A novel role for caveolin-1 in regulating endothelial nitric oxide synthase activation in response to H2O2 and shear stress.
A novel role for caveolin-1 in regulating endothelial nitric oxide synthase activation in response to H2O2 and shear stress.
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DOI：
10.1016/j.freeradbiomed.2010.03.023
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发表时间：
2010-07-15
影响因子：
7.4
通讯作者：
Black, Stephen M.
中科院分区：
文献类型：
--
作者：
Tian, Jing;Hou, Yali;Lu, Qing;Wiseman, Dean A.;Fonsesca, Fabio Vasconcelos;Elms, Shawn;Fulton, David J.;Black, Stephen M.
先前的研究表明，过氧化氢（H2O2）诱导的氧化应激急性增加可以通过增加eNOS丝氨酸1177位点的磷酸化来增加内皮型一氧化氮合酶（eNOS）的催化活性。然而，目前尚不清楚当内皮细胞暴露于生物力学力时，H2O2的增加如何影响一氧化氮（NO）信号。因此，本研究的目的是评估H2O2在存在或不存在层流剪切应力的情况下对NO信号的急性影响。我们发现，牛主动脉内皮细胞中H2O2水平的急性持续增加并没有改变基本的NO生成，但响应剪切应力产生的NO显著增加。NO信号的扩增被发现与h2o2诱导的质膜上eNOS的增加和总小窝蛋白-1蛋白水平的增加有关。我们进一步证明，过表达caveolin-1再次增加了定位在质膜上的eNOS，而不改变eNOS总蛋白水平。我们还发现，只有在H2O2存在的情况下，过表达caveolin-1才能增加剪切应力下NO的生成。相反，用siRNA消耗caveolin-1减少了定位于质膜的eNOS，并消除了增强的NO生成。最后，我们发现在COS-7细胞中表达eNOS的caveolin-1结合位点缺失突变体降低了其质膜定位，导致钙激活时NO的产生减弱。总之，我们已经发现了一个新的作用，即小洞蛋白-1在促进eNOS向质膜运输的过程中，似乎参与了在氧化应激条件下启动eNOS的流动介导激活。据我们所知，这是第一次报道H2O2通过改变其亚细胞位置来调节eNOS活性，并且caveolin-1可以在NO信号传导中发挥刺激作用。
Previous studies have shown that acute increases in oxidative stress induced by the addition of hydrogen peroxide (H2O2) can increase endothelial nitric oxide synthase (eNOS) catalytic activity via an increase in the phosphorylation of eNOS at serine 1177. However, it is unclear how increased H2O2 affects nitric oxide (NO) signaling when endothelial cells are exposed to biomechanical forces. Thus, the purpose of this study was to evaluate the acute effects of H2O2 on NO signaling in the presence or absence of laminar shear stress. We found that acute sustained increases in cellular H2O2 levels in bovine aortic endothelial cells did not alter basal NO generation but the NO produced in response to shear stress was significantly increased. This amplification in NO signaling was found to correlate with an H2O2-induced increase in eNOS localized to the plasma membrane and an increase in total caveolin-1 protein levels. We further demonstrated that overexpressing caveolin-1 increased eNOS localized to the plasma membrane again without altering total eNOS protein levels. We also found that caveolin-1 overexpression increased NO generation in response to shear stress but only in the presence of H2O2. Conversely, depleting caveolin-1 with an siRNA decreased eNOS localized to the plasma membrane and abolished the enhanced NO generation. Finally, we found that expressing a caveolin-1 binding-site deletion mutant of eNOS in COS-7 cells decreased its plasma membrane localization and resulted in attenuated NO production in response to calcium activation. In conclusion, we have identified a new role for caveolin-1 in enhancing eNOS trafficking to the plasma membrane that seems to be involved in priming eNOS for flow-mediated activation under conditions of oxidative stress. To our knowledge, this is the first report that H2O2 modulates eNOS activity by altering its subcellular location and that caveolin-1 can play a stimulatory role in NO signaling.
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影响因子：
4.8
作者：
GarciaCardena, G;Fan, R;Sessa, WC
通讯作者：
Sessa, WC
影响因子：
82.9
作者：
Bucci, M;Gratton, JP;Sessa, WC
通讯作者：
Sessa, WC
DOI：
10.1152/ajplung.90205.2008
发表时间：
2008-08-01
影响因子：
4.9
作者：
Kumar, Sanjiv;Sun, Xutong;Black, Stephen M.
通讯作者：
Black, Stephen M.
影响因子：
56.9
作者：
Drab, M;Verkade, P;Kurzchalia, TV
通讯作者：
Kurzchalia, TV
影响因子：
20.1
作者：
Drummond, GR;Cai, H;Harrison, DG
通讯作者：
Harrison, DG