title: Folic acid supplementation during pregnancy induces sex-specific changes in methylation and expression of placental 11β-hydroxysteroid dehydrogenase 2 in rats.
abstract: In the placenta, 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) limits fetal glucocorticoid exposure and its inhibition has been associated to low birth weight. Its expression, encoded by the HSD11B2 gene is regulated by DNA methylation. We hypothesized that maternal diets supplemented with folic acid (FA) during pregnancy modify the expression of placental HSD11B2 through gene methylation. Wistar rats were fed with high (8 mg/kg) or normal low (1mg/kg, control) levels of FA during pregnancy. Concentrations of mRNA and protein in placentas were determined by qRT-PCR and Western blot respectively. Methylation in five CpG sites of the placental HSD11B2 promoter (-378 to -275) was analyzed by bacterial cloning and subsequent sequencing. In the FA-supplemented group, mRNA and protein levels of 11β-HSD2 decreased by 58% and increased by 89%, respectively, only in placentas attached to males. In controls, most CpG sites were not methylated except for the CpG2 site which was 80% methylated. CpG2 methylation level increased under the FA treatment; however, only in placentas attached to females was this increase significant (113%). This change was not related to HSD11B2 expression. Fetal weight of females from FA- supplemented mothers was 6% higher than females from control mothers. In conclusion, this is the first study reporting that FA over supplementation during pregnancy modifies the placental HSD11B2 gene expression and methylation in a sex-dependent manner, suggesting that maternal diets with high content of FA can induce early sex-specific responses, which may lead to long-term consequences for the offspring.
authors: Laboratory of Nutrition and Metabolic Regulation, Human Nutrition Unit, Institute of Nutrition and Food Technology (INTA), Universidad de Chile, Santiago, Chile.
authors: Reyna
authors: R
authors: Penailillo
authors: Laboratory of Nutrition and Metabolic Regulation, Human Nutrition Unit, Institute of Nutrition and Food Technology (INTA), Universidad de Chile, Santiago, Chile.
authors: Angelica
authors: A
authors: Guajardo
authors: Laboratory of Nutrition and Metabolic Regulation, Human Nutrition Unit, Institute of Nutrition and Food Technology (INTA), Universidad de Chile, Santiago, Chile.
authors: Miguel
authors: M
authors: Llanos
authors: Laboratory of Nutrition and Metabolic Regulation, Human Nutrition Unit, Institute of Nutrition and Food Technology (INTA), Universidad de Chile, Santiago, Chile.
authors: Sandra
authors: S
authors: Hirsch
authors: Laboratory of Nutrition and Metabolic Regulation, Human Nutrition Unit, Institute of Nutrition and Food Technology (INTA), Universidad de Chile, Santiago, Chile.
authors: Ana Maria
authors: AM
authors: Ronco
mesh_terms: D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2 / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D018899:CpG Islands / Q000235:genetics; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation / Q000187:drug effects*; D005260:Female; D005333:Fetus / Q000187:drug effects / Q000378:metabolism; D005492:Folic Acid / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D010920:Placenta / Q000187:drug effects / Q000201:enzymology*; D011247:Pregnancy; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D012333:RNA, Messenger; D005492:Folic Acid; D043209:11-beta-Hydroxysteroid Dehydrogenase Type 2; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases