Joint together: The etiology and pathogenesis of ankylosing spondylitis

IDO1-mediated M2 macrophage polarization alleviates the progression of ankylosing spondylitis

Indoleamine 2,3-dioxygenase 1 (IDO1) plays an anti-inflammatory role in autoimmune disease. However, its specific function in ankylosing spondylitis (AS) remain unclear. This study aimed to investigate the potential role of IDO1 in AS. Immunofluorescence, RT-qPCR, and western blot assays were employed to measure gene expression, while ELISA was used to quantify the release of M1 macrophage and M2 macrophage markers. CCK-8, EdU, flow cytometry, ALP staining, and Alizarin red staining (ARS) assays were conducted for functional analysis. JASPAR predicted the binding sites between PPARγ and the promoter, which were further validated by luciferase and ChIP assays. Our findings revealed that the expression of IDO1 was markedly elevated in AS patients. IDO1 overexpression promoted the proliferation of THP-1 cells and M2 macrophage polarization. Conversely, IDO1 knockdown facilitated the osteogenic differentiation of BMSCs. Furthermore, IDO1-mediated upregulation of PPARγ modulated RUNX2 transcription. PPARγ overexpression counteracted the effects of IDO1 knockdown, thereby inhibiting the osteogenic differentiation of BMSCs. In conclusion, the IDO1/PPARγ/RUNX2 signaling pathway may protect against AS by promoting M2 macrophage polarization and inhibiting osteogenic differentiation.

Significant correlations of upregulated MPO expression with cytokine imbalance in ankylosing spondylitis patients and the inhibitory effect mediated by mesenchymal stem cells

BACKGROUND

Little is known regarding both the role of myeloperoxidase (MPO) and the impact of mesenchymal stem cells (MSCs) on inflammatory and immune responses in ankylosing spondylitis (AS). This study is aimed to explore the role of MPO and the regulatory effect of umbilical cord-derived MSCs on MPO expression in monocytes in AS.

METHODS

MPO mRNA expression in the peripheral blood mononuclear cells (PBMCs) was detected by Real-time PCR. Cytokines including IL-2, IFN-γ, IL-17 A, IL-4, IL-10, IL-6 and TNF-α were determined by flow cytometry. A co-culture system was established by culturing THP-1 cells with MSCs at a ratio of 5:1.

RESULTS

Increased mRNA expression of MPO was observed in PBMCs of AS patients compared to healthy controls (P < 0.05). The mRNA expression of MPO was positively associated with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) (P < 0.05) in AS. Besides, the levels of IL-2, IL-10, IFN-γ, IL-17 A, IL-4, IL-6, TNF-α in plasma were notably increased in AS (P < 0.05). Positive correlations between MPO expression and IL-2, IFN -γ, IL-4, TNF-α as well as IL-6 were demonstrated in AS (P < 0.05). Furthermore, MSCs remarkably suppressed the mRNA expression of MPO along with the secretion of IL-17 A and TNF-α, but promoted IL-10 generation in monocytes.

CONCLUSION

MPO expression is significantly upregulated and correlates with cytokine imbalance in AS. It may serve as a valuable immunotherapeutic target for AS. MSCs can significantly inhibit monocyte-mediated inflammatory response potentially by downregulating MPO in monocytes.

Unveiling Cuproptosis-Driven Molecular Clusters and Immune Dysregulation in Ankylosing Spondylitis

Background

Ankylosing spondylitis (AS) is a chronic autoimmune disease characterized by inflammation of the sacroiliac joints and spine. Cuproptosis is a newly recognized copper-induced cell death mechanism. Our study explored the novel role of cuproptosis-related genes (CRGs) in AS, focusing on immune cell infiltration and molecular clustering.

Methods

By analyzing the peripheral blood gene expression datasets obtained from GSE73754, GSE25101, and GSE11886, we identified the expression patterns of cellular factors and immune infiltration cell related to cuproptosis. Subsequently, we employed weighted gene co-expression network analysis (WGCNA) to identify differentially expressed genes (DEGs) within each cluster and utilized the "GSVA" and "GSEABase" software packages to examine variations in gene sets enriched across various CRG clusters. Finally, we selected the best-performing machine learning model to predict genes associated with AS. Datasets (GSE25101 and GSE73754) and ELISA to assess the expression levels of the five genes and their corresponding proteins.

