Association of PAI-1 4G/5G and -844G/A Gene Polymorphism and Changes in PAI-1/tPA Levels in Stroke: A Case-Control Study

The dos, don'ts, and nuances of thrombophilia testing

Considerable progress has been made in elucidating genetic and biologic risk factors for venous thromboembolism (VTE). Despite being able to identify heritable defects in a substantial proportion of patients with VTE, testing has not, in general, proven useful in management. Despite efforts to reduce inappropriate testing, it often falls to the hematologist to consult on patients having undergone thrombophilia testing. Through a series of cases, we discuss how D-dimer testing can be helpful in VTE recurrence risk stratification in younger women as well as how to approach patients with persistently elevated D-dimer levels in the absence of thrombosis. While elevated factor VIII coagulant activity levels are a significant risk factor for a first episode of VTE, its biologic basis is not fully understood, and studies have not shown it to be a useful predictor of recurrence. Abnormal results of genetic tests for methylene tetrahydrofolate reductase or plasminogen activator 1 promoter polymorphisms may be encountered, which carry little if any thrombotic risk and should never be ordered. We also discuss protein S deficiency, the most difficult of the hereditary thrombophilias to diagnose due to a wider "normal" range in the general population as compared with protein C, the presence of both free and bound forms in plasma, and the characteristics of the various assays in use. We also present a rare type of protein C deficiency that can be missed by functional assays using an amidolytic rather than a clotting end point.

Relation of resistin gene variants to resistin plasma levels and altered susceptibility to polycystic ovary syndrome: A case control study

BACKGROUND

A role for resistin in the pathogenesis of polycystic ovarian syndrome (PCOS) and related features were described for various ethnicities. As its expression is partly inherited, a role for RETN polymorphisms in regulating resistin levels and PCOS risk was shown, but with varied results.

AIM

To investigate the association of rs34124816 (-537A>C), rs1862513 (-420C>G), rs3219175 (-358G>A), rs3745367 (+299G>A), rs3745369 (+1263G>C), and rs1423096 (+4965C>T) RETN SNPs with PCOS.

METHODS

Study subjects included 583 women with PCOS, and 713 eumenorrheic women serving as controls. Genotyping was done by real-time PCR.

RESULTS

Higher minor allele frequency (MAF) of rs34124816, rs3219175, and rs3745369, and lower MAF of rs1862513 and rs1423096 were seen in PCOS cases. Reduced PCOS risk was found with rs3745367 minor-allele homozygotes and rs1423096 minor-allele homozygotes, while increased risk was linked with rs3745367 heterozygotes, and with rs3745369 heterozygotes and minor-allele homozygotes. While it did not reach statistical significance, serum resistin levels were elevated in PCOS cases than in control women and major-allele homozygotes of rs34124816 and rs1862513, and in rs1423096 minor-allele-containing carriers. Carriage of rs34124816 correlated positively with age and LH, whereas rs1862513 positively and rs3745367 negatively correlated with fasting glucose. Six-locus (rs34124816-rs1862513-rs3219175-rs3745367-rs3745369-rs1423096) haplotype analysis demonstrated a significant reduction in AGGGGG and a marked increase in AGGGCG haplotypes between cases and controls, thus assigning PCOS protective and susceptible nature to these haplotypes, respectively.

CONCLUSIONS

This study is the first to document the contribution of rs34124816 and rs1423096 RETN variants to the risk of PCOS. The varied association of RETN gene variants with PCOS suggests an ethnic contribution of RETN association with PCOS.

Novel Association of IGF2BP2 Gene Variants With Altered Risk of Breast Cancer and as Potential Molecular Biomarker of Triple Negative Breast Cancer

BACKGROUND

Several studies documented that insulin-like growth factor-2 mRNA-binding protein 2 (IGF2BP2) contributes to carcinogenesis, and 1 report documented the association of IGF2BP2 rs4402960 with increased risk of breast cancer (BC). This study investigated the association of rs4402960 and rs1470579 IGF2BP2 variants with BC and triple negative BC (TNBC).

MATERIALS AND METHODS

This case-control study included 488 BC patients comprising 130 TNBC and 358 non-TNBC patients, and 476 cancer-free controls. Genomic DNA was obtained from peripheral venous blood, and genotyping was done by allelic exclusion method on real-time PCR.

