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

MiRNA-146a-A Key Player in Immunity and Diseases

miRNA-146a, a single-stranded, non-coding RNA molecule, has emerged as a valuable diagnostic and prognostic biomarker for numerous pathological conditions. Its primary function lies in regulating inflammatory processes, haemopoiesis, allergic responses, and other key aspects of the innate immune system. Several studies have indicated that polymorphisms in miRNA-146a can influence the pathogenesis of various human diseases, including autoimmune disorders and cancer. One of the key mechanisms by which miRNA-146a exerts its effects is by controlling the expression of certain proteins involved in critical pathways. It can modulate the activity of interleukin-1 receptor-associated kinase, IRAK1, IRAK2 adaptor proteins, and tumour necrosis factor (TNF) targeting protein receptor 6, which is a regulator of the TNF signalling pathway. In addition, miRNA-146a affects gene expression through multiple signalling pathways, such as TNF, NF-κB and MEK-1/2, and JNK-1/2. Studies have been carried out to determine the effect of miRNA-146a on cancer pathogenesis, revealing its involvement in the synthesis of stem cells, which contributes to tumourigenesis. In this review, we focus on recent discoveries that highlight the significant role played by miRNA-146a in regulating various defence mechanisms and oncogenesis. The aim of this review article is to systematically examine miRNA-146a's impact on the control of signalling pathways involved in oncopathology, immune system development, and the corresponding response to therapy.

Association between polymorphisms in miRNAs and ischemic stroke: A meta-analysis

BACKGROUND

Atherosclerosis remains a predominant cause of ischemic stroke (IS). Four miRNA polymorphisms associated with arteriosclerosis mechanism were meta-analyzed to explore whether they had predictive significance for IS.

METHODS

PubMed, Excerpta Medica database, Web of Science, Cochrane Library, Scopus, China National Knowledge Infrastructure, and China Wanfang Database were searched for relevant case-control studies published before September 2022. Two researchers independently reviewed the studies and extracted the data. Data synthesis was carried out on eligible studies. Meta-analysis, subgroup analysis, sensitivity analysis, and publication bias analysis were performed using Stata software 16.0.

RESULTS

Twenty-two studies were included, comprising 8879 cases and 12,091 controls. The results indicated that there were no significant associations between miR-146a C>G (rs2910164), miR-196a2 T>C (rs11614913) and IS risk in the overall analyses, but miR-149 T>C (rs2292832) and miR-499 A>G (rs3746444) increased IS risk under the allelic model, homozygote model and recessive model. The subgroup analyses based on Trial of Org 101072 in Acute Stroke Treatment classification indicated that rs2910164 increased small artery occlusion (SAO) risk under the allelic model, heterozygote model and dominant model; rs11614913 decreased the risk of SAO under the allelic model, homozygote model, heterozygote model and dominant model.

CONCLUSION

This Meta-analysis showed that all 4 single nucleotide polymorphisms were associated with the risk of IS or SAO, even though the overall and subgroup analyses were not entirely consistent.

MiR-665 Participates in the Protective Effect of Dexmedetomidine in Ischemic Stroke by ROCK2/NF-κB Axis

