Maternal intake of supplemental iron and risk of autism spectrum disorder

Iron metabolism dysfunction in neuropsychiatric disorders: Implications for therapeutic intervention

Iron is a trace metal that takes part in the maintenance of body homeostasis by, for instance, aiding in energy production and immunity. A body of evidence now demonstrates that dysfunction in iron metabolism can have detrimental effects and is intricately associated with the development of neuropsychiatric disorders, including Major Depressive Disorder (MDD), anxiety, and schizophrenia. For instance, changes in serum and central nervous system (CNS) levels of iron and in proteins mediating iron metabolism have been documented in patients grappling with the aforementioned diseases. By contrast, targeting iron metabolism by using iron chelators, for instance, has proven to be effective in alleviating disease burden. Therefore, here we review the state-of-the-art regarding the role of iron metabolism and its dysfunction in the context of neuropsychiatric disorders. Furthermore, we discuss how targeting iron metabolism can be an effective therapeutic option to tackle this class of diseases. Finally, we discuss the mechanisms linking this dysfunction to behavioral changes in these disorders. Harnessing the knowledge of iron metabolism is not only key to the characterization of novel molecular targets and disease biomarkers but also crucial to drug repurposing and drug design.

Whole Brain MRI Assessment of Age and Sex-Related R2* Changes in the Human Fetal Brain

Iron in the brain is essential to neurodevelopmental processes, as it supports neural functions, including processes of oxygen delivery, electron transport, and enzymatic activity. However, the development of brain iron before birth is scarcely understood. By estimating R2* (1/T2*) relaxometry from a sizable sample of fetal multiecho echo-planar imaging (EPI) scans, which is the standard sequence for functional magnetic resonance imaging (fMRI), across gestation, this study investigates age and sex-related changes in iron, across regions and tissue segments. Our findings reveal that brain R2* levels significantly increase throughout gestation spanning many different regions, except the frontal lobe. Furthermore, females exhibit a faster rate of R2* increase compared to males, in both gray matter and white matter. This sex effect is particularly notable within the left insula. This work represents the first MRI examination of iron accumulation and sex differences in developing fetal brains. This is also the first study to establish R2* estimation methodology in fetal multiecho functional MRI.

Associations of maternal and paternal preconception and maternal pregnancy urinary phthalate biomarker and bisphenol A concentrations with offspring autistic behaviors: The PEACE study

BACKGROUND

Environmental chemical exposures in utero may play a role in autism development. While preconception risk factors for autism are increasingly being investigated, little is known about the influence of chemical exposures during the preconception period, particularly for paternal exposures.

METHODS

In 195 children from the Preconception Environmental exposures And Childhood health Effects (PEACE) cohort born to parents recruited from a fertility clinic in Boston, Massachusetts between 2004 and 2017, we quantified concentrations of 11 phthalate metabolites and bisphenol A (BPA) in urine samples collected from mothers and fathers before conception and mothers throughout pregnancy. When children were 6-15 years old, parents completed the Social Responsiveness Scale (SRS) questionnaire assessing autistic behaviors. We used linear mixed effect models to estimate covariate-adjusted associations of phthalate biomarker and BPA concentrations, separately for maternal preconception (n = 179), paternal preconception (n = 121), and maternal pregnancy (n = 177), with SRS T-scores, based on age and gender, in offspring. We used quantile g-computation models for mixture analyses and evaluated modification by selected dietary factors.

RESULTS

The mean SRS T-score was 47.7 (±7.4), lower than the normative mean of 50. In adjusted models for individual biomarkers or mixtures, few associations were observed and estimates were generally negative (e.g., lower SRS T-scores) and imprecise. We observed associations of higher mono-isobutyl phthalate (MiBP) concentrations measured in maternal preconception and paternal preconception periods with lower SRS T-scores (βmaternal_precon = -1.6, 95% CI -2.7; -0.4; βpaternal_precon = -2.9, 95% CI -4.6; -1.2) for each loge increase. In a subset of participants with maternal preconception nutrition information, we generally observed stronger inverse associations with higher folate and iron intake, particularly for folate intake and MiBP concentrations.

CONCLUSIONS

Urinary phthalate biomarker and BPA concentrations during preconception (maternal and paternal) and pregnancy (maternal) were not associated with adverse autistic behaviors in these children. Larger studies are needed to elucidate the observed associations, while considering interactions between maternal nutrition and chemical exposures.

Folate prevents the autism-related phenotype caused by developmental pyrethroid exposure in prairie voles

Neurodevelopmental disorders (NDDs) have dramatically increased in prevalence to an alarming one in six children, and yet both causes and preventions remain elusive. Recent human epidemiology and animal studies have implicated developmental exposure to pyrethroid pesticides, one of the most common classes of pesticides in the US, as an environmental risk factor for autism and neurodevelopmental disorders. Our previous research has shown that low-dose chronic developmental pyrethroid exposure (DPE) changes folate metabolites in the adult mouse brain. We hypothesize that DPE acts directly on molecular targets in the folate metabolism pathway, and that high-dose maternal folate supplementation can prevent or reduce the biobehavioral effects of DPE. We exposed pregnant prairie vole dams chronically to vehicle or low-dose deltamethrin (3 mg/kg/3 days) with or without high-dose folate supplementation (methylfolate, 5 mg/kg/3 days). The resulting DPE offspring showed broad deficits in five behavioral domains relevant to neurodevelopmental disorders (including the social domain); increased plasma folate concentrations; and increased neural expression of SHMT1, a folate cycle enzyme. Maternal folate supplementation prevented most of the behavioral phenotypes (except for repetitive behaviors) and caused potentially compensatory changes in neural expression of FOLR1 and MTHFR, two folate-related proteins. We conclude that DPE causes neurodevelopmental disorder-relevant behavioral deficits; DPE directly alters aspects of folate metabolism; and preventative interventions targeting folate metabolism are effective in reducing, but not eliminating, the behavioral effects of DPE.

Reliability of a short diet and vitamin supplement questionnaire for retrospective collection of maternal nutrient intake

Background

Gestational nutrition can protect against adverse neurodevelopmental outcomes.

Objectives

We developed a short tool for collecting maternal nutritional intake during pregnancy to facilitate research in this area and compared its retrospective use to prospectively-collected food frequency questionnaires (FFQ).

Methods

Maternal nutritional intake was retrospectively assessed using three versions (full interview, full self-administered online, and shortened interview) of the Early Life Exposure Assessment Tool (ELEAT) among participants of the MARBLES pregnancy cohort study of younger siblings of autistic children. Retrospective responses were compared with responses to supplement questions and the validated 2005 Block FFQ prospectively collected in MARBLES during pregnancies 2-7 years prior. ELEAT nutrient values were calculated using reported food intake frequencies and nutrient values from the USDA nutrient database. Correlations between retrospectively- and prospectively-reported intake were evaluated using Kappa coefficients, Youden's J, and Spearman Rank Correlation Coefficients (rs).

Results

MARBLES FFQ dietary intakes were compared among 54 women who completed the ELEAT full form including 12 online, and among 23 who completed the ELEAT short form. Correlations across most foods were fair to moderate. Most ELEAT quantified nutrient values were moderately correlated (rs = 0.3-0.6) with those on the Block FFQ. Supplement questions in both MARBLES and the ELEAT were completed by 114 women. Kappas were moderate for whether or not supplements were taken, but modest for timing. Correlations varied by version and child diagnosis or concerns, and were higher when mothers completed the ELEAT when their child was 4 years old or younger.

Conclusions

With recall up to several years, ELEAT dietary and supplement module responses were modestly to moderately reliable and produced nutrient values moderately correlated with prospectively-collected measures. The ELEAT dietary and vitamin supplements modules can be used to rank participants in terms of intake of several nutrients relevant for neurodevelopment.

Vitamins, minerals and their maternal levels' role in brain development: An updated literature-review

One's neurobehavioural and mental health are built during the exact and complex process of brain development. It is thought that fetal development is where neuropsychiatric disorders first emerged. Behavioural patterns can change as a result of neuropsychiatric illnesses. The incidence is rising quickly; nevertheless, providing exceptional care remains a significant challenge for families and healthcare systems. It has been demonstrated that one of the main factors causing the transmission of these diseases is maternal exposure. Through physiologic pathways, maternal health and intrauterine exposures can affect brain development. Our attention has been focused on epigenetic factors, particularly in the gestational environment, which may be responsible for human neurodegenerative diseases since our main mental development occurs during the nine months of intrauterine life. After thoroughly searching numerous databases, this study examined the effect of fat-soluble vitamins, water-soluble vitamins, and minerals and their maternal-level effect on brain development.