Results

Seven cuproptosis-related DEGs and four immune cell types were identified, revealing significant immune heterogeneity in the immune cell infiltration between the two cuproptosis-related molecular clusters in AS. The eXtreme Gradient Boosting (XGB) model showed the highest predictive accuracy, achieving an area under the receiver operating characteristic curve (AUC) of 0.725, and 5-gene prediction models were established. It showed satisfactory performance in the GSE25101 dataset (AUC = 0.812). According to the blood serum samples of AS patients and controls, PELI1 had a higher expression level (AUC = 0.703, p = 0.07), while ICAM2 and RANGAP1 had lower expression levels (AUC = 0.724, 0.745, and p = 0.011, 0.000, respectively) in AS patients.

Conclusion

We explored the correlation of cuproptosis in AS, and developed the optimal machine learning model to identify high-risk genes associated with AS. We also explored the pathogenesis and treatment strategies of AS, targeting PELI1, ICAM2, and RANGAP1.

Development of a fluorescent probe for detecting superoxide anions for monitoring the progression and treatment of acute spondylitis

The superoxide anion (O2˙-) is a vital reactive oxygen species (ROS) and participates in various physiological and pathological processes in organisms. The outbreak of O2˙- in the endoplasmic reticulum (ER) is believed to be closely related to many inflammatory diseases. In this work, a turn-on type ER-targeting fluorescent probe ERO was rationally designed for sensitive and selective detection of O2˙-. The minimum detection limit concentration for O2˙- was about 3.3 × 10-7 M in aqueous solution. More importantly, the probe ERO has minimal biological toxicity and can effectively target the ER and detect O2˙- in macrophage cells. Resveratrol is a natural drug closely related to anti-inflammatory effects. Through fluorescence monitoring of the probe ERO, it was found that there was an outbreak of O2˙- in the ER in acute spondylitis in mice and resveratrol reversed this increase. Thus, the probe ERO has the potential to become a favorable diagnostic tool to visualize the mouse spine during inflammation and the therapeutic effect of resveratrol.

The malic acid inhibiting inflammation in ankylosing spondylitis by interfering M1 macrophage polarization

Ankylosing spondylitis (AS) is a motor system immune disease with significant genetic characteristics, resulting in joint fusion, deformity, rigidity, seriously affecting the quality of life of patients. Inflammatory bowel disease (IBD), characterized by intestinal mucosal damage and inflammatory changes, the most common extra-articular manifestation of AS. Due to the limitations of the application of therapeutic drugs, it is urgent to look for new mechanisms and strategies to effectively inhibit AS inflammation is. The content of malic acid (MA) was significantly decreased in peripheral blood of AS patients, and it was significantly negatively correlated with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). MA dramatically alleviated spinal damage and intestinal inflammation in mouse models of AS induced by β-1, 3-glucan solution. Mechanically, MA suppressed the NF-κB pathway by inhibiting polarization of M1-type macrophages, thereby alleviating spinal and intestinal inflammation. From the perspective of material metabolism, this study explored the mechanism by which MA, an intermediate product of glucose metabolism, reducing M1 polarization of macrophages to inhibit AS inflammation, providing a reliable basis for the pathogenesis research and precise targeted treatment of AS in the later stage.

Analysis of ASAS health index and its influencing factors in ankylosing spondylitis: a prospective study based on the population of Chaoshan region

Objective

This study aimed to evaluate the health-related quality of life (HRQoL) in ankylosing spondylitis (AS) patients in the Chaoshan region and identify factors influencing the ASAS Health Index (ASAS-HI) to enhance comprehensive AS treatment strategies.

Methods

A survey of ASAS-HI was conducted on 82 AS patients from the rheumatology outpatient department of the First Affiliated Hospital of Shantou University Medical College. The Bath Ankylosing Spondylitis Global Score (BAS-G) assessed overall health status, the Ankylosing Spondylitis Quality of Life Questionnaire (AS-QOL) evaluated quality of life, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) measured disease activity, and the Bath Ankylosing Spondylitis Functional Index (BASFI) assessed functional difficulties. Inflammatory markers and patient data were collected, and univariate/multivariate logistic regression analyses were used to explore influencing factors of ASAS-HI.

Results

The mean ASAS-HI score was 3.52 ± 3.12. ASAS-HI was positively correlated with BASDAI (r = 0.478, p < 0.001), ASDAS-CRP (r = 0.406, p < 0.001), BASFI (r = 0.338, p < 0.002), and BAS-G (r = 0.335, p < 0.002). Patients with ASDAS-ESR ≥ 2.1, ASDAS-CRP ≥ 2.1, and spinal tenderness had significantly higher ASAS-HI scores than others (p < 0.001). Spinal tenderness and radiographic grading were identified as key influencing factors.

