Association between ankylosing spondylitis and the miR-146a and miR-499 polymorphisms

Challenges and promise of targeting miRNA in rheumatic diseases: a computational approach to identify miRNA association with cell types, cytokines, and disease mechanisms

MicroRNAs (miRNAs) are small non-coding RNAs that alter the expression of target genes at the post-transcriptional level, influencing diverse outcomes in metabolism, cell differentiation, proliferation, cell survival, and cell death. Dysregulated miRNA expression is implicated in various rheumatic conditions, including ankylosing spondylitis (AS), gout, juvenile idiopathic arthritis (JIA), osteoarthritis (OA), psoriatic arthritis, rheumatoid arthritis (RA), Sjogren's syndrome, systemic lupus erythematosus (SLE) and systemic sclerosis. For this review, we used an open-source programming language- PowerShell, to scan the massive number of existing primary research publications on PubMed on miRNAs in these nine diseases to identify and count unique co-occurrences of individual miRNAs and the disease name. These counts were used to rank the top seven most relevant immuno-miRs based on their research volume in each rheumatic disease. Individual miRNAs were also screened for publication with the names of immune cells, cytokines, and pathological processes involved in rheumatic diseases. These occurrences were tabulated into matrices to identify hotspots for research relevance. Based on this information, we summarize the basic and clinical findings for the top three miRNAs - miR-146, miR-155, and miR-21 - whose relevance spans across multiple rheumatic diseases. Furthermore, we highlight some unique miRNAs for each disease and why some rheumatic conditions lack research in this emerging epigenetics field. With the overwhelming number of publications on miRNAs in rheumatic diseases, this review serves as a 'relevance finder' to guide researchers in selecting miRNAs based on the compiled existing knowledge of their involvement in disease pathogenesis. This approach applies to other disease contexts with the end goal of developing miRNA-based therapeutics.

Rs3746444 T>C locus in miR-499 increases the susceptibility to hepatocellular carcinoma: A meta-analysis 14812 subjects

BACKGROUND

Recently, many investigations have suggested that the rs3746444 T>C locus in the microRNA (miR)-499 gene may contribute to the occurrence of cancer. However, reports on the association between rs3746444 and hepatocellular carcinoma (HCC) are conflicting.

AIM

To further understand and explore the potential correlation between the single-nucleotide polymorphism of rs3746444 and the incidence of HCC.

METHODS

In this meta-analysis, we obtained electronic literature by searching the PubMed, Embase and Chinese BioMedical Disc databases (through May 20, 2022). All eligible case-control, prospective cohort or nested case-control studies with sufficient data for calculating the odds ratios with their 95% confidence intervals were included.

RESULTS

Ultimately, a total of 17 independent studies were included. We identified that rs3746444 was associated with the development of HCC (C vs T: P = 0.019 and CC/CT vs TT: P = 0.016). In Asian individuals, rs3746444 was associated with susceptibility to HCC (C vs T: P = 0.013 and CC/CT vs TT: P = 0.016). In addition, this study identified that the miR-499 rs3746444 locus was associated with susceptibility to HCC in the normal/healthy control subgroup (C vs T: P = 0.034 and CC/CT vs TT: P = 0.024).

CONCLUSION

In summary, this meta-analysis highlights that rs3746444 in the miR-499 gene is involved in the occurrence of HCC, especially in Asian individuals.

Genetic variant in microRNA-146a gene is associated with risk of rheumatoid arthritis

OBJECTIVE

To investigated the association between single nucleotide polymorphisms (SNPs) in microRNA-146a (miR-146a) gene and susceptibility of rheumatoid arthritis (RA).

METHODS

We systemically extracted the genetic data of miR-146a from previous genome-wide association studies (GWASs) of RA. Subsequently, we performed a replication study in an independent Chinese cohort for selected variant. A meta-analysis combined the previous GWASs with the replication study was also conducted. The epigenetic annotation and cytokine assay were used for exploring potential variant function.

RESULTS

The extracted genetic association data from three previous GWASs showed that the allele T of functional SNP rs2431697 increased RA susceptibility. The significant association for the SNP was also found in the Chinese replication cohort (OR = 1.24, 95% CI = 1.06-1.46, p = 8.69E-03). The estimated effect size for this SNP was larger in Asian population than that in European population (Asian meta-analysis: OR = 1.15, 95% CI = 1.09-1.22, p = 4.37E-07; Tran-ethnic meta-analysis: OR = 1.07, 95% CI = 1.04-1.10, p = 1.79E-06). The cytokine assay also showed that the risk allele T of the SNP rs2431697 is inversely associated with plasma TNF-α levels in health controls (p = .016).

CONCLUSIONS

In summary, this study supports that genetic variant in miR-146a gene is associated with RA risk.KEY MESSAGESThe association between SNPs in miR-146a gene and susceptibility of RA was unclear.We investigated the genetic association using GWASs data and a replication study.The SNP rs2431697 in miR-146a gene is associated with RA risk.

