Association of polymorphisms in pre-miRNA with inflammatory biomarkers in rheumatoid arthritis in the Chinese Han population

MIR149 rs2292832 and MIR499 rs3746444 Genetic Variants Associated with the Risk of Rheumatoid Arthritis

INTRODUCTION

MicroRNAs (miRNAs) are small non-coding RNAs that play a key role in post-transcriptional modulation of individual genes' expression. Several miRNA variants from different populations are known to be associated with an increased risk of rheumatoid arthritis (RA).

AIM

This study was undertaken with the aim to investigate the association of single nucleotide variants; namely, rs2292832, rs3746444, rs11614913, rs1044165, and rs767649 of MIR149, MIR499, MIR196, MIR223, and MIR155, respectively, with RA in the Pakistani population.

METHODS

A case-control study was performed by recruiting and genotyping a total of 600 individuals (300 cases and 300 controls) for these five variants using a TaqMan single-nucleotide polymorphism (SNP) genotyping assay. The resultant genotypic data was statistically analyzed through a chi-squared test for its association with RA under different inheritance models.

RESULTS

We found a significant association of rs2292832 with RA at genotypic (co-dominant (p < 0.0001), dominant (CC vs. TT + CT: OR 2.063 (1.437-2.962); p = 0.0001), recessive (TT vs. CT + CC: OR 0.376 (0.259-0.548); p < 0.0001)), and allelic (allele C) levels ((OR 0.506 (0.402-0637); p < 0.0001)). Similarly, the rs3746444 showed a significant association with RA under co-dominant (p = 0.0001), dominant (GG vs. AA + AG: OR 5.246 (3.414-8.061); p < 0.0001), recessive (AA vs. GG + AG: OR 0.653 (0.466-0.916); p = 0.014), and additive models (G vs. A; OR 0.779 (0.620-0.978); p = 0.03). However, we did not observe any significant association of rs11614913, rs1044165, or rs767649 with RA in our subjects.

CONCLUSION

To our knowledge, this was the first study that investigated and found an association between functional polymorphisms in miRNAs and RA in the Pakistani population.

miRNAs insights into rheumatoid arthritis: Favorable and detrimental aspects of key performers

Rheumatoid arthritis (RA) is a severe autoimmune inflammation that mostly affects the joints. It's a multifactorial disease. Its clinical picture depends on genetic and epigenetic factors such as miRNAs. The miRNAs are small noncoding molecules that are able to negatively or positively modulate their target gene expression. In RA, miRNAs are linked to its pathogenesis. They disrupt immunity balance by controlling granulocytes, triggering the release of several proinflammatory cytokines such as interleukin-6 and tumor necrosis factor-α, finally leading to synovium hyperplasia and inflammation. Besides, they also may trigger activation of some pathways as nuclear factor kappa-β disrupts the balance between osteoclast and osteoblast activity, leading to increased bone destruction. Moreover, miRNAs are also applied with efficiency in RA diagnosis and prognosis. Besides the significant association between miRNAs and RA response to treatment, they are also applied as a choice for treatment based on their effects on the immune system and inflammatory cytokines. Hence, the review aims to present an updated overview of miRNAs, their biogenesis, implications in RA pathogenesis, and finally, the role of miRNAs in RA treatment.

miRNAs: A potentially valuable tool in pesticide toxicology assessment-current experimental and epidemiological data review

miRNAs are responsible for the regulation of many cellular processes such as development, cell differentiation, proliferation, apoptosis, and tumor growth. Several studies showed that they can also serve as specific, stable, and sensitive markers of chemical exposure. In this review, current experimental and epidemiological data evidencing deregulation in miRNA expression in response to fungicides, insecticides or herbicides were analyzed. As shown by Venn's diagrams, miR-363 and miR-9 deregulation is associated with fungicide exposure in vitro and in vivo, while let-7, miR-155, miR-181 and miR-21 were found to be commonly deregulated by at least three different insecticides. Furthermore, let-7, miR-30, miR-126, miR-181 and miR-320 were commonly deregulated by 3 different herbicides. Notably, these 5 miRNAs were also found to be deregulated by one or more insecticides, suggesting their participation in the cellular response to pesticides, regardless of their chemical structure. All these miRNAs have been proposed as potential biomarkers for fungicide, insecticide, or herbicide exposure. These results allow us to improve our understanding of the molecular mechanisms of toxicity upon pesticide exposure, although further studies are needed to confirm these miRNAs as definitive (not potential) biomarkers of pesticide exposure.

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.

Pre-microRNAs single nucleotide variants (rs3746444 A > G and rs2910164 C > G) increase the risk of ischemic stroke in the Egyptian population: a case–control study

Background

Ischemic stroke (IS) is the most leading cause of morbidity and mortality worldwide. Micro RNA (miRNA) genetic variants have been identified as a part of IS non-modifiable risk markers. This study aims to identify the possible association of rs2910164 C > G of pre-miRNA-146a and rs3746444 A > G of pre-miRNA-499 with increased IS risk. C-reactive protein (CRP) was studied as one of the mediators of the genetic disturbance in IS. The study included 100 patients with atherosclerotic IS and 100 age and sex matched healthy controls with more than one risk factor for IS. Variants were evaluated by the real-time polymerase chain reaction technique using TaqMan probes. CRP levels were assayed by immunoturbidimetry method on COBAS analyzer.

Results

Regarding rs3746444 A > G, the G allele, and its containing genotypes (GG and GG + AG) were associated with high IS incidence. Increased CRP levels were found to induce IS by GG and GG + AG genotypes, with a cut value of 7.5 mg/ L in differentiation between AA genotype and GG + AG genotypes. Combining the G allele of rs3746444 A > G with either G or C allele of rs2910164 C > G had enhanced the risk. For rs2910164 C > G, the G allele, and the combined GG + GC genotypes were associated with IS risk elevation with no correlation to CRP levels.

Conclusion

The G involving genetic variants of rs3746444 A > G and rs2910164 C > G were associated with an enhanced IS risk. CRP showed higher levels in GG and AG genotypes of rs3746444 with no relation to rs2910164 genotypes.

Association study of miR-149, miR-196a2, and miR-499a polymorphisms with coronary artery aneurysm of Kawasaki disease in southern Chinese population

Background

Accumulating evidence suggests that several microRNA (miRNA) polymorphisms are closely associated with disease susceptibility or progression, such as in Kawasaki disease (KD). Our previous studies revealed the association of miR‐149 rs2292832 T>C and miR‐196a2 rs11614913 C>T polymorphisms with KD susceptibility. The present study further focused on the relationship between three miRNA polymorphisms (miR‐149 rs2292832 T>C, miR‐196a2 rs11614913 C>T and miR‐499a rs3746444 A>G) and the risk of coronary artery aneurysm (CAA) in southern Chinese KD patients.

