Programmed hyperphagia due to reduced anorexigenic mechanisms in intrauterine growth-restricted offspring

Neurodevelopmental Programming of Adiposity: Contributions to Obesity Risk

This review analyzes the published evidence regarding maternal factors that influence the developmental programming of long-term adiposity in humans and animals via the central nervous system (CNS). We describe the physiological outcomes of perinatal underfeeding and overfeeding and explore potential mechanisms that may mediate the impact of such exposures on the development of feeding circuits within the CNS-including the influences of metabolic hormones and epigenetic changes. The perinatal environment, reflective of maternal nutritional status, contributes to the programming of offspring adiposity. The in utero and early postnatal periods represent critically sensitive developmental windows during which the hormonal and metabolic milieu affects the maturation of the hypothalamus. Maternal hyperglycemia is associated with increased transfer of glucose to the fetus driving fetal hyperinsulinemia. Elevated fetal insulin causes increased adiposity and consequently higher fetal circulating leptin concentration. Mechanistic studies in animal models indicate important roles of leptin and insulin in central and peripheral programming of adiposity, and suggest that optimal concentrations of these hormones are critical during early life. Additionally, the environmental milieu during development may be conveyed to progeny through epigenetic marks and these can potentially be vertically transmitted to subsequent generations. Thus, nutritional and metabolic/endocrine signals during perinatal development can have lifelong (and possibly multigenerational) impacts on offspring body weight regulation.

Accumbal μ-opioid receptors and salt taste-elicited hedonic responses in a rodent model of prenatal adversity, and their correlates using human functional genomics

Prenatal adversity is associated with behavioral obesogenic features such as preference for palatable foods. Salt appetite may play a role in the development of adiposity and its consequences in individuals exposed to prenatal adversity, and sodium consumption involves individual differences in accumbal µ-opioid receptors function. We investigated the hedonic responses to salt and the levels of µ-opioid receptors and tyrosine hydroxylase in the nucleus accumbens (Nacc) of pups from an animal model of prenatal dietary restriction. In children, we evaluated the interaction between fetal growth and the genetic background associated with the accumbal µ-opioid receptor gene (OPRM1) expression on sodium consumption during a snack test. Sprague-Dawley dams were randomly allocated from pregnancy day 10 to receive an ad libitum (Adlib) or a 50% restricted (FR) diet. The pups' hedonic responses to a salt solution (NaCl 2%) or water were evaluated on the first day of life. FR and Adlib pups differ in their hedonic responses to salt, and there were decreased levels of accumbal µ-opioid and p-µ-opioid receptors in FR pups. In humans, a test meal and genotyping from buccal epithelial cells were performed in 270 children (38 intrauterine growth restricted-IUGR) at 4 years old from a Canadian prospective cohort (MAVAN). The OPRM1 genetic score predicted the sodium intake in IUGR children, but not in controls. The identification of mechanisms involved in the brain response to prenatal adversity and its consequences in behavioral phenotypes and risk for chronic diseases later in life is important for preventive and therapeutic purposes.

The importance of optimal body condition to maximise reproductive health and perinatal outcomes in pigs

Overnutrition or undernutrition during all or part of the reproductive cycle predisposes sows to metabolic consequences and poor reproductive health which contributes to a decrease in sow longevity and an increase in perinatal mortality. This represents not only an economic problem for the pig industry but also results in poor animal welfare. To maximise profitability and increase sustainability in pig production, it is pivotal to provide researchers and practitioners with synthesised information about the repercussions of maternal obesity or malnutrition on reproductive health and perinatal outcomes, and to pinpoint currently available nutritional managements to keep sows' body condition in an optimal range. Thus, the present review summarises recent work on the consequences of maternal malnutrition and highlights new findings.

Thermoneutrality effects on developmental programming of obesity

Developmental programming studies using mouse models have housed the animals at human thermoneutral temperatures (22°C) which imposes constant cold stress. As this impacts energy homeostasis, we investigated the effects of two housing temperatures (22°C and 30°C) on obesity development in male and female offspring of Control and FR dams. Pregnant mice were housed at 22°C (cold-exposed, CE) or 30°C (thermoneutrality, TN) room temperature. At gestational age e10, mice were fed either an ad libitum diet (Control) or were 30% food-restricted (FR) to produce low birth weight newborns. Following delivery, all dams were fed an ad libitum diet and maternal mice continued to nurse their own pups. At 3 weeks of age, offspring were weaned to an ad libitum diet and housed at similar temperatures as their mothers. Body weights and food intake were monitored. At 6 months of age, body composition and glucose tolerance test were determined, after which, brain and adipose tissue were collected for analysis. FR/CE and FR/TN offspring exhibited hyperphagia and were significantly heavier with increased adiposity as compared to their respective Controls. There was sex-specific effects of temperature in both groups. Male offspring at TN were heavier with increased body fat, though the food intake was decreased as compared to CE males. This was reflected by hypertrophic adipocytes and increased arcuate nucleus satiety/appetite ratio. In contrast, female offspring were not impacted by housing temperature. Thus, unlike female offspring, there was a significant interaction of diet and temperature evident in the male offspring with accentuated adverse effects evident in FR/TN males.

Gestational Nutrition as a Predisposing Factor to Obesity Onset in Offspring: Role for Involvement of Epigenetic Mechanism

Maternal lifestyle has been implicated as a predisposing factor in the development of metabolic disorders in adulthood. This lifestyle includes the immediate environment, physical activity and nutrition. Maternal nutrition has direct influence on the developmental programming through biochemical alterations and can lead to modifications in the fetal genome through epigenetic mechanisms. Imbalance in basic micro or macro nutrients due to famine or food deficiency during delicate gestational periods can lead to onset of metabolic syndrome including obesity. A major example is the Dutch famine which led to a serious metabolic disorder in adulthood of affected infants. Notably due to gene variants, individualized responses to nutritional deficiencies are unconventional, therefore intensifying the need to study nutritional genomics during fetal programming. Epigenetic mechanisms can cause hereditary changes without changing the DNA sequence; the major mechanisms include small non-coding RNAs, histone modifications and most stable of all is DNA methylation. The significance association between obesity and DNA methylation is through regulation of genes implicated in lipid and glucose metabolism either directly or indirectly by hypomethylation or hypermethylation. Examples include CPT1A, APOA2, ADRB3 and POMC. Any maternal exposure to malnutrition or overnutrition that can affect genes regulating major metabolic pathways in the fetus, will eventually cause underlying changes that can predispose or cause the onset of metabolic disorder in adulthood. In this review, we examined the interaction between nutrition during gestation and epigenetic programming of metabolic syndrome.

Leptin as a key regulator of the adipose organ

Leptin is a hormone primarily produced by the adipose tissue in proportion to the size of fat stores, with a primary function in the control of lipid reserves. Besides adipose tissue, leptin is also produced by other tissues, such as the stomach, placenta, and mammary gland. Altogether, leptin exerts a broad spectrum of short, medium, and long-term regulatory actions at the central and peripheral levels, including metabolic programming effects that condition the proper development and function of the adipose organ, which are relevant for its main role in energy homeostasis. Comprehending how leptin regulates adipose tissue may provide important clues to understand the pathophysiology of obesity and related diseases, such as type 2 diabetes, as well as its prevention and treatment. This review focuses on the physiological and long-lasting regulatory effects of leptin on adipose tissue, the mechanisms and pathways involved, its main outcomes on whole-body physiological homeostasis, and its consequences on chronic diseases.

