Disease-Modifying Antirheumatic Drugs and Dementia Prevention: A Systematic Review of Observational Evidence in Rheumatoid Arthritis.

BACKGROUND: Many observational studies have examined the association of disease-modifying antirheumatic drugs (DMARDs) with dementia risk, but the evidence has been mixed, possibly due to methodological reasons. This systematic review (PROSPERO: CRD42023432122) aims to assess existing observational evidence and to suggest if repurposing DMARDs for dementia prevention merits further investigation. METHODS: Four electronic databases up to October 26, 2023, were searched. Cohort or case-control studies that examined dementia risk associated with DMARDs in people with rheumatoid arthritis were included. Risk of bias was evaluated using the Cochrane Collaboration's Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) criteria. Findings were summarized by individual drug classes and by risk of bias. RESULTS: Of 12,180 unique records, 14 studies (4 case-control studies, 10 cohort studies) were included. According to the ROBINS-I criteria, there were 2 studies with low risk of bias, 1 study with moderate risk, and 11 studies with serious or critical risk. Among studies with low risk of bias, one study suggested that hydroxychloroquine versus methotrexate was associated with lower incident dementia, and the other study showed no associations of tumor necrosis factor (TNF) inhibitors, tocilizumab, and tofacitinib, compared to abatacept, with incident dementia. CONCLUSION: Studies that adequately addressed important biases were limited. Studies with low risk of bias did not support repurposing TNF inhibitors, tocilizumab, abatacept or tofacitinib for dementia prevention, but hydroxychloroquine may be a potential candidate. Further studies that carefully mitigate important sources of biases are warranted, and long-term evidence will be preferred.

Usefulness of a Cementless Highly-Porous Acetabular Cup in Rheumatoid Arthritis Patients Undergoing Total Hip Arthroplasty.

BACKGROUND: Total hip arthroplasty in patients with rheumatoid arthritis is difficult and leads to worse implant survival and higher risk for complications compared to osteoarthritis. Poor periacetabular bone quality might challenge the stability of the acetabular cup. Contemporary 3D-printed highly-porous titanium cup designs have become the benchmark for cementless implants; however, their usefulness in rheumatoid arthritis is still unclear. The purpose of this study was to assess the short-term results of the use of a highly-porous 3D-printed acetabular titanium cup in patients with rheumatoid arthritis. MATERIAL AND METHODS: We studied a consecutive series of RA patients who underwent cementless THA between 2019 and 2020 in our center with the same 3D-printed highly-porous titanium acetabular cup. All patients were evaluated prospectively for a minimum 3-year follow-up with the Harris hip score, VAS and Roles and Maudsley score. Radiographic assessment focused on evidence of cup osseointegration. RESULTS: 37 RA patients, mean age at surgery of 51.3 years, were included. Mean follow-up was 3.2 years (3 to 4 years). By the last follow-up visit, the Harris hip score had increased significantly from 37.8 to 88.5, VAS had decreased from 6.1 to 1.0 and excellent satisfaction for 31 patients. All 5 Moore's radiographic signs were present in 35 hips, with only 4 signs present in the remaining 2 hips, thus indicating complete osseointegration of all cups. There were no complications on the acetabular side but one intraoperative proximal calcar fracture. CONCLUSION: 3D-printed highly porous implants used in primary THA worked well in patients with rheumatoid arthritis, showing excellent osseointegration and good clinical results in the short term.

Overview of mechanisms and novel therapies on rheumatoid arthritis from a cellular perspective.

