An Effect of the PAI-1 4G/5G Polymorphism on Cholesterol Levels May Explain Conflicting Associations with Myocardial Infarction and Stroke

Integrative Genetic Approach Facilitates Precision Strategies for Acute Myocardial Infarction

Acute myocardial infarction remains a significant cause of mortality worldwide and its burden continues to grow. Its pathophysiology is known to be complex and multifactorial, with several acquired and inherited risk factors. As advances in technology and medical therapy continue, there is now increasing recognition of the role that genetics play in the development and management of myocardial infarction. The genetic determinants of acute coronary syndrome are still vastly understudied, but the advent of whole-genome scanning and genome-wide association studies has significantly expanded the current understanding of genetics and simultaneously fostered hope that genetic profiling and gene-guided treatments could substantially impact clinical outcomes. The identification of genes associated with acute myocardial infarction can help in the development of personalized medicine, risk stratification, and improved therapeutic strategies. In this context, several genes have been studied, and their potential involvement in increasing the risk for acute myocardial infarction is being investigated. As such, this article provides a review of some of the genes potentially related to an increased risk for acute myocardial infarction as well as the latest updates in gene-guided risk stratification and treatment strategies.

Plasminogen Activator Inhibitor-1 4G/5G (rs1799889) Polymorphism in Chinese Patients with Diabetes Mellitus and Hypertension

Objective

To determine the plasminogen activator inhibitor-1 (PAI-1) 4G/5G (rs1799889) genotype of the subjects in a robust detection method and to explore the association of the PAI-1 4G/5G polymorphism with susceptibility to diabetes mellitus (DM) and hypertension (HTN) as well as clinical characteristics.

Methods

This study recruited 208 patients (68 patients were diagnosed with DM, 70 patients with HTN and 70 patients with DM combined with HTN) and 132 healthy controls (HC). A subset of the population was selected to evaluate the accuracy of the Real-time PCR (RT-PCR) method for detecting PAI-1 4G/5G polymorphism by using the sequencing method as the gold standard. Furthermore, the association of the PAI-1 4G/5G polymorphism with genetic susceptibility to DM and HTN was explored. Moreover, variations in clinical characteristics among individuals with various PAI-1 genotypes were also analyzed in the DM group, the HTN group and the DM+HTN group.

Results

There was a high concordance between the RT-PCR method and the sequencing method in determining the PAI-1 4G/5G polymorphism. No association was observed between the PAI-1 4G/5G polymorphism and susceptibility to DM, HTN and DM+HTN, respectively. There were no statistical differences in all study indicators among individuals that carrying various genotypes in the HC group. There were several variations in clinical characteristics among individuals harboring different PAI-1 4G/5G genotypes in the DM group, the HTN group and the DM+HTN group.

Conclusion

The RT-PCR method can accurately identify the PAI-1 4G/5G genotype in different individuals. The PAI-1 4G/5G polymorphism may not be associated with genetic susceptibility to DM, HTN and DM+HTN, but differences in clinical characteristics among individuals with various genotypes may provide a reference for disease assessment and personalized treatment of patients.

Clinical impact of the PAI-1 4G/5G polymorphism in Chinese patients with venous thromboembolism

Background

Venous thromboembolism (VTE) is a life-threatening cardiovascular syndrome that characterized by the imbalance of hemostasis and thrombosis and the formation of thrombi in the blood vessels. The aim of this study was to elucidate the clinical impact of the PAI-1 4G/5G polymorphism in Chinese patients with VTE.

Methods

A total of 169 subjects (89 VTE, 10 hyperbilirubinemia, 10 hyperlipidemia and 60 healthy controls) were recruited at Peking Union Medical College Hospital. The accuracy of the TaqMan-MGB RT-PCR method for detecting F5 G1691A (FVL) and PAI-1 4G/5G polymorphisms was evaluated by using sequencing method as the gold standard. Besides, the association of the PAI-1 4G/5G polymorphism with susceptibility, treatment efficacy and recurrence status of VTE in Chinese population were explored. Eventually, the plasma PAI-1 antigen levels and PAI-1 4G/5G polymorphisms were determined on additional 64 subjects (32 VTE and 32 healthy controls) simultaneously.