Early life stress and iron metabolism in developmental psychoneuroimmunology

An estimated 250 million children face adverse health outcomes from early life exposure to severe or chronic social, economic, and nutritional adversity, highlighting/emphasizing the pressing concern about the link between ELS and long-term implications on mental and physical health. There is significant overlap between populations experiencing high levels of chronic stress and those experiencing iron deficiency, spotlighting the potential role of iron as a key mediator in this association. Iron, an essential micronutrient for brain development and immune function, is often depleted in stress conditions. Iron deficiency among the most common nutrient deficiencies in the world. Fetal and infant iron status may thus serve as a crucial intermediary between early chronic psychological stress and subsequent immune system changes to impact neurodevelopment. The review presents a hypothesized pathway between early life stress (ELS), iron deficiency, and neurodevelopment through the hypothalamic-pituitary-adrenocortical (HPA) axis and the IL-6-hepcidin axis. This hypothesis is derived from (1) evidence that stress impacts iron status (2) long-term neurodevelopmental outcomes that are shared by ELS and iron deficiency exposure, and (3) possible mechanisms for how iron may mediate the relation between ELS and iron deficiency through alterations in the developing immune system. The article concludes by proposing future research directions, emphasizing the need for rigorous studies to elucidate how stress and iron metabolism interact to modify the developing immune system. Understanding these mechanisms could open new avenues for improving human health and neurodevelopment for women and children globally, making it a timely and vital area of study in psychoneuroimmunology research.

Sex-specific association between maternal mild anemia and children's behavioral development: a birth cohort study

There has been limited research on maternal anemia affecting children's behavioral development, with a lack of studies focusing on sex differences in this association. Based on the Ma'anshan Birth Cohort, 2132 mother-child pairs were included. Maternal anemia was evaluated based on the hemoglobin concentration and children's behavioral development was assessed by Achenbach Child Behavior Checklist 1.5-5. Binary logistic regression models indicated that compared with children born of mothers without anemia throughout pregnancy, maternal mild anemia during pregnancy or only anemia in the 3rd trimester was associated with increased risks of aggressive behaviors in boys. Maternal mild anemia only in the 2nd trimester was associated with increased risks of attention problems in boys. In girls, maternal mild anemia during pregnancy was associated with increased risks of withdrawn, internalizing problems and total problems. Girls born of mothers with mild anemia only in the 2nd trimester had higher risks of total problems. Maternal mild anemia in both 2nd and 3rd trimesters was associated with increased risks of internalizing problems in girls. Our study identified sex-specific effects of maternal mild anemia during pregnancy on children's behavioral development problems.

Disrupted Prenatal Metabolism May Explain the Etiology of Suboptimal Neurodevelopment: A Focus on Phthalates and Micronutrients and their Relationship to Autism Spectrum Disorder

Pregnancy is a time of high metabolic coordination, as maternal metabolism adapts to support the growing fetus. Many of these changes are coordinated by the placenta, a critical fetal endocrine organ and the site of maternal-fetal crosstalk. Dysregulation in maternal and placental metabolism during pregnancy has been linked to adverse outcomes, including altered neurodevelopment. Autism spectrum disorder (ASD) is a neurodevelopmental disorder linked to metabolic alterations in both children and their mothers. Prenatal environmental exposures have been linked to risk of ASD through dysregulated maternal, placental, and fetal metabolism. In this review, we focus on recent studies investigating the associations between prenatal metabolism in the maternal-placental-fetal unit and the impact of prenatal environmental exposures to phthalates and micronutrients on ASD risk. By identifying the mechanisms through which phthalates and other ubiquitous endocrine disrupting chemicals influence development, and how nutritional interventions can impact those mechanisms, we can identify promising ways to prevent suboptimal neurodevelopment.

Association between Autism Spectrum Disorder, Trace Elements, and Intracranial Fluid Spaces

(1) Autism spectrum disorder (ASD) belongs to the group of complex developmental disorders. Novel studies have suggested that genetic and environmental factors equally affect the risk of ASD. Identification of environmental factors involved in the development of ASD is therefore crucial for a better understanding of its etiology. Whether there is a causal link between trace elements, brain magnetic resonance imaging (MRI), and ASD remains a matter of debate and requires further studies. (2) In the prospective part of the study, we included 194 children, including an age-matched control group; in the retrospective study, 28 children with available MRI imaging were included. All children had urine analysis of trace elements performed. In those with available brain MRI, linear indexes for the ventricular volumes were measured and calculated. (3) We found the highest vanadium, rubidium, thallium, and silver levels in children with ASD. These elements also correlated with the estimated ventricular volume based on MRI indexes in children with ASD in the subanalysis. However, the severity of the deficits did not correlate with brain MRI indexes of our elements, except negatively with magnesium. (4) Trace elements have an impact on children with ASD, but further multi-centric studies are needed to explain the pathophysiological mechanisms.

Maternal choline supplementation in neurodevelopmental disorders: mechanistic insights from animal models and future directions

OBJECTIVES

To synthesize evidence from animal models of neurodevelopmental disorders (NDD) using maternal choline supplementation, to characterize current knowledge on the mechanisms of choline's protective effects against NDD, and to identify gaps in knowledge for future study.

METHODS

A literature review was conducted in PubMed to identify studies using prenatal choline supplementation interventions in rodent models of neurodevelopmental disorders. 24 studies were identified, and behavioral and biological findings were extracted from each. Studies examining both genetic and environmental risk factors were included.

RESULTS

Maternal choline supplementation during gestation is protective against both genetic and environmental NDD risk factors. Maternal choline supplementation improves both cognitive and affective outcomes throughout the lifespan in NDD models. Prenatal choline improved these outcomes through its participation in processes like neurogenesis, epigenetic regulation, and anti-inflammatory signaling.

DISCUSSION

Maternal choline supplementation improves behavioral and neurobiological outcomes in animal models of NDD, paralleling findings in humans. Animal models provide a unique opportunity to study the mechanisms by which gestational choline improves neurodevelopmental outcomes. This is especially important since nearly 90% of pregnant people in the United States are deficient in choline intake. However, much is still unknown about the mechanisms through which choline and its derivatives act. Further research into this topic, especially mechanistic studies in animal models, is critical to modernize maternal choline intake guidelines and to develop interventions to increase maternal choline intake in vulnerable populations.

Healthy Prenatal Dietary Pattern and Offspring Autism

Importance

Prenatal diet may be causally related to autism; however, findings are inconsistent, with a limited body of research based on small sample sizes and retrospective study designs.

Objective

To investigate the associations of prenatal dietary patterns with autism diagnosis and autism-associated traits in 2 large prospective cohorts, the Norwegian Mother, Father, and Child Cohort Study (MoBa), and the Avon Longitudinal Study of Parents and Children (ALSPAC).

Design, Setting, and Participants

This cohort study used data from MoBa and ALSPAC birth cohort studies conducted across Norway and in the Southwest of England, respectively. Participants were people with singleton pregnancies with self-reported food frequency questionnaire responses. MoBa recruited between 2002 and 2008, and ALSPAC recruited between 1990 and 1992, and children were followed-up until age 8 years or older. Recruitment rates were 41% (95 200 of 277 702 eligible pregnancies) in MoBa and 72% (14 541 of 20 248 eligible pregnancies) in ALSPAC. Data analysis occurred February 1, 2022, to August 1, 2023.

Exposure

A healthy prenatal dietary pattern was derived using factor analysis and modeled as low, medium, and high adherence.

Main Outcomes and Measures

In MoBa, the offspring outcomes were autism diagnosis and elevated social communication questionnaire score at ages 3 years and 8 years, with further analysis of the social communication difficulties and restrictive and repetitive behaviors subdomains. In ALSPAC, offspring outcomes were elevated social communication difficulties checklist score at age 8 years. Odds ratios (ORs) were estimated using generalized nonlinear models.

