Stroke Susceptibility Research Articles

Impact of MMP2 rs243849 and rs14070 genetic polymorphisms on the ischemic stroke susceptibility in Chinese Shaanxi population

Impact of MMP2 rs243849 and rs14070 genetic polymorphisms on the ischemic stroke susceptibility in Chinese Shaanxi population

Milk Fermented with Mushrooms Prevents Stroke in the Stroke-Prone Spontaneously Hypertensive Rats Independently of Blood Pressure

ObjectivesIn a previous study, a mushroom was shown to digest milk protein to a mixture of oligopeptides and free amino acids. The aim of this study was to examine effects of this mixture, i.e., mushroom-fermented milk, on blood pressure and stroke susceptibility in the stroke-prone spontaneously hypertensive rats (SHRSP). Materials and MethodsRats were fed mushroom-fermented milk with or without 1 % salt water. Blood pressure was monitored either by the tail-cuff method or the telemetry system. Symptoms of stroke were examined every day to determine the stroke latency. ResultsMushroom-fermented milk at 120 mg/Kg BW/day (estimated as a peptides/amino acids content) did not ameliorate hypertension in SHRSP. In contrast, mushroom-fermented milk significantly improved stroke susceptibility under salt-loading. The effects were replicated using milk fermented with three different mushrooms. To elucidate the effective components in mushroom-fermented milk, spermidine (3 mM), one of major components of mushroom-fermented milk, and a mixture of amino acids (0.8 g/L) was examined, both of which showed no significant effects on stroke susceptibility. Intake of mushroom-fermented milk did not affect sodium content significantly either in feces or in urine of the rats given 1% salt water. This observation indicated sodium absorption by the digestive system was not inhibited by intake of mushroom-fermented milk. ConclusionDespite that the mechanisms were not elucidated, intake of mushroom-fermented milk effectively prevented stroke in SHRSP. Mushroom-fermented milk would be a new candidate for a supplemental nutrient supporting the cardiovascular health.

Effect of PITX2 genetic variants on the susceptibility to stroke in the Chinese Han population.

Stroke is a multifactorial and complex disease caused by the obstruction or rupture of cerebrovascular. To explore the influence of genetic factors on stroke susceptibility, we investigated the association between four single nucleotide polymorphisms (SNPs) in the paired-like homeodomain transcription factor 2 (PITX2) gene and stroke risk. A total of 977 volunteers including 476 stroke patients and 501 control individuals were recruited. The association between PITX2 polymorphisms and stroke risk was evaluated using genetic models and haplotype analyses. The strength of the association between each studied polymorphisms and stroke risk was evaluated by calculating odds ratios (ORs) and 95% confidence intervals (CIs). What's more, multifactor dimensionality reduction (MDR) was used to predict the interaction between SNPs. Our study showed that rs6817105 in PITX2 was related to a significant increase in stroke susceptibility (OR=1.42, 95% CI=1.04-1.94, p=0.028). Stratified analyses based on gender indicated that rs6817105, rs13143308, and rs6843082 polymorphisms were significantly associated with an increased risk of stroke in male (OR=0.68, 95% CI=0.47-0.99, p=0.042; OR=0.53, 95% CI=0.30-0.96, p=0.035; and OR=0.55, 95% CI=0.30-0.99, p=0.047). Besides, SNP rs6817105 was significantly increased the risk of stroke in people at age over 65years (OR=1.87, 95% CI =1.12-3.11, p=0.016). MDR showed that the interaction model of rs6817105 and rs3853445 emerged as the best predictor between the PITX2 gene and stroke susceptibility. This study indicated that there was a significant association between the PITX2 gene and stroke risk, and provided some data as far as possible to support the prevention of stroke.

Genetic variations in ABCA1/G1 associated with plasma lipid levels and risk of ischemic stroke

