Objective Whether maternal selenium deficiency during gestation elevates the risk for fetal growth restriction (FGR) remains controversial. The present study is to explore the adverse effects of maternal exposure to low selenium diet before and during pregnancy on the growth and development of mouse fetuses and related potental mechanisms.
Methods Forty ICR female mice (three weeks old) were randomly divided into a control diet (CD) group (0.18 mg/kg selenium) and a low selenium diet (LSD) group (0.02 mg/kg selenium), with 20 mice in each group. Females and males were mated afer eight weeks of feeding, and the pregnant mice were fed with the same diet as before untl being sacrifced on gestatonal day (GD) 18. Growth and development of mouse fetuses were evaluated. Maternal and fetal mice serum and placenta samples were collected to detect serum selenium (Se) concentration by graphite furnace atomic absorpton spectrometry, the mRNA expression levels of Cat, Sod1, and Sod2 in placenta by quanttatve RT-PCR, and 3-nitrotyrosine (3-NT) expression level in placenta by immunohistochemistry and Western blot. All measurement data were presented as mean±SD and analyzed by t test.
Results No signifcant differences were observed in total food intake and weight gain between the CD and LSD groups before and during pregnancy (P>0.05). The serum selenium levels of pregnant mice and fetal mice were (121.7±43.0) and (79.5±30.8) μg/L in the CD group and (74.6±34.7) and (36.2±26.0) μg/L in the LSD group; the LSD group had signifcantly lower pregnant and fetal serum selenium levels than the CD group (P < 0.05). The examinaton results of growth and development showed that the fetal weight was (1.38±0.08) g in the CD group and (1.31±0.06) g in the LSD group; the LSD group had a signifcantly lower fetal weight than the CD group (P < 0.05). The results of quanttatve RT-PCR showed no differences between the LSD group and the CD group in the mRNA expression levels of Cat, Sod1, and Sod2 (P>0.05). Moreover, the results from immunostaining and Western blot showed that the 3-NT positve cells and protein expression levels in the LSD-exposed mice were signifcantly higher than those in the CD-exposed mice (P < 0.05).
Conclusion
Maternal exposure to low selenium diet before and during pregnancy could induce fetal growth restricton and the later may be associated with placental oxidatve stress.
DownLoad: