSs) with tumor necrosis factor (TNF) in the presence or absence of proteinogenic AAs and measured their response by QuantSeq 3' messenger RNA sequencing, quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay. Signal transduction events were determined by Western blot. We performed K/BxN serum transfer arthritis in mice receiving a normal and a low-protein diet and analyzed arthritis clinically and histologically.

RESULTS

Deprivation of AAs decreased the expression of a specific subset of genes, including the chemokines CXCL10, CCL2, and CCL5 in TNF-stimulated FLSs. Mechanistically, the presence of AAs was required for the TNF-induced activation of an interferon regulatory factor 1 (IRF1)-STAT1 signaling circuit that drives the expression of chemotactic factors. The expression of IRF1 and the IRF1-dependent gene set in FLSs was highly correlated with the presence of inflammatory cells in human RA, emphasizing the important role of this AA-dependent pathway in inflammatory cell recruitment to the synovial tissue. Finally, we show that mice receiving a low-protein diet expressed less IRF1 in the inflamed synovium and consequently developed reduced clinical and histologic signs of arthritis.

CONCLUSION

AA deprivation reduces the severity of arthritis by suppressing the expression of IRF1-STAT1-driven chemokines, which are crucial for leukocyte recruitment to the arthritic joint. Overall, our study provides novel insights into critical determinants of inflammatory arthritis and may pave the way for dietary intervention trials in RA.

Nanomedicine targeted anti-inflammatory therapy to deal with the 'crux' of rheumatoid arthritis

Rheumatoid arthritis is a chronic and complex autoimmune disease that is marked by an inflammatory response, synovial hyperplasia, vascularisation, fascial formation, cartilage and bone destruction, which can lead to joint deformity and even loss of function, ultimately affecting a person's health and quality of life. Although the pathogenesis of RA is unclear, growing evidence suggests that inflammation-associated cells infiltrate joints, causing tissue damage, inflammation and pain. This disruption in the balance between host tolerance and immune homeostasis the progression of RA. Existing drug therapy and surgical treatments for RA are unable to completely cure the disease or reverse its accelerated progression. Therefore, the design and development of an appropriate and effective drug delivery system will substantially improve the therapeutic effect. In this review, by describing the inflammatory microenvironment of rheumatoid arthritis and the associated inflammatory cells, the progress of targeting strategies and applications of nanotechnology in the disease is summarised, which will be helpful in providing new ideas for the subsequent treatment of rheumatoid arthritis.

NGF facilitates ICAM-1-dependent monocyte adhesion and M1 macrophage polarization in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disorder in which monocytes adhering to synovial tissue differentiate into the pro-inflammatory M1 macrophage phenotype. Nerve growth factors (NGF) referred to as neurotrophins have been associated with inflammatory events; however, researchers have yet to elucidate the role of NGF in RA. Our examination of clinical tissue samples and analysis of data sourced from the Gene Expression Omnibus dataset unveiled elevated expression levels of M1 macrophage markers in human RA synovial tissue samples compared to normal tissue, with no such distinction observed for M2 markers. Furthermore, immunofluorescence data depicted increased expression levels of NGF and M1 macrophages in RA mice in contrast to normal mice. It appears that NGF stimulation facilitates macrophage polarization from the M0 to the M1 phenotype. It also appears that NGF promotes ICAM-1 production in human RA synovial fibroblasts, which enhances monocyte adhesion through the TrkA, MEK/ERK, and AP-1 signaling cascades. Our findings indicate NGF/TrkA axis as a novel target for the treatment of RA.

NJK14047 inhibition of p38 MAPK ameliorates inflammatory immune diseases by suppressing T cell differentiation

p38 MAPK has been implicated in the pathogenesis of rheumatoid arthritis and psoriasis. To assess the therapeutic efficacy of the p38 MAPK inhibitor NJK14047 in the treatment of rheumatoid arthritis and psoriasis, we developed mouse models of collagen-induced rheumatoid arthritis (CIA) and imiquimod-induced psoriasis (IIP). NJK14047 was found to suppress arthritis development and psoriasis symptoms and also suppressed histopathological changes induced by CIA and IIP. Furthermore, we established that CIA and IIP evoked increases in the mRNA expression levels of Th1/Th17 inflammatory cytokines in the joints and skin, which was again suppressed by NJK14047. NJK14047 reversed the enlargement of spleens induced by CIA and IIP as well as increases in the levels of inflammatory cytokine in spleens following induction by CIA and IIP. In human SW982 synovial cells, NJK14047 was found to suppress lipopolysaccharide-induced increases in the mRNA expression of proinflammatory cytokines. NJK14047 inhibition of p38 MAPK suppressed the differentiation of naïve T cells to Th17 and Th1 cells. Our findings in this study provide convincing evidence indicating the therapeutic efficacy of the p38 MAPK inhibitor NJK14047 against CIA and IIP, which we speculate could be associated with the suppression on T-cell differentiation.

Impact of age and cardiovascular risk factors on the incidence of adverse events in patients with rheumatoid arthritis treated with Janus Kinase inhibitors: data from a real-life multicentric cohort

Inhibiting Janus Kinases (JAK) is a crucial therapeutic strategy in rheumatoid arthritis (RA). However, the use of JAK inhibitors has recently raised serious safety concerns. The study aims to evaluate the safety profile of JAKi in patients with RA and identify potential risk factors (RFs) for adverse events (AEs). Data of RA patients treated with JAKi in three Italian centers from January 2017 to December 2022 were retrospectively analyzed. 182 subjects (F:117, 64.3%) underwent 193 treatment courses. 78.6% had at least one RF, including age ≥ 65 years, obesity, smoking habit, hypertension, dyslipidemia, hyperuricemia, diabetes, previous VTE or cancer, and severe mobility impairment. We identified 70 AEs (28/100 patients/year), among which 15 were serious (6/100 patients/year). A high disease activity was associated with AEs occurrence (p = 0.03 for CDAI at T0 and T6; p = 0.04 for SDAI at T0 and T6; p = 0.01 and p = 0.04 for DAS28ESR at T6 and T12, respectively). No significant differences in AEs occurrence were observed after stratification by JAKi molecules (p = 0.44), age groups (p = 0.08) nor presence of RFs (p > 0.05 for all of them). Neither the presence of any RFs, nor the cumulative number of RFs shown by the patient, nor age ≥ 65 did predict AEs occurrence. Although limited by the small sample size and the limited number of cardiovascular events, our data do not support the correlation between cardiovascular RFs-including age-and a higher incidence of AEs during JAKi therapy. The role of uncontrolled disease activity in AEs occurrence should by emphasized.

Phytotherapeutic potential of compounds identified from fractionated extracts of Morus alba L., as an inhibitor of interleukin-6 in the treatment of rheumatoid arthritis: computational approach

The presence of HLA-DRB1 alleles that encode critical points associated with environmental interactions is associated with increased risk of rheumatoid arthritis caused by anti-citrullinated protein antibodies. Therefore, interleukin-6 (IL-6), a multifunctional cytokine that controls both local and systemic acute inflammatory responses through its ability to induce a phase response, plays a serious role. Its overexpression leads to pathological challenges such as rheumatoid arthritis and menopausal osteoporosis. However, targeting the IL-6 receptor and its region could be the major step in controlling the overexpression of this cytokine for therapeutic importance. Therefore, our research explored the computational insight needed to investigate the anti-RFA potential of phytochemicals from fractionated extracts of Morus alba L. against receptors, which have been implicated as druggable targets for the treatment of rheumatoid arthritis. In this study, fifty-nine (59) previously isolated and characterized phytochemicals from M. alba L. were identified from the literature and retrieved from the PubChem database. In silico screening was used to assess the mode of action of these phytochemicals from M. alba L. against receptors that may serve as therapeutic targets for rheumatoid arthritis. Molecular docking studies, toxicity prediction, drug visualization and molecular dynamics simulation (MD) of the ligands together with the receptor-identified target were carried out using the Schrodinger Molecular Drug Discovery Suite. The findings indicated that a selected group of ligands displayed significant binding strength to specific amino acid residues, revealing an important link between the building blocks of proteins (amino acids) and ligands at the inhibitor binding site through traditional chemical interactions, such as interactions between hydrophobic and hydrogen bonds. The binding affinities of the receptors were carefully checked via comparison with those of the approved ligands, and the results suggested structural and functional changes in the lead compounds. Therefore, the bioactive component from M. alba L. could be a lead foot interleukin-6 (IL-6) inhibitor and could be a promising lead compound for the treatment of rheumatoid arthritis and related challenges.Communicated by Ramaswamy H. Sarma.

