Association study of single nucleotide polymorphisms in pre-miRNA and rheumatoid arthritis in a Han Chinese population

Association analysis of miRNA-146a and miRNA-499 polymorphisms with rheumatoid arthritis: a case-control and trio-family study

Single nucleotide polymorphism is known to alter the expression and processing of miRNAs leading to a variety of diseases including rheumatoid arthritis (RA). However, disagreement is present up to date regarding the association of miRNA-146a and miRNA-499 polymorphisms with RA. The goal of this study was to assess the association of polymorphisms at miRNA-146a and miRNA-499 with the pathogenesis of RA in patients originating from Pakistan. Initially, eleven hundred subjects (1100) comprises of 550 RA patients and 550 healthy controls were investigated in the case-control analysis. Spectrophotometric measurement of lipids and C-reactive protein was used, whereas interleukin-1 receptor associated kinase-1 and TNF-receptor associated factor-6 values were quantified by an enzyme-linked immunosorbent assay. Secondly, heritability of susceptible alleles was tested from 70 trio-families. The miRNA-146a rs2910164 and miRNA-499 rs3746444 polymorphisms were genotyped using the polymerase chain reaction followed by restriction digestion. A Significant association of miRNA-146a and miRNA-499 genotypes was observed with RA patients (P < 0.05, respectively). The miRNA-146a rs2910164 G (OR = 1.4, P < 0.05) and miRNA-499 rs3746444 C (OR = 1.6, P < 0.0001) allele was significantly associated with RA in comparison with controls, respectively. Besides, the transmission analysis revealed a significant (P < 0.05) inheritance of rs2910164 G and rs3746444 C allele from parents to affected offspring. The current research concludes that miRNA-146a (rs2910164; C > G) and miRNA-499 (rs3746444; T > C) polymorphisms are linked to RA in the population studied. Furthermore, it was demonstrated for the first time in our high-risk cohort that the rs2910164 G and rs3746444 C allele was strongly related to familial RA.

Associations of miRNA-146a and miRNA-223 with Rheumatoid Arthritis and Their Predictive Values

Purpose

To analyze the independent associations of miRNA-146a and miRNA-223 with rheumatoid arthritis (RA) and evaluate their predictive values for RA.

Patients and Methods

A total of 68 RA patients were selected as cases, and meanwhile 68 patients with a traumatic knee condition were selected as controls by matching to the cases according to sex and age at the ratio of 1:1. The independent associations of miRNA-146a and miRNA-223 with RA were identified by binary logistic regression analysis. Receiver operating characteristic (ROC) curve was used to evaluate their predictive values for RA.

Results

MiRNA-146a and miRNA-223 expression levels in both synovial tissues and serums were statistically higher in cases than in controls, and their expression levels in serums were not statistically different from those in synovial tissues in both cases and controls. The expression levels of miRNA-146a and miRNA-223 in synovial tissues were independently associated with RA, as well as the expression levels of miRNA-146a and miRNA-223 in serums. The area under curve (AUC) of combination of miRNA-146a and miRNA-223 in synovial tissues for the prediction of RA was 0.910 [95% confidence interval (CI): 0.863-0.962], and the AUC of combination of miRNA-146a and miRNA-223 in serums was 0.904 (95% CI: 0.851-0.957). Their difference was not statistically significant (P=0.873), but the AUC of combination prediction was statistically higher than those of individual predictions (synovial tissues: 0.910 vs 0.773, P=0.005, 0.910 vs 0.788, P=0.009; serums: 0.904 vs 0.766, P=0.005, 0.904 vs 0.784, P=0.011).

Conclusion

MiRNA-146a and miRNA-223 in both synovial tissues and serums could be applied in predicting RA, and their combination could elevate the predictive value significantly.

A genetic study of the association of six polymorphisms with rheumatoid arthritis in the Egyptian population

Background

Rheumatoid arthritis (RA) is an autoimmune disease in which the immune system attacks the tissues of the joints by mistake. Different factors—either genetic or environmental—affect the development of the RA disease in patients. A lot of studies aimed to examine the genetic associations with this disease in different populations. This research aspires to perform a genetic association study between six single-nucleotide polymorphisms (SNPs) and RA disease in the Egyptian population with 49 controls and 52 patients. The SNPs that are included in this study are MIR146A rs2910164 (C:G), MIR499/MIR499A rs3746444 (T:C), MTMR3 rs12537(C:T), MIR155HG rs767649 (A:T), IRAK1 rs3027898 (A:C) and PADI4 rs1748033 (C:T).

Methods

Real-time PCR with TaqMan allelic discrimination assay were both used to perform the genotyping. The Odds ratio models with 95% confidence interval were used to test the associations. The used models are multiplicative, recessive, dominant and co-dominant.

Result

The demonstrated results indicated that rs2910164 and rs12537 were associated with RA, while rs3746444 showed no association in all the tested models. The remaining SNPs were excluded as they didn't pass the Hardy–Weinberg equilibrium test.

Conclusion

The MIR146A and MTMR3 polymorphisms showed susceptibility to RA. Moreover, MIR499/MIR499A had no role in the disease.

Association between miRNA-499 gene polymorphism and autoimmune diseases: A meta-analysis

Introduction

The association between miRNA-499 rs3746444 and a variety of autoimmune diseases has been reported. However, these results were contradictory and just focused on one or two autoimmune diseases. The present study aims to examine the possible association between rs3746444 polymorphism and the risk of autoimmune diseases.

Methods

The studies that evaluated the association between miRNA-499 gene polymorphism and autoimmune diseases were retrieved. Five different genetic models were used to evaluate the association. The random-effects model was used to pool the effect sizes. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the associations. Stratification analyses were performed by ethnicity and type of autoimmune diseases. False-positive report probability (FPRP) was performed for determining noteworthy associations.

