The early programming of metabolic health: is epigenetic setting the missing link?

Birth weight and nutritional status in school-age children from Boane city, Mozambique

BACKGROUND

Birth weight is considered an important marker of inadequate maternal nutrition, and it is a critical indicator of the newborn's health and development.

OBJECTIVE

This study evaluated the influence of low birth weight (LBW) on body composition in 7-10-year-old school children from Boane City-Mozambique.

METHODS

A total of 220 children (female = 122 and male = 98) were divided into two groups according to their birth weight (LBW, n = 41; and normal birth weight, NBW, n = 179). Anthropometric indicators of nutritional status were analyzed by the indices weight-for-age, height-for-age, BMI-for-age, and weight-for-height.

RESULTS

LBW children showed reduced skinfolds, and weight-for-height when compared to NBW children. Birth weight was positively associated with all anthropometric variables, except for BMI, which was not associated with any other variable. The r2 value ranged from .09 (weight-for-age) to .72 (height-for-age). For body composition variables, older children had higher fat mass (β = .26; 95% CI = 0.05-0.48) and fat-free mass (β = 1.10; 95% CI = 0.71-1.48), and boys had lower fat percentage (β = -3.49; 95% CI = -4.35 to -2.65) and fat mass (β = -.92; 95% CI = -1.31 to -0.55) than girls. Birth weight was also positively associated with fat-free mass.

CONCLUSION

LBW seems to influence some growth indicators of children living in Boane, however, current environmental factors seem to weaken this association. Our results suggest that public policies involving healthy nutrition and physical activity can reverse the effects of low weight in children from Boane.

The Current State of Knowledge on Osteoporosis in Holocaust Survivors and Their Descendants

OBJECTIVE

Starvation in early life can cause poor bone health and metabolic aberrations in bone minerals, leading to abnormal bone development. Holocaust survivors have been exposed to starvation and malnutrition before and during World War II. This paper aims to provide the current state of knowledge on the osteoporosis risk in Holocaust survivors and their descendants.

METHODS

The PubMed and Scopus databases were searched. Papers that reported original data on the risk of osteoporosis in Holocaust survivors and in their offspring were included in the study.

RESULTS

Ten studies were included in this review. The majority of studies were case-control ones (n=7) versus two self-reported and one longitudinal study. Despite the limited cohort numbers and the small number of studies in the literature, the data showed a potential increased risk of osteoporosis in Holocaust survivors and especially in their descendants.

CONCLUSIONS

The review of these studies showed a higher prevalence of osteoporosis among Holocaust survivors and their offspring. Knowledge of the trans-generational inheritance of osteoporosis in the descendants of Holocaust survivors should increase the awareness of primary care health workers on osteoporosis screening and early diagnosis and implementation of preventive measures, including adequate vitamin D and calcium supplementation, and pharmacological treatment.

Epigenetic Aging in Early Life: Role of Maternal and Early Childhood Nutrition

PURPOSE OF REVIEW

Early life presents a pivotal period during which nutritional exposures are more likely to cause epigenetic modifications, which may impact an individual's health during adulthood. This article reviews the current evidence regarding maternal and early childhood nutritional exposures and their role in epigenetic aging.

RECENT FINDINGS

Maternal and early life consumption of diets higher in fiber, antioxidants, polyphenols, B vitamins, vitamin D, and ω-3 fatty acids is associated with slower epigenetic aging. Conversely, diets higher in glycemic load, fat, saturated fat, and ω-6 fatty acids demonstrate a positive association with epigenetic aging. Maternal and early life nutrition directly and indirectly influences epigenetic aging via changes in one-carbon metabolism, cardiometabolic health, and the microbiome. Clinical trials are warranted to determine the specific foods, dietary patterns, and dietary supplements that will normalize or lower epigenetic aging across the life course.

Multigenerational transmission of obesity: A systematic review and meta-analysis

There is a strong link between parental and offspring obesity status. However, the state of epidemiological evidence on multigenerational transmission of overweight/obesity, such as from grandparents to grandchildren, is relatively unknown. This systematic review collates and appraises existing evidence on multigenerational transmission of overweight/obesity and uses meta-analytic estimates for quantitative synthesis. Six electronic databases were searched for publications reporting the relationship between grandparents and their grandchildren overweight/obesity status. A total of 25 studies from 17 countries with a combined population of 238,771 study participants met the inclusion criteria. About 60% (15) of the reviewed studies reported a positive association between grandparent-grandchild (GP-GC) overweight/obesity, out of which 11 were statistically significant. Seven studies reported odds ratios of GP-GC overweight/obesity associations and were included in the meta-analysis. The pooled estimates showed a significant GP-GC association in overweight/obesity status (odds ratio [OR]: 1.79, 95% confidence interval [CI]: 1.01-2.57). Thus, the current research evidence shows that grandchildren's overweight/obesity status is associated with their grandparents' overweight/obesity status, indicating a multigenerational transmission of obesity. However, more studies, especially from developing countries, are required to assess the robustness of these findings. Future studies should also focus on the mechanisms through which this transmission occurs.

Calcium supplementation during pregnancy and long‐term offspring outcome: a systematic literature review and meta‐analysis

The World Health Organization currently recommends calcium supplementation for pregnant women, especially those with low calcium intakes, to reduce the risk of hypertension and preeclampsia. We aimed to evaluate the effect of this intervention on selected offspring outcomes. A systematic search was conducted in 11 databases for published randomized controlled trials (RCTs) on the effect of maternal calcium supplementation with or without vitamin D during pregnancy on selected offspring cardiovascular, growth, and metabolic and neurodevelopmental outcomes. Screening of titles and abstracts of 3555 records and full texts of 31 records yielded six RCTs (nine reports, n = 1616). Forest plot analyses were performed if at least two studies presented comparable data on the same outcome. In one study (n = 591), high‐dose calcium supplementation during pregnancy was associated with a decreased risk of offspring high systolic blood pressure at 5–7 years of age (risk ratio = 0.59; 95% confidence interval: 0.39–0.90). The effects of the intervention on offspring growth, metabolic, and neurodevelopmental outcomes remain unknown because of conflicting or insufficient data. High risk of attrition bias decreased the quality of the evidence. Limited available data from RCTs do not provide sufficient evidence to conclude that prenatal calcium supplementation influences offspring health outcomes beyond the newborn period.

Leptin improves the in vitro development of preimplantation rabbit embryos under oxidative stress of cryopreservation

Vitrification is an economically effective method for embryo cryopreservation in human and livestock animals; however, it carries the risk of damage by the exposure to severe oxidative stress. The present study was conducted to evaluate the effect of leptin at different levels on the in vitro development of fresh and vitrified preimplantation embryos in a rabbit model. Normal embryos at morulae stage were randomly cultured for 2 h with 0, 10, 20 or 100 ng/mL of leptin, then were cultured for further 48 h as freshly or after vitrification. Thereafter, developed blastocysts form the best leptin level in fresh and vitrified embryos along with their controls were allocated to analyze the pro-oxidant (malondialdehyde, MDA; nitric oxide, NO), antioxidant (total antioxidant capacity, TAC; superoxide dismutase, SOD; glutathione peroxidase, GPx), apoptotic (Bcl-2 associated X protein, BAX; heat shock 60kD protein member 1, HSP60; tumor necrosis factor alpha, TNFα) and developmental (sex determining region Y box protein 2, SOX2; Nanog homeobox protein, NANOG; Octamer-binding protein 4, OCT4) biomarkers. Results indicate that expanding and hatching rates of embryos were significantly higher at 20 ng/mL leptin than the other levels, while vitrification had an independent suppression effect on the in vitro development rates. The MDA and NO were significantly higher, while TAC, SOD and GPx were significantly lower in the vitrified than fresh embryos. In contrast, leptin treatment significantly decreased the pro-oxidant biomarkers and increased the antioxidant biomarkers in both fresh and vitrified embryos. Vitrification significantly increased the antiapoptotic biomarkers, and decreased the developmental biomarkers in embryos. In contrast, leptin decreased the BAX and TNFα, increased the HSP60, and moreover, ameliorated the reduction of developmental biomarkers in the vitrified embryos. These results conclude that leptin could be used as antiapoptotic and antioxidant promotor to support the in vitro embryonic development, particularly under oxidative stress emerged from cryopreservation programs.