Methods

We evaluated 318 KD patients with CAAs and 784 patients without CAAs. TaqMan assays were used to estimate genotyping and analyze the relationship between miRNA polymorphisms (miR‐149 rs2292832 T>C, miR‐196a2 rs11614913 C>T and miR‐499a rs3746444 A>G) and risk associations of CAA by odds ratios (ORs) and 95% confidence intervals (CIs).

Results

We found that the miR‐149 rs2292832 TC/CC genotype increased the CAA risk (adjusted OR = 1.53, 95% CI = 1.15–2.03, p = 0.003 for TC, adjusted OR = 1.63, 95% CI = 1.08–2.47, p = 0.021 for CC), whereas the miR‐499a rs3746444 AG genotype decreased the CAA risk in KD patients (adjusted OR = 0.33, 95% CI = 0.25–0.45 p ≤ 0.001). Moreover, patients carrying two or three of these single nucleotide polymorphism (SNP) genotypes (rs2292832 TC/CC and rs11614913 TT and rs3746444 AA) had a higher risk for CAA than those who harbored only zero or one of these SNP genotypes.

Conclusions

Our results demonstrated that the miR‐149 rs2292832 T>C polymorphism increased the risk of CAA in KD patients and that the miR‐499a rs3746444 A>G polymorphism decreased the risk of CAA in KD patients. Further studies with larger sample sizes and different centers are needed to confirm the findings of the present study.

SNPs in miRNAs and Target Sequences: Role in Cancer and Diabetes

miRNAs are fascinating molecular players for gene regulation as individual miRNA can control multiple targets and a single target can be regulated by multiple miRNAs. Loss of miRNA regulated gene expression is often reported to be implicated in various human diseases like diabetes and cancer. Recently, geneticists across the world started reporting single nucleotide polymorphism (SNPs) in seed sequences of miRNAs. Similarly, SNPs are also reported in various target sequences of these miRNAs. Both the scenarios lead to dysregulated gene expression which may result in the progression of diseases. In the present paper, we explore SNPs in various miRNAs and their target sequences reported in various human cancers as well as diabetes. Similarly, we also present evidence of these mutations in various other human diseases.

The protective effects of allopurinol against IL-17A-induced inflammatory response in mast cells

Rheumatoid arthritis (RA) is a common autoimmune disease in the elderly and it has been recently reported to be significantly associated with the activation of mast cells in joint tissues. IL-17A is a vital mediator that stimulates the activation of inflammation. Allopurinol is a classic agent for the suppression of uric acid production, recently reported to exert therapeutic effects on RA. In the present study, we investigated the regulatory effect of allopurinol against IL-17A-induced inflammatory response in mast cells and explored the potential mechanism of allopurinol on RA treatment. Firstly, we found that compared to normal synovium, IL-17A was significantly upregulated in the human RA synovium. IL-17A was used to stimulate an inflammatory state in mast cells in the absence or presence of allopurinol. We found that the production of inflammatory factors, PGE₂, and COX-2 was significantly elevated in IL-17A-treated mast cells, accompanied by the activation of the iNOS/NO axis and the elevated secretion of ROS. After treatment with allopurinol, the elevated inflammation, activated COX-2/PGE₂ and iNOS/NO axis, and oxidative stress were all dramatically alleviated. Mechanistically, the activated JNK/AP-1 and NF-κB pathways in IL-17A-treated mast cells were dramatically suppressed by the introduction of allopurinol. Taken together, our data reveal that allopurinol significantly alleviated the IL-17A-induced inflammatory response in mast cells.

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.

Chitosan and Lecithin Ameliorate Osteoarthritis Symptoms Induced by Monoiodoacetate in a Rat Model

The present work aimed to assess the chondroprotective influence of chitosan and lecithin in a monoiodoacetate (MIA)-induced experimental osteoarthritis (OA) model. Forty male rats weighing 180–200 g were randomly distributed among the following five experimental groups (eight per group): control, MIA-induced OA, MIA-induced OA + chitosan, MIA-induced OA + lecithin, and MIA-induced OA + chitosan + lecithin. The levels of TNF-α, IL6, RF, ROS, and CRP, as well as mitochondrial markers such as mitochondrial swelling, cytochrome C oxidase (complex IV), MMP, and serum oxidative/antioxidant status (MDA level) (MPO and XO activities) were elevated in MIA-induced OA. Also, SDH (complex II) activity in addition to the levels of ATP, glutathione (GSH), and thiol was markedly diminished in the MIA-induced OA group compared to in control rats. These findings show that mitochondrial function is associated with OA pathophysiology and suggest that chitosan and lecithin could be promising potential ameliorative agents in OA animal models. Lecithin was more effective than chitosan in ameliorating all of the abovementioned parameters.

Synthesis of N,N'-bis(1,5-dimethyl-2-phenyl-1,2-dihydro-3-oxopyrazol-4-yl) sebacamide that ameliorate osteoarthritis symptoms and improve bone marrow matrix structure and cartilage alterations induced by monoiodoacetate in the rat model: "Suggested potent anti-inflammatory agent against COVID-19"

To assess the chondroprotective effect and influence of N,N′-bis(1,5-dimethyl-2-phenyl-1,2-dihydro-3-oxopyrazol-4-yl) sebacamide (dpdo) that was synthesized through the reaction of phenazone with sebacoyl chloride and screened for its biological activity especially as anti-arthritic and anti-inflammatory agent in a monoiodoacetate (MA)-induced experimental osteoarthritis (OA) model. Thirty male albino rats weighing “190–200 g” were divided randomly into three groups (10 each): control, MA-induced OA, and MA-induced OA + dpdo. In MA-induced OA rat, the tumor necrosis factor alpha, interleukin 6, C-reactive protein, rheumatoid factors, reactive oxygen species, as well as all the mitochondrial markers such as mitochondria membrane potential, swelling mitochondria, cytochrome c oxidase (complex IV), and serum oxidative/antioxidant status (malondialdehyde level and activities of myeloperoxidase and xanthine oxidase) are elevated. Also, the activity of succinate dehydrogenase (complex II), levels of ATP, the level of glutathione (GSH), and thiol were markedly diminished in the MA-induced OA group compared to the normal control rats. These findings showed that mitochondrial function is associated with OA pathophysiological alterations and high gene expressions of (IL-6, TNF-a, and IL-1b) and suggests a promising use of dpdo as potential ameliorative agents in the animal model of OA and could act as anti-inflammatory agent in case of severe infection with COVID-19. It is clearly appeared in improving the bone cortex and bone marrow in the treated group with the novel compound in histological and transmission electron microscopic sections which is a very important issue today in fighting severe infections that have significant effects on the blood indices and declining of blood corpuscles like COVID-19, in addition to declining the genotoxicity and inflammation induced by MA in male rats. The novel synthesized compound was highly effective in improving all the above mentioned parameters.

miR-149 and miR-499 gene polymorphism and the incident of ischemic stroke in the Asian population: From a case-control study to meta-analysis

OBJECTIVES

MiRNAs are the most abundant class of regulatory non-coding RNA, which may exert a significant role in the pathogenesis of ischemic stroke(IS). Previous studies have focused on the relationship between miRNA polymorphism and IS risk, but the results remain inconsistent. Therefore, we first conducted a case-control study to explore the association, and subsequently performed a meta-analysis to further to clarify the association of miRNA polymorphism with risk of ischemic stroke.

