arno gutleb | Luxembourg Institute of Science and Technology (original) (raw)

Papers by arno gutleb

Little is known about otters in Iran. OF the existing publications based on hunting data, one con... more Little is known about otters in Iran. OF the existing publications based on hunting data, one considres otters are only in the northeast and a nature reserve on the Afghanistan border, and the other considers that otters are widespread throughout all but the central desert and fringes of the Persian Gulf. Smooth coated otters may also be present, which hunters may not distinguish from Eurasian otters. A forthcoming set of expeditions should clarify the position.

Environmental science. Nano, 2020

Type I hypersensitivity reactions against environmental entities, i.e. allergens, are an ever gro... more Type I hypersensitivity reactions against environmental entities, i.e. allergens, are an ever growing problem, with increasing numbers of affected individuals in Western countries. In parallel, nanotechnology has been growing during the past decades, entering more and more areas of application in everyday life. Exposure to allergens may occur in a combined way with environmental particulate matter or (nano-)particles potentially abundant at the workplace. Such combinations may thus affect workers and consumers alike. The present study conceived a methodological and mechanistic approach based on recombinant allergen-SiO 2 nanoparticle conjugates and the novel hAELVi cell line as two well-defined model systems to investigate the effects of co-exposure towards allergens and nanoparticles. We applied pristine nanoparticles, allergen-nanoparticle conjugates and unbound allergen under submerged and air-liquid interface conditions. The uptake kinetics and mechanisms, cellular localization and resulting immune responses were studied in hAELVi cells, a cell line derived from human alveolar epithelium showing the characteristics of type I epithelial cells. Modification in the uptake kinetics as well as an increase in proinflammatory cyto-/chemokine expression was observed under submerged conditions, but much less under air-liquid interface conditions. While for mechanistic investigations the submerged culture system still proved suitable, more robust and cost-effective, these culture conditions showed considerable deviations in cellular susceptibility observed under more realistic conditions.

Aquatic Toxicology, May 1, 2019

Potential toxic effects of Ag NPs ingested through the food web and depending on the season have ... more Potential toxic effects of Ag NPs ingested through the food web and depending on the season have not been addressed in marine bivalves. This work aimed to assess differences in protein expression in the digestive gland of female mussels after dietary exposure to Ag NPs in autumn and spring. Mussels were fed daily with microalgae previously exposed for 24 hours to 10 µg/L of PVP/PEI coated 5 nm Ag NPs. After 21 days, mussels significantly accumulated Ag in both seasons and Ag NPs were found within digestive gland cells and gills. Two-dimensional electrophoresis distinguished 104 differentially expressed protein spots in autumn and 142 in spring. Among them, chitinase like protein-3, partial and glyceraldehyde-3-phosphate dehydrogenase, that are involved in amino sugar and nucleotide sugar metabolism, carbon metabolism, glycolysis/gluconeogenesis and the biosynthesis of amino acids KEGG pathways, were overexpressed in autumn but underexpressed in spring. In autumn, pyruvate metabolism, citrate cycle, cysteine and methionine metabolism and glyoxylate and dicarboxylate metabolism were altered, while in spring, proteins related to the formation of phagosomes and hydrogen peroxide metabolism were differentially expressed. Overall, protein expression signatures depended on season and Ag NPs exposure, suggesting that season significantly influences responses of mussels to NP exposure.

Food and Chemical Toxicology, Sep 1, 2019

This paper describes a methodology for hazard assessment of groups of related substances for whic... more This paper describes a methodology for hazard assessment of groups of related substances for which toxicity data are insufficient, and which utilises, next to conventional toxicological assessments and mechanistic information, the derivation of relative toxicity potency factors (RPFs). Zearalenone (ZEN) and T-2 toxin (T2) and HT-2 toxin (HT2) and their modified forms have been used as examples. A tolerable daily intake (TDI) for ZEN of 0.25 µg/kg bw was established. In vitro and in vivo studies suggested that modified forms of ZEN act via the same mode of action as ZEN (oestrogenicity). Results from in vivo uterotrophic assays were used to establish RPFs, allowing inclusion the different modified forms in a group TDI with ZEN. A TDI for the sum of T2/HT2 of 0.02 µg/kg bw per day and an acute reference dose (ARfD) of 0.3 µg/kg bw for the sum of T2/HT2 was established. In vitro studies show that phase I metabolites of T2/HT2 act via a similar mode of action as their parent compounds, namely protein synthesis inhibition with immune-and haematotoxicity. The phase I *Manuscript for revision (track changes hidden) Click here to view linked References metabolites as well as conjugates of T2/HT2 and their phase I metabolites can be included in a group TDI with T2/HT2 applying RPFs.

