110 results on '"Bresgen N"'
Search Results
2. Validation and application of sub-2 μm core–shell UHPLC–UV–ESI–Orbitrap MS for identification and quantification of β-carotene and selected cleavage products with preceding solid-phase extraction
- Author
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Martano, G., Bojaxhi, E., Forstenlehner, I. C., Huber, C. G., Bresgen, N., Eckl, P. M., and Stutz, H.
- Published
- 2014
- Full Text
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3. Antimutagenic effects of ethanolic extracts from selected Palestinian medicinal plants
- Author
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Khader, M., Bresgen, N., and Eckl, P.M.
- Published
- 2010
- Full Text
- View/download PDF
4. Solid-phase extraction and GC-MS analysis of potentially genotoxic cleavage products of β-carotene in primary cell cultures
- Author
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Martano, G., Vogl, C., Bojaxhi, E., Bresgen, N., Eckl, P., and Stutz, H.
- Published
- 2011
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5. Intracellular Fe2+ and 4-hydroxynonenal suppresses a swelling-activated chloride current in microglial cells: P10.31
- Author
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Jakab, M., Schmölzer, J., Bresgen, N., Ritter, M., and Kerschbaum, H. H.
- Published
- 2014
6. Release of 4-hydroxynonenal and 4-hydroxyhexenal-modified proteins in exosomes: S4-D5
- Author
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Kopp, F., Bresgen, N., Jakab, M., Ritter, M., and Kerschbaum, H. H.
- Published
- 2014
7. β-Carotene breakdown products enhance genotoxic effects of oxidative stress in primary rat hepatocytes
- Author
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Alija, A.J., Bresgen, N., Sommerburg, O., Langhans, C.D., Siems, W., and Eckl, P.M.
- Published
- 2006
8. Cyto- and genotoxic potential of β-carotene and cleavage products under oxidative stress
- Author
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Alija, A. J., Bresgen, N., Sommerburg, O., Langhans, C. D., Siems, W., and Eckl, P.M.
- Published
- 2005
9. Cytotoxic and genotoxic effects of β-carotene breakdown products on primary rat hepatocytes
- Author
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Alija, A.J., Bresgen, N., Sommerburg, O., Siems, W., and Eckl, P.M.
- Published
- 2004
10. CYTOTOXIC AND GENOTOXIC EFFECTS DUE TO BETA-CAROTENE CLEAVAGE PRODUCTS POSSIBLY FORMED IN INFLAMED LUNG TISSUE: S24-129
- Author
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Sommerburg, O., Alija, A., Bresgen, N., Eckl, P. M., and Siems, W.
- Published
- 2004
11. Analytical tools for the analysis of β-carotene and its degradation products
- Author
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Stutz, H., Bresgen, N., and Eckl, P. M.
- Subjects
cleavage products ,Molecular Structure ,Review Article ,β-Carotene ,Free Radical Scavengers ,Reference Standards ,Oxidants ,beta Carotene ,Chemistry Techniques, Analytical ,extraction and analysis methods ,in vitro oxidation methods ,Structure-Activity Relationship ,Drug Stability ,Solubility ,quantification and validation ,Calibration ,Animals ,Humans ,Biological Assay ,Hydrophobic and Hydrophilic Interactions ,Oxidation-Reduction ,Cells, Cultured - Abstract
β-Carotene, the precursor of vitamin A, possesses pronounced radical scavenging properties. This has centered the attention on β-carotene dietary supplementation in healthcare as well as in the therapy of degenerative disorders and several cancer types. However, two intervention trials with β-carotene have revealed adverse effects on two proband groups, that is, cigarette smokers and asbestos-exposed workers. Beside other causative reasons, the detrimental effects observed have been related to the oxidation products of β-carotene. Their generation originates in the polyene structure of β-carotene that is beneficial for radical scavenging, but is also prone to oxidation. Depending on the dominant degradation mechanism, bond cleavage might occur either randomly or at defined positions of the conjugated electron system, resulting in a diversity of cleavage products (CPs). Due to their instability and hydrophobicity, the handling of standards and real samples containing β-carotene and related CPs requires preventive measures during specimen preparation, analyte extraction, and final analysis, to avoid artificial degradation and to preserve the initial analyte portfolio. This review critically discusses different preparation strategies of standards and treatment solutions, and also addresses their protection from oxidation. Additionally, in vitro oxidation strategies for the generation of oxidative model compounds are surveyed. Extraction methods are discussed for volatile and non-volatile CPs individually. Gas chromatography (GC), (ultra)high performance liquid chromatography (U)HPLC, and capillary electrochromatography (CEC) are reviewed as analytical tools for final analyte analysis. For identity confirmation of analytes, mass spectrometry (MS) is indispensable, and the appropriate ionization principles are comprehensively discussed. The final sections cover analysis of real samples and aspects of quality assurance, namely matrix effects and method validation.
- Published
- 2015
12. Computer modeling of blastoderm formation inDrosophila
- Author
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Bresgen, N., Czihak, G., and Linhart, J.
- Published
- 1994
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13. Clinical Use of Carotenoids - Antioxidative Protection Versus Prooxidative Side Effects
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Siems, W., Wiswedel, I., Sommerburg, O., Langhans, C. D., Salerno, Costantino, Crifo', Carlo, Capuozzo, Elisabetta, Alija, A., Bresgen, N., Grune, T., and Eckl, P.
- Published
- 2005
14. Lysosomes play a key role in ferritin-mediated cell death
- Author
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Krenn, M.A., primary, Litsios, A., additional, Andosch, A., additional, Lütz-Meindl, U., additional, Eckl, P.M., additional, and Bresgen⁎, N., additional
- Published
- 2012
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15. The Na+/K+ ATPase inhibitor, ouabain, promotes lipid peroxidation in microglia
- Author
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Abfalter, C, primary, Schweinitzer, G., additional, Uchida, K., additional, Kerschbaum, H.H., additional, and Bresgen⁎, N., additional
- Published
- 2012
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16. Chemistry and biochemistry of lipid peroxidation products
- Author
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Guéraud, F., primary, Atalay, M., additional, Bresgen, N., additional, Cipak, A., additional, Eckl, P. M., additional, Huc, L., additional, Jouanin, I., additional, Siems, W., additional, and Uchida, K., additional
- Published
- 2010
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17. 249 DOWNSTREAM EFFECTS OF OXIDATIVE STRESS IN FERRITIN MEDIATED APOPTOSIS – ACTIVATION OF PROAPOPTOTIC FAS
- Author
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Ohlenschläger, I., primary, Jaksch, H., additional, Lacher, H., additional, Eckl, P.M., additional, and Bresgen, N., additional
- Published
- 2009
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18. In vitro toxicological properties of thymoquinone
- Author
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Khader, M., primary, Bresgen, N., additional, and Eckl, P.M., additional
- Published
- 2009
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19. Effects of aqueous extracts of medicinal plants on MNNG-treated rat hepatocytes in primary cultures
- Author
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Khader, M., Eckl, P.M., and Bresgen, N.
