Gestational iron deficiency differentially alters the structure and function of white and gray matter brain regions of developing rats

Supplemental Iron and Recombinant Erythropoietin for Anemia in Infants Born Very Preterm: A Survey of Clinical Practice in Europe

OBJECTIVES

To survey practices of iron and recombinant human erythropoietin (rhEpo) administration to infants born preterm across Europe.

STUDY DESIGN

Over a 3-month period, we conducted an online survey in 597 neonatal intensive care units (NICUs) of 18 European countries treating infants born with a gestational age of <32 weeks.

RESULTS

We included 343 NICUs (response rate 56.3%) in the survey. Almost all NICUs (97.7%) routinely supplement enteral iron, and 74.3% of respondents to all infants born <32 weeks of gestation. We found that 65.3% of NICUs routinely evaluate erythropoiesis and iron parameters beyond day 28 after birth. Most NICUs initiate iron supplementation at postnatal age of 2 weeks and stop after 6 months (34.3%) or 12 months (34.3%). Routine use of rhEpo was reported in 22.2% of NICUs, and in individual cases in 6.9%. RhEpo was mostly administered subcutaneously (70.1%) and most frequently at a dose of 250 U/kg 3 times a week (44.3%), but the dose varied greatly between centers.

CONCLUSIONS

This survey highlights wide heterogeneity in evaluating erythropoietic activity and iron deficiency in infants born preterm. Variation in iron supplementation during infancy likely reflects an inadequate evidence base. Current evidence on the efficacy and safety profile of rhEpo is only poorly translated into clinical practice. This survey demonstrates a need for standards to optimize patient blood management in anemia of prematurity.

Neurovascular unit impairment in iron deficiency anemia

Iron is one of the crucial elements for CNS development and function and its deficiency (ID) is the most common worldwide nutrient deficit in the world. Iron deficiency anemia (IDA) in pregnant women and infants is a worldwide health problem due to its high prevalence and its irreversible long-lasting effects on brain development. Even with iron supplementation, IDA during pregnancy and/or breastfeeding can result in irreversible cognitive, motor, and behavioral impairments. The neurovascular unit (NVU) plays an important role in iron transport within the CNS as well as in the blood brain-barrier (BBB) formation and maturation, vasculogenesis/angiogenesis, neurovascular coupling and metabolic waste clearance. In animal models of IDA, significant changes have been observed at the capillary level, including alterations in iron transport, vasculogenesis, astrocyte endfeet, and pericytes. Despite these findings, the role of the NVU in IDA remains poorly understood. This review summarizes the potential effects of ID/IDA on brain development, myelination and neuronal function and discusses the role of NVU cells in iron metabolism, BBB, vasculogenesis/angiogenesis, neurovascular coupling and metabolic waste clearance. Furthermore, it emphasizes the need to view the NVU as a whole and as a potential target for ID/IDA. However, it remains unclear to what extent NVU alterations contribute to neuronal dysfunction, myelination abnormalities, and synaptic disturbances described in IDA.

Potential Micronutrient Deficiencies in the First 1000 Days of Life: The Pediatrician on the Side of the Weakest

PURPOSE OF REVIEW

This study is to examine potential micronutrient deficiencies and any need for supplementation in children following specific diet plans in the first 1000 days of life.

RECENT FINDINGS

Optimal nutrition in the first 1000 days of life has a lifelong positive impact on child development. Specific intrauterine and perinatal factors, pathological conditions, and dietary restrictions can represent potential risk factors for micronutrient deficiencies in the first 1000 days of life, which can have negative systemic consequences. Preterm and low-birth-weight infants are intrinsically at risk because of immature body systems. Children affected by cystic fibrosis are prone to malnutrition because of intestinal malabsorption. The risk of micronutrient deficiency can increase in various situations, including but not limited to children following selective dietary regimens (vegetarian and vegan diets and children affected by specific neuropsychiatric conditions) or specific dietary therapies (children affected by food allergies or specific metabolic disorders and children following restricted diet as a part of therapeutic approach, i.e., ketogenic diet for epilepsy). In light of this situation, the micronutrient status in these categories of children should be investigated in order to tailor strategies specific to the individual's metabolic needs, with a particular focus on deficiencies which can impair or delay the physical and cognitive development of children, namely, vitamin B12, vitamin D and folic acid, as well as oligo-elements such as iron, zinc, calcium, sodium, magnesium, and phosphorus, and essential fatty acids such as omega-3. Identification of micronutrient deficiency in the first 1000 days of life and timely supplementation proves essential to prevent their long-term consequences.

Brain iron acquisition depends on age and sex in iron-deficient mice

Adequate and timely delivery of iron is essential for brain development. The uptake of transferrin-bound (Tf) iron into the brain peaks at the time of myelination, whereas the recently discovered H-ferritin (FTH1) transport of iron into the brain continues to increase beyond the peak in myelination. Here, we interrogate the impact of dietary iron deficiency (ID) on the uptake of FTH1- and Tf-bound iron. In the present study, we used C57BL/6J male and female mice at a developing (post-natal day (PND) 15) and adult age (PND 85). In developing mice, ID results in increased iron delivery from both FTH1 and Tf for both males and females. The amount of iron uptake from FTH1 was higher than the Tf and this difference between the iron delivery was much greater in females. In contrast, in the adult model, ID was associated with increased brain iron uptake by both FTH1 and Tf but only in the males. There was no increased uptake from either protein in the females. Moreover, transferrin receptor expression on the microvasculature as well as whole brain iron, and H and L ferritin levels revealed the male brains became iron deficient but not the female brains. Last, under normal dietary conditions, 55 Fe uptake was higher in the developing group from both delivery proteins than in the adult group. These results indicate that there are differences in iron acquisition between the developing and adult brain for FTH1 and Tf during nutritional ID and demonstrate a level of regulation of brain iron uptake that is age and sex-dependent.

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.

Importance of Maternal Iron Status on the Improvement of Cognitive Function in Children After Prenatal Iron Supplementation

INTRODUCTION

The effectiveness of prenatal iron supplementation improves maternal hematological outcomes, but little research has focused on child outcomes. The objective of this study was to assess whether prenatal iron supplementation adjusted to maternal needs improves children's cognitive functioning.

METHODS

The analyses included a subsample of nonanemic pregnant women recruited in early pregnancy and their children aged 4 years (n=295). Data were collected between 2013 and 2017 in Tarragona (Spain). On the basis of hemoglobin levels before the 12th gestational week, women receive different iron doses: 80 vs 40 mg/d if hemoglobin is 110-130 g/L and 20 vs 40 mg/d if hemoglobin >130 g/L. Children's cognitive functioning was assessed using the Wechsler Preschool and Primary Scale of Intelligence-IV and Developmental Neuropsychological Assessment-II tests. The analyses were carried out in 2022 after the completion of the study. Multivariate regression models were performed for assessing the association between different doses of prenatal iron supplementation and children's cognitive functioning.

