Shibanuma M, Kuroki T, Nose K
Department of Microbiology, Showa University School of Pharmaceutical Sciences, Tokyo, Japan.
FEBS Lett. 1994 Oct 10;353(1):62-6. doi: 10.1016/0014-5793(94)01014-5.
Redox-based modulation plays a role in transcriptional control of gene expression. In the present study, we investigated the possible role of reactive oxygen species in the induction of interleukin-6 (IL-6) mRNA and in increases in NF kappa B binding activity by tumor necrosis factor (TNF) alpha using a mouse fibroblastic cell line, Balb/3T3. Expression of IL-6 mRNA is known to be dependent upon NF kappa B that binds to the 5'-flanking region of the IL-6 gene. We found that: (i) TNF alpha increased IL-6 mRNA levels and this increase was inhibited by N-acetyl-L-cysteine (NAC), a scavenger of reactive oxygen species. (ii) NF kappa B binding activity in this cell line was also increased by TNF alpha, and the increase was inhibited in the presence of NAC. (iii) The treatment of cells with low doses of hydrogen peroxide increased the NF kappa B binding activity. (iv) Expression of a reporter gene in which the chloramphenicol acetyltransferase (CAT) gene was under the control of NF kappa B binding sites was induced by hydrogen peroxide. These results suggest that the induction of IL-6 mRNA is regulated by a mechanism involving reactive oxygen species and that NF kappa B, whose activity is sensitive to the cellular redox state, plays an important role in this induction in a fibroblastic cell line, Balb/3T3, stimulated with TNF alpha.
基于氧化还原的调节在基因表达的转录控制中发挥作用。在本研究中，我们使用小鼠成纤维细胞系Balb/3T3，研究了活性氧在肿瘤坏死因子（TNF）α诱导白细胞介素-6（IL-6）mRNA以及增加核因子κB（NFκB）结合活性方面的可能作用。已知IL-6 mRNA的表达依赖于与IL-6基因5'侧翼区域结合的NFκB。我们发现：（i）TNFα增加了IL-6 mRNA水平，而这种增加被活性氧清除剂N-乙酰-L-半胱氨酸（NAC）抑制。（ii）该细胞系中的NFκB结合活性也被TNFα增加，并且在NAC存在下这种增加受到抑制。（iii）用低剂量过氧化氢处理细胞增加了NFκB结合活性。（iv）过氧化氢诱导了氯霉素乙酰转移酶（CAT）基因受NFκB结合位点控制的报告基因的表达。这些结果表明，IL-6 mRNA的诱导受一种涉及活性氧的机制调节，并且其活性对细胞氧化还原状态敏感的NFκB在TNFα刺激的成纤维细胞系Balb/3T3的这种诱导中起重要作用。
