Treatment of Caenorhabditis elegans with Small Selenium Species Enhances Antioxidant Defense Systems

Abstract

Scope: Small selenium (Se) species play a key role in Se metabolism and act as dietary sources of the essential trace element. However, they are redox-active and trigger pro-and antioxidant responses. As health outcomes are strongly species-dependent, species-specific characteristics of Se compounds are tested in vivo. Methods and results: In the model organism Caenorhabditis elegans (C. elegans), immediate and sustained effects of selenite, selenomethionine (SeMet), and Se-methylselenocysteine (MeSeCys) are studied regarding their bioavailability, incorporation into proteins, as well as modulation of the cellular redox status. While all tested Se compounds are bioavailable, only SeMet persistently accumulates and is non-specifically incorporated into proteins. However, the protection toward chemically-induced formation of reactive species is independent of the applied Se compound. Increased thioredoxin reductase (TXNRD) activity and changes in mRNA expression levels of antioxidant proteins indicate the activation of cellular defense mechanisms. However, in txnrd-1 deletion mutants, no protective effects of the Se species are observed anymore, which is also reflected by differential gene expression data. Conclusion: Se species protect against chemically-induced reactive species formation. The identified immediate and sustained systemic effects of Se species give rise to speculations on possible benefits facing subsequent periods of inadequate Se intake.

Products Derived from Buchenavia tetraphylla Leaves Have In Vitro Antioxidant Activity and Protect Tenebrio molitor Larvae against Escherichia coli-Induced Injury

“…Since T. molitor is a multicellular organism, this approach also presents advantages over those that use cells as some insights into the toxicity of the antioxidant agent can also be assessed. Furthermore, the use of this insect offers some advantages in relation to Caenorhabditis elegans, the invertebrate organism traditionally used for in vivo antioxidant evaluation [41,42], such as ease of handling and direct inoculation of the compound agent in the larvae. In our in vivo model of stress induced by heat-killed E. coli (OP50 strain), BTFD induced higher protective effects than BTME and BTFC.…”

Application of Fluorescence Microscopy and Behavioral Assays to Demonstrating Neuronal Connectomes and Neurotransmitter Systems in C. elegans

“…A relatively short incubation or treatment period is needed for examining the mortality or behavioral trials, which may range from a few minutes [37,38] to hours [39][40][41]7]. Even if the exposure was carried out in L1 larval stage, the neuronal development is only completed in L4 and that should be considered under the evaluations.…”

Caenorhabditis elegans as a Model to Study Manganese-Induced Neurotoxicity

“…Caenorhabditis elegans ( C. elegans ) combines the simplicity of a small organism (reaching 1 mm when adult) with a notable biological conservancy with mammals, leveraging its use as a tool to solve crucial gaps in molecular biology [ 1 , 2 , 3 , 4 ], chemistry [ 5 ], biochemistry [ 6 ], toxicology [ 7 , 8 , 9 ], neuroscience [ 10 ], pathology [ 11 ], and genetics [ 12 ]. The easy genetic manipulation, including transgenics, mutants, and RNA interference (RNAi), which gave rise to multiple phenotypes highlights the biological dynamics in C. elegans .…”

“…Relevant parameters for toxicological screening can be evaluated in C. elegans , such as mortality, longevity, behavior, feeding, growth, and reproduction [ 32 , 33 ]. A relatively short incubation or treatment period is needed to examine the mortality or behavioral trials, ranging from a few minutes [ 26 ] to hours [ 5 , 7 , 8 , 34 ]. In this regard, neurodegeneration, reduction in growth, reproduction, feeding, locomotion, and worm lifespan have been evaluated under metal exposure, including with lead (Pb) [ 35 ], manganese (Mn) [ 36 ], titanium (Ti) [ 37 ], copper (Cu) [ 38 ], zinc (Zn) [ 39 ], gold (Au) [ 40 ], mercury (Hg) [ 41 ], iron (Fe) [ 42 ], and chrome (Cr) [ 43 ].…”