Transcriptome analysis reveals liver metabolism programming in kids from nutritional restricted goats during mid-gestation

Background

Maternal nutrient restriction during pregnancy causes a metabolic disorder that threatens the offspring's health in humans and animals. However, the molecular mechanism of how undernutrition affecting hepatic metabolism of fetal or postnatal offspring is still unclear. We aimed to investigate transcriptomic changes of fetal livers in response to maternal malnutrition in goats during mid-gestation and to explore whether these changes would disappear when the nutrition was recovered to normal level during mid-gestation using goats (Capra hircus) as the experimental animals.

Methods

Fifty-three pregnant goats were subjected to a control (100% of the maintenance requirements, CON) or a restricted (60% of the maintenance requirements on day 45 to day 100 of gestation and then realimentation, RES) diet. A total of 16 liver samples were collected from fetal goats on day 100 of gestation and goat kids of postnatal day 90 to obtain hepatic transcriptional profiles using RNA-Seq.

Results

Principal component analysis of the hepatic transcriptomes presented a clear separation by growth phase (fetus and kid) rather than treatment. Maternal undernutrition up-regulated 86 genes and down-regulated 76 genes in the fetal liver of the FR group as compared to the FC group. KEGG pathway analysis showed the DEGs mainly enriched in protein digestion and absorption, steroid biosynthesis, carbohydrate digestion and absorption and bile secretion. A total of 118 significant DEGs (fold change > 1.2 and FDR < 0.1) within KR vs. KC comparison was identified with 79 up-regulated genes and down-regulated 39 genes, and these DEGs mainly enriched in the biosynthesis of amino acids, citrate cycle, valine, leucine and isoleucine biosynthesis and carbon metabolism.

Conclusion

Hepatic transcriptome analysis showed that maternal undernutrition promoted protein digestion and absorption in the fetal livers, while which restrained carbohydrate metabolism and citric acid cycle in the livers of kid goats after realimentation. The results indicate that maternal undernutrition during mid-gestation causes hepatic metabolism programming in kid goats on a molecular level.

Maternal biomarker patterns for metabolism and inflammation in pregnancy are influenced by multiple micronutrient supplementation and associated with child biomarker patterns and nutritional status at 9-12 years of age

Maternal nutritional status influences fetal development and long-term risk for adult non-communicable diseases. However, the underlying mechanisms remain poorly understood. We examined whether biomarkers for metabolism and inflammation during pregnancy were associated with maternal health and with child biomarkers and health at 9-12 years of age in 44 maternal-child dyads from the Supplementation with Multiple Micronutrients Intervention Trial (SUMMIT, ISRCTN34151616) in Lombok, Indonesia. Archived blood for each dyad from maternal enrollment, later in pregnancy, postpartum, and from children at 9-12 years comprised 132 specimens. Multiplex microbead immunoassays were used to quantify vitamin D-binding protein (D), adiponectin (A), retinol-binding protein 4 (R), C-reactive protein (C), and leptin (L). Principal component analysis (PCA) revealed distinct variance patterns, i.e. principal components (PC), for baseline pregnancy, bp.pc1.D↓A↓R↓ and bp.pc2.C↓L↑; combined follow-up during pregnancy and postpartum, dp-pp.pc1.D↑↓A↑R↑↓L↓ and dp-pp.pc2.A↑C↑L↑; and children, ch.pc1.D↑R↑C↑ and ch.pc2.D↓A↑L↑. Maternal multiple micronutrient (MMN) supplementation led to an association of baseline maternal bp.pc2.C↓L↑ with decreased post-supplementation maternal dp-pp.pc2.A↑C↑L↑ (p = 0.022), which was in turn associated with both increased child ch.pc1.D↑R↑C↑ (p = 0.036) and decreased child BMI z-score (BMIZ) (p = 0.022). Further analyses revealed an association between maternal dp-pp.pc1.D↑↓A↑R↑↓L↓ and increased child BMIZ (p = 0.036). Child ch.pc1.D↑R↑C↑ was associated with decreased birth weight (p = 0.036) and increased child BMIZ (p = 0.002). Child ch.pc2.D↓A↑L↑ was associated with increased child BMIZ (p = 0.005), decreased maternal height (p = 0.030) and girls (p = 0.002). A pattern of elevated maternal adiponectin and leptin in pregnancy was associated with increased C-reactive protein, vitamin A, and D binding proteins pattern in children, suggesting biomarkers acting in concert may have qualitative as well as quantitative influence beyond single biomarker effects. Patterns in pregnancy proximal to birth were more associated with child status. In addition, child patterns were more associated with child status, particularly child BMI. MMN supplementation affects maternal biomarker patterns of metabolism and inflammation in pregnancy, and potentially in the child. However, child nutrition conditions after birth may have a greater impact on metabolism and inflammation.

Oxygen radical disease in the newborn, revisited: Oxidative stress and disease in the newborn period

Thirty years ago, there was an emerging appreciation for the significance of oxidative stress in newborn disease. This prompted a renewed interest in the impact of oxygen therapy for the newborn in the delivery room and beyond, especially in premature infants. Today, the complexity of oxidative stress both in normal regulation and pathology is better understood, especially as it relates to neonatal mitochondrial oxidative stress responses to hyperoxia. Mitochondria are recipients of oxidative damage and have a propensity for oxidative self-injury that has been implicated in the pathogenesis of neonatal lung diseases. Similarly, both intrauterine growth restriction (IUGR) and macrosomia are associated with mitochondrial dysfunction and oxidative stress. Additionally, reoxygenation with 100% O₂ in a hypoxic-ischemic newborn lamb model increased the production of pro-inflammatory cytokines in the brain. Moreover, the interplay between inflammation and oxidative stress in the newborn is better understood because of animal studies. Transcriptomic analyses have found a number of genes to be differentially expressed in murine models of bronchopulmonary dysplasia (BPD). Epigenetic changes have also been detected both in animal models of BPD and premature infants exposed to oxygen. Antioxidant therapy to prevent newborn disease has not been very successful; however, new therapeutic principles, like melatonin, are under investigation.

Developmental programming of adult haematopoiesis system

The Barker hypothesis of 'foetal origin of adult diseases' has led to emphasize the concept of 'developmental programming', based on the crucial role of epigenetic factors. Accordingly, it has been demonstrated that parental adversity (before conception and during pregnancy) and foetal factors (i.e., hypoxia, malnutrition and placental insufficiency) permanently modify the physiological systems of the progeny, predisposing them to premature ageing and chronic disease during adulthood. Thus, an altered functionality of the endocrine, immune, nervous and cardiovascular systems is observed in the progeny. However, it remains to be understood whether the haematopoietic system itself also represents a portrait of foetal programming. Here, we provide evidence, reporting and discussing related theories, and results of studies described in the literature. In addition, we have outlined our opinions and suggest how it is possible to intervene to correct foetal mal-programming. Some pro-health interventions and recommendations are proposed, with the hope of guarantee the health of future generations and trying to combat the continuous increase in age-related diseases in human populations.

Maternal and environmental risk factors for neonatal AKI and its long-term consequences

Acute kidney injury (AKI) is a common and life-threatening complication in critically ill neonates. Gestational risk factors for AKI include premature birth, intrauterine growth restriction and low birthweight, which are associated with poor nephron development and are often the consequence of pre-gestational and gestational factors, such as poor nutritional status. Our understanding of how to best optimize renal development and prevent AKI is in its infancy; however, the identification of pre-gestational and gestational factors that increase the risk of adverse neonatal outcomes and the implementation of interventions, such as improving nutritional status early in pregnancy, have the potential to optimize fetal growth and reduce the risk of preterm birth, thereby improving kidney health. The overall risk of AKI among critically ill and premature neonates is exacerbated postnatally as these infants are often exposed to dehydration, septic shock and potentially nephrotoxic medications. Strategies to improve outcomes - for example, through careful evaluation of nephrotoxic drugs - may reduce the incidence of AKI and its consequences among this population. Management strategies and updated technology that will support neonates with AKI are greatly needed. Extremely premature infants and those who survive an episode of AKI should be screened for chronic kidney disease until early adulthood. Here, we provide an overview of our current understanding of neonatal AKI, focusing on its relationship to preterm birth and growth restriction. We describe factors that prevent optimal nephrogenesis during pregnancy and provide a framework for future explorations designed to maximize outcomes in this vulnerable population.