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

Ankylosing spondylitis (AS) is a complex genetic disease characterized by axial skeletal inflammation. Available scientific evidence suggests that a relationship may exist between miRNA expression levels and the pathogenesis of AS. This study investigated the clinical diagnostic value of miR-146a, miR-15a, miR-20a, miR-125a-3p, miR-125a-5p, miR-125b-5p, miR-148a, miR-149a, miR-499, and miR-155a in AS. A total of 44 AS patients and 56 healthy controls (HCs) were included in the study. MiRNA expression levels were detected using fluorescence quantitative PCR (qPCR). Results showed that the expression levels of miR-146a, miR-125a-3p, miR-125a-5p, miR-125b-5p, and miR-155a decreased, whereas miR-499a expression increased significantly in AS patients compared to that in the controls. Logistic regression analysis with receiver operating characteristic (ROC) curves showed that combined miR-146a/miR-125a-5p/miR-125b-5p/miR-499a/miR-155a (area under curve [AUC] = 0.824, 95% confidence interval [CI] = 0.727-0.921) had high sensitivity and specificity for AS diagnosis. C-reactive protein (CRP) levels were positively correlated with the expression of miR-125a-5p (r_s = 0.438, p = 0.005) and miR-155a (r_s = 0.414, p = 0.006), which indicates that miR-125a-5p and miR-155a can perhaps aggravate AS-induced inflammation. Our findings suggest the association of miR-125a-5p and miR-155a with disease activity in AS patients. Furthermore, miR-146a, miR-125a-5p, miR-125b-5p, miR-499a, and miR-155a could have potential diagnostic value in AS.

Meta-Analysis of miRNA Variants Associated with Susceptibility to Autoimmune Disease

Purpose

Various studies have shown an association between miRNA polymorphisms and susceptibility to autoimmune disease (AD); however, the results are inconclusive. To evaluate whether miRNA polymorphisms account for a significant risk of AD, a total of 87 articles, including 39431 patients and 56708 controls, were identified to estimate their association with 12 AD subtypes.

Methods

Several electronic databases were searched to analyze population-based studies on the relationship between miRNA variants and AD risk. Fixed effects or random effect models were used in the meta-analysis for the risk assessment.

Results

In our meta-analysis, miR-146a rs2910164/rs57095329 conferred a marginally elevated risk for AD (allele model, OR = 1.08, 95% CI: 1.01-1.15, P = 0.019; allele model, OR = 1.09, 95 CI: 1.05-1.15, P < 0.001, respectively). Furthermore, miR-196a2 rs11614913 was also associated with AD risk (allele model, OR = 0.92, 95% CI: 0.88-0.97, P = 0.001) as well as miR-499 rs3746444 (allele model, OR = 1.16, 95% CI: 1.03-1.29, P = 0.011). In addition, associations were observed between miR-149 rs2292832/miR-27a rs895819 and AD susceptibility in the overall population (allele model, OR = 1.15, 95% CI: 1.06-1.24, P < 0.001; allele model, OR = 1.11, 95% CI:1.01-1.22, P = 0.043, respectively).

Conclusions

Evidence from our systematic review suggests that miR-146a, miR-196a2, miR-499, miR-149, and miR-27a polymorphisms are associated with susceptibility to AD.

Variants of MIRNA146A rs2910164 and MIRNA499 rs3746444 are associated with the development of cutaneous leishmaniasis caused by Leishmania guyanensis and with plasma chemokine IL-8

Leishmania are intracellular protozoan parasites that cause a wide spectrum of clinical manifestations in genetically susceptible individuals with an insufficient or balanced Th1 immune response to eliminate the parasite. MiRNAs play important regulatory role in numerous biological processes including essential cellular functions. miR146-a acts as an inhibitor of interleukin 1 receptor associated kinase 1 (IRAK1) and tumour necrosis factor (TNF) receptor associated factor 6 (TRAF6) present in the toll-like receptors pathway while miR499a modulates TGF-β and TNF signalling pathways. Here, we investigated whether MIRNA146A rs2910164 and MIRNA499 rs3746444 variants are associated with the development of L. guyanensis (Lg)-cutaneous leishmaniasis (CL). The variants MIR146A rs2910164 and MIR499A rs3746444 were assessed in 850 patients with Lg-CL and 891 healthy controls by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Plasma cytokines were measured using the BioPlex assay. Carriers of rs2910164 CC genotype have 30% higher odds of developing CL (ORadj_age/sex = 1.3 [95%CI 0.9–1.8]; Padj_age/sex 0.14) compared to individuals with the genotype GG (ORadj_age/sex = 0.77 [95%CI 0.56–1.0]; Padj_age/sex 0.14) if exposed to Lg-infection. Heterozygous GC individuals also showed lower odds of developing CL (ORadj_age/sex = 0.77 [95%CI 0.5–1.1]; Padj_age/sex 0.09). Homozygosity for the allele C is suggestive of an association with the development of Lg-CL among exposed individuals to Lg-infection. However, the odds of developing CL associated with the CC genotype was evident only in male individuals (OR_adjage = 1.3 [95% CI = 0.9–2.0]; P_adjage = 0.06). Individuals homozygous for the G allele tend to have higher plasma IL-8 and CCL5. Similarly, for the MIR499A rs3746444, an association with the G allele was only observed among male individuals (OR = 1.4 [1.0–1.9]; P = 0.009). In a dominant model, individuals with the G allele (GG-GA) when compared to the AA genotype reveals that carriers of the G allele have 40% elevated odds of developing Lg-CL (ORadj_age = 1.4 [1.1–1.9]). Individuals with the GG genotype have higher odds of developing Lg-CL (ORadj_age/sex = 2.0 [95%CI 0.83–5.0]; P_adjage = 0.01. Individuals homozygous for the G allele have higher plasma IL-8. Genetic combinations of both variants revealed that male individuals exposed to Lg bearing three or four susceptible alleles have higher odds of developing Lg-CL (OR = 2.3 [95% CI 1.0–4.7]; p = 0.017). Both MIR146A rs2910164 and MIR499A rs3746444 are associated with the development of Lg-CL and this association is prevalent in male individuals.

