| 1. |
- Niss, Frida, et al.
(författare)
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Toxicity bioassays with concentrated cell culture media-a methodology to overcome the chemical loss by conventional preparation of water samples
- 2018
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 25, s. 12183-12188
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Tidskriftsartikel (refereegranskat)abstract
- The use of in vitro bioassays for studies of toxic activity in environmental water samples is a rapidly expanding field of research. Cell-based bioassays can assess the total toxicity exerted by a water sample, regardless whether the toxicity is caused by a known or unknown agent or by a complex mixture of different agents. When using bioassays for environmental water samples, it is often necessary to concentrate the water samples before applying the sample. Commonly, water samples are concentrated 10-50 times. However, there is always a risk of losing compounds in the sample in such sample preparation. We have developed an alternative experimental design by preparing a concentrated cell culture medium which was then diluted in the environmental water sample to compose the final cell culture media for the in vitro assays. Water samples from five Swedish waste water treatment plants were analyzed for oxidative stress response, estrogen receptor (ER), and aryl hydrocarbon receptor (AhR) activity using this experimental design. We were able to detect responses equivalent to 8.8-11.3 ng/L TCCD for AhR activity and 0.4-0.9 ng/L 17 beta-estradiol for ER activity. We were unable to detect oxidative stress response in any of the studied water samples. In conclusion, we have developed an experimental design allowing us to examine environmental water samples in toxicity in vitro assays at a concentration factor close to 1, without the risk of losing known or unknown compounds during an extraction procedure.
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| 2. |
- Oskarsson, Agneta, et al.
(författare)
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Identification of a xenobiotic as a potential environmental trigger in primary biliary cholangitis
- 2018
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Ingår i: Journal of Hepatology. - : Elsevier BV. - 0168-8278 .- 1600-0641. ; 69, s. 1123-1135
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Primary biliary cholangitis (PBC) is an autoimmune-associated chronic liver disease triggered by environmental factors, such as exposure to xenobiotics, which leads to a loss of tolerance to the lipoic acid-conjugated regions of the mitochondrial pyruvate dehydrogenase complex, typically to the E2 component. We aimed to identify xenobiotics that might be involved in the environmental triggering of PBC.Methods: Urban landfill and control soil samples from a region with high PBC incidence were screened for xenobiotic activities using analytical, cell-based xenobiotic receptor activation assays and toxicity screens.Results: A variety of potential xenobiotic classes were ubiquitously present, as identified by their interaction with xenobiotic receptors - aryl hydrocarbon receptor, androgen receptor and peroxisome proliferator activated receptor alpha - in cell-based screens. In contrast, xenoestrogens were present at higher levels in soil extracts from around an urban landfill. Furthermore, two landfill sampling sites contained a chemical(s) that inhibited mitochondrial oxidative phosphorylation and induced the apoptosis of a hepatic progenitor cell. The mitochondrial effect was also demonstrated in human liver cholangiocytes from three separate donors. The chemical was identified as the ionic liquid [3-methyl-1-octyl-1H-imidazol-3-ium](+) (M8OI) and the toxic effects were recapitulated using authentic pure chemical. A carboxylate-containing human hepatocyte metabolite of M8OI, bearing structural similarity to lipoic acid, was also enzymatically incorporated into the E2 component of the pyruvate dehydrogenase complex via the exogenous lipoylation pathway in vitro.Conclusions: These results identify, for the first time, a xenobiotic in the environment that may be related to and/or be a component of an environmental trigger for PBC. Therefore, further study in experimental animal models is warranted, to determine the risk of exposure to these ionic liquids. (C) 2018 European Association for the Study of the Liver. Published by Elsevier B.V.
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| 3. |
- Rosenmai, Anna, et al.
