Contributions of reactive oxygen species and mitogen-activated protein kinase signaling in arsenite-stimulated hemeoxygenase-1 production
Contributions of reactive oxygen species and mitogen-activated protein kinase signaling in arsenite-stimulated hemeoxygenase-1 production
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DOI：
10.1016/j.taap.2006.09.020
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发表时间：
2007-01-15
影响因子：
3.8
通讯作者：
Hudson, Laurie G.
中科院分区：
文献类型：
--
作者：
Cooper, Karen L.;Liu, Ke Jian;Hudson, Laurie G.
血红氧合酶-1 （HO-1）是一种氧化应激反应基因，受各种生理和外源刺激上调。HO-1具有细胞保护活性，亚砷酸盐是许多细胞类型和组织（包括表皮角质形成细胞）中HO-1的有效诱导剂。我们研究了活性氧（ROS）的产生和丝裂原活化蛋白激酶（MAPK）的激活对HaCaT细胞（一种永生的人角质形成细胞系）中HO-1的亚砷酸盐依赖性调节的潜在贡献。采用双氢乙啶（DHE）染色和荧光显微镜检测表皮生长因子（EGF）和亚砷酸盐刺激ROS的产生。亚砷酸盐对HO-1的诱导呈时间和浓度依赖性，而HO-1对EGF的表达在延长的时间点（48-72 h）是温和而明显的。抑制EGF受体、MEK I/II或Src可使亚砷酸盐刺激的HO-1表达降低20-30%。相反，添加超氧化物清除剂或抑制p38活性可使亚砷酸盐依赖性反应降低80-90%，这表明ROS和p38是HO-1诱导所必需的。然而，仅产生ROS不足以引起观察到的亚砷酸盐依赖性反应，因为使用黄嘌呤/黄嘌呤氧化酶系统产生ROS并没有产生等效的HO-1上调。在EGF和黄嘌呤/黄嘌呤氧化酶共处理的细胞中，HO-1的协同诱导作用证明了ERK信号和ROS生成之间的合作关系，其反应几乎等同于亚砷酸盐的反应。这些发现表明，ERK/MAPK的激活是必需的，但不是亚砷酸盐刺激HO-1诱导的充分条件。HO-1的稳健和持续上调可能在细胞对慢性砷暴露的适应中起作用。(c) 2006年Elsevier Inc.出版
Hemeoxygenase-1 (HO-1) is an oxidative stress responsive gene upregulated by various physiological and exogenous stimuli. HO-1 has cytoprotective activities and arsenite is a potent inducer of HO-1 in many cell types and tissues, including epidermal keratinocytes. We investigated the potential contributions of reactive oxygen species (ROS) generation and mitogen-activated protein kinase (MAPK) activation to arsenite-dependent regulation of HO-1 in HaCaT cells, an immortalized human keratinocyte line. Both epidermal growth factor (EGF) and arsenite stimulated ROS production was detected by dihydroethidium (DHE) staining and fluorescence microscopy. Arsenite induced HO-1 in a time- and concentration-dependent manner, while HO-1 expression in response to EGF was modest and evident at extended time points (48-72 h). Inhibition of EGF receptor, MEK I/II or Src decreased arsenite-stimulated HO-1 expression by 20-30%. In contrast, addition of a superoxide scavenger or inhibition of p38 activity decreased the arsenite-dependent response by 80-90% suggesting that ROS and p38 are required for HO-1 induction. However, ROS generation alone was insufficient for the observed arsenite-dependent response as use of a xanthine/xanthine oxidase system to generate ROS did not produce an equivalent upregulation of HO-1. Cooperation between ERK signaling and ROS generation was demonstrated by synergistic induction of HO-1 in cells co-treated with EGF and xanthine/xanthine oxidase resulting in a response nearly equivalent to that observed with arsenite. These findings suggest that the ERK/MAPK activation is necessary but not sufficient for optimal arsenite-stimulated HO-1 induction. The robust and persistent Upregulation of HO-1 may have a role in cellular adaptation to chronic arsenic exposure. (c) 2006 Published by Elsevier Inc.