Association of PAI-1 gene promoter 4g/5g polymorphism with plasma PAI-1 activity in Chinese patients with and without hypertension

Compromised Cortical-Hippocampal Network Function From Transient Hypertension: Linking Mid-Life Hypertension to Late Life Dementia Risk

Mid-life hypertension is a major risk factor for developing dementia later in life. While anti-hypertensive drugs restore normotension, dementia risk remains above baseline suggesting that brain damage sustained during transient hypertension is irreversible. The current study characterized a rat model of transient hypertension with an extended period of normotensive recovery: F344 rats were treated with L-NG-Nitroarginine methyl ester (L-NAME) for 1 month to induce hypertension then allowed up to 4 months of recovery. With respect to cognitive deficits, comparison between 1 month and 4 months of recovery identified initial deficits in spatial memory that resolved by 4 months post-hypertension; contrastingly, loss of cognitive flexibility did not. The specific cells and brain regions underlying these cognitive deficits were investigated. Irreversible structural damage to the brain was observed in both the prefrontal cortex and the hippocampus, with decreased blood vessel density, myelin and neuronal loss. We then measured theta-gamma phase amplitude coupling as a readout for network function, a potential link between the observed cognitive and pathological deficits. Four months after hypertension, we detected decreased theta-gamma phase amplitude coupling within each brain region and a concurrent increase in baseline connectivity between the two regions reflecting an attempt to maintain function that may account for the improvement in spatial memory. Our results demonstrate that connectivity between prefrontal cortex and hippocampus is a vulnerable network affected by transient hypertension which is not rescued over time; thus demonstrating for the first time a mechanistic link between the long-term effects of transient hypertension and dementia risk.

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.

PAI-1 5G/5G genotype is an independent risk of intracranial hemorrhage in post-lysis stroke patients

Objective

Thrombolysis by recombinant tissue plasminogen activator (rt‐PA) is the main pharmacological therapy in acute ischemic stroke (IS); however, it is only effective in a subset of patients. Here we aimed to investigate the role of plasminogen activator inhibitor‐1 (PAI‐1), an effective inhibitor of t‐PA, and its major polymorphism (PAI‐1 4G/5G) in therapy outcome.

Methods

Study population included 131 consecutive IS patients who all underwent thrombolysis. Blood samples were taken on admission, 1 and 24 h after rt‐PA infusion. PAI‐1 activity and antigen levels were measured from all blood samples and the PAI‐1 4G/5G polymorphism was determined. Clinical data including NIHSS were registered on admission and day 1. ASPECTS was assessed using CT images taken before and 24 h after thrombolysis. Intracranial hemorrhage (ICH) was classified according to ECASS II. Long‐term outcome was defined 90 days post‐event by the modified Rankin Scale (mRS).

Results

PAI‐1 activity levels dropped transiently after thrombolysis, while PAI‐1 antigen levels remained unchanged. PAI‐1 4G/5G polymorphism had no effect on PAI‐1 levels and did not influence stroke severity. PAI‐1 activity/antigen levels as measured on admission were significantly elevated in patients with worse 24 h ASPECTS (<7). Logistic regression analysis including age, sex, NIHSS on admission, BMI, history of arterial hypertension, and hyperlipidemia conferred a significant, independent risk for developing ICH in the presence of 5G/5G genotype (OR:4.75, 95%CI:1.18–19.06). PAI‐1 levels and PAI‐1 4G/5G polymorphism had no influence on long‐term outcomes.

Interpretation

PAI‐1 5G/5G genotype is associated with a significant risk for developing ICH in post‐lysis stroke patients.

Combinatorial Treatment Using Umbilical Cord Perivascular Cells and Aβ Clearance Rescues Vascular Function Following Transient Hypertension in a Rat Model of Alzheimer Disease

Supplemental Digital Content is available in the text.

Transient hypertension is a risk factor for Alzheimer disease (AD), but the effects of this interaction on brain vasculature are understudied. Addressing vascular pathology is a promising avenue to potentiate the efficacy of treatments for AD. We used arterial spin labeling magnetic resonance imaging to longitudinally assess brain vascular function and immunohistopathology to examine cerebrovascular remodeling and amyloid load. Hypertension was induced for 1 month by administration of l-N^G-nitroarginine-methyl-ester in TgF344-AD rats at the prodromal stage. Following hypertension, nontransgenic rats showed transient cerebrovascular changes, whereas TgF344-AD animals exhibited sustained alterations in cerebrovascular function. Human umbilical cord perivascular cells in combination with scyllo-inositol, an inhibitor of Aβ oligomerization, resulted in normalization of hippocampal vascular function and remodeling, in contrast to either treatment alone. Prodromal stage hypertension exacerbates latter AD pathology, and the combination of human umbilical cord perivascular cells with amyloid clearance promotes cerebrovascular functional recovery.