PATIENTS AND METHODS

We first conducted a case-control study including 567 IS patients and 552 controls. Then we performed a meta-analysis combining the current study and previous studies with a total of 3015 cases and 2874 controls on miR-149 rs2292832 and 4119 cases and 4085 controls on miR-499 rs3746444 to further confirm our findings by searching PubMed, Web of Science and Chinese National Knowledge Infrastructure (CNKI) databases database up to Nov 2019.

RESULTS

In our case-control study, no association between miR-499 rs3746444, miR-149 rs2292832 and IS were found. When combined with previous studies, however, a significant relationship between miR-149 rs2292832 and ischemic stroke incident was found under recessive model and allelic model. In other words, CC genotype and C allele of miR-149 rs2292832 were increased risk of ischemic stroke.

CONCLUSION

Our meta-analysis results suggest that miR-149 rs2292832 might contribute to stroke susceptibility in the Asian populations.

miRNA polymorphisms and risk of premature coronary artery disease

OBJECTIVE

Several microRNA (miRNA) polymorphisms have been associated with susceptibility to specific health disorders, including cardiovascular diseases. The aim of the present study was to investigate whether four well-studied miRNA polymorphisms in non-Caucasian populations, namely miR146a G>C (rs2910164), miR149 C>T (rs2292832), miR196a2 C>T (rs11614913) and miR499 A>G (rs3746444), contribute to the risk for the development of premature Coronary Artery Disease (CAD) in the Greek population.

METHODS

We used a case-control study to examine these associations in 400 individuals: 200 CAD patients [including a subgroup of myocardial infraction (MI) patients] and 200 healthy controls, all of Greek origin. MiRNA polymorphisms were genotyped using three different assays: Polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP), High resolution Melting (HRM) and Sanger sequencing.

RESULTS

Two of these polymorphisms, miR196a2 C>T (rs11614913) and miR499 A>G (rs3746444) were found to be strongly associated with increased risk for CAD (p=0.0388 and p=0.0013, respectively) and for MI (p=0.0281 and p=0.0273, respectively). Furthermore, miR146C-miR149C-miR196T-miR499G allele combination appeared to be significantly related to CAD (p=0.0185) and MI (p=0.0337) prevalence.

CONCLUSIONS

Our results suggest that at least two of the studied polymorphisms, miR196a2 C>T (rs11614913) and miR499 A>G (rs3746444), as well as the miR146C-miR149C-miR196T-miR499G allele combination could represent useful biomarkers of CAD and/or MI susceptibility in the Greek population. These special genetic characteristics, in combination with environmental factors and personal habits, might contribute to CAD and/or MI prevalence.

Influence of miRNA Gene Polymorphism on Recurrence and Age at Onset of Ischemic Stroke in a Chinese Han Population

Polymorphisms in microRNAs (miRNAs) are associated with ischemic stroke occurrence and traditional risk factors for ischemic stroke such as atherosclerosis, hypertension, hyperlipidemia, and diabetes. However, few studies have examined recurrent ischemic stroke as an outcome. Thus, the aim of our study was to examine association of miRNA gene polymorphisms (namely, miR-126 rs4636297, miR-149 rs2292832, miR-124 rs531564, miR-499 rs3746444, miR-143 rs12655723, and miR-122 rs17669) with recurrence of ischemic stroke. miRNA gene polymorphisms were genotyped using the polymerase chain reaction-ligation detection reaction (PCR-LDR) method in 657 patients with ischemic stroke. Association of miRNA polymorphisms with prognosis outcomes was examined by the Kaplan-Meier method, log-rank test, and Cox proportional hazards models. miR-122 rs17669 was significantly associated with recurrence risk of ischemic stroke under the recessive model. Cox regression analysis showed that the CC genotype of rs17669 was associated with an increased risk of 1.9-fold for stroke recurrence (hazard ratio = 1.879; 95% confidence interval = 1.182-2.985; P = 0.008). Further, this effect was more evident among the non-drinker and male subgroups. We found no difference in risk of recurrent ischemic stroke among the other five miRNA polymorphisms. Furthermore, we identified a significant association between the miR-149 rs2292832 polymorphism and age at onset of first-ever stroke. Altogether, miR-122 rs17669 is a significant predictor for the risk of recurrent stroke, independent of traditional risk factors.

Nuclear factor-κB1 and MicroRNA-146a polymorphisms and risk of acute graft versus host disease post allogeneic stem cell transplantation

Acute graft-versus-host disease (aGVHD) is a severe inflammatory complication of haematopoeitic stem cell transplantation. The nuclear factor- Kappa Beta (NF-κB) signaling pathway regulates T cell activation. The NF-κB controls the expression of microRNA-146a (miR-146a) that in turn regulates NF-κB activation through a negative feedback loop. We aim to analyze the association between NF-κB1 encoding p50 (rs28362491, -94 in.ertion/deletion ATTG) and miR-146a (rs2910164, G > C) polymorphisms and risk of aGVHD. Genotyping was performed for 135 HLA-matched donors using polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP).The incidence of aGVHD grades II-IV was 24/135 (17.8 %). NF-κB1 genotype and cytomegalovirus infection were significantly associated with risk of aGVHD II-IV (p = 0.022, HR = 3.17, 95 % CI:1.18-8.51 and p = 0.048, HR = 2.56, 95 % CI:1.01-6.52, respectively). In multivariate analysis, NF-κB1homozygous deletion/deletion genotype was the only independent risk factor associated with aGVHD II-IV (p = 0.013, HR = 3.50, 95 % CI:1.30-9.44). No significant association could be observed between miR-146a polymorphism and aGVHD. Combined NF-κB1 and miR146a genotype analysis warrants investigation in a larger cohort. Our preliminary data do not support the association between miR146a and aGVHD, but suggest an association between NF-κB1 and risk of aGVHD that may pave the way for the development of a novel targeted therapy if proved in a larger cohort.

