Role of premature leptin surge in obesity resulting from intrauterine undernutrition

A Bird's-Eye Overview of Leptin and Female Reproduction -with Mammalian Comparisons

Leptin, a key regulator of reproductive physiology, influences various processes in vertebrates, including oocyte proliferation, embryogenesis, the onset of puberty, ovarian function, and follicle development. In mammals, leptin affects steroidogenesis, folliculogenesis, and hormonal regulation through the hypothalamic-pituitary-gonadal axis. Instead, in avian species, leptin-controlled mechanisms are poorly understood, because birds do not produce leptin in adipocytes. In birds, leptin is expressed in the brain, pituitary glands, and gonads, where it enhances ovarian function and egg-laying performance, particularly during feed deprivation. In this review, we discuss and summarize the recently discovered role of leptin in regulating ovarian function during different life stages in birds and compare it with its function in mammals.

Maternal circadian rhythms during pregnancy dictate metabolic plasticity in offspring

Tissue-level oscillation is achieved by tissue-intrinsic clocks along with network-dependent signals originating from distal organs and organismal behavior. Yet, it remains unexplored whether maternal circadian rhythms during pregnancy influence fetal rhythms and impact long-term susceptibility to dietary challenges in offspring. Here, we demonstrate that circadian disruption during pregnancy decreased placental and neonatal weight yet retained transcriptional and structural maturation. Intriguingly, diet-induced obesity was exacerbated in parallel with arrhythmic feeding behavior, hypothalamic leptin resistance, and hepatic circadian reprogramming in offspring of chronodisrupted mothers. In utero circadian desynchrony altered the phase-relationship between the mother and fetus and impacted placental efficiency. Temporal feeding restriction in offspring failed to fully prevent obesity, whereas the circadian alignment of caloric restriction with the onset of the active phase virtually ameliorated the phenotype. Thus, maternal circadian rhythms during pregnancy confer adaptive properties to metabolic functions in offspring and provide insights into the developmental origins of health and disease.

Postnatal surge of adipose-secreted leptin is a robust predictor of fat mass trajectory in mice

The transient postnatal increase in circulating leptin levels, known as leptin surge, may increase later susceptibility to diet-induced obesity in rodents. However, the source of leptin during the surge needs to be better characterized, and the long-term effects of leptin are contradictory. Characterization of the interaction of leptin with the genetic background, sex, and other factors is required. Here, we focused on the impact of circulating leptin levels and several related variables, measured in 2- and 4-wk-old i) obesity-prone C57BL/6 (B6) and ii) obesity-resistant A/J mice. In total, 264 mice of both sexes were used. Posttranscriptionally controlled leptin secretion from subcutaneous white adipose tissue, the largest adipose tissue depot in mice pups, was the primary determinant of plasma leptin levels. When the animals were randomly assigned standard chow or high-fat diet (HFD) between 12 and 24 wk of age, the obesogenic effect of HFD feeding was observed in B6 but not A/J mice. Only leptin levels at 2 wk, i.e., close to the maximum in the postnatal leptin surge, correlated with both body weight (BW) trajectory throughout the life and adiposity of the 24-wk-old mice. Leptin surge explained 13 and 7% of the variance in BW and adiposity of B6 mice, and 9 and 35% of the variance in these parameters in A/J mice, with a minor role of sex. Our results prove the positive correlation between the leptin surge and adiposity in adulthood, reflecting the fundamental biological role of leptin. This role could be compromised in subjects with obesity.NEW & NOTEWORTHY The postnatal surge in circulating leptin levels in mice reflects particularly posttranscriptionally controlled release of this hormone from subcutaneous white adipose tissue. Leptinemia in 2-wk-old pups predicts both body weight and adiposity in adult mice fed a high-fat diet. The extent of these effects depends on genetically determined differences in propensity to obesity between C57BL/6 and A/J mice. The leptin effect on adiposity is compromised in the obesity-prone C57BL/6 mice.

