Perinatal α-linolenic acid availability alters the expression of genes related to memory and to epigenetic machinery, and the Mecp2 DNA methylation in the whole brain of mouse offspring

Macronutrient Intake in Pregnancy and Child Cognitive and Behavioural Outcomes

Prenatal nutrient exposures can impact on brain development and disease susceptibility across the lifespan. It is well established that maternal macronutrient intake during pregnancy influences foetal and infant development. Therefore, we hypothesise that macronutrient intakes during pregnancy are correlated with cognitive development during early childhood. The current study aimed to investigate the relationship between maternal macronutrient intake during pregnancy and child cognitive and behavioural outcomes at age 4 years. We analysed prospective data from a cohort of 64 Australian mother-child dyads. Maternal macronutrient intake was assessed using a validated 74-item food frequency questionnaire at 2 timepoints during pregnancy. Child cognition and behaviour were measured at age 4 years using the validated Wechsler Preschool and Primary Scale of Intelligence, 3rd version (WPPSI-III) and the Child Behaviour Checklist (CBC). Linear regression models were used to quantify statistical relationships and were adjusted for maternal age, education, pre-pregnancy BMI, breastfeeding duration and birthweight. Child Performance IQ was inversely associated with maternal starch intake (b = -11.02, p = 0.03). However, no other associations were found. Further research is needed to explore the association between different types of starch consumed during pregnancy and child cognitive development.

Perinatal and Early-Life Nutrition, Epigenetics, and Allergy

Epidemiological studies have shown a dramatic increase in the incidence and the prevalence of allergic diseases over the last several decades. Environmental triggers including risk factors (e.g., pollution), the loss of rural living conditions (e.g., farming conditions), and nutritional status (e.g., maternal, breastfeeding) are considered major contributors to this increase. The influences of these environmental factors are thought to be mediated by epigenetic mechanisms which are heritable, reversible, and biologically relevant biochemical modifications of the chromatin carrying the genetic information without changing the nucleotide sequence of the genome. An important feature characterizing epigenetically-mediated processes is the existence of a time frame where the induced effects are the strongest and therefore most crucial. This period between conception, pregnancy, and the first years of life (e.g., first 1000 days) is considered the optimal time for environmental factors, such as nutrition, to exert their beneficial epigenetic effects. In the current review, we discussed the impact of the exposure to bacteria, viruses, parasites, fungal components, microbiome metabolites, and specific nutritional components (e.g., polyunsaturated fatty acids (PUFA), vitamins, plant- and animal-derived microRNAs, breast milk) on the epigenetic patterns related to allergic manifestations. We gave insight into the epigenetic signature of bioactive milk components and the effects of specific nutrition on neonatal T cell development. Several lines of evidence suggest that atypical metabolic reprogramming induced by extrinsic factors such as allergens, viruses, pollutants, diet, or microbiome might drive cellular metabolic dysfunctions and defective immune responses in allergic disease. Therefore, we described the current knowledge on the relationship between immunometabolism and allergy mediated by epigenetic mechanisms. The knowledge as presented will give insight into epigenetic changes and the potential of maternal and post-natal nutrition on the development of allergic disease.

Maternal dietary deficiency of n-3 fatty acids affects metabolic and epigenetic phenotypes of the developing fetus

Polyunsaturated fatty acids (PUFAs) play multiple physiological roles. They regulate the structure and function of cell membranes and cell growth and proliferation, and apoptosis. In addition, PUFAs are involved in cellular signaling, gene expression and serve as precursors to second messengers such as eicosanoids, docosanoids etc. and regulate several physiological processes including placentation, inflammation, immunity, angiogenesis, platelet function, synaptic plasticity, neurogenesis, bone formation, energy homeostasis, pain sensitivity, stress, and cognitive functions. Linoleic acid, 18:2n-6 (LA) and alpha-linolenic acid, 18:3n-3 (ALA) are the two essential fatty acids obtained from the diets and subsequently their long-chain polyunsaturated fatty acids (LCPUFAs) are accumulated in the body. The maternal plasma LCPUFAs especially accumulated in larger amounts in the brain during the third trimester of pregnancy via the placenta and postnatally from mother's breast milk. Various studies, including ours, suggest PUFA's important role in placentation, as well as in growth and development of the offspring. However, intakes of maternal n-3 PUFAs during pregnancy and lactation are much lower in India compared with the Western population. In India, n-3 fatty acid status is further reduced by higher intake of n-6 PUFA rich oils and trans fats. More data on the impacts of long term maternal n-3 PUFA deficiency on placental structure and function, gene expression, epigenetic changes and resultant cognitive function of fetus & infants are emerging. This review summarizes the impacts of n-3 PUFA deficiency in utero on fetal growth and development, adiposity, energy metabolism, musculoskeletal development, and epigenetic changes in feto-placental axis from the recently available pre-clinical and clinical data.