- Published
- 2007
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20. Ferritin and FasL (CD95L) mediate density dependent apoptosis in primary rat hepatocytes
- Author
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Bresgen, N., primary, Ohlenschläger, I., additional, Wacht, N., additional, Afazel, S., additional, Ladurner, G., additional, and Eckl, P.M., additional
- Published
- 2008
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21. Toxicological properties of thymoquinone in primary rat hepatocyte cultures
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Khader, M, primary, Bresgen, N, additional, and Eckl, P, additional
- Published
- 2008
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22. Evaluation of the toxicological properties of ground- and surface-water samples from the Aral Sea Basin
- Author
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BOSCH, K, primary, ERDINGER, L, additional, INGEL, F, additional, KHUSSAINOVA, S, additional, UTEGENOVA, E, additional, BRESGEN, N, additional, and ECKL, P, additional
- Published
- 2007
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23. Antimutagenic effects of ethanolic extracts from three Palestinian medicinal plants
- Author
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Khader, M, primary, Eckl, PM, additional, and Bresgen, N, additional
- Published
- 2006
- Full Text
- View/download PDF
24. Cyto- and genotoxic potential ofβ-carotene and cleavage products under oxidative stress
- Author
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Alija, A.J., primary, Bresgen, N., additional, Sommerburg, O., additional, Langhans, C.D., additional, Siems, W., additional, and Eckl, P.M., additional
- Published
- 2005
- Full Text
- View/download PDF
25. Functional interaction in establishment of ribosomal integrity between small subunit protein rpS6 and translational regulator rpL10/Grc5p
- Author
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PACHLER, K, primary, KARL, T, additional, KOLMANN, K, additional, MEHLMER, N, additional, EDER, M, additional, LOEFFLER, M, additional, OENDER, K, additional, HOCHLEITNER, E, additional, LOTTSPEICH, F, additional, and BRESGEN, N, additional
- Published
- 2004
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26. Oxidative stress in cultured cerebral endothelial cells induces chromosomal aberrations, micronuclei, and apoptosis
- Author
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Bresgen, N., primary, Karlhuber, G., additional, Krizbai, I., additional, Bauer, H., additional, Bauer, H.C., additional, and Eckl, P.M., additional
- Published
- 2003
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27. Cyto- and genotoxicity evaluation of water samples collected from two rivers in the Kosovo.
- Author
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Asllani FH, Alija AJ, Eckl PM, and Bresgen N
- Subjects
- Animals, Rats, Kosovo, Environmental Monitoring methods, Comet Assay, Micronucleus Tests, Mutagens toxicity, Seasons, Male, Mutagenicity Tests, Rivers chemistry, Water Pollutants, Chemical toxicity, Water Pollutants, Chemical analysis, DNA Damage drug effects, Hepatocytes drug effects
- Abstract
River water in Kosovo is exposed to various discharges from industrial and agricultural activities as well as to urban wastewater. Rivers Sitnica and Drenica are among the most affected ones and water samples drawn from these rivers show the presence of various toxic substances. Genotoxic effects are seen in fish living in these rivers indicating a cytotoxic and mutagenic potential of the river water. Aiming at substantiating these observations, we assessed the cyto- and genotoxic effects of water samples collected at different locations from the Drenica and Sitnica rivers. Samples drawn from Lake Badovc served for comparison. To address seasonal effects, samples were collected at different seasons/time points during the period of summer 2016-spring 2018. The water samples were analyzed employing primary rat hepatocytes as a reliable in vitro cell model for the assessment of cytotoxic effects (mitotic arrest and cell death) and DNA damage/genotoxicity (micronucleus assay and Comet assay). The results do not account for significant effects associated with specific locations but demonstrate seasonal differences of the genotoxic potential of the water samples collected along both rivers, which are accompanied by a limited cytotoxic potential. Our data provide substantial support to earlier observations and strongly warrant the need for continuous chemical as well as biological monitoring of the river water in Kosovo, focusing on improved toxicant profiling of the river water and investigations addressing the observed seasonal variations., (© The Author(s) 2024. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)
- Published
- 2024
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28. Fly into the light: eliminating Drosophila melanogaster with chlorophyllin-based Photodynamic Inactivation.
- Author
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Fellner A, Bresgen N, Fefer M, Liu J, and Plaetzer K
- Subjects
- Animals, Light, Chlorophyllides pharmacology, Drosophila melanogaster drug effects, Photosensitizing Agents pharmacology, Photosensitizing Agents chemistry, Insecticides pharmacology
- Abstract
Fruit flies spoil crops in agricultural settings. As conventional pesticides may generate negative off-target effects on humans or the environment, existing treatment methods need eco-friendly and safe alternatives. Photodynamic Inactivation (PDI) is based on the photosensitizer-mediated and light-induced overproduction of reactive oxygen species in targets. We here explore the potential of PDI for the control of fruit fly pests. Drosophila melanogaster serves as well-established model organism in this study. Two distinct experimental approaches are presented: the feed assay, in which fruit flies are provided with sodium magnesium chlorophyllin (Chl, approved as food additive E140) along with sucrose (3%) as their food, and the spray assay, where the photosensitizer is sprayed onto the insects. We show that PDI based on Chl can induce moribundity rates of Drosophila melanogaster of more than 99% with 5 mM Chl and LED illumination (395 nm, 8 h incubation in the dark, radiant exposure 78.9 J/cm
2 ) with the feed assay. If the radiant exposure is doubled to 157.8 J/cm2 , 88% of insects are killed by PDI based on 1 mM Chl. The photoactive compound is also effective if presented on strawberries without addition of sucrose with somewhat lower moribundity (71% at 5 mM Chl). Spraying Chl onto insects is less effective than feeding the photosensitizer: 5 mM Chl resulted in 79.5% moribundity (drug to light interval 8 h, radiant exposure 78.9 J/cm2 ), but if 5 h of sun light (532 J/cm2 ) and overnight (14 h) dark incubation is used for activation of Chl, more than 95% of insects are killed. As conclusion, Chl serves as effective photoinsecticide against Drosophila melanogaster if a drug to light interval of 8 h is maintained. Feeding the photoactive compound together with sucrose is more effective than spraying it onto insects and increasing the radiant exposure allows for lowering the photosensitizer concentration. Photodynamic Inactivation might therefore represent an eco-friendly addition to the farmers armamentarium against (semi-transparent) insects., (© 2024. The Author(s).)- Published
- 2024
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29. Lipedema: The Use of Cultured Adipocytes for Identification of Diagnostic Markers.