BackgroundATP binding cassette transporters ABCA1 and ABCG1 play a crucial role in cholesterol efflux and reverse cholesterol transport (RCT), thereby rendering ischemic stroke (IS) susceptibility. Variants of ABCA1/G1 have been implicated in etiology of IS. This study aimed to investigate the association between single-nucleotide polymorphisms (SNPs) of ABCA1/G1 with plasma lipid variability and the risk of IS in Chinese Han Population. MethodsTotally 249 IS patients and 226 healthy controls were enrolled and 10 SNPs of ABCA1/G1 were screened for genotyping by kompetitive allele-specific polymerase chain reaction (KASP) and validated by sanger sequencing. The logistic regression analysis was performed to identify risk alleles of IS and appropriate genetic model. The genetic risk scores (GRS) and predicted risks for all individuals was computed. Based on different plasma lipid levels, we applied stratified analyses for subgroups. Linkage disequilibrium (LD) test was used to explore different functional haplotype combinations. Association between specific allele or genotype of the SNPs of ABCA1/G1 and plasma lipid or lipoproteins levels were also investigated. ResultsBesides total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), significant differences of clinical data were observed between IS and control group. The rare GG genotype frequencies of rs4149338 on ABCA1 was higher in IS patients than those in controls (11.4%, 4.6%, respectively, P = 0.037). Frequencies of rs57137919 on ABCG1 for rare AA genotype was lower in IS group than those in control group (4.6%, 13.3%, respectively, P = 0.030). GRS showed ability to discriminate IS patients and controls (AUC = 0.633, P < 0.001). Haplotype A-A (rs4149339-rs4149338) was correlated with reduced risk of IS (P = 0.023). Association analysis showed that subjects with rare AA genotype of rs57137919 had the lowest LDL-C levels while rare GG genotype of rs4149338 had lower TC level than those with AA genotype. The mRNA expression of ABCG1 was higher in IS patients, especially in the patients with frequent GG genotype of rs57137919, and was positively correlated with higher ABCG1 expression level and plasma LDL-C level. ConclusionsPolymorphisms of ABCA1/G1 associated with varieties of plasma lipid levels and risk of IS.

Apolipoprotein E ε4 Polymorphism as a Risk Factor for Ischemic Stroke: A Systematic Review and Meta-Analysis

Introduction Rising studies indicate that the apolipoprotein E (APOE) gene is related to the susceptibility of ischemic stroke (IS). However, certain consensus is limited by the lack of a large sample size of researches. This meta-analysis was performed to explore the potential association between the APOE gene and IS. Methods To identify relevant case control studies in English publications by October 2020, we searched PubMed, Embase, Web of Science, and the Cochrane Library. Pooled odds ratios (ORs) with fixed- or random-effect models and corresponding 95% confidence intervals (CIs) were calculated to analyze potential associations. Results A total of 55 researches from 32 countries containing 12207 IS cases and 27742 controls were included. The association between APOE gene ε4 mutation and IS was confirmed (ε4 vs. ε3 allele: pooled OR = 1.374, 95% CI, 1.214-1.556; ε2/ε4 vs. ε3/ε3: pooled OR = 1.233, 95% CI, 1.056-1.440; ε3/ε4 vs. ε3/ε3: pooled OR = 1.340, 95% CI, 1.165-1.542; ε4/ε4 vs. ε3/ε3: pooled OR = 1.833, 95% CI, 1.542-2.179; and APOE ε4 carriers vs. non-ε4 carriers: pooled OR = 1.377; 95% CI, 1.203-1.576). Interestingly, APOE ε4 mutation showed a dose-response correlation with IS risk (ε4/ε4 vs. ε2/ε4: pooled OR = 1.625; 95% CI, 1.281-2.060; ε4/ε4 vs. ε3/ε4: pooled OR = 1.301; 95% CI, 1.077-1.571). Similar conclusions were drawn in the small artery disease (SAD) subtype, but not in large artery atherosclerosis (LAA) or in cardioaortic embolism (CE), by subgroup analysis. Conclusions These observations reveal that specific APOE ε4 mutation was significantly associated with the risk of IS in a dose-dependent manner, while APOE ε4 mutation was related to SAD subtype onset without a cumulative effect.

Abstract 154: Sex-specific Genome Wide Association Study Of Early-onset Ischemic Stroke

Introduction: Genetic studies of early-onset disease have been an effective strategy to identify novel pathways and drug targets generalizable also to later-onset disease. Few studies have investigated the sex-specific genetic associations with early-onset ischemic stroke even though several features of ischemic stroke differ between males and females. We hypothesized that stratifying the GWAS by sex would reveal novel stroke loci. Methods: We performed a transethnic ischemic stroke GWAS of 3,056 female cases and 4,462 male cases &lt; 60 years-old and 16,192 and 16,048 sex-matched controls, respectively, from the Early Onset Stroke Genetics Consortium. Results: We identified a significant association in women with a locus in close proximity to TMX1 , a transmembrane platelet protein that inhibits platelet function. Additionally, we identified 2 other suggestive (P &lt; 5 x 10 -6 ) loci in females (see Table), i.e., at APOH , which encodes beta2-glycoprotein I, an established GWAS locus for lipoprotein(a), and LRFN2 which has been previously reported to associate with obesity-related measures and type II diabetes. We observed suggestive evidence for association in males with MMP3/MMP12 , a known stroke susceptibility locus. Conclusions: Despite a very modest sample size, sex-specific analyses identified suggestive associations at biologically important novel loci in females and a known stroke locus in males. Further studies of sex-specific associations in both early- and later-onset ischemic stroke are needed.

