title: A combination of transcriptomics and metabolomics uncovers enhanced bile acid biosynthesis in HepG2 cells expressing CCAAT/enhancer-binding protein β (C/EBPβ), hepatocyte nuclear factor 4α (HNF4α), and constitutive androstane receptor (CAR).
abstract: The development of hepatoma-based in vitro models to study hepatocyte physiology is an invaluable tool for both industry and academia. Here, we develop an in vitro model based on the HepG2 cell line that produces chenodeoxycholic acid, the main bile acid in humans, in amounts comparable to human hepatocytes. A combination of adenoviral transfections for CCAAT/enhancer-binding protein β (C/EBPβ), hepatocyte nuclear factor 4α (HNF4α), and constitutive androstane receptor (CAR) decreased intracellular glutamate, succinate, leucine, and valine levels in HepG2 cells, suggestive of a switch to catabolism to increase lipogenic acetyl CoA and increased anaplerosis to replenish the tricarboxylic acid cycle. Transcripts of key genes involved in bile acid synthesis were significantly induced by approximately 160-fold. Consistently, chenodeoxycholic acid production rate was increased by more than 20-fold. Comparison between mRNA and bile acid levels suggest that 12-alpha hydroxylation of 7-alpha-hydroxy-4-cholesten-3-one is the limiting step in cholic acid synthesis in HepG2 cells. These data reveal that introduction of three hepatocyte-related transcription factors enhance anabolic reactions in HepG2 cells and provide a suitable model to study bile acid biosynthesis under pathophysiological conditions.
authors: Unidad de Hepatología Experimental, CIBERehd, Instituto de Investigación Sanitaria La Fe, Valencia 46009, Spain.
authors: Marina
authors: M
authors: Blazquez
authors: Aitor
authors: A
authors: Carretero
authors: James K
authors: JK
authors: Ellis
authors: Toby J
authors: TJ
authors: Athersuch
authors: Rachel
authors: R
authors: Cavill
authors: Timothy M D
authors: TM
authors: Ebbels
authors: Hector C
authors: HC
authors: Keun
authors: José V
authors: JV
authors: Castell
authors: Agustín
authors: A
authors: Lahoz
authors: Roque
authors: R
authors: Bort
mesh_terms: D000105:Acetyl Coenzyme A / Q000378:metabolism; D000256:Adenoviridae / Q000235:genetics; D000596:Amino Acids / Q000378:metabolism; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000235:genetics / Q000378:metabolism*; D002635:Chenodeoxycholic Acid / Q000096:biosynthesis*; D000090702:Constitutive Androstane Receptor; D015870:Gene Expression; D020869:Gene Expression Profiling; D005822:Genetic Vectors; D056945:Hep G2 Cells; D051557:Hepatocyte Nuclear Factor 4 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D055432:Metabolomics; D008954:Models, Biological; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D000596:Amino Acids; D022782:CCAAT-Enhancer-Binding Protein-beta; C545012:CEBPB protein, human; D000090702:Constitutive Androstane Receptor; C496592:HNF4A protein, human; D051557:Hepatocyte Nuclear Factor 4; D018160:Receptors, Cytoplasmic and Nuclear; D002635:Chenodeoxycholic Acid; D000105:Acetyl Coenzyme A