Polymorphisms of miRNAs genes are associated with the risk and prognosis of coronary artery disease

The miRNA variants MIR196A2 (rs11614913) and MIR423 (rs6505162) contribute to an increase in the risk of myocardial infarction

INTRODUCTION

MicroRNAs (miRNAs) are small, single-stranded RNA molecules that negatively regulate gene expression and play a key role in the pathogenesis of human diseases. Recent studies have suggested that miRNAs contribute to cardiovascular diseases (CVDs). However, the association between single-nucleotide polymorphisms (SNPs) in miRNAs and myocardial infarction (MI) remains in infancy.

AIM

The current study was designed to find out the association of SNPs in MIR196A2 and MIR423 (rs11614913 and rs6505162, respectively).

METHODS

Using Tetra-Primer Amplification Refractory Mutation System-Polymerase Chain Reaction (T-ARMS PCR) in 400 cases (MI patients) and 336 healthy controls. Using different inheritance models (co-dominant, homozygous dominant, homozygous recessive, and additive models), the association of these SNPs was genotyped with MI risk.

RESULTS

For variant rs11614913, significant distribution of the genotypes among the cases and controls was determined by co-dominant [χ2  = 29.19, 2; p value < 0.0001], dominant (C/C vs. C/T + T/T) [OR = 0.45 (0.34 to 0.61); p < 0.0001], recessive (T/T vs. C/T + C/C) [OR = 1.009 (0.63 to 1.63); p-value p value > 0.999], and additive models [OR = 0.65 (0.52 to 0.80); p value = 0.0001]. Similarly, a significant association of rs6505162 was determined by co-dominant [χ2  = 24.29, 2; p value < 0.0001], dominant (C/C vs. A/C+ A/A) [OR = 0.44 (0.32 to 0.61); p value < 0.0001], recessive (A/A vs. A/C + C/C) [OR = 1.29 (0.85 to 1.98); p value = 0.28], and additive models [OR = 0.65 (0.52 to 0.81); p value = 0.0001].

CONCLUSION

Therefore, the current study showed that both variants rs11614913 and rs6505162 are significantly associated with MI in the Pakistani population.

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 microRNA gene polymorphisms with Type 2 diabetes mellitus: A systematic review and meta-analysis

Background:

Type 2 diabetes mellitus (T2DM) is a metabolic disorder with growing prevalence and increasing economic burden. Based on the role of genetics and epigenetic factors on T2DM, we aimed to carry a systematic review and meta-analysis for all miRNA gene polymorphisms and risk of T2DM.

Materials and Methods:

A computerized literature search was carried out on PubMed, Web of Science, Scopus, Embase, as well as references of relevant review/meta-analysis. Key search terms were “Diabetes Mellitus, Type 2,” “MicroRNAs,” and “Polymorphism, Single Nucleotide.” All types of observational studies from January 1, 1992, to November 30, 2019, were included, without language restriction. Data analysis was performed using R programming language (3.5.2). Level of heterogeneity was obtained by Cochran's Q test (P < 0.05), and subgroup analysis was performed based on ethnicity.

Results:

Thirty-two polymorphisms from fifteen articles were included. Meta-analysis was carried out based on minor allele frequencies. Seven studies with 2193 cases and 3963 controls were included for rs2910164 polymorphism. In subgroup analysis, there were significant results in Caucasian population in dominant model (odds ratio [OR] =1.12; 95% confidence interval [CI]: 0.83–1.51), homozygote model (OR = 1.78; 95% CI: 1.06–3.00), heterozygote model (OR = 1.77; 95% CI: 1.03–3.05), and recessive model (OR = 1.78; 95% CI: 1.07–2.96). Four studies with 2085 cases and 1933 controls were included for rs895819 polymorphism. Overall, there was no significant result for association with rs895819, but subgroup analysis revealed that minor allele significantly decreased the risk of T2DM in Caucasians by recessive model (OR = 0.34; 95% CI: 0.18–0.66), dominant model (OR = 0.70; 95% CI: 0.52–0.94), homozygote model (OR = 0.32; 95% CI: 0.16–0.62), heterozygote model (OR = 0.37; 95% CI: 0.19–0.74), allelic model (OR = 0.67; 95% CI: 0.52–0.85).

Conclusion:

The minor allele of rs2910164 may increase the risk of T2DM by leading to lower level of miR-146a. In contrast, minor allele of rs895819 may decrease the risk of T2DM by leading to higher level of miR-27a.

Associations Between microRNA Polymorphisms and Development of Coronary Artery Disease: A Case-Control Study

Coronary artery disease (CAD), a common cardiovascular disease, has become a vital cause of mortality worldwide. Genetic microRNA (miR) polymorphisms might contribute to CAD susceptibility. In this study, we selected miR-146a, miR-196a2, and miR-499 single nucleotide polymorphisms and conducted a case-control study. In total, 505 CAD cases and 1109 controls were recruited. We used SNPscan™ genotyping assay to obtain genotyping of miR rs2910164, rs11614913, and rs3746444 variants. We found that miR-196a2 rs11614913 T > C decreased the susceptibility of myocardial infarction (MI) (TC vs. TT: adjusted p = 0.007 and CC/TC vs. TT: adjusted p = 0.012). In female subgroup, our results indicated that miR-196a2 rs11614913 T > C variants might also decrease the susceptibility of CAD (TC vs. TT: adjusted p = 0.017 and TC/CC vs. TT: adjusted p = 0.015). In summary, these results suggest that miR-196a2 rs11614913 T > C locus decreases the susceptibility of CAD in female and MI subgroups. However, further studies are needed to validate the potential associations of miR-196a2 rs11614913 locus with CAD.