FoxO1 Regulates Neuropeptide Y and Pro-opiomelanocortin in the Hypothalamus of Rat Offspring Small for Gestational Age

Adulthood obesity, diabetes, and metabolic diseases are associated with small for gestational age (SGA) newborns. This association could be related to abnormal appetite signaling pathways in the hypothalamus. This study investigated the appetite regulation by the hypothalamus of SGA newborns by establishing an SGA rat model and culturing SGA neural progenitor cells (NPCs) in vitro. Models of SGA were established by maternal food restriction embryonic day 10 (E10). At E18, postpartum day 1 (P1), and P5, hypothalamic neural precursor cells (NPCs) of offspring were cultured in vitro. Immunofluorescence, Western blot (WB), and qRT-PCR were used to assess NPY, POMC, and FoxO1 expression levels. The effects on mRNA expression of the FoxO1-specific inhibitor AS1842856 were examined. The results indicated that compared with controls, NPY was higher, and POMC was lower at embryonic day 18 (E18), postpartum day 1 (P1), and P5. The proliferation and migration of NPCs in the third ventricle of SGA hypothalami were lower than in controls. After treatment with the FoxO1 inhibitor AS1842856, the differences in the mRNA expression of NPY and POMC between the two groups disappeared. NPY and POMC mRNA levels in the SGA group treated with AS1842856 were not significantly different compared with the control group without AS1842856 treatment. In conclusion, SGA pups showed an increase in appetite-promoting NPY and a decrease in appetite-reducing POMC, probably contributing to adulthood weight gain, obesity, and endocrine disorders.

Insights into the Mechanisms of Fetal Growth Restriction-Induced Programming of Hypertension

In recent decades, both clinical and animal studies have shown that fetal growth restriction (FGR), caused by exposure to adverse uterine environments, is a risk factor for hypertension as well as for a variety of adult diseases. This observation has shaped and informed the now widely accepted theory of developmental origins of health and disease (DOHaD). There is a plethora of evidence supporting the association of FGR with increased risk of adult hypertension; however, the underlying mechanisms responsible for this correlation remain unclear. This review aims to explain the current advances in the field of fetal programming of hypertension and a brief narration of the underlying mechanisms that may link FGR to increased risk of adult hypertension. We explain the theory of DOHaD and then provide evidence from both clinical and basic science research which support the theory of fetal programming of adult hypertension. In addition, we have explored the underlying mechanisms that may link FGR to an increased risk of adult hypertension. These mechanisms include epigenetic changes, metabolic disorders, vascular dysfunction, neurohormonal impairment, and alterations in renal physiology and function. We further describe sex differences seen in the developmental origins of hypertension and provide insights into the opportunities and challenges present in this field.

Perinatal Nutritional and Metabolic Pathways: Early Origins of Chronic Lung Diseases

Lung development is not completed at birth, but expands beyond infancy, rendering the lung highly susceptible to injury. Exposure to various influences during a critical window of organ growth can interfere with the finely-tuned process of development and induce pathological processes with aberrant alveolarization and long-term structural and functional sequelae. This concept of developmental origins of chronic disease has been coined as perinatal programming. Some adverse perinatal factors, including prematurity along with respiratory support, are well-recognized to induce bronchopulmonary dysplasia (BPD), a neonatal chronic lung disease that is characterized by arrest of alveolar and microvascular formation as well as lung matrix remodeling. While the pathogenesis of various experimental models focus on oxygen toxicity, mechanical ventilation and inflammation, the role of nutrition before and after birth remain poorly investigated. There is accumulating clinical and experimental evidence that intrauterine growth restriction (IUGR) as a consequence of limited nutritive supply due to placental insufficiency or maternal malnutrition is a major risk factor for BPD and impaired lung function later in life. In contrast, a surplus of nutrition with perinatal maternal obesity, accelerated postnatal weight gain and early childhood obesity is associated with wheezing and adverse clinical course of chronic lung diseases, such as asthma. While the link between perinatal nutrition and lung health has been described, the underlying mechanisms remain poorly understood. There are initial data showing that inflammatory and nutrient sensing processes are involved in programming of alveolarization, pulmonary angiogenesis, and composition of extracellular matrix. Here, we provide a comprehensive overview of the current knowledge regarding the impact of perinatal metabolism and nutrition on the lung and beyond the cardiopulmonary system as well as possible mechanisms determining the individual susceptibility to CLD early in life. We aim to emphasize the importance of unraveling the mechanisms of perinatal metabolic programming to develop novel preventive and therapeutic avenues.

Gestational intermittent hypoxia induces endothelial dysfunction, reduces perivascular adiponectin and causes epigenetic changes in adult male offspring

KEY POINTS

Obstructive sleep apnoea (OSA) is characterized by intermittent hypoxia, which causes oxidative stress and inflammation and increases the risk of cardiovascular disease. OSA during pregnancy causes adverse maternal and fetal outcomes. The effects of pre-existing OSA in pregnant women on cardiometabolic outcomes in the offspring are unknown. We evaluated basic metabolic parameters, as well as aortic vascular and perivascular adipose tissue (PVAT) function in response to adiponectin, and examined DNA methylation of adiponectin gene promoter in PVAT in 16-week-old adult offspring exposed to gestational intermittent hypoxia (GIH). GIH decreased body weights at week 1 in both male and female offspring, and caused subsequent increases in body weight and food consumption in male offspring only. Adult female offspring had normal levels of lipids, glucose and insulin, with no endothelial dysfunction. Adult male offspring exhibited dyslipidaemia, insulin resistance and hyperleptinaemia. Decreased endothelial-dependent vasodilatation, loss of anti-contractile activity of PVAT and low circulating PVAT adiponectin levels, as well as increased pro-inflammatory gene expression and DNA methylation of adiponectin gene promoter, occurred in adult male offspring. Our results suggest that male offspring of women with OSA could be at risk of developing cardiometabolic disease during adulthood.

ABSTRACT

Perturbations during pregnancy can program the offspring to develop cardiometabolic diseases later in life. Obstructive sleep apnoea (OSA) is a chronic condition that frequently affects pregnancies and leads to adverse fetal outcomes. We assessed the offspring of female mice experiencing gestational intermittent hypoxia (GIH), a hallmark of OSA, for changes in metabolic profiles, aortic nitric oxide (NO)-dependent relaxations, perivascular adipose tissue (PVAT) anti-contractile activities and the responses to adiponectin, and DNA methylation of the adiponectin gene promoter in PVAT tissue. Pregnant mouse dams were exposed to intermittent hypoxic cycles ( F I O 2 21-12%) for 18 days. GIH resulted in lower body weights of pups at week 1, followed by significant weight gain by week 16 of age in male but not female offspring. Plasma lipids, leptin and insulin resistance were higher in GIH male adult offspring. Endothelium-dependent relaxation in response to ACh and the anti-contractile activity of PVAT in the abdominal aorta was reduced in GIH adult male offspring. Incubation of arteries from GIH adult male offspring with adiponectin restored the anti-contractile activity of PVAT. Both circulating and PVAT tissue homogenate levels of adiponectin, as well as gene expression of adiponectin in PVAT, were lower in GIH male offspring, along with an increased gene expression of inflammatory cytokines. Pyrosequencing of adiponectin gene promoter in PVAT showed increased DNA methylation in GIH male offspring. Our results indicate that GIH leads to vascular disease in adult male offspring through PVAT dysfunction, which was associated with low adiponectin levels and epigenetic modifications on the adiponectin gene promoter.

