Department of Pharmaceutics, University of Washington, Seattle, 98195, USA.
Biopharm Drug Dispos. 2012 May;33(4):207-17. doi: 10.1002/bdd.1788. Epub 2012 May 2.
Human immunodeficiency virus (HIV) protease inhibitors (PIs) produce profound and unpredictable drug-drug interactions (DDIs) that cannot be explained fully by their inhibition/inactivation of CYP3A enzymes. Delineating and quantifying the CYPs and transporters inducible by PIs are crucial in developing an integrative mechanistic understanding and prediction of PI-based DDIs. To do so, two LC-MS/MS cocktail assays were modified and validated simultaneously to quantify the CYP activity of CYP3A, 2B6, 2C8, 2C9, 2C19, 1A, 2E1, 2A6 and 2D6 enzymes. These new assays were applied to evaluate the induction potential of eight PIs in microsomes isolated from PI-treated human hepatocytes. The mRNA expression of these CYPs and transporters (OATP1B1, OATP1B3, OATP1A2, MDR1, MRP2 and MRP4) was also evaluated using relative RT-PCR. The majority of PIs were net inducers of CYP3As and 2B6 at both the mRNA and activity level (> 2-fold), while ritonavir, saquinavir, nelfinavir or lopinavir did not induce CYP3A activity (< 2-fold), presumably due to CYP3A inactivation. OATP1B1 and MDR1 were the only two hepatic transporters induced (> 2-fold) by the PIs. Amprenavir was the most potent net inducer. In conclusion, our validated cocktail assays can be implemented to comprehensively quantify CYP activities in human liver microsomes and hepatocyte studies. The results also provide the much needed data on the net induction potential of the PIs for hepatic CYPs and transporters. A qualitative agreement was observed between our results and published PI-based DDIs, suggesting that human hepatocytes are a useful platform for more extensive and quantitative in vitro-in vivo prediction of PI-based DDIs.
人类免疫缺陷病毒（HIV）蛋白酶抑制剂（PI）会产生深刻且不可预测的药物-药物相互作用（DDI），这些作用不能完全用它们对 CYP3A 酶的抑制/失活来解释。阐明和量化 PI 诱导的 CYP 和转运体对于开发基于 PI 的 DDI 的综合机制理解和预测至关重要。为此，我们同时修改和验证了两种 LC-MS/MS 鸡尾酒测定法来定量 CYP3A、2B6、2C8、2C9、2C19、1A、2E1、2A6 和 2D6 酶的 CYP 活性。这些新测定法用于评估 8 种 PI 在 PI 处理的人肝细胞分离的微粒体中的诱导潜力。还使用相对 RT-PCR 评估这些 CYP 和转运体（OATP1B1、OATP1B3、OATP1A2、MDR1、MRP2 和 MRP4）的 mRNA 表达。大多数 PI 在 mRNA 和活性水平上都是 CYP3A 和 2B6 的净诱导剂（> 2 倍），而利托那韦、沙奎那韦、奈非那韦或洛匹那韦则不会诱导 CYP3A 活性（< 2 倍），可能是由于 CYP3A 失活。OATP1B1 和 MDR1 是唯一两种被 PI 诱导（> 2 倍）的肝转运体。安普那韦是最强的净诱导剂。总之，我们验证的鸡尾酒测定法可用于全面定量人肝微粒体和肝细胞研究中的 CYP 活性。结果还为 PI 对肝 CYP 和转运体的净诱导潜力提供了急需的数据。我们的结果与已发表的基于 PI 的 DDI 观察到定性一致，这表明人肝细胞是更广泛和定量的基于 PI 的 DDI 体外-体内预测的有用平台。
