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

Epigenetic Changes in the Pathogenesis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease that affects about 1% of the world’s population. The etiology of RA remains unknown. It is considered to occur in the presence of genetic and environmental factors. An increasing body of evidence pinpoints that epigenetic modifications play an important role in the regulation of RA pathogenesis. Epigenetics causes heritable phenotype changes that are not determined by changes in the DNA sequence. The major epigenetic mechanisms include DNA methylation, histone proteins modifications and changes in gene expression caused by microRNAs and other non-coding RNAs. These modifications are reversible and could be modulated by diet, drugs, and other environmental factors. Specific changes in DNA methylation, histone modifications and abnormal expression of non-coding RNAs associated with RA have already been identified. This review focuses on the role of these multiple epigenetic factors in the pathogenesis and progression of the disease, not only in synovial fibroblasts, immune cells, but also in the peripheral blood of patients with RA, which clearly shows their high diagnostic potential and promising targets for therapy in the future.

Genetic variation in microRNA-100 (miR-100) rs1834306 T/C associated with Hepatitis B virus (HBV) infection: Correlation with expression level

Circulating microRNAs (miRNAs) have a vital role in Hepatitis B virus (HBV) diagnosis and therapeutics. miR-100 was reported to be associated with various aspects of HBV biology. This study focused on a miR-100 Single Nucleotide Polymorphism (SNP) (rs1834306 T/C) and its contribution to an individual's susceptibility and prognosis of HBV infection. The effect of SNP on miR-100 expression will be also evaluated. Two hundred subjects: 100 HBV infected patients and 100 age-and-sex-matched healthy individuals served as a control group. SNP detection was performed using polymerase chain reaction technique with sequence-specific primers (PCR-SSP) method and miR-100 expression through quantitative real-time PCR (qRT-PCR). Our result showed a significant up-regulation of miR-100 expression in HBV patients versus the control group (P < .01). A positive correlation was found between viral load and elevation in miR-100 expression (r = 0.508; P < .01). Concerning miR-100 expression in different genotypes/alleles, TC genotype and T allele in coincides with a significantly elevated expression level of miR-100 (P < .001) in HBV patients than in controls. Best of our knowledge, it is the first observational prospective case-control study concerned with miR-100 (rs1834306 T/C) SNP in the Egyptian population. However, the small size of this preliminary work required more prospective investigations to confirm our data.

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.

Association between miRNA-146a rs2910164 (G/C) polymorphism with the susceptibility to chronic HBV infection and spontaneous viral clearance in an Iranian population

Hepatitis B virus (HBV) infection is one of the clinical dilemmas in chronic liver diseases. MicroRNAs (miRNAs) are small noncoding RNA molecules that play an important role in the pathogenesis of liver diseases and single nucleotide polymorphisms (SNPs) in miRNA genes affect the clinical course of HBV infection. Previous studies have shown that miRNA-146a rs2910164 polymorphism can be associated with the pathogenesis of liver diseases such as hepatocellular carcinoma. The present study investigated the association between miRNA-146a rs2910164 polymorphism and susceptibility to HBV infection in an Iranian population. The study comprised 266 patients with chronic HBV infection, 172 patients with spontaneous viral clearance (SVC) after acute HBV infection, and 266 healthy control adjusted for sex and age. The genotyping of the miRNA-146a rs2910164 polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Our data revealed that GG genotype and G allele of miRNA-146a rs2910164 SNP is dominated (P < 0.001) in patients with chronic HBV infection (Odds ratio [OR] = 3.92; 95% confidence interval [CI] = 2.1-7.32). miRNA-146a rs2910164 polymorphism showed a statistically significant association (P < 0.001) between CC genotype and allele C with SVC (OR = 2.92; 95% CI = 1.56-546). Our findings suggest miRNA-146a SNP (C/G) in our population may be associated with the susceptibility to HBV infection and CC genotype is associated with SVC. Also, the GG genotype and G allele at miRNA-146a rs2910164 is associated with chronic HBV infection in our population.

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.

miR-146a Controls Immune Response in the Melanoma Microenvironment

MicroRNAs (miR) are small noncoding RNAs that regulate gene expression, posttranscription, and manipulate immune responses in different types of cancers. In this study, we identify miR-146a as a negative regulator of immune activation, comparable to immune-checkpoint molecules. miR-146a levels were increased in melanoma microenvironmental tissue, and miR-146a^-/- mice survived longer and developed less metastases in comparison with wild-type melanoma-bearing mice. T cells isolated from miR-146a^-/- mice revealed higher expression levels of the miR-146a target gene Stat1 and the Stat1-regulated cytokine IFNγ. Neutralization of IFNγ in miR-146a^-/- mice decreased survival and increased melanoma metastasis patterns to those of wild-type mice. In vitro, IFNγ reduced melanoma cell migration, cell-cycle activity, and basal metabolic rate. Conversely, IFNγ also increased PD-L1 levels on the melanoma cells, which may counterbalance some of the beneficial effects increasing immune escape in vivo. Combined treatment with a miR-146a antagomiR and anti-PD-1 resulted in improved survival over isotype control or anti-PD-1 treatment alone. In summary, these data show that miR-146a plays a central role within the STAT1/IFNγ axis in the melanoma microenvironment, affecting melanoma migration, proliferation, and mitochondrial fitness as well as PD-L1 levels. Additionally, combined inhibition of PD-1 and miR-146a could be a novel strategy to enhance antitumor immune response elicited by checkpoint therapy. SIGNIFICANCE: These findings identify a microRNA-based mechanism by which melanoma cells escape the immune system, providing a new therapeutic strategy to improve the current management of patients with melanoma.