Neonatal Consumption of Oligosaccharides Greatly Increases L-Cell Density without Significant Consequence for Adult Eating Behavior

Oligosaccharides (OS) are commonly added to infant formulas, however, their physiological impact, particularly on adult health programming, is poorly described. In adult animals, OS modify microbiota and stimulate colonic fermentation and enteroendocrine cell (EEC) activity. Since neonatal changes in microbiota and/or EEC density could be long-lasting and EEC-derived peptides do regulate short-term food intake, we hypothesized that neonatal OS consumption could modulate early EECs, with possible consequences for adult eating behavior. Suckling rats were supplemented with fructo-oligosaccharides (FOS), beta-galacto-oligosaccharides/inulin (GOS/In) mix, alpha-galacto-oligosaccharides (αGOS) at 3.2 g/kg, or a control solution (CTL) between postnatal day (PND) 5 and 14/15. Pups were either sacrificed at PND14/15 or weaned at PND21 onto standard chow. The effects on both microbiota and EEC were characterized at PND14/15, and eating behavior at adulthood. Very early OS supplementation drastically impacted the intestinal environment, endocrine lineage proliferation/differentiation particularly in the ileum, and the density of GLP-1 cells and production of satiety-related peptides (GLP-1 and PYY) in the neonatal period. However, it failed to induce any significant lasting changes on intestinal microbiota, enteropeptide secretion or eating behavior later in life. Overall, the results did not demonstrate any OS programming effect on satiety peptides secreted by L-cells or on food consumption, an observation which is a reassuring outlook from a human perspective.

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.

A proteomics-metabolomics approach indicates changes in hypothalamic glutamate-GABA metabolism of adult female rats submitted to intrauterine growth restriction

PURPOSE

Intrauterine growth restriction (IUGR) has been shown to induce the programming of metabolic disturbances and obesity, associated with hypothalamic derangements. The present study aimed at investigating the effects of IUGR on the protein and metabolite profiles of the hypothalamus of adult female rats.

METHODS

Wistar rats were mated and either had ad libitum access to food (control group) or received only 50% of the control intake (restricted group) during the whole pregnancy. Both groups ate ad libitum throughout lactation. At 4 months of age, the control and restricted female offspring was euthanized for blood and tissues collection. The hypothalami were processed for data independent acquisition mass spectrometry-based proteomics or targeted mass spectrometry-based metabolomics.

RESULTS

The adult females submitted to IUGR showed increased glycemia and body adiposity, with normal body weight and food intake. IUGR modulated significantly 28 hypothalamic proteins and 7 hypothalamic metabolites. The effects of IUGR on hypothalamic proteins and metabolites included downregulation of glutamine synthetase, glutamate decarboxylase, glutamate dehydrogenase, isocitrate dehydrogenase, α-ketoglutarate, and up-regulation of NADH dehydrogenase and phosphoenolpyruvate. Integrated pathway analysis indicated that IUGR affected GABAergic synapse, glutamate metabolism, and TCA cycle, highly interconnected pathways whose derangement has potentially multiple consequences.

CONCLUSION

The present findings suggested that the effects of IUGR on GABA/glutamate-glutamine cycle may be involved in the programming of obesity and hyperglycemia in female rats.

Hypothalamic effects of neonatal diet: reversible and only partially leptin dependent

Early life diet influences metabolic programming, increasing the risk for long-lasting metabolic ill health. Neonatally overfed rats have an early increase in leptin that is maintained long term and is associated with a corresponding elevation in body weight. However, the immediate and long-term effects of neonatal overfeeding on hypothalamic anorexigenic pro-opiomelanocortin (POMC) and orexigenic agouti-related peptide (AgRP)/neuropeptide Y (NPY) circuitry, and if these are directly mediated by leptin, have not yet been examined. Here, we examined the effects of neonatal overfeeding on leptin-mediated development of hypothalamic POMC and AgRP/NPY neurons and whether these effects can be normalised by neonatal leptin antagonism in male Wistar rats. Neonatal overfeeding led to an acute (neonatal) resistance of hypothalamic neurons to exogenous leptin, but this leptin resistance was resolved by adulthood. While there were no effects of neonatal overfeeding on POMC immunoreactivity in neonates or adults, the neonatal overfeeding-induced early increase in arcuate nucleus (ARC) AgRP/NPY fibres was reversed by adulthood so that neonatally overfed adults had reduced NPY immunoreactivity in the ARC compared with controls, with no further differences in AgRP immunoreactivity. Short-term neonatal leptin antagonism did not reverse the excess body weight or hyperleptinaemia in the neonatally overfed, suggesting factors other than leptin may also contribute to the phenotype. Our findings show that changes in the availability of leptin during early life period influence the development of hypothalamic connectivity short term, but this is partly resolved by adulthood indicating an adaptation to the metabolic mal-programming effects of neonatal overfeeding.

Intrauterine Growth Restriction Programs the Hypothalamus of Adult Male Rats: Integrated Analysis of Proteomic and Metabolomic Data

Programming of hypothalamic functions regulating energy homeostasis may play a role in intrauterine growth restriction (IUGR)-induced adulthood obesity. The present study investigated the effects of IUGR on the hypothalamus proteome and metabolome of adult rats submitted to 50% protein-energy restriction throughout pregnancy. Proteomic and metabolomic analyzes were performed by data independent acquisition mass spectrometry and multiple reaction monitoring, respectively. At age 4 months, the restricted rats showed elevated adiposity, increased leptin and signs of insulin resistance. 1356 proteins were identified and 348 quantified while 127 metabolites were quantified. The restricted hypothalamus showed down-regulation of 36 proteins and 5 metabolites and up-regulation of 21 proteins and 9 metabolites. Integrated pathway analysis of the proteomics and metabolomics data indicated impairment of hypothalamic glucose metabolism, increased flux through the hexosamine pathway, deregulation of TCA cycle and the respiratory chain, and alterations in glutathione metabolism. The data suggest IUGR modulation of energy metabolism and redox homeostasis in the hypothalamus of male adult rats. The present results indicated deleterious consequences of IUGR on hypothalamic pathways involved in pivotal physiological functions. These results provide guidance for future mechanistic studies assessing the role of intrauterine malnutrition in the development of metabolic diseases later in life.

Perinatal Western Diet Consumption Leads to Profound Plasticity and GABAergic Phenotype Changes within Hypothalamus and Reward Pathway from Birth to Sexual Maturity in Rat

Perinatal maternal consumption of energy dense food increases the risk of obesity in children. This is associated with an overconsumption of palatable food that is consumed for its hedonic property. The underlying mechanism that links perinatal maternal diet and offspring preference for fat is still poorly understood. In this study, we aim at studying the influence of maternal high-fat/high-sugar diet feeding [western diet (WD)] during gestation and lactation on the reward pathways controlling feeding in the rat offspring from birth to sexual maturity. We performed a longitudinal follow-up of WD and Control offspring at three critical time periods (childhood, adolescence, and adulthood) and focus on investigating the influence of perinatal exposure to palatable diet on (i) fat preference, (ii) gene expression profile, and (iii) neuroanatomical/architectural changes of the mesolimbic dopaminergic networks. We showed that WD feeding restricted to the perinatal period has a clear long-lasting influence on the organization of homeostatic and hedonic brain circuits but not on fat preference. We demonstrated a period specific evolution of the preference for fat that we correlated with specific brain molecular signatures. In offspring from WD fed dams, we observed during childhood the existence of fat preference associated with a higher expression of key gene involved in the dopamine (DA) systems; at adolescence, a high-fat preference for both groups, progressively reduced during the 3 days test for the WD group and associated with a reduced expression of key gene involved in the DA systems for the WD group that could suggest a compensatory mechanism to protect them from further high-fat exposure; and finally at adulthood, a preference for fat that was identical to control rats but associated with profound modification in key genes involved in the γ-aminobutyric acid network, serotonin receptors, and polysialic acid-NCAM-dependent remodeling of the hypothalamus. Altogether, these data reveal that maternal WD, restricted to the perinatal period, has no sustained impact on energy homeostasis and fat preference later in life even though a strong remodeling of the hypothalamic homeostatic and reward pathway involved in eating behavior occurred. Further functional experiments would be needed to understand the relevance of these circuits remodeling.

