Genistein reduces tumor necrosis factor α-induced plasminogen activator inhibitor-1 transcription but not urokinase expression in human endothelial cells
article
The plasminogen activator inhibitor PAI-1 is markedly elevated in vivo and in vitro upon exposure to the inflammatory mediators tumor necrosis factor α (TNFα), interleukin-1 (IL-1), and bacterial lipopolysaccharide. Here we report that the isoflavone compound genistein prevents the increase in synthesis of PAI-1 induced by these inflammatory mediators in human endothelial cells in vitro, and partially reduces the basal PAI-1 production by these cells. These effects of genistein were accompanied by a decrease in PAI-1 mRNA and in a suppression of the PAI-1 transcription rate as shown by run-on assay. A specific action of genistein, probably by inhibiting a tyrosine protein kinase, is likely, because the structural genistein analogue daidzein, which has a low tyrosine protein kinase inhibitor activity, did not inhibit PAI-1 synthesis. Vanadate, a tyrosine protein phosphatase inhibitor, increased PAI-1 production. The effect of genistein on PAI-1 synthesis was rather selective. Herbimycin A also reduced PAI-1 synthesis, but several other tyrosine protein kinase inhibitors, namely tyrphostin A47, methyl-2,5- dihydroxy-cinnamate, and compound 5, were unable to do so. All these tyrosine protein kinase inhibitors reduced basic fibroblast growth factor (b-FGF)- induced [3H]thymidine incorporation in endothelial cells. This indicates that the effect of genistein on PAI-1 transcription proceeds independently of its effect on mitogenesis. In contrast to TNFα-induced PAI-1 production, the transcription and synthesis of urokinase-type plasminogen activator (u-PA) was not inhibited by genistein. A TNFα-mutant (Trp12Thr36TNFα) that specifically recognizes the 55-kD TNF-receptor, mimicked the effects of TNFα on both PAI-1 and u-PA. Because genistein affected PAI-1, but not u-PA induced by this mutant, involvement of different TNF-receptors cannot underlie the difference in the effects of genistein on PAI-1 and u-PA synthesis. Because genistein also inhibited PAI-1 induction by thrombin and IL-4, it is likely that genistein does not act on a TNFα-receptor-coupled protein kinase but on the signal transduction pathway enhancing PAI-1 transcription. Our results suggest that the TNFα-induced signal transduction pathway of PAI-1 transcription involves a genistein-sensitive step that is not involved in the induction of u-PA by TNFα. Given the limited sensitivity to several other tyrosine protein kinase inhibitors, this genistein- sensitive step may be a potential target for pharmacologic intervention to reduce elevated plasma PAI-1 levels. Chemicals/CAS: Fibroblast Growth Factor 2, 103107-01-3; Genistein, 446-72-0; Isoflavones; Plasminogen Activator Inhibitor 1; Protein-Tyrosine Kinase, EC 2.7.1.112; Receptors, Tumor Necrosis Factor; Tissue Plasminogen Activator, EC 3.4.21.68; Tumor Necrosis Factor; Urinary Plasminogen Activator, EC 3.4.21.73
Topics
bacterium lipopolysaccharidedaidzeingenisteinherbimycin aplasminogen activatorprotein tyrosine phosphatasetranscription factortumor necrosis factor alphatyrphostinurokinasevanadic acidcell migrationendothelium cellenzyme activationenzyme inhibitionfibrinolysisgenetic transcriptionhuman cellmitogenesisplasminogen activationpriority journalsignal transductionCells, CulturedEndothelium, VascularFibroblast Growth Factor 2GenisteinHumanIn VitroIsoflavonesPlasminogen Activator Inhibitor 1Protein-Tyrosine KinaseReceptors, Tumor Necrosis FactorSignal TransductionSupport, Non-U.S. Gov'tTissue Plasminogen ActivatorTumor Necrosis FactorUrinary Plasminogen Activator
TNO Identifier
232702
ISSN
00064971
Source
Blood, 84(9), pp. 2984-2991.
Pages
2984-2991
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