The CYP2E1-humanized transgenic mouse:: Role of CYP2E1 in acetaminophen hepatotoxicity
The CYP2E1-humanized transgenic mouse:: Role of CYP2E1 in acetaminophen hepatotoxicity
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DOI：
10.1124/dmd.104.002402
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发表时间：
2005-03-01
影响因子：
3.9
通讯作者：
Gonzalez, FJ
中科院分区：
文献类型：
--
作者：
Cheung, C;Yu, AM;Gonzalez, FJ
细胞色素P450(P450)CYP2E1酶代谢和激活广泛的毒理底物，包括酒精、广泛使用的止痛药对乙酰氨基酚、丙酮、苯、氟烷以及致癌物，如偶氮甲烷和二甲基肼。大多数关于CYP2E1的生化和药理作用的研究都来自于对啮齿动物、兔子和培养的肝细胞的研究；因此，将结果外推到人类可能是困难的。通过将人的CYP2E1基因引入到CYP2E1缺失的小鼠中，创造出“人源化”的小鼠，可以绕过这一缺点。建立了表达人细胞色素P450-2E1基因的转基因小鼠系。Western印迹和高效液相色谱/质谱仪分析表明，人的CYP2E1蛋白在人源化的小鼠肝脏中有表达和酶活性。用CYP2E1诱导剂丙酮处理小鼠，证明在该转基因模型中人的CYP2E1是可诱导的。在CYP2E1人源化的小鼠中，探索了对CYP2E1底物对乙酰氨基酚的反应。肝脏毒性是由CYP2E1介导的对乙酰氨基酚激活引起的，表现为血清丙氨酸氨基转移酶水平升高，肝细胞坏死增加，P450水平降低。这些数据证实，在这个人源化的小鼠模型中，人的CYP2E1是有功能的，可以代谢和激活不同的CYP2E1底物，如氯唑沙宗、对硝基苯酚、对乙酰氨基酚和丙酮。CYP2E1人源化小鼠对于阐明人CYP2E1在乙醇诱导的氧化应激和酒精性肝损伤中的作用具有重要的价值。它们还将作为体内预测药物代谢和处置以及药物与药物相互作用的重要工具，这些化学物质是人类CYP2E1的底物。
The cytochrome P450 (P450) CYP2E1 enzyme metabolizes and activates a wide array of toxicological substrates, including alcohols, the widely used analgesic acetaminophen, acetone, benzene, halothane, and carcinogens such as azoxymethane and dimethylhydrazine. Most studies on the biochemical and pharmacological actions of CYP2E1 are derived from studies with rodents, rabbits, and cultured hepatocytes; therefore, extrapolation of the results to humans can be difficult. Creating "humanized" mice by introducing the human CYP2E1 gene into Cyp2e1-null mice can circumvent this disadvantage. A transgenic mouse line expressing the human CYP2E1 gene was established. Western blot and high-performance liquid chromatography/ mass spectrometry analyses revealed human CYP2E1 protein expression and enzymatic activity in the liver of CYP2E1-humanized mice. Treatment of mice with the CYP2E1 inducer acetone demonstrated that human CYP2E1 was inducible in this transgenic model. The response to the CYP2E1 substrate acetaminophen was explored in the CYP2E1-humanized mice. Hepatotoxicity, resulting from the CYP2E1-mediated activation of acetaminophen, was demonstrated in the livers of CYP2E1-humanized mice by elevated serum alanine aminotransferase levels, increased hepatocyte necrosis, and decreased P450 levels. These data establish that in this humanized mouse model, human CYP2E1 is functional and can metabolize and activate different CYP2E1 substrates such as chlorzoxazone, p-nitrophenol, acetaminophen, and acetone. CYP2E1-humanized mice will be of great value for delineating the role of human CYP2E1 in ethanol-induced oxidative stress and alcoholic liver damage. They will also function as an important in vivo tool for predicting drug metabolism and disposition and drug-drug interactions of chemicals that are substrates for human CYP2E1.