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In vivo Molecular Mechanism of Human CYP3A Induction Involved in Drug Interaction

人CYP3A诱导参与药物相互作用的体内分子机制

基本信息

批准号：
12672207
负责人：
NAGATA Kiyoshi
金额：
$ 2.43万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12672207/
关键词：
P450 CYP3A4 Induction Adenovirus human in vivo cis-element Nuclear Receptor cis-element CYP3A1 PXR nuclear receptor rat

项目摘要

Cytochrome P450s including in the CYP3A subfamily are involved in metabolism of numbers of clinically relevant substrates as well as numerous endogenous compounds. CYP3A forms are induced by treatment with various drugs, but those induction profiles differ between experimental animals and humans. Recently, a novel orphan receptor, pregnane X receptor (PXR) has been isolated and reported to make a heterodimer with retinoid X receptera (RXRa). In our experiment, co-expression of human PXR (hPXR) with RXRa did not show the CYP3A1 gene activation by treatment with rifampicin. When hPXR co-expressed with other orphan receptors, COUPs, apolipoprotein AI regulatory protein 1 (ARP-1) and v-ErbA-related protein 3, the CYP3A1 gene expression was activated by rifampicin in HepG2 cells. On the contrary, neither co-expression of PXR with RXRa nor with COUPs showed the CYP3A4 gene activation by the treatment, although the activation was observed on single expression of hPXR in HepG2 cells. On the ot … More her hand, both CYP3A1 and CYP3A4 inductions through hPXR activation by rifampicin were basically similar at the level of their cis-elements. The transactivation of the CYP3A4 gene is mainly mediated through dNR-1 locating around at its -7600 bp and enhance through ER-6. To further verify the in vivo activation of the CYP3A4 gene expression by drugs, adenovirus expression vectors, AdCYP3A4-362 and AdCYP3A4-362-7k, were constructed with the proximal promoter (+11 to -364) and the enhancer (-7.2 k to -7.8 k) regions of the CYP3A4 gene, respectively. AdCYP3A4-362 infection to HepG2 cells showed the CYP3A4 gene activation by treatment with clotrimazole and dexamethsone. The gene activation was enhanced by co-infection of AdhPXR. AdCYP3A4-362-7k infection to HepG2 cells showed the CYP3A4 gene activation not only by clotrimazole but also by rifampicin. Therefore in vivo experiment of the CYP3A4 gene activation by use of AdCYP3A4-362-7k was carried out in mouse and rat. Strong CYP3A4 gene activation was observed in mouse livers by administration of all drugs used in this experiment. The activation was strongly enhanced in both animal livers treated only with rifampicin by co-transfection of AdhPXR. These results suggest that PXR is one of essential factors for the CYP3A induction, and others factors are also predicted from our experiment. Less

包括CYP 3A亚家族在内的细胞色素P450参与许多临床相关底物以及许多内源性化合物的代谢。CYP 3A形式通过用各种药物处理诱导，但这些诱导特征在实验动物和人类之间不同。最近，一种新的孤儿受体，甾烷X受体（PXR）已被分离和报告，使异源二聚体与类维生素A X受体（RXRa）。在我们的实验中，人PXR（hPXR）与RXR a的共表达没有显示出利福平处理的CYP 3A 1基因激活。当hPXR与其他孤儿受体COUPs、载脂蛋白AI调节蛋白1（阿普-1）和v-ErbA相关蛋白3共表达时，HepG 2细胞中CYP 3A 1基因的表达被利福平激活。相反，PXR与RXRa或与COUP的共表达均未显示出通过处理的CYP 3A 4基因激活，尽管在HepG 2细胞中单一表达hPXR时观察到激活。在外面 ...更多信息她的手，CYP 3A 1和CYP 3A 4通过利福平激活hPXR的诱导作用在其顺式元件水平上基本相似。CYP 3A 4基因的反式激活主要通过位于其-7600 bp附近的dNR-1介导，并通过ER-6增强。为了进一步验证药物在体内对CYP 3A 4基因表达的激活作用，分别构建了含有CYP 3A 4基因近端启动子（+11至-364）和增强子（-7.2 k至-7.8 k）区域的腺病毒表达载体AdCYP 3A 4 -362和AdCYP 3A 4 -362- 7 k。AdCYP 3A 4 -362感染HepG 2细胞后，经克霉唑和地塞米松处理后，CYP 3A 4基因被激活。AdhPXR共感染可增强基因的激活。AdCYP 3A 4 -362- 7 k感染HepG 2细胞后，CYP 3A 4基因不仅被克霉唑激活，而且被利福平激活。因此，在小鼠和大鼠中进行了通过使用AdCYP 3A 4 -362- 7 k激活CYP 3A 4基因的体内实验。通过给予本实验中使用的所有药物，在小鼠肝脏中观察到强烈的CYP 3A 4基因激活。通过共转染AdhPXR，仅用利福平处理的两种动物肝脏中的激活强烈增强。这些结果表明，PXR是CYP 3A诱导的重要因素之一，其他因素也可以从我们的实验中预测。少