Predictive value of thrombus susceptibility for cardioembolic stroke by quantitative susceptibility mapping.

The hypointense blooming signal of thrombi on susceptibility-weighted imaging (SWI), known as the susceptibility vessel sign (SVS), is predictive of cardioembolic stroke. The SVS originates from the local magnetic susceptibility effect; thus, the susceptibility value of thrombi may provide useful information in discriminating stroke etiology. We aim to utilize quantitative susceptibility mapping (QSM) to assess thrombus's susceptibility value in acute ischemic stroke patients and explore the relationship of thrombus susceptibility with cardioembolic stroke. From 2018 to 2020, 132 consecutive acute ischemic stroke patients with middle cerebral artery occlusion were recruited within 48 hours of onset. All patients underwent a three-dimensional multi-echo SWI scan using a 3 Tesla magnetic resonance imaging scanner. The SVS presence and the diameter of the SVS-related hypointense signal were assessed on SWI. QSM was applied to compute the susceptibility value of the thrombus. The receiver operating characteristic (ROC) methodology was used to define the optimal cutoff value of the susceptibility in QSM and the diameter on SWI for predicting cardioembolic stroke. The SVS was identified in 93 (70.5%) patients with symptomatic middle cerebral artery occlusion and was significantly associated with cardioembolism. The hyperintense signal on QSM in the corresponding middle cerebral artery occlusion was present in 116 (87.9%) patients. ROC analysis indicated that thrombus susceptibility had a greater area under the curve than that of the SVS diameter (0.88 vs. 0.70, P<0.001) and that the optimal cutoff value of thrombus susceptibility for cardioembolism was 0.35 ppm. Multivariate analysis demonstrated that thrombus susceptibility (≥0.35 ppm) was an independent predictor of cardioembolic stroke (odds ratio =20.75; 95% CI, 7.19-59.87; P<0.001), with sensitivity, specificity, a positive predictive value, and a negative predictive value of 85.2%, 80.8%, 75.4%, and 88.7%, respectively, while the SVS presence showed sensitivity, specificity, a positive predictive value, and a negative predictive value of 90.7%, 43.6%, 87.2%, and 52.7%, respectively. Thrombus susceptibility provides superior diagnostic performance over the SVS for discriminating between cardioembolism and other stroke subtypes. Quantitative susceptibility measurements of thrombi may help predict cardioembolic stroke in patients with acute middle cerebral artery occlusion.

A 3-Mbp fragment on rat chromosome 1 affects susceptibility both to stroke and kidney injury under salt loading in the stroke-prone spontaneously hypertensive rat: a genetic approach using multiple congenic strains.

We have previously reported that a major quantitative trait locus (QTL) responsible for susceptibility to salt-induced stroke in the stroke-prone spontaneously hypertensive rat (SHRSP) is located in a 3-Mbp region on chromosome 1 covered by SHRSP.SHR-(D1Rat23-D1Rat213)/Izm (termed Pr1.31), a congenic strain with segments from SHRSP/Izm introduced into the stroke-resistant SHR/Izm. Here, we attempted to narrow down the candidate region on chromosome 1 further through analyses of subcongenic strains constructed for the target region. Simultaneously, salt-induced kidney injury was evaluated through the measurement of urinary albumin and the gene expression of renal tubular injury markers (Kim-1 and Clu) to explore a possible mechanism leading to the onset of stroke. All subcongenic strains examined in this study showed lower susceptibility to salt-induced stroke than SHRSP. Interestingly, Pr1.31 had the lowest stroke susceptibility when compared with newly constructed subcongenic strains harboring fragments of the congenic sequence in Pr1.31. Although Kim-1 and Clu expression after 1 week of salt loading in Pr1.31 did not differ significantly from those in SHRSP, the urinary albumin level of Pr1.31 was significantly lower than those of the other subcongenic strains and that of SHRSP. The present results indicated that, although the congenic fragment in Pr1.31 harbored the gene(s) related to salt-induced organ damages, further genetic dissection of the candidate region was difficult due to multiple QTLs suggested in this region. Further analysis using Pr1.31 will unveil genetic and pathophysiological mechanisms underlying salt-induced end organ damages in SHRSP.

