@article{VaraoMouraAparecidoRosiniSilvaDomingosSantodaSilvaetal.2022, author = {Var{\~a}o Moura, Alexandre and Aparecido Rosini Silva, Alex and Domingos Santo da Silva, Jos{\´e} and Aleixo Leal Pedroza, Lucas and Bornhorst, Julia and Stiboller, Michael and Schwerdtle, Tanja and Gubert, Priscila}, title = {Determination of ions in Caenorhabditis elegans by ion chromatography}, series = {Journal of chromatography. B}, volume = {1204}, journal = {Journal of chromatography. B}, publisher = {Elsevier}, address = {Amsterdam [u.a.]}, issn = {1570-0232}, doi = {10.1016/j.jchromb.2022.123312}, pages = {6}, year = {2022}, abstract = {The Caenorhabditis elegans (C. elegans) is a model organism that has been increasingly used in health and environmental toxicity assessments. The quantification of such elements in vivo can assist in studies that seek to relate the exposure concentration to possible biological effects. Therefore, this study is the first to propose a method of quantitative analysis of 21 ions by ion chromatography (IC), which can be applied in different toxicity studies in C. elegans. The developed method was validated for 12 anionic species (fluoride, acetate, chloride, nitrite, bromide, nitrate, sulfate, oxalate, molybdate, dichromate, phosphate, and perchlorate), and 9 cationic species (lithium, sodium, ammonium, thallium, potassium, magnesium, manganese, calcium, and barium). The method did not present the presence of interfering species, with R2 varying between 0.9991 and 0.9999, with a linear range from 1 to 100 mu g L-1. Limits of detection (LOD) and limits of quantification (LOQ) values ranged from 0.2319 mu g L-1 to 1.7160 mu g L-1 and 0.7028 mu g L-1 to 5.1999 mu g L-1, respectively. The intraday and interday precision tests showed an Relative Standard Deviation (RSD) below 10.0 \% and recovery ranging from 71.0 \% to 118.0 \% with a maximum RSD of 5.5 \%. The method was applied to real samples of C. elegans treated with 200 uM of thallium acetate solution, determining the uptake and bioaccumulated Tl+ content during acute exposure.}, language = {en} } @article{GubertPuntelLehmenetal.2018, author = {Gubert, Priscila and Puntel, Bruna and Lehmen, Tassia and Fessel, Joshua P. and Cheng, Pan and Bornhorst, Julia and Trindade, Lucas Siqueira and Avila, Daiana S. and Aschner, Michael and Soares, Felix A. A.}, title = {Metabolic effects of manganese in the nematode Caenorhabditis elegans through DAergic pathway and transcription factors activation}, series = {Neurotoxicology : the interdisciplinary journal of effects to toxic substances on the nervous system}, volume = {67}, journal = {Neurotoxicology : the interdisciplinary journal of effects to toxic substances on the nervous system}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0161-813X}, doi = {10.1016/j.neuro.2018.04.008}, pages = {65 -- 72}, year = {2018}, abstract = {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.}, language = {en} } @article{GubertPuntelLehmenetal.2016, author = {Gubert, Priscila and Puntel, Bruna and Lehmen, Tassia and Bornhorst, Julia and Avila, Daiana Silva and Aschner, Michael A. and Soares, Felix A. A.}, title = {Reversible reprotoxic effects of manganese through DAF-16 transcription factor activation and vitellogenin downregulation in Caenorhabditis elegans}, series = {Life sciences : molecular, cellular and functional basis of therapy}, volume = {151}, journal = {Life sciences : molecular, cellular and functional basis of therapy}, publisher = {Elsevier}, address = {Oxford}, issn = {0024-3205}, doi = {10.1016/j.lfs.2016.03.016}, pages = {218 -- 223}, year = {2016}, abstract = {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\&\#8242;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.}, language = {en} }