Dendritic cells, T cells and their interaction in rheumatoid arthritis

Unleashing the Potential: Exploring the Application and Mechanism of Mesenchymal Stem Cells in Autoimmune Diseases

Autoimmune diseases (AIDs) occur when the immune system mistakenly attacks the body's own antigens. Traditionally, these conditions are treated with nonspecific immunosuppressive therapies, including corticosteroids, immunosuppressants, biological agents, and human immunoglobulins. However, these treatments often fail to achieve optimal outcomes, especially for patients with severe cases. Mesenchymal stem cells (MSCs) present a promising alternative due to their robust self-renewal capabilities and multidirectional differentiation potential. MSCs are easily accessible, exhibit low immunogenicity, and can help reduce graft rejection. MSCs can inhibit T cell proliferation, reduce proinflammatory T cells, inhibit B cell differentiation, induce macrophage polarization towards the anti-inflammatory M2 phenotype, and suppress activity of natural killer (NK) cells and dendritic cells (DCs). Additionally, MSCs can regulate T cells, macrophages, and fibroblast-like synoviocytes (FLS) by releasing microRNA (miRNA) through exosomes or extracellular vesicles (EVs), thus providing therapeutic benefits for various diseases. Numerous clinical trials have highlighted the therapeutic benefits of MSCs in treating various AIDs, leading to increased interest in MSC transplantation. This review summarizes the current applications and mechanisms of action of MSCs in the treatment of AIDs.

Identification of Disulfidptosis-Related Genes and Molecular Subgroups in Rheumatoid Arthritis for Diagnostic Model and Patient Stratification

Introduction

Cell death contributes to the pathogenesis of rheumatoid arthritis (RA) through various pathways. Disulfidptosis is a recently discovered novel form of cell death characterized by the abnormal accumulation of intracellular disulfide bonds. It remains unclear for the association between RA and disulfidptosis.

Methods

A comprehensive analysis of three GEO datasets was presented in this study. First, the analysis involved the use of weighted gene co-expression network analysis (WGCNA) and differential analysis and were employed to identify the key module genes related to RA and disulfidptosis-related genes. The machine learning algorithms were used to identify the hub genes. Second, a diagnostic model was constructed for RA based on the hub genes. The nomogram and receiver operating characteristic (ROC) curves were utilized to evaluate the diagnostic value of the model. Third, two RA subtypes were identified based on hub genes by using consensus clustering analysis. Then, the disease activity scores, clinical markers, and immune cells were compared between the two RA subgroups. Finally, the differential expression of hub genes was validated between healthy controls and RA patients by qPCR.

Results

Four hub genes (KLHL2, POLK, CLEC4D, NXT2) were identified. The expression of the four hub genes was verified to be significantly higher in RA patients compared with healthy controls. The superior diagnostic value of the model was validated, which demonstrated that the model outperforms each hub gene individually. Two subtypes of RA were determined. Patients in cluster A exhibited relatively lower levels of DAS28-CRP, DAS28-ESR, CDAI, SDAI, RF, CRP, and MMP3. In contrast, patients in cluster B had significantly higher levels of the above markers.

Conclusion

Four hub genes were identified to provide unique insights into the role of disulfidptosis in RA. Additionally, a promising diagnosis model and patient stratification were established based on the hub genes to assess the risk of RA onset and RA disease activity.

Norwogonin Attenuates Inflammatory Osteolysis and Collagen-Induced Arthritis via Modulating Redox Signalling and Calcium Oscillations

Norwogonin is a flavonoid extraction derived from Scutellaria baicalensis. However, its potential mechanisms in the context of rheumatoid arthritis (RA) are unclear. This study investigates the specific effects and associated targets of Norwogonin in RA-related inflammatory osteolysis. Network pharmacology was conducted to analyse the core targets and signalling pathways of Norwogonin in RA. In vitro experiments were carried out to explore the actual effects of Norwogonin on osteoclast behaviours and related signalling mechanisms. In vivo studies further validated the therapeutic effect of Norwogonin in collagen-induced arthritis (CIA) mice. The network pharmacological analysis identified 18 shared targets between Norwogonin and RA, indicating a connection with inflammatory response and oxidoreductase activity. For biological validations, the results of in vitro experiments revealed 160 μM of Norwogonin inhibited LPS-driven osteoclast differentiation and function. The qPCR assay and Western blot analysis also disclosed consistently diminished changes to osteoclastic marker genes and proteins due to Norwogonin treatment, including those for osteoclast differentiation (Traf6, Tnfrsf11a and Nfatc1), fusion (Atp6v0d2, Dcstamp and Ocstamp) and function (Mmp9, Ctsk and Acp5). Further mechanism study revealed Norwogonin suppressed LPS-driven ROS production and calcium (Ca2+) oscillations. Also, intraperitoneal injection of 30 mg/kg Norwogonin every other day successfully mitigated clinical arthritis progression and attenuated bone destruction in the CIA model. Our study scrutinises Norwogonin's therapeutic prospects in treating RA and illustrates its inhibitory effects and potential mechanism within LPS-induced osteoclastogenesis and CIA mice, providing a basis for further translational research on Norwogonin in the treatment of RA-related inflammatory osteolysis.

Recombinant probiotic Escherichia coli delivers the polymeric protein of swine influenza virus for protection

Swine influenza virus invades the host through the respiratory mucosa, which severely restricts the development of the pig breeding industry. To construct monomeric and trimeric vaccines, we developed recombinant Escherichia coli Nissle 1917 (EcN) strains that express the receptor binding site (RBS) of the hemagglutinin (HA) antigen from H1N1 swine influenza virus. After the mucosal immunization of mice, we found that probiotics activated CD40 and CD86 in DCs and increased the levels of IL-4 and IFN-γ secretion by T cells. Furthermore, the probiotics improved the function of the mucosal immune system, increased the level of SIgA, level of IgG and number of B220+IgA+, and activated germinal center B cells. The challenge experiment revealed that the probiotics alleviated weight loss, reduced pathological injury to the lungs, and protected the mice from virus infection. We also observed that the serum neutralizing antibodies of immunized piglets significantly increased, which reduced the shedding frequency of swine influenza virus in the nose of the piglets and reduced the pathological damage by activating the T cell immune response in infected piglets. Thus, the constructed probiotics are promising candidates for effective non-traditional swine influenza vaccines.

Bidirectional Mendelian randomization reveals causal immune cell phenotypes in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent inflammation in synovial joints and influenced by genetic and environmental factors. The immune system, comprising various cells that either exacerbate or reduce inflammation, plays a central role in RA pathogenesis. Despite extensive research, the causal relationships between immune cell phenotypes and RA remain unclear. We employed a two-sample Mendelian randomization (MR) approach to investigate the causal associations between 731 immune cell phenotypes and RA. Genetic variants, carefully selected based on rigorous criteria, served as instrumental variables to ensure analytical validity. Data on RA were derived from the FinnGen database, whereas immune cell phenotype data were obtained from the genome-wide association studies catalog. We employed 5 MR methods, including inverse variance weighted and MR Egger, to ensure robust causal inference. We assessed for pleiotropy and heterogeneity and adjusted findings using the False Discovery Rate. After False Discovery Rate adjustment (threshold < 0.05), inverse variance weighted analysis revealed potential causal relationships between 4 immune cell types and RA: CD62L- dendritic cells %dendritic cells (P = 3.88E-05; 95% confidence interval [CI] = 1.056), CD19 on IgD+ CD38- naive cells (P = 1.75E-04; 95% CI = 0.969), CD45RA on TD CD8br (P = 5.59E-04; 95% CI = 0.919), and HLA DR on CD33- HLA DR+ (P = 8.13E-05; 95% CI = 1.422). In reverse Mendelian studies, specific immune cell phenotypes were found to be associated with RA risk and progression: the percentage of memory B cells among lymphocytes (P = 2.74E-04; 95% CI = 0.861), IgD+ CD24+ cells among lymphocytes (P = 6.93E-04; 95% CI = 0.867), CD4+ CD8dim cells among lymphocytes (P = 2.92E-04; 95% CI = 0.802), CD4+ CD8dim cells among leukocytes (P = 4.37E-04; 95% CI = 0.814), and CD24 expression on IgD+CD24+ cells (P = 1.05E-04; 95% CI = 0.857). These results identify immune cell phenotypes closely linked to RA susceptibility and progression. The findings suggest that specific immune cell phenotypes are not only influenced by RA but may also contribute to its development and progression. These results offer new insights into the immunological underpinnings of RA and highlight potential targets for therapeutic intervention. Future research should focus on validating these causal relationships in diverse populations and exploring the molecular mechanisms involved.

Gut microbiota and their metabolites in the immune response of rheumatoid arthritis: Therapeutic potential and future directions

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent joint inflammation, damage, and loss of function. In recent years, the role of gut microbiota and its metabolites in immune regulation has attracted increasing attention. The gut microbiota influences the host immune system's homeostasis through various mechanisms, regulating the differentiation, function, and immune tolerance of immune cells. Dysbiosis of the gut microbiota in RA patients is closely associated with abnormal activation of immune cells and excessive secretion of inflammatory cytokines. Metabolites produced by the gut microbiota, such as short-chain fatty acids (SCFAs), tryptophan metabolites, bile acids, and amino acid metabolites, play a critical role in immune responses, regulating the functions of immune cells like T cells, B cells, and macrophages, and inhibiting the release of pro-inflammatory cytokines. Restoring the balance of the gut microbiota and optimizing the production of metabolic products may become a new strategy for RA treatment. This review discusses the role of gut microbiota and its metabolites in the immune response of RA, exploring how they influence the immunopathological process of RA through the regulation of immune cells and key immune factors. It also provides a theoretical basis for future therapeutic strategies based on gut microbiota modulation.