Association between MicroRNA-4669 Polymorphism and Ischemic Stroke in a Korean Population

Recent studies have explored the association between single-nucleotide polymorphisms (SNPs) in microRNAs (miRNAs) and ischemic stroke (IS). In particular, the associations of rs2910164 (miRNA-146A), rs11614913 (miRNA-196A2), and rs3746444 (miRNA-499A) were intensively studied in IS. In this study, we investigated the associations between SNPs in miRNAs and IS including rs2910164, rs11614913, and rs3746444 in a Korean population. For a pilot study, we selected 19 SNPs in pre-miRNA region (including mature miRNA region) and genotyped in 140 IS patients and 240 control subjects using the Fluidigm Dynamic Array. Our pilot study showed a weak association of rs79402775 in miRNA-933 (p = 0.044) and a relatively strong association of rs35196866 in miRNA-4669 (p = 0.016) with IS. From the pilot study, we selected rs79402775, rs35196866, and rs7202008 (miRNA-2117; p = 0.055) as candidate miRNA SNPs on IS and further genotyped these SNPs in 264 IS patients and 455 control subjects using direct sequencing. In addition, we further analyzed the associations of rs2910164, rs11614913, and rs3746444 that have been intensively studied in previous studies. In the further analysis, we found the significant association between rs35196866 and IS (p = 0.0014 in additive model and p = 0.00015 in dominant model; p = 0.00037 in allele frequency analysis). However, the association between rs2910164, rs11614913, rs3746444, rs79402775, and rs7202008 and IS was not shown. These results suggest that miRNA-4669 may be involved in the susceptibility of IS.

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.

Associations of miR-146a, miR-149, miR-196a2, and miR-499 Polymorphisms with Ischemic Stroke in the Northern Chinese Han Population

BACKGROUND Recently, miR-146a C>G, miR- 149 T>C, miR-196a2 T>C and miR-499 A>G polymorphisms have been associated with susceptibility to many diseases, including ischemic stroke (IS). However, results have been reported inconsistency in IS, especially in the Chinese population. This study aimed to investigate the polymorphisms of the 4 miRNAs and IS risk in the Chinese population. MATERIAL AND METHODS We used a case-control study to explore these associations in 396 patients with IS and 378 healthy controls. According to TOAST standards, the selected patients were divided into subgroups: the large artery atherosclerosis (LAA) subgroup and the small artery occlusion (SAO) subgroup. The method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect the genotypes. RESULTS The miR-146a C>G polymorphism was remarkably different (CC vs. CG+GG: P=0.027; CC+CG vs. GG: P=0.020; C vs. G: P=0.006). The miR-149 T>C polymorphism was also remarkably different (TT vs. TC+CC: P=0.017; TT+TC vs. CC: P=0.020; T vs. C: P=0.004). The miR-146a and miR-149 polymorphisms were also remarkably different in the LAA subgroup (P<0.05). However, we did not find an association of miR-196a2 T>C or miR-499 A>G polymorphisms with IS (P>0.05); we did not find any association in the LAA subgroup or the SAO subgroup (P>0.05). CONCLUSIONS Our study suggested that miR-146a C>G and miR-149 T>C polymorphisms might remarkably increase the risk of IS, which might be mainly associated with an increased risk in LAA stroke; however, the miR-196a2 T>C and miR-499 A>G polymorphisms might not be associated with IS risk in the northern Chinese Han population.

Association between polymorphisms in microRNAs and ischemic stroke in an Asian population: evidence based on 6,083 cases and 7,248 controls

Background

Polymorphisms in miR-146a (rs2910164), miR-196a2 (rs11614913), miR-149 (rs2292832) and miR-499 (rs3746444) have been associated with ischemic stroke (IS), but studies have given inconsistent results.

Methods

This meta-analysis investigated the possible association between IS risk and the four polymorphisms. A total of 14 case-control studies from Asian populations involving 6,083 cases and 7,248 controls for the four polymorphisms were included.

Results

Results showed that the GG genotype of miR-146a (rs2910164) may be associated with increased IS risk according to the recessive model (OR=1.20, 95% CI=1.02–1.42, P=0.03). Similarly, the CC genotype of miR-149 (rs2292832) may be associated with increased IS risk according to the recessive model (OR=1.28, 95% CI=1.08–1.52, P=0.005) and the homozygous model (OR=1.31, 95% CI=1.09–1.58, P=0.004). In contrast, miR-196a2 (rs11614913) and miR-499 (rs3746444) polymorphisms did not show significant association with IS risk in any of the five genetic models.

Conclusion

These results indicate that the GG genotype of miR-146a (rs2910164) and CC genotype of miR-149 (rs2292832) may confer increased susceptibility to IS, while miR-196a2 (rs11614913) and miR-499 (rs3746444) polymorphisms may not be associated with IS risk in Asian populations. These conclusions should be verified in large and well-designed studies.

Altered microRNA expression signature in Chikungunya-infected mammalian fibroblast cells

Chikungunya virus (CHIKV) infection can cause severe arthralgia and chronic arthritis in humans. MicroRNAs (miRNA) have demonstrated their potential use as biomarker in variety of human pathologies and infections. This study was conducted to understand the miRNA signature in early CHIKV infection stages. In the current study, we used TaqMan-based quantitative PCR method to identify the miRNA signature of host response upon CHIKV infection in human and mouse fibroblast cells. The GO enrichment analysis suggests that the putative target genes of these differentially expressed miRNAs are to be involved in RIG-I pathway, TGF-beta-signaling pathway, JAK-STAT-signaling pathway, MAPK-signaling pathway, cytokine-cytokine receptor interactions, and Fc gamma R-mediated phagocytosis. The results obtained in the current study and earlier studies indicate the potential use of miR15, miR-16, miR-17, let-7e, miR-125, miR-99, and miR-23a as a biomarker in CHIKV infection. miRNAs such as miR-15a, miR-16, miR-140, miR-146a, miR-155, miR203, miR223, miR-499, and miR-363 which are implicated in rheumatoid arthritis showed differential regulation in CHIKV infection. The data obtained in this study provide valuable information on CHIKV-induced miRNA expression in mammalian fibroblast cells, and suggest that CHIKV may establish infection by regulating miRNA expression profile.

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.

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.