Results

Seventeen articles (twenty studies) involving 4,376 cases and 4,991 controls were identified and included in our meta-analysis. The pooled ORs of all eligible case-control studies indicated a significant association between miRNA-499 gene polymorphism and autoimmune diseases: (T vs. C: OR = 0.877; 95% CI: 0.774, 0.993; P = 0.039). Stratified analysis indicated a significant association across both Caucasian (TT vs. TC+CC: OR = 0.779; 95% CI: 0.622, 0.976; P = 0.030) and Asian (T vs. C: OR = 0.895; 95% CI: 0.808, 0.992; P = 0.035) populations. There was also a significant association in Behcet’s disease, rheumatoid arthritis, systemic lupus erythematosus, and ulcerative colitis populations.

Conclusions

Our meta-analysis suggested that the miRNA-499 rs3746444 polymorphism was associated with an elevated risk of autoimmune diseases in the overall analysis as well as Caucasian and Asian populations.

MicroRNA-Mediated Epigenetic Regulation of Rheumatoid Arthritis Susceptibility and Pathogenesis

MicroRNAs (miRNAs) play crucial roles in regulating the transcriptome and development of rheumatoid arthritis (RA). Currently, a comprehensive map illustrating how miRNAs regulate transcripts, pathways, immune system differentiation, and their interactions with terminal cells such as fibroblast-like synoviocytes (FLS), immune-cells, osteoblasts, and osteoclasts are still laking. In this review, we summarize the roles of miRNAs in the susceptibility, pathogenesis, diagnosis, therapeutic intervention, and prognosis of RA. Numerous miRNAs are abnormally expressed in cells involved in RA and regulate target genes and pathways, including NF-κB, Fas-FasL, JAK-STAT, and mTOR pathways. We outline how functional genetic variants of miR-499 and miR-146a partly explain susceptibility to RA. By regulating gene expression, miRNAs affect T cell differentiation into diverse cell types, including Th17 and Treg cells, thus constituting promising gene therapy targets to modulate the immune system in RA. We summarize the diagnostic and prognostic potential of blood-circulating and cell-free miRNAs, highlighting the opportunity to combine these miRNAs with antibodies to cyclic citrullinated peptide (ACCP) to allow accurate diagnosis and prognosis, particularly for seronegative patients. Furthermore, we review the evidence implicating miRNAs as promising biomarkers of efficiency and response of, and resistance to, disease-modifying anti-rheumatic drugs and immunotherapy. Finally, we discuss the autotherapeutic effect of miRNA intervention as a step toward the development of miRNA-based anti-RA drugs. Collectively, the current evidence supports miRNAs as interesting targets to better understand the pathogenetic mechanisms of RA and design more efficient therapeutic interventions.

MicroRNA Variants and HLA-miRNA Interactions are Novel Rheumatoid Arthritis Susceptibility Factors

Genome-wide association studies have identified >100 genetic risk factors for rheumatoid arthritis. However, the reported genetic variants could only explain less than 40% heritability of rheumatoid arthritis. The majority of the heritability is still missing and needs to be identified with more studies with different approaches and populations. In order to identify novel function SNPs to explain missing heritability and reveal novel mechanism pathogenesis of rheumatoid arthritis, 4 HLA SNPs (HLA-DRB1, HLA-DRB9, HLA-DQB1, and TNFAIP3) and 225 common SNPs located in miRNA, which might influence the miRNA target binding or pre-miRNA stability, were genotyped in 1,607 rheumatoid arthritis and 1,580 matched normal individuals. We identified 2 novel SNPs as significantly associated with rheumatoid arthritis including rs1414273 (miR-548ac, OR = 0.84, p = 8.26 × 10^-4) and rs2620381 (miR-627, OR = 0.77, p = 2.55 × 10^-3). We also identified that rs5997893 (miR-3928) showed significant epistasis effect with rs4947332 (HLA-DRB1, OR = 4.23, p = 0.04) and rs2967897 (miR-5695) with rs7752903 (TNFAIP3, OR = 4.43, p = 0.03). In addition, we found that individuals who carried 8 risk alleles showed 15.38 (95%CI: 4.69-50.49, p < 1.0 × 10^-6) times more risk of being affected by RA. Finally, we demonstrated that the targets of the significant miRNAs showed enrichment in immune related genes (p = 2.0 × 10^-5) and FDA approved drug target genes (p = 0.014). Overall, 6 novel miRNA SNPs including rs1414273 (miR-548ac, p = 8.26 × 10^-4), rs2620381 (miR-627, p = 2.55 × 10^-3), rs4285314 (miR-3135b, p = 1.10 × 10^-13), rs28477407 (miR-4308, p = 3.44 × 10^-5), rs5997893 (miR-3928, p = 5.9 × 10^-3) and rs45596840 (miR-4482, p = 6.6 × 10^-3) were confirmed to be significantly associated with RA in a Chinese population. Our study suggests that miRNAs might be interesting targets to accelerate understanding of the pathogenesis and drug development for rheumatoid arthritis.

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.