Vitamin, antioxidant and micronutrient supplementation and the risk of developing incident autoimmune diseases: a systematic review and meta-analysis

Background

Autoimmune diseases pose significant health challenges worldwide and affect millions. In recent years, there has been growing interest in exploring preventive strategies through nutritional interventions using vitamins, antioxidants, and micronutrients to reduce the risk of developing autoimmune diseases. However, excessive supplementation has also been associated with toxicity.

Objective

We aim to assess how the intake of vitamins, antioxidants and micronutrients affect the risk of developing autoimmune diseases.

Methods

This PRISMA-adherent systematic review involved a systematic search of PubMed, Embase and Cochrane for controlled studies that evaluated the risk of incident autoimmune diseases after supplementation. Random effects meta-analyses were used for primary analysis.

Results

18 studies were included. Overall meta-analyses observed that vitamin D did not influence the risk of autoimmune diseases (RR=0.99, 95%CI: 0.81-1.20). However, among the different vitamin D dosages, subgroup analysis demonstrated that those who were supplemented with 600-800IU/day may have a statistically significant reduction in risk (RR=0.55, 95%CI: 0.38; 0.82). Systematic review suggested that consumption of most vitamins, micronutrients and antioxidants may not have any effect on the risk of autoimmune diseases. Smoking, age, physical or outdoor activity and diet were significant confounding factors that affected the efficacy of such interventions.

Conclusion

We studied the effect of various vitamins, micronutrients and antioxidants on the risk of developing autoimmune diseases. Our study contributes to the evolving landscape of nutritional immunology, providing a foundation for future research to unravel more definite relationships with supplementation and the development of incident autoimmune diseases.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024504796.

Applications of single-cell RNA sequencing in rheumatoid arthritis

Single cell RNA sequencing (scRNA-seq) is a relatively new technology that provides an unprecedented, detailed view of cellular heterogeneity and function by delineating the transcriptomic difference among individual cells. This will allow for mapping of cell-type-specific signaling during physiological and pathological processes, to build highly specific models of cellular signaling networks between the many discrete clusters that are present. This technology therefore provides a powerful approach to dissecting the cellular and molecular mechanisms that contribute to autoimmune diseases, including rheumatoid arthritis (RA). scRNA-seq can offer valuable insights into RA unique cellular states and transitions, potentially enabling development of novel drug targets. However, some challenges that still limit its mainstream utilization and include higher costs, a lower sensitivity for low-abundance transcripts, and a relatively complex data analysis workflow relative to bulk or traditional RNA-seq. This minireview explores the emerging application of scRNA-seq in RA research, highlighting its role in producing important insights that can help pave the way for innovative and more effective therapeutic strategies.

Intestinal Permeability In Subjects With Rheumatoid Arthritis: A Critical Therapeutic Priority

Rheumatoid arthritis is increasingly being recognized as the synovial manifestation of a group of systemic autoinflammatory conditions known as immune-mediated inflammatory diseases. While each of these conditions displays unique diagnostic signs and symptoms based on the tissue targeted by inflammation, most immune-mediated inflammatory diseases share common features, including their immune-signaling pathways. Owing to these similarities, great advances have emerged in the past few decades using therapies designed to block downstream inflammatory mediators (eg, cytokine-blocking biologics, Janus Kinase (JAK) inhibitors). Unfortunately, fewer advances have been made in therapies that have the potential to target the upstream antecedents and triggers of these complex inflammatory diseases, such as the immunologic chain of events triggered by intestinal hyperpermeability (ie, leaky gut) or gastrointestinal dysbiosis (ie, alterations in the gut microbiota). In the past few decades, intestinal hyperpermeability has emerged as an important antecedent for a wide range of chronic immunological and metabolic conditions, including celiac disease, obesity, cardiovascular disease, and a number of immune-mediated inflammatory diseases such as inflammatory bowel disease, psoriasis, and rheumatoid arthritis. In this narrative review, we discuss the growing awareness that biomarkers of intestinal permeability are frequently associated with non-gastrointestinal immune-mediated inflammatory diseases, particularly those associated with the gut-joint axis, such as rheumatoid arthritis. We suggest that measures of intestinal permeability, along with lifestyle and nutrient interventions that target gut-barrier function, may be important adjunctive clinical tools to help patients with rheumatoid arthritis achieve and maintain remission.

Application Value of Platelet-to-Lymphocyte Ratio as a Novel Indicator in Rheumatoid Arthritis: A Review Based on Clinical Evidence

Rheumatoid arthritis (RA) is a chronically progressive autoimmune disease with increasing age-standardized prevalence and incidence of RA worldwide. Its pathological features are persistent synovitis of the joint, accompanied by the release of a large number of inflammatory cytokines and cartilage and bone destruction. RA can lead to progressive joint damage, stiffness and swelling, vascular and bone-related complications, and irreversible disability, which seriously affects patients' life treatment. Early diagnosis and treatment can enhance the quality of life of RA patients. Platelet-to-lymphocyte ratio (PLR), as a common indicator in routine blood tests, has been proposed as an indicator of systemic inflammation in recent years. Its clinical detection is less invasive, economical, rapid and simple, and has been applied to the clinical evaluation of a variety of diseases. Of note, this indicator is important in assessing disease activity in RA, co-diagnosing RA, detecting subclinical complications, and monitoring responses to anti-inflammatory therapy. Therefore, this review summarizes the relationship between PLR and RA and the relevant mechanisms, further advancing the understanding of the clinical value of PLR.

The role of dendritic cells in tertiary lymphoid structures: implications in cancer and autoimmune diseases

Tertiary Lymphoid Structures (TLS) are organized aggregates of immune cells such as T cells, B cells, and Dendritic Cells (DCs), as well as fibroblasts, formed postnatally in response to signals from cytokines and chemokines. Central to the function of TLS are DCs, professional antigen-presenting cells (APCs) that coordinate the adaptive immune response, and which can be classified into different subsets, with specific functions, and markers. In this article, we review current data on the contribution of different DC subsets to TLS function in cancer and autoimmunity, two opposite sides of the immune response. Different DC subsets can be found in different tumor types, correlating with cancer prognosis. Moreover, DCs are also present in TLS found in autoimmune and inflammatory conditions, contributing to disease development. Broadly, the presence of DCs in TLS appears to be associated with favorable clinical outcomes in cancer while in autoimmune pathologies these cells are associated with unfavorable prognosis. Therefore, it is important to analyze the complex functions of DCs within TLS in order to enhance our fundamental understanding of immune regulation but also as a possible route to create innovative clinical interventions designed for the specific needs of patients with diverse pathological diseases.

Association between vitamin B6 levels and rheumatoid arthritis: a two-sample Mendelian randomization study

Background

Micronutrients play a crucial role in rheumatoid arthritis (RA). Changes in micronutrient levels in RA patients can lead to the worsening of their condition. Though significant correlations between RA and micronutrients have been found in earlier observational studies, their underlying causal relationship is still unknown. This study aimed to elucidate the causal genetic relationships between 15 micronutrients (copper, zinc, magnesium, vitamins A, C, E, D, B6, B12, folate, carotene, iron, selenium, calcium, potassium) and RA.

Method

The exposure factors and outcome data used in the two-sample Mendelian randomization (MR) were derived from publicly available summary statistics data of European populations. The GWAS data for exposure factors were obtained from the OpenGWAS database. For the outcome data of RA, we utilized data from the FinnGen database. We used the MR principle to remove confounding factors and conducted MR analyses using five methods: inverse variance weighted (IVW), MR Egger, weighted median, simple mode, and weighted mode, with IVW as the primary method. Then, we identified micronutrients related to RA and performed MR analyses on these elements, including heterogeneity analysis and pleiotropy analysis such as MR-Egger intercept, MR-PRESSO method, and "leave-one-out" analysis. Finally, we conducted multivariable MR analyses and performed sensitivity analyses again.

Results

The IVW analysis revealed a relationship between vitamin B6 and RA (p: 0.029, OR: 1.766, and 95% CI: 1.062-2.938). Sensitivity analysis confirmed the validity and reliability of this result.

Conclusion

This study revealed a causal relationship between vitamin B6 and RA, with vitamin B6 being identified as a risk factor for RA. This finding could contribute to the diagnosis and supplementary treatment of RA patients, providing a reference for subsequent basic research and developing new drugs.

The combination of apatinib and antigen-specific DC-induced T cells exert antitumor effects by potently improving the immune microenvironment of osteosarcoma

Objective

Osteosarcoma (OS) is the most common primary bone sarcoma with a high propensity for local invasion and metastasis. Although the antitumor effect of apatinib has been well confirmed in advanced OS, the synergistic effect of apatinib and immunotherapies has not yet been elucidated.