Conclusion

ASAS-HI is significantly impacted by disease activity and functional limitations. Early assessment of ASAS-HI is crucial for optimizing disease management in AS patients.

Regnase-1 regulates inflammation in T cells of ankylosing spondylitis through the TRAF6

The study aimed to investigate the regulatory role of Regnase-1 in ankylosing spondylitis (AS) inflammation. We collected 10 ml peripheral venous blood and epidemiological data from 45 AS patients and 45 healthy controls and performed enzyme-linked immunosorbent assay (ELISA) experiments to measure the levels of inflammatory cytokines. Then CD3 + T lymphocytes were isolated by magnetic bead sorting method, and the transcriptional levels of Regnase-1 and TNF receptor-associated factor 6 (TRAF6) were detected by real-time quantitative PCR (qRT-PCR). The regnase-1 knockdown human T lymphocyte leukemia cell (Jurkat T) model was constructed by small interfering RNA (siRNA) technology. Then PCR and Western blot were used to detect the transcription level and protein level of downstream genes. Co-immunoprecipitation was used to verify the interaction between Regnase-1 and TRAF6. Regnase-1 and TRAF6 transcription levels were down-regulated and positively correlated with each other in T cells from AS patients. The ROC curve analysis indicates that both Regnase-1 and TRAF6 possess diagnostic capabilities, with Regnase-1 demonstrating a particularly high area under the curve (AUC) of 0.876 (95% CI: 0.789-0.936). Subgroup analysis shows NSAIDs boost Regnase-1 and TRAF6 transcription while reducing IL23 and IL17 levels. The results of cell experiments showed that si-Regnase-1 significantly reduced the mRNA and protein levels of TRAF6 in Jurkat T cells and increased the expression level of inflammatory gene TNF-α. Co-immunoprecipitation assay further verified the binding between the two proteins. Regnase-1 may participate in the chronic inflammatory process of AS by regulating TNF-α through TRAF6.

Exploring T Cell and NK Cell Involvement in Ankylosing Spondylitis Through Single-Cell Sequencing

To uncover the complex immune mechanisms driving inflammation in ankylosing spondylitis and lay the groundwork for identifying new therapeutic targets and innovative approaches, we conducted 10× single-cell sequencing on bone marrow cell samples collected from the vertebrae of three AS patients and three non-AS patients. Using single-cell sequencing data, we analysed the expression of differentially expressed genes (DEGs) by comparing AS patients with non-AS patients. Key genes among the related DEGs were identified through protein-protein interaction networks and hub gene screening and further validated using immunohistochemistry. We performed clustering and annotation of the single-cell sequencing data and externally validated the findings using the GSE232131 single-cell dataset. By integrating transcriptome data, we assessed the differential expression of immune cells in AS. Finally, we explored the interactions between immune cells in AS through cell communication analysis. The upregulated gene CD74 was identified as a hub gene in T cells in AS. Further research revealed the important relationship between T cells and NK cells in the fundamental processes of AS. Additionally, we found that the macrophage migration inhibitory factor signalling pathway is prominently expressed in the interactions among various cell types in AS.

An Actual Insight into the Pathogenic Pathways of Ankylosing Spondylitis

Spondyloarthritis refers to a broad group of conditions that include ankylosing spondylitis, psoriatic arthritis, reactive arthritis, and enteropathic arthritis associated with Crohn's disease or ulcerative colitis. They have been classified by the ASAS group (ASsessment in Ankylosing Spondylitis) into axial spondyloarthritis and peripheral spondyloarthritis. Common features include the absence of autoantibodies, genetic predisposition, and clinical aspects such as axial joint involvement, peripheral manifestations, and extra-articular involvement. However, the pathogenic mechanisms remain complex and incompletely elucidated, despite the fact that the specialized literature has described several pathways that act in synergy: genetic predisposition, environmental factors (infections and mechanical stress), or innate and acquired immune mechanisms. Finally, an inflammatory response is triggered by the recruitment of a large number of inflammatory cells and the release of innate cytokines in the affected areas: joints or periarticular or extraarticular tissues. The current article aims to update and systematize the knowledge accumulated so far on this topic, focusing on the mechanisms that have been involved in the onset, progression, and severity of ankylosing spondylitis.

Two-sample Mendelian Randomization to evaluate the causal relationship between inflammatory arthritis and female-specific cancers

BACKGROUND

There is evidence that inflammatory arthritis in the form of ankylosing spondylitis (AS), psoriatic arthritis (PsA), and rheumatoid arthritis are both positively and negatively associated with certain female-specific cancers. However, the study results are very heterogeneous.