Association of miR-499 Polymorphism and Its Regulatory Networks with Hashimoto Thyroiditis Susceptibility: A Population-Based Case-Control Study

Hashimoto thyroiditis (HT) is a common autoimmune disorder with a strong genetic background. Several genetic factors have been suggested, yet numerous genetic contributors remain to be fully understood in HT pathogenesis. MicroRNAs (miRs) are gene expression regulators critically involved in biological processes, of which polymorphisms can alter their function, leading to pathologic conditions, including autoimmune diseases. We examined whether miR-499 rs3746444 polymorphism is associated with susceptibility to HT in an Iranian subpopulation. Furthermore, we investigated the potential interacting regulatory network of the miR-499. This case-control study included 150 HT patients and 152 healthy subjects. Genotyping of rs3746444 was performed by the PCR-RFLP method. Also, target genomic sites of the polymorphism were predicted using bioinformatics. Our results showed that miR-499 rs3746444 was positively associated with HT risk in heterozygous (OR = 3.32, 95%CI = 2.00–5.53, p < 0.001, CT vs. TT), homozygous (OR = 2.81, 95%CI = 1.30–6.10, p = 0.014, CC vs. TT), dominant (OR = 3.22, 95%CI = 1.97–5.25, p < 0.001, CT + CC vs. TT), overdominant (OR = 2.57, 95%CI = 1.62–4.09, p < 0.001, CC + TT vs. CT), and allelic (OR = 1.92, 95%CI = 1.37–2.69, p < 0.001, C vs. T) models. Mapping predicted target genes of miR-499 on tissue-specific-, co-expression-, and miR-TF networks indicated that main hub-driver nodes are implicated in regulating immune system functions, including immunorecognition and complement activity. We demonstrated that miR-499 rs3746444 is linked to HT susceptibility in our population. However, predicted regulatory networks revealed that this polymorphism is contributing to the regulation of immune system pathways.

Meta-analysis of association of microRNAs genetic variants with susceptibility to rheumatoid arthritis and systemic lupus erythematosus

BACKGROUND

An increasing body of studies has investigated that genetic polymorphisms in microRNA (miRNA) may be related to susceptibility to rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). However, some results remain controversial. Thus, a meta-analysis was embarked on assessing whether some miRNA polymorphisms are associated with the risk of RA and SLE.

METHODS

Relevant studies were acquired on PubMed, Web of Science, Cochrane Library, CNKI, and Embase electronic databases from inception to December 2019. The strength of the association of miRNA polymorphisms with the risk of RA and SLE was assessed by odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Eligible 20 articles (36 studies) involving 5 miRNAs were enrolled in the meta-analysis. For RA, the polled result showed that there was no significant relationship between miR-146a rs2910164 and RA, but subgroup analysis based on ethnicity demonstrated that CC genotype may be a genetic protect factor for RA in Caucasians (CC vs CG+GG, OR = 0.825, 95% CI: 0.684-0.996, Pz = .045, Ph = .166). Besides, statistical significance of miR-499 rs3746444 (T/C) with susceptibility to RA was observed as well in the overall population, and the association was only significant in Caucasians but not Asians. For SLE, the associations of miR-146a rs2431697 T allele/T-carrier with increased risk of SLE were observed.

CONCLUSIONS

Our results highlight that miR-499 rs3746444 may contribute to RA susceptibility, particularly in Caucasians. In addition, CC genotype in miR-146a rs2910164 may act as a protector of RA in Caucasians. For SLE, miR-146a rs2431697 (C/T) is most likely to the increased the risk of SLE. These findings do not support the genetic association between miR-196a2 rs11614913 and RA/SLE susceptibility, as well as the association of miR-146a rs2910164, miR-146a rs57095329, miR-499 rs3746444 with SLE.

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.

Impaired microRNA processing in neutrophils from rheumatoid arthritis patients confers their pathogenic profile. Modulation by biological therapies

The aim of this study was to investigate the microRNA (miRNA) expression pattern in neutrophils from rheumatoid arthritis (RA) patients and its contribution to their pathogenic profile and to analyze the effect of specific autoantibodies or inflammatory components in the regulation of miRNA in RA neutrophils and its modulation by biological therapies. Neutrophils were isolated from paired peripheral blood (PB) and synovial fluid samples of 40 patients with RA and from PB of 40 healthy donors. A miRNA array was performed using nCounter technology. Neutrophils from healthy donors were treated in vitrowith antibodies to citrullinated protein antigens isolated from RA patients and tumor necrosis factor-a (TNF-a) or interleukin-6. A number of cytokines and chemokines were analyzed. In vitro treatments of RA-neutrophils with tocilizumab or infliximab were carried out. Transfections with pre-miRNA and DICER downregulation experiments were further performed. RA-neutrophils showed a global downregulation of miRNA and genes involved in their biogenesis, alongside with an upregulation of various potential mRNA targets related to migration and inflammation. Decreased levels of miRNA and DICER correlated with autoimmunity, inflammation and disease activity. Citrullinated protein antigens and TNF-a decreased the expression of numerous miRNA and their biogenesis-related genes, increasing their potential mRNA targets. Infliximab reversed those effects. Transfections with pre-miRNA-223, -126 and -148a specifically modulated genes regulating inflammation, survival and migration whereas DICER depletion influenced the inflammatory profile of neutrophils. Taken together RA-neutrophils exhibited a global low abundance of miRNA induced by autoantibodies and inflammatory markers, which potentially contributed to their pathogenic activation. miRNA biogenesis was significantly impaired in RAneutrophils and further associated with a greater downregulation of miRNA mainly related to migration and inflammation in synovial fluid neutrophils. Finally, anti-TNF-a and anti-interleukin-6 receptor treatments can modulate miRNA levels in the neutrophils, minimizing their inflammatory profile.

Long non-coding RNA MALAT1 and microRNA-499a expression profiles in diabetic ESRD patients undergoing dialysis: a preliminary cross-sectional analysis

Background: Circulating non-coding RNAs (ncRNAs) have been implicated in health and disease. This study aimed to evaluate the serum expression profile of microRNA-499a (miR-499a) and its selected bioinformatically predicted partner long-ncRNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) in diabetes-related end-stage renal disease (ESRD) patients and to correlate the expressions with the patients' clinicolaboratory data.Subjects and methods: Real-time quantitative polymerase chain reaction was applied in diabetics with and without ESRD (n = 90 for each).Results: Serum MALAT1 expression levels were increased in the ESRD group relative to diabetics without ESRD with median (quartile) values of 10.5 (1.41-126.7) (p < .001). However, miR-499a levels were decreased in more than half of ESRD patients with a median of 0.96 (0.13-3.14). Both MALAT1 and miR-499a expression levels were inversely correlated in the ESRD patient-group.Conclusions: MALAT1 up-regulation and miR-499 down-regulation might be involved in diabetic nephropathy-related ESRD pathogenesis. Functional validation studies are warranted to confirm the MALAT1/miR-499a partnership.