Antidepressant-Like Effect of Selected Egyptian Cultivars of Flaxseed Oil on a Rodent Model of Postpartum Depression

Flaxseed (Linum usitatissimum L.) is a multipurpose crop with health promoting potential. This study was undertaken to investigate the fatty acid profile and yield of fixed oil of six Egyptian flaxseed cultivars. The selected cultivars with the highest content of polyunsaturated fatty acids (PUFAs) (G9 and G10) were assessed for their antidepressant-like effect in rat model of postpartum depression (PPD) induced by hormone-simulated pregnancy followed by hormone withdrawal and compared to fluoxetine. As compared to control group, administration of G9 and G10 (270 mg/kg/day, p.o) for two weeks during the postpartum period can alleviate anxiety and depressive-like behaviors and biochemical changes in PPD-induced rats. This was confirmed by evaluation of anxiety-like behaviors (elevated plus maze, open field test, and forced swim test tests), in addition to biochemical analysis (brain monoamine oxidase-A, corticosterone level, proinflammatory cytokines, and hippocampal redox state). In conclusion, flaxseed oil of Egyptian cultivars G9 and G10 exhibited significant antidepressant-like effect in rat model of PPD without affecting locomotor activity. At the treatment doses, the antidepressant-like activity of Giza 9 oil is comparable to fluoxetine.

The cognitive impairment induced by zinc deficiency in rats aged 0∼2 months related to BDNF DNA methylation changes in the hippocampus

OBJECTIVE

This study was carried out to understand the effects of zinc deficiency in rats aged 0∼2 months on learning and memory, and the brain-derived neurotrophic factor (BDNF) gene methylation status in the hippocampus.

METHODS

The lactating mother rats were randomly divided into three groups (n = 12): zinc-adequate group (ZA: zinc 30 mg/kg diet), zinc-deprived group (ZD: zinc 1 mg/kg diet), and a pair-fed group (PF: zinc 30 mg/kg diet), in which the rats were pair-fed to those in the ZD group. After weaning (on day 23), offspring were fed the same diets as their mothers. After 37 days, the zinc concentrations in the plasma and hippocampus were measured, and the behavioral function of the offspring rats was measured using the passive avoidance performance test. We then assessed the DNA methylation patterns of the exon IX of BDNF by methylation-specific quantitative real-time PCR and the mRNA expression of BDNF in the hippocampus by RT-PCR.

RESULTS

Compared with the ZA and PF groups, rats in the ZD group had shorter latency period, lower zinc concentrations in the plasma and hippocampus (P < 0.05). Interestingly, the DNA methylation of the BDNF exon IX was significantly increased in the ZD group, compared with the ZA and PF groups, whereas the expression of the BDNF mRNA was decreased. In addition, the DNMT1 mRNA expression was significantly upregulated and DNMT3A was downregulated in the ZD group, but not in the ZA and PF groups.

CONCLUSION

The learning and memory damage in offspring may be a result of the epigenetic changes of the BDNF genes in response to the zinc-deficient diet during 0∼2 month period. Furthermore, this work supports the speculative notion that altered DNA methylation of BDNF in the hippocampus is one of the main causes of cognitive impairment by zinc deficiency.

