Five frequent polymorphisms of the PAI-1 gene: lack of association between genotypes, PAI activity, and triglyceride levels in a healthy population

Quantile-specific heritability of plasminogen activator inhibitor type-1 (PAI-1, aka SERPINE1) and other hemostatic factors

BACKGROUND

Plasminogen activator inhibitor type-1 (PAI-1, aka SERPINE1) is a moderately heritable glycoprotein that regulates fibrin clot dissolution (fibrinolysis).

OBJECTIVES

Test whether the heritabilities (h2 ) of PAI-1 and other hemostatic factors are constant throughout their distribution or whether they are quantile-specific (i.e., a larger or smaller h2 depending on whether their concentrations are high or low).

METHODS

Quantile regression was applied to 5606 parent-offspring pairs and 5310 full siblings of the Framingham Heart Study. Quantile-specific heritability was estimated from the parent-offspring regression slope (βPO , h2  = 2βPO /(1+rspouse )) and the full-sib regression slope (βFS , h2  = {(1+8rspouse βFS )0.5 -1}/(2rspouse )).

RESULTS

Heritability (h2  ± SE) increased significantly with increasing percentiles of the offspring's age- and sex-adjusted PAI-1 distribution when estimated from βPO (plinear trend  = 0.0001): 0.09 ± 0.02 at the 10th, 0.09 ± 0.02 at the 25th, 0.16 ± 0.02 at the 50th, 0.29 ± 0.04 at the 75th, and 0.26 ± 0.08 at the 90th percentile of the PAI-1 distribution, and when estimated from βFS (plinear trend  = 6.5x10-7 ). There was no significant evidence for quantile-specific heritability for factor VII (plinear trend  = 0.35), D-dimer (plinear trend  = 0.08), tPA (plinear trend  = 0.74), or von Willebrand factor (plinear trend  = 0.79).

CONCLUSION

Higher mean plasma PAI-1 antigen concentrations tend to accentuate genetic effects (quantile-dependent expressivity), which is consistent with the greater reported differences in PAI-1 concentrations between rs1799889 SERPINE1 (4G/5G) genotypes in patients with osteonecrosis, meningococcal sepsis, obesity, prior myocardial infarction, deep vein thrombosis, and polycystic ovarian syndrome than in healthy controls. It is also consistent with the greater increases in PAI-1 concentrations in 4G-allele carriers than 5G/5G homozygotes following fibrinolytic treatment, low-salt intake, and high saturated fat intake.

The -675 4G/5G PAI-1 polymorphism confers genetic susceptibility to systemic lupus erythematosus, its clinical manifestations, and comorbidities in Mexican-Mestizo population

Systemic lupus erythematosus (SLE) involves a broad range of factors that contribute to the development of the disease and its comorbidities. Genetic predisposition influences the development of SLE, and the -675 4G/5G PAI-1 polymorphism has been associated with several pathologies with a chronic inflammatory component. Our objective was to investigate the genetic association between the -675 4G/5G PAI-1 polymorphism with SLE, its clinical manifestations, and comorbidities in a Mexican-Mestizo population. The -675 PAI-1 polymorphism was determined by PCR-RFLP in 716 subjects: 293 SLE patients and 423 control subjects. Significant associations for SLE genetic susceptibility were found in carriers of 4G/5G (OR = 2.63; CI 1.81-3.87; p < .001) and 4G/4G (OR = 2.70; CI 1.62-4.51; p < .001) genotype in comparison with the 5G/5G genotype; 4G allele carriers also presented genetic risk for SLE (OR = 1.63; CI 1.31-2.03; p < .001) compared to the 5G allele. Following a dominant genetic model, a similar association was found with the 4G allele to SLE (OR = 2.66; CI1.84-3.84; p < .001). The 4G/5G genotype was associated with shorter disease duration (p = .039), as well as lower levels of haemoglobin (p = .001) and haematocrit (p = .009); the need for prednisone treatment (p = .001), higher BMI (p = .03), presence of type 2 DM (p = .015), clinical activity (Mex-SLEDAI = 57%; p = .047), Chronicity (SLICC-ACR = 0; p = .015) and CRP levels (p = .015) were associated with 5G/5G genotypes. In conclusion, the -675 4G/5G and 4G/4G PAI-1genotypes were found as genetic risk markers of susceptibility for SLE in the Mexican-Mestizo population, and each genotype could influence the clinical manifestations and comorbidities differently in SLE.

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.

Functional stability of plasminogen activator inhibitor-1

Plasminogen activator inhibitor-1 (PAI-1) is the main inhibitor of plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA), and a major regulator of the fibrinolytic system. PAI-1 plays a pivotal role in acute thrombotic events such as deep vein thrombosis (DVT) and myocardial infarction (MI). The biological effects of PAI-1 extend far beyond thrombosis including its critical role in fibrotic disorders, atherosclerosis, renal and pulmonary fibrosis, type-2 diabetes, and cancer. The conversion of PAI-1 from the active to the latent conformation appears to be unique among serpins in that it occurs spontaneously at a relatively rapid rate. Latency transition is believed to represent a regulatory mechanism, reducing the risk of thrombosis from a prolonged antifibrinolytic action of PAI-1. Thus, relying solely on plasma concentrations of PAI-1 without assessing its function may be misleading in interpreting the role of PAI-1 in many complex diseases. Environmental conditions, interaction with other proteins, mutations, and glycosylation are the main factors that have a significant impact on the stability of the PAI-1 structure. This review provides an overview on the current knowledge on PAI-1 especially importance of PAI-1 level and stability and highlights the potential use of PAI-1 inhibitors for treating cardiovascular disease.

The study of t-PA, u-PA and PAI-1 genes polymorphisms in patients with abdominal aortic aneurysm

The most important feature of abdominal aortic aneurysm (AAA) pathogenesis is an enzymatic degradation of elastic lamellae and extracellular matrix proteins particularly with participation of matrix metalloproteinases. Plasmin, which is responsible for the dissolution of fibrin in blood vessels, plays also a key role in the cascade for activation of the metalloproteinases. The purpose of this study was to evaluate the influence of selected polymorphisms in genes coding for tissue plasminogen activator (−7351 C/T polymorphism), urokinase-type plasminogen activator (1788 C/T polymorphism) and plasminogen activator inhibitor 1 (−675 4G/5G and −844 G/A polymorphism) on the susceptibility to AAA. We performed a case–control study of 153 polish patients hospitalized due to AAA and compared them with matched healthy control subjects. The polymorphisms were ascertained through genotyping by polymerase chain reaction and restriction digestion of amplified fragments or through high-resolution melting analysis. In this study we have found lower frequency of wild-type GG genotype of the −844G/A PAI-1 polymorphism in cases than in controls, what may suggest the protective effect of this genotype for the risk of AAA development. None of the remaining polymorphisms tested were associated with AAA occurrence.