Risk Factors Associated with Adverse Events Leading to Methotrexate Withdrawal in Elderly Rheumatoid Arthritis Patients: A Retrospective Cohort Study

Background: Rheumatoid arthritis (RA) in elderly population represents a challenge for physicians in terms of therapeutic management. Methotrexate (MTX) is the first-line treatment among conventional synthetic-disease-modifying anti-rheumatic drugs (cs-DMARDs); however, it is often associated with adverse events (AEs). Therefore, the objective of this study was to identify the incidence and risk factors of MTX discontinuation due to AEs in elderly patients with RA in a long-term retrospective cohort study. Methods: Clinical sheets from elderly RA patients taking MTX from an outpatient rheumatology consult in a university centre were reviewed. To assess MTX persistence, we used Kaplan-Meir curves and Cox regression models to identify the risk of withdrawing MTX due to adverse events. Results: In total, 198 elderly RA patients who reported using MTX were included. Of them, the rates of definitive suspension of MTX due to AEs were 23.0% at 5 years, 35.6% at 10 years and 51.7% at 15 years. The main organs and system involved were gastrointestinal (15.7%) and mucocutaneous (3.0%). Factors associated with withdrawing MTX due to AEs were MTX dose ≥ 15 mg/wk (adjusted HR: 2.46, 95% CI: 1.22-4.96, p = 0.012); instead, the folic acid supplementation was protective for withdrawal (adjusted HR: 0.28, 95% CI: 0.16-0.49, p < 0.001). Conclusions: Higher doses of MTX increase the risk of withdrawals in elderly RA, while folic acid supplementation reduces the risk. Therefore, physicians working in therapeutic management for elderly patients using MTX must focus on using lower MTX doses together with the concomitant prescription of folic acid.

Coassembly Nanomedicine Mediated by Intermolecular Interactions Between Methotrexate and Baricitinib for Improved Rheumatoid Arthritis Treatment

The combination of anti-rheumatoid arthritis (RA) drugs methotrexate (MTX) and baricitinib (BTN) has been reported to improve RA treatment efficacy. However, study on the strategy of combination is elusive when considering the benefit of the synergy between MTX and BTN. In this study, we found that the N-heterocyclic rings in the MTX and BTN offer hydrogen bonds and π-π stacking interactions, driving the formation of exquisite vesicular morphology of nanovesicles, denoted as MB NVs. The MB NVs with the MTX/BTN weight ratio of 2:1, MB NVs (2:1), showed an improved anti-RA effect through the synergy between the anti-inflammatory and antiproliferative responses. This work presents that the intermolecular interactions between drug molecules could mediate the coassembly behavior into nanomedicine as well as the therapy synergy both in vitro and in vivo, which may provide further understanding on the rational design of combination nanomedicine for therapeutic purposes.

Cannabinoid Receptor 2 Gene Polymorphism and the Risk of Developing Rheumatoid Arthritis in Lebanese Patients

Objective: Evidence supports a role of cannabinoid receptor 2 (CB2) in regulating the immune response. Some variations in the CB2 receptor gene (CB2) were linked to the susceptibility of developing rheumatoid arthritis (RA). The aim of this study is to assess the relationship between CNR2 rs2501431 and the risk of developing RA in Lebanese patients. Methods: A total of one hundred five Lebanese RA patients and one hundred five controls participated in the study. CNR2 was genotyped and analyzed. Results: Using χ2 test, our results show that the CC genotype was the most common (47.6%, p<0.00001) and that the C allele highly predominated (64%, p<0.00001) in the RA group compared to the control group. The relative odds ratio show that carriers of the CC genotype have more than 13-fold risk of developing RA as compared to TT. Conclusion: Our results suggest that the rs2501431 variant of CNR2 gene can be considered as a risk factor for RA development, and thus implicate the potential targeting of CB2 receptor for the treatment of RA.

Novel and potential future therapeutic options in systemic autoimmune diseases

Autoimmune inflammation is caused by the loss of tolerance to specific self-antigens and can result in organ-specific or systemic disorders. Systemic autoimmune diseases affect a significant portion of the population with an increasing rate of incidence, which means that is essential to have effective therapies to control these chronic disorders. Unfortunately, several patients with systemic autoimmune diseases do not respond at all or just partially respond to available conventional synthetic disease-modifying antirheumatic drugs and targeted therapies. However, during the past few years, some new medications have been approved and can be used in real-life clinical settings. Meanwhile, several new candidates appeared and can offer promising novel treatment options in the future. Here, we summarize the newly available medications and the most encouraging drug candidates in the treatment of systemic lupus erythematosus, rheumatoid arthritis, Sjögren's disease, systemic sclerosis, systemic vasculitis, and autoimmune myositis.

PIM Kinases as Potential Biomarkers and Therapeutic Targets in Inflammatory Arthritides

The Proviral Integration site for the Moloney murine leukemia virus (PIM)-1 kinase and its family members (PIM-2 and PIM-3) regulate several cellular functions including survival, proliferation, and apoptosis. Recent studies showed their involvement in the pathogenesis of rheumatoid arthritis RA, while no studies are available on psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA). The main objective of this study is to assess the expression of PIM kinases in inflammatory arthritides, their correlation with proinflammatory cytokines, and their variation after treatment with biologic disease-modifying anti-rheumatic drugs or JAK inhibitors. We evaluated PIM-1, -2, and -3 expression at the gene and protein level, respectively, in the peripheral blood mononuclear cells and serum of patients with RA, PsA, axSpA, and healthy individuals (CTR). All the samples showed expression of PIM-1, -2, and -3 kinases both at the gene and protein level. PIM-1 was the most expressed protein, PIM-3 the least. PIM kinase levels differed between controls and disease groups, with reduced PIM-1 protein and increased PIM-3 protein in all disease samples compared to controls. No difference was found in the expression of these molecules between the three different pathologies. PIM levels were not modified after 6 months of therapy. In conclusion, our preliminary data suggest a deregulation of the PIM pathway in inflammatory arthritides. In-depth studies on the role of PIM kinases in this field are warranted.

Rheumatoid arthritis and the intestinal microbiome: probiotics as a potential therapy

Rheumatoid arthritis (RA) is a systemic autoimmune disorder characterized by swollen joints, discomfort, stiffness, osteoporosis, and reduced functionality. Genetics, smoking, dust inhalation, high BMI, and hormonal and gut microbiota dysbiosis are all likely causes of the onset or development of RA, but the underlying mechanism remains unknown. Compared to healthy controls, patients with RA have a significantly different composition of gut microbiota. It is well known that the human gut microbiota plays a key role in the initiation, maintenance, and operation of the host immune system. Gut microbiota dysbiosis has local or systematic adverse effects on the host immune system, resulting in host susceptibility to various diseases, including RA. Studies on the intestinal microbiota modulation and immunomodulatory properties of probiotics have been reported, in order to identify their potential possibility in prevention and disease activity control of RA. This review summarized current studies on the role and potential mechanisms of gut microbiota in the development and progression of RA, as well as the preventative and therapeutic effects and potential mechanisms of probiotics on RA. Additionally, we proposed the challenges and difficulties in the application of probiotics in RA, providing the direction for the research and application of probiotics in the prevention of RA.

The effects of intermittent fasting diet on quality of life, clinical symptoms, inflammation, and oxidative stress in overweight and obese postmenopausal women with rheumatoid arthritis: study protocol of a randomized controlled trial

BACKGROUND

Rheumatoid arthritis (RA) is known as a chronic systemic autoimmune disorder that primarily targets synovial joints, and may cause pain and functional limitations. Studies show diet can have beneficial effects on symptoms and oxidative stress of this disease. Intermittent fasting (IF) is a dietary approach with cycles of fasting and intake. The current study aims to investigate the effect of IF on quality of life, clinical symptoms, inflammation, and oxidative stress in overweight and obese postmenopausal women with RA.

METHODS

The current study is a randomized clinical trial, in which 44 patients with mild to moderate severity of RA will be randomly allocated to receive either IF (n = 22) or the usual diet (n = 22) for 8 weeks. Anthropometric measures and biochemical indicators including serum concentrations of erythrocyte sedimentation rate (ESR), c-reactive protein (CRP), and total oxidant and antioxidant capacity (TOC and TAC) will be assessed at the baseline and end of the study. Also, disease severity will be assessed by Disease Activity Score-28 (DAS-28) and clinical disease activity index (CDAI), and disability index will be assessed by Health Assessment Questionnaire-Disability Index (HAQ-DI) questionnaire.

DISCUSSION

Studies show fasting has beneficial effects on inflammatory markers and results in an improvement in the health of different populations. Literature review shows it seems there is no study in this field to evaluate the effects of IF on RA patients, and they are limited to other types of fasting. However, studies show IF can have many positive effects on chronic and autoimmune diseases. Therefore, IF may have positive effects on these patients.

TRIAL REGISTRATION

IRCT20230217057441N1. Registered on 14 February 2023. https://en.irct.ir/user/trial/68669 .

