TY - JOUR A1 - Baesler, Jessica A1 - Kopp, Johannes Florian A1 - Pohl, Gabriele A1 - Aschner, Michael A1 - Haase, Hajo A1 - Schwerdtle, Tanja A1 - Bornhorst, Julia T1 - Zn homeostasis in genetic models of Parkinson’s disease in Caenorhabditis elegans JF - Journal of Trace Elements in Medicine and Biology N2 - While the underlying mechanisms of Parkinson’s disease (PD) are still insufficiently studied, a complex interaction between genetic and environmental factors is emphasized. Nevertheless, the role of the essential trace element zinc (Zn) in this regard remains controversial. In this study we altered Zn balance within PD models of the versatile model organism Caenorhabditis elegans (C. elegans) in order to examine whether a genetic predisposition in selected genes with relevance for PD affects Zn homeostasis. Protein-bound and labile Zn species act in various areas, such as enzymatic catalysis, protein stabilization pathways and cell signaling. Therefore, total Zn and labile Zn were quantitatively determined in living nematodes as individual biomarkers of Zn uptake and bioavailability with inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) or a multi-well method using the fluorescent probe ZinPyr-1. Young and middle-aged deletion mutants of catp-6 and pdr-1, which are orthologues of mammalian ATP13A2 (PARK9) and parkin (PARK2), showed altered Zn homeostasis following Zn exposure compared to wildtype worms. Furthermore, age-specific differences in Zn uptake were observed in wildtype worms for total as well as labile Zn species. These data emphasize the importance of differentiation between Zn species as meaningful biomarkers of Zn uptake as well as the need for further studies investigating the role of dysregulated Zn homeostasis in the etiology of PD. KW - Caenorhabditis elegans KW - Zinc KW - Zinc homeostasis KW - Parkinson disease KW - Labile zinc Y1 - 2019 U6 - https://doi.org/10.1016/j.jtemb.2019.05.005 VL - 55 SP - 44 EP - 49 PB - Elsevier CY - München ER - TY - JOUR A1 - Baesler, Jessica A1 - Kopp, Johannes F. A1 - Pohl, Gabriele A1 - Aschner, Michael A1 - Haase, Hajo A1 - Schwerdtle, Tanja A1 - Bornhorst, Julia T1 - Zn homeostasis in genetic models of Parkinson’s disease in Caenorhabditis elegans JF - Journal of trace elements in medicine and biology KW - Caenorhabditis elegans KW - Zinc KW - Zinc homeostasis KW - Parkinson disease KW - Labile zinc Y1 - 2019 U6 - https://doi.org/10.1016/j.jtemb.2019.05.005 SN - 0946-672X VL - 55 SP - 44 EP - 49 PB - Elsevier GMBH CY - München ER - TY - THES A1 - Baeseler, Jessica T1 - Trace element effects on longevity and neurodegeneration with focus on C. elegans T1 - Effekte von Spurenelementen auf die Lebensdauer und Neurodegeneration mit Fokus auf C. elegans N2 - The trace elements zinc and manganese are essential for human health, especially due to their enzymatic and protein stabilizing functions. If these elements are ingested in amounts exceeding the requirements, regulatory processes for maintaining their physiological concentrations (homeostasis) can be disturbed. Those homeostatic dysregulations can cause severe health effects including the emergence of neurodegenerative disorders such as Parkinson’s disease (PD). The concentrations of essential trace elements also change during the aging process. However, the relations of cause and consequence between increased manganese and zinc uptake and its influence on the aging process and the emergence of the aging-associated PD are still rarely understood. This doctoral thesis therefore aimed to investigate the influence of a nutritive zinc and/or manganese oversupply on the metal homeostasis during the aging process. For that, the model organism Caenorhabditis elegans (C. elegans) was applied. This nematode suits well as an aging and PD model due to properties such as its short life cycle and its completely sequenced, genetically amenable genome. Different protocols for the propagation of zinc- and/or