RESULTS

The rs440960, but not rs1470579, minor allele was significantly associated with BC, and significantly higher rs4402960 T/T genotype frequency was noted in BC patients than controls; the distribution of rs1470579 genotypes were comparable between BC patients and controls. In contrast, significantly lower rs1470579 minor allele frequency, and reduced rs1470579 A/C and C/C, and rs4402960 T/T genotype frequencies were seen in TNBC cases. Among TNBC cases, rs4402960 and rs1470579 correlated with menses pattern, histological type, breastfeeding, oral contraceptive use and hormonotherapy. Among non-TNBC patients, and rs1470579 correlated significantly with breast feeding, oral contraceptive use, hormonotherapy, and nodal status; rs4402960 also correlated with menses pattern. Two-locus (rs440960-rs1470579) haplotype analysis confirmed the positive association of TC, and negative association of GC and TA haplotypes with BC, while TC and GC haplotypes were negatively associated with TNBC.

CONCLUSION

Whereas rs440960 was positively associated with BC, both rs4402960 and rs1470579 were negatively associated with TNBC, suggesting potential diagnostic/prognostic role in BC and its complications.

Relation of CRP gene variants to altered risk of Helicobacter pylori - associated chronic gastritis: A case-control study in Tunisia

BACKGROUND

We investigated the association between CRP variants and chronic gastritis in H. pylori-infected patients at the allele, genotype, and haplotype levels. This was also assessed according to serum hs-CRP levels.

METHODS

Study subjects consisted of 77 H. pylori-infected patients and 96 H. pylori-negative controls. Genotyping of the CRP rs1572970, rs876537, rs2794520, rs2808630, rs1130864, rs1417938, rs7553007, and rs4285692 variants were analyzed by real-time PCR.

RESULTS

Significantly higher MAF and increased risk of chronic gastritis were associated with rs1130864, rs1417938, and rs7553007, which persisted after controlling for key covariates. Significant differences in the genotype distribution of rs1130864, rs1417938, and rs7553007 were also seen between H. pylori-infected patients and healthy controls. Increased risk of H. pylori-associated chronic gastritis was associated with carriage of rs1130864 C/T, and more with T/T genotype carriers, as well as with rs1417938 T/A and A/A genotype carriers. Functionally, the distribution of rs1130864 and rs1417938 genotypes were significantly different between H. pylori-infected patients and controls in the low hs-CRP (<6 mg/L) group. CRP haplotype analysis identified Block 1 (rs1572970, rs876537, rs2794520), and Block 2 (rs2808630, rs1130864, rs1417938) associated with H. pylori infection. Haplotypes ACC (Block 1) and TTA and TTT (Block 2) were positively associated with H. pylori-associated chronic gastritis with low hs-CRP levels.

CONCLUSION

Altered serum levels of hs-CRP, stemming in part from the presence of specific genetic variants in CRP gene, modulate the risk of H. pylori infection.

PAI-1: A Major Player in the Vascular Dysfunction in Obstructive Sleep Apnea?

Obstructive sleep apnea is a chronic and prevalent condition that is associated with endothelial dysfunction, atherosclerosis, and imposes excess overall cardiovascular risk and mortality. Despite its high prevalence and the susceptibility of CVD patients to OSA-mediated stressors, OSA is still under-recognized and untreated in cardiovascular practice. Moreover, conventional OSA treatments have yielded either controversial or disappointing results in terms of protection against CVD, prompting the need for the identification of additional mechanisms and associated adjuvant therapies. Plasminogen activator inhibitor-1 (PAI-1), the primary inhibitor of tissue-type plasminogen activator (tPA) and urinary-type plasminogen activator (uPA), is a key regulator of fibrinolysis and cell migration. Indeed, elevated PAI-1 expression is associated with major cardiovascular adverse events that have been attributed to its antifibrinolytic activity. However, extensive evidence indicates that PAI-1 can induce endothelial dysfunction and atherosclerosis through complex interactions within the vasculature in an antifibrinolytic-independent matter. Elevated PAI-1 levels have been reported in OSA patients. However, the impact of PAI-1 on OSA-induced CVD has not been addressed to date. Here, we provide a comprehensive review on the mechanisms by which OSA and its most detrimental perturbation, intermittent hypoxia (IH), can enhance the transcription of PAI-1. We also propose causal pathways by which PAI-1 can promote atherosclerosis in OSA, thereby identifying PAI-1 as a potential therapeutic target in OSA-induced CVD.

