Folate-Dependent Cognitive Impairment Associated With Specific Gene Networks in the Adult Mouse Hippocampus

Identification of MicroRNA Profiles in Fetal Spina Bifida: The Role in Pathomechanism and Diagnostic Significance

Distinct miRNA expression patterns may reflect anomalies related to fetal congenital malformations such as spinal bifida (SB). The aim of this preliminary study was to determine the maternal miRNA expression profile of women carrying fetuses with SB. Therefore, six women carrying fetuses with SB and twenty women with euploid healthy fetuses were enrolled in this study. Using NanoString technology, we evaluated the expression level of 798 miRNAs in both plasma and amniotic fluid samples. A downregulation of miR-1253, miR-1290, miR-194-5p, miR-302d-3p, miR-3144-3p, miR-4536-5p, miR-548aa + miR-548t-3p, miR-548ar-5p, miR-548n, miR-590-5p, miR-612, miR-627-5p, miR-644a, and miR-122-5p, and an upregulation of miR-320e, let-7b-5p, miR-23a-3p, miR-873-3p, and miR-30d-5p were identified in maternal amniotic fluid samples in SB when compared to the control group. The target genes of these miRNAs play a predominant role in regulating the synthesis of several biological compounds related to signaling pathways such as those regulating the pluripotency of stem cells. Moreover, the maternal plasma expression of miR-320e was increased in pregnancies with SB, and this marker could serve as a valuable non-invasive screening tool. Our results highlight the SB-specific miRNA signature and the differentially expressed miRNAs that may be involved in SB pathogenesis. Our findings emphasize the role of miRNA as a predictive factor that could potentially be useful in prenatal genetic screening for SB.

Influence of intermittent iron and folic acid supplementation on cognitive abilities among adolescent girls in northwestern Tanzania

Iron and folic acid (IFA) supplementation to reduce anemia is key for improving substantial lost disability adjusted life years (DALYs) for adolescent girls. This study assessed the impact of weekly IFA supplementation (WIFAS) on cognitive ability among adolescent girls in the Simiyu Region in northernwestern Tanzania. This cross-sectional comparative evaluation study of 770 adolescent girls (396 -WIFAS supplemented; 374 -not supplemented) evaluated the association between WIFAS and cognitive ability through a face-to-face survey and cognitive ability assessment using standardized tests (Span-forward Test, Span-backward Test and Maze Test). Using a modified Poisson regression, we controlled for the geographic setting (urban vs rural), availability of potable water and feeding programs in schools, age and school level of adolescent girls, parental status, main parental economic activities, and the number of teachers. Participants were between the ages of 11 and 19 years, with more than half (57%) between 12-15 years of age. Those with WIFAS had higher cognitive ability (Span-forward scores, χ2 = 46.34% p <0.001; Span-forward, χ2 = 46.34% p <0.001; and Global Composite Cognitive Performance (GCCP), χ2 = 32.52% p<0.001). Among the IFA supplemented adolescent girls, secondary school level had a significantly higher score with respect to Span-backward (aPR = 1.43, 95% CI = 1.06-1.62); Span-forward ability (aPR = 1.26, 95% CI = 1.04-1.53) and Maze Test ability (aPR = 1.12, 95% CI = 1.01-1.25) as compared to their counterpart in primary school level. Individual adolescent girls with WIFAS and living with both parents performed much better on the Span-backward Test (aPR = 1.22, 95% CI = 1.07-1.68) as compared to those living with relatives and/or orphans. The presence of potable water program among the WIFAS schools resulted in a higher Span-backward ability (aPR = 1.34, 95% CI = 1.03-1.89); and GCCP (aPR = 1.27, 95% CI = 1.03-1.75). Adolescent girls from WIFAS schools with feeding program had higher Span-forward (aPR = 1.38, 95% CI = 1.03-1.63) ability as well as a higher Maze Test (aPR = 1.15, 95% CI = 1.07-1.26) score. The present study provides compelling evidence that WIFAS is positively associated with higher cognitive ability among adolescent girls. Nevertheless, IFA interventions are still rare in communities across Tanzania.

