title: Phenobarbital induces alterations in the proteome of hepatocytes and mesenchymal cells of rat livers.
abstract: Preceding studies on the mode of action of non-genotoxic hepatocarcinogens (NGCs) have concentrated on alterations induced in hepatocytes (HCs). A potential role of non-parenchymal liver cells (NPCs) in NGC-driven hepatocarcinogenesis has been largely neglected so far. The aim of this study is to characterize NGC-induced alterations in the proteome profiles of HCs as well as NPCs. We chose the prototypic NGC phenobarbital (PB) which was applied to male rats for a period of 14 days. The livers of PB-treated rats were perfused by collagenase and the cell suspensions obtained were subjected to density gradient centrifugation to separate HCs from NPCs. In addition, HCs and NPC isolated from untreated animals were treated with PB in vitro. Proteome profiling was done by CHIP-HPLC and ion trap mass spectrometry. Proteome analyses of the in vivo experiments showed many of the PB effects previously described in HCs by other methods, e.g. induction of phase I and phase II drug metabolising enzymes. In NPCs proteins related to inflammation and immune regulation such as PAI-1 and S100-A10, ADP-ribosyl cyclase 1 and to cell migration such as kinesin-1 heavy chain, myosin regulatory light chain RLC-A and dihydropyrimidinase-related protein 1 were found to be induced, indicating major PB effects on these cells. Remarkably, in vitro treatment of HCs and NPCs with PB hardly reproduced the proteome alterations observed in vivo, indicating differences of NGC induced responses of cells at culture conditions compared to the intact organism. To conclude, the present study clearly demonstrated that PB induces proteome alterations not only in HCs but also in NPCs. Thus, any profound molecular understanding on the mode of action of NGCs has to consider effects on cells of the hepatic mesenchyme.
authors.affiliation: Department of Inner Medicine I, Comprehensive Cancer Center, Institute of Cancer Research, Medical University of Vienna, Vienna, Austria.
authors.forename: Philip
authors.initials: P
authors.lastname: Klepeisz
authors.forename: Sandra
authors.initials: S
authors.lastname: Sagmeister
authors.forename: Verena
authors.initials: V
authors.lastname: Haudek-Prinz
authors.forename: Melanie
authors.initials: M
authors.lastname: Pichlbauer
authors.forename: Bettina
authors.initials: B
authors.lastname: Grasl-Kraupp
authors.forename: Christopher
authors.initials: C
authors.lastname: Gerner
mesh_terms: D000818:Animals; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000378:metabolism*; D010634:Phenobarbital / Q000008:administration & dosage / Q000494:pharmacology*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D051381:Rats; D015398:Signal Transduction; D013347:Subcellular Fractions
chemical_list: D020543:Proteome; D010634:Phenobarbital