Intestinal gluconeogenesis controls the neonatal development of hypothalamic feeding circuits

OBJECTIVE

Intestinal gluconeogenesis (IGN) regulates adult energy homeostasis in part by controlling the same hypothalamic targets as leptin. In neonates, leptin exhibits a neonatal surge controlling axonal outgrowth between the different hypothalamic nuclei involved in feeding circuits and autonomic innervation of peripheral tissues involved in energy and glucose homeostasis. Interestingly, IGN is induced during this specific time-window. We hypothesized that the neonatal pic of IGN also regulates the development of hypothalamic feeding circuits and sympathetic innervation of adipose tissues.

METHODS

We genetically induced neonatal IGN by overexpressing G6pc1 the catalytic subunit of glucose-6-phosphatase (the mandatory enzyme of IGN) at birth or at twelve days after birth. The neonatal development of hypothalamic feeding circuits was studied by measuring Agouti-related protein (AgRP) and Pro-opiomelanocortin (POMC) fiber density in hypothalamic nuclei of 20-day-old pups. The effect of the neonatal induction of intestinal G6pc1 on sympathetic innervation of the adipose tissues was studied via tyrosine hydroxylase (TH) quantification. The metabolic consequences of the neonatal induction of intestinal G6pc1 were studied in adult mice challenged with a high-fat/high-sucrose (HFHS) diet for 2 months.

RESULTS

Induction of intestinal G6pc1 at birth caused a neonatal reorganization of AgRP and POMC fiber density in the paraventricular nucleus of the hypothalamus, increased brown adipose tissue tyrosine hydroxylase levels, and protected against high-fat feeding-induced metabolic disorders. In contrast, inducing intestinal G6pc1 12 days after birth did not impact AgRP/POMC fiber densities, adipose tissue innervation or adult metabolism.

CONCLUSION

These findings reveal that IGN at birth but not later during postnatal life controls the development of hypothalamic feeding circuits and sympathetic innervation of adipose tissues, promoting a better management of metabolism in adulthood.

Maternal Diet during Pregnancy Alters the Metabolites in Relation to Metabolic and Neurodegenerative Diseases in Young Adult Offspring

Maternal nutrition during the critical period of pregnancy increases the susceptibility of offspring to the development of diseases later in life. This study aimed to analyze metabolite profiles to investigate the effect of maternal diet during pregnancy on changes in offspring plasma metabolites and to identify correlations with metabolic parameters. Pregnant Sprague-Dawley rats were exposed to under- and overnutrition compared to controls, and their offspring were fed a standard diet after birth. Plasma metabolism was profiled in offspring at 16 weeks of age using liquid chromatography-mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS). We analyzed 80 metabolites to identify distinct metabolites and metabolic and neurodegenerative disease-associated metabolites that were sex-differentially altered in each group compared to controls (p < 0.05, VIP score > 1.0). Specifically, changes in 3-indolepropionic acid, anthranilic acid, linoleic acid, and arachidonic acid, which are involved in tryptophan and linoleic acid metabolism, were observed in male offspring and correlated with plasma leptin levels in male offspring. Our results suggest that fatty acids involved in tryptophan and linoleic acid metabolism, which are altered by the maternal diet during pregnancy, may lead to an increased risk of metabolic and neurodegenerative diseases in the early life of male offspring.

Associations of pre- and postnatal per- and polyfluoroalkyl substance exposure with adolescents' eating behaviors

Background

Per- and polyfluoroalkyl substances (PFAS), persistent environmental chemicals, may act as obesogens by interacting with neuroendocrine pathways regulating energy homeostasis and satiety signals influencing adolescent eating behaviors.

Methods

In 211 HOME Study adolescents (Cincinnati, OH; recruited 2003-2006), we measured PFAS concentrations in serum collected during pregnancy, at delivery, and at ages 3, 8, and 12 years. Caregivers completed the Child Eating Behavior Questionnaire (CEBQ) at age 12, and we calculated food approach and food avoidance scores. Using quantile-based g-computation, we estimated covariate-adjusted associations between a mixture of four gestational PFAS and CEBQ scores. We identified high (n = 76, 36%) and low (n = 135, 64%) longitudinal PFAS mixture exposure profiles between delivery and age 12 years using latent profile analysis and related these to CEBQ scores. We examined whether child sex or physical activity modified these associations.