An Overview of Therapeutic Targeting of Nrf2 Signaling Pathway in Rheumatoid Arthritis

Rheumatoid arthritis (RA), an autoimmune condition that has a significant inflammatory component and is exacerbated by dysregulated redox-dependent signaling pathways. In RA, the corelationship between oxidative stress and inflammation appears to be regulated by the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway. Furthermore, it has been shown that transcriptional pathways involving Nrf2 and NFκB significantly interact under conditions of oxidative stress and inflammation. Because pathologic cells in RA have a higher chance of surviving, Nrf2's influence on concomitant pathologic mechanisms in the disease is explained by its interaction with key redox-sensitive inflammatory pathways. The current review not only updates knowledge about Nrf2's function in RA but also highlights the complex interactions between Nrf2 and other redox-sensitive transcription factors, which are essential to the self-sustaining inflammatory processes that define RA. This paper also reviews the candidates for treating RA through Nrf2 activation. Finally, future directions for pharmacologic Nrf2 activation in RA are suggested.

Disparities in burden of disease in patients with rheumatoid arthritis across racial and ethnic groups

To examine racial/ethnic differences in rheumatoid arthritis (RA) disease burden and change in clinical outcomes over time. We included CorEvitas Rheumatoid Arthritis Registry patients from two time periods (2013-2015 and 2018-2020). Clinical Disease Activity Index (CDAI) (as a continuous measure and as a dichotomous measure) and the Health Assessment Questionnaire-Disability Index (HAQ-DI) were assessed at each visit. Marginal means and their corresponding 95% confidence interval (CI) by race/ethnicity were estimated for each outcome using adjusted mixed effects linear and logistic regression models. Overall and pairwise tests were conducted to detect differences between race/ethnicity groups. Of 9,363 eligible patients (8,142 White, 527 Black, 545 Hispanic, 149 Asian), most (76%-85%) were female. At Visit 1, the mean disease duration ranged from 9.8-11.8 years. Estimated CDAI was significantly higher for Hispanics compared to Whites at Visit 1 (11.1 vs. 9.9; pairwise P = 0.033) and Visit 2 (9.2 vs. 8.0, pairwise P = 0.005). Disease activity improved over the 5-year study period among all race/ethnicity groups, though Hispanics improved less than Whites. Disease activity improved over the 5-year period across all racial/ethnicity groups, and disparities between racial/ethnicity groups in disease activity and functional status did persist over time, suggesting that further effort is needed to understand the drivers of these discrepancies to close this race/ethnicity gap. Key Points • Disease activity improved over the 5-year period across all racial and ethnic groups. • Disparities between racial and ethnic groups in disease activity and functional status did persist over time, suggesting that further effort is needed to understand the drivers of these discrepancies and close this racial gap.

Patterns and determinants of response to novel therapies in juvenile and adult-onset polyarthritis

Biologic and targeted synthetic DMARDs (b/tsDMARDs) have revolutionized the management of multiple rheumatic inflammatory conditions. Among these, polyarticular JIA (pJIA) and RA display similarities in terms of disease pathophysiology and response pattern to b/tsDMARDs. Indeed, the therapeutic efficacy of novel targeted drugs is variable among individual patients, in both RA and pJIA. The mechanisms and determinants of this heterogeneous response are diverse and complex, such that the development of true 'precision'-medicine strategies has proven highly challenging. In this review, we will discuss pathophysiological, patient-specific, drug-specific and environmental factors contributing to individual therapeutic response in pJIA in comparison with what is known in RA. Although some biomarkers have been identified that stratify with respect to the likelihood of either therapeutic response or non-response, few have proved useful in clinical practice so far, likely due to the complexity of treatment-response mechanisms. Consequently, we propose a pragmatic, patient-centred and clinically based approach, i.e. personalized instead of biomarker-based precision medicine in JIA.

Ingenious Synergy of a Pathology-Specific Biomimetic Multifunctional Nanoplatform for Targeted Therapy in Rheumatoid Arthritis

Based on the pathological characteristics of rheumatoid arthritis, including the overproduction of reactive oxygen species (ROS), inflammatory responses, and osteoclast differentiation, a biomimetic multifunctional nanomedicine (M-M@I) is designed. Iguratimod (IGU) is loaded, which inhibits inflammatory responses and osteoclast differentiation, into mesoporous polydopamine (MPDA), which scavenges ROS. Subsequently, the nanoparticles are coated with a cell membrane of macrophages to achieve actively targeted delivery of the nanoparticles to inflamed joints. It is shown that the M-M@I nanoparticles are taken up well by lipopolysaccharide-induced RAW 264.7 macrophages or bone marrow-derived macrophages (BMDMs). In vitro, the M-M@I nanoparticles effectively scavenge ROS, downregulate genes related to inflammation promotion and osteoclast differentiation, and reduce the proinflammatory cytokines and osteoclast-related enzymes. They also reduce the polarization of macrophages to a pro-inflammatory M1 phenotype and inhibit differentiation into osteoclasts. In mice with collagen-induced arthritis, the M-M@I nanoparticles accumulate at arthritic sites and circulate longer, significantly mitigating arthritis symptoms and bone destruction. These results suggest that the pathology-specific biomimetic multifunctional nanoparticles are effective against rheumatoid arthritis, and they validate the approach of developing multifunctional therapies that target various pathological processes simultaneously.

Do Dynamic Plantar Pressures Differ Based on Sonographic Evidence of Metatarsophalangeal Joint Synovitis in People With Rheumatoid Arthritis?

OBJECTIVE

The metatarsophalangeal joints (MTPJs) are the most common location for synovitis in people with rheumatoid arthritis (RA), yet their association with plantar foot pressures has received very little attention. This study aimed to determine whether plantar pressures differed based on sonographic evidence of MTPJ synovitis in people with RA.

METHOD

Ultrasound was used to assess synovitis (grey scale synovial hypertrophy and power Doppler signal) in MTPJs 1 to 5 using the combined EULAR/Outcome Measures in Rheumatology scoring system. Peak pressure (PP) and pressure time integrals (PTIs) were assessed during barefoot walking for seven plantar foot regions (heel, midfoot, first metatarsal, second metatarsal, third to fifth metatarsals, hallux, lesser toes). Mixed-effects linear regression was used to determine the difference in PP and PTI between MTPJs with none/minimal synovitis and MTPJs with moderate/severe synovitis.

RESULTS

Thirty-five participants with RA were included. Mean age was 66.3 years and mean disease duration was 22.2 years. Participants with sonographic evidence of moderate/severe synovitis at the first MTPJ had reduced PTI at the hallux compared with those with none/minimal synovitis at this joint (P = 0.039). Participants with moderate/severe synovitis at the second MTPJ and fourth MTPJ had reduced PP and reduced PTI at lesser toes compared with those with none/minimal synovitis in these joints (all P ≤ 0.048). No significant differences were observed for synovitis in other joints.

CONCLUSION

These findings may be suggestive of an inverse relationship between plantar pressure and soft tissue pathology, which is consistent with an offloading strategy and reduced use of the toes during propulsion.

Inflammation-Targeting Mesenchymal Stem Cells Combined with Photothermal Treatment Attenuate Severe Joint Inflammation

Current clinical therapeutic efficacy for the treatment of osteo- and rheumatoid-arthritis is obviously limited. Although mesenchymal stem cells (MSCs) are considered as a source of promising regenerative therapy, un-modified or genetically engineered MSCs injected in vivo restrict their clinical utility because of the low drug efficacy and unpredicted side effect, respectively. Herein, a strategy to enhance the migration efficacy of MSCs to inflamed joints via an inflammation-mediated education process is demonstrated. To reinforce the limited anti-inflammatory activity of MSCs, gold nanostar loaded with triamcinolone is conjugated to MSC. Furthermore, near-infrared laser-assisted photothermal therapy (PTT) induced by gold nanostar significantly elevates the anti-inflammatory efficacy of the developed drugs, even in advanced stage arthritis model. An immunological regulation mechanism study of PTT is first suggested in this study; the expression of the interleukin 22 receptor, implicated in the pathogenesis of arthritis, is downregulated in T lymphocytes by PTT, and Th17 differentiation from naïve CD4 T cell is inhibited. Collectively, inflammation-targeting MSCs conjugated with triamcinolone-loaded gold nanostar (Edu-MSCs-AuS-TA) promote the repolarization of macrophages and decrease neutrophil recruitment in joints. In addition, Edu-MSCs-AuS-TA significantly alleviate arthritis-associated pain, improve general locomotor activity, and more importantly, induce cartilage regeneration even for severe stages of arthritis model.

Postoperative function of patients with rheumatoid arthritis after total knee arthroplasty in the last decade was comparable in the unadjusted cohort but inferior in the propensity score matched cohort with that of patients with osteoarthritis

BACKGROUND

The perioperative pain and function of total knee arthroplasty (TKA) in patients with rheumatoid arthritis (RA) approach those in patients with osteoarthritis (OA). This study aimed to evaluate whether the clinical outcomes, especially functions, of patients with RA reached those of OA, utilizing a background-matched cohort.

METHODS

Patients who underwent TKA between 2013 and 2021 were enrolled. Preoperative and minimum 2-year postoperative scores, specifically the Original Knee Society Score (OKSS) and New Knee Society Score (2011KSS), between RA and OA were compared. Clinical assessments were performed on unadjusted and propensity-score matched cohorts, ensuring age, sex, body mass index, and valgus deformity rate parity.

