title: Differences in the Epigenetic Regulation of Cytochrome P450 Genes between Human Embryonic Stem Cell-Derived Hepatocytes and Primary Hepatocytes.
abstract: Human pluripotent stem cell-derived hepatocytes have the potential to provide in vitro model systems for drug discovery and hepatotoxicity testing. However, these cells are currently unsuitable for drug toxicity and efficacy testing because of their limited expression of genes encoding drug-metabolizing enzymes, especially cytochrome P450 (CYP) enzymes. Transcript levels of major CYP genes were much lower in human embryonic stem cell-derived hepatocytes (hESC-Hep) than in human primary hepatocytes (hPH). To verify the mechanism underlying this reduced expression of CYP genes, including CYP1A1, CYP1A2, CYP1B1, CYP2D6, and CYP2E1, we investigated their epigenetic regulation in terms of DNA methylation and histone modifications in hESC-Hep and hPH. CpG islands of CYP genes were hypermethylated in hESC-Hep, whereas they had an open chromatin structure, as represented by hypomethylation of CpG sites and permissive histone modifications, in hPH. Inhibition of DNA methyltransferases (DNMTs) during hepatic maturation induced demethylation of the CpG sites of CYP1A1 and CYP1A2, leading to the up-regulation of their transcription. Combinatorial inhibition of DNMTs and histone deacetylases (HDACs) increased the transcript levels of CYP1A1, CYP1A2, CYP1B1, and CYP2D6. Our findings suggest that limited expression of CYP genes in hESC-Hep is modulated by epigenetic regulatory factors such as DNMTs and HDACs.
authors.affiliation: Department of Biological Sciences and Center for Stem Cell Differentiation, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea; Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon, 305-343, Republic of Korea.
authors.forename: Han-Jin
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon, 305-343, Republic of Korea; Human and Environmental Toxicology, School of Engineering, University of Science and Technology, Daejeon, 303-333, Republic of Korea.
authors.forename: Young-Jun
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon, 305-343, Republic of Korea.
authors.forename: Ji Woo
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon, 305-343, Republic of Korea.
authors.forename: Hang-Suk
authors.initials: HS
authors.lastname: Chun
authors.affiliation: Department of Biological Sciences and Center for Stem Cell Differentiation, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea.
authors.forename: Ilkyun
authors.initials: I
authors.lastname: Im
authors.affiliation: Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon, 305-343, Republic of Korea; Human and Environmental Toxicology, School of Engineering, University of Science and Technology, Daejeon, 303-333, Republic of Korea.
authors.forename: Seokjoo
authors.initials: S
authors.lastname: Yoon
authors.affiliation: Department of Biological Sciences and Center for Stem Cell Differentiation, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea.
authors.forename: Yong-Mahn
authors.initials: YM
authors.lastname: Han
authors.affiliation: Department of Inhalation Research, Korea Institute of Toxicology, Jeollabuk-do, 580-185, Republic of Korea; Human and Environmental Toxicology, School of Engineering, University of Science and Technology, Daejeon, 303-333, Republic of Korea.
authors.forename: Chang-Woo
authors.initials: CW
authors.lastname: Song
authors.affiliation: Department of Predictive Toxicology, Korea Institute of Toxicology, Daejeon, 305-343, Republic of Korea.
authors.forename: Hyemin
authors.initials: H
authors.lastname: Kim
mesh_terms: D002454:Cell Differentiation; D002460:Cell Line; D002843:Chromatin / Q000378:metabolism / Q000648:ultrastructure; D018899:CpG Islands; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics / Q000378:metabolism; D019388:Cytochrome P-450 CYP1A2 / Q000235:genetics / Q000378:metabolism; D065633:Cytochrome P-450 CYP1B1 / Q000235:genetics / Q000378:metabolism; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics / Q000378:metabolism; D019392:Cytochrome P-450 CYP2E1 / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000235:genetics* / Q000378:metabolism; D044127:Epigenesis, Genetic; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism*; D006655:Histone Deacetylases / Q000235:genetics* / Q000378:metabolism; D006657:Histones / Q000235:genetics / Q000378:metabolism; D000066449:Human Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D009928:Organ Specificity; D061251:Primary Cell Culture; D011499:Protein Processing, Post-Translational; D015398:Signal Transduction; D014158:Transcription, Genetic
chemical_list: D002843:Chromatin; D006657:Histones; D019392:Cytochrome P-450 CYP2E1; C569463:CYP1A1 protein, human; C504573:CYP1A2 protein, human; C585496:CYP1B1 protein, human; D019363:Cytochrome P-450 CYP1A1; D019388:Cytochrome P-450 CYP1A2; D065633:Cytochrome P-450 CYP1B1; D019389:Cytochrome P-450 CYP2D6; D015254:DNA Modification Methylases; D006655:Histone Deacetylases