METHODS

Based on up to 375,814 European women, we performed an iterative two-sample Mendelian randomization to assess causal effects of the occurrence of the inflammatory arthritis on the risk of female-specific cancer in form of breast, endometrial, and ovarian cancer sites as well as their subtypes. Evidence was strengthened by using similar exposures for plausibility or by replication with a subsequent meta-analysis. P-values were Bonferroni adjusted.

RESULTS

Genetic liability to AS was associated with ovarian cancer (OR = 1.03; 95% CI: [1.01; 1.04]; [Formula: see text]=0.029) and liability to PsA with breast cancer (OR = 1.02; CI: [1.01; 1.04]; [Formula: see text]=0.002). Subgroup analyses revealed that the high-grade serous ovarian cancer (OR = 1.04; CI: [1.02; 1.06]; [Formula: see text]=0.015) and the ER- breast cancer (OR = 1.04; CI: [1.01; 1.07]; [Formula: see text]=0.118) appeared to drive the observed associations, respectively. No further associations were found between the remaining inflammatory arthritis phenotypes and female-specific cancers.

CONCLUSIONS

This study suggests that AS is a risk factor for ovarian cancer, while PsA is linked to an increased breast cancer risk. These results are important for physicians caring women with inflammatory arthritis to advise their patients on cancer screening and preventive measures.

Identification of cuproptosis-related genes related to the progression of ankylosing spondylitis by integrated bioinformatics analysis

Ankylosing spondylitis (AS) is an autoimmune disease, and the relationship between copper death and AS is not clear. The aim of this study was to analyze and identify potential cuprosis-related genes associated with the onset of AS by bioinformatics methods. We obtained the AS gene expression profile GSE25101 from the Gene Expression Omnibus (GEO) database, which consists of blood samples from 16 active AS patients and 16 sex-and age-matched controls. After analyzing the data, we utilized the WGCNA method to identify genes that exhibited significant differential expression. In order to assess the prognostic and predictive power of these genes, we constructed receiver operating characteristic (ROC) curves. To further validate our predictions, we employed nomograms, calibration curves, decision curve analysis, and external datasets. Lastly, we conducted an analysis on immune infiltration and explored the correlation between key genes and immune response. Three genes, namely INPP5E, CYB5R1, and HGD, have been identified through analysis to be associated with AS. The diagnosis of patients using these genes has been found to possess a high level of accuracy. The area under the ROC curve is reported to be 0.816 for INPP5E, 0.879 for CYB5R1, and also 0.879 for HGD. Furthermore, the nomogram demonstrates an excellent predictive power, and it has been calibrated using a Calibration curve. Its clinical usefulness and net benefit have been thoroughly analyzed and estimated through the use of a DCA curve. Moreover, INPP5E, CYB5R1, and HGD are found to be associated with various types of immune cells. In conclusion, the systematic analysis of cuprosis-related genes may aid in the identification of mechanisms related to copper-induced cell death in AS and offer valuable biomarkers for the diagnosis and treatment of AS.

The shared role of neutrophils in ankylosing spondylitis and ulcerative colitis

This study aimed to analyze single-cell sequencing data to investigate immune cell interactions in ankylosing spondylitis (AS) and ulcerative colitis (UC). Vertebral bone marrow blood was collected from three AS patients for 10X single-cell sequencing. Analysis of single-cell data revealed distinct cell types in AS and UC patients. Cells significantly co-expressing immune cells (P < 0.05) were subjected to communication analysis. Overlapping genes of these co-expressing immune cells were subjected to GO and KEGG analyses. Key genes were identified using STRING and Cytoscape to assess their correlation with immune cell expression. The results showed the significance of neutrophils in both diseases (P < 0.01), with notable interactions identified through communication analysis. XBP1 emerged as a Hub gene for both diseases, with AUC values of 0.760 for AS and 0.933 for UC. Immunohistochemistry verified that the expression of XBP1 was significantly lower in the AS group and significantly greater in the UC group than in the control group (P < 0.01). This finding highlights the critical role of neutrophils in both AS and UC, suggesting the presence of shared immune response elements. The identification of XBP1 as a potential therapeutic target offers promising intervention avenues for both diseases.

Exploring the common mechanisms and biomarker ST8SIA4 of atherosclerosis and ankylosing spondylitis through bioinformatics analysis and machine learning

Background

Atherosclerosis (AS) is a major contributor to cerebrovascular and cardiovascular events. There is growing evidence that ankylosing spondylitis is closely linked to AS, often co-occurring with it; however, the shared pathogenic mechanisms between the two conditions are not well understood. This study employs bioinformatics approaches to identify common biomarkers and pathways between AS and ankylosing spondylitis.