Results

MoBa included 84 548 pregnancies (mean [SD] age, 30.2 [4.6] years; 43 277 [51.2%] male offspring) and ALSPAC had 11 760 pregnancies (mean [SD] age, 27.9 [4.7] years; 6034 [51.3%] male offspring). In the final adjusted models, high adherence to a healthy dietary pattern, compared with low adherence, was associated with reduced odds of autism diagnosis (OR, 0.78; 95% CI, 0.66-0.92) and social communication difficulties at age 3 years in MoBa (OR 0.76, 95% CI, 0.70-0.82) and age 8 years in ALSPAC (OR, 0.74; 95% CI, 0.55-0.98). There was no consistent evidence of association with the other outcomes.

Conclusions and Relevance

In this cohort study of mother-child dyads, adherence to a healthy prenatal dietary pattern was associated with a lower odds of autism diagnosis and social communication difficulties but not restrictive and repetitive behaviors.

Newborn Dried Blood Spot Folate in Relation to Maternal Self-reported Folic Acid Intake, Autism Spectrum Disorder, and Developmental Delay

BACKGROUND

Maternal folic acid intake has been associated with decreased risk for neurodevelopmental disorders including autism spectrum disorder (ASD). Genetic differences in folate metabolism could explain some inconsistencies. To our knowledge, newborn folate concentrations remain unexamined.

METHODS

We measured folate in archived newborn dried blood spots of children from the CHARGE (Childhood Autism Risks from Genetics and the Environment) case-control study who were clinically confirmed at 24-60 months to have ASD (n = 380), developmental delay (n = 128), or typical development (n = 247). We quantified monthly folic acid intake from maternally-reported supplements and cereals consumed during pregnancy and 3 months prior. We assessed associations of newborn folate with maternal folic acid intake and with ASD or developmental delay using regression. We stratified estimates across maternal and child MTHFR genotypes.

RESULTS

Among typically developing children, maternal folic acid intake in prepregnancy and each pregnancy month and prepregnancy prenatal vitamin intake were positively associated with newborn folate. Among children with ASD, prenatal vitamin intake in pregnancy months 2-9 was positively associated with newborn folate. Among children with developmental delay, maternal folic acid and prenatal vitamins during the first pregnancy month were positively associated with neonatal folate. Associations differed by MTHFR genotype. Overall, neonatal folate was not associated with ASD or developmental delay, though we observed associations with ASD in children with the MTHFR 677 TT genotype (odds ratio: 1.76, 95% CI = 1.19, 2.62; P for interaction = 0.08).

CONCLUSION

Maternal prenatal folic acid intake was associated with neonatal folate at different times across neurodevelopmental groups. Neonatal folate was not associated with reduced ASD risk. MTHFR genotypes modulated these relationships.

The Experience of Anaemia and Ingesting Oral Iron Supplementation in Pregnancy: A Qualitative Study

INTRODUCTION

The objective of this study was to understand the experience of iron deficiency anaemia requiring oral iron in pregnancy and the factors affecting compliance with oral iron supplementation. Participants' understanding regarding the possible consequences of anaemia in pregnancy was also explored. Feedback on a proposed randomised controlled trial of daily versus alternate day oral iron in pregnancy was sought.

MATERIALS & METHODS

Following ethical approval, fourteen semi-structured one-to-one interviews were carried out using an interview tool with open-ended questions. Recruitment was carried out through social media and from an antenatal out-patient setting. Interviews were audio-recorded, transcribed and analysed thematically.

RESULTS

Fatigue emerged as a predominant and troubling symptom. Awareness was often highlighted through friends/family and from healthcare professionals, particularly in first pregnancies. Knowledge surrounding the potential short-term and long-term adverse consequences of untreated anaemia however was limited. Gastro-intestinal side-effects, a previous experience of poor tolerance and forgetfulness all negatively impacted compliance with oral iron supplementation in pregnancy. Routine, a perceived improvement in fatigue with supplementation and reduced dose frequency recurred as themes which positively affected compliance. Pregnancy as a motivating factor recurred as a theme in analysis. The role of diet was felt to be important. Knowledge of iron-rich foods and absorption aids and inhibitors was good, but practice on optimal ingestion of oral iron supplementation varied. Feedback on trial acceptability was positive with the benefit of extra supportive care noted. Incorporating study visits with routine care was advised in view of time constraints. This area of research was perceived as important.

CONCLUSION

In order to successfully reduce the rates of iron deficiency anaemia in pregnancy, it is crucial that all factors affecting compliance with oral iron are considered. Providing women with the important information on the possible consequences of sub optimally treated anaemia may help to improve this public health issue.

Chromatin accessibility and H3K9me3 landscapes reveal long-term epigenetic effects of fetal-neonatal iron deficiency in rat hippocampus

BACKGROUND

Iron deficiency (ID) during the fetal-neonatal period results in long-term neurodevelopmental impairments associated with pervasive hippocampal gene dysregulation. Prenatal choline supplementation partially normalizes these effects, suggesting an interaction between iron and choline in hippocampal transcriptome regulation. To understand the regulatory mechanisms, we investigated epigenetic marks of genes with altered chromatin accessibility (ATAC-seq) or poised to be repressed (H3K9me3 ChIP-seq) in iron-repleted adult rats having experienced fetal-neonatal ID exposure with or without prenatal choline supplementation.

RESULTS

Fetal-neonatal ID was induced by limiting maternal iron intake from gestational day (G) 2 through postnatal day (P) 7. Half of the pregnant dams were given supplemental choline (5.0 g/kg) from G11-18. This resulted in 4 groups at P65 (Iron-sufficient [IS], Formerly Iron-deficient [FID], IS with choline [ISch], and FID with choline [FIDch]). Hippocampi were collected from P65 iron-repleted male offspring and analyzed for chromatin accessibility and H3K9me3 enrichment. 22% and 24% of differentially transcribed genes in FID- and FIDch-groups, respectively, exhibited significant differences in chromatin accessibility, whereas 1.7% and 13% exhibited significant differences in H3K9me3 enrichment. These changes mapped onto gene networks regulating synaptic plasticity, neuroinflammation, and reward circuits. Motif analysis of differentially modified genomic sites revealed significantly stronger choline effects than early-life ID and identified multiple epigenetically modified transcription factor binding sites.

CONCLUSIONS

This study reveals genome-wide, stable epigenetic changes and epigenetically modifiable gene networks associated with specific chromatin marks in the hippocampus, and lays a foundation to further elucidate iron-dependent epigenetic mechanisms that underlie the long-term effects of fetal-neonatal ID, choline, and their interactions.

Maternal selenium dietary supplementation alters sociability and reinforcement learning deficits induced by in utero exposure to maternal immune activation in mice

Maternal immune activation (MIA) during pregnancy increases the risk for the unborn foetus to develop neurodevelopmental conditions such as autism spectrum disorder and schizophrenia later in life. MIA mouse models recapitulate behavioural and biological phenotypes relevant to both conditions, and are valuable models to test novel treatment approaches. Selenium (Se) has potent anti-inflammatory properties suggesting it may be an effective prophylactic treatment against MIA. The aim of this study was to determine if Se supplementation during pregnancy can prevent adverse effects of MIA on offspring brain and behaviour in a mouse model. Selenium was administered via drinking water (1.5 ppm) to pregnant dams from gestational day (GD) 9 to birth, and MIA was induced at GD17 using polyinosinic:polycytidylic acid (poly-I:C, 20 mg/kg via intraperitoneal injection). Foetal placenta and brain cytokine levels were assessed using a Luminex assay and brain elemental nutrients assessed using inductively coupled plasma- mass spectrometry. Adult offspring were behaviourally assessed using a reinforcement learning paradigm, the three-chamber sociability test and the open field test. MIA elevated placental IL-1β and IL-17, and Se supplementation successfully prevented this elevation. MIA caused an increase in foetal brain calcium, which was prevented by Se supplement. MIA caused in offspring a female-specific reduction in sociability, which was recovered by Se, and a male-specific reduction in social memory, which was not recovered by Se. Exposure to poly-I:C or selenium, but not both, reduced performance in the reinforcement learning task. Computational modelling indicated that this was predominantly due to increased exploratory behaviour, rather than reduced rate of learning the location of the food reward. This study demonstrates that while Se may be beneficial in ameliorating sociability deficits caused by MIA, it may have negative effects in other behavioural domains. Caution in the use of Se supplementation during pregnancy is therefore warranted.