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Ernst AM, Steiner M, Kainz V, Tempfer H, Spitzer G, Plank T, Bauer HC, Bresgen N, Habenbacher A, Bauer H, and Lipp AT
- Subjects
- Humans, Female, Adiponectin metabolism, Adipocytes physiology, Obesity complications, Cells, Cultured, Leptin metabolism, Lipedema diagnosis, Lipedema pathology
- Abstract
Background: Lipedema, diagnosed most often in women, is a progressive disease characterized by the disproportionate and symmetrical distribution of adipose tissue, primarily in the extremities. Although numerous results from in vitro and in vivo studies have been published, many questions regarding the pathology and genetic background of lipedema remain unanswered., Methods: In this study, adipose tissue-derived stromal/stem cells were isolated from lipoaspirates derived from nonobese and obese donors with or without lipedema. Growth and morphology, metabolic activity, differentiation potential, and gene expression were evaluated using quantification of lipid accumulation, metabolic activity assay, live-cell imaging, reverse transcription polymerase chain reaction, quantitative polymerase chain reaction, and immunocytochemical staining., Results: The adipogenic potential of lipedema and nonlipedema adipose tissue-derived stromal/stem cells did not rise in parallel with the donors' body mass index and did not differ significantly between groups. However, in vitro differentiated adipocytes from nonobese lipedema donors showed significant upregulation of adipogenic gene expression compared with nonobese controls. All other genes tested were expressed equally in lipedema and nonlipedema adipocytes. The adiponectin/leptin ratio was significantly reduced in adipocytes from obese lipedema donors compared with their nonobese lipedema counterparts. Increased stress fiber-integrated smooth muscle actin was visible in lipedema adipocytes compared with nonlipedema controls and appeared enhanced in adipocytes from obese lipedema donors., Conclusions: Not only lipedema per se but also body mass index of donors affect adipogenic gene expression substantially in vitro. The significantly reduced adiponectin/leptin ratio and the increased occurrence of myofibroblast-like cells in obese lipedema adipocyte cultures underscores the importance of attention to the co-occurrence of lipedema and obesity. These are important findings toward accurate diagnosis of lipedema., Clinical Relevance Statement: Our study highlights not only the difficulty in lipedema diagnostics but also the tremendous need for further studies on lipedema tissue. Although lipedema might seem to be an underestimated field in plastic and reconstructive surgery, the power it holds to provide better treatment to future patients can not be promoted enough., (Copyright © 2023 by the American Society of Plastic Surgeons.)
- Published
- 2023
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30. The Janus-Faced Role of Lipid Droplets in Aging: Insights from the Cellular Perspective.
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Bresgen N, Kovacs M, Lahnsteiner A, Felder TK, and Rinnerthaler M
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- Animals, Drosophila melanogaster, Aging, Longevity physiology, Caenorhabditis elegans metabolism, Saccharomyces cerevisiae, Mammals, Lipid Droplets metabolism, Diabetes Mellitus, Type 2 metabolism
- Abstract
It is widely accepted that nine hallmarks-including mitochondrial dysfunction, epigenetic alterations, and loss of proteostasis-exist that describe the cellular aging process. Adding to this, a well-described cell organelle in the metabolic context, namely, lipid droplets, also accumulates with increasing age, which can be regarded as a further aging-associated process. Independently of their essential role as fat stores, lipid droplets are also able to control cell integrity by mitigating lipotoxic and proteotoxic insults. As we will show in this review, numerous longevity interventions (such as mTOR inhibition) also lead to strong accumulation of lipid droplets in Saccharomyces cerevisiae , Caenorhabditis elegans , Drosophila melanogaster , and mammalian cells, just to name a few examples. In mammals, due to the variety of different cell types and tissues, the role of lipid droplets during the aging process is much more complex. Using selected diseases associated with aging, such as Alzheimer's disease, Parkinson's disease, type II diabetes, and cardiovascular disease, we show that lipid droplets are "Janus"-faced. In an early phase of the disease, lipid droplets mitigate the toxicity of lipid peroxidation and protein aggregates, but in a later phase of the disease, a strong accumulation of lipid droplets can cause problems for cells and tissues.
- Published
- 2023
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31. Peter Eckl: Research on the Pro-/Antioxidant Balance.
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Bresgen N and Siems W
- Abstract
Peter Maria ECKL started his scientific career in the late 1970s at the Paris-Lodron University of Salzburg working in the field of radiation research [...].
- Published
- 2022
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32. Trypan Blue - Adapting a Dye Used for Labelling Dead Cells to Visualize Pinocytosis in Viable Cells.
- Author
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Kerschbaum HH, Tasa BA, Schürz M, Oberascher K, and Bresgen N
- Subjects
- Animals, Cell Death, Cell Line, Cell Survival, Mice, Microscopy, Fluorescence methods, Staining and Labeling methods, Coloring Agents analysis, Microglia cytology, Pinocytosis, Trypan Blue analysis
- Abstract
Background/aims: Trypan blue is routinely used in cell culture experiments to distinguish between dead cells, which are labelled by trypan blue, and viable cells, which are apparently free of any staining. The assumption that trypan blue labelling is restricted to dead cells derives from the observation that rupture of the plasma membrane correlates with intense trypan blue staining. However, decades ago, trypan blue has been used to trace fluid uptake by viable macrophage-like cells in animals. These studies contributed to the concept of the reticuloendothelial system in vertebrates. Trypan blue itself does not show a fluorescence signal, but trypan blue-labelled proteins do. Therefore, intracellular localization of trypan blue-labelled proteins could give a clue to the entrance pathway of the dye in viable cells., Methods: We used fluorescence microscopy to visualize trypan blue positive structures and to evaluate whether the bactericide, silver, enhances cellular trypan blue uptake in the brain macrophage-like cell line, BV-2. The pattern of chromatin condensation, visualized by DAPI staining, was used to identify the cell death pathway., Results: We observed that silver nitrate at elevated concentrations (≥ 10 µM) induced in most cells a necrotic cell death pathway. Necrotic cells, identified by pycnotic nuclei, showed an intense and homogenous trypan blue staining. Apoptotic cells, characterized by crescent-like nuclear chromatin condensations, were not labelled by trypan blue. At lower silver nitrate concentrations, most cells were viable, but they showed trypan blue labelling. Viable cells showed a cell-type specific distribution of heterochromatin and revealed a perinuclear accumulation of bright trypan blue-labelled vesicles and, occasionally, a faint homogenous trypan blue labelling of the cytoplasm and nucleus. Amiloride, which prevents macropinocytosis by blocking the Na
+ / H+ exchange, suppressed perinuclear accumulation of dye-labelled vesicles. Swelling of cells in a hypotonic solution induced an intense intracellular accumulation of trypan blue. Cells exposed to a hypotonic solution in the presence of 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB), which blocks volume-regulated ion channels, prevented labelling of the cytoplasm and nucleus but did not affect labelling of perinuclear vesicles., Conclusion: In viable cells trypan blue-labelled vesicles indicate trypan blue uptake by macropinocytosis and trypan blue-labelled cytosol could indicate a further entry pathway for the dye, like activated volume-regulated channels. Accordingly, fluorescence microscopic analysis of trypan blue-labelled cells allows not only a discrimination between necrotic and apoptotic cell death pathway but also a discrimination between the mode of trypan blue uptake in viable cells - via pinocytosis or via activated volume-regulated ion channels - in the same preparation at the single cell level., Competing Interests: The authors declare that no conflict of interests exist., (© Copyright by the Author(s). Published by Cell Physiol Biochem Press.)- Published
- 2021
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33. From Pinocytosis to Methuosis-Fluid Consumption as a Risk Factor for Cell Death.
