a1 Molecular Prevention Group, Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Heinrich-Hecht-Platz 10, 24118 Kiel, Germany
a2 Food Science Research Group, Institute of Human Nutrition and Food Science, Christian-Albrechts-University of Kiel, Hermann-Rodewald-Strasse 6, 24118 Kiel, Germany
The aim of the present study was to determine the effects of a 6-month dietary vitamin E (VE) deficiency on DNA methylation and gene expression in rat liver. Two enzymes, 5-α-steroid reductase type 1 (SRD5A1) and the regulatory subunit of γ-glutamylcysteinyl synthetase (GCLM), which are differentially expressed on the mRNA level, were analysed for promoter methylation in putative cytosine-phospho-guanine (CpG) island regions located at the 5′ end using base-specific cleavage and matrix-assisted laser desorption ionisation time-of-flight MS. A twofold increase in the mRNA level of SRD5A1 gene and a twofold decrease in the mRNA level of GCLM gene in VE-deficient animals were not associated with different CpG methylation of the analysed promoter region. Furthermore, global DNA methylation was not significantly different in these two groups. Thus, the present results indicate that the VE-induced regulation of SRD5A1 and GCLM in rat liver is not directly mediated by changes in promoter DNA methylation.
(Received January 12 2010)
(Revised March 08 2010)
(Accepted March 25 2010)
(Online publication May 07 2010)
Abbreviations: αT, α-tocopherol; CpG, cytosine-phospho-guanine; GCLM, γ-glutamylcysteinyl synthetase; SRD5A1, 5-α-steroid reductase type 1; VE, vitamin E; VE− , VE-deficient; VE+, VE-sufficient