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation of joints in response to autoimmune disorders. Once triggered, many factors were involved in the development of RA, including both cellular factors like osteoclasts, synovial fibroblasts, T cells, B cells, and soluble factors like interleukin-1 (IL-1), IL-6, IL-17 and tumor necrosis factor-α (TNF-α), etc. The complex interplay of those factors results in such pathological abnormality as synovial hyperplasia, bone injury and multi-joint inflammation. To treat this chronic life-affecting disease, the primary drugs used in easing the patient's symptoms are disease-modifying antirheumatic drugs (DMARDs). However, these traditional drugs could cause serious side effects, such as high blood pressure and stomach ulcers. Interestingly, recent discoveries on the pathogenesis of RA have led to various new kinds of drugs or therapeutic strategies. Therefore, we present a timely review of the latest development in this field, focusing on the cellular aspects of RA pathogenesis and new therapeutic methods in clinical application. Hopefully it can provide translational guide to the pre-clinical research and treatment for the autoimmune joint disease.

Regulating the lncRNA DSCR9/RPLP2/PI3K/AKT axis: an important mechanism of Xinfeng capsules in improving rheumatoid arthritis.

Background: Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic and symmetrical polyarthritis. RA patients often experience inflammatory reaction and hypercoagulable state, which together affect the self-perception of patient (SPP). Currently, inhibiting inflammation and hypercoagulable state are common treatment methods for alleviating RA symptoms. Xinfeng Capsules (XFC) has a long history of treating RA, and can effectively improve the inflammatory response and hypercoagulable state of RA. However, the potential mechanisms have not yet been determined. Purpose and study design: This study elucidated the action mechanism of XFC in RA inflammation and hypercoagulability through the lncDSCR9/RPLP2/PI3K/AKT axis. Results: Clinical observations indicated that there was a strong link between XFC therapy and improvements in inflammatory and coagulation biomarkers, as well as SPP among RA patients. The subsequent network pharmacology analysis results identified the PI3K/AKT signaling pathway as a potential mediator for XFC treatment of RA. Furthermore, clinical validation and sequencing results revealed that lncRNA DSCR9 expression (a gene implicated in inflammation and coagulation) was negatively correlated with clinical markers of inflammation and coagulation, while positively correlated with SF-36 indicators. Notably, XFC treatment remarkably upregulated lncRNA DSCR9 expression and downregulated PI3K and AKT expressions, showing opposite expression trends to the untreated cases.The regulatory effect of XFC on the lncRNA DSCR9/RPLP2/PI3K/AKT axis in RA was investigated using techniques such as RNA pull-down assay, Western blot analysis, RT-PCR, and EdU assay. Moreover, the administration of the PI3K/AKT agonist RMH can counteract the effects of XFC on p-PI3K, p-AKT, inflammation, and hypercoagulability, reinforcing the role of pathway. Finally, animal studies utilizing HE staining and transmission electron microscopy (TEM) demonstrated that XFC notably decreased PI3K and AKT expressions in adjuvant-induced arthritis (AA) rats, mitigated inflammation and hypercoagulability, and enhanced the ultrastructure of synovial cells. These findings underscored the potential mechanisms of XFC in the treatment of RA. Conclusion: Regulating the lncRNA DSCR9/RPLP2/PI3K/AKT axis may be an important mechanism by which XFC improved RA inflammatory response and hypercoagulable state.

Biologic and targeted synthetic disease-modifying anti-rheumatic drugs improve body composition in rheumatoid arthritis patients more than conventional synthetic disease-modifying anti-rheumatic drugs: Results from the PRESENT study.

