Update on ankylosing spondylitis: current concepts in pathogenesis

Exploring the molecular mechanism of Epimedium for the treatment of ankylosing spondylitis based on network pharmacology, molecular docking, and molecular dynamics simulations

Ankylosing spondylitis (AS) is a rheumatic disease that causes inflammation and bone formation in the spine. Despite significant advances in treatment, adverse side effects have triggered research into natural compounds. Epimedium (EP) is a traditional Chinese herb with a variety of pharmacological activities, including antirheumatic, anti-inflammatory, and immunomodulatory activities; however, its direct effects on AS treatment and the underlying molecular mechanisms have not been systematically studied. Thus, here, we used network pharmacology, molecular docking, and molecular dynamics simulations to explore the targets of EP for treating AS. We constructed an interaction network to elucidate the complex relationship between EP and AS. Sixteen active ingredients in EP were screened; 80 potential targets were identified. In particular, 8-(3-methylbut-2-enyl)-2-phenylchromone, anhydroicaritin, and luteolin were the core components and TNF, IL-6, IL-1β, MMP9, and PTGS2 were the core targets. The GO and KEGG analyses indicated that EP may modulate multiple biological processes and pathways, including the AGE-RAGE, TNF, NF-κB/MAPK, and TLR signaling pathways, for AS treatment. Molecular docking and molecular dynamics simulations showed good affinity between the active components and core targets of EP, with stable binding within 100 nanoseconds. In particular, 8-(3-methylbut-2-enyl)-2-phenylchromone possessed the highest free energy of binding to PTGS2 and TNF (-115.575 and - 87.676 kcal/mol, respectively). Thus, EP may affect AS through multiple pathways, including the alleviation of inflammation, oxidative stress, and immune responses. In summary, we identified the active components and potential targets of EP, highlighting new strategies for the further experimental validation and exploration of lead compounds for treating AS.

Defining a genetic background for bamboo spine and axial spondyloarthritis

OBJECTIVE

Bamboo spine is the most severe complication of axial spondyloarthritis (AxSpA). This study aims to address whether haplotypes of endoplasmic reticulum aminopeptidase (ERAP)1 and ERAP2 single nucleotide polymorphisms (SNPs), previously associated with AxSpA, are associated with the development of bamboo spine in an AxSpA cohort.

METHODS

The study included 192 patients with AxSpA followed in MARS (MARmara Spondyloarthritis) clinic and fulfilling the modified New York criteria. ERAP1 and ERAP2 polymorphisms were determined by real-time PCR on genomic DNA using the TaqMan SNP Genotyping Assay for SNPs rs72773968, rs3734016, rs26653, rs26618, rs27895, rs2287987, rs30187, rs10050860, rs17482078, rs27044, rs2549782, rs2248374. The HLA-B genotypes were assessed using the LABTypeTM SSO method.

RESULTS

Male gender (P<0.001) and HLA-B27 positivity (P<0.05) were associated with an increased risk of developing a bamboo spine, and peripheral arthritis was significantly less prevalent in AxSpA patients with a bamboo spine (P<0.05). Of the ten ERAP1 haplotypes, haplotype 3 was significantly more prevalent in AxSpA patients with bamboo spine adjusted for HLA-B27 status (P<0.05). Haplotype 3 and -6 were significantly more prevalent exclusively in HLA-B27 (+) patients (P<0.05). Allele frequencies and genotype distributions of single ERAP1 SNPs alone were not significantly different between AxSpA patients with and without bamboo spines. There was no association between bamboo spine development and ERAP2 SNPs.

CONCLUSIONS

Our results indicate that HLA-B27 positivity, ERAP1 haplotype 3 and -6, and being male confer a significant risk for developing bamboo spine. Whether the association of haplotype 3 and -6 with bamboo spine is confined only to our Turkish patient cohort may deserve attention in other ethnicities.

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.

Association between iridocyclitis and immune-related disease: A 2-sample Mendelian randomization study

The genetic basis of iridocyclitis, an inflammatory eye disease, remains poorly understood, particularly in relation to autoimmune diseases. This study aimed to explore the causal associations between 6 immune-related diseases and iridocyclitis using Mendelian randomization (MR). A total of 230 single nucleotide polymorphisms (SNPs) significantly associated with systemic lupus erythematosus, ankylosing spondylitis (AS), rheumatoid arthritis (RA), Graves disease (GD), Crohn disease (CD), and allergic contact dermatitis were identified based on stringent MR assumptions. These SNPs served as instrumental variables to estimate the causal effect of each autoimmune disease on iridocyclitis risk. The analysis utilized the inverse variance weighted method, complemented by sensitivity analyses including MR-Egger regression and leave-one-out testing to assess pleiotropy and robustness. The MR analysis revealed significant associations between genetically predicted AS (odds ratio [OR]: 1.544, 95% confidence interval [CI]: 1.494-1.595, P = 1.99 × 10-226), RA (OR: 1.207, 95% CI: 1.052-1.385, P = .003), and CD (OR: 1.654, 95% CI: 1.263-2.166, P = 2.54 × 10⁻⁶) with an increased risk of iridocyclitis. Conversely, higher genetically predicted GD was associated with a decreased risk of iridocyclitis (OR: 0.763, 95% CI: 0.674-0.865, P = .0002). Although systemic lupus erythematosus and allergic contact dermatitis appeared to have a protective effect, these results were not statistically significant, and no causal relationship could be established. Heterogeneity was observed among the SNPs, but no significant horizontal pleiotropy was detected. This study identifies potential genetic links between AS, RA, CD, GD, and the risk of iridocyclitis, providing new insights into the genetic underpinnings of this eye disease. The results support the need for further investigation into the genetic and molecular mechanisms underlying these associations.

The harmful effect of ankylosing spondylitis on diabetes mellitus: new evidence from the Mendelian randomization analysis

Background

While observational research has highlighted a possible link between ankylosing spondylitis (AS) and type 2 diabetes (T2DM), the quality of evidence remains limited, and the causal relationship is yet to be established. This study aims to explore the causal link between AS and T2DM, as well as its impact on traits related to glucose metabolism.

Method

To infer a causal relationship between AS and various diabetes-related traits, including type 1 diabetes (T1DM), T2DM, blood glucose levels, fasting glucose, glycated hemoglobin, and fasting insulin, we employed Mendelian randomization (MR) analysis. We sourced GWAS summary data for both exposure and outcome variables from the IEU OpenGWAS database, GWAS Catalog, and FinnGen database. To synthesize the results of the MR analyses, we applied meta-analysis techniques using either a fixed or random effects model. For identifying and excluding instrumental variants (IVs) that exhibit horizontal pleiotropy with the outcomes, we utilized the MR-PRESSO method. Sensitivity analyses were conducted using the MR-Egger method, along with Q and I^2 tests, to ensure the robustness of our findings.

Results

Our analysis revealed a significant association between AS and an increased risk of T1DM with an odds ratio (OR) of 1.5754 (95% CI: 1.2935 to 1.9187) and T2DM with an OR of 1.0519 (95% CI: 1.0059 to 1.1001). Additionally, AS was associated with elevated levels of fasting glucose (beta coefficient = 0.0165, 95% CI: 0.0029 to 0.0301) and blood glucose (beta coefficient = 0.0280, 95% CI: 0.0086 to 0.0474), alongside a decrease in fasting insulin levels (beta coefficient = -0.0190, 95% CI: -0.0330 to -0.0050).

Conclusion

Our findings collectively underscore the detrimental impact of AS on the development of diabetes, highlighting the critical influence of autoimmune disorders in diabetes onset. This provides profound insights into the pathogenesis of diabetes from an immunological standpoint.

Polymorphic variation of the DEFB1 gene might contribute to the development of ankylosing spondylitis: a preliminary study

BACKGROUND

Ankylosing spondylitis (AS) is an inflammatory disease that affects the spine and can cause peripheral arthritis, enthesitis, and dactylitis, as well as extra-articular manifestations such as uveitis and inflammatory bowel disease. β-Defensins are antimicrobial peptides involved in the activation and regulation of several immune cell types that may influence the inflammatory response in AS. The aim was to analyze the association and interaction of two functional variants of the DEFB1 gene in AS patients, and their role with inflammatory markers.

METHODS AND RESULTS

The rs11362 and rs1800972 variants were genotyped using TaqMan probes in Mexican AS patients and controls. C-reactive protein (CRP) levels and erythrocyte sedimentation rate (ESR) were quantified. SPSS software was used for statistical analysis and multifactor dimensionality reduction (MDR) for interactions. The AA and GG genotypes were associated with AS risk in the age- and sex-adjusted model (OR = 6.89, P = 0.008 and OR = 3.43, P = 0.046, respectively); furthermore, the A-G haplotype showed a significant association with AS risk (OR = 2.94, P = 0.012). ESR and CRP were elevated in carriers of the AA genotype compared to the GA and GG genotypes of the rs11362 variant (20.89 ± 9.78 vs. 5.63 ± 4.61 and 4.10 ± 2.65 mm/h, P < 0.0001; and 10.92 ± 14.09 vs. 2.14 ± 2.02 and 2.15 ± 2.13 mg/L, P < 0.001, respectively). Using the MDR method, strong interactions of the rs11362 variant with sex were identified in the adjusted and unadjusted models.

CONCLUSIONS

These results suggest that the DEFB1 gene may play a key role in AS pathogenesis.

Annexin A family: A new perspective on the regulation of bone metabolism

Osteoblast-mediated bone formation and osteoclast-mediated bone resorption are critical processes in bone metabolism. Annexin A, a calcium-phospholipid binding protein, regulates the proliferation and differentiation of bone cells, including bone marrow mesenchymal stem cells, osteoblasts, and osteoclasts, and has gradually become a marker gene for the diagnosis of osteoporosis. As calcium channel proteins, the annexin A family members are closely associated with mechanical stress, which can target annexins A1, A5, and A6 to promote bone cell differentiation. Despite the significant clinical potential of annexin A family members in bone metabolism, few studies have reported on these mechanisms. Therefore, based on a review of relevant literature, this article elaborates on the specific functions and possible mechanisms of annexin A family members in bone metabolism to provide new ideas for their application in the prevention and treatment of bone diseases, such as osteoporosis.