RESULTS

Taking 80 mg/d of iron was positively associated with all the scales of the Wechsler Preschool and Primary Scale of Intelligence-IV and Neuropsychological Assessment-II when mothers had initial serum ferritin <15 µg/L, but it was negatively associated with Verbal Comprehension Index, Working Memory Index, Processing Speed Index, and Vocabulary Acquisition Index from Wechsler Preschool and Primary Scale of Intelligence-IV and verbal fluency index from Neuropsychological Assessment-II when mothers showed initial serum ferritin >65 µg/L. In the other group, taking 20 mg/d of iron was positively associated with Working Memory Index, Intelligence Quotient, verbal fluency, and emotion recognition indices when women had initial serum ferritin >65 µg/L.

CONCLUSIONS

Prenatal iron supplementation adjusted to the maternal hemoglobin levels and baseline iron stores improves cognitive functioning in children aged 4 years.

Brain Iron Metabolism, Redox Balance and Neurological Diseases

The incidence of neurological diseases, such as Parkinson's disease, Alzheimer's disease and stroke, is increasing. An increasing number of studies have correlated these diseases with brain iron overload and the resulting oxidative damage. Brain iron deficiency has also been closely linked to neurodevelopment. These neurological disorders seriously affect the physical and mental health of patients and bring heavy economic burdens to families and society. Therefore, it is important to maintain brain iron homeostasis and to understand the mechanism of brain iron disorders affecting reactive oxygen species (ROS) balance, resulting in neural damage, cell death and, ultimately, leading to the development of disease. Evidence has shown that many therapies targeting brain iron and ROS imbalances have good preventive and therapeutic effects on neurological diseases. This review highlights the molecular mechanisms, pathogenesis and treatment strategies of brain iron metabolism disorders in neurological diseases.

Gestational iron supplementation reverses depressive-like behavior in post-partum Sprague Dawley rats: Evidence from behavioral and neurohistological studies

Background

Postpartum depression is a mood disorder that affects about 9–20% of women after child birth. Reports suggest that gestational iron deficiency can cause a deficit in behavioral, cognitive and affective functions and can precipitate depressive symptoms in mothers during the postpartum period. The present study examined the effect of iron supplementation on depressive behavior during postpartum period in a rat model.

Method

Female Sprague-Dawley rats were crossed. Pregnant rats received iron, fluoxetine, desferrioxamine or vehicle throughout the period of gestation. During the postpartum period, mothers from all groups were taken through the open field test (OFT), forced swim test (FST), novelty-induced hypophagia (NIH) and sacrificed for histological examination of the brains.

Results

Results showed that rats treated with iron-chelating agent, desferrioxamine, and vehicle during gestation exhibited increased immobility scores in the FST, increased latency to feed and reduced feeding in the NIH with corresponding decreased number of neurons and dendritic branches in the cortex of the brain. These depression-related effects were attenuated by perinatal iron supplementation which showed decreased immobility scores in the FST comparable to rats treated with fluoxetine, a clinically effective antidepressant. Iron treatment also decreased latency to feeding while increasing feeding behavior in the NIH. Iron-treated dams had a higher number of neurons with dendritic connections in the frontal cortex compared to vehicle- and desferrioxamine-treated groups.

Conclusion

The results suggest that, iron supplementation during gestation exerts an antidepressant-like effect in postpartum Sprague-Dawley rats, attenuates neuronal loss associated with depression and increases dendritic spine density.

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Iron supplementation during gestation exerts an antidepressant-like effect in postpartum Sprague-Dawley rats.

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Iron supplementation during gestation attenuates neuronal loss associated with depression.

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Iron-treated dams had a higher number of neurons with dendritic connections in the frontal cortex.

Effects of Daily Iron Supplementation on Motor Development and Brain Connectivity in Preterm Infants: A Diffusion Magnetic Resonance Study

Objectives: The aim of the study is to demonstrate the characteristic of motor development and MRI changes of related brain regions in preterm infants with different iron statuses and to determine whether the daily iron supplementation can promote motor development for preterm in early infancy. Methods: The 63 preterm infants were grouped into non-anemia with higher serum ferritin (NA-HF) group and anemia with lower serum ferritin (A-LF) group according to their lowest serum Hb level in the neonatal period as well as the sFer at 3 months old. Forty-nine participants underwent MRI scans and Infant Neurological International Battery (INFANIB) at their 3 months. At 6 months of corrected age, these infants received the assessment of Peabody Developmental Motor Scales (PDMS) after 2 mg/kg/day iron supplementation. Results: In total, 19 preterm infants were assigned to the NA-HF group while 44 preterm infants to the A-LF groups. The serum ferritin (sFer) level of the infants in A-LF group was lower than that in NA-HF group (44.0 ± 2.8 mg/L vs. 65.1 ± 2.8 mg/L, p < 0.05) and was with poorer scores of INFANIB (66.8 ± 0.9 vs. 64.4 ± 0.6, p < 0.05) at 3 months old. The structural connectivity between cerebellum and ipsilateral thalamus in the NA-HF group was significantly stronger than that in the A-LF group (n = 17, 109.76 ± 23.8 vs. n = 32, 70.4 ± 6.6, p < 0.05). The decreased brain structural connectivity was positively associated with the scores of PDMS (r = 0.347, p < 0.05). After 6 months of routine iron supplementation, no difference in Hb, MCV, MCHC, RDW, and sFer was detected between A-LF and NA-HF groups as well as the motor scores of PDMS-2 assessments. Conclusion: Iron status at early postnatal period of preterm infant is related to motor development and the enrichment of brain structural connectivity. The decrease in brain structural connectivity is related to the motor delay. After supplying 2 mg/kg of iron per day for 6 months, the differences in the iron status and motor ability between the A-LF and NA-HF groups were eliminated.

Association of Iron-Deficiency Anemia and Non-Iron-Deficiency Anemia with Neurobehavioral Development in Children Aged 6-24 Months

(1) Background: Anemia has comprehensive adverse effects on the growth and development of children. In this study, we analyzed the potential effects of different types of anemia on early-life neurobehavioral development. (2) Methods: A total of 2601 children aged 6-24 months, whose parents agreed to participate in this study, underwent routine blood tests and neurobehavioral development assessment. The children's parents or other primary caregivers were interviewed with a face-to-face questionnaire at the time of enrollment in the study. Anemia was determined by hemoglobin < 110 g/L and classified into iron-deficiency and non-iron-deficiency anemia according to the levels of serum ferritin, C-reactive protein, and alpha-1-acid glycoprotein. Neurobehavioral development was assessed by the China Developmental Scale for Children and divided into five domains: gross motor, fine movement, adaptability, language, and social behavior. The development quotient (DQ) was used to measure the level of total neurobehavioral development and each domain of neurobehavioral development. (3) Results: The prevalence of anemia in children aged 6-24 months was 26.45%, of which iron-deficiency anemia only accounted for 27.33%. Compared with children without anemia, those with iron-deficiency anemia had a significantly lower developmental quotient (DQ) for total neurobehavioral development and gross motor and adaptability development. The partial regression coefficients were -1.33 (95% CI -2.36, -0.29; p = 0.012), -1.88 (95% CI -3.74, -0.03; p = 0.047), and 1.48 (95% CI -2.92, -0.05; p = 0.042), respectively. Children with non-iron-deficiency anemia had significantly lower DQ for total neurobehavioral development and gross motor and fine movement development than those without anemia. The partial regression coefficients were -0.94 (95% CI -1.64, -0.25; p = 0.008), -1.25 (95% CI -2.48, -0.03; p = 0.044), and -1.18 (95% CI -2.15, -0.21; p = 0.017), respectively. There were no statistically significant differences in total neurobehavioral development and the five domains of neurobehavioral development between children with non-iron-deficiency and iron-deficiency anemia. The partial β values were 0.40 (95% CI -1.53, 2.33; p = 0.684), 0.21 (95% CI -1.39, 1.81; p = 0.795), 0.63 (95% CI -1.03, 2.28; p = 0.457), 0.16 (95% CI -1.78, 2.10; p = 0.871), 0.35 (95% CI -1.32, 2.01; p = 0.684), and 0.34 (95% CI -0.77, 1.46; p = 0.545), respectively. (4) Conclusions: Both iron-deficiency anemia and non-iron-deficiency anemia were negatively correlated with the neurobehavioral development of children. Negative correlations were found between iron-deficiency anemia and gross motor and adaptability development and between non-iron-deficiency anemia and gross motor and fine movement development.

Iron Deficiency and Iron Excess Differently Affect Dendritic Architecture of Pyramidal Neurons in the Hippocampus of Piglets

BACKGROUND

Both iron deficiency and overload may adversely affect neurodevelopment.

OBJECTIVES

The study assessed how changes in early-life iron status affect iron homeostasis and cytoarchitecture of hippocampal neurons in a piglet model.

METHODS

On postnatal day (PD) 1, 30 Hampshire × Yorkshire crossbreed piglets (n = 15/sex) were stratified by sex and litter and randomly assigned to experimental groups receiving low (L-Fe), adequate (A-Fe), or high (H-Fe) levels of iron supplement during the pre- (PD1-21) and postweaning periods (PD22-35). Pigs in the L-Fe, A-Fe, and H-Fe groups orally received 0, 1, and 30 mg Fe · kg weight-1 · d-1 preweaning and were fed a diet containing 30, 125, and 1000 mg Fe/kg postweaning, respectively. Heme indexes were analyzed weekly, and gene and protein expressions of iron regulatory proteins in duodenal mucosa, liver, and hippocampus were analyzed through qRT-PCR and western blot, respectively, on PD35. Hippocampal neurons stained using the Golgi-Cox method were traced and their dendritic arbors reconstructed in 3-D using Neurolucida. Dendritic complexity was quantified using Sholl and branch order analyses.

RESULTS

Pigs in the L-Fe group developed iron deficiency anemia (hemoglobin = 8.2 g/dL, hematocrit = 20.1%) on PD35 and became stunted during week 5 with lower final body weight than H-Fe group pigs (6.6 compared with 9.6 kg, P < 0.05). In comparison with A-Fe, H-Fe increased hippocampal ferritin expression by 38% and L-Fe decreased its expression by 52% (P < 0.05), suggesting altered hippocampal iron stores. Pigs in the H-Fe group had greater dendritic complexity in CA1/3 pyramidal neurons than L-Fe group pigs as shown by more dendritic intersections with Sholl rings (P ≤ 0.04) and a greater number of dendrites (P ≤ 0.016).

CONCLUSIONS

In piglets, the developing hippocampus is susceptible to perturbations by dietary iron, with deficiency and overload differentially affecting dendritic arborization.

Minerals in Pregnancy and Their Impact on Child Growth and Development

During pregnancy, women undergo metabolic and physiological changes, and their needs are higher, to maintain growth and development of the fetus. If the nutritional status of the expectant mother is not satisfactory, some maternal and neonatal complications can occur. In the second and third trimester of pregnancy, there is a reserve of nutrients in the fetus that can be utilized after birth; thereby, children present an accelerated growth in the first years of life, which is a proven response to the available nutrition pattern. However, if such a pattern is insufficient, there will be deficits during development, including brain function. Therefore, despite many recent published works about gestational nutrition, uncertainties still remain on the mechanisms of absorption, distribution, and excretion of micronutrients. Further elucidation is needed to better understand the impacts caused either by deficiency or excess of some micronutrients. Thus, to illustrate the contributions of minerals during prenatal development and in children, iodine, selenium, iron, zinc, calcium, and magnesium were selected. Our study sought to review the consequences related to gestational deficiency of the referred minerals and their impact on growth and development in children born from mothers with such deficiencies

Intravenous iron isomaltoside versus oral iron supplementation for treatment of iron deficiency in pregnancy: protocol for a randomised, comparative, open-label trial

BACKGROUND

Iron deficiency is common in pregnancy. If left untreated, iron deficiency can lead to iron deficiency anaemia, which is a condition related to maternal and neonatal morbidity. The prevalence of iron deficiency increases through the trimesters, which means that women with iron deficiency in the beginning of pregnancy also have a great risk of developing iron deficiency anaemia during pregnancy. Standard treatment is oral iron in individualised intensified doses based on screening values in 1st trimester. Maternal symptoms of iron deficiency and iron deficiency anaemia include fatigue, reduced physical performance, and restless legs syndrome (RLS). Severe anaemia may cause dizziness, dyspnea, palpitation, orthostatism, and syncope, and it decreases the woman's ability to cope with blood loss during delivery. The anaemia may also compromise contractility in the uterine musculature increasing the risk for prolonged labour, caesarean section, and postpartum haemorrhage. Foetal iron deficiency may cause low birthweight and adversely affect foetal and early childhood brain development with long-term deficits.

METHODS

In this randomised comparative, open-label, single-centre, phase IV trial, 200 pregnant women between 14 and 21 weeks of gestation who have iron deficiency after 4 weeks of standard treatment will be randomised 1:1 to either a single 1000 mg dose of intravenously administered ferric derisomaltose/iron isomaltoside 1000 or a fixed dose of 100 mg oral ferrous fumarate containing 60 mg ascorbic acid. The primary endpoint is to prevent iron deficiency anaemia defined by a low level of haemoglobin throughout the trial. Other endpoints include other haematological indices of iron deficiency and anaemia, clinical outcomes by questionnaires, and collection of adverse events. Explorative endpoints by medical record follow-up include complications up to 7 days after delivery.