Micro-RNA 196a2 expression and miR-196a2 (rs11614913) polymorphism in T1DM: a pilot study

Background Recent emerging evidence supports the role of miR-196a2 in various human diseases. However, its role in type 1 diabetes mellitus (T1DM) is still underestimated. We aimed, for the first time, to investigate the expression of miR-196a2 in T1DM and the association of miR-196a2 (rs11614913) polymorphism with susceptibility of T1DM in a sample of patients from Cairo, Egypt. Methods The study included 150 patients and 150 healthy subjects. Evaluation of rs11614913 genotypes and miR-196a2 expression was done using the allelic discrimination and quantitative reverse transcriptase polymerase chain reaction (PCR) method, respectively. Results The Hardy-Weinberg equilibrium of single nucleotide polymorphism(SNP) was detected among controls (p = 0.2). Our results revealed that the TT genotype was more frequent in patients (22.6%) than controls (10%) while the CC genotype was more frequent in controls (47.3%) than patients (39.3%) (p = 0.01). The frequency of the T allele was significantly higher in patients than in controls (41.7 vs. 31.3%), while the C allele was more frequent in controls (p = 0.008). After adjustment for traditional risk factors, the association of the TT genotype with T1DM remained significant (TT vs. CC, odds ration [OR] = 3.2, 95% confidence interval [CI]: 1.4-7.4, p = 0.005). Power analysis of the data yielded a statistical power of 80% for the miR-196a2 rs11614913 with T1DM. Relative expression of miR-196a2 showed significant decrease in patients compared to controls (median = 0.09, 0.5, interquartile range [IQR] = 0.03-1.6, 0.1-2.1). However, miR-196a2 expression showed no significant difference between different rs11614913 genotypes (p = 0.5). Conclusions Our findings demonstrated that miR-196a rs11614913 is associated with T1DM and decreased expression of miR-196a2 may play a role in pathogenesis of T1DM.

Association between miRNA-196a2 rs11614913 T>C polymorphism and Kawasaki disease susceptibility in southern Chinese children

Background

miRNAs play important roles in a variety of diseases. Thus, the association between miRNA‐196a2 rs11614913 T>C polymorphism and Kawasaki disease susceptibility is still unknown.

Methods

We included 532 children with Kawasaki disease and 623 healthy children from South China, and their DNA was extracted for genotyping by TaqMan methodology. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the strength of association.

Results

No significant associations were observed between the miRNA‐196a2 rs11614913 T>C polymorphisms and Kawasaki disease risk (TC vs TT: adjusted OR = 1.04, 95% CI = 0.79‐1.37; CC vs TT: adjusted OR = 0.87, 95% CI = 0.63‐1.21; dominant model: adjusted OR = 0.99, 95% CI = 0.76‐1.27; and recessive model: adjusted OR = 0.85, 95% CI = 0.64‐1.13). There was also no significant correlation found in stratified analyses.

Conclusion

This study suggests that miRNA‐196a2 rs11614913 T>C may not be associated with Kawasaki disease susceptibility in a southern Chinese population. Larger, multicenter studies are needed to confirm our conclusions.

Association between miR-499 rs3746444 polymorphism and coronary heart disease susceptibility: An evidence-based meta-analysis of 5063 cases and 4603 controls

MicroRNA-499 (miR-499) rs3746444 polymorphism has been associated with the risk of coronary heart disease (CHD). However, results from several studies are inconsistent. This meta-analysis aimed to further investigate the possible association between miR-499 rs3746444 polymorphism and CHD risk. A total of 9 case-control studies included 5063 CHD cases and 4603 healthy subjects. The A allele at rs374644 was associated with significantly decreased CHD risk in the total population according to the allelic model (OR = 0.80, 95% CI = 0.68-0.93, P = 0.005), homozygous model (OR = 0.52, 95% CI = 0.39-0.71, P < 0.001) and heterozygous model (OR = 0.57, 95% CI = 0.43-0.77, P < 0.001). A similar trend was found specifically in Asian and Chinese populations. In contrast, the wild-type GG genotype at rs374644 was associated with significantly increased CHD risk in the total population, according to the dominant model (OR = 1.83, 95% CI = 1.39-2.42, P < 0.001), and a similar trend was found in Asian and Chinese populations. These results indicate that in the total population, as well as in Asian and Chinese populations, the wild-type GG genotype at rs374644 may be related to increased susceptibility to CHD, while the A allele may be protective against CHD.

Circulating microRNA in cardiovascular disease

Acute myocardial infarction (AMI) and heart failure (HF) are two major causes of cardiovascular mortality and morbidity. Early diagnosis of these conditions is essential to instigate immediate treatment that may result in improved outcomes. Traditional biomarkers of AMI include cardiac troponins and other proteins released from the injured myocardium but there are a number of limitations with these biomarkers especially with regard to specificity. In the past few years circulating nucleic acids, notably microRNA that are small non-coding RNAs that regulate various cellular processes, have been investigated as biomarkers of disease offering improved sensitivity and specificity in the diagnosis and prognostication of various conditions. In this review, the role of microRNAs as biomarkers used in the diagnosis of AMI and HF is discussed, their advantage over traditional biomarkers is outlined and the potential for their implementation in clinical practice is critically assessed.

miR-499-5p Attenuates Mitochondrial Fission and Cell Apoptosis via p21 in Doxorubicin Cardiotoxicity

Doxorubicin (DOX) is a broad-spectrum anti-tumor drug, but its cardiotoxicity limits its clinical application. A better understanding of the molecular mechanisms underlying DOX cardiotoxicity will benefit clinical practice and remedy heart failure. Our present study observed that DOX caused cardiomyocyte (H9c2) apoptosis via the induction of abnormal mitochondrial fission. Notably, the expression levels of p21 increased in DOX-treated cardiomyocytes, and the silencing of p21 using siRNA greatly attenuated mitochondrial fission and apoptosis in cardiomyocytes. We also found that miR-499-5p could directly target p21 and attenuated DOX-induced mitochondrial fission and apoptosis. The role of the miR-499-5p-p21 axis in the prevention of DOX cardiotoxicity was also validated in the mice model. DOX treatment induced an upregulation of p21, which induced subsequent abnormal mitochondrial fission and myocardial apoptosis in mouse heart. Adenovirus-harboring miR-499-5p-overexpressing mice exhibited significantly reduced p21 expression, mitochondrial fission and myocardial apoptosis in hearts following DOX administration. The miR-499-5p-overexpressing mice also exhibited improved cardiomyocyte hypertrophy and cardiac function after DOX treatment. However, miR-499-5p was not involved in the DOX-induced apoptosis of cancer cells. Taken together, these findings reveal an emerging role of p21 in the regulation of mitochondrial fission program. miR-499-5p attenuated mitochondrial fission and DOX cardiotoxicity via the targeting of p21. These results provide new evidence for the miR-499-5p-p21 axis in the attenuation of DOX cardiotoxicity. The development of new therapeutic strategies based on the miR-499-5p-p21 axis is a promising path to overcome DOX cardiotoxicity as a chemotherapy for cancer treatment.