Sex Differences in Hemostatic Factors in Patients With Ischemic Stroke and the Relation With Migraine-A Systematic Review

Background: Women are more affected by stroke than men. This might, in part, be explained by sex differences in stroke pathophysiology. The hemostasis system is influenced by sex hormones and associated with female risk factors for stroke, such as migraine.

Aim: To systematically review possible sex differences in hemostatic related factors in patients with ischemic stroke in general, and the influence of migraine on these factors in women with ischemic stroke.

Results: We included 24 studies with data on sex differences of hemostatic factors in 7247 patients with ischemic stroke (mean age 57–72 years, 27–57% women) and 25 hemostatic related factors. Levels of several factors were higher in women compared with men; FVII:C (116% ± 30% vs. 104% ± 30%), FXI (0.14 UI/mL higher in women), PAI-1 (125.35 ± 49.37 vs. 96.67 ± 38.90 ng/mL), D-dimer (1.25 ± 0.31 vs. 0.95 ± 0.24 μg/mL), and aPS (18.7% vs. 12.0% positive). In contrast, protein-S (86.2% ± 23.0% vs. 104.7% ± 19.8% antigen) and P-selectin (48.9 ± 14.4 vs. 79.1 ± 66.7 pg/mL) were higher in men. Most factors were investigated in single studies, at different time points after stroke, and in different stroke subtypes. Only one small study reported data on migraine and hemostatic factors in women with ischemic stroke. No differences in fibrinogen, D-dimer, t-PA, and PAI-1 levels were found between women with and without migraine.

Conclusion: Our systematic review suggests that sex differences exist in the activation of the hemostatic system in ischemic stroke. Women seem to lean more toward increased levels of procoagulant factors whereas men exhibit increased levels of coagulation inhibitors. To obtain better insight in sex-related differences in hemostatic factors, additional studies are needed to confirm these findings with special attention for different stroke phases, stroke subtypes, and not in the least women specific risk factors, such as migraine.

Association of PAI-1 rs1799889 Polymorphism with Susceptibility to Ischemic Stroke: a Huge Meta-Analysis based on 44 Studies

BACKGROUND

the PAI-1 rs1799889 polymorphism has been reported to be associated with susceptibility to ischemic stroke. However, the results of previous studies have been inconsistent or controversial. Hence, we performed a systematic review and meta-analysis to evaluate the association of PAI-1 rs1799889 polymorphism with ischemic stroke risk.

METHODS

A comprehensive literature search was performed on PubMed, Web of Science, Scopus, SciELO, CNKI, and CBD databases up to November 05, 2019. Pooled odds ratio (OR) with 95% confidence interval (CI) were used to access the strength of this association in fixed- or random-effects model.

RESULTS

A total of 44 case-control studies with 8,620 cases and 10,260 controls were selected. Pooled data showed a significant association between PAI-1 rs1799889 polymorphism and ischemic stroke risk in the overall populations (GG vs. AA: OR = 0.791, 95% CI 0.633-0.988, p = 0.039; GA vs. AA: OR = 0.807, 95% CI 0.683-0.953, p = 0.012; and GG+GA vs. AA: OR = 0.795, 95% CI 0.637-0.993, p = 0.043). Subgroup analysis by ethnicity revealed a significant association in Asian and Mixed populations, but not in Caucasians. Moreover, stratified analysis by country of origin revealed an increased risk of ischemic stroke in Chinese populations, but not among Dutch (Netherlands) and Swedish.

CONCLUSIONS

This meta-analysis result suggested that PAI-1 rs1799889 polymorphism was associated with an increased risk of ischemic stroke, especially in Asian and Mixed populations.

