RT Journal Article
SR Electronic
T1 EXPRESSION OF HUMAN PHASE II ENZYMES IN CHIMERIC MICE WITH HUMANIZED LIVER
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP 1333
OP 1340
DO 10.1124/dmd.105.005157
VO 33
IS 9
A1 Katoh, Miki
A1 Matsui, Tomohito
A1 Okumura, Hirotoshi
A1 Nakajima, Miki
A1 Nishimura, Masuhiro
A1 Naito, Shinsaku
A1 Tateno, Chise
A1 Yoshizato, Katsutoshi
A1 Yokoi, Tsuyoshi
YR 2005
UL http://dmd.aspetjournals.org/content/33/9/1333.abstract
AB We clarified that major human cytochrome P450 (P450) enzymes were expressed in a chimeric mouse line established recently in Japan, in which the liver could be replaced by more than 80% with human hepatocytes. In this study, we investigated major human phase II enzymes such as UDP-glucuronosyltransferase (UGT), sulfotransferase (SULT), N-acetyltransferase (NAT), and glutathione S-transferase (GST) in the livers of chimeric mice by mRNA, protein, and enzyme activity using reverse transcription-polymerase chain reaction, Western blot analysis, and high-performance liquid chromatography, respectively. Human UGT, SULT, NAT, and GST mRNA were expressed in the liver of the chimeric mice, and UGT2B7, SULT1E1, SULT2A1, and GSTA1 proteins could be detected. The expression of mRNA and protein was correlated with the human albumin (hAlb) concentration in mouse blood, the replacement of which by human hepatocytes could be estimated by the hAlb concentration in the blood of the chimeric mice, because the chimeric mice produce human albumin. The enzyme activities, such as morphine 6-glucuronosyltransferase activity and estrone 3-sulfotransferase activity, activities that are specific to humans but not to mice, were increased in a hAlb concentration-dependent manner. The chimeric mice with humanized liver with nearly 90% replacement by human hepatocytes demonstrated almost the same protein contents of human phase II enzymes and enzyme activities as those of the donor. In conclusion, the chimeric mice exhibited an efficient capacity of drug conjugation similar to that in humans. These chimeric mice expressed human phase II enzymes as well as P450s, suggesting that they could be a useful animal model in drug development. The American Society for Pharmacology and Experimental Therapeutics