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.

Association between IRAK1 rs3027898 and miRNA-499 rs3746444 polymorphisms and rheumatoid arthritis : A case control study and meta-analysis

BACKGROUND

The IRAK1 and miR-499 polymorphisms play an important role in the etiology of rheumatoid arthritis (RA). Several studies have been carried out to estimate the association between IRAK1 rs3027898 and miR-499 rs3746444 and RA risk; however, the results were inconsistent.

AIM

A case control study was carried out to explore the association between IRAK1 rs3027898 and miR-499 rs3746444 and the RA risk in a Chinese population. Meta-analyses combining present with previous studies were conducted to further explore the association.

MATERIAL AND METHODS

A total of 386 RA patients were enrolled along with 576 matched healthy controls. Genotyping was performed by using TaqMan genotyping assays on Fluidigm 192.24 system. For the meta-analysis, a systematic literature search was conducted to identify all relevant studies.

RESULTS

This case control study showed that the IRAK1 rs3027898 C allele was associated with increased risk of RA with an odds ratio (OR) = 1.4 and 95 % confidence intervals (CI) = 1.093-1.793, P = 0.008 but miR-499 rs3746444 polymorphisms were not significantly associated with the risk for RA. The meta-analyses included a total of 4 case control studies on IRAK1 rs3027898 and 4 studies on miR-499 rs3746444. The IRAK1 rs3027898 C allele had an overall OR of 1.268 (95 % CI = 1.130-1.424, P < 0.001). After stratification by ethnicity the C allele had an OR of 1.238 (95 % CI = 1.096-1.398, P = 0.001) in Asians. No association between miR-499 rs3746444 polymorphism and RA was found in the overall and Asian populations.

CONCLUSION

The results from our case control study and the meta-analyses indicate that the IRAK1 rs3027898 C allele is significantly associated with an increased risk of RA, especially in Asians.

Plasma MicroRNAs in Established Rheumatoid Arthritis Relate to Adiposity and Altered Plasma and Skeletal Muscle Cytokine and Metabolic Profiles

Background: MicroRNAs have been implicated in the pathogenesis of rheumatoid arthritis (RA), obesity, and altered metabolism. Although RA is associated with both obesity and altered metabolism, expression of RA-related microRNA in the setting of these cardiometabolic comorbidities is unclear. Our objective was to determine relationships between six RA-related microRNAs and RA disease activity, inflammation, body composition, and metabolic function. Methods: Expression of plasma miR-21, miR-23b, miR-27a, miR-143, miR-146a, and miR-223 was measured in 48 persons with seropositive and/or erosive RA (mean DAS-28-ESR 3.0, SD 1.4) and 23 age-, sex-, and BMI-matched healthy controls. Disease activity in RA was assessed by DAS-28-ESR. Plasma cytokine concentrations were determined by ELISA. Body composition was assessed using CT scan to determine central and muscle adipose and thigh muscle tissue size and tissue density. Plasma and skeletal muscle acylcarnitine, amino acid, and organic acid metabolites were measured via mass-spectroscopy. Plasma lipoproteins were measured via nuclear magnetic resonance (NMR) spectroscopy. Spearman correlations were used to assess relationships for microRNA with inflammation and cardiometabolic measures. RA and control associations were compared using Fisher transformations. Results: Among RA subjects, plasma miR-143 was associated with plasma IL-6 and IL-8. No other RA microRNA was positively associated with disease activity or inflammatory markers. In RA, microRNA expression was associated with adiposity, both visceral adiposity (miR-146a, miR-21, miR-23b, and miR-27a) and thigh intra-muscular adiposity (miR-146a and miR-223). RA miR-146a was associated with greater concentrations of cardiometabolic risk markers (plasma short-chain dicarboxyl/hydroxyl acylcarnitines, triglycerides, large VLDL particles, and small HDL particles) and lower concentrations of muscle energy substrates (long-chain acylcarnitines and pyruvate). Despite RA and controls having similar microRNA levels, RA, and controls differed in magnitude and direction for several associations with cytokines and plasma and skeletal muscle metabolic intermediates. Conclusion: Most microRNAs thought to be associated with RA disease activity and inflammation were more reflective of RA adiposity and impaired metabolism. These associations show that microRNAs in RA may serve as an epigenetic link between RA inflammation and cardiometabolic comorbidities.

Association of rs2910164 Polymorphism in miRNA-146 and rs3746444 Polymorphism in miRNA-499 with Inflammatory Arthritis: A Meta-Analysis

Objectives

The purpose of this study was to explore the association of miRNA-146 and miRNA-499 polymorphisms with inflammatory arthritis.

Methods

A systematic search of studies on the association of miRNA-146 and miRNA-499 polymorphisms with inflammatory arthritis susceptibility was conducted in PubMed, Web of science, Elsevier ScienceDirect, and Cochrane Library. Eventually, 18 published studies were included. The strength of association between miRNA-146/499 polymorphisms and inflammatory arthritis susceptibility was assessed by odds ratios (ORs) with its 95% confidence intervals (CIs).

Results

A total of 18 case-control studies, consisting of 3385 inflammatory arthritis patients and 4584 controls, were included in the meta-analysis. This meta-analysis showed significant association between miRNA-499 rs3746444 polymorphism and inflammatory arthritis susceptibility in overall population (C vs T, OR: 1.422, 95% CI= 1.159-1.745, P=0.001). Similar results were found in subgroup analysis by region. But we did not find association between miRNA-146 rs2910164 polymorphism and inflammatory arthritis susceptibility in overall population (C vs T, OR: 1.061, 95% CI= 0.933-1.207, P=0.365).