Methods

In this study, we established tumour-bearing mice and observed tumour size with low and high doses of apatinib treatments. The expression of 17 cytokines, including vascular endothelial growth factor (VEGF), was detected by protein microarray analysis. Moreover, we designed apatinib and antigen-specific dendritic cell (DC)-T combination treatment for tumour-bearing mice. Tumour growth was detected by statistical analysis of tumour size and microvessel density (MVD) counting, the protein expression of VEGF by western blotting, the cytokines interleukin 6 (IL-6), IL-17 and interferon-gamma (IFN-γ) by enzyme-linked immunosorbent assay (ELISA), and the numbers of myeloid-derived suppressor cells (MDSCs) and tumour-infiltration macrophages (TAMs) by flow cytometry.

Results

The results showed that apatinib efficiently suppressed tumour growth, and high-dose apatinib achieved a stronger effect. The same was true for DC-T immunotherapy. However, their combination treatment revealed a better oncolytic effect. Meanwhile, apatinib or DC-T treatment inhibited the expression of VEGF and the proangiogenic mediators IL-6 and IL-17 but increased IFN-γ production. Combination therapy further reduced/increased these effects. In addition, the combination treatment reduced MDSC but enhanced TAM-M1 ratios in the OS microenvironment. These findings indicated that apatinib and antigen-specific DC-T combination therapy was more efficient in oncolysis by regulating pro-/anti-angiogenic inducers and improving the immune state in the OS microenvironment.

Conclusion

This study proved that it was feasible to employ immunotherapy with therapeutic agents in OS treatment, which may provide a new approach in addition to the combination of surgery with chemotherapy in tumour treatment.

The association between the aggregate index of systemic inflammation and risk of rheumatoid arthritis: retrospective analysis of NHANES 1999-2018

Objective

The investigation purpose was to examine the correlation between the aggregate index of systemic inflammation (AISI) and rheumatoid arthritis (RA) by utilizing the NHANES database from the years 1999 to 2018.

Methods

The NHANES database was utilized to extract data spanning from 1999 to 2018. AISI, comprising neutrophils (NEU), monocytes (MONO), platelets (PLT), and lymphocytes (LYM), was computed based on counts. The identification of RA patients was accomplished through questionnaire data. To investigate the connection between AISI and RA, a weighted multivariate regression and subgroup analysis were conducted. In addition, restricted cubic splines (RCS) were employed for examining non-linear associations.

Results

The study encompassed a total of 41,986 patients, among whom 2,642 (6.29%) were diagnosed with RA. Upon controlling for all covariates, the outcomes of the multivariate logistic regression assay demonstrated a statistically significant association between higher Ln(AISI) levels and elevated odds of RA (odds ratio [OR]: 1.097; 95% confidence interval [CI]: 1.096-1.099, p < 0.001). The interaction test findings indicate that there is no statistically significant impact within this particular association. The results of the RCS regression model revealed a non-linear pattern in the correlation between Ln(AISI) and RA. The threshold level of AISI for RA was determined as 298.9. The risk of RA rises steeply when AISI surpasses the threshold value.

Conclusion

Overall, a positive association has been observed between AISI and RA. This study highlights the potential of AISI as an innovative, vital, and appropriate inflammatory biomarker for predicting the risk of developing rheumatoid arthritis in older individuals residing in the United States.

Advancements in rheumatoid arthritis therapy: a journey from conventional therapy to precision medicine via nanoparticles targeting immune cells

Rheumatoid arthritis (RA) is a progressive autoimmune disease that mainly affects the inner lining of the synovial joints and leads to chronic inflammation. While RA is not known as lethal, recent research indicates that it may be a silent killer because of its strong association with an increased risk of chronic lung and heart diseases. Patients develop these systemic consequences due to the regular uptake of heavy drugs such as disease-modifying antirheumatic medications (DMARDs), glucocorticoids (GCs), nonsteroidal anti-inflammatory medicines (NSAIDs), etc. Nevertheless, a number of these medications have off-target effects, which might cause adverse toxicity, and have started to become resistant in patients as well. Therefore, alternative and promising therapeutic techniques must be explored and adopted, such as post-translational modification inhibitors (like protein arginine deiminase inhibitors), RNA interference by siRNA, epigenetic drugs, peptide therapy, etc., specifically in macrophages, neutrophils, Treg cells and dendritic cells (DCs). As the target cells are specific, ensuring targeted delivery is also equally important, which can be achieved with the advent of nanotechnology. Furthermore, these nanocarriers have fewer off-site side effects, enable drug combinations, and allow for lower drug dosages. Among the nanoparticles that can be used for targeting, there are both inorganic and organic nanomaterials such as solid-lipid nanoparticles, liposomes, hydrogels, dendrimers, and biomimetics that have been discussed. This review highlights contemporary therapy options targeting macrophages, neutrophils, Treg cells, and DCs and explores the application of diverse nanotechnological techniques to enhance precision RA therapies.

Biological Clock Perspective in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic polyarticular pain, and its main pathological features include inflammatory cell infiltration, synovial fibroblast proliferation, and cartilage erosion. Immune cells, synovial cells and neuroendocrine factors play pivotal roles in the pathophysiological mechanism underlying rheumatoid arthritis. Biological clock genes regulate immune cell functions, which is linked to rhythmic changes in arthritis pathology. Additionally, the interaction between biological clock genes and neuroendocrine factors is also involved in rhythmic changes in rheumatoid arthritis. This review provides an overview of the contributions of circadian rhythm genes to RA pathology, including their interaction with the immune system and their involvement in regulating the secretion and function of neuroendocrine factors. A molecular understanding of the role of the circadian rhythm in RA may offer insights for effective disease management.

Identification of diagnostic genes and drug prediction in metabolic syndrome-associated rheumatoid arthritis by integrated bioinformatics analysis, machine learning, and molecular docking

Background

Interactions between the immune and metabolic systems may play a crucial role in the pathogenesis of metabolic syndrome-associated rheumatoid arthritis (MetS-RA). The purpose of this study was to discover candidate biomarkers for the diagnosis of RA patients who also had MetS.

Methods

Three RA datasets and one MetS dataset were obtained from the Gene Expression Omnibus (GEO) database. Differential expression analysis, weighted gene co-expression network analysis (WGCNA), and machine learning algorithms including Least Absolute Shrinkage and Selection Operator (LASSO) regression and Random Forest (RF) were employed to identify hub genes in MetS-RA. Enrichment analysis was used to explore underlying common pathways between MetS and RA. Receiver operating characteristic curves were applied to assess the diagnostic performance of nomogram constructed based on hub genes. Protein-protein interaction, Connectivity Map (CMap) analyses, and molecular docking were utilized to predict the potential small molecule compounds for MetS-RA treatment. qRT-PCR was used to verify the expression of hub genes in fibroblast-like synoviocytes (FLS) of MetS-RA. The effects of small molecule compounds on the function of RA-FLS were evaluated by wound-healing assays and angiogenesis experiments. The CIBERSORT algorithm was used to explore immune cell infiltration in MetS and RA.

Results

MetS-RA key genes were mainly enriched in immune cell-related signaling pathways and immune-related processes. Two hub genes (TYK2 and TRAF2) were selected as candidate biomarkers for developing nomogram with ideal diagnostic performance through machine learning and proved to have a high diagnostic value (area under the curve, TYK2, 0.92; TRAF2, 0.90). qRT-PCR results showed that the expression of TYK2 and TRAF2 in MetS-RA-FLS was significantly higher than that in non-MetS-RA-FLS (nMetS-RA-FLS). The combination of CMap analysis and molecular docking predicted camptothecin (CPT) as a potential drug for MetS-RA treatment. In vitro validation, CPT was observed to suppress the cell migration capacity and angiogenesis capacity of MetS-RA-FLS. Immune cell infiltration results revealed immune dysregulation in MetS and RA.

Conclusion

Two hub genes were identified in MetS-RA, a nomogram for the diagnosis of RA and MetS was established based on them, and a potential therapeutic small molecule compound for MetS-RA was predicted, which offered a novel research perspective for future serum-based diagnosis and therapeutic intervention of MetS-RA.

Galangin: A Promising Flavonoid for the Treatment of Rheumatoid Arthritis-Mechanisms, Evidence, and Therapeutic Potential

Rheumatoid Arthritis (RA) is a chronic autoimmune disease characterized by progressive joint inflammation and damage. Oxidative stress plays a critical role in the onset and progression of RA, significantly contributing to the disease's symptoms. The complex nature of RA and the role of oxidative stress make it particularly challenging to treat effectively. This article presents a comprehensive review of RA's development, progression, and the emergence of novel treatments, introducing Galangin (GAL), a natural flavonoid compound sourced from various plants, as a promising candidate. The bioactive properties of GAL, including its anti-inflammatory, antioxidant, and immunomodulatory effects, are discussed in detail. The review elucidates GAL's mechanisms of action, focusing on its interactions with key targets such as inflammatory cytokines (e.g., TNF-α, IL-6), enzymes (e.g., SOD, MMPs), and signaling pathways (e.g., NF-κB, MAPK), which impact inflammatory responses, immune cell activation, and joint damage. The review also addresses the lack of comprehensive understanding of potential treatment options for RA, particularly in relation to the role of GAL as a therapeutic candidate. It highlights the need for further research and clinical studies to ascertain the effectiveness of GAL in RA treatment and to elucidate its mechanisms of action. Overall, this review provides valuable insights into the potential of GAL as a therapeutic option for RA, shedding light on its multifaceted pharmacological properties and mechanisms of action, while suggesting avenues for future research and clinical applications.

