Disease relevance of selenium

• Murine leukemia L1210 cells grown for 5-7 d in the presence of 1% serum without added selenium [Se(-) cells] expressed < 5% of the glutathione peroxidase (GPX) activity of selenium-supplemented controls [Se(+) cells] [1].
• Hypersensitivity of Se(-) cells to t-BuOOH was partially reversed by treating them with Ebselen, a selenoperoxidase mimetic; thus, selenoperoxidase insufficiency was probably the most serious defect of Se deprivation [1].
• On the other hand, in adult rats, TMSe increased only marginally despite that the rats suffered much more greatly from the Se toxicity, suggesting that TMSe cannot be a biomarker of Se toxicity [2].
• Se-deficient mice develop myocarditis when infected with a normally benign strain of coxsackievirus [3].
• Serum copper (Cu), zinc (Zn) the Cu/Zn ratio (Cu/Zn) and selenium (Se) were evaluated in 84 patients with non-small cell lung cancer (NSCLC) before surgery [4].

Psychiatry related information on selenium

• Levels of mercury (Hg), selenium (Se), iron (Fe), rubidium (Rb), and zinc (Zn) were measured in the pituitary gland to assess the possibility of a potential difference in the environmental Hg exposure of Alzheimer's disease (AD) patients and control subjects and levels of other elements of interest in AD [5].

High impact information on selenium

• Selenium deficiency reduces the abundance of mRNA for Se-dependent glutathione peroxidase 1 by a UGA-dependent mechanism likely to be nonsense codon-mediated decay of cytoplasmic mRNA [6].
• Immunocytochemical studies with affinity-purified anti-hD2 antibody show a Se-dependent increase in immunofluorescence [7].
• Our results reveal that SeMSC accumulation closely correlated with the BoSMT gene expression and the total Se status in tissues and provide important information for maximizing the SeMSC production in this beneficial vegetable plant [8].
• Astrocytes were depleted in Se by maintaining them in Se-free chemically defined medium for 7 days [9].
• Taken together, the data support the hypothesis that the monomethyl Se pool is a proximal Se for inhibiting the expression of MMP-2 and VEGF and of angiogenesis [10].

Chemical compound and disease context of selenium

• CONCLUSION: The levels of Zn, Se, Cu, and oxidative stress (MDA), as well as related anti-oxidative enzymes (GR and GPX) in blood have important impact on the viral factors in chronic hepatitis C [11].
• The levels of zinc (Zn), copper (Cu), manganese (Mn), and selenium (Se) in serum, normal skin and scar of 40 keloid and hypertrophic scar patients were assessed [12].

Biological context of selenium

• Based on slope-ratio analyses, the bioavailability of Se-methionine and Se-yeast was greater than that of selenite in both lactating dams and their nursing pups [13].
• During lactation, groups (n = 8) were fed experimental diets containing either 0.1, 0.25 or 0.5 ppm Se as selenite, Se-methionine, or Se-yeast [13].
• CYS, GLT, and DHT had little effect on cell growth, while SEL was inhibitory to cell growth [14].
• Se content and its chemical form in young plants were studied, and its impact on plant respiratory potential, measured as terminal electron transport system (ETS) activity, determined [15].
• These results indicate that equimolar Hg and Se bind to Sel P to form the ¿(Hg-Se)n¿m-Sel P complex, where n is the number of Hg-Se complexes and m the number of binding sites in Sel P [16].

Anatomical context of selenium

• This study examines the effect of Se on the D-III activity in cultures of rat brain astrocytes [9].
• Addition of GLA/Se/I reduced PCP of the endothelial cells [17].
• This study aimed to determine whether the function of TJs in endothelial cells can be strengthened by gamma linolenic acid (GLA), selenium (Se) and iodine (I) in the presence of 17beta-estradiol (17beta-estradiol), which causes leakage of endothelial cells by disruption of TJs in endothelium [17].
• Concentrations of selenium (Se), copper (Cu), and zinc (Zn)-cofactors of these enzymes-were determined both in erythrocytes and in plasma [18].
• The immune system was altered in the Se-deficient animals, as was the viral pathogen itself [3].

Associations of selenium with other chemical compounds

• These data suggest adequate expression and Se-dependent regulation of a couple of selenoproteins involved in antioxidant defense and thyroid hormone metabolism in XTC.UC1 cells, so far giving no evidence of a role of these proteins in the pathogenesis of HTCs [19].
• However, erythrocyte SOD activities and plasma Se levels measured after the reuse period were not found to be statistically different from the control values; MDA levels still remained elevated above the control values, and GPx activities were not attained to those of controls, after the reuse practice [20].
• CONCLUSIONS: The data supports an association between lower levels of Se, Zn, vitamin E, and risk of carcinoma of the gallbladder and suggest that Cu/Zn ratio could be a useful parameter in evaluating the patients of carcinoma of the gallbladder [21].
• Plasma selenium (Se), manganese (Mn), zinc (Zn), copper (Cu), and iron (Fe) levels were measured by atomic absorption spectrophotometry [22].
• Egg consumption did not change Se concentration in plasma, blood pressure, total plasma lipid concentrations or the concentrations of total cholesterol and HDL-cholesterol in plasma [23].

Gene context of selenium

• Dietary selenium requirements based on glutathione peroxidase-1 activity and mRNA levels and other Se-dependent parameters are not increased by pregnancy and lactation in rats [24].
• Plasma levels of PCBs, blood levels of Se and MeHg, plasma lipids (triacylglycerols, total, LDL-, and high-density lipoprotein cholesterol [LDL-C and HDL-C, respectively], apolipoprotein B-LDL), erythrocyte n-3 PUFAs, OxLDL, Hcy, blood GPx, GSH, and GR have been determined [25].
• These findings are consistent with H2O2 intermediacy in photokilling and suggest that L1210 cells depend mainly on GPX for protection against this species but switch to overexpressed CAT after chronic Se deprivation [26].
• Selenium-independent epididymis-restricted glutathione peroxidase 5 protein (GPX5) can back up failing Se-dependent GPXs in mice subjected to selenium deficiency [27].
• By contrast, long-term ( > 20 week) Se-deprived [L'.Se(-)] cells whose catalase (CAT) activity was elevated > 100-fold were far more resistant to UVA/B than L.Se(+) cells [26].

Analytical, diagnostic and therapeutic context of selenium

• Optimization of selenium status by a single intraperitoneal injection of Se in Se-deficient rat: possible application to burned patient treatment [28].
• Binding of equimolar mercury (Hg) and selenium (Se) to a specific plasma protein in the detoxification of Hg was studied in vitro by the HPLC/inductively coupled argon plasma-mass spectrometry (ICP-MS) method with use of an enriched stable isotope [16].
• Selenium (Se) has been shown to be protective against cancers in animal models at concentrations exceeding those considered essential for normal nutritional requirements [29].
• Immunofluorescence revealed that after treatment with Se/I/GLA over 24 h there was increasing relocation to endothelial cell-cell junctions of the TJ proteins Claudin-5, Occludin, and ZO-1 [17].
• However, in a second study, with Se yeast providing Se at 1 ppm, 4 ppm, and 8 ppm throughout the experiment, a significant reduction in tumors was observed with 8 ppm Se (colon tumor incidence was 15% lower and colon tumor burden was 35% lower, P < 0.05) [29].

References