title: Characterization of the recalcitrant CYP1 phenotype found in Atlantic killifish (Fundulus heteroclitus) inhabiting a Superfund site on the Elizabeth River, VA.
abstract: Fundulus heteroclitus (Atlantic killifish) found at the Atlantic Wood Industries Superfund site on the Elizabeth River (ER) in Portsmouth, VA (USA), have been shown to be resistant to the teratogenic effects of creosote-contaminated sediments found at this highly contaminated site. Many of the polycyclic aromatic hydrocarbons (PAHs) found at the ER are known to activate the aryl hydrocarbon receptor (AHR), and are thought to mediate their toxic effects through this pathway. Activation of the AHR results in the induction of several Phase I and II metabolic enzymes. It has been previously shown that the AHR of killifish from the ER are refractory to induction by AHR agonists. To more fully characterize this altered AHR response, we exposed embryos from the ER and from a reference site on King's Creek, VA (KC) to two PAHs, benzo[alpha]pyrene (BaP) and benzo[k]fluoranthene (BkF), and to the dioxin-like compound (DLC), 3,3',4,4',5-pentachlorobiphenyl (PCB126). We compared their developmental and molecular responses by screening the embryos for CYP1A enzyme activity, cardiac deformities, and mRNA expression of CYP1A, CYP1B1, CYP1C1, and AHR2. Basal gene expression of both CYP1A and CYP1B1 was 40% higher in the KC control embryos compared to those from the ER, while AHR2 and CYP1C1 were not significantly different between the populations. Exposure of KC embryos to BaP, BkF, and PCB126 induced CYP1A activity and cardiac deformities. In contrast, CYP1A activity was induced in ER embryos only in response to BkF exposure, although this induction in ER embryos was significantly lower than that observed in KC fish at comparable concentrations. ER embryos did not develop cardiac deformities in response to any of the chemicals tested. CYP1A, CYP1B1 and CYP1C1 mRNA were all significantly induced in the KC embryos after exposure to BaP, BkF and PCB126. Exposure to BaP and BkF in ER embryos resulted in a significant induction of CYP1A mRNA, albeit significantly lower than observed in KC fish. Interestingly, BaP exposure resulted in induction of CYP1B1 at comparable levels in embryos from both populations. CYP1s were not induced in ER embryos in response to PCB126, nor was CYP1C1 for any treatment examined. Additionally, AHR2 was not significantly induced for any of the treatment groups. This study further characterizes the AHR response in killifish, and provides greater insight into the adapted ER phenotype. The ER adaptation involves the suppression of normal AHR-inducible gene expression for all three CYP1 genes, and therefore is likely an alteration in AHR signaling or control.
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, NC 27708-0328, United States.
authors.forename: Lauren P
authors.initials: LP
authors.lastname: Wills
authors.forename: Cole W
authors.initials: CW
authors.lastname: Matson
authors.forename: Chelsea D
authors.initials: CD
authors.lastname: Landon
authors.forename: Richard T
authors.initials: RT
authors.lastname: Di Giulio
mesh_terms: D000818:Animals; D001483:Base Sequence; D001564:Benzo(a)pyrene / Q000633:toxicity; D001681:Biological Assay; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics / Q000378:metabolism*; D005449:Fluorenes / Q000633:toxicity; D023781:Fundulidae / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D011078:Polychlorinated Biphenyls / Q000633:toxicity; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D016133:Polymerase Chain Reaction; D045483:Rivers / Q000737:chemistry*; D014768:Virginia; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D005449:Fluorenes; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D001564:Benzo(a)pyrene; C007738:fluoranthene; D011078:Polychlorinated Biphenyls; D019363:Cytochrome P-450 CYP1A1; C023035:3,4,5,3',4'-pentachlorobiphenyl
references.citation: Mol Pharmacol. 2002 Oct;62(4):806-16
references.pmid: 12237327
references.citation: Arch Biochem Biophys. 2009 Feb;482(1-2):7-16
references.pmid: 19103147
references.citation: Arch Biochem Biophys. 2005 Apr 1;436(1):50-61
references.pmid: 15752708
references.citation: Environ Toxicol Chem. 2003 Oct;22(10):2337-43
references.pmid: 14551997
references.citation: Toxicol Sci. 2006 Oct;93(2):331-40
references.pmid: 16873418
references.citation: Mar Environ Res. 2004 Aug-Dec;58(2-5):95-100
references.pmid: 15178019
references.citation: Mar Environ Res. 2008 Jul;66(1):19-20
references.pmid: 18400289
references.citation: Mol Pharmacol. 2004 Sep;66(3):512-21
references.pmid: 15322242
references.citation: Methods. 2001 Dec;25(4):402-8
references.pmid: 11846609
references.citation: Aquat Toxicol. 2009 Jul 26;93(4):234-43