DISCUSSION

This trial will provide evidence on how to prevent iron deficiency anaemia. The trial population represents a clinical reality where pregnant women often have sustained iron deficiency despite an increased oral iron dose. Thus, this evidence can be used to consider the optimal 2nd line of treatment in iron-deficient pregnant women.

TRIAL REGISTRATION

European Union Drug Regulating Authorities Clinical Trials Database 2017-000776-29. Registered on 3 May 2017. ClinicalTrials.gov NCT03188445 . Registered on 15 June 2017.

Nutrition and growth in children

The well-balanced nourishment during "the first 1000 days," the period between conception (day 18) and the age of two years, is quite important for two main reasons. Firstly, the nutritive requirement is high due to the rapid physiological growth and functional development. Then, this period is characterized by extreme susceptibility to external stimuli such as inadequate maternal and infant nutritional status which they can interfere with the different stages of the development process leading to short and long-term consequences for health. Linear growth and brain development are particularly impaired from not sufficient nutrition. In consideration of the irreversible damage of malnutrition, especially on developing brain, an adequate nutrition during the first 1000 days of life is paramount. The aim of this review was to overview the latest scientific evidences on the relationship between nutrition and growth, focusing on nutritional requirements during the first 1000 days, and the impact of inadequate nutrition on brain development and linear growth.

Association of Iron Status and Intake During Pregnancy with Neuropsychological Outcomes in Children Aged 7 Years: The Prospective Birth Cohort Infancia y Medio Ambiente (INMA) Study

Early iron status plays an important role in prenatal neurodevelopment. Iron deficiency and high iron status have been related to alterations in child cognitive development; however, there are no data about iron intake during pregnancy with other environmental factors in relation to long term cognitive functioning of children. The aim of this study is to assess the relationship between maternal iron status and iron intake during pregnancy and child neuropsychological outcomes at 7 years of age. We used data from the INMA Cohort population-based study. Iron status during pregnancy was assessed according to serum ferritin levels, and iron intake was assessed with food frequency questionnaires. Working memory, attention, and executive function were assessed in children at 7 years old with the N-Back task, Attention Network Task, and the Trail Making Test, respectively. The results show that, after controlling for potential confounders, normal maternal serum ferritin levels (from 12 mg/L to 60 mg/L) and iron intake (from 14.5 mg/day to 30.0 mg/day), respectively, were related to better scores in working memory and executive functioning in offspring. Since these functions have been associated with better academic performance and adaptation to the environment, maintaining a good state of maternal iron from the beginning of pregnancy could be a valuable strategy for the community.

Influence of iron-deficient diets during gestation and lactation on cerebral fatty acids and eicosanoids in guinea pig offspring-Comparison of studies with different sources of dietary lipids

Previous studies showed that mild iron deficiency anaemia (IDA) induced by feeding an iron deficient (ID) diet to female guinea pigs during gestation and lactation to alters the auditory functions of the offspring when corn oil is the only source of dietary lipids. Conversely, feeding an ID diet with a dietary fatty acid composition similar to that of typical human western diets induced minor impairments. Since tissue fatty acid metabolism is affected by dietary iron, the current study measured the impacts of these ID diets (ID-corn and ID-west) compared to the corresponding iron-sufficient control diets (IS-corn and IS-west) on encephalum fatty acid metabolism in the offspring at post-natal day 24. IDA induced by the ID-corn diet resulted in significant increases in encephalum n-6 PUFA content, but IDA induced by the ID-west diet had little impact on fatty acid profiles compared to the IS-west group. Brain COX II protein expression and FADS2 mRNA expression were statistically unaffected in both experiments, but encephalum PGE₂ concentrations were significantly reduced in ID-west pups. These results suggest IDA studies during prenatal development should consider dietary lipid compositions.

Impairment of the Developing Human Brain in Iron Deficiency: Correlations to Findings in Experimental Animals and Prospects for Early Intervention Therapy

Due to the necessity of iron for a variety of cellular functions, the developing mammalian organism is vulnerable to iron deficiency, hence causing structural abnormalities and physiological malfunctioning in organs, which are particularly dependent on adequate iron stores, such as the brain. In early embryonic life, iron is already needed for proper development of the brain with the proliferation, migration, and differentiation of neuro-progenitor cells. This is underpinned by the widespread expression of transferrin receptors in the developing brain, which, in later life, is restricted to cells of the blood–brain and blood–cerebrospinal fluid barriers and neuronal cells, hence ensuring a sustained iron supply to the brain, even in the fully developed brain. In embryonic human life, iron deficiency is thought to result in a lower brain weight, with the impaired formation of myelin. Studies of fully developed infants that have experienced iron deficiency during development reveal the chronic and irreversible impairment of cognitive, memory, and motor skills, indicating widespread effects on the human brain. This review highlights the major findings of recent decades on the effects of gestational and lactational iron deficiency on the developing human brain. The findings are correlated to findings of experimental animals ranging from rodents to domestic pigs and non-human primates. The results point towards significant effects of iron deficiency on the developing brain. Evidence would be stronger with more studies addressing the human brain in real-time and the development of blood biomarkers of cerebral disturbance in iron deficiency. Cerebral iron deficiency is expected to be curable with iron substitution therapy, as the brain, privileged by the cerebral vascular transferrin receptor expression, is expected to facilitate iron extraction from the circulation and enable transport further into the brain.

Ontogenetic oligodendrocyte maturation through gestational iron deprivation: The road not taken

Developmental iron deficiency (dID) models facilitate the study of specific oligodendrocyte (OL) requirements for their progression to a mature state and subsequent contribution to myelination. In the current work, we used the dID model in transgenic mice expressing green fluorescence protein under the CNPase promoter allowing the identification of cells belonging to the oligodendroglial lineage, and the visualization of the entire myelin structure and single OL morphology. The present work evaluates dID effects on OL complexity in different brain areas. Control animals showed an increase in OL complexity both during development and along the anterior-posterior axis. In contrast, dID animals exhibited an initial increase in CNPase+ cells with prevalence of immature-OL (i-OL), an effect later compensated during development by selective death of those i-OL. As a consequence, developmental behavior was impaired in terms of body balance, muscle response, and sensorimotor functions. To explore why i-OL fail to mature in dID, expression levels of transcriptional factors involved in the maturation of the OL lineage were studied. In nuclear fractions, dID animals showed an increase in Hes5, which prevents the maturation of i-OL, and a decrease in Sox10, a positive regulator of OL maturation. The cytoplasmic fractions showed a decrease in Olig1, which is critical for precursor cell differentiation into premyelinating OL. Overall, the expression levels of Hes5, Sox10, and Olig1 in dID conditions correlated with an unfavorable OL maturation profile. In sum, the current results provide further evidence of dID impact on myelination, keeping OL away from the maturational path.