Identification of Immune Infiltration and Iron Metabolism-Related Subgroups in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder with a broad spectrum of symptoms and prognoses. Effective therapy requires understanding this variability. ASD children's cognitive and immunological development may depend on iron homoeostasis. This study employs a machine learning model that focuses on iron metabolism hub genes to identify ASD subgroups and describe immune infiltration patterns. A total of 97 control and 148 ASD samples were obtained from the GEO database. Differentially expressed genes (DEGs) and an iron metabolism gene collection achieved the intersection of 25 genes. Unsupervised cluster analysis determined molecular subgroups in individuals with ASD based on 25 genes related to iron metabolism. We assessed gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, gene set variation analysis (GSVA), and immune infiltration analysis to compare iron metabolism subtype effects. We employed machine learning to identify subtype-predicting hub genes and utilized both training and validation sets to assess gene subtype prediction accuracy. ASD can be classified into two iron-metabolizing molecular clusters. Metabolic enrichment pathways differed between clusters. Immune infiltration showed that clusters differed immunologically. Cluster 2 had better immunological scores and more immune cells, indicating a stronger immune response. Machine learning screening identified SELENBP1 and CAND1 as important genes in ASD's iron metabolism signaling pathway. These genes express in the brain and have AUC values over 0.8, implying significant predictive power. The present study introduces iron metabolism signaling pathway indicators to predict ASD subtypes. ASD is linked to immune cell infiltration and iron metabolism disorders.

Perinatal Exposure to Trace Elements: The Dubious Culprit of Autistic Spectrum Disorder in Children

There is evidence that few trace elements in the environment work as hazardous materials in terms of their exposure in the perinatal period, causing autistic spectrum disorder (ASD) in children, and avoiding these exposures in the environment can reduce the number of new cases. This perspective study provides preliminary evidence to consider a few trace elements as culprits for ASD. More studies with larger cohorts are needed, but meanwhile, as per available evidence, exposure to these hazardous materials must be warranted during pregnancy and early stages of life.

Prenatal iron supplementation adjusted to maternal iron stores reduces behavioural problems in 4-year-old children

Prenatal iron supplementation improves children's health and cognitive performance, but few studies explore behavioural development. This study assessed the effects of adjusting prenatal iron supplementation to maternal iron stores during early pregnancy on children's behavioural problems. Randomized controlled trial conducted in Tarragona (Spain) involving 230 nonanaemic pregnant women and their children after a 4-year follow-up. Based on haemoglobin (Hb) levels before gestational week (GW) 12, women receive different iron doses: those with Hb = 110-130 g/L were randomized to receive 80 or 40 mg/day and those with Hb > 130 g/L were randomized to receive 20 or 40 mg/day. Maternal iron stores at GW12 were classified using serum ferritin (SF) as low (SF < 15 µg/L), normal (SF = 15-65 µg/L), and normal-high (SF > 65 µg/L). Children's behaviour was assessed by parents using the Child Behaviour Checklist for ages 1.5-5 years and the Behaviour Rating Inventory of Executive Function-Preschool Version, and by teachers using the Teacher's Report Form for ages 1.5-5 years. Multivariable regression models were performed. Taking 80 mg/day of iron improved child behaviour when women had low iron stores but worsened it when mothers had normal-high iron stores, except for depressive and attention/hyperactivity problems. Taking 20 mg/day of iron improved behaviour only in those children whose mothers had SF > 65 µg/L in early pregnancy. Additionally, executive functioning improved at high doses of prenatal iron when maternal baseline SF < 15 µg/L. Adjusting prenatal iron supplementation to both maternal baseline Hb levels and iron stores reduces behavioural problems in 4-year-old children.

Maternal-placental axis and its impact on fetal outcomes, metabolism, and development

Maternal obesity could impact offspring's health. During "critical period" such as pregnancy insults have a significant role in developing chronic diseases later in life. Literature has shown that diet can play a major role in essential metabolic and development processes on fetal outcomes. Moreover, the placenta, an essential organ developed in pregnancy, seems to have its functions impaired based on pre-gestational and gestational nutritional status. Specifically, a high-fat diet has been shown as a potential nutritional insult that also affects the maternal-placental axis, which is involved in offspring development and outcome. Moreover, some classes of nutrients are associated with pregnancy complications such as reduced intake of micronutrients and diabetes, preeclampsia, and preterm delivery. Thus, we will summarize the current literature on maternal environment factors that impacts the placental development and consequently the fetal an offspring health, or the maternal-placental axis, and this on fetal outcomes, metabolism, and development.

Epigenetic modification impacting brain functions: Effects of physical activity, micronutrients, caffeine, toxins, and addictive substances

Changes in gene expression are involved in many brain functions. Epigenetic processes modulate gene expression by histone modification and DNA methylation or RNA-mediated processes, which is important for brain function. Consequently, epigenetic changes are also a part of brain diseases such as mental illness and addiction. Understanding the role of different factors on the brain epigenome may help us understand the function of the brain. This review discussed the effects of caffeine, lipids, addictive substances, physical activity, and pollutants on the epigenetic changes in the brain and their modulatory effects on brain function.

Early-life iron deficiency persistently disrupts affective behaviour in mice

BACKGROUND/OBJECTIVE

Iron deficiency (ID) is the most common nutrient deficiency, affecting two billion people worldwide, including about 30% of pregnant women. During gestation, the brain is particularly vulnerable to environmental insults, which can irrevocably impair critical developmental processes. Consequently, detrimental consequences of early-life ID for offspring brain structure and function have been described. Although early life ID has been associated with an increased long-term risk for several neuropsychiatric disorders, the effect on depressive disorders has remained unresolved.

MATERIALS AND METHODS

A mouse model of moderate foetal and neonatal ID was established by keeping pregnant dams on an iron-deficient diet throughout gestation until postnatal day 10. The ensuing significant decrease of iron content in the offspring brain, as well as the impact on maternal behaviour and offspring vocalization was determined in the first postnatal week. The consequences of early-life ID for depression- and anxiety-like behaviour in adulthood were revealed employing dedicated behavioural assays. miRNA sequencing of hippocampal tissue of offspring revealed specific miRNAs signatures accompanying the behavioural deficits of foetal and neonatal ID in the adult brain.

RESULTS

Mothers receiving iron-deficient food during pregnancy and lactation exhibited significantly less licking and grooming behaviour, while active pup retrieval and pup ultrasonic vocalizations were unaltered. Adult offspring with a history of foetal and neonatal ID showed an increase in depression- and anxiety-like behaviour, paralleled by a deranged miRNA expression profile in the hippocampus, specifically levels of miR200a and miR200b.

CONCLUSION

ID during the foetal and neonatal periods has life-long consequences for affective behaviour in mice and leaves a specific and persistent mark on the expression of miRNAs in the brain. Foetal and neonatal ID needs to be further considered as risk factor for the development of depression and anxiety disorders later in life.Key MessagesMarginal reduction of gestational alimentary iron intake decreases brain iron content of the juvenile offspring.Early-life ID is associated with increased depression- and anxiety-like behaviour in adulthood.Reduction of maternal alimentary iron intake during pregnancy is reflected in an alteration of miRNA signatures in the adult offspring brain.

Brain Iron Homeostasis and Mental Disorders

Iron plays an essential role in various physiological processes. A disruption in iron homeostasis can lead to severe consequences, including impaired neurodevelopment, neurodegenerative disorders, stroke, and cancer. Interestingly, the link between mental health disorders and iron homeostasis has not received significant attention. Therefore, our understanding of iron metabolism in the context of psychological diseases is incomplete. In this review, we aim to discuss the pathologies and potential mechanisms that relate to iron homeostasis in associated mental disorders. We propose the hypothesis that maintaining brain iron homeostasis can support neuronal physiological functions by impacting key enzymatic activities during neurotransmission, redox balance, and myelination. In conclusion, our review highlights the importance of investigating the relationship between trace element nutrition and the pathological process of mental disorders, focusing on iron. This nutritional perspective can offer valuable insights for the clinical treatment of mental disorders.