Leishmaniasis is caused by infection with Leishmania parasites. In regions with the presence of Leishmania parasites, all people do not develop the disease despite similar exposure. Only a proportion of inhabitants progress to the development of disease. Clinical manifestations depend on the vector and Leishmania species, as well the host genetic background and genetically determined immune responses. miRNAs play important roles in regulating gene expression and many biological processes including immune pathways. miR-146a targets TRAF6 and IRAK1 genes, that encode key adaptor molecules downstream of toll-like receptors (TLRs). TLRs are critical in immune response to Leishmania-infection. miR499-a modulates inflammation-related signalling pathways such as TGFβ, TNFα and TLR pathways. In this study, we showed that MIR146A and MIR499A variants are risk factors to developing cutaneous leishmaniasis caused by L. guyanensis in Amazonas state of Brazil. Individuals with these variants are susceptible to the development of CL.

MicroRNAs as Biomarkers for the Diagnosis of Ankylosing Spondylitis: A Systematic Review and Meta-Analysis

Background: Abnormal expression levels of microRNAs (miRNAs) were observed in ankylosing spondylitis (AS) in recent articles, suggesting that miRNAs may be used as biomarkers for AS diagnoses. In this paper, we conducted a meta-analysis to identify the overall diagnostic accuracy of miRNA biomarkers in AS patients.

Methods: An extensive search was undertaken in PubMed, Embase, Cochrane databases, and Wan Fang database up to 30 December 2020 using the following key words: (“microRNAs” or “microRNA” or “miRNA” or “miR” or “RNA, Micro” or “Primary MicroRNA”) and (“Spondylitis Ankylosing” or “Spondyloarthritis Ankylopoietica” or “Ankylosing Spondylarthritis” or “Ankylosing Spondylarthritides” or “Spondylarthritides Ankylosing” or “Ankylosing Spondylitis”) and (“blood” or “serum” or “plasma”). Statistical evaluation of dysregulated miRNAs using the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the area under the curve (AUC).

Results: Twenty-nine articles reporting on the miRNAs of AS were included. A total of 42 miRNAs were observed to be up-regulated and 45 miRNAs were down-regulated in the AS cases compared with the controls. Besides, 29 studies from nine articles were included in our meta-analysis. The pooled sensitivity, specificity, PLR, NLR, DOR, and AUC were 0. 76 (95% CI, 0.70–0.81), 0.80 (95% CI, 0.74–0.85), 3.75 (95% CI, 2.82–5.01), 0.30 (95% CI, 0.24–0.39), 12.32 (95% CI, 7.65–19.83), 0.85 (95% CI, 0.81–0.88), respectively, suggesting a good diagnostic accuracy of miRNAs for AS.

Conclusions: Circulating miRNAs are deregulated in AS patients. miRNAs may be used as a relatively non-invasive biomarkers for the detection of AS.

Genetics, Epigenetics, and Gender Impact in Axial-Spondyloarthritis Susceptibility: An Update on Genetic Polymorphisms and Their Sex Related Associations

Spondyloarthritis (SpA) is a group of chronic inflammatory rheumatic disease that can be divided into predominantly axial or predominantly peripheral involvement, with or without associated psoriasis, inflammatory bowel disease or previous infection. Axial SpA (axSpA) encompasses ankylosing spondylitis (AS) with radiological sacroiliitis, and a type without radiographic sacroiliitis, called “non-radiographic axial SpA” (nr-axSpA). Males and females show large differences in their susceptibility to SpA, such as distinctions in clinical patterns, phenotypes and in therapeutical response, particularly to TNF inhibitors (TNFi). Several studies indicate that AS women have doubled risk to failure TNFi compared with males. This diversity in drugs’ efficacy among women and men may be caused by differences in the balance of sex hormones and in gene-specific expression likely triggered by X-chromosome instability and gene-specific epigenetic modifications. Evidence reported that polymorphisms in microRNAs on X- and other chromosomes, such as miR-146a, miR-155, miR-125a-5p, miR-151a-3p and miR-22-3p, miR-199a-5p could be involved in the different clinical presentation of SpA, as well as disease activity. In addition, association with non−response to TNFi treatment and presence of IRAK3 and CHUCK genes in SpA patients was recently detected. Finally, polymorphisms in genes involved in IL-23/IL-17 pathway, such as in drug pharmacodynamics and pharmacokinetics may have a role in response to TNFi, IL17i, and IL23i. A major understanding of genomic variability could help in the development of new therapeutic targets or in taking advantages of different mechanisms of action of biological drugs. Moving from the multifactorial etiology of disease, the present review aims at evaluating genetic and epigenetic factors and their relationship with sex and bDMARDs response, helping to investigate the different expression among males and females of genes on X- and other chromosomes, as well as mi-RNA, to highlight relationships between sex and occurrence of specific phenotypes and symptoms of the disease. Moreover, the role of the epigenetic modification in relation to immune-regulatory mechanisms will be evaluated.