Nutritional Behaviors of Polish Adolescents: Results of the Wise Nutrition-Healthy Generation Project

BACKGROUND

Recognition of the dominant dietary behaviors with respect to gender and specific age groups can be helpful in the development of targeted and effective nutritional education. The purpose of the study was to analyze the prevalence of the selected eating behaviors (favorable: Consuming breakfasts, fruit, vegetables, milk and milk beverages, whole grain bread and fish; adverse: Regular consumption of sweets, sugared soft drinks and fast-foods) among Polish adolescents.

METHODS

Data on the nutritional behaviors were collected using a questionnaire. Body mass status was assessed based on weight and height measurements.

RESULTS

14,044 students aged 13-19 years old from 207 schools participated in the study. Significant differences were found in the nutritional behaviors depending on age, gender and nutritional status. Favorable nutritional behaviors corresponded with each other, the same relationship was observed for adverse behaviors. The frequency of the majority of healthy eating behaviors decreased with age, whereas the incidence of adverse dietary behaviors increased with age. Underweight adolescents more often consumed sugared soft drinks, sweets and fast food compared to their peers with normal and excessive body mass.

CONCLUSIONS

A significant proportion of adolescents showed unhealthy nutritional behaviors. Showing changes in the incidence of nutritional behaviors depending on age, gender and body weight status, we provide data that can inform the development of dietary interventions tailored to promote specific food groups among adolescents on different stages of development to improve their diet quality.

Programmed Epigenetic DNA Methylation-Mediated Reduced Neuroprogenitor Cell Proliferation and Differentiation in Small-for-Gestational-Age Offspring

Small-for-gestational age (SGA) human newborns have an increased risk of hyperphagia and obesity, as well as a spectrum of neurologic and neurobehavioral abnormalities. We have shown that the SGA hypothalamic (appetite regulatory site) neuroprogenitor cells (NPCs) exhibit reduced proliferation and neuronal differentiation. DNA methylation (DNA methyltransferase; DNMT1) regulates neurogenesis by maintaining NPC proliferation and suppressing premature differentiation. Once differentiation ensues, DNMT1 preferentially promotes neuronal and inhibits astroglial fate. We hypothesized that the programmed dysfunction of NPC proliferation and differentiation in SGA offspring is epigenetically mediated via DNMT1. Pregnant rats received either ad libitum food (Control) or were 50% food-restricted to create SGA offspring. Primary hypothalamic NPCs from 1 day old SGA and Controls newborns were cultured and transfected with nonspecific or DNMT1-specific siRNA. NPC proliferation and protein expression of specific markers of NPC (nestin), neuroproliferative transcription factor (Hes1), neurons (Tuj1) and astrocytes (GFAP) were determined. Under basal conditions, SGA NPCs exhibited decreased DNMT1 and reduced proliferation and differentiation, as compared to Controls. In both SGA and Controls, DNMT1 siRNA in complete media inhibited NPC proliferation, consistent with reduced expression of nestin and Hes1. In differentiation media, DNMT1 siRNA decreased expression of Tuj1 but increased GFAP. In vivo data replicated these findings. In SGA offspring, impaired neurogenesis is epigenetically mediated, in part, via reduction in DNMT1 expression and suppression of Hes1 resulting in NPC differentiation. It is likely that the maturation of regions beyond the hypothalamus (e.g., cerebral cortex, hippocampus) may be impacted, contributing to poor cognitive and neurobehavioral competency in SGA offspring.

The Long-Term Effects of Dietary Nutrient Intakes during the First 2 Years of Life in Healthy Infants from Developed Countries: An Umbrella Review

The role of both qualitative and quantitative early nutrient intakes on later health has been suggested for decades and supported by observational studies on humans, mainly preterm and low-birth-weight infants, and animal models. However, to date, no comprehensive review has been conducted to evaluate the full impact of nutritional variables on healthy full-term infants. This umbrella review considers meta-analyses and systematic reviews on the health effects of different nutritional exposures or interventions in the first 2 y of life of healthy full-term infants in developed countries. The systematic reviews and meta-analyses published by March 2018 in MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews were included. The following outcomes were considered: growth and obesity, cardiovascular disease, neurodevelopment, allergy and autoimmunity, infections, and malignancy. Breastfeeding and complementary feeding were considered separately and analyzed by means of their differences in delivering heterogeneous food-related variables. The resulting data on the long-term effect of early nutritional differences in healthy full-term infants were found to be inconclusive. Only breastfeeding has a beneficial effect, which is nevertheless slight and limited to just a few outcome measures, whereas the type and duration required to be effective are still unclear. As regards the complementary feeding period, no clear effects of different dietary interventions emerge in terms of health outcomes. Available evidence on the health effects of differences in early nutrition in healthy full-term infants still remains largely inconclusive.

Neonatal and Long-Term Consequences of Fetal Growth Restriction

BACKGROUND

Fetal Growth Restriction (FGR) is one of the most common noxious antenatal conditions in humans, inducing a substantial proportion of preterm delivery and leading to a significant increase in perinatal mortality, neurological handicaps and chronic diseases in adulthood. This review summarizes the current knowledge about the postnatal consequences of FGR, with a particular emphasis on the long-term consequences on respiratory, cardiovascular and neurological structures and functions.

RESULT AND CONCLUSION

FGR represents a global health challenge, and efforts are urgently needed to improve our understanding of the critical factors leading to FGR and subsequent insults to the developing organs.

Development of a new diet-induced obesity (DIO) model using Wistar lean rats

Obesity is an increasingly severe socioeconomic health issue worldwide. Rodents with diet-induced obesity (DIO) are widely used as models of obesity. The main aim of this study was to establish a DIO model using Wistar lean (+/+ or +/-) rats by feeding a high-fat diet (45 kcal% fat) to dams during the latter term of gestation and the lactation period. A second aim was to examine the effect of post-weaning nutrition independently of maternal nutrition. Some pups (group D) were fed the same high-fat diet after weaning, while others (group C) were fed a chow diet after weaning. In the control groups, the dams were fed only the chow diet and the pups were fed either the chow diet (group A) or high-fat diet (group B) after weaning. Between 16-21 weeks of age, group D showed the heaviest body weight and visceral adipose tissue weight among groups, in addition to glucose intolerance and high concentrations of glucose and cholesterol in plasma. Group B showed mild obesity with dysfunctions in glucose and lipid metabolism. Interestingly, group C showed mild obesity and impaired glucose tolerance, similar to the phenotype of group B. In summary, the high-fat diet challenge of dams during gestation and lactation caused an increase in adipose tissue weight and abnormalities of glucose and lipid metabolism in their adult offspring. Our results suggest the importance of both maternal and post-weaning nutrition for DIO production and provide useful DIO models.

Maternal obesity increases inflammation and exacerbates damage following neonatal hypoxic-ischaemic brain injury in rats

OBJECTIVE

In humans, maternal obesity is associated with an increase in the incidence of birth related difficulties. However, the impact of maternal obesity on the severity of brain injury in offspring is not known. Recent studies have found evidence of increased glial response and inflammatory mediators in the brains as a result of obesity in humans and rodents. We hypothesised that hypoxic-ischaemic (HI) brain injury is greater in neonatal offspring from obese rat mothers compared to lean controls.

METHODS

Female Sprague Dawley rats were randomly allocated to high fat (HFD, n=8) or chow (n=4) diet and mated with lean male rats. On postnatal day 7 (P7), male and female pups were randomly assigned to HI injury or control (C) groups. HI injury was induced by occlusion of the right carotid artery followed by 3h exposure to 8% oxygen, at 37°C. Control pups were removed from the mother for the same duration under ambient conditions. Righting behaviour was measured on day 1 and 7 following HI. The extent of brain injury was quantified in brain sections from P14 pups using cresyl violet staining and the difference in volume between brain hemispheres was measured.

RESULTS

Before mating, HFD mothers were 11% heavier than Chow mothers (p<0.05, t-test). Righting reflex was delayed in offspring from HFD-fed mothers compared to the Chow mothers. The Chow-HI pups showed a loss in ipsilateral brain tissue, while the HFD-HI group had significantly greater loss. No significant difference was detected in brain volume between the HFD-C and Chow-C pups. When analysed on a per litter basis, the size of the injury was significantly correlated with maternal weight. Similar observations were made with neuronal staining showing a greater loss of neurons in the brain of offspring from HFD-mothers following HI compared to Chow. Astrocytes appeared to more hypertrophic and a greater number of microglia were present in the injured hemisphere in offspring from mothers on HFD. HI caused an increase in the proportion of amoeboid microglia and exposure to maternal HFD exacerbated this response. In the contralateral hemisphere, offspring exposed to maternal HFD displayed a reduced proportion of ramified microglia.

CONCLUSIONS

Our data clearly demonstrate that maternal obesity can exacerbate the severity of brain damage caused by HI in neonatal offspring. Given that previous studies have shown enhanced inflammatory responses in offspring of obese mothers, these factors including gliosis and microglial infiltration are likely to contribute to enhanced brain injury.

A Systematic Examination of the Association between Parental and Child Obesity across Countries

Childhood obesity has become a global epidemic. Parents can have an important influence on their children's health behaviors and weight status. Many studies have examined the association between parental and childhood weight status. However, much heterogeneity between studies exists, and the parent-child (P-C) association in obesity has varied. The purpose of this systematic examination and meta-analysis was to examine the strength and variation of the P-C association in obesity and to identify factors (e.g., demographic characteristics and country's economic level) that may influence this association. PubMed was searched for relevant studies published between January 2000 and July 2015. Thirty-two studies from 21 countries met inclusion criteria; 27 reported ORs for the P-C obesity association and were included in a meta-analysis. The meta-analysis showed a strong P-C obesity association (pooled OR: 2.22; 95% CI: 2.09, 2.36), which varied by type of P-C pair (i.e., parents-child, father-child, and mother-child), child age, parent and child weight status, and the country's economic level. Stronger associations were shown in older children than in younger children (β ± SE: 0.02 ± 0.01), in both parents than in father only (β ± SE: 0.51 ± 0.11) or mother only (β ± SE: 0.38 ± 0.11), in parental obesity (β ± SE: 0.26 ± 0.10) and child obesity (β ± SE: 0.28 ± 0.12) than in parental and child overweight, and in high- than in middle-income countries (β ± SE: 0.23 ± 0.08). Thus, research from multiple countries shows significant P-C associations in weight status, but this association varies by child age, type of P-C pair, weight status, and the country's economic level. Results suggest that families and parents should be a key target for obesity intervention efforts.

Maternal Caloric Restriction Implemented during the Preconceptional and Pregnancy Period Alters Hypothalamic and Hippocampal Endocannabinoid Levels at Birth and Induces Overweight and Increased Adiposity at Adulthood in Male Rat Offspring

Exposure to inadequate nutritional conditions in critical windows of development has been associated to disturbances on metabolism and behavior in the offspring later in life. The role of the endocannabinoid system, a known regulator of energy expenditure and adaptive behaviors, in the modulation of these processes is unknown. In the present study, we investigated the impact of exposing rat dams to diet restriction (20% less calories than standard diet) during pre-gestational and gestational periods on: (a) neonatal outcomes; (b) endocannabinoid content in hypothalamus, hippocampus and olfactory bulb at birth; (c) metabolism-related parameters; and (d) behavior in adult male offspring. We found that calorie-restricted dams tended to have a reduced litter size, although the offspring showed normal weight at birth. Pups from calorie-restricted dams also exhibited a strong decrease in the levels of anandamide (AEA), 2-arachidonoylglycerol (2-AG), arachidonic acid (AA) and palmitoylethanolamide (PEA) in the hypothalamus at birth. Additionally, pups from diet-restricted dams displayed reduced levels of AEA in the hippocampus without significant differences in the olfactory bulb. Moreover, offspring exhibited increased weight gain, body weight and adiposity in adulthood as well as increased anxiety-related responses. We propose that endocannabinoid signaling is altered by a maternal caloric restriction implemented during the preconceptional and pregnancy periods, which might lead to modifications of the hypothalamic and hippocampal circuits, potentially contributing to the long-term effects found in the adult offspring.

Intrauterine growth restriction impairs right ventricular response to hypoxia in adult male rats

BACKGROUND

Intrauterine growth restriction (IUGR) predisposes to cardiovascular diseases in adulthood. The mechanisms of this phenomenon remain cryptic. We hypothesized that heart mitochondria in IUGR-born adult rats are more sensitive to acute hypoxia which translates into dysfunctional cardiac response to hypoxic stress.

METHODS

Adult IUGR-born male rats (the offspring of dams fed with calories-restricted diet during pregnancy) were exposed to acute hypoxic stress with echocardiographic assessment of cardiac function. In parallel, mitochondrial respiration in organelles isolated from left ventricle (LV) and right ventricle (RV) was tested in normoxic and anoxic conditions. The extent of post-anoxic inhibition of mitochondrial respiration and cardiac function was compared with controls, non-IUGR rats.

RESULTS

Compared with controls, in the IUGR rats hypoxia significantly reduced only RV contractility, evidenced by decreased fractional shortening, functional area of contraction, and tricuspid annular plane systolic excursion. In isolated mitochondria, anoxic challenge inhibited respiratory chain in both groups of rats. However, compared with controls, the extent of anoxic mitochondrial depression was significantly greater in IUGR-born rats, but only in the organelles isolated from RV.

CONCLUSIONS

In adult IUGR-born rats, mitochondria from RV are hypersensitive to oxygen deprivation and this translates into maladaptive RV cardiac response to acute hypoxia.

Assessment of body composition in Wistar rat offspring by DXA in relation to prenatal and postnatal nutritional manipulation

BACKGROUND

This experimental study aims to investigate the impact of combinations of prenatal and postnatal food manipulation on body composition in rat offspring.

METHODS

On day 12 of gestation, 100 timed pregnant rats were randomized into two nutritional groups: standard laboratory and 50% starved. Pups born to starved mothers were subdivided, based on birthweight (BiW), into fetal growth restricted (FGR) and non-FGR. Pups were born on day 21, cross-fostered, then left undisturbed lactating until the 26th postnatal day when they underwent dual-energy X-ray absorptiometry (DXA) examination.

RESULTS

Prenatally control-fed animals had a significantly greater body weight at 26 d postnatally than the prenatally starved groups, irrespective of their postnatal diet (P < 0.001). Postnatal control diet was associated with significantly increased abdominal and total fat in non-FGR compared to FGR rats (P < 0.001). non-FGR/CONTROL rats showed higher values of abdominal fat than prenatally starved animals that were starved postnatally irrespective of their birth weight (P < 0.001). Postnatal control diet significantly increased total bone mineral content (BMC), head BMC, head area, abdominal BMC in non-FGR compared to FGR rats (P < 0.001).

CONCLUSION

Interaction between prenatal and postnatal nutrition affects growth, abdominal adiposity, and bone accrual in Wistar rats' offspring at 26 d of life.

Extrauterine growth restriction on pulmonary vascular endothelial dysfunction in adult male rats: the role of epigenetic mechanisms

Objective:

Early postnatal life is considered as a critical time window for the determination of long-term metabolic states and organ functions. Extrauterine growth restriction (EUGR) causes the development of adult-onset chronic diseases, including pulmonary hypertension. However, the effects of nutritional disadvantages during the early postnatal period on pulmonary vascular consequences in later life are not fully understood. Our study was designed to test whether epigenetics dysregulation mediates the cellular memory of this early postnatal event.

Methods and results:

To test this hypothesis, we isolated pulmonary vascular endothelial cells by magnetic-activated cell sorting from EUGR and control rats. A postnatal insult, nutritional restriction-induced EUGR caused development of an increased pulmonary artery pressure at 9 weeks of age in male Sprague–Dawley rats. Methyl-DNA immune precipitation chip, genome-scale mapping studies to search for differentially methylated loci between control and EUGR rats, revealed significant difference in cytosine methylation between EUGR and control rats. EUGR changes the cytosine methylation at approximately 500 loci in male rats at 9 weeks of age, preceding the development of pulmonary hypertension and these represent the candidate loci for mediating the pathogenesis of pulmonary vascular disease that occurs later in life. Gene ontology analysis on differentially methylated genes showed that hypermethylated genes in EUGR are vascular development-associated genes and hypomethylated genes in EUGR are late-differentiation-associated and signal transduction genes. We validated candidate dysregulated loci with the quantitative assays of cytosine methylation and gene expressions.

Conclusion:

These results demonstrate that epigenetics dysregulation is a strong mechanism for propagating the cellular memory of early postnatal events, causing changes in the expression of genes and long-term susceptibility to pulmonary hypertension, and further providing a new insight into the prevention and treatment of EUGR-related pulmonary hypertension.

