den Braver-Sewradj Shalenie P, den Braver Michiel W, Vermeulen Nico P E, Commandeur Jan N M, Richert Lysiane, Vos J Chris
AIMMS-Division of Molecular Toxicology, Department of Chemistry & Pharmaceutical Sciences, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
Kaly-Cell, 20A Rue du Général Leclerc, France; Université de Franche-Comté, Besançon, France.
Toxicol In Vitro. 2016 Jun;33:71-9. doi: 10.1016/j.tiv.2016.02.013. Epub 2016 Feb 26.
Cytochrome P450s (CYPs), UDP-glucuronosyltransferases (UGTs) and sulfotransferases (SULTs) are the most important enzymes for metabolic clearance. Characterization of phase I and phase II metabolism of a given drug in cellular models is therefore important for an adequate interpretation of the role of drug metabolism in toxicity. We investigated phase I (CYP) and phase II (UGT and SULT) metabolism of three drugs related to drug-induced liver injury (DILI), namely acetaminophen (APAP), diclofenac (DF) and tolcapone (TC), in cryopreserved primary human hepatocytes from 5 donors in suspension and monolayer. The general phase II substrate 7-hydroxycoumarin (7-HC) was included for comparison. Our results show that the decrease in CYP, UGT and SULT activity after plating is substrate dependent. As a consequence the phase I/phase II metabolism ratio is significantly affected, with a shift in monolayer towards phase I metabolism for TC and towards phase II metabolism for APAP and DF. Inter-donor variability in drug metabolism is significant, especially in sulfation of 7-HC or APAP. As CYP, UGT and SULT metabolism may lead to bioactivation and/or detoxification of drugs, a changed ratio in phase I/phase II metabolism may have important consequences for metabolism-related toxicity.
细胞色素P450（CYPs）、尿苷二磷酸葡萄糖醛酸转移酶（UGTs）和磺基转移酶（SULTs）是代谢清除最重要的酶。因此，在细胞模型中对特定药物的I相和II相代谢进行表征，对于充分解释药物代谢在毒性中的作用至关重要。我们研究了与药物性肝损伤（DILI）相关的三种药物，即对乙酰氨基酚（APAP）、双氯芬酸（DF）和托卡朋（TC），在来自5名供体的冷冻保存的原代人肝细胞悬浮液和单层培养物中的I相（CYP）和II相（UGT和SULT）代谢。将一般的II相底物7-羟基香豆素（7-HC）纳入进行比较。我们的结果表明，接种后CYP、UGT和SULT活性的降低是底物依赖性的。因此，I相/II相代谢比率受到显著影响，在单层培养中，TC的代谢向I相代谢转变，而APAP和DF的代谢向II相代谢转变。药物代谢的供体间变异性显著，尤其是在7-HC或APAP的硫酸化方面。由于CYP、UGT和SULT代谢可能导致药物的生物活化和/或解毒，I相/II相代谢比率的改变可能对与代谢相关的毒性产生重要影响。