Altered expression of miR-142, miR-155, miR-499a and of their putative common target MDM2 in systemic lupus erythematosus

Aim: To evaluate genetic and expression variability of three miRNAs potentially involved in systemic lupus erythematosus (SLE) and to identify any miRNA's target gene. Materials & methods: Gene polymorphisms and expression levels of three miRNAs have been evaluated in a cohort of SLE patients and controls. Results: miR-142 and miR-499a were significantly down-expressed in patients (p = 0.005 and p = 0.02, respectively). A trend for down-expression of miR-155 was also observed (p = 0.07). The lower expression of miR-142 was associated with the rs2632516 polymorphism variant allele (p = 0.002). Predictive analyses identified a target gene common to the three miRNAs, MDM2, whose higher expression was seen in patients compared with controls (p = 0.03). Conclusion: The three miRNAs and MDM2 might be involved in SLE.

Human disease-associated single nucleotide polymorphism changes the orientation of DROSHA on pri-mir-146a

The Microprocessor complex of DROSHA and DGCR8 initiates the biosynthesis of microRNAs (miRNAs) by processing primary miRNAs (pri-miRNAs). The Microprocessor can be oriented on pri-miRNAs in opposite directions to generate productive and unproductive cleavages at their basal and apical junctions, respectively. However, only the productive cleavage gives rise to miRNAs. A single nucleotide polymorphism (SNP, rs2910164) in pri-mir-146a is associated with various human diseases. Although this SNP was found to reduce the expression of miRNA, it is still not known if it affects the activity of the Microprocessor directly, and how it functions. In this study, we revealed that the SNP creates an unexpected mGHG motif at the apical junction of pri-mir-146a. This mGHG motif interacts with the double-stranded RNA-binding domain (dsRBD) of DROSHA, switching its orientation on pri-mir-146a from the basal to the apical junction. As a result, the SNP facilitates Microprocessor to cleave SNP-pri-mir-146a at its unproductive sites. Our findings help to elucidate the molecular mechanism that explains how the disease-associated SNP modulates the biogenesis of pri-mir-146a and thereby affects its cellular functions.

Down-regulated miR-495 can target programmed cell death 10 in ankylosing spondylitis

Background

MicroRNAs (miRNAs) play crucial roles in regulating eukaryotic gene expression. Recent studies indicated that aberrantly expressed miRNAs are involved in the pathogenesis of ankylosing spondylitis (AS). Indeed, hsa-miR-495-3p (miR-495) has been reported as an anti-oncogene in different cancers. However, the role of miR-495 in AS is still unknown.

Methods

In this study, quantitative real-time polymerase chain reaction (PCR) was used to detect the expression of miR-495 in the peripheral blood mononuclear cells (PBMCs), whole blood, and serum of patients with AS. Bisulfite-specific PCR sequencing and methylated DNA immunoprecipitation were used to detect the methylation in the promoter region of miR-495. To determine the influence of miR-495 expression on the target gene, programmed cell death 10 (PDCD10), dual luciferase reporter assays together with an adenoviral vector containing the miR-495 locus were used. Receiver operating characteristic (ROC) curves were used to evaluate the efficacy of miR-495 as a diagnostic biomarker of AS. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway analysis, and western blotting were used to explore the potential role of miR-495 in AS pathogenesis and the mechanism by which it facilitates AS pathogenesis.

Results

miR-495 is down-regulated and the promoter region of miR-495 is highly methylated in AS. The expression of miR-495 is negatively associated with PDCD10 expression in both patients with AS and healthy controls. Further experiments showed that PDCD10 can be targeted by miR-495. The ROC curves of miR-495 suggested that it is a very specific and sensitive biomarker for AS diagnosis. Bioinformatics analysis and signal pathway studies indicated that miR-495 can down-regulate β-catenin and transforming growth factor-β1.

Conclusions

Our studies indicated that down-regulation of miR-495 can be used as a potential molecular marker for the diagnosis and treatment of AS, thus providing new insights into the role of miRNAs in AS pathology.

LncRNA MEG3 inhibits the inflammatory response of ankylosing spondylitis by targeting miR-146a

Ankylosing spondylitis (AS) is a progressive systemic disease characterized by chronic inflammation response of the sacroiliac joint and spine. Long non-coding RNAs (lncRNAs) are widely involved in the regulation of various diseases. However, the role of lncRNA maternally expressed gene 3 (MEG3) in the inflammatory response of AS has not been studied. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory cytokines interleukin-1β (IL-1β) and interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in tissues and cells. The expression levels of MEG3, microRNA-146a (miR-146a), and inflammatory cytokines were measured by quantitative real-time PCR (qRT-PCR). Correlation between MEG3 or miR-146a and inflammatory cytokines was analyzed by Pearson analysis. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to clarify the interaction between MEG3 and miR-146a. MEG3 was downregulated in AS patients, negatively correlated with the levels of IL-1β, IL-6, and TNF-α, and blocked the inflammatory response of AS. MiR-146a was upregulated in AS patients and could interact with MEG3. The expression of miR-146a was positively correlated with IL-1β, IL-6, and TNF-α levels. Overexpression of miR-146a reversed the inhibitory effect of abnormal MEG3 expression on inflammatory cytokines. LncRNA MEG3 plays an anti-inflammatory role in AS partially through targeting miR-146a, which provides a potential new means for the treatment of AS patients.

