The Potential Role of Genetics, Environmental Factors, and Gut Dysbiosis in the Aberrant Non-Coding RNA Expression to Mediate Inflammation and Osteoclastogenic/Osteogenic Differentiation in Ankylosing Spondylitis

Environmental and Genetic Determinants of Ankylosing Spondylitis

Exposure to heavy metals and lifestyle factors like smoking contribute to the production of free oxygen radicals. This fact, combined with a lowered total antioxidant status, can induce even more damage in the development of ankylosing spondylitis (AS). Despite the fact that some researchers are looking for more genetic factors underlying AS, most studies focus on polymorphisms within the genes encoding the human leukocyte antigen (HLA) system. The biggest challenge is finding the effective treatment of the disease. Genetic factors and the influence of oxidative stress, mineral metabolism disorders, microbiota, and tobacco smoking seem to be of great importance for the development of AS. The data contained in this review constitute valuable information and encourage the initiation and development of research in this area, showing connections between inflammatory disorders leading to the pathogenesis of AS and selected environmental and genetic factors.

Effect of Lifestyle Counselling via a Mobile Application on Disease Activity Control in Inflammatory Arthritis: A Single-Blinded, Randomized Controlled Study

BACKGROUND

Mobile applications (apps) are a resource for information on lifestyle and nutrition which are associated to improved outcomes in inflammatory arthritis.

OBJECTIVE

The aim of this study was to explore whether targeted lifestyle counselling via an app improves disease activity in arthritis patients.

METHODS

Patients with rheumatoid arthritis (RA), spondyloarthritis (SpA), psoriatic arthritis (PsA) were randomized to 12 weeks of lifestyle counselling via an app (Mida, Midaia GmbH, Germany) pertaining to a healthy Mediterranean Diet, physical activity, and mental health. Disease activity was measured with specific instruments by a blinded physician and categorized (remission, low, moderate, high). Dietary adherence was assessed by the Mediterranean Diet Adherence Screener (MEDAS). Mixed effects logistic regression adjusted to baseline disease activity, age, and sex were calculated.

RESULTS

Of 158 patients included (73% female, 53.3 ± 11.7 years), 74 were in the active counselling group (ACG). All showed improvement in low disease activity or remission. ACG patients had an odds ratio (OR) of 2.8 (95%-CI 1.1-7.2, p = 0.035), while OR in the control group was not significant OR = 2.1 (0.9-5.0, p = 0.097). The control group was less likely to reach a MEDAS >= 4 (OR = 0.16 (0.03-0.77), p = 0.02), while this was not seen in the ACG (OR = 0.54 (0.06-4.63), p = 0.6). Patients in the ACG showed a tendency towards improved adhesion to a Mediterranean Diet (MEDAS) (β = 0.35 (-0.05-0.74), p = 0.086). This tendency was not observed in the control group (β = 0.09 (-0.29-0.46), p = 0.64).

CONCLUSIONS

Individualized lifestyle and dietary counselling via app may help to improve disease control in inflammatory arthritis patients.

Reduced expression of miRNAs as potential biomarkers in axial spondyloarthritis

OBJECTIVE

This study aimed to investigate the value of miR-29a-3p, miR-27a, miR126-3p, miR-146a-5p, miR-625-3p, miR-130a, miR-32, miR-218, miR-131, and miR5196 in the diagnosis of axial spondyloarthritis and to determine whether there is a difference in miRNA expression levels between radiographic axial spondyloarthritis and non-radiographic axial spondyloarthritis, as well as the relationship between miRNA expression levels, disease activity, and uveitis history.

METHODS

This study included 50 patients with axial spondyloarthritis (25 with radiographic axial spondyloarthritis and 25 with non-radiographic axial spondyloarthritis) and 25 healthy individuals. The fold change of miRNA expression for each miRNA was calculated using the 2-ΔΔCt method.