Association of TAFI gene polymorphisms with severity of coronary stenosis in stable coronary artery disease

INTRODUCTION

Coronary stenosis is a consequence of atherosclerotic plaque progression that is associated with impaired fibrinolysis. Thrombin-activatable fibrinolysis inhibitor (TAFI) and plasminogen activator inhibitor 1 (PAI-1) are fibrinolysis inhibitors whose levels are influenced by acquired conditions and by polymorphisms. This study therefore aimed to investigate the association of TAFI and PAI-1 gene polymorphisms with severity of coronary stenosis in subjects with stable coronary artery disease (CAD).

MATERIALS AND METHODS

A total of 327 subjects suspected with CAD who underwent a coronary angiogram were recruited. Gensini score was applied to stratify the severity of coronary stenosis. Based on the Gensini score, the subjects were categorized into low-medium (<20) or high (≥20) groups. The study polymorphisms included TAFI Ala147Thr (505G/A), Thr325Ile (1040C/T), +1542C/G, +1583T/A and PAI-1 -675 4G/5G. Most polymorphisms were genotyped by allele-specific polymerase chain reaction, except for TAFI Thr325Ile that was genotyped by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

A significant increase in the Gensini score was found in TAFI 505A and +1583A allele carriers. Binary regression analysis revealed the independent association of the TAFI 505G/A and +1583T/A polymorphisms with a high Gensini score [adjusted OR = 1.67 (95% CI: 1.03, 2.73) and 1.69 (95% CI: 1.04, 2.76), respectively]. Neither the homozygous PAI-1 -675 4G/4G nor the heterozygous 4G/5G was associated with a high Gensini score.

CONCLUSIONS

The results indicated the contribution of TAFI polymorphisms to atherosclerosis progression and severity of coronary stenosis in stable CAD.

The association between plasminogen activator inhibitor type 1 (PAI-1) levels, PAI-1 4G/5G polymorphism, and myocardial infarction: a Mendelian randomization meta-analysis

BACKGROUND

The circulating levels of plasminogen activator inhibitor type 1 (PAI-1) are increased in individuals carrying the 4G allele at position -675 of the PAI-1 gene. In turn, overexpression of PAI-1 has been found to affect both atheroma and thrombosis. However, the association between PAI-1 levels and the incidence of myocardial infarction (MI) is complicated by the potentially confounding effects of well-known cardiovascular risk factors. The current study tried to investigate in parallel the association of PAI-1 activity with the PAI-1 4G/5G polymorphism, with MI, and some components of metabolic syndrome (MetS).

METHODS

Using meta-analytical Mendelian randomization approaches, genotype-disease and genotype-phenotype associations were modeled simultaneously.

RESULTS

According to an additive model of inheritance and the Mendelian randomization approach, the MI-related odd ratio for individuals carrying the 4G allele was 1.088 with 95% confidence interval (CI) 1.007, 1.175. Moreover, the 4G carriers had, on average, higher PAI-1 activity than 5G carriers by 1.136 units (95% CI 0.738, 1.533). The meta-regression analyses showed that the levels of triglycerides (p=0.005), cholesterol (p=0.037) and PAI-1 (p=0.021) in controls were associated with the MI risk conferred by the 4G carriers.

CONCLUSIONS

The Mendelian randomization meta-analysis confirmed previous knowledge that the PAI-1 4G allele slightly increases the risk for MI. In addition, it supports the notion that PAI-1 activity and established cardiovascular determinants, such as cholesterol and triglyceride levels, could lie in the etiological pathway from PAI-1 4G allele to the occurrence of MI. Further research is warranted to elucidate these interactions.

