Excess Folic Acid Supplementation before and during Pregnancy and Lactation Alters Behaviors and Brain Gene Expression in Female Mouse Offspring.

Xingyue Yang,Fei Liu,Zhixing Lu,Yan Zhou,Hongyan Lin,Qian Wu,Wenyan Sun,Li Huang,Yongqi Chen,Feng Wu,Xin Shen,Dandan Chu

doi:10.3390/nu14010066

Xingyue Yang, Fei Liu + Show 10 more

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https://doi.org/10.3390/nu14010066

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Abstract

Use of folic acid (FA) during early pregnancy protects against birth defects. However, excess FA has shown gender-specific neurodevelopmental toxicity. Previously, we fed the mice with 2.5 times the recommended amount of FA one week prior to mating and during the pregnancy and lactation periods, and detected the activated expression of Fos and related genes in the brains of weaning male offspring, as well as behavioral abnormalities in the adults. Here, we studied whether female offspring were affected by the same dosage of FA. An open field test, three-chamber social approach and social novelty test, an elevated plus-maze, rotarod test and the Morris water maze task were used to evaluate their behaviors. RNA sequencing was performed to identify differentially expressed genes in the brains. Quantitative real time-PCR (qRT-PCR) and Western blots were applied to verify the changes in gene expression. We found increased anxiety and impaired exploratory behavior, motor coordination and spatial memory in FA-exposed females. The brain transcriptome revealed 36 up-regulated and 79 down-regulated genes in their brains at weaning. The increase of Tlr1; Sult1a1; Tph2; Acacb; Etnppl; Angptl4 and Apold1, as well as a decrease of Ppara mRNA were confirmed by qRT-PCR. Among these genes; the mRNA levels of Etnppl; Angptl4 and Apold1 were increased in the both FA-exposed female and male brains. The elevation of Sult1a1 protein was confirmed by Western blots. Our data suggest that excess FA alteres brain gene expression and behaviors in female offspring, of which certain genes show apparent gender specificity.

Highlights

The water-soluble micronutrient folate participates in multiple biological processes in mammals, such as DNA and protein synthesis, as well as nucleic acid and protein methylation [1]
The body weight of female offspring (2.5 × folic acid (FA) hereafter) was tracked for 5 months, and there was no difference when compared with the control (Figure 1B, FA→F1, 114 = 1.418, p = 0.2362; Day→F5, 114 = 138.9, p < 0.0001; Day × FA→F5, 114 = 1.058, p = 0.3873), suggesting that early-life FA supplementation did not affect the physical growth of the female offspring
Hereafter) was tracked for 5 months, and there was no difference when compared with the control (Figure 1B, FA→F1, 114 = 1.418, p = 0.2362; Day→F5, 114 = 138.9, p < 0.0001; D6aoyf 1×7 FA→F5, 114 = 1.058, p = 0.3873), suggesting that early-life FA supplementation did not affect the physical growth of the female offspring

Summary

Introduction

The water-soluble micronutrient folate (vitamin B-9) participates in multiple biological processes in mammals, such as DNA and protein synthesis, as well as nucleic acid and protein methylation [1]. Appropriate FA supplement (0.4 mg per day) is widely accepted to prevent against neural tube defects (NTD) and other birth defects [2]. FA fortification has been introduced in the United States, Canada and several other countries to diminish the number of NTD [3]. Due to vitamin supplements and mandatory fortification, high concentrations of folate have been detected in maternal serum as well as in breast milk [4,5,6,7]. Whether excess FA supplementation during pregnancy and lactation affects the neurodevelopment of offspring has become an important public health issue

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