Trans-chromosomic mice containing a human CYP3A cluster for prediction of xenobiotic metabolism in humans
Trans-chromosomic mice containing a human CYP3A cluster for prediction of xenobiotic metabolism in humans
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DOI：
10.1093/hmg/dds468
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发表时间：
2013-02-01
影响因子：
3.5
通讯作者：
Oshimura, Mitsuo
中科院分区：
文献类型：
--
作者：
Kazuki, Yasuhiro;Kobayashi, Kaoru;Oshimura, Mitsuo
人类 CYP3A 是人类肝脏和小肠中含量最丰富的 P450 同工酶，可代谢市场上约 50 种医疗药物。人类CYP3A亚家族由编码在人类7号染色体上的四个成员（CYP3A4、CYP3A5、CYP3A7、CYP3A43）组成。然而，由于传统克隆技术的限制，携带整个人类CYP3A簇的转基因小鼠系尚未构建。在这里，我们证明引入包含整个基因组人类 CYP3A 位点的人类人工染色体 (HAC) 重现了人类 CYP3A 基因的组织和阶段特异性表达以及小鼠中的外源代谢。将大约 700 kb 的整个 CYP3A 基因组片段克隆到 HAC (CYP3A-HAC) 中，并通过染色体工程技术生成携带单个拷贝的种系可传递 CYP3A-HAC 的转染色体 (Tc) 小鼠。 CYP3A 基因的组织和阶段特异性表达谱与人类中观察到的一致。我们进一步生成了背景纯合携带 CYP3A-HAC 的小鼠，用于靶向删除大多数内源性 Cyp3a 基因。在这种具有完全人源化 CYP3A 基因的小鼠品系中，很好地再现了在人类中观察到的三唑仑代谢动力学、CYP3A 介导的基于机制的失活效应以及胎儿特异性脱氢表雄酮代谢物的形成。因此，这些小鼠可能对于评估 CYP3A 酶代谢的新药物和研究人类 CYP3A 基因表达的调节有价值。此外，该系统还可用于产生携带其他人类代谢基因的Tc小鼠。
Human CYP3A is the most abundant P450 isozyme present in the human liver and small intestine, and metabolizes around 50 of medical drugs on the market. The human CYP3A subfamily comprises four members (CYP3A4, CYP3A5, CYP3A7, CYP3A43) encoded on human chromosome 7. However, transgenic mouse lines carrying the entire human CYP3A cluster have not been constructed because of limitations in conventional cloning techniques. Here, we show that the introduction of a human artificial chromosome (HAC) containing the entire genomic human CYP3A locus recapitulates tissue- and stage-specific expression of human CYP3A genes and xenobiotic metabolism in mice. About 700 kb of the entire CYP3A genomic segment was cloned into a HAC (CYP3A-HAC), and trans-chromosomic (Tc) mice carrying a single copy of germline-transmittable CYP3A-HAC were generated via a chromosome-engineering technique. The tissue- and stage-specific expression profiles of CYP3A genes were consistent with those seen in humans. We further generated mice carrying the CYP3A-HAC in the background homozygous for targeted deletion of most endogenous Cyp3a genes. In this mouse strain with ofully humanized' CYP3A genes, the kinetics of triazolam metabolism, CYP3A-mediated mechanism-based inactivation effects and formation of fetal-specific metabolites of dehydroepiandrosterone observed in humans were well reproduced. Thus, these mice are likely to be valuable in evaluating novel drugs metabolized by CYP3A enzymes and in studying the regulation of human CYP3A gene expression. Furthermore, this system can also be used for generating Tc mice carrying other human metabolic genes.