The 4G/4G PAI-1 genotype is associated with elevated plasma PAI-1 levels regardless of variables of the metabolic syndrome and smoking status. A population-based study in Spanish population

Plasminogen activator inhibitor-1 activity and the 4G/5G polymorphism are prospectively associated with blood pressure and hypertension status

OBJECTIVES

Plasminogen activator inhibitor-1 (PAI-1) has consistently shown positive associations with blood pressure (BP). Whether elevations in PAI-1 levels precede or result from raised BP is still under debate and data on prospective studies are limited. Hence, we investigated the prospective associations of PAI-1 and the 4G/5G polymorphism with brachial and central BP and pulse pressure (PP) over a 10-year period.

METHODS

Black South Africans aged 30 years and older were included. Baseline data collection commenced in 2005 (n = 2010) with follow-up data collection in 2010 (n = 1288) and 2015 (n = 926). Plasma PAI-1 activity (PAI-1act), 4G/5G polymorphism genotyping, waist circumference and BP measurements were performed and analysed using sequential regression and mixed models.

RESULTS

In multivariable adjusted analyses, PAI-1act and the 4G/4G (vs. the 5G/5G) genotype increased the odds of developing hypertension in the total group [1.04 (1.01; 1.08) and 1.82 (1.07; 3.12) respectively]. Furthermore, PAI-1act was prospectively associated with brachial SBP (r = 0.0815) and PP (r = 0.0832) in the total group, and with central PP in women (r = 0.1125; all P < 0.05). Addition of waist circumference to the models either decreased or nullified the contribution of PAI-1act to BP and hypertension development.

CONCLUSION

PAI-1act and the 4G/4G (vs. the 5G/5G) genotype increased the odds of developing hypertension. Furthermore, PAI-1act associated prospectively with both brachial and central BP. These associations were mediated in part by central adiposity. The study supports the hypothesis that PAI-1 also contributes to hypertension development rather than solely being a consequence thereof.

Plasminogen activator inhibitor-1 gene polymorphism as a risk factor for vascular complications in type 2 diabetes mellitus

Background

Diabetes mellitus (DM) can lead to microvascular and macrovascular damages through hyperglycemia that is the main cause of diabetic complications. Other factors such as hypertension, obesity, and hyperlipidemia may worsen or accelerate the others. Several studies have revealed definitive genetic predispositions to the development of type 2 diabetes mellitus (T2DM) and development of vascular complications. This study aimed to address the association between plasminogen activator inhibitor-1 (PAI-1) gene polymorphism and T2DM, and if this gene polymorphism may have a possible role in the development of vascular complications in T2DM. This study is a case control; it included 200 patients with T2DM, 117 patients had no vascular complications, and 83 had previous vascular complications (VCs). One hundred eighty volunteer blood donors were selected as a healthy control group. All patients and controls were subjected to clinical examination, and laboratory investigations included lipid profile, fasting and 2 h blood glucose, complete blood cell count, d-dimer, PAI-1, thrombin activatable fibrinolysis inhibitor (TAFI), and detection of PAI-1 gene polymorphism by real-time polymerase chain reaction (PCR).

Results

The most prevalent genotype of PAI-1 gene polymorphism in all studied groups, including controls, was 4G/5G with the highest allele frequency as 4G. The 4G/5G and 4G/4G genotypes were associated with increased risk of DM development as compared to 5G/5G genotype. The 4G/5G and 4G/4G genotypes also had a highly significant increased risk of VCs among diabetic patients, as compared to 5G/5G. The 4G allele also was highly associated with DM with VCs. The d-dimer TAFI, PAI-1 showed the highest levels in 4G/5G genotype followed by 4G/4G genotype. The lowest level was expressed in 5G/5G genotype in diabetic patients with and without VCs. The univariable analysis showed that genotypes 4G/5G and 4G/4G were potentially risk factors for development of VCs with T2DM patients.

