title: Generation and characterization of a transgenic mouse model with hepatic expression of human CYP2A6.
abstract: The aim of this study was to prepare and characterize a transgenic mouse model in which CYP2A6, a human P450 enzyme, is expressed specifically in the liver. CYP2A6, which is mainly expressed in human liver, is active toward many xenobiotics. Our transgene construct contained the mouse transthyretin promoter/enhancer, a full-length CYP2A6 cDNA, and a downstream neomycin-resistance gene for positive selection in embryonic stem cells. Hepatic expression of the CYP2A6 transgene was demonstrated by immunoblotting, whereas tissue specificity of CYP2A6 expression was confirmed by RNA-PCR. The transgenic mouse was further characterized after being backcrossed to the B6 strain for six generations. Hepatic microsomes from homozygous transgenic mice had activities significantly higher than those of B6 mice toward coumarin. The in vivo activity of transgenic CYP2A6 was also determined. Systemic clearance of coumarin was significantly higher in the transgenic mice than in B6 controls, consistent with the predicted role of CYP2A6 as the major coumarin hydroxylase in human liver. The CYP2A6-transgenic mouse model should be valuable for studying the in vivo function of this polymorphic human enzyme in drug metabolism and chemical toxicity.
authors.affiliation: Wadsworth Center, New York State Department of Health, School of Public Health, State University of New York at Albany, NY 12201, USA.
authors.forename: Qing-Yu
authors.initials: QY
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Gu
authors.forename: Ting
authors.initials: T
authors.lastname: Su
authors.forename: Huadong
authors.initials: H
authors.lastname: Cui
authors.forename: Xiuling
authors.initials: X
authors.lastname: Zhang
authors.forename: Jaime
authors.initials: J
authors.lastname: D'Agostino
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Zhuo
authors.forename: Weizhu
authors.initials: W
authors.lastname: Yang
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Swiatek
authors.forename: Xinxin
authors.initials: X
authors.lastname: Ding
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D003374:Coumarins / Q000097:blood; D065637:Cytochrome P-450 CYP2A6; D005260:Female; D006801:Humans; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D006899:Mixed Function Oxygenases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D023421:Models, Animal; D014468:Umbelliferones / Q000097:blood
chemical_list: D003374:Coumarins; D014468:Umbelliferones; C031477:7-hydroxycoumarin; C030123:coumarin; D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C585710:CYP2A6 protein, human; D065637:Cytochrome P-450 CYP2A6