Epigenetics and Human Disease

Genetic causes for human disorders are being discovered at an unprecedented pace. A growing subclass of disease-causing mutations involves changes in the epigenome or in the abundance and activity of proteins that regulate chromatin structure. This article focuses on research that has uncovered human diseases that stem from such epigenetic deregulation. Disease may be caused by direct changes in epigenetic marks, such as DNA methylation, commonly found to affect imprinted gene regulation. Also described are disease-causing genetic mutations in epigenetic modifiers that either affect chromatin in trans or have a cis effect in altering chromatin configuration.

DNA hypermethylation of acetoacetyl-CoA synthetase contributes to inhibited cholesterol supply and steroidogenesis in fetal rat adrenals under prenatal nicotine exposure

Prenatal nicotine exposure is a risk factor for intrauterine growth retardation (IUGR). Steroid hormones synthesized from cholesterol in the fetal adrenal play an important role in the fetal development. The aim of this study is to investigate the effects of prenatal nicotine exposure on steroidogenesis in fetal rat adrenals from the perspective of cholesterol supply and explore the underlying epigenetic mechanisms. Pregnant Wistar rats were administered 1.0mg/kg nicotine subcutaneously twice a day from gestational day (GD) 7 to GD17. The results showed that prenatal nicotine exposure increased IUGR rates. Histological changes, decreased steroid hormone concentrations and decreased cholesterol supply were observed in nicotine-treated fetal adrenals. In the gene expression array, the expression of genes regulating ketone metabolic process decreased in nicotine-treated fetal adrenals. The following conjoint analysis of DNA methylation array with these differentially expressed genes suggested that acetoacetyl-CoA synthetase (AACS), the enzyme utilizing ketones for cholesterol supply, may play an important role in nicotine-induced cholesterol supply deficiency. Moreover, the decreased expression of AACS and increased DNA methylation in the proximal promoter of AACS in the fetal adrenal was verified by real-time reverse-transcription PCR (RT-PCR) and bisulfite sequencing PCR (BSP), respectively. In conclusion, prenatal nicotine exposure can cause DNA hypermethylation of the AACS promoter in the rat fetal adrenal. These changes may result in decreased AACS expression and cholesterol supply, which inhibits steroidogenesis in the fetal adrenal.

FXR expression is associated with dysregulated glucose and lipid levels in the offspring kidney induced by maternal obesity

Background

Maternal obesity is associated with dysregulation of glucose and lipid metabolism with consequent exposure of the fetus to an abnormal metabolic milieu. It is recognized that maternal obesity predisposes offspring to chronic kidney disease (CKD). We aimed to determine whether the nuclear Farnesoid X receptor (FXR), known to play a role in maintaining homeostasis of glucose and lipid metabolism, is involved in renal injury in offspring of obese mothers.

Methods

Maternal obesity was established in a rat model by feeding dams with high-fat diet prior to and during pregnancy and lactation. The offspring’s kidneys were examined at postnatal Day 1and Day 20. Human kidney 2 (HK2) cells were exposed to high glucose with or without the FXR agonist GW4064 or when FXR mRNA was silenced.

Results

Glucose intolerance in the offspring of obese mothers was evident at weaning, with associated downregulation of renal FXR expression and upregulation of monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor-β1 (TGF-β1). HK2 cells exposed to high glucose had reduced FXR expression and increased MCP-1, TGF-β1, fibronectin and collagen IV expression, which was reversed in the presence of GW4064. FXR-silenced HK2 cells had amplified pro-inflammatory and pro-fibrotic markers under high glucose conditions.

Conclusions

Maternal obesity influences renal expression of pro-inflammatory and fibrotic factors that predispose the offspring to CKD. This was associated with the downregulation of the renal FXR expression suggesting a potential protective role for FXR.

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-015-0032-3) contains supplementary material, which is available to authorized users.

Maternal health and eating habits: metabolic consequences and impact on child health

Apart from direct inheritance and the effects of a shared environment, maternal health, eating habits and diet can affect offspring health by developmental programming. Suboptimal maternal nutrition (i.e., either a reduction or an increase above requirement) or other insults experienced by the developing fetus can induce significant changes in adipose tissue and brain development, energy homeostasis, and the structure of vital organs. These can produce long-lasting adaptations that influence later energy balance, and increase the susceptibility of that individual to obesity and the components of the metabolic syndrome. Studies that elucidate the mechanisms behind these associations will have a positive impact on the health of the future adult population and may help to contain the obesity epidemic.

Early Life Nutrition and Energy Balance Disorders in Offspring in Later Life

The global pandemic of obesity and type 2 diabetes is often causally linked to changes in diet and lifestyle; namely increased intake of calorically dense foods and concomitant reductions in physical activity. Epidemiological studies in humans and controlled animal intervention studies have now shown that nutritional programming in early periods of life is a phenomenon that affects metabolic and physiological functions throughout life. This link is conceptualised as the developmental programming hypothesis whereby environmental influences during critical periods of developmental plasticity can elicit lifelong effects on the health and well-being of the offspring. The mechanisms by which early environmental insults can have long-term effects on offspring remain poorly defined. However there is evidence from intervention studies which indicate altered wiring of the hypothalamic circuits that regulate energy balance and epigenetic effects including altered DNA methylation of key adipokines including leptin. Studies that elucidate the mechanisms behind these associations will have a positive impact on the health of future populations and adopting a life course perspective will allow identification of phenotype and markers of risk earlier, with the possibility of nutritional and other lifestyle interventions that have obvious implications for prevention of non-communicable diseases.

Methylating micronutrient supplementation during pregnancy influences foetal hepatic gene expression and IGF signalling and increases foetal weight

PURPOSE

Maternal diet during pregnancy impacts foetal growth and development. In particular, dietary levels of methylating micronutrients (methionine, folate, choline, vitamins B6, and B12) interfere with the availability and allocation of methyl groups for methylation reactions, thereby influencing normal transcription. However, the currently recommended methylating micronutrient supplementation regimen is haphazard and arbitrary at best.

METHODS

To investigate the effects of a methylating micronutrient-rich maternal diet, pregnant Pietrain sows were fed either a standard diet (CON) or a diet supplemented with methionine, folate, choline, B6, B12, and zinc (MET). Foetal liver and muscle (M. longissimus dorsi) tissues were collected at 35, 63, and 91 days post-conception. Transcriptional responses to diet were assessed in foetal liver. Altered insulin-like growth factor (IGF) signalling in transcriptome analyses prompted investigation of IGF-2 and insulin-like growth factor binding proteins (IGFBPs) levels in muscle and liver.

RESULTS

Maternal diet enriched with methylating micronutrients was associated with increased foetal weight in late gestation. Hepatic transcriptional patterns also revealed differences in vitamin B6 and folate metabolism between the two diets, suggesting that supplementation was effective. Additionally, shifts in growth-supporting metabolic routes of the lipid and energy metabolism, including IGF signalling, and of cell cycle-related pathways were found to occur in liver tissue in supplemented individuals. Weight differences and modulated IGF pathways were also reflected in the muscle content of IGF-2 (increased in MET) and IGFBP-2 (decreased in MET).

CONCLUSIONS

Maternal dietary challenges provoke stage-dependent and tissue-specific transcriptomic modulations in the liver pointing to molecular routes contributing to the organismal adaptation. Subtle effects on late foetal growth are associated with changes in the IGF signalling mainly in skeletal muscle tissue that is less resilient to dietary stimuli than liver.

Fetal programming in meat production

Nutrient fluctuations during the fetal stage affects fetal development, which has long-term impacts on the production efficiency and quality of meat. During the early development, a pool of mesenchymal progenitor cells proliferate and then diverge into either myogenic or adipogenic/fibrogenic lineages. Myogenic progenitor cells further develop into muscle fibers and satellite cells, while adipogenic/fibrogenic lineage cells develop into adipocytes, fibroblasts and resident fibro-adipogenic progenitor cells. Enhancing the proliferation and myogenic commitment of progenitor cells during fetal development enhances muscle growth and lean production in offspring. On the other hand, promoting the adipogenic differentiation of adipogenic/fibrogenic progenitor cells inside the muscle increases intramuscular adipocytes and reduces connective tissue, which improves meat marbling and tenderness. Available studies in mammalian livestock, including cattle, sheep and pigs, clearly show the link between maternal nutrition and the quantity and quality of meat production. Similarly, chicken muscle fibers develop before hatching and, thus, egg and yolk sizes and hatching temperature affect long-term growth performance and meat production of chicken. On the contrary, because fishes are able to generate new muscle fibers lifelong, the impact of early nutrition on fish growth performance is expected to be minor, which requires further studies.