Identification of necroptosis-related genes in ankylosing spondylitis by bioinformatics and experimental validation

The pathogenesis of ankylosing spondylitis (AS) remains unclear, and while recent studies have implicated necroptosis in various autoimmune diseases, an investigation of its relationship with AS has not been reported. In this study, we utilized the Gene Expression Omnibus database to compare gene expressions between AS patients and healthy controls, identifying 18 differentially expressed necroptosis-related genes (DENRGs), with 8 upregulated and 10 downregulated. Through the application of three machine learning algorithms-least absolute shrinkage and selection operation, support vector machine-recursive feature elimination and random forest-two hub genes, FASLG and TARDBP, were pinpointed. These genes demonstrated high specificity and sensitivity for AS diagnosis, as evidenced by receiver operating characteristic curve analysis. These findings were further supported by external datasets and cellular experiments, which confirmed the downregulation of FASLG and upregulation of TARDBP in AS patients. Immune cell infiltration analysis suggested that CD4+ T cells, CD8+ T cells, NK cells and neutrophils may be associated with the development of AS. Notably, in the group with high FASLG expression, there was a significant infiltration of CD8+ T cells, memory-activated CD4+ T cells and resting NK cells, with relatively less infiltration of memory-resting CD4+ T cells and neutrophils. Conversely, in the group with high TARDBP expression, there was enhanced infiltration of naïve CD4+ T cells and M0 macrophages, with a reduced presence of memory-resting CD4+ T cells. In summary, FASLG and TARDBP may contribute to AS pathogenesis by regulating the immune microenvironment and immune-related signalling pathways. These findings offer new insights into the molecular mechanisms of AS and suggest potential new targets for therapeutic strategies.

Exploration of the combined role of immune checkpoints and immune cells in the diagnosis and treatment of ankylosing spondylitis: a preliminary study immune checkpoints in ankylosing spondylitis

OBJECTIVE

Immune checkpoints have emerged as promising therapeutic targets for autoimmune diseases. However, the specific roles of immune checkpoints in the pathophysiology of ankylosing spondylitis (AS) remain unclear.

METHODS

Hip ligament samples were obtained from two patient groups: those with AS and femoral head deformity, and those with femoral head necrosis but without AS, undergoing hip arthroplasty. Label-Free Quantification (LFQ) Protein Park Analysis was used to identify the protein composition of the ligaments. Peripheral blood samples of 104 AS patients from public database were used to validate the expression of key proteins. KEGG, GO, and GSVA were employed to explore potential pathways regulated by immune checkpoints in AS progression. xCell was used to calculate cell infiltration levels, LASSO regression was applied to select key cells, and the correlation between immune checkpoints and immune cells was analyzed. Drug sensitivity analysis was conducted to identify potential therapeutic drugs targeting immune checkpoints in AS. The expression of key genes was validated through immunohistochemistry (IHC).

RESULTS

HLA-DMB and HLA-DPA1 were downregulated in the ligaments of AS and this has been validated through peripheral blood datasets and IHC. Significant differences in expression were observed in CD8 + Tcm, CD8 + T cells, CD8 + Tem, osteoblasts, Th1 cells, and CD8 + naive T cells in AS. The infiltration levels of CD8 + Tcm and CD8 + naive T cells were significantly positively correlated with the expression levels of HLA-DMB and HLA-DPA1. Immune cell selection using LASSO regression showed good predictive ability for AS, with AUC values of 0.98, 0.81, and 0.75 for the three prediction models, respectively. Furthermore, this study found that HLA-DMB and HLA-DPA1 are involved in Th17 cell differentiation, and both Th17 cell differentiation and the NF-kappa B signaling pathway are activated in the AS group. Drug sensitivity analysis showed that AS patients are more sensitive to drugs such as doramapimod and GSK269962A.

CONCLUSION

Immune checkpoints and immune cells could serve as avenues for exploring diagnostic and therapeutic strategies for AS.

Causal relationship between the immune cells and ankylosing spondylitis: univariable, bidirectional, and multivariable Mendelian randomization

Background

Ankylosing spondylitis (AS) is an autoimmune disease that affects millions of individuals. Immune cells have been recognized as having a crucial role in the pathogenesis of AS. However, their relationship has not been fully explored.

Methods

We chose to employ Mendelian randomization (MR) to investigate the potential correlation between immune cells and AS. We sourced the data on immune cells from the latest genome-wide association studies (GWASs). We obtained data on AS from the FinnGen consortium. Our comprehensive univariable MR analysis covered 731 immune cells to explore its potential causal relationship with AS. The primary analysis method was inverse-variance weighted (IVW). Additionally, we used Cochran's Q test and the MR-Egger intercept test to assess the presence of pleiotropy and heterogeneity. We examined whether our results could be influenced by individual single-nucleotide polymorphisms (SNPs) using the leave-one-out test. We conducted a bidirectional MR to investigate the reverse relationship. We also applied multivariable MR to decrease the potential influence between the immune cells.

Results

Overall, our univariable MR analysis revealed eight immune cells associated with AS. Among these, four immune cells contributed to an increased risk of AS, while four immune cells were identified as protective factors for AS. However, the Bonferroni test confirmed only one risk factor and one protective factor with a significance level of p < 6.84E-05. CD8 on effector memory CD8+ T cell could increase the risk of AS (p: 1.2302E-05, OR: 2.9871, 95%CI: 1.8289-4.8786). HLA DR on CD33dim HLA DR+ CD11b+ could decrease the risk of AS (p: 1.2301E-06, OR: 0.5446, 95%CI: 0.4260-0.6962). We also identified a bidirectional relationship between CD4 on CD39+ activated CD4 regulatory T cells and AS utilizing the bidirectional MR. To address potential confounding among immune cells, we employed multivariable MR analysis, which revealed that only one immune cell had an independent effect on AS. HLA DR on CD33dim HLA DR+ CD11b+ could decrease the risk of AS (p: 2.113E-06, OR: 0.0.5423, 95%CI: 0.4210-0.6983). Our findings were consistently stable and reliable.

Conclusions

Our findings indicated a potential link between immune cells and AS, which could provide a new idea for future research. Nevertheless, the specific underlying mechanisms require further exploration.

The Association Between Epidermal Growth Factor rs3756261 A/G Gene Polymorphism and the Risk of Ankylosing Spondylitis in a Chinese Han Population

Background

Epidermal growth factor (EGF) is a potent pro-angiogenic molecule promoting the angiogenic phenotype of ankylosing spondylitis (AS). Studies demonstrated that EGF rs3756261 polymorphism was associated with the risk of inflammatory diseases, but not including AS.

Methods

To investigate the association between EGF rs3756261 polymorphism and the risk of AS, we genotyped the EGF rs3756261 polymorphism in 208 patients with AS and 412 controls in a Chinese Han population using a custom-by-design 48-Plex SNP scanTM Kit. The serum EGF levels were measured using an enzyme-linked immunosorbent assay in 208 AS patients and 412 controls.

Results

Our data indicated that EGF rs3756261 polymorphism was associated with an increased risk of AS in the Chinese Han population. Stratified analyses indicated that the EGF rs3756261 polymorphism elevated the risk of AS among the males, smokers, drinkers and those aged <30 years. In addition, the EGF rs3756261 polymorphism was related to increased CRP and HLA-B27 levels in AS patients. Next, we found that the average serum levels of EGF were significantly higher in AS patients compared with controls. Meanwhile, EGF serum levels were significantly higher in AG genotype carriers when compared with AA genotype carriers in AS patients.

Conclusion

In conclusion, this study indicated that EGF rs3756261 polymorphism was associated with the risk of AS and EGF serum levels in a Chinese Han population.

MICA and NLRP3 gene polymorphisms interact synergistically affecting the risk of ankylosing spondylitis

Ankylosing spondylitis (AS) is an autoinflammatory disease that affects the sacroiliac joints, causing stiffness and pain in the back. MICA is a ligand of the NKG2D receptor, and an increase in its expression affects the immune response in various diseases. NLRP3 is a multiprotein complex that promotes the release of IL-1β, but its role in AS has been minimally explored. The objective of this study was to analyze the association and interaction of polymorphic variants of the MICA and NLRP3 genes in patients with AS. In this case-control study, patients with AS were included and compared with healthy controls of Mexican origin. The polymorphisms rs4349859 and rs116488202 of MICA and rs3806268 and rs10754558 of NLRP3 were genotyped using TaqMan probes. Associations were determined using logistic regression models, while interactions were analyzed by the multifactorial dimensionality reduction (MDR) method. A P value < 0.05 was considered statistically significant. The minor allele of rs4349859 (A) and rs116488202 (T) of MICA polymorphisms showed risk associations with AS (OR = 9.22, 95% CI = 4.26-20.0, P < 0.001; OR = 9.36, 95% CI = 4.17-21.0, P < 0.001), while the minor allele of the rs3806268 (A) polymorphism of NLRP3 was associated with protection (OR = 0.55, 95% CI = 0.33-0.91, P = 0.019). MDR analysis revealed synergistic interactions between the MICA and NLRP3 polymorphisms (P = 0.012). In addition, high- and low-risk genotypes were identified among these variants. The study findings suggest that the MICA rs4349859 A allele and rs116488202 T allele are associated with AS risk. An interaction between MICA and NLRP3 was observed which could increase the genetic risk in AS.

Expression and Clinical Significance of microRNA-138-5p and TGF-β3 in Peripheral Blood of Patients With Ankylosing Spondylitis

STUDY DESIGN

Clinical study.

OBJECTIVE

Our work was aimed at exploring the expression and clinical significance of microRNA-138-5p (miR-138-5p) and Transforming Growth Factor-beta 3 (TGF-β3) in peripheral blood of patients with ankylosing spondylitis (AS).

METHODS

Forty-seven patients with AS were selected as the AS group, and the staging of the enrolled AS patients was based on the BASDAI score: <4 points were classified as the stable stage (stable group) and ≥4 points were classified as the active stage (active group). Forty-seven cases were selected from the same period of healthy physical examination in our hospital as the control group. miR-138-5p and TGF-β3 levels and disease activity factors in peripheral blood were measured in all patients.