Is cerebral vascular pathology a bystander of Alzheimer’s disease? Evidence from a genetic perspective

Alzheimer's disease (AD) is a multifactorial caused neurodegenerative disorder. The latest AD research framework proposed by the National Institute on aging-Alzheimer's Association described a biomarker-based pathological definition of AD, focusing on amyloid-β (Aβ), tau and neurodegeneration. This proposal separated the role of vascular involvement in the pathophysiology of AD, indicating vascular event is a bystander in AD. To testify this concept, we explored the common genetic evidences for the shared common initiative molecular pathways in AD and ischemic stroke.The common Single Nucleotide Polymorphisms (SNPs) susceptible to AD and ischemic stroke and their mapped genes were identified using GWAS Catalog database. Signaling pathways associated with these genes were obtained from the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Genecards database. The Gene Radar online tool in Gene-cloud of biotechnology information (GCBI) was used to identify the transcription factors involved in these genes.Up to December 15, 2020, 54 AD and 14 ischemic stroke Genome-wide association study(GWAS) datasets were chosen. In AD, 1009 susceptibility SNPs and its 1019 mapped genes were identified; while 138 susceptibility SNPs and its 162 mapped genes were identified in ischemic stroke. No any common AD and ischemic stroke susceptibility SNP was found, but ten common risk genes, accounting for 0.98% AD susceptibility genes and 6.17% ischemic stroke susceptibility genes, were identified. They are AC008125.1, AC011029.1, AGBL1, F13A1, FARP1, HDAC9, HNF4G, MMP12, MMP3 and PTPRG. The common signaling pathways with at least two of these gene products involved are G protein-coupled receptors (GPCR) (HDAC9, MMP12, MMP3), immune response (F13A1 and MMP3) and extracellular matrix (F13A1, MMP12 and MMP3). C-Ets-1 is the common transcription factor for F13A1 and MMP3. For the most AD risk gene apolipoprotein E(ApoE), there is no evidence of its direct association with ischemic stroke, but its putative homologs SERPRINA 1 and FGB associate with ischemic stroke in GWAS studies.There are some evidences of common molecular pathways involved in AD and ischemic stroke, which require further investigations to evaluate cerebral vascular impacts on the pathogenesis of AD.

Sex-specific association of RAGE and HMGB1 genotype variations with susceptibility to ischemic stroke in Caucasians

BackgroundThe role of genotype variants of HMGB1 and RAGE in susceptibility to acute ischemic stroke remains inconclusive. MethodsCaucasian acute ischemic stroke patients admitted to three hospitals within a large healthcare system in the U.S. between 2009 and 2017 were reviewed. For each stroke case, three age and sex-matched non-stroke patients were identified as controls. Associations of phased-genotype data for RAGE (rs1035798, rs2070600, rs1800624, rs1800625) and HMGB1 (rs1360485, rs1045411, rs3742305, rs2249825, rs1412125) single-nucleotide-polymorphisms (SNPs) and haplotypes with stroke susceptibility were analyzed. The Benjamini-Hochberg procedure was performed. ResultsCollectively, 4,264 patients, 1,066 acute ischemic stroke and 3,198 controls were identified. Genotype distributions were in Hardy-Weinberg equilibrium. None of the SNPs alternate allele frequencies differed from the NCBI SNP database. No differences were found in the genotype distributions when analyzing each SNP and the two most common haplotypes in a covariate adjusted model. In a sex-specific stratification, males harboring the RAGE SNP rs1800625 AG or GG genotype had an independently increased risk for ischemic strokes compared to controls (adjusted OR = 1.27,95%CI 1.03–1.57, pa = 0.0276). After the Benjamini-Hochberg procedure, a trend towards this association remained (pBH = 0.1104). ConclusionNo association of RAGE and HMGB1 genotypes variations with risk for overall ischemic stroke or specific stroke subtypes could be observed. Congruent with the literature, a sex-specific role of RAGE SNPs might associate with stroke susceptibility. The functional role of the HMGB1-RAGE axis in this context warrants further exploration.

