Development of a common carp (Cyprinus carpio) pregnane X receptor (cPXR) transactivation reporter assay and its activation by azole fungicides and pharmaceutical chemicals.
Development of a common carp (Cyprinus carpio) pregnane X receptor (cPXR) transactivation reporter assay and its activation by azole fungicides and pharmaceutical chemicals.
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DOI：
10.1016/j.tiv.2017.02.023
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发表时间：
2017-06
期刊：
影响因子：
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通讯作者：
Tyler CR
中科院分区：
文献类型：
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作者：
Lange A;Corcoran J;Miyagawa S;Iguchi T;Winter MJ;Tyler CR
在哺乳动物中，甾烷X受体（PXR）是一种转录因子，在调节参与药物生物转化的几个基因的表达中起关键作用。PXR存在于鱼类中，并且已知在其控制下的一些基因可以被哺乳动物PXR配体上调。尽管如此，PXR在鱼类药物生物转化中的直接参与尚未确定。在这里，全长PXR序列克隆鲤鱼（鲤鱼），并用于荧光素酶报告分析，以阐明其在鱼类异源生物质代谢的作用。还建立了人PXR（hPXR）的报告基因测定，以比较人和鲤鱼（cPXR）异构体之间的反式激活。利福平如预期激活hPXR，但不激活cPXR。相反，克霉唑（CTZ）激活两种亚型，对cPXR更有效，EC50在水生环境中测量的CTZ浓度范围内。两种亚型对其他唑类药物的反应相似。测试的一系列药物对cPXR或hPXR没有激活或活性非常弱。总体而言，这些结果表明，cPXR可能不同于hPXR在其响应和/或敏感性诱导不同的环境化学品，与风险评估的影响，因为物种差异。鲤鱼PXR报告基因检测方法的建立PXR反式激活因激动剂和物种而异。PXR的物种差异对风险评估的影响。鱼类可能不是研究人类PXR潜在化学激活的良好模型。
In mammals, the pregnane X receptor (PXR) is a transcription factor with a key role in regulating expression of several genes involved in drug biotransformation. PXR is present in fish and some genes known to be under its control can be up-regulated by mammalian PXR ligands. Despite this, direct involvement of PXR in drug biotransformation in fish has yet to be established. Here, the full length PXR sequence was cloned from carp (Cyprinus carpio) and used in a luciferase reporter assay to elucidate its role in xenobiotic metabolism in fish. A reporter assay for human PXR (hPXR) was also established to compare transactivation between human and carp (cPXR) isoforms. Rifampicin activated hPXR as expected, but not cPXR. Conversely, clotrimazole (CTZ) activated both isoforms and was more potent on cPXR, with an EC50 within the range of concentrations of CTZ measured in the aquatic environment. Responses to other azoles tested were similar between both isoforms. A range of pharmaceuticals tested either failed to activate, or were very weakly active, on the cPXR or hPXR. Overall, these results indicate that the cPXR may differ from the hPXR in its responses and/or sensitivity to induction by different environmental chemicals, with implications for risk assessment because of species differences. Establishment of a reporter gene assay for carp PXR. PXR-transactivation differs with agonists and species. Implications of species-differences in PXR for risk assessment. Fish might not be good models for studying potential chemical activation of human PXR.