The COX-2 G/C −765 polymorphism may modulate the occurrence of cerebrovascular ischemia

The Link between Prostanoids and Cardiovascular Diseases

Cardiovascular diseases are the leading cause of global deaths, and many risk factors contribute to their pathogenesis. In this context, prostanoids, which derive from arachidonic acid, have attracted attention for their involvement in cardiovascular homeostasis and inflammatory processes. Prostanoids are the target of several drugs, but it has been shown that some of them increase the risk of thrombosis. Overall, many studies have shown that prostanoids are tightly associated with cardiovascular diseases and that several polymorphisms in genes involved in their synthesis and function increase the risk of developing these pathologies. In this review, we focus on molecular mechanisms linking prostanoids to cardiovascular diseases and we provide an overview of genetic polymorphisms that increase the risk for cardiovascular disease.

Pharmacogenomics in Stroke and Cardiovascular Disease: State of the Art

There is considerable interindividual variability in the response to antiplatelet and anticoagulant therapies, and this variation may be attributable to genetic variants. There has been an increased understanding of the genetic architecture of stroke and cardiovascular disease, which has been driven by advancements in genomic technologies and this has raised the possibility of more targeted pharmaceutical treatments. Pharmacogenetics promises to use a patient's genetic profile to treat those who are more likely to benefit from a particular intervention by selecting the best possible therapy. Although there are numerous studies indicating strong evidence for the effect of specific genotypes on the outcomes of vascular drugs, the adoption of pharmacogenetic testing in clinical practice has been slow. This resistance may stem from sometimes conflicting findings among pharmacogenetic studies, a lack of stroke-specific randomized controlled trials to test the effectiveness of genetically-guided therapies, and the practical and cost-effective implementation of genetic testing within the clinic. Thus, this review provides an overview of the genetic variants that influence the individual responses to aspirin, clopidogrel, warfarin and statins and the different methods for pharmacogenetic testing and guidelines for clinical implementation for stroke patients.

Identification of hub Genes in the Pathogenesis of Ischemic Stroke Based on Bioinformatics Analysis

Objective

The present study aimed to identify the function of ischemic stroke (IS) patients’ peripheral blood and its role in IS, explore the pathogenesis, and provide direction for clinical research progress by comprehensive bioinformatics analysis.

Methods

Two datasets, including GSE58294 and GSE22255, were downloaded from Gene Expression Omnibus database. GEO2R was utilized to obtain differentially expressed genes (DEGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs were performed using the database annotation, visualization and integrated discovery database. The protein-protein interaction (PPI) network of DEGs was constructed by search tool of searching interactive gene and visualized by Cytoscape software, and then the Hub gene was identified by degree analysis. The microRNA (miRNA) and miRNA target genes closely related to the onset of stroke were obtained through the miRNA gene regulatory network.

Results

In total, 36 DEGs, containing 27 up-regulated and nine down-regulated DEGs, were identified. GO functional analysis showed that these DEGs were involved in regulation of apoptotic process, cytoplasm, protein binding and other biological processes. KEGG enrichment analysis showed that these DEGs mediated signaling pathways, including HTLV-I infection and microRNAs in cancer. The results of PPI network and cytohubba showed that there was a relationship between DEGs, and five hub genes related to stroke were obtained : SOCS3, KRAS, PTGS2, EGR1, and DUSP1. Combined with the visualization of DEG-miRNAs, hsa-mir-16-5p, hsa-mir-181a-5p and hsa-mir-124-3p were predicted to be the key miRNAs in stroke, and three miRNAs were related to hub gene.

Conclusion

Thirty-six DEGs, five Hub genes, and three miRNA were obtained from bioinformatics analysis of IS microarray data, which might provide potential targets for diagnosis and treatment of IS.

Interaction between COX-1 and COX-2 increases susceptibility to ischemic stroke in a Chinese population

Background

Mutations of cyclooxygenase gene (COX gene) may increase the susceptibility of ischemic stroke. We investigated five variants (rs5788, rs1330344, rs3842788, rs20417, and rs689466) of two COX genes in order to explaining the association between these polymorphisms and we also investigated the association between these variants and ischemic stroke risk to determine whether gene–gene interaction between these genes increases the susceptibility of ischemic stroke or its subtypes.

Methods

A total of 1981 study subjects (1078 cases and 903 control subjects) were recruited. The interaction of multiple factors was investigated using Multifactor Dimensionality Reduction. The additive effect of single nucleotide polymorphisms on ischemic stroke or its subtypes were analyzed by multiple factor logistic regression.

Results

At COX-1(rs1330344), AA genotype carriers had a lower susceptibility of ischemic stroke (OR = 0.657, 95%CI = 0.437–0.988, P = 0.044), and A allele carriers had a lower susceptibility of ischemic stroke (OR = 0.812, 95%CI = 0.657–0.978, P = 0.029). At COX-1(rs3842788), AA genotype carriers had a higher susceptibility of ischemic stroke (OR = 5.203, 95% CI = 1.519–5.159, P = 0.016). At COX-2 (rs689466), AA genotype carriers had a higher susceptibility of large-artery atherosclerosis (OR = 1.404, 95% CI = 1.019–1.934, P = 0.038). COX-1(rs1330344, rs3842788) and COX-2 rs689466 interacted in SVO, but had no additive effect with ischemic stroke and other subtypes.

