Influence of Genetic Variations in Selenoprotein Genes on the Pattern of Gene Expression after Supplementation with Brazil Nuts.

Selenium (Se) is an essential micronutrient for human health. Its beneficial effects are exerted by selenoproteins, which can be quantified in blood and used as molecular biomarkers of Se status. We hypothesize that the presence of genetic polymorphisms in selenoprotein genes may: (1) influence the gene expression of specific selenoproteins and (2) influence the pattern of global gene expression after Brazil nut supplementation. The study was conducted with 130 healthy volunteers in Sao Paulo, Brazil, who consumed one Brazil nut (300 μg/Se) a day for eight weeks. Gene expression of and and genotyping were measured by real-time PCR using TaqMan Assays. Global gene expression was assessed by microarray using Illumina HumanHT-12 v4 BeadChips Brazil nut supplementation significantly increased mRNA expression only in subjects with CC genotype at rs1050450 ( < 0.05). mRNA expression was significantly higher in A-carriers at rs7579 either before or after supplementation ( < 0.05). Genotype for rs713041 in affected the pattern of blood cell global gene expression. Genetic variations in selenoprotein genes modulated both and selenoprotein gene expression and global gene expression in response to Brazil nut supplementation.