Ischemic stroke is a grievous intimidation to the healthiness of sufferers. Previous studies have reported that dexmedetomidine (DEX) has a protective effect on a variety of organs. This paper aimed to explore the regulatory mechanism of DEX in ischemic stroke through miR-665/ROCK2 axis. The mice model of ischemic stroke was constructed by middle cerebral artery occlusion (MCAO). The cell model of ischemic stroke was constructed by oxygen-glucose deprivation (OGD). Cell viability and apoptosis were assessed by CCK-8 assay and flow cytometry. The expression of cytokines was detected by ELISA. Lactate dehydrogenase (LDH) concentration was evaluated by LDH kit. The cerebral infarct volume of MCAO mice was detected by TTC staining, and the apoptosis of brain cells was detected by TUNEL staining. The target relationship between ROCK2 and miR-665 was analyzed by dual-luciferase reporter assay. DEX contributed cell viability from 42 to 66% (1 μM) and restrained cell apoptosis from 26 to 18% in HT22 cells treated with OGD (P < 0.01). Meanwhile, DEX decreased the expression of cytokines and LDH concentration from 184 to 126% (P < 0.001). Moreover, the expression of miR-665 enhanced 2.9 times (P < 0.05) and the expression of ROCK2 (P < 0.05) and NF-κB p65 (P < 0.01) reduced 1.8 times and 2.2 times after DEX treatment in OGD induced HT22. And miR-665 knockdown attenuated the effect of DEX on inflammation damage (the levels of TNF-α, IL-1β and IL-6 increased 1.36 times, 1.31 times, 1.43 time, respectively, and IL-10 decreased 1.68 times) and apoptosis from 17 to 25% (P < 0.01). MiR-665 directly targeted ROCK2 and regulated ROCK2 and NF-κB p65 expression (P < 0.01). Furthermore, ROCK2 overexpression inhibited the protective effect of DEX in HT22 induced by OGD (P < 0.001), while miR-665 overexpression reversed the regulatory of ROCK2 (P < 0.01). In vivo, DEX decreased cerebral infarction volume and inhibited apoptosis of brain cell (P < 0.001). DEX has a protective effect in ischemic stroke by promoting miR-665 expression to downregulate ROCK2/NF-κB axis, suggesting DEX has a beneficial effect on ischemic stroke and miR-665 is a conceivable target for the therapeutics and diagnosis of ischemic stroke.

Pre-micro RNA polymorphism detection in small versus large vessel disease in stroke Egyptian patients

Stroke is the main cause of adult disability and is responsible for around 11% of deaths all over the world. Ischemic stroke encompasses about 80-85% of total stroke cases. Several studies have shown the relation between microRNAs polymorphism and ischemic stroke. The aim of the study was to evaluate the influence of three common single nucleotide polymorphisms in pre-miRNAs (hsa-miR-146a/rs2910164, hsa-miR-196a2/rs11614913 and hsa-miR-499/rs3746444) on individual susceptibility to the risk of ischemic stroke subtypes in Egyptian population with 117 ischemic stroke patients. Results showed that hsa-miR-146a/rs2910164 was significantly associated with the risk of small vessel disease stroke in Egyptian population with no significant association between hsa-miR-196a2/rs11614913 and hsa-miR-499/rs3746444 with the risk of ischemic stroke. Therefore, it can be concluded that miR-146a/rs2910164 polymorphism is involved in the vulnerability to small vessel disease ischemic stroke risk in Egyptian population.

Pre-micro RNA polymorphism detection in small versus large vessel disease in stroke Egyptian patients

Stroke is the main cause of adult disability and is responsible for around 11% of deaths all over the world. Ischemic stroke encompasses about 80-85% of total stroke cases. Several studies have shown the relation between microRNAs polymorphism and ischemic stroke. The aim of the study was to evaluate the influence of three common single nucleotide polymorphisms in pre-miRNAs (hsa-miR-146a/rs2910164, hsa-miR-196a2/rs11614913 and hsa-miR-499/rs3746444) on individual susceptibility to the risk of ischemic stroke subtypes in Egyptian population with 117 ischemic stroke patients. Results showed that hsa-miR-146a/rs2910164 was significantly associated with the risk of small vessel disease stroke in Egyptian population with no significant association between hsa-miR-196a2/rs11614913 and hsa-miR-499/rs3746444 with the risk of ischemic stroke. Therefore, it can be concluded that miR-146a/rs2910164 polymorphism is involved in the vulnerability to small vessel disease ischemic stroke risk in Egyptian population.

Carotid Intima-Media Thickness, Genetic Risk, and Ischemic Stroke: A Family-Based Study in Rural China

BACKGROUND

Carotid intima-media thickness (cIMT) has been associated with an elevated risk of ischemic stroke (IS) in several studies, but the results are inconsistent. We investigated whether the association between cIMT and IS varied across different IS subtypes, and further assessed gene-cIMT interactions' association with IS risk.

METHODS

A total of 1048 IS cases (795 large-artery atherosclerosis (LAA) cases, 103 small-vessel occlusion (SVO) cases, and 150 other subtypes) and 2696 IS-free controls across 2179 families were included in the analysis. Self-reported IS cases were confirmed through medical records' review and head imaging by computed tomography and/or magnetic resonance imaging. The mean values of the common cIMT obtained in bilateral distal and proximal carotid artery segments were used. The genotype information of rs2910164 polymorphism in microRNA-146a (miR-146a) was also collected.

