Institute of Nutritional Science, University of Potsdam, 14558, Nuthetal, Germany.
Albert Einstein College of Medicine, 10461, NY, USA.
Mol Nutr Food Res. 2019 May;63(9):e1801304. doi: 10.1002/mnfr.201801304. Epub 2019 Mar 13.
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.
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.
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.
小硒（Se）物种在硒代谢中起着关键作用，是必需微量元素的膳食来源。然而，它们具有氧化还原活性，并引发促氧化剂和抗氧化剂反应。由于健康结果强烈依赖于物种，因此在体内测试硒化合物的特定物种特征。
在模式生物秀丽隐杆线虫（C. elegans）中，研究了亚硒酸盐、硒代蛋氨酸（SeMet）和硒代半胱氨酸（MeSeCys）的即时和持续影响，包括它们的生物利用度、掺入蛋白质以及细胞氧化还原状态的调节。虽然所有测试的硒化合物都是生物可利用的，但只有 SeMet 会持续积累并非特异性地掺入蛋白质中。然而，对化学诱导的活性物质形成的保护与所应用的硒化合物无关。硫氧还蛋白还原酶（TXNRD）活性的增加和抗氧化蛋白的 mRNA 表达水平的变化表明细胞防御机制被激活。然而，在 txnrd-1 缺失突变体中，不再观察到硒物种的保护作用，这也反映在差异基因表达数据中。
硒物种可防止化学诱导的活性物质形成。所鉴定的硒物种的即时和持续全身效应引发了对后续可能出现的硒摄入不足时期的潜在益处的猜测。