(författare)
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Effect-based assessment of recipient waters impacted by on-site, small scale, and large scale waste water treatment facilities-combining passive sampling with in vitro bioassays and chemical analysis
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Waste water treatment facilities are a major sources of organic micropollutants (MPs) in surface water. In this study, surface water samples were collected from seven sites along a river system in Uppsala, Sweden, during four seasons and evaluated based on the occurrence of MPs in the samples and bioactivity using in vitro bioassays. The sampling sites were differentially impacted by on-site sewage treatment facilities (OSSFs), small scale, and large scale waste water treatment plants (WWTPs). The bioassays used included activation of aryl hydrocarbon receptor (AhR), estrogen receptor (ER), nuclear factor kappa-light-chain-enhancer of activated B cells (NFkB), nuclear factor erythroid 2-related factor 2 (Nrf2), and androgen receptor (AR). Occurrence of 80 MPs, were analyzed using liquid chromatography coupled to tandem mass spectrometry. Most water samples induced AhR activity, and all sampling sites showed a similar profile regarding this activity. With the exception of one water sample, we did not detect any NFkB, Nrf2 or AR activity of the water samples. The exception was a sample impacted by OSSFs, which showed an activity in multiple bioassays, but the activity could not be explained by the occurrence of target MPs. The occurrence of MPs showed a spatial trend, with the highest number and amount of MPs detected in the samples collected downstream of the WWTPs, where up to 47 MPs were detected in one single sample. A seasonal variation was observed with highest levels of MPs and highest AhR activities in samples collected in June and September 2015. However, neither the seasonal activity nor the on-site activity could be explained by the measured MPs, suggesting unknown contributory agents in the water.
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| 4. |
- Rosenmai, Anna, et al.
(författare)
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Impact of natural organic matter in water on in vitro bioactivity assays
- 2018
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 200, s. 209-216
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Tidskriftsartikel (refereegranskat)abstract
- Surface water can be contaminated with pollutants from multiple sources and contain a vast number of various chemicals. In vitro bioassays are valuable tools to assess the total bioactivity of micropollutants in water samples. Besides anthropogenic chemicals, natural organic matter (NOM) is ubiquitous in water, which also may have an impact on the bioactivity in water samples.In the present study we investigated concentration-dependent effects of Nordic Aquatic fulvic acid (NA-FA) and Nordic reservoir NOM (NR-NOM) on bioactivity measured by a panel of luciferase reporter gene assays. The assays included measurements of both induction of activities and inhibition of induced activation on aryl hydrocarbon receptor (AhR), androgen receptor (AR), estrogen receptor (ER), peroxisome proliferator-activated receptor alpha, and on the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) activity as a marker of oxidative stress.At non-cytotoxic concentrations both NA-FA and NR-NOM induced AhR activity, inhibited AR activity with and without the known inducer dihydrotestosterone, inhibited Nrf2 activity, and NR-NOM induced ER activity. The results indicate that the presence of NOM in water samples may lead to false positive results for AhR activity and false positive results for AR and Nrf2 activity, when assessing inhibition of induced bioactivities from anthropogenic substances. We have demonstrated that NA-FA and NR-NOM have an impact on in vitro bioactivities and conclude that the impact of NOM in water should be considered in the evaluation of results from bioactivity assays. (C) 2018 Elsevier Ltd. All rights reserved.
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| 5. |
- Rosenmai, Anna Kjerstine, et al.