Iron Deficiency Reduces Synapse Formation in the Drosophila Clock Circuit

Iron serves as a critical cofactor for proteins involved in a host of biological processes. In most animals, dietary iron is absorbed in enterocytes and then disseminated for use in other tissues in the body. The brain is particularly dependent on iron. Altered iron status correlates with disorders ranging from cognitive dysfunction to disruptions in circadian activity. The exact role iron plays in producing these neurological defects, however, remains unclear. Invertebrates provide an attractive model to study the effects of iron on neuronal development since many of the genes involved in iron metabolism are conserved, and the organisms are amenable to genetic and cytological techniques. We have examined synapse growth specifically under conditions of iron deficiency in the Drosophila circadian clock circuit. We show that projections of the small ventrolateral clock neurons to the protocerebrum of the adult Drosophila brain are significantly reduced upon chelation of iron from the diet. This growth defect persists even when iron is restored to the diet. Genetic neuronal knockdown of ferritin 1 or ferritin 2, critical components of iron storage and transport, does not affect synapse growth in these cells. Together, these data indicate that dietary iron is necessary for central brain synapse formation in the fly and further validate the use of this model to study the function of iron homeostasis on brain development.

Iron as a model nutrient for understanding the nutritional origins of neuropsychiatric disease

Adequate nutrition during the pre- and early-postnatal periods plays a critical role in programming early neurodevelopment. Disruption of neurodevelopment by nutritional deficiencies can result not only in lasting functional deficits, but increased risk of neuropsychiatric disease in adulthood. Historical periods of famine such as the Dutch Hunger Winter and the Chinese Famine have provided foundational evidence for the long-term effects of developmental malnutrition on neuropsychiatric outcomes. Because neurodevelopment is a complex process that consists of many nutrient- and brain-region-specific critical periods, subsequent clinical and pre-clinical studies have aimed to elucidate the specific roles of individual macro- and micronutrient deficiencies in neurodevelopment and neuropsychiatric pathologies. This review will discuss developmental iron deficiency (ID), the most common micronutrient deficiency worldwide, as a paradigm for understanding the role of early-life nutrition in neurodevelopment and risk of neuropsychiatric disease. We will review the epidemiologic data linking ID to neuropsychiatric dysfunction, as well as the underlying structural, cellular, and molecular mechanisms that are thought to underlie these lasting effects. Understanding the mechanisms driving lasting dysfunction and disease risk is critical for development and implementation of nutritional policies aimed at preventing nutritional deficiencies and their long-term sequelae.

[Association between iron deficiency and brain developmental disorder in children]

Iron deficiency (ID) is the most common trace element deficiency in childhood. Recent studies have shown that late fetus period, neonatal period, and infancy are important periods for brain development, and ID during these periods may cause irreversible damage to brain development, including abnormal emotion and behavior, cognitive decline, and attention deficit, which may still be present in adulthood. Therefore, it should be taken seriously. This article summarizes the research advances in major mechanisms involved in brain developmental disorder due to ID in the early stage of life and related intervention measures.

Nutritional influences on brain development

There is increasing evidence from preclinical and human studies that nutrition in the late foetal and early neonatal period has a significant impact on neurodevelopment across the lifespan. Certain nutrients have particularly large effects in this time period, and their deficits cause greater long-term risk. The mechanisms by which nutrients influence early brain growth and the sensitive periods for when certain nutrients should be provided are being elucidated. Assessments of nutritional status that index brain growth and predict long-term development are important to assess the efficacy of early life nutritional therapies.

CONCLUSION

Optimizing nutrition during foetal and early postnatal life is a golden opportunity to impact neurodevelopment and brain function across the lifespan.

Iron deficiency and iron treatment in the fetal developing brain - a pilot study introducing an experimental rat model

Background

Iron deficiency is especially common in women during the reproductive age and it is estimated that 52% of pregnant women have iron deficiency anemia. Maternal iron deficiency with or without anemia in pregnancy may have consequences for the fetus, where it may have an impact on the cerebral development of the brain. Both animals and adult human studies support that iron deficiency affects psychomotor development, behavioral traits, and cognitive functions in the offspring. However, it has not yet been established whether the availability of sufficient iron is particularly important in certain phases during brain development, and whether possible damages are reversible if iron supplementation is provided during pregnancy. Here we report results from a pilot study in an experimental rat model suitable for introducing iron deficiency in the fetal rat brain.

Methods

The model was utilized for examination of the potential to reverse changes in fetal brain iron by maternal parenteral iron administration. Fertilized females subjected to iron deficiency without anemia were subcutaneously injected with iron isomaltoside at the day of mating (E0), 14 days into pregnancy (E14), or at the day of birth (Postnatal (P) 0). Blood, brain and liver in the offspring were examined on P0 or in adulthood on postnatal day P70.

Results

Maternal iron restriction during pregnancy led to significantly lower levels of iron in the brains of newborn rats compared to levels in pups of iron sufficient mothers. Females fed ID diet (5.2 mg/kg Fe) had offspring with significantly lower cerebral iron compared to a control group fed a standard diet (158 mg/kg Fe). Injection of IIM to pregnant ID females on E0 or E14 yielded normalization of Fe in the developing brain known to express elevated levels of capillary transferrin receptors, indicating that the administered iron passed the placenta and fetal blood brain barrier.

Conclusions

In future studies, this translational model may be applied to examine morphological and biochemical consequences of iron deficiency and iron deficiency treatment in the developing fetal brain.

Dietary lipophilic iron alters amyloidogenesis and microglial morphology in Alzheimer's disease knock-in APP mice

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized pathologically by amyloid beta (Aβ) deposition, microgliosis, and iron dyshomeostasis. Increased labile iron due to homeostatic dysregulation is believed to facilitate amyloidogenesis. Free iron is incorporated into aggregating amyloid peptides during Aβ plaque formation and increases potential for oxidative stress surrounding plaques. The goal of this work was to observe how brain iron levels temporally influence Aβ plaque formation, plaque iron concentration, and microgliosis. We fed humanized APP^NL-F and APP^NL-G-F knock-in mice lipophilic iron compound 3,5,5-trimethylhexanoyl ferrocene (TMHF) and iron deficient diets for twelve months. TMHF elevated brain iron by 22% and iron deficiency decreased brain iron 21% relative to control diet. Increasing brain iron with TMHF accelerated plaque formation, increased Aβ staining, and increased senile morphology of amyloid plaques. Increased brain iron was associated with increased plaque-iron loading and microglial iron inclusions. TMHF decreased IBA1+ microglia branch length while increasing roundness indicative of microglial activation. This body of work suggests that increasing mouse brain iron with TMHF potentiates a more human-like Alzheimer's disease phenotype with iron integration into Aβ plaques and associated microgliosis.

