TY - JOUR T1 - CYP3A4 induction in the liver and intestine of PXR/CYP3A-humanized mice: approaches by mass spectrometry imaging and portal blood analysis JF - Molecular Pharmacology JO - Mol Pharmacol DO - 10.1124/mol.119.117333 SP - mol.119.117333 AU - Kaoru Kobayashi AU - Jiro Kuze AU - Satoshi Abe AU - Shoko Takehara AU - Genki Minegishi AU - Katsuhide Igarashi AU - Satoshi Kitajima AU - Jun Kanno AU - Takushi Yamamoto AU - Mitsuo Oshimura AU - Yasuhiro Kazuki Y1 - 2019/01/01 UR - http://molpharm.aspetjournals.org/content/early/2019/08/27/mol.119.117333.abstract N2 - Induction of cytochrome P450 3A (CYP3A) in response to pregnane X receptor (PXR) activators shows species-specific differences. To study the induction of human CYP3A in response to human PXR activators, we generated a double humanized mouse model of PXR and CYP3A. CYP3A-humanized mice generated by using a mouse artificial chromosome (MAC) vector containing the entire genomic human CYP3A locus (hCYP3A-MAC mouse line) were bred with PXR-humanized mice in which the ligand binding domain of mouse PXR was replaced with that of human PXR, resulting in double humanized mice (hCYP3A-MAC/hPXR mouse line). Oral administration of the human PXR activator rifampicin increased hepatic expression of CYP3A4 mRNA and triazolam 1'- and 4-hydroxylation activities, CYP3A probe activities, in the liver and intestine microsomes of hCYP3A-MAC/hPXR mice. The plasma concentration of triazolam after oral dosing was significantly decreased by rifampicin treatment in hCYP3A-MAC/hPXR mice but not in hCYP3A-MAC mice. In addition, mass spectrometry imaging analysis showed that rifampicin treatment increased the formation of hydroxytriazolam in the intestine of hCYP3A-MAC/hPXR mice after oral dosing of triazolam. The plasma concentration of 1'- and 4-hydroxytriazolam in portal blood was also increased by rifampicin treatment in hCYP3A-MAC/hPXR mice. These results suggest that the hCYP3A-MAC/hPXR mouse line may be a useful model to predict human PXR-dependent induction of metabolism of CYP3A4 substrates in the liver and intestine.SIGNIFICANCE STATEMENT We generated a double humanized mouse line for CYP3A and PXR. Briefly, CYP3A-humanized mice generated by using a mouse artificial chromosome vector containing the entire genomic human CYP3A locus were bred with PXR-humanized mice in which the ligand binding domain of mouse PXR was replaced with that of human PXR. Expression of CYP3A4 and metabolism of triazolam, a typical CYP3A substrate, in the liver of CYP3A/PXR-humanized mice were enhanced in response to rifampicin, a typical human PXR activator. Enhancement of triazolam metabolism in the intestine of CYP3A/PXR-humanized mice was firstly shown by combination of mass spectrometry imaging of sliced intestine and LC-MS/MS analysis of metabolite concentration in portal blood after oral dosing of triazolam. ER -