Uno Yasuhiro, Morikuni Saho, Shiraishi Mitsuya, Asano Atsushi, Murayama Norie, Yamazaki Hiroshi
Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan (Y.U., M.S., A.A.) and Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan (S.M., N.M., H.Y.)
Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima, Japan (Y.U., M.S., A.A.) and Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan (S.M., N.M., H.Y.).
Drug Metab Dispos. 2023 May;51(5):637-644. doi: 10.1124/dmd.122.001236. Epub 2023 Feb 8.
Cytochromes P450 (P450s or CYPs) are important drug-metabolizing enzymes. Because dogs are frequently used in drug metabolism studies, knowledge of dog CYP2C enzymes is essential because in humans these enzymes are abundant and play major roles in liver and intestine. The present study identified and characterized novel dog CYP2C94 along with previously identified dog CYP2C21 and CYP2C41. Dog CYP2C21, CYP2C41, and CYP2C94 cDNAs, respectively, contained open reading frames of 490, 489, and 496 amino acids and shared high-sequence identities (70%, 75%, and 58%) with human CYP2Cs. Dog CYP2C94 mRNA was preferentially expressed in liver, just as dog CYP2C21 and CYP2C41 mRNAs were. In dog liver, CYP2C21 mRNA was the most abundant, followed by CYP2C94 and CYP2C41 mRNAs. Moreover, the hepatic expressions of all three dog CYP2C mRNAs varied in four individual dogs, two of which did not express CYP2C41 mRNA. The three dog genes had similar gene structures, and , although located on the same chromosome, was in a genomic region far from the gene cluster containing and Metabolic assays with recombinant proteins showed that dog CYP2C94, along with CYP2C21 and CYP2C41, efficiently catalyzed oxidations of diclofenac, warfarin, and/or omeprazole, indicating that dog CYP2C94 is a functional enzyme. Novel dog is expressed abundantly in liver and encodes a functional enzyme that metabolizes human CYP2C substrates; it is, therefore, likely responsible for drug clearances in dogs. SIGNIFICANCE STATEMENT: Novel dog cytochrome P450 2C94 (CYP2C94) was identified and characterized along with dog CYP2C21 and CYP2C41. Dog CYP2C94, isolated from liver, had 58% sequence identity and a close phylogenetic relationship with its human homologs and was expressed in liver at the mRNA level. Dog CYP2C94 (and CYP2C21 and CYP2C41) catalyzed oxidations of diclofenac and omeprazole, human CYP2C9 and CYP2C19 substrates, respectively, but CYP2C41 also hydroxylated warfarin. CYP2C94 is therefore a functional drug-metabolizing enzyme likely responsible for drug clearances in dogs.
细胞色素P450（P450s或CYPs）是重要的药物代谢酶。由于狗常用于药物代谢研究，了解犬CYP2C酶至关重要，因为在人类中这些酶含量丰富，在肝脏和肠道中发挥主要作用。本研究鉴定并表征了新型犬CYP2C94以及先前鉴定的犬CYP2C21和CYP2C41。犬CYP2C21、CYP2C41和CYP2C94的cDNA分别包含490、489和496个氨基酸的开放阅读框，与人CYP2C具有较高的序列同一性（分别为70%、75%和58%）。犬CYP2C94 mRNA优先在肝脏中表达，犬CYP2C21和CYP2C41 mRNA也是如此。在犬肝脏中，CYP2C21 mRNA含量最丰富，其次是CYP2C94和CYP2C41 mRNA。此外，三只犬CYP2C mRNA在四只个体犬中的肝脏表达各不相同，其中两只不表达CYP2C41 mRNA。这三个犬基因具有相似的基因结构，并且尽管位于同一条染色体上，但处于远离包含 和 的基因簇的基因组区域。重组蛋白的代谢分析表明，犬CYP2C94与CYP2C21和CYP2C41一起有效地催化双氯芬酸、华法林和/或奥美拉唑的氧化，表明犬CYP2C94是一种功能性酶。新型犬 在肝脏中大量表达，编码一种代谢人CYP2C底物的功能性酶；因此，它可能负责犬体内的药物清除。意义声明：新型犬细胞色素P450 2C94（CYP2C94）与犬CYP2C21和CYP2C41一起被鉴定和表征。从肝脏中分离出的犬CYP2C94与其人类同源物具有58%的序列同一性和密切的系统发育关系，并在mRNA水平在肝脏中表达。犬CYP2C94（以及CYP2C21和CYP2C41）分别催化双氯芬酸和奥美拉唑的氧化，双氯芬酸和奥美拉唑分别是人CYP2C9和CYP2C19的底物，但CYP2C41也使华法林羟基化。因此，CYP2C94是一种功能性药物代谢酶，可能负责犬体内的药物清除。
