Tissue distribution and influence of selenium status on levels of selenoprotein W

Abstract

Rabbits were immunized with two synthetic peptides based on hydrophilic regions of selenoprotein W from rat muscle. The resulting polyclonal antibodies were used in Western blots to determine the compartmentation and tissue distribution of selenoprotein W, and to determine the influence of selenium on the levels of this selenoprotein in rat muscle. Selenoprotein W exists mainly in cytosol, but very small amounts were associated with membranes. Western blots revealed selenoprotein W in muscle, spleen, testis, and brain of rats. Rats were fed diets of either no addition of selenium (0 ppm Se) or additions of 0.1 and 4.0 mg selenium/g (0.1 ppm Se and 4.0 ppm Se) diet for 6 wk. Selenoprotein W was undetectable in skeletal muscle of rats fed the basal diet, detectable in those fed 0.1 ppm selenium in the diet, and much higher in muscle from rats fed 4 ppm selenium diet. In a species comparison, Western blots indicated the presence of selenoprotein W in muscle of rabbits, sheep, and cattle.

Reduction of the Ascorbyl Free Radical to Ascorbate by Thioredoxin Reductase

“…Nonetheless, it is possible that low molecular weight intracellular selenoproteins, which have been shown to exist in brain and muscle, may facilitate such a reaction. One candidate in those tissues is selenoprotein W, which has a molecular weight of 9550 in rat muscle and for which a function has not been discovered (43,44).…”

Cloning and expression of selenoprotein W from pearl mussels Cristaria plicata

“…The expression of SelW2a was less restricted, and was more abundant in the central nervous system marginal zone or retina (Thisse et al, 2003). Furthermore, SelW levels were significantly low in Se deficient diets, and its expression might be regulated by Se levels (Yeh et al, 1995(Yeh et al, , 1997Pagmantidis et al, 2005). The expression level was no significant in muscles and heart from human and sheep (Whanger, 2001;Schweizer et al, 2004), but CpSelW was constitutively expressed in tissues, and was predominantly expressed in the hepatopancreas, followed by gill and mantle, adductor muscle, and weak expression in the hemocytes.…”

“…Dissociation curve analysis of amplification products was performed at the end of each PCR reaction to confirm that only one PCR product was amplified and detected. supplemented animals, with abundantly expression in the skeletal and cardiac muscles, and lower expression in the liver (Yeh et al, 1995(Yeh et al, , 1997Gu et al, 2000). The chicken SelW was widely expressed in tissues, with predominant expression in the nervous tissue, muscle tissue, gizzard, blood vessel, and cartilaginous tissue, and weak expression in the pancreas, testis, ovary, kidney and veins .…”

“…The mRNA transcripts of FcTRX (thioredoxin), as another antioxidant protein from the Chinese white shrimp, were also down-regulated in the hepatopancreas by the WSSW challenge (Ren et al, 2010). The levels of SelW were strongly dependent on selenium concentrations, and selenium-deficient leads to a decrease in the expression of SelW in various tissues (Yeh et al, 1995(Yeh et al, , 1997Pagmantidis et al, 2005). Therefore, we considered that the upregulated expression of se-GPX in mussel altered selenium metabolism, and it might be part of a redistribution of selenium through selenoprotein utilization.…”

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“…Within the cell, SelW is localized predominantly in the cytoplasm, and a small fraction is bound to the cell membrane (344). SelW binds glutathione with very high affinity, which in early studies suggested a potential antioxidant function (28).…”