Results

The TaqMan-MGB RT-PCR method was proven to be highly accurate in determining the FVL and PAI-1 4G/5G polymorphisms without interference from bilirubin and lipids in the samples. No obvious correlation of the PAI-1 4G/5G polymorphism with VTE was observed in our study by using five genetic models (allele, genotype, dominant, recessive and additive). Additionally, we also observed that individuals with the 4G/5G genotype had lower neutrophil counts and neutrophil-to-lymphocyte ratio (NLR) than the 5G/5G genotype. Furthermore, we found that the patients with the 5G/5G genotype were more likely to achieve complete recanalization compared to the 4G/4G genotype. In addition, individuals carrying the 5G/5G genotype were more likely to develop a recurrence-free status as compared to individuals with the 4G/4G or 4G/5G genotypes. PAI-1 antigen levels in the VTE group were significantly higher than those in the HC group. However, there was no significant difference in the antigen levels of PAI-1 among subjects carrying various genotypes in the VTE group or HC group.

Conclusion

The PAI-1 4G/5G polymorphism has potential value in assessing the prognosis of Chinese patients with VTE. Our study has laid the foundation for the application of PAI-1 4G/5G polymorphism in the personalized management and monitoring of patients with VTE.

GLU298ASP and 4G/5G Polymorphisms and the Risk of Ischemic Stroke in Young Individuals

BACKGROUND

Polymorphisms in the endothelial nitric oxide synthase (eNOS) and in the plasminogen activator inhibitor -1 (PAI-1) genes have been implicated in stroke pathogenesis but results are still controversial. The aim of this study was to examine the possible contribution of Glu298Asp in the eNOS and 4G/5G in the PAI-1polymorphisms with ischemic stroke in a young Mexican population.

MATERIALS AND METHODS

In a case-control study, conducted between January 2006 and June 2010, 204 patients ≤45 years of age with ischemic stroke and 204 controls matched by age and gender, were recruited. The Glu298Asp and 4G/5G polymorphisms were determined in all participants by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

There was a significant difference in the Glu298Asp genotype distribution (P=0.001) and allele frequency between the two groups (P=0.001). The 4G/5G genotype distribution (P=0.40) and the allele frequency was similar between groups; (P=0.13). There were independent factors for ischemic stroke: Asp carriage (GluAsp+AspAsp) (P=0.02); smoking (P=0.01); hypertension (P=0.03), and familial history of atherothrombotic disease (P=0.04).

CONCLUSIONS

The Asp allele from the Gu298Asp gene represents an independent risk factor for ischemic stroke in a young Mexican population. In contrast, the 4G/5G was not associated with an increased risk for this disease in the same group of patients, as previously has been demonstrated in other populations.

High Incidence of ACE/PAI-1 in Association to a Spectrum of Other Polymorphic Cardiovascular Genes Involving PBMCs Proinflammatory Cytokines in Hypertensive Hypercholesterolemic Patients: Reversibility with a Combination of ACE Inhibitor and Statin

Cardiovascular diseases (CVDs) are significantly high in the Lebanese population with the two most predominant forms being atherosclerosis and venous thrombosis. The purpose of our study was to assess the association of a spectrum of CVD related genes and combined state of hypertension hypercholesterolemia (HH) in unrelated Lebanese. Twelve polymorphisms were studied by multiplex PCR and reverse hybridization of DNA from 171 healthy individuals and 144 HH subjects. Two genes were significantly associated with HH: ACE (OR: 9.20, P<0.0001) and PAI-1 (OR: 2.29, P = 0.007), respectively with the occurrence of the risky alleles “Del” and “4G”. The frequencies of the Del and 4G alleles were found to be 0.98 and 0.90 in the HH group versus 0.84 and 0.79 in the healthy group, respectively. Serum ACE activity and PAI-I increased significantly with Del/Del and 4G/5G genotypes. The co-expression of Del/4G(+/+) was detected in 113 out of 171 (66.0%) controls and 125 out of 144 (86.8%) HH subjects. Del/4G(-/-) was detected in only 6 (3.5%) controls and undetected in the HH group. Three venous thrombosis related genes [FV(Leiden), MTHFR(A1298C) and FXIII(V34L)] were significantly related to the prominence of the co-expression of Del/4G(+/+). A range of 2 to 8 combined polymorphisms co-expressed per subject where 5 mutations were the most detected. In Del/4G(+/+) subjects, peripheral blood mononuclear cells (PBMCs) produced significant elevated levels of IFN-γ and TNF-α contrary to IL-10, and no variations occurred for IL-4. ACE inhibitor (ramipril) in combination with statin (atorvastatin) and not alone reversed significantly the situation. This first report from Lebanon sheds light on an additional genetic predisposition of a complex spectrum of genes involved in CVD and suggests that the most requested gene FVL by physicians may not be sufficient to diagnose eventual future problems that can occur in the cardiovascular system. Subjects expressing the double mutations (Del/4G) are at high risk for the onset of CVDs.