In black South Africans from rural and urban communities, the 4G/5G PAI-1 polymorphism influences PAI-1 activity, but not plasma clot lysis time

Data on genetic and environmental factors influencing PAI-1 levels and their consequent effect on clot lysis in black African populations are limited. We identified polymorphisms in the promoter area of the PAI-1 gene and determined their influence on PAI-1_act levels and plasma clot lysis time (CLT). We also describe gene-environment interactions and the effect of urbanisation. Data from 2010 apparently healthy urban and rural black participants from the South African arm of the PURE study were cross-sectionally analysed. The 5G allele frequency of the 4G/5G polymorphism was 0.85. PAI-1_act increased across genotypes in the urban subgroup (p = 0.009) but not significantly in the rural subgroup, while CLT did not differ across genotypes. Significant interaction terms were found between the 4G/5G polymorphism and BMI, waist circumference and triglycerides in determining PAI-1_act, and between the 4G/5G polymorphism and fibrinogen and fibrinogen gamma prime in determining CLT. The C428T and G429A polymorphisms did not show direct relationships with PAI-1_act or CLT but they did influence the association of other environmental factors with PAI-1_act and CLT. Several of these interactions differed significantly between rural and urban subgroups, particularly in individuals harbouring the mutant alleles. In conclusion, although the 4G/5G polymorphism significantly affected PAI-1_act, it contributed less than 1% to the PAI-1_act variance. (Central) obesity was the biggest contributor to PAI-1_act variance (12.5%). Urbanisation significantly influenced the effect of the 4G/5G polymorphism on PAI-1_act as well as gene-environment interactions for the C428T and G429A genotypes in determining PAI-1_act and CLT.

Body adiposity but not insulin resistance is associated with -675 4G/5G polymorphism in the PAI-1 gene in a sample of Mexican children

OBJECTIVE

To assess whether the -675 4G/5G polymorphism in the plasminogen activator inhibitor-1 gene is associated with obesity and insulin resistance in Mexican children.

METHODS

A cross-sectional study was performed in 174 children, 89 with normal-weight and 85 with obesity, aged from 6 to 13 years. All children were from state of Guerrero, and recruited from three primary schools in the city of Chilpancingo, state of Guerrero, Mexico. Insulin levels were determined by immunoenzymatic assay. The homeostasis model assessment was used to determine insulin resistance. The -675 4G/5G polymorphism in PAI-1 gene was analyzed by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

The prevalence of insulin resistance in the obese group was higher (49.41%) than in the normal-weight group (16.85%). The 4G/5G PAI-1 polymorphism was found in Hardy Weinberg equilibrium. The 4G/5G genotype contributed to a significant increase in waist-hip ratio (β=0.02, p=0.006), waist circumference (β=4.42, p=0.009), and subscapular skinfold thickness (β=1.79, p=0.04); however, it was not related with insulin resistance.

CONCLUSION

The -675 4G/5G genotype of PAI-1 gene was associated with increase of body adiposity in Mexican children.

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.

Relationship of metabolic syndrome and its components with -844 G/A and HindIII C/G PAI-1 gene polymorphisms in Mexican children

Background

Several association studies have shown that -844 G/A and HindIII C/G PAI-1 polymorphisms are related with increase of PAI-1 levels, obesity, insulin resistance, glucose intolerance, hypertension and dyslipidemia, which are components of metabolic syndrome. The aim of this study was to analyze the allele and genotype frequencies of these polymorphisms in PAI-1 gene and its association with metabolic syndrome and its components in a sample of Mexican mestizo children.

Methods

This study included 100 children with an age range between 6-11 years divided in two groups: a) 48 children diagnosed with metabolic syndrome and b) 52 children metabolically healthy without any clinical and biochemical alteration. Metabolic syndrome was defined as the presence of three or more of the following criteria: fasting glucose levels ≥ 100 mg/dL, triglycerides ≥ 150 mg/dL, HDL-cholesterol < 40 mg/dL, obesity BMI ≥ 95^th percentile, systolic blood pressure (SBP) and diastolic blood pressure (DBP) ≥ 95^th percentile and insulin resistance HOMA-IR ≥ 2.4. The -844 G/A and HindIII C/G PAI-1 polymorphisms were analyzed by PCR-RFLP.

Results

For the -844 G/A polymorphism, the G/A genotype (OR = 2.79; 95% CI, 1.11-7.08; p = 0.015) and the A allele (OR = 2.2; 95% CI, 1.10-4.43; p = 0.015) were associated with metabolic syndrome. The -844 G/A and A/A genotypes were associated with increase in plasma triglycerides levels (OR = 2.6; 95% CI, 1.16 to 6.04; p = 0.02), decrease in plasma HDL-cholesterol levels (OR = 2.4; 95% CI, 1.06 to 5.42; p = 0.03) and obesity (OR = 2.6; 95% CI, 1.17-5.92; p = 0.01). The C/G and G/G genotypes of the HindIII C/G polymorphism contributed to a significant increase in plasma total cholesterol levels (179 vs. 165 mg/dL; p = 0.02) in comparison with C/C genotype.

Conclusions

The -844 G/A PAI-1 polymorphism is related with the risk of developing metabolic syndrome, obesity and atherogenic dyslipidemia, and the HindIII C/G PAI-1 polymorphism was associated with the increase of total cholesterol levels in Mexican children.

Impact of the -675 4G/5G polymorphism of the plasminogen activator inhibitor-1 gene on childhood IgA nephropathy

Plasminogen activator inhibitor-1 (PAI-1) is an important regulator of the fibrinolytic pathway and extracellular matrix (ECM) turnover. The -675 4G/5G polymorphism in the PAI-1 promoter is associated with altered PAI-1 transcription, suggesting that this polymorphism may be a candidate risk factor for diseases characterized by ECM accumulation, such as immunoglobulin A nephropathy (IgAN) and mesangial proliferative glomerulonephritis (MesPGN). We genotyped childhood patients with biopsy-confirmed IgAN (n=111) and MesPGN (n=47), and healthy control subjects (n=230) for the -675 4G/5G PAI-1 polymorphism by polymerase chain reaction-restriction fragment length polymorphism methods. The distribution of the 4G/4G (27.9%), 4G/5G (45.1%) and 5G/5G (27.0%) genotypes in IgAN patients was significantly different from the healthy controls (32.2, 54.3 and 13.5%, respectively) (p=0.0092). There was no significant difference in the genotype distributions of the 4G/5G polymorphism between MesPGN patients and the healthy controls. Regarding the impact of the polymorphism on IgAN, the 4G/4G genotype was markedly increased in patients with proteinuria (≥1,000 mg/day) and/or hypertension when compared to patients without proteinuria and hypertension (OR=5.23, 95% CI 1.34-20.38, P=0.0183). These findings indicate that the PAI-1 gene polymorphism may affect the susceptibility of childhood IgAN.

