Gestational Age-Dependent Changes in Gene Expression of Metabolic Enzymes and Transporters in Pregnant Mice

Abstract

Pregnancy-induced changes in drug pharmacokinetics can be explained by changes in expression of drug-metabolizing enzymes and transporters and/or normal physiology. In this study, we determined gestational age-dependent expression profiles for all metabolic enzyme and transporter genes in the maternal liver, kidney, small intestine, and placenta of pregnant mice by microarray analysis. We specifically examined the expression of genes important for xenobiotic, bile acid, and steroid hormone metabolism and disposition, namely, cytochrome P450s (Cyp), UDPglucuronosyltranserases (Ugt), sulfotransferases (Sult), and ATPbinding cassette (Abc), solute carrier (Slc), and solute carrier organic anion (Slco) transporters. Few Ugt and Sult genes were affected by pregnancy. Cyp17a1 expression in the maternal liver increased 3-to 10-fold during pregnancy, which was the largest observed change in the maternal tissues. Cyp1a2, most Cyp2 isoforms, Cyp3a11, and Cyp3a13 expression in the liver decreased on gestation days (gd) 15 and 19 compared with nonpregnant controls (gd 0). In contrast, Cyp2d40, Cyp3a16, Cyp3a41a, Cyp3a41b, and Cyp3a44 in the liver were induced throughout pregnancy. In the placenta, Cyp expression on gd 10 and 15 was upregulated compared with gd 19. Notable changes were also observed in Abc and Slc transporters. Abcc3 expression in the liver and Abcb1a, Abcc4, and Slco4c1 expression in the kidney were downregulated on gd 15 and 19. In the placenta, Slc22a3 (Oct3) expression on gd 10 was 90% lower than that on gd 15 and 19. This study demonstrates important gestational age-dependent expression of metabolic enzyme and transporter genes, which may have mechanistic relevance to drug disposition in human pregnancy.

Effect of Gestational Age on mRNA and Protein Expression of Polyspecific Organic Cation Transporters during Pregnancy

“…3A). This activation of mOct3 mRNA in mouse placenta between early and middle pregnancy was also previously noticed by other investigators (Zwart et al, 2001;Shuster et al, 2013). Using LC-MS/MS, we further showed that mOct3 protein levels in the mouse placenta also increased dramatically at gd 15 and 19 (Fig.…”

“…Although the effect of pregnancy on mRNA expression of drug transporters has been analyzed in large-scale microarray studies and/or in tissue-specific manners in pregnant animal models (Shuster et al, 2013;Yacovino et al, 2013), comprehensive and quantitative mRNA analysis of polyspecific OC transporters has not been performed. Furthermore, few studies have quantified and compared the protein levels of OC transporters between nonpregnant and pregnant states.…”

Maternal-Fetal Disposition of Glyburide in Pregnant Mice Is Dependent on Gestational Age

“…This study further confirmed that hepatic CYP3A activity in pregnant mice is induced in a gestational age-dependent manner. It is not known which mouse CYP3A isoforms are responsible for increased glyburide metabolism during pregnancy as we and others have shown that mRNA levels of Cyp3a16, Cyp3a41, and Cyp3a44 are induced, whereas Cyp3a11, Cyp3a13, and Cyp3a25 genes are downregulated in a gestational age-dependent manner (Zhang et al, 2008;Shuster et al, 2013). Increases in V ss and V b most likely reflect increases in total body water and fat content during pregnancy, and further suggest that distribution of glyburide into maternal tissues is increased during pregnancy.…”

“…In humans, M1 undergoes glucuronidation mediated by uridine 59-diphospho-glucuronosyltransferases (UGTs) and M2b is excreted unchanged in the urine (Naraharisetti et al, 2007). UGT1A1 and UGT1A4 expression is indeed induced during human pregnancy (Feghali and Mattison, 2011); however, mRNA levels of UGTs in pregnant mice are relatively unchanged (Shuster et al, 2013). Mechanisms of renal clearance (i.e., active tubular secretion and/or reabsorption) remain unknown for all glyburide metabolites Fetal/ maternal plasma glyburide concentration ratios.…”

“…Like in humans, glyburide clearance in pregnant mice was similarly doubled on gestation day (gd) 15 compared with nonpregnant controls (Zhou et al, 2010b), suggesting that the pregnant mouse may be an appropriate animal model to study glyburide PK during pregnancy. The mRNA levels of several hepatic Cyp3a isoforms and CYP3A activity in pregnant mice are significantly increased in a gestational age-dependent manner compared with nonpregnant controls (Zhang et al, 2008;Shuster et al, 2013). Therefore, we used pregnant mice to study gestational age-dependent effects on maternal-fetal disposition of glyburide.…”