Results

We observed no association of gestational PFAS mixture with food approach or food avoidance scores. Children in the higher longitudinal PFAS mixture profile had slightly higher food approach scores (β: 0.47, 95% CI: -0.27, 1.23) and similar food avoidance scores (β: -0.15, 95% CI: -0.75, 0.46) compared with children in the lower profile. We found some evidence that higher physical activity favorably modified the association between longitudinal PFAS mixture profiles and emotional overeating (interaction P value = 0.13). Child sex did not consistently modify any associations.

Conclusions

Serum PFAS concentrations were not consistently linked to adolescent eating behaviors in this study, suggesting alternative pathways, such as metabolic rate, may underlie previously observed associations between PFAS exposure and childhood obesity.

Solubilized β-Glucan Supplementation in C57BL/6J Mice Dams Augments Neurodevelopment and Cognition in the Offspring Driven by Gut Microbiome Remodeling

A maternal diet rich in dietary fiber, such as β-glucan, plays a crucial role in the offspring's acquisition of gut microbiota and the subsequent shaping of its microbiome profile and metabolome. This in turn has been shown to aid in neurodevelopmental processes, including early microglial maturation and immunomodulation via metabolites like short chain fatty acids (SCFAs). This study aimed to investigate the effects of oat β-glucan supplementation, solubilized by citric acid hydrolysis, from gestation to adulthood. Female C57BL/6J mice were orally supplemented with soluble oat β-glucan (ObG) or carboxymethyl cellulose (CMC) via drinking water at 200 mg/kg body weight during breeding while the control group received 50 mg/kg body weight of carboxymethyl cellulose. ObG supplementation increased butyrate production in the guts of both dams and 4-week-old pups, attributing to alterations in the gut microbiota profile. One-week-old pups from the ObG group showed increased neurodevelopmental markers similar to four-week-old pups that also exhibited alterations in serum markers of metabolism and anti-inflammatory cytokines. Notably, at 8 weeks, ObG-supplemented pups exhibited the highest levels of spatial memory and cognition compared to the control and CMC groups. These findings suggest a potential enhancement of neonatal neurodevelopment via shaping of early-life gut microbiome profile, and the subsequent increased later-life cognitive function.

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.

Maternal undernutrition results in transcript changes in male offspring that may promote resistance to high fat diet induced weight gain

Maternal nutrition during embryonic development and lactation influences multiple aspects of offspring health. Using mice, this study investigates the effects of maternal caloric restriction (CR) during mid-gestation and lactation on offspring neonatal development and on adult metabolic function when challenged by a high fat diet (HFD). The CR maternal model produced male and female offspring that were significantly smaller, in terms of weight and length, and females had delayed puberty. Adult offspring born to CR dams had a sexually dimorphic response to the high fat diet. Compared to offspring of maternal control dams, adult female, but not male, CR offspring gained more weight in response to high fat diet at 10 weeks. In adipose tissue of male HFD offspring, maternal undernutrition resulted in blunted expression of genes associated with weight gain and increased expression of genes that protect against weight gain. Regardless of maternal nutrition status, HFD male offspring showed increased expression of genes associated with progression toward nonalcoholic fatty liver disease (NAFLD). Furthermore, we observed significant, sexually dimorphic differences in serum TSH. These data reveal tissue- and sex-specific changes in gene and hormone regulation following mild maternal undernutrition, which may offer protection against diet induced weight gain in adult male offspring.