INTRODUCTION: The effects of biologic and targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) and conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) on body composition and muscle function in rheumatoid arthritis (RA) patients requiring treatment enhancement were compared. METHODS: This multicenter, prospective, observational study (PRESENT Study) divided RA patients non-randomly into a csDMARD group (n = 100) and a b/tsDMARD group (n = 100). Changes in body composition and muscle function were examined in 80 patients in each group followed for 52 weeks. The percentages of new-onset and improved sarcopenia over 1 year were investigated. Patients in the b/tsDMARD group were divided into three groups by drug type: TNF inhibitors (n = 30), non-TNF inhibitors (n = 23), and JAK inhibitors (n = 27). RESULTS: Baseline median age and disease duration were 70.0 and 4.0 years, respectively. Changes in weight (24 and 52 weeks) and muscle mass (52 weeks) were significantly higher in the b/tsDMARD group (p = .035, p < .001, and p = .002, respectively). On multivariate logistic regression analysis, b/tsDMARD treatment (OR 3.21, p = .002), DAS28-ESR (OR 0.65 p = .011), and muscle mass (OR 0.90, p = .023) were independently associated with increased muscle mass at 52 weeks. The percentages of new-onset and improved sarcopenia were almost equal. There were no significant differences in the time-dependent changes (52 weeks) of clinical status, body composition, muscle function, and status of sarcopenia among TNF inhibitors, non-TNF inhibitors, and JAK inhibitors. CONCLUSIONS: Weight and muscle mass increased significantly more with b/tsDMARD than with csDMARD treatment. There were no differences in body composition changes by mode of action with b/tsDMARDs.

TLR2 reprograms glucose metabolism in CD4+ T cells of rheumatoid arthritis patients to mediate cell hyperactivation and TNF-α secretion.

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease in which activated CD4+ T cells participate in the disease process by inducing inflammation. We aimed to investigate the role of Toll-like receptor 2 (TLR2) on CD4+ T cells in RA patients, and to elucidate the underlying mechanisms by which TLR2 contributes to the pathogenesis of RA. METHODS: Serum samples were collected from RA patients and healthy controls. Soluble TLR2 levels were quantified using an enzyme-linked immunosorbent assay (ELISA). Flow cytometry was employed to assess the TLR2 expression level, activation status, cytokine production, reactive oxygen species (ROS) levels, and glucose uptake capacity of CD4+ T cells. Quantitative polymerase chain reaction (qPCR) was used to measure the expression of enzymes associated with glucose and lipid metabolism. The concentration of lactic acid in the culture supernatant was determined using a dedicated detection kit. RESULTS: RA patients had higher levels of TLR2 in their serum, which positively correlated with C-reactive protein and rheumatoid factor. The expression level of TLR2 in CD4+ T cells of RA patients was increased, and TLR2+ cells showed higher activation levels than TLR2- cells. Activation of TLR2 in CD4+ T cells of RA patients promoted their activation, TNF-α secretion, and increased production of ROS. Furthermore, TLR2 activation led to changes in enzymes related to glucose metabolism, causing a shift in glucose metabolism towards the pentose phosphate pathway. Blocking oxidative phosphorylation and the pentose phosphate pathway had varying effects on CD4+ T cell function. CONCLUSION: TLR2 reprograms the glucose metabolism of CD4+ T cells in RA patients, contributing to the development of RA through ROS-mediated cell hyperactivation and TNF-α secretion. Key Points • TLR2 is upregulated in CD4+ T cells of RA patients and correlates with disease severity markers such as CRP and RF. • Activation of TLR2 in CD4+ T cells promotes cell activation, TNF-α secretion, and increased ROS production, contributing to the pathogenesis of RA. • TLR2 activates glucose metabolism in CD4+ T cells, shifting towards the pentose phosphate pathway, which may be a novel therapeutic target for RA treatment. • Blocking glucose metabolism and ROS production can reduce CD4 + T cell hyperactivation and TNF-α secretion, indicating potential therapeutic strategies for RA management.

Methotrexate promotes the release of granulocyte-macrophage colony-stimulating factor from rheumatoid arthritis fibroblast-like synoviocytes via autocrine interleukin-1 signaling.

