TY - GEN A1 - Baesler, Jessica A1 - Michaelis, Vivien A1 - Stiboller, Michael A1 - Haase, Hajo A1 - Aschner, Michael A1 - Schwerdtle, Tanja A1 - Sturzenbaum, Stephen R. A1 - Bornhorst, Julia T1 - Nutritive manganese and zinc overdosing in aging c. elegans result in a metallothionein-mediated alteration in metal homeostasis T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Manganese (Mn) and zinc (Zn) are not only essential trace elements, but also potential exogenous risk factors for various diseases. Since the disturbed homeostasis of single metals can result in detrimental health effects, concerns have emerged regarding the consequences of excessive exposures to multiple metals, either via nutritional supplementation or parenteral nutrition. This study focuses on Mn-Zn-interactions in the nematode Caenorhabditis elegans (C. elegans) model, taking into account aspects related to aging and age-dependent neurodegeneration. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1364 KW - aging KW - C. elegans KW - homeostasis KW - manganese KW - zinc Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-514995 SN - 1866-8372 IS - 8 ER - TY - JOUR A1 - Baesler, Jessica A1 - Michaelis, Vivien A1 - Stiboller, Michael A1 - Haase, Hajo A1 - Aschner, Michael A1 - Schwerdtle, Tanja A1 - Sturzenbaum, Stephen R. A1 - Bornhorst, Julia T1 - Nutritive manganese and zinc overdosing in aging c. elegans result in a metallothionein-mediated alteration in metal homeostasis JF - Molecular Nutrition and Food Research N2 - Manganese (Mn) and zinc (Zn) are not only essential trace elements, but also potential exogenous risk factors for various diseases. Since the disturbed homeostasis of single metals can result in detrimental health effects, concerns have emerged regarding the consequences of excessive exposures to multiple metals, either via nutritional supplementation or parenteral nutrition. This study focuses on Mn-Zn-interactions in the nematode Caenorhabditis elegans (C. elegans) model, taking into account aspects related to aging and age-dependent neurodegeneration. KW - aging KW - C. elegans KW - homeostasis KW - manganese KW - zinc Y1 - 2021 U6 - https://doi.org/10.1002/mnfr.202001176 SN - 1613-4133 SN - 1613-4125 VL - 65 IS - 8 SP - 1 EP - 11 PB - Wiley-VCH GmbH CY - Weinheim ER - TY - JOUR A1 - Alker, Wiebke A1 - Schwerdtle, Tanja A1 - Schomburg, Lutz A1 - Haase, Hajo T1 - A Zinpyr-1-based Fluorimetric Microassay for Free Zinc in Human Serum JF - International journal of molecular sciences N2 - Zinc is an essential trace element, making it crucial to have a reliable biomarker for evaluating an individual’s zinc status. The total serum zinc concentration, which is presently the most commonly used biomarker, is not ideal for this purpose, but a superior alternative is still missing. The free zinc concentration, which describes the fraction of zinc that is only loosely bound and easily exchangeable, has been proposed for this purpose, as it reflects the highly bioavailable part of serum zinc. This report presents a fluorescence-based method for determining the free zinc concentration in human serum samples, using the fluorescent probe Zinpyr-1. The assay has been applied on 154 commercially obtained human serum samples. Measured free zinc concentrations ranged from 0.09 to 0.42 nM with a mean of 0.22 ± 0.05 nM. It did not correlate with age or the total serum concentrations of zinc, manganese, iron or selenium. A negative correlation between the concentration of free zinc and total copper has been seen for sera from females. In addition, the free zinc concentration in sera from females (0.21 ± 0.05 nM) was significantly lower than in males (0.23 ± 0.06 nM). The assay uses a sample volume of less than 10 µL, is rapid and cost-effective and allows us to address questions regarding factors influencing the free serum zinc concentration, its connection with the body’s zinc status, and its suitability as a future biomarker for an individual’s zinc status. KW - zinc KW - free zinc KW - serum KW - biomarker KW - fluorescent probe KW - Zinypr-1 Y1 - 2019 U6 - https://doi.org/10.3390/ijms20164006 SN - 1661-6596 SN - 1422-0067 VL - 20 IS - 16 PB - MDPI CY - Basel ER - TY - GEN A1 - Alker, Wiebke A1 - Schwerdtle, Tanja A1 - Schomburg, Lutz A1 - Haase, Hajo T1 - A Zinpyr-1-based fluorimetric microassay for free zinc in human serum T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Zinc is an essential trace element, making it crucial to have a reliable biomarker for evaluating an individual’s zinc status. The total serum zinc concentration, which is presently the most commonly used biomarker, is not ideal for this purpose, but a superior alternative is still missing. The free zinc concentration, which describes the fraction of zinc that is only loosely bound and easily exchangeable, has been proposed