Conclusions

The present study indicates that miRNA-499 rs3746444 polymorphism is associated with inflammatory arthritis susceptibility. However, there is lack of association between miRNA-146 rs2910164 polymorphism and inflammatory arthritis susceptibility. But, we also find miRNA-146 rs2910164 and miRNA-499 rs3746444 polymorphism are associated with inflammatory arthritis in Middle East. Therefore, more large-scale studies are warranted to replicate our findings.

An Updated Meta-Analysis of the Associations Between MicroRNA Polymorphisms and Susceptibility to Rheumatoid Arthritis

Aims: Rheumatoid arthritis (RA) is characterized by cartilage and bone damage leading to disability. Here, the association between microRNA (miRNA) polymorphisms and susceptibility to RA was evaluated by performing an updated meta-analysis and systematic review.

Main methods: An electronic search of databases including PubMed and Embase was performed from inception to December 8, 2017 to retrieve studies investigating the association between miRNA polymorphisms and RA risk. Two reviewers independently screened literature according to the inclusion and exclusion criteria and extracted data. The meta-analysis was conducted using Stata 14.0 software.

Key findings: Thirteen case-control studies with 2660 cases and 4098 controls were screened out after a systematic search. One study from the miR-146a rs2910164 G > C polymorphism group and two from the miR-499 rs3746444 T > C polymorphism group were excluded because of deviations from Hardy-Weinberg equilibrium. Pooled analysis demonstrated that miR-146a rs2910164 G > C polymorphism was not significantly associated with susceptibility to RA. However, a significant association was observed between miR-499 rs3746444 T > C polymorphism and RA risk (C vs. T: OR = 1.22, 95% CI = 1.05–1.42, P = 0.008; TC vs. TT: OR = 1.26, 95% CI = 1.05–1.50, P = 0.011; TC/CC vs. TT: OR = 1.26, 95% CI = 1.07–1.5, P = 0.007). Subgroup analysis based on ethnicity showed no significant association between miR-499 T > C polymorphism and susceptibility to RA in the Asian population (P > 0.05). However, in Caucasian population, the C allele in the miR-499 T > C polymorphism was a contributor to RA susceptibility in some genetic models (C vs. T: OR = 1.64, 95% CI = 1.28–2.11, P < 0.001; TC vs. TT: OR = 1.95, 95% CI = 1.40–2.71, P < 0.001; TC/CC vs. TT: OR = 1.96, 95% CI = 1.43–2.69, P < 0.001).

Significance: The miR-146a rs2910164 G > C polymorphism was not associated with susceptibility to RA. In the Caucasian population, the C allele in the miR-499 T > C polymorphism contributed to RA susceptibility.

Possible use of miRNAs-146a and -499 expression and their polymorphisms as diagnostic markers for rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disorder affecting the peripheral joints. Different microRNAs had been investigated in RA including miRNA-146a meanwhile, miRNA-499 there were no studies to prove its expression in RA serum samples. This study was performed to investigate expression of both miRNAs-146a and -499 and their polymorphisms in Egyptian patients with RA and to evaluate their relationship with clinico-pathological data. The present study includes 108 subjects classified into two main groups: 52 RA patients and 56 unrelated healthy controls. RA patients were subclassified according to DAS28 score into inactive (23 patients) and active (29 patients). Quantitative expression of serum miRNA-146a, miRNA-499 as well as their Genotyping rs2910164 (C/G) and rs3746444 (T/C), respectively, were done to all subjects using real-time PCR. Serum miRNA-146a and -499 were significantly over expressed in RA patients, but they were not correlated to disease activity. Serum miRNA-146a was negatively correlated with anti-nuclear antibodies (ANA). miRNA-146a (rs2910164) genotyping revealed that the GG genotype and the frequency of the G allele were significantly higher in RA patients compared to the controls. miRNA-499 (rs3746444), genotyping revealed that the CC genotype and the frequency of the C allele were significantly higher. It can be concluded that both miRNAs-146a and -499 can be used as diagnostic markers for RA patients. Both miRNA-146a (rs2710164) and miRNA-499 (rs3746444) were significantly associated with RA susceptibility. The C allele of miRNA-146a (rs2710164) can be considered to be protective. On the other hand, the C allele of miRNA-499 (rs3746444) was significantly associated with RA susceptibility.

Functional polymorphisms in pre-miR146a and pre-miR499 are associated with systemic lupus erythematosus but not with rheumatoid arthritis or Graves' disease in Mexican patients

Recently, different microRNA (miRNA) gene polymorphisms have been evaluated in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and Graves’ disease (GD). In the present study, we examined three single-nucleotide polymorphisms (SNPs) located in the pre-miR-146a (rs2910164G/C), pre-miR-196a-2 (rs11614913C/T), and pre-miR-499 (rs3746444A/G) genes. Our study population included 900 Mexican patients with RA, SLE, or GD, as well as 486 healthy control individuals with no family history of inflammatory or autoimmune diseases. Genotyping was performed using TaqMan probes and a 5′ exonuclease assay. None of the investigated SNPs were associated with RA or GD susceptibility under any genetic model (co-dominant, recessive, or dominant). Genotype and allele frequencies of the miR-196a-2 rs11614913C/T polymorphism were similar between SLE cases and controls. In contrast, the miR-146a rs2910164G/C and miR-499 rs3746444A/G polymorphisms were associated with SLE susceptibility. These SNPs were not associated with lupus nephritis (LN). Our results suggest that polymorphisms in miR-146a, miR-196a-2, and miR-499 are not associated with RA or GD susceptibility. This is the first report documenting that the miR-146a rs2910164G/C and miR-499 rs3746444 polymorphisms are associated with SLE susceptibility but not with LN.

