Basic nutritional investigationEffect of maternal dietary energy types on placenta nutrient transporter gene expressions and intrauterine fetal growth in rats

ObjectiveThe objectives of this study were to investigate the effects of maternal dietary energy types on the mRNA expressions of the placental nutrient transporter and intrauterine fetal growth and to examine whether altered intrauterine fetal growth could be associated with different gene expressions relating to fetal energy metabolism and DNA methylation.MethodsSeventy-two 3-mo-old rats were allocated to one of four groups: low fat/low fiber (L-L), low fat/high fiber, high fat/low fiber (H-L), or high fat/high fiber. Rats were fed the treatment diets 4 wk before mating and continued in pregnancy until sample collections were obtained on days 13.5 and 17.5 of pregnancy.ResultsThe fetal weight in the L-L group was significantly lower than that in the H-L group (P < 0.05). The placental nutrient transporter mRNA expressions of glucose transporter-3 (Slc2a3) and cationic amino acid transporter-1 (Slc7a1) in the L-L group with a decreased fetal weight were downregulated compared with that in the H-L group with an increased fetal weight. However, placental Slc2a1 and the system A amino acid transporter gene Slc38a4 mRNA expressions were adaptively upregulated by the L-L diet with a decreased fetal weight (P < 0.05). For the placental imprinted gene Igf-2 and H19 expressions, lower Igf-2 and higher H19 expressions were associated with the decreased fetal growth in the L-L group compared with the H-L group with an increased fetal weight. Different fetal growth was associated with different DNA methyltransferase-1 and methyltransferase-3a expressions (P > 0.05) and energy metabolism-related genes.ConclusionCollectively, these results demonstrated that intrauterine fetal growth could be affected by different energy intake types through placenta nutrient transporter gene expressions, and different fetal growths were associated with altered fetal genes related to DNA methylation and energy metabolism.