Conclusions

At rs1330344, AA genotype may reduce the susceptibility of ischemic stroke. At rs3842788, AA genotype may increase the susceptibility of ischemic stroke. At rs689466, AA genotype may increase the susceptibility of large-artery atherosclerosis (LAA). COX − 1(rs1330344, rs3842788) and COX-2 rs689466 interacted in small vessel occlusion (SVO), but had no additive effect with ischemic stroke and other subtypes.

Association of COX2 -765G>C promoter polymorphism and coronary artery disease in Korean population

BACKGROUND

Cyclooxygenase-2 (COX2) plays a role in the formation of prostaglandins, which contribute to the inflammation involved in atherosclerosis. However, the role of the COX2 -765G>C polymorphism in susceptibility to coronary artery disease (CAD) is controversial.

OBJECTIVE

To identify the association between COX2 -765G>C polymorphism with CAD risk in Korean patients. We recruited 622 patients who were diagnosed to have coronary artery disease and 202 controls who did not have history and vascular disease risk factors.

METHODS

Using polymerase chain reaction-restriction fragment length polymorphism, the COX2 -765G>C polymorphism was analyzed in 622 Korean patients who received percutaneous coronary intervention and in 202 healthy control subjects.

RESULTS

The GC+CC genotype frequencies of the -765G>C polymorphism were significantly different between the CAD and control groups. The COX2 -765G>C polymorphism showed peculiar associations with CAD according to the presence of hyperlipidemia and plasma folate levels. However, there were no associations between the -765G>C polymorphism and the rates of hypertension, diabetes mellitus, or homocysteine levels.

CONCLUSION

This study suggests that the COX2 -765G>C polymorphism is a possible genetic determinant for the risk of CAD, and an individual risk factor in Koreans. Thus, further association studies between the COX2 polymorphism and atherosclerotic-related diseases such as cerebrovascular or cardiovascular diseases in other races or ethnicities will be needed.

Association of GPIa and COX-2 gene polymorphism with aspirin resistance

Objective

This study aimed to explore the association between GPIa, COX‐2 gene polymorphisms and aspirin resistance in the ischemic stroke patients from the southern part of Jiangsu province.

Methods

In all, 97 patients with acute ischemic stroke were enrolled in the study. GPIa gene polymorphism at 807C>T (rsl126643) locus and COX‐2 gene polymorphism at ‐765G>C (rs20417) locus were genotyped by PCR pyrosequencing technology. Patients were divided into the aspirin sensitivity (AS) group and aspirin resistance (AR) group according to the platelet aggregation rate. The relationship between the two gene polymorphisms and aspirin resistance was investigated and analyzed.

Results

The distribution of the genotype (CC, CT, TT, CT + TT, and CC) and the frequency of allele T of GPIa gene at 807C>T locus were significantly different in AS and AR groups in female patients (P < .05). Logistic regression analysis showed that the genotype of CT+TT at 807C>T locus was significantly correlated with AR after adjustment for relative factors (P = .047, OR = 4.856, 95% CI: 1.020–23.108). There were no significant differences in the genotype distribution and allele frequency of the COX‐2 gene ‐765G>C site between two groups (P > .05).

Conclusion

GPIa gene polymorphism at 807C>T locus was associated with AR in Chinese Han females, and the expression of allele T increased the incidence of AR. The gene polymorphism of COX‐2 gene at ‐765G>C locus was not significantly correlated with AR.

Recent developments and future directions for the use of pharmacogenomics in cardiovascular disease treatments

INTRODUCTION

Cardiovascular disease is still the leading cause of death worldwide. There are many environmental and genetic factors that play a role in the development of cardiovascular disease. The treatment of cardiovascular disease is beginning to move in the direction of personalized medicine by using biomarkers from the patient's genome to design more effective treatment plans. Pharmacogenomics have already uncovered many links between genetic variation and response of many different drugs. Areas covered: This article will focus on the main polymorphisms that impact the risk of adverse effects and response efficacy of statins, clopidogrel, aspirin, β-blockers, warfarin dalcetrapib and vitamin E. The genes discussed include SLCO1B1, ABCB1, CYP3A4, CYP3A5, CYP2C19, PTGS1, PTGS2, ADRB1, ADCY9, CYP2C19, PON1, CES1, PEAR1, GPIIIa, CYP2D6, CKORC1, CYP2C9 and Hp. Expert opinion: Although there are some convincing results that have already been incorporated in the labelling treatment guidelines, most gene-drug relationships have been inconsistent. A better understanding of the relationships between genetic factors and drug response will provide more opportunities for personalized diagnosis and treatment of cardiovascular disease.

Interactions among Variants in Eicosanoid Genes Increase Risk of Atherothrombotic Stroke in Chinese Populations

BACKGROUND

Eicosanoids are lipid mediators that may play a role in ischemic stroke (IS). However, the association of variants in eicosanoid genes and these interactions with IS risk has not been investigated. The aim of the present study was to investigate the association of 11 variants in eicosanoid genes with IS and to determine whether these gene-gene interactions increase the risk of IS.

METHODS

Eleven variants in prostaglandin H synthase-1 (PTGS1), PTGS2, thromboxane A2 synthase (TBXAS1), prostacyclin synthase (PTGIS), and prostaglandin E synthase (PTGES) genes were examined using mass spectrometry method in 297 patients with atherothrombotic stroke and 291 controls. Gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR) method. Platelet aggregation and platelet-leukocyte aggregates were measured on admission.