Methods

Gene expression datasets for AS (GSE100927, GSE28829, GSE155512) and ankylosing spondylitis (GSE73754, GSE25101) were obtained from the Gene Expression Omnibus (GEO). Differential expression genes (DEGs) and module genes for AS and ankylosing spondylitis were identified using the Limma R package and weighted gene co-expression network analysis (WGCNA) techniques, respectively. The machine learning algorithm SVM-RFE was applied to pinpoint promising biomarkers, which were then validated in terms of their expression levels and diagnostic efficacy in AS and ankylosing spondylitis, using two separate GEO datasets. Furthermore, the interaction of the key biomarker with the immune microenvironment was investigated via the CIBERSORT algorithm, single-cell analysis was used to identify the locations of common diagnostic markers.

Results

The dataset GSE100927 contains 524 DEGs associated with AS, whereas dataset GSE73754 includes 1,384 genes categorized into modules specific to ankylosing spondylitis. Analysis of these datasets revealed an overlap of 71 genes between the DEGs of AS and the modular genes of ankylosing spondylitis. Utilizing the SVM-RFE algorithm, 15 and 24 central diagnostic genes were identified in datasets GSE100927 and GSE73754, respectively. Further validation of six key genes using external datasets confirmed ST8SIA4 as a common diagnostic marker for both conditions. Notably, ST8SIA4 is upregulated in samples from both diseases. Additionally, ROC analysis confirmed the robust diagnostic utility of ST8SIA4. Moreover, analysis through CIBERSORT suggested an association of the ST8SIA4 gene with the immune microenvironment in both disease contexts. Single-cell analysis revealed that ST8SIA4 is primarily expressed in Macrophages, Monocytes, T cells, and CMPs.

Conclusion

This study investigates the role of ST8SIA4 as a common diagnostic gene and the involvement of the lysosomal pathway in both AS and ankylosing spondylitis. The findings may yield potential diagnostic biomarkers and offer new insights into the shared pathogenic mechanisms underlying these conditions.

Xinfeng capsule inhibits lncRNA NONHSAT227927.1/TRAF2 to alleviate NF-κB-p65-induced immuno-inflammation in ankylosing spondylitis

ETHNOPHARMACOLOGICAL RELEVANCE

Ankylosing spondylitis (AS) is a chronic rheumatic disease known for its insidious and refractory symptoms, primarily associated with immuno-inflammation in its early stages, that affects the self-perception of patients (SPP). The exploration of long noncoding RNA (lncRNA) in immuno-inflammation of AS has garnered considerable interest. Additionally, the effectiveness of traditional Chinese medicine Xinfeng Capsule (XFC) in mitigating immuno-inflammation in AS has also been observed. However, the specific mechanisms still need to be characterized.

AIM OF THE STUDY

This study elucidated the mechanism of the lncRNA NONHSAT227927.1/TRAF2/NF-κB axis in the immuno-inflammation of AS and XFC in AS treatment.

METHODS

LncRNA NONHSAT227927.1 and mRNA expression were assessed utilizing real-time fluorescence quantitative PCR. Protein level was determined using Western blot, and cytokine expression was measured using ELISA. Furthermore, mass spectrometry was used to analyze the binding proteins of lncRNA and rescue experiments were conducted to validate the findings. Inconsistencies in clinical baseline data were addressed using propensity score matching. The association between the XFC effect and indicator changes was evaluated using the Apriori algorithm.

RESULTS

The study revealed a substantial elevation in the expression of lncRNA NONHSAT227927.1 and tumor necrosis factor receptor-associated factor 2 (TRAF2) in AS-peripheral blood mononuclear cells. Its expression was also notably reduced after XFC treatment. In addition to this, there was a positive correlation between lncRNA NONHSAT227927.1 and TRAF2 with clinical immuno-inflammatory indicators. On the other hand, they showed a negative association with the SPP indicators. In vitro experiments have demonstrated that lncRNA NONHSAT227927.1 activated the nuclear factor (NF)-κB-p65 pathway by promoting TRAF2 expression. This activation resulted in enhanced IL-6 and TNF-α levels and reduced IL-10 and IL-4 levels. Conversely, XFC decreased the expression of lncRNA NONHSAT227927.1 and TRAF2, inhibiting the stimulation of the NF-κB-p65 cascade and restoring balance to the cytokines. The association rule analysis results indicated a strong association between XFC and decreased levels of C-reactive protein, erythrocyte sedimentation rate, and immunoglobulin A. Furthermore, XFC was strongly associated with improved SPP indicators, including general health, vitality, mental health, and role-emotional.

