Genistein acutely stimulates nitric oxide synthesis in vascular endothelial cells by a cyclic adenosine 5′-monophosphate-dependent mechanism
Genistein acutely stimulates nitric oxide synthesis in vascular endothelial cells by a cyclic adenosine 5′-monophosphate-dependent mechanism
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DOI：
10.1210/en.2004-0102
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发表时间：
2004-12-01
期刊：
影响因子：
4.8
通讯作者：
Dillon, JS
中科院分区：
文献类型：
--
作者：
Liu, DM;Homan, LL;Dillon, JS
金雀异黄素可以改善血管功能，但其作用机制尚不清楚。我们验证了金雀异黄素通过刺激内皮一氧化氮合酶直接调节血管功能的假设。金雀异黄素在10分钟的孵育期内激活完整的牛主动脉内皮细胞和人脐静脉内皮细胞的内皮型一氧化氮合酶(ENOS)。ENOS活性在金雀异黄素1min时达到最大。与此激活模式一致，1MU染料木素在孵育10min时最大限度地刺激丝氨酸1179位eNOS的磷酸化。金雀异黄素对eNOS的快速激活不依赖于RNA转录或新的蛋白质合成，也不被特定的雌激素受体拮抗剂阻断。此外，抑制MAPK或磷脂酰肌醇3-羟基激酶/Akt激酶对金雀异黄素激活eNOS无影响。此外，金雀异黄素对eNOS的作用也不依赖于酪氨酸激酶的抑制。然而，H89对cAMP依赖的激酶[蛋白激酶A(PKA)]的抑制完全阻断了染料木素刺激的eNOS的激活和磷酸化，提示染料木素通过PKA依赖的途径发挥作用。这些结果表明金雀异黄素对血管内皮细胞eNOS活性有直接的非基因组效应，导致eNOS激活和一氧化氮合成。这些效应是由PKA介导的，与雌激素效应无关。这一细胞机制可能是大豆植物雌激素的一些心血管保护作用的基础。
Genistein may improve vascular function, but the mechanism of this effect is unclear. We tested the hypothesis that genistein directly regulates vascular function through stimulation of endothelial nitric oxide synthesis. Genistein activated endothelial nitric oxide synthase (eNOS) in intact bovine aortic endothelial cells and human umbilical vein endothelial cells over an incubation period of 10 min. The maximal eNOS activity was at 1 muM genistein. Consistent with this activation pattern, 1 muM genistein maximally stimulated the phosphorylation of eNOS at serine 1179 at 10 min of incubation. The rapid activation of eNOS by genistein was not dependent on RNA transcription or new protein synthesis and was not blocked by a specific estrogen receptor antagonist. In addition, inhibition of MAPK or phosphatidylinositol 3-OH kinase/Akt kinase had no affect on eNOS activation by genistein. Furthermore, the genistein effect on eNOS was also independent of tyrosine kinase inhibition. However, inhibition of cAMP-dependent kinase [protein kinase A (PKA)] by H89 completely abolished the genistein-stimulated eNOS activation and phosphorylation, suggesting that genistein acted through a PKA-dependent pathway. These findings demonstrated that genistein had direct nongenomic effects on eNOS activity in vascular endothelial cells, leading to eNOS activation and nitric oxide synthesis. These effects were mediated by PKA and were unrelated to an estrogenic effect. This cellular mechanism may underlie some of the cardiovascular protective effects proposed for soy phytoestrogens.