RESULTS

Compared to healthy subjects, reduced miR-138-5p levels and increased TGF-β3 levels were found in AS patient. Even more, level of miR-138-5p was decreased and level of TGF-β3 was found to be increased in active disease stage of AS in comparison to inactive disease. Correlation analysis disclosed that miR-138-5p expression in peripheral blood of AS patients was negatively correlated with TGF-β3, HLA-B27, ESR, CRP, and BASDAI; serum TGF-β3 was positively correlated with HLA-B27, ESR, CRP, and BASDAI. The ROC curve analysis disclosed that miR-138-5p and TGF-β3 had certain diagnostic value for AS, and the combined detection could improve the clinical diagnostic capability of this disease.

CONCLUSION

miR-138-5p and TGF-β3 in peripheral blood of AS patients are potential biological markers for the diagnosis of AS and are expected to be new clinical diagnostic indicators.

Biologic Treatment Modification Efficacy in Concurrent Inflammatory Bowel Disease and Ankylosing Spondylitis: A Retrospective Cohort Study at a Single Tertiary Center

BACKGROUND

The link between ankylosing spondylitis (AS) and inflammatory bowel disease (IBD) is well-established, with concurrent prevalence estimates ranging from 5-10%. However, there are still significant gaps in our understanding, and a comprehensive treatment guideline for these co-diagnosed patients has yet to be established. Our objective was to explore patterns of treatment alterations following the diagnosis of AS in patients previously diagnosed with IBD, and vice versa. Additionally, we sought to determine how these modifications influence clinical outcomes in both conditions.

METHODS

This retrospective data-based cohort study included patients with coexisting IBD and AS that were diagnosed between the years 2009-2022 and were followed by the gastroenterology and the rheumatology units of the Sheba Medical Center, Israel. The data were extracted from the electronic health record and included demographic information, medication history, treatment modification at the time of second diagnosis, and the characteristics and activity of both IBD and AS at the index time and at the 3-month mark.

RESULTS

The study included a total of 68 patients, with a male predominance (40 patients, 59%). The median age was 43 years (IQR 31-55) and 78% had Crohn's disease (CD). The median duration between the diagnosis of the first disease to the second one was 4 years (IQR 1-9.5). A significant proportion of patients (85%) underwent treatment modification at their second diagnosis. Out of the total cohort, 28% initiated biological therapy, 17.6% switched their biologic regimen, and 16.2% discontinued NSAIDS. Patients who underwent biologic modifications at time of the second diagnosis (the initiation/switch/augmentation of a concurrent regimen) experienced significantly higher rates of clinical improvement in either IBD or AS at the 90-day follow-up compared to patients who did not (68% vs. 32%, p = 0.004), and biologic modification was found to be an independent predictor for clinical improvement (OR 3.69, CI 1.08-12.58, p = 0.037).

CONCLUSIONS

Our findings suggest that biologic therapy modification at the time of the second diagnosis was associated with a higher rate of improvement in AS/IBD at the 90-day follow-up.

Gas Chromatography-Mass Spectrometry Reveals Stage-Specific Metabolic Signatures of Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a type of chronic rheumatic immune disease, and the crucial point of AS treatment is identifying the correct stage of the disease. However, there is a lack of effective diagnostic methods for AS staging. The primary objective of this study was to perform an untargeted metabolomic approach in AS patients in an effort to reveal metabolic differences between patients in remission and acute stages. Serum samples from 40 controls and 57 AS patients were analyzed via gas chromatography-mass spectrometry (GC-MS). Twenty-four kinds of differential metabolites were identified between the healthy controls and AS patients, mainly involving valine/leucine/isoleucine biosynthesis and degradation, phenylalanine/tyrosine/tryptophan biosynthesis, glutathione metabolism, etc. Furthermore, the levels of fatty acids (linoleate, dodecanoate, hexadecanoate, and octadecanoate), amino acids (serine and pyroglutamate), 2-hydroxybutanoate, glucose, etc., were lower in patients in the acute stage than those in the remission stage, which may be associated with the aggravated inflammatory response and elevated oxidative stress in the acute stage. Multiple stage-specific metabolites were significantly correlated with inflammatory indicators (CRP and ESR). In addition, the combination of serum 2-hydroxybutanoate and hexadecanoate plays a significant role in the diagnosis of AS stages. These metabolomics-based findings provide new perspectives for AS staging, treatment, and pathogenesis studies.

Ankylosing spondylitis PET imaging and quantifications via P2X7 receptor-targeting radioligand [18F]GSK1482160

PURPOSE

Ankylosing spondylitis (AS) is a chronic inflammatory disease of the axial spine; however, the quantitative detection of inflammation in AS remains a challenge in clinical settings. We aimed to investigate the feasibility of using a specific P2X7R-targeting 18F-labeled tracer [18F]GSK1482160 for positron emission tomography (PET) imaging and the quantification of AS.

METHODS

The radioligand [18F]GSK1482160 was obtained based on nucleophilic aliphatic substitution. Dynamic [18F]GSK1482160 and [18F]FDG micro-PET/CT imaging were performed on AS mice (n = 8) and age-matched controls (n = 8). Tracer kinetics modeling was performed using Logan's graphical arterial input function analysis to quantify the in vivo expression of P2X7R. The post-PET tissues were collected for hematoxylin-eosin (H&E), immunohistochemical (IHC), and immunofluorescence (IF) staining.

RESULTS

[18F]GSK1482160 PET/CT imaging revealed that the specific binding in the ankle joint and sacroiliac joint (SIJ) of the AS at 8 weeks group (BPNDankle-AS-8W (non-displaceable binding potential of the ankle) 3.931 ± 0.74; BPND SIJ-AS-8W (BPBD of the SIJ) 4.225 ± 0.84) were significantly higher than the controls at 8 weeks group (BPNDankle-Ctr-8W 0.325 ± 0.15, BPNDSJJ-Ctr-8W 0.319 ± 0.17) respectively, and the AS at 14 weeks group (BPNDankle-AS-14W 12.212 ± 2.25; BPNDSJJ-AS-14W 13.389 ± 3.60) were significantly higher than the controls at 14 weeks group (BPNDankle-Ctr-14W 0.204 ± 0.16, BPNDSJJ-Ctr-14W 0.655 ± 0.35) respectively. The four groups had no significant difference in the [18F]FDG uptake of ankle and SIJ. IHC and IF staining revealed that the overexpression of P2X7R was colocalized with activated macrophages from the ankle synovium and spinal endplate in mice with AS, indicating that quantification of P2X7R may contribute to the understanding of the pathogenesis of inflammation in human AS.

CONCLUSION

This study developed a novel P2X7R-targeting PET tracer [18F]GSK1482160 to detect the expression of P2X7R in AS mouse models and provided powerful non-invasive PET imaging and quantification for AS.

Peripheral CD4+ /CD8+ T cell composition distinct from healthy individuals is shared by ankylosing spondylitis and rheumatoid arthritis

OBJECTIVE

Ankylosing spondylitis (AS) and rheumatoid arthritis (RA) are chronic inflammatory joint diseases, linking to the alterations of immune cells. We attempted to assess whether the alterations in the composition of CD4+ /CD8+ T cells are different between AS and RA and identify the characteristic cells between male and female patients.

METHODS

The proportions of CD3+ or double positive T cells, 6 CD4+ T subsets and 9 CD8+ T cell subsets were detected by flow cytometry and compared in 30 healthy individuals, 42 AS patients and 45 RA patients. The differentially altered cells were individually analyzed for associations with disease activity parameters. In addition, their proportions were compared between different genders in the 3 groups.

RESULTS

The proportions of CD4+ T cells, naive CD4+ T cells and central memory CD4+ T cells were lower in AS patients (P = 0.001, P = 0.002 and P = 0.007, respectively) and RA patients (P = 0.032, P < 0.001 and P = 0.016, respectively), but the proportion of effector memory ones was higher when compared with healthy populations (both P < 0.001), as were the decrease of naive/central memory CD8+ T cells in AS (P = 0.003 and P = 0.016, respectively) and RA (P < 0.001 and P = 0.006, respectively), and the increased tendency of terminally differentiated CD8+ T cells. However, these above-mentioned cells, regulatory T (Treg) cells and CD8+ T cells with different CD127 expressions between AS and RA were similar in proportion. Furthermore, naive CD4+ T cells were positively associated with C-reactive protein (CRP) in AS, whereas CD4+ T cells and terminally differentiated CD8+ T of RA patients were associated with CRP in RA. The gender-related alterations predominantly displayed the overexpressions of Treg cells and naive CD8+ T cells in female patients with AS and RA, respectively.

CONCLUSIONS

AS patients and RA patients have some similar peripheral CD4+ /CD8+ T cell subsets but are distinct from healthy individuals, which may contribute to disease severity. Females are respectively characterized by the up-regulation of Treg cells and naive CD8+ T cells in AS patients and RA patients. The study offers an in-depth understanding of the role of T cell subsets in the similarities of the disorders and helps us to monitor disease changes and may offer a theoretical basis of developing novel therapies against common targets.

Cervical spine fractures in ankylosing spondylitis patients: an analysis of the presentation and clinical results of 110 surgically managed patients in two spine centers

PURPOSE

In this work, a two-center study was performed to study the clinical presentation of cervical spine fractures in ankylosing spondylitis (AS) patients and assess the surgical management of these fractures.

METHODS

A retrospective analysis of prospectively collected data in two level-1 spine surgery centers was performed. Both spine centers have a standard database for all admitted patients. Inclusion criteria were surgically treated AS with cervical spine fracture diagnosis (from C1 to Th3) and postoperative follow-up minimum of 12 months.

RESULTS

One hundred ten patients (105 male/5 female) were included. The mean age was 62 ± 10 years. The mean time between trauma and surgery was 49 ± 42 days. There was a history of mild trauma in 72 patients (65.4%). The clinical presentation was a pain in all patients. Twenty-seven (24.6%) had a neurological deficit at admission. The most common fracture level was C6/7 in 63 patients (57.23%). The VAS was 7 ± 1, and NDI was 34 ± 8 in the preoperative assessment. The mean preoperative kyphosis angle was 48 ± 26° between C2 and C7. Positioning and preparing of the patients on the operation table took a mean of 57 ± 28 min. The surgical approach was dorsal in 59 patients (53.6%), combined in 45 patients (40.9%), and ventral in 6 patients (6,5%). The mean number of the fixed levels was 6 ± 2 levels. Intraoperative complications occurred in 9 patients (8.2%). Postoperative Cobb angle improved to a mean of 17 ± 9 degrees. Neurological improvement occurred in 20/27 patients. In 12 patients, the recovery was complete. The mean postoperative follow-up was 46 ± 18 months. VAS improved to 3 ± 1, and NDI improved to 14 ± 6 at the last postoperative visit. The improvement was clinically significant (p = 0.01 and 0.00, respectively).

CONCLUSION

High suspicion of cervical spine fractures is necessary for patients with AS. CT and MRI images are necessary to rule out cervical spine fractures in AS patients, especially to detect occult fractures. Surgical treatment is safe, and the posterior approach with long-segment fusion is the approach of choice in this group of patients.

Assessment of Circulating lncRNA H19 in Ankylosing Spondylitis Patients and Its Correlation with Disease Activity

Ankylosing spondylitis (AS) is a chronic inflammatory disease that results in severe pain and stiffness in the joints. The causes and pathophysiology of AS are still largely unknown. The lncRNA H19 plays key roles in the pathogenesis of AS by mediating inflammatory progression by acting in the axis of IL-17A/IL-23. The aims of this study were determining the role of lncRNA H19 in AS and assessing its clinical correlation. A case-control study was conducted and qRT-PCR was utilized to measure H19 expression. Comparing AS cases to healthy controls, it was found that H19 expression was significantly upregulated. For AS prediction, H19 demonstrated a 81.1% sensitivity, 100% specificity, and 90.6% diagnostic accuracy at a lncRNA H19 expression value of 1.41. lncRNA H19 had a significantly positive correlation with AS activity, MRI results, and inflammatory markers. lncRNA H19 seemed to be an independent predictor of AS (adjusted OR of 211 (95% CI: 4.7-939; p = 0.025)). After 3 months of clinical follow-up, seventeen patients (32.1%) showed minimal clinical improvement and fifteen patients (28.3%) showed major improvement. AS activity scores were significantly decreased in patients with high H19 expression. A significantly elevated lncRNA H19 expression was observed in AS cases compared with that in healthy controls. These results suggest that upregulation of lncRNA H19 expression may be involved in the pathogenesis of AS. The expression of the lncRNA H19 is related to the duration and activity of the disease. LncRNA H19 expression seems to be an independent predictor of AS.

Screening and identification of key chromatin regulator biomarkers for ankylosing spondylitis and drug prediction: evidence from bioinformatics analysis

BACKGROUND

Ankylosing spondylitis (AS) is one of the most common immune-mediated arthritic diseases worldwide. Despite considerable efforts to elucidate its pathogenesis, the molecular mechanisms underlying AS are still not fully understood.

METHODS

To identify candidate genes involved in AS progression, the researchers downloaded the microarray dataset GSE25101 from the Gene Expression Omnibus (GEO) database. They identified differentially expressed genes (DEGs) and functionally enriched them for analysis. They also constructed a protein-protein interaction network (PPI) using STRING and performed cytoHubba modular analysis, immune cell and immune function analysis, functional analysis and drug prediction.The results showed that DEGs were mainly associated with histone modifications, chromatin organisation, transcriptional coregulator activity, transcriptional co-activator activity, histone acetyltransferase complexes and protein acetyltransferase complexes.

RESULTS

The researchers analysed the differences in expression between the CONTROL and TREAT groups in terms of immunity to determine their effect on TNF-α secretion. By obtaining hub genes, they predicted two therapeutic agents, AY 11-7082 and myricetin.

CONCLUSION

The DEGs, hub genes and predicted drugs identified in this study contribute to our understanding of the molecular mechanisms underlying the onset and progression of AS. They also provide candidate targets for the diagnosis and treatment of AS.

LncRNA HOTTIP impacts the proliferation and differentiation of fibroblast-like synoviocytes in ankylosing spondylitis through the microRNA-30b-3p/PGK1 axis

OBJECTIVE

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been reported to exert regulatory effects on biological processes. This study intended to assess the role of the lncRNA HOXA transcript at the distal tip (HOTTIP)/miR-30b-3p/phosphoglycerate kinase 1 (PGK1) axis in ankylosing spondylitis (AS).

METHODS

Levels of HOTTIP, miR-30b-3p and PGK1 in AS synovial tissues and cultured AS fibroblast-like synoviocytes (ASFLSs) were assessed. The ASFLSs were identified and, respectively, treated with altered expression of HOTTIP and miR-30b-3p, and then, the proliferation and differentiation of the ASFLSs were assessed. The AS mouse models were established by injection of proteoglycan and Freund's complete adjuvant and then were treated with altered expression of HOTTIP and miR-30b-3p, and the pathological changes and apoptosis of synoviocytes in mice' synovial tissues were measured. The relationship of HOTTIP, miR-30b-3p and PGK1 was verified.

RESULTS

HOTTIP and PGK1 were elevated, while miR-30b-3p was reduced in AS synovial tissues and ASFLSs. Elevated miR-30b-3p or inhibited HOTTIP restrained proliferation and differentiation of ASFLSs and also improved the pathological changes and promoted apoptosis of synoviocytes in mice's synovial tissues. PGK1 was a target of miR-30b-3p, and miR-30b-3p could directly bind to HOTTIP. Silencing miR-30b-3p or overexpressing PGK1 reversed the improvement of AS by knocking down HOTTIP or up-regulating miR-30b-3p.

CONCLUSION

Our study suggests that reduced HOTTIP ameliorates AS progression by suppressing the proliferation and differentiation of ASFLSs through the interaction of miR-30b-3p and PGK1.

Novel aspects of muscle involvement in immune-mediated inflammatory arthropathies and connective tissue diseases

Myalgia, myopathy and myositis are the most important types of muscle impairment in immune-mediated inflammatory arthropathies and connective tissue diseases. Multiple pathogenetic and histological changes occur in the striated muscles of these patients. Clinically, the most important muscle involvement is the one that causes complaints to the patients. In everyday practice, insidious symptoms present a serious problem for the clinician; in many cases, it is difficult to decide when and how to treat the muscle symptoms that are often present only subclinically. In this work, authors review the international literature on the types of muscle problems in autoimmune diseases. In scleroderma histopathological picture of muscle shows a very heterogeneous picture, necrosis and atrophy are common. In rheumatoid arthritis and systemic lupus erythematosus, myopathy is a much less defined concept, further studies are needed to describe it. According to our view, overlap myositis should be recognized as a separate entity, preferably with distinct histological and serological characteristics. More studies are needed to describe muscle impairment in autoimmune diseases which may help to explore this topic more in depth and be of clinical use.

Efficacy and safety of Duhuo Jisheng decoction combined with Western medicine in the treatment of ankylosing spondylitis: A systematic review and meta-analysis

BACKGROUND

and purpose: The effects of Duhuo Jisheng Decoction (DJD) on ankylosing spondylitis (AS) remain controversial. This study aimed to assess the efficacy and safety of DJD combined with Western medicine in treating AS.

METHODS

A total of nine databases were searched from the establishment of the databases to August 13th, 2021, for randomized controlled trials (RCTs) concerning the use of DJD combined with Western medicine to treat AS. Review Manager was used for the meta-analysis of the retrieved data. The risk of bias was evaluated using the revised Cochrane risk of bias tool for RCTs.

RESULTS

The results indicated that the combinational use of DJD and Western medicine resulted in significantly higher outcomes in terms of effective rate (RR = 1.40, 95% CI: 1.30, 1.51); thoracic mobility (MD = 0.32, 95% CI: 0.21, 0.43); morning stiffness time (SMD = -0.38, 95% CI: 0.61, -0.14); BASDAI (MD = -0.84, 95% CI: 1.57, -0.10); VAS for pain [spinal (MD = -2.76, 95% CI: 3.10, -2.42); peripheral joint (MD = -0.84, 95% CI: 1.16, -0.53)]; CRP (MD = -3.75, 95% CI: 6.36, -1.14); ESR: (MD = -4.80, 95% CI: 7.63, -1.97); and adverse reactions (RR = 0.50, 95% CI: 0.38, 0.66) in comparison to the Western medicine alone in treating AS.

CONCLUSION

Compared to the use of Western medicine, DJD combined with Western medicine improves the effective rate, functional scores, and symptoms of AS patients, with a reduced rate of adverse reactions.

MicroRNA Let-7i Regulates Innate TLR4 Pathways in Peripheral Blood Mononuclear Cells of Patients with Ankylosing Spondylitis

Purpose

This study aimed to compare the changes in the expression of microRNA Let-7i in peripheral blood mononuclear cells (PBMCs) of patients with ankylosing spondylitis (AS) and the correlation between Let-7i and innate pro-inflammatory factors. It is necessary to search for a new biomarker to guide the prognosis of AS.

Methods

A total of 10 patients with AS and 10 healthy volunteers were selected as AS and control groups, respectively. The expression levels of Let-7i, Toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB), and interferon-gamma (IFN-γ) in PBMCs were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting (WB) to explore the relationship between Let-7i and pro-inflammatory factors. Furthermore, the relationship between Let-7i and TLR4 was determined by the luciferase reporter technology.

Results

The expression level of Let-7i in PBMCs of patients with AS was significantly lower than that of healthy control. The expression levels of TLR4, NF-κB, and IFN-γ in PBMCs derived from patients with AS were significantly higher than those of healthy control. The results show that Let-7i manipulation can regulate lipopolysaccharide (LPS)-induced TLR4 and IFN-γ expression in CD4+ T cells of patients with AS. The overexpression of Let-7i in T cells of patients with AS can suppress TLR4 and IFN-γ LPS-induced expression levels of cellular mRNA and protein. Let-7i can directly interfere TLR4-3'untranslated region (UTR) sequence and regulate the expression of the TLR4 gene in Jurkat T cells.

