Genetic variants of arachidonate 5-lipoxygenase-activating protein, and risk of incident myocardial infarction and ischemic stroke: a nested case-control approach

Association of the LPA gene polymorphisms with coronary artery disease risk in the Xinjiang population of China: A case-control study

Lipoprotein(a) is a well-known independent risk factor for coronary artery disease (CAD) and primarily determined by variation in the LPA gene coding for the apolipoprotein(a) moiety. Our study purpose was to evaluate the association between the human LPA gene polymorphisms and CAD in Han and Uyghur populations in Xinjiang, China. A case-control study was conducted with 831 Han people (392 CAD patients and 439 control subjects) and 829 Uygur people (513 CAD patients and 316 control subjects). All participants were genotyped for the same 3 single nucleotide polymorphisms (rs1801693, rs6923877, and rs9364559) of the LPA gene by a Real-time PCR instrument. In CAD patients, the levels of lipoprotein(a) were significantly higher in the Han population with the C/C genotype at the rs1801693 (P = .018) and the A/A genotype at the rs9364559 (P = .029) than in the Uyghur population. The polymorphisms rs1801693, rs6923877, and rs9364559 were found to be associated with CAD in the Han population. For men, the distribution of rs1801693 in genotypes, alleles and recessive model (CC vs CT + TT) showed a significant difference (all P < .05), and the difference in recessive model was retained after adjustment for covariates (odds ratio [OR]: 0.557, 95% confidence interval [CI]: 0.355-0.874, P = .011). But the distribution of rs6923877 in genotypes and dominant model (GG vs AG + AA) showed a significant difference (both P < .05) in both men and women, and the difference was kept in dominant model after adjustment (OR: 1.473, 95% CI:1.009-2.148, P = .045). For women, a significant difference was found in the distribution of rs9364559 in the alleles and dominant model (AA vs AG + GG) (for alleles: P = .021, for dominant model: P = .025, OR: 0.560, 95% CI:0.350-0.898, P = .016) after adjustment. Polymorphisms rs1801693, rs6923877, and rs9364559 of the LPA gene are associated with CAD in the Han population in Xinjiang Uygur Autonomous Region of China.

Genetic and Epigenetic Regulation of Lipoxygenase Pathways and Reverse Cholesterol Transport in Atherogenesis

Atherosclerosis is one of the most important medical and social problems of modern society. Atherosclerosis causes a large number of hospitalizations, disability, and mortality. A considerable amount of evidence suggests that inflammation is one of the key links in the pathogenesis of atherosclerosis. Inflammation in the vascular wall has extensive cross-linkages with lipid metabolism, and lipid mediators act as a central link in the regulation of inflammation in the vascular wall. Data on the role of genetics and epigenetic factors in the development of atherosclerosis are of great interest. A growing body of evidence is strengthening the understanding of the significance of gene polymorphism, as well as gene expression dysregulation involved in cross-links between lipid metabolism and the innate immune system. A better understanding of the genetic basis and molecular mechanisms of disease pathogenesis is an important step towards solving the problems of its early diagnosis and treatment.

Genetic variation at the coronary artery disease risk locus GUCY1A3 modifies cardiovascular disease prevention effects of aspirin

AIMS

Efficacy of aspirin in primary prevention of cardiovascular disease (CVD) may be influenced by a common allele in guanylate cyclase GUCY1A3, which has been shown to modify platelet function and increase CVD risk.

METHODS AND RESULTS

We investigated whether homozygotes of the GUCY1A3 rs7692387 risk (G) allele benefited from aspirin in two long-term, randomized placebo-controlled trials of aspirin in primary CVD prevention: the Women's Genome Health Study (WGHS, N = 23 294) and a myocardial infarction (MI, N = 550) and stroke (N = 382) case-control set from the Physician's Health Study (PHS, N = 22 071). Bleeding risk was evaluated in the WGHS. In the placebo group of the WGHS, the GUCY1A3 risk (G) allele was confirmed to increase CVD risk [hazard ratio 1.38; 95% confidence interval (CI) 1.08-1.78; P = 0.01]. Random-effects meta-analysis of the WGHS and PHS revealed that aspirin reduced CVD events among risk allele homozygotes [G/G: odds ratio (OR) 0.79; 95% CI 0.65-0.97; P = 0.03] but increased CVD events among non-risk allele carriers (e.g. G/A: OR 1.39; 95% CI 1.03-1.87; P = 0.03) thus implying an interaction between genotype stratum and aspirin intake (Pinteraction = 0.01). Bleeding associated with aspirin increased in all genotype groups, with higher risks in heterozygotes.

CONCLUSION

In two randomized placebo-controlled trials in the setting of primary prevention, aspirin reduced the incidence of CVD events in individuals homozygous for the GUCY1A3 risk (G) allele, whereas heterozygote individuals had more events when taking aspirin.

Establishing molecular signatures of stroke focusing on omic approaches: a narrative review

Stroke or 'brain attack' is considered to be the major cause of mortality and morbidity worldwide after myocardial infraction. Inspite of the years of research and clinical practice, the pathogenesis of stroke still remains incompletely understood. Omics approaches not only enable the description of a huge number of molecular platforms but also have a potential to recognize new factors associated with various complex disorders including stroke. The most significant development among all other omics technologies over the recent years has been seen by genomics which is a powerful tool for exploring the genetic architecture of stroke. Genomics has decisively established itself in stroke research and by now wealth of data has been generated providing new insights into the physiology and pathophysiology of stroke. However, the efficacy of genomic data is restricted to risk prediction only. Omics approaches not only enable the description of a huge number of molecular platforms but also have a potential to recognize new factors associated with various complex disorders including stroke. The data generated by omics technologies enables clinicians to provide detailed insight into the makeup of stroke in individual patients, which will further help in developing diagnostic procedures to direct therapies. Present review has been compiled with an aim to understand the potential of integrated omics approach to help in characterization of mechanisms leading to stroke, to predict the patient risk of getting stroke by analyzing signature biomarkers and to develop targeted therapeutic strategies.

Lack of association between ALOX5AP genetic polymorphisms and risk of ischemic stroke: evidence from meta-analyses

BACKGROUND

In recent years, there has been substantial research evaluating the relationship between arachidonate 5-lipoxygenase-activating protein (ALOX5AP) polymorphisms and ischemic stroke (IS). The objective of this study was to systematically review and analyze the existing evidence.

METHODS

A comprehensive search of major electronic databases for studies published between 1990 and 2018 was carried out. Data were synthesized as OR and 95% CI using fixed-effects and random-effects models.

RESULTS

A total of 30 studies were available for analysis. The aggregate sample size across all studies was 32,782 (16,294 cases and 16,488 controls). We found no association of the ALOX5AP rs10507391 (OR=1.03 for A allele vs T allele; 95% CI: 0.93-1.14; P=0.557), rs4769874 (OR=1.13 for A allele vs G allele; 95% CI: 1.00-1.28; P=0.050), rs9551963 (OR=1.03 for A allele vs C allele; 95% CI: 0.96-1.11; P=0.372), rs17222814 (OR=1.09 for A allele vs G allele; 95% CI: 0.96-1.24; P=0.195), rs17222919 (OR=0.89 for G allele vs T allele; 95% CI: 0.75-1.06; P=0.175), and rs4073259 (OR=1.20 for A allele vs G allele; 95% CI: 1.00-1.45; P=0.056) polymorphisms with IS risk. Haplotype analysis also did not yield significant findings for the HapA (rs17222814G-rs10507391T-rs4769874G-rs9551963A; OR=1.20; 95% CI: 0.91-1.56; P=0.192) and HapB (rs17216473A-rs10507391A-rs9315050A-rs17222842G; OR=1.11; 95% CI: 0.90-1.38; P=0.339) haplotypes.

CONCLUSION

Current evidence does not support an association of rs10507391, rs4769874, rs9551963, rs17222814, rs17222919, rs4073259, and HapA and HapB with IS risk.