MTHFR A1298C gene polymorphism on stroke risk: an updated meta-analysis

BackgroundPrevious studies have shown the effect of MTHFR A1298C gene polymorphism on stroke risk. But the results of published studies remained inconclusive and controversial. So we conducted a meta-analysis to accurately estimate the potential association between MTHFR A1298C gene polymorphism and stroke susceptibility.MethodsA systematic literature search on Embase, Pubmed, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI) and WanFang electronic database identified 40 articles including 5725 cases and 8655 controls. Strength of association was evaluated by pooled odds ratio (OR), 95% confidence interval (CI) and p value. Funnel plots and Begger’s regression test were applied for testing the publication bias. Statistical analysis of all data was performed by Stata 12.0.ResultsThe meta-analysis results indicated a significant relationship between MTHFR gene A1298C polymorphisms and stoke risk under the C allelic genetic model (OR = 1.19, 95%CI = 1.07–1.32, p = 0.001), dominant genetic model (OR = 1.19, 95%CI = 1.06–1.33, p = 0.004) and recessive genetic model (OR = 1.43, 95%CI =1.15–1.77, p = 0.001). In subgroup analysis, we discovered obvious correlation in three genetic model of Asian, stroke type, adult by ethnicity, population, stroke type, source of control and case size. Additionally, in studies of control from hospital and case size equal 100, obvious correlation was also found in the three genetic model.ConclusionsOur meta-analysis results indicated that there was evidence to support the correlation between MTHFR A1298C polymorphism and stroke susceptibility, especially in adults and ischemic stroke.

The Effect of Renalase rs2576178 and rs10887800 Polymorphisms on Ischemic Stroke Susceptibility in Young Patients (

Background Ischemic stroke (IS) is the most common form of cerebrovascular accident which its precise etiology remains mysterious. Renalase is a catecholamine-degrading enzyme playing a major role in blood pressure control. Recent studies show the effect of renalase activity on various diseases like IS. In the current study, we examined the possible effects of renalase gene (RNLS) rs2576178 and rs10887800 variants at the 5′-flanking and intron 6 regions on IS, respectively. Methods One hundred and fifty-four IS patients younger than 50 years and 165 age- and sex-matched controls were recruited in the study. For genotyping of rs2576178 and rs10887800 variants, the PCR-RFLP method was used. Results The RNLS rs10887800 AG genotype was more repeated in IS patients, but the difference was marginally nonsignificant (P = 0.054). This variant was associated with IS in the overdominant model, and the AG genotype is associated with a1.6-fold increased risk of IS compared to AA+ GG genotypes (OR = 1.6, 95% CI: 1-2.5, P = 0.033). No relationship was observed between RNLS rs2576178 polymorphism and IS in all genetic models. The findings of the haplotype and combination effects of rs10887800 and rs2576178 variants on IS showed no significant association. The in silico analysis showed no effect of rs2576178 and rs10887800 polymorphisms in the RNA structure, but the alteration of RNA sequence in rs2576178 results in the lack of a MBNL1 protein binding site. ConclusionsRNLS rs10887800 but not rs2576178 polymorphism was associated with IS susceptibility in the overdominant model (AG vs AA+ GG genotypes).

Influence of the rs6736 Polymorphism on Ischemic Stroke Susceptibility in Han Chinese Individuals via the Disruption of miR-7-1 Binding to the C14orf119 Gene.

This study investigates the association between the C14orf119 gene rs6736 polymorphism and ischemic stroke (IS) susceptibility, and explores the influence of the rs6736 polymorphism on the binding between miR-7-1 and the C14orf119 gene. mRNA expression levels were determined in 45 IS patients and 45 matched controls via real-time quantitative PCR. A total of 774 IS patients and 793 matched controls were recruited from a Han Chinese population for genotyping, performed with the Sequenom MassARRAY iPLEX platform. A dual-luciferase reporter assay was used for the analysis of miRNA-mRNA binding. The results showed that the mRNA expression of C14orf119 differed significantly between IS patients and controls (t = -2.235, P = 0.030). Significant associations were noted between the C14orf119 gene rs6736 polymorphism and IS susceptibility in Han Chinese individuals under the additive model [ORadj (95% CI) = 0.87 (0.76-1.00) Padj = 0.048] and dominant model [ORadj (95% CI) = 0.76 (0.61-0.94), Padj = 0.014], with adjustment for age and sex. Mutations in the rs6736 polymorphism disrupted the binding of miR-7-1 and the C14orf119 gene. The results of this study show that the rs6736 polymorphism in the 3'-untranslated region of the C14orf119 gene not only is associated with IS but also modifies the binding between miR-7-1 and the C14orf119 gene. The C14orf119 gene may participate in the relationship between IS and miR-7-1.

