title: Effects of time culture and prototypical cytochrome P450 3A (CYP3A) inducers on CYP2B22, CYP2C, CYP3A and nuclear receptor (NR) mRNAs in long-term cryopreserved pig hepatocytes (CPHs).
abstract: In the present study, transcriptional and post-translational effects of culturing time and prototypical cytochrome P450 3A (CYP3A) inducers on principal nuclear receptors (NRs), CYP2B22, 2C and 3A were investigated in long-term stored (~10 years) cryopreserved pig hepatocytes (CPHs). In the time-course study, a crush and rise effect was observed for pregnane X receptor (NR1I2) and constitutive androstane receptor (NR1I3) mRNAs, while a time-dependent increase of retinoid X receptor alpha (NR2B1) was noticed. Cytochrome P450 gene expression profiles were down-regulated as a function of time. In the induction study, an increase of NR1I2, NR1I3 and NR2B1 mRNAs was observed in dexamethasone-exposed CPHs. About CYPs, an overall up-regulation was seen in CPHs exposed to phenobarbital, while dexamethasone and rifampicin up-regulated only CYP3A. In both studies, transcriptional CYP results were confirmed at the post-translational level (immunoblotting and enzyme activities), except for CYP2B immunoblotting in the induction study. The present data demonstrate that long-term stored CPHs may be used to investigate mechanisms involved in CYPs regulation, expression and function; provide further info about NR regulation of CYPs, and confirm species-differences in these mechanisms of regulation; finally, they suggest the usefulness and relevance of gene expression profiling to early detect any modulation of CYP expression and bioactivity.
authors.affiliation: Dipartimento di Biomedicina Comparata e Alimentazione, Università degli Studi di Padova, Padova, Italy. mery.giantin@unipd.it
authors.forename: Mery
authors.initials: M
authors.lastname: Giantin
authors.forename: Vanessa
authors.initials: V
authors.lastname: Zancanella
authors.forename: Rosa Maria
authors.initials: RM
authors.lastname: Lopparelli
authors.forename: Anna
authors.initials: A
authors.lastname: Granato
authors.forename: Monica
authors.initials: M
authors.lastname: Carletti
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Vilei
authors.forename: Maurizio
authors.initials: M
authors.lastname: Muraca
authors.forename: Chiara
authors.initials: C
authors.lastname: Baratto
authors.forename: Mauro
authors.initials: M
authors.lastname: Dacasto
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D000090702:Constitutive Androstane Receptor; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D004790:Enzyme Induction / Q000187:drug effects; D022781:Hepatocytes / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D007527:Isoenzymes; D011499:Protein Processing, Post-Translational / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics*; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics* / Q000378:metabolism; D047490:Retinoid X Receptor alpha / Q000235:genetics / Q000378:metabolism; D013552:Swine; D014158:Transcription, Genetic / Q000187:drug effects; D059467:Transcriptome / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000090702:Constitutive Androstane Receptor; D007527:Isoenzymes; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D047490:Retinoid X Receptor alpha; D003907:Dexamethasone; D003577:Cytochrome P-450 Enzyme System