miRNA Polymorphisms and Risk of Cardio-Cerebrovascular Diseases: A Systematic Review and Meta-Analysis

Recently extensive focus has been concentrated on the role of miRNAs in the initiation and progression of cardio-cerebrovascular diseases (CCDs) which constitute a range of conditions including cardiovascular diseases (CVDs, especially coronary artery disease (CAD)), congenital heart disease (CHD) and cerebrovascular diseases (CBVDs, especially the ischemic stroke (IS)). An increasing number of studies are evaluating the association between different miRNA polymorphisms and risk of CCDs, but results have been inconclusive. This study represents a comprehensive systematic review and meta-analysis of the association between miRNA polymorphisms and risk of CCDs. PubMed, Embase, Scopus, and Web of Science were queried to identify eligible articles. Odds ratios and 95% confidence intervals were used to assess the association of miRNA polymorphisms with CCD susceptibility. A total of 51 eligible articles evaluating the association of 31 miRNA polymorphisms were identified. Meta-analysis was performed for six miRNA polymorphisms. miR-146a rs2910164 (30 studies: 13,186 cases/14,497 controls), miR-149 rs2292832 (Nine studies: 4116 cases/3511 controls), miR-149 rs71428439 (Three studies: 1556 cases/1567 controls), miR-196a2 rs11614913 (20 studies: 10,144 cases/10,433 controls), miR-218 rs11134527 (Three studies: 2,322 cases/2,754 controls) were not associated with overall CCD. miR-499 rs3746444 was associated with CCD (20 studies: 9564 cases/8876 controls). In the subgroups, rs2910164 and rs3746444 were only associated with CVDs, especially CAD. In conclusion, the results support the existence of a role for miR-146a rs2910164 and miR-499 rs3746444 in determining susceptibility to CCDs, especially CAD.

miR-196a2 (rs11614913) polymorphism is associated with coronary artery disease, but not with in-stent coronary restenosis

OBJECTIVE

The aim of the study was to evaluate the association of miRNA-146a G/C (rs2910164), and miRNA-196a2 C/T (rs11614913) polymorphisms with the presence of coronary artery disease (CAD) and/or restenosis in patients with coronary stent.

MATERIALS AND METHODS

The polymorphisms were determined in 218 patients with CAD who underwent coronary artery stenting (66 with restenosis and 152 without restenosis) and 611 healthy controls using 5' exonuclease TaqMan assays.

RESULTS

The distribution of both polymorphisms was similar in patients with and without restenosis. However, when the whole group of patients (with and without restenosis) was compared to healthy controls, under co-dominant, dominant and additive genetic models, the T allele of the miRNA-196a2 C/T (rs11614913) polymorphism was associated with increased risk of CAD (OR = 2.18, P_co-dom = 0.006, OR = 1.86, P_dom = 0.002, and OR = 1.52, P_add = 0.002, respectively). All models were adjusted for age, type 2 diabetes mellitus, dyslipidemia, hypertension and smoking habit. The "GT" haplotype was associated with increased risk of developing CAD (OR = 1.36, P = 0.046).

CONCLUSIONS

Our data suggests that the T allele of the miRNA-196a2 C/T (rs11614913) polymorphism is associated with the risk of developing CAD, but no association with restenosis was observed.

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.

A polymorphism rs3746444 within the pre-miR-499 alters the maturation of miR-499-5p and its antiapoptotic function

microRNAs (miRNAs) are non‐coding RNAs that function as post‐transcriptional regulators of cardiac development and cardiovascular diseases. Single nucleotide polymorphisms (SNPs) in miRNA genes are a novel class of genetic variations in the human genome that confer the risk of cardiovascular diseases. Here, we identified a polymorphism A→G (rs3746444) in miR‐499 precursor (pre‐miR‐499) that affects the maturation of miR‐499‐5p and alters its antiapoptotic function by converting stable A‐U base pair to wobble G‐U base pair in pre‐miR‐499 secondary structure. Furthermore, our results showed that the concentrations of plasma miR‐499‐5p could be correlated with myocardial infarction (MI) and heart failure (HF) patients in comparison with control subjects and polymorphism rs3746444 in miR‐499 could influence its abundance in plasma. Finally, our results also showed that the variant of polymorphism in miR‐499 influenced the severity of the myocardial infarction significantly. This is the first report to highlight the biological significance of this polymorphism on the maturation of miR‐499‐5p and its antiapoptotic role during MI. These findings may pave a way to better understand the individual variability based on miRNA SNPs in heart diseases and may contribute to better treatment for disease severity on a personalized level.

A Meta-Analysis of the Association between Microrna-196A2 and Risk of Ischemic Stroke and Coronary Artery Disease in Asian Population

OBJECT

Single nucleotide polymorphisms (SNPs) of small non-coding RNAs (sncRNAs) that affect the sncRNA function and target gene expression to mediate the risk of certain diseases. The association between the miR-196a2 rs11614913 and ischemic stroke (IS) and coronary artery disease (CAD) is still conflicting and inconclusive. This meta-analysis aimed at analysing studies which have been done so far to get a more precise assessment of the association between the mutation and these two diseases.

METHODS

Electronic databases dated up to April 2018 were searched, retrieved and used. Revman 5.2 software and STATA version 12.0 were used for statistical analysis. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to identify any potential associations. Heterogeneity, publication bias and sensitivity analysis were conducted to measure the robustness of our findings.