Association between the polymorphism (rs17222919, -1316T/G) of 5-lipoxygenase-activating protein gene (ALOX5AP) and the risk of stroke: A meta analysis

BACKGROUND

The objective of this study was to evalutate the relationship between 5-lipoxygenase-activating protein gene (ALOX5AP) -rs17222919-1316T/G polymorphisms and the risk of stroke.

METHODS

Relative studies were searched in January 2018. Case-control studies with extractable data were selected. Four gene models were analyzed including, allele genetic model (G vs T), additive genetic model (GG vs TT, GT vs TT), recessive genetic model (GG vs GT + TT), and dominant genetic model (GG + GT vs TT). Effect sizes included odds ratio (OR) and 95% confidence interval (CI). Heterogeneity was assessed by using Q test and I test. Publication bias was evaluated by using Egger method. The reliability of the results was assessed with sensitivity analysis. All the data analysis was performed with R 3.10 software.

RESULTS

A total of 5 studies inclusing 8492 patients were included. There were significant relationship between ALOX5AP-rs17222919-1316T/G polymorphisms and stroke under all models (P < .05) except the additive genetic model GT versus TT (P > .05). No publication bias was noted. Sensitivity analysis indicated that the results were not stable.

CONCLUSION

This meta-analysis indicates that ALOX5AP-rs17222919-1316T/G may be a protective factor aginst stroke.

The association of single nucleotide polymorphism rs189037C>T in ATM gene with coronary artery disease in Chinese Han populations: A case control study

Accumulated evidence has indicated that ataxia telangiectasia mutated (ATM) is closely related to atherosclerosis and cardiovascular diseases. So we aimed to examine potential association between a gene variant [single nucleotide polymorphisms (SNPs), i.e., rs189037C>T] in the promoter of ATM gene and coronary artery disease (CAD) in Chinese Han populations.In this hospital-based case-control study, a total of 1308 participants were divided into CAD group (652 patients) and control group (656 subjects) after performing coronary angiography. The SNP rs189037 was genotyped by using polymerase chain reaction-restriction fragment length polymorphism.The distribution of rs189037 genotypes and alleles showed a significant difference between CAD and control subjects (genotypes: P = .032; alleles: P = .028). The percentage of the TT genotype is much higher in control group than that in CAD group (22.0% vs 16.3%, P = .009). After adjustment of the major confounding factors, such difference remained significant (OR = 0.62, 95% CI = 0.43-0.89, P = .010). After analyzing data from different groups divided by genders and smoking status respectively, we found that the protective effect of TT genotype on CAD was significant in males (P = .007) and smokers (P = .031). The difference remained statistically significant after multivariate adjustment (adjusted in males: OR = 0.60, 95% CI = 0.38-0.93, P = .022; adjusted in smokers: OR = 0.47, 95% CI = 0.27-0.81, P = .006).Our study suggests that ATM rs189037 polymorphism is associated with CAD in Chinese Han populations. The TT genotype of rs189037 seems to be associated with a lower risk of CAD and a protective genetic marker of CAD, especially in males and smokers.

The SG13S114 polymorphism of the ALOX5AP gene is associated with ischemic stroke in Europeans: a meta-analysis of 8062 subjects

The association between ALOX5AP SG13S114 polymorphism and ischemic stroke (IS) susceptibility has extensively been investigated, especially in white populations; however, the results were inconclusive. Here, we perform a meta-analysis to clarify the effect of SG13S114 variant on the IS risk in Europeans. The Web of Science, PubMed, EMBASE, and Medline were searched up to August 1st, 2016. Data were extracted and the odd ratios (ORs) and 95% confidence intervals (CIs) were calculated by a fixed-effects or random-effects model. In total, 8 case control studies involved 8062 subjects were finally included in this meta-analysis. We observed a significantly decreased IS risk in persons carrying an A allele at the SG13S114 polymorphism compared with those with a T allele (A vs T, OR = 0.856, 95% CI = 0.797-0.919, p < 0.001). In addition, the results of sensitivity and cumulative meta-analysis indicated the robustness of our results. In addition, the publication bias was not detected using the funnel plot and Egger's tests. In summary, the present meta-analysis suggested that the A allele at the ALOX5AP SG13S114 polymorphism is a protective factor for the IS in the Europeans. In addition, further studies with large sample size are needed to validate the association, as well as in other ethnic groups.

Exome Sequencing in a Family Identifies RECQL5 Mutation Resulting in Early Myocardial Infarction

Coronary artery disease (CAD) including myocardial infarction (MI) is the leading cause of death worldwide and is commonly caused by the interaction between genetic factors and environmental risks. Despite intensive efforts using linkage and candidate gene approaches, the genetic etiology for the majority of families with a multigenerational early CAD /MI predisposition is unknown.In this study, we used whole-exome sequencing of 10 individuals from 1 early MI family, in which 4 siblings were diagnosed with MI before the age of 55, to identify potential predisposing genes.We identified a mutation in the RECQL5 gene, 1 of the 5 members of the RECQ family which are involved in the maintenance of genomic stability. This novel mutation, which is a TG insert at position 73,626,918 on the 13 chromosome and occurs before the last nucleotide of the introns 11 acceptor splice site affecting splicing of RECQL5. RT-PCR suggested the control subject had a full-length mRNA including exon 12, but the patients with RECQL5 mutation had a shorter mRNA form involving splicing of exons 11 to 13 directly, with skipping of exon 12. Quantitative RT-PCR analysis of RECQL5 exon 12 demonstrated that individuals whose genotype is mutant homozygote had only trace amounts of mRNA containing this exon and the family members who carry the heterozygous genotype had a level at 48% to 55% of the control's level.These findings provide insight into both the pathogenesis of MI and the role of RECQL5 gene in human disease.

Variants in the Atherogenic ALOX5AP, THBD, and KNG1 Genes Potentiate the Risk of Ischemic Stroke via a Genetic Main Effect and Epistatic Interactions in a Chinese Population

BACKGROUND

Ischemic stroke (IS) is a multifactorial disease that displays a strong genetic predisposition. However, the genetic architecture of IS has yet to be fully elucidated. It was hypothesized that epistasis between genes in multiple atherothrombotic pathways may play a vital role in determining the susceptibility to IS. The aim of the present study was to investigate the contributions of the hypothesized genetic factors to IS and the interactions between these genetic factors in a Chinese population.

METHODS

In this study, 351 cases with IS and 417 control subjects from a Chinese population were genotyped for single-nucleotide polymorphisms (SNPs) in 12 genes hypothesized to be involved in atherosclerosis, coagulation, and related pathways. We examined SNP main effects and epistatic interactions between these polymorphic loci.

RESULTS

rs710446 of the KNG1 gene was associated with IS susceptibility based on an additive genetic model (rs710446: P = .012; odds ratio [OR], 1.247; 95% confidence interval [CI], 1.050-1.481) after adjusting for covariates. Furthermore, an epistatic interaction between the ALOX5AP, THBD, and KNG1 gene was also identified in association with stroke susceptibility (P < .001 after 1000 permutations). Based on the chi-squared test, the OR of the high-risk combination of the three-locus model increased the risk of IS by 2.53-fold (95% CI, 1.60-4.01; P < .0001).

CONCLUSIONS

Our findings support the association of the epistatic interactions of ALOX5AP, THBD, and KNG1 and present novel evidence for the main effect of KNG1 gene on IS susceptibility, suggesting a modulation of stroke risk by a genetic main effect and gene-gene interactions.

Relationship between CYP17A1 genetic polymorphism and coronary artery disease in a Chinese Han population

BACKGROUND

CYP17A1 gene encodes P450c17 proteins, which is a key enzyme that catalyzes the formation of sex hormones. Many clinical studies showed that sex hormones levels play an important role in the pathogenesis of coronary artery disease (CAD). However, the relationship between CYP17A1 genetic polymorphisms and CAD remains unclear. The aim of this study was to investigate the association of CYP17A1 genetic polymorphisms with CAD in a Han population of China.

METHODS

A total of 997 people include 490 patients and 507 controls were selected for the present study. Five single-nucleotide polymorphisms (SNPs) (rs4919686, rs1004467, rs4919687, rs10786712, and rs2486758) were genotyped by using the real-time PCR (TaqMan) method.