Overview of multifunctional Tregs in cardiovascular disease: From insights into cellular functions to clinical implications

Regulatory T cells (Tregs) are crucial in regulating T-cell-mediated immune responses. Numerous studies have shown that dysfunction or decreased numbers of Tregs may be involved in inflammatory cardiovascular diseases (CVDs) such as atherosclerosis, hypertension, myocardial infarction, myocarditis, cardiomyopathy, valvular heart diseases, heart failure, and abdominal aortic aneurysm. Tregs can help to ameliorate CVDs by suppressing excessive inflammation through various mechanisms, including inhibition of T cells and B cells, inhibition of macrophage-induced inflammation, inhibition of dendritic cells and foam cell formation, and induction of anti-inflammatory macrophages. Enhancing or restoring the immunosuppressive activity of Tregs may thus serve as a fundamental immunotherapy to treat hypertension and CVDs. However, the precise molecular mechanisms underlying the Tregs-induced protection against hypertension and CVDs remain to be investigated. This review focuses on recent advances in our understanding of Tregs subsets and function in CVDs. In addition, we discuss promising strategies for using Tregs through various pharmacological approaches to treat hypertension and CVDs.

Investigational bispecific antibodies for the treatment of rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is an autoimmune disorder with a characteristic chronic inflammation of the synovium that may lead to the destruction of the joints in untreated patients. Interestingly, despite the availability of several effective treatments, many patients do not achieve remission or low disease activity or may experience disease relapse.Following the above unmet needs, bispecific antibodies (BsAbs) have emerged as a new approach to improve the disease's treatment. BsAbs are designed to simultaneously target two different proteins involved in RA pathogenesis, leading to enhanced efficacy and reduced side effects compared to traditional monoclonal antibodies (mAbs).

AREAS COVERED

In this review, we discuss the development of BsAbs for RA treatment, including their mechanism of action, efficacy, and safety profile. We also deal with the challenges and future directions in this field.

EXPERT OPINION

BsAbs show promise in preclinical and clinical evaluations for treating RA. Further research is needed to optimize design and dosage and identify ideal patient groups. BsAbs can benefit disease management and improve outcomes of RA patients.

Mechanistic insights into anti-inflammatory and immunosuppressive effects of plant secondary metabolites and their therapeutic potential for rheumatoid arthritis

The anti-inflammatory and immunosuppressive activities of plant secondary metabolites are due to their diverse mechanisms of action against multifarious molecular targets such as modulation of the complex immune system associated with rheumatoid arthritis (RA). This review discussed and critically analyzed the potent anti-inflammatory and immunosuppressive effects of several phytochemicals and their underlying mechanisms in association with RA in experimental studies, including preliminary clinical studies of some of them. A wide range of phytochemicals including phenols, flavonoids, chalcones, xanthones, terpenoids, alkaloids, and glycosides have shown significant immunosuppressive and anti-inflammatory activities in experimental RA models and a few have undergone clinical trials for their efficacy and safety in reducing RA symptoms and improve patient outcomes. These phytochemicals have potential as safer alternatives to the existing drugs in the management of RA, which possess a wide range of serious side effects. Sufficient preclinical studies on safety and efficacy of these phytochemicals must be performed prior to proper clinical studies. Further studies are needed to address the barriers that have so far limited their human use before the therapeutic potential of these plant-based chemicals as anti-arthritic agents in the treatment of RA is fully realized.

A systematic review: Sinomenine

Sinomenine (SIN), an alkaloid derived from the traditional Chinese medicine, Caulis Sinomenii, has been used as an anti-inflammatory drug in China for over 30 years. With the continuous increase in research on the pharmacological mechanism of SIN, it has been found that, in addition to the typical rheumatoid arthritis (RA) treatment, SIN can be used as a potentially effective therapeutic drug for anti-tumour, anti-renal, and anti-nervous system diseases. By reviewing a large amount of literature and conducting a summary analysis of the literature pertaining to the pharmacological mechanism of SIN, we completed a review that focused on SIN, found that the current research is insufficient, and offered an outlook for future SIN development. We hope that this review will increase the public understanding of the pharmacological mechanisms of SIN, discover SIN research trial shortcomings, and promote the effective treatment of immune diseases, inflammation, and other related diseases.

PD-1 Receptor (+) T cells are associated with the efficacy of the combined treatment with regulatory t cells and rituximab in type 1 diabetes children via regulatory t cells suppressive activity amelioration

An imbalance between exaggerated autoaggressive T cell responses, primarily CD8 + T cells, and impaired tolerogenic mechanisms underlie the development of type 1 diabetes mellitus. Disease-modifying strategies, particularly immunotherapy focusing on FoxP3 + T regulatory cells (Treg), and B cells facilitating antigen presentation for T cells, show promise. Selective depletion of B cells may be achieved with an anti-CD20 monoclonal antibody (mAb). In a 2-year-long flow cytometry follow-up, involving 32 peripheral blood T and B cell markers across three trial arms (Treg + rituximab N = 12, Treg + placebo N = 13, control N = 11), we observed significant changes. PD-1 receptor (+) CD4 + Treg, CD4 + effector T cells (Teffs), and CD8 + T cell percentages increased in the combined regimen group by the end of follow-up. Conversely, the control group exhibited a notable reduction in PD-1 receptor (+) CD4 + Teff percentages. Considering clinical endpoints, higher PD-1 receptor (+) expression on T cells correlated with positive responses, including a higher mixed meal tolerance test AUC, and reduced daily insulin dosage. PD-1 receptor (+) T cells emerged as a potential therapy outcome biomarker. In vitro validation confirmed that successful Teff suppression was associated with elevated PD-1 receptor (+) Treg levels. These findings support PD-1 receptor (+) T cells as a reliable indicator of treatment with combined immunotherapy consisting of Tregs and anti-CD20 mAb efficacy in type 1 diabetes mellitus.

Exploring the therapeutic opportunities of potassium channels for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that affects the synovial joint, which leads to inflammation, loss of function, joint destruction, and disability. The disease biology of RA involves complex interactions between genetic and environmental factors and is strongly associated with various immune cells, and each of the cell types contributes differently to disease pathogenesis. Several immunomodulatory molecules, such as cytokines, are secreted from the immune cells and intervene in the pathogenesis of RA. In immune cells, membrane proteins such as ion channels and transporters mediate the transport of charged ions to regulate intracellular signaling pathways. Ion channels control the membrane potential and effector functions such as cytotoxic activity. Moreover, clinical studies investigating patients with mutations and alterations in ion channels and transporters revealed their importance in effective immune responses. Recent studies have shown that voltage-gated potassium channels and calcium-activated potassium channels and their subtypes are involved in the regulation of immune cells and RA. Due to the role of these channels in the pathogenesis of RA and from multiple pieces of clinical evidence, they can be considered therapeutic targets for the treatment of RA. Here, we describe the role of voltage-gated and calcium-activated potassium channels and their subtypes in RA and their pharmacological application as drug targets.

ABCD of IA: A multi-scale agent-based model of T cell activation in inflammatory arthritis

Biomaterial-based agents have been demonstrated to regulate the function of immune cells in models of autoimmunity. However, the complexity of the kinetics of immune cell activation can present a challenge in optimizing the dose and frequency of administration. Here, we report a model of autoreactive T cell activation, which are key drivers in autoimmune inflammatory joint disease. The model is termed a multi-scale Agent-Based, Cell-Driven model of Inflammatory Arthritis (ABCD of IA). Using kinetic rate equations and statistical theory, ABCD of IA simulated the activation and presentation of autoantigens by dendritic cells, interactions with cognate T cells and subsequent T cell proliferation in the lymph node and IA-affected joints. The results, validated with in vivo data from the T cell driven SKG mouse model, showed that T cell proliferation strongly correlated with the T cell receptor (TCR) affinity distribution (TCR-ad), with a clear transition state from homeostasis to an inflammatory state. T cell proliferation was strongly dependent on the amount of antigen in antigenic stimulus event (ASE) at low concentrations. On the other hand, inflammation driven by Th17-inducing cytokine mediated T cell phenotype commitment was influenced by the initial level of Th17-inducing cytokines independent of the amount of arthritogenic antigen. The introduction of inhibitory artificial antigen presenting cells (iaAPCs), which locally suppress T cell activation, reduced T cell proliferation in a dose-dependent manner. The findings in this work set up a framework based on theory and modeling to simulate personalized therapeutic strategies in IA.

Shared genetic architecture between hypothyroidism and rheumatoid arthritis: A large-scale cross-trait analysis

BACKGROUND

In recent years, mounting evidence has indicated a co-morbid relationship between hypothyroidism and rheumatoid arthritis (RA), however, the shared genetic factors underlying this association remain unclear. This study aims to investigate the common genetic architecture between hypothyroidism and RA.

METHODS

Genome-wide association study (GWAS) summary statistics from recently published studies were utilized to examine the genetic correlation, shared genetic loci, and potential causal relationship between hypothyroidism and RA. Statistical methods included linkage disequilibrium score regression (LDSC), high-definition likelihood (HDL), cross-trait meta-analyses, colocalization analysis, multi-marker analysis of genomic annotation (MAGMA), tissue-specific enrichment analysis (TSEA), functional enrichment analysis, and latent causal variable method (LCV).

