Laboratory of Drug Delivery and Disposition, KU Leuven , Campus Gasthuisberg, O&N 2, Herestraat 49 box 921, B-3000 Leuven, Belgium.
Mol Pharm. 2013 Mar 4;10(3):1056-62. doi: 10.1021/mp300512r. Epub 2013 Feb 19.
Rodent models are less suitable for predicting drug-drug interactions at the level of the human intestinal mucosa, especially when nuclear receptors such as pregnane X receptor (PXR) are involved. Recently, a transgenic mouse model, expressing both human PXR and CYP3A4, was developed and shown to be a better predictor of CYP3A4 induction by xenobiotics in humans as compared to wild-type mice. In the present study, we tested the hypothesis that this mouse model can also predict PXR-mediated induction of intestinal P-gp in humans. By use of the in situ intestinal perfusion technique with mesenteric blood sampling, the effect of oral rifampicin treatment on intestinal permeability for the HIV protease inhibitor darunavir, a dual CYP3A4/P-gp substrate, was investigated. Rifampicin treatment lowered the intestinal permeability for darunavir by 50% compared to that in nontreated mice. The P-gp inhibitor GF120918 increased the permeability for darunavir by 400% in rifampicin-treated mice, whereas this was only 56% in mice that were not treated, thus indicating P-gp induction by rifampicin. The nonspecific P450 inhibitor aminobenzotriazole (100 μM) did not affect the permeability for darunavir. Quantitative Western blot analysis of the intestinal tissue showed that rifampicin treatment induced intestinal P-gp levels 4-fold, while CYP3A4 levels remained unchanged. Oral co-administration of rifampicin with the phytochemical sulforaphane for 3 days increased the permeability for darunavir by 50% compared to that with rifampicin treatment alone. These data show that PXR/CYP3A4-humanized mice can be used to study the inducing effects of xenobiotics on intestinal P-gp.
啮齿类动物模型不太适合预测人类肠道黏膜水平的药物-药物相互作用，尤其是当涉及核受体如孕烷 X 受体 (PXR) 时。最近，开发了一种表达人 PXR 和 CYP3A4 的转基因小鼠模型，该模型被证明比野生型小鼠更能预测外源性物质对 CYP3A4 的诱导作用。在本研究中，我们检验了这样一个假设，即该小鼠模型也可以预测 PXR 介导的人类肠道 P-糖蛋白的诱导作用。通过使用肠系膜采血的原位肠灌注技术，研究了口服利福平治疗对 HIV 蛋白酶抑制剂达鲁那韦（CYP3A4/P-糖蛋白双重底物）肠道通透性的影响。与未治疗的小鼠相比，利福平治疗使达鲁那韦的肠道通透性降低了 50%。P-糖蛋白抑制剂 GF120918 使利福平治疗的小鼠中达鲁那韦的通透性增加了 400%，而未治疗的小鼠中仅增加了 56%，表明利福平诱导了 P-糖蛋白。非特异性 P450 抑制剂氨基苯并三唑（100μM）对达鲁那韦的通透性没有影响。对肠道组织的定量 Western blot 分析表明，利福平治疗使肠道 P-糖蛋白水平增加了 4 倍，而 CYP3A4 水平保持不变。与单独使用利福平相比，利福平与植物化学物萝卜硫素连续口服 3 天共同给药使达鲁那韦的通透性增加了 50%。这些数据表明，PXR/CYP3A4 人源化小鼠可用于研究外源性物质对肠道 P-糖蛋白的诱导作用。