CONCLUSIONS

LncRNA NONHSAT227927.1 plays a pro-inflammatory role in AS. XFC treatment may reverse lncRNA NONHSAT227927.1 to suppress TRAF2-mediated NF-κB-p65 activation, which in turn suppresses immuno-inflammation and improves SPP, thereby making XFC a promising candidate for therapeutic applications in AS management.

Evaluation of interleukins (IL-1α, IL-1Ra, IL-12, IL-17A, IL-31, and IL-33) and chemokines (CXCL10 and CXCL16) in the serum of male patients with ankylosing spondylitis

BACKGROUND

A case-control study was performed to explore eight pro-inflammatory and anti-inflammatory cytokines, namely interleukin (IL)-1α, IL-1Ra (IL-1 receptor antagonist), IL-12, IL-17A, IL-31, IL-33, CXCL10 (C-X-C motif chemokine ligand 10), and CXCL16, with the aim to understand their role in ankylosing spondylitis (AS) pathogenesis and evaluate their utility as markers to differentiate between diseased and healthy individuals. Among these cytokines, IL-31 and CXCL16 have not been well studied in AS.

PATIENTS AND METHODS

The study included 94 male patients with AS and 91 age-matched control males. Interleukin and chemokine levels were measured using ELISA kits.

RESULTS

Serum levels of IL-17A, CXCL10, and CXCL16 were significantly elevated in patients compared to controls, while IL-31 levels were significantly decreased in patients. IL-17A, CXCL10, and CXCL16 were associated with an increased risk of AS, while IL-31 was associated with a decreased risk of disease (odds ratio = 1.22, 1.78, 1.14, and 0.89, respectively). As indicated by the area under the curve (AUC), IL-17A, IL-31, CXCL10, and CXCL16 were potential markers to differentiate between AS patients and controls (AUC = 0.877, 0.735, 0.8, and 0.7, respectively). IL-1α, IL-1Ra, IL-12, and IL-33 levels showed no significant variations between patients and controls.

CONCLUSIONS

Among the eight cytokines examined, IL-17A, CXCL10, and CXCL16 were up-regulated in the serum of AS patients, while IL-31 was down-regulated. The levels of IL-1α, IL-1Ra, IL-12, and IL-33 showed no significant differences between patients and controls. Serum levels of all cytokines were not affected by disease duration, HLA-B27 positivity, or disease activity.

Efficacy of TNF-α Inhibitors in the Treatment of nr-axSpA: A Systematic Review and Meta-Analysis Based on Randomized Controlled Trials

INTRODUCTION

A growing number of randomized controlled trials (RCTs) have demonstrated the effectiveness of tumor necrosis factor-α (TNF-α) inhibitors in treating non-radiographic axial spondyloarthritis (nr-axSpA). This study aimed to evaluate the efficacy of TNF-α inhibitors in the treatment of nr-axSpA.

METHODS

PubMed, EMBASE, Web of Science, and the Cochrane Library databases were systematically searched for relevant RCTs using specific keywords up to June 2023. The primary outcome was the proportion of patients who achieved Assessment in SpondyloArthritis international Society 40% (ASAS40). Secondary outcomes included ASAS20, Bath Ankylosing Spondylitis Disease Activity Index 50% (BASDAI50), ASAS partial remission, and ASAS5/6.

RESULTS

A total of eight RCTs involving 1,376 patients were included. Patients receiving anti-TNF therapy exhibited a higher rate of ASAS40 (pooled RR = 2.36; 95% CI: 1.63-3.42; p < 0.001). In addition, the TNF-α inhibitor group showed higher BASDAI50 rates (pooled RR = 2.06; 95% CI: 1.48-2.89), ASAS20 rates (pooled RR = 1.48; 95% CI: 1.31-1.67), ASAS partial remission rates (pooled RR = 2.33; 95% CI: 1.58-3.43), and ASAS5/6 rates (RR = 3.46; 95% CI: 2.05-5.83) than the placebo group.

CONCLUSION

The TNF-α inhibitors were effective in treating nr-axSpA.

Regulation mechanisms of disulfidptosis-related genes in ankylosing spondylitis and inflammatory bowel disease

Introduction

Disulfidptosis is a recently identified form of cell death that contributes to maintaining the internal environment balance of an organism. However, the molecular basis of disulfidptosis in ulcerative colitis (UC), ankylosing spondylitis (AS), and Crohn's disease (CD) has not been thoroughly explored.