Early-Life Iron Deficiency Reduces Brain Iron Content and Alters Brain Tissue Composition Despite Iron Repletion: A Neuroimaging Assessment

Early-life iron deficiency has lifelong influences on brain structure and cognitive function, however characterization of these changes often requires invasive techniques. There is a need for non-invasive assessment of early-life iron deficiency with potential to translate findings to the human clinical setting. In this study, 28 male pigs were provided either a control diet (CONT; n = 14; 23.5 mg Fe/L milk replacer) or an iron-deficient diet (ID; n = 14; 1.56 mg Fe/L milk replacer) for phase 1 of the study, from postnatal day (PND) 2 until 32. Twenty pigs (n = 10/diet from phase 1 were used in phase 2 of the study from PND 33 to 61, where all pigs were provided a common iron-sufficient diet, regardless of their phase 1 dietary iron status. All pigs were subjected to magnetic resonance imaging at PND 32 and again at PND 61, and quantitative susceptibility mapping was used to assess brain iron content at both imaging time-points. Data collected on PND 61 were analyzed using voxel-based morphometry and tract-based spatial statistics to determine tissue concentration difference and white matter tract integrity, respectively. Quantitative susceptibility mapping outcomes indicated reduced iron content in the pons, medulla, cerebellum, left cortex, and left hippocampus of ID pigs compared with CONT pigs, regardless of imaging time-point. In contrast, iron contents were increased in the olfactory bulbs of ID pigs compared with CONT pigs. Voxel-based morphometric analysis indicated increased grey and white matter concentrations in CONT pigs compared with ID pigs that were evident at PND 61. Differences in tissue concentrations were predominately located in cortical tissue as well as the cerebellum, thalamus, caudate, internal capsule, and hippocampi. Tract-based spatial statistics indicated increased fractional anisotropy values along subcortical white matter tracts in CONT pigs compared with ID pigs that were evident on PND 61. All described differences were significant at p ≤ 0.05. Results from this study indicate that neuroimaging can sensitively detect structural and physiological changes due to early-life iron deficiency, including grey and white matter volumes, iron contents, as well as reduced subcortical white matter integrity, despite a subsequent period of dietary iron repletion.

The Ferroxidase Hephaestin But Not Amyloid Precursor Protein is Required for Ferroportin-Supported Iron Efflux in Primary Hippocampal Neurons

Iron efflux in mammalian cells is mediated by the ferrous iron exporter ferroportin (Fpn); Fpn plasma membrane localization and function are supported by a multicopper ferroxidase and/or the soluble amyloid precursor protein (sAPP). Fpn and APP are ubiquitously expressed in all cell types in the central nervous system including neurons. In contrast, neuronal ferroxidase(s) expression has not been well characterized. Using primary cultures of hippocampal neurons, we examined the molecular mechanism of neuronal Fe efflux in detail. Developmental increases of Fpn, APP, and the ferroxidase hephaestin (Hp) were observed in hippocampal neurons. Iron efflux in these neurons depended on the level of Fpn localized at the cell surface; as noted, Fpn stability is supported by ferroxidase activity, an enzymatic activity that is required for Fe efflux. Iron accumulation increases and iron efflux decreases in Hp knockout neurons. In contrast, suppression of endogenous APP by RNAi knockdown does not affect surface Fpn stability or Fe efflux. These data support the model that the neuronal ferroxidase Hp plays a unique role in support of Fpn-mediated Fe efflux in primary hippocampal neurons. Our data also demonstrate that Hp ferroxidase activity relies on copper bioavailability, which suggests neuronal iron homeostasis will be modulated by cellular copper status.

Iron prevents demyelination of frog sciatic nerves

Metal ions are of particular importance in nervous system function, notably iron. However, very little has been done to investigate its physiological role in frog peripheral nervous system. The present research aim to evaluate i) the time-effect of sciatic nerve ligation and/or ii) iron sulphate (1.50mg/kg, in lymphatic sac) on frog myelin sheaths. Histological sections following ligation shows degeneration of some fibres with axonal and myelin breakdown associated to a decrease of Schwann cells number following 2h (45.00±0.30, p<0.0001), 24h (28.00±0.020, p<0.0001). Interestingly, iron administration reduces the degeneration of myelin sheaths classically observed in frog ligated sciatic nerve associated with an increase of Schwann cells number (139.00±0.50, p<0.0001). Thus, iron could prevent degeneration or promote regeneration induced by ligation in frog sciatic nerve.

Tactile stimulation partially prevents neurodevelopmental changes in visual tract caused by early iron deficiency

Iron deficiency has a critical impact on maturational mechanisms of the brain and the damage related to neuroanatomical parameters is not satisfactorily reversed after iron replacement. However, emerging evidence suggest that enriched early experience may offer great therapeutic efficacy in cases of nutritional disorders postnatally, since the brain is remarkably responsive to its interaction with the environment. Given the fact that tactile stimulation (TS) treatment has been previously shown to be an effective therapeutic approach and with potential application to humans, here we ask whether exposure to TS treatment, from postnatal day (P) 1 to P32 for 3min/day, could also be employed to prevent neuroanatomical changes in the optic nerve of rats maintained on an iron-deficient diet during brain development. We found that iron deficiency changed astrocyte, oligodendrocyte, damaged fiber, and myelinated fiber density, however, TS reversed the iron-deficiency-induced alteration in oligodendrocyte, damaged fiber and myelinated fiber density, but failed to reverse astrocyte density. Our results suggest that early iron deficiency may act by disrupting the timing of key steps in visual system development thereby modifying the normal progression of optic nerve maturation. However, optic nerve development is sensitive to enriching experiences, and in the current study we show that this sensitivity can be used to prevent damage from postnatal iron deficiency during the critical period.

Iron Deficiency Impairs Developing Hippocampal Neuron Gene Expression, Energy Metabolism, and Dendrite Complexity

Iron deficiency (ID), with and without anemia, affects an estimated 2 billion people worldwide. ID is particularly deleterious during early-life brain development, leading to long-term neurological impairments including deficits in hippocampus-mediated learning and memory. Neonatal rats with fetal/neonatal ID anemia (IDA) have shorter hippocampal CA1 apical dendrites with disorganized branching. ID-induced dendritic structural abnormalities persist into adulthood despite normalization of the iron status. However, the specific developmental effects of neuronal iron loss on hippocampal neuron dendrite growth and branching are unknown. Embryonic hippocampal neuron cultures were chronically treated with deferoxamine (DFO, an iron chelator) beginning at 3 days in vitro (DIV). Levels of mRNA for Tfr1 and Slc11a2, iron-responsive genes involved in iron uptake, were significantly elevated in DFO-treated cultures at 11DIV and 18DIV, indicating a degree of neuronal ID similar to that seen in rodent ID models. DFO treatment decreased mRNA levels for genes indexing dendritic and synaptic development (i.e. BdnfVI,Camk2a,Vamp1,Psd95,Cfl1, Pfn1,Pfn2, and Gda) and mitochondrial function (i.e. Ucp2,Pink1, and Cox6a1). At 18DIV, DFO reduced key aspects of energy metabolism including basal respiration, maximal respiration, spare respiratory capacity, ATP production, and glycolytic rate, capacity, and reserve. Sholl analysis revealed a significant decrease in distal dendritic complexity in DFO-treated neurons at both 11DIV and 18DIV. At 11DIV, the length of primary dendrites and the number and length of branches in DFO-treated neurons were reduced. By 18DIV, partial recovery of the dendritic branch number in DFO-treated neurons was counteracted by a significant reduction in the number and length of primary dendrites and the length of branches. Our findings suggest that early neuronal iron loss, at least partially driven through altered mitochondrial function and neuronal energy metabolism, is responsible for the effects of fetal/neonatal ID and IDA on hippocampal neuron dendritic and synaptic maturation. Impairments in these neurodevelopmental processes likely underlie the negative impact of early life ID and IDA on hippocampus-mediated learning and memory.