Conclusion

Let-7i may be involved in the pathogenesis of AS, and Let-7i expression in PBMCs may be helpful for the diagnosis and treatment of AS in the future.

Assessing the association of leukocyte telomere length with ankylosing spondylitis and rheumatoid arthritis: A bidirectional Mendelian randomization study

Background

Telomere length shortening can cause senescence and apoptosis in various immune cells, resulting in immune destabilization and ageing of the organism. In this study, we aimed to systematically assess the causal relationship of leukocyte telomere length (LTL) with ankylosing spondylitis (AS) and rheumatoid arthritis (RA) using a Mendelian randomization study.

Methods

LTL (n=472174) was obtained from the UK Biobank genome-wide association study pooled data. AS (n=229640), RA (n=212472) were obtained from FinnGen database. MR-Egger, inverse variance weighting, and weighted median methods were used to estimate the effects of causes. Cochran's Q test, MR Egger intercept test, MR-PRESSO, leave-one-out analysis, and funnel plots were used to look at sensitivity, heterogeneity, and multiple effects. Forward MR analysis considered LTL as the exposure and AS, RA as the outcome. Reverse MR analysis considered AS, RA as the exposure and LTL as the outcome.

Results

In the forward MR analysis, inverse variance-weighted and weighted median analysis results indicated that longer LTL might be associated with increased risk of AS (IVW: OR = 1.55, 95% CI: 1.14-2.11, p = 0.006). MR Egger regression analysis showed no pleiotropy between instrumental variables (IVs) (Egger intercept= 0.008, p = 0.294). The leave-one-out analysis showed that each single nucleotide polymorphism (SNP) of AS was robust to each outcome. No significant causal effects were found between AS, RA and LTL in the reverse MR analysis.

Conclusion

Longer LTL may be related with an increased risk of developing AS, and these findings provide a foundation for future clinical research on the causal association between LTL and AS.

Efficacy and safety of Iguratimod in the treatment of Ankylosing Spondylitis: A systematic review and meta-analysis of randomized controlled trials

Objective

To explore the efficacy and safety of Iguratimod (IGU) intervention in the treatment of Ankylosing Spondylitis (AS).

Methods

We used computer to search literature databases, collected randomized controlled trials (RCTs) related to IGU treatment of AS, and searched the relevant literature in each database until Sep. 2022. Two researchers independently carried out literature screening, data extraction, and evaluation and analysis of the risk of bias in the included studies, and then used Rev Man5.3 software for meta-analysis. The protocol is CRD42020220798.

Results

A total of 10 RCTs involves in 622 patients were collected. The statistical analysis showed that IGU can decrease the BASDAI score (SMD -1.62 [-2.20, -1.05], P<0.00001. Quality of evidence: low), the BASFI score (WMD -1.30 [-1.48, -1.12], P<0.00001. Quality of evidence: low) and the VAS (WMD -2.01 [-2.83, -1.19], P<0.00001. Quality of evidence: very low). Meanwhile, the addition of IGU into the conventional therapy would not increase the adverse events (RR 0.65 [0.43, 0.98], P=0.04. Quality of evidence: moderate).

Conclusion

IGU may be an effective and safe intervention for AS.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?, identifier CRD42020220798.

Immune activation of characteristic gut mycobiota Kazachstania pintolopesii on IL-23/IL-17R signaling in ankylosing spondylitis

It is very important to understand the communication and interaction mechanisms between the host and its resident microorganisms on host physiology and for precise diagnosis and treatment. Although intestinal fungi and bacteria dysbiosis is increasingly linked to ankylosing spondylitis (AS), their mechanisms of action have been rarely illustrated. In this paper, fecal samples from 10 AS monkeys and 10 healthy controls were collected to systematically characterize the gut mycobiota and microbiota in AS monkeys by 16S rRNA and ITS2 DNA sequencing. Our results showed the gut fungi of Kazachstania pintolopesii, Saccharomycetaceae, Kazachstania, and Saccharomyceteles. Saccharomycetes were specially enriched in AS, and the microbiota of AS monkeys was characterized by an increased abundance of Clostridia, Clostridiales, Ruminococcaceae, and Prevotella 2, using Line Discriminant Analysis Effect Size. Compared to healthy controls, decreased ITS2/16S biodiversity ratios and altered bacterial-fungal interkingdom networks were observed in AS monkeys. Oral administration of K. pintolopesii activates IL-17RA pathway and induce inflammatory reaction in the colonic tissue of C57BL/6 mice, as well as multiple AS phenotypes, including fungal and bacterial dysbiosis, immune responses of NK cells, platelets, T cells, leukocytes, B-cell activation, rheumatoid arthritis, and inflammatory bowel disease. We also found the secreted products of K. pintolopesii could activate the IL-17RA pathway, which induces PANoptosis in macrophage RAW264.7 cells. Much worse, the PANoptosis products could promote the proliferation and morphological changes of K. pintolopesii, which resulted in much more K. pintolopesii and a severe inflammatory reaction. Interestingly, the inflammatory factor TNF-α can promote the morphological transformation of Candida albicans and K. pintolopesii, which is worthy of further study. The characteristic fungi in all these findings implied that fungal and bacterial dysbiosis have a close link to AS and that their communication and interaction indeed play an important role in autoimmune responses, and K. pintolopesii could be a potential marker microorganism in AS, although its specific mechanism is not fully elucidated.

Effectiveness of interleukin-17A inhibitors in patients with ankylosing spondylitis: A protocol for systematic review and meta-analysis

BACKGROUND

Ankylosing spondylitis is a chronic immune-mediated inflammatory arthritis. Interleukin-17A (IL-17A) inhibitors is recognized as a novel therapeutic target for ankylosing spondylitis. However, there is still a lack of high-quality research evidence regarding the issues. Therefore, we performed a protocol for systematic review and meta-analysis to evaluate the efficacy and safety of IL-17A inhibitors in patients with ankylosing spondylitis.

METHODS

This protocol will be conducted under the preferred reporting items for systematic reviews and meta-analyses protocols (PRISMA-P) guidelines. Furthermore, the study has been registered on PROSPERO (CRD42022375885). The following electronic databases will be searched regardless of language and publication status: Pubmed, MEDLINE, EMBASE, China Biomedical Database, China National Knowledge Infrastructure, VIP Database, and Wanfang Database. Cochrane "bias risk" tool is used to assess the bias risk of the quality of the included literature. Data synthesis and statistical analysis will be performed using the RevMan 5.3 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark) software.

RESULTS

A synthesis of current evidence of IL-17A inhibitors for ankylosing spondylitis will be shown in this protocol.

CONCLUSION

This review can provide convincing evidence to help clinicians make decisions when dealing with ankylosing spondylitis.

The Presence of Ankylosing Spondylitis and the Incidence of Subsequent External Eye Diseases: A Population-Based Cohort Study

We aimed to survey the risk of external eye diseases in those with ankylosing spondylitis (AS) via the National Health Insurance Research Database (NHIRD) in Taiwan. We conducted a retrospective cohort study, and subjects diagnosed with AS were selected from the NHIRD. Then, the AS patients were matched 1:1 by propensity-score matching (PSM) to non-AS patients, and a total of 6754 participants were included in the AS and non-AS groups. The main outcomes were regarded as the occurrence of dry eye disease (DED), superficial keratopathy and corneal ulcers. We used Cox proportional hazard regression to yield the adjusted hazard ratios (AHR) with 95% confidence intervals (CI) between the AS and non-AS groups. There were 709 and 408 external eye disease events that occurred in the AS and non-AS groups after a tracking interval of up to 17 years. The incidence of all external eye diseases was significantly higher in the AS group than the non-AS group (AHR: 1.826, 95% CI: 1.616−2.063, p < 0.0001). Additionally, the rates of DED (AHR: 1.973, 95% CI: 1.701−2.290, p < 0.0001) and superficial keratopathy (AHR: 1.593, 95% CI: 1.347−1.883, p < 0.0001) were significantly higher in the AS group than the non-AS group. In the sub-group analyses, the possibility of any external eye disease (p = 0.0030) and DED (p = 0.0386) was decreased in the older age group compared to those in the middle-aged group. In conclusion, AS is significantly correlated to subsequent external eye diseases, mainly the DED and superficial keratopathy.

Metallothionein-1 is Positively Correlated with Inflammation and Ankylosing Spondylitis Activity

Introduction

Ankylosing spondylitis (AS) is a common form of chronic inflammatory rheumatic disease. Metallothionein-1 (MT-1) has been known to play an immunosuppressive role in various noninfectious inflammatory diseases, especially osteoarthritis and rheumatoid arthritis, thus inhibiting inflammation and pathogenesis in various diseases. However, whether MT-1 is related to AS is unclear. Here, we examined the levels of MT-1 in patients with AS and its correlation with the disease activity, complication, clinical indexes, and inflammatory cytokines and attempted to explain the effect of MT-1 on inflammation in AS.

Methods

The messenger RNA (mRNA) and protein expression of MT-1 in patients with AS were detected through real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The associations between serum MT-1 protein level and clinical indexes or proinflammatory cytokines in AS were analyzed using the Spearman correlation test.

Results

The mRNAs and serum protein levels of MT-1 were significantly higher in patients with AS, especially in patients with active AS and patients with osteoporosis (OP) than in healthy controls (HCs), and no difference was observed between patients with inactive AS and HCs. Serum MT-1 levels positively correlated with disease activity, proinflammatory cytokines, and clinical indexes Ankylosing Spondylitis Disease Activity Score with C-Reactive Protein, C-reactive protein level, and erythrocyte sedimentation rate in patients with AS.

Conclusion

MT-1 expression was upregulated in patients with active AS but not in those with inactive AS and positively correlated with clinical indexes, especially in OP, as well as with proinflammatory cytokines tumor necrosis factor–alpha, interleukin (IL)-1β, and IL-6 in patients with AS.