manganese-supplemented young, middle-aged and aged C. elegans were established. Therefore, wildtypes, as well as genetically modified worm strains modeling inheritable forms of parkinsonism were applied. To identify homeostatic and neurological alterations, the nematodes were investigated with different methods including the analysis of total metal contents via inductively-coupled plasma tandem mass spectrometry, a specific probe-based method for quantifying labile zinc, survival assays, gene expression analysis as well as fluorescence microscopy for the identification and quantification of dopaminergic neurodegeneration.. During aging, the levels of iron, as well as zinc and manganese increased.. Furthermore, the simultaneous oversupply with zinc and manganese increased the total zinc and manganese contents to a higher extend than the single metal supplementation. In this relation the C. elegans metallothionein 1 (MTL-1) was identified as an important regulator of metal homeostasis. The total zinc content and the concentration of labile zinc were age-dependently, but differently regulated. This elucidates the importance of distinguishing these parameters as two independent biomarkers for the zinc status. Not the metal oversupply, but aging increased the levels of dopaminergic neurodegeneration. Additionally, nearly all these results yielded differences in the aging-dependent regulation of trace element homeostasis between wildtypes and PD models. This confirms that an increased zinc and manganese intake can influence the aging process as well as parkinsonism by altering homeostasis although the underlying mechanisms need to be clarified in further studies. N2 - Die Spurenelemente Zink und Mangan sind vor allem aufgrund ihrer enzymatischen und Protein-stabilisierenden Funktionen essentiell für die menschliche Gesundheit. Werden sie allerdings in Mengen aufgenommen, die den Bedarf übersteigen, können regulatorische Prozesse für die Aufrechterhaltung physiologischer Konzentrationen dieser Metalle (Homöostase) aus dem Gleichgewicht geraten. Das kann ernsthafte gesundheitliche Konsequenzen nach sich ziehen, unter anderem die Entstehung neurodegenerativer Krankheiten, wie zum Beispiel der Parkinson’schen Erkrankung. Auch während des Alterungsprozesses verändern sich die Gehalte an lebensnotwendigen Spurenelementen im Körper. Jedoch sind die Zusammenhänge zwischen Ursache und Wirkung einer erhöhten Aufnahme an Zink und Mangan und deren Einfluss auf den Alterungsprozess und die Entstehung der altersassoziierten Parkinson’schen Erkrankung bisher nur unzureichend verstanden. Im Rahmen dieser Doktorarbeit wurde deshalb der Einfluss einer nutritiven Zink- und/oder Manganüberversorgung auf die Metallhomöostase während der Alterung untersucht. Dazu wurde Caenorhabditis elegans (C. elegans) als Modellorganismus verwendet. Diese Fadenwürmer eignen sich aufgrund verschiedener Eigenschaften, wie einem kurzen Lebenszyklus und einem komplett sequenzierten und leicht manipulierbarem Genom, hervorragend als Alters- und Parkinson-Modelle. Es wurden verschiedene Protokolle etabliert, die die Anzucht von Zink- und/oder Mangan-supplementierten jungen, mittelalten bzw. gealterten C. elegans erlaubten. Neben Wildtypen wurden auch Wurmstämme untersucht, die genetische Modifikationen aufweisen, die mit vererbbaren Formen des Parkinsonismus assoziiert werden können. Die Würmer wurden mithilfe verschiedener Methoden, wie der analytischen Bestimmung des Gesamtmetallgehaltes mittels Massenspektrometrie mit induktiv-gekoppeltem Plasma, einer Sonden-spezifischen Methode zur Bestimmung von freiem Zink, Letalitätsassays, Genexpressionsanalysen und der Fluoreszenz-mikroskopischen Untersuchung der dopaminergen Neurodegeneration auf verschiedene Parameter untersucht, die Aufschluss über homöostatische und neurologische Veränderungen geben. Es wurde eine altersbedingte Zunahme von Eisen, sowie Zink und Mangan in den Würmern beobachtet. Weiterhin stellte sich heraus, dass