Influence of cAMP on reporter bioassays for dioxin and dioxin-like compounds
Influence of cAMP on reporter bioassays for dioxin and dioxin-like compounds
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DOI：
10.1016/j.taap.2005.05.005
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发表时间：
2006-02-15
影响因子：
3.8
通讯作者：
Kitamura, M
中科院分区：
文献类型：
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作者：
Kasai, A;Yao, J;Kitamura, M
在检测二恶英的报告分析中，二恶英响应元件（DRE）通常用作传感器序列。在一些系统中，将含有DREs的CYP1A1启动子（DREcyp）插入小鼠乳腺肿瘤病毒（LTRMMTV）长末端重复序列的一部分，以提高检测的敏感性。我们发现drypp - ltrmmtv不仅对二恶英和二恶英样化合物有反应，而且对福斯克林（一种camp升高剂）也有反应。这种效应是剂量依赖性的，并可被其他camp升高剂再现，包括8-溴camp和3-异丁基甲基黄嘌呤。cAMP反应元件（CRE）和CRE样序列在(DRELTRMMTV)-L-cyp中缺失，不参与该过程。与二恶英的作用相反，cAMP对DREcyp-LTRMMTV的激活不依赖于DRE的配体依赖性转录因子芳烃受体（AhR）。此外。DREcyp、LTMMTV和DRE的一致序列在cAMP作用下均未被激活。这些数据首次阐明了DREcyp与LTRMMTV联合可引起对cAMP的特殊反应，并表明使用AhR拮抗剂对于排除基于DREcyp-LTRMMTV的生物测定法检测和定量二恶英和二恶英样化合物的假阳性反应至关重要。(c) 2005爱思唯尔公司版权所有。
In reporter assays for detection of dioxins, the dioxin-responsive element (DRE) is generally used as a sensor sequence. In several systems, the CYP1A1 promoter containing DREs (DREcyp) is inserted into a part of the long terminal repeat of mouse mammary tumor virus (LTRMMTV) to improve sensitivity of assays. We found that DREcyp-LTRMMTV responds not only to dioxins and dioxin-like compounds but also to forskolin, a cAMP-elevating agent. This effect was dose-dependent and reproduced by other cAMP-elevating agents including 8-bromo-cAMP and 3-isobutyl-methylxanthine. The cAMP response element (CRE) and CRE-like sequences were absent in (DRELTRMMTV)-L-cyp and not involved in this process. In contrast to the effect of dioxin, the activation of DREcyp-LTRMMTV by cAMP was independent of the aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor for DRE. Furthermore. neither DREcyp, LTMMTV nor the consensus sequence of DRE alone was activated in response to cAMP. These data elucidated for the first time that the combination of DREcyp with LTRMMTV causes a peculiar response to cAMP and suggested that use of AhR antagonists is essential to exclude false-positive responses of DREcyp-LTRMMTV-based bioassays for detection and quantification of dioxins and dioxin-like compounds. (c) 2005 Elsevier Inc. All rights reserved.