Increased DNA methylation of scavenger receptor class B type I contributes to inhibitory effects of prenatal caffeine ingestion on cholesterol uptake and steroidogenesis in fetal adrenals

Steroid hormones synthesized from cholesterol in the fetal adrenal are crucial for fetal development. We have observed the inhibited fetal adrenal corticosterone synthesis and increased intrauterine growth retardation (IUGR) rate in rats under prenatal caffeine ingestion. The aim of this study is to evaluate the effects of prenatal caffeine ingestion on cholesterol supply in fetal adrenal steroidogenesis in rats and explore the underlying epigenetic mechanisms. Pregnant Wistar rats were treated with 60 mg/kg · d caffeine from gestational day (GD) 7 to GD17. Histological changes of fetal adrenals and increased IUGR rates were observed in the caffeine group. There were significantly decreased steroid hormone contents and cholesterol supply in caffeine-treated fetal adrenals. Data from the gene expression array suggested that prenatal caffeine ingestion caused increased expression of genes related to DNA methylation and decreased expression of genes related to cholesterol uptake. The following conjoint analysis of DNA methylation array with these differentially expressed genes suggested that scavenger receptor class B type I (SR-BI) may play an important role in caffeine-induced cholesterol supply deficiency. Moreover, real-time RT-PCR and immunohistochemical detection certified the inhibitory effects of caffeine on both mRNA expression and protein expression of SR-BI in the fetal adrenal. And the increased DNA methylation frequency in the proximal promoter of SR-BI was confirmed by bisulfite-sequencing PCR. In conclusion, prenatal caffeine ingestion can induce DNA hypermethylation of the SR-BI promoter in the rat fetal adrenal. These effects may lead to decreased SR-BI expression and cholesterol uptake, which inhibits steroidogenesis in the fetal adrenal.

DNA methylation mediates the effect of maternal smoking during pregnancy on birthweight of the offspring

Background: We examined whether the effect of maternal smoking during pregnancy on birthweight of the offspring was mediated by smoking-induced changes to DNA methylation in cord blood.

Methods: First, we used cord blood of 129 Dutch children exposed to maternal smoking vs 126 unexposed to maternal and paternal smoking (53% male) participating in the GECKO Drenthe birth cohort. DNA methylation was measured using the Illumina HumanMethylation450 Beadchip. We performed an epigenome-wide association study for the association between maternal smoking and methylation followed by a mediation analysis of the top signals [false-discovery rate (FDR) < 0.05]. We adjusted both analyses for maternal age, education, pre-pregnancy BMI, offspring’s sex, gestational age and white blood cell composition. Secondly, in 175 exposed and 1248 unexposed newborns from two independent birth cohorts, we replicated and meta-analysed results of eight cytosine-phosphate-guanine (CpG) sites in the GFI1 gene, which showed the most robust mediation. Finally, we performed functional network and enrichment analysis.

Results: We found 35 differentially methylated CpGs (FDR < 0.05) in newborns exposed vs unexposed to smoking, of which 23 survived Bonferroni correction (P < 1 × 10^-7). These 23 CpGs mapped to eight genes: AHRR, GFI1, MYO1G, CYP1A1, NEUROG1, CNTNAP2, FRMD4A and LRP5. We observed partial confirmation as three of the eight CpGs in GFI1 replicated. These CpGs partly mediated the effect of maternal smoking on birthweight (Sobel P < 0.05) in meta-analysis of GECKO and the two replication cohorts. Differential methylation of these three GFI1 CpGs explained 12–19% of the 202 g lower birthweight in smoking mothers. Functional enrichment analysis pointed towards activation of cell-mediated immunity.

Conclusions: Maternal smoking during pregnancy was associated with cord blood methylation differences. We observed a potentially mediating role of methylation in the association between maternal smoking during pregnancy and birthweight of the offspring. Functional network analysis suggested a role in activating the immune system.

Nutritional influences over the life course on lean body mass of individuals in developing countries

The double burden of childhood undernutrition and adult-onset adiposity in transitioning societies poses a significant public health challenge. The development of suboptimal lean body mass (LBM) could partly explain the link between these two forms of malnutrition. This review examines the evidence on both the role of nutrition in “developmental programming” of LBM and the nutritional influences that affect LBM throughout the life course. Studies from developing countries assessing the relationship of early nutrition with later LBM provide important insights. Overall, the evidence is consistent in suggesting a positive association of early nutritional status (indicated by birth weight and growth during first 2 years) with LBM in later life. Evidence on the impact of maternal nutritional supplementation during pregnancy on later LBM is inconsistent. In addition, the role of nutrients (protein, zinc, calcium, vitamin D) that can affect LBM throughout the life course is described. Promoting optimal intakes of these important nutrients throughout the life course is important for reducing childhood undernutrition as well as for improving the LBM of adults.

Regulation of early human growth: impact on long-term health

Growth and development are central characteristics of childhood. Deviations from normal growth can indicate serious health challenges. The adverse impact of early growth faltering and malnutrition on later health has long been known. In contrast, the impact of rapid early weight and body fat gain on programming of later disease risk have only recently received increased attention. Numerous observational studies related diet in early childhood and rapid early growth to the risk of later obesity and associated disorders. Causality was confirmed in a large, double-blind randomised trial testing the 'Early Protein Hypothesis'. In this trial we found that attenuation of protein supply in infancy normalized early growth and markedly reduced obesity prevalence in early school age. These results indicate the need to describe and analyse growth patterns and their regulation through diet in more detail and to characterize the underlying metabolic and epigenetic mechanisms, given the potential major relevance for public health and policy. Better understanding of growth patterns and their regulation could have major benefits for the promotion of public health, consumer-orientated nutrition recommendations, and the development of improved food products for specific target populations.

Insulin resistance, selfish brain, and selfish immune system: an evolutionarily positively selected program used in chronic inflammatory diseases

Insulin resistance (IR) is a general phenomenon of many physiological states, disease states, and diseases. IR has been described in diabetes mellitus, obesity, infection, sepsis, trauma, painful states such as postoperative pain and migraine, schizophrenia, major depression, chronic mental stress, and others. In arthritis, abnormalities of glucose homeostasis were described in 1920; and in 1950 combined glucose and insulin tests unmistakably demonstrated IR. The phenomenon is now described in rheumatoid arthritis, systemic lupus erythematosus, ankylosing spondylitis, polymyalgia rheumatica, and others. In chronic inflammatory diseases, cytokine-neutralizing strategies normalize insulin sensitivity. This paper delineates that IR is either based on inflammatory factors (activation of the immune/ repair system) or on the brain (mental activation via stress axes). Due to the selfishness of the immune system and the selfishness of the brain, both can induce IR independent of each other. Consequently, the immune system can block the brain (for example, by sickness behavior) and the brain can block the immune system (for example, stress-induced immune system alterations). Based on considerations of evolutionary medicine, it is discussed that obesity per se is not a disease. Obesity-related IR depends on provoking factors from either the immune system or the brain. Chronic inflammation and/or stress axis activation are thus needed for obesity-related IR. Due to redundant pathways in stimulating IR, a simple one factor-neutralizing strategy might help in chronic inflammatory diseases (inflammation is the key), but not in obesity-related IR. The new considerations towards IR are interrelated to the published theories of IR (thrifty genotype, thrifty phenotype, and others).

Xenotransplantation of human fetal adipose tissue: a model of in vivo adipose tissue expansion and adipogenesis

Obesity during childhood and beyond may have its origins during fetal or early postnatal life. At present, there are no suitable in vivo experimental models to study factors that modulate or perturb human fetal white adipose tissue (WAT) expansion, remodeling, development, adipogenesis, angiogenesis, or epigenetics. We have developed such a model. It involves the xenotransplantation of midgestation human WAT into the renal subcapsular space of immunocompromised SCID-beige mice. After an initial latency period of approximately 2 weeks, the tissue begins expanding. The xenografts are healthy and show robust expansion and angiogenesis for at least 2 months following transplantation. Data and cell size and gene expression are consistent with active angiogenesis. The xenografts maintain the expression of genes associated with differentiated adipocyte function. In contrast to the fetal tissue, adult human WAT does not engraft. The long-term viability and phenotypic maintenance of fetal adipose tissue following xenotransplantation may be a function of its autonomous high rates of adipogenesis and angiogenesis. Through the manipulation of the host mice, this model system offers the opportunity to study the mechanisms by which nutrients and other environmental factors affect human adipose tissue development and biology.