Heliyon, Sep 1, 2020

Today, nanotechnology plays an important role in our ever-continuous quest to improve the quality... more Today, nanotechnology plays an important role in our ever-continuous quest to improve the quality of human life. Because of their infinitesimal size, nanostructures can actively interact and alter cellular functions. Therefore, while the clinical benefits of nanotechnology may outweigh most of the associated risks, assessment of the cytotoxicity of nanostructures in respect to cells and tissues early in product development processes is of great significance. To the best of our knowledge, no such assessment has been performed for nanomaterials on the ovarian cortex before. Herein, silica-coated, PEGylated silica-coated, and uncoated iron oxide nanoparticles (IONP) with core diameter of 11 nm (AE4.2 nm) were synthesized. The oxidative stress in cultured ovarian tissue exposed to the various IONP was subsequently assessed. The results indicate that among the four groups, uncoated IONP induce the most oxidative stress on the ovarian cortex while tissues treated with PEGylated IONP exhibit no significant change in oxidative stress.

HAL (Le Centre pour la Communication Scientifique Directe), May 15, 2022

General comments: Manuscript gives review on bladder cancer aetiology related with environmental ... more General comments: Manuscript gives review on bladder cancer aetiology related with environmental exposures and life style. Data on such causality are limited on arsenic and smoking. Cutting out of chapter on occupational exposure is suggested.

Persistent chemicals accumulate in the arctic environment due to their chemical reactivity and ph... more Persistent chemicals accumulate in the arctic environment due to their chemical reactivity and physicochemical properties and polychlorinated biphenyls (PCBs) are the most concentrated pollutant class in polar bears (Ursus maritimus). Metabolism of PCB and polybrominated biphenyl ether (PBDE) flame-retardants alter their toxicological properties and these metabolites are known to interfere with the binding of thyroid hormone (TH) to transthyretin (TTR) in rodents and humans. In polar bear plasma samples no binding of [125I]-T4 to TTR was observed after incubation and PAGE separation. Incubation of the plasma samples with [14C]-4-OH-CB107, a compound with a higher binding affinity to TTR than the endogenous ligand T4 resulted in competitive binding as proven by the appearance of a radio labeled TTR peak in the gel. Plasma incubation with T4 up to 1 mM, a concentration that is not physiologically relevant anymore did not result in any visible competition. These results give evidence that the binding sites on TTR for T4 in wild living polar bears are completely saturated. Such saturation of binding sites can explain observed lowered levels of THs and could lead to contaminant transport into the developing fetus.

Current Nutrition & Food Science, Feb 1, 2010

Toxicology in Vitro, Sep 1, 2022

Scientific Reports, Oct 15, 2018

Gene expression profiling via RT-qPCR is a robust technique increasingly used in ecotoxicology. D... more Gene expression profiling via RT-qPCR is a robust technique increasingly used in ecotoxicology. Determination and validation of optimal reference genes is a requirement for initiating RT-qPCR experiments. To our best knowledge, this study is the first attempt of identifying a set of reference genes for the freshwater crustacean Gammarus fossarum. Six candidate genes (Actin, TUB, UB, SDH, Clathrin and GAPDH) were tested in order to determine the most stable ones in different stress conditions and to increase the robustness of RT-qPCR data. SDH and Clathrin appeared as the most stable ones. A validation was performed using G. fossarum samples exposed for 15 days to AgNO 3 , silver nanoparticles (AgNPs) 40 nm and gold nanoparticles (AuNPs) 40 nm. Effects on HSP90 were evaluated and data normalized using Clathrin and SDH. A down-regulation of HSP90 was observed when G. fossarum were exposed to AuNPs 40 nm whereas no effects were observed when G. fossarum were exposed to AgNPs 40 nm. This study highlights the importance of the preliminary determination of suitable reference genes for RT-qPCR experiments. Additionally, this study allowed, for the first time, the determination of a set of valuable genes that can be used in other RT-qPCR studies using G. fossarum as model organism.

Ecotoxicology and Environmental Safety, Mar 1, 2021

The aim of the present study was the assessment of the sub-chronic effects of silver (AgNPs) and ... more The aim of the present study was the assessment of the sub-chronic effects of silver (AgNPs) and gold nanoparticles (AuNPs) of 40 nm primary size either stabilised with citrate (CIT) or coated with polyethylene glycol (PEG) on the freshwater invertebrate Gammarus fossarum. Silver nitrate (AgNO 3) was used as a positive control in order to study the contribution of silver ions potentially released from AgNPs on the observed effects. A multibiomarker approach was used to assess the long-term effects of AgNPs and AuNPs 40 nm on molecular, cellular, physiological and behavioural responses of G. fossarum. Specimen of G. fossarum were exposed for 15 days to 0.5 and 5 µg L − 1 of CIT and PEG AgNPs and AuNPs 40 nm in the presence of food. A significant uptake of both Ag and Au was observed in exposed animals but was under the toxic threshold leading to mortality of G. fossarum. Silver nanoparticles (CIT-AgNPs and PEG-AgNPs 40 nm) led to an up-regulation of Na + K + ATPase gene expression. An up-regulation of Catalse and Chitinase gene expressions due to exposure to PEG-AgNPs 40 nm was also observed. Gold nanoparticles (CIT and PEG-AuNPs 40 nm) led to an increase of CuZnSOD gene expression. Furthermore, both AgNPs and AuNPs led to a more developed digestive lysosomal system indicating a general stress response in G. fossarum. Both AgNPs and AuNPs 40 nm significantly affected locomotor activity of G. fossarum while no effects were observed on haemolymphatic ions and ventilation.

Science of The Total Environment, Oct 1, 2016

Amphipods are one of the most important components of freshwater ecosystems. Among them, gammarid... more Amphipods are one of the most important components of freshwater ecosystems. Among them, gammarids are the most widespread group in Europe and are often used as bioindicators and model organisms in ecotoxicology. However, their use, especially of Gammarus fossarum for the study of the environmental impact of nanoparticles, has been rather limited so far. G. fossarum was selected to assess effects of well-characterized chemically synthesized silver nanoparticles (AgNPs 20nm and 200nm) and &amp;amp;amp;amp;amp;quot;green&amp;amp;amp;amp;amp;quot; laboratory synthetized (from plant leaf extracts) AgNPs (AgNPs 23nm and 27nm). AgNO3 was used as a positive control to compare AgNPs effects and silver ions effects. A multibiomarker approach was used to investigate the sub-lethal effects of AgNPs on physiological and behavioural responses of G. fossarum. Two different experiments were carried out. In a preliminary experiment, two populations of G. fossarum (G.f1 and G.f2) were tested for sensitivity differences and the most sensitive one was exposed, in a final experiment, to sub-lethal concentrations of AgNO3 and the most toxic AgNPs. AgNO3 and AgNPs 23nm led to a significant decrease in survival rates, osmoregulation and locomotor activity. Ag internalisation, performed with Secondary Ion Mass Spectrometry (SIMS), showed the presence of silver in gills of G.f2 exposed to AgNPs 23 and 27nm. This study highlighted the influence of method of synthesis on ion release, uptake and toxic effects of AgNPs on G. fossarum. Osmoregulation appeared to be an effective biomarker indicating the physiological health status of G. fossarum. Locomotor activity, which was the most impacted response, reflects the potential effects of released ions from AgNPs 23nm at the population level as locomotion is necessary for foraging, finding mates and escaping from predators. Therefore, we propose G. fossarum as a suitable model for environmental nanotoxicology, providing information both at individual and population levels.