Pre-micro RNA-499 Gene Polymorphism rs3746444 T/C is Associated with Susceptibility to Rheumatoid Arthritis in Egyptian Population

Pre-miRNA-499 gene is associated with autoimmune disease. Mir-449 rs3746444 polymorphism is inconsistent for rheumatoid arthritis (RA). This study aimed to investigate association of mir-499 rs3746444 polymorphism with RA activity and severity in Egyptian population. The study population was conducted as case control study in 100 RA patients diagnosed according to the American College of Rheumatology classification criteria for RA, and the control group included 100 healthy subjects who were age-and sex-matched to the RA group. Different genotypes were assessed using polymerase chain reaction-restriction fragment length polymorphism. 95% Confidence interval and odds ratio were defined to assess the strength of association. Regarding patients, thirty-three patients carried TT genotype, fifty-three patients carried TC genotype and fourteen patients carried CC genotype. So the frequency of the minor C allele in RA patients was significantly higher than the control subjects (P = 0.037). TC, CC genotypes and C allele frequencies were significantly associated with disease severity as they had high rheumatoid factor (55.78 µIU/ml) and anti-cyclic citrullinated peptide (Anti-CCP) antibody (297.32 µIU/ml). Moreover, the heterozygote TC had more severe and more active form of the disease compared with homozygote CC or TT as they had high Anti-CCP antibody, and disease activity score 28 (score 5). Our work suggests that C allele of Pre-miRNA rs3746444 polymorphism contributes to heritability of susceptibility to RA compared to T allele. This polymorphism was associated with the activity and severity of the disease.

Dysregulation of miRNA-146a contributes to the development of lupus nephritis via targeting of TRAF6

Aim: The objective of this study was to identify the association between genotypes of miR-146a rs2910164 and expression of TRAF6 as well as the risk of lupus nephritis (LN). Results: A total of 567 systemic lupus erythematosus patients both with and without LN were included in the study. The luciferase activity of cells that carried miR-146a mimics was much lower than control and the miR-146a mRNA expression with the GG SNP was significantly overexpressed compared with that in GC and CC groups. Expressions of TRAF6 mRNA and protein with GG were markedly lower than those in GC and CC groups. Mesangial cells treated with miR-146a inhibitors displayed higher expression of TRAF6 mRNA and protein compared with scramble control, miR-146a mimics and TRAF6 siRNA groups. Conclusion: Rs2910164 is associated with the risk of LN and could function as a therapeutic target of the disease.

Evaluation of a Panel of Single-Nucleotide Polymorphisms in miR-146a and miR-196a2 Genomic Regions in Patients with Chronic Periodontitis

BACKGROUND

Periodontitis is an inflammatory disease caused by bacterial triggering of the host immune-inflammatory response, which in turn is regulated by microRNAs (miRNA). Polymorphisms in the miRNA pathways affect the expression of several target genes such as tumor necrosis factor-α and interleukins, which are associated with progression of disease.

OBJECTIVE

The objective of this study was to identify the association between the MiR-146a single nucleotide polymorphisms (SNPs) (rs2910164, rs57095329, and rs73318382), the MiR-196a2 (rs11614913) SNP and chronic periodontitis.

METHODS

Genotyping was performed for the MiR-146a (rs2910164, rs57095329, and rs73318382) and the MiR-196a2 (rs11614913) polymorphisms in 180 healthy controls and 190 cases of chronic periodontitis by the direct Sanger sequencing technique. The strength of the association between the polymorphisms and chronic periodontitis was evaluated using logistic regression analysis. Haplotype and linkage analyses among the polymorphisms was performed. Multifactorial dimensionality reduction was performed to determine epistatic interaction among the polymorphisms.

RESULTS

The MiR-196a2 polymorphism revealed a significant inverse association with chronic periodontitis. Haplotype analysis of MiR-146a and MiR-196a2 polymorphisms revealed 13 different combinations, of which 5 were found to have an inverse association with chronic periodontitis.

CONCLUSION

The present study has demonstrated a significant inverse association of MiR-196a2 polymorphism with chronic periodontitis.

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.

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.

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

miRNAs are small, non-coding RNAs that regulate the expression of multiple target genes at the post-transcriptional level. Single-nucleotide polymorphisms (SNPs) in miRNA sequences may alter miRNA expression and have been implicated in the pathogenesis of multiple forms of arthritis, including rheumatoid arthritis (RA) and osteoarthritis. The present study explored the association between ankylosing spondylitis (AS) and two single nucleotide polymorphisms (SNPs), miR-146a rs2910164G>C and miR-499 rs3746444T>C, in a Han Chinese population. A case-control study consisting of 102 subjects with AS and 105 healthy controls was designed. The two miRNA SNPs were identified by direct sequencing. Subsequently, their gene and genotype frequencies were compared with healthy controls. A significant difference was observed in the miR-146a rs2910164G>C SNP. The frequency of the G allele was markedly higher in the AS patients than in the healthy controls (P = 0.005, Pc = 0.01, OR = 1.787), and the frequency of the GG genotype was higher in AS patients than in controls (P = 0.014, Pc = 0.042, OR = 2.516). However, no significant association was found between the miR-499 rs3746444T>C variant and susceptibility to AS. This is the first study to address the association between the miR-146a rs2910164G>C and miR-499 rs3746444T>C polymorphisms and AS, and it suggests a potential pathogenic factor for AS. Further studies are needed to validate our findings in a larger series, as well as in other ethnic backgrounds.

