ETHANOL TRANSCRIPTIONALLY UP-REGULATES T-PA AND U-PA GENE-EXPRESSION IN CULTURED HUMAN ENDOTHELIAL-CELLS

Epidemiological studies have suggested that moderate alcohol consumpti on reduces the risk of cardiovascular mortality, This cardioprotective benefit may be mediated, in part, by promoting fibrinolysis through c hanges in fibrinolytic components and/or activity, resulting in the de creased risk for thrombosis, coronary artery disease, and eventual myo cardial infarction. Endothelial cells (ECs) play a pivotal role in mai ntaining normal hemostasis by regulating fibrinolysis through the synt hesis of plasminogen activators (PAs), tissue-type plasminogen activat or (t-PA), and urokinase-type plasminogen activator (u-PA), The studie s described herein were conducted to determine whether a single brief preincubation (1 hr, 37 degrees C) of cultured human umbilical vein EC s (HUVECs) with low ethanol (0.1%, v/v), will upregulate t-PA and/or u -PA gene expression at the transcriptional level, using a combination of nuclear transcription run-on assays and transient transfections of cultured HUVECs with the pPA/luc promoter constructs. Nuclear run-on a ssays showed similar to 2- to 3-fold and similar to 6- to 7-fold incre ase in the transcription of new t-PA and u-PA mRNAs, respectively. In addition, transient transfections of cultured HUVECs with the pt-PA363 /luc and pu-PA-236/luc promoter constructs, using lipofectamine, demon strated similar to 4- to 6-fold and similar to 6- to g-fold increase i n luciferase activity for t-PA and u-PA, respectively. These combined results demonstrate that low ethanol transcriptionally upregulates bot h t-PA and u-PA gene expression in cultured HUVECs and provides a mole cular basis for the ethanol-induced increase in EC-mediated fibrinolyt ic activity that may underlie and contribute, in part, to the cardiopr otective benefit associated with moderate alcohol consumption.