Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 11/11/2010
Publication Date: 3/17/2011
Citation: Zeng, H., Jackson, M.I., Cheng, W., Combs, G.F. 2011. Chemical form of selenium affects its uptake and transport in the human intestinal cell model, Caco-2. Federation of American Societies for Experimental Biology Conference. 25:786.2. Interpretive Summary:
Technical Abstract: Determining the effect of selenium (Se) chemical form on uptake and transport in human intestinal cells is critical to assess Se bioavailability. In the present study, we measured the uptake and transport of various Se compounds in the human intestinal Caco-2 cell model. We found that two sources of selenomethionine, the purified L-isomer (L-SeMet) and an in vitro-digested, Se-enriched yeast each increased intracellular Se content more effectively than selenite or methylselenocysteine (SeMSC). Interestingly, SeMSC, SeMet and Se-enriched yeast were transported at comparable rates from the apical to basolateral sides, each being about 3 fold that of selenite. This observation suggests the presence of a transcellular pathway for Se-amino acids. In addition, these forms of Se, whether located on the apical or basolateral side, had comparable potential to support glutathione peroxidase (GPx) activity. Because selenoprotein P has been postulated to be a key Se transport protein, we also examined its expression and found that the addition of selenite, SeMSC, L-SeMet or Se-enriched yeast digest did not affect intracellular selenoprotein P expression. Taken together, these studies show that the chemical form of Se can affect the absorptive (apical to basolateral side) efficacy and retention of Se by intestinal cells; but that, these effects are not related to the potential to support GPx activity.