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| 2. |
- Beijer, Kristina, 1980-, et al.
(författare)
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Azoles additively inhibit cytochrome P450 1 (EROD) and 19 (aromatase) in rainbow trout (Oncorhynchus mykiss)
- 2018
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 198, s. 73-81
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Tidskriftsartikel (refereegranskat)abstract
- Antifungal azoles are widely used in medicine, agriculture, and material protection and several antifungal azoles have been found in environmental samples. Although these compounds were designed to inhibit fungal enzymes such as lanosterol-14-demethylase (cytochrome P450 (CYP) 51), it is well established that the inhibitory actions of azoles are not specific for fungal CYP isozymes.We refined a gill filament assay to determine the inhibition of CYP1, measured as reduced 7-ethoxyresorufin-O-deethylase (EROD) activity, in rainbow trout (Oncorhynchus mykiss) gill tissue ex vivo. The advantage of this method is that both induction and inhibition of EROD are performed ex vivo. Among thirteen azoles studied, the five that caused the strongest inhibition of gill EROD activity at a concentration of 5 μM were selected for concentration–response assessment. These compounds (bifonazole, clotrimazole, imazalil, miconazole, and prochloraz) showed IC50 values ranging from 0.1 to 1.5 μM. CYP19 (aromatase) inhibition was measured using microsomes from rainbow trout brains. Concentration-response curves for CYP19 inhibition were determined for letrozole, bifonazole, clotrimazole, imazalil, miconazole and prochloraz, which gave IC50 values ranging from 0.02 to 3.3 μM. It was further found that mixtures of the five most potent azoles reduced both CYP1 and 19 catalytic activity in an additive fashion (IC50 = 0.7 μM and 0.6 μM, in the respective assay). Bifonazole (IC50 = 0.1 μM) is not previously known to inhibit CYP1 activity.The additive inhibition of CYP1 and CYP19 catalytic activity is an important finding of the present study. We conclude that this additive action of azoles could mediate adverse impacts on CYP regulated physiological functions in environmentally exposed fish.
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- Beijer, Kristina
(författare)
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Azoles and Contaminants in Treated Effluents Interact with CYP1 and CYP19 in Fish :
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Numerous contaminants are present in mixtures in the aquatic environment. Among these are the azoles, a group of chemicals that includes both pharmaceuticals and pesticides. Azole fungicides are designed to inhibit lanosterol 14-demethylase (cytochrome P450 (CYP) 51), while other azoles are intended to inhibit aromatase (CYP19), i.e. the enzyme catalyzing biosynthesis of estrogens. In fish, a variety of CYP enzymes are involved in biotransformation of waterborne contaminants, and in metabolism of endogenous compounds including steroidal hormones. The induction of CYP1A protein and 7-ethoxyresorufin O-deethylase (EROD) activity are common biomarkers for exposure to aryl hydrocarbon receptor (AhR) agonists in fish. We developed an assay to measure inhibition of CYP1A activity (EROD) in three-spined stickleback and rainbow trout gill tissue ex vivo. Several azole fungicides were found to be potent inhibitors of CYP1A activity. A wastewater effluent containing high concentrations of pharmaceuticals was also shown to inhibit CYP1A activity. Further, several azoles inhibited CYP19 activity in rainbow trout brain microsomes in vitro. Azole mixtures reduced both CYP1A and CYP19 activity monotonically and in an additive way. Given the additive action of the azoles, studies to determine adverse effects of azole mixtures on CYP-regulated physiological functions in fish are needed. Induction of EROD and of gene expression of CYP1 in several organs was observed in an in vivo exposure with the same effluent shown to inhibit EROD. This finding could imply that there was a mixture of AhR agonists and CYP1A inhibitors in the effluent. Finally, wastewater treatment technologies were evaluated using biomarker responses in rainbow trout exposed to effluents of different treatments. The results from chemical analysis together with the biomarker results show that ozone and granulated active carbon treatment removed most pharmaceuticals, as well as AhR agonists and other chemicals present in the regular effluent. This part of the thesis demonstrates that biomarkers in fish such as induction of CYP1 gene expression are applicable to evaluate the efficiency of different treatment technologies for wastewater.
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| 4. |
- Beijer, Kristina, et al.