RESULTS

The overall meta-analysis results showed that miR-196a2 rs11614913 T > C polymorphism was significantly associated with CAD risk in certain genetic models, as well as in subgroup analysis (CC versus TT, OR = .43, 95%CI = .39-.47, P < .00001). However, no significant association was detected between the miR-196a2 rs11614913 T > C and IS risk in all genetic models.

CONCLUSIONS

Our study suggests that miR-196a2 rs11614913 T > C may contribute to CAD susceptibility but further well-designed studies with larger sample size and comprehensive data are needed to confirm our findings and provide a profound conclusion.

Interpreting the various associations of MiRNA polymorphisms with susceptibilities of cardiovascular diseases: Current evidence based on a systematic review and meta-analysis

BACKGROUND

To interpret the various associations between miRNA polymorphisms and cardiovascular diseases (CVD).

METHODS

Literature search has identified relevant studies up to June 2016. A meta-analysis was performed followed the guidelines from the Cochrane review group and the PRISMA statement. Studies were identified by searching the Cochrane Library, EMBASE, PUBMED and WHO clinical trials registry center. A meta-analysis has been done with a fixed/random-effect model using STATA 14.0, which also has been used to estimate the publication bias and meta-regression.

RESULTS

The results from 11 case-control studies were included. The miR-146a G/C makes a contribution to the causing of CVD as recessive genetic model. And the miR-499 G/A raised the risks of cardiomyopathy, however it could still accelerate the procedure of CVD combined with myocardial infraction. At this point, we consider that it could deepen the adverse of outcomes from coronary artery disease (CAD), but it's hard to draw an association between miR-499 G/A and CAD. At last the miR-196a2 T/C demonstrated a contrary role between development problem and metabolic issues, which protects the development procedure and impairs the metabolism to cause different disease phenotypes.

CONCLUSION

Despite inter-study variability, the polymorphisms from miR-146a, miR-499 and miR-196a2 have impacts on cardiovascular disease. Each type of miRNA has individual role in either cardiac development or the origins of CVD.

Association of MIR-499a expression and seed region variant (rs3746444) with cardiovascular disease in Egyptian patients

BACKGROUND

Circulating microRNAs could be powerful markers of acute myocardial infarction (MI) and its functional genetic variants could increase susceptibility to cardiovascular disease (CVD). The current study aimed to quantify the microRNA (miR)-499a levels in serum of MI patients compared to hypertensive and healthy subjects and to investigate the association of its A/G variant rs3746444 with CVD in a sample of an Egyptian population.

METHODS

Serum miR-499a relative expressions were measured in 110 acute MI patients, 76 hypertensive patients, and 121 healthy controls by Real-time quantitative polymerase chain reaction. MIR-499a genotyping was performed for an additional 107 coronary artery disease patients by Real-time allele discrimination assay.

RESULTS

Acute MI patients showed high relative expression of miR-499a (> 105-fold, p < .001), and it was nearly undetectable in healthy controls and hypertensive patients. It showed an area under the curve of 0.953, with a sensitivity of 97.2% and a specificity of 75.0%. ST-elevation MI (STEMI) patients had higher miR-499a serum levels than patients with Non-STEMI. There was a significant association of MIR-499a variant with acute MI but not with hypertension under all genetic models tested. As a new finding, in overall and stratified analysis, the miR-499a variant was not correlated with its expression profile.

CONCLUSIONS

Circulating miR-499a levels could be a useful biomarker, discriminating acute MI within 12 hours from healthy subjects. Its variant rs3746444 A/G is associated with increased susceptibility to acute MI and CAD in Egyptian population.

The diagnostic and prognostic value of circulating microRNAs in coronary artery disease: A novel approach to disease diagnosis of stable CAD and acute coronary syndrome

Coronary artery disease (CAD) is the most common manifestation of CVD and the acute coronary syndrome (ACS) is associated with a substantial morbidity and mortality in most populations globally. There are several biomarkers for diagnosis of MI. Troponin is routinely used as a biomarker in patients with chest pain, but it lacks sensitivity in the first hours of onset of symptoms, and so there is still a clinical need for new biomarkers for the diagnosis of CAD events. Recent studies have shown that miRNAs are involved in atherosclerotic plaque formation and their expression is altered during CAD events. Whilst studies have shown that several miRNAs are not superior to troponin in the diagnosis of a MI, they may be useful in the early diagnosis and prognosis of patients with CAD, however further studies are required. In this review we have summarized the recent studies investigating circulating miRNAs as novel biomarkers for the early detection of MI, CVD risk stratification and in the assessment of the prognosis of patients with ACS.

Significant association between functional microRNA polymorphisms and coronary heart disease susceptibility: a comprehensive meta-analysis involving 16484 subjects

Molecular epidemiological studies suggest that microRNA polymorphisms may be associated with an increased risk of coronary heart disease (CHD). However, the results of these studies were inconsistent and inconclusive. To derive a more precise evaluation, we performed a meta-analysis focused on the associations between microRNA polymorphisms and CHD risk. PubMed, Embase, CNKI and Wanfang databases were searched. Odds ratios (ORs) with 95% confidence intervals (CIs) were applied to assess the association between microRNA-146a rs2910164, microRNA-196a2 rs11614913, microRNA-499 rs3746444 and microRNA-149 rs71428439 polymorphisms and CHD susceptibility. Heterogeneity, publication bias and sensitivity analysis were conducted to measure the robustness of our findings. A total of thirteen related studies involving 8,120 patients and 8,364 controls were analyzed. Significant associations between microRNA-146a rs2910164 polymorphism and CHD risk were observed in the total population, as well as in subgroup analysis. For microRNA-196a2 rs11614913 and microRNA-499 rs3746444, similarly increased risks were also found. In addition, no significant association was detected between microRNA-149 rs71428439 polymorphism and CHD risk. In conclusion, our meta-analyses suggest that microRNA polymorphisms may be associated with increased risk of CHD development.