Hyperleptinemia in Neonatally Overfed Female Rats Does Not Dysregulate Feeding Circuitry

Neonatal overfeeding during the first weeks of life in male rats is associated with a disruption in the peripheral and central leptin systems. Neonatally overfed male rats have increased circulating leptin in the first 2 weeks of life, which corresponds to an increase in body weight compared to normally fed counterparts. These effects are associated with a short-term disruption in the connectivity of neuropeptide Y (NPY), agouti-related peptide (AgRP), and pro-opiomelanocortin (POMC) neurons within the regions of the hypothalamus responsible for control of energy balance and food intake. Female rats that are overfed during the first weeks of their life experience similar changes in circulating leptin levels as well as in their body weight. However, it has not yet been studied whether these metabolic changes are associated with the same central effects as observed in males. Here, we hypothesized that hyperleptinemia associated with neonatal overfeeding would lead to changes in central feeding circuitry in females as it does in males. We assessed hypothalamic NPY, AgRP, and POMC gene expression and immunoreactivity at 7, 12, or 14 days of age, as well as neuronal activation in response to exogenous leptin in neonatally overfed and control female rats. Neonatally overfed female rats were hyperleptinemic and were heavier than controls. However, these metabolic changes were not mirrored centrally by changes in hypothalamic NPY, AGRP, and POMC fiber density. These findings are suggestive of sex differences in the effects of neonatal overfeeding and of differences in the ability of the female and male central systems to respond to changes in the early life nutritional environment.

Maternal protein restriction during pregnancy and lactation alters central leptin signalling, increases food intake, and decreases bone mass in 1 year old rat offspring

The effects of perinatal nutrition on offspring physiology have mostly been examined in young adult animals. Aging constitutes a risk factor for the progressive loss of metabolic flexibility and development of disease. Few studies have examined whether the phenotype programmed by perinatal nutrition persists in aging offspring. Persistence of detrimental phenotypes and their accumulative metabolic effects are important for disease causality. This study determined the effects of maternal protein restriction during pregnancy and lactation on food consumption, central leptin sensitivity, bone health, and susceptibility to high fat diet-induced adiposity in 1-year-old male offspring. Sprague-Dawley rats received either a control or a protein restricted diet throughout pregnancy and lactation and pups were weaned onto laboratory chow. One-year-old low protein (LP) offspring exhibited hyperphagia. The inability of an intraperitoneal (i.p.) leptin injection to reduce food intake indicated that the hyperphagia was mediated by decreased central leptin sensitivity. Hyperphagia was accompanied by lower body weight suggesting increased energy expenditure in LP offspring. Bone density and bone mineral content that are negatively regulated by leptin acting via the sympathetic nervous system (SNS), were decreased in LP offspring. LP offspring did not exhibit increased susceptibility to high fat diet induced metabolic effects or adiposity. The results presented here indicate that the programming effects of perinatal protein restriction are mediated by specific decreases in central leptin signalling to pathways involved in the regulation of food intake along with possible enhancement of different CNS leptin signalling pathways acting via the SNS to regulate bone mass and energy expenditure.

Cord blood leptin and gains in body weight and fat mass during infancy

OBJECTIVES

Low early-life leptin concentrations may promote faster weight gain in infancy. We aimed to examine the associations between cord blood leptin concentrations and changes in weight and body composition during infancy.

DESIGN AND METHODS

Serum leptin was measured at 15 weeks gestation, in umbilical cord blood collected at delivery and at 2 years in 334 children from the Cork Baseline Birth Cohort Study. Body composition was measured at 2 days and 2 months using air displacement plethysmography. Conditional change in weight standard deviation scores over a number of age intervals in the first 2 years and conditional change in fat mass index (FMI) and fat-free mass index (FFMI) (kg/(length)m(2)) between birth and 2 months were calculated and associations with cord blood leptin were examined using linear regression.

RESULTS

At birth, cord blood leptin was positively correlated with FMI (r = 0.48, P < 0.001) and showed a weaker correlation with FFMI (r = 0.12, P = 0.05). After adjustment for confounders, higher cord blood leptin (per ng/mL) was associated with slower conditional weight gain between birth and 2 months (β (95% CI): -0.024 (-0.035, -0.013), P < 0.001) but not over subsequent age intervals. Cord blood leptin was also inversely associated with conditional change in FMI (-0.021 (-0.034, -0.007, P = 0.003) but not FFMI between birth and 2 months.

CONCLUSIONS

These are the first data to show that associations between higher cord blood leptin and slower weight gain during infancy are driven by lower increases in adiposity, at least in early infancy.

Protein Restriction During the Last Third of Pregnancy Malprograms the Neuroendocrine Axes to Induce Metabolic Syndrome in Adult Male Rat Offspring

Metabolic malprogramming has been associated with low birth weight; however, the interplay between insulin secretion disruption and adrenal function upon lipid metabolism is unclear in adult offspring from protein-malnourished mothers during the last third of gestation. Thus, we aimed to study the effects of a maternal low-protein diet during the last third of pregnancy on adult offspring metabolism, including pancreatic islet function and morphophysiological aspects of the liver, adrenal gland, white adipose tissue, and pancreas. Virgin female Wistar rats (age 70 d) were mated and fed a protein-restricted diet (4%, intrauterine protein restricted [IUPR]) from day 14 of pregnancy until delivery, whereas control dams were fed a 20.5% protein diet. At age 91 d, their body composition, glucose-insulin homeostasis, ACTH, corticosterone, leptin, adiponectin, lipid profile, pancreatic islet function and liver, adrenal gland, and pancreas morphology were assessed. The birth weights of the IUPR rats were 20% lower than the control rats (P < .001). Adult IUPR rats were heavier, hyperphagic, hyperglycemic, hyperinsulinemic, hyperleptinemic, and hypercorticosteronemic (P < .05) with higher low-density lipoprotein cholesterol and lower high-density lipoprotein cholesterol, adiponectin, ACTH, and insulin sensitivity index levels (P < .01). The insulinotropic action of glucose and acetylcholine as well as muscarinic and adrenergic receptor function were impaired in the IUPR rats (P < .05). Maternal undernutrition during the last third of gestation disrupts the pancreatic islet insulinotropic response and induces obesity-associated complications. Such alterations lead to a high risk of metabolic syndrome, characterized by insulin resistance, visceral obesity, and lower high-density lipoprotein cholesterol.

The Programming Power of the Placenta

Size at birth is a critical determinant of life expectancy, and is dependent primarily on the placental supply of nutrients. However, the placenta is not just a passive organ for the materno-fetal transfer of nutrients and oxygen. Studies show that the placenta can adapt morphologically and functionally to optimize substrate supply, and thus fetal growth, under adverse intrauterine conditions. These adaptations help meet the fetal drive for growth, and their effectiveness will determine the amount and relative proportions of specific metabolic substrates supplied to the fetus at different stages of development. This flow of nutrients will ultimately program physiological systems at the gene, cell, tissue, organ, and system levels, and inadequacies can cause permanent structural and functional changes that lead to overt disease, particularly with increasing age. This review examines the environmental regulation of the placental phenotype with particular emphasis on the impact of maternal nutritional challenges and oxygen scarcity in mice, rats and guinea pigs. It also focuses on the effects of such conditions on fetal growth and the developmental programming of disease postnatally. A challenge for future research is to link placental structure and function with clinical phenotypes in the offspring.