vor allem die simultane Überversorgung mit Zink und Mangan den Gesamtmetallgehalt dieser Metalle in C. elegans in einem Maß steigerte, das das der Einzelmetallsupplementierung überstieg. Dabei konnte vor allem das C. elegans Metallothionein 1 (MTL-1) als wichtiger Faktor in der Regulation der Metallhomöostase identifiziert werden. Außerdem wurde die Wichtigkeit verdeutlicht, zwischen dem Gesamtzinkgehalt und der Konzentration an freiem Zink als Biomarkern für den Zinkstatus eines Organismus zu unterscheiden. Beide Parameter wurden altersabhängig unterschiedlich reguliert. Im Gegensatz zur Alterung, wurde durch die Überversorgung mit Metallen keine zusätzliche Schädigung der dopaminergen Neuronen beobachtet. In nahezu all diesen Ergebnissen verdeutlichten sich weiterhin Unterschiede in der altersabhängigen Regulation der Spurenelementhomöostase zwischen Wildtypen und Parkinson-Modellen. Dies bestätigt die Annahme, dass sich eine erhöhte Aufnahme von Mangan und Zink durch die Beeinflussung der Homöostase sowohl auf die Alterung, als auch den Parkinsonismus auswirken kann, jedoch müssen die mechanistischen Grundlagen dessen in zukünftigen Studien aufgeklärt werden. KW - Caenorhabditis elegans KW - aging KW - trace element KW - zinc KW - manganese KW - Caenorhabditis elegans KW - Alterung KW - Spurenelement KW - Zink KW - Mangan Y1 - 2021 ER - TY - JOUR A1 - Kim, Shin Woong A1 - Leifheit, Eva F. A1 - Maaß, Stefanie A1 - Rillig, Matthias C. T1 - Time-dependent toxicity of tire particles on soil nematodes JF - Frontiers in Environmental Science N2 - Tire-wear particles (TWPs) are being released into the environment by wearing down during car driving, and are considered an important microplastic pollution source. The chemical additive leaching from these polymer-based materials and its potential effects are likely temporally dynamic, since amounts of potentially toxic compounds can gradually increase with contact time of plastic particles with surrounding media. In the present study, we conducted soil toxicity tests using the soil nematode Caenorhabditis elegans with different soil pre-incubation (30 and 75 days) and exposure (short-term exposure, 2 days; lifetime exposure, 10 days) times. Soil pre-incubation increased toxicity of TWPs, and the effective concentrations after the pre-incubation were much lower than environmentally relevant concentrations. The lifetime of C. elegans was reduced faster in the TWP treatment groups, and the effective concentration for lifetime exposure tests were 100- to 1,000-fold lower than those of short-term exposure tests. Water-extractable metal concentrations (Cr, Cu, Ni, Pb, and Zn) in the TWP-soils showed no correlation with nominal TWP concentrations or pre-incubation times, and the incorporated metals in the TWPs may be not the main reason of toxicity in this study. Our results show that toxic effects of TWPs can be time-dependent, both in terms of the microplastic particles themselves and their interactions in the soil matrix, but also because of susceptibility of target organisms depending on developmental stage. It is vital that future works consider these aspects, since otherwise effects of microplastics and TWPs could be underestimated. KW - Caenorhabditis elegans KW - exposure time KW - lifetime KW - microplastics KW - soil KW - incubation Y1 - 2021 U6 - https://doi.org/10.3389/fenvs.2021.744668 SN - 2296-665X VL - 9 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Rohn, Isabelle A1 - Kroepfl, Nina A1 - Aschner, Michael A1 - Bornhorst, Julia A1 - Kuehnelt, Doris A1 - Schwerdtle, Tanja T1 - Selenoneine ameliorates peroxide-induced oxidative stress in C. elegans JF - Journal of trace elements in medicine and biology N2 - Scope: Selenoneine (2-selenyl-N-alpha, N-alpha, N-alpha-trimethyl-L-histidine), the selenium (Se) analogue of the ubiquitous thiol compound and putative antioxidant ergothioneine, is the major organic selenium species in several marine fish species. Although its antioxidant efficacy has been proposed, selenoneine has been poorly characterized, preventing conclusions on its possible beneficial health effects. Methods and results: Treatment of Caenorhabditis elegans (C. elegans) with selenoneine for 18 h attenuated the induction of reactive oxygen and nitrogen species (RONS). However, the effect was not immediate, occurring 48 h post-treatment. Total Se and Se speciation analysis revealed that selenoneine was efficiently taken up and present in its original form directly after treatment, with no metabolic transformations observed. 