Menadione cytotoxicity to hep G2 cells and protection by activation of nuclear factor-kappa B
Menadione cytotoxicity to hep G2 cells and protection by activation of nuclear factor-kappa B
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DOI：
10.1124/mol.52.4.648
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发表时间：
1997-10-01
影响因子：
3.6
通讯作者：
Cederbaum, AI
中科院分区：
文献类型：
--
作者：
Chen, Q;Cederbaum, AI
甲萘醌（维生素K-3，2-甲基-1，4-萘醌），氧化还原循环试剂，产生活性氧中间体，导致氧化损伤。加入甲萘醌的Hep G2细胞产生了时间和浓度依赖性的细胞活力的损失。Hep G2细胞与低无毒浓度的甲萘醌预孵育增加了细胞对毒性剂量的甲萘醌或H2O2的生存力。最大的保护被发现与甲萘醌浓度类似3 μ M和预孵育时间类似45分钟。这种保护作用可以被阻断的蛋白质合成抑制剂放线菌酮和各种抗氧化剂。已知转录因子核因子-κ F（NF-κ B）被许多化合物激活，包括活性氧中间体。甲萘醌激活NF-κ B，通过电泳迁移率变化测定。这种激活被阻止了相同的抗氧化剂，阻止对细胞毒性与甲萘醌预孵育产生保护。抗p50 IgG阻止甲萘醌刺激的NF-κ B与寡核苷酸探针的结合，而抗p65 IgG产生NF-κ B/寡核苷酸复合物的超位移。水杨酸盐阻止甲萘醌激活NF-κ B，在这些条件下，水杨酸盐增强甲萘醌或H2O2的细胞毒性。用含有编码小鼠I κ B β（NF-κ B的抑制剂）的cDNA的质粒转染，导致甲萘醌的毒性增加。此外，当蛋白激酶C被下调的长期治疗与积极的佛波酯（佛波-12-肉豆蔻酸酯-13-乙酸酯），Hep G2细胞变得更加敏感甲萘醌治疗。然而，用激活NF-κ B的PMA短期治疗导致对甲萘醌细胞毒性的保护。当Hep G2细胞中GSH耗尽时，甲萘醌的细胞毒性增强。甲萘醌预处理后观察到GSH水平增加;水杨酸盐阻断了这种增加，从而将GSH增加与甲萘醌激活NF-κ B联系起来。目前的研究结果表明，甲萘醌预处理通过NF-κ B相关机制保护Hep G2细胞免受氧化损伤，这可能部分涉及GSH的产生增加。
Menadione (vitamin K-3,2-methyl-1,4-naphthoquinone), a redox cycling reagent, generates reactive oxygen intermediates and causes oxidative injury. The addition of menadione to Hep G2 cells produced a time-and concentration-dependent loss of cell viability. Preincubation of Hep G2 cells with low, nontoxic concentrations of menadione increased the viability of the cells against toxic doses of menadione or H2O2. Maximum protection was found with menadione concentrations of similar to 3 mu M and preincubation times of similar to 45 min. This protective effect could be blocked by the protein synthesis inhibitor cycloheximide and by a variety of antioxidants. The transcription factor nuclear factor-kappa F (NF-kappa B) is known to be activated by many compounds, including reactive oxygen intermediates. Menadione activated NF-kappa B as determined by electrophoretic mobility shift assays. This activation was prevented by the same antioxidants that blocked protection against cytotoxicity produced by preincubation with menadione. Anti-p50 IgG prevented the menadione-stimulated binding of NF-kappa B to the oligonucleotide probe, whereas anti-p65 IgG produced a supershift of the NF-kappa B/oligonucleotide complex. Salicylate prevented the activation of NF-kappa B by menadione, and under these conditions, salicylate potentiated the cytotoxicity of menadione or H2O2. Transfection with a plasmid containing cDNA encoding mouse I kappa B beta, an inhibitor of NF-kappa B, resulted in increased toxicity by menadione. Furthermore, when protein kinase C was down-regulated by prolonged treatment with active phorbol eater (phorbol-12-myristate-13-acetate), the Hep G2 cells became more sensitive to menadione treatment. However, short term treatment with PMA, which activated NF-kappa B, resulted in protection against menadione cytotoxicity. Menadione cytotoxicity was enhanced when the Hep G2 cells were depleted of GSH. An increased level of GSH was observed after menadione pretreatment; this increase was blocked by salicylate, thereby linking the GSH increase to activation of NF-kappa B by menadione. The results of the current study suggest that menadione pretreatment protects Hep G2 cells from oxidative injury through an NF-kappa B-related mechanism, which may involve, in part, increased production of GSH.