Poster Topical Area: Nutrient-Gene Interactions
Location: Hall D
Poster Board Number: 419
Objectives: To investigate whether four functional SNPs in glutathione peroxidases (GPX1 and GPX4) and selenoprotein P (SELENOP) modify the effect of intervention with Se-rich foods on concentrations of blood Se and selenoprotein expression (erythrocyte GPX activity and plasma selenoprotein P concentration).
Methods: In a parallel dietary intervention study 83 healthy men and women aged 50-74 years were randomly assigned to either a control or an intervention group. Participants in the intervention group were provided with five portions of 200 g/week raw fish and shellfish once a week for 26 weeks, corresponding to approximately 50.3 μg Se/day. The participants in the control group received no intervention and were advised to maintain their habitual diets. Selected functional polymorphisms were GPX1/rs1050450, GPX4/rs713041, SELENOP/rs3877899 and SELENOP/rs7579. Genotypes were determined using RT-PCR and allelic discrimination on ABI 7900HT instruments. Samples were run in duplicates with known positive controls and three negative controls. Duplicates yielded 100% identical genotypes. Whole blood Se analyses were conducted using an ELAN 6100 DRC ICP-MS and plasma selenoprotein P concentration was determined using its selective retention by heparin-affinity HPLC and on-line detection by ICP-DRC-MS of Se. GPX activity was spectrophotometrically assayed in erythrocyte lysates on a Pentra 400 using t-butylhydroperoxide as substrate and related to the amount of hemoglobin in the lysates.
Results: The intervention diet resulted in higher concentrations of both selenoprotein P (P=0.018) and blood Se (P=0.088) in CC homozygotes of the SELENOP/rs3877899 polymorphism compared to T-allele carriers. None of the other polymorphisms modified the biomarker responses following the intervention. T-allele carriers of the GPX1 polymorphism had significantly lower erythrocyte GPX enzyme activity compared to CC homozygotes independent of intervention.
Conclusions: Our study shows that variation in the SELENOP gene modifies biomarkers of Se status after intake of Se-rich foods. This opens for a more personalized approach to micronutrient requirements.
National Food Institute
Kgs. Lyngby, Hovedstaden, Denmark