Association of microRNAs genes polymorphisms with arthritis: a systematic review and meta-analysis

Objective: To investigate whether microRNAs genes’ polymorphisms are associated with arthritis. Methods: The PubMed, Cochrane Library et al. were systematically searched to identify case–control studies, systematic reviews and meta-analyses. A meta-analysis was performed to calculate odds ratios (ORs), and confidence intervals (CIs) at 95% using fixed-effect model or random-effects model. Results: Twenty-two case–control studies involving 10489 participants fulfilled the inclusion criteria. MiR-146a rs2910164 (G/C) was not significantly associated with the risk of rheumatoid arthritis (RA) in any model. Significant associations were found between miR-146a rs2910164 (G/C) and the risk of psoriatic arthritis (PsA) in the heterozygous model and the dominant model. The heterozygous model showed a significant association between the miR-146a rs2910164 (G/C) polymorphism and ankylosing spondylitis (AS). And there was no significant association of miR-146a rs2910164 (G/C) with risk of juvenile rheumatoid arthritis (JRA) at any model. Additionally, there was a significant association of miR-499 rs3746444 (T/C) with risk of RA at two genetic models, and with a moderate heterogeneity. When subgroup analysis by ethnicity, significant associations were almost found between miR-499 rs3746444 (T/C) and the risk of RA in any model in Caucasian populations, and there is no heterogeneity. Conclusions: The association of miR-146a rs2910164 (G/C) with RA was not found. And there was a significant association between miR-146a rs2910164(G/C) and PsA or AS. MiR-499 rs3746444 (T/C) was associated with RA in Caucasian populations. These findings did not support the genetic association between miR-146a rs2910164 (G/C) and JRA susceptibility, as well as the association of miR-196a-2 rs11614913 (C/T), miR-146a rs2431697, miR-146a rs57095329, miR-149 rs22928323 with arthritis.

Noncoding RNAs Involved in the Pathogenesis of Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a form of arthritis that can lead to fusion of vertebrae and sacroiliac joints following syndesmophyte formation. The etiology of this painful disease remains poorly defined due to its complex genetic background. There are no commonly accepted methods for early diagnosis of AS, nor are there any effective or efficient clinical treatments. Several noncoding RNAs (ncRNAs) have been linked to AS pathogenesis and inflammation via selective binding of their downstream targets. However, major gaps in knowledge remain to be filled before such findings can be translated into clinical treatments for AS. In this review, we outline recent findings that demonstrate essential roles of ncRNAs in AS mediated via multiple signaling pathways such as the Wnt, transforming growth factor-β/bone morphogenetic protein, inflammatory, T-cell prosurvival, and nuclear factor-κB pathways. The summary of these findings provides insight into the molecular mechanisms by which ncRNAs can be targeted for AS diagnosis and the development of therapeutic drugs against a variety of autoimmune diseases.

Single nucleotide polymorphism rs3746444 in miR‑499a affects susceptibility to non‑small cell lung carcinoma by regulating the expression of CD200

The present study evaluated the association between single nucleotide polymorphism (SNP) rs3746444 and the risk of non‑small cell lung carcinoma (NSCLC) in a Chinese population. Computational analyses and luciferase assays were performed to investigate the regulatory relationship between miR‑499a and CD200. In addition, reverse transcription‑quantitative polymerase chain reaction and western blot assays were performed to examine the effect of rs3746444 on the expression of miR‑499a and CD200. The results demonstrated a significant difference in the smoking history of patients carrying malignant pulmonary nodules and those carrying benign pulmonary nodules. Furthermore, CD200 was demonstrated to be a direct target of miR‑499a, and a miR‑499a binding site was located in the 3'UTR of CD200. Notably, the levels of miR‑499a in malignant pulmonary nodules were higher compared with benign pulmonary nodules, while the levels of CD200 were higher in benign pulmonary nodules compared with malignant pulmonary nodules. In addition, the subjects carrying the AA genotype of SNP rs3746444 exhibited upregulated miR‑499a expression and reduced CD200 expression, compared with the subjects carrying AG and GG genotypes. These findings indicate that the SNP rs3746444 in miR‑499a could affect the prognosis of NSCLC patients by regulating the expression of CD200.