Maternal gestational iron status and infant haematological and neurodevelopmental outcomes

Prevention of iron deficiency (ID), the most common micronutrient deficiency in infants and children, begins prenatally by ensuring adequate fetal loading. Adequate intrauterine iron status is crucial for normal fetal brain development, postnatal brain performance and prevention of early postnatal iron deficiency, particularly in infants fed exclusively human milk. Adequate fetal loading may be achieved in some cases through adequate maternal iron levels prior to pregnancy and oral iron supplementation during pregnancy. However, because so many women are iron-deficient leading up to pregnancy, coupled with the negative iron balance induced by pregnancy, a large number of women remain iron-deficient during pregnancy. More consistent iron-specific early screening and more effective iron delivery approaches are needed to solve this global problem.

Gestational iron deficiency affects the ratio between interneuron subtypes in the postnatal cerebral cortex in mice

Gestational iron deficiency (gID) is highly prevalent and associated with an increased risk of intellectual and developmental disabilities in affected individuals that are often defined by a disrupted balance of excitation and inhibition (E/I) in the brain. Using a nutritional mouse model of gID, we previously demonstrated a shift in the E/I balance towards increased inhibition in the brains of gID offspring that was refractory to postnatal iron supplementation. We thus tested whether gID affects embryonic progenitor cells that are fated towards inhibitory interneurons. We quantified relevant cell populations during embryonic inhibitory neuron specification and found an increase in the proliferation of Nkx2.1+ interneuron progenitors in the embryonic medial ganglionic eminence at E14 that was associated with increased Shh signaling in gID animals at E12. When we quantified the number of mature inhibitory interneurons that are known to originate from the MGE, we found a persistent disruption of differentiated interneuron subtypes in early adulthood. Our data identify a cellular target that links gID with a disruption of cortical interneurons which play a major role in the establishment of the E/I balance.

The Interaction between Psychological Stress and Iron Status on Early-Life Neurodevelopmental Outcomes

This review presents evidence from animal and human studies demonstrating the possible connection and significant impact of poor iron status and psychological distress on neurocognitive development during pregnancy and the neonatal period, with implications for long-term cognition. Stress and iron deficiency are independently prevalent and thus are frequently comorbid. While iron deficiency and early-life stress independently contribute to long-term neurodevelopmental alterations, their combined effects remain underexplored. Psychological stress responses may engage similar pathways as infectious stress, which alters fundamental iron metabolism processes and cause functional tissue-level iron deficiency. Psychological stress, analogous to but to a lesser degree than infectious stress, activates the hypothalamic-pituitary-adrenocortical (HPA) axis and increases proinflammatory cytokines. Chronic or severe stress is associated with dysregulated HPA axis functioning and a proinflammatory state. This dysregulation may disrupt iron absorption and utilization, likely mediated by the IL-6 activation of hepcidin, a molecule that impedes iron absorption and redistributes total body iron. This narrative review highlights suggestive studies investigating the relationship between psychological stress and iron status and outlines hypothesized mechanistic pathways connecting psychological stress exposure and iron metabolism. We examine findings regarding the overlapping impacts of early stress exposure to iron deficiency and children's neurocognitive development. We propose that studying the influence of psychological stress on iron metabolism is crucial for comprehending neurocognitive development in children exposed to prenatal and early postnatal stressors and for children at risk of early iron insufficiency. We recommend future directions for dual-exposure studies exploring iron as a potential mediating pathway between early stress and offspring neurodevelopment, offering opportunities for targeted interventions.

Examining Prenatal Dietary Factors in Association with Child Autism-Related Traits Using a Bayesian Mixture Approach: Results from 2 United States Cohorts

Background

Prior work has suggested relationships between prenatal intake of certain nutrients and autism.

Objectives

We examined a broad set of prenatal nutrients and foods using a Bayesian modeling approach.

Methods

Participants were drawn from the Early Autism Risks Longitudinal Investigation (n = 127), a cohort following women with a child with autism through a subsequent pregnancy. Participants were also drawn from the Nurses' Health Study II (NHSII, n = 713), a cohort of United States female nurses, for comparison analyses. In both studies, information on prospectively reported prenatal diet was drawn from food frequency questionnaires, and child autism-related traits were measured by the Social Responsiveness Scale (SRS). Bayesian kernel machine regression was used to examine the combined effects of several nutrients with neurodevelopmental relevance, including polyunsaturated fatty acids (PUFAs), iron, zinc, vitamin D, folate, and other methyl donors, and separately, key food sources of these, in association with child SRS scores in crude and adjusted models.

Results

In adjusted analyses, the overall mixture effects of nutrients in Early Autism Risks Longitudinal Investigation and foods in both cohorts on SRS scores were not observed, though there was some suggestion of decreasing SRS scores with increasing overall nutrient mixture in NHSII. No associations were observed with folate within the context of this mixture, but holding other nutrients fixed, n-6 PUFAs were associated with lower SRS scores in NHSII. In both cohorts, lower SRS scores were observed with higher intake of some groupings of vegetables, though for differing types of vegetables across cohorts, and some vegetable groups were associated with higher SRS scores in NHSII.

Conclusions

Our work extends prior research and suggests the need to further consider prenatal dietary factors from a combined effects perspective. In addition, findings here point to potential differences in nutrient associations based on a family history of autism, which suggests the need to consider gene interactions in future work.

The importance of iron deficiency in pregnancy on fetal, neonatal, and infant neurodevelopmental outcomes

The role of iron in neurodevelopment has long been recognized, and the adverse effects of early-life iron deficiency on brain development and subsequent function across the lifespan continue to be a subject of research. A greater appreciation of the contribution of maternal preconceptional iron status and fetal iron accretion to offspring, postnatal iron status, and brain health across the lifespan has occurred over the past decade. This paradigm shift in thinking links two previously relatively siloed literatures: neonatal iron deficiency and postnatal iron deficiency. The understanding that iron accretion during the fetal period strongly influences postnatal iron balance has led to an appreciation of the importance and value of ensuring proper fetal iron loading. This article reviews the dynamics of fetal iron metabolism, the role of iron in the developing fetal brain, the short- and long-term neurobehavioral consequences of fetal iron underloading, and the potential mechanisms that account for the long-term effects of fetal/neonatal iron deficiency.

Rice biofortification: breeding and genomic approaches for genetic enhancement of grain zinc and iron contents

Rice is a highly consumed staple cereal cultivated predominantly in Asian countries, which share 90% of global rice production. Rice is a primary calorie provider for more than 3.5 billion people across the world. Preference and consumption of polished rice have increased manifold, which resulted in the loss of inherent nutrition. The prevalence of micronutrient deficiencies (Zn and Fe) are major human health challenges in the 21^st century. Biofortification of staples is a sustainable approach to alleviating malnutrition. Globally, significant progress has been made in rice for enhancing grain Zn, Fe, and protein. To date, 37 biofortified Fe, Zn, Protein and Provitamin A rich rice varieties are available for commercial cultivation (16 from India and 21 from the rest of the world; Fe > 10 mg/kg, Zn > 24 mg/kg, protein > 10% in polished rice as India target while Zn > 28 mg/kg in polished rice as international target). However, understanding the micronutrient genetics, mechanisms of uptake, translocation, and bioavailability are the prime areas that need to be strengthened. The successful development of these lines through integrated-genomic technologies can accelerate deployment and scaling in future breeding programs to address the key challenges of malnutrition and hidden hunger.