RESULTS

Our study demonstrated a significant genetic correlation between hypothyroidism and RA(LDSC:rg=0.3803,p=7.23e-11;HDL:rg=0.3849,p=1.02e-21). Through cross-trait meta-analysis, we identified 1035 loci, including 43 novel genetic loci. By integrating colocalization analysis and the MAGMA algorithm, we found a substantial number of genes, such as PTPN22, TYK2, and CTLA-4, shared between the two diseases, which showed significant enrichment across 14 tissues. These genes were primarily associated with the regulation of alpha-beta T cell proliferation, positive regulation of T cell activation, positive regulation of leukocyte cell-cell adhesion, T cell receptor signaling pathway, and JAK-STAT signaling pathway. However, our study did not reveal a significant causal association between the two diseases using the LCV approach.

CONCLUSION

Based on these findings, there is a significant genetic correlation between hypothyroidism and RA, suggesting a shared genetic basis for these conditions.

Bispecific antibodies tethering innate receptors induce human tolerant-dendritic cells and regulatory T cells

There is an urgent need for alternative therapies targeting human dendritic cells (DCs) that could reverse inflammatory syndromes in many autoimmune and inflammatory diseases and organ transplantations. Here, we describe a bispecific antibody (bsAb) strategy tethering two pathogen-recognition receptors at the surface of human DCs. This cross-linking switches DCs into a tolerant profile able to induce regulatory T-cell differentiation. The bsAbs, not parental Abs, induced interleukin 10 and transforming growth factor β1 secretion in monocyte-derived DCs and human peripheral blood mononuclear cells. In addition, they induced interleukin 10 secretion by synovial fluid cells in rheumatoid arthritis and gout patients. This concept of bsAb-induced tethering of surface pathogen-recognition receptors switching cell properties opens a new therapeutic avenue for controlling inflammation and restoring immune tolerance.

Identification of Hedyotis diffusa Willd-specific mRNA-miRNA-lncRNA network in rheumatoid arthritis based on network pharmacology, bioinformatics analysis, and experimental verification

Hedyotis diffusa Willd (HDW) possesses heat-clearing, detoxification, anti-cancer, and anti-inflammatory properties. However, its effects on rheumatoid arthritis (RA) remain under-researched. In this study, we identified potential targets of HDW and collected differentially expressed genes of RA from the GEO dataset GSE77298, leading to the construction of a drug-component-target-disease regulatory network. The intersecting genes underwent GO and KEGG analysis. A PPI protein interaction network was established in the STRING database. Through LASSO, RF, and SVM-RFE algorithms, we identified the core gene MMP9. Subsequent analyses, including ROC, GSEA enrichment, and immune cell infiltration, correlated core genes with RA. mRNA-miRNA-lncRNA regulatory networks were predicted using databases like TargetScan, miRTarBase, miRWalk, starBase, lncBase, and the GEO dataset GSE122616. Experimental verification in RA-FLS cells confirmed HDW's regulatory impact on core genes and their ceRNA expression. We obtained 11 main active ingredients of HDW and 180 corresponding targets, 2150 RA-related genes, and 36 drug-disease intersection targets. The PPI network diagram and three machine learning methods screened to obtain MMP9, and further analysis showed that MMP9 had high diagnostic significance and was significantly correlated with the main infiltrated immune cells, and the molecular docking verification also showed that MMP9 and the main active components of HDW were well combined. Next, we predicted 6 miRNAs and 314 lncRNAs acting on MMP9, and two ceRNA regulatory axes were obtained according to the screening. Cellular assays indicated HDW inhibits RA-FLS cell proliferation and MMP9 protein expression dose-dependently, suggesting HDW might influence RA's progression by regulating the MMP9/miR-204-5p/MIAT axis. This innovative analytical thinking provides guidance and reference for the future research on the ceRNA mechanism of traditional Chinese medicine in the treatment of RA.

Advantages of Chinese herbal medicine in treating rheumatoid arthritis: a focus on its anti-inflammatory and anti-oxidative effects

Oxidative stress is a condition characterized by an imbalance between the oxidative and antioxidant processes within the human body. Rheumatoid arthritis (RA) is significantly influenced by the presence of oxidative stress, which acts as a pivotal factor in its pathogenesis. Elevated levels of mitochondrial reactive oxygen species (ROS) and inflammation have been found to be closely associated in the plasma of patients with RA. The clinical treatment strategies for this disease are mainly chemical drugs, such as nonsteroidal anti-inflammatory drugs (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs), glucocorticoids (GCs) and biological agents, but it is difficult for patients to accept long-term drug treatment and its side effects. In the theory of traditional Chinese medicine (TCM), RA is thought to be caused by the attack of "wind, cold, damp humor," and herbs with the effect of removing wind and dampness are used to relieve pain. Chinese herbal medicine boasts a rich heritage in effectively attenuating the symptoms of RA, and its global recognition continues to ascend. In particular, RA-relevant anti-inflammatory/anti-oxidative effects of TCM herbs/herbal compounds. The main aim of this review is to make a valuable contribution to the expanding pool of evidence that advocates for the incorporation of Chinese herbal medicine in conventional treatment plans for RA.

Zingiber Officinale Roscoe: The Antiarthritic Potential of a Popular Spice-Preclinical and Clinical Evidence

The health benefits of ginger rhizomes (Zingiber officinale Roscoe) have been known for centuries. Recently, ginger root has gained more attention due to its anti-inflammatory and analgesic activities. Many of the bioactive components of ginger may have therapeutic benefits in treating inflammatory arthritis. Their properties seem especially helpful in treating diseases linked to persistent inflammation and pain, symptoms present in the course of the most prevalent rheumatic diseases, such as osteoarthritis (OA) and rheumatoid arthritis (RA). This review analyzes the current knowledge regarding ginger's beneficial anti-inflammatory effect in both in vitro and in vivo studies as well as clinical trials. The drug delivery systems to improve ginger's bioavailability and medicinal properties are discussed. Understanding ginger's beneficial aspects may initiate further studies on improving its bioavailability and therapeutic efficacy and achieving more a comprehensive application in medicine.

Exploring the potential of Toxoplasma gondii in drug development and as a delivery system

Immune-mediated inflammatory diseases are various groups of conditions that result in immune system disorders and increased cancer risk. Despite the identification of causative cytokines and pathways, current clinical treatment for immune-mediated inflammatory diseases is limited. In addition, immune-mediated inflammatory disease treatment can increase the risk of cancer. Several previous studies have demonstrated that Toxoplasma gondii manipulates the immune response by inhibiting or stimulating cytokines, suggesting the potential for controlling and maintaining a balanced immune system. Additionally, T. gondii also has the unique characteristic of being a so-called "Trojan horse" bacterium that can be used as a drug delivery system to treat regions that have been resistant to previous drug delivery therapies. In this study, we reviewed the potential of T. gondii in drug development and as a delivery system through current research on inflammation-regulating mechanisms in immune-mediated inflammatory diseases.

Immunomodulatory Nanoparticles for Modulating Arthritis Flares

Disease-modifying drugs have improved the treatment for autoimmune joint disorders, such as rheumatoid arthritis, but inflammatory flares are a common experience. This work reports the development and application of flare-modulating poly(lactic-co-glycolic acid)-poly(ethylene glycol)-maleimide (PLGA-PEG-MAL)-based nanoparticles conjugated with joint-relevant peptide antigens, aggrecan70-84 and type 2 bovine collagen256-270. Peptide-conjugated PLGA-PEG-MAL nanoparticles encapsulated calcitriol, which acted as an immunoregulatory agent, and were termed calcitriol-loaded nanoparticles (CLNP). CLNP had a ∼200 nm hydrodynamic diameter with a low polydispersity index. In vitro, CLNP induced phenotypic changes in bone marrow derived dendritic cells (DC), reducing the expression of costimulatory and major histocompatibility complex class II molecules, and proinflammatory cytokines. Bulk RNA sequencing of DC showed that CLNP enhanced expression of Ctla4, a gene associated with downregulation of immune responses. In vivo, CLNP accumulated in the proximal lymph nodes after intramuscular injection. Administration of CLNP was not associated with changes in peripheral blood cell numbers or cytokine levels. In the collagen-induced arthritis and SKG mouse models of autoimmune joint disorders, CLNP reduced clinical scores, prevented bone erosion, and preserved cartilage proteoglycan, as assessed by high-resolution microcomputed tomography and histomorphometry analysis. The disease protective effects were associated with increased CTLA-4 expression in joint-localized DC and CD4+ T cells but without generalized suppression of T cell-dependent immune response. The results support the potential of CLNP as modulators of disease flares in autoimmune arthropathies.

Traditional uses, phytochemistry, pharmacology, processing methods and quality control of Lindera aggregata (Sims) Kosterm: A critical review

ETHNOPHARMACOLOGICAL RELEVANCE

Dried root tubers of L.aggregata have been widely used in Chinese herbal medicine for thousands of years to promote qi, relieve pain, warm kidney, and disperse cold.

AIM OF THE STUDY

This review aims to assess the research progress of L.aggregata, to comprehensively understand its development status, to point out the shortcomings of the existing researches, and to provide reference for further research on L.aggregata.

