Ethanol downregulates transcription of the PAI-1 gene in cultured human endothelial cells

Human endothelial cells are a major site of synthesis for plasminogen activ ator inhibitor type-1. Elevated plasminogen activator inhibitor type-1 leve ls in young survivors of myocardial infarction [1] suggest that plasminogen activator inhibitor type-1 may have an important pathologic role in the de velopment of coronary artery disease. Epidemiological studies indicate that moderate alcohol consumption (1-2 drinks/day) reduces the risk for cardiov ascular mortality, This cardioprotective benefit has been attributed in par t to an increase in fibrinolysis, which decreases fibrin-based thrombosis. The studies described herein were performed to determine whether moderate l evels of ethanol affect plasminogen activator inhibitor type-1 gene express ion. Cultured human endothelial cells were exposed to 0.1% v/v ethanol for 1 hour. Following incubation in the absence of ethanol plasminogen activato r inhibitor type-1, mRNA levels were decreased in a time- and dose-dependen t manner, reaching a maximum decrease of 3- to 4-fold at 2 to 4 hours follo wing ethanol challenge. This decline in mRNA occurs at the transcription le vel; therefore, nuclear transcription run-on assays were performed. A 2.5- to 5-fold decrease in the rate of plasminogen activator inhibitor type-1 ge ne transcription was measured at 2 and 4 hours following ethanol challenge. Next, a 3.4- and a 1.1-kb fragment from the plasminogen activator inhibito r type-1 promoter region were linked to a luciferase reporter gene, and the se constructs were transfected into human endothelial cells. Treatment of t hese transiently transfected human endothelial cells with ethanol showed a 2- to 3.5-fold decrease in promoter activity, respectively. These results i ndicate that low doses of ethanol downregulate transcription of the plasmin ogen activator inhibitor type-1 gene in cultured human endothelial cells. H owever, the mechanism(s) for this transcriptional decrease is currently unk nown. (C) 2000 Elsevier Science Ltd. All rights reserved.