Barua Subit, Chadman Kathryn K, Kuizon Salomon, Buenaventura Diego, Stapley Nathan W, Ruocco Felicia, Begum Umme, Guariglia Sara R, Brown W Ted, Junaid Mohammed A
Department of Developmental Biochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America.
Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, United States of America.
PLoS One. 2014 Jul 9;9(7):e101674. doi: 10.1371/journal.pone.0101674. eCollection 2014.
Studies have indicated that altered maternal micronutrients and vitamins influence the development of newborns and altered nutrient exposure throughout the lifetime may have potential health effects and increased susceptibility to chronic diseases. In recent years, folic acid (FA) exposure has significantly increased as a result of mandatory FA fortification and supplementation during pregnancy. Since FA modulates DNA methylation and affects gene expression, we investigated whether the amount of FA ingested during gestation alters gene expression in the newborn cerebral hemisphere, and if the increased exposure to FA during gestation and throughout the lifetime alters behavior in C57BL/6J mice.
Dams were fed FA either at 0.4 mg or 4 mg/kg diet throughout the pregnancy and the resulting pups were maintained on the diet throughout experimentation. Newborn pups brain cerebral hemispheres were used for microarray analysis. To confirm alteration of several genes, quantitative RT-PCR (qRT-PCR) and Western blot analyses were performed. In addition, various behavior assessments were conducted on neonatal and adult offspring.
Results from microarray analysis suggest that the higher dose of FA supplementation during gestation alters the expression of a number of genes in the newborns' cerebral hemispheres, including many involved in development. QRT-PCR confirmed alterations of nine genes including down-regulation of Cpn2, Htr4, Zfp353, Vgll2 and up-regulation of Xist, Nkx6-3, Leprel1, Nfix, Slc17a7. The alterations in the expression of Slc17a7 and Vgll2 were confirmed at the protein level. Pups exposed to the higher dose of FA exhibited increased ultrasonic vocalizations, greater anxiety-like behavior and hyperactivity. These findings suggest that although FA plays a significant role in mammalian cellular machinery, there may be a loss of benefit from higher amounts of FA. Unregulated high FA supplementation during pregnancy and throughout the life course may have lasting effects, with alterations in brain development resulting in changes in behavior.
研究表明，母体微量营养素和维生素的改变会影响新生儿的发育，而一生中营养暴露的改变可能对健康产生潜在影响，并增加患慢性病的易感性。近年来，由于孕期强制补充叶酸（FA），叶酸暴露量显著增加。由于叶酸可调节DNA甲基化并影响基因表达，我们研究了孕期摄入的叶酸量是否会改变新生儿脑半球的基因表达，以及孕期和一生中叶酸暴露量的增加是否会改变C57BL/6J小鼠的行为。
在整个孕期，给母鼠喂食含0.4毫克或4毫克/千克叶酸的饲料，所产幼崽在整个实验过程中都维持该饮食。使用新生幼崽的脑半球进行微阵列分析。为了确认几个基因的改变，进行了定量逆转录聚合酶链反应（qRT-PCR）和蛋白质印迹分析。此外，对新生和成年后代进行了各种行为评估。
微阵列分析结果表明，孕期补充较高剂量的叶酸会改变新生儿脑半球中许多基因的表达，包括许多与发育相关的基因。qRT-PCR证实了9个基因的改变，包括Cpn2、Htr4、Zfp353、Vgll2的下调以及Xist、Nkx6-3、Leprel1、Nfix、Slc17a7的上调。Slc17a7和Vgll2表达的改变在蛋白质水平得到证实。暴露于较高剂量叶酸的幼崽表现出超声波发声增加、焦虑样行为增加和多动。这些发现表明，尽管叶酸在哺乳动物细胞机制中起着重要作用，但过量叶酸可能会失去益处。孕期和整个生命过程中不受控制地高剂量补充叶酸可能会产生持久影响，导致大脑发育改变，进而引起行为变化。