Meta-analysis of microRNA-146a rs2910164 G>C polymorphism association with autoimmune diseases susceptibility, an update based on 24 studies

BACKGROUND

Published data showed that the susceptibility of autoimmune diseases (ADs) was associated with the polymorphism rs2910164 in microRNA-146a (miR-146a). However, the results remain controversial so far. Two meta-analyses published in 2013 and 2014 came to opposite conclusions. In order to derive a more precise estimation of the relationship, we performed this meta-analysis.

METHODS

We searched the PubMed, OvidSP and CNKI databases (published prior to September 8th, 2014) and extracted data from eligible studies. The procedure of meta-analysis was performed by using the Stata 12.0 software. Random effect model or fixed effect model were chosen respectively, according to the between study heterogeneities.

RESULTS

A total of 24 case-control studies, 11 more than previous meta-analysis on this topic, were involved. We took stratified analyses by different ethnicities and different types of diseases in different genetic models. In Caucasian subgroup, significant increased risks of GC genotype and GC+CC genotype with ADs susceptibility were found in heterozygote model (GC vs GG, OR = 1.38, 95% CI 1.04-1.83, p = 0.024) and dominant model (GC+CC vs GG, OR = 1.37, 95% CI 1.01-1.85, p = 0.041), respectively. Meanwhile, in other disease subgroup, significant increased risks of C allele, CC genotype and GC+CC genotype were found in allele model (C vs G, OR = 1.16, 95% CI 1.04-1.31, p = 0.010), homozygote model (CC vs GG, OR = 1.42, 95% CI 1.10-1.84, p = 0.006) and dominant model (GC+CC vs GG, OR = 1.25, 95% CI 1.04-1.51, p = 0.020), respectively.

CONCLUSIONS

MiR-146a rs2910164 G>C polymorphism was associated with the susceptibility of ADs.

Genetic Variation in miR-146a Is Not Associated with Susceptibility to IgA Nephropathy in Adults from a Chinese Han Population

BACKGROUND

MicroRNA 146a (miR-146a) is a 19 to 23 nucleotide long, small non-coding RNA with gene regulatory functions that has influence on the pathogenesis of many diseases. A single nucleotide polymorphism (rs2910164 C>G) in pre-miR-146a is correlated with the expression of miR-146a. The aim of this study was to perform an association analysis of rs2910164 with IgA nephropathy in adult patients from a Chinese Han population.

METHODS

A total of 145 patients with renal biopsy-proved IgA nephropathy (IgAN) and 179 healthy controls were recruited to the current study. rs2910164 was genotyped by the polymerase chain reaction (PCR) and high-resolution melting methods (HRM). Clinical characteristics and pathology grading of patients with IgAN were recorded at the time of kidney biopsy.

RESULT

There were significant differences among the population of patients grouped by different age of onset in a co-dominant model (CG vs. CC vs. GG) (p = 0.033) and a recessive model (CG+CC vs. GG) (p = 0.001). However, no significant difference was observed in the distribution of genotypes between cases and controls (p = 0.144). There was also no significant difference between rs2910164 and patient quantitative traits (all p > 0.003) or different pathology grading (Lee's grading system and tubular atrophy/interstitial fibrosis in the Oxford classification) (all p > 0.05).

CONCLUSIONS

There was no association of rs2910164 with susceptibility to IgAN in adults from a Chinese Han population. However, rs2910164 was correlated with the age of onset of IgAN in adult patients.

MicroRNA-146a: A Dominant, Negative Regulator of the Innate Immune Response

MicroRNAs (miRNAs) are a class of small non-coding RNA molecules that can play critical roles as regulators of numerous pathways and biological processes including the immune response. Emerging as one of the most important miRNAs to orchestrate immune and inflammatory signaling, often through its recognized target genes, IRAK1 and TRAF6, is microRNA-146a (miR-146a). MiR-146a is one, of a small number of miRNAs, whose expression is strongly induced following challenge of cells with bacterial endotoxin, and prolonged expression has been linked to immune tolerance, implying that it acts as a fine-tuning mechanism to prevent an overstimulation of the inflammatory response. In other cells, miR-146a has been shown to play a role in the control of the differentiation of megakaryocytic and monocytic lineages, adaptive immunity, and cancer. In this review, we discuss the central role prescribed to miR-146a in innate immunity. We particularly focus on the role played by miR-146a in the regulation and signaling mediated by one of the main pattern recognition receptors, toll/IL-1 receptors (TLRs). Additionally, we also discuss the role of miR-146a in several classes of autoimmune pathologies where this miRNA has been shown to be dysregulated, as well as its potential role in the pathobiology of neurodegenerative diseases.

Comprehensive review of genetic association studies and meta-analysis on miRNA polymorphisms and rheumatoid arthritis and systemic lupus erythematosus susceptibility

BACKGROUND

MicroRNAs (miRNAs), small RNA molecules, play a role in the development and differentiation of immune cells in both innate and adaptive immune responses. Our study was aimed to investigate the association between three miRNA polymorphism and rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) by using meta-analysis approach.

METHODS

A PubMed database search was conducted during August 2013 to identify case-control studies of miRNAs and RA or SLE risk. Two authors independently extracted information on the study design, the characteristics of the study participants, exposure and outcome assessments. The fix-effects and random-effects models were used for the risk estimates by Stata 11.0 software.

RESULTS

Our meta-analysis of six case-control studies involving a total of 998 RA cases and 1493 controls identified no significant association between mir-146a rs2910164 and RA, with an overall OR of 0.843 (95% CI=0.642-1.105; CC vs. GG). No association was observed in three studies with a total of 1532 cases and 2168 controls between miR-146a rs2910164 and SLE risk (OR=0.911, 95% CI=0.710-1.171; CC vs. GG). Three studies with a total of 529 cases and 595 controls evaluated the mir-499 rs3746444 polymorphism and its association with RA. There was a decreased overall risk of RA under the allelic and genotypic models [OR=0.616, 95% CI=0.384-0.981, (T vs. C allele) and OR=0.386, 95% CI=0.226-0.659, (TT vs. CC)]. Two studies with 4826 cases and 4181 controls evaluated miR-146a rs57095329 and its association with SLE. There was a significant association between miR-146a rs57095329 and SLE (OR=1.263, 95% CI=1.136-1.405, G vs. A allele).