RESULTS

The expression of all miRNAs except miR-130a was downregulated in axial spondyloarthritis patients (miR-27a: fold regulation: -11.21, p<0.001; miR-29a-3p: fold regulation: -2.63, p<0.001; miR-32: fold regulation: -2.94, p=0.002; miR-126-3p: fold regulation -10.94, p<0.001; miR-132: fold regulation: -2.18, p<0.001; miR-146-5p: fold regulation: -9.78, p<0.001; miR-218: fold regulation: -2.65, p<0.001; miR-625-3p: fold regulation: -2.01, p=0.001; miR-5196-3p: fold regulation: -7.04, p<0.001). The expression levels of these miRNAs did not differ significantly between non-radiographic axial spondyloarthritis and radiographic axial spondyloarthritis patients (p>0.05 for all).

CONCLUSION

Particularly, miR-27a, miR-126-3p, miR-146-5p, and miR-5196-3p were found to be substantially downregulated in both non-radiographic axial spondyloarthritis and radiographic axial spondyloarthritis patients, suggesting their potential as diagnostic biomarkers for axial spondyloarthritis.

Heat shock protein-related diagnostic signature and molecular subtypes in ankylosing spondylitis: new pathogenesis insights

Heat shock proteins (HSP) have been associated with a range of persistent inflammatory disorders; however, little research has been conducted on the involvement of HSP in the development of ankylosing spondylitis (AS). The research aims to identify a diagnostic signature based on HSP-related genes and determine the molecular subtypes of AS. We gathered the transcriptional data of patients with AS from the GSE73754 dataset and conducted a literature search for HSP-related genes (HRGs). The logistic regression model was utilized for the identification of hub HRGs associated with AS. Subsequently, these HRGs were employed in the construction of a nomogram prediction model. We employed a consensus clustering approach to identify novel molecular subgroups. Subsequently, we conducted functional analyses, encompassing GO, KEGG, and GSEA, to elucidate the underlying mechanisms between these subgroups. To assess the immunological landscape, we employed the xCell algorithm. Through logistic regression analysis, the four core HRGs (CCT2, HSPA6, DNAJB14, and DNAJC5) were confirmed as potential biomarkers for AS. Subsequent stratification revealed two distinct molecular phenotypes, designated as Cluster 1 and Cluster 2. Notably, Cluster 2 was characterized by the upregulation of pathways pertinent to immune response and inflammation. Our research suggests that the CCT2, HSPA6, DNAJB14, and DNAJC5 exhibit potential as effective blood-based diagnostic biomarkers for AS. These findings contribute to a deeper comprehension of the underlying mechanisms involved in the development of AS and offer potential targets for personalized therapeutic interventions.

HLA-B*27 and Ankylosing Spondylitis: 50 Years of Insights and Discoveries

PURPOSE OF REVIEW

To commemorate the 50th anniversary of the groundbreaking discovery of a remarkably strong association between HLA-B*27 and ankylosing spondylitis (AS).

RECENT FINDINGS

In addition to HLA-B*27, more than 116 other recognized genetic risk variants have been identified, while epigenetic factors largely remain unexplored in this context. Among patients with AS who carry the HLA-B*27 gene, clonally expanded CD8 + T cells can be found in their bloodstream and within inflamed tissues. Moreover, the α and β chain motifs of these T-cell receptors demonstrate a distinct affinity for certain self- and microbial-derived peptides, leading to an autoimmune response that ultimately results in the onset of the disease. These distinctive peptide-binding and presentation characteristics are a hallmark of the disease-associated HLA-B*27:05 subtype but are absent in HLA-B*27:09, a subtype not associated with the disease, differing by only a single amino acid. This discovery represents a significant advancement in unraveling the 50-year-old puzzle of how HLA-B*27 contributes to the development of AS. These findings will significantly accelerate the process of identifying peptides, both self- and microbial-derived, that instigate autoimmunity. This, in return, will pave the way for the development of more accurate and effective targeted treatments. Moreover, the discovery of improved biomarkers, in conjunction with the emerging technology of electric field molecular fingerprinting, has the potential to greatly bolster early diagnosis capabilities. A very recently published groundbreak paper underscores the remarkable effectiveness of targeting and eliminating disease-causing T cells in a HLA-B*27 patients with AS. This pivotal advancement not only signifies a paradigm shift but also bolsters the potential for preventing the disease in individuals carrying high-risk genetic variants.