Developmental Changes in Hypothalamic and Serum Oxytocin Levels in Prenatally Normally Nourished and Undernourished Rats

Changes in the activities of some metabolic factors have been suggested to increase the risk of conditions associated with the Developmental Origins of Health and Disease (DOHaD). We examined changes in oxytocin (OT), a metabolic factor, and OT receptor (OTR) mRNA levels throughout the developmental period in rats of intrauterine undernutrition. Pregnant rats were divided into two groups: a maternal normal nutrition (mNN) and maternal undernutrition (mUN) group. Serum OT concentrations and hypothalamic mRNA levels of OT and OTR were measured in both offspring at various postnatal stages. Both offspring showed significant increases in serum OT concentrations during the neonatal period, significant reductions around the pubertal period, and significant increases in adulthood. Hypothalamic OT mRNA expression levels gradually increased from the neonatal to pubertal period and decreased in adulthood in both offspring. In the pre-weaning period, hypothalamic OT mRNA expression levels were significantly lower in the mUN offspring than in the mNN offspring. In the mUN offspring, hypothalamic OTR mRNA expression levels transiently increased during the neonatal period, decreased around the pubertal period, and increased again in adulthood, whereas transient changes were not detected in mNN offspring. These changes could affect nutritional and metabolic regulation systems in later life and play a role in the mechanisms underlying DOHaD.

Effects of Exogenous Glucocorticoid Infusion on Appetitic Center Development in Postnatal Dairy Bull Calves

The objective of this study was to determine the effects of exogenous glucocorticoid administration on leptin concentrations and brain development markers, such as protein and hypothalamic gene expression, in dairy bull calves. Within 4 h of parturition, Holstein bulls were intravenously infused with either a low cortisol dose (LC; n = 9, 3.5 µg/kg of body weight (BW)), high cortisol dose (HC; n = 9, 7.0 µg/kg BW), or control (CON; n = 9, saline) dose, with a 2nd infusion 24 h postpartum. Jugular blood was collected prior to infusion and daily until the calves were euthanized (day 5). Cerebrospinal fluid (CSF) from the third ventricle and adipose (omental, perirenal, and mesenteric) and hypothalamic tissue were collected. The blood and CSF samples were analyzed for leptin concentrations. The data were analyzed using SAS. Serum (p = 0.013) and CSF (p = 0.005) leptin concentrations in HC- and LC-treated calves were decreased compared with CON-treated calves. Leptin protein expression was decreased (p < 0.044) in perirenal and omental adipose tissue of LC-treated calves compared with CON-treated calves. Gene abundance of brain-derived neurotrophic factor and fibroblast growth factors 1 and 2 were decreased (p < 0.006) in HC- and LC-treated calves compared with CON-treated calves. In summary, cortisol administered to dairy bull calves reduced leptin concentrations, decreased leptin protein expression in perirenal and omental adipose tissue, and altered gene expression in hypothalamic tissue.

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.

Transgenerational impacts of oral probiotic administration in pregnant mice on offspring gut immune cells and colitis susceptibility

BACKGROUND AND AIM

The study of the impact of environmental factors during pregnancy on fetal development has so far been focused primarily on those negatively affecting human health; however, little is known about the effects of probiotic treatment during pregnancy on inflammatory bowel diseases (IBD). In this study, we investigated whether oral administration of heat-killed probiotics isolated from fermented foods decreased the vulnerability of offspring to IBD.

METHODS

Probiotics were administered to the pregnant mice until the birth of pups, after which the parent mice were maintained with autoclaved water. Partial pups were evaluated for dextran sodium sulfate-induced colitis. The influence of CD11c⁺ CD103⁺ dendritic cells (DCs) and regulatory T cells (Tregs) in mesenteric lymph nodes of parent mice and their pups was analyzed.

RESULTS

Oral administration of heat-killed probiotics to pregnant dams significantly decreased inflammation induced by dextran sodium sulfate in pups. Probiotic treatment increased the number of CD103⁺ DCs, and the expression of β8-integrin in CD103⁺ DCs and Tregs in mesenteric lymph nodes, not only in dams themselves but also in their offspring.

CONCLUSIONS

Oral administration of probiotics during gestation induced transgenerational immunomodulatory effects on the gut-associated immune system and resilience to experimental colitis in the offspring. Our results suggest that consumption of fermented foods during pregnancy can be effective in preventing inflammatory diseases such as IBD beyond generation.