CONCLUSIONS

The present meta-analysis suggests important roles for the mir-499 rs3746444 polymorphism in RA, especially in the Caucasian population and for miR-146a rs57095329 polymorphism in SLE. Further studies with large sample size are needed to confirm these associations.

Common polymorphisms in MIR146a, MIR128a and MIR27a genes contribute to neuropathy susceptibility in type 2 diabetes

Diabetic polyneuropathy (DPN) and cardiovascular autonomic neuropathy (CAN) are common type 2 diabetes complications with a large inter-individual variability in terms of clinical manifestations and severity. Our aim was to evaluate a possible involvement of genetic polymorphisms in miRNA regions in the susceptibility to DPN and CAN. Nine polymorphisms in miRNA genes were studied in a sample of 132 type 2 diabetes patients (T2D) analysed for DPN and 128 T2D patients analysed for CAN. A genotype-phenotype correlation analysis was performed. The T allele of rs11888095 single nucleotide polymorphism (SNP) in MIR128a was significantly associated with a higher risk (ORadj = 4.89, P adj = 0.02), whereas the C allele of rs2910164 SNP in MIR146a was associated with a lower risk to develop DPN (ORadj = 0.49, P adj = 0.09), respectively. A multivariate logistic regression analysis confirmed that both SNPs contribute to DPN (p < 0.001 and p = 0.01 for MIR128a and MIR146a, respectively). MIR128a SNP significantly contributed also to DPN score (p = 0.026). Rs895819 SNP in MIR27a was significantly associated with a higher risk to develop early CAN (P adj = 0.023 and ORadj = 3.43). The rs2910164 SNP in MIR146a showed a protective effect respect to early CAN (P adj = 0.052, ORadj = 0.32) and to confirmed CAN (P adj = 0.041, ORadj = 0.13). The same SNP resulted significantly associated with a lower CAN score and a higher E/I (p = 0.002 and p = 0.003, respectively). In conclusion, we described associations of MIR128a and MIR146a SNPs with DPN susceptibility and of MIR146a and MIR27a SNPs with CAN susceptibility. This is the first study showing that genetic variability in miRNA genes could be involved in diabetic neuropathies susceptibility.

Association of two polymorphisms rs2910164 in miRNA-146a and rs3746444 in miRNA-499 with rheumatoid arthritis: a meta-analysis

BACKGROUND

It has been reported that two single nucleotide polymorphisms (SNPs) rs2910164 in miRNA-146a and rs3746444 in miRNA-499 might be associated with the susceptibility to rheumatoid arthritis (RA). Owing to mixed and inconclusive results, we conducted a meta-analysis to systematically summarize and clarify the association between the two SNPs and RA risk.

METHODOLOGY/MAIN RESULTS

A systematic search of studies on the association of two SNPs with susceptibility to RA was conducted in PubMed and Embase. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to pool the effect size. A total of 6 case-control studies on rs2910164 and 3 studies on rs3746444 were included. Though no evidence of association was found between rs2910164 polymorphism and RA risk in all the genetic models, a trend of reduced risk could be drawn. (C versus G: OR=0.93, 95% CI 0.82-1.05; GC versus GG: OR=0.89, 95% CI 0.73-1.10; CC versus GG: OR=0.84, 95% CI 0.64-1.10; GC/CC versus GG: OR=0.89, 95% CI 0.73-1.08; CC versus

GC/GG

OR=0.94, 95% CI 0.77-1.14). A significant increased risk of RA was observed in the rs3746444 polymorphism in homozygote comparison, recessive comparison, and allele comparison, but there was insufficient data to fully confirm the association of RA and rs3746444 in miRNA-499.

CONCLUSIONS

MiRNA-146a rs2910164 polymorphism is not associated with RA risk, while miRNA-499 rs3746444 polymorphism is correlated with RA risk. However, the results of miRNA-499 rs3746444 should be interpreted with caution due to limited sample and heterogeneity. Large-scale and well-designed studies are needed to validate our findings.

A functional polymorphism in the promoter region of microRNA-146a is associated with the risk of Alzheimer disease and the rate of cognitive decline in patients

miR146a is well known for its regulatory role in the immune response and inflammation. Recent studies have demonstrated the links between miR146a and Alzheimer disease (AD) and suggested that miR146a may be involved in neuroinflammation and the metabolism of amyloid-β (Aβ), which are critical events in AD pathology. Although genetic studies have focused on the association between the miR146a gene and susceptibility to several diseases, no association study of miR146a variability with AD has been conducted. In this report, we performed a case-control association study to analyze the genotype and allele distributions of the miR146a, rs2910464 and rs57095329 polymorphisms in a Chinese population consisting of 292 AD cases and 300 healthy controls. We found a significant difference in the genotypes and allele frequencies of rs57095329 between the AD cases and the controls (p = 0.0147 and p = 0.0184, respectively), where the AA genotype of rs57095329 was associated with an increased risk of AD as well the cognitive decline in AD patients. Additionally, the AA genotype of rs57095329 exhibited significantly higher miR146a expression than the GG+GA genotypes of rs2910164 in the peripheral blood cells (PBMCs) of healthy individuals and had a stronger effect on the production of IL-6 and IL-1β when the cells were stimulated with LPS. Our data provide preliminary evidence that the rs57095329 polymorphism in the miR146a promoter is involved in the genetic susceptibility to AD, and this risk AA genotype may increase the expression of miR146a and influence certain proinflammatory cytokines, thus playing a role in the pathogenesis of AD.