RESULTS

We found that cIMT was significantly associated with a higher risk of IS and LAA subtype but not SVO subtype in the multivariate-adjusted models. The odds ratio (OR) and 95% confidence interval (CI) in the highest quartile versus the lowest quartile of cIMT was 2.48 (1.92-3.20) for IS and 2.75 (2.08-3.64) for LAA (both p trend <0.001). The results also showed that there was a significant interaction between cIMT and rs2910164 genotype with the risk of IS (p interaction = 0.03) and LAA (p interaction = 0.02). The associations of cIMT with IS and LAA were strengthened among participants carried rs2910164_GG genotype compared with those with rs2910164_CC genotype.

CONCLUSIONS

Our results indicate that higher cIMT levels were significantly associated with IS and LAA subtype but not SVO subtype, and the relations were modified by rs2910164 polymorphism in miR-146a.

MiR-10a, 27a, 34b/c, and 300 Polymorphisms are Associated with Ischemic Stroke Susceptibility and Post-Stroke Mortality

A recent study of the ischemic stroke described the roles played by miRNAs in the downregulation of specific cell-cycle gene expression and it is thought to require the development of biomarkers for the prognostic of ischemic stroke. Here, we hypothesized that four miRNA polymorphisms (miR-10a, miR-27a, miR-34b/c, and miR-300) may affect stroke susceptibility and mortality. Blood samples were collected from 530 patients and 403 controls. Genetic polymorphisms were detected by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis and real-time PCR. We found that the miR-300 rs12894467 TC genotype and the dominant model (AOR: 2.069, p-value: 0.017; AOR: 1.931, p-value: 0.027) were significantly associated with an increased risk for the ischemic stroke subtype. In Cox proportional hazard regression models, the miR-10a rs3809783 A>T and miR-34b/c rs4938723 T>C polymorphisms were associated with the mortality rates among ischemic stroke patients. We found that a miR-300 polymorphism was associated with increased ischemic stroke susceptibility among the Korean population. Additionally, polymorphisms in miR-10a and miR-34b/c were associated with the increased or decreased mortality of ischemic stroke patients. This study marks the first report of an association between ischemic stroke and miRNA polymorphisms (miR-10aA>T, miR-27aT>C, miR-34b/cT>C, and miR-300T>C) in the Korean population.

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.

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.

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.

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.

Associations between miR-146a rs2910164 polymorphisms and risk of ischemic cardio-cerebrovascular diseases

BACKGROUND

Many studies investigated the association between miR-146a rs2910164 polymorphisms and risk of ischemic cardio-cerebrovascular diseases. However, the results were inconsistent.

METHODS

We searched the PubMed, EMBASE, Cochrane library, Web of Science, Chinese National Knowledge Infrastructure, VIP, and Wanfang databases for appropriate studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the associations. Heterogeneity, sensitivity, and publication bias were conducted to measure the robustness of our findings.All analyses were based on previous published studies, thus, no ethical approval and patient consent are required.

RESULTS

We conducted a meta-analysis to evaluate the relationship between miR-146a rs2910164 polymorphisms and risk of ischemic cardio-cerebrovascular diseases. A total of 26 related studies involving 11,602 cases and 14,016 controls were identified and included in our meta-analysis. After considering the heterogeneity of the global analysis, we inferred that rs2910164 polymorphisms were associated with a lower risk of coronary heart disease (CHD) significantly in all genetic models. In addition, it was also found that the miR-146a rs2910164 polymorphisms were associated with the low risk of ischemic cardio-cerebrovascular diseases in large sample size subgroup analysis.

CONCLUSION

These results indicate that miR-146a rs2910164 polymorphisms were significantly associated with a lower risk of ischemic cardio-cerebrovascular. The miR-146a rs29101164 might be recommended as a predictor for susceptibility of ischemic cardio-cerebrovascular diseases.

Can Epigenetics of Endothelial Dysfunction Represent the Key to Precision Medicine in Type 2 Diabetes Mellitus?