Conclusion

This study concludes that the PAI-1 4G/5G polymorphism may be associated with T2DM and may be considered as a risk factor for development of thrombotic events. It may also help in selection and dosing of patients being treated with anticoagulant and fibrinolytic agents. Further large-scale studies are recommended to assess the possible role of environmental factors and gene interactions in the development of T2DM vascular risks.

The Intrinsically Disordered Loop in the USF1 bHLHZ Domain Modulates Its DNA-Binding Sequence Specificity in Hereditary Asthma

USF1, a basic region/helix-loop-helix/leucine zipper (bHLHZ) transcription factor, binds to the E-box in the PAI-1 (plasminogen activator inhibitor) promoter. Two alleles containing the E-box control PAI-1 transcription; these alleles are termed "4G" and "5G" based on the G tract flanking E-box. USF1-governed transcription of PAI-1 is elevated in heritable asthma sufferers: the 4G/4G genotype has the highest plasma levels of PAI-1. While USF1 uses its basic region to bind E-box, we found that it uses its 12 amino-acid loop to recognize the flanking sequence and discern the single-nucleotide difference between the alleles. We used the bacterial one-hybrid and electrophoretic mobility shift assays to assess protein-DNA recognition, and circular dichroism to examine protein secondary structure. We mutated Ser233 and Thr234 in the USF1 bHLHZ loop to Ala to generate S233A and T234A. Interestingly, USF1 bHLHZ, S233A, and T234A prefer the 5G sequence (USF1 bHLHZ K_d values 4.1 ± 0.3 nM and 7.0 ± 0.4 nM for 5G and 4G, respectively), whereas studies in stimulated human mast cells showed a preference for 4G. We replaced the 8 amino-acid loop of transcription factor Max bHLHZ with the 12 amino-acid USF1 loop: this mutant now distinguishes the 4G/5G polymorphism-while Max bHLHZ does not-confirming that USF1 differentiation of the 4G/5G is driven by the loop.

Hypofibrinolytic State in Subjects with Type 2 Diabetes Mellitus Aggravated by the Metabolic Syndrome before Clinical Manifestations of Atherothrombotic Disease

Background. Metabolic and genetic factors induce plasminogen activator inhibitor type-1 (PAI-1) overexpression; higher PAI-1 levels decrease fibrinolysis and promote atherothrombosis. Aim. To assess PAI-1 antigen levels among subjects with type 2 diabetes mellitus (T2DM) plus Metabolic Syndrome (MetS) before clinical manifestations of atherothrombosis and the contribution of metabolic factors and 4G/5G polymorphism of PAI-1 gene on the variability of PAI-1. Methods. We conducted an observational, cross-sectional assay in a hospital in Mexico City from May 2010 to September 2011. MetS was defined by the International Diabetes Federation criteria. PAI-1 levels and 4G/5G polymorphism were determined by ELISA and PCR-RFLP analysis. Results. We enrolled 215 subjects with T2DM plus MetS and 307 controls. Subjects with T2DM plus MetS had higher PAI-1 levels than the reference group (58.4 ± 21 versus 49.9 ± 16 ng/mL, p = 0.026). A model with components of MetS explained only 12% of variability on PAI-1 levels (R² = 0.12; p = 0.001), with β = 0.18 (p = 0.03) for hypertension, β = -0.16 (p = 0.05) for NL HDL-c, and β = 0.15 (p = 0.05) for NL triglycerides. Conclusion. Subjects with T2DM plus MetS have elevated PAI-1 levels before clinical manifestations of atherothrombotic disease. Metabolic factors have a more important contribution than 4G/5G polymorphism on PAI-1 plasma variability.