Plasminogen activator inhibitor-1 polymorphisms (-844 G>A and HindIII C>G) in systemic lupus erythematosus: association with clinical variables

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the presence of autoantibodies against nuclear autoantigens as well as cytoplasmic and circulating proteins. Recent studies have demonstrated mechanisms responsible for modulation of the immune response by the plasminogen activator inhibitor-1 (PAI-1). Furthermore, the endogenous PAI-1 has shown to promote a Th2 immune response. We assessed the -844 G>A and HindIII C>G PAI-1 polymorphisms in SLE. In a case-control study of 71 SLE patients classified according to ACR criteria and 71 healthy subjects (HS). The A allele of -844 PAI-1 polymorphism showed a significant difference in SLE patients (41%) when compared with HS (27%) [P = 0.01; OR = 1.8, 95%, CI = 1.1-3.0]. In addition, the -844 G>A PAI-1 polymorphism was associated with increased risk for SLE in a dominant genetic model (G/G vs. G/A + A/A; OR = 2.3, 95% CI = 1.14-4.44). Also, anti-RNP positive antibodies in SLE were associated with G/G -844 PAI-1 genotype. The HindIII polymorphism did not show any differences. The haplotype analysis showed that the AC haplotype confers susceptibility to SLE (OR = 3.1, 95% CI, 1.45-6.52; P = 0.003). The AC haplotype of the -844 and HindIII PAI-1 polymorphism might be an additional susceptibility factor to SLE in Mexicans.

Association of PAI-1 4G/5G and -844G/A gene polymorphisms and changes in PAI-1/tissue plasminogen activator levels in myocardial infarction: a case-control study

BACKGROUND

Myocardial infarction (MI) is induced by acquired and inherited risk factors, including the plasminogen activator inhibitor-1 (PAI-1) -844G/A and -675G/A (4G/5G) gene variants.

OBJECTIVE

The aim of this study was to investigate the association between PAI-1-844G/A and 4G/5G polymorphisms and changes in PAI-1 and tissue plasminogen activator (tPA) levels in MI in a Tunisian population.

METHODS

This was a case-control study involving 305 patients with MI and 328 unrelated healthy controls. PAI-1 genotyping was done by polymerase chain reaction-restriction fragment length polymorphism (RFLP) (-844G/A) or by polymerase chain reaction-allele specific amplification. PAI-1 and tPA levels were assayed by serological assays.

RESULTS

In contrast to tPA levels, mean plasma PAI-1 antigen levels were higher in cases than in control subjects. The elevation in PAI-1 levels was more pronounced in -844A and 4G allele carriers. Significantly higher frequencies of (mutant) 4G and -844A alleles and 4G/4G and -844A/-844A genotypes, and corresponding lower frequencies of (wild-type) 5G and -844G alleles and 5G/5G and -844G/-844G genotypes were seen in patients than in controls. Increased prevalence of 4G/-844A and decreased prevalence of 5G/-844G haplotypes were seen in patients than in controls, thereby conferring a susceptibility and protective nature to these haplotypes, respectively. Regression analysis confirmed the independent association of 4G/4G and -844A/A with MI, after controlling for a number of covariates.

CONCLUSION

This study indicated that the risk of MI was notably high in 4G and -844A carriers with elevated plasma PAI-1 and were associated with reduced tPA levels.

Diabetic retinopathy, PAI-1 4G/5G and -844G/A polymorphisms, and changes in circulating PAI-1 levels in Tunisian type 2 diabetes patients

AIM

The association of altered plasminogen activator inhibitor (PAI)-1 levels and PAI-1 polymorphisms (4G/5G and -844G/A) with diabetic retinopathy (DR) was investigated in 856 type 2 diabetes (T2D) patients, of whom 383 presented with (DR group), and 473 presented without (DWR group), retinopathy.

METHODS

PAI-1 4G/5G and -844G/A genotyping were done by PCR-RFLP, and PAI-1 levels were measured by ELISA testing.

RESULTS

The genotype distribution of 4G/5G and -844G/A polymorphisms did not deviate from the Hardy-Weinberg equilibrium model among healthy subjects. Higher frequencies of the 4G/4G genotype, and lower frequencies of the -844A allele, -844G/A and -844A/A genotypes, were seen in DR patients, conferring disease susceptibility and protection, respectively. While PAI-1 levels were significantly elevated in the 4G/4G compared with other PAI-1 genotypes, significant differences in PAI-1 levels between DR and DWR patients were seen in the 4G/-844A, 4G/-844G and 5G/-844A haplotype carriers among DR patients. However, comparable distributions of 4G/5G and -844G/A alleles, genotypes and haplotypes, and similar PAI-1 levels, were seen in the proliferative retinopathy (PR) and non-proliferative retinopathy (NPR) patients, indicating that neither PAI-1 variants nor changes in PAI-1 levels were linked to DR severity. Multivariate analyses identified 4G/-844A and 4G/-844G haplotypes as negatively and positively associated, respectively, with DR, but not with DR severity (PR vs NPR) after adjusting for a number of covariates.

CONCLUSION

The present study identifies changes in PAI-1 levels and genetic variations at the PAI-1 locus as risk factors for DR, but not DR severity, that may serve as useful markers of increased DR susceptibility.

The genomic basis of cerebral palsy: a HuGE systematic literature review

Cerebral palsy has been associated with a number of candidate genes. To date, no systematic review has been conducted to synthesise genetic polymorphism associations with cerebral palsy. We apply the HuGE NET guidelines to search PubMed and EMBASE databases for publications investigating single nucleotide polymorphisms (SNPs) and cerebral palsy outcome. 22 papers were identified and are discussed in this review. Candidate genes were grouped as (1) thrombophilic, (2) cytokine, (3) apolipoprotein E or (4) other SNPs, largely related to cardiovascular physiology/pathophysiology and the functioning of the immune system. Of the studies identified, cohorts were usually small, without adequate control and ethnically diverse, making direct comparison between studies difficult. The most promising candidate genes include factor V Leiden, methylenetetrahydrofolate reductase, lymphotoxin-alpha, tumour necrosis factor-alpha, eNOS and mannose binding lectin. Large case-control studies are needed to confirm these candidates with attention given to cohort ethnicity, cerebral palsy subtype analysis and possible multiple gene and gene-environment interactions.