Multigenerational effects of parental prenatal exposure to famine on adult offspring cognitive function

The effects of prenatal nutrition on adult cognitive function have been reported for one generation. However, human evidence for multigenerational effects is lacking. We examined whether prenatal exposure to the Chinese famine of 1959-61 affects adult cognitive function in two consecutive generations. In this retrospective family cohort study, we investigated 1062 families consisting of 2124 parents and 1215 offspring. We assessed parental and offspring cognitive performance by means of a comprehensive test battery. Generalized linear regression model analysis in the parental generation showed that prenatal exposure to famine was associated with a 8.1 (95% CI 5.8 to 10.4) second increase in trail making test part A, a 7.0 (1.5 to 12.5) second increase in trail making test part B, and a 5.5 (-7.3 to -3.7) score decrease in the Stroop color-word test in adulthood, after adjustment for potential confounders. In the offspring generation, linear mixed model analysis found no significant association between parental prenatal exposure to famine and offspring cognitive function in adulthood after adjustment for potential confounders. In conclusion, prenatal exposure to severe malnutrition is negatively associated with visual- motor skill, mental flexibility, and selective attention in adulthood. However, these associations are limited to only one generation.

Neurological and Epigenetic Implications of Nutritional Deficiencies on Psychopathology: Conceptualization and Review of Evidence

In recent years, a role for epigenetic modifications in the pathophysiology of disease has received significant attention. Many studies are now beginning to explore the gene-environment interactions, which may mediate early-life exposure to risk factors, such as nutritional deficiencies and later development of behavioral problems in children and adults. In this paper, we review the current literature on the role of epigenetics in the development of psychopathology, with a specific focus on the potential for epigenetic modifications to link nutrition and brain development. We propose a conceptual framework whereby epigenetic modifications (e.g., DNA methylation) mediate the link between micro- and macro-nutrient deficiency early in life and brain dysfunction (e.g., structural aberration, neurotransmitter perturbation), which has been linked to development of behavior problems later on in life.

The interaction between epigenetics, nutrition and the development of cancer

Unlike the genome, the epigenome can be modified and hence some epigenetic risk markers have the potential to be reversed. Such modifications take place by means of drugs, diet or environmental exposures. It is widely accepted that epigenetic modifications take place during early embryonic and primordial cell development, but it is also important that we gain an understanding of the potential for such changes later in life. These “later life” epigenetic modifications in response to dietary intervention are the focus of this paper. The epigenetic modifications investigated include DNA methylation, histone modifications and the influence of microRNAs. The epigenotype could be used not only to predict susceptibility to certain cancers but also to assess the effectiveness of dietary modifications to reduce such risk. The influence of diet or dietary components on epigenetic modifications and the impact on cancer initiation or progression has been assessed herein.

Early-life adversity programs emotional functions and the neuroendocrine stress system: the contribution of nutrition, metabolic hormones and epigenetic mechanisms

Clinical and pre-clinical studies have shown that early-life adversities, such as abuse or neglect, can increase the vulnerability to develop psychopathologies and cognitive decline later in life. Remarkably, the lasting consequences of stress during this sensitive period on the hypothalamic-pituitary-adrenal axis and emotional function closely resemble the long-term effects of early malnutrition and suggest a possible common pathway mediating these effects. During early-life, brain development is affected by both exogenous factors, like nutrition and maternal care as well as by endogenous modulators including stress hormones. These elements, while mostly considered for their independent actions, clearly do not act alone but rather in a synergistic manner. In order to better understand how the programming by early-life stress takes place, it is important to gain further insight into the exact interplay of these key elements, the possible common pathways as well as the underlying molecular mechanisms that mediate their effects. We here review evidence that exposure to both early-life stress and early-life under-/malnutrition similarly lead to life-long alterations on the neuroendocrine stress system and modify emotional functions. We further discuss how the different key elements of the early-life environment interact and affect one another and next suggest a possible role for the early-life adversity induced alterations in metabolic hormones and nutrient availability in shaping later stress responses and emotional function throughout life, possibly via epigenetic mechanisms. Such knowledge will help to develop intervention strategies, which gives the advantage of viewing the synergistic action of a more complete set of changes induced by early-life adversity.