Prevalence of thrombophilic gene polymorphisms in an azari population of iran

There is several evidence suggests that thrombophilic gene polymorphisms may influence susceptibility to thromboembolic events. The prevalence of these polymorphisms is different in various races and ethnics. Accordingly, we studied the prevalence of Factor V (G1691A and A4070G), prothrombin G20210A and PAI-1 4G/5G in healthy northwest population of Iran. In this prospective study, 500 healthy individuals, who had no history of both personal and family history of thromboembolic disorders, were selected as a sample of healthy population in northwestern Iran. Genotyping of these polymorphisms was performed using the amplification refractory mutation system-polymerase chain reaction method. No significant differences were detected between the expected and observed frequencies of FV G1691A and A4070G, prothrombin G20210A polymorphisms (P>0.05), while the expected frequency of 4G allele was significantly more than observed frequency in the studied population (P<0.01). These findings were compared with other reports from various populations. In conclusion, the allele frequency for FV G1691A and PAI-1 4G/5G polymorphisms showed relative consistency compared to those of previous studies, while the incidence pattern of FV A4070G polymorphism in Northwestern population of Iran showed conflicting results regarding other studied population. The prothrombin G20210A polymorphism was observed at a higher frequency than other studied populations.

Genetic polymorphisms associated with retinal vein occlusion: a Greek case-control study and meta-analysis

BACKGROUND

The genetic background of retinal vein occlusion (RVO) remains unclear. In the current study, we aimed to replicate polymorphisms related to thrombophilia/hypofibrinolysis in a Greek population and also systematically summarize current evidence available on the topic.

MATERIALS AND METHODS

A total of 48 RVO patients and 53 controls were genotyped for factor V H1299R and V Leiden, β-fibrinogen G455A, PAI-1 4G/5G, ACE I/D, HPA1, prothrombin G20210A, factor XIII Val34Leu, MTHFR A1298C and C677T polymorphisms. We examined the association between RVO and the above polymorphisms under a per-allele genetic model in a Greek unrelated case/control population. Additionally, searching PubMed up to January 2012, we identified existing evidence on these polymorphisms and performed meta-analyses.

RESULTS

A total of three polymorphisms had nominally significant associations with RVO. These associations pertained to ACE D allele (odds ratio, OR, 2.08 [95% CI, 1.12-3.85], p = 0.02); factor XIII 34Leu allele (OR = 0.41 [95% CI, 0.18-0.95], p = 0.037] and MTHFR 677T variant (OR = 2.20 [95% CI 1.10-4.40], p = 0.026). We performed a meta-analysis on the associations between RVO and PAI-1 (n = 5), factor V Leiden (n = 21), MTHFR C677T (n = 19) and prothrombin G20210A (n = 21). We observed nominally significant associations only for PAI-1 (OR = 1.27 [95% CI, 1.02-1.60, p = 0.036]) (I(2) = 44.7%), and factor V Leiden (OR = 1.40 [95% CI, 1.07-1.84, p = 0.015]) (I(2) = 3.6%) using random effects model.

CONCLUSIONS

Our results suggest that there may be an association between increased risk for RVO and ACE I/D, MTHFR C677T, PAI-1 4G/5G and factor V Leiden polymorphisms, whereas the Val34Leu variant may exert a protective effect.

Failure to lyse venous thrombi because of elevated plasminogen activator Inhibitor 1 (PAI-1) and 4G polymorphism of its promotor genome (The PAI-1/4G Syndrome)

Plasminogen activator Inhibitor 1 (PAI-1) inhibits plasminogen activators leading to decreased fibrinolysis and increased risk of thromboembolic disease (TED). Shifts in PAI-1 promoter genome from normal 5G>5G to 4G>5G or 4G>4G alleles are associated with overexpression of PAI-1. In this study patients with residual venous thrombi were observed to have increased PAI-1 levels and more frequent shifts to 4G alleles. Of the 26, 20 (76.9%) patients with unresolved thrombus had elevated PAI-1 values. 4G genomic shifts were found in 92.9% patients studied. Normal PAI-1 levels were found in 5 patients with 4G polymorphisms. Thus, PAI-1 is often elevated among patients with residual thrombus, with an unexpectedly high prevalence of the 4G polymorphism of the promoter genome. Patients with persistent thrombus should be considered at risk of having constituently increased PAI-1 due to genomic changes in the PAI-1 promoter genome. Hypotheses are proposed to explain those with normal PAI-1, despite having 4G polymorphisms.