In both developing and industrialized Countries, the growing prevalence of Type 2 Diabetes Mellitus (T2DM) and the severity of its related complications make T2DM one of the most challenging metabolic diseases worldwide. The close relationship between genetic and environmental factors suggests that eating habits and unhealthy lifestyles may significantly affect metabolic pathways, resulting in dynamic modifications of chromatin-associated proteins and homeostatic transcriptional responses involved in the progression of T2DM. Epigenetic mechanisms may be implicated in the complex processes linking environmental factors to genetic predisposition to metabolic disturbances, leading to obesity and type 2 diabetes mellitus (T2DM). Endothelial dysfunction represents an earlier marker and an important player in the development of this disease. Dysregulation of the endothelial ability to produce and release vasoactive mediators is recognized as the initial feature of impaired vascular activity under obesity and other insulin resistance conditions and undoubtedly concurs to the accelerated progression of atherosclerotic lesions and overall cardiovascular risk in T2DM patients. This review aims to summarize the most current knowledge regarding the involvement of epigenetic changes associated with endothelial dysfunction in T2DM, in order to identify potential targets that might contribute to pursuing “precision medicine” in the context of diabetic illness.

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.

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.

MicroRNA, Proteins, and Metabolites as Novel Biomarkers for Prediabetes, Diabetes, and Related Complications

Type 2 diabetes mellitus (T2DM) is no more a lifestyle disease of developed countries. It has emerged as a major health problem worldwide including developing countries. However, how diabetes could be detected at an early stage (prediabetes) to prevent the progression of disease is still unclear. Currently used biomarkers like glycated hemoglobin and assessment of blood glucose level have their own limitations. These classical markers can be detected when the disease is already established. Prognosis of disease at early stages and prediction of population at a higher risk require identification of specific markers that are sensitive enough to be detected at early stages of disease. Biomarkers which could predict the risk of disease in people will be useful for developing preventive/proactive therapies to those individuals who are at a higher risk of developing the disease. Recent studies suggested that the expression of biomolecules including microRNAs, proteins, and metabolites specifically change during the progression of T2DM and related complications, suggestive of disease pathology. Owing to their omnipresence in body fluids and their association with onset, progression, and pathogenesis of T2DM, these biomolecules can be potential biomarker for prognosis, diagnosis, and management of disease. In this article, we summarize biomolecules that could be potential biomarkers and their signature changes associated with T2DM and related complications during disease pathogenesis.

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.

Genetic variants in microRNA genes and targets associated with cardiovascular disease risk factors in the African-American population

The purpose of this study is to identify microRNA (miRNA) related polymorphism, including single nucleotide variants (SNVs) in mature miRNA-encoding sequences or in miRNA-target sites, and their association with cardiovascular disease (CVD) risk factors in African-American population. To achieve our objective, we examined 1900 African-Americans from the Atherosclerosis Risk in Communities study using SNVs identified from whole-genome sequencing data. A total of 971 SNVs found in 726 different mature miRNA-encoding sequences and 16,057 SNVs found in the three prime untranslated region (3'UTR) of 3647 protein-coding genes were identified and interrogated their associations with 17 CVD risk factors. Using single-variant-based approach, we found 5 SNVs in miRNA-encoding sequences to be associated with serum Lipoprotein(a) [Lp(a)], high-density lipoprotein (HDL) or triglycerides, and 2 SNVs in miRNA-target sites to be associated with Lp(a) and HDL, all with false discovery rates of 5%. Using a gene-based approach, we identified 3 pairs of associations between gene NSD1 and platelet count, gene HSPA4L and cardiac troponin T, and gene AHSA2 and magnesium. We successfully validated the association between a variant specific to African-American population, NR_039880.1:n.18A>C, in mature hsa-miR-4727-5p encoding sequence and serum HDL level in an independent sample of 2135 African-Americans. Our study provided candidate miRNAs and their targets for further investigation of their potential contribution to ethnic disparities in CVD risk factors.