Association Between MicroRNAs Polymorphisms and Risk of Ischemic Stroke: A Meta-Analysis in Chinese Individuals

Objective: Previous studies have demonstrated that some single-nucleotide polymorphisms (SNPs) in miRNAs are related to the risk of ischemic stroke (IS), but the conclusions are still controversial and inconclusive. We performed this meta-analysis to further assess the association between miR-146a C>G (rs2910164), miR-149 T>C (rs2292832), miR-196a2 T>C (rs11614913), miR-499 A>G (rs3746444) and risk of IS in Chinese individuals. Methods: Relevant studies were identified in the databases of PubMed, Embase. The strength of correlation between microRNAs polymorphisms and IS risk was assessed by odds ratios (ORs) and 95% confidence intervals (95% CIs) under five genetic models. Results: 5 studies, containing 2,632 cases and 3,191 controls, were included in this meta-analysis. The overall results of meta-analysis indicated that there were no significant association between miR-146a C>G (rs2910164), miR-149 T>C (rs2292832), miR-196a2 T>C (rs11614913), and the IS risk in the overall analyses. MiR-499 A>G (rs3746444) was associated with an increased IS risk under allele model (OR = 1.30, 95% CI = 1.02-1.66), heterozygous model (OR = 1.35, 95% CI = 1.01-1.79) and dominant model (OR = 1.36, 95% CI = 1.02-1.80) in Chinese. The sensitivity analysis results of these four polymorphisms were similar to the overall results. Conclusion: MiR-499 A>G (rs3746444) G allele and AG, AG + AA genotype might be risk factors of IS in Chinese. No significant association was observed between miR-146a C>G (rs2910164), miR-149 T>C (rs2292832), miR-196a2 T>C (rs11614913), and IS risk. The associations may be different due to geographical factors of China. More explorations in more diverse geographically regions with large sample size are expected to further verify the findings in the future.

Reduced DICER1 Expression Bestows Rheumatoid Arthritis Synoviocytes Proinflammatory Properties and Resistance to Apoptotic Stimuli

OBJECTIVE

While the regulatory role of individual microRNAs (miRNAs) in rheumatoid arthritis (RA) is well established, the role of DICER1 in the pathogenesis of the disease has not yet been investigated. The purpose of this study was to analyze the expression of factors involved in miRNA biogenesis in fibroblast-like synoviocytes (FLS) from RA patients and to monitor the arthritis triggered by K/BxN serum transfer in mice deficient in the Dicer gene (Dicer(d/d) ).

METHODS

The expression of genes and precursor miRNAs was quantified by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). MicroRNA macroarray profiling was monitored by qRT-PCR. Cytokines were quantified by enzyme-linked immunosorbent assay. Experimental arthritis in mice was achieved by the transfer of serum from K/BxN donors. Apoptosis was quantified using an enzyme-linked immunosorbent assay.

RESULTS

We found decreased DICER1 and mature miRNA expression in synovial fibroblasts from RA patients. These cells were hyperresponsive to lipopolysaccharide, as evidenced by their increased interleukin-6 secretion upon stimulation. Experimental serum-transfer arthritis in Dicer(d/d) mice confirmed that an unbalanced biogenesis of miRNAs correlated with an enhanced inflammatory response. Synoviocytes from both RA patients and Dicer(d/d) mice exhibited increased resistance to apoptotic stimuli.

CONCLUSION

The findings of this study further substantiate the important role of DICER1 in the maintenance of homeostasis and the regulation of inflammatory responses.

Association of miR-146a, miR-149, miR-196a2, miR-499 gene polymorphisms with ischemic stroke in a Chinese people

This study aimed to investigate genetic polymorphisms of miR-146a, miR-149, miR-196a2, and miR-499 and genetic susceptibility of ischemic stroke in the population of Guangxi in China. A case–control study was used to investigate miRNAs genetic polymorphisms in 298 patients with ischemic stroke and 303 healthy controls. Single-base extension polymerase chain reaction genotyping principle was used to detect genetic polymorphisms of miRNAs,and the relationship of genotype in each group and blood lipid was compared and analyzed. The genetic polymorphism of miR-499A>G (rs3746444) was associated with ischemic stroke (P < 0.05), and the risk of ischemic stroke was high in patients with G allele (OR = 1.455; 95% CI = 0.531–2.381; P = 0.039) and AG (OR = 1.339; 95% CI = 1.126–1.967; P = 0.037) genotype. The levels of low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, homocysteine, and lipoprotein in the ischemic stroke group were higher than those in the control group (P < 0.05). The genetic polymorphism of miR-499A>G (rs3746444) was related to ischemic stroke, and G allele and AG genotype may increase the risk of ischemic stroke in the population of Guangxi in China.

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.

Association of miR-196a-2 and miR-499 variants with ulcerative colitis and their correlation with expression of respective miRNAs

Background and aim

MicroRNAs are small non-coding RNAs that play an important role in regulating the gene expression of their target genes. SNP miR-196a-2 rs11614913 and miR-499 rs3746444 are reported to have association with the risk and prognosis of multiple-types of inflammatory diseases including IBD. This study was conducted to show if any association of SNP miR-196a-2rs11614913 and miR-499 rs3746444 exists with ulcerative colitis (UC) patients of north Indian population and how these polymorphisms modulate the expression profile of the respective miRNAs.

Methods

A total of 638 participants including 197 UC patients and 441 controls were included in this study. Polymorphisms were genotyped by PCR-RFLP and the miRNA expression was measured using qRT-PCR. Genotypes and allele frequencies were calculated using SPSS 16 software.

Results

MiR-196a-2 rs11614913 (C>T) and miR-499 rs3746444 (T>C) were found to be associated with UC. TT genotype of miR-196a-2 rs11614913 (p = 0.03) was negatively associated with UC whereas the heterozygous TC genotype of miR-499 rs3746444 (p = 0.003) was showing positive association with UC. Patients having a combination of both SNPs, developed disease at older age and they suffered from severe disease extent. Genotype that showed association with the disease also showed correlation with the changes in miRNA expression.

Conclusion

In this study we found miR-196a-2 rs11614913 and miR-499 rs3746444 were associated with UC in north Indian population. We found the genotype that showed association with UC also altered the expression of respective miRNA in the patient harboring the genotype. There was correlation between associated genotype and altered miRNA expression.

A functional variant of miRNA-149 confers risk for allergic rhinitis and comorbid asthma in Chinese children

The prevalence of allergic rhinitis (AR) and asthma has been increasing, and the comorbidity rates of these diseases are very high. Here, 176 AR patients, 124 patients with comorbid AR and asthma (AR-A) and 206 healthy Chinese children as controls were included in a case-control study. Six single-nucleotide polymorphisms (SNPs), miR-146a (rs2910164, rs57095329 and rs6864584), miR-196a2 (rs11614913), miR-499 (rs3746444) and miR-149 (rs2292832), were genotyped. The prevalence of homozygous miR-149 (rs2292832) CC genotype and C allele were considerably increased in AR and AR-A patients, compared with the controls. AR-A group showed higher frequencies of CC genotype and C allele of rs2292832 than AR group. No significant difference in the genotypic and allelic frequencies of other miRNA SNPs was found between the groups. MiR-149 levels in peripheral blood mononuclear cells (PBMCs) were significantly lower in CC (variant type) cases compared with TT (wild-type) cases. In further experiments, PBMCs obtained from the healthy controls with CC, CT and TT genotypes were stimulated by house dust mite extracts, which led to a significant decrease in the levels of miR-149 in PBMCs obtained from CC and TT individuals. This decrease was more pronounced in CC compared with TT cases. Our results demonstrate that miR-149 rs2292832 variant is not only strongly associated with AR and AR-A, but it may lead to an increase in the susceptibility to allergies following the stimulation with an allergen, through the changes in miR149 expression. Additionally, AR patients with CC genotypes were shown to be more susceptible to asthma.