Stroke in Africa: profile, progress, prospects and priorities

Stroke is a leading cause of disability, dementia and death worldwide. Approximately 70% of deaths from stroke and 87% of stroke-related disability occur in low-income and middle-income countries. At the turn of the century, the most common diseases in Africa were communicable diseases, whereas non-communicable diseases, including stroke, were considered rare, particularly in sub-Saharan Africa. However, evidence indicates that, today, Africa could have up to 2-3-fold greater rates of stroke incidence and higher stroke prevalence than western Europe and the USA. In Africa, data published within the past decade show that stroke has an annual incidence rate of up to 316 per 100,000, a prevalence of up to 1,460 per 100,000 and a 3-year fatality rate greater than 80%. Moreover, many Africans have a stroke within the fourth to sixth decades of life, with serious implications for the individual, their family and society. This age profile is particularly important as strokes in younger people tend to result in a greater loss of self-worth and socioeconomic productivity than in older individuals. Emerging insights from research into stroke epidemiology, genetics, prevention, care and outcomes offer great prospects for tackling the growing burden of stroke on the continent. In this article, we review the unique profile of stroke in Africa and summarize current knowledge on stroke epidemiology, genetics, prevention, acute care, rehabilitation, outcomes, cost of care and awareness. We also discuss knowledge gaps, emerging priorities and future directions of stroke medicine for the more than 1 billion people who live in Africa.

Exploring Overlaps Between the Genomic and Environmental Determinants of LVH and Stroke: A Multicenter Study in West Africa

BACKGROUND

Whether left ventricular hypertrophy (LVH) is determined by similar genomic and environmental risk factors with stroke, or is simply an intermediate stroke marker, is unknown.

OBJECTIVES

We present a research plan and preliminary findings to explore the overlap in the genomic and environmental determinants of LVH and stroke among Africans participating in the SIREN (Stroke Investigative Research and Education Network) study.

METHODS

SIREN is a transnational, multicenter study involving acute stroke patients and age-, ethnicity-, and sex-matched control subjects recruited from 9 sites in Ghana and Nigeria. Genomic and environmental risk factors and other relevant phenotypes for stroke and LVH are being collected and compared using standard techniques.

RESULTS

This preliminary analysis included only 725 stroke patients (mean age 59.1 ± 13.2 years; 54.3% male). Fifty-five percent of the stroke subjects had LVH with greater proportion among women (51.6% vs. 48.4%; p < 0.001). Those with LVH were younger (57.9 ± 12.8 vs. 60.6 ± 13.4; p = 0.006) and had higher mean systolic and diastolic blood pressure (167.1/99.5 mm Hg vs 151.7/90.6 mm Hg; p < 0.001). Uncontrolled blood pressure at presentation was prevalent in subjects with LVH (76.2% vs. 57.7%; p < 0.001). Significant independent predictors of LVH were age <45 years (adjusted odds ratio [AOR]: 1.91; 95% confidence interval [CI]: 1.14 to 3.19), female sex (AOR: 2.01; 95% CI: 1.44 to 2.81), and diastolic blood pressure > 90 mm Hg (AOR: 2.10; 95% CI: 1.39 to 3.19; p < 0.001).

CONCLUSIONS

The prevalence of LVH was high among stroke patients especially the younger ones, suggesting a genetic component to LVH. Hypertension was a major modifiable risk factor for stroke as well as LVH. It is envisaged that the SIREN project will elucidate polygenic overlap (if present) between LVH and stroke among Africans, thereby defining the role of LVH as a putative intermediate cardiovascular phenotype and therapeutic target to inform interventions to reduce stroke risk in populations of African ancestry.

Neurogenomics in Africa: Perspectives, progress, possibilities and priorities

The understanding of the genetic basis of neurological disorders has grown rapidly in the last two decades. Despite the genomic heterogeneity within African populations, large-scale candidate gene or linkage and exome studies are lacking. However, current knowledge on neurogenetics in African populations is limited and geographically very uneven. Isolated reports indicate the existence of autosomal dominant or recessive conditions incorporating cerebrovascular, movement, neuromuscular, seizure and motor neuron disorders in Africans. In addition, few African families with neurodegenerative disorders associated with dementia have been characterized in North, West and South Africa. The current insurgency in genomic research triggered by among others the Human Health and Heredity (H3) Africa Initiative indicates that there are unique opportunities to advance our knowledge and understanding of the influence of genomic variation on the pattern, presentations and prognosis of neurological disorders in Africa. These have enormous potential to unmask novel genes and molecular pathways germane to the neurobiology of brain disorders. It would facilitate the development of novel diagnostics, preventative and targeted treatments in the new paradigm of precision medicine. Nevertheless, it is crucial to strike a balance between effective traditional public health strategies and personalized genome based care. The translational barriers can be overcome through robust stakeholder engagement and sustainable multilevel, multigenerational and multidisciplinary capacity building and infrastructural development for genomic medicine in Africa.