(författare)
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In vitro bioanalysis of drinking water from source to tap
- 2018
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 139, s. 272-280
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Tidskriftsartikel (refereegranskat)abstract
- The presence of chemical pollutants in sources of drinking water is a key environmental problem threatening public health. Efficient removal of pollutants in drinking water treatment plants (DWTPs) is needed as well as methods for assessment of the total impact of all present chemicals on water quality. In the present study we have analyzed the bioactivity of water samples from source to tap, including effects of various water treatments in a DWTP, using a battery of cell-based bioassays, covering health-relevant endpoints. Reporter gene assays were used to analyze receptor activity of the aryl hydrocarbon receptor (AhR), estrogen receptor (ER), androgen receptor (AR), peroxisome proliferator-activated receptor alpha (PPAR alpha) and induction of oxidative stress by the nuclear factor erythroid 2-related factor 2 (Nrf2). DNA damage was determined by Comet assay. Grab water samples were concentrated by HLB or ENV solid phase extraction and the water samples assayed at a relative enrichment factor of 50. The enrichment procedure did not induce any bioactivity. No bioactivity was detected in Milli-Q water or drinking water control samples. Induction of AhR, ER and Nrf2 activities was revealed in source to tap water samples. No cytotoxicity, PPAR alpha or AR antagonist activity, or DNA damage were observed in any of the water samples. A low AR agonist activity was detected in a few samples of surface water, but not in the samples from the DWTP. The treatment steps at the DWTP, coagulation, granulated activated carbon filtration, UV disinfection and NH2CI dosing had little or no effect on the AhR, Nrf2 and ER bioactivity. However, nano filtration and passage through the distribution network drastically decreased AhR activity, while the effect on Nrf2 activity was more modest and no apparent effect was observed on ER activity. The present results suggest that bioassays are useful tools for evaluation of the efficiency of different treatment steps in DWTPs in reducing toxic activities. Bioassays of AhR and Nrf2 are useful for screening of effects of a broad range of chemicals in drinking water and ER activity can be monitored with a high sensitivity.
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| 6. |
- Rosenmai, Anna, et al.
(författare)
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Relationship between peroxisome proliferator‐activated receptor alpha activity and cellular concentration of 14 perfluoroalkyl substances in HepG2 cells
- 2018
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Ingår i: Journal of Applied Toxicology. - : Wiley. - 0260-437X .- 1099-1263. ; 38, s. 219-226
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Tidskriftsartikel (refereegranskat)abstract
- Peroxisome proliferator-activated receptor alpha (PPAR) is a molecular target for perfluoroalkyl substances (PFASs). Little is known about the cellular uptake of PFASs and how it affects the PPAR activity. We investigated the relationship between PPAR activity and cellular concentration in HepG2 cells of 14 PFASs, including perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates and perfluorooctane sulfonamide (FOSA). Cellular concentrations were determined by high-performance liquid chromatography-tandem mass spectrometry and PPAR activity was determined in transiently transfected cells by reporter gene assay. Cellular uptake of the PFASs was low (0.04-4.1%) with absolute cellular concentrations in the range 4-2500ng mg(-1) protein. Cellular concentration of PFCAs increased with perfluorocarbon chain length up to perfluorododecanoate. PPAR activity of PFCAs increased with chain length up to perfluorooctanoate. The maximum induction of PPAR activity was similar for short-chain (perfluorobutanoate and perfluoropentanoate) and long-chain PFCAs (perfluorododecanoate and perfluorotetradecanoate) (approximately twofold). However, PPAR activities were induced at lower cellular concentrations for the short-chain homologs compared to the long-chain homologs. Perfluorohexanoate, perfluoroheptanoate, perfluorooctanoate, perfluorononanoate (PFNA) and perfluorodecanoate induced PPAR activities >2.5-fold compared to controls. The concentration-response relationships were positive for all the tested compounds, except perfluorooctane sulfonate PFOS and FOSA, and were compound-specific, as demonstrated by differences in the estimated slopes. The relationships were steeper for PFCAs with chain lengths up to and including PFNA than for the other studied PFASs. To our knowledge, this is the first report establishing relationships between PPAR activity and cellular concentration of a broad range of PFASs.The relationship between peroxisome proliferator-activated receptor alpha (PPAR) activity and cellular concentrations of perfluoroalkyl substances was investigated in HepG2 cells. PPAR activity was determined in transiently transfected cells by reporter gene assay and cellular concentrations by high-performance liquid chromatography-tandem mass spectrometry The cellular concentrations and PPAR activity of perfluoroalkyl substances was dependent on perfluorocarbon chain -length and functional group, and positive relationships between PPAR activity and cellular concentrations were established for all compounds, except perfluorooctane sulfonate and perfluorooctane sulfonamide
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