Association of CD14 and macrophage migration inhibitory factor gene polymorphisms with inflammatory microRNAs expression levels in ankylosing spondylitis and polyarthralgia

This study aimed to investigate the genetic basis of ankylosing spondylitis (AS) and polyarthralgia (PA) conditions among Indian subjects through genotyping two immune regulatory genes CD14 (-159C>T) and MIF (-173G>C) and find their association with the expression levels of three circulating inflammatory miRNAs. This investigation may provide early genetic cause of these two forms of arthritis and more optimal biological targets to predict early therapeutic outcomes. A total of 140 patients (AS: 70 and PA: 70) and 156 controls were recruited from Indian population. CD14 and MIF genotyping was performed using ARMS-PCR. Expression level of three inflammatory miRNAs (miRNA-146a, miRNA-155 and miRNA-181) was quantified using RT-qPCR. C/T genotype of CD14 gene was found to cause 2.06-fold risk of developing AS (CI 1.06-5.98, p = .04) as compared to others and G/C genotype in MIF also shown significant variation between AS and control subjects. In PA subjects, CD14 genotypes (C/T) was found to be associated with disease susceptibility and G/C genotype of MIF gene polymorphism showed 4.71-fold risk of developing PA (CI 2.58-8.62, p = .0001). The study also revealed significant upregulation of miRNA-155 expression in AS subjects (p = .0001) with more than 1.3-fold difference between AS and PA as compared to the control subjects. miRNA-155 had strong association with AS patients with CD14 genotypes (p < .05) than PA and control subjects. This study provides better understanding of the mechanisms and disease susceptibility for MIF and CD14 genetic variants and inflammatory miRNAs networks involved in AS and PA.

Polymorphisms in miRNA genes and their involvement in autoimmune diseases susceptibility

MicroRNAs (miRNAs) are small non-coding RNA molecules that negatively regulate the expression of multiple protein-encoding genes at the post-transcriptional level. MicroRNAs are involved in different pathways, such as cellular proliferation and differentiation, signal transduction and inflammation, and play crucial roles in the development of several diseases, such as cancer, diabetes, and cardiovascular diseases. They have recently been recognized to play a role also in the pathogenesis of autoimmune diseases. Although the majority of studies are focused on miRNA expression profiles investigation, a growing number of studies have been investigating the role of polymorphisms in miRNA genes in the autoimmune diseases development. Indeed, polymorphisms affecting the miRNA genes can modify the set of targets they regulate or the maturation efficiency. This review is aimed to give an overview about the available studies that have investigated the association of miRNA gene polymorphisms with the susceptibility to various autoimmune diseases and to their clinical phenotypes.

MicroRNA implications in the etiopathogenesis of ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic immune-mediated inflammatory disease that affects both axial and peripheral skeletons as well as soft tissues. Recent investigations offer that disease pathogenesis is ascribed to a complex interplay of genetic, environmental, and immunological factors. Until now, there is no appropriate method for early diagnosis of AS and the successful available therapy for AS patients stay largely undefined. MicroRNAs (miRNAs), endogenous small noncoding RNAs controlling the functions of target mRNAs and cellular processes, are present in human plasma in a stable form and have appeared as possible biomarkers for activity, pathogenesis, and prognosis of the disease. In the present review, we have tried to summarize the recent findings related to miRNAs in AS development and discuss the possible utilization of these molecules as prognostic biomarkers or important therapeutic strategies for AS. Further examinations are needed to determine the unique miRNAs signatures in AS and characterize the mechanisms mediated by miRNAs in the pathology of this disease.

MicroRNA-146a knockdown suppresses the progression of ankylosing spondylitis by targeting dickkopf 1

Ankylosing spondylitis (AS) seriously threatens healthy and life quality of patients, however, there is no extremely effective drug to cure the disease. Therefore, it is urgent to understand molecular basis in the progression of AS. MicroRNA-146a (miR-146a) has been demonstrated to be associated with the development of AS. However, its molecular mechanism has not been fully established. In this study, it is found that the expression levels of miR-146a and dickkopf 1 (DKK1) were respectively upregulated and downregulated in hip capsule tissues of AS patients. Moreover, a negative correlation was displayed between miR-146a and DKK1 expression. Functional analysis revealed that miR-146a inhibitor restrained cell proliferation and osteogenic potential as well as enhanced apoptosis in AS fibroblasts, while miR-146a overexpression enhanced proliferation and osteogenic potential of AS fibroblasts. Bioinformatics analysis, dual luciferase reporter assays, qRT-PCR and immunoblotting assays revealed that miR-146a inhibited DKK1 expression by directly targeting 3'UTR region of DKK1. Mechanism studies further revealed that loss of DKK1 partly reversed the effect of miR-146a inhibitor on cell proliferation, apoptosis and osteogenic potential in AS fibroblasts. Taken together, our finding revealed that miR-146a knockdown hindered AS progression partially by regulating target DKK1 expression, offering a potential therapy application for AS patients.

Genetic variations in LIGHT are associated with susceptibility to ankylosing spondylitis in a Chinese Han population

Ankylosing spondylitis (AS) is a common chronic autoimmune disease characterized by inflammation of axial skeleton and has strong genetic susceptibility. Single nucleotide polymorphisms (SNPs) have been found playing an important role in the development of AS. This study intends to explore whether the susceptibility to AS is associated with rs2171513 C>T, rs1077667 G>A in LIGHT (lymphotoxin, expressed on T lymphocytes) and rs12609318 A>G in B and T lymphocyte attenuator (BTLA) in a Chinese Han population. We studied a total of 497 AS patients and 387 healthy controls in the current research. Clinical characteristics were recorded when they were recruited. Single nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction (PCR) and high-resolution melting methods (HRM). Statistically significant difference was found in both co-dominant model (GG vs. GA vs. AA) (p = 4.00E-06) and alleles (p = 4.59E-08) of rs1077667 between patients and controls. There was also a significant difference in alleles of rs2171513 (p = 0.037) between patients and controls. We found rs1077667 in LIGHT and rs2171513 in BTLA with susceptibility to AS, while 12609318 in LIGHT associate with susceptibility to AS. Our results showed that LIGHT might be involved in pathogenesis of AS.