Bioinformatics Analysis of a Functional ANGPT1 Variant That Interferes with miR-607 and Its Association with Susceptibility and Outcome of Ischemic Stroke in a Han Population.

PurposeIschemic stroke (IS) is a major cause of disability and death. We used bioinformatics approaches to investigate a functional ANGPT1 variant that interferes with miR-607 and explored its association with IS.Materials and MethodsAn IS expression microarray (GSE16561) was downloaded from the GEO and used to identify differentially expressed genes (DEGs) and functional enrichment pathways. Analyses showed that ANGPT1 participated in six key pathways and was susceptible to a key functional polymorphism rs2507799. We genotyped 567 IS patients and 500 controls for ANGPT1 rs2507799. Luciferase assays were also conducted to investigate the binding between miR-607 and ANGPT1 rs2507799.ResultsIn total, we identified 458 DEGs between IS patients and healthy controls in the GSE16561 dataset. GO functional enrichment analysis showed that these DEGs were mainly enriched in cell-substrate junctions, the regulation of peptide secretion, and the regulation of cytokine secretion involved in immune response. ANGPT1 rs2507799 T-carriers had a significantly higher risk of IS (Dominant model: OR = 1.48, 95% CI = 1.01–2.17, P = 0.044). IS patients harboring the TC/TT genotype experienced significantly more severe injuries in terms of neurological function (Dominant model: OR = 2.06, 95% CI = 1.28–3.31, P = 0.003). Analysis also showed that IS patients harboring the TC/TT genotype had a significantly worse outcome (Dominant model: OR = 2.22, 95% CI = 1.35–3.67, P = 0.002). Luciferase assays indicated that miR-607 could affect luciferase activity by binding to the ANGPT1 mutant type.ConclusionIn this study, we used bioinformatical methods to investigate a key IS-related gene ANGPT1 and its functional polymorphism rs2507799. rs2507799 was found to be associated with a significantly increased risk for IS, a significantly more severe initial stroke severity, and a worse outcome. These results may help to improve the future management of ischemic stroke.

SLC17A3 rs9379800 and Ischemic Stroke Susceptibility at the Northern Region of Malaysia

ObjectivesThe relationships of Paired Like Homeodomain 2 (PITX2), Ninjurin 2 (NINJ2), TWIST-Related Protein 1 (TWIST1), Ras Interacting Protein 1 (Rasip1), Solute Carrier Family 17 Member 3 (SLC17A3), Methylmalonyl Co-A Mutase (MUT) and Fer3 Like BHLH Transcription Factor (FERD3L) polymorphisms and gene expression with ischemic stroke have yet to be determined in Malaysia. Hence, this study aimed to explore the associations of single nucleotide polymorphisms (SNPs) and gene expression with ischemic stroke risk among population who resided at the Northern region of Malaysia. Materials and methodsStudy subjects including 216 ischemic stroke patients and 203 healthy controls were recruited upon obtaining ethical clearance. SNP genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism assays. Gene expression levels were quantified by real-time polymerase chain reaction assays. Statistical and genetic analyses were conducted with SPSS version 22.2, PLINK version 1.07 and multifactor dimensionality reduction software. ResultsStudy subjects with G allele, CG or GG genotypes of SLC17A3 rs9379800 demonstrated increased risk of ischemic stroke with the odds ratios ranging from 1.76-fold to 3.14-fold (p<0.05). When stratified study subjects according to the ethnicity, SLC17A3 rs9379800 G allele and CG genotype contributed to 2.14- and 2.96-fold of ischemic stroke risk among Malay population significantly, in the multivariate analysis (p<0.05). However, no significant associations were observed for PITX2, NINJ2, TWIST1, Rasip1, and MUT polymorphisms with ischemic stroke risk in the multivariate analysis for the pooled cases and controls as well as when stratified them according to the ethnicity. Lower mRNA expression levels of Rasip1, SLC17A3, MUT and FERD3L were observed among cases (p<0.05). After FDR adjustment, the mRNA level of SLC17A3 remained significantly associated with ischemic stroke among Malay population (q=0.034). ConclusionIn conclusion, this study suggests that SLC17A3 rs9379800 polymorphism and its gene expression contribute to significant ischemic stroke risk among Malaysian population, particularly the Malay who resided at the Northern Region of the country. Our findings can provide useful information for the future diagnosis, management and treatment of ischemic stroke patients.

