Nongenomic stimulation of nitric oxide release by estrogen is mediated by estrogen receptor alpha localized in caveolae.
Nongenomic stimulation of nitric oxide release by estrogen is mediated by estrogen receptor alpha localized in caveolae.
复制标题
DOI：
10.1006/bbrc.1999.1348
复制
发表时间：
1999-09
影响因子：
3.1
通讯作者：
H. Kim;J. Lee;J. K. Jeong;S. Bae;Hongchan Lee;In-Cheol Jo
中科院分区：
文献类型：
--
作者：
H. Kim;J. Lee;J. K. Jeong;S. Bae;Hongchan Lee;In-Cheol Jo
健康绝经后妇女急性服用17 β-雌二醇（E（2））可发挥抗动脉粥样硬化作用。E（2）的血管保护作用可能部分是通过迅速增加内皮细胞（EC）中的一氧化氮（NO）水平来解释的。然而，产生这种上升的信号机制是未知的。为了研究E（2）对内皮细胞NO产生的短期影响，将融合的牛主动脉内皮细胞（BAEC）在不存在或存在E（2）的情况下孵育，并测量NO的产生。在暴露于E2 5分钟后，NO水平显著升高，而内皮NO合酶（eNOS）的蛋白水平没有变化。雌激素的这种短期效应被各种降低细胞内Ca（2+）浓度的配体显著减弱。此外，质膜不可渗透的BSA结合的E（2）（E（2）BSA）刺激内皮NO释放，表明在当前系统中，E（2）的作用位点是在质膜上，而不是经典的核受体。部分拮抗剂他莫昔芬不能阻断E（2）诱导的NO产生;然而，纯雌激素受体α（ER α）拮抗剂ICI 182，780完全抑制E（2）刺激的NO释放。使用FITC标记的E（2）BSA（E（2）BSA-FITC）确认E（2）与膜的结合。蛋白质印迹分析表明，质膜小窝具有ER α除了众所周知的小窝相关蛋白eNOS和小窝蛋白。这项研究表明，E2对内皮细胞NO释放的非基因组和短期效应是Ca（2+）依赖性的，并通过位于质膜小窝的ER α发生。
Acute administration of 17beta-estradiol (E(2)) exerts antiatherosclerotic effects in healthy postmenopausal women. The vasoprotective action of E(2) may be partly accounted for by a rapid increase in nitric oxide (NO) levels in endothelial cells (ECs). However, the signaling mechanisms producing this rise are unknown. In an attempt to address the short-term effect of E(2) on endothelial NO production, confluent bovine aortic endothelial cells (BAECs) were incubated in the absence or presence of E(2), and NO production was measured. Significant increases in NO levels were detected after only 5 min of E(2) exposure without a change in the protein levels of endothelial NO synthase (eNOS). This short-term effect of estrogen was significantly blunted by various ligands which decrease intracellular Ca(2+) concentration. Furthermore, plasma membrane-impermeable BSA-conjugated E(2) (E(2)BSA) stimulated endothelial NO release, indicating that in the current system the site of action of E(2) is on the plasma membrane rather than the classical nuclear receptor. The partial antagonist tamoxifen did not block E(2)-induced NO production; however, a pure estrogen receptor alpha (ERalpha) antagonist ICI 182,780 completely inhibited E(2)-stimulated NO release. The binding of E(2) to the membrane was confirmed using FITC-labeled E(2)BSA (E(2)BSA-FITC). Western blot analysis showed that plasmalemmal caveolae possess ERalpha in addition to well-known caveolae-associated proteins eNOS and caveolin. This study demonstrates that the nongenomic and short-term effect of E(2) on endothelial NO release is Ca(2+)-dependent and occurs via ERalpha localized in plasmalemmal caveolae.