BACKGROUND: Activated fibroblast-like synoviocytes (FLS) are drivers of synovitis and structural joint damage in rheumatoid arthritis (RA). Despite the use of disease-modifying drugs, only about 50% of RA patients reach remission in real-world settings. We used an unbiased approach to investigate the effects of standard-of-care methotrexate (MTX) and a Janus kinase inhibitor, tofacitinib (TOFA), on gene expression in RA-FLS, in order to identify untargeted disease mediators. METHODS: Primary RA-FLS were activated by stimulation with interleukin-1ß (IL-1ß) or platelet-derived growth factor + IL-1ß in the presence or absence of MTX or TOFA, with or without additional inhibitors. Co-cultures of synovial cells were performed in direct and indirect systems. Cells were collected for RNA sequencing or qPCR, and supernatants were analyzed for protein concentrations. RESULTS: Six thousand three hundred fifty genes were differentially expressed, the majority being upregulated, in MTX-treated activated RA-FLS and 970 genes, the majority being downregulated, in TOFA-treated samples. Pathway analysis showed that MTX had largest effects on 'Molecular mechanisms of cancer' and TOFA on 'Interferon signaling'. Targeted analysis of disease-associated genes revealed that MTX increased the expression of cell cycle-regulating genes but also of pro-inflammatory mediators like IL-1α (IL1A) and granulocyte-macrophage colony-stimulating factor, GM-CSF (CSF2). The MTX-promoted expression of CSF2 in activated RA-FLS peaked at 48 h, could be mediated via either NF-κB or AP-1 transcription factors, and was abrogated by IL-1 inhibitors (IRAK4 inhibitor and anakinra). In a co-culture setting, MTX-treatment of activated RA-FLS induced IL1B expression in macrophages. CONCLUSIONS: MTX treatment induces secretion of IL-1 from activated RA-FLS which by autocrine signaling augments their release of GM-CSF. This unexpected effect of MTX might contribute to the persistence of synovitis.

Gastrointestinal symptoms in patients using methotrexate: A cross-sectional study in a sample with rheumatoid arthritis.

BACKGROUND: Gastrointestinal intolerance is common in rheumatoid arthritis (RA) patients using methotrexate and may lead to treatment discontinuation. AIM: To study the prevalence of gastrointestinal symptoms in a sample of RA methotrexate users as well as its possible association with clinical and epidemiological variables. METHODS: Cross-sectional study of 192 patients with gastrointestinal symptoms using the MISS (methotrexate intolerance severity score). Clinical and epidemiological variables were collected through chart review and direct questioning. Patients' adherence to methotrexate was evaluated through Moriski-Green-Levin questionnaire. RESULTS: The prevalence of gastrointestinal complaints was high with 55.7% of the sample classified as intolerant. Nausea and pain after drug ingestion were the most common reported complaints. This intolerance was associated with afro-descendant background (p=0.02); presence of associated fibromyalgia (p=0.04), concomitant use of glucocorticoids (p=0.03) and Jak inhibitors (0.03). A tendency towards association with leflunomide use was observed (p=0.06). Logistic regression was used to test drug associations with methotrexate intolerance, and showed that glucocorticoid use was independently associated with methotrexate intolerance OR=1.85; 95% CI=1.01-3.44; p=0.04. Route of administration, presence of previous gastric complaints, age and methotrexate dose did not interfere with MISS. MISS results were associated with moderate adherence to the drug. CONCLUSIONS: There is a high rate of methotrexate intolerance that is more common in afro-descendants, those with associated fibromyalgia, glucocorticoid and Jak inhibitors users.

[Rheumatoid arthritis with Castleman-like histopathology in lymph nodes: A case report].