Excess nutrient supply in early life and its later metabolic consequences

Suboptimal nutrition in early life, both in utero and during infancy, is linked to increased risk of adult obesity and its associated adverse metabolic health problems. Excess nutrient supply during early life can lead to metabolic programming in the offspring. Such overnutrition can occur in the offspring of obese mothers, the offspring of mothers who gain excess weight during gestation, infants of diabetic mothers and infants who undergo rapid growth, particularly weight gain, during early infancy. Postnatal overnutrition is particularly detrimental for infants who are born small for gestational age, who are overfed to attain 'catch-up growth'. Potential mechanisms underlying metabolic programming that results from excess nutrition during early life include resetting of hypothalamic energy sensing and appetite regulation, altered adipose tissue insulin sensitivity and impaired brown adipose tissue function. More detailed understanding of the mechanisms involved in metabolic programming could enable the development of therapeutic strategies for ameliorating its ill effects. Research in this field could potentially identify optimal and appropriate preventative interventions for a burgeoning population at risk of increased mortality and morbidity from obesity and its concomitant metabolic conditions.

Race, regionality and pre-diabetes in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study

OBJECTIVE

To determine the association between race, region and pre-diabetes.

METHOD

The study used 2003-2007 United States baseline data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study for this cross-sectional analysis. Participants in this study were 45years or older at recruitment. Logistic regression was used to assess whether race and region are associated with pre-diabetes independent of demographics, socioeconomic factors and risk factors.

RESULTS

Twenty-four percent of the study participants (n=19,889) had pre-diabetes. The odds ratio (95% confidence interval) for having pre-diabetes was 1.28 (1.19-1.36) for blacks relative to whites and 1.18 (1.10-1.26) for people living in the Stroke Belt region relative to the other parts of the United States. The odds of having pre-diabetes for Stroke Belt participants changed minimally after additional adjustment for race (OR=1.20; 1.13-1.28), age and sex (OR=1.24; 1.16-1.32), socioeconomic status (OR=1.22; 1.15-1.31) and risk factors (OR=1.26; 1.17-1.35). In the adjusted model, being black was independently associated with pre-diabetes (OR=1.19; 1.10-1.28).

CONCLUSION

The prevalence of pre-diabetes was higher for both blacks and whites living in the Stroke Belt relative to living outside the Stroke Belt, and the prevalence of pre-diabetes was higher for blacks independent of region.

Metabolic profiles of adult Wistar rats in relation to prenatal and postnatal nutritional manipulation: the role of birthweight

OBJECTIVE

This experimental study aimed to prospectively investigate the impact of combinations of prenatal and postnatal food manipulations on the metabolic profile of adult offspring.

DESIGN

On day 12 of gestation, 67 timed pregnant rats were randomized into three nutritional groups, control: standard laboratory food; starved: 50% food restricted, FR; fat-fed: fat-rich diet, FF. Seven hundred and seventy-four (774) pups were born on day 21 and culled to 8 (4 males, 4 females) per litter to normalize rearing. Rats born to starved mothers were later subdivided, based on birthweight (BiW), into fetal growth restricted (FGR) and non-FGR. The pups were then weaned to the diet of their fostered mother until one year old. Thus, 12 groups were studied: 1.

CONTROL/CONTROL

14 rats, 2.

CONTROL/FR

12 rats, 3.

CONTROL/FF

15 rats, 4.

FGR/CONTROL

16 rats, 5.

FGR/FR

10 rats, 6.

FGR/FF

15 rats, 7. non-

FGR/CONTROL

10 rats, 8. non-

FGR/FR

17 rats, 9. non-

FGR/FF

10 rats, 10.

FF/CONTROL

15 rats, 11.

FF/FR

14 rats, and 12.

FF/FF

13 rats. During sacrifice, body weight (BW) and liver weight (LW) were measured (expressed in grams) and concentrations of serum glucose, triglycerides, HDL and NEFA were determined.

RESULTS

Postnatal food restriction, compared to control diet significantly reduced BW (p=0.004, p=0.036, p<0.001, p=0.008) and LW (p<0.001) in all study groups. Postnatal control diet significantly increased BW in non-FGR compared to FGR rats (p=0.027). No significant differences were detected in biochemical parameters (excluding NEFA) between FGR and non-FGR, regardless of the postnatal diet.

CONCLUSIONS

Interaction between prenatal and postnatal nutrition produces distinct metabolic profiles. Apart from BiW, prenatal diet had an important impact on the metabolic profile of the adult offspring, implying that intrauterine events should be considered in the estimation of the metabolic risk of an individual, independently of BiW.

Maternal high-fat diet during pregnancy or lactation changes the somatic and neurological development of the offspring

The maternal exposure to high fat diet (HFD) during pregnancy and breastfeeding have been considered an important inducer of alterations in offspring normal programming, both in animals and humans, and may disturb brain development. In the present study we investigated the somatic and sensory-motor development of the offspring from rat dams fed a HFD, compared with dams fed a control diet, during pregnancy or lactation. Indicators of the body growth, physical maturation, and reflex ontogeny were evaluated. Offspring of dams fed a HFD showed reduced weight and body growth, delayed physical maturation, and delayed maturation of the physiological reflexes, such as vibrissa placing, auditory startle response, and free-fall righting. Our findings suggest that maternal HFD during pregnancy or lactation modifies somatic and neurological development of the offspring, possibly increasing the risk of neuroendocrine and neuropsychiatric disorders later in life.

Programming effects of FTO in the development of obesity

It is becoming increasingly recognized that early-life nutritional, metabolic and environmental factors can have a long-term impact on the early onset of obesity, type 2 diabetes and cardiovascular diseases. Numerous experimental and epidemiological observations support the concept that an individual's response to their adult lifestyle and nutritional environment depends not only on their genetic susceptibility but also on their previous early-life experiences. The current research challenge is to determine the primary pathways contributing to 'non- or epi-genetic' causes of excess adult weight gain and adiposity. Evidence from the fields of genetic epidemiology, life course modelling and diet-induced foetal programming all support a role for the FTO gene in this complex biological interaction. It may provide a missing link in the developmental regulation of energy metabolism. Our review therefore considers the role of the FTO gene in the early-life determination of body weight, body composition and energy balance. We will summarize current knowledge on FTO biology combining human genetic epidemiology, molecular models and findings from animal studies. Notably, we will focus on the role of FTO in energy balance in humans, the importance of FTO polymorphisms in childhood growth and the impact of foetal nutrition. Ultimately, we propose a new hypothesis for future research designed to understand the role of FTO in setting gene expression in metabolically active tissues.

Fine-tuning notes in the behavioral symphony: parent-of-origin allelic gene expression in the brain

The gene encoding the thyroid hormone (TH)-metabolizing enzyme, deiodinase type III (Dio3), exhibits a preferential paternal expression in most tissues. Dio3 is part of the Dlk1-Dio3 imprinted locus, so named according to its ancestral genes, Delta-like homolog 1 (Dlk1) and Dio3, which among other important functions control metabolic programming in the developing embryo and fetus. Here, we describe the aspects of the genomic imprinting patterns exhibited by Dio3 across brain regions and development. The corresponding local changes in the dosage of the Dio3 enzyme are inversely related to TH levels that vary from one brain region to another, and affect social and cognitive behaviors. We show that this regional tuning of brain region-specific expression is dependent on parent of origin-specific genetic polymorphisms in the rat, is sexually dimorphic, and is affected by the early environmental challenge of fetal exposure to alcohol, opening the possibility that the potential for variant expression patterns of the Dio3 gene is quite large. The multiple regulatory genomic features within the Dlk1-Dio3 locus, and other imprinted loci, allow mammals to specifically modulate parent-of-origin allelic gene expression brain region. These regulatory structures seem to have evolved as a possible mechanism of adaptation in response to the simultaneous need for highly regulated expression in some tissues during development, but variable expression across specific regions of the brain over the complete life span. Here, we use Dio3 as a single gene example of the epigenetic parent-of-origin allelic expression in specific brain regions and discuss the potential of this general phenomenon to shape evolutionarily relevant social and cognitive behavior in eutherian mammals.