Regulatory RNAs and cardiovascular disease - with a special focus on circulating microRNAs

MicroRNAs (miRNAs) are a class of short non-coding regulatory RNA molecules which play an important role in intracellular communication and cell signaling and which influence cellular processes such as proliferation, differentiation, and cellular death. Over the past two decades, the crucial role of microRNAs in controlling tissue homeostasis and disease in cardiovascular systems has become widely recognized. By controlling the expression levels of their targets, several miRNAs have been shown to modulate the function of endothelial cells (miR-221/222 and -126), vascular smooth muscle cells (miR-143/145) and macrophages (miR-33, -758, and -26), thereby regulating the development and progression of atherosclerosis. The stability of miRNAs within the blood suggests that circulating miRNAs may function as important biomarkers of disease development and progression. Numerous circulating miRNAs have been found to be dysregulated in a wide variety of different disease states, including diabetes, cancer, and cardiovascular disease.

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.

Role of MicroRNAs in Type 2 Diabetes and Associated Vascular Complications

Type 2 diabetes mellitus (T2DM) has become a major health threat worldwide. MicroRNAs (miRNAs) are a group of non-coding RNAs known to regulate various biological processes including the pathogenesis of T2DM. Recent studies have pointed out that specific miRNAs play a critical role in controlling β cell activities and the development of diabetic vascular complications. Their association with the disease pathogenesis and omnipresence in body fluids have made them important players for prognosis, diagnosis and management of T2DM. Owing to the limitations of classical biomarkers of diabetes such as fasting plasma glucose, glycosylated haemoglobin (HbA_1c) lack in predicting the risk of development of diabetes complications in a susceptible population. The miRNAs can act as ideal biomarkers for diabetes associated complications. Identification of specific miRNA signatures to detect diabetes and ideally to find out the risk of development of diabetes-associated complications in susceptible population is the essential requirement of the present clinical strategies for controlling diabetes worldwide. In this article, we summarize the potential miRNAs and miRNA signatures involved in the β cell activities and diabetes associated macrovascular and microvascular complications.

Association of MicroRNA-146a and MicroRNA-149 Polymorphisms With Strokes in Asian Populations: An Updated Meta-Analysis

Strokes are a major cause of disability and death worldwide. An association between microRNA-146a (miR-146a) and miR-149 polymorphisms and strokes was inconclusive. This meta-analysis aimed to reevaluate the strength of the association by searching online databases and retrieving relevant case-control studies published between 2000 and 2016. Nine articles including 8 on miR-146a rs2910164 G/C and 3 on miR-149 rs2292832 C/T in 3372 patients with stroke and 4394 controls were included. The miR-149 rs2292832 was significantly associated with the risk of a stroke under allelic (C vs T: odds ratio [OR] = 1.14; 95% confidence interval [CI] = 1.01-1.29; P = .03), homologous (CC vs TT: OR = 1.36; 95% CI = 1.05-1.77; P = .02), and recessive models (CC vs CT + TT: OR = 1.34; 95% CI = 1.05-1.71; P = .02). No correlation was detected between miR-146a rs2910164 and susceptibility to a stroke. In conclusion, the results suggested that miR-149 might be a risk factor for the development of a stroke, while miR-146a might not be. Well-designed studies with large populations are needed to clarify the association between miR-146a and miR-149 polymorphisms and strokes.

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.

A Variant in the Precursor of MicroRNA-146a is Responsible for Development of Erectile Dysfunction in Patients with Chronic Prostatitis via Targeting NOS1

Background

The morbidity of erectile dysfunction (ED) has been found to be substantially increased in patients with chronic prostatitis (CP). Accumulating evidence shows that single-nucleotide polymorphism (SNP) located in pre-miRNA or mature microRNA may affect the processing of microRNA (miRNA) and alter the expression of the miRNA, as well as its target gene. In this study we investigated the association between rs2910164 G/C polymorphism and risk of ED in patients with CP, as well as the underlying molecular mechanism.

Material/Methods

Computational analysis was used to search for the target of miR-146a, and the luciferase reporter assay system was used to validate NOS1 to be the target gene of miR-146a. We also treated PC-3 cells with miR-146a mimics/inhibitors to verify the negative regulatory relationship between miR-146a and NOS1, and real-time PCR and Western blot analysis were used to estimate the expression of the NOS1 mRNA and miR-146a.