48 h posttreatment, total Se in worms was slightly higher compared to controls and no selenoneine could be detected. Conclusion: The protective effect of selenoneine may not be attributed to the presence of the compound itself, but rather to the activation of molecular mechanisms with consequences at more protracted time points. KW - Selenoneine KW - Caenorhabditis elegans KW - Selenium KW - Oxidative stress Y1 - 2019 U6 - https://doi.org/10.1016/j.jtemb.2019.05.012 SN - 0946-672X VL - 55 SP - 78 EP - 81 PB - Elsevier GMBH CY - München ER - TY - JOUR A1 - Gubert, Priscila A1 - Puntel, Bruna A1 - Lehmen, Tassia A1 - Bornhorst, Julia A1 - Avila, Daiana Silva A1 - Aschner, Michael A. A1 - Soares, Felix A. A. T1 - Reversible reprotoxic effects of manganese through DAF-16 transcription factor activation and vitellogenin downregulation in Caenorhabditis elegans JF - Life sciences : molecular, cellular and functional basis of therapy N2 - Aims Vitellogenesis is the yolk production process which provides the essential nutrients for the developing embryos. Yolk is a lipoprotein particle that presents lipids and lipid-binding proteins, referred to as vitellogenins (VIT). The Caenorhabditis elegans nematode has six genes encoding VIT lipoproteins. Several pathways are known to regulate vitellogenesis, including the DAF-16 transcription factor. Some reports have shown that heavy metals, such as manganese (Mn), impair brood size in C. elegans; however the mechanisms associated with this effect have yet to be identified. Our aim was to evaluate Mn′s effects on C. elegans reproduction and better understand the pathways related to these effects. Main methods. Young adult larval stage worms were treated for 4 h with Mn in 85 mM NaCl and Escherichia coli OP50 medium. Key findings. Mn reduced egg-production and egg-laying during the first 24 h after the treatment, although the total number of progenies were indistinguishable from the control group levels. This delay may have occurred due to DAF-16 activation, which was noted only after the treatment and was not apparent 24 h later. Moreover, the expression, protein levels and green fluorescent protein (GFP) fluorescence associated with VIT were decreased soon after Mn treatment and recovered after 24 h. Significance Combined, these data suggest that the delay in egg-production is likely regulated by DAF-16 and followed by the inhibition of VIT transport activity. Further studies are needed to clarify the mechanisms associated with Mn-induced DAF-16 activation. KW - Manganese KW - Vitellogenin KW - Caenorhabditis elegans KW - DAF-16 transcription factor KW - Brood size Y1 - 2016 U6 - https://doi.org/10.1016/j.lfs.2016.03.016 SN - 0024-3205 SN - 1879-0631 VL - 151 SP - 218 EP - 223 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Gubert, Priscila A1 - Puntel, Bruna A1 - Lehmen, Tassia A1 - Fessel, Joshua P. A1 - Cheng, Pan A1 - Bornhorst, Julia A1 - Trindade, Lucas Siqueira A1 - Avila, Daiana S. A1 - Aschner, Michael A1 - Soares, Felix A. A. T1 - Metabolic effects of manganese in the nematode Caenorhabditis elegans through DAergic pathway and transcription factors activation JF - Neurotoxicology : the interdisciplinary journal of effects to toxic substances on the nervous system N2 - Manganese (Mn) is an essential trace element for physiological functions since it acts as an enzymatic co-factor. Nevertheless, overexposure