Programmed hyperphagia in offspring of obese dams: Altered expression of hypothalamic nutrient sensors, neurogenic factors and epigenetic modulators

Maternal overnutrition results in programmed offspring obesity, mediated in part, by hyperphagia. This is remarkably similar to the effects of maternal undernutrition on offspring hyperphagia and obesity. In view of the marked differences in the energy environment of the over and under-nutrition exposures, we studied the expression of select epigenetic modifiers associated with energy imbalance including neurogenic factors and appetite/satiety neuropeptides which are indicative of neurogenic differentiation. HF offspring were exposed to maternal overnutrition (high fat diet; HF) during pregnancy and lactation. We determined the protein expression of energy sensors (mTOR, pAMPK), epigenetic factors (DNA methylase, DNMT1; histone deacetylase, SIRT1/HDAC1), neurogenic factors (Hes1, Mash1, Ngn3) and appetite/satiety neuropeptides (AgRP/POMC) in newborn hypothalamus and adult arcuate nucleus (ARC). Despite maternal obesity, male offspring born to obese dams had similar body weight at birth as Controls. However, when nursed by the same dams, male offspring of obese dams exhibited marked adiposity. At 1 day of age, HF newborn males had significantly decreased energy sensors, DNMT1 including Hes1 and Mash1, which may impact neuroprogenitor cell proliferation and differentiation. This is consistent with increased AgRP in HF newborns. At 6 months of age, HF adult males had significantly increased energy sensors and decreased histone deactylases. In addition, the persistent decreased Hes1, Mash1 as well as Ngn3 are consistent with increased AgRP and decreased POMC. Thus, altered energy sensors and epigenetic responses which modulate gene expression and adult neuronal differentiation may contribute to hyperphagia and obesity in HF male offspring.

Lower birth weight is associated with alterations in dietary intake in adolescents independent of genetic factors: A twin study

BACKGROUND & AIMS

Lower birth weight is associated with an increased risk of cardiovascular and metabolic disease. These associations may, at least in part, be explained by alterations in dietary intake in later life. The aim of this study is to examine whether lower birth weight is associated with alterations in dietary intake in later life, and whether this association is due to intrauterine environmental or genetic factors.

METHODS

In this observational study birth weight and dietary intake were investigated in 78 dizygotic (DZ) and 94 monozygotic (MZ) adolescent same-sex twin subjects. Birth weight was obtained from the mothers. Dietary intake was assessed by two-day dietary records.

RESULTS

In the total group of twins, lower birth weight was associated with higher intake of saturated fat after adjustment for current weight (1.2 per cent of total energy intake (E%) per kg increase in birth weight, P < 0.01). Intra-pair analysis in all twin pairs demonstrated that twins with the lower birth weight had a 115 kcal higher total energy intake and a 0.7 E% higher saturated fat intake compared to their co-twins with the higher birth weight (P < 0.05). Intra-pair differences in birth weight were negatively associated with differences in energy intake and differences in intake of saturated fat after adjustment for differences in current weight (P = 0.07 and P < 0.05, respectively). Intra-pair differences in birth weight were positively associated with intra-pair differences in intake of dietary fibres (P < 0.05). These intra-pair differences and associations were similar for DZ and MZ twins (P for difference > 0.6).

CONCLUSIONS

Lower birth weight was related with higher intake of energy and saturated fat within twin pairs, and these associations were independent of zygosity, suggesting that the association between birth weight and alterations in dietary intake in later life is explained by intrauterine environmental rather than genetic factors.

The fetal programming of food preferences: current clinical and experimental evidence

Increased energy consumption is one of the major factors implicated in the epidemic of obesity. There is compelling evidence, both clinical and experimental, that fetal paucity of nutrients may have programming effects on feeding preferences and behaviors that can contribute to the development of diseases. Clinical studies in different age groups show that individuals born small for their gestational age (SGA) have preferences towards highly caloric foods such as carbohydrates and fats. Some studies have also shown altered eating behaviors in SGA children. Despite an apparent discrepancy in different age groups, all studies seem to converge to an increased intake of palatable foods in SGA individuals. Small nutrient imbalances across lifespan increase the risk of noncommunicable diseases in adult life. Homeostatic factors such as altered responses to leptin and insulin and alterations in neuropeptides associated with appetite and satiety are likely involved. Imbalances between homeostatic and hedonic signaling are another proposed mechanism, with the mesocorticolimbic dopaminergic pathway having differential reward and pleasure responses when facing palatable foods. Early exposure to undernutrition also programs hypothalamic-pituitary-adrenal axis, with SGA having higher levels of cortisol in different ages, leading to chronic hyperactivity of this neuroendocrine axis. This review summarizes the clinical and experimental evidence related to fetal programming of feeding preferences by SGA.

Mechanisms involved in developmental programming of hypertension and renal diseases. Gender differences

BACKGROUND

A substantial body of epidemiological and experimental evidence suggests that a poor fetal and neonatal environment may "program" susceptibility in the offspring to later development of cardiovascular, renal and metabolic diseases.

MATERIALS AND METHODS

This review focuses on current knowledge from the available literature regarding the mechanisms linking an adverse developmental environment with an increased risk for cardiovascular, renal and metabolic diseases in adult life. Moreover, this review highlights important sex-dependent differences in the adaptation to developmental insults.

RESULTS

Developmental programming of several diseases is secondary to changes in different mechanisms inducing important alterations in the normal development of several organs that lead to significant changes in birth weight. The different diseases occurring as a consequence of an adverse environment during development are secondary to morphological and functional cardiovascular and renal changes, to epigenetic changes and to an activation of several hormonal and regulatory systems, such as angiotensin II, sympathetic activity, nitric oxide, COX2-derived metabolites, oxidative stress and inflammation. The important sex-dependent differences in the developmental programming of diseases seem to be partly secondary to the effects of sex hormones. Recent studies have shown that the progression of these diseases is accelerated during aging in both sexes.

CONCLUSIONS

The cardiovascular, renal and metabolic diseases during adult life that occur as a consequence of several insults during fetal and postnatal periods are secondary to multiple structural and functional changes. Future studies are needed in order to prevent the origin and reduce the incidence and consequences of developmental programmed diseases.

Vascular effects of aerobic exercise training in rat adult offspring exposed to hypoxia-induced intrauterine growth restriction

KEY POINTS

Prenatal hypoxia, one of the most common consequences of complicated pregnancies, leads to intrauterine growth restriction (IUGR) and impairs later-life endothelium-dependent vascular function. Early interventions are needed to ultimately reduce later-life risk for cardiovascular disease. Aerobic exercise training has been shown to prevent cardiovascular diseases. Whether exercise can be used as an intervention to reverse the vascular phenotype of this susceptible population is unknown. Aerobic exercise training enhanced endothelium-derived hyperpolarization-mediated vasodilatation in gastrocnemius muscle arteries in male IUGR offspring, and did not improve nitric oxide-mediated vasodilatation in IUGR offspring. Understanding the mechanisms by which exercise impacts the cardiovascular system in a susceptible population and the consideration of sexual dimorphism is essential to define whether exercise could be used as a preventive strategy in this population.

ABSTRACT

Hypoxia in utero is a critical insult causing intrauterine growth restriction (IUGR). Adult offspring born with hypoxia-induced IUGR have impaired endothelium-dependent vascular function. We tested whether aerobic exercise improves IUGR-induced endothelial dysfunction. Pregnant Sprague-Dawley rats were exposed to control (21% oxygen) or hypoxic (11% oxygen) conditions from gestational day 15 to 21. Male and female offspring from normoxic and hypoxic (IUGR) pregnancies were randomized at 10 weeks of age to either an exercise-trained or sedentary group. Exercise-trained rats ran on a treadmill for 30 min at 20 m min(-1) , 5 deg gradient, 5 days week(-1) , for 6 weeks. Concentration-response curves to phenylephrine and methylcholine were performed in second order mesenteric and gastrocnemius muscle arteries, in the presence or absence of l-NAME (100 μm), MnTBAP (peroxynitrite scavenger; 10 μm), apamin (0.1 μm) and TRAM-34 (an intermediate-conductance calcium-activated potassium channel blocker; 10 μm), or indomethacin (5 μm). In adult male IUGR offspring, prenatal hypoxia had no effect on total vasodilator responses in either vascular bed. Aerobic exercise training in IUGR males, however, improved endothelium-derived hyperpolarization (EDH)-mediated vasodilatation in gastrocnemius muscle arteries. Female IUGR offspring had reduced NO-mediated vasodilatation in both vascular beds, along with decreased total vasodilator responses and increased prostaglandin-mediated vasoconstriction in gastrocnemius muscle arteries. In contrast to males, aerobic exercise training in IUGR female offspring had no effect on either vascular bed. Exercise may not prove to be a beneficial therapy for specific vascular pathways affected by prenatal hypoxia, particularly in female offspring.