Genetic Polymorphism of miR-196a-2 is Associated with Bone Mineral Density (BMD)

MicroRNAs (miRNAs) are small non-coding RNA molecules that post-transcriptionally regulate the translation of messenger RNAs. Given the crucial role of miRNAs in gene expression, genetic variants within miRNA-related sequences may affect miRNA function and contribute to disease risk. Osteoporosis is characterized by reduced bone mass, and bone mineral density (BMD) is a major diagnostic proxy to assess osteoporosis risk. Here, we aimed to identify miRNAs that are involved in BMD using data from recent genome-wide association studies (GWAS) on femoral neck, lumbar spine and forearm BMD. Of 242 miRNA-variants available in the GWAS data, we found rs11614913:C > T in the precursor miR-196a-2 to be significantly associated with femoral neck-BMD (p-value = 9.9 × 10⁻⁷, β = −0.038) and lumbar spine-BMD (p-value = 3.2 × 10⁻¹¹, β = −0.061). Furthermore, our sensitivity analyses using the Rotterdam study data showed a sex-specific association of rs11614913 with BMD only in women. Subsequently, we highlighted a number of miR-196a-2 target genes, expressed in bone and associated with BMD, that may mediate the miRNA function in BMD. Collectively, our results suggest that miR-196a-2 may contribute to variations in BMD level. Further biological investigations will give more insights into the mechanisms by which miR-196a-2 control expression of BMD-related genes.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Associations of microRNA single nucleotide polymorphisms and disease risk and pathophysiology

Single nucleotide polymorphisms (SNPs) are genetic variations that contribute to human phenotypes associated with various diseases. SNPs are involved in the regulation of a broad range of physiological and pathological processes, such as cellular senescence, apoptosis, inflammation, and immune response, by upregulating the expression of classical inflammation markers. Recent studies have suggested that SNPs located in gene-encoding microRNAs (miRNAs) affect various aspects of diseases by regulating the expression or activity of miRNAs. In the last few years, miRNA polymorphisms that increase and/or reduce the risk of developing many diseases, such as cancers, autoimmune diseases, and cardiovascular diseases, have attracted increasing attention not only because of their involvement in the pathophysiology of diseases but also because they can be used as prognostic biomarkers for a variety of diseases. In this review, we summarize the relationships between miRNA SNPs and the pathophysiology and risk of diseases.

MicroRNAs and Cardiovascular Disease in Diabetes Mellitus

Cardiovascular disease (CVD) is the major macrovascular complication of diabetes mellitus. Recently, although CVD morbidity and mortality have decreased as a result of comprehensive control of CVD risk factors, CVD remains the leading cause of death of patients with diabetes in many countries, indicating the potential underlying pathophysiological mechanisms. MicroRNAs are a class of noncoding, single-stranded RNA molecules that are involved in β-cell function, insulin secretion, insulin resistance, skeletal muscle, and adipose tissue and which play an important role in glucose homeostasis and the pathogenesis of diabetic complications. Here, we review recent progress in research on microRNAs in endothelial cell and vascular smooth muscle cell dysfunction, macrophage and platelet activation, lipid metabolism abnormality, and cardiomyocyte repolarization in diabetes mellitus. We also review the progress of microRNAs as potential biomarkers and therapeutic targets of CVD in patients with diabetes.

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.

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.

A Genetic Variant in Pre-miR-146a (rs2910164 C>G) Is Associated with the Decreased Risk of Acute Coronary Syndrome in a Chinese Population

MicroRNAs (miRNAs) can contribute to the development of cardiovascular diseases, and single nucleotide polymorphisms (SNPs) in miRNA genes may influence disease susceptibility by altering mature miRNA expression levels. However, the effect of SNPs located in miR-146a and miR-196a2 genes on risk of acute coronary syndrome (ACS) has not been reported in the Chinese population. Two miRNA polymorphisms located in miRNA genes (miR-146a rs2910164 C>G and miR-196a2 rs11614913 T>C) were genotyped in 722 ACS patients and 721 control subjects. The CG genotype of rs2910164 was significantly associated with decreased risk of ACS [CG vs. CC, odds ratio (OR) = 0.72, 95% confidence interval (CI): 0.55-0.95, P = 0.020; dominant model, OR = 0.77, 95% CI: 0.60-0.99, P = 0.044]. We did not find any association of rs11614913 with the risk of ACS. Stratification analysis showed that the rs2910164 CG genotype was associated with decreased risk of ACS (dominant model) in males, subjects with body mass index more than 24 kg/m(2), and in hypertensive subjects. Significant combined effects were also observed between rs2910164 and blood lipids or C-reactive protein levels. In summary, this study provides the first evidence that the CG genotype of miR-146a rs2910164 is associated with a significantly decreased risk of ACS in a Chinese population. Moreover, rs2910164 and blood lipids or an inflammatory marker may have a combined effect on the onset of ACS. These findings indicate that miR-146a rs2910164 may act as a novel molecular marker for ACS susceptibility.

MiR-196a2 rs11614913 T>C Polymorphism is Associated with an Increased Risk of Tetralogy of Fallot in a Chinese Population

BACKGROUND

MicroRNAs (miRNAs) are a family of endogenous, small, noncoding single-stranded RNAs that act as post-transcriptional gene regulatory elements. MiRNA polymorphisms may be associated with susceptibility to congenital heart disease (CHD). The aim of this study was to evaluate the impact of miRNA single nucleotide polymorphisms (SNPs) on CHD susceptibility.

METHODS

We genotyped two functional SNPs, miR-196a2 rs11614913 and miR-146a rs2910164, in a case-control cohort of 173 Chinese patients with tetralogy of Fallot (TOF) and 207 non-CHD controls.

RESULTS

When the miR-196a2 rs11614913 TT homozygote genotype was used as the reference group, the TC genotype was not associated with an increased risk of TOF. The CC genotype was associated with a borderline significantly increased risk for TOF. In the recessive model, when the miR-196a2 rs11614913 TT/TC genotypes were used as the reference group, the CC homozygote genotype was associated with a significantly increased risk of TOF (OR = 1.96, 95% CI = 1.18-3.25, p = 0.01). The miR-146a rs2910164 C>G polymorphism was not associated with developing TOF.

CONCLUSIONS

Our findings suggested that the miR-196a2 rs11614913 T>C polymorphism may play a role in the development of TOF. Future larger studies that include populations of other ethnicities are required to confirm these findings.