Maternal Protein Restriction in Rats Alters Postnatal Growth and Brain Lipid Sensing in Female Offspring

Perinatal nutrition is a key player in the susceptibility to developing metabolic diseases in adulthood, leading to the concept of "metabolic programming". The aim of this study was to assess the impact of maternal protein restriction during gestation and lactation on glucose homeostasis and eating behaviour in female offspring. Pregnant rats were fed a normal or protein-restricted (PR) diet and followed throughout gestation and lactation. Body weight, glucose homeostasis, and eating behaviour were evaluated in offspring, especially in females. Body weight gain was lower in PR dams during lactation only, despite different food and water intakes throughout gestation and lactation. Plasma concentration of leptin, adiponectin and triglycerides increased drastically before delivery in PR dams in relation to fat deposits. Although all pups had identical birth body weight, PR offspring body weight differed from control offspring around postnatal day 10 and remained lower until adulthood. Offspring glucose homeostasis was mildly impacted by maternal PR, although insulin secretion was reduced for PR rats at adulthood. Food intake, satiety response, and cerebral activation were examined after a lipid preload and demonstrated some differences between the two groups of rats. Maternal PR during gestation and lactation does induce extrauterine growth restriction, accompanied by alterations in maternal plasma leptin and adiponectin levels, which may be involved in programming the alterations in eating behaviour observed in females at adulthood.

Maternal obesity blunts antimicrobial responses in fetal monocytes

Maternal pre-pregnancy (pregravid) obesity is associated with adverse outcomes for both mother and offspring. Amongst the complications for the offspring is increased susceptibility and severity of neonatal infections necessitating admission to the intensive care unit, notably bacterial sepsis and enterocolitis. Previous studies have reported aberrant responses to LPS and polyclonal stimulation by umbilical cord blood monocytes that were mediated by alterations in the epigenome. In this study, we show that pregravid obesity dysregulates umbilical cord blood monocyte responses to bacterial and viral pathogens. Specifically, interferon-stimulated gene expression and inflammatory responses to respiratory syncytial virus (RSV) and E. coli were significantly dampened, respectively . Although upstream signaling events were comparable, translocation of the key transcription factor NF-κB and chromatin accessibility at pro-inflammatory gene promoters following TLR stimulation was significantly attenuated. Using a rhesus macaque model of western style diet-induced obesity, we further demonstrate that this defect is detected in fetal peripheral monocytes and tissue-resident macrophages during gestation. Collectively, these data indicate that maternal obesity alters metabolic, signaling, and epigenetic profiles of fetal monocytes leading to a state of immune paralysis during late gestation and at birth.

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.

Maternal Protein Restriction and Post-Weaning High-Fat Feeding Alter Plasma Amino Acid Profiles and Hepatic Gene Expression in Mice Offspring

Maternal undernutrition during pregnancy is closely associated with epigenetic changes in the child, and it affects the development of obesity throughout the child’s life. Here, we investigate the effect of fetal low protein exposure and post-weaning high-fat consumption on plasma amino acid profiles and hepatic gene expression. Mother C57BL/6J mice were fed a 20% (CN) or 9% (LP) casein diet during pregnancy. After birth, the male offspring of both these groups were fed a high-fat diet (HF) from 6 to 32 weeks. At 32 weeks, the final body weight between the two groups remained unchanged, but the LP-HF group showed markedly higher white fat weight and plasma leptin levels. The LP-HF group exhibited a significant increase in the concentrations of isoleucine, leucine, histidine, phenylalanine, serine, and tyrosine. However, no differences were observed in the lipid content in the liver. According to the hepatic gene expression analysis, the LP-HF group significantly upregulated genes involved in the chromatin modification/organization pathways. Thus, maternal low protein and a post-weaning high-fat environment contributed to severe obesity states and changes in gene expression related to hepatic chromatin modification in offspring. These findings provide novel insights for the prevention of lifestyle-related diseases at the early life stage.