for this purpose, as it reflects the highly bioavailable part of serum zinc. This report presents a fluorescence-based method for determining the free zinc concentration in human serum samples, using the fluorescent probe Zinpyr-1. The assay has been applied on 154 commercially obtained human serum samples. Measured free zinc concentrations ranged from 0.09 to 0.42 nM with a mean of 0.22 ± 0.05 nM. It did not correlate with age or the total serum concentrations of zinc, manganese, iron or selenium. A negative correlation between the concentration of free zinc and total copper has been seen for sera from females. In addition, the free zinc concentration in sera from females (0.21 ± 0.05 nM) was significantly lower than in males (0.23 ± 0.06 nM). The assay uses a sample volume of less than 10 µL, is rapid and cost-effective and allows us to address questions regarding factors influencing the free serum zinc concentration, its connection with the body’s zinc status, and its suitability as a future biomarker for an individual’s zinc status. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1086 KW - zinc KW - free zinc KW - serum KW - biomarker KW - fluorescent probe KW - Zinypr-1 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472833 SN - 1866-8372 IS - 1086 ER - 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 - JOUR A1 - Maares, Maria A1 - Keil, Claudia A1 - Koza, Jenny A1 - Straubing, Sophia A1 - Schwerdtle, Tanja A1 - Haase, Hajo T1 - In Vitro Studies on Zinc Binding and Buffering by Intestinal Mucins JF - International Journal of Molecular Sciences N2 - The investigation of luminal factors influencing zinc availability and accessibility in the intestine is of great interest when analyzing parameters regulating intestinal zinc resorption. Of note, intestinal mucins were suggested to play a beneficial role in the luminal availability of zinc. Their exact zinc binding properties, however, remain unknown and the impact of these glycoproteins on human intestinal zinc resorption has not been investigated in detail. Thus, the aim of this study is to elucidate the impact of intestinal mucins on luminal uptake of zinc into enterocytes and its transfer into the blood. In the present study, in vitro zinc binding properties of mucins were analyzed using commercially available porcine mucins and secreted mucins of the goblet cell line HT-29-MTX. The molecular zinc binding capacity and average zinc binding affinity of these glycoproteins demonstrates that mucins contain multiple zinc-binding sites with biologically relevant affinity within one mucin molecule. Zinc uptake into the enterocyte cell line Caco-2 was impaired by zinc-depleted mucins. Yet this does not represent their form in the intestinal lumen in vivo under zinc adequate conditions. In fact, zinc-uptake studies into enterocytes in the presence of mucins with differing degree of zinc saturation revealed zinc buffering by these glycoproteins, indicating that mucin-bound zinc is still available for the cells. Finally, the impact of mucins on zinc resorption using three-dimensional cultures was studied comparing the zinc transfer of a Caco-2/HT-29-MTX co-culture and conventional Caco-2 monoculture. Here, the mucin secreting co-cultures yielded higher fractional zinc resorption and elevated zinc transport rates, suggesting that intestinal mucins facilitate the zinc uptake into enterocytes and act as a zinc delivery system for the intestinal epithelium. KW - intestinal zinc resorption KW - zinc binding KW - mucus layer KW - intestinal mucins KW - in vitro intestinal model KW - goblet cells KW - Caco-2/HT-29-MTX-model Y1 - 2018 U6 - https://doi.org/10.3390/ijms19092662 SN - 1422-0067 VL - 19 IS - 9 ER - TY - GEN A1 - Maares, Maria A1 - Keil, Claudia A1 - Koza, Jenny A1 - Straubing, Sophia A1 - Schwerdtle, Tanja A1 - Haase, Hajo T1 - In Vitro Studies on Zinc Binding and Buffering by Intestinal Mucins T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The investigation of luminal factors influencing zinc availability and accessibility in the intestine is of great interest when analyzing parameters regulating intestinal zinc resorption. Of note, intestinal mucins were suggested to play a beneficial role in the luminal availability of zinc. Their exact zinc binding properties, however, remain unknown and the impact of these glycoproteins on human intestinal zinc resorption has not been investigated in detail. Thus, the aim of this study is to elucidate the impact of intestinal mucins on luminal uptake of zinc into enterocytes and its transfer into the blood. In the present study, in vitro zinc binding properties of mucins were analyzed using commercially available porcine mucins and secreted mucins of the goblet cell line HT-29-MTX. The molecular zinc binding capacity and average zinc binding affinity of these glycoproteins