A likelihood model that accounts for censoring due to fetal loss can accurately test the effects of maternal and fetal genotype on the probability of miscarriage

OBJECTIVE

Heritable maternal and fetal thrombophilia and/or hypofibrinolysis are important causes of miscarriage. Under the constraint that fetal genotype is observed only after a live birth, estimating risk is complicated. Censoring prevents use of published statistical methodology. We propose techniques to determine whether increases in miscarriage are due to the fetal genotype, maternal genotype, or both.

METHODS

We propose a study to estimate the risk of miscarriage contributed by an allele, expressed in either dominant or recessive fashion. Using a multinomial likelihood, we derive maximum likelihood estimates of risk for different genotype groups. We describe likelihood ratio tests and a planned hypothesis testing strategy.

RESULTS

Parameter estimation is accurate (bias <0.0011, root mean squared error <0.0780, n = 500). We used simulation to estimate power for studies of three gene mutations: the 4G hypofibrinolytic mutation in the plasminogen activator inhibitor gene (PAI-1), the prothrombin G20210A mutation, and the Factor V Leiden mutation. With 500 families, our methods have approximately 90% power to detect an increase in the miscarriage rate of 0.2, above a background rate of 0.2.

CONCLUSION

Our statistical method can determine whether increases in miscarriage are due to fetal genotype, maternal genotype, or both despite censoring.

Distribution of —844 G/A and Hind III C/G PAI-1 Polymorphisms and Plasma PAI-1 Levels in Mexican Subjects: Comparison of Frequencies Between Populations

Several polymorphisms have been described in the PAI-1 gene including the —844 G/A and Hind III C/G polymorphisms. These polymorphisms have been associated with different diseases such as preeclampsia and cardiovascular diseases. The allele and genotype frequencies of both PAI-1 polymorphism where investigated in Mexican subjects and compared with other healthy worldwide populations. The hematological and biochemical parameters where classified according each genotype in our studied group. One hundred Mexican subjects were recruited. Demographic data and hematological and biochemical parameters were collected, and genomic DNA isolation was performed in all the participants. Screening of both polymorphisms studied was made by polymerase chain reaction and restriction analysis. Levels of plasminogen activator inhibitor-1 in plasma were measured by ELIS-ARA plasminogen activator inhibitor antigen kit. The —844 and Hind III genotypes frequencies were as follows: 49% (G/G), 40% (G/A), 11% (A/A) and 50% (C/C), 44% (C/G), 6% (G/G), respectively. The wild-type genotypes (G/G and C/C) were significantly higher with respect to the compared populations. In addition, a significant increase of apolipoprotein A1 in the carriers of G/A —844 and C/G Hind III genotypes was observed. However, when the plasma plasminogen activator inhibitor levels were analyzed with respect to each genotype and haplotype, no significant differences were found.

The influence of metabolic syndrome components on plasma PAI-1 concentrations is modified by the PAI-1 4G/5G genotype and ethnicity

Coronary artery disease (CAD) is less common in African than Indian or White subjects and elevated plasminogen activator inhibitor (PAI)-1 levels may be a risk factor for CAD. Therefore, PAI-1 levels were measured in the three populations and related to the -675 PAI-1 4G/5G promoter genotype. PAI-1 levels and anthropometric variables were measured in 310 Indian, 269 White and 107 African subjects. The PAI-1 4G allele frequency was lower in the African (0.13) than Indian (0.54) or White (0.58) populations and explained the lower PAI-1 levels in African (41.5+/-25.1 versus 68.0+/-33.3 and 70.5+/-35.7 ng/ml, respectively; p<0.0001) subjects. Except for White subjects, PAI-1 levels were higher in those with metabolic syndrome or type 2 diabetes. PAI-1 genotype did not associate with either disorder. Metabolic syndrome-related factors had little influence on PAI-1 levels in White subjects but in African and Indians subjects these variables had a major influence on PAI-1 levels in those with the 5G/5G genotype but not in subjects with the 4G/4G genotype. Ethnic differences in PAI-1 levels are largely due to differences in the frequency of the 4G and 5G alleles at the -675 locus. In Indian and African, but not White populations, the ability of metabolic syndrome-related factors to influence PAI-1 levels is modulated by the -675 genotype.

The -844 G/A PAI-1 polymorphism is associated with mRNA expression in rheumatoid arthritis

We assessed whether the -844 G/A polymorphism and mRNA expression of plasminogen activator inhibitor 1 (PAI-1) gene are associated with rheumatoid arthritis (RA). Demographic data, hematological, biochemical parameters, disease activity-disability indexes, -844 G/A genotypes and mRNA expression levels of the PAI-1 gene were determined in 50 RA patients and 50 healthy subjects (HS). Non-significant differences in genotype and allele frequencies related to -844 G/A polymorphism in RA versus HS, were found. High mRNA expression of the PAI-1 gene, was demonstrated in RA versus HS (P < 0.05). In addition, A/A genotype carriers showed increase of PAI-1 mRNA expression (3.1-fold) respect to G/G and G/A genotypes in RA patients (P < 0.05). Our finding suggest an association of A/A -844 PAI-1 genotype with high PAI-1 mRNA expression in RA patients.

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

Mutations in the plasminogen activator inhibitor-1 (PAI-1) gene, along with altered PAI-1 and tissue-type plasminogen activator (tPA) levels, have been implicated in stroke pathogenesis. We investigated the association of PAI-1 and tPA levels with stroke as a function of PAI-1 4G/5G and -844G/A genotypes, as well as the link between these PAI-1 gene variants and stroke risk, in a case-control study of 135 ischemic stroke patient, diagnosed according to clinical and radiologic findings and confirmed by computed tomography scan. Controls (n = 118) were age- and sex-matched and had no personal/family history of stroke. PAI-1 4G/5G and -844G/A genotyping were done by polymerase chain reaction-restriction fragment length polymorphism, and PAI-1 and tPA levels were measured by enzyme immunoassay. Significant elevation in PAI-1 and marked reduction in tPA levels were seen in stroke patients and were correlated with 4G/5G, but not with -844G/A, PAI-1 variants. Whereas the frequencies of 4G or -844A alleles were comparable between patients and controls, 4G/4G carriers had reduced risk of stroke compared with other genotypes (odds ratio [OR] = 0.54; 95% confidence interval [CI] = 0.31-0.95). The 4G/-844A haplotype also was more closely associated with reduced stroke risk (OR = 0.43; 95% CI = 0.20-0.97) than 5G/-844A or 4G/-844G haplotypes. Regression analysis demonstrated that 4G homozygosity (OR = 0.176), hypertension (OR = 6.288), and body mass index (OR = 1.325) were independent predictors of stroke. The protective effect of 4G allele against stroke suggests involvement of PAI-1 4G/5G polymorphism in stroke through a mechanism not related to fibrinolysis, possibly involving altered plaque stabilization, and/or through antagonism of tPA effects.

