Genistein reduces tumor necrosis factor alpha-induced plasminogen activator inhibitor-1 transcription but not urokinase expression in human endothelial cells.
Genistein reduces tumor necrosis factor alpha-induced plasminogen activator inhibitor-1 transcription but not urokinase expression in human endothelial cells.
复制标题
Genistein 减少肿瘤坏死因子 α 诱导的纤溶酶原激活物抑制剂-1 转录，但不减少人内皮细胞中尿激酶的表达。
作者：
V. Hinsbergh;M. Vermeer;P. Koolwijk;J. Grimbergen;Teake Kooistra
纤溶酶原激活物抑制剂派-1在体内和体外暴露于炎症介质肿瘤坏死因子α（TNF α）、白细胞介素-1（IL-1）和细菌脂多糖后显著升高。在这里，我们报告的化合物染料木黄酮防止增加合成的派-1诱导这些炎症介质在体外人内皮细胞，并部分减少这些细胞的基础派-1的生产。染料木黄酮的这些作用伴随着派-1 mRNA的减少和派-1转录速率的抑制，如运行试验所示。染料木黄酮可能通过抑制酪氨酸蛋白激酶而发挥特异性作用，因为染料木黄酮结构类似物大豆苷元具有低酪氨酸蛋白激酶抑制剂活性，不抑制派-1的合成。钒酸盐，酪氨酸蛋白磷酸酶抑制剂，增加派-1的生产。染料木黄酮对派-1合成的影响具有选择性。除此之外，Herbimycin A还能降低派-1的合成，但其他几种酪氨酸蛋白激酶抑制剂，如tyrphostin A47、2，5-二羟基肉桂酸甲酯和化合物5却不能。所有这些酪氨酸蛋白激酶抑制剂减少碱性成纤维细胞生长因子（b-FGF）诱导的[3 H]胸苷掺入内皮细胞。这表明染料木黄酮对派-1转录的影响独立于其对有丝分裂的影响。与TNF-α诱导的派-1产生相反，染料木素不抑制尿激酶型纤溶酶原激活物（u-PA）的转录和合成。特异性识别55 kD TNF受体的TNF-α突变体（Trp 32 Thr 86 TNF α）模拟TNF α对派-1和u-PA的作用。由于染料木黄酮影响派-1，但不u-PA诱导的突变体，参与不同的TNF受体不能在派-1和u-PA合成的染料木黄酮的影响的差异。由于染料木黄酮也抑制凝血酶和IL-4对派-1的诱导，因此染料木黄酮可能不作用于TNF α受体偶联蛋白激酶，而是作用于增强派-1转录的信号转导途径。我们的研究结果表明，TNF α诱导的派-1转录的信号转导途径涉及一个染料木素敏感的步骤，不参与TNF α诱导u-PA。鉴于对其他几种酪氨酸蛋白激酶抑制剂的敏感性有限，染料木黄酮敏感的步骤可能是一个潜在的药物干预目标，以降低血浆派-1水平升高。
The plasminogen activator inhibitor PAI-1 is markedly elevated in vivo and in vitro upon exposure to the inflammatory mediators tumor necrosis factor alpha (TNF alpha), 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 TNF-alpha-induced PAI-1 production, the transcription and synthesis of urokinase-type plasminogen activator (u-PA) was not inhibited by genistein. A TNF-alpha-mutant (Trp32Thr86TNF alpha) that specifically recognizes the 55-kD TNF-receptor, mimicked the effects of TNF alpha 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 TNF alpha-receptor-coupled protein kinase but on the signal transduction pathway enhancing PAI-1 transcription. Our results suggest that the TNF alpha-induced signal transduction pathway of PAI-1 transcription involves a genistein-sensitive step that is not involved in the induction of u-PA by TNF alpha. 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.