Maternal undernutrition induces premature reproductive senescence in adult female rat offspring

OBJECTIVE

To determine the effects of maternal undernutrition (MUN) on the reproductive axis of aging offspring.

DESIGN

Animal (rat) study.

SETTING

Research laboratory.

ANIMAL(S)

Female Sprague-Dawley rats.

INTERVENTION(S)

Food restriction during the second half of pregnancy in rats.

MAIN OUTCOME MEASURE(S)

Circulating gonadotropins, antimüllerian hormone (AMH), ovarian morphology, estrous cyclicity, and gene expression studies in the hypothalamus and ovary in 1-day-old (P1) and aging adult offspring.

RESULT(S)

Offspring of MUN dams had low birth weight (LBW) and by adult age developed obesity. In addition, 80% of adult LBW offspring had disruption of estrous cycle by 8 months of age, with the majority of animals in persistent estrous. Ovarian morphology was consistent with acyclicity, with ovaries exhibiting large cystic structures and reduced corpora lutea. There was an elevation in circulating T, increased ovarian expression of enzymes involved in androgen synthesis, an increase in plasma LH/FSH levels, a reduction in E2 levels, and no changes in AMH in adult LBW offspring compared with in control offspring. Hypothalamic expression of leptin receptor (ObRb), estrogen receptor-α (ER-α), and GnRH protein was altered in an age-dependent manner with increased ObRb and ER-α expression in P1 LBW hypothalami and a reversal of this expression pattern in adult LBW hypothalami.

CONCLUSION(S)

Our data indicate that the maternal nutritional environment programs the reproductive potential of the offspring through alteration of the hypothalamic-pituitary-gonadal axis. The premature reproductive senescence in LBW offspring could be secondary to the development of obesity and hyperleptinemia in these animals in adult life.

Programmed hyperphagia secondary to increased hypothalamic SIRT1

Small for gestational age (SGA) offspring exhibit reduced hypothalamic neural satiety pathways leading to programmed hyperphagia and adult obesity. Appetite regulatory site, the hypothalamic arcuate nucleus (ARC) contains appetite (NPY/AgRP) and satiety (POMC) neurons. Using in vitro culture of hypothalamic neuroprogenitor cells (NPC) which form the ARC, we demonstrated that SGA offspring exhibit reduced NPC proliferation and neuronal differentiation. bHLH protein Hes1 promotes NPC self-renewal and inhibits differentiation by repressing neuronal differentiation genes (Mash1, neurogenin3). We hypothesized that Hes1/Mash1 and ultimately ARC neuronal differentiation and expression of NPY/POMC neurons are influenced by SIRT1 which is a nutrient sensor and a histone deacetylase. Control dams received ad libitum food, whereas study dams were 50% food-restricted from pregnancy day 10 to 21 (SGA). In vivo studies showed that SGA newborns and adult offspring had increased protein expression of hypothalamic/ARC SIRT1 and AgRP with decreased POMC. Additionally, SGA newborns had decreased expression of hypothalamic neurogenic factors with reduced in vivo NPC proliferation. In vitro culture of hypothalamic NPCs showed similar changes with elevated SIRT1 binding to Hes1 in SGA newborn. Silencing SIRT1 increased NPC proliferation and Hes1 and Tuj1expression in both Control and SGA NPCs. Although SGA NPC proliferation remained below that of Controls, it was higher than Control NPCs in the absence of SIRT1 siRNA. The direct impact of SIRT1 on NPC proliferation and differentiation were further confirmed with pharmacologic SIRT1 inhibitor and activator. Thus, in SGA newborns elevated SIRT1 induces premature differentiation of NPCs, reducing the NPC pool and cell proliferation.

Effects of in utero conditions on adult feeding preferences

The fetal or early origins of adult disease hypothesis states that environmental factors, particularly nutrition, act in early life to program the risks for chronic diseases in adult life. As eating habits can be linked to the development of several diseases including obesity, diabetes and cardiovascular disease, it could be proposed that persistent food preferences across the life-span in people who were exposed to an adverse fetal environment may partially explain their increased risk to develop metabolic disease later in life. In this paper, we grouped the clinical and experimental evidence demonstrating that the fetal environment may impact the individual's food preferences. In addition, we review the feeding preferences development and regulation (homeostatic and hedonic pathways, the role of taste/olfaction and the reward/pleasure), as well as propose mechanisms linking early life conditions to food preferences later in life. We review the evidence suggesting that in utero conditions are associated with the development of specific food preferences, which may be involved in the risk for later disease. This may have implications in terms of public health and primary prevention during early ages.

Mechanism of programmed obesity: altered central insulin sensitivity in growth-restricted juvenile female rats

Intrauterine growth-restricted (IUGR) offspring are at increased risk of adult obesity, as a result of changes in energy balance mechanisms. We hypothesized that impairment of hypothalamic insulin signaling contributes to hyperphagia in IUGR offspring. Study pregnant dams were 50% food restricted from days 10 to 21 to create IUGR newborns. At 5 weeks of age, food intake was measured following intracerebroventricular (icv) injection of vehicle or insulin (10 mU) in control and IUGR pups. At 6 weeks of age, with pups in fed or fasted (48 h) states, pups received icv vehicle or insulin after which they were decapitated, and hypothalamic arcuate (ARC) nucleus dissected for RNA and protein expression. IUGR rats consumed more food than controls under basal conditions, consistent with upregulated ARC phospho AMP-activated protein kinase (pAMPK) and neuropeptide Y (NPY). Insulin acutely reduced food intake in both control and IUGR rats. Consistent with anorexigenic stimulation, central insulin decreased AMP-activated protein kinase and NPY mRNA expression and increased proopiomelanocortin mRNA expression and pAkt, with significantly reduced responses in IUGR as compared with controls. Despite feeding, IUGR offspring exhibit a persistent state of orexigenic stimulation in the ARC nucleus and relative resistance to the anorexigenic effects of icv insulin. These results suggest that impaired insulin signaling contributes to hyperphagia and obesity in IUGR offspring.

Prenatal programming in an obese swine model: sex-related effects of maternal energy restriction on morphology, metabolism and hypothalamic gene expression

Maternal energy restriction during pregnancy predisposes to metabolic alterations in the offspring. The present study was designed to evaluate phenotypic and metabolic consequences following maternal undernutrition in an obese pig model and to define the potential role of hypothalamic gene expression in programming effects. Iberian sows were fed a control or a 50 % restricted diet for the last two-thirds of gestation. Newborns were assessed for body and organ weights, hormonal and metabolic status, and hypothalamic expression of genes implicated in energy homeostasis, glucocorticoid function and methylation. Weight and adiposity were measured in adult littermates. Newborns of the restricted sows were lighter (P <0·01), but brain growth was spared. The plasma concentration of TAG was lower in the restricted newborns than in the control newborns of both the sexes (P <0·01), while the concentration of cortisol was higher in females born to the restricted sows (P <0·04), reflecting a situation of metabolic stress by nutrient insufficiency. A lower hypothalamic expression of anorexigenic peptides (LEPR and POMC, P <0·01 and P <0·04, respectively) was observed in females born to the restricted sows, but no effect was observed in the males. The expression of HSD11B1 gene was down-regulated in the restricted animals (P <0·05), suggesting an adaptive mechanism for reducing the harmful effects of elevated concentrations of cortisol. At 4 and 7 months of age, the restricted females were heavier and fatter than the controls (P< 0·01). Maternal feed restriction induces asymmetrical growth retardation and metabolic alterations in the offspring. Differences in gene expression at birth and higher growth and adiposity in adulthood suggest a female-specific programming effect for a positive energy balance, possibly due to overexposure to endogenous stress-induced glucocorticoids.

