title: The human constitutive androstane receptor promotes the differentiation and maturation of hepatic-like cells.
abstract: Expression of the constitutive androstane receptor (CAR, NR1I3) is enriched in the mature mammalian liver and increasingly recognized for its prominent role in regulating a myriad of processes including biotransformation, chemical transport, energy metabolism and lipid homeostasis. Previously, we demonstrated that CAR levels were markedly enhanced during the differentiation of hepatic-like cells derived from hESCs, prompting the hypothesis that CAR contributes a key functional role in directing human hepatogenesis. Here we demonstrate that over-expression of CAR in human embryonic stem cells (ESCs), transduced by a lentiviral vector, accelerates the maturation of hepatic-like cells, with CAR over-expressing cells exhibiting a 2.5-fold increase in albumin secretion by day 20 in culture differentiation, and significantly enhanced levels of mRNA expression of several liver-selective markers, including hepatic transcription factors, plasma proteins, biotransformation enzymes, and metabolic enzymes. CAR over-expressing cells also exhibited enhanced CITCO-inducible CYP3A7 enzymatic activity. Knockdown of CAR via siRNA attenuated the differentiation-dependent expression programs. In contrast, expression levels of the pregnane X receptor (PXR), a nuclear receptor most similar to CAR in primary sequence, were negligible in human fetal liver tissues or in the differentiating hESCs, and stable over-expression of PXR in hepatic-induced hESCs failed to enhance expression of hepatic phenotype markers. Together, these results define a novel role for human CAR in hepatic lineage commitment.
authors.affiliation: Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Fengming
authors.initials: F
authors.lastname: Chen
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Zamule
authors.forename: Denise M
authors.initials: DM
authors.lastname: Coslo
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.forename: Curtis J
authors.initials: CJ
authors.lastname: Omiecinski
mesh_terms: D001483:Base Sequence; D002454:Cell Differentiation / Q000502:physiology*; D002460:Cell Line; D000090702:Constitutive Androstane Receptor; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D017931:DNA Primers; D053595:Embryonic Stem Cells / Q000166:cytology; D006801:Humans; D008099:Liver / Q000166:cytology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering; D018160:Receptors, Cytoplasmic and Nuclear / Q000502:physiology*; D013234:Stem Cells / Q000166:cytology
chemical_list: D000090702:Constitutive Androstane Receptor; D017931:DNA Primers; C000716327:NR1I3 protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D018160:Receptors, Cytoplasmic and Nuclear; D003577:Cytochrome P-450 Enzyme System
keywords: CAR; Drug metabolism; Hepatic differentiation; Lentivirus; PXR; hESCs; siRNA