Lifestyle modification and inflammation in people with axial spondyloarthropathy-A scoping review

INTRODUCTION

People with axial spondyloarthritis (AS) have an inflammatory profile, increasing the risk of hypertension, type 2 diabetes, obesity, and dyslipidaemia. Consequently, AS is linked with co-morbidities such as cardiovascular disease (CVD). Physical inactivity, diet, smoking, alcohol consumption, and obesity influence inflammation, but knowledge of the interaction between these with inflammation, disease activity, and CVD risk in AS is dominated by cross-sectional research.

METHODS

A review of the literature was conducted between July 2020 and December 2021. The focus of the scoping review is to summarise longitudinal and randomised control trials in humans to investigate how tracking or modifying lifestyle influences inflammation and disease burden in patients with AS.

KEY MESSAGES

(1) Lifestyle modifications, especially increased physical activity (PA), exercise, and smoking cessation, are critical in managing AS. (2) Smoking is negatively associated with patient reported outcome measures with AS, plus pharmaceutical treatment adherence, but links with structural radiographic progression are inconclusive. (3) Paucity of data warrant structured studies measuring inflammatory cytokine responses to lifestyle modification in AS.

CONCLUSION

Increased PA, exercise, and smoking cessation should be supported at every given opportunity to improve health outcomes in patients with AS. The link between smoking and radiographic progression needs further investigation. Studies investigating the longitudinal effect of body weight, alcohol, and psychosocial factors on disease activity and physical function in patients with AS are needed. Given the link between inflammation and AS, future studies should also incorporate markers of chronic inflammation beyond the standard C-reactive protein and erythrocyte sedimentation rate measurements.

Survivin; a novel therapeutic target that correlates with survival of autoreactive T lymphocytes obtained from patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is progressive immune-mediated arthritis. Persistent autoreactivity of T cells with an up-regulated Survivin expression is strongly implicated in AS immunopathogenesis. Besides, Survivin can inhibit proapoptotic caspase 9 activations. Moreover, microRNAs are small non-coding RNAs that are dysregulated in various diseases, in which their altered expression could modulate Survivin expression. The primary goal of this study was to assess the role of Survivin and its-targeting microRNAs in the immunopathogenesis of AS disease. For this aim, peripheral blood mononuclear cells (PBMCs) were isolated from 15 patients with AS and healthy matched controls using Ficoll-Hypaque. T cells were obtained using the magnetic-activated cell sorting (MACS) method. After that, the expression levels of Survivin, Caspase 9, and specific miRNAs were determined using qT-qPCR. Also, the expression of Survivin and Caspase 9 at protein levels was determined by western blotting. Then, the isolated T cells were co-cultured with interleukin (IL)-2 and muromonab-CD3 (OKT-3) for active-induced cell death (AICD) induction, Survivin siRNA for inhibition of Survivin expression, and their combination to assess the implication of Survivin expression in autoreactive T lymphocytes' resistance to apoptosis by determining the rate of apoptosis by Flowcytometry assay. The results showed that Survivin was up-regulated while Caspase 9 was downregulated in patients with AS. It was also revealed that microRNAs that directly or indirectly target the Survivin mRNA were dysregulated in patients with AS. It was also revealed that T cells obtained from AS patients were more resistant to apoptosis induction than those obtained from healthy people. In summary, the results obtained from this study showed that dysregulation of Survivin and Survivin-targeting miRNAs in T lymphocytes obtained from AS patients contribute to their resistance to apoptosis, suggesting the future development of targeted therapies for AS.

Ezetimibe ameliorates clinical symptoms in a mouse model of ankylosing spondylitis associated with suppression of Th17 differentiation

Ankylosing spondylitis (AS) is a chronic inflammatory disease that causes spinal inflammation and fusion. Although the cause of AS is unknown, genetic factors (e.g., HLA-B27) and environmental factors (e.g., sex, age, and infection) increase the risk of AS. Current treatments for AS are to improve symptoms and suppress disease progression. There is no way to completely cure it. High blood cholesterol and lipid levels aggravate the symptoms of autoimmune diseases. We applied hyperlipidemia drugs ezetimibe and rosuvastatin to AS mice and to PBMCs from AS patients. Ezetimibe and rosuvastatin was administered for 11 weeks to AS model mice on the SKG background. Then, the tissues and cells of mice were performed using flow cytometry, computed tomography, immunohistochemistry, and immunofluorescence. Also, the normal mouse splenocytes were cultured in Th17 differentiation conditions for in vitro analysis such as flow cytometry, ELISA and RNA sequencing. The 10 AS patients’ PBMCs were treated with ezetimibe and rosuvastatin. The patients’ PBMC were analyzed by flow cytometry and ELISA for investigation of immune cell type modification. Ezetimibe caused substantial inhibition for AS. The present study showed that ezetimibe inhibits Th17 cell function, thereby slowing the progression of AS. It is well known that statins are more effective in reducing blood lipid concentrations than ezetimibe, however, our results that ezetimibe had a better anti-inflammatory effect than rosuvastatin in AS. This data suggests that ezetimibe has an independent anti-inflammatory effect independent of blood lipid reduction. To investigate whether ezetimibe has its anti-inflammatory effect through which signaling pathway, various in vitro experiments and RNA sequencing have proceeded. Here, this study suggests that ezetimibe can be an effective treatment for AS patients by inhibiting Th17 differentiation-related genes such as IL-23R and IL-1R. Thus, this study suggests that ezetimibe has therapeutic potential for AS through inhibition of Th17 differentiation and the production of pro-inflammatory cytokines.

Complete Bilateral Ankle Fusion: A Rare Complication of Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disorder primarily affecting the axial skeleton and is strongly associated with a positive human leukocyte antigen B27 (HLA-B27) genotype. Patients typically present with chronic low back pain that typically starts before the age of 40 years. Common initial clinical features include lower back, hip, and joint pain with stiffness that is worse in the morning and with inactivity. As the disease progresses over a prolonged period, it leads to fusion of sacroiliac joints and ankylosis of the vertebrae with the iconic "bamboo spine" on imaging. Joint fusion or ankylosis is the sequela of either undiagnosed or untreated AS. We report a case of a 69-year-old male with complete fusion of the ankle joint, hindfoot, and midfoot of both feet in the clinical context of an incidental finding of an ankylosed spine on computed tomography (CT) imaging. The ankle joint is a very uncommon site for fusion in ankylosing spondylitis. We would like to suggest the terminology “boot sign” for this rare radiographic finding of complete ankle and subtalar fusion given the appearance of a boot. “Boot sign” is associated with either inability to ambulate or a steppage gait from loss of ankle dorsiflexion as a result of ankle and hindfoot fusion with or without fusion of forefoot and midfoot.

Curcumin and Curcuma longa Extract in the Treatment of 10 Types of Autoimmune Diseases: A Systematic Review and Meta-Analysis of 31 Randomized Controlled Trials

Objective

To evaluate the randomized controlled trials (RCTs) of Curcumin and Curcuma longa Extract in the treatment of autoimmune diseases.

Methods

Databases such as Embase, Web of Science, PubMed and The Cochrane Library were searched from the database establishment to February 2022 to collect RCTs of Curcumin and Curcuma longa Extract in the treatment of autoimmune diseases. Then the literature was screened and the data were extracted. Meta-analysis was performed using RevMan 5.3 software.

Results

A total of 34 records were included, involving 31 RCTs and 10 types of autoimmune disease. Among them, ankylosing spondylitis (AS) involves one RCT, Behcet ‘s disease (BD) involves one RCT, Crohn ‘s disease involves two RCTs, multiple sclerosis (MS) involves two RCTs, oral lichen planus involves six RCTs, psoriasis involves two RCTs, rheumatoid arthritis (RA) involves five RCTs, systemic lupus erythematosus (SLE) involves two RCTs, arteritis involves one RCT, ulcerative colitis (UC) involves nine RCTs. Among them, most of the RCTs of ulcerative colitis (UC), oral lichen planus, RA showed that curcumin and curcumin extracts improved clinical or laboratory results. Crohn ‘ s disease, MS, SLE, psoriasis included two RCTs; they all showed improvements (at least one RCT reported improvements in clinical outcomes). AS, BD and arteritis included only one RCT, and the clinical results showed improvement. However, due to the small number of RCTs and the small number of patients involved in each disease, there is still a need for more high-quality RCTs.

Conclusion

Curcumin and Curcuma longa Extract had good clinical efficacy in the treatment of Psoriasis, UC and RA, so Curcumin and Curcuma longa Extract could be used in the treatment of the above diseases in the future. The results of Meta-analysis showed that Curcumin and Curcuma longa Extract did not show efficacy in the treatment of oral lichen planus, while Takayasu arteritis, SLE, MS, AS, BD and CD did not report sufficient clinical data for meta-analysis. Therefore, large-sample, multi-center clinical trials are still needed for revision or validation.

MicrobiomeGWAS: A Tool for Identifying Host Genetic Variants Associated with Microbiome Composition

The microbiome is the collection of all microbial genes and can be investigated by sequencing highly variable regions of 16S ribosomal RNA (rRNA) genes. Evidence suggests that environmental factors and host genetics may interact to impact human microbiome composition. Identifying host genetic variants associated with human microbiome composition not only provides clues for characterizing microbiome variation but also helps to elucidate biological mechanisms of genetic associations, prioritize genetic variants, and improve genetic risk prediction. Since a microbiota functions as a community, it is best characterized by β diversity; that is, a pairwise distance matrix. We develop a statistical framework and a computationally efficient software package, microbiomeGWAS, for identifying host genetic variants associated with microbiome β diversity with or without interacting with an environmental factor. We show that the score statistics have positive skewness and kurtosis due to the dependent nature of the pairwise data, which makes p-value approximations based on asymptotic distributions unacceptably liberal. By correcting for skewness and kurtosis, we develop accurate p-value approximations, whose accuracy was verified by extensive simulations. We exemplify our methods by analyzing a set of 147 genotyped subjects with 16S rRNA microbiome profiles from non-malignant lung tissues. Correcting for skewness and kurtosis eliminated the dramatic deviation in the quantile–quantile plots. We provided preliminary evidence that six established lung cancer risk SNPs were collectively associated with microbiome composition for both unweighted (p = 0.0032) and weighted (p = 0.011) UniFrac distance matrices. In summary, our methods will facilitate analyzing large-scale genome-wide association studies of the human microbiome.

