Down-regulation of P4501A1 and P4501A2 mRNA expression in isolated hepatocytes by oxidative stress.
Down-regulation of P4501A1 and P4501A2 mRNA expression in isolated hepatocytes by oxidative stress.
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DOI：
10.1016/s0021-9258(17)41731-5
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发表时间：
1994-02
期刊：
影响因子：
--
通讯作者：
C. Barker;J. Fagan;D. Pasco
中科院分区：
文献类型：
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作者：
C. Barker;J. Fagan;D. Pasco
我们先前已经表明，炎症介质白细胞介素-1抑制CYP 1A 1和CYP 1A 2 mRNA的转录（Barker，C.W.，Fagan，J.B.，和帕斯科，D.S.（1992）J.Biol.Chem.267，8050-8055）。由于许多炎症介质的行动是模仿氧化应激，我们处理了分离的肝细胞与0.25-1.0 mM H2 O2，以确定这些基因的表达是否也调制氧化应激。1.0 mM H2 O2使CYP 1A 1和CYP 1A 2 mRNA的诱导剂依赖性蓄积分别最大降低约50%和70%。Run-on转录分析表明，H2 O2的影响是转录介导的。CYP 1A mRNA水平的降低不是由于一些一般毒性作用导致的所有mRNA水平的降低，因为H2 O2不会降低甘油醛-3-磷酸脱氢酶、α-微管蛋白、β-纤维蛋白原或白蛋白mRNA水平，也不会增加释放到培养基中的乳酸脱氢酶。胰岛素模拟H2 O2作用，减少两种mRNA的表达，N-乙酰半胱氨酸，增加细胞内谷胱甘肽水平，完全逆转胰岛素对两种mRNA的作用和H2 O2对CYP 1A 1 mRNA的作用，但仅部分逆转H2 O2对CYP 1A 2 mRNA的作用。这项研究表明，CYP 1A 1和CYP 1A 2基因对氧化应激有反应，并且这种反应性的大部分可以通过细胞氧化还原电位进行修饰。
We have previously shown that the inflammatory mediator interleukin-1 suppressed transcription of CYP1A1 and CYP1A2 mRNAs (Barker, C.W., Fagan, J.B., and Pasco, D.S. (1992) J. Biol. Chem. 267, 8050-8055). Since many of the actions of inflammatory mediators are mimicked by oxidative stress, we treated isolated hepatocytes with 0.25-1.0 mM H2O2 to determine whether expression of these genes is also modulated by oxidative stress. Inducer-dependent accumulation of CYP1A1 and CYP1A2 mRNAs were maximally reduced approximately 50 and 70%, respectively, by 1.0 mM H2O2. Run-on transcription analysis suggested that the effect of H2O2 was mediated transcriptionally. The reduction in CYP1A mRNA levels was not due to a reduction in the levels of all mRNAs due to some general toxic effect since H2O2 did not reduce glyceraldehyde-3-phosphate dehydrogenase, alpha-tubulin, beta-fibrinogen, or albumin mRNA levels, and did not increase lactate dehydrogenase released into the medium. Insulin-mimicked H2O2 action, reducing the expression of both mRNAs, and N-acetylcysteine, which increases intracellular glutathione levels, completely reversed the insulin effect on both mRNAs and the H2O2 effect on CYP1A1 mRNA, but only partially reversed the H2O2 effect on CYP1A2 mRNA. This study indicates that the CYP1A1 and CYP1A2 genes are responsive to oxidative stress and that the majority of this responsiveness can be modified by cellular redox potential.