Toxicology Letters, 2017

Nanoparticles (NPs) represent foreign objects for the body. As such, they may be recognized and p... more Nanoparticles (NPs) represent foreign objects for the body. As such, they may be recognized and processed by immune cells, among which macrophages play a crucial role in elimination of

Andrologia, 2020

In this study, Swiss male mice were intraperitoneally administered with titanium dioxide (TiO 2) ... more In this study, Swiss male mice were intraperitoneally administered with titanium dioxide (TiO 2) and zinc oxide (ZnO) nanoparticles (NPs) and their mixture (1:1) at doses between 9.38 and 75 mg/kg for 5 weeks to evaluate reproductive toxicity. Both NPs and their mixture significantly (p < .001) altered sperm motility, reduced sperm numbers and increased abnormalities, while their mixture induced more sperm abnormalities than either TiO 2 NPs or ZnO NPs. Both NPs and their mixture significantly (p < .05) reduced the LH level, while ZnO NPs alone and their mixture (p < .001) increased the testosterone levels at tested doses. The testes of exposed mice showed pathological changes and altered histomorphometrics. TiO 2 NPs and ZnO NPs individually induced a significant (p < .01) reduction in SOD and CAT activities, while the mixture significantly (p < .001) decreased CAT activity and increased SOD activity. TiO 2 NPs alone at 9.38 mg/kg induced a significant (p < .001) reduction in the GSH level, while both NPs and their mixture increased the MDA level significantly (p < .05). The data showed that the mixture had a synergistic interaction to induce testicular damage. Overall, oxidative stress may be involved in the NP-mediated testicular damage observed.

Journal of Wildlife Diseases, 2020

Toxoplasma gondii is a worldwidedistributed protozoon that infects warm-blooded animals. We deter... more Toxoplasma gondii is a worldwidedistributed protozoon that infects warm-blooded animals. We determined T. gondii exposure in one marine otter (Lontra felina) and four domestic cats (Felis catus) along the northern and central coast of Chile, indicating a low seroprevalence of 5% (1/19) and 8% (4/50) respectively, likely related to arid environment.

Toxicology Letters, 2020

Biological impact of exposure to an aerosol of an e-vapor device was investigated using human bro... more Biological impact of exposure to an aerosol of an e-vapor device was investigated using human bronchial and alveolar models. The biological impact of e-vapor aerosol exposure was lower than that of cigarette smoke at similar nicotine levels. The exposure effects at the molecular levels were evaluated using a systems toxicology approach.

Archives of Environmental Contamination and Toxicology, 2019

One of the direct causes of biodiversity loss is environmental pollution resulting from the use o... more One of the direct causes of biodiversity loss is environmental pollution resulting from the use of chemicals. Different kinds of chemicals, such as persistent organic pollutants and some heavy metals, can be endocrine disruptors, which act at low doses over a long period of time and have a negative effect on the reproductive and thyroid system in vertebrates worldwide. Research on the effects of endocrine disruptors and the use of bioindicators in neotropical ecosystems where pressure on biodiversity is high is scarce. In Chile, although endocrine disruptors have been detected at different concentrations in the environments of some ecosystems, few studies have been performed on their biological effects in the field. In this work, Xenopus laevis (African clawed frog), an introduced species, is used as a bioindicator for the presence of endocrine disruptors in aquatic systems with different degrees of contamination in a Mediterranean zone in central Chile. For the first time for Chile, alterations are described that can be linked to exposure to endocrine disruptors, such as vitellogenin induction, decreased testosterone in male frogs, and histological changes in gonads. Dioxin-like and oestrogenic activity was detected in sediments at locations where it seem to be related to alterations found in the frogs. In addition, an analysis of land use/ cover use revealed that urban soil was the best model to explain the variations in frog health indicators. This study points to the usefulness of an invasive species as a bioindicator for the presence of endocrine-disruptive chemicals. Human activity is responsible for the loss of natural habitat observed worldwide, which affects not only biodiversity but also human well-being (Millennium Ecosystem Assessment