The impact of amino acid metabolism on adult neurogenesis

Adult neurogenesis is a multistage process during which newborn neurons are generated through the activation and proliferation of neural stem cells (NSCs) and integrated into existing neural networks. Impaired adult neurogenesis has been observed in various neurological and psychiatric disorders, suggesting its critical role in cognitive function, brain homeostasis, and neural repair. Over the past decades, mounting evidence has identified a strong association between metabolic status and adult neurogenesis. Here, we aim to summarize how amino acids and their neuroactive metabolites affect adult neurogenesis. Furthermore, we discuss the causal link between amino acid metabolism, adult neurogenesis, and neurological diseases. Finally, we propose that systematic elucidation of how amino acid metabolism regulates adult neurogenesis has profound implications not only for understanding the biological underpinnings of brain development and neurological diseases, but also for providing potential therapeutic strategies to intervene in disease progression.

Folate administration ameliorates neurobehavioral effects of prenatal ethanol exposure

Background: Prenatal ethanol exposure (PEE) induces heightened ethanol intake at adolescence in preclinical studies. Ethanol intake alters the absorption of folate, a methyl-group donor critical for numerous cellular functions. The prenatal administration of folate is, therefore, a promising approach to reduce the effects of PEE.Objectives: Experiment 1 determined if prenatal folate modulated the effects of PEE on ethanol intake, anxiety-like response, and exploratory behaviors (Experiment 1) in Wistar rats. Experiment 2 assessed, in rats not given PEE, if postnatal folate reversed effects of ethanol exposure at postnatal days 28-42. Experiment 3 assessed if folate altered blood ethanol levels (BELs).Methods: Experiment 1 involved 242 (125 male) adolescent Wistar rats derived from dams given folate (20 mg/kg, gestational days - GD- 13-20) + ethanol (2.0 g/kg, GD 17-20), ethanol, or vehicle only at pregnancy. Experiment 2 involved 29 male adolescents administered vehicle or ethanol doses co-administered or not with folate. In Experiment 3 twelve adult females were tested for BELs after folate administration. These tests were applied: intake tests, light dark box (LDB), elevated plus maze, open field and concentric square field.Results: PEE heightened ethanol intake (η² ps = 0.06-07) and induced hyperactivity and a reduced latency to exit the white area of the LDB (η² ps = 0.12-17). These effects were partially inhibited by folate (p > .05). Rats exposed to ethanol exposure at adolescence exhibited reduced motor activity (η² p = .17), regardless of folate treatment. Folate did not affect BELs.Conclusion: Folate administration should be considered as a preventive or acute treatment to attenuate the neurobehavioral effects of PEE.

Targeting DNA Methylation in the Adult Brain through Diet

Metabolism and nutrition have a significant role in epigenetic modifications such as DNA methylation, which can influence gene expression. Recently, it has been suggested that bioactive nutrients and gut microbiota can alter DNA methylation in the central nervous system (CNS) through the gut-brain axis, playing a crucial role in modulating CNS functions and, finally, behavior. Here, we will focus on the effect of metabolic signals in shaping brain DNA methylation during adulthood. We will provide an overview of potential interactions among diet, gastrointestinal microbiome and epigenetic alterations on brain methylation and behavior. In addition, the impact of different diet challenges on cytosine methylation dynamics in the adult brain will be discussed. Finally, we will explore new ways to modulate DNA hydroxymethylation, which is particularly abundant in neural tissue, through diet.

Maternal One-Carbon Metabolism during the Periconceptional Period and Human Foetal Brain Growth: A Systematic Review

The maternal environment during the periconceptional period influences foetal growth and development, in part, via epigenetic mechanisms moderated by one-carbon metabolic pathways. During embryonic development, one-carbon metabolism is involved in brain development and neural programming. Derangements in one-carbon metabolism increase (i) the short-term risk of embryonic neural tube-related defects and (ii) long-term childhood behaviour, cognition, and autism spectrum disorders. Here we investigate the association between maternal one-carbon metabolism and foetal and neonatal brain growth and development. Database searching resulted in 26 articles eligible for inclusion. Maternal vitamin B6, vitamin B12, homocysteine, and choline were not associated with foetal and/or neonatal head growth. First-trimester maternal plasma folate within the normal range (>17 nmol/L) associated with increased foetal head size and head growth, and high erythrocyte folate (1538-1813 nmol/L) with increased cerebellar growth, whereas folate deficiency (<7 nmol/L) associated with a reduced foetal brain volume. Preconceptional folic acid supplement use and specific dietary patterns (associated with increased B vitamins and low homocysteine) increased foetal head size. Although early pregnancy maternal folate appears to be the most independent predictor of foetal brain growth, there is insufficient data to confirm the link between maternal folate and offspring risks for neurodevelopmental diseases.