MicroRNA-146a rs2910164 is associated with severe preeclampsia in Black South African women on HAART

BACKGROUND

South African (SA) Black women have a high prevalence of preeclampsia and HIV, both conditions associated with increased inflammation. miR-146a is an inflammatory-associated miR and a common single nucleotide polymorphism (rs2910164) has been associated with several disease conditions. To date, this SNP has not been investigated in SA Black women. We therefore aimed to investigate the miR-146a G > C SNP in SA Blacks with preeclampsia, and further examine possible association among preeclamptic (PE) women with HIV infection on HAART.

METHODS

This hospital-based, case-control study included 95 normotensive and 98 PE Black SA women (aged 16-46 years old). Patients and controls were genotyped by PCR-RFLP. Using a Cytometric Bead Array assay, serum cytokine levels (including Th1- and Th2-related cytokines) were determined in 4 groups of pregnant women, viz: normotensive, HIV infected, PE + HIV infected, and PE women.

RESULTS

There was no significant association between the miR-146a polymorphism and PE susceptibility in our data. However, in the subgroup analyses, the variant genotypes (GC/CC) were significantly associated with lower severe PE risk (p = 0.0497), more especially in the presence of HIV and HAART (p = 0.017). In the normotensive group, the variant genotypes were associated with lower IL-2 in both the total normotensive group (269 ± 1.26 (36) vs 273 ± 1.31 (23); p = 0.035) and the PE HIV+ sub-group 265 ± 1.54 (19) vs 271 ± 1.38 (11); p = 0.008).

CONCLUSIONS

Our study suggests that miR-146a rs2910164 polymorphism might not be associated with PE susceptibility, cytokines or related features. However, the miR-146a GC/CC genotype might reduce susceptibility to severe PE, which might be further influenced by the presence of co-morbid HIV infection among pregnant women on HAART. This variant genotype may also be associated with reduced circulating IL-2 levels and thus reduced pro-inflammatory response in normotensive women, which may be further influenced by the presence of HIV infection and HAART.

Polymorphisms in MIR499A and MIR125A gene are associated with autoimmune thyroid diseases

BACKGROUND

Single nucleotide polymorphisms (SNPs) of the miR-146a, miR-499a and miR-125a have been shown to be associated with the susceptibility to several autoimmune diseases. This study was conducted to identify the association of SNPs rs2910164, rs57095329, rs3746444 and rs12976445 with autoimmune thyroid diseases (AITDs) in a Chinese Han population.

METHODS

We enrolled 1061 patients with AITDs, including 701 patients with Graves' disease (GD) and 360 patients with Hashimoto's thyroiditis (HT), and 938 healthy individuals for a case-control genetic association study. Four SNPs were selected for genotyping by multiplex polymerase chain reaction and ligase detection reaction.

RESULTS

The frequencies of rs3746444 genotypes in patients with AITD and GD differed significantly from those in the controls. The frequencies of rs12976445 genotypes in patients with HT differed significantly from those in the controls. The frequencies of allele C in HT groups were significantly higher than those in control group. For the rs3746444 polymorphism, genetic associations between the combinational genotype and AITD/GD risk were observed in the dominant model, recessive model, and overdominant model. For the rs12976445 polymorphism, genetic associations between the combinational genotype and HT risk were also found in the dominant model and overdominant model. Moreover, gene-sex interactions were identified by GMDR and 2 × 2 crossover analysis.

CONCLUSIONS

Our results suggest rs3746444 (miR-499a) and rs12976445 (miR-125a) associated with AITD susceptibility and potential gene-sex interactions between the four polymorphisms and AITD.

Association between microRNA polymorphisms and coronary heart disease : A meta-analysis

The association between microRNA polymorphisms (miR polymorphisms) and coronary heart disease (CHD) risk has been studied intensively, but the results have been conflicting. Therefore, we conducted the present meta-analysis to obtain a more conclusive answer. We searched for eligible articles in PubMed, MEDLINE, EMBASE, Scopus, and CNKI. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to identify any potential associations. Ten case-control studies including 5,292 CHD patients and 5,446 control subjects were analyzed. The overall meta-analysis results showed that the miR-146a rs2910164 polymorphism, the miR-196a2 rs11614913 polymorphism, and the miR-499 rs3746444 polymorphism were all significantly associated with CHD risk in certain genetic models. Besides, the C allele of the miR-146a rs2910164 and miR-499 rs3746444 polymorphisms conferred increased susceptibility to CHD (C versus G, p < 0.0001, OR = 1.14, 95% CI = 1.07-1.21; p = 0.003, OR = 1.14, 95% CI = 1.05-1.25). Overall, our findings suggest that the miR-146a rs2910164, miR-196a2 rs11614913, and miR-499 rs3746444 polymorphisms may be correlated with the risk of CHD.

X-Linked miRNAs Associated with Gender Differences in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that predominantly affects women. MicroRNAs have emerged as crucial regulators of the immune system, whose expression is deregulated in RA. We aimed at quantifying the expression level of 14 miRNAs located on the X chromosome and at identifying whether differences are associated with disease and/or sex. A case-control study of 21 RA patients and 22 age- and sex-matched healthy controls was performed on peripheral blood mononuclear cells. The expression level of five miRNAs (miR-221, miR-222, miR-532, miR-106a, and miR-98) was significantly different between RA and controls when stratifying by sex, and the expression level of four miRNAs (miR-222, miR-532, miR-98, and miR-92a) was significantly different between RA females and males. The expression quantitative trait loci (eQTL) analysis revealed a significant gender effect of the FoxP3 promoter polymorphism rs3761548A/C on miR-221, miR-222 and miR-532 expression levels, and of the FoxP3 polymorphism rs2232365A/G on miR-221 expression levels in PBMC of RA patients. These data further support the involvement of the X chromosome in RA susceptibility. X-linked miRNAs, in the context of sex differences, might provide novel insight into new molecular mechanisms and potential therapeutic targets in RA for disease treatment and prevention.

Association of miR-146a, miR-149, miR-196a2, and miR-499 Polymorphisms with Ossification of the Posterior Longitudinal Ligament of the Cervical Spine

Background

Ossification of the posterior longitudinal ligament (OPLL) of the spine is considered a multifactorial and polygenic disease. We aimed to investigate the association between four single nucleotide polymorphisms (SNPs) of pre-miRNAs [miR-146aC>G (rs2910164), miR-149T>C (rs2292832), miR-196a2T>C (rs11614913), and miR-499A>G (rs3746444)] and the risk of cervical OPLL in the Korean population.

