Geldanamycin enhances hepatocyte growth factor stimulation of eNOS phosphorylation in endothelial cells
Geldanamycin enhances hepatocyte growth factor stimulation of eNOS phosphorylation in endothelial cells
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DOI：
10.1016/j.ejphar.2007.12.018
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发表时间：
2008-03-17
影响因子：
5
通讯作者：
Kimura, Kazuhiro
中科院分区：
文献类型：
--
作者：
Makondo, Kennedy;Kamikawa, Akihiro;Kimura, Kazuhiro
此前，我们证明肝细胞生长因子 (HGF) 通过钙和 Akt 介导的牛主动脉内皮细胞 Ser-1179（人 Ser-1177）磷酸化，有效刺激内皮一氧化氮合酶 (eNOS) 活性和一氧化氮 (NO) 产生。然而，eNOS 的调节还涉及与伴侣蛋白（例如热休克蛋白 (HSP) 90）的相互作用，这种相互作用可以通过酶的激动剂刺激来增强。在目前的工作中，在内皮细胞培养系统中检查了 HGF 刺激 eNOS 中 HSP90 的作用。用格尔德霉素（一种常用的 HSP90 抑制剂）处理内皮细胞，可增强 HGF 刺激的 eNOS Ser-1179 磷酸化，但不会改变 eNOS Thr-497 磷酸化。然而，其他 HSP90 抑制剂，即 17-(烯丙氨基)-17-去甲氧基格尔德霉素 (17-AAG) 和根赤霉素，不具有类似的作用。 HGF 和格尔德霉素单独或联合治疗均不会改变内皮细胞中的 HSP90/eNOS 相互作用。此外，格尔德霉素处理不会增强 HGF 诱导的 Akt、ERK1/2 和 p38MAPK 磷酸化。 PP2 抑制 Src 激酶也未能阻断格尔德霉素的作用。这些结果表明，格尔德霉素（但 17-AAG 和根底考都不是）可以增强 HGF 介导的 eNOS Ser-1179 磷酸化。通过一些独立于 HSP90 抑制的迄今未知的机制。 (c) 2007 Elsevier B.V. 保留所有权利。
Previously, we demonstrated that hepatocyte growth factor (HGF) potently stimulates endothelial nitric oxide synthase (eNOS) activity and nitric oxide (NO) production through a calcium- and Akt-mediated phosphorylation at Ser-1179 (Ser-1177 human) in bovine aortic endothelial cells. The regulation of eNOS, however, also involves interaction with chaperone proteins such as heat shock protein (HSP) 90, which can be enhanced by agonist stimulation of the enzyme. In the present work, the role of HSP90 in HGF stimulation of eNOS was examined in an endothelial cell culture system. Treatment of endothelial cells with geldanamycin, a commonly used HSP90 inhibitor, augmented HGF-stimulated eNOS phosphorylation at Ser-1179, while it did not alter eNOS phosphorylation at Thr-497. However, other HSP90 inhibitors, namely 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) and radicicol, did not possess similar effects. Neither HGF nor geldanamycin treatment, independently or in combination, altered HSP90/eNOS interaction in endothelial cells. In addition, geldanamycin treatment did not enhance the HGF-induced phosphorylation of Akt, ERK1/2 and p38MAPK. Src kinase inhibition by PP2 also failed to block the geldanamycin effects. These results suggest that geldanamycin, but neither 17-AAG nor radicicol, may enhance HGF-mediated eNOS Ser-1179 phosphorylation. by some as yet unknown mechanisms independently of HSP90 inhibition. (c) 2007 Elsevier B.V. All rights reserved.