RESULTS

In an unadjusted cohort involving 98 patients with RA and 560 patients with OA, patients with RA demonstrated inferior preoperative OKSS-Function Score (FS) but similar postoperative functional scores to OA patients. In the matched cohort of 83, patients with RA displayed lower preoperative OKSS- FS (median difference: 20, P < 0.001) and 2011KSS functional activities (difference: 9, P = 0.01) beyond minimum clinically important differences than patients with OA. Patients with RA improved more in OKSS-FS, yielding no postoperative difference compared with patients with OA. However, postoperative 2011KSS functional activities remained lower in patients with RA (difference: 9.5, P = 0.03), especially in advanced functions, than in those with OA.

CONCLUSION

Postoperative function showed no difference between patients with RA and OA in the unadjusted cohort; within the background-matched cohort, postoperative function, especially advanced function, was inferior in patients with RA to those with OA.

Performance of Anti-Carbamylated Protein Antibody Testing in the Routine Evaluation of Rheumatoid Arthritis from a Single Center

BACKGROUND

Detection of anticyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factors (RF) in sera support the diagnosis of rheumatoid arthritis (RA); however, these markers are not detected in about 20% of RA patients. More recently, antibodies against carbamylated proteins (anti-CarP) have emerged with implications for preclinical RA diagnosis. The objective of this study was to assess the clinical performance of anti-CarP and correlate with disease severity in routine clinical practice.

METHODS

Retrospective chart review of 331 subjects submitted for RA panel serology: 136 clinically defined RA-positive and 195 RA-negative patients. Fifty additional individuals were recruited for healthy controls. Patients' sera were tested for anti-CCP, anti-CarP, and RF antibodies. Clinical performance characteristics were evaluated for anti-CarP individually and in combination with anti-CCP and RF. Documented erosions and synovitis were correlated with anti-CarP positivity.

RESULTS

Anti-CarP had a clinical sensitivity and specificity of 27% and 94%, respectively, for established RA. This sensitivity was lower than anti-CCP (79%) and RF (85%). The specificity of anti-CarP was similar to anti-CCP (93%) and higher than RF (69%). Anti-CarP in combination with anti-CCP and RF increased specificity (100%) but decreased sensitivity (21%). There was no correlation of anti-CarP positivity with presence of bone erosions; however, there was an increase in anti-CarP positivity among patients with synovitis.

CONCLUSIONS

Anti-CarP demonstrates high specificity in diagnosis of established RA but lacks clinical sensitivity. In combination, anti-CarP does not improve clinical performance of anti-CCP and RF but may be useful in anti-CCP negative patients and in identifying patients with more active disease.

Serum amyloid A expression in liver promotes synovial macrophage activation and chronic arthritis via NFAT5

Nuclear factor of activated T-cells 5 (NFAT5), an osmo-sensitive transcription factor, can be activated by isotonic stimuli, such as infection. It remains unclear, however, whether NFAT5 is required for damage-associated molecular pattern-triggered (DAMP-triggered) inflammation and immunity. Here, we found that several DAMPs increased NFAT5 expression in macrophages. In particular, serum amyloid A (SAA), primarily generated by the liver, substantially upregulated NFAT5 expression and activity through TLR2/4-JNK signalling pathway. Moreover, the SAA-TLR2/4-NFAT5 axis promoted migration and chemotaxis of macrophages in an IL-6- and chemokine ligand 2-dependent (CCL2-dependent) manner in vitro. Intraarticular injection of SAA markedly accelerated macrophage infiltration and arthritis progression in mice. By contrast, genetic ablation of NFAT5 or TLR2/4 rescued the pathology induced by SAA, confirming the SAA-TLR2/4-NFAT5 axis in vivo. Myeloid-specific depletion of NFAT5 also attenuated SAA-accelerated arthritis. Of note, inflammatory arthritis in mice strikingly induced SAA overexpression in the liver. Conversely, forced overexpression of the SAA gene in the liver accelerated joint damage, indicating that the liver contributes to bolstering chronic inflammation at remote sites by secreting SAA. Collectively, this study underscores the importance of the SAA-TLR2/4-NFAT5 axis in innate immunity, suggesting that acute phase reactant SAA mediates mutual interactions between liver and joints and ultimately aggravates chronic arthritis by enhancing macrophage activation.

Socioeconomic deprivation is associated with reduced response and lower treatment persistence with TNF inhibitors in rheumatoid arthritis

OBJECTIVE

To investigate the association between socioeconomic deprivation and outcomes following TNF inhibitor (TNFi) treatment.

METHODS

Individuals commencing their first TNFi in the British Society for Rheumatology Biologics Register for RA (BSRBR-RA) and Biologics in RA Genetics and Genomics Study Syndicate (BRAGGSS) cohort were included. Socioeconomic deprivation was proxied using the Index of Multiple Deprivation and categorized as 20% most deprived, middle 40% or 40% least deprived. DAS28-derived outcomes at 6 months (BSRBR-RA) and 3 months (BRAGGSS) were compared using regression models with the least deprived as referent. Risks of all-cause and cause-specific drug discontinuation were compared using Cox models in the BSRBR-RA. Additional analyses adjusted for lifestyle factors (e.g. smoking, BMI) as potential mediators.

RESULTS

16 085 individuals in the BSRBR-RA were included (mean age 56 years, 76% female), of whom 18%, 41% and 41% were in the most, middle and least deprived groups, respectively. Of 3459 included in BRAGGSS (mean age 57, 77% female), proportions were 22%, 36% and 41%, respectively. The most deprived group had 0.3-unit higher 6-month DAS28 (95% CI 0.22, 0.37) and were less likely to achieve low disease activity (odds ratio [OR] 0.76; 95% CI 0.68, 0.84) in unadjusted models. Results were similar for 3-month DAS28 (β = 0.23; 95% CI 0.11, 0.36) and low disease activity (OR 0.77; 95% CI 0.63, 0.94). The most deprived were more likely to discontinue treatment (hazard ratio 1.18; 95% CI 1.12, 1.25), driven by ineffectiveness rather than adverse events. Adjusted estimates were generally attenuated.

CONCLUSION

Socioeconomic deprivation is associated with reduced response to TNFi. Improvements in determinants of health other than lifestyle factors are needed to address socioeconomic inequities.

Mortality in patients with incident rheumatoid arthritis and depression: a Danish cohort study of 11 071 patients and 55 355 comparators

OBJECTIVES

In patients with RA, the association between mortality and depression has been investigated only in patients with prevalent RA. In this study, we estimated the mortality risk associated with depression, defined as the first filling of a prescription for antidepressants, in patients with incident RA and background population comparators.

METHODS

From 2008 to 2018, we identified patients with incident RA in the nationwide Danish rheumatologic database, DANBIO. For each patient, we randomly selected five comparators. Participants were not treated with antidepressants or diagnosed with depression 3 years prior to the index date. From other registers we collected data on socioeconomic status, mortality and cause of death using unique personal identifiers. Using Cox models, we calculated hazard rate ratios (HRR) with 95% CI.

RESULTS

In depressed patients with RA vs patients without depression, adjusted HRR for all-cause mortality was 5.34 (95% CI 3.02, 9.45) during 0-2 years and 3.15 (95% CI 2.62, 3.79) during the total follow-up period, and highest in patients <55 years with HRR 8.13 (95% CI 3.89, 17.02). In comparators with depression vs comparators without depression, the association with mortality was similar to that in patients with RA. There were no unnatural causes of death among depressed patients with RA. The most frequent natural causes of death were cancer, cardiovascular disease, stroke and pneumonia.

CONCLUSION

In patients with RA, depression was a predictor of death but with a strength similar to that in matched comparators.

Transient receptor potential vanilloid 1: A potential therapeutic target for the treatment of osteoarthritis and rheumatoid arthritis

This study aims to determine the molecular mechanisms and analgesic effects of transient receptor potential vanilloid 1 (TRPV1) in the treatments of osteoarthritis (OA) and rheumatoid arthritis (RA). We summarize and analyse current studies regarding the biological functions and mechanisms of TRPV1 in arthritis. We search and analyse the related literature in Google Scholar, Web of Science and PubMed databases from inception to September 2023 through the multi-combination of keywords like 'TRPV1', 'ion channel', 'osteoarthritis', 'rheumatoid arthritis' and 'pain'. TRPV1 plays a crucial role in regulating downstream gene expression and maintaining cellular function and homeostasis, especially in chondrocytes, synovial fibroblasts, macrophages and osteoclasts. In addition, TRPV1 is located in sensory nerve endings and plays an important role in nerve sensitization, defunctionalization or central sensitization. TRPV1 is a non-selective cation channel protein. Extensive evidence in recent years has established the significant involvement of TRPV1 in the development of arthritis pain and inflammation, positioning it as a promising therapeutic target for arthritis. TRPV1 likely represents a feasible therapeutic target for the treatment of OA and RA.