Sex differences in metabolic and adipose tissue responses to juvenile-onset obesity in sheep

Sex is a major factor determining adipose tissue distribution and the subsequent adverse effects of obesity-related disease including type 2 diabetes. The role of gender on juvenile obesity and the accompanying metabolic and inflammatory responses is not well established. Using an ovine model of juvenile onset obesity induced by reduced physical activity, we examined the effect of gender on metabolic, circulatory, and related inflammatory and energy-sensing profiles of the major adipose tissue depots. Despite a similar increase in fat mass with obesity between genders, males demonstrated a higher storage capacity of lipids within perirenal-abdominal adipocytes and exhibited raised insulin. In contrast, obese females became hypercortisolemic, a response that was positively correlated with central fat mass. Analysis of gene expression in perirenal-abdominal adipose tissue demonstrated the stimulation of inflammatory markers in males, but not females, with obesity. Obese females displayed increased expression of genes involved in the glucocorticoid axis and energy sensing in perirenal-abdominal, but not omental, adipose tissue, indicating a depot-specific mechanism that may be protective from the adverse effects of metabolic dysfunction and inflammation. In conclusion, young males are at a greater risk than females to the onset of comorbidities associated with juvenile-onset obesity. These sex-specific differences in cortisol and adipose tissue could explain the earlier onset of the metabolic-related diseases in males compared with females after obesity.

Epigenetics and obesity: a relationship waiting to be explained

Obesity can have multifactorial causes that may change with development and are not simply attributable to one's genetic constitution. To date, expensive and laborious genome-wide association studies have only ascribed a small contribution of genetic variants to obesity. The emergence of the field of epigenetics now offers a new paradigm with which to study excess fat mass. Currently, however, there are no compelling epigenetic studies to explain the role of epigenetics in obesity, especially from a developmental perspective. It is clear that until there are advances in the understanding of the main mechanisms by which different fat types, i.e. brown, beige, and white, are established and how these differ between depots and species, population-based studies designed to determine specific aspects of epigenetics will be potentially limited. Obesity is a slowly evolving condition that is not simply explained by changes in the intake of one macronutrient. The latest advances in epigenetics, coupled with the establishment of relevant longitudinal models of obesity, which incorporate functionally relevant end points, may now permit the precise contribution of epigenetic modifications to excess fat mass to be effectively studied.

Delayed physical and neurobehavioral development and increased aggressive and depression-like behaviors in the rat offspring of dams fed a high-fat diet

Early maternal exposure to a high-fat diet (HFD) may influence the brain development of rat offspring and consequently affect physiology and behavior. Thus, in the present study, we investigated the somatic, physical, sensory-motor and neurobehavioral development of the offspring of dams fed an HFD (52% calories from fat, mainly saturated) and the offspring of dams fed a control diet (CD - 14.7% fat) during lactation from the 1st to the 21st postnatal day (P). Maternal body weights were evaluated during lactation. In the progeny, somatic (body weight, head and lengths axes) and physical (ear unfolding, auditory conduit opening, eruption of the incisors and eye opening) development and the consolidation of reflex responses (palm grasp, righting, vibrissa placing, cliff avoidance, negative geotaxis, auditory startle response and free-fall righting) were determined during suckling. Depressive and aggressive behaviors were tested with the forced swimming test (FST) and the "foot-shock" test on days 60 and 110, respectively. The open field test was used to assess motor function. Compared to controls, the HFD-pups exhibited decreases in body weight (P7-P21) and body length (P4-P18), but by days P71 and P95, these pups were overweight. All indicators of physical maturation and the consolidation of the following reflexes, vibrissa placing, auditory startle responses, free-fall righting and negative geotaxis, were delayed in HFD-progeny. In addition, the pups from HFD dam rats also exhibited reduced swimming and climbing times in the FST and increased aggressive behavior. No changes in locomotion were observed. These findings show developmental and neurobehavioral changes in the rat offspring of dams fed the HFD during lactation and suggest possible disruption of physical and sensory-motor maturation and increased susceptibility to depressive and aggressive-like behavior.

[Interaction between environment and genetic background in type 2 diabetes: lessons from animal models]

The respective roles of predisposing genetic factors and environmental factors in the development of type 2 diabetes (T2D) in obese subjects is poorly documented. Rodent models have been set up in an attempt to better understand of the differential effect of a prolonged metabolic stress induced by a high fat diet on glycaemic control according to the genetic background. In utero growth retardation resulting from a hypocaloric diet in pregnant rats induces a dramatic alteration of the development of islet cells leading to diabetes and insulin secretory defects in adult age. Experimentally induced diabetes in rodents results in hyperglycaemia and hyperinsulinemia in the fetus related to accelerated endocrine pancreas maturation responsible for the onset of diabetes in the adult. Deranged metabolic environment during fetal life may therefore further contribute to the onset of diabetes in the adult. Normal mouse strains with different genetic backgrounds show a wide range of responses to a high fat diet, with strains resistant to the diet and other more or less sensitive to the diet, the most sensitive exhibiting obesity diabetes and, insulin deficiency. The inability of the β cell to respond to the increased insulin demand related to insulin resistance seems to be pivotal in the pathophysiologic process and a new notion is emerging: "nutritional genetics" which studies the influence of nutrients on gene expression.

Long term effects of pre- and early postnatal nutrition and environment on the gut

The Developmental Origins of Health and Disease hypothesis formulated in the early 1990 s has stimulated research on long-term effects of early nutrition and environment over the last decades. Long-term is understood in this review as physiologically relevant periods such as after weaning, around sexual maturity, and in adulthood, as opposed to early developmental periods. The small and large intestines as targets for the study of long-term effects have received little attention until recent years and the stomach has been considered very rarely. Data have accumulated for laboratory animal models but they are still scarce in the swine species. Following the epidemics of metabolic diseases and obesity in western countries, experimental evidence has been published showing that nutritional factors, including energy, fat and fatty acids, protein, and micronutrients impact various facets of gut function. These include alterations in intestinal digestive, absorptive, secretory, barrier, and defense systems, often in a way potentially detrimental to the host. Environmental factors with long-term influence include stress (e.g., maternal deprivation, neonatal gut irritation), chemical pollutants (e.g., bisphenol A), and gut microbiota disturbances (e.g., by antibiotics). Examples of such long-term effects on the gut are provided in both laboratory animals and pigs together with underlying physiological mechanisms whenever available. Experimental evidence for the involvement of underlying epigenetic modifications (e.g., genomic DNA methylation) in long-term studies has just started to emerge with regard to the gastrointestinal tract. Also, interactions between the microbiota and the host are being considered pivotal in the early programming of gut functions. Finally, suggestions for future research are provided in order to better understand and then control early programming as an attempt to optimize vital functions of the gastrointestinal tract throughout adult life.

DNA methyltransferase candidate polymorphisms, imprinting methylation, and birth outcome

Background

Birth weight and prematurity are important obstetric outcomes linked to lifelong health. We studied a large birth cohort to look for evidence of epigenetic involvement in birth outcomes.

Methods

We investigated the association between birth weight, length, placental weight and duration of gestation and four candidate variants in 1,236 mothers and 1,073 newborns; DNMT1 (rs2162560), DNMT3A (rs734693), DNMT3B (rs2424913) and DNMT3L (rs7354779). We measured methylation of LINE1 and the imprinted genes, PEG3, SNRPN, and IGF2, in cord blood.

Results

The minor DNMT3L allele in the baby was associated with higher birth weight (+54 95% CI 10,99 g; p = 0.016), birth length (+0.23 95% CI 0.04,0.42 cm; p = 0.017), placental weight, (+18 95% CI 3,33 g; p = 0.017), and reduced risk of being in the lowest birth weight decile (p = 0.018) or requiring neonatal care (p = 0.039). The DNMT3B minor allele in the mother was associated with an increased risk of prematurity (p = 0.001). Placental size was related to PEG3 (p<0.001) and IGF2 (p<0.001) methylation. Birth weight was related to LINE1 and IGF2 methylation but only at p = 0.052. The risk of requiring neonatal treatment was related to LINE1 (p = 0.010) and SNRPN (p = 0.001) methylation. PEG3 methylation was influenced by baby DNMT3A genotype (p = 0.012) and LINE1 by baby 3B genotype (p = 0.044). Maternal DNMT3L genotype was related to IGF2 methylation in the cord blood but this effect was only seen in carriers of the minor frequency allele (p = 0.050).

Conclusions

The results here suggest that epigenetic processes are linked birth outcome and health in early life. Our emerging understanding of the role of epigenetics in health and biological function across the lifecourse suggests that these early epigenetic events could have longer term implications.