to Mn has been associated with a pathologic condition called manganism. Furthermore, Mn has been reported to affect lipid metabolism by mechanisms which have yet to be established. Herein, we used the nematode Caenorhabditis elegans to examine Mn’s effects on the dopaminergic (DAergic) system and determine which transcription factors that regulate with lipid metabolism are affected by it. Worms were exposed to Mn for four hours in the presence of bacteria and in a liquid medium (85 mM NaCl). Mn increased fat storage as evidenced both by Oil Red O accumulation and triglyceride levels. In addition, metabolic activity was reduced as a reflection of decreased oxygen consumption caused by Mn. Mn also affected feeding behavior as evidenced by decreased pharyngeal pumping rate. DAergic neurons viability were not altered by Mn, however the dopamine levels were significantly reduced following Mn exposure. Furthermore, the expression of sbp-1 transcription factor and let-363 protein kinase responsible for lipid accumulation control was increased and decreased, respectively, by Mn. Altogether, our data suggest that Mn increases the fat storage in C. elegans, secondary to DAergic system alterations, under the control of SBP-1 and LET-363 proteins. KW - Manganese KW - Caenorhabditis elegans KW - Lipid metabolism KW - Dopaminergic system KW - Manganism Y1 - 2018 U6 - https://doi.org/10.1016/j.neuro.2018.04.008 SN - 0161-813X SN - 1872-9711 VL - 67 SP - 65 EP - 72 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bornhorst, Julia A1 - Nustede, Eike Jannik A1 - Fudickar, Sebastian T1 - Mass Surveilance of C. elegans-Smartphone-Based DIY Microscope and Machine-Learning-Based Approach for Worm Detection JF - Sensors N2 - The nematode Caenorhabditis elegans (C. elegans) is often used as an alternative animal model due to several advantages such as morphological changes that can be seen directly under a microscope. Limitations of the model include the usage of expensive and cumbersome microscopes, and restrictions of the comprehensive use of C. elegans for toxicological trials. With the general applicability of the detection of C. elegans from microscope images via machine learning, as well as of smartphone-based microscopes, this article investigates the suitability of smartphone-based microscopy to detect C. elegans in a complete Petri dish. Thereby, the article introduces a smartphone-based microscope (including optics, lighting, and housing) for monitoring C. elegans and the corresponding classification via a trained Histogram of Oriented Gradients (HOG) feature-based Support Vector Machine for the automatic detection of C. elegans. Evaluation showed classification sensitivity of 0.90 and specificity of 0.85, and thereby confirms the general practicability of the chosen approach. KW - Caenorhabditis elegans KW - machine learning KW - smartphone KW - microscope KW - SVM KW - HOG Y1 - 2019 U6 - https://doi.org/10.3390/s19061468 SN - 1424-8220 VL - 19 IS - 6 PB - MDPI CY - Basel ER - TY - JOUR A1 - Schumacher, Fabian A1 - Chakraborty, Sudipta A1 - Kleuser, Burkhard A1 - Gulbins, Erich A1 - Schwerdtle, Tanja A1 - Aschner, Michael A. A1 - Bornhorst, Julia T1 - Highly sensitive isotope-dilution liquid-chromatography-electrospray ionization-tandem-mass spectrometry approach to study the drug-mediated modulation of dopamine and serotonin levels in Caenorhabditis elegans JF - Talanta : the international journal of pure and applied analytical chemistry N2 - Dopamine (DA) and serotonin (SRT) are monoamine neurotransmitters that play a key role in regulating the central and peripheral nervous system. Their impaired metabolism has been implicated in several neurological disorders, such as Parkinson's disease and depression. Consequently, it is imperative to monitor changes in levels of these low-abundant neurotransmitters and their role in mediating disease. For the first time, a rapid, specific and sensitive