RESULTS

There were no significant differences in the genotype distributions of the 11 variants between patients and controls. However, GMDR analysis showed a significant gene-gene interaction among rs20417, rs5602, and rs41708, which scored 10 for cross-validation consistency and 9 for the sign test (P = .014). Logistic regression analysis showed that high-risk interaction among rs20417, rs5602, and rs41708 was an independent risk factor for atherothrombotic stroke (OR = 2.45, 95% CI: 1.33-3.27, P = .019). The high-risk interactive genotypes were associated with higher platelet aggregation and platelet-leukocyte aggregates.

CONCLUSIONS

PTGS2 rs20417, PTGIS rs5602, and TBXAS1 rs41708 three-locus interactions may confer a higher risk for atherothrombotic stroke. The combinatorial analysis used in this study may be helpful to elucidate complex genetic risk for IS.

Genetic variants of PTGS2, TXA2R and TXAS1 are associated with carotid plaque vulnerability, platelet activation and TXA2 levels in ischemic stroke patients

Eicosanoids may play a role in ischemic stroke. However, the associations of variants in cyclooxygenase (COX) pathway genes and interaction among these variants with carotid plaque vulnerability are not fully understood. In present study, twelve variants in COX pathway genes were examined using matrix-assisted laser desorption ionization time-of-flight mass spectrometry method in 396 patients with ischemic stroke and 291 controls. Platelet aggregation, platelet-leukocyte aggregates, and urine 11-dehydrothromboxane B2 (11-dTxB2) were also measured. According to the results of carotid high-resolution B-mode ultrasound, the patients were stratified into the following groups [i.e., non-carotid plaque and carotid plaque. The carotid plaque was further classified into subgroups of echolucent plaque (ELP) and echogenic plaque (EGP)]. Additionally, gene-gene interactions were analyzed to assess whether there was any interactive role for assessed variants in affecting carotid plaque vulnerability, platelet activation and 11-dTxB2 levels. There were no significant differences in the frequencies of genotypes of the twelve variants between patients and controls. Among 396 patients, 294 cases (74.2%) had carotid plaques (106 had ELP, 188 had EGP). Frequency of PTGS2 rs20417CC, TXAS1 rs2267679TT, TXAS1 rs41708TT, PTGIS rs5602CC, and TXA2R rs1131882TT genotype was significantly higher in patients with plaque compared with patients without plaque, or in patients with ELP compared with patients with EGP. 11-dTxB2 levels, platelet aggregation and platelet-leukocyte aggregates were significantly higher in patients with ELP compared with patients without plaque or with EGP. Multivariate logistic regression analysis revealed that PTGS2 rs20417CC, TXA2R rs1131882TT, and high-risk interaction among variants in PTGS2 rs20417, TXA2R rs1131882 and TXAS1 rs41708 were independently associated with the risk of ELP after adjusting for confounding variables. The variants in COX pathway genes and the high-risk interactions among variants in PTGS2 rs20417, TXA2R rs1131882 and TXAS1 rs41708 were associated with high 11-dTxB2 and platelet activation, and independently associated with the risk of carotid plaque vulnerability. These variants might be potential markers for plaque instability.

Use of genetic data to guide therapy in arterial disease

There is considerable interindividual variation in the response to antiplatelet and anticoagulant therapies. It has been proposed that this variability in drug response may be attributable to genetic variants. Thus, pharmacogenetics may help to accurately predict response to cardiovascular disease (CVD) therapies in order to maximize drug efficacy, minimize drug toxicity, and to tailor personalized care for these patients. Although the clinical utility of pharmacogenetics is promising, its adoption in clinical practice has been slow. This resistance may stem from sometimes conflicting findings among pharmacogenetic studies. Thus, this review focuses on the genetic determinants of commonly used platelet antagonists and anticoagulants including aspirin, clopidogrel, dabigatran, and warfarin. We also explore the clinical translation of pharmacogenetics in the management of patients with CVD.

Polymorphisms in inflammatory and immune response genes associated with cerebral cavernous malformation type 1 severity

BACKGROUND

Familial cerebral cavernous malformation type 1 (CCM1) is an autosomal dominant disease caused by mutations in the Krev Interaction Trapped 1 (KRIT1/CCM1) gene, and characterized by multiple brain lesions that often result in intracerebral hemorrhage (ICH), seizures, and neurological deficits. Carriers of the same genetic mutation can present with variable symptoms and severity of disease, suggesting the influence of modifier factors. Evidence is emerging that inflammation and immune response play a role in the pathogenesis of CCM. The purpose of this study was to investigate whether common variants in inflammatory and immune response genes influence the severity of familial CCM1 disease, as manifested by ICH and greater brain lesion count.

METHODS

Hispanic CCM1 patients (n=188) harboring the founder Q455X 'common Hispanic mutation' (CHM) in the KRIT1 gene were analyzed at baseline. Participants were enrolled between June 2010 and March 2014 either through the Brain Vascular Malformation Consortium (BVMC) study or through the Angioma Alliance organization. Clinical assessment and cerebral susceptibility-weighted magnetic resonance imaging were performed to determine ICH as well as total and large (≥5 mm in diameter) lesion counts. Samples were genotyped on the Affymetrix Axiom Genome-Wide LAT1 Human Array. We analyzed 830 variants in 56 inflammatory and immune response genes for association with ICH and residuals of log-transformed total or large lesion count adjusted for age at enrollment and gender. Variants were analyzed individually or grouped by sub-pathways or whole pathways.