Apolipoprotein E and paraoxonase 1 polymorphisms are associated with lower serum thyroid hormones in postmenopausal women

OBJECTIVE

Autoimmune thyroiditis and overt or subclinical hypothyroidism have been associated with increased prevalence of cardiovascular disease (CVD).

DESIGN

Cross-sectional investigation of the association between gene polymorphisms related to CVD with thyroid function and autoimmunity.

PATIENTS

In total 84 healthy postmenopausal women aged 49-69 years.

MEASUREMENTS

FT3, FT4, anti-TPO and anti-TG were assessed in the sera of participants. The following polymorphisms were assessed from peripheral lymphocyte DNA: Apolipoprotein E E2/E3/E4, paraoxonase 1 A/B, Glycoprotein IIIa leu33pro, MTHFR ala222val, ApoBarg3500gln, plasminogen activator inhibitor 1 4G/5G, cholesterol 7-alpha hydroxylase A204C and cholesterol ester transfer protein B1/B2.

RESULTS

A statistically significant correlation was found between Apolipoprotein E and paraoxonase 1 polymorphisms and serum thyroid hormones: carriers of the E2 or E4 allele of the ApoE gene had lower levels of FT4 (P = 0.0005) than women with the E3/E3 genotype. Carriers of the B allele of paraoxonase 1 gene had lower levels of FT3 compared to women with the wild-type genotype (P = 0.047). A statistically significant positive association (P = 0.049) was also observed between anti-TG antibodies and the presence of the E2 allele of the Apolipoprotein E gene.

CONCLUSIONS

Polymorphisms of apolipoprotein E and paraoxonase 1 are associated with different levels of thyroid hormone and anti-Tg antibody levels in the study population in this pilot study. The mechanism underlying this association remains to be elucidated.

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

INTRODUCTION AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Hemostatic gene polymorphisms in severe acute pancreatitis

OBJECTIVE

Systemic inflammatory reaction in acute pancreatitis (AP) is associated with activation of the coagulation system. The prothrombotic component of the coagulation system, which may promote microvascular thrombosis and vital organ injury, is strengthened by genetic factors such as polymorphism of plasminogen activator inhibitor type 1 (PAI-1) and factor V Leiden (FVL) mutation. This prompted us to study the occurrence of FVL and PAI-1 4G/5G polymorphisms in patients with AP.

METHODS

This case control association study included 397 patients with AP and 310 controls. Severe AP was determined according to the Atlanta Classification. Genotyping was performed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry-assisted genotyping method.

RESULTS

Factor V Leiden was identified in 5 (3.3%) of 152 cases of severe AP and in 8 (3.3%) of 245 cases of mild AP. The prothrombotic PAI-1 4G allele frequency was 0.49 for patients with severe AP and 0.57 for patients with mild AP (P < 0.05). Patients with septic infectious complications (n = 47) and patients with organ failure (n = 55) had genotype distribution not different from those with mild, uncomplicated disease (n = 245).

CONCLUSIONS

The results do not support the hypothesis that prothrombotic polymorphisms such as FVL mutation and PAI-1 4G/5G are associated with AP severity.

Binding of upstream stimulatory factor 1 to the E-box regulates the 4G/5G polymorphism-dependent plasminogen activator inhibitor 1 expression in mast cells

BACKGROUND

Plasminogen activator inhibitor (PAI)-1 is a key regulator of the fibrinolytic system. PAI-1 levels are markedly elevated in the asthmatic airways. The 4G/5G polymorphism of the PAI-1 gene is associated with allergic asthma.