Developmental pyrethroid exposure causes a neurodevelopmental disorder phenotype in mice

Neurodevelopmental disorders (NDDs) are a widespread and growing public health challenge, affecting as many as 17% of children in the United States. Recent epidemiological studies have implicated ambient exposure to pyrethroid pesticides during pregnancy in the risk for NDDs in the unborn child. Using a litter-based, independent discovery-replication cohort design, we exposed mouse dams orally during pregnancy and lactation to the Environmental Protection Agency's reference pyrethroid, deltamethrin, at 3 mg/kg, a concentration well below the benchmark dose used for regulatory guidance. The resulting offspring were tested using behavioral and molecular methods targeting behavioral phenotypes relevant to autism and NDD, as well as changes to the striatal dopamine system. Low-dose developmental exposure to the pyrethroid deltamethrin (DPE) decreased pup vocalizations, increased repetitive behaviors, and impaired both fear conditioning and operant conditioning. Compared with control mice, DPE mice had greater total striatal dopamine, dopamine metabolites, and stimulated dopamine release, but no difference in vesicular dopamine capacity or protein markers of dopamine vesicles. Dopamine transporter protein levels were increased in DPE mice, but not temporal dopamine reuptake. Striatal medium spiny neurons showed changes in electrophysiological properties consistent with a compensatory decrease in neuronal excitability. Combined with previous findings, these results implicate DPE as a direct cause of an NDD-relevant behavioral phenotype and striatal dopamine dysfunction in mice and implicate the cytosolic compartment as the location of excess striatal dopamine.

The causal association between iron status and the risk of autism: A Mendelian randomization study

Emerging evidence indicates a connection between serum iron levels and autism, but the underlying causal association is yet unclear. Thus, we performed two-sample Mendelian randomization (MR) analysis to evaluate the causal link between iron status on autism, using genetic instruments (p < 5E-08) strongly associated with iron status (N = 48,972), including serum iron, ferritin, transferrin levels, and transferrin saturation. Summary statistics of autism was obtained from two independent studies conducted by Psychiatric Genomics Consortium (PGC, Ncases = 5,305, Ncontrols = 5,305) and FinnGen Consortium (FC, Round six, Ncases = 344, Ncontrols = 258,095), respectively. Using the inverse-variance weighted (IVW) method, the combined results of PGC and FC demonstrated that genetically determined serum transferrin level was significantly associated with an increased risk of autism [odds ratio (OR) = 1.16, 95% CI: 1.03-1.30, p = 0.013]. There was no significant causal effect of serum iron (OR = 0.99, 95% CI: 0.72-1.37, p = 0.951), ferritin (OR = 0.88, 95% CI: 0.47-1.64, p = 0.676), and transferrin saturation (OR = 0.89, 95% CI: 0.72-1.09, p = 0.252) on autism. No obvious pleiotropy was found in this MR study. Taken together, our findings highlight that elevation of serum transferrin level might be associated with a high risk of autism, suggesting a potential role of iron deficiency in autism development. Future studies are warranted to clarify the underlying mechanism, which will pave a new path for the prevention and treatment of autism.

Early life nutrition and brain development: breakthroughs, challenges and new horizons

The role of early life nutrition's impact on relevant health outcomes across the lifespan laid the foundation for the field titled the developmental origins of health and disease. Studies in this area initially concentrated on nutrition and the risk of adverse cardio-metabolic and cancer outcomes. More recently the role of nutrition in early brain development and the subsequent influence of later mental health has become more evident. Scientific breakthroughs have elucidated two mechanisms behind long-term nutrient effects on the brain, including the existence of critical periods for certain nutrients during brain development and nutrient-driven epigenetic modifications of chromatin. While multiple nutrients and nutritional conditions have the potential to modify brain development, iron can serve as a paradigm to understand both mechanisms. New horizons in nutritional medicine include leveraging the mechanistic knowledge of nutrient-brain interactions to propose novel nutritional approaches that protect the developing brain through better timing of nutrient delivery and potential reversal of negative epigenetic marks. The main challenge in the field is detecting whether a change in nutritional status truly affects the brain's development and performance in human subjects. To that end, a strong case can be made to develop and utilise bioindicators of a nutrient's effect on the developing brain instead of relying exclusively on biomarkers of the nutrient's status.

Birth related parameters are important contributors in autism spectrum disorders

Autism spectrum disorders is a group of childhood onset neurodevelopmental disorders affecting millions of children across the globe. Characterised by age inappropriate lack of reciprocal social interaction, repetitive behaviours and deficits in communication skills, it has been found to have genetic, epigenetic and environmental contributions. In this work, we wanted to identify the effects of birth related parameters on the disease pathogenesis in an exposed population of West Bengal, India. We have considered age of both parents at birth, difference in parental age, familial history of mental illness, delay in developmental-milestones, birth-weight, birth-order, birth-term, mode of delivery and gestational complications as contributors. We found the parental age and their age difference to be the most important contributors towards ASD in this population. Birth order, sex of the probands, complications during gestation, birth weight, family history of mental illness and birth history also contributed to the condition, although to a lesser extent. Since such types of data are lacking in Indian population, this report adds useful information to the relevant field.

Maternal iron status in early pregnancy and DNA methylation in offspring: an epigenome-wide meta-analysis

BACKGROUND

Unbalanced iron homeostasis in pregnancy is associated with an increased risk of adverse birth and childhood health outcomes. DNA methylation has been suggested as a potential underlying mechanism linking environmental exposures such as micronutrient status during pregnancy with offspring health. We performed a meta-analysis on the association of maternal early-pregnancy serum ferritin concentrations, as a marker of body iron stores, and cord blood DNA methylation. We included 1286 mother-newborn pairs from two population-based prospective cohorts. Serum ferritin concentrations were measured in early pregnancy. DNA methylation was measured with the Infinium HumanMethylation450 BeadChip (Illumina). We examined epigenome-wide associations of maternal early-pregnancy serum ferritin and cord blood DNA methylation using robust linear regression analyses, with adjustment for confounders and performed fixed-effects meta-analyses. We additionally examined whether associations of any CpGs identified in cord blood persisted in the peripheral blood of older children and explored associations with other markers of maternal iron status. We also examined whether similar findings were present in the association of cord blood serum ferritin concentrations with cord blood DNA methylation.

RESULTS

Maternal early-pregnancy serum ferritin concentrations were inversely associated with DNA methylation at two CpGs (cg02806645 and cg06322988) in PRR23A and one CpG (cg04468817) in PRSS22. Associations at two of these CpG sites persisted at each of the follow-up time points in childhood. Cord blood serum ferritin concentrations were not associated with cord blood DNA methylation levels at the three identified CpGs.

CONCLUSION

Maternal early-pregnancy serum ferritin concentrations were associated with lower cord blood DNA methylation levels at three CpGs and these associations partly persisted in older children. Further studies are needed to uncover the role of these CpGs in the underlying mechanisms of the associations of maternal iron status and offspring health outcomes.

Maternal levels of acute phase proteins in early pregnancy and risk of autism spectrum disorders in offspring

Previous research supports a contribution of early-life immune disturbances in the etiology of autism spectrum disorders (ASD). Biomarker studies of the maternal innate (non-adaptive) immune status related to ASD risk have focused on one of the acute phase proteins (APP), C-reactive protein (CRP), with conflicting results. We evaluated levels of eight different APP in first-trimester maternal serum samples, from 318 mothers to ASD cases and 429 mothers to ASD-unaffected controls, nested within the register-based Stockholm Youth Cohort. While no overall associations between high levels of APP and ASD were observed, associations varied across diagnostic sub-groups based on co-occurring conditions. Maternal levels of CRP in the lowest compared to the middle tertile were associated with increased risk of ASD without ID or ADHD in offspring (OR = 1.92, 95% CI 1.08-3.42). Further, levels of maternal ferritin in the lowest (OR = 1.78, 95% CI 1.18-2.69) and highest (OR = 1.64, 95% CI 1.11-2.43) tertiles were associated with increased risk of any ASD diagnosis in offspring, with stronger associations still between the lowest (OR = 3.81, 95% CI 1.91-7.58) and highest (OR = 3.36, 95% CI 1.73-6.53) tertiles of ferritin and risk of ASD with ID. The biological interpretation of lower CRP levels among mothers to ASD cases is not clear but might be related to the function of the maternal innate immune system. The finding of aberrant levels of ferritin conferring risk of ASD-phenotypes indicates a plausibly important role of iron during neurodevelopment.

Prenatal Diet as a Modifier of Environmental Risk Factors for Autism and Related Neurodevelopmental Outcomes

PURPOSE OF REVIEW

Environmental chemicals and toxins have been associated with increased risk of impaired neurodevelopment and specific conditions like autism spectrum disorder (ASD). Prenatal diet is an individually modifiable factor that may alter associations with such environmental factors. The purpose of this review is to summarize studies examining prenatal dietary factors as potential modifiers of the relationship between environmental exposures and ASD or related neurodevelopmental outcomes.

