Figure 4

Characterization of POR cKO humanized liver mice. (A) Immunohistochemical staining of human Mitochondria (hMIT), CYP1A2, CYP2C9, and CYP3A4 proteins in liver tissue from POR cKO humanized liver mice. Rectangular area on top panel was enlarged in lower panel. Dotted circles indicate the region comprising mouse hepatocytes (m). P, portal tract, C, central vein. Scale bar, 5 mm (top panel) and 500 μm (lower panel). (B) Expression level of human pharmacokinetics-related genes in the liver from humanized liver TK-NOG (Normal Hu-liver) mice (n = 3) and POR cKO humanized liver (POR cKO Hu-liver) mice (n = 3) were measured via qRT-PCR. Data are presented as the mean ± SD. Statistically significant difference when compared with that in normal-Hu-liver mice; ****p < 0.0001. (C) Drug-metabolizing activity in liver microsomes from TK-NOG humanized liver mice (Normal Hu-liver), POR cKO mice, POR cKO humanized liver mice (POR cKO Hu-liver), and humans. Phenacetin (50 μM), diclofenac (40 μM), omeprazole (10 μM), metoprolol (5 μM), and midazolam (5 μM) were incubated with pooled liver microsomes (0.20 mg/mL) from normal Hu-liver mice (n = 4), POR cKO mice (n = 5), POR cKO Hu-liver mice (n = 4), and humans (n = 50) at 37 °C for 10–20 min. Data are presented as the mean ± SD.