RESULTS

For men, the rs10786712 was found to be associated with CAD in a recessive model (P=0.016), after adjustment of the major confounding factors, the significant difference was retained (OR=1.644, 95% confidence interval [CI]: 1.087-2.488, P=0.019). For women, the rs1004467 was also found to be associated with CAD in a dominant model (P=0.038), the difference remained statistically significant after multivariate adjustment (OR=1.623, 95% CI: 1.023-2.576, P=0.040). The distribution of rs4919687 genotypes showed a significant difference between CAD and control participants in a recessive model (P=0.019), the significant difference was retained after adjustment for covariates (OR=0.417, 95% CI: 0.188-0.926, P=0.032).

CONCLUSION

Rs1004467, rs4919687, rs10786712 of CYP17A1 gene are associated with CAD in Han population of China. The TT genotype of rs10786712 could be a protective genetic marker of CAD in men. The CC genotype of rs1004467 and the AA genotype of rs4919687 could be risk genetic markers of CAD in women. However, large sample size study including other SNPs of CYP17A1 should be performed in future studies.

Haplotype analyses of CYP17A1 genetic polymorphisms and coronary artery disease in a Uygur population

BACKGROUND

The relationship between CYP17A1 genetic polymorphisms and coronary artery disease (CAD) remains unclear. The aim of the present study was to assess the association between CYP17A1 gene polymorphism and CAD in a Chinese Uygur population.

METHODS

A total of 493 people including 266 patients and 227 controls were selected for the present study. All CAD patients and controls were genotyped for the same five single nucleotide polymorphisms (SNPs) (rs4919686, rs1004467, rs4919687, rs10786712, and rs2486758) by a real-time PCR method.

RESULTS

The rs4919686, rs1004467, and rs4919687 polymorphisms were found to be associated with CAD in genotypes, dominant model, recessive model, and allele frequency (rs4919686: all p<0.05, rs1004467: all p ≤ 0.001, rs4919687: all p<0.001); the significant difference was retained (all p<0.05) after adjustment for the major confounding factors. The overall distribution of haplotypes established by SNP1-SNP4 (in total subjects and men) and SNP1-SNP4-SNP5 (in total subjects) were significantly different between the CAD patients and the control subjects (p=0.006, men: p=0.026, and p=0.030, respectively).

CONCLUSION

Polymorphisms rs4919686, rs4919687 and rs1004467 were found to be associated with CAD in this Uygur population.

Genetic polymorphisms of ALOX5AP and CYP3A5 increase susceptibility to ischemic stroke and are associated with atherothrombotic events in stroke patients

BACKGROUND

The contributions of gene-gene interactions to pathogenesis of stroke remain largely elusive. The present study was designed to investigate the associations between genetic variations and ischemic stroke risk, the roles of gene-gene interactions in ischemic stroke, and their associations with atherothrombotic events.

METHODS

Among 396 patients with ischemic stroke and 378 controls, we examined 8 variants from 5 genes, including ALOX5AP-SG13S32 (rs9551963), SG13S42 (rs4769060), SG13S89 (rs4769874), SG13S114 (rs10507391), EPHX2 G860A (rs751141), CYP2C9*2 C430T (rs1799853), CYP2C9*3 A1075C (rs1057910), and CYP3A5 A6986G (rs776746), using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Gene-gene interactions were determined by the generalized multifactor dimensionality reduction (GMDR) method. All ischemic stroke patients were followed up 12 months for atherothrombotic events, including recurrent ischemic stroke and other vascular events.

RESULTS

Single-gene variant analysis showed no significant differences in the genotype distributions of the 8 variants between the 2 groups. However, the GMDR analysis showed a significant interaction between rs10507391 and rs776746, in those cases carrying rs10507391 AA and rs776746 GG, the risk of ischemic stroke increased by 2.014 times (95% confidence interval [CI], 1.896-6.299; P = .006), and the atherothrombotic events occurred more frequently in those patients during follow-up period (P < .001). Multiple Cox regression analysis showed that the interaction between rs10507391 AA and rs776746 GG was an independent risk factor for atherothrombotic events (relative risk = 2.921; 95% CI, 1.118-7.012; P = .008).

CONCLUSIONS

The interaction between rs10507391 and rs776746 increases the susceptibility to ischemic stroke and is associated with atherothrombotic events in stroke patients.

Association of ALOX5AP rs10507391/SG13S114 A>T polymorphism with cerebral infarction in the Chinese population: a meta-analysis study

Various studies have investigated that the single nucleotide polymorphisms (SNPs) rs10507391/SG13S114 A>T polymorphism could increase the risk of cerebral infarction, however these results still remain controversial. Therefore we conducted a meta-analysis to estimate the association of the 5-lipoxygenase-activating protein gene (ALOX5AP) rs10507391/SG13S114 A > T polymorphism with the incidence of cerebral infarction in the Chinese population. Our researchers searched PubMed, Embase, Web of Science databases, China Biological Medicine Database (CBMD), Wanfang Chinese database, and the Chinese National Knowledge Infrastructure (CNKI) database. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were extracted and pooled to assess the strength of the association between the ALOX5AP rs10507391/SG13S114 A>T polymorphism and incidence of cerebral infarction. A total of 12 eligible studies including 6,844 cases and 7,850 controls based on the search criteria were involved in this meta-analysis. The distributions of genotypes in the cases and controls were all in agreement with Hardy-Weinberg equilibrium. We observed that the ALOX5AP rs10507391/SG13S114 A>T polymorphism carried with T allele contrast model, the homozygote codominant model, the heterozygote codominant model, the dominant model and the recessive model (all the models p > 0.05) had no risk of cerebral infarction when all studies were pooled into the meta-analysis. The results of the meta-analysis indicate that ALOX5AP rs10507391/SG13S114 A>T polymorphism is not associated with the risk of cerebral infarction in the Chinese population.

Association of ALOX5AP with ischemic stroke in eastern Chinese

BACKGROUND

5-lipoxygenase protein (ALOX5AP) has been recognized as a susceptibility gene for stroke and coronary artery diseases. The present study was to explore the role of this gene in the eastern Chinese patients with ischemic stroke.

METHODS

Using a case-control design, we studied 658 patients with ischemic stroke and 704 unrelated population-based controls who were age- and sex-matched. The 658 patients were classified by the Trial of Org 10172 in Acute Stroke Treatment (TOAST). Two single-nucleotide polymorphisms (SNPs) covering ALOX5AP were genotyped.

RESULTS

The genotype frequencies of TG of the SNPs rs17222919 located in the promoter of the ALOX5AP gene were significantly higher in patients with ischemic stroke than in controls (OR (*)=1.34, 95%CI(*)=1.02-1.75), especially in patients with ischemic stroke caused by small-artery occlusion (SAO) (OR (*)=1.40, 95%CI(*)=1.02-1.93). Meanwhile, the genotype frequencies of TG and TG/GG were higher in female patients than in the controls. After specification, the genotype frequencies of TG and TG/GG were higher in the patients than in controls with hypertension. The genotype frequencies of AG and AG/GG of the SNPs rs9579646 located in the intron of the ALOX5AP gene were higher in the controls than in the patients. After specification, the genotype frequencies of TG were higher in the controls than patients without hypertension.

CONCLUSION

The present study suggests that sequence variants in the ALOX5AP gene are significantly associated with ischemic stroke.

A novel polymorphism of the GP78 gene is associated with coronary artery disease in Han population in China

BACKGROUND

GP78 is a membrane-anchored ubiquitin ligase mediating the degradation of 3-hydroxy-3-methyl-glutaryl-CoA coenzyme A reductase (HMGCR) and Insig-1, which was very essential for the synthesis of cholesterol process. Cholesterol levels have a causal role in the development of cardiovascular disease. The aim of the present study was to assess the association between the human gp78 gene polymorphism and coronary artery disease (CAD) in a Han and Uygur population of China.