Rheumatoid arthritis (RA) is a common chronic autoimmune inflammatory disease, characterized by persistent polyarthritis. Patients with RA may exhibit varying degrees of B lymphocyte activation, clinically manifested as enlarged lymph nodes. Disease-modifying anti-rheumatic drugs and glucocorticoid are often used to treat RA. Biological agents targeting tumor necrosis factor alpha, interleukin-6(IL-6), and B lymphocytes are often used to treat rheumatoid arthritis. Castleman disease (CD) is a rare benign lymphoproliferative disorder. Histopathological examination is the most important method to diagnose this disease. Based on the different lymph node involvement areas CD can be divided into unicentric CD(UCD) and multicentric CD(MCD). Surgical removal of lymph nodes is a common treatment method for UCD. MCD often requires chemotherapeutic drugs combined with glucocorticoid therapy. For the most recent years, biological agents targeting IL-6 and B lymphocytes have shown good curative effects on CD. In the past, patients with rheumatic immune disease accompanied by Castleman like histopathology in lymph nodes were commonly referred to as rheumatic immune disease combined with CD. In 2021, experts unanimously agreed that autoimmune diseases with Castleman like lymphadenopathy should be diagnosed as rheumatic autoimmune diseases with Castleman like histopathology in lymph nodes. This report introduces a 65-year-old female patient with rheumatoid arthritis who was admitted to the hospital due to joint swelling and pain. Physical and chemical examinations after admission showed that rheumatoid arthritis was in an active phase. Chest CT revealed multiple enlarged lymph nodes in the right armpit. Then it was removed by surgery. The histopathological report showed that the lymphatic sinus disappeared, the lymphoid tissue proliferated, the lymphoid follicles increased, and the size was inconsistent. The small lymphocytes around the germinal centers of some follicles were concentric circles, and the follicular interstitial blood vessels proliferated. She was diagnosed with rheumatoid arthritis with Castleman like histopathology in lymph nodes and was treated with methotrexate and hydroxychloroquine sulfate combined with glucocorticoids. The patient was followed up for 2 years. In the first year after sur-gery, the patient' s condition remained stable and there was no growth of lymph nodes in the right axilla. The patient passed away due to severe infection in the second year after the surgery.

The gut homeostasis-immune system axis: novel insights into rheumatoid arthritis pathogenesis and treatment.

Rheumatoid arthritis is a widely prevalent autoimmune bone disease that imposes a significant burden on global healthcare systems due to its increasing incidence. In recent years, attention has focused on the interaction between gut homeostasis and the immune system, particularly in relation to bone health. Dysbiosis, which refers to an imbalance in the composition and function of the gut microbiota, has been shown to drive immune dysregulation through mechanisms such as the release of pro-inflammatory metabolites, increased gut permeability, and impaired regulatory T cell function. These factors collectively contribute to immune system imbalance, promoting the onset and progression of Rheumatoid arthritis. Dysbiosis induces both local and systemic inflammatory responses, activating key pro-inflammatory cytokines such as tumor necrosis factor-alpha, Interleukin-6, and Interleukin-17, which exacerbate joint inflammation and damage. Investigating the complex interactions between gut homeostasis and immune regulation in the context of Rheumatoid arthritis pathogenesis holds promise for identifying new therapeutic targets, revealing novel mechanisms of disease progression, and offering innovative strategies for clinical treatment.

A case report and review of rheumatoid arthritis co-occurring with tuberous sclerosis complex, a rare occurrence.

Rheumatoid arthritis (RA) is a common autoimmune disease. Tuberous sclerosis complex(TSC) is a rare autosomal dominant disorder. We report a case of RA with TSC. The patient was a 46-year-old woman with polyarthritis and cough symptoms, rheumatoid arthritis associated interstitial lung disease (RA-ILD) was initially considered, and after more than 3 months of anti-rheumatic treatment, the patient still had cough, and further examination revealed that the patient had lymphangioleiomyomatosis in the lungs, hepatic and renal angiomyolipomas, multiple subependymal nodules, Vertebral osteosclerotic nodules, as well as facial angiofibromas and periungual fibroma, RA was finally diagnosed with TSC, and everolimus 10mg qd was added to anti-rheumatic therapy for 1 month, and the patient's cough symptoms were relieved.

Metabolic effects of quercetin on inflammatory and autoimmune responses in rheumatoid arthritis are mediated through the inhibition of JAK1/STAT3/HIF-1α signaling.