RESULTS

At baseline, 30.3% of CCM1-CHM subjects had ICH, with a mean ± standard deviation (SD) of 60.1±115.0 (range 0-713) for total lesions and 4.9±8.7 (range 0-104) for large lesions. The heritability estimates explained by all autosomal variants were 0.20 (SE=0.31), 0.81 (SE=0.17), and 0.48 (SE=0.19), for ICH, total lesion count, and large lesion count, respectively. TGFBR2 rs9823731 was significantly associated with ICH as well as with the total and large lesion counts (p≤0.017). Further, IL-4 rs9327638, CD14 rs778588, IL-6R rs114660934 and MSR1 rs62489577 were associated with two markers of disease severity. Finally, the whole pathway was associated with total lesion count (p=0.005) with TLR-4 rs10759930, CD14 rs778588, IL-6R rs114660934 and IGH rs57767447 mainly bearing this association. Eicosanoid signaling, extracellular pattern recognition, and immune response sub-pathways were also associated with the total lesion count.

CONCLUSIONS

These results suggest that polymorphisms in inflammatory and immune response pathways contribute to variability in CCM1 disease severity and might be used as predictors of disease severity. In particular, TGFBR2 rs9823731 was associated with all three markers of CCM1 disease severity tested, suggesting that TGFBR2 might be a key participant in the mechanism underlying CCM1 disease severity and phenotype variability. However, further longitudinal studies in larger sample sizes are needed to confirm these findings.

Association of cyclooxygenase-2 genetic variant with cardiovascular disease

AIM

A genetic variant (rs20417) of the PTGS2 gene, encoding for COX-2, has been associated with decreased COX-2 activity and a decreased risk of cardiovascular disease (CVD). However, this genetic association and the role of COX-2 in CVD remain controversial.

METHODS AND RESULTS

The association of rs20417 with CVD was prospectively explored in 49 232 subjects (ACTIVE-A, CURE, epiDREAM/DREAM, ONTARGET, RE-LY, and WGHS) and the effect of potentially modifiable risk factors on the genetic association was further explored in 9363 INTERHEART participants. The effect of rs20417 on urinary thromboxane and prostacyclin metabolite concentrations was measured in 117 healthy individuals. Carriage of the rs20417 minor allele was associated with a decreased risk of major CVD outcomes (OR = 0.78, 95% CI: 0.70-0.87; P = 1.2 × 10(-5)). The genetic effect was significantly stronger in aspirin users (OR: 0.74, 95% CI: 0.64-0.84; P = 1.20 × 10(-5)) than non-users (OR: 0.87, 95% CI: 0.72-1.06; P = 0.16) (interaction P-value: 0.0041). Among patients with previous coronary artery disease (CAD), rs20417 carriers had a stronger protective effect on risk of major adverse events when compared with individuals without previous CAD (interaction P-value: 0.015). Carriers had significantly lower urinary levels of thromboxane (P = 0.01) and prostacyclin (P = 0.01) metabolites when compared with non-carriers.

CONCLUSION

The rs20417 polymorphism is associated with a reduced risk of major cardiovascular events and lower levels of thromboxane and prostacyclin. Our results suggest that a genetic decrease in COX-2 activity may be beneficial with respect to CVD risk, especially, in higher risk patients on aspirin.

The COX-2 rs20417 polymorphism and risk of coronary artery disease: evidence from 17,621 subjects

BACKGROUND

The Cyclooxygenase-2 (COX-2) rs20417 polymorphism has been implicated in coronary artery disease (CAD) risk, but individually published studies have shown inconsistent results. The aim of this study was to clarify the effects of COX-2 rs20417 polymorphism on CAD risk.

METHODS

A systematic literature search up to October 27, 2013 was carried out in PubMed, EMBASE, and Chinese National Knowledge Infrastructure (CNKI) databases, and the references of retrieved articles were screened. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were analysed for co-dominant model (CC vs. GG), additive model (C vs. G), dominant model (CC+GC vs. GG), and recessive model (CC vs. GG+GC) to assess the association using fixed- or random-effect model.

RESULTS

We identified nine articles (10 case-control studies) that included 3,439 cases and 14,182 controls for the present meta-analysis. Significant association between COX-2 rs20417 polymorphism and risk of CAD was observed in co-dominant model (OR=0.64, 95% CI=0.43-0.95, p=0.026) and recessive model (OR=0.77, 95% CI=0.61-0.97, p=0.025). Moreover, in the subgroup analysis stratified by ethnicity, significant associations were observed in Asians (OR=0.28, 95% CI=0.13-0.61, p=0.001 for CC vs. GC+GG; OR=0.24, 95% CI=0.11-0.51, p<0.001 for CC vs. GG) but not in Caucasians.

CONCLUSIONS

These results suggest that COX-2 rs20417 polymorphism may contribute to CAD development, especially in Asians.

Cyclooxygenase-2 genetic polymorphism and stroke subtypes in Chinese

BACKGROUND

Cyclooxygenase-2 (COX-2) catalyzes the formation of prostaglandins that contribute to the inflammation in atherosclerosis. The aim of the present study was to investigate the relationship between two polymorphisms (-1195G>A and -765G>C) in the COX-2 gene and subtypes of ischemic stroke in a Chinese population.

METHODS

Genomic DNA of 224 patients with large artery atherosclerosis (LAA), 329 patients with small vessel occlusion (SVO), and 450 controls were genotyped for the COX-2 1195G>A (rs689466) and -765G>C (rs20417) polymorphisms using polymerase chain reaction-restriction fragment length polymorphism. Chi-square test and logistic regression analysis were performed for association analysis.