Methods

Firstly, the differentially expressed genes (DEGs) and disulfidptosis-associated genes (DAGs) were obtained through differential analysis between diseases (AS, CD, and UC) and control groups. After the disulfidptosis score was acquired using the single-sample gene set enrichment analysis (ssGSEA) algorithm, the DE-DAGs were screened by overlapping DAGs and DEGs of the three diseases. Next, the feature genes were selected through a combination of machine learning algorithms, receiver operating characteristic (ROC) curves, and expression analysis. Based on these feature genes, nomograms were created for AS, CD and UC. The co-feature genes were then identified by taking the intersections of the genes featured in all three diseases. Meanwhile, single-gene set enrichment analysis (GSEA) and the TF-mRNA-miRNA network were utilized to investigate the molecular mechanisms of the co-feature genes. To validate the expression differences of the co-feature genes between healthy controls and patients (AS and IBD), RT-PCR was performed. Lastly, mendelian randomization (MR) analysis was utilized to explore the causality between genetic variants of S100A12 with AS, UC and CD.

Results

In this study, 11 DE-DAGs were obtained. Functional enrichment analysis revealed their involvement in cytokine production and fatty acid biosynthesis. Latterly, AS/CD/UC -feature genes were derived, and they all had decent diagnostic performance. Through evaluation, the performance of the nomogram was decent for three diseases. Then, 2 co-feature genes (S100A12 and LILRA5) were obtained. The GSEA enrichment results indicated that the co-feature genes were mainly enriched in the cytokine-cytokine receptor interaction and drug metabolism cytochrome P450. As shown by functional experiments, there was a correlation between the mRNA expression of S100A12 with AS, UC and CD. Additionally, a causal connection between S100A12 and IBD was detected through MR analysis.

Discussion

In this study, 2 co-feature genes (S100A12 and LILRA5) were screened, and their functions were investigated in AS, CD and UC, providing a basis for further research into diagnosis and treatment.

Association between type 1 diabetes mellitus and ankylosing spondylitis: a two-sample Mendelian randomization study

Objective

The development of ankylosing spondylitis (AS) is closely related to autoimmune system dysfunction. Type 1 diabetes mellitus (T1DM) is an autoimmune disease that is a risk factor for many diseases. This study aimed to investigate the causal relationship between T1DM mellitus and AS genetically.

Methods

A genome-wide association study (GWAS) of causal relationships between exposure (T1DM) and outcome (AS) was performed using summary data from the GWAS database. We conducted a two-sample Mendelian randomization (MR) study of these two diseases. Inverse variance weighting (IVW) was used as the primary analysis method, with MR Egger, weighted median, and weighted mode used as supplementary methods. Sensitivity analyses were performed using Cochran's Q test, MR-Egger intercept, MR-Pleiotropy RESidual Sum and outlier methods, leave-one-out analysis, and funnel plots.

Results

A total of 11 single nucleotide polymorphisms (SNPs)were identified for instrumental variables(IVs) for MR analysis.IVW found that T1DM was causally associated with AS ((IVW: OR = 1.0006 (95% CI 1.0001, 1.0011), p = 0.0057; MR-Egger: OR = 1.0003 (95% CI 0.9995, 1.0012), p = 0.4147; weighted median: OR = 1.0006 (95% CI 1.0003, 1.0008), p = 0.0001; weighted mode: OR = 1.0007 (95% CI 1.0005, 1.0009), p = 0.0001). No horizontal pleiotropy was found for the MR-Egger intercept, and leave -one-out analysis found that the results remained stable after the removal of individual SNPs.

Conclusion

The results of the two-sample MR analysis supported a causal relationship between T1DM and AS risk.

Updates on ankylosing spondylitis: pathogenesis and therapeutic agents

Ankylosing spondylitis (AS) is an autoinflammatory disease that manifests with the unique feature of enthesitis. Gut microbiota, HLA-B*27, and biomechanical stress mutually influence and interact resulting in setting off a flame of inflammation. In the HLA-B*27 positive group, dysbiosis in the gut environment disrupts the barrier to exogenous bacteria or viruses. Additionally, biomechanical stress induces inflammation through enthesial resident or gut-origin immune cells. On this basis, innate and adaptive immunity can propagate inflammation and lead to chronic disease. Finally, bone homeostasis is regulated by cytokines, by which the inflamed region is substituted into new bone. Agents that block cytokines are constantly being developed to provide diverse therapeutic options for preventing the progression of inflammation. In addition, some antibodies have been shown to distinguish disease selectively, which support the involvement of autoimmune immunity in AS. In this review, we critically analyze the complexity and uniqueness of the pathogenesis with updates on the findings of immunity and provide new information about biologics and biomarkers.

