Uehara Shotaro, Uno Yasuhiro, Inoue Takashi, Kawano Mirai, Shimizu Makiko, Toda Akiko, Utoh Masahiro, Sasaki Erika, Yamazaki Hiroshi
Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan (S.U., M.K., M.S., H.Y.); Pharmacokinetics and Bioanalysis Center, Shin Nippon Biomedical Laboratories, Ltd., Kainan, Wakayama, Japan (Y.U., A.T., M.U.); Department of Applied Developmental Biology (T.I.) and Center of Applied Developmental Biology (E.S.), Central Institute for Experimental Animals, Kawasaki, Japan; and Keio Advanced Research Center, Keio University, Minato-ku, Tokyo, Japan (E.S.).
Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan (S.U., M.K., M.S., H.Y.); Pharmacokinetics and Bioanalysis Center, Shin Nippon Biomedical Laboratories, Ltd., Kainan, Wakayama, Japan (Y.U., A.T., M.U.); Department of Applied Developmental Biology (T.I.) and Center of Applied Developmental Biology (E.S.), Central Institute for Experimental Animals, Kawasaki, Japan; and Keio Advanced Research Center, Keio University, Minato-ku, Tokyo, Japan (E.S.)
Drug Metab Dispos. 2016 Jul;44(7):911-5. doi: 10.1124/dmd.116.070383. Epub 2016 Apr 20.
Marmoset cytochrome P450 2C19, highly homologous to human P450 2C9 and 2C19, has been identified in common marmosets (Callithrix jacchus), a nonhuman primate species used in drug metabolism studies. Although genetic variants in human and macaque P450 2C genes account for the interindividual variability in drug metabolism, genetic variants have not been investigated in the marmoset P450 2C19 In this study, sequencing of P450 2C19 in 24 marmosets identified three variants p.[(Phe7Leu; Ser254Leu; Ile469Thr)], which showed substantially reduced metabolic capacity of S-warfarin compared with the wild-type group in vivo and in vitro. Although mean plasma concentrations of R-warfarin in marmosets determined after chiral separation were similar between the homozygous mutant and wild-type groups up to 24 hours after the intravenous and oral administrations of racemic warfarin, S-warfarin depletion from plasma was significantly faster in the three wild-type marmosets compared with the three homozygous mutant marmosets. These variants, cosegregating in the marmosets analyzed, influenced metabolic activities in 18 marmoset liver microsomes because the homozygotes and heterozygotes showed significantly reduced catalytic activities in liver microsomes toward S-warfarin 7-hydroxylation compared with the wild-type group. Kinetic analysis for S-warfarin 7-hydroxylation indicated that the recombinant P450 2C19 Ser254Leu variant would change the metabolic capacity. These results indicated that the interindividual variability of P450 2C-dependent drug metabolism such as S-warfarin clearance is at least partly accounted for by P450 2C19 variants in marmosets, suggesting that polymorphic P450 2C-dependent catalytic functions are relatively similar between marmosets and humans.
狨猴细胞色素P450 2C19与人类P450 2C9和2C19高度同源，已在普通狨猴（Callithrix jacchus）中被鉴定出来，普通狨猴是一种用于药物代谢研究的非人类灵长类动物。尽管人类和猕猴P450 2C基因中的遗传变异解释了药物代谢的个体间差异，但狨猴P450 2C19中的遗传变异尚未得到研究。在本研究中，对24只狨猴的P450 2C19进行测序，鉴定出三个变异体p.[(Phe7Leu; Ser254Leu; Ile469Thr)]，与野生型组相比，它们在体内和体外显示出S-华法林代谢能力显著降低。尽管在手性分离后测定的狨猴中R-华法林的平均血浆浓度在静脉内和口服消旋华法林后24小时内，纯合突变体和野生型组之间相似，但与三只纯合突变体狨猴相比，三只野生型狨猴血浆中S-华法林的清除明显更快。这些在分析的狨猴中共分离的变异体影响了18个狨猴肝微粒体中的代谢活性，因为与野生型组相比，纯合子和杂合子在肝微粒体中对S-华法林7-羟化的催化活性显著降低。对S-华法林7-羟化的动力学分析表明，重组P450 2C19 Ser254Leu变异体将改变代谢能力。这些结果表明，P450 2C依赖的药物代谢如S-华法林清除的个体间差异至少部分是由狨猴中的P450 2C19变异体引起的，这表明多态性P450 2C依赖的催化功能在狨猴和人类之间相对相似。