Comparative Analysis of Gene Expression Profiles in the Adipose Tissue of Obese Adult Mice With Rapid Infantile Growth After Undernourishment In Utero

Rapid infantile growth (RG) markedly increases the risk of obesity and metabolic disorders in adulthood, particularly among neonates born small. To elucidate the molecular mechanisms by which RG following undernourishment in utero (UN) contributes to the deterioration of adult fat deposition, we developed a UN mouse model using maternal energy restriction, followed by RG achieved by adjustments to 4 pups per litter soon after birth. A high-fat diet (HFD) was fed to weaned pups treated or not (Veh) with tauroursodeoxycholic acid (TU). UN-RG pups showed the deterioration of diet-induced obesity and fat deposition, which was ameliorated by TU. We performed a microarray analysis of epididymal adipose tissue and two gene enrichment analyses (NN-Veh vs UN-RD-Veh and UN-RG-Veh vs UN-RG-TU). The results obtained identified 4 common gene ontologies (GO) terms of inflammatory pathways. In addition to the inflammatory characteristics of 4 GO terms, the results of heatmap and principal component analyses of the representative genes from 4 GO terms, genes of interest (GOI; Saa3, Ubd, S100a8, Hpx, Casp1, Agt, Ptgs2) selected from the 4 GO terms, and immunohistochemistry of macrophages collectively suggested the critical involvement of inflammation in the regulation of fat deposition in the responses to UN and TU. Therefore, the present results support the 'Developmental Origins of Metaflammation', the last word of which was recently proposed by the concept of metabolic disorders induced by low-grade systemic inflammation.

The postnatal leptin surge in mice is variable in both time and intensity and reflects nutritional status

BACKGROUND/OBJECTIVES

The murine postnatal leptin surge occurs within the first 4 weeks of life and is critical for neuronal projection development within hypothalamic feeding circuits. Here we describe the influence of nutritional status on the timing and magnitude of the postnatal leptin surge in mice.

METHODS

Plasma leptin concentrations were measured 1-3 times per week for the first 4 weeks of life in C57BL/6J pups reared in litters adjusted to 3 (small), 7-8 (normal), or 11-12 (large) pups per dam fed breeder chow or raised in litters of 7-8 by dams fed high-fat diet (HFD) ad libitum starting either prior to conception or at parturition.

RESULTS

Mice raised in small litters become fatter than pups raised in either normal or large litters. The leptin surge in small litter pups starts earlier, lasts longer, and is dramatically larger in magnitude compared to normal litter pups, even when leptin concentrations are normalized to fat mass. In mice reared in large litters, weight gain is diminished and the surge is both significantly delayed and lower in magnitude compared to control pups. Pups reared by HFD-fed dams (starting preconception or at parturition) are fatter and have augmented leptin surge magnitude compared to pups suckled by chow-fed dams. Surge timing varies depending upon nutritional status of the pup; the source of the surge is primarily subcutaneous adipose tissue. At peak leptin surge, within each group, fat mass and plasma leptin are uncorrelated; in comparison with adults, pups overproduce leptin relative to fat mass. Plasma leptin elevation persists longer than previously described; at postnatal day 27 mice continue overproducing leptin relative to fat mass.

CONCLUSIONS

In mice, small litter size and maternal HFD feeding during the perinatal period augment the plasma leptin surge whereas large litter size is associated with a delayed surge of reduced magnitude.

Umbilical Cord Blood Leptin and IL-6 in the Presence of Maternal Diabetes or Chorioamnionitis