RECENT FINDINGS

Twelve studies were identified; five examined ASD diagnosis or ASD-related traits as the outcome (age at assessment range: 2-5 years) while the remainder addressed associations with neurodevelopmental scores (age at assessment range: 6 months to 6 years). Most studies focused on folic acid, prenatal vitamins, or omega-3 fatty acids as potentially beneficial effect modifiers. Environmental risk factors examined included air pollutants, endocrine disrupting chemicals, pesticides, and heavy metals. Most studies took place in North America. In 10/12 studies, the prenatal dietary factor under study was identified as a significant modifier, generally attenuating the association between the environmental exposure and ASD or neurodevelopment. Prenatal diet may be a promising target to mitigate adverse effects of environmental exposures on neurodevelopmental outcomes. Further research focused on joint effects is needed that encompasses a broader variety of dietary factors, guided by our understanding of mechanisms linking environmental exposures with neurodevelopment. Future studies should also aim to include diverse populations, utilize advanced methods to optimize detection of novel joint effects, incorporate consideration of timing, and consider both synergistic and antagonistic potential of diet.

Non-parental caregivers, low maternal education, gastrointestinal problems and high blood lead level: predictors related to the severity of autism spectrum disorder in Northeast China

Background

The prevalence of autism spectrum disorder (ASD) has increased rapidly in recent years. Environmental factors may play an important role in the pathogenesis of ASD. These factors may include socioeconomic factors, nutritional factors, heavy metal exposure, air pollution, etc. Our aim is to analyze possible environmental factors associated with the severity of ASD.

Methods

All participating children were divided into two groups (mild and moderate/severe) according to the severity of their symptoms, as determined by their Childhood Autism Rating Scale (CARS) scores. The socioeconomic, demographic factors and the nutritional factors that may affect the severity of ASD were included in the logistic regression to analyze whether they were predictors that affected the severity of ASD.

Results

Logistic regression showed that caregivers(P = 0.042), maternal education (P = 0.030), gastrointestinal problems (P = 0.041) and a high serum concentration of lead (P = 0.003) were statistically significantly associated with ASD severity.

Conclusion

Many environmental factors affect the severity of ASD. We concluded that non-parental caregivers, low maternal education, gastrointestinal problems and high blood lead level maybe predictors that affected the severity of ASD in northeast China.

Nutrition and Brain Development

All nutrients are essential for brain development, but pre-clinical and clinical studies have revealed sensitive periods of brain development during which key nutrients are critical. An understanding of these nutrient-specific sensitive periods and the accompanying brain regions or processes that are developing can guide effective nutrition interventions as well as the choice of meaningful circuit-specific neurobehavioral tests to best determine outcome. For several nutrients including protein, iron, iodine, and choline, pre-clinical and clinical studies align to identify the same sensitive periods, while for other nutrients, such as long-chain polyunsaturated fatty acids, zinc, and vitamin D, pre-clinical models demonstrate benefit which is not consistently shown in clinical studies. This discordance of pre-clinical and clinical results is potentially due to key differences in the timing, dose, and/or duration of the nutritional intervention as well as the pre-existing nutritional status of the target population. In general, however, the optimal window of success for nutritional intervention to best support brain development is in late fetal and early postnatal life. Lack of essential nutrients during these times can lead to long-lasting dysfunction and significant loss of developmental potential.

Developmental Iron Deficiency Dysregulates TET Activity and DNA Hydroxymethylation in the Rat Hippocampus and Cerebellum

Iron deficiency (ID) during neurodevelopment is associated with lasting cognitive and socioemotional deficits and increased risk for neuropsychiatric disease throughout the lifespan. These neurophenotypical changes are underlain by gene dysregulation in the brain that outlasts the period of ID; however, the mechanisms by which ID establishes and maintains gene expression changes are incompletely understood. The epigenetic modification of 5-hydroxymethylcytosine (5hmC), or DNA hydroxymethylation, is one candidate mechanism because of its dependence on iron-containing TET enzymes. The aim of the present study was to determine the effect of fetal-neonatal ID on regional brain TET activity, Tet expression, and 5hmC in the developing rat hippocampus and cerebellum and to determine whether changes are reversible with dietary iron treatment. Timed pregnant Sprague Dawley rats were fed iron-deficient diet (ID; 4 mg/kg Fe) from gestational day 2 to generate iron-deficient anemic (IDA) offspring. Control dams were fed iron-sufficient diet (IS; 200 mg/kg Fe). At postnatal day (P)7, a subset of ID-fed litters was randomized to IS diet, generating treated IDA (TIDA) offspring. At P15, the hippocampus and cerebellum were isolated for subsequent analysis. TET activity was quantified by ELISA from nuclear proteins. Expression of Tet1, Tet2, and Tet3 was quantified by qPCR from total RNA. Global %5hmC was quantified by ELISA from genomic DNA. ID increased DNA hydroxymethylation (p = 0.0105), with a corresponding increase in TET activity (p < 0.0001) and Tet3 expression (p < 0.0001) in the P15 hippocampus. In contrast, ID reduced TET activity (p = 0.0016) in the P15 cerebellum, with minimal effect on DNA hydroxymethylation. Neonatal dietary iron treatment resulted in partial normalization of these changes in both brain regions. These results demonstrate that the TET/DNA hydroxymethylation system is disrupted by developmental ID in a brain region-specific manner. Differential regional disruption of this epigenetic system may contribute to the lasting neural circuit dysfunction and neurobehavioral dysfunction associated with developmental ID.

Prenatal Iron Deficiency and Choline Supplementation Interact to Epigenetically Regulate Jarid1b and Bdnf in the Rat Hippocampus into Adulthood

Early-life iron deficiency (ID) causes long-term neurocognitive impairments and gene dysregulation that can be partially mitigated by prenatal choline supplementation. The long-term gene dysregulation is hypothesized to underlie cognitive dysfunction. However, mechanisms by which iron and choline mediate long-term gene dysregulation remain unknown. In the present study, using a well-established rat model of fetal-neonatal ID, we demonstrated that ID downregulated hippocampal expression of the gene encoding JmjC-ARID domain-containing protein 1B (JARID1B), an iron-dependent histone H3K4 demethylase, associated with a higher histone deacetylase 1 (HDAC1) enrichment and a lower enrichment of acetylated histone H3K9 (H3K9ac) and phosphorylated cAMP response element-binding protein (pCREB). Likewise, ID reduced transcriptional capacity of the gene encoding brain-derived neurotrophic factor (BDNF), a target of JARID1B, associated with repressive histone modifications such as lower H3K9ac and pCREB enrichments at the Bdnf promoters in the adult rat hippocampus. Prenatal choline supplementation did not prevent the ID-induced chromatin modifications at these loci but induced long-lasting repressive chromatin modifications in the iron-sufficient adult rats. Collectively, these findings demonstrated that the iron-dependent epigenetic mechanism mediated by JARID1B accounted for long-term Bdnf dysregulation by early-life ID. Choline supplementation utilized a separate mechanism to rescue the effect of ID on neural gene regulation. The negative epigenetic effects of choline supplementation in the iron-sufficient rat hippocampus necessitate additional investigations prior to its use as an adjunctive therapeutic agent.

Early-Life Iron Deficiency Anemia Programs the Hippocampal Epigenomic Landscape

Iron deficiency (ID) anemia is the foremost micronutrient deficiency worldwide, affecting around 40% of pregnant women and young children. ID during the prenatal and early postnatal periods has a pronounced effect on neurodevelopment, resulting in long-term effects such as cognitive impairment and increased risk for neuropsychiatric disorders. Treatment of ID has been complicated as it does not always resolve the long-lasting neurodevelopmental deficits. In animal models, developmental ID results in abnormal hippocampal structure and function associated with dysregulation of genes involved in neurotransmission and synaptic plasticity. Dysregulation of these genes is a likely proximate cause of the life-long deficits that follow developmental ID. However, a direct functional link between iron and gene dysregulation has yet to be elucidated. Iron-dependent epigenetic modifications are one mechanism by which ID could alter gene expression across the lifespan. The jumonji and AT-rich interaction domain-containing (JARID) protein and the Ten-Eleven Translocation (TET) proteins are two families of iron-dependent epigenetic modifiers that play critical roles during neural development by establishing proper gene regulation during critical periods of brain development. Therefore, JARIDs and TETs can contribute to the iron-mediated epigenetic mechanisms by which early-life ID directly causes stable changes in gene regulation across the life span.