references.pmid: 19515436
references.citation: Cancer Sci. 2004 Jan;95(1):1-6
references.pmid: 14720319
references.citation: Environ Health Perspect. 2004 Dec;112(17):1658-64
references.pmid: 15579409
references.citation: Mol Pharmacol. 2004 May;65(5):1225-37
references.pmid: 15102951
references.citation: Chem Biol Interact. 2002 Sep 20;141(1-2):131-60
references.pmid: 12213389
references.citation: Mar Environ Res. 2008 Jul;66(1):85-7
references.pmid: 18378296
references.citation: Biomarkers. 1999;4(1):48-58
references.pmid: 23898794
references.citation: J Comp Physiol B. 2005 May;175(4):221-30
references.pmid: 15900503
references.citation: Chem Res Toxicol. 2008 Jan;21(1):102-16
references.pmid: 18076143
references.citation: Toxicol Sci. 2008 Sep;105(1):5-23
references.pmid: 18156145
references.citation: Environ Toxicol Chem. 2005 Oct;24(10):2526-32
references.pmid: 16268154
references.citation: Aquat Toxicol. 2007 Dec 30;85(4):241-50
references.pmid: 17964672
references.citation: Aquat Toxicol. 2002 Dec 3;61(3-4):195-209
references.pmid: 12359390
references.citation: Annu Rev Pharmacol Toxicol. 2003;43:309-34
references.pmid: 12540743
references.citation: Chemosphere. 2008 Dec;74(1):149-54
references.pmid: 18840388
references.citation: Biochem Biophys Res Commun. 2005 Jun 17;331(4):1016-24
references.pmid: 15882979
references.citation: Carcinogenesis. 1992 Mar;13(3):505-7
references.pmid: 1547543
references.citation: Mar Environ Res. 2000 Jul-Dec;50(1-5):7-10
references.pmid: 11460754
references.citation: Fish Physiol Biochem. 1991 Dec;9(4):369-76
references.pmid: 24213733
references.citation: Mar Environ Res. 2004 Aug-Dec;58(2-5):163-8
references.pmid: 15178029
references.citation: Toxicol Sci. 2006 Aug;92(2):526-36
references.pmid: 16687390
references.citation: Mar Environ Res. 2006 Jul;62 Suppl:S332-6
references.pmid: 16697458
references.citation: Environ Toxicol Chem. 2005 Mar;24(3):717-25
references.pmid: 15779774
references.citation: Toxicol Appl Pharmacol. 2007 May 15;221(1):29-41
references.pmid: 17445853
references.citation: Genes Cells. 1997 Oct;2(10):645-54
references.pmid: 9427285
references.citation: Chem Biol Interact. 2005 Jan 15;151(2):101-19
references.pmid: 15698582
references.citation: Toxicol Sci. 2003 Nov;76(1):138-50
references.pmid: 12883077
references.citation: Comp Biochem Physiol B Biochem Mol Biol. 2002 Sep;133(1):55-68
references.pmid: 12223212
references.citation: Environ Toxicol Chem. 2002 Sep;21(9):1845-53
references.pmid: 12206424
references.citation: Ecotoxicol Environ Saf. 2004 Nov;59(3):292-9
references.pmid: 15388268
references.citation: Aquat Toxicol. 2003 Dec 10;65(4):377-95
references.pmid: 14568353
references.citation: Toxicol Sci. 2008 May;103(1):158-68
references.pmid: 18308702
references.citation: Mar Environ Res. 2002 Sep-Dec;54(3-5):247-51
references.pmid: 12408570
references.citation: Cancer Res. 2003 Nov 15;63(22):7825-33
references.pmid: 14633709
references.citation: Toxicol Sci. 2001 Mar;60(1):77-91
references.pmid: 11222875
references.citation: Toxicol Sci. 2007 Nov;100(1):180-93
references.pmid: 17686920
references.citation: Toxicol Sci. 2002 Jul;68(1):69-81
references.pmid: 12075112
references.citation: Aquat Toxicol. 2008 May 30;87(4):289-95
references.pmid: 18378331
references.citation: Aquat Toxicol. 2010 Aug 15;99(2):232-40
references.pmid: 20605646
references.citation: Arch Pharm Res. 2005 Mar;28(3):249-68
references.pmid: 15832810
references.citation: Toxicol Appl Pharmacol. 1996 Sep;140(1):173-9
references.pmid: 8806883
references.citation: Comp Biochem Physiol Part D Genomics Proteomics. 2007 Dec;2(4):257-86
references.pmid: 18071578
references.citation: Aquat Toxicol. 2007 Mar 10;81(3):275-85
references.pmid: 17257690
references.citation: J Biol Chem. 1999 Nov 19;274(47):33814-24
references.pmid: 10559277
references.citation: Toxicol Sci. 2002 Aug;68(2):403-19
references.pmid: 12151636
references.citation: Biochim Biophys Acta. 1999 Jan 18;1444(1):35-48
references.pmid: 9931422
references.citation: Biochem Pharmacol. 2005 Mar 1;69(5):741-50
references.pmid: 15710352
references.citation: Environ Toxicol Chem. 2002 Sep;21(9):1897-902
references.pmid: 12206429
references.citation: Toxicol Sci. 2008 May;103(1):191-206
references.pmid: 18096572
references.citation: Annu Rev Cell Dev Biol. 1996;12:55-89
references.pmid: 8970722
references.citation: Proc Natl Acad Sci U S A. 1999 Mar 2;96(5):1977-82
references.pmid: 10051580
references.citation: Mutat Res. 2004 Aug 18;552(1-2):73-100
references.pmid: 15288543
references.citation: Toxicol Sci. 2004 Feb;77(2):307-14
references.pmid: 14691214
references.citation: Toxicol Sci. 2000 Oct;57(2):229-39
references.pmid: 11006353
references.citation: Mol Pharmacol. 2006 Oct;70(4):1369-79
references.pmid: 16835354