Rheumatoid arthritis molecular targets and their importance to flavonoid-based therapy

Rheumatoid arthritis (RA) is a progressive, chronic, autoimmune, inflammatory, and systemic condition that primarily affects the synovial joints and adjacent tissues, including bone, muscle, and tendons. The World Health Organization recognizes RA as one of the most prevalent chronic inflammatory diseases. In the last decade, there was an expansion on the available RA therapeutic options which aimed to improve patient's quality of life. Despite the extensive research and the emergence of new therapeutic approaches and drugs, there are still significant unwanted side effects associated to these drugs and still a vast number of patients that do not respond positively to the existing therapeutic strategies. Over the years, several references to the use of flavonoids in the quest for new treatments for RA have emerged. This review aimed to summarize the existing literature about the flavonoids' effects on the major pathogenic/molecular targets of RA and their potential use as lead compounds for the development of new effective molecules for RA treatment. It is demonstrated that flavonoids can modulate various players in synovial inflammation, regulate immune cell function, decrease synoviocytes proliferation and balance the apoptotic process, decrease angiogenesis, and stop/prevent bone and cartilage degradation, which are all dominant features of RA. Although further investigation is necessary to determine the effectiveness of flavonoids in humans, the available data from in vitro and in vivo models suggest their potential as new disease-modifying anti-rheumatic drugs. This review highlights the use of flavonoids as a promising avenue for future research in the treatment of RA.

Predictive value of baseline concomitant glucocorticoid for abatacept-mediated long-term inhibition of radiographic progression: insights from the KURAMA cohort

Abatacept (ABT) is a biological disease-modifying antirheumatic drug (bDMARDs) for rheumatoid arthritis (RA) when conventional synthetic DMARDs are ineffective. We aimed to evaluate the long-term effects of ABT on joint destruction in patients treated for over 2 years. Radiographic progression was evaluated using the van der Heijde-modified Total Sharp Score (mTSS) by two rheumatologists at ABT initiation and after 2 years. Multivariate logistic regression analysis was used to identify factors associated with structural remission, defined as the mean annual change in mTSS ≤0.5. Among the 111 patients included, 48 discontinued, and 63 continued ABT treatment until radiographic evaluation was performed. The rate of patients who achieved estimated TSS REM (yearly progression of van der Heijde modified total Sharp scores ≤0.5) was significantly lower in ABT-dropouts than in the ABT-continued group (69% vs. 48%, p = .0336 by Fisher's exact test). Among the continued ABT cases, concomitant glucocorticoid treatment at ABT initiation was the strongest negative predictive factor of estimated TSS REM in univariate and multivariate logistic regression analyses. Radiographic progression after ABT administration should be evaluated separately for dropout and non-dropout cases. Glucocorticoids at the initiation of ABT may serve as a predictive factor for joint destruction in long-term ABT use.

Patients' experience of a novel interdisciplinary nurse-led self-management intervention (INSELMA)-a qualitative evaluation

BACKGROUND

Despite continuous improvements in anti-rheumatic pharmacological treatment, people with chronic inflammatory arthritis still report substantial disease impact. Based on the framework for complex interventions, we thus developed INSELMA, a novel nurse-coordinated multidisciplinary self-management intervention for patients with rheumatoid arthritis, psoriatic arthritis or axial spondyloarthritis. Based on individual biopsychosocial assessments, a rheumatology nurse facilitated goal setting and coordinated interdisciplinary support. The aim of this study was to explore the patients' experience of participating in the six-months INSELMA intervention.

METHODS

Individual semi-structured interviews were conducted with 15 of the participants after their final follow-up. Thematic analysis was applied.

RESULTS

The analysis derived four overall themes. (1) A new opportunity at the right time. The participants' disease impacted all areas of daily life. Participation in INSELMA was experienced as an opportunity to improve symptoms and together reduce long-held challenges they had fought alone, until now. (2) The importance of person-centred goals. The participants found it meaningful to work with their individual goals, which encompassed physical, psychological, and social factors. Having time between consultations to work with goals at home was important. (3) Empathy, partnership and a little nudging from health professionals are essential. The empathic nurses' continuous support and coaching helped participants become aware of their own resources. The participants highlighted having access to support from a physiotherapist and occupational therapist with rheumatology experience as important. (4) I got more than I could have hoped for. Most of the participants experienced decreased symptom load and improvement in physical strength, mobility, sleep, and mood as well as increased energy, knowledge, and self-management ability. The participants expressed new hope for the future with an improved ability to manage their symptoms and work towards new goals.

CONCLUSION

The participants found the INSELMA intervention meaningful and feasible. They experienced decreased disease impact and increased activity levels, facilitated by empathy and self-management support from health professionals.

Rheumatoid arthritis: pathogenesis and therapeutic advances

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by the unresolved synovial inflammation for tissues-destructive consequence, which remains one of significant causes of disability and labor loss, affecting about 0.2-1% global population. Although treatments with disease-modifying antirheumatic drugs (DMARDs) are effective to control inflammation and decrease bone destruction, the overall remission rates of RA still stay at a low level. Therefore, uncovering the pathogenesis of RA and expediting clinical transformation are imminently in need. Here, we summarize the immunological basis, inflammatory pathways, genetic and epigenetic alterations, and metabolic disorders in RA, with highlights on the abnormality of immune cells atlas, epigenetics, and immunometabolism. Besides an overview of first-line medications including conventional DMARDs, biologics, and small molecule agents, we discuss in depth promising targeted therapies under clinical or preclinical trials, especially epigenetic and metabolic regulators. Additionally, prospects on precision medicine based on synovial biopsy or RNA-sequencing and cell therapies of mesenchymal stem cells or chimeric antigen receptor T-cell are also looked forward. The advancements of pathogenesis and innovations of therapies in RA accelerates the progress of RA treatments.

Metabolic changes in fibroblast-like synoviocytes in rheumatoid arthritis: state of the art review

Fibroblast-like synoviocytes (FLS) are important components of the synovial membrane. They can contribute to joint damage through crosstalk with inflammatory cells and direct actions on tissue damage pathways in rheumatoid arthritis (RA). Recent evidence suggests that, compared with FLS in normal synovial tissue, FLS in RA synovial tissue exhibits significant differences in metabolism. Recent metabolomic studies have demonstrated that metabolic changes, including those in glucose, lipid, and amino acid metabolism, exist before synovitis onset. These changes may be a result of increased biosynthesis and energy requirements during the early phases of the disease. Activated T cells and some cytokines contribute to the conversion of FLS into cells with metabolic abnormalities and pro-inflammatory phenotypes. This conversion may be one of the potential mechanisms behind altered FLS metabolism. Targeting metabolism can inhibit FLS proliferation, providing relief to patients with RA. In this review, we aimed to summarize the evidence of metabolic changes in FLS in RA, analyze the mechanisms of these metabolic alterations, and assess their effect on RA phenotype. Finally, we aimed to summarize the advances and challenges faced in targeting FLS metabolism as a promising therapeutic strategy for RA in the future.

To flare or not to flare: patients' and rheumatologists' perceptions on the on-flare retreatment strategy of rituximab in rheumatoid arthritis

Background

Several retreatment strategies exist for rituximab in rheumatoid arthritis (RA). In some countries, reimbursement criteria require a loss of disease control for rituximab retreatment. Understanding the patients' and rheumatologists' perceptions regarding this retreatment strategy would be informative in identifying the optimal treatment administration schedule.

Objectives

This study aimed to uncover patients' and rheumatologists' perceptions regarding retreatment strategies of rituximab.

Design

Qualitative study - semi-structured interviews.

Methods

Patients with RA, treated with rituximab, and rheumatologists were invited to participate in a qualitative study consisting of individual, in-depth, semi-structured interviews. Interviews were analysed according to the Qualitative Analysis Guide of Leuven.

Results

A total of 16 patients and 13 rheumatologists were interviewed. Benefits (e.g. decreased risk of overtreatment, cost savings and long-lasting effectiveness of rituximab) and barriers (e.g. fluctuating disease activity, slow mode of action and increased glucocorticoid use) of on-flare retreatment were identified. To effectively treat on-flare, flares must first be identified timely. Both stakeholder groups acknowledged that patients are capable of recognizing flares. However, the patient's ability to discriminate between inflammatory and other types of pain was perceived as difficult. Furthermore, patients and rheumatologists stressed that patients must timely seek professional help in case of a flare, followed by a swift response from the rheumatologists. Remarkably, retreatment was approached in various ways among rheumatologists, and not always adhering strictly to the on-flare reimbursement criteria.

Conclusion

This study revealed that both stakeholder groups perceived the heterogeneity in recognition of and reaction to a flare as important in influencing the effectiveness of the on-flare retreatment strategy. Moreover, this study identified the benefits and barriers of treating on-flare, which could be informative for daily practice decisions.

Associations of disease duration and anti-citrullinated peptide antibody status with the effectiveness of abatacept in biologic-naïve patients with rheumatoid arthritis: Post hoc analysis of a multicentre, real-world observational study in Japan (ORIGAMI)

OBJECTIVES

The aim of the article is to investigate the associations of disease duration and anti-cyclic citrullinated peptide antibody (ACPA) status with the effectiveness of abatacept in biologic-naïve patients with rheumatoid arthritis (RA).