(författare)
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CYP1A inhibition in fish gill filaments : a novel assay applied on pharmaceuticals and other chemicals
- 2010
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 96:2, s. 145-150
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Tidskriftsartikel (refereegranskat)abstract
- The gill filament 7-ethoxyresorufin O-deethylase (EROD) assay was originally developed as a biomarker for cytochrome P4501A (CYP1A) induction by Ah-receptor agonists in water. In this study, the assay was adapted to measure inhibition of CYP1A activity in fish gill filaments ex vivo. The experiments were carried out using gill arch filaments from beta-naphthoflavone (betaNF)-exposed three-spined stickleback (Gasterosteus aculeatus). Candidate CYP1A inhibitors were added to the assay buffer. Nine selected pharmaceuticals and five known or suspected CYP1A-modulating chemicals were examined with regard to their ability to reduce EROD activity in gill filaments. Ellipticine, a well characterized CYP1A inhibitor, was the most effective inhibitor of the compounds tested. At a concentration in the assay buffer of 1 microM the antifungal azoles ketoconazole, miconazole and bitertanol, and the plant flavonoid acacetin reduced gill EROD activity by more than 50%, implying IC50 values below 1 microM. These compounds have previously been shown to inhibit EROD activity in liver microsomes from fish and mammals at similar concentrations. The proton pump inhibitor omeprazole reduced the gill EROD activity by 39% at 10 microM. It is concluded that the modified gill filament EROD assay is useful to screen for waterborne pollutants that inhibit catalytic CYP1A activity in fish gills.
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| 5. |
- Beijer, Kristina, et al.
(författare)
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Effluent from drug manufacturing affects cytochrome P450 1 regulation and function in fish
- 2013
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 90:3, s. 1149-1157
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Tidskriftsartikel (refereegranskat)abstract
- We have previously reported very high concentrations of pharmaceuticals in the effluent from a treatment plant receiving wastewater from about 90 bulk drug manufacturers near Hyderabad, India. The main objective of the present study was to examine how high dilutions of this effluent affect mRNA expression of cytochrome P450 (CYP) 1 family genes and ethoxyresorufin O-deethylase (EROD) activity in exposed wildlife, using the three-spined stickleback (Gasterosteus aculeatus) as a model. In gill filaments exposed to diluted effluent ex vivo, EROD activity was strongly inhibited in a concentration-dependent manner. In a subsequent in vivo study, groups of fish were exposed (24. h) to three concentrations of effluent, 0.8%, 1.6% or 3.2%. In this experiment, EROD in gills was induced 27-, 52- or 60-fold, respectively. Accordingly, CYP1A mRNA was markedly up-regulated in gill, liver and brain of fish exposed to all three effluent concentrations. Expression of mRNA for CYP1B1 and CYP1C1 was induced in gills at all concentrations while effects on these genes in liver and brain were weak or absent. The results of a time course study suggested that most CYP1-inducing substances in the effluent were readily metabolised or excreted, because the induced EROD activity and mRNA expression decreased when the fish were transferred to clean water. Considering that CYP1 enzymes play important roles in biotransformation of endogenous and foreign compounds, the observed dual effect of the effluent on CYP1 catalytic activity and mRNA expression suggests that multiple physiological functions could be affected in exposed wildlife.
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| 6. |
- Beijer, Kristina, et al.
(författare)
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In search of causal pathways in diabetes : a study using proteomics and genotyping data from a cross-sectional study
- 2019
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Ingår i: Diabetologia. - : SPRINGER. - 0012-186X .- 1432-0428. ; 62:11, s. 1998-2006
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Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis: The pathogenesis of type 2 diabetes is not fully understood. We investigated whether circulating levels of preselected proteins were associated with the outcome 'diabetes' and whether these associations were causal.Methods: In 2467 individuals of the population-based, cross-sectional EpiHealth study (45-75 years, 50% women), 249 plasma proteins were analysed by the proximity extension assay technique. DNA was genotyped using the Illumina HumanCoreExome-12 v1.0 BeadChip. Diabetes was defined as taking glucose-lowering treatment or having a fasting plasma glucose of >= 7.0 mmol/l. The associations between proteins and diabetes were assessed using logistic regression. To investigate causal relationships between proteins and diabetes, a bidirectional two-sample Mendelian randomisation was performed based on large, genome-wide association studies belonging to the DIAGRAM and MAGIC consortia, and a genome-wide association study in the EpiHealth study.Results: Twenty-six proteins were positively associated with diabetes, including cathepsin D, retinal dehydrogenase 1, alpha-l-iduronidase, hydroxyacid oxidase 1 and galectin-4 (top five findings). Three proteins, lipoprotein lipase, IGF-binding protein 2 and paraoxonase 3 (PON-3), were inversely associated with diabetes. Fourteen of the proteins are novel discoveries. The Mendelian randomisation study did not disclose any significant causal effects between the proteins and diabetes in either direction that were consistent with the relationships found between the protein levels and diabetes.Conclusions/interpretation: The 29 proteins associated with diabetes are involved in several physiological pathways, but given the power of the study no causal link was identified for those proteins tested in Mendelian randomisation. Therefore, the identified proteins are likely to be biomarkers for type 2 diabetes, rather than representing causal pathways.
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| 7. |
- Beijer, Kristina, et al.