RESULTS

The frequencies of variant allele with -1195G>A and -765G>C polymorphisms were 0.46 and 0.22, respectively. The -1195GA genotype and 1195A allele carriers were identified independently to be related with ischemic stroke (adjusted OR = 1.51, 95 % CI: 1.09-2.10, P = 0.02; OR = 1.45, 95 % CI: 1.06-1.97, P = 0.02) and SVO (adjusted OR = 1.57, 95 % CI: 1.07-2.30, P = 0.02; OR = 1.50, 95 % CI: 1.05-2.16, P = 0.03). In contrast, the 1195G>A polymorphism was not associated with LAA. No relationship between the -765G>C polymorphism and risk of either ischemic stroke was observed. The linkage disequilibrium analysis showed that -1195G>A and -765G>C SNPs are moderate linkage disequilibrium in this study population (D' = 0.72, r (2) = 0.16). Compared with G-1195-G-765 haplotype, the haplotype of A-1195-G-765 showed significant increased risk of ischemic stroke (OR = 1.27, 95 % CI: 1.05-1.54, P = 0.02) and SVO (OR = 1.27, 95 % CI: 1.02-1.58, P = 0.03) but not LAA.

CONCLUSIONS

In conclusion, we found that -1195G>A polymorphism and A-1195-G-765 haplotype of COX-2 were associated with susceptibility to ischemic stroke in a Chinese population. The effects were confined to SVO among the stroke subtypes rather than to LAA.

Cyclooxygenase 2 genetic polymorphism may increase the risk of developing leukoaraiosis in Chinese

Cyclooxygenase-2 (COX-2) is a key enzyme involved in the conversion of arachidonic acid into prostaglandins, which are important mediators of inflammation. To clarify the role of inflammation in the pathogenesis of cerebral small vessel disease (SVD), we investigate the possible modulating effect of the functional COX-2 polymorphisms -1195G > A (rs689466) and -765G > C (rs20417) on the risk for development of cerebral SVD in a Chinese population. Genomic DNA of 116 patients with lacunar infarction (LI), 334 patients with leukoaraiosis (LA) and 450 control subjects was genotyped for the COX-2 -1195G > A and -765G > C polymorphisms using polymerase chain reaction-restriction fragment length polymorphism. Distribution of genotypes and haplotypes in patients and controls were compared. The genotype distribution of the -765G > C polymorphism was not different between the patients with LI or LA and the control group. The 1195A allele carriers was identified independently to be related with LA (adjusted OR = 1.41, 95 % confidence interval (CI) = 1.09-2.10, P = 0.03) but not associated with LI. The linkage disequilibrium analysis showed that -1195G > A and -765G > C SNPs are moderate linkage disequilibrium in this study population (D' = 0.70, r(2) = 0.16). Compared with G-1195-G-765 haplotype, the haplotype of A-1195-G-765 showed significantly increased the risk of LA (OR = 1.24, 95 % CI = 1.10-1.55, P = 0.04) but not LI. In conclusion, we found that -1195G > A polymorphism and A-1195-G-765 haplotype of COX-2 were associated with susceptibility to LA in a Chinese population.

Association of COX-2 rs20417 with aspirin resistance

Aspirin is the most commonly used antiplatelet drug for treatment of a serious vascular event, most notably stroke and myocardial infarction. However, despite the demonstrated benefit of aspirin, significant fraction of aspirin-treated patients may be resistant to the antiplatelet effects of the drug. The possible mechanisms of aspirin resistance (AR) are multifactorial. A genetic basis for AR has been suggested to exist. Therefore, the present study was taken up to investigate the role of -765G/C polymorphism (rs20417) in the cyclooxygenase-2 (COX-2) gene with AR in stroke patients. Four hundred and fifty stroke patients and four hundred and forty age and sex matched healthy controls were involved in the study. Baseline clinical data were collected and follow-up telephone interviews were conducted with patients at 3 months post event to determine stroke outcome using Modified Rankin Scale. Blood samples were collected and genotypes determined by polymerase chain reaction-restriction digestion technique. The association between the genotypes and outcome was evaluated by stepwise multiple logistic regression analysis. The COX-2 CC and GC genotype showed a significant association with bad outcome. Therefore, the carriers of C allele of COX-2 -765G/C polymorphism are more prone to AR in comparison with non-carriers. These results support a potential role of -765G/C COX-2 gene polymorphism with AR in ischemic stroke patients.

Platelet response to aspirin in Chinese stroke patients is independent of genetic polymorphisms of COX-1 C50T and COX-2 G765C

AIM

Aspirin resistance (AR) is common in Chinese stroke patients taking antiplatelet medications; however, few studies have documented the role of cyclooxygenase (COX)-1 C50T and COX-2 G765C polymorphisms in AR. The aim of this study was to investigate the prevalence of AR in Chinese stroke patients and the relationships between AR and COX-1 C50T and COX-2 G765C polymorphisms, and to evaluate the effect of these polymorphisms on platelet response to aspirin.

METHODS

We prospectively enrolled 634 Chinese stroke patients. Platelet aggregation testing was performed before and after aspirin administration. The pre- and post-aspirin levels of 11-dehydrothromboxane B(2) (11-dTxB(2)) were determined in urine samples. COX-1 C50T and COX-2 G765C genotypes were determined by a polymerase chain reaction-allelic restriction assay.

