A novel polymorphism in the PAI-1 gene promoter enhances gene expression. A novel pro-thrombotic risk factor?

作者：Liguori Renato; Quaranta Sandro; Di Fiore Rosanna; Elce Ausilia; Castaldo Giuseppe^*; Amato Felice

来源：Thrombosis Research, 2014, 134(6): 1229-1233.

DOI：10.1016/j.thromres.2014.09.021

• PAI-1
• Thrombotic risk
• Single-nucleotide polymorphism
• Fibrinolytic disorders
• Gene

Introduction: Plasminogen activator inhibitor-1 (PAI-1) is the major physiological inhibitor of tissue-type plasminogen activator in plasma and the most important regulator of the fibrinolytic pathway. The 4G/5G polymorphism (rs1799889) in the PAI-1 promoter is associated with altered PAI-1 transcription. We have identified a new 4G/5G allele, in which a T is inserted near the 4G tract or replaces a G in the 5G tract, forming a T plus 4G (T4G) region. %26lt;br%26gt;Materials and Methods: This new variant was first identified in two women, one had experienced juvenile myocardial infarction, the other repeated miscarriage; both had increased PAI-1 plasma activity. In view of the important influence of this promoter region on PAI-1 protein plasma level, we performed in vitro evaluation of the effects of the T4G variant on the transcription activity of the PAI-1 gene promoter. %26lt;br%26gt;Results and Conclusions: In silico prediction analysis showed that presence of the T4G allele disrupts the E-Box region upstream of the T4G variant, altering the affinity of the target sequence for E-Box binding factors like upstream stimulatory factor-1 (USF-1). Basal T4G promoter activity was 50% higher compared to 4G and 5G variants, but it was less stimulated by USF-1 overexpression. We also analyzed the effects of IL-1 beta and IL-6 on the PAI-1 promoter activity of our three constructs and showed that the T4G variant was less affected by IL-1 beta than the other variants. These findings indicate that the T4G variant may be a novel risk factor for thrombotic events.

• 出版日期2014-12