Maternal Iron Status in Pregnancy and Long-Term Health Outcomes in the Offspring

Iron is an essential micronutrient and is important not only in carrying oxygen but also to the catalytic activity of a variety of enzymes. In the fetus, it is vital to the synthesis of hemoglobin and in brain development. Iron deficiency (ID) anemia in pregnancy is a common problem, even in high-income country settings. Around 50% of pregnant women worldwide are anemic, with at least half of this burden due to ID. Iron supplements are widely recommended and used during pregnancy globally. However, the evidence on the extent of benefit they contribute to the offspring's health is not well established, and their routine use has its side effects and drawbacks. Dietary iron intake is difficult to assess accurately and it is unlikely to be sufficient to meet the demands of pregnancy if women start with inadequate body iron stores at conception. Evidence from experimental animal models suggests that maternal ID during pregnancy is associated with fetal growth restriction, as well as offspring obesity and high blood pressure later in life. The possible biological mechanisms for this observed association may be due to ID-induced changes in placental structure and function, enzyme expression, nutrient absorption, and fetal organ development. However, such evidence is limited in human studies. Prenatal ID in experimental animal models also adversely affected the developing brain structures, neurotransmitter systems, and myelination resulting in acute brain dysfunction during the period of deficiency and persistence of various postnatal neurobehavioral abnormalities as well as persistent dysregulation of some genes into adult life after iron repletion pointing to the possibility of gene expression changes. The evidence from human population studies is limited and heterogeneous and more research is needed in the future, investigating the effects of ID in pregnancy on future offspring health outcomes.

Postnatal Iron Deficiency Alters Brain Development in Piglets

BACKGROUND

Cognitive deficits associated with postnatal iron deficiency (ID) suggest abnormal brain development, but little is known about animals with gyrencephalic brains.

OBJECTIVE

The objective was to assess the impact of ID on brain development in piglets.

METHODS

Male and female Yorkshire piglets were reared from postnatal day (PD) 2 until PD 29 or 30 by using milk replacer adequate [control (CON)] or deficient (100 compared with 10 mg/kg) in iron and subjected to MRI to assess brain macrostructure, microstructure, and metabolites in the dorsal hippocampi and intervening space. After MRI, brains were collected for histology. Hematocrit, hemoglobin, and liver iron were measured to determine iron status.

RESULTS

Hematocrit and hemoglobin in ID piglets were less than CON after PD 14 (P < 0.001), and at the study end liver iron in ID piglets was less than CON (P < 0.001). Brain region volumes were not affected by ID, but changes in brain composition were evident. ID piglets had less white matter in 78,305 voxels, with large clusters in the hippocampus and cortex. ID piglets had less gray matter in 13,625 voxels primarily in cortical areas and more gray matter in 28,017 voxels, most notably in olfactory bulbs and hippocampus. The major effect of ID on white matter was supported by lower fractional anisotropy values in the corpus callosum (0.300 compared with 0.284, P = 0.006) and in whole brain white matter (0.313 compared with 0.307, P = 0.002) in ID piglets. In coronal brain sections, corpus callosum width was less (P = 0.043) in ID piglets. Inositol was lower (P = 0.01) and phosphocholine was higher (P = 0.03) in hippocampus of ID piglets.

CONCLUSIONS

Postnatal ID in piglets affects brain development, especially white matter. If the effects of ID persist, it might explain the lasting detrimental effects on cognition.

Iron Status Is Associated with Performance on Executive Functioning Tasks in Nonanemic Young Women

BACKGROUND

Iron deficiency (ID) is prevalent, particularly among women of reproductive age (WRA). How mild ID without anemia relates to cognition is poorly understood. Executive functioning (EF) has emerged as potentially being affected by mild ID in WRA.

OBJECTIVE

We sought to examine how iron markers relate to performance on EF tasks in nonanemic WRA.

METHODS

Participants included 127 females aged 18-35 y. Hematological indicators included hemoglobin, RBC distribution width, transferrin saturation (TSAT), ferritin, transferrin receptor (TfR), and total body iron (TBI). EF was assessed using 5 tasks. Associations between EF outcomes and iron status were examined using continuous iron predictors and group comparisons.

RESULTS

Better iron status was associated with better attention [faster reaction time (RT) with lower TfR (P = 0.028) and higher TSAT (P = 0.013)], inhibitory control [lower RT variability with higher TSAT (P = 0.042) and planning ability (faster planning time and a smaller planning time increase with increasing difficulty with higher ferritin; P = 0.010)]. No associations with iron status were found for several EF outcomes, possibly due to performance ceilings. Paradoxically, worse performance on a working memory task was related to better iron status, which may reflect hippocampal-frontal interference [lower capacity with lower TfR (P = 0.034) and higher TBI (P = 0.043) and a larger accuracy change with increasing difficulty with higher TBI (P = 0.016)]. Longer RTs on a working memory task were observed among those with positive TBI (iron surplus; P = 0.021) and <2 abnormal iron markers (P = 0.013) compared with those with negative TBI (iron deficit) and ≥2 abnormal markers, respectively.

CONCLUSIONS

These findings suggest cognitive ramifications of mild ID in otherwise healthy WRA and have implications for daily well-being. Future investigators should explore how brain system interactions change according to iron availability.

Identifying the threshold of iron deficiency in the central nervous system of the rat by the auditory brainstem response

The deleterious effects of anemia on auditory nerve (AN) development have been well investigated; however, we have previously reported that significant functional consequences in the auditory brainstem response (ABR) can also occur as a consequence of marginal iron deficiency (ID). As the ABR has widespread clinical use, we evaluated the ability of this electrophysiological method to characterize the threshold of tissue ID in rats by examining the relationship between markers of tissue ID and severity of ABR latency defects. To generate various levels of ID, female Long-Evans rats were exposed to diets containing sufficient, borderline, or deficient iron (Fe) concentrations throughout gestation and offspring lifetime. We measured hematological indices of whole body iron stores in dams and offspring to assess the degree of ID. Progression of AN ID in the offspring was measured as ferritin protein levels at different times during postnatal development to complement ABR functional measurements. The severity of ABR deficits correlated with the level of Fe restriction in each diet. The sufficient Fe diet did not induce AN ID and consequently did not show an impaired ABR latency response. The borderline Fe diet, which depleted AN Fe stores but did not cause systemic anemia resulted in significantly increased ABR latency isolated to Peak I.The low Fe diet, which induced anemia and growth retardation, significantly increased ABR latencies of Peaks I to IV. Our findings indicate that changes in the ABR could be related to various degrees of ID experienced throughout development.