isotope-dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantification of DA and SRT in the nematode Caenorhabditis elegans (C. elegans). This model organism offers a unique approach for studying the effect of various drugs and environmental conditions on neurotransmitter levels, given by the conserved DA and SRT biology, including synaptic release, trafficking and formation. We introduce a novel sample preparation protocol incorporating the usage of sodium thiosulfate in perchloric acid as extraction medium that assures high recovery of the relatively unstable neurotransmitters monitored. Moreover, the use of both deuterated internal standards and the multiple reaction monitoring (MRM) technique allows for unequivocal quantification. Thereby, to the best of our knowledge, we achieve a detection sensitivity that clearly exceeds those of published DA and SRT quantification methods in various matrices. We are the first to show that exposure of C elegans to the monoamine oxidase B (MAOB) inhibitor selegiline or the catechol-O-methyltransferase (COMT) inhibitor tolcapone, in order to block DA and SRT degradation, resulted in accumulation of the respective neurotransmitter. Assessment of a behavioral output of the dopaminergic system (basal slowing response) corroborated the analytical LC-MS/MS data. Thus, utilization of the C elegans model system in conjunction with our analytical method is well-suited to investigate drug-mediated modulation of the DA and SRT system in order to identify compounds with neuroprotective or regenerative properties. (C) 2015 Elsevier B.V. All rights reserved. KW - Caenorhabditis elegans KW - Dopamine KW - Serotonin KW - Liquid chromatography-tandem mass spectrometry KW - Isotope-dilution analysis Y1 - 2015 U6 - https://doi.org/10.1016/j.talanta.2015.05.057 SN - 0039-9140 SN - 1873-3573 VL - 144 SP - 71 EP - 79 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Nicolai, Merle Marie A1 - Weishaupt, Ann-Kathrin A1 - Baesler, Jessica A1 - Brinkmann, Vanessa A1 - Wellenberg, Anna A1 - Winkelbeiner, Nicola Lisa A1 - Gremme, Anna A1 - Aschner, Michael A1 - Fritz, Gerhard A1 - Schwerdtle, Tanja A1 - Bornhorst, Julia T1 - Effects of manganese on genomic integrity in the multicellular model organism Caenorhabditis elegans JF - International Journal of Molecular Sciences N2 - Although manganese (Mn) is an essential trace element, overexposure is associated with Mn-induced toxicity and neurological dysfunction. Even though Mn-induced oxidative stress is discussed extensively, neither the underlying mechanisms of the potential consequences of Mn-induced oxidative stress on DNA damage and DNA repair, nor the possibly resulting toxicity are characterized yet. In this study, we use the model organism Caenorhabditis elegans to investigate the mode of action of Mn toxicity, focusing on genomic integrity by means of DNA damage and DNA damage response. Experiments were conducted to analyze Mn bioavailability, lethality, and induction of DNA damage. Different deletion mutant strains were then used to investigate the role of base excision repair (BER) and dePARylation (DNA damage response) proteins in Mn-induced toxicity. The results indicate a dose- and time-dependent uptake of Mn, resulting in increased lethality. Excessive exposure to Mn decreases genomic integrity and activates BER. Altogether, this study characterizes the consequences of Mn exposure on genomic integrity and therefore broadens the molecular understanding of pathways underlying Mn-induced toxicity. Additionally, studying the basal poly(ADP-ribosylation) (PARylation) of worms lacking poly(ADP-ribose) glycohydrolase (PARG) parg-1 or parg-2 (two orthologue of PARG), indicates that parg-1 accounts for most of the glycohydrolase activity in worms. KW - manganese KW - oxidative stress KW - DNA repair KW - DNA damage response KW - Caenorhabditis elegans Y1 - 2021 U6 - https://doi.org/10.3390/ijms222010905 SN - 1422-0067 VL - 22 IS - 20 PB - MDPI CY - Basel ER -