METHODS

We used two independent case-control studies: a Han population (602 CAD patients and 572 control subjects) and a Uygur population (374 CAD patients and 376 control subjects). All CAD patients and controls were genotyped for the same three single nucleotide polymorphisms (SNPs) (rs731119, rs2617849 and rs2440472) of gp78 gene by a Real-time PCR instrument.

RESULTS

In the Han population, for total and men, the distribution of SNP3 (rs2440472) alleles and the dominant model (AA vs AG + GG) and recessive model (GG vs AG + AA) showed a significant difference between CAD and control participants (for allele: P = 0.003 and P = 0.002, respectively; for dominant model: P = 0.041 and P = 0.026, respectively; for recessive model: p = 0.004 and p = 0.004, respectively).The significant difference in both the two models was retained after adjustment for covariates (for dominant model OR:0.760, 95% confidence interval [CI]:0.584-0.99, P = 0.042; OR:0.686, 95% CI: 0.498-0.946, P = 0.022, respectively; for recessive model OR: 1.451, 95% CI: 1.067-1.974, P = 0.018; OR: 1.789, 95% CI: 1.219-2.627, P = 0.000). Our data was also assessed via haplotype-based case-control studies. For the Han population, for total, The G-T-G haplotype in CAD was significantly higher than that in the control group (P = 0.02), and the G-C-A haplotype in CAD was significantly lower than that in the control group (P = 0.0443), And for man, the G-T-G haplotype in CAD was significantly higher than that in the control group (P = 0.0048).

CONCLUSIONS

The GG genotype and G allele of rs2440472 in gp78 gene could be a risk genetic marker of CAD in Han population in China.

-94 ATTG insertion/deletion polymorphism of the NFKB1 gene is associated with coronary artery disease in Han and Uygur women in China

OBJECTIVES

The nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) signaling pathway plays a key role in the regulatory network of inflammation. The deletion variant allele of the NFKB1-94 insertion/deletion (ins/del) ATTG promoter polymorphism results in lower transcription levels of the p50 subunit, and the variant allele has been associated with several inflammatory diseases as well as with coronary artery disease (CAD) with inflammation playing an important part in the pathogenesis. The aim of the present study was to assess the association between the human NFKB1 gene polymorphism and CAD in a Han and Uygur population of China.

METHODS

We used the following two independent case-control studies: a Han population (633 CAD patients and 616 control subjects) and a Uygur population (437 CAD patients and 356 control subjects). All participants were genotyped for the same one single nucleotide polymorphism (SNP) (rs28362491) of the NFKB1 gene, that is, DD, ATTG deleted homozygote; ID, ATTG inserted and deleted heterozygote and II, ATTG inserted homozygote by real-time polymerase chain reaction.

RESULTS

The distribution of the SNP (rs28362491) genotypes was significantly different between CAD and control participants in women of the Han (p=0.029) and the Uygur (p=0.032) populations, but not in men. Further, DD carriers of the SNP in the NFKB1 gene were more frequent in female CAD patients than in controls in both the Han (23.2% vs. 13.5%, p=0.009) and the Uygur (19.8% vs. 8.3%, p=0.012) population. The significant difference between DD and ID+II genotypes was retained after adjustment for covariates (for Han, odds ratio [OR]: 1.805, p=0.029 and for Uygur, OR: 3.192, p=0.011).

CONCLUSIONS

The DD genotype of the SNP (rs28362491) in the NFKB1 gene may be considered a genetic marker of CAD in Han and Uygur women in China.

Synergistic effect of ALOX5AP polymorphisms and cigarette smoking on the risk of atherosclerotic cerebral infarction in a Northern Han Chinese population

The effect of activating 5-lipoxygenase (ALOX5AP) gene polymorphisms on stroke risk may be influenced by the coexistence of modifiable predisposing conditions. We explored the interactions of ALOX5AP polymorphisms and cigarette smoking in a case-control study of patients with atherosclerotic cerebral infarction (ACI). Three polymorphisms of the ALOX5AP gene (rs10507391, rs4769874, and rs9551963) were analyzed in 420 ACI patients and 488 unrelated healthy controls matched for age and sex from a Northern Han Chinese population. Among the three single nucleotide polymorphisms, only rs10507391 genotype TT/TA was observed to be associated with an increased risk of ACI on multivariate analysis (odds ratio [OR]=1.82, 95% confidence interval [CI]=1.14-2.92, p=0.012) compared with the AA genotype. However, after stratifying by smoking status, multivariate logistic regression analysis revealed that rs10507391 genotype TT/TA and rs9551963 genotype CC/CA had a 5.63-fold (OR=5.63, 95%CI=2.00-15.84, p=0.001) and a 2.71-fold (OR=2.71, 95%CI=1.28-5.73, p=0.009) increased risk for ACI patients who smoked compared with the AA genotype, respectively. Additionally, according to the haplotype analysis, the risk of haplotype TGC (OR=3.12, 95%CI=2.00-4.88, p<0.001, corrected p [pc]<0.001) increased for ACI patients who smoked compared to the data (OR=1.60, 95%CI=1.28-1.98, p<0.001, pc<0.001) in total samples. These results suggest that ALOX5AP polymorphisms are associated with ACI, and cigarette smoking along with ALOX5AP could increase the risk of ACI.

A novel risk haplotype of ALOX5AP gene is associated with ischemic stroke in Chinese Han population

Previous studies have implicated that two at-risk haplotypes (HapA and HapB) of gene-encoding 5-lipoxygenase-activating protein (ALOX5AP) were significantly associated with stroke. The aim of this study was to explore the association between haplotypes of ALOX5AP gene and risk for ischemic stroke (IS) in Chinese Han population. A total of 492 patients with IS and 490 matched control subjects were recruited. Six ALOX5AP SNPs (SG13S377, SG13S114, SG13S41, SG13S89, SG13S32 and SG13S35) were genotyped by SNaPshot minisequence technique. A common genetic variant SG13S114/AA in the ALOX5AP gene was associated with IS in this Chinese cohort (OR = 2.514, 95 % CI = 1.667 ~ 3.790). HapA (TGA) and HapB (AAAG) had no significant difference in the patients (36.3 and 18.5 %, respectively) and controls (37.6 and 16.3 %, respectively) (P = 0.631 and P = 0.375, respectively). But, the frequency of Hap (GAAG) was significantly higher in the patients than that in the controls after Bonferroni's adjustment (P = 0.006). To conclude, SG13S114/AA of the ALOX5AP gene was associated with an increased risk for IS. A novel risk haplotype, Hap (GAAG) was a genetic risk factor for IS in this Chinese population.

The arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene SG13S114 polymorphism and ischemic stroke in Chinese population: a meta-analysis

Previous studies have indicated that the arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene SG13S114 polymorphism is associated with risk of ischemic stroke (IS), but the results remain inconclusive even in Chinese population. A meta-analysis of 10 case-control studies was conducted on the relationship between ALOX5AP SG13S114 polymorphism and susceptibility to IS in Chinese population published domestically and abroad from September 2007 to December 2012. Data were extracted by two authors and pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Meta-analysis results showed that the significant association between SG13S114 variant and IS was found under the allelic (OR=0.87, 95% CI: 0.80-0.96, P=0.004), dominant (OR=0.75, 95% CI: 0.62-0.92, P=0.005), and recessive (OR=0.89, 95% CI: 0.82-0.97, P=0.005) genetic models in Chinese population. In subgroup meta-analysis, SG13S114 variant and atherothrombotic stroke, rather than lacunar stroke, showed the significant association under the allelic (OR=0.86, 95% CI: 0.80-0.92, P<0.0001), dominant (OR=0.72, 95% CI: 0.57-0.91, P=0.006), and recessive (OR=0.86, 95% CI: 0.78-0.95, P=0.002) models. ALOX5AP SG13S114 polymorphism is associated with susceptibility to IS in Chinese population.

A novel polymorphism (901G > a) of C5L2 gene is associated with coronary artery disease in Chinese Han and Uyghur population

BACKGROUND

C5L2, a G protein-coupled receptor (GPCR), has been demonstrated to be a ligand for acylation-stimulating protein (ASP). The aim of the present study is to evaluate the association of a novel variation (901A > G) of C5L2 gene with coronary artery disease (CAD).