Common polymorphisms of the PAI1 gene do not play a major role in the development of diabetic nephropathy in Type 1 diabetes

AIM

Plasminogen activator inhibitor 1 (PAI1) plays a key role in the regulation of extracellular matrix (ECM) degradation. ThePAI1 gene is therefore an excellent candidate gene for diabetic nephropathy. The aim of this study was to employ gene resequencing to identify common DNA polymorphisms in thePAI1gene, and subsequently assess haplotype tagged single nucleotide polymorphisms(htSNPs) using a case control design. METHODS All nine exons, exon-intron boundaries, introns 1, 4 and 7 and approximately 3 kb upstream and 5 kb downstream of thePAI1 gene were screened for DNA polymorphisms in 15 case and 15 control subjects using WAVE denaturing high-performance liquid chromatography technology and confirmed by DNA sequencing. Polymorphisms were genotyped in 86 healthy individuals using direct sequencing and haplotype tagged single nucleotide polymorphisms (htSNPs) identified. Genotyping of the htSNPs was performed in 583 Type 1 diabetic patients (222 with nephropathy, 361 without nephropathy)using Pyrosequencing.

RESULTS

Twenty-one polymorphisms with a minor allele frequency (MAF)>1%were identified; 14 had a MAF> or =10%. Five htSNPs [c.-1968_69insG, c.43 G-->A (Ala15Thr), c.1092-105 A-->G, c.*1737 G-->A, c.*3711 C-->T] were identified. Haplotype frequencies were similar in case and control groups (likelihood ratio chi2 test,P=0.66).

CONCLUSION

It is unlikely that common polymorphisms of thePAI1 gene strongly influence susceptibility to diabetic nephropathy in the White Type 1 diabetic population.

An association between the 4G polymorphism in the PAI-1 promoter and the development of aggressive fibromatosis (desmoid tumor) in familial adenomatous polyposis patients

Aggressive fibromatosis is a mesenchymal neoplasm associated with mutations resulting in beta-catenin mediated transcriptional activation. Plasminogen activator inhibitor-1 (PAI-1) is expressed at a high level in aggressive fibromatosis, and using transgenic mice, we found that PAI-1 plays an important role in aggressive fibromatosis tumor formation. Familial adenomatous polyposis is associated with Adenomatous Polyposis Coli gene mutations resulting in beta-catenin mediated transcriptional activation, yet only some patients develop aggressive fibromatosis. Since PAI-1 expression is influenced by a promoter 4G/5G polymorphism, we investigated the incidence of this polymorphism in familial adenomatous polyposis patients who did and who did not develop aggressive fibromatosis, as well as sporadic aggressive fibromatosis patients. There was a trend towards association of the 4G allele (associated with high PAI-1 expression) with the development of aggressive fibromatosis in familial adenomatous polyposis patients (50% vs. 19%, P = 0.1). In familial adenomatous polyposis patients who did not develop aggressive fibromatosis, there was a significantly lower proportion of patients with a 4G allele compared to the healthy control (19% vs. 51%, P = 0.0286). The lower incidence of 4G polymorphism in the PAI-1 promoter may be preventive against the development of aggressive fibromatosis. This data provides additional evidence supporting an important role for PAI-1 in the pathogenesis of aggressive fibromatosis.

Increase in plasma plasminogen activators inhibitor type 1 concentration after fibrinolytic treatment in patients with acute myocardial infarction is associated with 4G/5G polymorphism of PAI-1 gene

BACKGROUND

Preliminary data suggest that plasma concentration of plasminogen activators inhibitor type 1 (PAI-1) is genetically determined and may be related to differential regulation of plasma PAI-1 concentration at baseline and after stimulation.

AIM

This study aimed to evaluate whether increase in the plasma PAI-1 antigen concentration or activity after fibrinolytic therapy in patients with acute myocardial infarction is associated with the -675 4G/5G genetic polymorphism in the promoter region of PAI-1 gene.

RESULTS & CONCLUSIONS

Our study revealed that a rebound effect is observed in PAI-1 activity (ActPAI-1) and PAI-1 antigen (AgPAI-1) concentration after standard streptokinase treatment with maximal values of 3 h (t3) after the completion of streptokinase infusion. Both ActPAI-1 and AgPAI-1 were significantly higher at t3 compared to the levels before fibrinolytic treatment: 37.3 (20.0-67.7) vs. 10.0 (3.6-26.0) IU L(-1); P = 0.00001 and 29.9 (15.6-42.3) vs. 20.9 (13.0-30.2) ng mL(-1); P = 0.001, respectively. The stratification of the patients by genotype revealed that carriers of the 4G allele had higher concentrations of PAI-1 antigen 3 h after streptokinase infusion: 30.9 vs. 13.8 ng mL(-1); P = 0.019. No significant association between PAI-1 activity and genotype was found. In conclusion, the rebound effect in serum PAI-1 concentration observed after streptokinase treatment may be related to the 4G/5G polymorphism in the PAI-1 gene promoter.

Plasminogen Activator Inhibitor-1 Promoter Polymorphism is Not Associated With the Aggressiveness of Disease in Prostate Cancer

AIMS

PAI-1 (plasminogen activator inhibitors-1) regulates plasminogen activation, and is related to tumour development. This study aims to test whether the promoter polymorphism in the PAI-1 gene is related to the aggressiveness of disease in prostate cancer.

MATERIALS AND METHODS

In the present study, Taqman SNP genotyping assay was used to detect PAI-1 4G/5G polymorphism in DNA from paraffin-embedded tissues of 98 Caucasian patients with prostate cancer.

RESULTS

The distribution of the genotypes is in Hardy-Weinberg equilibrium. The genotype had no statistically significant relationship with other prognostic factors. Similar risks for recurrence were seen in individuals with the 4G/4G and 4G/5G genotypes compared to those with 5G/5G genotype (odds ratio [OR] 2.65, 95% CI: 0.41-16.94, P = 0.30; OR = 2.19, 95% CI: 0.38-12.49, P = 0.38).

CONCLUSION

We concluded that PAI-1 promoter polymorphism is not associated with the aggressiveness of disease in prostate cancer.

Plasminogen activator inhibitor-1 4G/5G polymorphism in breast cancer patients and its association with tissue PAI-1 levels and tumor severity

BACKGROUND

The plasminogen activator inhibitor type 1 (PAI-1) 4G/5G polymorphism may have significance for PAI-1 expression. High levels of PAI-1 in breast cancer patients are associated with a poor prognosis. In this study, we analyzed the influence of the PAI-1 4G/5G polymorphism on tissue PAI-1 levels and its association with tumor severity in women with breast cancer.

