TY - JOUR
T1 - Direct comparison of UDP-glucuronosyltransferase and cytochrome P450 activities in human liver microsomes, plated and suspended primary human hepatocytes from five liver donors
AU - den Braver-Sewradj, Shalenie P
AU - den Braver, Michiel W
AU - Baze, Audrey
AU - Decorde, Joachim
AU - Fonsi, Massimiliano
AU - Bachellier, Philippe
AU - Vermeulen, Nico P E
AU - Commandeur, Jan N M
AU - Richert, Lysiane
AU - Vos, J Chris
PY - 2017/11/15
Y1 - 2017/11/15
N2 - UDP-glucuronosyltransferases (UGTs) and cytochrome P450s (CYPs) are the major enzymes involved in hepatic metabolism of drugs. Hepatic drug metabolism is commonly investigated using human liver microsomes (HLM) or primary human hepatocytes (PHH). We describe the development of a sensitive assay to phenotype activities of six major hepatic UGT isoforms (UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9 and UGT2B7) in intact PHH by analysis of glucuronidation of selective probe substrates. The non-selective, general substrate 7-hydroxycoumarin was included for comparison. For each liver donor preparation (five donors) UGT activities in cryopreserved suspended and plated PHH were compared to HLM prepared from the same donors. Standard CYP reaction phenotyping of seven major isoforms was performed in parallel. For all donors, CYP- and UGT-isoforms activity profiles were comparable in PHH and HLM, indicating that reaction phenotyping with selective probe substrates in intact cells primarily reflects respective CYP or UGT activity. System-dependent effects on UGT and CYP isoform activity were still found. While UGT activity of UGT1A1 was equivalent in plated and suspended PHH, UGT1A3, UGT1A6 and UGT2B7 activity was higher in suspended PHH and UGT1A9 and UGT1A4 activity was higher in plated PHH. The well-known decrease in activity of most CYP isoforms in plated compared to suspended PHH was confirmed. Importantly, we found a significant loss in CYP2C19 and CYP2B6 in HLM, activity being lower than in intact cells. Taken together, these findings implicate that, dependent on the UGT or CYP isoforms involved in the metabolism of a given compound, the outcome of metabolic assays is strongly dependent on the choice of the in vitro system. The currently described UGT- and CYP- activity profiling method can be used as a standard assay in intact cells and can especially aid in reaction phenotyping of in vitro systems for which a limited number of cells are available.
AB - UDP-glucuronosyltransferases (UGTs) and cytochrome P450s (CYPs) are the major enzymes involved in hepatic metabolism of drugs. Hepatic drug metabolism is commonly investigated using human liver microsomes (HLM) or primary human hepatocytes (PHH). We describe the development of a sensitive assay to phenotype activities of six major hepatic UGT isoforms (UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9 and UGT2B7) in intact PHH by analysis of glucuronidation of selective probe substrates. The non-selective, general substrate 7-hydroxycoumarin was included for comparison. For each liver donor preparation (five donors) UGT activities in cryopreserved suspended and plated PHH were compared to HLM prepared from the same donors. Standard CYP reaction phenotyping of seven major isoforms was performed in parallel. For all donors, CYP- and UGT-isoforms activity profiles were comparable in PHH and HLM, indicating that reaction phenotyping with selective probe substrates in intact cells primarily reflects respective CYP or UGT activity. System-dependent effects on UGT and CYP isoform activity were still found. While UGT activity of UGT1A1 was equivalent in plated and suspended PHH, UGT1A3, UGT1A6 and UGT2B7 activity was higher in suspended PHH and UGT1A9 and UGT1A4 activity was higher in plated PHH. The well-known decrease in activity of most CYP isoforms in plated compared to suspended PHH was confirmed. Importantly, we found a significant loss in CYP2C19 and CYP2B6 in HLM, activity being lower than in intact cells. Taken together, these findings implicate that, dependent on the UGT or CYP isoforms involved in the metabolism of a given compound, the outcome of metabolic assays is strongly dependent on the choice of the in vitro system. The currently described UGT- and CYP- activity profiling method can be used as a standard assay in intact cells and can especially aid in reaction phenotyping of in vitro systems for which a limited number of cells are available.
KW - Journal Article
UR - http://www.scopus.com/inward/record.url?scp=85026789501&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85026789501&partnerID=8YFLogxK
U2 - 10.1016/j.ejps.2017.07.032
DO - 10.1016/j.ejps.2017.07.032
M3 - Article
C2 - 28778465
SN - 0928-0987
VL - 109
SP - 96
EP - 110
JO - European Journal of Pharmaceutical Sciences
JF - European Journal of Pharmaceutical Sciences
ER -