title: Co-cultures of enterocytes and hepatocytes for retinoid transport and metabolism.
abstract: Dietary retinoid bioavailability involves the interplay of the intestine (transport and metabolism) and the liver (secondary metabolism). To reproduce these processes in vitro, differentiated human intestinal Caco-2/TC7 cells were co-cultured with two hepatocyte cell lines. Murine 3A cells and the more highly differentiated human HepaRG hepatocytes were both shown to respond to β-carotene (BC) and retinol (ROH) treatment by secreting Retinol Binding Protein 4 (RBP4). In co-culture experiments, Caco-2/TC7 were differentiated on filter inserts and transferred for the time of the experiment to culture wells containing confluent 3A or differentiated HepaRG cells. Functionality of the co-cultures was assayed using as endpoints the retinol-dependent secretion of RBP4 and the retinoic acid-dependent induction of CYP26A1 in hepatocytes. BC and ROH added to intestinal Caco-2/TC7 induced a reduction in intracellular RBP4 levels in the underlying hepatocytes and its secretion into the medium. HepaRG hepatocytes were also shown to up-regulate the expression of CYP26A1 mRNA in response to retinoid treatment. This in vitro model represents a useful tool to analyze the absorption and metabolism of retinoids and could be further developed to investigate other dietary compounds and molecules of pharmacological interest.
authors.affiliation: National Research Institute on Food and Nutrition (INRAN), Rome, Italy.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Rossi
authors.forename: Barbara
authors.initials: B
authors.lastname: Guantario
authors.forename: Simonetta
authors.initials: S
authors.lastname: Ferruzza
authors.forename: Christiane
authors.initials: C
authors.lastname: Guguen-Guillouzo
authors.forename: Yula
authors.initials: Y
authors.lastname: Sambuy
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Scarino
authors.forename: Diana
authors.initials: D
authors.lastname: Bellovino
mesh_terms: D000818:Animals; D001692:Biological Transport; D002454:Cell Differentiation; D002460:Cell Line; D018920:Coculture Techniques; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D020895:Enterocytes / Q000378:metabolism*; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D051379:Mice; D008954:Models, Biological; D012319:RNA Polymerase II / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D000072516:Retinoic Acid 4-Hydroxylase; D015854:Up-Regulation / Q000187:drug effects; D014801:Vitamin A / Q000493:pharmacokinetics*; D019207:beta Carotene / Q000493:pharmacokinetics*
chemical_list: D012333:RNA, Messenger; D019207:beta Carotene; D014801:Vitamin A; D003577:Cytochrome P-450 Enzyme System; C000607080:Cyp26a1 protein, mouse; D000072516:Retinoic Acid 4-Hydroxylase; C505957:POLR2D protein, human; D012319:RNA Polymerase II