Methods

The genotypic frequencies of these four SNPs were analyzed in 207 OPLL patients and 200 controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay.

Findings

For four SNPs in pre-miRNAs, no significant differences were found between OPLL patients and controls. However, subgroup analysis based on OPLL subgroup (continuous: continuous type plus mixed type, segmental: segmental and localized type) showed that miR-499GG genotype was associated with an increased risk of segmental type OPLL (adjusted odds ratio = 4.314 with 95% confidence interval: 1.109–16.78). In addition, some allele combinations (C-T-T-G, G-T-T-A, and G-T-C-G of miR-146a/-149/-196a2/-499) and combined genotypes (miR-149TC/miR-196a2TT) were associated with increased OPLL risk, whereas the G-T-T-G and G-C-C-G allele combinations were associated with decreased OPLL risk.

Conclusion

The results indicate that GG genotype of miR-499 is associated with significantly higher risks of OPLL in the segmental OPLL group. The miR-146a/-149/-196a2/-499 allele combinations may be a genetic risk factor for cervical OPLL in the Korean population.

miRNA-216 and miRNA-499 target cyb561d2 in zebrafish in response to fipronil exposure

MicroRNA (miRNA) can regulate the expression of its target gene by mediating mRNA cleavage or by translational repression at a post-transcriptional level. Usually, one miRNA may regulate many genes as its targets, while one gene may also be targeted by many miRNAs. We previously demonstrated that cyb561d2, whose protein product is involved in cell defense, and chemical stress, is targeted by miR-155 in adult zebrafish (Danio rerio) when exposed to fipronil (5-amino-1-[2,6-dichloro-4-(trifluoromethyl) phenyl]-4-[(trifluoromethyl) sulphinyl]-1H-pyrazole-3-carbonitrile). Microcosm Targets prediction showed that the cyb561d2 gene is also highly possibly targeted by miR-194a, miR-216b, miR-429, and miR-499. These interactions need to be further validated experimentally. In this study, we evaluated the effects of fipronil on miR-194a, miR-216b, miR-429, miR-499 and cyb561d2 in zebrafish and investigated whether these four miRNAs could regulate the expression of cyb561d2 in both mRNA and protein levels. The expression of cyb561d2 was upregulated in both mRNA and protein level in a dose-dependent manner upon stimulation of fipronil, and miR-216b and miR-499 were downregulated concurrently, whereas there was no significant changes were observed in the expression level of miR-194a and miR-429. The dual luciferase report assay demonstrated that miR-216b and miR-499 interacted with cyb561d2 3'-untranslated regions (3'-UTR), miR-194a and miR-429 did not stimulate degradation of cyb561d2 mRNA. The expression of cyb561d2 was reduced in both mRNA and protein level when ZF4 cells were transfected with miR-499 mimic, whereas expression level of both mRNA and protein was increased when endogenous miR-499 was inhibited by transfection with miR-499 inhibitor. Likewise, the mRNA and protein level of cyb561d2 was affected by treatment with the mimics and the inhibitor of miR-216b. In contrast, when ZF4 cells were transfected with a mimic of miR-194a or miR-429, the expression of cyb561d2 mRNA was not significantly changed. As a result, cyb561d2 is targeted by miR-155, miR-216b and miR-499 upon fipronil exposure, and miR-194a and miR-429 can not target cyb561d2. The expression pattern of these 3 miRNAs presents novel fipronil responses that could be used as a toxicological biomarker.

RNAi agents as chikungunya virus therapeutics

Chikungunya virus (CHIKV) is a mosquito-borne emerging pathogen that presents a major health impact in humans. The virus causes acute febrile illness accompanied by joint pains and, in many cases, persistent arthralgia lasting for weeks to years. There are currently no licensed antiviral agents available against CHIKV. A few lead compounds and natural products have recently shown promising results and could emerge as effective treatments for CHIKV. Further, with the emerging knowledge of the biology of CHIKV, RNAi-based gene silencing approaches also hold great promise for the treatment of CHIKV. This review summarizes the applicability of RNAi agents, siRNA, shRNA and miRNA central to RNAi as therapeutic approaches against CHIKV.

MicroRNA-499 Rs3746444 polymorphism and biliary atresia

BACKGROUND

Single nucleotide polymorphisms within microRNAs are known to affect the risk in development and prognosis of many diseases. This study was designed to investigate whether polymorphism of microRNA-499 (miR-499, rs3746444 A>G) is associated with risk to biliary atresia (BA).

METHODS

A hospital-based cases-control study was performed on a total of 507 Han Chinese (207 BA cases and 300 ethnically-matched healthy controls without any evidence of liver diseases) so as to analyze the association between miR-499 rs3746444 polymorphism and BA risk as well as liver function remission (LFR) after liver transplantation.

RESULTS

A significant higher frequency of the rs3746444 G alleles was found in the BA cases than the control group (odd ratio, 1.55, 95% confidence intervals [CIs], 1.15-2.10). This polymorphism was also observed to correlate with some clinic-pathological features of BA cases such as liver inflammatory. Further research found both higher levels of IL-6 (P<0.05) and TNF-α (P<0.05) in removed liver as well as in serum. What is more, the miR-499 rs3746444 polymorphism significantly affected the status of LFR (hazard ratio, 1.37; 95% CI, 1.08-1.83).

CONCLUSIONS

MiR-499 (rs3746444) gene polymorphisms may be genetic determinants for increased risk of BA and prolonged recovery of BA patients after liver transplantation in Han Chinese.

Genetic Variants in MicroRNAs Predict Recurrence of Ischemic Stroke

MicroRNAs are a recently discovered class of small noncoding RNA, which play key roles in every aspect of brain function, including neural development and neurogenesis. Since abnormal expression and function of microRNAs has been observed in ischemic stroke, we evaluated whether genetic variations in microRNAs can influence the clinical behavior of ischemic stroke. Common functional microRNA SNPs (i.e., miR-146a rs2910164, miR-149 rs2292832, miR-196a2 rs11614913, miR-499 rs3746444, miR-605 rs2043556, and miR-618 rs2682818) were genotyped in 914 patients with ischemic stroke. MicroRNAs variants were not associated with age of ischemic stroke onset (P > 0.05). However, we found that miR-618 rs2682818 GT/TT genotypes were significantly associated with an increased risk of ischemic stroke recurrence, compared with the GG genotype (hazard ratio [HR] = 1.72; 95 % confidential interval [CI], 1.08 to 2.74; log-rank P = 0.006), and this effect was more pronounced among subjects with small-vessel disease (HR = 2.60; 95 % CI, 1.11 to 6.08; log-rank P = 0.007). Moreover, the variant genotypes (GT/TT) of rs2682818 were an independent prognostic factor for ischemic stroke in the multivariate Cox regression model. Our findings suggest that miR-618 SNP rs2682818 may play an important role in the recurrence of ischemic stroke.