Global fibrinolytic activity, PAI-1 level, and 4G/5G polymorphism in Thai children with arterial ischemic stroke

BACKGROUND

Prolonged euglobulin clot lysis time (ECLT) and increased level of plasminogen activator inhibitor-1 (PAI-1) were reported to be risk factors of arterial ischemic stroke (AIS) by some studies; however, these findings were not supported by other studies. The objective of this study was to determine the association of ECLT, PAI-1 level, and polymorphisms of 4G and 5G of PAI-1 gene to the development of AIS in Thai children.

METHODS

This study included patients aged 1-18 years old. Diagnosis of AIS was confirmed by imaging study. The control group was age- and sex-matched healthy subjects. Demographic data were recorded, and blood was tested for ECLT, PAI-1 level, lipid profiles, fasting blood sugar (FBS), and 4G and 5G polymorphisms of PAI-1 gene.

RESULTS

There were 70 subjects participating in this study, consisting of 30 patients and 40 controls. Demographic data, lipid profiles, and FBS were similar between the 2 groups. Furthermore, ECLT and PAI-1 level did not differ between patient and control groups; however, both showed significant correlation (r = .352, P = .006). The 4G/5G polymorphism was the most common genotype in both patient and control groups (69.0% vs. 80.0%). However, 4G and 5G polymorphisms of PAI-1 gene did not correlate with PAI-1 level in this study (P = .797).

CONCLUSIONS

The PAI-1 level and 4G/5G polymorphism may not be a risk factor of AIS in this population. It was also found that the 4G/5G polymorphism was the most common PAI-1 genotype in this study.

Pai-1 gene variants and COC use are associated with stroke risk: a case-control study in the Han Chinese women

Genetic variants of plasminogen activator inhibitor type 1 (PAI-1) gene have been suggested to influence the PAI-1 transcription activity and PAI-1 levels as well as might be involved in the pathophysiology of stroke. The aims of this study are to investigate whether the polymorphisms at the PAI-1 gene are associated with the risk of stroke and to explore the combined effects of PAI-1 variants and combined oral contraceptive (COC) use for stroke risk. We conducted a nested case-control study using 453 first-ever female stroke cases and 919 age- and region-matched controls that were recruited from our prospective surveillance cohort. SNP rs1799889 was genotyped by allele-specific polymerase chain reaction (PCR), and SNPs rs7242 and rs2227631 were detected by the TaqMan SNP genotyping assay. We identified that rs1799889 5G allele conferred a protective effect against ischemic stroke while 4G allele conferred an increased risk of ischemic stroke. But we failed to suggest associations of rs7242 and rs2227631. COC users had a 1.31-fold (OR=1.31, 95% CI=1.01-1.71) increased risk of stroke compared with the non-users. Furthermore, COC users with rs1799889 4G5G/5G5G genotype had a decreased risk of ischemic stroke (OR=0.53, 95% CI=0.34-0.83). Moreover, haplotype G-5G-T was associated with an increased risk of overall stroke (OR=1.28, 95% CI=1.01-1.62). In contrast, haplotype A-4G-G and haplotype G-5G-T were slightly associated with the protection from ischemic stroke (OR=0.61, 95% CI=0.46-0.82; OR=0.61, 95% CI=0.44-0.85, respectively). The study assessed the associations of three PAI-1 SNPs and also suggested combined effects of these PAI-1 gene variants and COC use on stroke risk in the Han Chinese women.

Association between the rs6950982 polymorphism near the SERPINE1 gene and blood pressure and lipid parameters in a high-cardiovascular-risk population: interaction with Mediterranean diet