Association between circulating miRNAs and spinal involvement in patients with axial spondyloarthritis

OBJECTIVES

Dysregulation of miRNAs and their target genes contributes to the pathophysiology of autoimmune diseases. Circulating miRNAs may serve as diagnostic/prognostic biomarkers. We aimed to investigate the association between circulating miRNAs, disease activity and spinal involvement in patients with axial spondyloarthritis (AxSpA).

METHODS

Total RNA was isolated from the plasma of patients with non-radiographic (nr)AxSpA, patients with ankylosing spondylitis (AS) and healthy controls (HC) via phenol-chloroform extraction. A total of 760 miRNAs were analysed with TaqMan® Low Density Arrays, and the expression of 21 miRNAs was assessed using single assays.

RESULTS

Comprehensive analysis demonstrated the differential expression of miRNAs among patients with progressive spinal disease. Of the 21 miRNAs selected according to their expression patterns, the levels of miR-625-3p were significantly different between nr-AxSpA patients and HCs. We found no correlation between miRNA levels and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) in nr-AxSpA patients. Selected miRNAs, such as miR-29a-3p, miR-146a-5p or miR-222-3p with an established role in extracellular matrix formation and inflammation were associated with spinal changes and/or disease activity assessed by BASDAI in AS patients, including miR-625-3p reflecting disease activity in AS with spinal involvement.

CONCLUSIONS

Our data indicate that circulating miRNAs play a role in the pathogenesis of AxSpA and are also suggestive of their potential as biomarkers of disease progression. We hypothesize that differential systemic levels of miRNA expression reflect miRNA dysregulation at sites of spinal inflammation or bone formation where these molecules contribute to the development of pathophysiological features typical of AxSpA.

Structure and functional impact of seed region variant in MIR-499 gene family in bronchial asthma

BACKGROUND

Small non-coding RNAs (microRNAs) have been evolved to master numerous cellular processes. Genetic variants within microRNA seed region might influence microRNA biogenesis and function. The study aimed at determining the role of microRNA-499 (MIR-499) gene family polymorphism as a marker for susceptibility and progression of bronchial asthma and to analyze the structural and functional impact of rs3746444 within the seed region.

METHODS

Genotyping for 192 participants (96 patients and 96 controls) in the discovery phase and 319 subjects (115 patients and 204 controls) in the replication phase was performed via Real Time-Polymerase Chain Reaction technology. Patients underwent the methacholine challenge test and biochemical analysis. Gene structural and functional analysis, target prediction, annotation clustering, and pathway enrichment analysis were executed. Predicted functional effect of rs37464443 SNP was analyzed.

RESULTS

miR-499 gene family is highly implicated in inflammation-related signaling pathways. Rs374644 (A > G) in MIR499A and MIR499B within the seed region could disrupt target genes and create new genes. The G variant was associated with high risk of developing asthma under all genetic association models (G versus A: OR = 3.27, 95% CI = 2.53-4.22; GG versus AA: OR = 9.52, 95% CI = 5.61-16.5; AG versus AA: OR = 2.13, 95% CI = 1.24-3.46; GG + AG versus AA: OR = 4.43, 95% CI = 2.88-6.82). GG genotype was associated with poor pre-bronchodilator FEV1 (p = 0.047) and the worst bronchodilator response after Salbutamol inhalation, represented in low peaked expiratory flow rate (p = 0.035).

CONCLUSIONS

miR-499 rs3746444 (A > G) polymorphism was associated with asthma susceptibility and bronchodilator response in Egyptian children and adolescents. Further functional analysis is warranted to develop more specific theranostic agents for selecting targeted therapy.

Expression levels of the microRNA maturing microprocessor complex components; Drosha, Dicer, and DGCR8 in PBMCs from ankylosing spondylitis patients

Objective/Aim:

Two major enzymes in the microRNA maturation process, Dicer and Drosha, as well as DGCR8, the assistant of Drosha, function in the microprocessor complex. In this survey, the mRNA expression profiles of Drosha, Dicer, and DGCR8 in peripheral blood mononuclear cells (PBMCs) from ankylosing spondylitis (AS) patients and healthy controls were measured

Methods:

Forty patients with AS and 40 age and gender matched healthy individuals were included in the study. PBMCs were separated, total RNA content of the cells was isolated, and first strand cDNA was synthesized. Quantitative analysis was performed through real-time PCR using the SYBR Green gene expression master mix.

Results:

AS cases expressed the Drosha mRNA almost equal to that of healthy controls (Fold Change= −0.94; P= 0.200). However, both Dicer and DGCR8 mRNA expressions were downregulated in patients relative to healthy subjects (Fold Change= −0.54 and −0.60; P= 0.002 and 0.004, respectively).

Conclusion:

Our results suggest that downregulation of miRNA maturation components, namely Dicer and DGCR8 may be contributing in the pathogenesis procedure of AS.