DNA methylation and transcriptional profiles of IRF5 gene in ankylosing spondylitis: A case-control study

BACKGROUND

Interferon regulatory factor 5 (IRF5) plays an important role in the inflammation and immune responses, but its association with ankylosing spondylitis (AS) is under investigated. We aimed to examine the association of IRF5 promoter methylation patterns and transcript levels with the susceptibility to AS.

METHODS

A total of 60 AS patients and 60 healthy controls were included in this study. We used the bisulfite conversion to detect the DNA methylation pattern of IRF5 promoter in whole blood, and the quantitative real-time PCR (qRT-PCR) to detect the relative mRNA expression level in peripheral blood mononuclear cells (PBMCs).

RESULTS

The overall methylation level of IRF5 promoter was lower in AS patients compared to healthy controls (P < 0.001). The methylation level of IRF5 promoter was negatively correlated with mRNA level (P = 0.005). The results of receiver operating characteristic curve (ROC) showed that the area under the curve (AUC) was 0.810 (P < 0.001), and the sensitivity and specificity were 71.67% and 85.00%, respectively. There were significant differences between the severe dysfunction group and healthy control group, and between the mild dysfunction group and healthy control group (P = 0.006 and P < 0.001, respectively). Only CRP was significantly correlated with mRNA relative level, while the others were not significant.

CONCLUSION

These findings indicate that IRF5 methylation profile may be involved in the pathological process of AS, and that it may help identify AS patients.

Associations between ERAP1 polymorphisms and ankylosing spondylitis susceptibility in HLA-B27 positive population: a Meta-analysis and bioinformatics analysis

Human leukocyte antigen (HLA)-B27 confers a key role in ankylosing spondylitis (AS) susceptibility. Endoplasmic reticulum aminopeptidase 1 (ERAP1) polymorphisms are associated with AS susceptibility in common population. In this study we intended to evaluate the possible association between ERAP1 polymorphisms and AS susceptibility in HLA-27 positive population. Data were collected from Pubmed, Embase, and Cochrane databases. The pooled odds ratios and 95% confidence intervals of the minor allele of each locus were calculated to appraise the associations under ERAP1 polymorphisms and AS in HLA-B27 positive population. Bioinformatics analysis was performed to explore the underlying mechanism. Four studies were included in this meta-analysis. There was a significant association between the minor allele of rs2287987 and reducing the risk of developing AS in HLA-B27 positive population. But there was no significant association between the minor allele of rs30187, rs27044, rs10050860 and rs17482078 and AS susceptibility. According to HaploReg, 5 motifs changed for rs2287987 were found. The eQTL analysis demonstrated that rs2287987 may influence ERAP1 expression. Rs2287987 in ERAP1 may have small influence on AS susceptibility in HLA-B27 positive population. Bioinformatics analysis indicated that the altered motifs and the change of EARP1 expression may influence the AS susceptibility.

Primary Biliary Cholangitis with Ankylosing Spondylitis

Primary biliary cholangitis is a chronic inflammatory autoimmune liver disease that is characterized by a positive antimitochondrial antibodies test and progressive destruction of the small intrahepatic bile duct. Ankylosing spondylitis is a chronic, systemic, inflammatory disease of the spine and the sacroiliac joints. The association between these two is very low. This paper reports a rare case who had ankylosing spondylitis and developed primary biliary cholangitis.

TNF inhibitors have a protective role in the risk of dementia in patients with ankylosing spondylitis: Results from a nationwide study

OBJECTIVES

Ankylosing spondylitis (AS) is a chronic progressive and debilitating form of arthritis with associated extra-articular features including uveitis, intestinal and lung apical inflammation and psoriasis. Putative associations between AS and neurologic disorders has been relatively overlooked. The purpose of this study is to assess the link between AS and major neurologic disorders and whether treatment with Tumor-Necrosis-Factor inhibitors (TNFi) has an impact on that association.

METHODS

A retrospective cross-sectional study was carried out based on the Clalit Health Services (CHS) computerized database. AS patients were compared to age- and gender-matched controls with respect to the proportion of Alzheimer's disease (AD), Parkinson's disease (PD), epilepsy, and multiple sclerosis (MS). The impact of AS therapy (biologic vs conventional therapy) was assessed as well.

RESULTS

4,082 AS patients and 20,397 age- and gender-matched controls were identified. AS was associated with a higher prevalence of AD (odds-ratio(OR) 1.46 [95%Confidence-interval(CI) 1.13-1.87], p=0.003), epilepsy (OR 2.33 [95%CI 1.75-3.09] p<0.0001) and PD (OR 2.75 [95%CI 2.04-3.72], p<0.0001), whereas no statistically significant association was found for MS. Association with PD remained significant in the multivariate analysis (OR 1.49 [95%CI 1.05- 2.13],p=0.027). Within AS patients, the use of TNFi (OR 0.10 [95%CI 0.01-0.74], p=0.024) were associated with a lowered risk of developing AD.

CONCLUSION

AS is positively associated with AD, PD, and epilepsy but not MS. AS patients treated with TNFi have lower rates of AD.

Previous biological therapy and impairment of the IFN-γ/IL-10 axis are associated with low immune response to 17DD-YF vaccination in patients with spondyloarthritis

Yellow fever (YF) vaccination is known to induce a suboptimal response in patients with autoimmune diseases (AIDs). To date, few studies have focused on the performance of 17DD-YF vaccination in patients with spondyloarthritis (SpA). In general, patients with SpA are young and have less comorbidities than other patients with AIDs, and frequently receive biological disease-modifying antirheumatic drugs (DMARDs) that may impact their response to vaccines. Taking this background information, the present study aimed to investigate whether the use of biological DMARDs, even after planned washout, or disease activity measured by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), would impact the overall performance of planned 17DD-YF primary vaccination in patients with SpA. For this purpose, 74 subjects were enrolled in a prospective study, including adult patients with SpA (SpA; n = 51) and a healthy control (HC; n = 23) group. Analysis of YF specific neutralizing antibodies test (PRNT), along with YF viremia and the levels of serum chemokines, cytokines, and growth factors were performed at distinct time points (D0, D3, D4, D5, D6, D7, D14, and D28). The BASDAI scores were evaluated at D0 and D180. Data demonstrated that overall, the SpA group presented lower PRNT titers and seropositivity rates as compared to the HC group (GeoMean = 112 vs. 440; 73% vs. 96%, respectively). In SpA subgroup analyses, previous biological DMARDs (BIO-IT) led to a lower PRNT titers (BIO-IT 79, 95% CI [39-150] vs. without biological DMARDs [non-BIO-IT] 159, 95% CI [94-267], p < 0.001). The non-BIO-IT group achieved a response similar to the HC group (81% vs. 96%, p = 0.112), whereas the BIO-IT group had a lower seroconversion rate (64% vs. 96% HC, p = 0.007). The BASDAI was not associated with PRNT levels and did not change after 6 months of follow-up. No differences in YF viremia were observed amongst subgroups. Higher baseline levels of serum biomarkers were observed in the BIO-IT group vs. the non-BIO-IT group, as well as in those with a BASDAI ≥ 4 vs. those with a BASDAI < 4. Increasing levels of several biomarkers were observed in SpA, especially in the BIO-IT and BASDAI ≥ 4 subgroups throughout the timeline kinetics, with impairment/disturbance in the IFN-γ/IL-10 axis around the peak of viremia (D5). Altogether, these findings suggested that the use of biological DMARDs impacts the response to the 17DD-YF vaccine, even after planned washout. Therefore, previous biological DMARD therapy, the inflammatory status prior vaccination, and impairment of the IFN-γ/IL-10 axis at the peak of viremia may determine the immunogenicity of 17DD-YF vaccination in patients with SpA.

Comparison of the efficacy and safety of the adalimumab biosimilar TQ-Z2301 and adalimumab for the treatment of Chinese patients with active ankylosing spondylitis: a multi-center, randomized, double-blind, phase III clinical trial

OBJECTIVE

To assess the clinical equivalence of TQ-Z2301, a biosimilar of adalimumab, to the reference adalimumab in the treatment of Chinese patients with active ankylosing spondylitis.

METHODS

This multicenter, randomized, double-blind, positive-controlled phase III clinical trial was conducted in 19 centers across China. Chinese adults with active ankylosing spondylitis despite being treated with non-steroidal anti-inflammatory drugs for ≥ 4 weeks were randomized in a 1:1 ratio to subcutaneously receive 40 mg of TQ-Z2301 or adalimumab every other week for 24 weeks. The primary endpoint was the percentage of patients who achieved at least 20% improvement according to the Assessment of Spondyloarthritis International Society criteria (ASAS20) at week 24. The equivalence was established if the 90% CI for RR of ASAS20 between two groups at week 24 fell within (0.80, 1.25). Secondary endpoints included efficacy measures of disease activity, spinal mobility, physical function and quality of life, immunogenicity, and pharmacokinetic parameters. Safety analysis was done for all patients who received at least one study drug.

RESULTS

A total of 380 patients were enrolled in the study between September 2018 and October 2019, including 188 in the TQ-Z2301 group and 192 in the adalimumab group. In the full analysis population, the ASAS20 response rate at week 24 was 86.70% in the TQ-Z2301 group, and 80.73% in the adalimumab group, the RR of ASAS20 for TQ-Z2301 versus adalimumab was 1.074, 90% CI (0.997, 1.157), fell within the predefined equivalence boundary (0.80, 1.25). Except for the SF-36 at week 12, there was no statistical difference between the two groups for all the secondary endpoints (P>0.05). The incidence of adverse events group was 82.45% in the TQ-Z2301, and 83.85% in the adalimumab group, the safety profile of the two groups was similar. The profiles of immunogenicity and pharmacokinetics were also similar between the two groups.

CONCLUSION

TQ-Z2301 is equivalent to adalimumab for the treatment of Chinese patients with active ankylosing spondylitis. The safety, immunogenicity, and pharmacokinetic characteristics of both drugs are similar.