RESULTS

AR was detected in 129 patients (20.4%), aspirin semi-resistance (ASR) was detected in 28 patients (4.4%), and aspirin sensitivity (AS) was detected in 477 patients (75.2%). There was no association between COX-1 C50T or COX-2 G765C polymorphisms and ASR+AR. Aspirin could efficiently reduce 11-dTxB(2) production by approximately 75%. In addition, platelet aggregation, both in response to arachidonic acid (AA) and adenosine 5'-diphosphate (ADP), was inhibited by more than 80% and 40%, respectively; however, the percentage reduction in platelet aggregation and 11-dTxB(2) levels was not significantly different between the COX-1 C50T and COX-2 G765C genotypes (p＞0.05).

CONCLUSIONS

There was no association between COX-1 C50T and COX-2 G765C polymorphisms and AR in Chinese stroke patients. In addition, COX-1 C50T and COX-2 G765C polymorphisms had no effect on the platelet response to aspirin.

The risk of coronary thrombosis with cyclo-oxygenase-2 inhibitors does not vary with polymorphisms in two regions of the cyclo-oxygenase-2 gene

AIMS

To investigate whether polymorphisms of the cyclo-oxygenase-2 (COX-2) gene modify the adverse cardiovascular effects of COX-2 inhibitors.

METHODS

A case control study was conducted in the Hunter Region of New South Wales, Australia. Cases (n= 460) were hospitalized with acute coronary syndrome (ACS). Controls (n= 640) were recruited from the electoral rolls. Structured interviews gathered information on variables including recent ingestion of non-steroidal anti-inflammatory drugs (NSAIDs). Targeted genotyping of rs 20417(G > C) and rs5275 (T > C) polymorphisms was performed by real-time polymerase chain reaction using allele-specific probes.

RESULTS

Ingestion of any NSAID in the week prior to interview was associated with an elevated risk for ACS: adjusted odds ratio 1.8 (1.2, 2.5). The rs 20417 and rs 5275 polymorphisms were not singly associated with risk for ACS: adjusted odds ratios 1.1 (0.80, 1.5) and 1.2 (0.88, 1.5), respectively. Individually, the polymorphisms did not modify the risk of ACS with the drugs. When analyses were conducted by haplotype, the adjusted odds ratio with celecoxib or rofecoxib in individuals who had one or two copies of the 'low risk' haplotype (no GT) was 1.2 (0.29, 5.0), compared with 2.1 (1.1, 4.0) with the 'high risk' haplotype (one or two copies of GT).

CONCLUSIONS

We found little evidence of a gene/drug interaction. We found a statistically non-significant trend toward a lower risk of coronary events with NSAIDs in the presence of the 'low risk' haplotype. Even if confirmed, the clinical utility of the finding would be limited as this haplotype is carried by a minority of the population.

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.

Impact of COX-2 rs5275 and rs20417 and GPIIIa rs5918 polymorphisms on 90-day ischemic stroke functional outcome: a novel finding

We hypothesized that polymorphisms in 5 genes related to thrombolytic and inflammation pathways will independently influence occurrence, severity, and 3-month functional outcome in patients with ischemic stroke. This was a case-control design with ischemic stroke patients recruited from 4 public hospitals (n = 640) and community controls (n = 627). Baseline clinical data were collected, and follow-up telephone interviews were conducted with 520 patients at 90 days postevent to determine stroke outcome using the Barthel Index (BI), Modified Rankin Scale (mRS) and Glasgow Outcome Scale (GOS). Blood samples were collected and genotyped for polymorphisms in platelet glycoprotein Ibα (GPIbα) rs224309 and rs6065, glycoprotein IIIa (GPIIIa) rs5918, tissue plasminogen activator (tPA) rs63020761, plasminogen activating inhibitor (PAI-1) rs72578597, and cyclooxygenase-2 (COX-2) rs5275 and rs20417. COX-2 polymorphism rs5275 demonstrated a significant association with poststroke mRS, with a dominant genetic model demonstrating the best fit (CC + TC) (adjusted odds ratio [aOR] = 1.61; P = .026). The COX-2 rs20417 C allele showed an association with GOS (aOR = 1.95; P = .012), and again a dominant genetic model demonstrated the best fit (CC + GC). GPIIIa rs5918 (A1A2) was associated with poststroke BI, with a dominant model demonstrating the best fit (A1A2 + A2A2) (aOR = 0.56; P = .014). There was a significant association between stroke severity and tPA rs63020761 TT allele (aOR = 1.96; 95% CI = 1.03-3.72; P = .040). This is the first study to demonstrate associations between stroke functional outcome and 2 COX-2 variants (rs20417 and rs5275) and a GPIIIa variant (rs5918).

Omega-3 Polyunsaturated Fatty Acids (n-3 PUFAs) in Cardiovascular Diseases (CVDs) and Depression: The Missing Link?

Background. Based on epidemiological data, clinical trials, and meta-analytic reviews, omega-3 polyunsaturated fatty acids (n-3 PUFAs) seem to be a biological link between depression and cardiovascular diseases (CVDs). Presentation. Involvement of n-3 PUFAs in depression and CVDs may be associated with a chronic, low-grade, inflammation. We hypothesize that n-3 PUFAs link depression and CVDs via “PUFA-prostaglandin E2 (PGE2) cascade.” Testing. To further support our hypothesis, case-control studies are needed to test the role of COX2 and PLA2 functions in depression and in CVDs. In addition, the effects of n-3 PUFAs on cardiovascular markers in depression and on depressive symptoms in CVDs should be investigated in clinical trials. Finally, the effects of manipulating COX2 and PLA2 functions on depression-like behaviors and cardiovascular functions could be explored in animal studies. Implications. n-3 PUFAs might be a promising treatment for both cardiovascular diseases and depression via its anti-inflammatory, cardioprotective, and neuroprotective effects.

