Humanizing the zebrafish liver shifts drug metabolic profiles and improves pharmacokinetics of CYP3A4 substrates.
Understanding and predicting whether new drug candidates will be safe in the clinic is a critical hurdle in pharmaceutical development, that relies in part on absorption, distribution, metabolism, excretion and toxicology studies in vivo. Zebrafish is a relatively new model system for drug metabolism and toxicity studies, offering whole organism screening coupled with small size and potential for high-throughput screening. Through toxicity and absorption analyses of a number of drugs, we find that zebrafish is generally predictive of drug toxicity, although assay outcomes are influenced by drug lipophilicity which alters drug uptake. In addition, liver microsome assays reveal specific differences in metabolism of compounds between human and zebrafish livers, likely resulting from the divergence of the cytochrome P450 superfamily between species. To reflect human metabolism more accurately, we generated a transgenic "humanized" zebrafish line that expresses the major human phase I detoxifying enzyme, CYP3A4, in the liver. Here, we show that this humanized line shows an elevated metabolism of CYP3A4-specific substrates compared to wild-type zebrafish. The generation of this first described humanized zebrafish liver suggests such approaches can enhance the accuracy of the zebrafish model for toxicity prediction.
['Poon|Kar Lai|KL|', 'Wang|Xingang|X|', 'Ng|Ashley S|AS|', 'Goh|Wei Huang|WH|', 'McGinnis|Claudia|C|', 'Fowler|Stephen|S|', 'Carney|Tom J|TJ|http://orcid.org/0000-0003-2371-1924', 'Wang|Haishan|H|', 'Ingham|Phillip W|PW|']
D000818:Animals D030801:Animals, Genetically Modified D002851:Chromatography, High Pressure Liquid D051544:Cytochrome P-450 CYP3A D006801:Humans D057927:Hydrophobic and Hydrophilic Interactions D008658:Inactivation, Metabolic D008099:Liver D013058:Mass Spectrometry D004364:Pharmaceutical Preparations D010599:Pharmacokinetics D012995:Solubility D018675:Toxicity Tests D015027:Zebrafish
Humanized Zebrafish Liver CYP3A4 Toxicity Microsomes Midazolam