MATERIAL AND METHODS

We studied 104 women with breast carcinoma (patient group) and 104 healthy age-matched women (control group). In patients and controls, the PAI-1 4G/5G polymorphism was determined by PCR amplification using allele-specific primers. In patients, PAI-1 levels were quantified in breast cancer tissue by using an ELISA.

RESULTS

The frequency of the PAI-1 4G allele tended to be higher in patients than in controls (p=0.062). The presence of the 4G allele (4G/5G plus 4G/4G genotypes) was significantly higher among patients with histological grade 3 tumors than among those with grade 1 tumors (p=0.026). Furthermore, patients with the 4G/4G genotype had significantly higher tissue PAI-1 levels than those with the 5G/5G genotype. Moreover, tissue PAI-1 antigen levels were significantly and positively correlated with tumor severity (p=0.003) and tumor size (p=0.009). However, no significant differences in PAI-1 level were observed in relation to menopause, hormone receptor or nodal status.

CONCLUSION

Tissue PAI-1 antigen levels and tumor severity seem to be associated with the PAI-1 4G/5G polymorphism. Further studies with a larger number of patients are needed to clarify the influence of this polymorphism in breast cancer.

Increased PAI-1 plasma levels and risk of death from dengue: no association with the 4G/5G promoter polymorphism

Background

Dengue virus infected patients have high plasminogen activator inhibitor type I (PAI-1) plasma concentrations. Whether the insertion/deletion (4G/5G) polymorphism in the promotor region of the PAI-1 gene is associated with increased PAI-1 plasma concentrations and with death from dengue is unknown. We, therefore, investigated the relationship between the 4G/5G polymorphism and PAI-1 plasma concentrations in dengue patients and risk of death from dengue.

Methods

A total of 194 patients admitted to the Dr. Kariadi Hospital in Semarang, Indonesia, with clinical suspected severe dengue virus infection were enrolled. Blood samples were obtained on day of admission, days 1, 2 and 7 after admission and at a 1-month follow-up visit. Plasma concentrations of PAI-1 were measured using a sandwich ELISA kit. The PAI-1 4G/5G polymorphism was typed by allele-specific PCR analysis.

Results

Concentrations of PAI-1 on admission and peak values of PAI-1 during admission were higher than the values measured in healthy controls. Survival was significantly worse in patients with PAI-1 concentrations in the highest tertile (at admission: OR 4.7 [95% CI 0.9–23.8], peak value during admission: OR 6.3 [95%CI 1.3–30.8]). No association was found between the PAI-1 4G/5G polymorphism, and PAI-1 plasma concentrations, dengue disease severity and mortality from dengue.

Conclusion

These data suggest that the 4G/5G polymorphism has no significant influence on PAI-1 concentrations in dengue virus infected patients and is not associated with the risk of death from dengue. Other factors contributing to the variability of PAI-1 plasma concentrations in patients with dengue need to be explored.

Plasminogen-activator inhibitor-1 polymorphisms are associated with obesity and fat distribution in the Quebec Family Study: evidence of interactions with menopause

OBJECTIVE

Obesity is associated with increased plasma levels of plasminogen-activator inhibitor-1 (PAI1), the major fibrinolysis inhibitor. PAI1 levels are also increased at menopause, a condition that is associated with fat mass gain, especially in the abdominal area.

DESIGN

We hypothesized that genetic variations within PAI1 gene are related to the amount of body fat and its regional distribution. We genotyped 666 subjects of the Quebec Family Study for five PAI1 gene polymorphisms. Stratified analyses were performed with analysis of covariance in men (n = 280) and women (n = 386) separately.

RESULTS

PAI1-675 4G/5G polymorphism was strongly associated with body mass index (P < or = 0.01) and fat mass (P < or = 0.05) in women. The PAI1-675 4G/5G promoter polymorphism and the c.43G<A (p.A15T, rs6092) variant within the exon 1 were associated with abdominal visceral fat but only in postmenopausal women (P < or = 0.05). More specifically, homozygotes for the -675 5G and the 43A alleles had about 50% more visceral fat compared to carriers of the -675 4G allele as well as carriers of the 43G allele. No association was observed in men.

CONCLUSION

Taken together, these results suggest that the PAI1 gene is associated with obesity and may modulate the changes in adipose tissue distribution generally observed at menopause.

The plasminogen activator inhibitor-1 (PAI-1) promoter haplotype is related to PAI-1 plasma concentrations in lean individuals

BACKGROUND

Elevated plasminogen activator inhibitor-1 (PAI-1) concentrations are associated with cardiovascular diseases. PAI-1 antigen levels are influenced by environmental factors such as body mass index (BMI), and by genetic factors. The PAI-1 promoter of the PAI-1 gene contains two common polymorphisms (-844A/G and -675(4G/5G)) and the 4G allele of the -675(4G/5G) variation has been associated with elevated PAI-1 concentrations and on some occasions with an increased risk of cardiovascular disease.

OBJECTIVES

The aim of our study was to investigate the effect of the PAI-1 promoter haplotype on PAI-1 concentrations and to determine the role of BMI.

METHODS

The association between the PAI-1 promoter haplotype and PAI-1 antigen levels was investigated in two independent populations, each including 600 healthy Caucasians. Furthermore, to assess the effect of the PAI-1 promoter haplotype on PAI-1 promoter activity, in vitro reporter gene assays were performed in HepG2 and BAEC cells.

RESULTS

We observed significantly higher PAI-1 concentrations in A-4G homozygotes than in G-5G carriers in lean subjects (BMI in the lowest quartile). In these lean subjects, the PAI-1 concentrations in A-4G/G-5G heterozygotes were reduced to 60-75%, and the concentrations in G-5G homozygotes to 45-55%, compared to the PAI-1 concentrations of A-4G homozygotes (p < 0.01). PAI-1 concentrations increased approximately four-fold from the lowest to the highest BMI quartile (p < 0.01). The reporter gene assays did not support a direct effect of the PAI-1 promoter haplotype on promoter activity in HepG2 or BEAC cells.

CONCLUSIONS

Our study suggests that the PAI-1 promoter haplotype and BMI affect PAI-1 concentrations and that BMI is a stronger determinant than PAI-1 promoter variation.