MATERIALS AND METHODS

By searching various databases for literatures on "Lindera aggregata", "Linderae Radix" and "Lindera strychnifolia", as well as relevant textbooks and digital documents, an overall and critical review of the subject was conducted.

RESULTS

Through phytochemical studies on different parts of L.aggregata, about 260 compounds were isolated, including flavonoids, alkaloids, terpenes, volatile oils, and other compounds. A large number of in vivo and in vitro studies have shown that L.aggregata has a plethora of pharmacological effects such as anti-cancer, anti-arthritis, anti-bacterial, anti-oxidation, anti-diabetic nephropathy, hepatoprotective, lipid-lowering effect and so on.

CONCLUSION

While the pharmacological effects of L.aggregata have been confirmed, most studies only use simple in vitro cell lines or animal disease models to evaluate their pharmacological activities. Therefore, future research should be conducted in a more comprehensive clinical manner. Further pharmacological research is also necessary to fully clarify the action mechanism of L.aggregata. It is also interesting to note that L.aggregata is often used to treat frequent urination in ancient times, but its molecular basis and mechanism of action are still unclear, and systematic studies are lacking. In terms of quality control, the source of L.aggregata is single, mostly wild, and the main medicinal part of L.aggregata is the tuber, while the yield of straight root is large. Therefore, further attention should be paid to the rapid propagation technology of L.aggregata and whether straight root can be included in medicinal use. It is also worth thinking whether sulfur-fumigation is necessary for preserving L.aggregata. As vinegar-processing is a common processing method for L. aggregata, the mechanism of such processing method remains to be investigated. In addition, in-depth research on the pharmacokinetics and long-term toxicity of L.aggregata is necessary to ensure its efficacy and safety.

Mutant p53R211* ameliorates inflammatory arthritis in AIA rats via inhibition of TBK1-IRF3 innate immune response

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune inflammation disease characterized by imbalance of immune homeostasis. p53 mutants are commonly described as the guardian of cancer cells by conferring them drug-resistance and immune evasion. Importantly, p53 mutations have also been identified in RA patients, and this prompts the investigation of its role in RA pathogenesis.

METHODS

The cytotoxicity of disease-modifying anti-rheumatic drugs (DMARDs) against p53 wild-type (WT)/mutant-transfected RA fibroblast-like synoviocytes (RAFLSs) was evaluated by MTT assay. Adeno-associated virus (AAV) was employed to establish p53 WT/R211* adjuvant-induced arthritis (AIA) rat model. The arthritic condition of rats was assessed by various parameters such as micro-CT analysis. Knee joint samples were isolated for total RNA sequencing analysis. The expressions of cytokines and immune-related genes were examined by qPCR, ELISA assay and immunofluorescence. The mechanistic pathway was determined by immunoprecipitation and Western blotting in vitro and in vivo.

RESULTS

Among p53 mutants, p53R213* exhibited remarkable DMARD-resistance in RAFLSs. However, AAV-induced p53R211* overexpression ameliorated inflammatory arthritis in AIA rats without Methotrexate (MTX)-resistance, and our results discovered the immunomodulatory effect of p53R211* via suppression of T-cell activation and T helper 17 cell (Th17) infiltration in rat joint, and finally downregulated expressions of pro-inflammatory cytokines. Total RNA sequencing analysis identified the correlation of p53R211* with immune-related pathways. Further mechanistic studies revealed that p53R213*/R211* instead of wild-type p53 interacted with TANK-binding kinase 1 (TBK1) and suppressed the innate immune TBK1-Interferon regulatory factor 3 (IRF3)-Stimulator of interferon genes (STING) cascade.

CONCLUSIONS

This study unravels the role of p53R213* mutant in RA pathogenesis, and identifies TBK1 as a potential anti-inflammatory target.

Pharmacological mechanisms of sinomenine in anti-inflammatory immunity and osteoprotection in rheumatoid arthritis: A systematic review

BACKGROUND

Sinomenine (SIN) is the main pharmacologically active component of Sinomenii Caulis and protects against rheumatoid arthritis (RA). In recent years, many studies have been conducted to elucidate the pharmacological mechanisms of SIN in the treatment of RA. However, the molecular mechanism of SIN in RA has not been fully elucidated.

PURPOSE

To summarize the pharmacological effects and molecular mechanisms of SIN in RA and clarify the most valuable regulatory mechanisms of SIN to provide clues and a basis for basic research and clinical applications.

METHODS

We systematically searched SciFinder, Web of Science, PubMed, China National Knowledge Internet (CNKI), the Wanfang Databases, and the Chinese Scientific Journal Database (VIP). We organized our work based on the PRISMA statement and selected studies for review based on predefined selection criteria.

OUTCOME

After screening, we identified 201 relevant studies, including 88 clinical trials and 113 in vivo and in vitro studies on molecular mechanisms. Among these studies, we selected key results for reporting and analysis.

CONCLUSIONS

We found that most of the known pharmacological mechanisms of SIN are indirect effects on certain signaling pathways or proteins. SIN was manifested to reduce the release of inflammatory cytokines such as Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), and IL-1β, thereby reducing the inflammatory response, and apparently blocking the destruction of bone and cartilage. The regulatory effects on inflammation and bone destruction make SIN a promising drug to treat RA. More notably, we believe that the modulation of α7nAChR and the regulation of methylation levels at specific GCG sites in the mPGES-1 promoter by SIN, and its mechanism of directly targeting GBP5, certainly enriches the possibilities and the underlying rationale for SIN in the treatment of inflammatory immune-related diseases.

Mechanistic target of rapamycin (mTOR): a potential new therapeutic target for rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by systemic synovitis and bone destruction. Proinflammatory cytokines activate pathways of immune-mediated inflammation, which aggravates RA. The mechanistic target of rapamycin (mTOR) signaling pathway associated with RA connects immune and metabolic signals, which regulates immune cell proliferation and differentiation, macrophage polarization and migration, antigen presentation, and synovial cell activation. Therefore, therapy strategies targeting mTOR have become an important direction of current RA treatment research. In the current review, we summarize the biological functions of mTOR, its regulatory effects on inflammation, and the curative effects of mTOR inhibitors in RA, thus providing references for the development of RA therapeutic targets and new drugs.

Identification of immunological characteristics and cuproptosis-related molecular clusters in Rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterised by progressive articular damage, functional loss, and comorbidities. The relationship between cuproptosis, a form of programmed cell death, and RA remains unknown. Therefore, this study aimed to explore cuproptosis-related molecular clusters in RA.

METHODS

Gene expression profiles of GSE93272 were downloaded from the Gene Expression Omnibus to identify the expression profiles of cuproptosis regulators and the immune infiltration characteristics of RA. The molecular clusters of cuproptosis-related genes and the related immune cell infiltration were explored. Cluster-specific differentially expressed genes were identified using the weighted gene co-expression network analysis. Further, an external dataset (GSE15573) was used, and an enzyme-linked immunosorbent assay was performed to validate the predictive efficiency.

RESULTS

Thirteen cuproptosis-related genes and activated immune responses were identified between patients with RA and controls. Immune infiltration revealed significant immunological heterogeneity in the two cuproptosis-related molecular clusters in RA. Functional enrichment indicated that Cluster1 and Cluster2 were predominantly enriched in the toll-like receptor signalling pathway and regulation of autophagy, respectively. Further, the performance of FAM96A and CGRRF1 genes in the external validation dataset was observed to be relatively satisfactory (area under the receiver operating characteristic curve = 0.687 and 0.674, respectively). Based on our serum samples, FAM96A and CGRRF1 both exhibited higher expression levels in patients with RA (p = 0.001; p = 0.000).

CONCLUSIONS

Our study systematically illustrated the involvement of cuproptosis in the progression of RA, and explored the pathogenic mechanisms and novel therapeutic strategies for RA, targeting FAM96A and CGRRF1.

Exponentially decreasing exposure of antigen generates anti-inflammatory T-cell responses

Rheumatoid Arthritis (RA) is a chronic debilitating disease characterized by auto-immune reaction towards self-antigen such as collagen type II. In this study, we investigated the impact of exponentially decreasing levels of antigen exposure on pro-inflammatory T cell responses in the collagen-induced arthritis (CIA) mouse model. Using a controlled delivery experimental approach, we manipulated the collagen type II (CII) antigen concentration presented to the immune system. We observed that exponentially decreasing levels of antigen generated reduced pro-inflammatory T cell responses in secondary lymphoid organs in mice suffering from RA. Specifically, untreated mice exhibited robust pro-inflammatory T cell activation and increased paw inflammation, whereas, mice exposed to exponentially decreasing concentrations of CII demonstrated significantly reduced pro-inflammatory T cell responses, exhibited lower levels of paw inflammation, and decreased arthritis scores in right rear paw. The data also demonstrate that the decreasing antigen levels promoted the induction of regulatory T cells (Tregs), which play a crucial role in maintaining immune tolerance and suppressing excessive inflammatory responses. Our findings highlight the importance of antigen concentration in modulating pro-inflammatory T cell responses in the CIA model. These results provide valuable insights into the potential therapeutic strategies that target antigen presentation to regulate immune responses and mitigate inflammation in rheumatoid arthritis and other autoimmune diseases. Further investigations are warranted to elucidate the specific mechanisms underlying the antigen concentration-dependent modulation of T cell responses and to explore the translational potential of this approach for the development of novel therapeutic interventions in autoimmune disorders.

