title: Cell type-specific expression and localization of cytochrome P450 isoforms in tridimensional aggregating rat brain cell cultures.
abstract: Within the Predict-IV FP7 project a strategy for measurement of in vitro biokinetics was developed, requiring the characterization of the cellular model used, especially regarding biotransformation, which frequently depends on cytochrome P450 (CYP) activity. The extrahepatic in situ CYP-mediated metabolism is especially relevant in target organ toxicity. In this study, the constitutive mRNA levels and protein localization of different CYP isoforms were investigated in 3D aggregating brain cell cultures. CYP1A1, CYP2B1/B2, CYP2D2/4, CYP2E1 and CYP3A were expressed; CYP1A1 and 2B1 represented almost 80% of the total mRNA content. Double-immunolabeling revealed their presence in astrocytes, in neurons, and to a minor extent in oligodendrocytes, confirming the cell-specific localization of CYPs in the brain. These results together with the recently reported formation of an amiodarone metabolite following repeated exposure suggest that this cell culture system possesses some metabolic potential, most likely contributing to its high performance in neurotoxicological studies and support the use of this model in studying brain neurotoxicity involving mechanisms of toxication/detoxication.
authors: Istituto Superiore di Sanità, Environment and Primary Prevention Department, Mechanisms of Toxicity Unit, Rome, Italy. Electronic address: susanna.vichi@iss.it.
authors: S
authors: S
authors: Vichi
authors: Department of Physiology, University of Lausanne, Lausanne, Switzerland; Swiss Center for Applied Human Toxicology (SCAHT), Switzerland.
authors: J
authors: J
authors: Sandström von Tobel
authors: Istituto Superiore di Sanità, Environment and Primary Prevention Department, Mechanisms of Toxicity Unit, Rome, Italy.
authors: S
authors: S
authors: Gemma
authors: Department of Biostatistics, German Cancer Research Center, Heidelberg, Germany.
authors: S
authors: S
authors: Stanzel
authors: Department of Biostatistics, German Cancer Research Center, Heidelberg, Germany.
authors: A
authors: A
authors: Kopp-Schneider
authors: Department of Physiology, University of Lausanne, Lausanne, Switzerland; Swiss Center for Applied Human Toxicology (SCAHT), Switzerland.
authors: F
authors: F
authors: Monnet-Tschudi
authors: Istituto Superiore di Sanità, Environment and Primary Prevention Department, Mechanisms of Toxicity Unit, Rome, Italy.
authors: E
authors: E
authors: Testai
authors: Department of Physiology, University of Lausanne, Lausanne, Switzerland; Swiss Center for Applied Human Toxicology (SCAHT), Switzerland.
authors: M G
authors: MG
authors: Zurich
mesh_terms: D000375:Aging; D000818:Animals; D001921:Brain / Q000166:cytology*; D002478:Cells, Cultured; D003577:Cytochrome P-450 Enzyme System / Q000145:classification / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology; D015971:Gene Expression Regulation, Enzymologic; D022781:Hepatocytes; D007527:Isoenzymes; D009474:Neurons / Q000378:metabolism*; D021381:Protein Transport; D051381:Rats
chemical_list: D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System
keywords: 3D aggregating brain cell cultures; Biokinetics; Cytochrome P450