KEY WORDS

Congenital heart disease; MiRNA; Molecular epidemiology; Polymorphisms; Tetralogy of Fallot.

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.

Meta-analysis of Hsa-mir-499 polymorphism (rs3746444) for cancer risk: evidence from 31 case-control studies

BACKGROUND

MicroRNAs (miRNAs) are a family of endogenous, small and non-coding RNAs that regulate gene expression negatively at the post-transcriptional level by suppressing translation or degrading target mRNAs, and are involved in diverse biological and pathological processes. Single nucleotide polymorphisms (SNPs) which are located in the miRNA-coding genes may participate in the process of development and diseases by altering the expression of mature miRNA. Recent studies investigating the association between hsa-mir-499 polymorphism (rs3746444) and cancer risk have yielded conflicting results.

METHODS

In this meta-analysis, we conducted a search of case-control studies on the associations of SNP rs3746444 with susceptibility to cancer in electronic databases. A total of 31 studies involving 12799 cases and 14507 controls were retrieved and the strength of the association was estimated by pooled odds ratios (ORs) and 95% confidence intervals (CIs). Hardy-Weinberg equilibrium (HWE) was assessed by the goodness-of-fit chi-square test in controls. Subgroup analyses were done by racial descent and cancer type. Publication bias of literatures was evaluated by visual inspection of funnel plots and the linear regression asymmetry test by Egger et al. Sensitivity analysis was conducted by excluding one study at a time to examine the influence of individual data set on the pooled ORs.

RESULTS

Overall, significant association between rs3746444 polymorphism and susceptibility to cancer was identified in TC versus TT and TC/CC versus TT (dominant) models. In the stratified analyses, increased risks were found in Asians, but not in Caucasians in all comparison models tested. Moreover, significant association with an increased risk was found in Chinese population. Also, much higher significant association with increased cancer risks were found in Iranian population. In different cancer types, a decreased risk was found in esophageal cancer.

CONCLUSION

Our meta-analysis suggested that hsa-mir-499 rs3746444 T > C polymorphism is associated with the risk of cancer in Asians, mainly in Iranian and Chinese population. However, rs3746444 T > C polymorphism is negatively associated with the risk of esophageal cancer.

miRNAs as biomarkers of myocardial infarction: a step forward towards personalized medicine?

miRNAs are small noncoding RNAs known to post-transcriptionally regulate gene expression. miRNAs are expressed in the heart where they regulate multiple pathophysiological processes. The discovery of stable cardiac miRNAs in the bloodstream has also motivated the investigation of their potential as biomarkers. This review gathers the current knowledge on the use of miRNAs as novel biomarkers to improve risk stratification, diagnosis, and prognosis of patients with myocardial infarction. In the rapidly evolving era of biomarkers, the potential of miRNAs as promising tools to move personalized medicine a step forward is discussed.

hsa-mir-499 rs3746444 gene polymorphism is associated with susceptibility to breast cancer in an Iranian population

AIM

Our study aimed to evaluate the possible association between four miRNA polymorphisms, hsa-miR-146a (rs2910164 G>C), hsa-miR-499 (rs3746444 T>C) and hsa-miRNA-196a2 (rs11614913 C>T and rs185070757 T>G), and susceptibility to breast cancer in an Iranian population.

MATERIALS & METHODS

In this case-control study we enrolled 236 patients with breast cancer and 203 healthy individuals. Tetra primer amplification refractory mutation system PCR was applied for genotyping the four miRNA SNPs.

RESULTS

Our study indicated that the hsa-mir-499 rs3746444 CC homozygote increased the risk of breast cancer in the dominant (odds ratio [OR]: 2.42; 95% CI: 1.43-4.09; p = 0.001; CC vs TT) and recessive (OR: 2.48; 95% CI: 1.49-4.13; p = 0.004; CC vs TT+TC) inheritance models tested. In addition, the rs3746444 C allele increased the risk of breast cancer (OR: 1.71; 95% CI: 1.27-2.29; p = 0.0004) in comparison with the T allele. However, distribution of the rs2910164 G>C, rs11614913 C>T and rs185070757 T>G genotypes was not statistically different between cases and controls (p > 0.05).

CONCLUSION

Our findings demonstrated that the hsa-mir-499 rs3746444 polymorphism is associated with higher risk of developing breast cancer in our population.

Polymorphism in microRNA-196a2 contributes to the risk of cardiovascular disease in type 2 diabetes patients

AIMS

To investigate the effect of the microRNA-196a2 gene polymorphism (rs11614913) on risk of cardiovascular disease in type 2 diabetes patients.

METHODS

We examined 920 patients with diabetes and 834 healthy controls. All subjects were genotyped for the miRNA-196a2 SNP by polymerase chain reaction (PCR) and restriction analysis.

RESULTS

The genotype distribution among controls and patients was in Hardy-Weinberg equilibrium (p=0.227 and 0.308, respectively). The frequency of the T allele was lower in patients than in controls (p=0.044). The odds ratio 0.66 (95% CI 0.54-0.79) suggests an association of the T allele with decreased risk of T2DM. For the main purpose of the study, T2DM patients were stratified into patients with CVD and those without it. The T allele and TT genotype were significantly more frequent in patients with CVD compared to those without CVD (p=0.013, p<0.001, respectively). The odds ratio for the T allele in the CVD+subgroup vs. CVD- was 1.76 (1.35-2.30), p<0.0001, mostly due to the overrepresentation of TT homozygotes. The highest risk of development of CVD was observed in the additive model for TT homozygotes (OR 3.33, 95% CI 2.05-5.42, p<0.0001).

