TY - JOUR A1 - Aschner, Michael A. A1 - Palinski, Catherine A1 - Sperling, Michael A1 - Karst, U. A1 - Schwerdtle, Tanja A1 - Bornhorst, Julia T1 - Imaging metals in Caenorhabditis elegans JF - Metallomics : integrated biometal science N2 - Systemic trafficking and storage of essential metal ions play fundamental roles in living organisms by serving as essential cofactors in various cellular processes. Thereby metal quantification and localization are critical steps in understanding metal homeostasis, and how their dyshomeostasis might contribute to disease etiology and the ensuing pathologies. Furthermore, the amount and distribution of metals in organisms can provide insight into their underlying mechanisms of toxicity and toxicokinetics. While in vivo studies on metal imaging in mammalian experimental animals are complex, time- and resource-consuming, the nematode Caenorhabditis elegans (C. elegans) provides a suitable comparative and complementary model system. Expressing homologous genes to those inherent to mammals, including those that regulate metal homeostasis and transport, C. elegans has become a powerful tool to study metal homeostasis and toxicity. A number of recent technical advances have been made in the development and application of analytical methods to visualize metal ions in C. elegans. Here, we briefly summarize key findings and challenges of the three main techniques and their application to the nematode, namely sensing fluorophores, microbeam synchrotron radiation X-ray fluorescence as well as laser ablation ( LA) coupled to inductively coupled plasma-mass spectrometry (ICP-MS). Y1 - 2017 U6 - https://doi.org/10.1039/c6mt00265j SN - 1756-5901 SN - 1756-591X VL - 9 SP - 357 EP - 364 PB - Royal Society of Chemistry CY - Cambridge 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 - Avila, Daiana Silva A1 - Benedetto, Alexandre A1 - Au, Catherine A1 - Bornhorst, Julia A1 - Aschner, Michael A. T1 - Involvement of heat shock proteins on Mn-induced toxicity in Caenorhabditis elegans JF - Plant Methods N2 - Background: All living cells display a rapid molecular response to adverse environmental conditions, and the heat shock protein family reflects one such example. Hence, failing to activate heat shock proteins can impair the cellular response. In the present study, we evaluated whether the loss of different isoforms of heat shock protein (hsp) genes in Caenorhabditis elegans would affect their vulnerability to Manganese (Mn) toxicity. Conclusions: Taken together, our data suggest that Mn exposure modulates heat shock protein expression, particularly HSP-70, in C. elegans. Furthermore, loss of hsp-70 increases protein oxidation and dopaminergic neuronal degeneration following manganese exposure, which is associated with the inhibition of pink1 increased expression, thus potentially exacerbating the vulnerability to this metal. KW - Caenorhabitis elegans KW - Manganese KW - Heat shock proteins KW - hsp-70 KW - pink1 Y1 - 2016 U6 - https://doi.org/10.1186/s40360-016-0097-2 SN - 2050-6511 VL - 17 PB - BioMed Central CY - London ER - TY - JOUR A1 - Henze, Andrea A1 - Homann, Thomas A1 - Rohn, Isabelle A1 - Aschner, Michael A. A1 - Link, Christopher D. A1 - Kleuser, Burkhard A1 - Schweigert, Florian J. A1 - Schwerdtle, Tanja A1 - Bornhorst, Julia T1 - Caenorhabditis elegans as a model system to study post-translational modifications of human transthyretin JF - Scientific reports N2 - The visceral protein transthyretin (TTR) is frequently affected by oxidative post-translational protein modifications (PTPMs) in various diseases. Thus, better insight into structure-function relationships due to oxidative PTPMs of TTR should contribute to the understanding of pathophysiologic mechanisms. While the in vivo analysis of TTR in mammalian models is complex, time-and resource-consuming, transgenic Caenorhabditis elegans expressing hTTR provide an optimal model for the in vivo identification and characterization of drug-mediated oxidative PTPMs of hTTR by means of matrix assisted laser desorption/ionization - time of flight - mass spectrometry (MALDI-TOF-MS). Herein, we demonstrated that hTTR is expressed in all developmental stages of Caenorhabditis elegans, enabling the analysis of hTTR metabolism during the whole life-cycle. The suitability of the applied model was verified by exposing worms to D-penicillamine and menadione. Both drugs induced substantial changes in the oxidative PTPM pattern of hTTR. Additionally, for the first time a covalent binding of both drugs with hTTR was identified and verified by molecular modelling. Y1 - 2016 U6 - https://doi.org/10.1038/srep37346 SN - 2045-2322 VL - 6 PB - Nature Publ. Group CY - London ER - TY - GEN A1 - Chen, Pan A1 - Bornhorst, Julia A1 - Aschner, Michael A. T1 - Manganese metabolism in humans T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Manganese (Mn) is an essential nutrient for intracellular activities; it functions as a cofactor for a variety of enzymes, including arginase, glutamine synthetase (GS), pyruvate carboxylase and Mn superoxide dismutase (Mn-SOD). Through these metalloproteins, Mn plays critically important roles in development, digestion, reproduction, antioxidant defense, energy production, immune response and regulation of neuronal activities. Mn deficiency is rare. In contrast Mn poisoning may be encountered upon overexposure to this metal. Excessive Mn tends to accumulate in the liver, pancreas, bone, kidney and brain, with the latter being the major target of Mn intoxication. Hepatic cirrhosis, polycythemia, hypermanganesemia, dystonia and Parkinsonism-like symptoms have been reported in patients with Mn poisoning. In recent years, Mn has come to the forefront of environmental concerns due to its neurotoxicity. Molecular mechanisms of Mn toxicity include oxidative stress, mitochondrial dysfunction, protein misfolding, endoplasmic reticulum (ER) stress, autophagy dysregulation, apoptosis, and disruption of other metal homeostasis. The mechanisms of Mn homeostasis are not fully understood. Here, we will address recent progress in Mn absorption, distribution and elimination across different tissues, as well as the intracellular regulation of Mn homeostasis in cells. We will conclude with recommendations for future research areas on Mn metabolism. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 711 KW - Manganese KW - Metal Metabolism KW - Homeostasis KW - Blood-Brain Barrier KW - Neurotoxicity KW - Transporters KW - Review Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-427432 SN - 1866-8372 IS - 711 ER - TY - GEN A1 - Avila, Daiana Silva A1 - Benedetto, Alexandre A1 - Au, Catherine A1 - Bornhorst, Julia A1 - Aschner, Michael A. T1 - Involvement of heat shock proteins on Mn-induced toxicity in Caenorhabditis elegans T2 - BMC pharmacology and toxicology N2 - Background: All living cells display a rapid molecular response to adverse environmental conditions, and the heat shock protein family reflects one such example. Hence, failing to activate heat shock proteins can impair the cellular response. In the present study, we evaluated whether the loss of different isoforms of heat shock protein ( hsp ) genes in Caenorhabditis elegans would affect their vulnerability to Manganese (Mn) toxicity. Methods: We exposed wild type and selected hsp mutant worms to Mn (30 min) and next evaluated further the most susceptible strains. We analyzed survi val, protein carbonylation (as a marker of oxidative stress) and Parkinson ’ s disease related gene expression immediately after Mn exposure. Lastly, we observed dopaminergic neurons in wild type worms and in hsp-70 mutants following Mn treatment. Analysis of the data was performed by one-way or two way ANOVA, depending on the case, followed by post-hoc Bonferroni test if the overall p value was less than 0.05. Results: We verified that the loss of hsp-70, hsp-3 and chn-1 increased the vulnerability to Mn, as exposed mutant worms showed lower survival rate and increased protein oxidation. The importance of hsp-70 against Mn toxicity was then corroborated in dopaminergic neurons, where Mn neurotoxicity was aggravated. The lack of hsp-70 also blocked the transcriptional upregulation of pink1 , a gene that has been linked to Parkinson ’ sdisease. Conclusions: Taken together, our data suggest that Mn exposu re modulates heat shock protein expression, particularly HSP-70, in C. elegans .Furthermore,lossof hsp-70 increases protein oxidation and dopaminergic neuronal degeneration following manganese exposure, which is associated with the inhibition of pink1 increased expression, thus pot entially exacerbating the v ulnerability to this metal. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 439 KW - Caenorhabitis elegans KW - Manganese KW - heat shock proteins KW - hsp-70 KW - pink1 Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407286 ER - TY - JOUR A1 - Kumar, Kevin K. A1 - Goodwin, Cody R. A1 - Uhouse, Michael A. A1 - Bornhorst, Julia A1 - Schwerdtle, Tanja A1 - Aschner, Michael A. A1 - McLean, John A. A1 - Bowman, Aaron B. T1 - Untargeted metabolic profiling identifies interactions between JF - Metallomics : integrated biometal science Y1 - 2015 U6 - https://doi.org/10.1039/c4mt00223g SN - 1756-5901 SN - 1756-591X VL - 7 IS - 2 SP - 363 EP - 370 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Chen, Pan A1 - DeWitt, Margaret R. A1 - Bornhorst, Julia A1 - Soares, Felix A. A1 - Mukhopadhyay, Somshuvra A1 - Bowman, Aaron B. A1 - Aschner, Michael A. T1 - Age- and manganese-dependent modulation of dopaminergic phenotypes in a JF - Metallomics : integrated biometal science Y1 - 2015 U6 - https://doi.org/10.1039/c4mt00292j SN - 1756-5901 SN - 1756-591X VL - 7 IS - 2 SP - 289 EP - 298 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Chakraborty, Sudipta A1 - Chen, Pan A1 - Bornhorst, Julia A1 - Schwerdtle, Tanja A1 - Schumacher, Fabian A1 - Kleuser, Burkhard A1 - Bowman, Aaron B. A1 - Aschner, Michael A. T1 - Loss of pdr-1/parkin influences Mn homeostasis through altered ferroportin expression in C-elegans JF - Metallomics : integrated biometal science Y1 - 2015 U6 - https://doi.org/10.1039/c5mt00052a SN - 1756-5901 SN - 1756-591X VL - 7 IS - 5 SP - 847 EP - 856 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Crone, Barbara A1 - Aschner, Michael A. A1 - Schwerdtle, Tanja A1 - Karst, Uwe A1 - Bornhorst, Julia T1 - Elemental bioimaging of Cisplatin in Caenorhabditis elegans by LA-ICP-MS JF - Metallomics : integrated biometal science N2 - cis-Diamminedichloroplatinum(II) (Cisplatin) is one of the most important and frequently used cytostatic drugs for the treatment of various solid tumors. Herein, a laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) method incorporating a fast and simple sample preparation protocol was developed for the elemental mapping of Cisplatin in the model organism Caenorhabditis elegans (C. elegans). The method allows imaging of the spatially-resolved elemental distribution of platinum in the whole organism with respect to the anatomic structure in L4 stage worms at a lateral resolution of 5 mm. In addition, a dose- and time-dependent Cisplatin uptake was corroborated quantitatively by a total reflection X-ray fluorescence spectroscopy (TXRF) method, and the elemental mapping indicated that Cisplatin is located in the intestine and in the head of the worms. Better understanding of the distribution of Cisplatin in this well-established model organism will be instrumental in deciphering Cisplatin toxicity and pharmacokinetics. Since the cytostatic effect of Cisplatin is based on binding the DNA by forming intra- and interstrand crosslinks, the response of poly(ADP-ribose) metabolism enzyme 1 (pme-1) deletion mutants to Cisplatin was also examined. Loss of pme-1, which is the C. elegans ortholog of human poly(ADP-ribose) polymerase 1 (PARP-1) led to disturbed DNA damage response. With respect to survival and brood size, pme-1 deletion mutants were more sensitive to Cisplatin as compared to wildtype worms, while Cisplatin uptake was indistinguishable. Y1 - 2015 U6 - https://doi.org/10.1039/c5mt00096c SN - 1756-5901 SN - 1756-591X VL - 7 IS - 7 SP - 1189 EP - 1195 PB - Royal Society of Chemistry CY - Cambridge ER -