Machine learning and bioinformatics analysis to identify autophagy-related biomarkers in peripheral blood for rheumatoid arthritis

Background: Although rheumatoid arthritis (RA) is a common autoimmune disease, the precise pathogenesis of the disease remains unclear. Recent research has unraveled the role of autophagy in the development of RA. This research aims to explore autophagy-related diagnostic biomarkers in the peripheral blood of RA patients. Methods: The gene expression profiles of GSE17755 were retrieved from the gene expression ontology (GEO) database. Differentially expressed autophagy-related genes (DE-ARGs) were identified for the subsequent research by inserting autophagy-related genes and differentially expressed genes (DEGs). Three machine learning algorithms, including random forest, support vector machine recursive feature elimination (SVM-RFE), and least absolute shrinkage and selection operator (LASSO), were employed to identify diagnostic biomarkers. A nomogram model was constructed to assess the diagnostic value of the biomarkers. The CIBERSORT algorithm was performed to investigate the correlation of the diagnostic biomarkers with immune cells and immune factors. Finally, the diagnostic efficacy and differential expression trend of diagnostic biomarkers were validated in multiple cohorts containing different tissues and diseases. Results: In this study, 25 DE-ARGs were identified between RA and healthy individuals. In addition to "macroautophagy" and "autophagy-animal," DE-ARGs were also associated with several types of programmed cell death and immune-related pathways according to GO and KEGG analysis. Three diagnostic biomarkers, EEF2, HSP90AB1 and TNFSF10, were identified by the random forest, SVM-RFE, and LASSO. The nomogram model demonstrated excellent diagnostic value in GSE17755 (AUC = 0.995, 95% CI: 0.988-0.999). Furthermore, immune infiltration analysis showed a remarkable association between EEF2, HSP90AB1, and TNFSF10 expression with various immune cells and immune factors. The three diagnostic biomarkers also exhibited good diagnostic efficacy and demonstrated the same trend of differential expression in multiple validation cohorts. Conclusion: This study identified autophagy-related diagnostic biomarkers based on three machine learning algorithms, providing promising targets for the diagnosis and treatment of RA.

The role of TRPV1 in RA pathogenesis: worthy of attention

Transient receptor potential cation channel subfamily V member 1 (TRPV1) is a Ca2+permeable, non-selective cation channel that is found primarily in sensory nerve fibres. Previous studies focused on pain transmission. However, recent studies have found that the TRPV1 channel, in addition to being associated with pain, also plays a role in immune regulation and their dysregulation frequently affects the development of rheumatoid arthritis (RA). A thorough understanding of the mechanism will facilitate the design of new TRPV1-targeted drugs and improve the clinical efficacy of RA. Here, we provide an updated and comprehensive overview of how the TRPV1 channel intrinsically regulates neuronal and immune cells, and how alterations in the TRPV1 channel in synoviocytes or chondrocytes extrinsically affect angiogenesis and bone destruction. Rapid progress has been made in research targeting TRPV1 for the treatment of inflammatory arthritis, but there is still much-uncharted territory regarding the therapeutic role of RA. We present a strategy for targeting the TRPV1 channel in RA therapy, summarising the difficulties and promising advances in current research, with the aim of better understanding the role of the TRPV1 channel in RA pathology, which could accelerate the development of TRPV1-targeted modulators for the design and development of more effective RA therapies.

Efficacy of HDAC inhibitors and epigenetic modulation in the amelioration of synovial inflammation, cellular invasion, and bone erosion in rheumatoid arthritis pathogenesis

Rheumatoid arthritis (RA), an auto-immune disorder affected 1 % of the population around the globe. The pathophysiology of RA is highly concerted process including synovial hyperplasia, pannus formation, bone erosion, synovial cell infiltration in joints, and cartilage destruction. However, recent reports suggest that epigenetics play a pivotal role in the formation and organization of immune response in RA. Particularly, altered DNA methylation and impaired microRNA (miRNA) were detected in several immune cells of RA patients, such as T regulatory cells, fibroblast-like synoviocytes, and blood mononuclear cells. All these processes can be reversed by regulating the ubiquitous or tissue-based expression of histone deacetylases (HDACs) to counteract and terminate them. Hence, HDAC inhibitors (HDACi) could serve as highly potent anti-inflammatory regulators in the uniform amelioration of inflammation. Therefore, this review encompasses the information mainly focussing on the epigenetic modulation in RA pathogenesis and the efficacy of HDACi as an alternative therapeutic option for RA treatment. Overall, these studies have reported the targeting of HDAC1, 2 & 6 molecules would attenuate synoviocyte inflammation, cellular invasion, and bone erosion. Further, the inhibitors such as trichostatin A, suberoyl bis-hydroxamic acid, suberoyl anilide hydroxamic acid, and other compounds are found to attenuate synovial inflammatory immune response, clinical arthritis score, paw swelling, bone erosion, and cartilage destruction. Insight to view this, more clinical studies are required to determine the efficacy of HDACi in RA treatment and to unravel the underlying molecular mechanisms.

Disease-microenvironment modulation by bare- or engineered-exosome for rheumatoid arthritis treatment

BACKGROUND

Exosomes are extracellular vesicles secreted by eukaryotic cells and have been extensively studied for their surface markers and internal cargo with unique functions. A deeper understanding of exosomes has allowed their application in various research areas, particularly in diagnostics and therapy.

MAIN BODY

Exosomes have great potential as biomarkers and delivery vehicles for encapsulating therapeutic cargo. However, the limitations of bare exosomes, such as rapid phagocytic clearance and non-specific biodistribution after injection, pose significant challenges to their application as drug delivery systems. This review focuses on exosome-based drug delivery for treating rheumatoid arthritis, emphasizing pre/post-engineering approaches to overcome these challenges.

CONCLUSION

This review will serve as an essential resource for future studies to develop novel exosome-based therapeutic approaches for rheumatoid arthritis. Overall, the review highlights the potential of exosomes as a promising therapeutic approach for rheumatoid arthritis treatment.

Metabolic signature and proteasome activity controls synovial migration of CDC42hiCD14+ cells in rheumatoid arthritis

OBJECTIVE

Activation of Rho-GTPases in macrophages causes inflammation and severe arthritis in mice. In this study, we explore if Rho-GTPases define the joint destination of pathogenic leukocytes, the mechanism by which they perpetuate rheumatoid arthritis (RA), and how JAK inhibition mitigates these effects.

METHODS

CD14+ cells of 136 RA patients were characterized by RNA sequencing and cytokine measurement to identify biological processes and transcriptional regulators specific for CDC42 hiCD14+ cells, which were summarized in a metabolic signature (MetSig). The effect of hypoxia and IFN-γ signaling on the metabolic signature of CD14+ cells was assessed experimentally. To investigate its connection with joint inflammation, the signature was translated into the single-cell characteristics of CDC42 hi synovial tissue macrophages. The sensitivity of MetSig to the RA disease activity and the treatment effect were assessed experimentally and clinically.

RESULTS

CDC42 hiCD14+ cells carried MetSig of genes functional in the oxidative phosphorylation and proteasome-dependent cell remodeling, which correlated with the cytokine-rich migratory phenotype and antigen-presenting capacity of these cells. Integration of CDC42 hiCD14+ and synovial macrophages marked with MetSig revealed the important role of the interferon-rich environment and immunoproteasome expression in the homeostasis of these pathogenic macrophages. The CDC42 hiCD14+ cells were targeted by JAK inhibitors and responded with the downregulation of immunoproteasome and MHC-II molecules, which disintegrated the immunological synapse, reduced cytokine production, and alleviated arthritis.

CONCLUSION

This study shows that the CDC42-related MetSig identifies the antigen-presenting CD14+ cells that migrate to joints to coordinate autoimmunity. The accumulation of CDC42 hiCD14+ cells discloses patients perceptive to the JAKi treatment.

Vaccines prevent reinduction of rheumatoid arthritis symptoms in collagen-induced arthritis mouse model

Metabolic reprogramming of immune cells modulates their function and reduces the severity of autoimmune diseases. However, the long-term effects of the metabolically reprogrammed cells, specifically in the case of immune flare-ups, need to be examined. Herein, a re-induction rheumatoid arthritis (RA) mouse model was developed by injecting T-cells from RA mice into drug-treated mice to recapitulate the effects of T-cell-mediated inflammation and mimic immune flare-ups. Immune metabolic modulator paKG(PFK15 + bc2) microparticles (MPs) were shown to reduce clinical symptoms of RA in collagen-induced arthritis (CIA) mice. Upon re-induction, a significant delay in the reappearance of clinical symptoms in the paKG(PFK15 + bc2) microparticle treatment group was observed as compared to equal or higher doses of the clinically utilized U.S. Food and Drug Administration (FDA)-approved drug, Methotrexate (MTX). Furthermore, paKG(PFK15 + bc2) microparticle-treated mice were able to lower activated dendritic cells (DCs) and inflammatory T helper cell 1 (TH1) and increased activated, proliferating regulatory T-cells (Tregs) more effectively than MTX. The paKG(PFK15 + bc2) microparticles also led to a significant reduction in paw inflammation in mice as compared to MTX treatment. This study can pave the way for the development of flare-up mouse models and antigen-specific drug treatments.