METHODS

We identified a novel single nucleotide polymorphism (SNP), (901G > A), in exon 2 using a polymerase chain reaction direct-sequencing method. This nucleotide change causes the amino-acid order from Arginine to glutaminate at codon 300. We analyzed the relationship between this SNP and CAD in two independent case-control studies: one was in a Han population (492 CAD patients and 577 control subjects) and the other was in a Uygur population (319 CAD patients and 554 control subjects).

RESULTS

The frequency of AG genotype in CAD subjects was less than that in the control subjects not only in Han (1.8% vs 8.6%, P < 0.001, OR = 0.143, 95% CI: 0.068 ~ 0.302) but also in Uygur population (0.9% vs 5.2%, P = 0.001, OR = 0.246, 95% CI: 0.072 ~ 0.837). After adjustment for known CAD risk factors such as hypertension, diabetes, smoking, age and gender, the difference remained significant.

CONCLUSION

The 901G > A polymorphism of C5L2 may be a genetic maker of CAD in the Han and Uygur population in western China.

Association of ALOX5AP1 SG13S114T/A variant with ischemic stroke, stroke subtypes and aspirin resistance

The important role of genetic variants in the etiology and pathophysiology of stroke is being increasingly recognized. Simultaneously, the influence of genetic factors in the clinical outcome of drug therapy cannot be ignored. 5-lipoxygenase activating (ALOX5AP) gene involved in the synthesis of leukotrienes, has been recognized as an important gene contributing towards susceptibility of stroke risk. Leukotrienes are involved in the physiological mechanism of atherosclerotic events and inflammation. The present study was designed to identify the association of SG13S114T/A polymorphism in ALOX5AP1 gene with risk of stroke, its subtypes and aspirin resistance. We studied six hundred and ten patients with ischemic stroke and six hundred and ten age and sex matched healthy controls. The ischemic stroke was classified according to Trial of Org 10172 in Acute stroke Treatment. ALOX5AP1 SG13S114T/A polymorphism was determined using PCR RFLP methods. Follow-up was done for all the patients for a period of 3 months, 6 months and 12 months. The patients were classified into two groups responders and non-responders. The non-responders were identified to have a poor clinical outcome defined as a score of more than 2 on modified Rankin Scale Score and less than 5 on extended Glassgow Outcome Scale from stroke onset. We found statistically significant difference in the genotypic distribution between patients and controls (for AA vs TT, χ2=9.894; p=0.001, odds ratio=1.68 (95% confidence interval (CI); 1.215, 2.326). Significant difference was observed in the frequency of A and T alleles in patients and controls (A vs T χ(2)=10.23; p=0.001, odds ratio=1.301 (95% CI; 1.107, 1.528). Multiple logistic regression analysis revealed, the most predictive risk factor for stroke was AA genotype [adjusted odds ratio=1.660 (95% CI; 1.167-2.361) and p=0.005], hypertension, smoking and diabetes (p<0.001 in each case). We also found a significant association of AA genotype with intracranial large artery atherosclerosis (p=0.002, odds ratio=2.04, (95%CI; 1.279-3.275) and cardioembolism (p<0.001, odds ratio=4.73 (95% CI; 2.661-8.439). The risk of aspirin resistance was significantly higher among patients with AA genotype in comparison to carriers of homozygous TT genotype (AA vs TT, χ2=22.25, odds ratio=2.983, 95% CI; 1.884- 4.723, p<0.001). The frequency of recurrence and death events was more in non-responders. We didn't find a significant association of the aspirin dose with outcome. Our results indicate that the individuals bearing AA genotype of ALOX5AP1 SG13S114T/A polymorphism are more prone to stroke and bad outcome as well as with aspirin resistance than TA and TT genotypes.

Association of Leukotriene Gene Variants and Plasma LTB4 Levels with Coronary Artery Disease in Asian Indians

Leukotrienes are potent inflammatory and lipid mediators that participate in atherosclerosis. We analyzed the association of Leukotriene gene (ALOX5, ALOX5AP, LTA4H, and LTC4S) polymorphisms and plasma Leukotriene B4 (LTB4) levels with coronary artery disease (CAD) in a representative cohort of Asian Indians. In all, 136 functional single nucleotide polymorphisms (SNPs) were selected using in silico tools. Forty-five polymorphic SNPs were ranked for predicted functional effect using FastSNP. Finally, 14 functional SNPs along with 10 SNPs identified from the literature were genotyped in 340 CAD patients and 340 controls. Plasma LTB4 levels were measured in 150 cases and 150 controls. None of the 24 SNPs showed significant association with CAD. Plasma LTB4 levels were higher in cases than in controls (76.42 ± 4.46 pg/mL versus 60.89 ± 2.61 pg/mL) (P=0.003), with greater risk being associated with the top quartile as compared to the bottom quartile after adjusting for potential confounders (OR 8.94, 95% CI 2.56–31.95; P=0.001). Four SNPs in the LTA4H gene showed significant association with LTB4 levels (P<0.05) of which rs1978331 (P=0.035) remained significant after correction for multiple testing. LTB4 showed strong correlation with lipids (r=0.24–34) only in cases. Our pilot study suggests that the association between Leukotrienes gene polymorphisms and CAD risk may be modulated through plasma LTB4 levels.

Variants of the arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene and risk of ischemic stroke in Han Chinese of eastern China

Variants of the arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene have been suggested to play an important role in the pathogenesis of atherosclerosis and ischemic stroke. This study was aimed to explore the association of ALOX5AP variants with ischemic stroke risk in Han Chinese of eastern China. A total of 690 ischemic stroke cases and 767 controls were recruited. The subjects were further subtyped according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. On the basis of that, two polymorphisms of the ALOX5AP gene (rs10507391 and rs12429692) were determined by TaqMan genotyping assay. In addition, plasma leukotriene B4 (LTB4) levels were analyzed in these subjects. There was no evidence of association between the two variants of ALOX5AP and the risk of ischemic stroke or its TOAST-subtypes. Haplotype analysis and stratification analysis according to sex, age, body mass index, hypertension, and diabetes also showed negative association. Analysis of LTB4 levels in a subset of cases and controls revealed that LTB4 levels were significantly higher in ischemic stroke cases than in the controls (70.06±14.75 ng/L vs 57.34±10.93 ng/L; P = 0.000) and carriers of the T allele of the rs10507391 variant were associated with higher plasma LTB4 levels (P = 0.000). The present study suggests there is no association of the two polymorphisms in the ALOX5AP gene with ischemic stroke risk in Han Chinese of eastern China.

Correlation between cerebral infarction and ALOX5AP gene expression

Linkage/linkage-disequilibrium analysis studies, based on positional information and gene function, indicated that ALOX5AP gene was an independent risk factor of cerebral infarction in humans; however, this needs to be verified among different populations. Herein, we verified whether ALOX5AP was a risk factor of cerebral infarction in the Chinese Han population. For this purpose, 547 cerebral infarction patients were enrolled as the case group; the control group comprised 794 healthy, age-matched individuals unrelated to case group and had no history of cerebral infarction/transient ischemic attack. Regarding single-nucleotide polymorphism (SNP) selection and ALOX5AP genotyping, we selected four SNP loci (SG13S25, SG13S114, SG13S89, and SG13S32) and determined allelic frequencies. Genotyping of SG13S114 and SG13S32 adopted a method of combining real-time quantitative PCR and allele-specific PCR. A linkage-disequilibrium analysis of ALOX5AP was also performed. We found that the allelic frequencies of SG13S25 and SG13S89 were below 5% and those of SG13S114 and SG13S32 were above 5%. We did not find any differences between the case and control groups regarding allele, allele types, and haplotype gene frequencies of two SNP loci. The results indicate that the two genetic polymorphisms of ALOX5AP, SG13S114 and SG13S32, are not associated with cerebral infarction in Chinese Han population.