Haplotype analysis of the preprotachykinin-1 (TAC1) gene in multiple sclerosis

The potential relevance of chromosome 7q21-22 in susceptibility to multiple sclerosis (MS) has been highlighted in genome-wide linkage screens as well as in association studies of 7q-specific polymorphic microsatellites. Especially, recent, independently performed studies have provided evidence for significant association of the markers D7S554 and D7S3126 with MS in Sardinian, Northern Irish and Spanish-American cohorts. The gene most closely located to these markers is the neuropeptide preprotachykinin-1 (TAC1) gene. Both its position and the array of biological functions exerted by its expression products make it a logical primary choice for further scrutiny as the putative chromosome 7q21-22 MS susceptibility gene. We report identification of eight polymorphisms in this gene by means of a sequencing approach. A Northern Irish case-control was typed for six of these polymorphisms. One of these, an intron 1 single-nucleotide polymorphism (SNP), showed significant association with MS (P=0.009). Two-marker haplotypes composed of allelic combinations of TAC1 promoter-intron 1 SNPs were highly significantly associated with MS and more so with the relapsing-remitting form of this disease. While independent reproduction of these data in other data sets is indicated, our work is suggestive for a role of the TAC1 gene in MS. Genes and Immunity (2005) 6, 265-270. doi:10.1038/sj.gene.6364175 Published online 24 February 2005.

Age-related increase of pulse pressure and plasminogen activator inhibitor-1 I/D gene polymorphism in essential hypertension

BACKGROUND

Pulse pressure (PP), a marker of cyclic strain on the arterial wall, is a significant predictor of cardiovascular (CV) risk, particularly regarding the incidence of coronary arterial stenosis. Genes related to haemostatic and/or fibrinolytic factors are consistently influenced in vitro by mechanical strain.

OBJECTIVE

The goal of the present study was to determine, in the three genotypes of the plasminogen activator inhibitor (PAI)-1 gene polymorphism, the gender-adjusted difference in the relationships between age and PP in subjects with never treated essential hypertension.

RESULTS

In the studied population, the genotype deletion (D)/D at position -675 of the PAI-1 insertion (I)/D gene polymorphism was associated with a significant increase in the adjusted slope of the curve relating age to PP by comparison with the two other genotypes. No comparable difference in age-related changes in systolic, diastolic or mean blood pressure was found.

CONCLUSION

In subjects with essential hypertension, the PAI-1 I/D gene polymorphism modulates the age-mediated increase of PP, suggesting new insights on the complex interactions between genes, mechanical factors and CV risk.

Pleiotropic functions of plasminogen activator inhibitor-1

Plasminogen activator inhibitor-1 (PAI-1), a 45-kDa serine proteinase inhibitor with reactive site peptide bond Arg345-Met346, is the main physiological plasminogen activator inhibitor. It occurs in human plasma at an antigen concentration of about 20 ng mL(-1). Besides the active inhibitory form of PAI-1 that spontaneously converts to a latent form, also a substrate form exists that is cleaved at the P1-P1' site by its target enzymes, but does not form stable complexes. Besides its role in regulating hemostasis, PAI-1 plays a role in several biological processes dependent on plasminogen activator or plasmin activity. Studies with transgenic mice have revealed a functional role for PAI-1 in wound healing, atherosclerosis, metabolic disturbances such as obesity and insulin resistance, tumor angiogenesis, chronic stress, bone remodeling, asthma, rheumatoid arthritis, fibrosis, glomerulonephritis and sepsis. It is not always clear if these functions depend on the antiproteolytic activity of PAI-1, on its binding to vitronectin or on its intereference with cellular migration or matrix binding.

The PAI-1 gene 4G/5G polymorphism and deep vein thrombosis in patients with inherited thrombophilia

Genetic and acquired factors may influence phenotypic expression of inherited thrombophilia. Hypofibrinolysis due to excess PAI-1 can be found in patients with deep vein thrombosis (DVT) and 4G/5G polymorphism of the PAI-1 gene may modulate the inhibitor's synthesis. In 149 patients with inherited thrombophilia, the possible thrombotic contribution of both 4G/5G polymorphism and PAI-1 plasma levels was evaluated. Sixty-seven patients with idiopathic DVT and 98 normal subjects were also studied. By comparison with controls, a significantly higher prevalence of 4G/4G genotype was seen in idiopathic DVT and in thrombophilia patients, although in this latter group the difference only remained significant in cases symptomatic for thrombosis (p = 0.01). The 4G/4G genotype was associated with a greater risk of thrombosis both in symptomatic thrombophilia patients (OR 2.85, 95% CI 1.26-6.46) and in idiopathic DVT patients (OR 3.1, 95% CI 1.26-7.59). The greater frequency of 4G allele in symptomatic thrombophilia patients with respect to controls was statistically significant (p = 0.04). Compared to healthy subjects, PAI-1:Ag levels were higher in symptomatic thrombophilia patients and related to the 4G/5G polymorphism, with significantly higher values in the 4G/4G carriers. In conclusion, PAI-1 4G/5G polymorphism may influence PAI-1 expression and thrombotic risk in patients with inherited thrombophilia.

Association of plasminogen activator inhibitor-1 4G/5G gene polymorphism with variations in the LDL particle size in healthy Japanese men

BACKGROUND

Several studies have supported the association between a predominance of small, dense low-density lipoprotein (LDL) and the risk of coronary artery disease. As another potentially atherogenic factor, impaired fibrinolytic activity due to increased plasminogen activator inhibitor-1 (PAI-1) concentrations has been shown. In addition, the 4G allele of the 4G/5G polymorphism in the promoter region of the PAI-1 gene is reported to be associated with the atherogenic lipid profile. We investigated the relation between the PAI-1 gene polymorphism and LDL particle size.

METHODS

A total of 156 healthy Japanese male subjects were recruited. The diameter of LDL particles was determined at their peak size using polyacrylamide gels using fresh plasma samples.

RESULTS

Fasting insulin and triglyceride concentrations were found to be significantly higher, and the LDL particle size was smaller in the homozygotes for the 5G allele than in the carriers of the 4G allele. An analysis of covariance (ANCOVA) adjusting for insulin and triglyceride concentrations showed a consistently significant difference in LDL particle size between the two groups. In the forward stepwise multiple regression analysis, triglycerides, insulin, and the PAI-1 5G/5G genotype remained in the model as independent and significant predictors capable of influencing the LDL particle size.

CONCLUSIONS

Our findings suggest that the 4G/5G polymorphism of the PAI-1 gene might be associated with LDL particle size in healthy Japanese males.