METHODS

We performed post hoc analyses of the Orencia® Registry in Geographically Assembled Multicenter Investigation (ORIGAMI) study of biologic-naïve RA patients aged ≥20 years with moderate disease activity who were prescribed abatacept. Changes in the Simplified Disease Activity Index (SDAI) and Japanese Health Assessment Questionnaire (J-HAQ) at 4, 24, and 52 weeks of treatment were analysed in patients divided according to ACPA serostatus (positive/negative), disease duration (<1/≥1 year), or both.

RESULTS

SDAI scores decreased from baseline in all groups. SDAI scores tended to decrease more in the ACPA-positive group and disease duration <1-year group than in the ACPA-negative group and disease duration ≥1-year group, respectively. In the disease duration <1-year group, SDAI tended to decrease more in the ACPA-positive group than in the ACPA-negative group. Disease duration was independently associated with the change in SDAI and SDAI remission at Week 52 in multivariable regression models.

CONCLUSIONS

These results suggest that starting abatacept within 1 year of diagnosis was associated with greater effectiveness of abatacept in biologic-naïve patients with RA and moderate disease activity.

The gut-joint axis: Genetic evidence for a causal association between gut microbiota and seropositive rheumatoid arthritis and seronegative rheumatoid arthritis

This study aimed to assess the causal relationship between GM and RA (seropositive RA and seronegative RA). A two-sample Mendelian randomization (MR) analysis was performed to assess the causality of GM on seropositive RA and seronegative RA. GM's genome-wide association study (GWAS) was used as the exposure, whereas the GWAS datasets of seropositive RA and seronegative RA were the outcomes. The primary analysis approach was used as inverse-variance weighted (IVW), followed by 3 additional MR methods (MR-Egger, weighted median, and weighted mode). Cochran's Q test was used to identify heterogeneity. The MR-Egger intercept test and leave-one-out analyses were used to assess horizontal pleiotropy. All statistical analyses were performed in R software. We discovered that Alloprevotella (IVW OR 0.84, 95% CI 0.71-0.99, P = .04) and Christensenellaceae R 7 group (IVW OR 0.71, 95% CI 0.52-0.99, P = .04) were negatively correlated with seropositive RA, Ruminococcaceae UCG002 (IVW OR 1.30, 95% CI 1.10-1.54, P = .002) was positively associated with seropositive RA. Actinomyces (IVW OR 0.73, 95% CI 0.54-0.99, P = .04), Christensenellaceae R 7 group (IVW OR 0.62, 95% CI 0.39-0.97, P = .04), Terrisporobacter (IVW OR 0.64, 95% CI 0.44-0.93, P = .02), Lactobacillales (IVW OR 0.65, 95% CI 0.47-0.90, P = .01) were negatively correlated with seronegative RA. The present MR analysis showed a protective effect of Alloprevotella and Christensenellaceae R 7 group and a potentially anti-protective effect of Ruminococcaceae UCG002 on seropositive RA; and a protective effect of Actinomyces, Christensenellaceae R 7 group, Terrisporobacter, and Lactobacillales on seronegative RA. Further experimental studies and randomized controlled trials are needed to validate these findings.

Burden of non-serious infections during biological use for rheumatoid arthritis

INTRODUCTION

Biologicals have become a cornerstone in rheumatoid arthritis (RA) treatment. The increased risk of serious infections associated with their use is well-established. Non-serious infections, however, occur more frequently and are associated with a high socioeconomic burden and impact on quality of life but have not received the same attention in the literature to date. The aim of this study was to gain insight into the various non-serious infections reported in RA patients using biologicals and their experienced burden.

MATERIALS AND METHODS

The Dutch Biologic Monitor was a prospective observational study that included adults with rheumatoid arthritis and biological use who answered bimonthly questionnaires on the adverse drug reactions (ADRs) they experienced from their biological and reported the associated impact score (ranging from 1, no impact, to 5, very high impact). ADRs were assigned a MedDRA code by pharmacovigilance experts and labeled as definite, probable, possible or no infection by infectious disease professionals. Descriptive statistics were performed using medians and interquartile ranges.

RESULTS

A total of 586 patients were included in the final analysis. Eighty-five patients (14.5%) reported a total of 421 ADRs labeled as probable or definite infections by the experts. Patient-assigned burden was ADR-specific. Upper respiratory tract infections were most frequently reported and had a high rate of recurrence or persistence, with a median impact score of 3.0 (IQR 2.0-3.0) which remained stable over time.

DISCUSSION

Non-serious infections significantly outnumbered serious infections in this real-life cohort of RA patients using biologicals (77.1 non-serious infections and 1.3 serious infections per 100 patient years, respectively). Infections in the upper respiratory tract were rated as having an average burden, which remained constant over a long period of time. Awareness of the impact of recurrent and chronic non-serious infections may enable healthcare professionals to timely treat and maybe even prevent them, which would lessen the associated personal and socioeconomic burden.

The Role of the Dysregulated JNK Signaling Pathway in the Pathogenesis of Human Diseases and Its Potential Therapeutic Strategies: A Comprehensive Review

JNK is named after c-Jun N-terminal kinase, as it is responsible for phosphorylating c-Jun. As a member of the mitogen-activated protein kinase (MAPK) family, JNK is also known as stress-activated kinase (SAPK) because it can be activated by extracellular stresses including growth factor, UV irradiation, and virus infection. Functionally, JNK regulates various cell behaviors such as cell differentiation, proliferation, survival, and metabolic reprogramming. Dysregulated JNK signaling contributes to several types of human diseases. Although the role of the JNK pathway in a single disease has been summarized in several previous publications, a comprehensive review of its role in multiple kinds of human diseases is missing. In this review, we begin by introducing the landmark discoveries, structures, tissue expression, and activation mechanisms of the JNK pathway. Next, we come to the focus of this work: a comprehensive summary of the role of the deregulated JNK pathway in multiple kinds of diseases. Beyond that, we also discuss the current strategies for targeting the JNK pathway for therapeutic intervention and summarize the application of JNK inhibitors as well as several challenges now faced. We expect that this review can provide a more comprehensive insight into the critical role of the JNK pathway in the pathogenesis of human diseases and hope that it also provides important clues for ameliorating disease conditions.

The Hippo-YAP Signaling Pathway in Osteoarthritis and Rheumatoid Arthritis

Arthritis is the most prevalent joint disease and is characterized by articular cartilage degradation, synovial inflammation, and changes in periarticular and subchondral bone. Recent studies have reported that Yes-associated protein (YAP) and the transcriptional coactivator with PDZ-binding motif (TAZ) have significant effects on the proliferation, migration, and survival of chondrocytes and fibroblast-like synovial cells (FLSs). YAP/TAZ signaling pathway, as well as the related Hippo-YAP signaling pathway, are responsible for the condition of cells and articular cartilage in joints. They are tightly regulated to maintain metabolism in chondrocytes and FLSs because abnormal expression may result in cartilage damage. However, the roles and mechanisms of the Hippo-YAP pathway in arthritis remain largely unknown. This review summarizes the roles and key functions of YAP/TAZ and the Hippo-YAP signaling pathway in FLSs and chondrocytes for the induction of proliferation, migration, survival, and differentiation in rheumatoid arthritis (RA) and osteoarthritis (OA) research. We also discuss the therapeutic strategies involving YAP/TAZ and the related Hippo-YAP signaling pathway involved in OA.

Expression quantitative trait loci analysis in rheumatoid arthritis identifies tissue specific variants associated with severity and outcome

OBJECTIVE

Genome-wide association studies have successfully identified more than 100 loci associated with susceptibility to rheumatoid arthritis (RA). However, our understanding of the functional effects of genetic variants in causing RA and their effects on disease severity and response to treatment remains limited.

METHODS

In this study, we conducted expression quantitative trait locus (eQTL) analysis to dissect the link between genetic variants and gene expression comparing the disease tissue against blood using RNA-Sequencing of synovial biopsies (n=85) and blood samples (n=51) from treatment-naïve patients with RA from the Pathobiology of Early Arthritis Cohort.

RESULTS

This identified 898 eQTL genes in synovium and genes loci in blood, with 232 genes in common to both synovium and blood, although notably many eQTL were tissue specific. Examining the HLA region, we uncovered a specific eQTL at HLA-DPB2 with the critical triad of single-nucleotide polymorphisms (SNPs) rs3128921 driving synovial HLA-DPB2 expression, and both rs3128921 and HLA-DPB2 gene expression correlating with clinical severity and increasing probability of the lympho-myeloid pathotype.

CONCLUSIONS

This analysis highlights the need to explore functional consequences of genetic associations in disease tissue. HLA-DPB2 SNP rs3128921 could potentially be used to stratify patients to more aggressive treatment immediately at diagnosis.