Serum Levels of IL-6 and TNF-α May Correlate with Activity and Severity of Rheumatoid Arthritis

Background

We aimed to investigate the association of rheumatoid arthritis (RA) with interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) through a meta-analysis.

Material/Methods

The case-control studies that investigated the association between RA and serum levels of IL-6 and TNF-α were retrieved strictly according to the inclusion and exclusion criteria. The statistical analysis was performed using STATA statistical software (Version 12.0, Stata Corporation, College Station, TX, USA).

Results

Fourteen studies were enrolled in our meta-analysis, with a total of 890 patients with RA and 441 healthy people as the controls. The results of this meta-analysis revealed that the serum IL-6 and TNF-α levels of RA patients were significantly higher than in the controls, and this difference was statistically significant (IL-6: SMD=2.40, 95% CI=1.57~3.24, P<0.001; TNF-α: SMD=1.93, 95% CI=1.23~2.64, P<0.001). According to ethnic subgroup analysis, the serum IL-6 and TNF-α levels of RA patients were also significantly higher compared with the controls in Asians and Caucasians (IL-6: Asians: SMD=3.64, 95% CI=2.16~5.12, P<0.001; Caucasians: SMD=0.75, 95% CI=0.47~1.02, P<0.001; TNF-α: Asians: SMD=2.74, 95%CI=1.58~3.91, P<0.001; Caucasians: SMD=0.81, 95% CI=0.50~1.11, P<0.001).

Conclusions

IL-6 and TNF-α may play crucial roles in the activity and severity of RA.

A Meta-Analysis of the Association between Polymorphisms in MicroRNAs and Risk of Ischemic Stroke

Ischemic stroke (IS) is responsible for a high death rate and for adult disability worldwide. MiR-146a (rs2910164), miR-149 (rs2292832), miR-196a2 (rs11614913) and miR-499 (rs3746444) are found to be associated with ischemic stroke. However, the results were inconsistent and inconclusive. The present study performed a meta-analysis to get a more precise and comprehensive estimation of the association between the four polymorphisms and IS risk. The databases Pubmed, Embase, Cochrane Central Register of Controlled Trials, Chinese National Knowledge Infrastructure, and Chinese Biomedical Literature Database were searched for related studies. A total of five studies including 2230 cases and 2229 controls were identified for the meta-analysis. The results indicate that TT genotype and T allele of miR-149 (rs2292832) are associated with significantly lower risks of IS in a homozygous model (OR = 0.70) and an allelic model (OR = 0.86). No significant associations were found between miR-146a (rs2910164), miR-196a2 (rs11614913), miR-499 (3746444) and IS susceptibility in any of the studies. However, subgroup analysis by sample size indicates a significant decrease in risks of IS for CC genotype and C allele of miR-146a (rs2910164) in the large sample size group. Therefore, miR-149 (rs2292832) might be recommended as a predictor for IS risk, while miR-146a (rs2910164), miR-196a2 (rs11614913), miR-499 (3746444) are not.

Association Between Single-Nucleotide Polymorphism (SNP) in miR-146a, miR-196a2, and miR-499 and Risk of Ischemic Stroke: A Meta-Analysis

Background

The association between 3 well known SNPs – miR-146a C/G (rs2910164), miR-196a2 T/C (rs11614913), and miR-499 A/G (rs3746444) – in pre-miRNA sequences and ischemic stroke (IS) are still conflicting and inconclusive. This meta-analysis aimed to pool previous studies get a more precise assessment of the association between these 3 SNPs and the risk of IS.

Material/Methods

Relevant studies were searched in online databases. The strength of the association between the SNPs and IS were estimated by pooling odds ratios (OR) and 95% confidence intervals (CI) using Review Manager (version 5.3).

Results

Rs2910164 C allele was associated with lower IS risk. But this trend was only observed in Koreans under the allele model (OR=0.81, 95% CI=0.68–0.95, p=0.009), dominant model (OR=0.68, 95% CI=0.50–0.93, p=0.02), recessive model (OR=0.79, 95% CI=0.63–1.00, p=0.05), and homozygous model (OR=0.63, 95%CI=0.45–0.88, p=0.007). Rs11614913 T allele might be associated with higher IS risk under the dominant model (OR=1.45, 95% CI=1.19–1.78, p=0.0003), while rs3746444 A allele might be associated with decreased IS risk under the homozygous model (OR=0.48, 95% CI=0.23–0.98, p=0.04) only in Chinese, but not in Koreans.

Conclusions

Although the 3 SNPs might be associated with IS, the association varied significantly in different countries.

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.

Association of the genetic polymorphisms in pre-microRNAs with risk of ischemic stroke in a Chinese population

microRNA (miRNA) plays a role in the pathogenesis of ischemic stroke, and single nucleotide polymorphisms in miRNA genes may contribute to disease susceptibility. However, the effect of miR-146a, miR-196a2, and miR-499 polymorphisms on ischemic stroke susceptibility has been rarely reported. Using the TaqMan assay, we evaluated the association of hsa-miR-146a/rs2910164, hsa-miR-196a2/rs11614913, and hsa-miR-499/rs3746444 polymorphisms with the risk of ischemic stroke in a Chinese population with 531 ischemic stroke patients and 531 control subjects. Rs2910164 C/G genotypes were significantly associated with increased risk of ischemic stroke in different genetic model (homozygote comparison: OR = 2.00, 95% CI, 1.29–3.12, P = 0.002; additive model: OR = 1.35, 95% CI, 1.10–1.65, P = 0.004;dominant model: OR = 1.33, 95% CI, 1.00–1.75, P = 0.049; recessive model: OR = 1.82, 95% CI, 1.20–2.74, P = 0.004). Subjects with allele G of hsa-miR-146a/ rs2910164 also showed increased risk of ischemic stroke (OR = 1.33, 95% CI, 1.09–1.62, P = 0.005). Stratification analysis showed that the association between rs2910164 and the risk of ischemic stroke was more pronounced in subjects over 60 years old, females, non-drinkers, subjects without hypertension or diabetes mellitus. There were significant combined effects between miR-146a/rs2910164 and fasting glucose/low-density lipoprotein cholesterol levels on ischemic stroke susceptibility. However, we failed to find any association between the alleles/genotypes of rs11614913 T/C and ischemic stroke, respectively (P> 0.05). In summary, this study provides evidence that miR-146a/rs2910164 might be associated with a significantly increased risk of ischemic stroke in a Chinese population, and the combined effects between miRNA polymorphism and fasting glucose /blood lipid levels may contribute to stroke pathogenesis.