Significance of Polymorphism and Expression of miR-146a and NFkB1 Genetic Variants in Patients with Rheumatoid Arthritis

MicroRNA-146a (miR-146a) has been shown to play an important role in the regulation of inflammatory innate immune responses, and found to be differentially expressed in rheumatoid arthritis (RA). Through NF-κB pathway, this molecule is able to stimulate the release of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-17. It has been also suggested that single-nucleotide polymorphisms (SNPs) in miRNA sequences may alter miRNA expression and that miR-146a rs2910164 SNP may contribute to RA development. These observations prompted us to analyze the potential associations between the miR-146a-3p (rs2910164, G > C) and NFkB1 (rs28362491, ins/del ATTG) polymorphisms and miR-146a-5p expression in patients’ sera in relation to clinical outcome of the treatment as well as predisposition to RA. Genotyping was performed in 111 patients and 130 healthy individuals while 16 controls and 13 RA patients (before and after three months of therapy with TNF-α inhibitors (TNFi)) were studied for the circulating miR-146a-5p serum expression level. Patients carrying the NFkB1 ins/ins genotype were characterized by worse response to TNFi treatment (p = 0.023). In patients, before TNFi therapy, expression levels of miR-146a-5p were less (0.422 ± 0.171) as compared to those detected after three months of treatment (1.809 ± 0.658, p = 0.033) and observed for healthy controls (5.302 ± 2.112, p = 0.048). Moreover, patients with higher circulating miR-146a-5p levels after three months of TNFi administration were more frequently carrying the rs2910164-C allele (p = 0.032). These results support the hypothesis that miR-146a might be involved in pathogenesis of RA and imply that miR-146a-3p polymorphism may be associated with miR-146a-5p levels in serum after anti-TNF-α treatment.

Association between the three functional miR-146a single-nucleotide polymorphisms, rs2910164, rs57095329, and rs2431697, and autoimmune disease susceptibility: A meta-analysis

Studies suggest associations between the miR-146a single nucleotide polymorphisms (SNPs) and susceptibility to autoimmune diseases. However, the results are inconsistent and inconclusive. Therefore, the aim of this study was to arrive at a conclusion about the association between the three functional miR-146a SNPs and autoimmune disease risk. Studies were identified through PubMed/MEDLINE searches for studies published up to January 2016 using as keywords rs2910164, rs57095329, rs2431697, and miR-146a polymorphisms. Thirty studies were included in the meta-analysis. The SNP rs2910164 G > C was found to be associated with increased risk of multiple sclerosis (CC + CG versus GG, OR = 1.25, 95% CI: 1.01-1.55), with decreased risks of psoriasis (C versus G, OR = 0.81, 95% CI: 0.69-0.96; CC versus GC + GG, OR = 0.73, 95% CI: 0.56-0.94), Behcet's disease (CC versus GC + GG, OR = 0.60, 95% CI: 0.50-0.73), asthma (C versus G, OR = 0.80, 95% CI: 0.69-0.93; CC versus GC + GG, OR = 0.65, 95% CI: 0.48-0.86), and uveitis (CC + CG versus GG, OR = 0.61, 95% CI: 0.49-0.77). The SNP rs2431697 C > T was found to be associated with an increased risk of SLE (T versus C, OR = 1.26, 95% CI: 1.15-1.38; TC + TT versus CC, OR = 1.28, 95% CI: 1.03-1.58; TT versus TC + CC, OR = 1.40, 95% CI: 1.21-1.62). The SNP rs57095329 A > G was found to be associated with an increased risk of SLE (G versus C, OR = 1.25, 95% CI: 1.17-1.35). The miR-146a SNPs rs2910164, rs57095329, rs2431697 are associated with susceptibility to certain autoimmune diseases. However, for other autoimmune diseases, they may be protective or insignificant.

The Role of MicroRNAS in Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a common and genetically heterozygous inflammatory rheumatic disease characterized by new bone formation, ankylosis and inflammation of hip, sacroiliac joints and spine. Until now, there is no method for early diagnosis of AS and the effective treatment available for AS patients remain largely undefined.We searched articles indexed in PubMed (MEDLINE) database using Medical Subject Heading (MeSH) or Title/Abstract words ("microRNA" and "ankylosing spondylitis") from inception up to November 2015.Genetic polymorphisms of miRNAs and their targets might alter the risk of AS development whereas certain miRNAs exhibit correlation with inflammatory index.Let-7i and miR-124 were upregulated whereas miR-130a was downregulated in circulating immune cells of AS patients. These deregulated miRNAs could modulate key immune cell functions, such as cytokine response and T-cell survival.miRNA deregulation is key to AS pathogenesis. However, clinical utilization of miRNAs for management of AS patients requires further support from future translational studies.

Common MIR146A Polymorphisms in Chinese Ankylosing Spondylitis Subjects and Controls

Common polymorphisms of microRNA gene MIR146A were reported as associated with different autoimmune diseases, include systemic lupus erythematosus, psoriatic arthritis, asthma and ankylosing spondylitis. In this study we investigated MIR146A SNPs in Chinese people with ankylosing spondylitis. Three common SNPs: rs2910164, rs2431697 and rs57095329 were selected and genotyped in 611 patients and 617 controls. We found no association between these SNPs and ankylosing spondylitis in our samples.