Leukotriene A4 hydrolase haplotype, diet and atherosclerosis: a twin study

OBJECTIVE

Atherosclerosis is an inflammatory process resulting from the interaction between genetic and environmental factors. Leukotrienes are inflammatory mediators generated from arachidonic acid, and genetic polymorphisms involved in leukotriene metabolism are implicated in atherosclerosis. The objectives of this study are to examine whether genetic variants in key leukotriene enzymes are associated with atherosclerosis, and whether dietary intake of competing leukotriene substrates modifies the effect of leukotriene variants on atherosclerosis.

METHODS

Atherosclerosis was assessed by common carotid intima-media thickness (IMT) using ultrasound. Sequence variants within arachidonate 5-lipoxygenase activating protein (ALOX5AP) and leukotriene A4 hydrolase (LTA4H) genes were analyzed with 32 single nucleotide polymorphisms (SNPs) in 169 Caucasian twin pairs from the Vietnam Era Twin Registry. The associations between genetic polymorphisms and carotid atherosclerosis, and gene × diet interactions were examined by generalized estimating equation controlling for potential confounders.

RESULTS

A six-SNP haplotype in LTA4H, designated HapE, was significantly associated with carotid IMT after adjusting for known coronary risk factors. Twins carrying HapE had a much lower IMT compared to twins not carrying (695 μm vs. 750 μm, p = 0.0007). Moreover, dietary intake of polyunsaturated fatty acids strongly augmented the cardioprotective effect of HapE among those with this haplotype but not those without, suggesting a haplotype × diet interaction (interaction P(HapE×n-3) = 0.03, P(HapE×n-6) = 0.015).

CONCLUSION

We identified a novel leukotriene haplotype that appears to be protective toward subclinical atherosclerosis. This association is modified by dietary intake of polyunsaturated fatty acids.

Genetic variation in members of the leukotrienes biosynthesis pathway confers risk of ischemic stroke in Eastern Han Chinese

This study was aimed to explore the association of genetic variation in members of the leukotrienes biosynthesis pathway as potential mediators with ischemic stroke (IS) risk in Eastern Han Chinese. A case-control study of was conducted with five selected single nucleotide polymorphisms (SNPs). In the single-locus analysis, carriers of C allele of rs730012 in LTC4S were more susceptible to IS (OR, 1.28; 95% CI, 1.02-1.60; P=0.033). Under the recessive genetic model, ALOX5 rs2029253 variant reduced IS risk (adjusted OR, 0.78; 95% CI, 0.60-1.00; P=0.048) while LTA4H rs6538697 and LTC4S rs730012 variants increased (adjusted OR, 1.66; 95% CI, 1.04-2.64; P=0.032 and adjusted OR, 3.63; 95% CI, 1.01-13.05; P=0.048, respectively). However, there was no evidence of association between all five SNPs and IS risk after correction for multiple testing. In combined analysis of multiple genes and loci, individuals with ALOX5AP rs12429692 T allele, ALOX5 rs2029253 A allele, and LTA4H rs6538697 C allele suggested a significantly increased susceptibility to IS (adjusted OR, 1.70; 95% CI, 1.07-2.69; P=0.024). The present study suggested gene-gene interactions in leukotrienes pathway could exert influences on the risk of IS.

Association of inflammatory response gene polymorphism with atherothrombotic stroke in Northern Han Chinese

Atherosclerosis is an important pathophysiological basis of atherothrombotic stroke (ATS), and inflammation plays a significant role in atherosclerosis formation. In this study, single-nucleotide polymorphisms (SNPs) in three key inflammation-related genes, 5-lipoxygenase activating protein (ALOX5AP), phosphodiesterase 4D (PDE4D), and interleukin-1α (IL-1α), were investigated to determine their association with ATS in Northern Han Chinese. Six-hundred and eighty-two ATS patients and 598 unrelated controls were recruited. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism and matrix-assisted laser desorption ionization time-of-flight mass spectrometry primer extension. The genotype and allele frequencies of each SNP were statistically analyzed. Risk of ATS was found for the ALOX5AP SG13S114A/T AA genotype (P = 0.040) and A allele (P = 0.033), PDE4D SNP83C/T TT genotype (P = 0.010) and T allele (P = 0.008) and SNP219A/G GG genotype (P = 0.025) and G allele (P = 0.022), and the IL-1α-889C/T T allele (P = 0.035). The differences still remained significant after adjustment. The ALOX5AP HapA haplotype was not correlated with ATS (P = 0.834), but GCGA represented an at-risk haplotype (P = 0.008). Furthermore, the PDE4D AA haplotype at SNP219-220 might be an at-risk haplotype (P = 0.013), while GA might be a protective haplotype (P = 0.005). The ALOX5AP (SG13S114A/T), PDE4D (SNP83C/T, 219A/G), and IL-1α (-889C/T) SNPs were associated with an increased risk of ATS in Northern Han Chinese.

Association of ALOX5AP gene single nucleotide polymorphisms and cerebral infarction in the Han population of northern China

BACKGROUND

To explore the association of ALOX5AP single nucleotide polymorphisms (SNPs) and haplotype with the occurrence of cerebral infarction in the Han population of northern China.

METHODS

Blood samples were collected from 236 patients of Han ancestry with a history of cerebral infarction and 219 healthy subjects of Han ancestry with no history of cerebral infarction or cardiovascular disease. Applied Biosystems(®) TaqMan(®) SNP Genotyping Assays for SNP genotyping were used to determine the genotypes of 7 ALOX5AP SNP alleles (rs4073259, rs4769874, rs9315050, rs9551963, rs10507391, rs9579646, and rs4147064).

RESULTS

One SNP allele (A) of rs4073259 was significantly associated with development of cerebral infarction (P = 0.049). In comparison to control groups, haplotype rs9315050&rs9551963 AAAC [OR (95% CI) = 1.53 (1.02-2.29)], and genotypes rs4147064 CT [OR (95% CI) = 1.872 (1.082-3.241)], and rs9551963 AC [OR (95% CI) = 2.015 (1.165-3.484)] increased the risk of cerebral infarction in patients with hypertension. Genotype rs9579646 GG [OR (95% CI) = 2.926 (1.18-7.251)] increased the risk of, while rs4073259 GG [OR (95% CI) = 0.381 (0.157-0.922)] decreased the risk of cerebral infarction in patients with diabetes.

CONCLUSION

These results suggest the ALOX5AP SNP A allele in rs4073259 and genotype rs9579646 GG, rs9551963 AC, and haplotype rs9315050 & rs9551963 AAAC were associated with an increased risk of ischemic stroke in the Han population, while rs4073259 GG was associated with a decreased risk.

Association of ALOX5AP haplotypes with susceptibility to coronary artery disease in a Chinese Han population

BACKGROUND

The 5-lipoxygenase activating protein (FLAP), encoded by the activating 5-lipoxygenase (ALOX5AP) gene, is a crucial mediator of the biosynthesis of leukotrienes, which have been implicated in atherosclerosis. This study investigates whether ALOX5AP polymorphisms are associated with coronary artery disease (CAD) in a Chinese Han population.

METHODS

The promoter, exons, splice site region and 3'-untranslated region of the ALOX5AP gene were sequenced in 48 subjects. Three polymorphic sites (-1340T/G, +8733T/C, +20616G/C) found through sequencing were evaluated in 656 patients with angiographically proven CAD and 678 controls with normal coronary angiograms using a polymerase chain reaction and restriction fragment length polymorphism assay. Allelic, genotypic linkage disequilibrium and haplotypic association testing were performed using SHEsis and LDA software. Binary logistic regression was used to control for the presence of vascular risk factors.

RESULTS

Seven single nucleotide polymorphisms (SNPs) were found through screening. No significant differences in allele carriers and genotype frequencies of the ALOX5AP polymorphisms were observed between the two groups. However, when the results of the three SNPs were combined, there was a significant association between two of the haplotypes and the risk of CAD. The haplotype GCG had a significantly greater frequency in patients than in controls (P<0.001, OR=1.728, 95%CI=1.375-2.171), and the frequency of haplotype TCG was higher in controls (P<0.001, OR=0.623, 95%CI=0.519-0.748).

