Analysis of inflammation-related microRNA expression in patients with ankylosing spondylitis

Dysregulated Non-Coding RNA Expression in T Cells from Patients with Ankylosing Spondylitis Contributes to Its Immunopathogenesis

Ankylosing spondylitis (AS) is a chronic inflammatory disorder characterized by inflammatory back pain and bony fusion of vertebral joints. Genetic associations and environmental factors have been proposed to explain the immunopathogenesis of AS. In the past few years, there have been major advances in understanding T cell dysfunction in AS. Clinically, targeting interleukin-17A, a major cytokine secreted by T helper 17 cells, has been approved for treating patients with active AS. Non-coding RNAs (ncRNAs) are RNA transcripts that do not translate into proteins. The ncRNAs regulate both innate and adaptive immunity and participate in the pathogenesis of autoimmune diseases, including AS. The main purpose of this article is to review the up-to-date studies investigating the aberrant expression of ncRNAs in T cells from patients with AS and to summarize their roles in its pathogenesis. After searching PubMed for studies published between January 2013 and June 2024, nine studies investigating the expression of ncRNAs in AS T cells were included. We found that aberrantly expressed ncRNAs in AS T cells could cause abnormal cytokine release, cell signaling abnormalities, and dysregulated cell proliferation and death, which contribute to the immunopathogenesis of AS. We discussed some limitations of these studies and suggested several research fields for further investigation.

Predictive values of circulating miR-146a and miR-155 for disease activity and clinical response to TNF-α blocking therapy in patients with ankylosing spondylitis

OBJECTIVE

Ankylosing spondylitis is an insidiously progressive and debilitating form of arthritis involving the axial skeleton. MicroRNAs have been reported to act as candidate biomarkers for ankylosing spondylitis diagnosis and progression. The study aimed to assess the roles of circulating miR-146a and miR-155 in ankylosing spondylitis and their prediction to clinical response to TNF-α blocking therapy.

METHODS

The study included 62 ankylosing spondylitis patients who were given originator TNFi with a 6-month period. Responders to anti-TNF treatment were defined as those reaching the Assessment of SpondyloArthritis international Society 40 (ASAS40) response at the 6-month interval, and nonresponders were defined those not (n = 24).

RESULTS

The ankylosing spondylitis patients at M0 (before beginning TNFi treatment) had higher serum levels of miR-146a and miR-155 than the healthy controls (p < .0001). Lower serum levels of miR-146a and miR-155 were noted in the responders (n = 38) compared with the nonresponders (n = 24) at different time points after anti-TNF treatment (p < .0001). The serum levels of miR-146a and miR-155 alone or in combination used to predict treatment outcomes produced AUCs of 0.884, 0.902, and 0.936, respectively. We submitted the following variables: miR-146a and miR-155 levels, BASDAI, ASDASCRP, ESR (mm/h), and CRP (mg/L) into multivariate logistic regression analysis, and results showed that higher levels of miR-146a (OR: 13.75, 95%CI: 1.32 to 143.57, p = .029), miR-155 (OR: 5.74, 95% CI: 1.63 to 20.20, p = .006), and ESR (OR: 1.08, 95% CI: 1.01 to 1.15, p = .022) were independent baseline predictors of ASAS40 response at 6-month anti-TNF-a treatment.

CONCLUSION

These findings obtained from the study suggest that high serum levels of miR-146a and miR-155 could aid in prediction of poor treatment outcomes after TNF-α blocking therapy.

Novel regulatory role of non-coding RNAs in ankylosing spondylitis

Ankylosing spondylitis (AS) is a type of arthritis that primarily affects the spine and involves disorders of the immune and skeletal systems. However, the exact pathogenesis of AS is not fully understood. Non-coding RNAs (ncRNAs), particularly, long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and micro RNAs (miRNAs) and their interactions have been shown to influence many biological processes such as inflammatory responses, osteogenic differentiation and apoptosis, pyroptosis, and proliferation. In addition, ncRNAs reflect the disease activity of AS. In this review, we discuss the regulatory roles of ncRNAs in AS cell functions (inflammatory responses, cellular osteogenic differentiation and apoptosis, pyroptosis, and proliferation) and their potential applications in AS diagnosis and treatment. Understanding the role of ncRNAs in the pathogenesis of AS will lay the foundation for exploring potential new therapeutic approaches for AS.

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.