Plasminogen activator inhibitor-1 4G/5G polymorphism is associated with metabolic syndrome parameters in Malaysian subjects

The plasminogen activator inhibitor-1 4G/5G and tissue plasminogen activator Alu-repeat insertion/deletion polymorphisms might be genetic determinations of increased or decreased of their plasma activities. The aim of this study was to investigate the association of plasminogen activator inhibitor-1 4G/5G and tissue plasminogen activator Alu-repeat I/D polymorphisms with metabolic syndrome parameters in normal Malaysian subjects and to assess the impact of these polymorphisms on their plasma activities and antigens. The genetic polymorphisms were genotyped in 130 normal subjects. In addition, the plasma activities and antigens of plasminogen activator inhibitor-1 and tissue plasminogen activator as well as levels of insulin, glucose, and lipid profile at fasting state were investigated. The subjects with homozygous 4G/4G showed association with an increased triglyceride (p = 0.007), body mass index (p = 0.01) and diastolic blood pressure (p = 0.03). In addition, the plasminogen activator inhibitor-1 4G/5G polymorphism modulates plasma plasminogen activator inhibitor-1 activity and antigen and tissue plasminogen activator activity (p = 0.002, 0.014, 0.003) respectively. These results showed that, the plasminogen activator inhibitor-1 4G/5G polymorphism is associated with metabolic syndrome parameters, plasminogen activator inhibitor-1 and tissue plasminogen activator activities in Malaysian subjects, and may serve to increase the risk of type 2 diabetes and cardiovascular disease in Malaysian subjects.

Gender-specific association of the plasminogen activator inhibitor-1 4G/5G polymorphism with central arterial blood pressure

BACKGROUND

The functional plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism has previously been associated with hypertension. In recent years, central blood pressure, rather than brachial has been argued a better measure of cardiovascular damage and clinical outcome. The aim of this study was to investigate the possible influence of the 4G/5G polymorphism on central arterial blood pressure in a cohort of elderly individuals.

METHODS

We studied 410 individuals, 216 men and 194 women, aged 70-88. Central pressures and pulse waveforms were calculated from the radial artery pressure waveform by the use of the SphygmoCor system and a generalized transfer function. Brachial pressure was recorded using oscillometric technique (Dinamap, Critikon, Tampa, FL). PAI-1 antigen was determined in plasma.

RESULTS

The results showed that central pressures were higher in women carrying the PAI-1 4G/4G genotype compared to female carriers of the 5G/5G genotype, (P = 0.025, P = 0.002, and P = 0.002 for central systolic-, diastolic-, and mean arterial pressure, respectively). The association remained after adjustment for potentially confounding factors related to hypertension. No association of the PAI-1 genotype with blood pressure was found in men. Multiple regression analysis revealed an association between PAI-1 genotype and plasma PAI-1 levels (P = 0.048).

CONCLUSIONS

Our findings show a gender-specific association of the PAI-1 4G/5G polymorphism with central arterial blood pressure. The genotype effect was independent of other risk factors related to hypertension, suggesting that impaired fibrinolytic potential may play an important role in the development of central hypertension in women.

Plasminogen activator inhibitor type-1 gene 4G/5G polymorphism is associated with hypertensive patients in the Turkish population

This study has been performed on hypertensive patients in the Turkish population to determine the frequency of 4G/5G polymorphism genotypes of plasminogen activator inhibitor type-1 gene and with the aim of examining the role of this polymorphism in hypertension development. Genomic DNA obtained from 284 persons (176 patients with hypertension and 108 healthy controls) was used in the study. DNA was multiplied by polymerase chain reaction using 4G and 5G allele-specific primers. Polymerase chain reaction products were assessed by being exposed to 2% agarose gel electrophoresis. Results were evaluated with the chi-square test. The 4G allele frequency was 31.25% and the 5G allele frequency was 68.75% in patients, whereas it was 49/51% in a control group. 5G5G genotype was found statistically high (p < 0.001) in patients relative to controls. This study showed that the plasminogen activator inhibitor type-1 gene 4G/5G polymorphism and the 5G5G genotype appear to be associated with an elevated risk of developing hypertension in a representative sample of Turkish population.

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.

Plasma C-reactive protein and 5-lipoxygenase-activating protein gene promoter poly-A polymorphism in patients with coronary artery disease

OBJECTIVES

The purpose of this study was to explore the possible associations of the 5-lipoxygenase-activating protein (FLAP) poly-A genotype, plasma high-sensitivity C-reactive protein (hsCRP) and the extent score of coronary artery disease (CAD).

METHODS

The 17A/21A genotypes and plasma hsCRP levels were determined in 555 Chinese patients, 424 with and 131 without CAD. The luciferase reporter assay was performed to explore the functional significance of promoter poly-A polymorphism.

RESULTS

CAD patients showed significantly higher plasma hsCRP (p = 0.007) than non-CAD subjects, but no differences in the 17A allele carriers and frequency. The extent score of CAD was significantly correlated with plasma hsCRP (p = 0.03). Furthermore, the 17A allele carriers showed significantly higher hsCRP than the 21A homozygotes (p = 0.02). Multiple linear regression analysis documented an impact of the poly-A genotype on plasma hsCRP (p = 0.03). In vitro, the 17A construct was found to have greater promoter activity than the 21A construct (p = 0.02).