Stroke genomics in people of African ancestry: charting new paths

One in six people worldwide will experience a stroke in his/her lifetime. While people in Africa carry a disproportionately higher burden of poor stroke outcomes, compared to the rest of the world, the exact contribution of genomic factors to this disparity is unknown. Despite noteworthy research into stroke genomics, studies exploring the genetic contribution to stroke among populations of African ancestry in the United States are few. Furthermore, genomics data in populations living in Africa are lacking. The wide genomic variation of African populations offers a unique opportunity to identify genomic variants with causal relationships to stroke across different ethnic groups. The Stroke Investigative Research and Educational Network (SIREN), a component of the Human Health and Heredity in Africa (H3Africa) Consortium, aims to explore genomic and environmental risk factors for stroke in populations of African ancestry in West Africa and the United States. In this article, we review the literature on the genomics of stroke with particular emphasis on populations of African origin.

Association Between Plasminogen Activator Inhibitor-1 Genetic Polymorphisms and Stroke Susceptibility

The plasminogen activator inhibitor-1 (PAI-1) is a candidate gene for stroke based on PAI-1's crucial role in fibrinolytic system. However, association studies have yielded conflicting results regarding the association between PAI-1 polymorphisms and stroke susceptibility. To further elucidate the putative association, we performed a systematic review and meta-analysis to provide a complete picture of the loci investigated for association of PAI-1 polymorphism with stroke risk and to derive a precise estimation. PubMed, Embase, and China National Knowledge Infrastructure (CNKI) databases were searched until June 2015 to identify eligible studies. Forty data sets from 39 studies with a total of 8336 cases and 14,403 controls were included. The most commonly investigated polymorphism was -675 4G/5G, followed by -844 G/A, 11053 T>G, HindIII C/G, and (CA)n. Overall, our meta-analysis provided evidence for the significant association of PAI-1 4G/5G polymorphism with an increased risk of adult but not pediatric ischemic stroke (adult: 4G/4G vs. 4G/5G + 5G/5G, OR = 1.21, 95 % CI = 1.04-1.42). In the subgroup analysis, significant association was detected in Asians (4G/4G vs. 4G/5G + 5G/5G, OR = 1.45, 95 % CI = 1.14-1.85) but not Caucasians. Moreover, we found that -844 G/A but not 11053 T>G polymorphism was associated with an increased risk of ischemic stroke (-844G/A: A/A vs. G/G: OR = 1.32, 95 % CI = 1.01-1.73). A tendency of PAI-1 4G/5G polymorphism towards a decreased risk of hemorrhagic stroke was observed (4G/4G + 4G/5G vs. 5G/5G, OR = 0.77, 95 % CI = 0.59-1.02, P = 0.066). Future well-designed studies in large well-characterized sample size and presenting results stratified by gender, age, and stroke subtype are warranted.

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.

Biomarkers for arterial and venous thrombotic disorders

The haemostatic system maintains the blood in a fluid state, but allows rapid clot formation at sites of vascular injury to prevent excessive bleeding. Unbalances within the haemostatic system can lead to thrombosis. Inspite of successful research our understanding of the disease pathogenesis is still incomplete. There is great hope that genetic, genomic, and epigenetic discoveries will enhance the diagnostic capability, and improve the treatment options. During the preceding 20 years, the identification of polymorphisms and the elucidation of their role in arterial and venous thromboses became an important area of research. Today, a large body of data is available regarding associations of single nucleotide polymorphisms (SNPs) in candidate genes with plasma concentrations and e. g. the risk of ischaemic stroke or myocardial infarction. However, the results for individual polymorphisms and genes are often controversial. It is now well established that besides acquired also hereditary risk factors influence the occurrence of thrombotic events, and environmental factors may add to this risk. Currently available statistical methods are only able to identify combined risk genotypes if very large patient collectives (>10,000 cases) are tested, and appropriate algorithms to evaluate the data have yet to be developed. Further research is needed to understand the functional effects of genetic variants in genes of blood coagulation proteins that are critical to the pathogenesis of arterial and venous thrombotic disorders. In this review genetic variants in selected genes of the haemostatic system and their relevance for arterial and venous thrombosis will be discussed.