STAT4 Gene Variant rs7574865 Is Associated with Rheumatoid Arthritis Activity and Anti-CCP Levels in the Western but Not in the Southern Population of Mexico

Rheumatoid Arthritis (RA) is a multifactorial autoimmune disease. Currently, several genes play an important role in the development of the disease. The objective was to evaluate the association of the STAT4 rs7574865 and rs897200 gene variants with RA susceptibility, DAS28, RF, and anti-CCP in Western and Southern Mexico populations. Genotyping was performed on 476 samples (cases = 240; controls = 236) using the Taqman® system and qPCR probes. Disease activity was assessed using DAS28 and HAQ DI. CRP, ESR, RF, and anti-CCP were determined for clinical assessment. Our study showed there is a statistically significant association with susceptibility to RA for the rs7574865 variant in the Western population for the GT and TT genotypes. The same genotypes also showed a moderate-to-high activity according to DAS28 and positive anti-CCP compared to the control group. This association was not found in the Southern population. This work confirms the association of the rs7574865 variant with RA, as well as a moderate-to-high activity and positive anti-CCP in the Western population but not in the Southern population. No association of the rs897200 variant was found in any of the studied populations.

Recent advances of m6A methylation in skeletal system disease

Skeletal system disease (SSD) is defined as a class of chronic disorders of skeletal system with poor prognosis and causes heavy economic burden. m6A, methylation at the N6 position of adenosine in RNA, is a reversible and dynamic modification in posttranscriptional mRNA. Evidences suggest that m6A modifications play a crucial role in regulating biological processes of all kinds of diseases, such as malignancy. Recently studies have revealed that as the most abundant epigentic modification, m6A is involved in the progression of SSD. However, the function of m6A modification in SSD is not fully illustrated. Therefore, make clear the relationship between m6A modification and SSD pathogenesis might provide novel sights for prevention and targeted treatment of SSD. This article will summarize the recent advances of m6A regulation in the biological processes of SSD, including osteoporosis, osteosarcoma, rheumatoid arthritis and osteoarthritis, and discuss the potential clinical value, research challenge and future prospect of m6A modification in SSD.

DNA hypomethylation ameliorates erosive inflammatory arthritis by modulating interferon regulatory factor-8

Epigenetic regulation plays a crucial role in the pathogenesis of autoimmune diseases such as inflammatory arthritis. DNA hypomethylating agents, such as decitabine (DAC), have been shown to dampen inflammation and restore immune homeostasis. In the present study, we demonstrate that DAC elicits potent anti-inflammatory effects and attenuates disease symptoms in several animal models of arthritis. Transcriptomic and epigenomic profiling show that DAC-mediated hypomethylation regulates a wide range of cell types in arthritis, altering the differentiation trajectories of anti-inflammatory macrophage populations, regulatory T cells, and tissue-protective synovial fibroblasts (SFs). Mechanistically, DAC-mediated demethylation of intragenic 5'-Cytosine phosphate Guanine-3' (CpG) islands of the transcription factor Irf8 (interferon regulatory factor 8) induced its re-expression and promoted its repressor activity. As a result, DAC restored joint homeostasis by resetting the transcriptomic signature of negative regulators of inflammation in synovial macrophages (MerTK, Trem2, and Cx3cr1), TREGs (Foxp3), and SFs (Pdpn and Fapα). In conclusion, we found that Irf8 is necessary for the inhibitory effect of DAC in murine arthritis and that direct expression of Irf8 is sufficient to significantly mitigate arthritis.

The causal effect of two occupational factors on osteoarthritis and rheumatoid arthritis: a Mendelian randomization study

Background

Osteoarthritis (OA) and rheumatoid arthritis (RA) are two common types of arthritis. We conducted a two-sample Mendelian randomization (MR) study to estimate the causal effects of two common occupational factors-job involves heavy manual or physical work and job involves mainly walking or standing-on OA and RA in individuals of European ancestry.

Methods

Instruments were chosen from genome-wide association studies (GWASs) that identified independent single nucleotide polymorphisms (SNPs) robustly linked to job involves heavy manual or physical work (N = 263,615) as well as job involves mainly walking or standing (N = 263,556). Summary statistics for OA and RA were taken from the Integrative Epidemiology Unit (IEU) GWAS database; both discovery and replication GWAS datasets were considered. The primary analysis utilized the inverse variance weighted (IVW) MR method supplemented by various sensitivity MR analyses.

Results

In the IVW model, we found that genetically predicted job involves heavy manual or physical work was significantly associated with OA in both the discovery [odds ratio (OR) = 1.034, 95% confidence interval (CI): 1.016-1.053, P = 2.257 × 10-4] and replication (OR = 1.857, 95% CI: 1.223-2.822, P = 0.004) analyses. The causal associations were supported in diverse sensitivity analyses. MR analyses suggested no causal effect of genetically predicted job involves heavy manual or physical work on RA. Similarly, our data provided no evidence that genetically predicted job involves mainly walking or standing was related to OA and RA.

Conclusions

Our MR study suggests that job involves heavy manual or physical work is a risk factor for OA. It is of utmost importance to create preventive strategies aimed at reducing its impact on OA at such work sites.

Real-world effects of Yishen Tongbi decoction for rheumatoid arthritis: protocol for a prospective, observational, multicenter cohort study with validation against double-blind, randomized, controlled trial

Introduction: Rheumatoid arthritis (RA) is a globally challenging and refractory autoimmune disease, constituting a serious menace to human health. RA is characterized by recurrent pain and is difficult to resolve, necessitating prolonged medication for control. Yishen Tongbi decoction is a traditional Chinese herbal compound prescribed for treating RA. We have completed a 3-year RCT study that confirmed the clinical efficacy of Yishen Tongbi decoction for RA. Notably, we observed a faster clinical remission rate compared to MTX by week 4 of treatment. In our forthcoming study, we intend to conduct a comprehensive assessment of the efficacy and safety of Yishen Tongbi decoction in the real-world treatment of RA through a prospective study. Methods and analysis: This prospective, multicenter, real-world observational study will be conducted at two designated centers in China from October 2023 to August 2025. The study will include 324 patients with active rheumatoid arthritis. One group will receive Yishen Tongbi decoction combined with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs). The other group will receive standard treatment. Standard treatment can be further divided into subgroups: csDMARDs, targeted synthetic disease-modifying antirheumatic drugs (tsDMARDs), and biologic disease-modifying antirheumatic drugs (bDMARDs). In each group, the number of tender joints, number of swollen joints, pain score, patient global assessment, physician global assessment, disease activity index (DAS28-ESR or DAS28-CRP), clinical disease activity index (cDAI), simplified disease activity index (sDAI) and relevant laboratory data will be compared. Clinical indicators and disease activity of the patients will be assessed at baseline, week 4 and week 12 after the initiation of treatment. The primary outcome will be the American College of Rheumatology 20% improvement criteria (ACR20) attainment rate among patients at week 12 after treatment. Every adverse event will be reported. Ethics and dissemination: This study has been approved by the Ethics Committee of the first affiliated Hospital of Guangzhou University of traditional Chinese Medicine (NO.K-2023-009). The results of the study will be published in national and international peer-reviewed journals and at scientific conferences. The researchers will inform participants and other RA patients of the results through health education. Clinical Trial Registration: https://www.chictr.org.cn/index.html, identifier ChiCTR2300076073.

B Cells Dynamic in Aging and the Implications of Nutritional Regulation

Aging negatively affects B cell production, resulting in a decrease in B-1 and B-2 cells and impaired antibody responses. Age-related B cell subsets contribute to inflammation. Investigating age-related alterations in the B-cell pool and developing targeted therapies are crucial for combating autoimmune diseases in the elderly. Additionally, optimal nutrition, including carbohydrates, amino acids, vitamins, and especially lipids, play a vital role in supporting immune function and mitigating the age-related decline in B cell activity. Research on the influence of lipids on B cells shows promise for improving autoimmune diseases. Understanding the aging B-cell pool and considering nutritional interventions can inform strategies for promoting healthy aging and reducing the age-related disease burden.

Recent advances of NFATc1 in rheumatoid arthritis-related bone destruction: mechanisms and potential therapeutic targets

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease characterized by inflammation of the synovial tissue and joint bone destruction, often leading to significant disability. The main pathological manifestation of joint deformity in RA patients is bone destruction, which occurs due to the differentiation and proliferation of osteoclasts. The transcription factor nuclear factor-activated T cell 1 (NFATc1) plays a crucial role in this process. The regulation of NFATc1 in osteoclast differentiation is influenced by three main factors. Firstly, NFATc1 is activated through the upstream nuclear factor kappa-B ligand (RANKL)/RANK signaling pathway. Secondly, the Ca2+-related co-stimulatory signaling pathway amplifies NFATc1 activity. Finally, negative regulation of NFATc1 occurs through the action of cytokines such as B-cell Lymphoma 6 (Bcl-6), interferon regulatory factor 8 (IRF8), MAF basic leucine zipper transcription factor B (MafB), and LIM homeobox 2 (Lhx2). These three phases collectively govern NFATc1 transcription and subsequently affect the expression of downstream target genes including TRAF6 and NF-κB. Ultimately, this intricate regulatory network mediates osteoclast differentiation, fusion, and the degradation of both organic and inorganic components of the bone matrix. This review provides a comprehensive summary of recent advances in understanding the mechanism of NFATc1 in the context of RA-related bone destruction and discusses potential therapeutic agents that target NFATc1, with the aim of offering valuable insights for future research in the field of RA. To assess their potential as therapeutic agents for RA, we conducted a drug-like analysis of potential drugs with precise structures.

