Wilson Joanna Y.

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Wilson
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Joanna Y.
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  • Preprint
    Changes in persistent contaminant concentration and CYP1A1 protein expression in biopsy samples from northern bottlenose whales, Hyperoodon ampullatus, following the onset of nearby oil and gas development
    ( 2007-05-09) Hooker, Sascha K. ; Metcalfe, Tracy L. ; Metcalfe, Chris D. ; Angell, Carolyn M. ; Wilson, Joanna Y. ; Moore, Michael J. ; Whitehead, Hal
    A small population of endangered northern bottlenose whales (Hyperoodon ampullatus) inhabits “The Gully” Marine Protected Area on the Scotian Shelf, eastern Canada. Amid concerns regarding nearby oil and gas development, we took 36 skin and blubber biopsy samples in 1996-97 (prior to major development) and 2002-03 (five years after development began), and 3 samples from a population in the Davis Strait, Labrador in 2003. These were analysed for cytochrome P4501A1 (CYP1A1) protein expression (n=36), and for persistent contaminants (n=23). CYP1A1 showed generally low expression in whales from The Gully, but higher levels during 2003, potentially co-incident with recorded oil spills, and higher levels in Davis Strait whales. A range of PCB congeners and organochlorine compounds were detected, with concentrations similar to other North Atlantic odontocetes. Concentrations were higher in whales from The Gully than from the Davis Strait, with significant increases in 4,4’-DDE and trans-nonachlor in 2002-03 relative to 1996-97.
  • Article
    Systemic effects of Arctic pollutants in beluga whales indicated by CYP1A1 expression
    (National Institute of Environmental Health Sciences, 2005-07-14) Wilson, Joanna Y. ; Cooke, Suzy R. ; Moore, Michael J. ; Martineau, Daniel ; Mikaelian, Igor ; Metner, Donald A. ; Lockhart, W. Lyle ; Stegeman, John J.
    Cytochrome P450 1A1 (CYP1A1) is induced by exposure to polycyclic aromatic hydrocarbons (PAHs) and planar halogenated aromatic hydrocarbons (PHAHs) such as non-ortho polychlorinated biphenyls (PCBs). In this study, we examined CYP1A1 protein expression immunohistochemically in multiple organs of beluga whales from two locations in the Arctic and from the St. Lawrence estuary. These beluga populations have some of the lowest (Arctic sites) and highest (St. Lawrence estuary) concentrations of PCBs in blubber of all cetaceans. Samples from these populations might be expected to have different contaminant-induced responses, reflecting their different exposure histories. The pattern and extent of CYP1A1 staining in whales from all three locations were similar to those seen in animal models in which CYP1A has been highly induced, indicating a high-level expression in these whales. CYP1A1 induction has been related to toxic effects of PHAHs or PAHs in some species. In St. Lawrence beluga, the high level of CYP1A1 expression coupled with high levels of contaminants (including CYP1A1 substrates, e.g., PAH procarcinogens potentially activated by CYP1A1) indicates that CYP1A1 could be involved in the development of neoplastic lesions seen in the St. Lawrence beluga population. The systemic high-level expression of CYP1A1 in Arctic beluga suggests that effects of PAHs or PHAHs may be expected in Arctic populations, as well. The high-level expression of CYP1A1 in the Arctic beluga suggests that this species is highly sensitive to CYP1A1 induction by aryl hydrocarbon receptor agonists.
  • Preprint
    Cytochrome P4501A is induced in endothelial cell lines from the kidney and lung of the bottlenose dolphin, Tursiops truncatus
    ( 2005-10-15) Garrick, Rita Anne ; Woodin, Bruce R. ; Wilson, Joanna Y. ; Middlebrooks, Bobby L. ; Stegeman, John J.
    Marine mammals respond to the presence of polycyclic and planar halogenated aromatic hydrocarbons (PAH or PHAH) with the induced expression in endothelium of cytochrome P4501A1, regulated through the aryl hydrocarbon receptor (AHR) transcription factor. Physiological responses in other animals, such as edema and inflammation indicate that the endothelium may be compromised by exposure to AHR agonists, which are ubiquitous in the marine environment. In other mammals and fish the cellular and molecular consequences of exposure to AHR agonists have been elucidated in cultured endothelial cells. We have cultured and characterized cetacean endothelial cells (EC) and used them in induction studies. Endothelial cells were cultured from the lung and kidney of the bottlenose dolphin Tursiops truncatus and exposed to the AHR agonists β-naphthoflavone (βNF) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). βNF (1-3 μM) induced significant increases in CYP1A1(O-deethylation of 7-ethoxyresorufin to resorufin;EROD) activity to 3.6 and 0.92 pmol/mg/min in lung and kidney EC, respectively. TCDD was more potent than βNF, and more efficacious, with maximum induction of CYP1A1activity of 10.1 and 15.2 pmol/mg/min in lung and kidney EC at 3-10 nM TCDD. The differential response indicates that the lung and kidney endothelial cells in culture retain the ability to respond in a selective manner to specific stimuli. Both the molecular mechanisms of induction and the physiological consequences, especially in the vasculature, of toxicant exposure can be studied in this system.
  • Thesis
    Cytochrome P450 1A1 and aromatase (CYP19) in cetaceans : enzyme expression and relationship to contaminant exposure
    (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2003-09) Wilson, Joanna Y.
    Contamnant exposure has been associated with toxic effects in marine mammals. Studies on early biochemical and molecular responses prior to, but associated with, contaminant-induced toxicity will aid in understanding the susceptibility of cetaceans to such exposures. Cytochrome P450 1A1 (CYP1A1) induction by planar halogenated aromatic hydrocarbons, including certain polychlorinated biphenyls (PCBs), has been correlated with toxic effects in rodents. CYP1A1 expression was measured in multiple organs from beluga whales and white-sided dolphins and integument biopsies from bottlenose dolphins. Age and sex do not appear to influence CYP1A1 expression in these species. Mono-artha PCB concentrations were correlated with CYP1A1 in bottlenose dolphin integument and white-sided dolphin liver. White-sided dolphins, with PCBs concentrations six times higher than Arctic beluga, have lower hepatic CYP1A1 expression. Beluga whales thus appear very sensitive to the induction of CYP1A1 by PHAHs. These studies demonstrate that comparative studies between cetacean species, with reference to experimental work in model organisms, could determine the relative susceptibility of cetaceans to contaminant exposures. Aromatase is the enzyme responsible for estrogen production and recent studies suggest that PCBs may alter its activity or expression. We determined the sequence and characterized the catalytic properties of a cetacean aromatase, which was similar to other mammalian aromatases. Evolutionary analyses of vertebrate aromatases revealed striking functional conservation. Although much work is required, these data show that similar to CYP1A1, aromatase studies in other mammals are applicable to cetacean species. Experimental work in model organisms, coupled with careful studies with cetacean tissues, could infer the physiological role and transcriptional control of aromatase in cetacean species.