- Author
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Ritter M, Bresgen N, and Kerschbaum HH
- Abstract
The volumes of a cell [cell volume (CV)] and its organelles are adjusted by osmoregulatory processes. During pinocytosis, extracellular fluid volume equivalent to its CV is incorporated within an hour and membrane area equivalent to the cell's surface within 30 min. Since neither fluid uptake nor membrane consumption leads to swelling or shrinkage, cells must be equipped with potent volume regulatory mechanisms. Normally, cells respond to outwardly or inwardly directed osmotic gradients by a volume decrease and increase, respectively, i.e., they shrink or swell but then try to recover their CV. However, when a cell death (CD) pathway is triggered, CV persistently decreases in isotonic conditions in apoptosis and it increases in necrosis. One type of CD associated with cell swelling is due to a dysfunctional pinocytosis. Methuosis, a non-apoptotic CD phenotype, occurs when cells accumulate too much fluid by macropinocytosis. In contrast to functional pinocytosis, in methuosis, macropinosomes neither recycle nor fuse with lysosomes but with each other to form giant vacuoles, which finally cause rupture of the plasma membrane (PM). Understanding methuosis longs for the understanding of the ionic mechanisms of cell volume regulation (CVR) and vesicular volume regulation (VVR). In nascent macropinosomes, ion channels and transporters are derived from the PM. Along trafficking from the PM to the perinuclear area, the equipment of channels and transporters of the vesicle membrane changes by retrieval, addition, and recycling from and back to the PM, causing profound changes in vesicular ion concentrations, acidification, and-most importantly-shrinkage of the macropinosome, which is indispensable for its proper targeting and cargo processing. In this review, we discuss ion and water transport mechanisms with respect to CVR and VVR and with special emphasis on pinocytosis and methuosis. We describe various aspects of the complex mutual interplay between extracellular and intracellular ions and ion gradients, the PM and vesicular membrane, phosphoinositides, monomeric G proteins and their targets, as well as the submembranous cytoskeleton. Our aim is to highlight important cellular mechanisms, components, and processes that may lead to methuotic CD upon their derangement., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Ritter, Bresgen and Kerschbaum.)
- Published
- 2021
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34. Ferritin in glioblastoma.
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Jaksch-Bogensperger H, Spiegl-Kreinecker S, Arosio P, Eckl P, Golaszewski S, Ebner Y, Al-Schameri R, Strasser P, Weis S, and Bresgen N
- Subjects
- Apoptosis genetics, Biomarkers, Tumor genetics, Cell Line, Tumor, Cell Proliferation genetics, Female, Ferritins genetics, Gene Expression Regulation, Neoplastic genetics, Glioblastoma genetics, Glioblastoma pathology, Glioma genetics, Glioma pathology, Humans, Male, Paraffin Embedding, Signal Transduction genetics, Biomarkers, Tumor blood, Ferritins blood, Glioblastoma blood, Glioma blood
- Abstract
Elevated levels of serum ferritin (SF) are observed in several types of cancer; however, little is known on the association between ferritin and glioma, the most frequent type of human primary brain tumour. Here we report that GBM patients show significantly increased pre-surgical SF levels (i.e. ferritinaemia) within the SF reference range and a marked ferritin immunoreactivity of resected tumour tissue. Our findings account for an indirect association between ferritin synthesis in glioma-tissue and altered SF levels, which limits the clinical value of SF as a tumour marker in glioma. Importantly, we show for the first time that GBM-derived glioma cells release ferritin in vitro, which exerts an apoptosis-stimulating activity. Albeit the pathophysiologic context of apoptosis induction by a tumour-derived ferritin remains to be defined, our findings account for a distinct growth-regulatory role of these ferritin species in tumour biology.
- Published
- 2020
- Full Text
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35. In Vitro Aging of Human Skin Fibroblasts: Age-Dependent Changes in 4-Hydroxynonenal Metabolism.
- Author
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Petkovic I, Bresgen N, Gilardoni E, Regazzoni L, Uchida K, Aldini G, Siems W, and Eckl P
- Abstract
Evidence suggests that the increased production of free radicals and reactive oxygen species lead to cellular aging. One of the consequences is lipid peroxidation generating reactive aldehydic products, such as 4-hydroxynonenal (HNE) that modify proteins and form adducts with DNA bases. To prevent damage by HNE, it is metabolized. The primary metabolic products are the glutathione conjugate (GSH-HNE), the corresponding 4-hydroxynonenoic acid (HNA), and the alcohol 1,4-dihydroxynonene (DHN). Since HNE metabolism can potentially change during in vitro aging, cell cultures of primary human dermal fibroblasts from several donors were cultured until senescence. After different time points up to 30 min of incubation with 5 µM HNE, the extracellular medium was analyzed for metabolites via liquid chromatography coupled with electrospray ionization mass spectrometry (LC/ESI-MS). The metabolites appeared in the extracellular medium 5 min after incubation followed by a time-dependent increase. But, the formation of GSH-HNL and GSH-DHN decreased with increasing in vitro age. As a consequence, the HNE levels in the cells increase and there is more protein modification observed. Furthermore, after 3 h of incubation with 5 µM HNE, younger cells showed less proliferative capacity, while in older cells slight increase in the mitotic index was noticed., Competing Interests: The authors declare no conflict of interest.
- Published
- 2020
- Full Text
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36. Genotoxicity risk assessment in fish (Rutilus rutilus) from two contaminated rivers in the Kosovo.
