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Analysis of human fetus-specific cytochrome P450 : Evaluation of its function (s) by using transgenic mice and estimation of regulation mechnism (S).

人类胎儿特异性细胞色素P450的分析：通过使用转基因小鼠评估其功能并估计调节机制（S）。

基本信息

批准号：
06454593
负责人：
KAMATAKI Tetsuya
金额：
$ 4.48万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1996
项目状态：
已结题

项目摘要

The human fetus-specific P450, CYP3A7, was expressed in C57BL/6N mice by microinjection into the mouse fertilized eggs of a CYP3A7 cDNA fused to a murine metallothionein-I promoter. Six transgenic lines of mice carrying different copies of the MT-I-CYP3A7 transgene were established. In M10 line of mice, the expression of the CYP3A7 at mRNA and/or protein levels were detected in the liver, testis, and other tissues, while in M2 line of mice the expression of CYP3A7 was found in the kiney and many other tissues. The expression of the CYP3A7 was induced by the treatment with zinc sulfate, an inducer of MT-I promoter. The CYP3A7 was expressed perinatally in the M10 mice, beginning on the day 15 of gestation. The expression level was low in fetal life and increased markedly in the livers of neonates 3 days after birth. The CYP3A7 protein expressed in the livers of M10 neonates as well as in the adults was functionally active in terms of midazolam 1'-hydroxylation in vivo. Using M2 and M10 mice as an animal model, the involvement of human CYP3A7 in the bioactivation of AFB_1 in vivo was further evidenced by a significantly higher AFB1-N^7-Guanine adduct level as well as DNA damage in the liver and kidney of M10 and M2 mice, respectively. These give the first evidence that human CYP3A7 plays a role in the bioactivation of AFB_1 in vivo. This transgenic animal model is the first to carry a human P450 gene and provides the first successful example of assessing a human P450 gene in rodent by transgenic technique.

通过将与鼠金属硫蛋白-I 启动子融合的 CYP3A7 cDNA 显微注射到小鼠受精卵中，在 C57BL/6N 小鼠中表达人类胎儿特异性 P450（CYP3A7）。建立了携带不同MT-I-CYP3A7转基因拷贝的六种转基因小鼠系。在M10系小鼠中，在肝脏、睾丸和其他组织中检测到CYP3A7在mRNA和/或蛋白质水平上的表达，而在M2系小鼠中，在肾脏和许多其他组织中发现CYP3A7表达。 CYP3A7的表达通过用MT-I启动子诱导剂硫酸锌处理来诱导。 CYP3A7 在 M10 小鼠围产期表达，从妊娠第 15 天开始。胎儿期表达水平较低，出生后3天新生儿肝脏中表达水平显着升高。 M10 新生儿和成人肝脏中表达的 CYP3A7 蛋白在体内咪达唑仑 1'-羟基化方面具有功能活性。使用M2和M10小鼠作为动物模型，M10和M2小鼠的AFB1-N^7-鸟嘌呤加合物水平显着升高以及肝脏和肾脏中的DNA损伤，进一步证明了人CYP3A7参与了AFB_1的体内生物激活。这些首次证明人类 CYP3A7 在体内 AFB_1 的生物激活中发挥作用。该转基因动物模型是第一个携带人类P450基因的动物模型，并提供了第一个通过转基因技术在啮齿动物中评估人类P450基因的成功范例。