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- Blomberg, Anders, 1956, et al.
(författare)
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Establishing the barnacle Balanus improvisus as a potent invertebrate monitoring system in marine ecotoxicogenomics
- 2009
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Ingår i: SETAC Europe 19th Annual Meeting Abstract Book, Göteborg 31 May - 4 June, 2009.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- There is a need for potent invertebrate systems for assessing the impacts of environmental contaminants on marine ecosystems. Balanus improvisus, a marine athropod, has a number of promising characteristics that make it a good candidate in such efforts. We have conducted sequencing of a cDNA library from the cyprid larval stage and identified several detoxification systems as well as novel B. improvisus specific genes. To investigate the toxicological gene expression response in this organism, we performed a short-term exposure experiment of the cyprid larvae to two different biofouling substances. From a natural population of B. improvisus, 300 - 1000 cyprids were treated for 23 hours with 390nM CuO or with two different concentrations (10nM or 10μM) of meditomidine. Protein expression changes were studied by 2D-PAGE analysis after DIGE labelling. For gene expression analysis by DNA miroarrays total RNA was extracted and used for cDNA and cRNA/aRNA templates. Roughly 2000 B. improvisus genes were studied represented by 3000 different probes on the arrays (each in duplicates). Candidate genes were confirmed by qPCR. A number of protein expression changes were detected on the 2D gels as a result of the different treatments. Interestingly, the response to the different treatments clearly formed distinct groups in principle component analysis. The DNA microarray analysis revealed several genes as toxicity indicators, e.g. various heat shock proteins, some proteases and factors involved in regulatory processes (transcription factors). Our data indicate that B. improvisus may serve as a tool to evaluate the impacts of marine pollution, and thus to fill the niche as an important invertebrate marine model organism for ecotoxicology and environmental genomics.
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| 2. |
- Einarsdottir, Ingibjörg, 1951, et al.
(författare)
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Plasma growth hormone-binding protein levels in Atlantic salmon Salmo salar during smoltification and seawater transfer
- 2014
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Ingår i: Journal of Fish Biology. - : Wiley. - 0022-1112. ; 85:4, s. 1279-1296
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Tidskriftsartikel (refereegranskat)abstract
- Specific growth hormone (GH)-binding protein (Ghbp) was purified from Atlantic salmon Salmo salar and rainbow trout Oncorhynchus mykiss plasma with immunoprecipitation and characterized in cross-linking studies using autoradiography and western blots. The size of the Ghbp was estimated to be c. 53 kDa. A radioimmunoassay was established to measure Ghbp in salmonids, using antibodies specific against the extracellular segment of the S. salar growth hormone receptor 1 (grh1; GenBank AY462105). Plasma Ghbp levels were measured in S. salar smolts in fresh water and after transfer to seawater (SW; experiments 1 and 2), and in post-smolts kept at different salinities (0, 12, 22 and 34) for 3 months (experiment 3). A transient increase in plasma Ghbp, which lasted for 1 month or less, was noted in smolts after transfer to SW. Concomitantly, plasma GH and gill Na+-K+-ATPase activity increased during smoltification (in experiment 2). No difference in plasma Ghbp was evident between post-smolts kept at different salinities, although the fish kept at salinity 34 had higher plasma GH than the group kept at salinity 22 and higher hepatic ghr1 expression than post-smolts kept at salinity 12. This suggests that plasma Ghbp regulation may respond to salinity changes in the short term. The lack of correlation between Ghbp, plasma GH and hepatic ghr1 expression in the long-term post-smolt experiment indicates that Ghbp levels may be regulated independently of other components of the endocrine GH system in salmonids.
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| 3. |
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| 4. |
- Hasselberg, Linda, 1974, et al.