- Author
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Asllani FH, Schürz M, Bresgen N, Eckl PM, and Alija AJ
- Subjects
- Animals, Comet Assay, Kosovo, Micronucleus Tests, Risk Assessment, Rivers chemistry, Seasons, Water Pollutants, Chemical analysis, Cyprinidae physiology, Environmental Monitoring, Water Pollutants, Chemical toxicity
- Abstract
Being exposed to untreated urban and industrial water, the rivers Drenica and Sitnica are considered to be the most polluted ones in the Kosovo. Our previous investigations on the cyto- and genotoxic potential of water samples from these rivers evaluated with primary rat hepatocyte cultures indicated a risk for the health of aquatic organisms. In order to assess the genotoxic risk to aquatic organisms, we therefore performed a two year study (2016-2017) on roach (Rutilus rutilus) from these rivers. Specimens were collected at three locations along the Drenica river and two locations along the Sitnica river, and the genotoxicity was evaluated by the micronucleus as well as the Comet assay (DNA damage) in erythrocytes. The frequencies of micronucleated cells were determined for samples collected in four seasons, whereas the Comet assay was employed on samples collected in five seasons during the two-year period. The data obtained revealed an increase of the frequency of micronucleated erythrocytes from Rutilus rutilus collected at most sampling locations and from both rivers at all seasons investigated. Significant differences to the control (lake Badovc) were found in summer 2016 and spring 2017 samples. When comparing the seasons, the summer 2016 samples were most genotoxic, followed by spring 2017 and autumn 2016. With regard to the Comet assay data, a similar but more prominent "response" was observed. Another important observation is that micronucleus rates as well as DNA damage levels were significantly higher in samples collected in 2016 compared to the respective seasons in 2017. Altogether, the "response" obtained with both markers confirmed a genotoxic risk for fish due the pollution of these rivers. Since there were, however, seasonal and annual variations of the genotoxicity levels further in depth studies have to be carried out addressing the nature of these changes., (Copyright © 2019. Published by Elsevier B.V.)
- Published
- 2019
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37. River pollution in the Kosovo: Cyto- and genotoxic effects of water samples in the primary rat hepatocyte assay.
- Author
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Alija AJ, Bresgen N, Bojaxhi E, Krenn M, Bajraktari ID, and Eckl PM
- Subjects
- Animals, Female, Kosovo, Mutagenicity Tests, Rats, Rats, Inbred F344, Toxicity Tests, Hepatocytes drug effects, Rivers chemistry, Water Pollutants, Chemical toxicity
- Abstract
The actual stage of the development of Kosovo is characterized by the concerning levels of environmental pollution and the serious health problems attributed to the emission of pollutants into air, soil and water. In this context, river pollution is one of the main threats due to the discharge of untreated urban and industrial waste waters that affect the quality of surface and ground water. In addition, urban and agricultural discharges are affecting the river water quality. In this article, we are presenting data on the cyto- and genotoxic potential of water samples from three rivers (Sitnica, Drenica and Lepenci) in the Kosovo as determined in the cultures of primary rat hepatocytes. Sitnica and Drenica (as the most important Sitnica tributary) drain into the Black Sea, whereas the Lepenci river drains into the Aegean Sea. These rivers are polluted mainly by industry in the Kosovo together with municipal discharges. The results of this study show that the samples have primarily a cytotoxic potential by causing necrotic cell death that was not accompanied by any increase of the rate of micronucleated cells as an indicator for a genotoxic potential. The different effects in 2 consecutive years can be attributed to variations in physico-chemical parameters such as water levels, intake of pollutants, and so on, indicating the need for continuous monitoring and risk assessment.
- Published
- 2018
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38. Genotoxicity of lipid oxidation compounds.
- Author
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Eckl PM and Bresgen N
- Subjects
- Acrolein metabolism, Aldehydes metabolism, Animals, CHO Cells, Cells, Cultured, Cricetulus, Epigenesis, Genetic, Epithelial Cells cytology, Epithelial Cells drug effects, Fibroblasts cytology, Fibroblasts drug effects, Histone Deacetylases genetics, Humans, Lipid Peroxidation, Lymphocytes cytology, Lymphocytes drug effects, Mutagens metabolism, Oxysterols metabolism, Salmonella typhimurium drug effects, Salmonella typhimurium growth & development, Acrolein toxicity, Aldehydes toxicity, Histone Deacetylases metabolism, Mutagens toxicity, Oxysterols toxicity
- Abstract
Lipid peroxidation, the oxidative degradation of membrane lipids by reactive oxygen species generates a large variety of breakdown products such as alkanes, aldehydes, ketones, alcohols, furans and others. Due to their reactivity aldehydes (alkanals, 2-alkenals, 2,4-alkadienals, 4-hydroxyalkenals) received a lot of attention, in particular because they can diffuse from the site of formation and interact with proteins and nucleic acids thus acting as second toxic messengers. The major aldehydic peroxidation product of membrane lipids is 4-hydroxynonenal (HNE). Since HNE and other 4-hydroxyalkenals are strong alkylating agents they have therefore been considered to be the biologically most important peroxidation products. Although initially research focused on the toxicological potential of these compounds it is now well known that they play also a crucial role in cell signaling under physiological and pathophysiological conditions. Thus, it is obvious that the biological effects will be determined by the intracellular concentrations which can trigger adaptation, DNA damage and cell death. This review will not cover all these aspects but will concentrate on the genotoxic properties of selected lipid oxidation products important in the context of pathophysiological developments together with a chapter on epigenetic modifications., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
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39. Is there a relationship between genetic factors and the incidence and severity of H1N1 in Kosova?: A preliminary investigation and pointers for further research.
- Author
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Dreshaj S, Alija AJ, Schlagenhauf P, Doda T, Geca N, Bajraktari I, Bresgen N, and Eckl PM
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- Adult, Female, Humans, Incidence, Kosovo epidemiology, Male, Phenotype, Retrospective Studies, Young Adult, Genetic Predisposition to Disease epidemiology, Genetic Predisposition to Disease genetics, Influenza A Virus, H1N1 Subtype, Influenza, Human epidemiology, Influenza, Human genetics
- Abstract
Background: Host genetic factors may impact susceptibility to infection. A small number of studies have investigated the association between factors such as ABO blood groups and selected phenotypes on the incidence and severity of H1N1 infections with inconclusive results., Methods: Using data from the Clinic of Infectious Diseases - University Clinical Centre Prishtina and based on the examination of 125 patients hospitalized with H1N1 in the period 2009-2014, the frequency of blood groups from ABO and Rhesus (Rh) systems as phenotypical markers were evaluated. In addition, other phenotypes such as ear lobe free/ear lobe attached, normal chin/cleft chin, tongue roller/non roller, hand clasping right thumb over/hand clasping left thumb over, right-handed/left-handed, dark eyes/light eyes were also analyzed. The data obtained from the 125 hospitalized patients were compared with the data from the Kosovar population (n = 2000) as a reference group., Results: A total of 303 patients with H1N1 were hospitalized in the period 2009-2015. Blood group and phenotype data available from 125 hospitalized H1N1 patients showed significant differences in the frequencies of the blood groups from Rh system as well as in two (out of six) phenotypes of the selected morphological traits compared to reference groups., Conclusions: The findings from this preliminary study indicate that these Rh system and phenotype differences may be linked to H1N1 susceptibility and may guide identification of risk groups and populations., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