TRIAL REGISTRATION

The study (CTR20181863) was registered in the Chinese Clinical Trial Registry on 19 October 2018. Key Points • TQ-Z2301 showed the equivalence of efficacy compared with the reference adalimumab for the treatment of Chinese patients with active ankylosing spondylitis. • The safety, immunogenicity, and pharmacokinetics profiles of TQZ-2301 were similar to those of the reference adalimumab.

miR‑148a‑3p facilitates osteogenic differentiation of fibroblasts in ankylosing spondylitis by activating the Wnt pathway and targeting DKK1

Ankylosing spondylitis (AS) is a chronic inflammatory form of arthritis. MicroRNAs (miRNAs) have been identified to serve as therapeutic targets in various inflammatory diseases. The aim of the present study was to determine the functional mechanism of miR-148a-3p on AS. Specimens were collected from AS patients and non-AS patients. Fibroblasts were delivered with the aid of miR-148a-3p inhibitor. Cell staining was performed to observe the morphological changes, calcified nodules, and mineralization degree. The binding sites of miR-148a-3p and DKK1 were predicted on the Starbase website and subsequently verified by means of dual-luciferase reporter assay. AS fibroblasts with silenced miR-148a-3p were transfected with si-DKK1. Levels of RUNX2 and Osteocalcin, DKK1 and Wnt1 protein and phosphorylation level of β-catenin were detected by means of western blot analysis. Results of the present study denoted that AS upregulated miR-148a-3p in fibroblasts to exacerbate osteogenic differentiation, resulting in increased calcified nodules and mineralization degree. Silencing miR-148a-3p could reverse the upregulation of RUNX2 and Osteocalcin in AS fibroblasts and reduce the calcified nodules and mineralization degree. miR-148a-3p targeted DKK1. DKK1 knockdown averted the effect of silencing miR-148a-3p in AS fibroblasts. In addition, silencing miR-148a-3p reversed the upregulation of Wnt1 and β-catenin proteins in AS fibroblasts. To conclude, miR-148a-3p exacerbated the osteogenic differentiation of AS fibroblasts by inhibiting DKK1 expression and activating the Wnt pathway.

KLF4 downregulates FGF21 to activate inflammatory injury and oxidative stress of LPS‑induced ATDC5 cells via SIRT1/NF‑κB/p53 signaling

Ankylosing spondylitis (AS) is a chronic inflammatory disease. Transcriptional regulation of fibroblast growth factor 21 (FGF21) by the transcription factor Krüppel-like factor 4 (KLF4) serves an important role in chronic inflammatory disease. However, to the best of our knowledge, the role of both these factors in AS has not been previously reported. In the present study, ATDC5 cells were induced by lipopolysaccharide (LPS) to establish an AS inflammatory injury model. The expression levels of FGF21 and KLF4 were detected using reverse transcription-quantitative PCR and western blotting. Cell transfection was performed to alter the expression levels of KLF4 and FGF21. Subsequently, the regulatory effects and mechanisms underlying KLF4 and FGF21 on oxidative stress and inflammation in AS were investigated by performing Cell Counting Kit-8 assays, ELISAs, TUNEL staining and western blotting. Moreover, the expression levels of sirtuin 1 (SIRT1)/NF-κB/p53 pathway-related proteins were detected via western blotting. FGF21 overexpression promoted LPS-induced viability on ATDC5 cells, inhibited LPS-induced apoptosis, and decreased the LPS-induced inflammatory response and oxidative stress levels of ATDC5 cells. Overexpression of the transcription factor KLF4 reversed the protective effect of FGF21 overexpression on LPS-induced inflammatory injury in ATDC5 cells. The results suggested that this process may be achieved via regulating the SIRT1/NF-κB/p53 signaling pathway. Overall, the present study demonstrated that KLF4 downregulates FGF21 to activate inflammatory injury and oxidative stress of LPS-induced ATDC5 cells via SIRT1/NF-κB/p53 signaling.

Leukemia inhibitory factor is dysregulated in ankylosing spondylitis and contributes to bone formation

AIM

Ankylosing spondylitis (AS) is a chronic inflammatory disease. However, the key inflammatory cytokines disrupted in this disease are not well defined. In this study, we performed protein array and multiple protein quantification to investigate the differentially expressed cytokines in plasma between AS patients and healthy subjects.

METHOD

In the discovery cohort, 5 AS patients who never underwent biologic therapy and 5 gender- and age-matched healthy subjects were enrolled in the protein array analysis. Another 40 AS patients and 20 healthy participants were recruited in the validation stage. In addition, the messenger RNA and protein levels of osteogenesis-related genes were quantified in hFOB1.19 cells in an in vitro osteoblast model.

RESULTS

Of the 318 cytokines found to be differentially expressed by protein array, leukemia inhibitor factor (LIF) was significantly increased in AS patients as compared to controls. The "signaling by interleukins" pathway was the most enriched pathway in AS patients, and "signaling by interleukins"-related cytokines, including LIF, interleukin (IL)-6, IL-23, and IL-31, were significantly differentially expressed in the validation stage. Additionally, we correlated the expression of LIF with C-reactive protein (CRP) and inflammation of magnetic resonance imaging lesions in the spine (MRI-SPINE) in AS patients. We further analyzed the effects of LIF in hFOB cells and found that LIF promoted the growth factor receptor-bound protein 2 / phospho-extracellular signal-regulated kinase / runt-related transcription factor 2 / alkaline phosphatase pathway at the protein level and activated several osteogenesis-related genes (RUNX2 and BGLAP).

CONCLUSION

LIF was increased in the plasma of AS patients as compared with healthy subjects and significantly correlated with inflammation indices (CRP and MRI-SPINE) in AS patients. Thus, LIF may play a critical role in the pathogenesis of AS via promoting osteogenic differentiation.

Tofacitinib for the treatment of active ankylosing spondylitis in adults

INTRODUCTION

Ankylosing spondylitis, also known as radiographic axial spondyloarthritis, is a complex, immune-mediated inflammatory disorder most commonly involving the spine including the sacroiliac joints.

AREAS COVERED

Complex pathogenesis of axial spondyloarthritis involving genetic, environmental, and both innate and adaptive immune systems. Treatment options for ankylosing spondylitis. Pharmacologic properties, efficacy, and safety of tofacitinib, a JAK inhibitor. Data regarding efficacy of approved JAK inhibitors in the treatment of ankylosing spondylitis, including tofacitinib, upadacitinib, and filgotinib.

EXPERT OPINION

Current treatment options of ankylosing spondylitis include NSAIDs, TNFi, and IL-17i. JAK inhibitors present a new class of therapy that has shown efficacy in the treatment of active ankylosing spondylitis in adults. While it has not been directly compared to alternate therapies, tofacitinib has been shown to be effective in both phase II and phase III trials for the treatment of ankylosing spondylitis. While these trials did not show any significant difference from placebo in terms of safety, the ORAL Surveillance study showed tofacitinib to be inferior to TNFi when comparing adverse events. Thus, tofacitinib presents a viable treatment option for the management of AS, however shared decision making regarding risks and benefits will be important.

Comprehensive lncRNA and mRNA profiles in peripheral blood mononuclear cells derived from ankylosing spondylitis patients by RNA-sequencing analysis

The present study aimed to investigate the comprehensive expression profiles of long non-coding RNA (lncRNA) in ankylosing spondylitis (AS).The peripheral blood samples were collected from 6 AS patients and 6 age- and gender-matched healthy controls (HCs), and separated for peripheral blood mononuclear cells, followed by RNA-sequencing. Further bioinformatics analyses were performed to explore the significantly enriched biological processes, signaling pathways of differentially expressed lncRNAs (DElncRNAs) (based on cis-target and trans-target genes) and differentially expressed mRNAs (DEmRNAs).Principal component analysis plots indicated that both lncRNA and mRNA expression profiles could distinguish AS patients from HCs; heatmap diagram exhibited a relatively good consistency and tendency of lncRNA and mRNA expression profiles in AS patients and HCs, respectively; volcano plots exhibited 114 upregulated and 45 downregulated DElncRNAs, 284 upregulated and 435 downregulated DEmRNAs in AS patients compared with HCs; Gene ontology enrichment analyses indicated that DElncRNAs (based on cis-target and trans-target genes) and DEmRNAs were enriched in molecular functions (including DNA binding, protein binding, etc) and biological process (including immune response, inflammatory response, etc); Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that these DElncRNAs (based on cis-target and trans-target genes) and DEmRNAs were enriched in immune and inflammation-related signaling, such as B cell receptor signaling pathway, TNF signaling pathway, NF-kappa B signaling pathway, etc.Our study displays the comprehensive expression profiles and functions of lncRNAs involved in AS, which provides reference for further researches discovering candidate lncRNAs with value in assisting early AS diagnosis.

Dysregulation of SAA1, TUBA8 and Monocytes Are Key Factors in Ankylosing Spondylitis With Femoral Head Necrosis

Introduction

The mechanism of ankylosing spondylitis with femoral head necrosis is unknown, and our study aimed investigate the effects of genetic and immune cell dysregulation on ankylosing spondylitis.

Materials and Methods

The protein expression of all ligaments in ankylosing spondylitis with femoral head necrosis was obtained using label-free quantification protein park analysis of six pairs of specimens. The possible pathogenesis was explored using differential protein analysis, weighted gene co-expression network analysis, recording intersections with hypoxia-related genes, immune cell correlation analysis, and drug sensitivity analysis. Finally, routine blood test data from 502 AS and 162 healthy controls were collected to examine immune cell differential analysis.

Results

SAA1 and TUBA8 were significantly expressed differentially in these two groups and correlated quite strongly with macrophage M0 and resting mast cells (P < 0.05). Routine blood data showed that monocytes were significantly more expressed in AS than in healthy controls (P < 0.05). SAA1 and TUBA8 were closely related to the sensitivity of various drugs, which might lead to altered drug sensitivity.

Conclusion

Dysregulation of SAA1, TUBA8 and monocytes are key factors in ankylosing spondylitis with femoral head necrosis.