Induction of Hepatic CYP3A Enzymes by Pregnancy-Related Hormones: Studies in Human Hepatocytes and Hepatic Cell Lines

Abstract

CYP3A activity is induced by approximately 2-fold during the third trimester of human pregnancy. Placental growth hormone (PGH), estrogens (primarily 17b-estradiol), cortisol, and progesterone have the potential to modulate CYP3A activity. Therefore, we determined whether the elevated plasma concentrations of these hormones during pregnancy induce hepatic CYP3A expression. We incubated sandwich-cultured human hepatocytes (SCHH) from premenopausal female donors (n = 2) with the physiologic (unbound, 13 total) and the 103 total third trimester hormone plasma concentrations (individually and in combination) and determined their effect on CYP3A activity and the transcripts of CYP3A4, CYP3A5, and the respective hormone receptors (growth hormone receptor, glucocorticoid receptor, and estrogen receptor alpha). Of all the hormones, cortisol was the most potent inducer of CYP3A activity and CYP3A4, CYP3A5 mRNA expression. The combination of PGH/growth hormone and cortisol induced CYP3A activity and expression significantly more than did cortisol alone. When incubated with the unbound or total plasma concentration of all the hormones, CYP3A activity in SCHH was induced to an extent comparable to that observed in vivo during the third trimester. These hormones had only a modest effect on the mRNA expression of the hormone receptors. The pattern of induction observed in SCHH was reproduced in HepaRG cells but not in HuH7/ HepG2 cells. SCHH or HepaRG cells could be used to determine the mechanistic basis of CYP3A induction during pregnancy and to predict the magnitude of induction likely to be observed during the first and second trimesters, when phenotyping studies to measure in vivo CYP3A activity are logistically difficult to perform.

Prediction of Gestational Age–Dependent Induction of In Vivo Hepatic CYP3A Activity Based on HepaRG Cells and Human Hepatocytes

“…The aforementioned observed pattern of induction is consistent with our previous observations where cortisol alone was the major inducer of CYP3A activity in HepaRG cells or SCHH (Papageorgiou et al, 2013). This work, together with our previous report, provides strong evidence that cortisol is a major inducer of CYP3A activity throughout pregnancy.…”

“…Previously, we have shown that of all the PRHs studied, cortisol was the major inducer of CYP3A activity in HepaRG cells and SCHH at T3 concentrations (Papageorgiou et al, 2013). Consistent with these findings, cortisol remained the major inducer in HepaRG cells at T1 or T2 concentrations (Figs.…”

“…Of all these hormones, cortisol was the most potent inducer of CYP3A activity in SCHHs. Additionally, the induction pattern observed in SCHHs was replicated in HepaRG cells (Papageorgiou et al, 2013). Both these in vitro models demonstrated their potential to predict the magnitude of CYP3A induction in early pregnancy.…”

“…Based on these observations and due to our previous data in SCHHs on C + GH-PGH demonstrating greater induction of CYP3A activity than with C alone (Papageorgiou et al, 2013), the number of hormonal ; n = 3) is expressed relative to control treatment (CTRL; unbound plasma concentrations of C + GH + E 2 + P observed in nonpregnant women). Data were analyzed by one-way analysis of variance followed by Dunnett's test.…”

“…Differentiated HepaRG cells were cultured in 96-well plates at a density of ;0.8 million cells/ml. Since the commercially available HepaRG maintenance and induction medium supplements contain hydrocortisone succinate, a CYP3A inducer, we conducted induction studies in the absence of hydrocortisone succinate to avoid confounding interpretation of our data (Papageorgiou et al, 2013). In brief, the differentiated HepaRG cells were maintained for 72 hours in William's Medium E supplemented with GlutaMAX-I, insulin-transferrin-selenium, and penicillin-streptomycin.…”