Developmental programming of offspring obesity, adipogenesis, and appetite

A newly recognized primary cause of the obesity epidemic is the developmental programming effects of infants born to mothers with obesity or gestational diabetes, intrauterine growth-restricted newborns, and offspring exposed to environmental toxins including bisphenol A. The mechanisms which result in offspring obesity include the programming of the hypothalamic appetite pathway and adipogenic signals regulating lipogenesis. Processes include nutrient sensors, epigenetic modifications, and alterations in stem cell precursors of both appetite/satiety neurons and adipocytes which are modulated to potentiate offspring obesity. Future strategies for the prevention and therapy of obesity must address programming effects of the early life environment.

Maternal nutrition and risk of obesity in offspring: the Trojan horse of developmental plasticity

Mammalian embryos have evolved to adjust their organ and tissue development in response to an atypical environment. This adaptation, called phenotypic plasticity, allows the organism to thrive in the anticipated environment in which the fetus will emerge. Barker and colleagues proposed that if the environment in which the fetus emerges differs from that in which it develops, phenotypic plasticity may provide an underlying mechanism for disease. Epidemiological studies have shown that humans born small- or large-for-gestational-age, have a higher likelihood of developing obesity as adults. The amount and quality of food that the mother consumes during gestation influences birth weight, and therefore susceptibility of progeny to disease in later life. Studies in experimental animals support these observations, and find that obesity occurs as a result of maternal nutrient-restriction during gestation, followed by rapid compensatory growth associated with ad libitum food consumption. Therefore, obesity associated with maternal nutritional restriction has a developmental origin. Based on this phenomenon, one might predict that gestational exposure to a westernized diet would protect against future obesity in offspring. However, evidence from experimental models indicates that, like maternal dietary restriction, maternal consumption of a westernized diet during gestation and lactation interacts with an adult obesogenic diet to induce further obesity. Mechanistically, restriction of nutrients or consumption of a high fat diet during gestation may promote obesity in progeny by altering hypothalamic neuropeptide production and thereby increasing hyperphagia in offspring. In addition to changes in food intake these animals may also direct energy from muscle toward storage in adipose tissue. Surprisingly, generational inheritance studies in rodents have further indicated that effects on body length, body weight, and glucose tolerance appear to be propagated to subsequent generations. Together, the findings discussed herein highlight the concept that maternal nutrition contributes to a legacy of obesity. Thus, ensuring adequate supplies of a complete and balanced diet during and after pregnancy should be a priority for public health worldwide. This article is part of a Special Issue entitled: Modulation of Adipose Tissue in Health and Disease.

Role of hypothalamic neurogenesis in feeding regulation

The recently described generation of new neurons in the adult hypothalamus, the center for energy regulation, suggests that hypothalamic neurogenesis is a crucial part of the mechanisms that regulate food intake. Accordingly, neurogenesis in both the adult and embryonic hypothalamus is affected by nutritional cues and metabolic disorders such as obesity, with consequent effects on energy-balance. This review critically discusses recent findings on the contribution of adult hypothalamic neurogenesis to feeding regulation, the impact of energy-balance disorders on adult hypothalamic neurogenesis, and the influence of embryonic hypothalamic neurogenesis upon feeding regulation in the adult. Understanding how hypothalamic neurogenesis contributes to food intake control will change the paradigm on how we perceive energy-balance regulation.

Sexual function improvement in association with serum leptin level elevation in patients with premature ejaculation following sertraline treatment: a preliminary observation

The objective of our work was to evaluate the effect of sertraline hydrochloride on serum levels of leptin and sexual function in patients with premature ejaculation (PE). A total of 124 patients with a history of PE at least 6 months, aged 20-50 years, were treated with sertraline hydrochloride. One hundred and four age-matched normal males without a history of PE were included control subjects and were untreated. Before and after the 8 week experiment, sexual performance parameters including the intravaginal ejaculation latency time (IELT) and the Chinese premature ejaculation index (CIPE) were collected from both PE patients and control subjects through a questionnaire survey and analyzed. Serum levels of leptin were measured. Correlations of serum leptin with Body Mass Index (BMI) were analyzed. Before sertraline treatment, serum levels of leptin were significantly higher (32.9 vs 8.8 μg/L, p<0.001) but IELT and CIPE score were significantly lower (54 vs 590, p <0.001; 8.7 vs 22.3, p <0.0001) in PE patients than control subjects. After 8 weeks of treatment with sertraline, serum levels of leptinl in PE patients were decreased markedly to 8.0 μg/L, which was not significantly different from the levels in control subjects (p >0.05); and IELT and CIPE score in PE patients were increased to the values similar to those in control subjects. The sensitivity and specificity values were 87.5% and 96.3% for leptin as a diagnosis target. These observations suggest sertraline as a selective serotonin reuptake inhibitor may offer an effective option for treating premature ejaculation.

Impaired hypothalamic mTOR activation in the adult rat offspring born to mothers fed a low-protein diet

Several epidemiological and experimental studies have clearly established that maternal malnutrition induces a high risk of developing obesity and related metabolic diseases in the offspring. To determine if altered nutrient sensing might underlie this enhanced disease susceptibility, here we examined the effects of perinatal protein restriction on the activation of the nutrient sensor mTOR in response to acute variations in the nutritional status of the organism. Female Wistar rats were fed isocaloric diets containing either 17% protein (control) or 8% protein (PR) throughout pregnancy and lactation. At weaning offspring received standard chow and at 4 months of age the effects of fasting or fasting plus re-feeding on the phosphorylation levels of mTOR and its downstream target S6 ribosomal protein (rpS6) in the hypothalamus were assessed by immuno-fluorescence and western blot. Under ad libitum feeding conditions, PR rats exhibited decreased mTOR and rpS6 phosphorylation in the arcuate (ARC) and ventromedial (VMH) hypothalamic nuclei. Moreover, the phosphorylation of mTOR and rpS6 in these hypothalamic nuclei decreased with fasting in control but not in PR animals. Conversely, PR animals exhibited enhanced number of pmTOR imunostained cells in the paraventricular nucleus (PVN) and fasting decreased the activation of mTOR in the PVN of malnourished but not of control rats. These alterations occurred at a developmental stage at which perinatally-undernourished animals do not show yet obesity or glucose intolerance. Collectively, our observations suggest that altered hypothalamic nutrient sensing in response to an inadequate foetal and neonatal energetic environment is one of the basic mechanisms of the developmental programming of metabolic disorders and might play a causing role in the development of the metabolic syndrome induced by malnutrition during early life.