(författare)
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Effects of alkylphenols on CYP1A and CYP3A expression in first spawning Atlantic cod (Gadus morhua)
- 2004
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X. ; 67:4, s. 303-313
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Tidskriftsartikel (refereegranskat)abstract
- Alkylphenols are continuously released into the ocean as a result of offshore oil production. Alkylphenols, including 4-tert-butylphenol (C-4), 4n-pentylphenol (C-5), 4n-hexylphenol (C-6), and 4n-heptylphenol (C-7) up to 237 ppb concentrations, have been detected in produced water from oil platforms. Previous studies have shown that alkylphenols induce vitellogenesis in fish. Atlantic cod (Gadus morhua) of both sexes were force-fed with various doses ranging between 0.02 and 80 ppm of a mixture of alkylphenols (C-4:C-5:C-6:C-7 ratio 1: 1: 1: 1) or 5 ppm 17beta-estradiol. We investigated effects on hepatic CYP1A and CYP3A protein expression in protein blots, using antibodies against scup (Stenotomus chrysops) CYP1A1 and rainbow trout (Oncorhynchus mykiss) CYP3A. There was asexually dimorphic expression of CYP1A and CYP3A protein levels, with females expressing higher levels than males. Treatment of male Atlantic cod with 17beta-estradiol resulted in increased CYP1A and CYP3A protein levels. Exposure to alkylphenols resulted in a dose-dependent increase of CYP1A and CYP3A protein expression in males, but not in females. However, this increase of CYP1A protein levels was not reflected on the CYP1A-mediated ethoxyresorufin-O-deethylase (EROD) activity, implying that alkylphenols inhibited the CYP1A enzyme activity in vivo. In vitro inhibition studies with pooled liver microsomes from Atlantic cod confirmed that the alkylphenols mixture efficiently inhibited the CYP1A activity (IC50 = 10 muM), although the inhibitory effect of each individual alkylphenol varied. The IC50 values for each individual alkylphenol on the CYP1A activity were, in a descending order of magnitude: [C-7 > C-6 > C-5 much greater than C-4], ranging from 12 to 300 muM with decreased length of the 4-alkyl chain. The effect of alkylphenols on the CYP3A activity in vitro in liver microsomes also was investigated, using the fluorescent 7-benzyloxy-4-[trifluoromethyl]-coumarin (BFC) as a diagnostic CYP3A substrate. The alkylphenol mixture inhibited CYP3A activity with IC50 value at 100 muM. The IC50 values for each individual alkylphenol on CYP3A activity were, in a descending order of magnitude: [C-5 > C-6 > C-7 > C-4] ranging between 60 and 250 muM. Taken together, our results show that the alkylphenol mixture and 17beta-estradiol resulted in elevated hepatic CYP1A and CYP3A expression in male Atlantic cod. The alkylphenol mixture strongly inhibited CYP1A activities, whereas it weakly inhibited CYP3A activity in Atlantic cod liver microsomes in vitro. In addition, 17beta-estradiol was a weak inhibitor of CYP3A activity (IC50 = 75 muM) and did not notably inhibit the CYP1A activity in vitro. (C) 2004 Elsevier B.V. All rights reserved.
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| 5. |
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| 6. |
- Hasselberg, Linda, 1974, et al.
(författare)
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Effects of alkylphenols on redox status in first spawning Atlantic cod (Gadus morhua)
- 2004
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X. ; 69:1, s. 95-105
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Tidskriftsartikel (refereegranskat)abstract
- Offshore oil production releases large amounts of lipophilic compounds in produced water and into the ocean. The discharge of produced water from the Norwegian petroleum sector has increased from 26 million m3 in 1993 to 120 million m3 in 2001, and it continues to increase. Produced water contains significant amounts of alkylphenols, which have been reported to be estrogenic, causing endocrine disruption in fish. In year 2000, approximately 44 tons of alkylphenols were released on the Norwegian continental shelf in connection with discharge of produced water. Except from being estrogenic, relatively little is known about the effects of alkylphenols when released in the marine environment. Our objective was to study how alkylphenols affect the redox status in first spawning Atlantic cod (Gadus morhua) of both sexes. Model compounds tested included 4-tert-butylphenol (C4), 4-n-pentylphenol (C5), 4-n-hexylphenol (C6) and 4-n-heptylphenol (C7), all found in produced water. First spawning Atlantic cod were force-fed a mixture of these four alkylphenols, ranging between 0.02 and 80 ppm or 5 ppm 17β-estradiol (E2), for 1 or 4 weeks. Increased hepatic total glutathione concentration in response to alkylphenol exposure was detected in female fish compared to control group after 1-week exposure, an effect not seen after 4 weeks. Furthermore, hepatic total glutathione concentration was sex dependent, where male fish sampled after 4 weeks had higher levels of glutathione than female fish. Increased glutathione reductase catalytic activities in both male and female fish were seen after exposure to 0.02 ppm alkylphenol mixture in 4 weeks. The glutathione S-transferase activity was only affected in male fish exposed to 0.02 ppm alkylphenols, and glucose-6-phosphate dehydrogenase activity increased in female fish exposed to 0.02 ppm alkylphenol mixture for 1 week. The increase of hepatic total glutathione content as well as the effects on glutathione reductase activities suggests that alkylphenol exposure affects the redox status in Atlantic cod.
