Antioxidant/pro-oxidant equilibrium regulates HIF-1α and NF-κB redox sensitivity -: Evidence for inhibition by glutathione oxidation in alveolar epithelial cells
Antioxidant/pro-oxidant equilibrium regulates HIF-1α and NF-κB redox sensitivity -: Evidence for inhibition by glutathione oxidation in alveolar epithelial cells
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DOI：
10.1074/jbc.m000737200
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发表时间：
2000-07-14
影响因子：
4.8
通讯作者：
Land, SC
中科院分区：
文献类型：
--
作者：
Haddad, JJE;Olver, RE;Land, SC
氧-2和氧化还原敏感转录因子缺氧诱导因子-1 α (HIF-1 α)和核因子- κ B （nf - κ B）在胎儿至新生儿氧紧张时在肺泡上皮中受到差异调节。我们使用胎儿肺泡II型上皮细胞来监测其与体外抗氧化预处理氧化还原反应相关的调节。n -乙酰- l-半胱氨酸，谷胱甘肽（GSH）前体和活性氧的有效清除剂，分别诱导HIF-1 α和改善nf - κ B核丰度和DNA结合活性，并呈剂量依赖性。对n -乙酰-(L)-半胱氨酸增加的Delta pO(2)方案中谷胱甘肽动态平衡变化的分析显示，谷胱甘肽的增加是以谷胱甘肽（GSSG）的氧化形式为代价的，从而使谷胱甘肽/GSSG进入还原平衡。二硫代氨基甲酸吡啶（pyrolidine dithiocarbamate， PDTC）具有抗氧化和促氧化双重作用，可显著增加HIF-1 α核丰度，但对其活性无明显影响。PDTC降低nf - κ B核丰度及其对结合活性的抑制作用是剂量依赖性的。PDTC对谷胱甘肽动态平衡的评估显示，GSSG水平的增加以GSH为代价，GSH/GSSG的降低有利于氧化平衡。我们的研究结果表明，胎儿上皮中HIF-1 α的缺氧激活和nf - κ B的高氧诱导是氧化还原敏感的，因此受到GSH/GSSG平衡的严格调节。这突出了谷胱甘肽作为一个关键的调控成分，决定在正常肺发育和病理生理条件下对氧化/抗氧化失衡的遗传反应。
The O-2 and redox-sensitive transcription factors hypoxia inducible factor-1 alpha (HIF-1 alpha) and nuclear factor-kappa B (NF-kappa B) are differentially regulated in the alveolar epithelium over fetal to neonatal oxygen tensions. We have used fetal alveolar type II epithelial cells to monitor their regulation in association with redox responsiveness to antioxidant pretreatment in vitro. N-Acetyl-L-cysteine, a glutathione (GSH) precursor and a potent scavenger of reactive oxygen species, induced HIF-1 alpha and ameliorated NF-kappa B nuclear abundance and DNA binding activity, respectively, in a dose-dependent manner. Analysis of variations in glutathione homeostasis at ascending Delta pO(2) regimen with N-acetyl-(L)-cysteine reveals increased GSH at the expense of the oxidized form of glutathione (GSSG;), thereby shifting GSH/GSSG into reduction equilibrium. Pyrrolidine dithiocarbamate (PDTC), which exerts both antioxidant and pro-oxidant effects, provoked a substantial increase in HIF-1 alpha nuclear abundance, with no apparent effect on its activation. PDTC reduced NF-kappa B nuclear abundance and its inhibitory effects on binding activity are dose-dependent. Assessment of glutathione homeostasis with PDTC shows increasing levels of GSSG at the expense of GSH, lowering GSH/GSSG in favor of an oxidative equilibrium. Our results indicate the hypoxic activation of HIF-1 alpha and the hyperoxic induction of NF-kappa B in the fetal epithelium is redox-sensitive and, thus, tightly regulated by the GSH/GSSG equilibrium. This highlights glutathione as a key regulatory component for determining genetic responsiveness to oxidant/antioxidant imbalance in normal lung development and pathophysiological conditions.