Poster Topical Area: Nutrient-Gene Interactions

Location: Hall D

Poster Board Number: 419

E14-01 - A genetic polymorphism in SEPP1 modifies biomarkers of Se status after intake of Se-rich foods

Sunday, Jun 10
8:00 AM – 6:00 PM

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).

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.

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.

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.

Funding Source: No funding.

CoAuthors: Tine Iskov Kopp – National Food Institute, Technical University of Denmark; Malene Outzen – Danish Cancer Society Research Center; Anja Olsen – Danish Cancer Society Research Center; Ulla Vogel – National Research Centre for the Working Environment

Gitte Ravn-Haren

National Food Institute
Kgs. Lyngby, Hovedstaden, Denmark