The SERPINE1 (serpin peptidase inhibitor, clade E, member 1) gene, better known by its previous symbol PAI-1 (plasminogen activator inhibitor 1), has been associated with cardiovascular phenotypes with differing results. Our aim was to examine the association between the rs6950982 (G > A) near the SERPINE1 gene, blood pressure (BP) and plasma lipid concentrations as well as the modulation of the polymorphism effects by adherence to Mediterranean diet (AMD). We studied 945 high-cardiovascular-risk subjects. Biochemical, clinical, dietary and genetic data (rs6950982) were obtained. We also determined the common rs1799768 (4G/5G), for checking independent effects. AMD was measured by a validated questionnaire, and four groups were considered. rs6950982 (A > G) and rs1799768 (4G/5G) were only in moderate-low linkage disequilibrium (D' = 0.719; r (2) = 0.167). The most significant associations we obtained were with rs6950982 (A > G). In males, the G allele was nominally associated with higher diastolic BP (AA: 81.5 ± 10.9, AG: 82.1 ± 11.4, GG: 85.7 ± 10.5 mmHg; P additive = 0.030) and systolic BP (AA + AG: 141.4 ± 6.9 mmHg vs. GG: 149.8 ± 8.0 mmHg; P recessive = 0.036). In the whole population, the rs6950982 was also associated with plasma lipids. Subject with the G allele presented higher total cholesterol (P additive = 0.016, P recessive = 0.011), low-density lipoprotein cholesterol (P additive = 0.032, P recessive = 0.031) and triglycerides (P additive = 0.040, P recessive = 0.029). AMD modulated the effect of rs6950982 on triglyceride concentrations (P for interaction = 0.036). Greater AMD reduced the higher triglyceride concentrations in GG subjects. No significant interactions were found for the other parameters. The rs6950982 was associated with higher BP in men and higher triglycerides in the whole population, this association being modulated by AMD.

Type I plasminogen activator inhibitor 4G allele frequency is associated with chronic venous insufficiency

Chronic venous insufficiency (CVI) is a common disease associated with poor quality of life. Genetic polymorphisms causing coagulation abnormalities may account for some of the CVI pathogenesis. Type I plasminogen activator inhibitor (PAI-1) is responsible for fibrinolytic system regulation, and plasma levels of PAI-1 are strongly correlated with PAI-1 4G/5G gene polymorphism. The association between PAI-1 4G/5G gene polymorphism and CVI was investigated. In 34 consecutive patients with clinically overt CVI, the PAI-1 4G/4G polymorphism was detected in three cases (8.8%); the 4G/5G polymorphism was detected in 28 (82.4%). In 34 age- and sex-matched controls, the PAI-1 4G/4G polymorphism was detected in one case (2.9%) and the 4G/5G polymorphism was detected in 14 cases (41.2%). The PAI-1 4G allele was found significantly more frequently in CVI patients than in controls. The 4G allele was associated with a 3.25-fold increase in CVI risk. Thus, a relationship between CVI and the PAI-1 4G allele is apparent.

An ontological modeling approach to cerebrovascular disease studies: the NEUROWEB case

The NEUROWEB project supports cerebrovascular researchers' association studies, intended as the search for statistical correlations between a feature (e.g., a genotype) and a phenotype. In this project the phenotype refers to the patients' pathological state, and thus it is formulated on the basis of the clinical data collected during the diagnostic activity. In order to enhance the statistical robustness of the association inquiries, the project involves four European Union clinical institutions. Each institution provides its proprietary repository, storing patients' data. Although all sites comply with common diagnostic guidelines, they also adopt specific protocols, resulting in partially discrepant repository contents. Therefore, in order to effectively exploit NEUROWEB data for association studies, it is necessary to provide a framework for the phenotype formulation, grounded on the clinical repository content which explicitly addresses the inherent integration problem. To that end, we developed an ontological model for cerebrovascular phenotypes, the NEUROWEB Reference Ontology, composed of three layers. The top-layer (Top Phenotypes) is an expert-based cerebrovascular disease taxonomy. The middle-layer deconstructs the Top Phenotypes into more elementary phenotypes (Low Phenotypes) and general-use medical concepts such as anatomical parts and topological concepts. The bottom-layer (Core Data Set, or CDS) comprises the clinical indicators required for cerebrovascular disorder diagnosis. Low Phenotypes are connected to the bottom-layer (CDS) by specifying what combination of CDS values is required for their existence. Finally, CDS elements are mapped to the local repositories of clinical data. The NEUROWEB system exploits the Reference Ontology to query the different repositories and to retrieve patients characterized by a common phenotype.

Association of the plasminogen activator inhibitor-1 gene 4G/5G polymorphism with ST elevation acute myocardial infarction in young patients

INTRODUCTION AND OBJECTIVES

To investigate the role of the 4G/5G polymorphism in the plasminogen activator inhibitor-1 (PAI-1) gene in patients with ST-elevation myocardial infarction (STEMI) aged < or =45 years and its influence on regulation of the plasma PAI-1 concentration.

METHODS

This case-control study included 127 consecutive patients aged < or =45 years with a diagnosis of STEMI who were admitted to a cardiovascular intensive care unit and 127 controls recruited between January 2006 and March 2007. Participants were genotyped for the 4G/5G polymorphism using the polymerase chain reaction and restriction fragment length polymorphism analysis, and their plasma PAI-1 concentrations were measured. Informed consent was obtained from all participants.