40. Effects of β-Carotene and Its Cleavage Products in Primary Pneumocyte Type II Cells.
- Author
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Haider C, Ferk F, Bojaxhi E, Martano G, Stutz H, Bresgen N, Knasmüller S, Alija A, and Eckl PM
- Abstract
β-Carotene has been shown to increase the risk of developing lung cancer in smokers and asbestos workers in two large scale trails, the Beta-Carotene and Retinol Efficacy Trial (CARET) and the Alpha-Tocopherol Beta-carotene Cancer Prevention Trial (ATBC). Based on this observation, it was proposed that genotoxic oxidative breakdown products may cause this effect. In support of this assumption, increased levels of sister chromatid exchanges, micronuclei, and chromosomal aberrations were found in primary hepatocyte cultures treated with a mixture of cleavage products (CPs) and the major product apo-8'carotenal. However, because these findings cannot directly be transferred to the lung due to the exceptional biotransformation capacity of the liver, potential genotoxic and cytotoxic effects of β-carotene under oxidative stress and its CPs were investigated in primary pneumocyte type II cells. The results indicate that increased concentrations of β-carotene in the presence of the redox cycling quinone dimethoxynaphthoquinone (DMNQ) exhibit a cytotoxic potential, as evidenced by an increase of apoptotic cells and loss of cell density at concentrations > 10 µM. On the other hand, the analysis of micronucleated cells gave no clear picture due to the cytotoxicity related reduction of mitotic cells. Last, although CPs induced significant levels of DNA strand breaks even at concentrations ≥ 1 µM and 5 µM, respectively, β-carotene in the presence of DMNQ did not cause DNA damage. Instead, β-carotene appeared to act as an antioxidant. These findings are in contrast with what was demonstrated for primary hepatocytes and may reflect different sensitivities to and different metabolism of β-carotene in the two cell types., Competing Interests: The authors declare no conflict of interest.
- Published
- 2017
- Full Text
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41. Clearing the outer mitochondrial membrane from harmful proteins via lipid droplets.
- Author
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Bischof J, Salzmann M, Streubel MK, Hasek J, Geltinger F, Duschl J, Bresgen N, Briza P, Haskova D, Lejskova R, Sopjani M, Richter K, and Rinnerthaler M
- Abstract
In recent years it turned out that there is not only extensive communication between the nucleus and mitochondria but also between mitochondria and lipid droplets (LDs) as well. We were able to demonstrate that a number of proteins shuttle between LDs and mitochondria and it depends on the metabolic state of the cell on which organelle these proteins are predominantly localized. Responsible for the localization of the particular proteins is a protein domain consisting of two α -helices, which we termed V-domain according to the predicted structure. So far we have detected this domain in the following proteins: mammalian BAX, BCL-XL, TCTP and yeast Mmi1p and Erg6p. According to our experiments there are two functions of this domain: (1) shuttling of proteins to mitochondria in times of stress and apoptosis; (2) clearing the outer mitochondrial membrane from pro- as well as anti-apoptotic proteins by moving them to LDs after the stress ceases. In this way the LDs are used by the cell to modulate stress response., Competing Interests: The authors declare no conflict of interest.
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- 2017
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42. Sex, age, and sex hormones affect recall of words in a directed forgetting paradigm.
- Author
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Kerschbaum HH, Hofbauer I, Gföllner A, Ebner B, Bresgen N, and Bäuml KT
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Cues, Female, Humans, Male, Memory Disorders physiopathology, Middle Aged, Saliva metabolism, Verbal Learning physiology, Young Adult, Aging physiology, Estradiol metabolism, Memory Disorders metabolism, Mental Recall physiology, Progesterone metabolism, Sex Characteristics, Vocabulary
- Abstract
During the course of serious discussion, an unexpected interruption may induce forgetting of the original topic of a conversation. Sex, age, and sex hormone levels may affect frequency and extension of forgetting. In a list-method directed forgetting paradigm, subjects have to learn two word lists. After learning list 1, subjects receive either a forget or a remember list 1 cue. When the participants had learned list 2 and completed a distraction task, they were asked to write down as many recalled items as possible, starting either with list 1 or list 2 items. In the present study, 96 naturally cycling women, 60 oral contraceptive users, 56 postmenopausal women, and 41 young men were assigned to one of these different experimental conditions. Forget-cued young subjects recall fewer list 1 items (list 1 forgetting) but more list 2 items (list 2 enhancement) compared with remember-cued subjects. However, forget-cued postmenopausal women showed reduced list 1 forgetting but enhanced list 2 retention. Remember-cued naturally cycling women recalled more list 1 items than oral contraceptive users, young men, and postmenopausal women. In forget-cued follicular women, salivary progesterone correlated positively with recalled list 2 items. Salivary 17β-estradiol did not correlate with recalled list 1 or list 2 items in either remember- or forget-cued young women. However, salivary 17β-estradiol correlated with item recall in remember-cued postmenopausal women. Our findings suggest that sex hormones do not globally modulate verbal memory or forgetting, but selectively affect cue-specific processing. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)
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- 2017
- Full Text
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43. Cyto- and genotoxic potential of water samples from polluted areas in Kosovo.
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Alija AJ, Bajraktari ID, Bresgen N, Bojaxhi E, Krenn M, Asllani F, and Eckl PM
- Subjects
- Animals, Cell Survival drug effects, Cities, Female, Hepatocytes drug effects, Hepatocytes pathology, Kosovo, Metals, Heavy analysis, Metals, Heavy toxicity, Micronuclei, Chromosome-Defective chemically induced, Mutagens toxicity, Polychlorinated Biphenyls analysis, Polychlorinated Biphenyls toxicity, Rats, Rats, Inbred F344, Wastewater chemistry, Water Pollutants, Chemical toxicity, Environmental Monitoring methods, Groundwater chemistry, Mutagens analysis, Rivers chemistry, Water Pollutants, Chemical analysis
- Abstract
Reports on the state of the environment in Kosovo have emphasized that river and ground water quality is affected by pollution from untreated urban water as well as the waste water from the industry. One of the main contributors to this pollution is located in Obiliq (coal power plants). Prishtina-the capital city of Kosovo-is heavily influenced too. Furthermore, the pollutants combined together with those from heavy traffic are dissolved in Prishtina runoff water, which is discharged into the creek entering the river Sitnica together with urban waste water. The available data show the complex pollution with excessive quantities of nitrites, suspended materials, organic compounds, detergents, heavy metals, polychlorinated biphenyls, etc. In this study, the cytotoxic and genotoxic potential of water samples taken at these sites was tested in primary rat hepatocytes. The results obtained indicate that water samples collected in Prishtina and Obiliq had a significant cytotoxic potential in primary rat hepatocyte cultures even when diluted to 1 %. The increased cytotoxicity, however, was not accompanied by an increased genotoxicity as measured by the percentage of micronucleated cells. Further investigations addressing the chemical composition of the samples and the identification of the toxicants responsible for the cytotoxic effects found will be carried out in a next step.