Perinatal undernutrition stimulates seeking food reward

Experiments in animals have revealed that perinatal nutritional restriction, which manifests in adulthood, increases food intake and preference for palatable foods. Considering this, we aimed to evaluate the effects of perinatal malnutrition on hedonic control of feeding behavior. In this study, we divided Wistar rats into two groups according to the diet provided to their mothers during pregnancy and lactation: the control group (diet with 17% casein) and low-protein group (diet with 8% casein). We assessed the animals' motivational behavior in adulthood by giving them a stimulus of food reward. We also assessed their neuronal activation triggered by the stimulus of palatable food using FOS protein labeling of neurons activated in the caudate putamen, paraventricular, dorsomedial, ventromedial, and lateral hypothalamic nuclei and amygdala. Evaluation of body weight in malnourished animals showed reduction from the 6th day of life until adulthood. Analysis of feeding behavior revealed that these animals were more motivated by food reward, but they had delays during learning of the task. This finding correlated with the number of c-FOS-immunoreactive neurons, which indicated that malnourished animals had an increase in the number of neurons activated in response to the palatable diet, especially in the amygdala and caudate putamen. The study therefore confirmed our hypothesis that early nutritional insults promote changes in encephalic control mechanisms, especially those related to food intake and search for reward.

The hypothalamic POMC mRNA expression is upregulated in prenatally undernourished male rat offspring under high-fat diet

Epidemiological studies demonstrated that adverse environmental factors leading to intrauterine growth retardation (IUGR) and low birth weight may predispose individuals to increased risk of metabolic syndrome. In rats, we previously demonstrated that adult male IUGR offspring from prenatal 70% food-restricted dams throughout gestation (FR30) were predisposed to energy balance dysfunctions such as impaired glucose intolerance, hyperleptinemia, hyperphagia and adiposity. We investigated whether postweaning moderate high-fat (HF) diet would amplify the phenotype focusing on the hypothalamus gene expression profile. Prenatally undernourished rat offspring were HF-fed from weaning until adulthood while body weight and food intake were measured. Tissue weights, glucose tolerance and plasma endocrine parameters levels were determined in 4-month-old rats. Hypothalamic gene expression profiling of adult FR30 rat was performed using Illumina microarray analysis and the RatRef-12 Expression BeadChip that contains 21,792 rat genes. Under HF diet, contrary to C animals, FR30 rats displayed increased body weight. However, most of the endocrine disorders observed in chow diet-fed adult FR30 were alleviated. We also observed very few gene expression changes in hypothalamus of FR30 rat. Amongst factors involved in hypothalamic energy homeostasis programming system, only the POMC and transthyretin mRNA expression levels were preferentially increased under HF diet. Both elevated gene expression levels may be seen as adaptive mechanisms counteracting against deleterious effects of HF feeding in FR30 animals. This study shows that the POMC gene expression is a key target of long-term developmental programming in prenatally undernourished male rat offspring, specifically within an obesogenic environment.

Renal denervation abolishes the age-dependent increase in blood pressure in female intrauterine growth-restricted rats at 12 months of age

Perinatal insults program sex differences in blood pressure, with males more susceptible than females. Aging may augment developmental programming of chronic disease, but the mechanisms involved are not clear. We previously reported that female growth-restricted offspring are normotensive after puberty. Therefore, we tested the hypothesis that age increases susceptibility to hypertension in female growth-restricted offspring. Blood pressure remained similar at 6 months of age; however, blood pressure was significantly elevated in female growth-restricted offspring relative to control by 12 months of age (137±3 vs 117±4 mm Hg; P<0.01, respectively). Body weight did not differ at 6 or 12 months of age; however, total fat mass and visceral fat were significantly increased at 12 months in female growth-restricted offspring (P<0.05 vs control). Glomerular filtration rate remained normal, yet renal vascular resistance was increased at 12 months of age in female growth-restricted offspring (P<0.05 vs control). Plasma leptin, which can increase sympathetic nerve activity, did not differ at 6 months but was increased at 12 months of age in female growth-restricted offspring (P<0.05 vs control). Because of the age-dependent increase in leptin, we hypothesized that the renal nerves may contribute to the age-dependent increase in blood pressure. Bilateral renal denervation abolished the elevated blood pressure in female growth-restricted offspring normalizing it relative to denervated female control offspring. Thus, these data indicate that age induces an increase in visceral fat and circulating leptin associated with a significant increase in blood pressure in female growth-restricted offspring, with the renal nerves serving as an underlying mechanism.

Developmental origins of obesity: programmed adipogenesis

The metabolic syndrome epidemic, including a marked increase in the prevalence of obesity and gestational diabetes mellitus (GDM) among pregnant women, represents a significant public health problem. There is increasing recognition that the risk of adult obesity is clearly influenced by prenatal and infant environmental exposures, particularly nutrition. This tenet is the fundamental basis of developmental programming. Low birth weight, together with infant catch-up growth, is associated with a significant risk of adult obesity. Exposure to maternal obesity, with or without GDM, or having a high birth weight also represents an increased risk for childhood and adult obesity. Animal models have replicated human epidemiologic findings and elucidated potential programming mechanisms that include altered organ development, cellular signaling responses, and epigenetic modifications. Prenatal care has made great strides in optimizing maternal, fetal, and neonatal health, and now has the opportunity to begin interventions which prevent or reduce childhood/adult obesity. Guidelines that integrate optimal pregnancy nutrition and weight gain, management of GDM, and newborn feeding strategies with long-term consequences on adult obesity, remain to be elucidated.

Role of maternal nutrition in programming adiposity in the offspring: potential implications of glucocorticoids

The epidemiological studies initially indicated that maternal undernutrition leading to a low birth weight may predispose to the long-lasting energy balance disorders. A high birth weight due to maternal obesity or diabetes, inappropriate early postnatal nutrition, and rapid catch-up growth, may also sensitize to an increased risk of obesity. As stated by the developmental origin of health and disease concept, the perinatal perturbation of the fetus/neonate nutrient supply might be a crucial determinant of the individual programming of the body weight set point. The adipose tissue is considered as the main fuel storage unit involved in the maintenance of the energy homeostasis. Several models have demonstrated that this tissue is a prime target of the developmental programming in a gender- and depot-specific manner. In the rodents, the perinatal period of life corresponds largely to the period of adipogenesis. In contrast, this phenomenon essentially takes place before birth in bigger mammals. Despite these different developmental time windows, the altricial and precocial species share several common offspring programming mechanisms. Thus, the adipose tissue of the offspring from malnourished dams exhibited impaired glucose uptake and leptin/insulin resistance with increased proinflammatory markers. It also displayed a modified sympathetic activity, circadian rhythm, fatty acid composition, and thermogenesis. This might lead to the reprogrammed metabolism and distribution of the adipose tissue with enhanced adipogenesis and fat accumulation predisposing to adiposity. The inappropriate glucocorticoid (GC) levels and modified tissue sensitivity might be key actors of perinatal programming and long-lasting altered adipose tissue activity in the offspring. Following maternal malnutrition, the epigenetic mechanisms might also be responsible for the adipose tissue programming.

Neurodevelopmental consequences of maternal distress: what do we really know?

A simple internet search of 'maternal stress and pregnancy' turns up hundreds of hits explaining that an adverse intrauterine environment can affect fetal development and potentially lead to various learning, behavioral, and mood disorders in childhood, as well as complex diseases such as obesity and cardiovascular conditions later in life. Indeed, a growing body of literature now links several intrauterine challenges, including maternal obesity and stress, with adverse developmental outcomes in the child. Over the past 5 years, nearly 5000 publications have explored the consequences of maternal distress on young offspring, a marked increase from the 475 published studies over a comparable period 20 years ago. Yet, despite this explosion of research and widespread warnings to pregnant mothers, we still lack a basic understanding of the pathophysiology linking adverse maternal health to the onset of disease in the child, especially regarding how prenatal and perinatal challenges might affect brain development. Recent studies have begun to explore the cellular basis of the abnormal brain cytoarchitecture associated with fetal exposure to intrauterine challenges. Here, our goal is to review the scientific evidence that maternal distress interferes with key neurodevelopmental steps, as an entry point toward mapping the pathophysiology of pre- and perinatal stress on the unborn child's brain.