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| 7. |
- Hasselberg, Linda, 1974
(författare)
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Interactions between cytochrome P450 and estrogenic compounds in fish
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- DISSERTATION ABSTRACT Hasselberg, Linda. Interactions between cytochrome P450 and estrogenic compounds in fish. Department of Zoophysiology, Göteborg University, Box 463, SE-405 30 Göteborg, Sweden Contamination by various pollutions is an environmental concern. Many fish populations are continuously exposed to xenobiotics, including endocrine disrupting chemicals. Cytochrome P450 (CYP) enzymes metabolize lipophilic compounds facilitating their excreation, which prevents bioaccumulation. The aim of this thesis was to study effects of estrogenic compounds on CYP, redox status and endocrine responses in fish. Furthermore, to identify possible sites of interaction between two classes of environmental pollutants, 1) estrogenic compounds, i.e. alkylphenols, ethynylestradiol (EE2) and 2) antifungal azoles, i.e. ketoconazole. We hypothesize that estrogenic compounds and azoles share common routes of excretion in fish through CYP1A and CYP3A. Atlantic cod (Gadus morhua) and rainbow trout (Oncorhynchus mykiss) were exposed orally or by i.p. injections. Effects on hepatic CYP1A and CYP3A protein expression and activities were investigated as well as glutathione, glutathione-related enzymes, vitellogenesis and sex steroid hormone levels. Alkylphenols induced CYP1A and CYP3A protein expressions in male Atlantic cod, but not in females. Alkylphenols had no effect on CYP1A activities in either males or females. In vitro inhibition studies showed that the alkylphenols efficiently inhibited CYP1A activity. In addition, ketoconazole induced CYP1A and CYP3A protein expression, whereas CYP1A and CYP3A activities were inhibited. These results indicate that CYP1A and CYP3A represent sites of interactions between these classes of xenobiotics. Combined exposure of ketoconazole with EE2 increased the responsiveness to EE2 measured as vitellogenesis. Thus, co-exposure to ketoconazole appears to make juvenile rainbow trout more sensitive to EE2 exposure. Combined exposure to ketoconazole and EE2 also decreased circulating androgens. This study shows interactions between ketoconazole and EE2, which affect the endocrine system and that CYP1A and CYP3A may play an important role in this interaction. Keywords: Cytochrome P450, CYP1A, CYP3A, glutathione, alkylphenols, ethynylestradiol, ketoconazole, vitellogenin, Atlantic cod, rainbow trout, fish ISBN 91-628-6270-7
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| 8. |
- Hasselberg, Linda, 1974, et al.
(författare)
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Interactions between xenoestrogens and ketoconazole on hepatic CYP1A and CYP3A, in juvenile Atlantic cod (Gadus morhua)
- 2005
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Ingår i: Comparative Hepatology. - : Springer Science and Business Media LLC. - 1476-5926. ; 4:2
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Tidskriftsartikel (refereegranskat)abstract
- Xenoestrogens and antifungal azoles probably share a common route of metabolism, through hepatic cytochrome P450 (CYP) enzymes. Chemical interactions with metabolic pathways may affect clearance of both xenobiotics and endobiotics. This study was carried out to identify possible chemical interactions by those substances on CYP1A and CYP3A, in Atlantic cod liver. We investigated effects of two xenoestrogens (nonylphenol and ethynylestradiol) and of the model imidazole ketoconazole, alone and in combination
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| 9. |
- Hasselberg, Linda, 1974, et al.
(författare)
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Ketoconazole, an antifungal imidazole, increases the sensitivity of rainbow trout to 17α-ethynylestradiol exposure
- 2008
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X. ; 86:2, s. 256-264
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Tidskriftsartikel (refereegranskat)abstract
- This study focuses on effects of two classes of xenobiotics, azole fungicides and xenoestrogens, both of which have been detected in the aquatic environment. We hypothesize that azoles and estrogenic compounds are metabolized by cytochrome P450 (CYP) enzymes, and in particular CYP1A and CYP3A, to more readily excreted metabolites. We exposed rainbow trout (Oncorhynchus mykiss) to two different pharmaceutical representatives of theses two classes, such as the imidazole ketoconazole and the synthetic estrogen analogue, 17α-ethynylestradiol (EE2). Juvenile rainbow trout were i.p. injected with a single low dose of EE2 (2.5 μg/kg), alone or in combination with ketoconazole (100 mg/kg). Hepatic microsomal CYP1A and CYP3A protein expressions were analyzed in Western blots using polyclonal antibodies (PAb) and enhanced cheminoluminescence. CYP1A activities were analyzed using the ethoxyresorufin-O-deethylase (EROD) assay and CYP3A activities were analyzed using the benzyloxy-4-[trifluoromethyl]-coumarin-O-debenzyloxylase (BFCOD) assay. Plasma vitellogenin (vtg) and sex steroid hormones (i.e. 17β-estradiol, testosterone and 11-keto-testosterone) were analyzed using commercially available ELISA-kits. The vtg mRNA expression was analyzed using quantitative (Q)-PCR. The dose of EE2 selected had little or no effect on the estrogen receptor (ER) mediated vtg induction. However, in combination with ketoconazole this threshold-dose of EE2 resulted in significantly elevated plasma vtg levels, 6 days post injection. Exposure to ketoconazole resulted in up to nine-fold induction of CYP1A after 3 days. However, this nine-fold induction was not reflected on the CYP1A catalytic activity, where exposure to ketoconazole resulted only in a two-fold increase in activity. Ketoconazole increased CYP3A protein levels 1.5-fold and decreased BFCOD activities by 80% at days 3 and 6. Treatment with ketoconazole and EE2 alone and in combination had no significant effect on sex steroid hormones, compared to vehicle-treated fish. This study demonstrates that exposure to ketoconazole compromises the function of key enzymes involved in metabolic clearance of xenobiotics and steroids, and increases the sensitivity to EE2 exposure in juvenile rainbow trout.
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