The role of purinergic signaling in acupuncture-mediated relief of neuropathic and inflammatory pain

Acupuncture is a traditional medicinal practice in China that has been increasingly recognized in other countries in recent decades. Notably, several reports have demonstrated that acupuncture can effectively aid in pain management. However, the analgesic mechanisms through which acupuncture provides such benefits remain poorly understood. Purinergic signaling, which is mediated by purine nucleotides and purinergic receptors, has been proposed to play a central role in acupuncture analgesia. On the one hand, acupuncture affects the transmission of nociception by increasing adenosine triphosphate dephosphorylation and thereby decreasing downstream P2X3, P2X4, and P2X7 receptors signaling activity, regulating the levels of inflammatory factors, neurotrophic factors, and synapsin I. On the other hand, acupuncture exerts analgesic effects by promoting the production of adenosine, enhancing the expression of downstream adenosine A1 and A2A receptors, and regulating downstream inflammatory factors or synaptic plasticity. Together, this systematic overview of the field provides a sound, evidence-based foundation for future research focused on the application of acupuncture as a means of relieving pain.

Anti-Acidification and Immune Regulation by Nano-Ceria-Loaded Mg-Al Layered Double Hydroxide for Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is a chronic autoimmune disease featuring an abnormal immune microenvironment and resultant accumulation of hydrogen ions (H+ ) produced by activated osteoclasts (OCs). Currently, clinic RA therapy can hardly achieve sustained or efficient therapeutic outcomes due to the failures in generating sufficient immune modulation and manipulating the accumulation of H+ that deteriorates bone damage. Herein, a highly effective immune modulatory nanocatalytic platform, nanoceria-loaded magnesium aluminum layered double hydroxide (LDH-CeO2 ), is proposed for enhanced immune modulation based on acid neutralization and metal ion inherent bioactivity. Specifically, the mild alkaline LDH initiates significant M2 repolarization of macrophages triggered by the elevated antioxidation effect of CeO2 via neutralizing excessive H+ in RA microenvironment, thus resulting in the efficient recruitment of regulatory T cell (Treg) and suppressions on T helper 17 cell (Th 17) and plasma cells. Moreover, the osteogenic activity is stimulated by the Mg ion released from LDH, thereby promoting the damaged bone healing. The encouraging therapeutic outcomes in adjuvant-induced RA model mice demonstrate the high feasibility of such a therapeutic concept, which provides a novel and efficient RA therapeutic modality by the immune modulatory and bone-repairing effects of inorganic nanocatalytic material.

Anethole mitigates H2 O2 -induced inflammation in HIG-82 synoviocytes by suppressing the aquaporin 1 expression and activating the protein kinase A pathway

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease affecting approximately 1% of the global population, with a higher prevalence in women than in men. Chronic inflammation and oxidative stress play pivotal roles in the pathogenesis of RA. Anethole, a prominent compound derived from fennel (Foeniculum vulgare), possesses a spectrum of therapeutic properties, including anti-arthritic, anti-inflammatory, antioxidant, and tumor-suppressive effects. However, its specific impact on RA remains underexplored. This study sought to uncover the potential therapeutic value of anethole in treating RA by employing an H2 O2 -induced inflammation model with HIG-82 synovial cells. Our results demonstrated that exposure to H2 O2 induced the inflammation and apoptosis in these cells. Remarkably, anethole treatment effectively countered these inflammatory and apoptotic processes triggered by H2 O2 . Moreover, we identified the aquaporin 1 (AQP1) and protein kinase A (PKA) pathway as critical regulators of inflammation and apoptosis. H2 O2 stimulation led to an increase in the AQP1 expression and a decrease in p-PKA-C, contributing to cartilage degradation. Conversely, anethole not only downregulated the AQP1 expression but also activated the PKA pathway, effectively suppressing cell inflammation and apoptosis. Furthermore, anethole also inhibited the enzymes responsible for cartilage degradation. In summary, our findings highlight the potential of anethole as a therapeutic agent for mitigating H2 O2 -induced inflammation and apoptosis in synovial cells, offering promising prospects for future RA treatments.

Clinical features of patients with hands arthralgia referred from primary care physicians to rheumatologists: A cohort study

PURPOSE

Early referral of patients with suspicious of rheumatoid arthritis (RA) has an impact on prognosis. Our study aimed to evaluate the clinical characteristics of patients with hands arthralgia who were referred from primary care physicians (PCP) to the rheumatologist.

METHODS

A descriptive, observational, prospective cohort study was performed. We included patients who visited a PCP for the first time for hands arthralgia. Demographics and the European Alliance of Associations for Rheumatology criteria for arthralgia suspicious for progression to RA plus seven complementary questions, the time to referral, the pressure needed to provoke pain with an automatic squeeze test machine in the metacarpophalangeal joints of both hands, and the diagnoses established at the last review of medical charts from patients on follow-up were documented. The primary outcome was the referral to a rheumatologist.

RESULTS

A total of 109 patients were included. The mean age was 49.9 years, 81.6% were women. 30.3% were referred to the rheumatologist. The time to referral was a median of 38 days. The main clinical characteristics associated with referral to the rheumatologist were the "most severe symptoms are present after midnight" (OR=6.29) and the "difficulty with making a fist" (OR=3.67). An isolated "positive squeeze test of metacarpophalangeal joints" was not associated with a referral to the rheumatologist.

CONCLUSIONS

Among patients with hands arthralgia who attended PCP, those with most severe symptoms after midnight and difficulty making a fist were more likely to be referred to the rheumatology clinic. Isolated positive squeeze tests are not a parameter for referral, it should only be performed if arthralgia is clinically suspected.

Efficacy and safety of JAK inhibitors in rheumatoid arthritis: update for the practising clinician

Janus kinase (JAK) inhibitors, including tofacitinib, baricitinib, upadacitinib and filgotinib, are increasingly used in the treatment of rheumatoid arthritis (RA). There has been debate about their safety, particularly following the issuance of guidance by regulatory agencies advising caution in their use in certain patients. The registrational clinical trials and registry data of JAK inhibitors did not identify a difference in the risk of major adverse cardiovascular events (MACEs), venous thromboembolism, malignancies or infections (other than herpes zoster) with a JAK inhibitor versus a biologic DMARD. In the ORAL Surveillance trial, which enrolled patients >50 years of age with ≥1 cardiovascular risk factor, tofacitinib was statistically inferior to TNF inhibitors for the occurrence of MACEs and malignancy. Further post hoc analysis of the data revealed that an age of ≥65 years, a high baseline cardiovascular risk, a history of smoking, sustained inflammation, disease activity and suboptimal treatment of cardiovascular comorbidities all increase the risk of these outcomes. The guidance issued by regulatory agencies should be carefully considered to ensure appropriate and safe treatment of patients with RA without undertreatment of patients who might benefit from JAK inhibitor, as well as biologic, treatment. As always, the risks associated with the use of these agents, treatment goals, costs and patient preferences should be discussed with the patient.

Knockdown of Galectin-9 alleviates rheumatoid arthritis through suppressing TNF-α-induced activation of fibroblast-like synoviocytes

The role of Galectin-9 (Gal-9) in the pathogenesis of rheumatoid arthritis (RA) remains unclear. This study aimed to investigate the mechanism of action and therapeutic potential of Gal-9 in RA. We detected Gal-9 expression in clinical samples, explored the mechanism of function of Gal-9 by knockdown and overexpression in fibroblast-like synoviocytes (FLSs), and further verified it in collagen-induced arthritis (CIA) model. We found that the levels of Gal-9 were considerably elevated in RA synovium than in osteoarthritis (OA) patients. A substantial decrease of Gal-9 was demonstrated after tumor necrosis factor (TNF-α) inhibitor treatment in the plasma of patients with RA. Additionally, transcriptome sequencing revealed that Gal-9 was involved in the regulation of the TNF-α pathway. Gal-9 was considerably upregulated after TNF-α stimulation in FLSs, and knockdown of Gal-9 substantially inhibited TNF-α activated proliferation, migration and inflammatory response. According to cell transcriptome sequencing results, we further confirmed that Gal-9 could achieve these effects by interacting with MAFB and affecting PI3K/AKT/mTOR pathway. Finally, we knocked down Gal-9 on the CIA model and found that it could alleviate the progression of arthritis. In conclusion, our study revealed that the knockdown of Gal-9 could inhibited TNF-α induced activation in RA through MAFB, PI3K/AKT/mTOR.