The -844 G>A PAI-1 polymorphism is associated with acute coronary syndrome in Mexican population

BACKGROUND

Acute coronary syndrome (ACS) has an important impact in public health with high morbidity and mortality. Prothrombotic and proinflammatory states are involved in the pathogenesis of the disease. Plasminogen activator inhibitor-1 (PAI-1) is the major inhibitor of the fibrinolysis and also is part of immune response. The -844 G>A gene polymorphism is related to increased PAI-1 protein levels. The aim of the study is to evaluate the association of -844 G>A PAI-1 polymorphism with ACS.

METHODS

A total of 646 individuals were recruited from Western Mexico: 350 unrelated healthy subjects and 296 patients with diagnosis of ACS.

RESULTS

The most important risk factor in our population was hypertension, followed by smoking. The genetic distribution showed an association of the A allele (OR = 1.27, P = 0.04) and AA genotype (OR = 1.86, P = 0.02) with ACS. The recessive model displayed similar results (OR = 1.76, P = 0.02). As additional finding, we observed significant differences in the genetic distribution of ACS dyslipidemic patients (OR = 1.99, P = 0.04). The A allele and AA genotype of -844 polymorphism of PAI-1 gene are risk factors for ACS. The AA genotype might be associated with the development of dyslipidemia in ACS patients.

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.

Association between plasminogen activator inhibitor-1 gene polymorphisms and recurrent pregnancy loss: a systematic review and meta-analysis

Human plasminogen activator inhibitor-1 (PAI-1) is closely related to embryonic development and pregnancy success. The association between PAI-1 gene polymorphisms (PAI-1-844G/A and PAI-1-675G/A) and the risk of recurrent pregnancy loss (RPL) is controversial. Therefore, we perform this review to clarify the association between PAI-1 gene polymorphisms and RPL risk. We performed a systematic search for studies that described the effect of PAI-1 polymorphisms on RPL risk. The odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were considered under recessive genetic models. Furthermore, we conducted a subgroup analysis based on the studies' geographic regions of origin. Data were analyzed using Stata 11.2 software. Eighteen studies were included, and a high degree of statistical heterogeneity existed among the studies. In this study, we found a significant association between the PAI-1-675G/A polymorphism and the risk of RPL under the recessive model (OR = 1.70, 95% CI = 1.21-2.38). However, no significant association between the PAI-1-844G/A polymorphism and RPL was noted. PAI-1-675G/A (4G/5G) polymorphisms play a potential role in RPL. The screening of PAI-1 (4G/5G) gene mutations should be included during an RPL diagnostic workup, and patients should be treated using anticoagulant therapy during pregnancy if necessary.

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.

Plasminogen activator inhibitor 1 4G/5G and -844G/A variants in idiopathic recurrent pregnancy loss

PROBLEM

Plasminogen activator inhibitor type 1 (PAI-1) regulates fibrinolysis, and the common promoter region variants -675G/A (4G/5G) and -844G/A are associated with increased thrombotic risk. Despite evidence linking altered fibrinolysis with adverse pregnancy events, including idiopathic recurrent pregnancy loss (RPL), the contribution of PAI-1 variants to RPL risk remains controversial. We investigated the association between the PAI-1 -844G/A and 4G/5G (-675G/A) variants with altered risk of RPL.

METHOD OF STUDY

This was a case-control study involving 304 women with confirmed RPL and 371 age- and ethnically matched control women. PAI-1 genotyping was performed by PCR single-specific primer -675 (G/A) and real-time PCR (-844G/A) analysis.

RESULTS

Minor allele frequency (MAF) of 4G/5G (P < 0.001), but not -844G/A (P = 0.507), was higher in RPL cases. PAI-1 4G/5G single-nucleotide polymorphism (SNP) was significantly associated with RPL under additive, dominant, and recessive genetic models; no association of -844G/A with RPL was seen irrespective of the genetic model tested. Taking common -844G/5G haplotype as reference (OR = 1.00), multivariate analysis confirmed the association of 4G-containing -844A/4G (P < 0.001) and -844G/4G (P = 0.011) haplotypes with increased RPL risk.

CONCLUSION

4G/5G, but not -844G/A, PAI-1 variant is associated with an increased risk of RPL.

Imbalance of plasminogen activator inhibitor type-1 (PAI-1) and tissue plasminogen activator (t-PA) activity in patients with Noonan syndrome

BACKGROUND

Patients with Noonan syndrome have been reported to have an increased incidence of bleeding with trauma and surgery. Although various abnormalities of hemostasis have been described in reported series, there has been no consistent abnormality described and none have investigated fibrinolytic pathways.