Knowledge of childhood autism among nurses working in governmental hospitals of Addis Ababa, Ethiopia

INTRODUCTION

Autism is a neurodevelopmental disorder that occurs in the early childhood period and is characterized by altered social interaction, communication problems, repetitive, and stereotyped behavior. Genetic, environmental, or physical risk factors are associated with prenatal, natal, or postnatal complications, leading to the development of autism spectrum disorders. Prompt diagnosis and management should be an integral component of the care provision in countries like Ethiopia.

OBJECTIVE

This study aimed to assess knowledge of childhood autism among nurses working in governmental hospitals in Addis Ababa, Ethiopia.

METHODS

Institutional based cross-sectional study design was used. The sample size was calculated using the single population proportion formula, and the final sample size was 360. Final study subjects were selected by using the simple random sampling method. Data were collected using structured self-administered questionnaires and were then coded and entered into Epi-data version 3.1 and exported to SPSS version 21 for analysis. Descriptive statistics were utilized to show frequencies and percentages, and analysis of variance was carried out to compute the association between the dependent and independent variables. Independent t-test was also done to see the association between dependent variables and independent variables with two means. A p-value of less than 0.05 was considered statistically significant.

RESULTS

The mean score for knowledge-related items was 8.79 ± 0.4. In this study, out of 331 nurses, 180 (54.35%) had good knowledge. Significant mean score difference was observed among age distribution (F-Ratio = 2.8, p-value = 0.04), level of education (F-ratio = 13.97, p < 0.001) and work experience (F-Ratio = 3.07 p-value = 0.017).

CONCLUSION

A significant gap was observed in the overall knowledge of childhood autism among nurses employed in the governmental hospitals of Addis Ababa. The respondents' knowledge level was significantly different among age group distributions, education levels, and work experience.

Autism spectrum disorder: Trace elements imbalances and the pathogenesis and severity of autistic symptoms

The identification of biomarkers as diagnostic tools and predictors of response to treatment of neurological developmental disorders (NDD) such as schizophrenia (SZ), attention deficit hyperactivity disorder (ADHD), or autism spectrum disorder (ASD), still remains an important challenge for clinical medicine. Metallomic profiles of ASD patients cover, besides essential elements such as cobalt, chromium, copper, iron, manganese, molybdenum, zinc, selenium, also toxic metals burden of: aluminum, arsenic, mercury, lead, beryllium, nickel, cadmium. Performed studies indicate that children with ASD present a reduced ability of eliminating toxic metals, which leads to these metals' accumulation and aggravation of autistic symptoms. Extensive metallomic studies allow a better understanding of the importance of trace elements as environmental factors in the pathogenesis of ASD. Even though a mineral imbalance is a fact in ASD, we are still expecting relevant tests and the elaboration of reference levels of trace elements as potential biomarkers useful in diagnosis, prevention, and treatment of ASD.

Liposomal ferric pyrophosphate and ascorbic acid supplementation in pregnant women with iron deficiency anaemia: haematochemical, obstetric, neonatal and psychological outcomes in a prospective observational study

This study aimed to determine the effects of liposomal iron pyrophosphate/ascorbic acid on clinical and psychological outcomes in pregnant women. Women at the 11th-13th weeks of gestation with iron deficiency anaemia assuming Sideremil™ from April 2018 to May 2019 were recruited. Haematochemical, obstetric, neonatal and psychological outcomes were investigated at the enrolment, 21-23 weeks of gestation, 30-32 weeks of gestation and after 6 weeks from childbirth. Results showed significant positive effects on haemoglobin, ferritin, sideremia and transferrin levels, compared to baseline data. A significant improvement of anxiety and depression levels was also observed. Regarding the quality of life, all the domains significantly improved, especially the Physical Role domain. Our results indicate that Sideremil^™ may be a valid treatment for iron deficiency anaemia in pregnant women, since it significantly improves haematological and mental health outcomes. However, further studies are needed to confirm these results.

Evidence-Based Recommendations for an Optimal Prenatal Supplement for Women in the U.S., Part Two: Minerals

The levels of many essential minerals decrease during pregnancy if un-supplemented, including calcium, iron, magnesium, selenium, zinc, and possibly chromium and iodine. Sub-optimal intake of minerals from preconception through pregnancy increases the risk of many pregnancy complications and infant health problems. In the U.S., dietary intake of minerals is often below the Recommended Dietary Allowance (RDA), especially for iodine and magnesium, and 28% of women develop iron deficiency anemia during their third trimester. The goal of this paper is to propose evidence-based recommendations for the optimal level of prenatal supplementation for each mineral for most women in the United States. Overall, the evidence suggests that optimal mineral supplementation can significantly reduce a wide range of pregnancy complications (including anemia, gestational hypertension, gestational diabetes, hyperthyroidism, miscarriage, and pre-eclampsia) and infant health problems (including anemia, asthma/wheeze, autism, cerebral palsy, hypothyroidism, intellectual disability, low birth weight, neural tube defects, preterm birth, rickets, and wheeze). An evaluation of 180 commercial prenatal supplements found that they varied widely in mineral content, often contained only a subset of essential minerals, and the levels were often below our recommendations. Therefore, there is a need to establish recommendations on the optimal level of mineral supplementation during pregnancy.

Iron, iodine and vitamin D deficiencies during pregnancy: epidemiology, risk factors and developmental impacts

Micronutrient deficiency persists throughout the world, and although the burden is higher in low-resource settings, it is also prevalent in wealthy countries, a phenomenon termed 'hidden hunger'. Due to their high requirements for vitamins and minerals relative to their energy intake, young women and children are particularly vulnerable to hidden hunger. As they share several risk factors and impact on overlapping outcomes, we consider how deficiency of iron, iodine and vitamin D can have profound impacts on perinatal health and infant development. We review the epidemiology of these micronutrient deficiencies during pregnancy, including social, environmental and dietary risk factors. We identify the main challenges in defining nutritional status of these nutrients using validated diagnostic criteria linked with meaningful clinical outcomes. Public health strategies are urgently required to improve the overall health and nutritional status of women of reproductive age. Obesity prevention and early detection of malnutrition with standardised screening methods would detect pregnant women at increased risk of iron deficiency. Development of sensitive, individual biomarkers of iodine status is required to protect maternal health and fetal/infant brain development. Risk assessments of vitamin D requirements during pregnancy need to be revisited from the perspective of fetal and neonatal requirements. International consensus on standardised approaches to micronutrient assessment, analysis and reporting as well as sensitive, clinically validated infant and child neuro-behavioural outcomes will enable progression of useful observational and intervention studies.

Expression analysis of selected genes involved in tryptophan metabolic pathways in Egyptian children with Autism Spectrum Disorder and learning disabilities

Autism Spectrum Disorder (ASD) and learning disabilities are neurodevelopmental disabilities characterized by dramatically increasing incidence rates, yet the exact etiology for these disabilities is not identified. Impairment in tryptophan metabolism has been suggested to participate in the pathogenesis of ASD, however, further validation of its involvement is required. Additionally, its role in learning disabilities is still uninvestigated. Our objective was to evaluate some aspects of tryptophan metabolism in ASD children (N = 45) compared to children with learning disabilities (N = 44) and healthy controls (N = 40) by measuring the expression levels of the MAOA, HAAO and AADAT genes using real-time RT-qPCR. We also aimed to correlate the expression patterns of these genes with parental ages at the time of childbirth, levels of serum iron, and vitamin D3 and zinc/copper ratio, as possible risk factors for ASD. Results demonstrated a significant decrease in the expression of the selected genes within ASD children (p < 0.001) relative to children with learning disabilities and healthy controls, which significantly associated with the levels of our targeted risk factors (p < 0.05) and negatively correlated to ASD scoring (p < 0.001). In conclusion, this study suggests that the expression of the MAOA, HAAO and AADAT genes may underpin the pathophysiology of ASD.