Results

The binding site of miR-146a was found to be located within the 3′-UTR of the NOS1 by searching an online miRNA database (www.mirdb.org), and luciferase reporter assay was done to confirm that NOS1 is a direct target gene of miR-146a. We also found that mRNA and protein expression level of NOS1 in PC-3 cells treated with miR-146a mimics and NOS1 siRNA was substantially down-regulated compared with scramble control, while cells treated with miR-146a inhibitors showed increased expression of NOS1. In addition, 705 people were recruited for our research – 342 CP patients with ED and 363 CP patients without ED – and we found that the presence of minor allele of rs2910164 polymorphism is significantly associated with reduced risk of ED in patients with CP.

Conclusions

The findings indicate a decreased risk of ED in patients with CP who are carriers of miR-146a rs2910164 C allele, and this association might be due to its ability to compromise the expression of miR-146a, and thereby increase the expression of its target gene, NOS1.

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.

miRNA-93-5p and other miRNAs as predictors of coronary artery disease and STEMI

BACKGROUND

MicroRNAs (miRNAs), small non-coding RNAs, have been implicated as regulators of all mediators of atherosclerosis, and some reports have suggested increased levels in coronary artery disease (CAD) and acute myocardial infarction (AMI). However, the potential of miRNAs as biomarkers or predictors of disease remains to be established.

METHODS

We designed a study comprising 150 patients (50 Control, 50 Stable CAD, and 50 ST Elevation Myocardial Infarction (STEMI)), and measured plasma miRNAs in each. We then determined the ability of differential miRNAs, adjusting for Framingham Heart Study (FHS) risk factors, to discriminate between CAD vs Control, and STEMI vs Control.

RESULTS

Three miRNAs (miR15a-5p, miR16-5p, and miR93-5p) were significantly increased in Stable CAD vs Control groups and one (miR146a-5p) was significantly decreased in Stable CAD vs Control. One miRNA - miR499a-5p - was significantly increased in the STEMI group compared to Controls. After adjustment for FHS risk factors, miR93-5p levels remained an independent predictor of the presence of CAD (Odds Ratio [OR]=8.76, P=0.002). All 4 miRNAs improved discriminatory power for CAD over FHS alone in ROC analysis. Similarly, after adjustment for risk factors miR499-5p remained an independent predictor of STEMI (OR=3.03, P=0.001) and improved discriminatory power for STEMI in ROC analyses.

CONCLUSION

We identified 4 miRNAs that were differentially expressed among stable CAD and control patients, and 1 miRNA that was elevated in STEMI patients vs controls. MiR93-5p was the strongest predictor of CAD after adjustment for traditional risk factors, suggesting potential diagnostic utility.

Association of the Single Nucleotide Polymorphisms in microRNAs 130b, 200b, and 495 with Ischemic Stroke Susceptibility and Post-Stroke Mortality

The microRNA (miRNA) is a small non-coding RNA molecule that modulates gene expression at the posttranscriptional level. Platelets have a crucial role in both hemostasis and thrombosis, a condition that can occlude a cerebral artery and cause ischemic stroke. miR-130b, miR-200b, and miR-495 are potential genetic modulators involving platelet production and activation. We hypothesized that single nucleotide polymorphisms (SNPs) in these miRNAs might potentially contribute to the susceptibility to ischemic stroke and post-stroke mortality. This study included 523 ischemic stroke patients and 400 control subjects. We investigated the association of three miRNA SNPs (miR-130bT>C, miR-200bT>C, and miR-495A>C) with ischemic stroke prevalence and post-stroke mortality. In the multivariate logistic regression, there was no statistically significant difference in the distribution of miR-130bT>C, miR-200bT>C, or miR-495A>C between the ischemic stroke and control groups. In the subgroup analysis based on ischemic stroke subtype, the miR-200b CC genotype was less frequently found in the large-artery atherosclerosis stroke subtype compared with controls (TT+CT vs CC; adjusted odds ratio for CC, 0.506; 95% confidence interval, 0.265-0.965). During a mean follow-up period of 4.80 ± 2.11 years after stroke onset, there were 106 all-cause deaths among the 523 stroke patients. Multivariate Cox regression analysis did not find a significant association between post-stroke mortality and three miRNA SNPs. Our findings suggest that the functional SNP of miR-200b might be responsible for the susceptibility to large-artery atherosclerotic stroke.

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.