METHODS

Fibrinolytic parameters including tissue plasminogen activator (t-PA; activity and antigen), plasminogen activator inhibitor type-1 (PAI-1; activity and antigen), plasminogen (activity and antigen), thrombin-antithrombin complex, prothrombin time (PT), and activated partial thromboplastin time where studied in 12 patients with Noonan syndrome (total of 15 data sets). PT and activated partial thromboplastin time were performed locally whereas the fibrinolytic parameters were performed in a single national reference laboratory. Individual results were compared with published age-appropriate norms and the mean values of the study patients were compared with the midpoint of normal range for each component measured. The ratio of PAI-1/t-PA activity was calculated for each set of results and compared with a "normal" value calculated from the midpoint normal range value for each component.

RESULTS

Patients with Noonan syndrome consistently demonstrated an elevation of t-PA activity in relationship to PAI-1 activity and a decreased PAI-1/t-PA ratio (P<0.01 for each comparison).

CONCLUSIONS

Patients with Noonan syndrome seem to have an imbalance in fibrinolytic components favoring fibrinolysis. This may be an important contributor to the bleeding noted in these patients.

Genetics of stroke

Stroke is the second most common cause of death and the most common cause of disability in developed countries. Stroke is a multi-factorial disease caused by a combination of environmental and genetic factors. Numerous epidemiologic studies have documented a significant genetic component in the occurrence of strokes. Genes encoding products involved in lipid metabolism, thrombosis, and inflammation are believed to be potential genetic factors for stroke. Although a large group of candidate genes have been studied, most of the epidemiological results are conflicting. Studies of stroke as a monogenic disease have made huge progress, and animal models serve as an indispensable tool to dissect the complex genetics of stroke. In the present review, we provide insight into the role of in vivo stroke models for the study of stroke genetics.

The plasminogen activator inhibitor-1 (PAI-1) gene -844 A/G and -675 4G/5G promoter polymorphism significantly influences plasma PAI-1 levels in women with polycystic ovary syndrome

Mutations in the plasminogen activator inhibitor-1 (PAI-1) gene, along with increased PAI-1 levels, have been implicated in the pathogenesis of polycystic ovarian syndrome (PCOS). We investigated a possible influence of the promoter polymorphism (-844 A/G and -675 4G/5G) in the PAI-1 gene on plasma PAI-1 levels in 126 PCOS patients and 97 healthy controls. Levels of total testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), fasting plasma glucose (FPG), fasting insulin, and PAI-1 were measured, and body mass index (BMI), waist-to-hip ratio (WHR), LH/FSH ratio, and homeostasis model assessment for insulin resistance (HOMA-IR) were calculated. PAI-1 -675 4G/5G and -844 A/G gene polymorphisms were also performed. Total testosterone, fasting insulin, and PAI-1 levels; BMI, LH/FSH, and HOMA-IR were significantly higher in PCOS patients than controls (P < 0.05). The odds ratio of 4G/4G genotype, 4G allele, and the combination genotype of 4G/4G and -844 A/A were 2.49 (95% confidence interval (CI), 1.4-4.44), 2.1 (95% CI, 1.43-3.08), and 2.9 (95% CI, 1.41-5.98), respectively, (P < 0.001). In the PCOS group, the PAI-1 level of the A/A was significantly higher than that of the A/G or G/G genotype, similarly was 4G/4G genotype compared with 4G/5G or 5G/5G genotype. The plasma PAI-1 levels of the combination of the PAI-1 -844 A/A and -675 4G/4G or 4G/5G genotypes, or the coadunation of 4G/4G and -844 non-G/G (A/A + A/G) genotypes were significantly high in PCOS women compared with controls. A trend to a positive interaction between PAI-1 -675 4G/5G and -844 A/G gene polymorphism may elevate plasma PAI-1 levels and hypofibrinolysis, which is probably an important hereditary risk factor in PCOS.

Direct determination of haplotypes from single DNA molecules

Determining the long-range haplotypes in a diploid individual is a major technical challenge. Here we report a method of molecular haplotyping by directly imaging multiple polymorphic sites on individual human DNA molecules simultaneously. We demonstrate the utility of this technology by accurately determining the haplotypes consisting of up to 16 single-nucleotide polymorphisms in genomic regions up to 50 kilobases.