Promoter polymorphism of TNF‑α (rs1800629) is associated with ischemic stroke susceptibility in a southern Thai population

Stroke represents the leading cause of disability and mortality amongst the elderly worldwide. Multiple risk factors, including both genetic and non-genetic components, as well as their interactions, are proposed as etiological factors involved in the development of ischemic stroke (IS). Promoter polymorphisms of the IL-6-174G/C (rs1800795) and TNF-α-308G/A (rs1800629) genes have been considered as predictive risk factors of IS; however, these have not yet been evaluated in a Thai population. The aims of this study were to investigate the association of IL-6-174G/C and TNF-α-308G/A polymorphisms with IS. Genomic DNA from 200 patients with IS and 200 controls were genotyped for IL-6-174G/C and TNF-α-308G/A polymorphisms using TaqMan™ SNP genotyping and quantitative PCR-high resolution melting analysis, respectively. It was found that the TNF-α-308 A allele was significantly associated with an increased risk of IS development compared with the G allele [odds ratio (OR)=2.044; 95% CI=1.154-3.620; P=0.014]. Moreover, the IS risk was significantly higher in the presence of TNF-α-308 GA or AA genotypes compared with that in the presence of GG genotypes with a dominant inheritance (OR=1.971; 95% CI=1.080-3.599; P=0.027). However, there was no association between IL-6-174G/C and the risk of IS development. The interaction study demonstrated that IL-6-174 GG and TNF-α-308 GG genotypes enhanced IS susceptibility when combined with hypertension, hyperlipidemia and alcohol consumption. Hypertensive and hyperlipidemic subjects with the TNF-α-308 GA and AA genotypes were more likely to develop IS compared with those who did not have these two conditions and had the GG genotype. In a matched study design (1:1), the IL-6-174 GC genotype was associated with higher IL-6 levels in the control group. Collectively, the present results highlight the utility of the TNF-α-308G/A polymorphism as a predictive genetic risk factor for development of IS.

Missense Genetic Polymorphisms of Microsomal (EPHX1) and Soluble Epoxide Hydrolase (EPHX2) and Their Relation to the Risk of Large Artery Atherosclerotic Ischemic Stroke in a Turkish Population.

PurposeSoluble epoxide hydrolase (sEH) and microsomal epoxide hydrolase (mEH) both catalyze the metabolism of epoxyeicosatrienoic acids (EETs), lipid signaling molecules that are protective against ischemic brain injury owing to their participation in the regulation of vascular tone and cerebral blood flow. In addition, mEH metabolizes polycyclic aromatic hydrocarbons, one of the causative factors of atherosclerotic lesion development. In this study, we aimed to investigate the association of enzyme activity-modifying missense single nucleotide polymorphisms (SNPs) of the sEH gene (EPHX2) and mEH gene (EPHX1) and ischemic stroke risk in a Turkish population.Patients and MethodsGenomic DNA of patients with large artery atherosclerotic ischemic stroke (n=237) and controls (n=120) was isolated from blood samples, and genotypes for Tyr113His (rs1051740) and His139Arg (rs2234922) SNPs of EPHX1 and Arg287Gln (rs751141) SNP of EPHX2 were attained by the PCR/RFLP method.ResultsMinor allele frequency and genotype distributions for Arg287Gln, Tyr113His and His139Arg SNPs did not differ significantly between stroke patients and controls. However, hypertension- and diabetes-associated ischemic stroke risk was decreased by EPHX1 and increased by EPHX2 variants in stratification analyses.ConclusionThis study has shown for the first time that the polymorphic alleles of EPHX1 were unlikely to be associated with large artery atherosclerotic ischemic stroke susceptibility; however, protective effects were evident within subgroups of hypertension and diabetes. In addition, EPHX2 Arg287Gln polymorphism, which has been studied for the first time in a Turkish population, was not significantly related to ischemic stroke, but increased the stroke risk in subgroup analysis.

The copy number variation and stroke (CaNVAS) risk and outcome study.