Associations of MicroRNA Polymorphisms (miR-146a, miR-196a2, and miR-499) with the Risk of Hypertension in the Korean Population

AIMS

Polymorphisms in microRNA (miR) genes are thought to be associated with various cancers and vascular diseases. To date, however, the effects of the miR gene polymorphisms on susceptibility to hypertension have rarely been investigated. In this study, we investigated the associations of three miR gene polymorphisms (miR-146aC>G/rs2910164, miR-196a2T>C/rs11614913, and miR-499A>G/rs3746444) with the risk of hypertension in Korean patients.

METHODS

A total of 855 study subjects (340 patients with hypertension and 515 healthy normotensive subjects) were included in this study. Genotyping of the three miR gene polymorphisms was accomplished by polymerase chain reaction-restriction fragment length polymorphism analyses.

RESULTS

Significant differences were observed in the genotype distributions of the miR-146aC>G polymorphism between the hypertensive patients and controls with the GG genotype, in both model-independent analyses, as well as in dominant (CC vs. CG+GG) and recessive (CC+CG vs. GG) models, being highly significantly associated with disease (AOR = 2.293, 95% CI: 1.466-3.586, p = 0.001; AOR = 1.727, 95% CI: 1.182-2.522, p = 0.015; AOR = 1.782, 95% CI: 1.267-2.506, p = 0.001, respectively). Neither the miR-196a2T>C nor the miR-499A>G polymorphisms were distributed significantly differently between hypertensive patients and control subjects. Several allelic combinations of the three miR polymorphisms were also associated with susceptibility to hypertension. Stratified analysis revealed that the miR-146aC>G and miR-499A>G polymorphisms are associated with a greater risk of hypertension.

CONCLUSION

This study suggests that the variant of miR-146aC>G polymorphism and allelic combinations, at least in Koreans, affect susceptibility to hypertension.

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.

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.

Lack of associations between rs2910164 and rs11614913 polymorphisms and the risk of ischemic stroke

Emerging evidence suggests that single nucleotide polymorphisms (SNPs) in microRNA genes may play a role in the development of cerebrovascular diseases including ischemic stroke through functionally modulating the expression of microRNA target genes. However, the current studies regarding the associations of the common microRNA polymorphisms with susceptibility to ischemic stroke have obtained discrepant results, which prompted us to perform a meta-analysis for a more precise estimation of the concerned associations. Relevant studies evaluating the associations between two common polymorphisms (miR-146a rs2910164 and miR-196a2 rs11614913) and the risk of ischemic stroke were retrieved from the PubMed, Embase, Cochrane Library, Google Scholar, Chinese Wanfang, Chinese Biomedical Database, and Chinese National Knowledge Infrastructure databases. The odds ratio (OR) with its 95% confidence interval (95% CI) were pooled to assess the strength of the associations using RevMan 5.2 and Stata 12.0 software. A total of 5 case-control studies with 2069 cases and 2061 controls on rs2910164, 4 case-control studies with 1873 cases and 1856 controls on rs11614913 polymorphisms were enrolled in the meta-analysis. Overall, neither allele frequency nor genotype distribution of the two common polymorphisms was found to be associated with risk for ischemic stroke in all genetic models. The subgroup analysis revealed a significant association between miR-146a rs2910164 polymorphism and increased risk of ischemic stroke in large sample size group and in Koreans under homozygous, allele, dominant and recessive models. The present meta-analysis suggests that the two common polymorphisms (rs2910164, rs11614913) may not contribute to the susceptibility to ischemic stroke. However, more well-designed studies with large sample size are warranted to further validate the results in different ethnicities.

Meta-Analysis of miR-146a Polymorphisms Association with Coronary Artery Diseases and Ischemic Stroke