CONCLUSION

Our findings suggest that miRNA-196a2 T/C polymorphism (rs11614913) is associated with an increased risk of CVD in type 2 diabetes patients. This provides further insights on pathogenesis of cardiovascular disease in type 2 diabetes patients.

miR-146a and miR-196a2 polymorphisms in patients with ischemic stroke in the northern Chinese Han population

MicroRNAs are endogenous non-coding RNAs about 22 nucleotides in length that can repress the expression of proteins by binding to the 3'-untranslated regions of target messenger RNAs. We hypothesized that polymorphisms in miR-146a and miR-196a2 are associated with risk of ischemic stroke in the northern Chinese Han population. In a case-control study of 368 ischemic stroke patients and 381 control subjects that were frequency matched by age and gender, we genotyped two single nucleotide polymorphisms (rs11614913 in miR-196a2 and rs2910164 in miR-146a) using polymerase chain reaction-ligation detection reaction. The frequencies of the rs2910164 CC genotype and C allele within miR-146a were not significantly different in patients with ischemic stroke compared with those in the healthy control group. In subgroup meta-analysis, rs2910164 in miR-146a and large-artery atherosclerosis, rather than small-vessel disease, showed the significant association under the dominant model (CC vs CG+GG, OR 1.694; 95 % CI 1.199-2.395 p = 0.003). After adjusting for confounding risk factors of ischemic stroke by logistic regression analysis, this significant correlation remained. In addition, the distributions of the miR-196a2 genotypes and alleles were not statistically different between ischemic stroke and healthy groups. We also did not find any significant association from stroke subtypes. The CC genotype and C allele of rs2910164 within miR-146a are associated with an increased incidence of large-artery atherosclerotic stroke in the northern Chinese Han population. This study indicates that miR-146a (rs2910164) might contribute to ischemic stroke susceptibility in the northern Chinese Han population.

Identification of putative pathogenic SNPs implied in schizophrenia-associated miRNAs

Background

Schizophrenia is a severe brain disorder, and SNPs (Single nucleotide polymorphism) in schizophrenia-associated miRNAs are believed to be one of the important reasons for dysregulation which might contribute to the altered expression of genes and ultimately result in the disease. Identification of causal SNPs in associated miRNAs may have certain significance in understanding the mechanism of schizophrenia.

Results

For the above purposes, a method based on detection of free energy change is proposed for identification of causal SNPs in schizophrenia-associated miRNAs. A miRNA is firstly segmented, and free energy change is computed after adding an SNP into a segment. The method discovers successfully 6 out of 32 known SNPs and some artificial SNPs could cause significant change in free energy, and among which, 6 known SNPs are supposed to be responsible for most cases of schizophrenia in population.

Conclusions

The proposed method is not only a convenient way to discover causal SNPs in schizophrenia-associated miRNAs without any biochemical assay or sample comparison between cases and controls, but it also has high resolution for causal SNPs even if the SNPs are not reported for their very rare cases in the population. Moreover, the method can be applied to discover the causal SNPs in miRNAs associated with other diseases.

A common variant in pre-miR-146 is associated with coronary artery disease risk and its mature miRNA expression

miRNAs are small non-coding RNAs that play an important role in numerous physiological processes. Common single nucleotide polymorphisms (SNPs) in pre-miRNAs may change their property through altering miRNAs expression and/or maturation, resulting in diverse functional consequences. To date, the role of genetic variants in pre-miRNAs on coronary artery disease (CAD) risk remains poorly understood. Here we aimed to evaluate the influence of three common SNPs in pre-miRNAs (miR-146a rs2910164 G>C, miR-196a2 rs11614913 C>T, miR-499 rs3746444 T>C) on individual susceptibility to CAD in a Chinese population of 295 CAD patients and 283 controls. Genotyping was performed using polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) method. In a logistic regression analysis, we detected an association of rs2910164 in pre-miR-146a with the CAD risk; compared with the GG homozygotes, the GC heterozygotes [odds ratio (OR)=1.89, 95% confidence interval (CI)=1.06-3.36, P=0.029] and the CC homozygotes (OR=1.83, 95% CI=1.01-3.32, P=0.046) genotype were statistically significantly associated with the increased risk for CADs. As we used further genotype association models, we found a similar trend of the association in recessive model (OR=1.86, 95% CI=1.09-3.19, P=0.023). We also found that the genotypes of miR-146a rs2910164 were associated with its mature miRNA expression by analyzing 23 PBMC samples from CAD patients. Individuals carrying rs11614913 GC or CC genotypes showed 3.2-fold higher expression compared to GG genotype carriers (P<0.05). We observed no association of the other two SNPs in miR-196a2 (rs11614913) and miR-499 (rs3746444) with the CAD incidence. Our data provide the first evidence that the miR-146a rs2910164 polymorphism is associated with increased risk of CAD in Chinese Han population, which may be through influencing the expression levels of the miRNA.

A functional polymorphism in the miR-146a gene is associated with the risk of childhood acute lymphoblastic leukemia: a preliminary report

Growing evidence showed that microRNAs (miRs) are involved in normal hematopoiesis and the pathogenesis of several hematological malignancies. Genetic variations or mutations occurring in the miR gene region may affect the property of miRs through altering miR expression and/or maturation. The aim of the present study was to evaluate the possible relationship between two miRs polymorphisms, hsa-miR-146a (rs2910164 G>C) and hsa-miR-499 (rs3746444 T>C), and the susceptibility to childhood acute lymphoblastic leukemia (ALL) in a sample of Iranian population. This case-control study was performed on 75 children diagnosed with ALL and 115 age- and sex-matched children with no history of cancer of any type (as the control group). Tetra-primer amplification refractory mutation system-polymerase chain reaction was applied for genotyping the variants. We found that the rs2910164 G>C variant of hsa-miR-146a significantly increased the risk of ALL (CC vs. GG, OR = 4.24, 95% CI = 1.52-11.87, P = 0.006; GC vs. GG, OR = 3.55, 95% CI = 1.41-8.93, P = 0.007; C vs. T, OR = 1.73, 95% CI = 1.13-2.67, P = 0.012). With respect to hsa-miR-499 rs3746444 T/C, no significant difference in allele and genotype frequencies of the rs3746444 variant between ALL patients and controls was observed. Our results for the first time demonstrated that the miR-146a rs2910164, but not miR-499 rs3746444 variant, was associated with increased risk for developing pediatrics ALL in an Iranian population.