Paving the way for adequate myelination: The contribution of galectin-3, transferrin and iron

Considering the worldwide incidence of well characterized demyelinating disorders such as Multiple Sclerosis (MS) and the increasing number of pathologies recently found to involve hypomyelinating factors such as micronutrient deficits, elucidating the molecular basis of central nervous system (CNS) demyelination, remyelination and hypomyelination becomes essential to the development of future neuroregenerative therapies. In this context, this review discusses novel findings on the contribution of galectin-3 (Gal-3), transferrin (Tf) and iron to the processes of myelination and remyelination and their potentially positive regulation of oligodendroglial precursor cell (OPC) differentiation. Studies were conducted in cuprizone (CPZ)-induced demyelination and iron deficiency (ID)-induced hypomyelination, and the participation of glial and neural stem cells (NSC) in the remyelination process was evaluated by means of both in vivo and in vitro assays on primary cell cultures.

Vitamin B12, folate and iron levels in primary nocturnal enuresis

Objective:

Folate, vitamin B12 and iron are important vitamin and minerals which play role in the development of nervous system. The aim of this study was looking at the presence of folate, vitamin B12 and iron deficiency among patients with Primary nocturnal enuresis (PNE) and possible relation between the delay of central nervous system (CNS) development, PNE and folate, vitamin B12 and iron states.

Methods:

Consecutively applied forty patients with PNE (23 girls and 17 boys) and otherwise normal thirty control subjects (17 girls and 13 boys) were included in the study. Average ages (in range) of PNE and the control group were 9.2(6-12) years and 9.3 (6-12) years accordingly. Age, height, weight, complete blood count, blood vitamin B12, folate, ferritin and iron values of both groups were recorded and compared to each other.

Results:

Average vitamin B12 and folate levels of patients with PNE were significantly and statistically lower compared to those of the control group. Average blood iron of patients with PNE was significantly higher than that of the control group and also average ferritin level of the PNE group was detected to be higher than the control group but this relation was statistically insignificant.

Conclusion:

Primary nocturnal enuresis is related to the delay in CNS maturation so it was thought that low vitamin B12 and folate which were found in patients with PNE may have role in the delay of CNS maturation. Additionally, further studies are needed to investigate the role of vitamin B12 and folate either alone or as combination in treatment of patients with PNE who have low vitamin B12and folate level.

Micronutrients in pregnancy in low- and middle-income countries

Pregnancy is one of the more important periods in life when increased micronutrients, and macronutrients are most needed by the body; both for the health and well-being of the mother and for the growing foetus and newborn child. This brief review aims to identify the micronutrients (vitamins and minerals) likely to be deficient in women of reproductive age in Low- and Middle-Income Countries (LMIC), especially during pregnancy, and the impact of such deficiencies. A global prevalence of some two billion people at risk of micronutrient deficiencies, and multiple micronutrient deficiencies of many pregnant women in LMIC underline the urgency to establishing the optimal recommendations, including for delivery. It has long been recognized that adequate iron is important for best reproductive outcomes, including gestational cognitive development. Similarly, iodine and calcium have been recognized for their roles in development of the foetus/neonate. Less clear effects of deficiencies of zinc, copper, magnesium and selenium have been reported. Folate sufficiency periconceptionally is recognized both by the practice of providing folic acid in antenatal iron/folic acid supplementation and by increasing numbers of countries fortifying flours with folic acid. Other vitamins likely to be important include vitamins B12, D and A with the water-soluble vitamins generally less likely to be a problem. Epigenetic influences and the likely influence of micronutrient deficiencies on foetal origins of adult chronic diseases are currently being clarified. Micronutrients may have other more subtle, unrecognized effects. The necessity for improved diets and health and sanitation are consistently recommended, although these are not always available to many of the world's pregnant women. Consequently, supplementation programmes, fortification of staples and condiments, and nutrition and health support need to be scaled-up, supported by social and cultural measures. Because of the life-long influences on reproductive outcomes, including inter-generational ones, both clinical and public health measures need to ensure adequate micronutrient intakes during pregnancy, but also during adolescence, the first few years of life, and during lactation. Many antenatal programmes are not currently achieving this. We aim to address the need for micronutrients during pregnancy, the importance of micronutrient deficiencies during gestation and before, and propose the scaling-up of clinical and public health approaches that achieve healthier pregnancies and improved pregnancy outcomes.

Prenatal choline supplementation ameliorates the long-term neurobehavioral effects of fetal-neonatal iron deficiency in rats

BACKGROUND

Gestational iron deficiency in humans and rodents produces long-term deficits in cognitive and socioemotional function and alters expression of plasticity genes in the hippocampus that persist despite iron treatment. Prenatal choline supplementation improves cognitive function in other rodent models of developmental insults.

OBJECTIVE

The objective of this study was to determine whether prenatal choline supplementation prevents the long-term effects of fetal-neonatal iron deficiency on cognitive and social behaviors and hippocampal gene expression.

METHODS

Pregnant rat dams were administered an iron-deficient (2-6 g/kg iron) or iron-sufficient (IS) (200 g/kg iron) diet from embryonic day (E) 3 to postnatal day (P) 7 with or without choline supplementation (5 g/kg choline chloride, E11-18). Novel object recognition (NOR) in the test vs. acquisition phase, social approach (SA), and hippocampal mRNA expression were compared at P65 in 4 male adult offspring groups: formerly iron deficient (FID), FID with choline supplementation (FID-C), IS, and IS with choline supplementation.

RESULTS

Relative to the intact NOR in IS rats (acquisition: 47.9%, test: 60.2%, P < 0.005), FID adult rats had impaired recognition memory at the 6-h delay (acquisition: 51.4%, test: 55.1%, NS), accompanied by a 15% reduction in hippocampal expression of brain-derived neurotrophic factor (Bdnf) (P < 0.05) and myelin basic protein (Mbp) (P < 0.05). Prenatal choline supplementation in FID rats restored NOR (acquisition: 48.8%, test: 64.4%, P < 0.0005) and increased hippocampal gene expression (FID-C vs. FID group: Bdnf, Mbp, P < 0.01). SA was also reduced in FID rats (P < 0.05 vs. IS rats) but was only marginally improved by prenatal choline supplementation.

CONCLUSIONS

Deficits in recognition memory, but not social behavior, resulting from gestational iron deficiency are attenuated by prenatal choline supplementation, potentially through preservation of hippocampal Bdnf and Mbp expression. Prenatal choline supplementation may be a promising adjunct treatment for fetal-neonatal iron deficiency.