BACKGROUND: Rheumatoid arthritis, a chronic autoimmune disease, is characterized by synovial hyperplasia and cartilage erosion. Here, we investigated the potential mechanism of action of quercetin, the main component of flavonoids, in treating rheumatoid arthritis. OBJECT: To examine the anti-arthritic effects of quercetin and elucidate the specific mechanisms that differentiate its metabolic effects on autoimmune and inflammatory responses at the synovial cell level. METHODS: We created a collagen-induced arthritis (CIA) model in Wistar rats, which were administered quercetin (50 or 100 mg/kg) continuously for four weeks via stomach perfusion. The arthritis score, histopathological staining, radiological assessment, and serum biochemical parameters were used to study the impact of quercetin on disease improvement. Additionally, immunofluorescence was employed to detect JAK1/STAT3/HIF-1α expression in rat joints. Moreover, the effects of quercetin (20, 40, and 80 µmol/L) on the properties and behavior of synovial fibroblasts were evaluated in an in vitro MH7A cell model using flow cytometry, CCK8, and transwell assays. Further, the mRNA expression levels of inflammatory cytokines IL1ß, IL6, IL17, and TNFα were assessed by quantitative real-time PCR. Glucose, lactate, lactate dehydrogenase, pyruvate, pyruvate dehydrogenase, and adenosine triphosphate assay kits were employed to measure the metabolic effects of quercetin on synovial fibroblasts. Finally, immunoblotting was used to examine the impact of quercetin on the JAK1/STAT3/HIF-1α signaling pathway in synovial fibroblasts. RESULTS: In vivo experiments confirmed the favorable effects of quercetin in CIA rats, including an improved arthritis score and reduced ankle bone destruction, in addition to a decrease in the pro-inflammatory cytokines IL-1ß, IL-6, IL-17, and TNF-α in serum. Immunofluorescence verified that quercetin may ameliorate joint injury in rats with CIA by inhibiting JAK1/STAT3/HIF-1α signaling. Various in vitro experiments demonstrated that quercetin effectively inhibits IL-6-induced proliferation of MH7A cells and reduces their migratory and invasive behavior, while inducing apoptosis and reducing the expression of the pro-inflammatory cytokines IL1ß, IL6, IL17, and TNFα at the mRNA level. Quercetin caused inhibition of glucose, lactate, lactate dehydrogenase, pyruvate, and adenosine triphosphate and increased pyruvate dehydrogenase expression in MH7A cells. It was further confirmed that quercetin may inhibit energy metabolism and inflammatory factor secretion in MH7A cells through JAK1/STAT3/HIF-1α signaling. CONCLUSIONS: Quercetin's action on multiple target molecules and pathways makes it a promising treatment for cartilage injury in rheumatoid arthritis. By reducing joint inflammation, improving joint metabolic homeostasis, and decreasing immune system activation energy, quercetin inhibits the JAK1/STAT3/HIF-1α signaling pathway to improve disease status.

Lipocalin-2 Serum Levels in Rheumatoid Arthritis Patients Treated with Adalimumab and Its Correlation with Proinflammatory Factors.

Background: Obesity is associated with an increased risk for different chronic diseases such as osteoarthritis (OA) or rheumatoid arthritis (RA). In fact, adipose tissue is now recognized as an endocrine organ able to secrete a wide variety of factors called adipokines, which have been demonstrated to participate in the pathophysiology of RA by regulating inflammation and immunity. LCN2 is one of these adipose tissue-derived factors. However, scarce information is available about the levels of this adipokine in different rheumatic diseases. Therefore, we aimed to analyze LCN2 serum levels in healthy, OA, and RA patients under different treatments. Methods: Serum levels of LCN2, among other proinflammatory and chemotactic factors, have been measured by ELISA or Multiplex in the following four groups of individuals: healthy, OA, and RA patients treated with conventional treatment or adalimumab. Results: We found increased serum levels of LCN2 in OA and RA patients. Interestingly, LCN2 serum levels show a similar pattern to that observed for different proinflammatory and chemotactic factors, being increased in RA conventional treated patients in comparison to RA patients treated with adalimumab. Also, RA patients under conventional treatment revealed a positive and significant correlation between LCN2 and CCL2, CCL3, IL-8, IL-1ß, IL-6, and CRP. In patients with RA treated with adalimumab, only IL-6 and CRP correlated significantly with LCN2. Conclusions: Our results clearly suggest that LCN2 is modulated and associated with inflammation in rheumatic diseases. Therefore, the serum levels of this adipokine might be used as an additional biomarker of the inflammatory/disease activity.