OBJECTIVE

To characterize the mechanisms of the 4G/5G-dependent PAI-1 expression in mast cells (MCs), a major source of PAI-1 and key effector cells in asthma.

METHODS

Transcription of PAI-1 was assessed by transiently transfecting human MC line (HMC-1) cells with the luciferase-tagged PAI-1 promoters containing the 4G or 5G allele (4G-PAI-1 or 5G-PAI-1 promoter). Upstream stimulatory factor (USF)-1 and the E-box interactions were studied by electrophoretic mobility shift assays and supershift assays. Expression of USF-1 was determined by Western blot analysis.

RESULTS

The 4G-PAI-1 promoter has higher promoter activity than the 5G-PAI-1 promoter in stimulated HMC-1 cells, and the E-box adjacent to the 4G/5G site (E-4G/5G) regulates the genotype-specific PAI-1 transcription. USF-1 binds to the E-4G with greater affinity than to the E-5G. USF-1 level is increased in HMC-1 cells after stimulation, and elevated USF-1 enhances PAI-1 transcription. Overexpression of wild-type USF-1 or dominant-negative USF remedies the 4G/5G-dependent PAI-1 transcription.

CONCLUSION

Binding of USF-1 to the E-4G/5G regulates the 4G/5G polymorphism-dependent PAI-1 expression in MCs.

Plasminogen activator inhibitor 1 expression in platelets is not influenced by the 4G/5G promoter polymorphism

In the present study we investigated the influence of the 4G/5G promoter polymorphism of the PAI-1 gene on the levels of PAI-1 mRNA and protein in platelets. After a screening of healthy male subjects, thirty-eight subjects homozygote for either the 4G or 5G allele were investigated. mRNA levels were quantified by real-time PCR and PAI-1 antigen in platelets and plasma was analysed by ELISA. The platelet PAI-1 mRNA levels correlated significantly with the PAI-1 antigen content, but there was no association between the polymorphism and mRNA levels, or protein levels in platelets. Also, plasma levels of PAI-1 antigen were not associated with homozygosity of the 4G/5G polymorphism, but as expected BMI and triglycerides emerged as significant predictors of plasma PAI-1 levels. The importance of the 4G/5G polymorphism on PAI-1 levels is controversial and the present study shows that although levels of platelet mRNA are related to its content of PAI-1 protein, there is no association between the 4G/5G promoter polymorphism and platelet PAI-1 mRNA or protein expression.

Is the plasminogen activator inhibitor-1 gene a candidate gene predisposing to hypertension? Results from a population-based study in Spain

BACKGROUND

Studies in humans and mice suggest that plasminogen activator inhibitor-1 (PAI-1) might be a candidate gene for arterial hypertension. Our aims were to analyse whether the functional 4G/5G PAI-1 polymorphism represents a risk marker for the development of arterial hypertension regardless of hypertension-related metabolic variables.

METHODS

Eight hundred and fifteen unrelated individuals (387 men, age 35-74 years) from a cross-sectional, population-based, epidemiological survey in the province of Segovia (Spain) were studied. Anthropometric/biochemical parameters--body mass index, waist circumference, diastolic and systolic blood pressures, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, fasting glucose, insulin, C-reactive protein, and PAI-1 levels--were analysed. The 4G/5G PAI-1 genotypes were established by restriction fragment length polymorphism. Insulin resistance was estimated by the homeostasis model assessment. Tobacco consumption data were obtained using a standard questionnaire.

RESULTS

The 4G/4G PAI-1 genotype was significantly associated with a high prevalence of arterial hypertension. This association remained statistically significant even after adjustment for hypertension-related metabolic variables in our population (adjusted odds ratio, 1.858; 95% confidence interval, 1.135-3.018; P = 0.013).

CONCLUSION

Our results show that the 4G/4G PAI-1 genotype appears to be associated with an elevated relative risk of developing arterial hypertension, regardless of PAI-1 levels and other hypertension-related factors, in a representative sample of the Spanish population.