(författare)
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Interaction between physical activity and television time on blood pressure level : cross-sectional data from 45000 individuals
- 2018
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Ingår i: Journal of Hypertension. - 0263-6352 .- 1473-5598. ; 36:5, s. 1041-1050
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Tidskriftsartikel (refereegranskat)abstract
- Objectives:The aim was to investigate if there is an interaction between sitting time and leisure time physical activity on blood pressure and if there are age differences and sex differences in this respect.Methods:Linear regression analysis on cross-sectional data was performed in more than 45000 men and women from two Swedish cohort studies, EpiHealth (45-75 years) and LifeGene (18-45 years). Self-reported leisure time physical activity was given in five levels from low (level 1) to vigorous physical activity (level 5) and television time was used as a proxy measure of sitting time.Results:High physical activity was associated with lower DBP (P=0.001), but not SBP. Active middle-aged men had lower DBP (-1.1mmHg; 95% CI -1.7 to -0.4) compared with inactive participants. Prolonged television time was associated with higher SBP (P<0.001) and DBP (P=0.011) in both sexes and in most age groups. Watching 3h instead of 1h television per day was associated with higher SBP in middle-aged women (SBP: 1.1mmHg; 95% CI 0.7-1.4) and men (SBP: 1.2mmHg; 95% CI 0.8-1.6). Only in young men, a high physical activity (level 4 instead of level 1) could compensate for a prolonged television time (3h per day) in terms of DBP.Conclusion:Prolonged television time was associated with higher SBP and DBP in both sexes and at most ages, whereas an increased physical activity was mainly associated with a lower DBP. Only in young men, a high physical activity could compensate for prolonged television time regarding DBP.
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| 8. |
- Beijer, Kristina, et al.
(författare)
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Physical activity may compensate for prolonged TV time regarding pulse rate-a cross-sectional study
- 2018
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Ingår i: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 123:4, s. 247-254
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Tidskriftsartikel (refereegranskat)abstract
- Background: Regular exercise reduces pulse rate, but it is less clear how prolonged sitting time affects pulse rate. Our hypothesis was that high physical activity could compensate for prolonged sitting time regarding the pulse rate.Methods: Regression analysis was performed on cross-sectional data including 47,457 men and women based on two Swedish cohort studies, EpiHealth (18–45 years) and LifeGene (45–75 years). Self-reported leisure time physical activity was given in five levels, from low (level 1) to vigorous (level 5), and television time was used as a proxy of sitting time.Results: A higher physical activity (level 4 compared to level 1) was associated with a lower pulse rate in middle-aged females (-2.7 beats per minute [bpm]; 95% CI -3.3 to -2.2) and males (-4.0 bpm; 95% CI -4.7 to -3.4). The relationship between physical activity and pulse rate was strongest in the young. A prolonged television time (3 h compared to 1 h per day) was associated with a slightly higher pulse rate in middle-aged females (+0.6 bpm; 95% CI +0.3 to +0.8) and males (+0.9 bpm; 95% CI +0.7 to +1.2). Among participants with a prolonged television time (3 h), those with a high physical activity (level 4) had a lower pulse rate compared to those with a low physical activity (level 1).Conclusions: A prolonged television time was associated with a high pulse rate, while high physical activity was associated with a low pulse rate. The results suggest that a high physical activity could compensate for a prolonged television time regarding pulse rate.
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| 10. |
- Beijer, Kristina, et al.
(författare)
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Removal of pharmaceuticals and unspecified contaminants in sewage treatment effluents by activated carbon filtration and ozonation : Evaluation using biomarker responses and chemical analysis
- 2017
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 176, s. 342-351
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Tidskriftsartikel (refereegranskat)abstract
- Traces of active pharmaceutical ingredients (APIs) and other chemicals are demonstrated in effluents from sewage treatment plants (STPs) and they may affect quality of surface water and eventually drinking water. Treatment of effluents with granular activated carbon (GAC) or ozone to improve removal of APIs and other contaminants was evaluated at two Swedish STPs, Kappala and Uppsala (88 and 103 APIs analyzed). Biomarker responses in rainbow trout exposed to regular and additionally treated effluents were determined. GAC and ozone treatment removed 87-95% of the total concentrations of APIs detected. In Kappala, GAC removed 20 and ozonation (7 g O-3/m(3)) 21 of 24 APIs detected in regular effluent. In Uppsala, GAC removed 25 and ozonation (5.4 g O-3/m(3)) 15 of 25 APIs detected in effluent. GAC and ozonation also reduced biomarker responses caused by unidentified pollutants in STP effluent water. Elevated ethoxyresorufin-O-deethylase (EROD) activity in gills was observed in fish exposed to effluent in both STPs. Gene expression analysis carried out in Kappala showed increased concentrations of cytochrome P450 (CYP1A5 and CYP1C3) transcripts in gills and of CYP1As in liver of fish exposed to effluent. In fish exposed to GAC- or ozone-treated effluent water, gill EROD activity and expression of CYP1As and CYP1C3 in gills and liver were generally equal to or below levels in fish held in tap water. The joint application of chemical analysis and sensitive biomarkers proved useful for evaluating contaminant removal in STPs with new technologies.
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