Novel Chimeric Peptides Based on the Enolase Peptide Antigen (CEP-1) Bearing Three Post-Translational Modifications (Citrullination, Homocitrullination and Acetylation) for Determining the Diagnosis and Severity of Rheumatoid Arthritis.

With the aim of improving the uncertainties associated with the correct diagnosis of seronegative rheumatoid arthritis (RA) and identifying those at risk of developing interstitial lung disease (ILD), we have designed new peptide antigens bearing three post-translational modifications (PTMs) (citrulline, homocitrulline and acetyl-lysine) related to RA that could complement existing tests based on anti-citrullinated peptide/protein antibodies (ACPAs). Several chimeric peptides were synthesized and comparatively tested as antigens in ELISAs with two cohorts of sera: 178 RAs and 110 healthy blood donors. The results indicated that although chimeric peptides containing all three PTMs and vimentin and enolase domains do not significantly outperform existing ACPA tests in terms of sensitivity and specificity, they show potential to complement current assays, especially when detecting antibodies in some seronegative patients. Furthermore, the presence of these autoantibodies significantly identified patients with RA and ILD. We can conclude that the identification of specific autoantibody profiles using synthetic antigens containing peptide domains derived from proteins present in the human joint could help in the early detection of the risk of ILD in patients with RA and be useful for adapting follow-up strategies and guiding decisions during treatment.

The Causal Relationship between Immune-Mediated Inflammatory Diseases and Aortic Aneurysm: A Bidirectional Two-Sample Mendelian Randomization Study.

Methods: We sourced genetic association data from public genome-wide association study databases for populations of European ancestry. Adhering to MR principles, we identified valid instrumental variables from genetic variants. A range of statistical methods were applied for MR analysis, with the inverse variance weighted (IVW) method emerging as the most reliable estimator of causality in this context. Results: The causal estimates obtained using the IVW method revealed a significant association between genetically predicted AA and rheumatoid arthritis (RA; OR = 1.06, 95% CI = 1.01-1.12, P=0.029). Conversely, genetically predicted RA showed nonsignificant causal estimates of AA (OR = 0.97, 95% CI = 0.92-1.02, P=0.204). Additionally, there was no evidence to suggest that AA may increase the risk of inflammatory bowel disease (IBD), Crohn's disease (CD), ulcerative colitis (UC), systemic lupus erythematosus (SLE), and psoriasis (PSO). The sensitivity analysis confirmed the absence of heterogeneity or horizontal pleiotropy effects. Conclusion: Our findings shed light on the causal effects between genetically predisposed AA and RA. They also suggest the potential clinical utility of human leukocyte antigen (HLA) risk genetic markers for developing personalized treatment and prevention strategies.

Association between serum iron status and the risk of five bone and joint-related diseases: a Mendelian randomization analysis.