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- 2016
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44. Effects of pollutants from power plants in Kosova on genetic loads of Drosophila melanogaster.
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Alija AJ, Bajraktari ID, Muharremi H, Bresgen N, and Eckl PM
- Subjects
- Animals, Carbon Dioxide toxicity, Carbon Monoxide toxicity, Chromosomes, Insect genetics, Drosophila melanogaster drug effects, Environmental Monitoring, Female, Industrial Waste adverse effects, Kosovo, Male, Metals, Heavy toxicity, Nitrogen Oxides toxicity, Particulate Matter toxicity, Sulfur Dioxide toxicity, Drosophila melanogaster genetics, Environmental Pollutants toxicity, Genetic Load, Power Plants
- Abstract
It has been reported by the Ministry of Environment in Kosova that particle emissions from one of the units of the coal-fired power plants (Kosova A) in Kastriot/Obiliq were exceeding the European standard by some 74 times. Besides the particle emission, there is also release of sulphur dioxide, mono-nitrogen oxide (NOx), carbon monoxide, carbon dioxide, organic compounds and heavy metals. In addition, there is also release of heavy metals and organic compounds from a nearby solid waste dumpsite. Together, they are considered to be responsible for the increased health problems of the population living in the vicinity.To study the genetic effects of these emissions we focused on the genetic load, that is, recessive mutations that affect the fitness of their carriers, of exposed wild living Drosophila melanogaster The effects of ash from the dumpsite on the other hand were investigated upon feeding the ash with the nutrient medium. Our results revealed that the D. melanogaster population from the Kastriot/Obiliq area carries a high genetic load of 54.7%. Drosophila fed with the nutrient medium containing ash in a concentration of 1% carried a genetic load of 37.1%, whilst increasing concentrations (2% and 3% of ash) led to higher genetic loads of 68.7% and 67.4%, respectively., (© The Author(s) 2014.)
- Published
- 2016
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45. Frequency Distribution and Association of some Morpho- and Physiological Traits in Patients with Lung Diseases in Kosova.
- Author
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Alija AJ, Bajraktari ID, Bresgen N, Hadziselimovic R, Beqiraj V, Selimi M, Salihu H, Mikullovci B, and Eckl PM
- Subjects
- Female, Humans, Male, Phenotype, Genetic Association Studies, Genetic Predisposition to Disease, Lung Diseases genetics
- Abstract
The aim of this study was to investigate the distribution of specific phenotypes in patients with lung diseases as well as their eventual association with the risk of developing lung diseases. For this purpose 2777 patients with lung diseases and 2778 healthy individuals from all over Kosova were examined for the appearance of the following selected phenotypes: ear lobe free (ELF)/ear lobe attached, normal chin (NC)/cleft chin, tongue roller (TR)/non roller, hand clasping right thumb over (HC)/hand clasping left thumb over, righthanded (RH)/lefthanded. In addition, the blood group from ABO system and the presence or absence of the Rhesus factor asphenotypical markers were observed. The results obtained show significant differences between control and lung disease patients for NC (p ≤ 0.05) and TR (p ≤ 0.005) as well as for blood groups AB (p ≤ 0.05) and O (p ≤ 0.005). These results point to eventually increased levels of genetic load as a result of the increased homozygosity in some gene loci causing an increased frequency of some recessive phenotypes in patients with lung diseases. Together with the specific associations observed, these preliminary findings could serve as a basis for further in depth investigations with respect to the types of lung diseases, occupational exposure and dietary habits, and thus is expected to contribute to an understanding of predispositions and susceptibility to lung diseases.
- Published
- 2015
46. 4-Hydroxy-nonenal-A Bioactive Lipid Peroxidation Product.
- Author
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Schaur RJ, Siems W, Bresgen N, and Eckl PM
- Subjects
- Acetylcysteine metabolism, Animals, Fatty Acids, Unsaturated metabolism, Humans, Oxidative Stress physiology, Lipid Peroxidation physiology
- Abstract
This review on recent research advances of the lipid peroxidation product 4-hydroxy-nonenal (HNE) has four major topics: I. the formation of HNE in various organs and tissues, II. the diverse biochemical reactions with Michael adduct formation as the most prominent one, III. the endogenous targets of HNE, primarily peptides and proteins (here the mechanisms of covalent adduct formation are described and the (patho-) physiological consequences discussed), and IV. the metabolism of HNE leading to a great number of degradation products, some of which are excreted in urine and may serve as non-invasive biomarkers of oxidative stress.
- Published
- 2015
- Full Text
- View/download PDF
47. Oxidative stress and the homeodynamics of iron metabolism.
- Author
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Bresgen N and Eckl PM
- Subjects
- Animals, Heme metabolism, Humans, Iron Metabolism Disorders genetics, Iron Metabolism Disorders metabolism, Iron-Binding Proteins genetics, Iron-Binding Proteins metabolism, Iron-Regulatory Proteins genetics, Iron-Regulatory Proteins metabolism, Oxygen metabolism, Homeostasis, Iron metabolism, Oxidative Stress
- Abstract
Iron and oxygen share a delicate partnership since both are indispensable for survival, but if the partnership becomes inadequate, this may rapidly terminate life. Virtually all cell components are directly or indirectly affected by cellular iron metabolism, which represents a complex, redox-based machinery that is controlled by, and essential to, metabolic requirements. Under conditions of increased oxidative stress—i.e., enhanced formation of reactive oxygen species (ROS)—however, this machinery may turn into a potential threat, the continued requirement for iron promoting adverse reactions such as the iron/H2O2-based formation of hydroxyl radicals, which exacerbate the initial pro-oxidant condition. This review will discuss the multifaceted homeodynamics of cellular iron management under normal conditions as well as in the context of oxidative stress.
- Published
- 2015
- Full Text
- View/download PDF
48. Ferritin-stimulated lipid peroxidation, lysosomal leak, and macroautophagy promote lysosomal "metastability" in primary hepatocytes determining in vitro cell survival.
