title: PCB153-elicited hepatic responses in the immature, ovariectomized C57BL/6 mice: comparative toxicogenomic effects of dioxin and non-dioxin-like ligands.
abstract: Polychlorinated biphenyls (PCBs) are ubiquitous contaminants found as complex mixtures of coplanar and non-coplanar congeners. The hepatic temporal and dose-dependent effects of the most abundant non-dioxin-like congener, 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153), were examined in immature, ovariectomized C57BL/6 mice, and compared to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the prototypical aryl hydrocarbon receptor (AhR) ligand. Animals were gavaged once with 300 mg/kg PCB153 or sesame oil vehicle and sacrificed 4, 12, 24, 72 or 168 h post dose. In the dose-response study, mice were gavaged with 1, 3, 10, 30, 100 or 300 mg/kg PCB153 or sesame oil for 24 h. Significant increases in relative liver weights were induced with 300 mg/kg PCB153 between 24 and 168 h, accompanied by slight vacuolization and hepatocellular hypertrophy. The hepatic differential expression of 186 and 177 genes was detected using Agilent 4 x 44 K microarrays in the time course (|fold change|> or =1.5, P1(t)> or =0.999) and dose-response (|fold change|> or =1.5, P1(t)> or =0.985) studies, respectively. Comparative analysis with TCDD suggests that the differential gene expression elicited by PCB153 was not mediated by the AhR. Furthermore, constitutive androstane and pregnane X receptor (CAR/PXR) regulated genes including Cyp2b10, Cyp3a11, Ces2, Insig2 and Abcc3 were dose-dependently induced by PCB153. Collectively, these results suggest that the hepatocellular effects elicited by PCB153 are qualitatively and quantitatively different from TCDD and suggestive of CAR/PXR regulation.
authors.affiliation: Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824-1319, USA.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Kopec
authors.forename: Lyle D
authors.initials: LD
authors.lastname: Burgoon
authors.forename: Daher
authors.initials: D
authors.lastname: Ibrahim-Aibo
authors.forename: Bryan D
authors.initials: BD
authors.lastname: Mets
authors.forename: Colleen
authors.initials: C
authors.lastname: Tashiro
authors.forename: Dave
authors.initials: D
authors.lastname: Potter
authors.forename: Bonnie
authors.initials: B
authors.lastname: Sharratt
authors.forename: Jack R
authors.initials: JR
authors.lastname: Harkema
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Zacharewski
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis / Q000302:isolation & purification; D004147:Dioxins / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D008024:Ligands; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D051379:Mice; D008810:Mice, Inbred C57BL; D020411:Oligonucleotide Array Sequence Analysis; D009929:Organ Size / Q000187:drug effects; D010052:Ovariectomy; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity; D012313:RNA / Q000096:biosynthesis / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016707:Tissue Fixation; D043922:Toxicogenetics; D014280:Triglycerides / Q000378:metabolism
chemical_list: D004147:Dioxins; D004785:Environmental Pollutants; D008024:Ligands; D000072317:Polychlorinated Dibenzodioxins; D014280:Triglycerides; D012313:RNA; D004247:DNA; D011078:Polychlorinated Biphenyls; C014024:2,4,5,2',4',5'-hexachlorobiphenyl