CONCLUSIONS

The present study demonstrated a significant correlation of FLAP gene promoter 17A allele carriers with higher plasma hsCRP levels in patients with CAD. This association might be related to the increased transcriptional activity of the FLAP gene and the resulting pro-inflammatory effect on the 5-lipoxygenase pathway.

Functional Plasminogen Activator Inhibitor-1 Gene Variants and Breast Cancer Survival

PURPOSE

Plasminogen activator inhibitor-1 (PAI-1) plays an important role in cancer invasion and metastasis. A common polymorphism (4G/5G) in the promoter region of the PAI-1 gene has been reported to influence transcription and plasma levels of PAI-1. We evaluated the association between PAI-1 4G/5G polymorphism and breast cancer survival in a population-based cohort of breast cancer patients.

EXPERIMENTAL DESIGN

Included in this analysis were 1,083 Chinese women diagnosed with stage 0 to III primary breast cancer at age 25 to 64 years who were recruited between 1996 and 1998 for the Shanghai Breast Cancer Study and followed for a median of 5.2 years. The Kaplan-Meier method and Cox model were used to evaluate the genotype and survival association.

RESULTS

After adjustment for known prognostic factors for breast cancer, patients homozygous for the 4G allele had significantly poorer disease-free survival [hazard ratio (HR), 1.7; 95% confidence interval (95% CI), 1.1-2.4] and overall survival (HR, 1.5; 95% CI, 1.0-2.3) than those homozygous for the 5G allele. The association was more evident in patients with advanced disease. The HRs (95% CI) were 3.5 (1.4-9.0) for disease-free survival and 3.1 (1.1-8.3) for overall survival in stage III patients.

CONCLUSIONS

The PAI-1 4G/5G polymorphism may be a prognostic marker for young and middle-aged Chinese breast cancer patients.

Plasma adiponectin, T94G gene polymorphism and PAI-1 in patients with and without hypertension

BACKGROUND

Reduced adiponectin level has been associated with metabolic syndrome, type 2 diabetes, coronary artery disease and gene polymorphisms, but the interrelationships of T94G genotype, plasma adiponectin and plasminogen activator inhibitor-1 (PAI-1) are less understood.

PATIENTS AND METHODS

The T94G genotypes and plasma levels of adiponectin, and PAI-1 were determined in 568 Chinese patients, 212 with and 356 without hypertension, to study the possible associations of T94G genotype, plasma adiponectin, PAI-1 and blood pressure.

RESULTS

Hypertensive patients showed significantly lower plasma adiponectin (9.7 +/- 11.1 vs. 11.5 +/- 10.0 microg/ml, p = 0.04) and higher PAI-1 (p < 0.001) levels but not significantly greater adiponectin TT genotype percentage (38.7 vs. 33.5%) and T allele frequency (0.620 vs. 0.585) than normotensive subjects. Plasma adiponectin was inversely related to PAI-1 activity (r = -0.09, p = 0.03) and antigen (r = -0.202, p < 0.001). Furthermore, the TT genotypic group showed significantly lower plasma adiponectin level (10.4 +/- 10.5 vs. 13.4 +/- 10.8 mug/ml, p = 0.03) and higher plasma PAI-1 activity (17.0 +/- 9.7 vs. 13.5 +/- 7.6 IU/ml, p = 0.003) and antigen (32.3 +/- 22.7 vs. 25.9 +/- 14.7 ng/ml, p = 0.01) than the GG genotypic group. Multiple linear regression analysis in all study subjects, in men and in normotensives documented an impact of adiponectin T94G genotype on plasma levels of adiponectin (p = 0.007, 0.003 and 0.03) and PAI-1 activity (p = 0.02, 0.03 and 0.04) and antigen (p = 0.03, 0.007 and 0.04) after adjustment for potential confounding factors.

CONCLUSIONS

The present study demonstrated a significant correlation of the TT genotype with lower plasma adiponectin and higher plasma PAI-1 levels in a Chinese population. The contribution of this genotype seemed greater in men and normotensives. It suggested the adiponectin gene T94G polymorphism might affect the regulation of circulating adiponectin and PAI-1.