- Author
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Krenn MA, Schürz M, Teufl B, Uchida K, Eckl PM, and Bresgen N
- Subjects
- Adenine analogs & derivatives, Adenine pharmacology, Aldehydes pharmacology, Animals, Apoptosis drug effects, Culture Media, Conditioned chemistry, Endocytosis, Epidermal Growth Factor pharmacology, Female, Glutathione metabolism, Glutathione Disulfide metabolism, Hepatocytes metabolism, Hepatocytes ultrastructure, Intracellular Membranes metabolism, Intracellular Membranes ultrastructure, Iron Chelating Agents pharmacology, Leupeptins pharmacology, Liver cytology, Liver drug effects, Liver metabolism, Lysosomes metabolism, Lysosomes ultrastructure, Molecular Imaging, Permeability drug effects, Primary Cell Culture, Protease Inhibitors pharmacology, Protein Aggregates, Rats, Rats, Inbred F344, Autophagy drug effects, Culture Media, Conditioned pharmacology, Ferritins pharmacology, Hepatocytes drug effects, Intracellular Membranes drug effects, Lysosomes drug effects
- Abstract
Several pathologies are associated with elevated levels of serum ferritin, for which growth inhibitory properties have been reported; however, the underlying mechanisms are still poorly defined. Previously we have described cytotoxic properties of isoferritins released from primary hepatocytes in vitro, which induce apoptosis in an iron and oxidative stress-dependent mode. Here we show that this ferritin species stimulates endosome clustering and giant endosome formation in primary hepatocytes accompanied by enhanced lysosomal membrane permeability (LMP). In parallel, protein modification by lipid peroxidation-derived 4-hydroxynonenal (HNE) is strongly promoted by ferritin, the HNE-modified proteins (HNE-P) showing remarkable aggregation. Emphasizing the prooxidant context, GSH is rapidly depleted and the GSH/GSSG ratio is substantially declining in ferritin-treated cells. Furthermore, ferritin triggers a transient upregulation of macroautophagy which is abolished by iron chelation and apparently supports HNE-P clearance. Macroautophagy inhibition by 3-methyladenine strongly amplifies ferritin cytotoxicity in a time- and concentration-dependent mode, suggesting an important role of macroautophagy on cellular responses to ferritin endocytosis. Moreover, pointing at an involvement of lysosomal proteolysis, ferritin cytotoxicity and lysosome fragility are aggravated by the protease inhibitor leupeptin. In contrast, EGF which suppresses ferritin-induced cell death attenuates ferritin-mediated LMP. In conclusion, we propose that HNE-P accumulation, lysosome dysfunction, and macroautophagy stimulated by ferritin endocytosis provoke lysosomal "metastability" in primary hepatocytes which permits cell survival as long as in- and extrinsic determinants (e.g., antioxidant availability, damage repair, EGF signaling) keep the degree of lysosomal destabilization below cell death-inducing thresholds., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
49. Iron-mediated oxidative stress plays an essential role in ferritin-induced cell death.
- Author
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Bresgen N, Jaksch H, Lacher H, Ohlenschläger I, Uchida K, and Eckl PM
- Subjects
- Aldehydes immunology, Aldehydes metabolism, Animals, Antibodies, Monoclonal, Apoptosis drug effects, Cell Culture Techniques, Cells, Cultured, Chromans pharmacology, Deferoxamine pharmacology, Female, Free Radical Scavengers pharmacology, Hepatocytes drug effects, Hepatocytes pathology, Iron Chelating Agents pharmacology, Lipid Peroxidation drug effects, Oxidative Stress, Rats, Rats, Inbred F344, Ferritins metabolism, Hepatocytes metabolism, Iron metabolism
- Abstract
Previously, we have demonstrated an apoptosis-inducing activity of an acidic, H-chain-rich isoferritin secreted from primary rat hepatocytes in vitro. Because this proapoptotic property may be responsible for the growth-inhibitory and immunosuppressive effects described for certain ferritin species, we aimed to address the mechanism by which ferritin can trigger cell death. Suggesting a pivotal role for iron, iron chelation by desferrioxamine significantly abrogates ferritin-mediated apoptosis and necrosis in primary rat hepatocytes and substantially lowers the extent of protein modification by 4-hydroxynonenal (HNE)-a major lipid peroxidation (LPO) product. Furthermore, supplementing the cultures with the radical-scavenging compound trolox also provided significant protection from ferritin-mediated apoptosis. Moreover, a significant increase in micronucleated cells upon exposure to ferritin indicates that ferritin also introduces damage to DNA. Based on these observations we therefore propose that endocytosis of extracellular ferritin increases the level of free ferrous iron in the lysosomal compartment, promoting Fenton chemistry-based oxidative stress involving LPO and increased lysosomal membrane permeability. Subsequently, the release of reactive lysosomal content leads to cellular damage, in particular modification of protein and DNA induced by HNE and other reactive aldehydic LPO products. Together, these effects will trigger apoptosis and necrosis based on the upregulation of p53, increased mitochondrial membrane permeability, and proapoptotic Fas signaling as described recently. In conclusion, based on their iron-storing ability, secreted acidic isoferritins may act as soluble mediators of oxidative stress under certain physiological and pathophysiological conditions., (Copyright 2010 Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
50. Cytotoxicity of β-carotene cleavage products and its prevention by antioxidants.
- Author
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Alija AJ, Bresgen N, Bojaxhi E, Vogl C, Siems W, and Eckl PM
- Subjects
- Animals, Apoptosis drug effects, Cell Survival drug effects, Cells, Cultured, Female, Hepatocytes cytology, Rats, beta Carotene chemistry, Antioxidants pharmacology, beta Carotene metabolism, beta Carotene toxicity
- Abstract
When we investigated the genotoxicity of beta-carotene cleavage products (CPs) in primary rat hepatocytes stimulated to proliferate, we observed dose-dependent increases of chromosomal aberrations, sister chromatid exchanges and micronuclei. In contrast to other genotoxic substances, however, this increased genotoxicity was not accompanied by increased cytotoxicity. As a consequence we observed metaphases showing massive chromosomal damage, indicating inhibition of apoptosis by CPs enabling these cells to proceed in the cell cycle. Since proliferative stimulation by growth factors may support this effect, the in vitro toxicological effects of CPs were studied on proliferatively quiescent primary rat hepatocytes. A significant increase of both apoptosis and necrosis was found. Supplementation with antioxidants did not significantly lower the level of apoptosis, while the level of necrosis was significantly reduced by Trolox and N-acetylcysteine at all concentrations tested as well as ascorbic acid (50 microM) and a combination of Trolox (50 microM) and ascorbic acid (50 microM). These observations indicate that a) the cytotoxic potential in combination with the genotoxic potential of CPs may promote the initiation of cells due to compensatory cell division in exposed tissues and may aggravate inflammatory processes under chronic exposure, and b) the applied antioxidants may protect from cytotoxicity primarily via the detoxification of aldehydic beta-carotene cleavage products.
- Published
- 2010
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