MiR-146a levels in rheumatoid arthritis and their correlation with disease activity: a meta-analysis

OBJECTIVE

To evaluate the relationship between miR-146a levels and rheumatoid arthritis (RA), and the correlation with RA activity.

METHODS

For the meta-analysis, we searched the PubMed, MEDLINE, EMBASE and Cochrane databases, comparing miR-146a levels in patients with RA and controls, and correlation coefficients between miR-146a levels and Disease Activity Score for 28 joints (DAS28) and erythrocyte sedimentation rate (ESR) in patients with RA.

RESULTS

Fourteen studies, totaling 683 patients with RA and 477 controls, were available. miR-146a levels were significantly higher in the RA group than in the control group (standardized mean difference [SMD] = 0.546, 95% CI = 0.033-1.059, P = 0.037). Stratification by adjustment for age and/or sex revealed significantly higher miR-146a levels in the adjusted, but not in the non-adjusted group (SMD = 0.747, 95% CI = 0.094-1.400, P = 0.025; SMD = 0.431, 95% CI = -0.430-1.291, P = 0.326, respectively). Stratification by sample size showed significantly higher miR-146a levels in RA groups of large sample sizes (N ≥ 50), but not in those of small size. miR-146a levels in synovial tissue/fluid were significantly higher in the RA group than in the OA group (SMD = 1.305, 95% CI = 1010-1.639, P < 0.001). A significant positive correlation was found between miR-146a levels and ESR (correlation coefficient = 0.534, 95% CI = 0.029-0.822, P = 0.039).

CONCLUSIONS

Circulating and synovial tissue/fluid miR-146a levels are high in patients with RA, and circulating miR-146a levels positively correlate with ESR.

The Role of MicroRNAs in Myeloid Cells during Graft-versus-Host Disease

The successful treatment of various hematologic diseases with allogeneic hematopoietic cell transplantation is often limited by the occurrence of graft-versus-host disease (GvHD). Several microRNAs (miRs) have recently been shown to impact the biology of GvHD by regulating pro- as well as anti-inflammatory target genes. There is increasing evidence that a single miR can have different effects by preferentially targeting certain genes depending on the cell type that the miR is analyzed in. This review will focus on the role of miRs in myeloid cells during the development of acute and chronic GvHD and autoimmune diseases. Because miRs act on the expression of multiple target genes and may thereby influence the immune system at different functional levels, they are potentially attractive targets for the modification of allogeneic immune responses using miR mimics and inhibitors.

Association of miR-146 rs2910164, miR-196a rs11614913, miR-221 rs113054794 and miR-224 rs188519172 polymorphisms with anti-TNF treatment response in a Greek population with Crohn’s disease

AIM

To investigate the correlation between rs2910164, rs11 614913, rs113054794, and rs188519172 polymorphisms and response to anti-TNF treatment in patients with Crohn’s disease (CD).

METHODS

One hundred seven patients with CD based on standard clinical, endoscopic, radiological, and pathological criteria were included in the study. They all received infliximab or adalimumab intravenously or subcutaneously at standard induction doses as per international guidelines. Clinical and biochemical response was assessed using the Harvey-Bradshaw index and CRP levels respectively. Endoscopic response was evaluated by ileocolonoscopy at week 12-20 of therapy. The changes in endoscopic appearance compared to baseline were classified into four categories, and patients were classified as responders and non-responders. Whole peripheral blood was extracted and genotyping was performed by PCR.

RESULTS

One hundred and seven patients were included in the study. Seventy two (67.3%) patients were classified as complete responders, 22 (20.5%) as partial while 13 (12.1%) were primary non-responders. No correlation was detected between response to anti-TNF agents and patients’ characteristics such as gender, age and disease duration while clinical and biochemical indexes used were associated with endoscopic response. Concerning prevalence of rs2910164, rs11614913, and rs188519172 polymorphisms of miR-146, miR-196a and miR-224 respectively no statistically important difference was found between complete, partial, and non-responders to anti-TNF treatment. Actually CC genotype of rs2910164 was not detected in any patient. Regarding rs113054794 of miR-221, normal CC genotype was the only one detected in all studied patients, suggesting this polymorphism is highly rare in the studied population.

CONCLUSION

No correlation is detected between studied polymorphisms and patients’ response to anti-TNF treatment. Polymorphism rs113054794 is not detected in our population.