CONCLUSION

The data indicate that ALOX5AP gene variation is a genetic factor associated with interindividual differences in CAD risk.

No association of ALOX5AP polymorphisms with risk of MRI-defined brain infarcts

The arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene has been associated with stroke. The majority of the reported ALOX5AP associations have considered non-radiologically confirmed infarcts as the stroke phenotype. We assessed the association of genetic variants in ALOX5AP with stroke defined by the presence of infarcts on brain magnetic resonance imaging (MRI). We studied 202 persons with MRI-defined brain infarcts and 487 healthy individuals of Caribbean Hispanic ancestry. Another sample of European ancestry comprised 1823 persons with MRI-defined brain infarct and 7578 control subjects. Subjects were genotyped for the 4 single nucleotide polymorphisms (SNPs) that define ALOX5AP HapA haplotype. No association was found between SNPs and MRI-defined brain infarcts. Our data do not support the hypothesis that variants in ALOX5AP are associated with risk of MRI-defined brain infarcts.

A Promoter polymorphism (rs17222919, -1316T/G) of ALOX5AP is associated with intracerebral hemorrhage in Korean population

To investigate whether single nucleotide polymorphisms (SNPs) of eicosanoid biosynthesis genes are associated with intracerebral hemorrhage (ICH) and ischemic stroke (IS), seven SNPs in the coding or promoter regions were selected: ALOX12 (rs434473, Asn322Ser), ALOX5 (rs2228064, Thr90Thr), ALOX5AP (rs17222919, -1316T/G), PTGES (rs7872802, -404A/G), PTGIS (rs5628, Leu256Leu), PTGS1 (rs3842788, Gln41Gln) and PTGS2 (rs5275, 3'UTR). A total of 398 control subjects and 196 stroke patients (79 ICH and 117 IS) were genotyped by direct sequencing. The rs17222919 SNP was associated with ICH in codominant 1 (P=0.008), dominant (P=0.003) and log-additive (P=0.004) models. Allele frequencies of rs17222919 were different between ICH and controls (P=0.007). However, the seven tested SNPs were not associated with clinical phenotypes (NIHSS, MBI and CRPS) in ICH and IS. These results suggest that the promoter SNP rs17222919 of ALOX5AP may be associated with the development of ICH in Korean population.

Relationship between a novel polymorphism of the C5L2 gene and coronary artery disease

Background

C5L2 has been demonstrated to be a functional receptor of acylation-stimulating protein (ASP), which is a stimulator of triglyceride synthesis or glucose transport. However, little is known about the variations in the coding region of the C5L2 gene and their association with coronary artery disease (CAD).

Methodology/Principal Findings

We identified a novel single nucleotide polymorphism (SNP), 698C>T (P233L), in exon 2 using a polymerase chain reaction direct-sequencing method. This nucleotide change causes the amino-acid order from proline to leucine at codon 233. We examined the role of this SNP for CAD using two independent case–control studies: one was in the Han population (492 CAD patients and 577 control subjects) and the other was in the Uygur population (319 CAD patients and 554 control subjects). Heterozygote carriers of the 698CT genotype were more frequent among CAD patients than among controls not only in the Han population (7.3% versus 1.7%) but also in the Uygur population (4.7% versus 1.6%). The odds ratio (OR) for carriers of the 698CT genotype for CAD was 4.484 (95% confidence interval (CI): 2.197–9.174) in the Han group and 2.989 (95% CI: 1.292–6.909) in the Uygur population. After adjustment of confounding factors such as sex, age, smoking, alcohol consumption, hypertension, diabetes, as well as serum levels of triglyceride, total cholesterol, high-density lipoprotein, the difference remained significant in the Han group (P<0.001, OR = 6.604, 95% CI: 2.776–15.711) and in the Uygur group (P = 0.047, OR = 2.602, 95% CI: 1.015–6.671).

Conclusion/Significance

The 698CT genotype of C5L2 may be a genetic maker of CAD in the Han and Uygur population in western China.

Genetic contribution of the leukotriene pathway to coronary artery disease

We evaluated the genetic contribution of the leukotriene (LT) pathway to risk of coronary artery disease (CAD) in 4,512 Caucasian and African American subjects ascertained through elective cardiac evaluation. Of the three previously associated variants, the shorter "3" and "4" alleles of a promoter repeat polymorphism in ALOX5 increased risk of CAD in African Americans (OR = 1.4, 95% CI 1.0-1.9; p = 0.04), whereas a haplotype of LTA4H (HapK) was associated with CAD in Caucasians (OR = 1.2, 95% CI 1.01-1.4; p = 0.03). In Caucasians, first-stage analysis of 254 haplotype-tagging SNPs in 15 LT pathway genes with follow-up of 19 variants in stage 2 revealed an LTA4H SNP (rs2540477) that increased risk of CAD (OR = 1.2, 95% CI 1.1-1.5; p = 0.003) and a PLA2G4A SNP (rs12746200) that decreased risk of CAD (OR = 0.7, 95% CI 0.6-0.9; p = 0.0007). The PLA2G4A rs12746200 variant also decreased risk of experiencing a major adverse cardiac event (MACE = myocardial infarction, stroke, or death) over 3 years of follow-up (HR = 0.7, 95% CI 0.5-0.9; p = 0.01), consistent with its cardioprotective effect. Functional experiments demonstrated that stimulated monocytes from carriers of LTA4H variants HapK or rs2540477 had 50% (p = 0.002) and 33% (p = 0.03) higher LTB(4) production, respectively, compared to non-carriers. These ex vivo results are consistent with LTB(4) being the direct product of the reaction catalyzed by LTA4H and its role in promoting monocyte chemotaxis to sites of inflammation, including the artery wall of atherosclerotic lesions. Taken together, this study provides additional evidence that functional genetic variation of the LT pathway can mediate atherogenic processes and the risk of CAD in humans.

Variants of arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene and risk of coronary heart disease: A meta-analysis

BACKGROUND AND AIMS

Previous studies indicated that the arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene polymorphisms are associated with risk of coronary heart disease (CHD). However, other studies have yielded contradictory results. This meta-analysis investigated the relationship between variants of arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene and CHD.

METHODS

We identified all studies published before January 2010 through computer-based searches of PubMed, EMBASE, Google Scholar databases, and CNKI (Chinese National Knowledge Infrastructure). Data were extracted by two authors and pooled odds ratio (OR) and 95% confidence interval (CI) were calculated.

RESULTS

In this meta-analysis, HapA haplotype (rs17222814G-rs10507391T-rs4769874G-rs9551963A) was associated with myocardial infarction (MI) (OR = 1.37, 95% CI: 1.02-1.82). Regarding the HapB haplotype (rs17216473A-rs10507391A- rs9315050A- rs17222842G), there was a significant association with CHD (OR = 1.33, 95% CI: 1.10-1.62). For the rs17222814, rs10507391, rs4769874, rs9551963, rs17216473, rs9315050 and rs9579646 polymorphisms, there were no associations with CHD. For the rs17222842 polymorphism, there was a marginal association with the risk of CHD (OR = 1.17, 95% CI: 1.00-1.36).

CONCLUSIONS

In this meta-analysis, the HapB haplotype and rs1722842 polymorphism in ALOX5AP gene were associated with CHD, and the HapA haplotype was associated with risk of MI. The HapB haplotype may be a predictor to the risk of CHD.