Exploring causal correlations between inflammatory cytokines and ankylosing spondylitis: a bidirectional mendelian-randomization study

Background

The impact of inflammatory factors on the development of Ankylosing Spondylitis (AS) is widely recognized, but the exact causal relationship remains unclear.

Methods

The bidirectional mendelian-randomization study utilized genetic data from a genome-wide association study (GWAS) of 186 AS cases and 456,162 controls of European ancestry. Inflammatory cytokines were obtained from a GWAS summary of 8,293 healthy participants. Causal associations were primarily investigated using the inverse variance-weighted method, supplemented by MR Egger, weighted median and weighted mode analyses. Heterogeneity in the results was assessed using the Cochrane Q test. Horizontal pleiotropy was evaluated through the MR-Egger intercept test and the MR pleiotropy residual sum and outliers (MR-PRESSO) test. Sensitivity analysis was conducted through leave-one-out analysis.

Results

The results suggest a genetically predicted potential association between beta-nerve growth factor (βNGF), Interleukin-1-beta (IL-1β), and TNF-related apoptosis inducing ligand (TRAIL) with the risk of AS (OR: 2.17, 95% CI: 1.13-4.16; OR: 0.41, 95% CI: 0.18-0.95,; OR: 1.47, 95% CI: 1.02-2.13).Additionally, Interleukin-12p70 (IL-12p70), Interleukin-17 (IL-17), Interleukin-6 (IL-6), Interleukin-4 (IL-4), Stromal-cell-derived factor 1 alpha (SDF-1α), Macrophage inflammatory protein 1β (MIP1β), Monocyte chemoattractant protein-3 (MCP-3), Platelet-derived growth factor bb (PDGFbb), Granulocyte-colony stimulating factor (GCSF), Fibroblast growth factor basic (bFGF), TNF-related apoptosis inducing ligand (TRAIL), and Interferon-gamma (IFN -γ) are suggested as consequences of AS in genetically prediction.No evidence of horizontal pleiotropy or heterogeneity between the genetic variants was found (P>0.05), and a leave-one-out test confirmed the stability and robustness of this association.

Conclusion

These findings suggest that βNGF, IL-1β, and TRAIL may play a crucial role in the pathogenesis of AS. Additionally, AS may impact the expression of cytokines such as IL-12p70, IL-17, IL-6, IL-4, SDF-1α, MIP1β, MCP-3, PDGFbb,GCSF, bFGF,TRAIL,and IFN-γ. Further investigations are warranted to determine whether these biomarkers can be utilized for the prevention or treatment of AS.

Cytokines and regulatory T cells in ankylosing spondylitis

Aims

To investigate the correlations among cytokines and regulatory T cells (T-regs) in ankylosing spondylitis (AS) patients, and their changes after anti-tumour necrosis factor-α (TNF-α) treatment.

Methods

We included 72 AS patients with detailed medical records, disease activity score (Bath Ankylosing Spondylitis Disease Activity Index), functional index (Bath Ankylosing Spondylitis Functional Index), and laboratory data (interleukin (IL)-2, IL-4, IL-10, TNF-α, interferon (IFN)-γ, transforming growth factor (TGF)-β, ESR, and CRP). Their peripheral blood mononuclear cells (PBMCs) were marked with anti-CD4, anti-CD25, and anti-FoxP3 antibodies, and triple positive T cells were gated by flow cytometry as T-regs. Their correlations were calculated and the changes after anti-TNF-α therapy were compared.

Results

The frequency of T-regs in PBMCs was positively correlated to ESR and CRP in AS (r = 0.35 and 0.43; p = 0.032 and 0.027, respectively), and there was also a significant correlation between serum level of TNF-α and CRP (p = 0.041). The frequency of T-regs in PBMCs positively correlated to serum levels of TNF-α, IL-10, and TGF-β, while IL-2, IL-4, and IFN-γ showed opposite results. After anti-TNF-α treatment, there were significantly lower serum levels of TNF-α, IL-10, TGF-β, and frequency of T-regs in PBMCs among these AS patients (p = 0.026, 0.032, 0.029, and 0.037, respectively).