Genotype and allele frequency of PAI-1 promoter polymorphism in healthy subjects from the west of Mexico. Association with biochemical and hematological parameters

We investigated the genotype and allelic frequency of the -675 bp insertion/deletion polymorphism at the PAI-1 gene promoter, in healthy Mexican subjects. It was compared to the lipid profile and hematological parameters, and to other healthy worldwide populations. A Mexican population sample of 110 individuals was studied. Demographic data and clinical characteristics of the subjects were registered. Fasting lipid profile, serum glucose, fibrinogen, hematological parameters and leukocyte genomic DNA isolation from peripheral blood were performed in all the participants. Screening of the PAI-1 genotype was done by PCR and restriction analysis. Genotype 4G/4G, 4G/5G, 5G/5G frequency in Mexican healthy subjects was: 14.55%, 39.09%, 46.36%, respectively, whereas the allelic frequency for 5G allele was 65.9%. A significant lesser frequency for 4G allele and related genotypes (4G/4G and 4G/5G) was established in healthy subjects from Mexico, respect to all the compared populations. A particular genotype and allelic frequency of this PAI-1 polymorphism was established in Mexico. The clinical parameters were not associated according to each genotype of PAI-1.

Positive impact of hormone replacement therapy on the fibrinolytic system: a long-term randomized controlled study in healthy postmenopausal women

BACKGROUND

The mechanisms by which postmenopausal hormone replacement therapy (HRT) may influence risk of cardiovascular disease are still unclear. Impaired fibrinolytic function is associated with an enhanced risk of cardiovascular disease and therefore the effect of HRT on fibrinolysis may be of importance.

OBJECTIVES

To investigate the prolonged effect of HRT on the fibrinolytic system and to determine whether two common polymorphisms in the plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA) genes modulate this effect.

METHODS

Healthy postmenopausal women (n = 248) were randomized to HRT (n = 122) or no substitution (n = 126) 5 years prior to investigation.

RESULTS

Significantly higher values of t-PA activity and lower values of PAI-1 activity and PAI-1 antigen were found in the HRT group compared with the control group. This effect was independent of smoking and without influence from the two common polymorphisms PAI-1 -675(4G/5G) and t-PA intron8ins311. Furthermore, no difference between opposed estrogen (with norethisterone acetate as the gestagen component) and unopposed estrogen therapy was found. Both an intention-to-treat and a per-protocol analysis were performed and similar results were obtained.

CONCLUSIONS

Long-term treatment with HRT in healthy postmenopausal women was found to be associated with a beneficial fibrinolytic profile. This effect was found independent of smoking status, opposed and unopposed estrogen therapy had equal effect, and no influence of the two common polymorphisms PAI-1-675(4G/5G) and t-PA intron8ins311 was found. This effect of HRT on fibrinolytic capacity may be one of the beneficial effects of HRT in relation to cardiovascular diseases.

Inherited Thrombophilia: Impact on Human Reproduction

The development of thrombotic disorders is a major threat for young women during pregnancy. It is one of the main causes of pregnancy-related disorders, which may also result in harm for the conceptus. Successful pregnancies require an even balance of coagulation and fibrinolysis, in order to secure stabilization of the basal plate as well as adequate placental perfusion. Thrombophilia is a laboratory definition for pre-disposing factors of thrombosis, which can be inherited or acquired. Many individuals, who carry a thrombotic defect remain asymptomatic, at least until additional boosting factors arise. The documentation of thrombophilic causes of recurrent miscarriage or pregnancy-related disorders is important, because of availability of effective early treatment. There is a rapidly growing awareness on the relationship of genetic factors influencing hemostasis and pregnancy-related disorders. The aim of our review is to summarize this knowledge, focusing on common genetic variations.

Plasminogen activator inhibitor type 1 (PAI1) and platelet glycoprotein IIIa (PGIIIa) polymorphisms in Black South Africans with pre-eclampsia

BACKGROUND

Association of fibrin abnormalities with pre-eclampsia prompted this study to examine whether polymorphisms in the plasminogen activator inhibitor Type 1 and platelet glycoprotein IIIa genes constitute risk factors for this condition.

METHODS

A group of 151 Black Zulu-speaking pre-eclamptics was examined for 4G/5G plasminogen activator inhibitor Type 1 and PlA1/A2 platelet glycoprotein IIIa polymorphic alleles using standard techniques. Results were compared with those found in 217 ethnically matched healthy normotensive pregnant women who had normal full-term gestations.

RESULTS

Pre-eclamptic patients had a slightly higher frequency of the 4G plasminogen activator inhibitor Type 1 allele (15%) compared with the controls (12%); this was reflected also in the heterozygote frequency (28% and 22%) for the patients and the controls, respectively. These differences were not significant. Only 2% of this population was found to be homozygous for the 4G allele. No differences were observed in the platelet glycoprotein IIIa polymorphism genotype and allele frequency distribution between the patients and the controls.

CONCLUSIONS

Neither the 4G allele of the plasminogen activator inhibitor Type 1 nor the PlA2 allele of the platelet glycoprotein IIIa have any significant role as risk factors in the patho-etiology of pre-eclampsia in Black South Africans, although these genes cannot yet be excluded as contributory to this disorder. It is possible that the underlying causes of pre-eclampsia may vary between different ethnic populations.

Identification of polymorphisms in the promoter and the 3' region of the TAFI gene: evidence that plasma TAFI antigen levels are strongly genetically controlled

Thrombin-activable fibrinolysis inhibitor (TAFI) is a recently described carboxypeptidase that is potentially involved in the regulation of fibrinolysis by decreasing plasminogen binding to the fibrin surface. This role makes the TAFI gene a good candidate in atherothrombotic diseases. The great interindividual variability of plasma TAFI antigen levels is poorly explained by lifestyle characteristics, thus suggesting its genetic determination. To test this hypothesis, the promoter and the 3'-untranslated region of the TAFI gene were screened for polymorphisms, and their contribution to the variability of plasma TAFI antigen levels was evaluated. Seven new polymorphisms are described, 5 in the promoter (C-2599G, -2345 2G/1G, A-1690G, G-1102T, and G-438A) and 2 in the 3'UTR (C+1542G and T+1583A). All these polymorphisms were in strong linkage disequilibrium with each other and with the previously described Ala147Thr polymorphism. They generated 4 main haplotypes, accounting for 80% of all observed haplotypes. In univariate analyses, all polymorphisms were associated with plasma TAFI Ag levels and, individually, contributed to a large fraction of plasma TAFI Ag levels, ranging from 20% to 52%. In a stepwise regression analysis including all polymorphisms, several combinations remained significantly and independently associated with plasma TAFI Ag levels: C+1542G associated with Ala147Thr, T+1583A, or -2345 2G/1G explaining 61.6%, 60.2%, and 58.1% of the variance, respectively. These findings clearly demonstrate that circulating levels of TAFI are strongly determined by polymorphic variations in the promoter and the 3'UTR of the TAFI gene. (Blood. 2001;97:2053-2058)