The genesis of cardiovascular risk in inflammatory arthritis: insights into glycocalyx shedding, endothelial dysfunction, and atherosclerosis initiation

This narrative review provides a comprehensive examination of the complex interplay between inflammatory arthritis (IA) and cardiovascular pathology. It particularly illuminates the roles of atherosclerosis initiation, endothelial dysfunction, and glycocalyx shedding. IA not only provokes tissue-specific inflammatory responses, but also engenders a considerable degree of non-specific systemic inflammation. This review underscores the accelerating influence of the chronic inflammatory milieu of IA on cardiovascular disease (CVD) progression. A focal point of our exploration is the critical function of the endothelial glycocalyx (EG) in this acceleration process, which possibly characterizes the earliest phases of atherosclerosis. We delve into the influence of inflammatory mediators on microtubule dynamics, EG modulation, immune cell migration and activation, and lipid dysregulation. We also illuminate the impact of microparticles and microRNA on endothelial function. Further, we elucidate the role of systemic inflammation and sheddases in EG degradation, the repercussions of complement activation, and the essential role of syndecans in preserving EG integrity. Our review provides insight into the complex and dynamic interface between systemic circulation and the endothelium.

Comparison of Sacroiliitis Grade Readings on the Same Plain Radiographs by the Same Observer at Different Periods

BACKGROUND

 This study aimed to investigate whether there is a difference between the readings of plain sacroiliac radiographs of patients with sacroiliitis by the same observer.

MATERIALS AND METHODS

 In the study, we included patients diagnosed with sacroiliitis through sacroiliac MRI who had undergone plain radiographs at our center between 2015 and 2022. The radiographic grading of patients was conducted by transferring their demographic and clinical information into a computerized environment so that these details would not be identifiable. The plain radiographs were numbered, and the responses were graded as grade 0, 1, 2, 3, or 4 for the right and left sacroiliac joints. The next day, using the same procedure, the same clinician re-evaluated the same plain radiographs in a different order without viewing the previous responses. This method was employed to prevent bias. The results (kappa value) were evaluated (0.00-0.20: slight agreement, 0.21-0.40: fair agreement, 0.41-0.60: moderate agreement, 0.61-0.80: substantial agreement, 0.81-1.00: perfect agreement).

RESULTS

 The study population included 478 patients and 956 sacroiliac joints from plain radiographs, both on the right and left. Following the observer's classification of the sacroiliac joints into 0, 1, 2, 3, and 4, a moderate level of agreement was found in the second evaluation of the same observer a day later with the same grades (p<0.001, kappa: 0.576). When categorized as grade 0-1 and grade 2-4, there was moderate agreement (p<0.001, kappa: 0.519), and categorization into grades 0-2 and 3-4 showed substantial agreement (p<0.001, kappa: 0.715). Analyzing the categorization into grades 0-3 and grade 4 revealed a higher kappa value, indicating substantial agreement (p<0.001, kappa: 0.766).

CONCLUSION

Intraobserver interpretation of radiographs may be more accurate than the interpretation of different specialists. While interpreting plain radiographs, we observed variability between adjacent grades but less variability between distant grades. However, these results need to be validated.

Sex differences in musculoskeletal injury and disease risks across the lifespan: Are there unique subsets of females at higher risk than males for these conditions at distinct stages of the life cycle?

Sex differences have been reported for diseases of the musculoskeletal system (MSK) as well as the risk for injuries to tissues of the MSK system. For females, some of these occur prior to the onset of puberty, following the onset of puberty, and following the onset of menopause. Therefore, they can occur across the lifespan. While some conditions are related to immune dysfunction, others are associated with specific tissues of the MSK more directly. Based on this life spectrum of sex differences in both risk for injury and onset of diseases, a role for sex hormones in the initiation and progression of this risk is somewhat variable. Sex hormone receptor expression and functioning can also vary with life events such as the menstrual cycle in females, with different tissues being affected. Furthermore, some sex hormone receptors can affect gene expression independent of sex hormones and some transitional events such as puberty are accompanied by epigenetic alterations that can further lead to sex differences in MSK gene regulation. Some of the sex differences in injury risk and the post-menopausal disease risk may be "imprinted" in the genomes of females and males during development and sex hormones and their consequences only modulators of such risks later in life as the sex hormone milieu changes. The purpose of this review is to discuss some of the relevant conditions associated with sex differences in risks for loss of MSK tissue integrity across the lifespan, and further discuss several of the implications of their variable relationship with sex hormones, their receptors and life events.