Conclusion

In AS patients, proinflammatory cytokine may give positive feedback to induce more T-reg production and anti-inflammatory cytokine secretion to suppress this inflammatory status, and they can be reversed by anti-TNF-α therapy. However, the detailed interactions among T-regs and complex cytokine networks in autoinflammatory diseases still need more studies and further functional assay.

Cite this article: Bone Joint Res 2023;12(2):133–137.

Epidemiological characteristics of ankylosing spondylitis in Guangxi Province of China from 2014 to 2021

INTRODUCTION

To explore the epidemiological characteristics of ankylosing spondylitis (AS) in Guangxi Province of China through a large sample survey of more than 50 million aboriginal aboriginal population.

MATERIAL AND METHODS

A systematic search was conducted using the International Classification of Diseases 10 (ICD-10) codes M45.x00(AS), M45.x03+(AS with iridocyclitis), and M40.101(AS with kyphosis) to search the database in the National Health Statistics Network Direct Reporting System (NHSNDRS). 14004 patients were eventually included in the study. The parameters analyzed included the number of patients, gender, marriage, blood type, occupation, age at diagnosis, and location of household registration data each year, and statistical analysis was performed.

RESULTS

AS incidence rates increased from 1.30 (95% CI: 1.20-1.40) per 100,000 person-years in 2014 to 5.71 (95% CI: 5.50-5.92) in 2020 in Guangxi Province, and decreased slightly in 2021. Males have a higher incidence than females; the ratio was 5.61 : 1. The mean age of diagnosis in male patients was 45.4 (95% CI: 45.1-45.7) years, in females 47.6 (95% CI: 46.8-48.4) years. The most frequent blood type was O, and the most frequent occupation was farmer. The AS incidence rate was disparate in different cities. Liuzhou city had the highest eight-year average AS incidence rates from 2014 to 2021, and Chongzuo city had the lowest (p < 0.05). There was no significant difference in the incidence between different ethnic groups (p > 0.05).

CONCLUSIONS

The AS person-years incidence rate was increasing in Guangxi province of China from 2014 to 2020, which had obvious gender and regional differences, showing the characteristics of local area aggregation.

Epigenetic regulation and T-cell responses in endometriosis – something other than autoimmunity

Endometriosis is defined as the presence of endometrial-like glands and stroma located outside the uterine cavity. This common, estrogen dependent, inflammatory condition affects up to 15% of reproductive-aged women and is a well-recognized cause of chronic pelvic pain and infertility. Despite the still unknown etiology of endometriosis, much evidence suggests the participation of epigenetic mechanisms in the disease etiopathogenesis. The main rationale is based on the fact that heritable phenotype changes that do not involve alterations in the DNA sequence are common triggers for hormonal, immunological, and inflammatory disorders, which play a key role in the formation of endometriotic foci. Epigenetic mechanisms regulating T-cell responses, including DNA methylation and posttranslational histone modifications, deserve attention because tissue-resident T lymphocytes work in concert with organ structural cells to generate appropriate immune responses and are functionally shaped by organ-specific environmental conditions. Thus, a failure to precisely regulate immune cell transcription may result in compromised immunological integrity of the organ with an increased risk of inflammatory disorders. The coexistence of endometriosis and autoimmunity is a well-known occurrence. Recent research results indicate regulatory T-cell (Treg) alterations in endometriosis, and an increased number of highly active Tregs and macrophages have been found in peritoneal fluid from women with endometriosis. Elimination of the regulatory function of T cells and an imbalance between T helper cells of the Th1 and Th2 types have been reported in the endometria of women with endometriosis-associated infertility. This review aims to present the state of the art in recognition epigenetic reprogramming of T cells as the key factor in the pathophysiology of endometriosis in the context of T-cell-related autoimmunity. The new potential therapeutic approaches based on epigenetic modulation and/or adoptive transfer of T cells will also be outlined.