Reactive oxygen species activate the HIF-1α promoter via a functional NFκB site
Reactive oxygen species activate the HIF-1α promoter via a functional NFκB site
复制标题
DOI：
10.1161/01.atv.0000258979.92828.bc
复制
发表时间：
2007-04-01
影响因子：
8.7
通讯作者：
Goerlach, Agnes
中科院分区：
文献类型：
--
作者：
Bonello, Steve;Zahringer, Christian;Goerlach, Agnes
目的：活性氧被认为是调节氧化还原敏感性转录因子如核因子κ B（NF-κ B）活性的信号分子。最近，转录因子缺氧诱导因子-1（HIF-1），已知介导基因表达的缺氧，已被发现也被激活的非缺氧因素在氧化还原敏感的方式。因此，我们的目的是阐明这2个重要的氧化还原敏感的转录factors.Methods和结果之间的联系-在肺动脉平滑肌细胞，活性氧产生的外源性过氧化氢或由一个NOX 4-含有NADPH氧化酶刺激凝血酶激活或诱导NF-κ B和HIF-1 α。活性氧介导的HIF-1 α诱导发生在转录水平，并依赖于NF-κ B B。用野生型或突变型HIF-1 α启动子构建体的转染实验揭示了尚未鉴定的NF-κ B结合元件的存在。凝胶位移分析和染色质免疫沉淀证实NF-κ B与该位点结合。此外，活性氧增强了纤溶酶原激活物抑制剂-1的表达，而显性负性I kappa B或纤溶酶原激活物抑制剂-1启动子内HIF-1结合位点的突变可以阻止这种表达。结论-这些发现首次表明，据我们所知，活性氧直接连接HIF-1 α和NF-κ B，暗示了这种新途径在与活性氧水平升高相关的疾病中的重要病理生理作用。
Objective - Reactive oxygen species have been implicated as signaling molecules modulating the activity of redox-sensitive transcription factors such as nuclear factor kappa B (NF-kappa B). Recently, the transcription factor hypoxia-inducible factor-1 (HIF-1), known to mediate gene expression by hypoxia, has been found to be also activated by nonhypoxic factors in a redox-sensitive manner. We therefore aimed to elucidate the link between these 2 important redox-sensitive transcription factors.Methods and Results - In pulmonary artery smooth muscle cells, reactive oxygen species generated either by exogenous H2O2 or by a NOX4-containing NADPH oxidase stimulated by thrombin activated or induced NF-kappa B and HIF-1 alpha. The reactive oxygen species-mediated HIF-1 alpha induction occurred on the transcriptional level and was dependent on NF-kappa B. Transfection experiments with wild-type or mutant HIF-1 alpha promoter constructs revealed the presence of a yet unidentified NF-kappa B binding element. Gel shift analyses and chromatin immunoprecipitation verified binding of NF-kappa B to this site. Furthermore, reactive oxygen species enhanced expression of plasminogen activator inhibitor-1, which was prevented by dominant-negative I kappa B or mutation of the HIF-1 binding site within the plasminogen activator inhibitor-1 promoter.Conclusion - These findings show for the first time to our knowledge that reactive oxygen species directly link HIF-1 alpha and NF-kappa B, implicating an important pathophysiological role of this novel pathway in disorders associated with elevated levels of reactive oxygen species.