ALOX5 gene variants affect eicosanoid production and response to fish oil supplementation

The objective of this study was to determine whether 5-lipoxygenase (ALOX5) gene variants associated with cardiovascular disease affect eicosanoid production by monocytes. The study was a randomized, double-masked, parallel intervention trial with fish oil (5.0 g of fish oil daily, containing 2.0 g of eicosapentaenoic acid [EPA] and 1.0 g of docosahexaenoic acid [DHA]) or placebo oil (5.0 g of corn/soy mixture). A total of 116 subjects (68% female, 20-59 years old) of African American ancestry enrolled, and 98 subjects completed the study. Neither ALOX5 protein nor arachidonic acid-derived LTB4, LTD4, and LTE4 varied by genotype, but 5-hydroxyeicosatetraenoate (5-HETE), 6-trans-LTB4, 5-oxo-ETE, 15-HETE, and 5,15-diHETE levels were higher in subjects homozygous for the ALOX5 promoter allele containing five Sp1 element tandem repeats ("55" genotype) than in subjects with one deletion (d) (three or four repeats) and one common ("d5" genotype) allele or with two deletion ("dd") alleles. The EPA-derived metabolites 5-HEPE and 15-HEPE and the DHA-derived metabolite 17-HDoHE had similar associations with genotype and increased with supplementation; 5-HEPE and 15-HEPE increased, and 5-oxo-ETE decreased to a greater degree in the 55 than in the other genotypes. This differential eicosanoid response is consistent with the previously observed interaction of these variants with dietary intake of omega-3 fatty acids in predicting cardiovascular disease risk.

A tagging SNP in ALOX5AP and risk of stroke: a haplotype-based analysis among eastern Chinese Han population

A genome-wide approach found significant association of two at-risk haplotypes (HapA, HapB) in the ALOX5AP gene with myocardial infarction and stroke. To date, it is still controversial whether ALOX5AP gene polymorphisms are risk factors for stroke. The aim of the present study is to investigate the association between the ALOX5AP gene polymorphism and the risk for stroke in Eastern Chinese Han population with a haplotype-based analysis. We conducted a comprehensive association study of 507 stroke patients and 510 healthy controls to assess the association between the ALOX5AP tagging single-nucleotide polymorphisms (tSNPs) and stroke risk. Genotyping was performed using the PCR-RFLP assay. In the single-locus analysis, we found that the rs9579646 AG genotype was associated with a marginally decreased risk for stroke (adjusted odds ratio, 0.65; 95% confidence interval, 0.45-0.96), compared with the AA genotype. Haplotype-based association analysis of block 2 involving rs10507391 and rs12429692 revealed that the decreased risk of stroke was significantly associated with haplotype AA (OR, 0.66; 95% CI, 0.46-0.95). These results suggested that the genetic variants in ALOX5AP might modulate the risk of stroke in Eastern Chinese Han population. The frequencies of single-marker alleles and haplotypes showed remarkable differences from those in other populations.

Interaction between COX-2 G-765C and smoking in relation to coronary artery disease in a Chinese Uighur population

BACKGROUND

Coronary artery disease (CAD) is a complex multifactorial and polygenic disorder where multiple environmental and genetic factors are involved simultaneously. The purpose of this study was to explore the relationship between the interaction of cyclooxygenase-2 (COX-2) gene polymorphism and smoking and CAD in a Uighur population.

METHODS

Using a case-control study of Chinese Uighur CAD patients (n=430) and healthy controls (n=470), we investigated the roles of G-765C polymorphism in the COX-2 gene (PTGS2) by the use of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

RESULTS

The PTGS2 GG genotype was significantly more prevalent in CAD patients (84.6% vs. 78.3%; p=0.014). Multiple logistic regression analysis showed two independent risk factors: smoking (OR 1.89, 95% CI 1.01-5.24; p=0.008) and hypertension (OR 2.73, 95% CI 1.59-7.21; p=0.001). Moreover, there was a synergistic effect between smoking and the PTGS2 polymorphism and the occurrence of CAD (interaction p=0.009). The odds ratio (OR) estimated by the combined analysis of the PTGS2 GG genotype and smoking history (OR 4.09, 95% CI 2.7-9.3) was markedly higher than that estimated separately from the PTGS2 GG genotype (OR 1.28, 95% CI 0.8-1.9) or smoking (OR 2.51, 95% CI 1.5-5.7) alone. Plasma 6-keto-PGF1α, a stable metabolite of PGI(2), was lower in individuals with the PTGS2 GG genotype (p<0.05). Smoking could further lower plasma 6-keto-PGF1α concentrations in GG genotype carriers than non-smokers, especially in patients with CAD.

CONCLUSIONS

The PTGS2 polymorphism and smoking were synergistically and significantly associated in Chinese Uighur patients with CAD.

Three periods of one and a half decade of ischemic stroke susceptibility gene research: lessons we have learned

Candidate gene association studies, linkage studies and genome-wide association studies have highlighted the role of genetic factors in the development of ischemic stroke. This research started over a decade ago, and can be separated into three major periods of research. In the first wave classic susceptibility markers associated with other diseases (such as the Leiden mutation in Factor V and mutations in the prothrombin and 5,10-methylenetetrahydrofolate reductase (MTHFR) genes) were tested for their role in stroke. These first studies used just a couple of hundred samples or even less. The second and still ongoing period bridges the two other periods of research and has led to a rapid increase in the spectrum of functional variants of genes or genomic regions, discovered primarily in relation to other diseases, tested on larger stroke samples of clinically better stratified patients. Large numbers of these alleles were originally discovered by array-based genome-wide association studies. The third period of research involves the direct array screening of large samples; this approach represents significant progress for research in the field. Research into susceptibility genes for stroke has taught us that careful stratification of patients is critical, that susceptibility alleles are often shared between diseases, and that not all susceptibility factors that associate with clinical traits that are themselves risk factors for stroke (such as increase of triglycerides) necessarily represent susceptibility for stroke. Research so far has been mainly focused on large- and small-vessel associated stroke, and knowledge on other types of stroke, which represent much smaller population samples, is still very scarce. Although some susceptibility allele tests are on the palette of some direct-to-consumer companies, the clinical utility and clinical validity of these test results still do not support their use in clinical practice.

ALOX5AP gene variants show differential association with coronary artery disease in different populations

Coronary artery disease (CAD) is a complex disease with various components, genetic as well as environmental. Previous reports correlating ALOX5AP gene variants and CAD showed conflicting results depending on the population studied. In this study, we examined the contribution of ALOX5AP genetic predisposition to CAD in a group of CAD patients and controls carefully selected from the Lebanese population. We genotyped SNPs for ALOX5AP variants in 289 catheterized patients aged ≤52 years with >50% stenosis in at least one main coronary artery and 227 catheterized control subjects aged 60 years and above with 0% stenosis. Chi-square (χ (2)) tests and logistic regression showed no significant difference in the allele and genotype frequencies between the CAD or myocardial infarction (MI) cases and the healthy controls. Haplotype analysis using PHASE showed that the distribution of the risk haplotypes among cases and controls were not significantly different and had no attributable risk to CAD (P = 1.00 and P = 0.5, respectively) or MI (P = 0.2 and P = 0.5, respectively). Our data revealed that ALOX5AP gene variants are not predictors of CAD risk or MI risk among Lebanese patients.

Genetics studies in ischaemic stroke

Conventional risk factors such as high blood pressure account for a significant proportion of stroke risk, but much stroke risk remains unexplained. Epidemiological evidence suggests genetic predisposition accounts for some of this unexplained risk. Many candidate genes association studies have been performed but have lead to largely disappointing results. The genome-wide association study (GWAS) approach allows novel associations to be identified with as many as one million polymorphisms (genetic variants) across the genome. It has been successfully applied to other complex diseases, including other cardiovascular diseases, but stroke has lagged behind. A number of GWAS projects in stroke are now underway. Genetic variants originally identified using the GWAS approach in atrial fibrillation and coronary artery disease have been shown to also confer an increased risk of stroke. These associations have been with specific subtypes of stroke, emphasising the importance of accurate stroke subtyping. The use of intermediate phenotypes for stroke, such as white matter hyperintensities on MRI and carotid intima-media thickness, is also discussed.

Genomics of heart failure

Cardiovascular disease is the leading cause of death in men and women, and heart failure (HF) is associated with high rates of morbidity and mortality. Most common forms of HF are non-mendelian and the evidence for heritability is modest. Study of the genetic susceptibility to HF has been limited to patients with rare familial forms of HF and candidate gene association studies in patients with distinct subtypes of HF. However, with the completion of the human genome project and the development of the HapMap template, new large-scale genome-wide association studies are possible. This article reviews the status of these and other important developments in genomics, in particular genome-wide sequencing, and other "omics".