The role of copy number variation (CNV) variation in stroke susceptibility and outcome has yet to be explored. The Copy Number Variation and Stroke (CaNVAS) Risk and Outcome study addresses this knowledge gap. Over 24,500 well-phenotyped IS cases, including IS subtypes, and over 43,500 controls have been identified, all with readily available genotyping on GWAS and exome arrays, with case measures of stroke outcome. To evaluate CNV-associated stroke risk and stroke outcome it is planned to: 1) perform Risk Discovery using several analytic approaches to identify CNVs that are associated with the risk of IS and its subtypes, across the age-, sex- and ethnicity-spectrums; 2) perform Risk Replication and Extension to determine whether the identified stroke-associated CNVs replicate in other ethnically diverse datasets and use biomarker data (e.g. methylation, proteomic, RNA, miRNA, etc.) to evaluate how the identified CNVs exert their effects on stroke risk, and lastly; 3) perform outcome-based Replication and Extension analyses of recent findings demonstrating an inverse relationship between CNV burden and stroke outcome at 3 months (mRS), and then determine the key CNV drivers responsible for these associations using existing biomarker data. The results of an initial CNV evaluation of 50 samples from each participating dataset are presented demonstrating that the existing GWAS and exome chip data are excellent for the planned CNV analyses. Further, some samples will require additional considerations for analysis, however such samples can readily be identified, as demonstrated by a sample demonstrating clonal mosaicism. The CaNVAS study will cost-effectively leverage the numerous advantages of using existing case-control data sets, exploring the relationships between CNV and IS and its subtypes, and outcome at 3 months, in both men and women, in those of African and European-Caucasian descent, this, across the entire adult-age spectrum.

Contribution of WNT2B Genetic Variants to Ischemic Stroke Occurrence in a Chinese Han Population.

Wnt signaling pathway-related WNT2B gene was upregulated in ischemic brain damage. We aimed to assess the contribution of WNT2B genetic variant to ischemic stroke (IS) susceptibility in the Chinese Han population. Five polymorphisms including rs3790606, rs351364, rs3790608, rs12037987, and rs10776752 in WNT2B were genotyped using Agena MassARRAY platform in 476 healthy controls and 501 patients with IS. Odds ratio (OR) and 95% confidence interval (CI) adjusted for age and gender were estimated by logistic regression analysis. Analysis of variance was used to evaluate the association between genotypes of WNT2B variants and blood lipid parameters. Rs12037987 (OR = 1.82, 95% CI: 1.18-2.82, P = 0.007) and rs10776752 (OR = 1.74, 95% CI: 1.13-2.68, P = 0.012) were related to the increased IS susceptibility. Interestingly, rs12037987 (OR = 2.01, P = 0.028) and rs10776752 (OR = 2.02, P = 0.028) had the higher IS risk in the subjects younger than or equal to 65 years. Rs12037987 (OR = 2.70, P = 0.013), rs10776752 (OR = 2.71, P = 0.012), and rs3790606 (OR = 1.89, P = 0.036) manifested an increasing-risk association with IS occurrence in women. Moreover, rs3790606 genotype was related to serum levels of triglyceride (P = 0.008) and total cholesterol (P = 0.001). Our study reported that rs12037987 and rs10776752 were associated with the increased risk for IS in the Chinese Han population. Our findings may be useful for insight into the contribution of WNT2B variants to the complex pathogenesis of IS.

Genetic Variants of lncRNA GAS5 Contribute to Susceptibility of Ischemic Stroke among Southern Chinese Population

Emerging evidence suggests that the long noncoding RNA (lncRNA) growth arrest special 5 (GAS5) plays crucial roles in the pathogenesis of ischemic stroke (IS). The current research is aimed at assessing the correlation between two functional GAS5 variants (rs145204276 and rs55829688) and susceptibility to IS in a Han Chinese population. This study genotyped the two GAS5 variants in 1086 IS patients as well as 1045 age-matched healthy controls by using an improved multitemperature ligase detection reaction (iMLDR-TM) genotyping technology. We observed a considerable change in the frequencies of the rs145204276 allele and genotype among the IS patients and healthy control group. The del-T haplotype was substantially more prevalent in the IS cases compared to the control individuals. When study participants were stratified according to environmental factors, we found that the rs145204276 del allele was correlated with a higher risk of IS in male, smokers, hypertensive, and those ≥65 years old. Additional stratification conforming to IS subtypes exhibited that individuals carrying the rs145204276 del allele conferred a higher risk of expanding a larger artery atherosclerosis stroke subset. Moreover, there was a significant association between the rs145204276 del allele and elevated expression of GAS5 in IS patients. In contrast, the frequency of the allele related to rs55829688 was not statistically correlated with IS in all analysis. Our study supports a model wherein the rs145204276 variant in the GAS5 lncRNA is associated with IS risk, thus representing a potentially viable biomarker for IS prevention and treatment.