Background: According to reports, iron status has been associated with the risk of bone and joint-related diseases. However, the exact role of iron status in the development of these conditions remains uncertain. Method: We obtained genetic data on iron status, specifically serum iron, ferritin, transferrin saturation (TSAT), and transferrin, as well as data on five common bone and joint-related diseases (osteoarthritis, osteoporosis, rheumatoid arthritis [RA], ankylosing spondylitis [AS], and gout) from independent genome-wide association studies involving individuals of European ancestry. Our primary approach for causal estimation utilized the inverse variance weighted (IVW) method. To ensure the reliability of our findings, we applied complementary sensitivity analysis and conducted reverse causal analysis. Result: Using the IVW method, we revealed a positive causal relationship between ferritin levels and the risk of osteoarthritis (OR [95% CI], 1.0114 [1.0021-1.0207]). Besides, we identified a protective causal relationship between serum iron levels and TSAT levels in the risk of RA (OR [95% CI] values of serum iron and TSAT were 0.9987 [0.9973-0.9999] and 0.9977 [0.9966-0.9987], respectively). Furthermore, we found a positive causal relationship between serum iron levels and the risk of AS (OR [95% CI], 1.0015 [1.0005-1.0026]). Regarding gout, both serum iron and TSAT showed a positive causal relationship (OR [95% CI] values of 1.3357 [1.0915-1.6345] and 1.2316 [1.0666-1.4221] for serum iron and TSAT, respectively), while transferrin exhibited a protective causal relationship (OR [95% CI], 0.8563 [0.7802-0.9399]). Additionally, our reverse causal analysis revealed a negative correlation between RA and ferritin and TSAT levels (OR [95% CI] values of serum iron and TSAT were 0.0407 [0.0034-0.4814] and 0.0049 [0.0002-0.1454], respectively), along with a positive correlation with transferrin (OR [95% CI], 853.7592 [20.7108-35194.4325]). To ensure the validity of our findings, we replicated the results through sensitivity analysis during the validation process. Conclusion: Our study demonstrated a significant correlation between iron status and bone and joint-related diseases.

Bivalent chromatin accommodates survivin and BRG1/SWI complex to activate DNA damage response in CD4+ cells.

BACKGROUND: Bivalent regions of chromatin (BvCR) are characterized by trimethylated lysine 4 (H3K4me3) and lysine 27 on histone H3 (H3K27me3) deposition which aid gene expression control during cell differentiation. The role of BvCR in post-transcriptional DNA damage response remains unidentified. Oncoprotein survivin binds chromatin and mediates IFNγ effects in CD4+ cells. In this study, we explored the role of BvCR in DNA damage response of autoimmune CD4+ cells in rheumatoid arthritis (RA). METHODS: We performed deep sequencing of the chromatin bound to survivin, H3K4me3, H3K27me3, and H3K27ac, in human CD4+ cells and identified BvCR, which possessed all three histone H3 modifications. Protein partners of survivin on chromatin were predicted by integration of motif enrichment analysis, computational machine-learning, and structural modeling, and validated experimentally by mass spectrometry and peptide binding array. Survivin-dependent change in BvCR and transcription of genes controlled by the BvCR was studied in CD4+ cells treated with survivin inhibitor, which revealed survivin-dependent biological processes. Finally, the survivin-dependent processes were mapped to the transcriptome of CD4+ cells in blood and in synovial tissue of RA patients and the effect of modern immunomodulating drugs on these processes was explored. RESULTS: We identified that BvCR dominated by H3K4me3 (H3K4me3-BvCR) accommodated survivin within cis-regulatory elements of the genes controlling DNA damage. Inhibition of survivin or JAK-STAT signaling enhanced H3K4me3-BvCR dominance, which improved DNA damage recognition and arrested cell cycle progression in cultured CD4+ cells. Specifically, BvCR accommodating survivin aided sequence-specific anchoring of the BRG1/SWI chromatin-remodeling complex coordinating DNA damage response. Mapping survivin interactome to BRG1/SWI complex demonstrated interaction of survivin with the subunits anchoring the complex to chromatin. Co-expression of BRG1, survivin and IFNγ in CD4+ cells rendered complete deregulation of DNA damage response in RA. Such cells possessed strong ability of homing to RA joints. Immunomodulating drugs inhibited the anchoring subunits of BRG1/SWI complex, which affected arthritogenic profile of CD4+ cells. CONCLUSIONS: BvCR execute DNA damage control to maintain genome fidelity in IFN-activated CD4+ cells. Survivin anchors the BRG1/SWI complex to BvCR to repress DNA damage response. These results offer a platform for therapeutic interventions targeting survivin and BRG1/SWI complex in autoimmunity.