Elsevier

Thrombosis Research

Volume 84, Issue 6, 15 December 1996, Pages 431-443
Thrombosis Research

A NOVEL G/A AND THE 4G/5G POLYMORPHISM WITHIN THE PROMOTER OF THE PLASMINOGEN ACTIVATOR INHIBITOR-1 GENE IN PATIENTS WITH DEEP VEIN THROMBOSIS

https://doi.org/10.1016/S0049-3848(96)00211-3Get rights and content

Abstract

Plasma plasminogen activator inhibitor-1 (PAI-1) level was observed to be associated with sequence variations at the PAI-1 locus. Therefore, PAI-1 gene promoter was screened for possibly new polymorphisms and to investigate the contribution of these sequence variations to PAI-1 levels in patients with deep vein thrombosis (DVT). DNA was isolated from blood of 83 consecutive unrelated patients (42±11 years old) and from 50 apparently healthy subjects of similar age and gender distribution. Six fragments covering DNA sequence - 1523 base pairs (bp) upstream from the start of PAI-1 gene transcription to +90 bp in the first exon, were amplified by polymerase chain reaction and analyzed by single-strand conformation polymorphisms. Two polymorphisms were found: a previously described 4G/5G deletion/insertion polymorphism - 675 bp upstream from the start of transcription and a novel G/A single base substitution polymorphism further upstream at −844 bp. The two polymorphisms were in strong linkage disequilibrium. Significant differences between patients and controls were observed neither for the frequencies of the 4G/5G alleles (0.600.40 and 0.590.41, respectively) nor for the frequencies of the G/A alleles (0.330.67 and 0.410.59, respectively). The distribution of both polymorphisms was similar in idiopathic and secondary DVT as well as in first and recurrent DVT. In patients association between the 4G/5G genotypes and PAI activity was observed, with the highest values in the 4G/4G genotype (13.3 U/mL), median values in the 4G/5G genotype (9.8 U/mL) and the lowest values in the 5G/5G genotype (2.0 U/mL). Despite the lack of association between the G/A genotypes and plasma PAI-1 levels, electrophoretic mobility shift assay showed specific binding of a nuclear protein from human vascular endothelial cells extracts to both the G and the A variant, suggesting functional importance of this novel G/A polymorphism in regulating the expression of PAI-1 gene. Copyright © 1996 Elsevier Science Ltd

Section snippets

Subjects

All subjects investigated were Caucasian, originated from Central Europe and were unrelated. They were asked to participate after they had given their full informed consent. The study was approved by the Slovene Ethical Committee.

Eighty-three consecutive patients (35 women and 48 men) aged 19 to 60 (42±11, mean±SD) years, were asked to participate at least three months, but on average 18±10 months (mean±SD) after acute DVT. At the time of the acute event clinical diagnosis of DVT was confirmed

RESULTS

The patients and the controls had similar age and gender distribution. The two groups did not differ significantly in body mass index, fasting blood glucose, HDL-cholesterol and triglyceride levels. On the other hand, patients had higher levels of total- and LDL-cholesterol than controls (Table 1).

In two of the PAI-1 promoter fragments single-strand conformation polymorphism was found. Fragment IV (Fig. 1) contained previously described 4G/5G deletion/insertion polymorphism at −675 bp from the

DISCUSSION

In this study a novel polymorphism in the promoter of the PAI-1 gene is described. This polymorphic site is located −844 bp upstream from the transcription start and represents a single guanine to adenine substitution (G/A polymorphism) according to the published sequence [17]. The distribution of the G/A genotypes both in the patient and in the control group differed from the distribution that would be expected from the Hardy-Weinberg equilibrium, with an over dominance of heterozygotes. The

Acknowledgements

The study was conducted while M. Stegnar was the recipient of a Slovenian Science Foundation Fellowship. Advice on genetic data of W. Pinsker (Institute for Medical Biology, University of Vienna), advice and help with the electrophoretic mobility shift assays of E. Hofer and technical assistance of M. Tehovnik are gratefully acknowledged. The study was supported by a grant No. 5566 from Austrian National Bank and grant No. J3-7822 from the Slovenian Ministry of Science and Technology. The

References (22)

  • S SCHULMAN et al.

    The significance of hypofibrinolysis for the risk of recurrence of venous thromboembolism

    Trombos Haemostas

    (1996)
  • Cited by (0)

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