TY  - JOUR
A1  - Rohn, Isabelle
A1  - Marschall, Talke Anu
A1  - Kröpfl, Nina
A1  - Jensen, Kenneth Bendix
A1  - Aschner, Michael
A1  - Tuck, Simon
A1  - Kuehnelt, Doris
A1  - Schwerdtle, Tanja
A1  - Bornhorst, Julia
T1  - Selenium species-dependent toxicity, bioavailability and metabolic transformations in Caenorhabditis elegans
JF  - Metallomics : integrated biometal science
N2  - The essential micronutrient selenium (Se) is required for various systemic functions, but its beneficial range is narrow and overexposure may result in adverse health effects. Additionally, the chemical form of the ingested selenium contributes crucially to its health effects. While small Se species play a major role in Se metabolism, their toxicological effects, bioavailability and metabolic transformations following elevated uptake are poorly understood. Utilizing the tractable invertebrate Caenorhabditis elegans allowed for an alternative approach to study species-specific characteristics of organic and inorganic Se forms in vivo, revealing remarkable species-dependent differences in the toxicity and bioavailability of selenite, selenomethionine (SeMet) and Se-methylselenocysteine (MeSeCys). An inverse relationship was found between toxicity and bioavailability of the Se species, with the organic species displaying a higher bioavailability than the inorganic form, yet being less toxic. Quantitative Se speciation analysis with HPLC/mass spectrometry revealed a partial metabolism of SeMet and MeSeCys. In SeMet exposed worms, identified metabolites were Se-adenosylselenomethionine (AdoSeMet) and Se-adenosylselenohomocysteine (AdoSeHcy), while worms exposed to MeSeCys produced Se-methylselenoglutathione (MeSeGSH) and -glutamyl-MeSeCys (-Glu-MeSeCys). Moreover, the possible role of the sole selenoprotein in the nematode, thioredoxin reductase-1 (TrxR-1), was studied comparing wildtype and trxr-1 deletion mutants. Although a lower basal Se level was detected in trxr-1 mutants, Se toxicity and bioavailability following acute exposure was indistinguishable from wildtype worms. Altogether, the current study demonstrates the suitability of C. elegans as a model for Se species dependent toxicity and metabolism, while further research is needed to elucidate TrxR-1 function in the nematode.
Y1  - 2018
U6  - https://doi.org/10.1039/c8mt00066b
SN  - 1756-5901
SN  - 1756-591X
VL  - 10
IS  - 6
SP  - 818
EP  - 827
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Meyer, Sören
A1  - Markova, Mariya
A1  - Pohl, Gabriele
A1  - Marschall, Talke Anu
A1  - Pivovarova, Olga
A1  - Pfeiffer, Andreas F. H.
A1  - Schwerdtle, Tanja
T1  - Development, validation and application of an ICP-MS/MS method to quantify minerals and (ultra-)trace elements in human serum
JF  - Journal of trace elements in medicine and biology
N2  - Multi-element determination in human samples is very challenging. Especially in human intervention studies sample volumes are often limited to a few microliters and due to the high number of samples a high-throughput is indispensable. Here, we present a state-of-the-art ICP-MS/MS-based method for the analysis of essential (trace) elements, namely Mg, Ca, Fe, Cu, Zn, Mo, Se and I, as well as food-relevant toxic elements such as As and Cd. The developed method was validated regarding linearity of the calibration curves, method LODs and LOQs, selectivity and trueness as well as precision. The established reliable method was applied to quantify the element serum concentrations of participants of a human intervention study (LeguAN). The participants received isocaloric diets, either rich in plant protein or in animal protein. While the serum concentrations of Mg and Mo increased in participants receiving the plant protein-based diet (above all legumes), the Se concentration in serum decreased. In contrast, the animal protein-based diet, rich in meat and dairy products, resulted in an increased Se concentration in serum.
KW  - ICP-MS
KW  - Elemental blood serum concentration
KW  - Human nutritional intervention
Y1  - 2018
U6  - https://doi.org/10.1016/j.jtemb.2018.05.012
SN  - 0946-672X
VL  - 49
SP  - 157
EP  - 163
PB  - Elsevier GMBH
CY  - München
ER  -