NO restores HIF-1α hydroxylation during hypoxia:: Role of reactive oxygen species
NO restores HIF-1α hydroxylation during hypoxia:: Role of reactive oxygen species
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DOI：
10.1016/j.freeradbiomed.2005.05.009
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发表时间：
2005-10-01
影响因子：
7.4
通讯作者：
Brüne, B
中科院分区：
文献类型：
--
作者：
Callapina, M;Zhou, J;Brüne, B
低氧诱导因子1（HIF- 1）的活性主要由其U亚基的稳定性调节决定，其在低氧下稳定，但在常氧下降解。脯氨酰羟化酶（PHD）对HIF- 1 α的羟化作用募集von Hippel-Lindau（pVHL）E3泛素连接酶复合物以启动α亚基的蛋白水解破坏。据报道，一氧化氮（NO）可拮抗HIF-1 α的低血压稳定作用.通过使用HIF-1 α-pVHL结合试验，我们表明，NO释放的β-NO恢复脯氨酰羟化酶活性缺氧。HIF-1 α的去稳定性由β-NO逆转自由基清除剂，如NAC和Tiron，从而指出参与活性氧（ROS）。因此，我们研究了ROS对HIF-1 α稳定性的影响.用低浓度的超氧化物发生剂2，3-二甲氧基-1，4-萘醌处理缺氧条件下的细胞，降低了HIF-Ia蛋白的稳定性.体外HIF-1 α-pVHL相互作用试验表明，低水平的ROS形成增加脯氨酰羟化酶活性，ROS清除剂拮抗这种作用。在确定细胞内ROS形成的同时，我们注意到，通过添加β-NO恢复了缺氧条件下减少的ROS产生。我们提出，ROS形成的增加有助于通过调节PHD活性在缺氧条件下通过NO供体使HIF-1 α不稳定。(c)2005年爱思唯尔公司All rights reserved.
The activity of hypoxia-inducible factor 1 (HIF- 1) is primarily determined by stability regulation of its U subunit, which is stabilized under hypoxia but degraded during normoxia. Hydroxylation of HIF- 1 alpha by prolyl hydroxylases (PHDs) recruits the von Hippel-Lindau (pVHL) E3 ubiquitin ligase complex to initiate proteolytic destruction of the alpha subunit. Hypoxic stabilization of HIF- I a has been reported to be antagonized by nitric oxide (NO). By using a HIF-1 alpha -pVHL binding assay, we show that NO released from DETA-NO restored prolyl hydroxylase activity under hypoxia. Destabilization of HIF-1 alpha by DETA-NO was reversed by free radical scavengers such as NAC and Tiron, thus pointing to the involvement of reactive oxygen species (ROS). Therefore, we examined the effects of ROS on HIF- I a stabilization. Treatment of cells under hypoxia with low concentrations of the superoxide generator 2,3-dimethoxy-1,4-naphthoquinone lowered HIF- I a protein stabilization. In vitro HIF-1 alpha-pVHL interaction assays demonstrated that low-level ROS formation increased prolyl hydroxylase activity, an effect antagonized by ROS scavengers. While determining intracellular ROS formation we noticed that reduced ROS production under hypoxia was restored by the addition of DETA-NO. We propose that an increase in ROS formation contributes to HIF-1 alpha destabilization by NO donors under hypoxia via modulation of PHD activity. (c) 2005 Elsevier Inc. All rights reserved.