demonstrates that mucins contain multiple zinc-binding sites with biologically relevant affinity within one mucin molecule. Zinc uptake into the enterocyte cell line Caco-2 was impaired by zinc-depleted mucins. Yet this does not represent their form in the intestinal lumen in vivo under zinc adequate conditions. In fact, zinc-uptake studies into enterocytes in the presence of mucins with differing degree of zinc saturation revealed zinc buffering by these glycoproteins, indicating that mucin-bound zinc is still available for the cells. Finally, the impact of mucins on zinc resorption using three-dimensional cultures was studied comparing the zinc transfer of a Caco-2/HT-29-MTX co-culture and conventional Caco-2 monoculture. Here, the mucin secreting co-cultures yielded higher fractional zinc resorption and elevated zinc transport rates, suggesting that intestinal mucins facilitate the zinc uptake into enterocytes and act as a zinc delivery system for the intestinal epithelium. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1079 KW - intestinal zinc resorption KW - zinc binding KW - mucus layer KW - intestinal mucins KW - in vitro intestinal model KW - goblet cells KW - Caco-2/HT-29-MTX-model Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-469078 SN - 1866-8372 IS - 1079 ER - TY - JOUR A1 - Maares, Maria A1 - Duman, Ayse A1 - Keil, Claudia A1 - Schwerdtle, Tanja A1 - Haase, Hajo T1 - The impact of apical and basolateral albumin on intestinal zinc resorption in the Caco-2/HT-29-MTX co-culture model JF - Metallomics : integrated biometal science N2 - The molecular mechanisms of intestinal zinc resorption and its regulation are still topics of ongoing research. To this end, the application of suitable in vitro intestinal models, optimized with regard to their cellular composition and medium constituents, is of crucial importance. As one vital aspect, the impact of cell culture media or buffer compounds, respectively, on the speciation and cellular availability of zinc has to be considered when investigating zinc resorption. Thus, the present study aims to investigate the impact of serum, and in particular its main constituent serum albumin, on zinc uptake and toxicity in the intestinal cell line Caco-2. Furthermore, the impact of serum albumin on zinc resorption is analyzed using a co-culture of Caco-2 cells and the mucin-producing goblet cell line HT-29-MTX. Apically added albumin significantly impaired zinc uptake into enterocytes and buffered its cytotoxicity. Yet, undigested albumin does not occur in the intestinal lumen in vivo and impairment of zinc uptake was abrogated by digestion of albumin. Interestingly, zinc uptake, as well as gene expression studies of mt1a and selected intestinal zinc transporters after zinc incubation for 24 h, did not show significant differences between 0 and 10% serum. Importantly, the basolateral application of serum in a transport study significantly enhanced fractional apical zinc resorption, suggesting that the occurrence of a zinc acceptor in the plasma considerably affects intestinal zinc resorption. This study demonstrates that the apical and basolateral medium composition is crucial when investigating zinc, particularly its intestinal resorption, using in vitro cell culture. Y1 - 2018 U6 - https://doi.org/10.1039/c8mt00064f SN - 1756-5901 SN - 1756-591X VL - 10 IS - 7 SP - 979 EP - 991 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Bornhorst, Julia A1 - Kipp, Anna P. A1 - Haase, Hajo A1 - Meyer, Soeren A1 - Schwerdtle, Tanja T1 - The crux of inept biomarkers for risks and benefits of trace elements JF - Trends in Analytical Chemistry N2 - Nowadays, the role of trace elements (TE) is of growing interest because dyshomeostasis of selenium (Se), manganese (Mn), zinc (Zn), and copper (Cu) is supposed to be a risk factor for several diseases. Thereby, research focuses on identifying new biomarkers for the TE status to allow for a more reliable description of the individual TE and health status. This review mirrors a lack of well-defined, sensitive, and selective biomarkers and summarizes technical limitations to measure them. Thus, the capacity to assess the relationship between dietary TE intake, homeostasis, and health is restricted, which would otherwise provide the basis to define adequate intake levels of single TE in both healthy and diseased humans. Besides that, our knowledge is even more limited with respect to the real life situation of combined TE intake and putative interactions between single TE. KW - Trace elements KW - Copper KW - Zinc KW - Manganese KW - Selenium KW - Biomarker KW - Inductively coupled plasma mass spectrometry KW - Hyphenated techniques KW - Isotope ratios Y1 - 2018 U6 - https://doi.org/10.1016/j.trac.2017.11.007 SN - 0165-9936 SN - 1879-3142 VL - 104 SP - 183 EP - 190 PB - Elsevier CY - Oxford ER -