Association of polymorphisms of PTGS2 and CYP8A1 with myocardial infarction

: Cyclooxygenase-2 (COX-2) and prostacyclin synthase (PGIS) are enzymes involved in prostaglandin and prostacyclin synthesis, which have been linked to cardiovascular disease risk. We hypothesized that genetic variations altering the function of these enzymes would modify the risk of myocardial infarction (MI).

: In a Chinese case control study of MI patients (n=356) and healthy controls (n=350), we investigated the roles of polymorphisms in the PGIS gene (

: The CC genotype of

: The CC genotype of

Clin Chem Lab Med 2009;47:347–52.

Polymorphisms cyclooxygenase-2 -765G>C and interleukin-6 -174G>C are associated with serum inflammation markers in a high cardiovascular risk population and do not modify the response to a Mediterranean diet supplemented with virgin olive oil or nuts

Inflammation is involved in cardiovascular diseases. Some studies have found that the Mediterranean diet (MD) can reduce serum concentrations of inflammation markers. However, none of these studies have analyzed the influence of genetic variability in such a response. Our objective was to study the effect of the -765G>C polymorphism in the cyclooxygenase-2 (COX-2) gene and the -174G>C polymorphism in the interleukin-6 (IL-6) gene on serum concentrations of IL-6, C-reactive protein, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule-1 as well as their influence on the response to a nutritional intervention with MD. An intervention study in a high cardiovascular risk Mediterranean population (314 men and 407 women) was undertaken. Participants were randomly assigned to consume a low-fat control diet or a MD supplemented with virgin olive oil or nuts. Measures were obtained at baseline and after a 3-mo intervention period. At baseline, the COX-2 -765G>C polymorphism was associated with lower serum IL-6 (5.85 +/- 4.82 in GG vs. 4.74 +/- 4.14 ng/L in C-allele carriers; P = 0.002) and ICAM-1 (265.8 +/- 114.8 in GG vs. 243.0 +/- 107.1 microg/L in C-carriers; P = 0.018) concentrations. These differences remained significant after multivariate adjustment. The IL-6 -174G>C polymorphism was associated with higher (CC vs. G-carriers) serum ICAM-1 concentrations in both men and women and with higher serum IL-6 concentrations in men. Following the dietary intervention, no significant gene x diet interactions were found. In conclusion, although COX-2 -765G>C and IL-6 -174G>C polymorphisms were associated with inflammation, consuming a MD (either supplemented with virgin olive oil or nuts) reduced the concentration of inflammation markers regardless of these polymorphisms.

Variation in eicosanoid genes, non-fatal myocardial infarction and ischemic stroke

OBJECTIVES

Eicosanoids are lipid mediators that may play a role in atherosclerosis. We investigated the association of common genetic variation in prostaglandin H synthase 1 (PTGS1), prostaglandin H synthase 2 (PTGS2), thromboxane A2 synthase (TBXAS1), prostacyclin synthase (PTGIS), prostaglandin E synthase (PTGES), 5-lipoxygenase activating protein (ALOX5AP), 12-lipoxygenase (ALOX12) and 15-lipoxygenase (ALOX15) with the risks of myocardial infarction (MI) and ischemic stroke. A secondary aim was to replicate the interaction of PTGS2 rs20417 (-765G to C) with aspirin use on coronary heart disease risk observed in the Atherosclerosis Risk in Communities Study (ARIC).

METHODS

We conducted a case-control study in a large Health Maintenance Organization. Cases were men and women, aged 30-79 years with incident non-fatal myocardial infarction (n=1063) or ischemic stroke (n=469) between January 1995 and December 2004. Controls (n=3462) were randomly selected and frequency matched to cases on age, sex, hypertension and calendar year.

RESULTS

Common variation in TBXAS1 and PTGIS was associated with MI risk (p-value for global Chi-square test, 0.01 and 0.03, respectively). Common variation in ALOX5AP, ALOX12, ALOX15, PTGS1, PTGS2 and PTGES was not associated with risks of MI and ischemic stroke. We replicated the observation of the Atherosclerosis Risk in Communities Study and observed an interaction of rs20417 with aspirin use on myocardial infarction risk (p for interaction=0.03).

CONCLUSIONS

Study results suggest that variation in TBXAS1 and PTGIS may influence MI risk, and carriers of rs20417C allele might derive greater benefits from aspirin use in primary prevention.

Genes and acute neurologic disease and injury: a primer for the neurologic intensive care nurse

The genetics revolution has not evaded the neuroscience community. Neurologic diseases and injuries, particularly of the type seen in neurologic intensive care units, are difficult to treat and often have poor prognoses. Recent work has begun to identify genotype-specific influences on development and treatment of multiple sclerosis and stroke. Additionally, responses to diseases and injuries to the brain and spinal cord have genetic influences. This article informs nurses working with neurologically impaired patients in the intensive care unit of specific genes involved in patient response and potential future therapeutics.