Signaling pathways involved in the biological functions of dendritic cells and their implications for disease treatment

The ability of dendritic cells (DCs) to initiate and regulate adaptive immune responses is fundamental for maintaining immune homeostasis upon exposure to self or foreign antigens. The immune regulatory function of DCs is strictly controlled by their distribution as well as by cytokines, chemokines, and transcriptional programming. These factors work in conjunction to determine whether DCs exert an immunosuppressive or immune-activating function. Therefore, understanding the molecular signals involved in DC-dependent immunoregulation is crucial in providing insight into the generation of organismal immunity and revealing potential clinical applications of DCs. Considering the many breakthroughs in DC research in recent years, in this review we focused on three basic lines of research directly related to the biological functions of DCs and summarized new immunotherapeutic strategies involving DCs. First, we reviewed recent findings on DC subsets and identified lineage-restricted transcription factors that guide the development of different DC subsets. Second, we discussed the recognition and processing of antigens by DCs through pattern recognition receptors, endogenous/exogenous pathways, and the presentation of antigens through peptide/major histocompatibility complexes. Third, we reviewed how interactions between DCs and T cells coordinate immune homeostasis in vivo via multiple pathways. Finally, we summarized the application of DC-based immunotherapy for autoimmune diseases and tumors and highlighted potential research prospects for immunotherapy that targets DCs. This review provides a useful resource to better understand the immunomodulatory signals involved in different subsets of DCs and the manipulation of these immune signals can facilitate DC-based immunotherapy.

The Epigenetic Reader Protein SP140 Regulates Dendritic Cell Activation, Maturation and Tolerogenic Potential

SP140 is an epigenetic reader protein expressed predominantly in immune cells. GWAS studies have shown an association between SP140 single nucleotide polymorphisms (SNPs) and diverse autoimmune and inflammatory diseases, suggesting a possible pathogenic role for SP140 in immune-mediated diseases. We previously demonstrated that treatment of human macrophages with the novel selective inhibitor of the SP140 protein (GSK761) reduced the expression of endotoxin-induced cytokines, implicating a role of SP140 in the function of inflammatory macrophages. In this study, we investigated the effects of GSK761 on in vitro human dendritic cell (DC) differentiation and maturation, assessing the expression of cytokines and co-stimulatory molecules and their capacity to stimulate T-cell activation and induce phenotypic changes. In DCs, lipopolysaccharide (LPS) stimulation induced an increase in SP140 expression and its recruitment to transcription start sites (TSS) of pro-inflammatory cytokine genes. Moreover, LPS-induced cytokines such as TNF, IL-6, and IL-1β were reduced in GSK761- or SP140 siRNA- treated DCs. Although GSK761 did not significantly affect the expression of surface markers that define the differentiation of CD14⁺ monocytes into immature DCs (iDCs), subsequent maturation of iDCs to mature DCs was significantly inhibited. GSK761 strongly reduced expression of the maturation marker CD83, the co-stimulatory molecules CD80 and CD86, and the lipid-antigen presentation molecule CD1b. Finally, when the ability of DCs to stimulate recall T-cell responses by vaccine-specific T cells was assessed, T cells stimulated by GSK761-treated DCs showed reduced TBX21 and RORA expression and increased FOXP3 expression, indicating a preferential generation of regulatory T cells. Overall, this study suggests that SP140 inhibition enhances the tolerogenic properties of DCs, supporting the rationale of targeting SP140 in autoimmune and inflammatory diseases where DC-mediated inflammatory responses contribute to disease pathogenesis.

"Cross-talk" between gut microbiome dysbiosis and osteoarthritis progression: a systematic review

Objectives

The aim of this systematic review was to summarize the available literature on gut microbiome (GMB) and osteoarthritis (OA), analyze the correlation between GMB and OA, and explore potential underlying mechanisms.

Methods

A systematic search of the PubMed, Embase, Cochrane, and Web of Science with the keywords "Gut Microbiome" and "Osteoarthritis" was conducted to identify the human and animal studies exploring the association between GMB and OA. The retrieval time range was from the database inception to July 31, 2022. Studies reported the other arthritic diseases without OA, reviews, and studies focused on the microbiome in other parts of the body with OA, such as oral or skin, were excluded. The included studies were mainly reviewed for GMB composition, OA severity, inflammatory factors, and intestinal permeability.

Results

There were 31 studies published met the inclusion criteria and were analyzed, including 10 human studies and 21 animal studies. Human and animal studies have reached a consistent conclusion that GMB dysbiosis could aggravate OA. In addition, several studies have found that alterations of GMB composition can increase intestinal permeability and serum levels of inflammatory factors, while regulating GMB can alleviate the changes. Owing to the susceptibility of GMB to internal and external environments, genetics, and geography, the included studies were not consistent in GMB composition analysis.

Conclusion

There is a lack of high-quality studies evaluating the effects of GMB on OA. Available evidence indicated that GMB dysbiosis aggravated OA through activating the immune response and subsequent induction of inflammation. Future studies should focus on more prospective, cohort studies combined with multi-omics to further clarify the correlation.

Vitamin D and Autoimmune Rheumatic Diseases

Vitamin D is a steroid hormone with potent immune-modulating properties. It has been shown to stimulate innate immunity and induce immune tolerance. Extensive research efforts have shown that vitamin D deficiency may be related to the development of autoimmune diseases. Vitamin D deficiency has been observed in patients with rheumatoid arthritis (RA) and has been shown to be inversely related to disease activity. Moreover, vitamin D deficiency may be implicated in the pathogenesis of the disease. Vitamin D deficiency has also been observed in patients with systemic lupus erythematosus (SLE). It has been found to be inversely related to disease activity and renal involvement. In addition, vitamin D receptor polymorphisms have been studied in SLE. Vitamin D levels have been studied in patients with Sjogren's syndrome, and vitamin D deficiency may be related to neuropathy and the development of lymphoma in the context of Sjogren's syndrome. Vitamin D deficiency has been observed in ankylosing spondylitis, psoriatic arthritis (PsA), and idiopathic inflammatory myopathies. Vitamin D deficiency has also been observed in systemic sclerosis. Vitamin D deficiency may be implicated in the pathogenesis of autoimmunity, and it may be administered to prevent autoimmune disease and reduce pain in the context of autoimmune rheumatic disorders.

Immunomodulatory Microparticles Epigenetically Modulate T Cells and Systemically Ameliorate Autoimmune Arthritis

Disease modifying antirheumatic drugs (DMARDs) have improved the prognosis of autoimmune inflammatory arthritides but a large fraction of patients display partial or nonresponsiveness to front-line DMARDs. Here, an immunoregulatory approach based on sustained joint-localized release of all-trans retinoic acid (ATRA), which modulates local immune activation and enhances disease-protective T cells and leads to systemic disease control is reported. ATRA imprints a unique chromatin landscape in T cells, which is associated with an enhancement in the differentiation of naïve T cells into anti-inflammatory regulatory T cells (Treg ) and suppression of Treg destabilization. Sustained release poly-(lactic-co-glycolic) acid (PLGA)-based biodegradable microparticles encapsulating ATRA (PLGA-ATRA MP) are retained in arthritic mouse joints after intra-articular (IA) injection. IA PLGA-ATRA MP enhance migratory Treg which in turn reduce inflammation and modify disease in injected and uninjected joints, a phenotype that is also reproduced by IA injection of Treg . PLGA-ATRA MP reduce proteoglycan loss and bone erosions in the SKG and collagen-induced arthritis mouse models of autoimmune arthritis. Strikingly, systemic disease modulation by PLGA-ATRA MP is not associated with generalized immune suppression. PLGA-ATRA MP have the potential to be developed as a disease modifying agent for autoimmune arthritis.

Cytokine Signatures in Psoriatic Arthritis Patients Indicate Different Phenotypic Traits Comparing Responders and Non-Responders of IL-17A and TNFα Inhibitors

This study aimed to explore the dynamic interactions between 32 cytokines and biomarkers in Psoriatic Arthritis (PsA) patients to compare cytokine signatures of treatment responders and non-responders. Biomarkers were measured before and after four months of treatment in 39 PsA patients initiating either Tumor Necrosis Factor alpha inhibitor (TNFi) or Interleukin-17A inhibitor (IL-17Ai). Response to treatment was defined by the composite measure, Disease Activity in Psoriatic Arthritis (DAPSA). A two-component principal component analysis (PCA) was implemented to describe cytokine signatures comparing DAPSA50 responders and non-responders. The cytokine signature of TNFi responders was driven by the correlated cytokines interferon γ (IFNγ) and IL-6, additionally associated with IL-12/IL-23p40, TNFα, and CRP, while the cytokine signature of TNFi non-responders was driven by the correlated cytokines IL-15, IL-8, and IFNγ. IL-17Ai responders were characterized by contributions of strongly correlated Th17 inflammatory cytokines, IL-17A, IL-12/IL-23p40, IL-22 to the cytokine signature, whereas IL-17A and IL-12/IL-23p40 did not demonstrate significant contribution in IL-17Ai non-responders. Based on PCA results it was possible to differentiate DAPSA50 responders and non-responders to treatment, endorsing additional examination of cytokine interaction models in PsA patients and supporting further PsA patient immune stratification to improve individualized treatment of PsA patients.