Gene polymorphisms of fibrinolytic enzymes in coal workers' pneumoconiosis

The authors assessed the gene polymorphisms of missense C/T polymorphism in exon 6 of the urokinase-plasminogen activator (PLAU) gene (PLAU P141L), Alu-repeat in intron 8 of the tissue-type plasminogen activator (PLAT) gene (PLAT TPA25 Alu insertion), and 4G/5G in the promoter region of the serine proteinase inhibitor, clade E (SERPINE) or plasminogen activator inhibitor type 1 gene (SERPINE1 -675 4G/5G) in 153 healthy volunteers and 154 retired coal miners with coal miners' pneumoconiosis (CWP). The CWP subjects included 94 individuals with simple pneumoconiosis and 60 individuals with progressive massive fibrosis presenting with worse pulmonary function. The distributions of genotypes of these three genes did not differ between the control and CWP subjects or between subjects with simple pneumoconiosis and those with progressive massive fibrosis. However, by assessing duration of work and its interaction with genotypes by means of logistic regression, the authors found the missense C/T polymorphism in exon 6 of the PLAU gene to be an effect modifier of the association between work duration and the development of progressive massive fibrosis.

Distribution of PAI-1 promoter 4G/5G polymorphism in healthy Chinese and functional characterization using a luciferase reporter vector

The aim of this study was to analyze the distribution of plasminogen activator inhibitor-1 (PAI-1) promoter 4G/5G polymorphism in healthy Chinese and compare the transcription activity of the two PAI-1 promoters using luciferase reporter vector pGL(3). PAI-1 promoter 4G/5G polymorphism was analyzed in 77 healthy Chinese using allele-specific polymerase chain reaction (PCR). The PAI-1 promoters from individuals homozygous for the insertion (5G) and deletion (4G) were cloned into luciferase reporter vector pGL(3), respectively. The transcription activities of the two promoters (PAI-1-4G and PAI-1-5G) were then compared using the luciferase reporter vectors expressed in ECV304 and HepG(2) cell lines. Among the 77 healthy Chinese the genotype frequency for 4G/4G, 4G/5G, and 5G/5G was 49.1, 44.1, and 6.5%, respectively. Both of the two PAI-1 promoters cloned into luciferase reporter vector pGL(3), expressed very well both in ECV304 and HepG(2), and have similar basic transcription activity. Thrombin (10-20 U/ml) has no effects on the transcription activity of the two promoters expressed in ECV304, while in the HepG(2) cell line interleukin-1 (IL-1) 158 U/ml increased the transcription activity of PAI-1-4G by 67% (p<0.05, n=5) without effects on PAI-1-5G transcription activity. The distribution of PAI-1 promoter 4G/5G polymorphism in Chinese is obviously different from that in Caucasians with the 4G allele more frequently found in Chinese. PAI-1 promoter 4G/5G polymorphism does not alter basic transcription activity and 4G promoter has increased response to IL-1.

No association of the plasminogen activator inhibitor-1 promoter 4G/5G polymorphism with inhibitor level during basal transcription in vitro

Plasminogen activator inhibitor type 1 (PAI-1) has been shown to be an independent risk factor for coronary artery disease, myocardial infarction, and cerebrovascular events. Previous studies on variations in plasma PAI-1 levels and associations between PAI-1 levels and PAI-1 genotypes have suggested that PAI-1 expression maybe regulated in a genotype-specific manner by insulin, hypertriglyceridemic very low-density lipoprotein, and lipoprotein. We investigated whether basal transcription of the PAI-1 gene also is regulated in a genotype-specific manner. Allele-specific polymerase chain reaction-amplified fragments containing a 4G/5G polymorphism of the PAI-1 gene promoter were ligated into the chloramphenicol acetyltransferase (CAT) reporter gene. The constructs of p4G-CAT or pSG-CAT and pSV-beta-galactosidase as an internal control were transiently cotransfected into human HepG2 hepatoma cells. Electrophoresis mobility shift assays (EMSA) employed a fragment from positions -687 to -664 (4G allele) or from -688 to -664 (5G allele) labeled with adenosine triphosphate tagged with phosphorous 32 in the gamma position and used nuclear extracts of HepG2 cells. Analysis of CAT produced by constructs containing the PAI-1 4G or 5G allele showed similar 3-fold increases in CAT activity in the PAI-1 4G/4G and PAI-1 5G/5G constructs, compared with the CAT activity in the pCAT3-Basic construct. Analyses using the probes containing the 4G or 5G allele site in the EMSA assay revealed no difference in the binding of nuclear protein. Our in vitro assay of basal transcription suggests no difference in the transcriptional activities of the alleles of the PAI-1 4G/5G polymorphism.