RESULTS

There was a significant difference in genotype distribution between the two groups (P< .002). The 4G allele occurred more frequently in the patient group (P=.032). In addition, there were significant independent associations between STEMI and the 4G allele (i.e., 4G/4G plus 4G/5G; odds ratio [OR]=2.29; 95% confidence interval [CI], 1.12-4.68; P=.022), smoking (OR=23.23; 95% CI, 8.92-60.47; P< .001), a family history of cardiovascular disease (OR=4.66; 95% CI, 2.06-10.52; P=.001) and hypertension (OR=5.42; 95% CI, 1.67-17.56; P=.005). The plasma PAI-1 concentration was higher in individuals who were homozygous for the 4G allele (P< .001).

CONCLUSIONS

The study findings indicate that the 4G allele is an independent risk factor for acute myocardial infarction in young patients, as are smoking, hypertension and a family history of inherited cardiovascular disease.

Genetic polymorphisms for the study of multifactorial stroke

Single-gene disorders explain only a minority of stroke cases. Stroke represents a complex trait, which is usually assumed to be polygenic. On this topic, the role of a wide number of candidate genes has been investigated in stroke through association studies, with controversial results. Therefore, it is difficult for the clinician to establish the validity and the level of clinical applicability of the previously reported associations between genetic factors and stroke. This review is an update and an extensive analysis of the more recent association studies conducted in stroke. We evaluated a number of studies on several candidate genes (including F5, F2, FGA/FGB/FGG, F7, F13A1, vWF, F12, SERPINE1, ITGB3/PLA1/PLA2/ITGA2B, ITGA2, GP1BA, ACE, AGT, NOS3, APOE, LPL, PON1, PDE4D, ALOX5AP, MTHFR, MTR, and CBS), providing a final panel of genes and molecular variants. We categorized this panel in relation to the degree of association with stroke, supported by the results of meta-analyses and case-control studies. Our findings could represent a useful tool to address further molecular investigations and to realize more detailed meta-analyses.

The effect of the plasminogen activator inhibitor-1 4G/5G polymorphism on the thrombotic risk

Plasminogen activator inhibitor (PAI-1), is the central component of the fibrinolytic system. A deletion/insertion (4G/5G) polymorphism in the promoter region of the PAI-1 gene has been correlated with levels of plasma PAI-1. The 4G allele is associated with higher levels of PAI-1, and might increase the risk for intravascular thrombosis. However, the contribution of this genetic variant to the risk for thrombosis, both arterial and venous, has not been clearly established. A broad spectrum of findings regarding the effect of the 4G allele on thrombotic risk in different target organs has been reported. Our aim is to summarize the variable influence of this polymorphism on thrombotic events in different tissues or organs and explain the underlying mechanisms accounting for these differences.

An Interactive Association of Common Sequence Variants in the Neuropeptide Y Gene With Susceptibility to Ischemic Stroke

Background and Purpose— Knowledge of the genetic architecture of ischemic stroke has been quite limited. Most significant associations of candidate genes with ischemic stroke have been difficult to replicate. This might be because the associations were not strong enough for results to be consistent, and testing a mixture of heterogeneous ischemic strokes might lead to confounded genetic associations.

Methods— A preliminary association analysis with 28 sequence variants in 18 candidate genes ( ACE, AGT, AGTR1, BDNF, CRP, F13B, LIF, MMP9, NPPA, NPY, PTGS2, SELP, SERPINE1, SREBF2, TFPI, THBD, VCAM1 , and VEGF ) revealed that NPY might be the most responsible for the susceptibility of ischemic stroke. Forty-five variants were discovered in the NPY gene by full sequencing, and 5 polymorphisms were selected based on their allele frequency and linkage disequilibrium estimates to conduct a thorough examination of their associations with ischemic stroke and its subtypes classified by TOAST. This study was conducted with 271 patients with ischemic stroke and 455 control subjects.

Results— In contrast to a slight significance for an allelic association with ischemic stroke, remarkable discrepancies between haplotype frequencies of control subjects and patients were found. Especially, TA and CC of the haplotypes composed of C4112T and A6411C in the NPY gene were associated with increased risk ( P =1.8×10 −21 , P =2.0×10 −13 ). The interchanged haplotypes, TC and CA, were protective against the diseases ( P =9.3×10 −12 , P =6.0×10 −17 ). The associations were also shown in major subtypes of ischemic stroke.

Conclusions— This remarkable haplotypic association suggested that the interaction between the 2 common sequence polymorphisms in NPY contributed to a great amount of phenotypic variability of ischemic stroke.