The Effects of Prenatal Stress on Cortical and Hippocampal Gene Expression Profiles of DNA Methyltransferases and Histone Deacetylases in Female Rats

The aim of this study was to investigate the effects of prenatal stress (PS) on mRNA levels of DNA methyltransferases (DNMTs) and histone deacetylases (HDACs) in cerebral cortex and hippocampus of female rats. PS was induced in rats with dexamethasone (Dex). From gestation day 14 to 21, pregnant rats were injected daily with Dex (100 ?g/kg) or saline. After birth, at 3 months of age, female rats were decapitated (n=5). The effects of Dex on epigenetic mechanisms were investigated by real-time PCR through mRNA levels of DNMT1, DNMT3a, DNMT3b, HDAC1 and HDAC2. Statistical significant differences were determined with one-way analysis of variance. Prenatal Dex exposure caused significant increases in DNMT3a, HDAC1 and HDAC2 mRNA levels in cortex and hippocampus. We further found that DNMT3b mRNA levels significantly increased in hippocampus but decreased in cortex of Dex group. No significant differences were found in DNMT1 mRNA levels. It was concluded that PS may trigger dysregulation of epigenetic mechanisms in cortex and hippocampus of female rats through alterations in gene expression profiles of DNMT3a, DNMT3b, HDAC1 and HDAC2.