COX-2 gene promoter polymorphism and coronary artery disease in middle-aged men: the Helsinki sudden death study

Cyclooxygenase (COX) catalyzes formation of prostaglandins that contribute to the inflammation in atherosclerosis. Our objective was to study whether the functional C variant of the -765G-->C polymorphism in the human COX-2 gene associates with the severity of coronary atherosclerosis measured at the coronary artery level. The Helsinki sudden death study autopsy material (n = 300) comprised of Finnish men who died suddenly. The area of atherosclerotic lesions in the coronary arteries was quantitated, and coronary narrowing was measured. The occurrence of myocardial infarction (MI) was assessed. Genotyping was by restriction endonuclease analysis. Men carrying the minor C allele had larger areas of complicated lesions (P = .024) and a higher number of coronary arteries that had over 50% stenosis (P = .036) compared to men representing the common GG genotype. The COX-2 polymorphism was not associated with MI. Our data suggest that COX-2 may be involved in plaque growth.

Pyrosequencing of polymorphisms in the COX-2 gene (PTGS2) with reported clinical relevance

INTRODUCTION

Genetic variants in the prostaglandin-endoperoxide synthase 2 (PTGS2) gene, which codes for COX-2, have been identified to modulate the response to COX-2-inhibiting drugs and to be possible risk factors for the incidence or prognosis of cardiovascular or neoplastic diseases, Alzheimer's disease, multiple sclerosis, asthma or osteoarthritis. Clinical evidence thus suggests a clinical importance of COX-2 genetics reaching from disease risk or prognostics up to a personalized therapy with COX-2 inhibitors. The aim of this study was to develop rapid and reliable screening assays for PTGS2 mutations with reported clinical consequences.

METHODS

SNPs (dbSNP-IDs rs689465, rs689466, rs3918304, rs20415, rs20417, rs5270, rs2745557, rs5277, rs2066826, rs4648276, rs5273, rs5275, rs4648298, rs689469) and a nucleotide-deletion variant (rs20431) were chosen according to reported functional associations. For this selection of variants spanning the whole PTGS2 gene range, Pyrosequencing assays were established in DNA from 350 healthy unrelated Caucasians.

RESULTS

In all 350 DNA samples, the 15 PTGS2 polymorphisms were identified correctly as verified by control samples obtained by conventional sequencing. In silico haplotype analysis based on ten SNPs of greater than 1% observed frequencies identified two haploblocks with a linkage disequilibrium of D' = 0.59. Approximately 50% of the reconstructed haplotypes consisted of non-mutated alleles.

CONCLUSION

The presently developed Pyrosequencing assays allow for quick and reliable detection of PTGS2 genotypes and may promote further research toward personalized approaches to pathophysiological conditions involving COX-2.

Increased risk of incident stroke associated with the cyclooxygenase 2 (COX-2) G−765C polymorphism in African-Americans: The Atherosclerosis Risk in Communities Study

BACKGROUND

A hallmark feature of atherosclerosis is inflammation mediated by prostaglandins (PGs) catalyzed by the enzyme cyclooxygenase (COX). The present study explored whether the COX-2 G-765C polymorphism contributes to increased incidence of coronary heart disease (CHD) or stroke in the large prospective Atherosclerosis Risk in Communities (ARIC) Study.

METHODS

Incidences of CHD and stroke were identified through annual follow-up and hospital and death certificate surveillance. The study included 1488 incident CHD and 527 stroke events after an average of 14 years of follow-up. The frequency of the -765C variant allele was markedly different between African-Americans and whites, therefore all analyses were performed separately by race. Due to the small number of persons with the -765CC genotype, heterozygous and homozygous variant genotypes were combined for this analysis.

RESULTS

The COX-2 G-765C polymorphism was not a significant predictor of CHD in either racial group, but it was a significant predictor of incident stroke in African-Americans. After adjustment for age and gender, the hazard rate ratio for developing stroke for the CG+CC genotypes relative to the GG genotype was 1.34 (95% confidence interval [CI] 1.03-1.74, P=0.03) in African-Americans. This result was essentially unchanged when established predictors such as smoking, diabetes and hypertension were added to the model (HRR 1.34, 95%CI 1.03-1.76, P=0.03).

CONCLUSION

We have found the COX-2 G-765C polymorphism to be a risk factor for incident stroke in African-Americans. This study provides additional evidence for utilizing inflammation-related genetic polymorphisms for identifying individuals at increased risk for stroke.

A fetal cyclooxygenase-2 gene polymorphism is associated with placental malperfusion

Prostaglandin levels vary during pregnancy, mostly under the control of the inducible enzyme cyclooxygenase-2 (COX-2). The expression of COX-2 has been associated with ischemic events in the heart and brain, but its direct effect on human placental perfusion has not been previously examined. The purpose of this study was to investigate whether a functional polymorphism in the COX-2 gene that controls enzyme expression levels is associated with placental histopathologic lesions. Maternal and neonatal DNA from twin gestations were analyzed by a polymerase chain reaction-based assay for a single G to C nucleotide polymorphism at position -765 in the COX-2 gene promoter. Placental histopathology was evaluated in 6 major categories: meconium, malperfusion, inflammation, umbilical cord problems, villitis, and thrombosis. There was no significant association between placental histopathologic findings and polymorphisms of the COX-2 gene in the mother. In the fetus, carriage of the COX-2 C allele, which is correlated with decreased COX-2 gene expression, was negatively associated with lesions of placental ischemia/malperfusion (P = 0.02). Placental ischemic lesions were positively associated with intrauterine growth restriction (IUGR; P < 0.001). No other group of histopathologic lesions was associated with fetal polymorphisms in the COX-2 gene or with IUGR. Thus, a fetal polymorphism in the COX-2 gene influences the occurrence of placental malperfusion and ischemia, which may be of sufficient severity to promote or allow the development of IUGR.