MiR-196a2 rs11614913 T > C polymorphism and risk of esophageal cancer in a Chinese population

BACKGROUND

Esophageal cancer is the eighth most common cancer and sixth leading cause of cancer associated death worldwide. Besides environmental risk factors, genetic factors might play an important role in the esophageal cancer carcinogenesis.

METHODS

We conducted a hospital based case-control study to evaluate the genetic susceptibility of functional single nucleotide polymorphisms (SNPs) in the microRNAs on the development of esophageal cancer. A total of 380 esophageal squamous cell carcinoma (ESCC) cases and 380 controls were recruited for this study. The miR-196a2 rs11614913 T > C, miR-146a rs2910164 C > G, miR-499 rs3746444 T > C, miR-26a-1 rs7372209 C > T and miR-27a rs895819 T > C genotypes were determined using a custom-by-design 48-Plex SNPscan™ Kit and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

RESULTS

MiR-196a2 rs11614913 T > C polymorphism was associated with borderline statistically decreased risk of ESCC. In the recessive model, when the miR-196a2 rs11614913 TT/TC genotypes were used as the reference group, the CC homozygote genotype was associated with a borderline statistically decreased risk for ESCC (adjusted OR 0.72, 95% CI 0.50-1.03, p = 0.070). In stratification analyses, a significantly decreased risk of ESCC associated with the miR-196a2 rs11614913 T > C polymorphism was evident among women patients and patients who never smoking or drinking.

CONCLUSIONS

These findings indicated that functional polymorphism miR-196a2 rs11614913 T > C might contribute to decreased ESCC risk among women patients and patients who never smoking or drinking. However, our results were obtained with a limited sample size. Future larger studies with other ethnic populations and tissue-specific biological characterization are required to confirm current findings.

Potential role of blood microRNAs as non-invasive biomarkers for early detection of asymptomatic coronary atherosclerosis in obese children with metabolic syndrome

The pandemic of the childhood obesity represent a major public health problem all over the world. This leads to detection of many health conditions that were previously considered an adulthood diseases. The rise in the prevalence of the obesity and overweight among children means that the world will face an explosion in the prevalence of the metabolic syndrome (MS), which increases the risk of atherosclerotic disease and death in adulthood. The atherosclerotic process has proved to develop silently for decades during childhood and adolescence before the cardiovascular complications such as myocardial infarction and stroke occur. This means that obese children especially with MS could have heart attacks and suffer from heart disease in an age when they should be very healthy, but most of these data either derived from autopsy findings or studies that confirmed the presence of peripheral atherosclerosis. Very early detection of coronary atherosclerosis in obese children with metabolic syndrome through a non invasive method will be of great importance, allowing for early therapeutic intervention. The discovery of microRNAs (miRNAs) is considered a major scientific breakthrough in the last years; recent studies have suggested a potentially important role of miRNAs in the control of diversity aspects of cardiac functions in health and disease including coronary atherosclerosis. Moreover, circulating miRNAs profiles recently used as a non-invasive biomarker for diagnosis of multiple cardiovascular diseases. The identification of distinct circulating miRNA profiles may impact the development of specific miRNAs as biomarkers in pediatric cardiovascular diseases. Therefore, we postulate that some of these circulating miRNAs may be a potential biomarker for early non-invasive diagnosis of coronary atherosclerosis in very early asymptomatic stage in obese children with metabolic syndrome, giving an excellent chance to fight against the first killer in the adult population in childhood period.

The association between hsa-miR-499 T>C polymorphism and cancer risk: a meta-analysis

MicroRNAs regulate gene expression at the post-transcriptional level and were involved in diverse biological and pathological processes. Single nucleotide polymorphism (SNP) which is located in the pre-miRNA may affect the processing and then influence the expression of mature miRNA. Previous studies yielded conflicting results as to the association of a common polymorphism in pre-miRNAs (i.e. hsa-miR-499 rs3746444) with various diseases. Therefore, here we performed a meta-analysis to address the association between this polymorphism and cancer risks. A total of twenty studies involving 10,584 cases and 12,414 controls were retrieved based on PubMed. No significant association was found either in cancers and other diseases in all genetic models. And then in the stratified analysis by ethnicity, significantly increased risks were found in Asians (OR=1.11; 95% CI=1.00-1.23 for C vs. T; OR=1.16; 95% CI=1.00-1.36 for TC vs. TT; OR=1.15; 95%CI=1.01-1.31 for TC/CC vs. TT), but not in Caucasians in all comparison models tested. Our meta-analysis suggested that polymorphism of hsa-miR-499 rs3746444 T>C was not associated with the increased susceptibility to cancers and other diseases.

Association of the miR-146aC>G, miR-196a2C>T, and miR-499A>G polymorphisms with moyamoya disease in the Korean population

Recent evidence has demonstrated associations between the single nucleotide polymorphism (SNP) rs11614913 in miR-196a2C>T and various pathologies. A main target of miRNA-196a is annexin A1 (lipocortin1, ANXA1), which is associated with increased multiple malignant tumors in brain models of ischemia and reperfusion injury. To determine the effects of miRNA SNPs in moyamoya disease, we recruited 107 patients with moyamoya disease and 240 healthy controls from a Korean study population and determined the genotype of each participant from whole blood samples. We compared the patient and the control genotypes and allele frequencies of rs2910164, rs11614913, and rs3746444 and investigated the association of the three SNPs with age and clinical characteristics, such as cerebral hemorrhage or infarction. rs11614913 in miR-196a2C>T was significantly associated with moyamoya disease. The association of this SNP with adult age and cerebral infarction was statistically significant compared to the control group, but the association with hemorrhagic moyamoya disease was not significant. The CT+CC genotype of miR-196a2 was represented at an increased frequency among patients with moyamoya disease. However, the distribution of miR-146aC>G and miR-499A>G genotypes was not statistically different between participants who were healthy and those with moyamoya disease. Thus, the SNP rs11614913 is significantly associated with moyamoya disease, as well as cerebral infarction and adult age in patients with moyamoya disease. This study demonstrates a higher frequency of the CT+CC genotype of the SNP rs11614913 in miR-196a2C>T, which suggests that miR-196a2 may play a role in the pathogenesis of moyamoya disease.