Vanadate-induced activation of activator protein-1: role of reactive oxygen species
Vanadate-induced activation of activator protein-1: role of reactive oxygen species
复制标题
DOI：
10.1093/carcin/20.4.663
复制
发表时间：
1999-04-01
期刊：
影响因子：
4.7
通讯作者：
Vallyathan, V
中科院分区：
文献类型：
--
作者：
Ding, M;Li, JJ;Vallyathan, V
本研究旨在验证钒的毒性和致癌性可能是由于活性氧升高导致转录因子激活蛋白-1（AP-1）激活所致的假设。AP-1的反式激活反应与佛波酯和生长因子的转化反应有关。为了研究钒在AP-1激活中的可能活性，我们用不同浓度的钒酸盐处理稳定转染AP-1荧光素酶报告质粒的小鼠表皮JB 6 P+细胞，这导致AP-1的浓度依赖性反式激活，超氧化物歧化酶（SOD）和过氧化氢酶抑制钒酸盐诱导的AP-1激活，表明超氧阴离子自由基（O-2（-.））参与，羟基自由基（. OH）和/或H2 O2参与钒酸盐诱导的AP-1活化机制。然而，甲酸钠，一个特定的.OH清除剂，并没有改变钒酸盐诱导的AP-1激活，这表明一个最小的作用。OH自由基。NADPH通过增加钒酸盐介导的O-2（-.）的产生来增强AP-1的激活。N-乙酰半胱氨酸，一种含巯基的抗氧化剂，降低了活化，进一步表明钒酸盐诱导的AP-1活化涉及氧化还原反应。Calphostin C是蛋白激酶C（PKC）的特异性抑制剂，其抑制AP-1的活化，表明PKC参与导致钒酸盐诱导的AP-1活化的细胞信号级联。电子自旋共振（ESR）测量表明，在NADPH存在下，JB 6 P+细胞能够还原钒酸盐生成钒（IV），在钒酸盐还原过程中消耗分子氧生成O-2（-.）如通过使用5，5-二甲基-L-吡咯啉N-氧化物作为自旋捕获剂的ESR自旋捕获所测量的。SOD抑制ESR自旋加合物信号，进一步证明O-2（-.）这些结果为钒与其他类型的肿瘤促进剂一样反式激活AP-1依赖性基因表达的模型提供了支持。在钒的情况下，AP-1反式激活依赖于O-2（-）的产生。H2 O2，但不是。哦
The present study was undertaken to test the hypothesis that the toxicity and carcinogenicity of vanadium might arise from elevation of reactive oxygen species leading to activation of the transcription factor activator protein-1 (AP-1), The AP-1 transactivation response has been implicated as causal in transformation responses to phorbol esters and growth factors. To investigate the possible activity of vanadium in the activation of AP-1, we treated mouse epidermal JB6 P+ cells stably transfected with an AP-1 luciferase reporter plasmid with various concentrations of vanadate, This resulted in concentration-dependent transactivation of AP-1, Superoxide dismutase (SOD) and catalase inhibited AP-1 activation induced by vanadate, indicating the involvement of superoxide anion radical (O-2(-.)), hydroxyl radical (. OH) and/or H2O2 in the mechanism of vanadate-induced AP-1 activation. However, sodium formate, a specific .OH scavenger, did not alter vanadate-induced AP-1 activation, suggesting a minimal role for the . OH radical. NADPH enhanced AP-1 activation by increasing vanadate-mediated generation of O-2(-.). N-acetylcysteine, a thiol-containing antioxidant, decreased activation, further showing that vanadate-induced AP-1 activation involved redox reactions. Calphostin C, a specific inhibitor of protein kinase C (PKC), inhibited activation of AP-1, demonstrating that PKC is involved in the cell signal cascades leading to vanadate-induced AP-1 activation. Electron spin resonance (ESR) measurements show that JB6 P+ cells are able to reduce vanadate to generate vanadium(IV) in the presence of NADPH, Molecular oxygen was consumed during the vanadate reduction process to generate O-2(-.) as measured by ESR spin trapping using 5,5-dimethyl-L-pyrroline N-oxide as the spin trapping agent. SOD inhibited the ESR spin adduct signal, further demonstrating the generation of O-2(-.) in the cellular reduction of vanadate, These results provide support for a model in which vanadium, like other classes of tumor promoters, transactivates AP-l-dependent gene expression. In the case of vanadium, AP-1 transactivation is dependent on the generation of O-2(-.) and H2O2, but not . OH.