Coronary artery disease (CAD) and ischemic stroke (IS) are manifestations of atherosclerosis, with a high death rate. miR-146a is a microRNA that participates in the progress of CAD and IS. A single nucleotide polymorphism (SNP) in the precursor of miR-146a, rs2910164, was found to be associated with the risks of CAD and IS. However, the results were inconsistent and inconclusive. A meta-analysis was performed to assess the relationship of rs2910164 and CAD as well as IS susceptibility. The database Pubmed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Chinese National Knowledge Infrastructure (CNKI), and Chinese Biomedical Literature Database (CBM) were searched for related studies. Crude odds ratios with 95% confidence intervals were used to investigate the strength of the association by random- or fixed-effect model. A total of eight studies, with 3138 cases and 3097 controls were identified for the meta-analysis. The results shows that rs2910164 is associated with the risk of CAD significantly in allelic model (OR = 0.86), homozygous model (OR = 0.70), heterozygous model (OR = 0.80) and dominant model (OR = 0.76). The subjects carrying the GG genotype, GG + GC genotype or G allele are at lower risks of CAD. For the susceptibility of IS, there are no significant associations between rs2910164 and total studies. However, in subgroup analysis by sample size and ethnicity, the GG, GG + GC and G allele of rs2910164 are found to be associated with higher risks of IS in large sample size group and in Koreans, under homozygous and dominant models. In conclusion, the current meta-analysis suggests lower risks of CAD for GG, GG + GC genotype and G allele of rs2910164, while rs2910164 is not associated with the risk of IS. Thus rs2910164 might be recommended as a predictor for susceptibility of CAD, but not IS.

Epigenetic mechanisms of endothelial dysfunction in type 2 diabetes

The development of type-2 diabetes mellitus (T2DM) and its complications is largely due to the complex interaction between genetic factors and environmental influences, mainly dietary habits and lifestyle, which can either accelerate or slow down disease progression. Recent findings suggest the potential involvement of epigenetic mechanisms as a crucial interface between the effects of genetic predisposition and environmental factors. The common denominator of environmental factors promoting T2DM development and progression is that they trigger an inflammatory response, promoting inflammation-mediated insulin resistance and endothelial dysfunction. Proinflammatory stimuli, including hyperglycemia, oxidative stress, and other inflammatory mediators, can affect epigenetic mechanisms, altering the expression of specific genes in target cells without changes in underlying DNA sequences. DNA methylation and post-translational histone modifications (PTHMs) are the most extensively investigated epigenetic mechanisms. Over the past few years, non-coding RNA, including microRNAs (miRNAs), have also emerged as key players in gene expression modulation. MiRNAs can be actively released or shed by cells in the bloodstream and taken up in active form by receiving cells, acting as efficient systemic communication tools. The miRNAs involved in modulation of inflammatory pathways (inflammamiRs), such as miR-146a, and those highly expressed in endothelial lineages and hematopoietic progenitor cells (angiomiRs), such as miR-126, are the most extensively studied circulating miRNAs in T2DM. However, data on circulating miRNA signatures associated with specific diabetic complications are still lacking. Since immune cells and endothelial cells are primarily involved in the vascular complications of T2DM, their relative contribution to circulating miRNA signatures needs to be elucidated. An integrated approach encompassing different epigenetic mechanisms would have the potential to provide new mechanistic insights into the genesis of diabetes and its severe vascular complications and identify a panel of epigenetic markers with diagnostic/prognostic and therapeutic relevance.

Association of miR-146a rs2910164 polymorphism with cardio-cerebrovascular diseases: A systematic review and meta-analysis

The microRNA146a rs2910164 polymorphism has been associated with the development of cardio-cerebrovascular diseases (CCDs); however, the results were inconsistent among different studies. The present report was aimed to investigate the association between rs2910164 G/C polymorphism and the risk of CCDs. Based on the data extracted from 12 eligible studies with a total of 5433 CCD cases and 6278 controls, we performed a meta-analysis to assess the diseases risk of rs2910164 G/C polymorphism under allelic contrast (C vs. G), homozygote comparisons (CC vs. GG), heterozygote comparisons (GC vs. GG), dominant model (CC+GC vs. GG) and recessive models (CC vs. GC+GG) in fixed or random effects models. We also conducted pathway enrichment analyses using the putative and validated miR-146a interacting targets to explore the functional impacts of rs2910164. The current meta-analysis results showed that rs2910164 CC genotype has a decreased risk with overall cardiovascular diseases and the specific coronary artery disease. Stratified analysis based on ethnicity showed that the CC genotype has a decreased risk with CCDs in Chinese population, but has an increased risk with CCDs in Korean and Indian populations. The results from pathway enrichment analysis also revealed the association of rs2910164 G allele with heart function and disease related pathways. Our findings suggested that miR-146a CC genotype might be a protective factor for cardiovascular diseases in Chinese population, but a risk factor in Korean and Indian populations.