Diabetes during pregnancy is associated with elevated maternal insulin, leptin and IL-6. Within the placenta, IL-6 can further stimulate leptin production. Despite structural similarities and shared roles in inflammation, leptin and IL-6 have contrasting effects on neurodevelopment, and the relative importance of maternal diabetes or chorioamnionitis on fetal hormone exposure has not been defined. We hypothesized that there would be a positive correlation between IL-6 and leptin with progressively increased levels in pregnancies complicated by maternal diabetes and chorioamnionitis. To test this hypothesis, cord blood samples were obtained from 104 term infants, including 47 exposed to maternal diabetes. Leptin, insulin, and IL-6 were quantified by multiplex assay. Factors independently associated with hormone levels were identified by univariate and multivariate linear regression. Unlike IL-6, leptin and insulin were significantly increased by maternal diabetes. Maternal BMI and birth weight were independent predictors of leptin and insulin with birth weight the strongest predictor of leptin. Clinically diagnosed chorioamnionitis and neonatal sepsis were associated with increased IL-6 but not leptin. Among appropriate for gestational age infants without sepsis, IL-6 and leptin were strongly correlated (R=0.6, P<0.001). In summary, maternal diabetes and birth weight are associated with leptin while chorioamnionitis is associated with IL-6. The constraint of the positive association between leptin and IL-6 to infants without sepsis suggests that the term infant and placenta may have a limited capacity to increase cord blood levels of the neuroprotective hormone leptin in the presence of increased cord blood levels of the potential neurotoxin IL-6.

Regulation of Pancreatic β-Cell Mass by Gene-Environment Interaction

The main pathogenic mechanism of diabetes consists of an increase in insulin resistance and a decrease in insulin secretion from pancreatic β-cells. The number of diabetic patients has been increasing dramatically worldwide, especially in Asian people whose capacity for insulin secretion is inherently lower than that of other ethnic populations. Causally, changes of environmental factors in addition to intrinsic genetic factors have been considered to have an influence on the increased prevalence of diabetes. Particular focus has been placed on "gene-environment interactions" in the development of a reduced pancreatic β-cell mass, as well as type 1 and type 2 diabetes mellitus. Changes in the intrauterine environment, such as intrauterine growth restriction, contribute to alterations of gene expression in pancreatic β-cells, ultimately resulting in the development of pancreatic β-cell failure and diabetes. As a molecular mechanism underlying the effect of the intrauterine environment, epigenetic modifications have been widely investigated. The association of diabetes susceptibility genes or dietary habits with gene-environment interactions has been reported. In this review, we provide an overview of the role of gene-environment interactions in pancreatic β-cell failure as revealed by previous reports and data from experiments.

Developmental Origins of Metaflammation; A Bridge to the Future Between the DOHaD Theory and Evolutionary Biology

Metabolic syndrome refers to obesity-associated metabolic disorders that increase the risk of type 2 diabetes, coronary diseases, stroke, and other disabilities. Environmental imbalance during the early developmental period affects health and increases susceptibility to non-communicable diseases, including metabolic syndrome, in later life; therefore, the Developmental Origins of Health and Disease (DOHaD) theory was established. According to the DOHaD theory, the hypothesis of the energy-saving 'Thrifty Phenotype' in undernourished fetuses is one of the well-accepted schemes as a risk of developing metabolic syndrome. This phenotype is evolutionarily advantageous for survival of the fittest in a hangry environment after birth, a strong selection pressure, but increases the risk of developing metabolic syndrome under an obesogenic diet according to the 'Mismatch' hypothesis. Increasing evidences support that chronic inflammation pathophysiologically connects obesity to metabolic disorders in metabolic syndrome, leading to the concept of 'Metaflammation'. 'Metaflammation' in humans is proposed to originate from the evolutionary conservation of crosstalk between immune and metabolic pathways; however, few studies have investigated the contribution of evolutionary maladaptation to the pathophysiology of 'Metaflammation'. Therefore, it is promising to investigate 'Metaflammation' from the viewpoint of selective advantages and its 'Mismatch' to an unexpected environment in contemporary lifestyles, in consideration of the principal concept of evolutionarily conserved nutrient sensing and immune signaling systems.

The Role of Leptin in the Development of Energy Homeostatic Systems and the Maintenance of Body Weight

LEP is a pleiotropic gene and the actions of leptin extend well beyond simply acting as the signal of the size of adipose tissue stores originally proposed. This is a discussion of the multi-system interactions of leptin with the development of the neural systems regulating energy stores, and the subsequent maintenance of energy stores throughout the lifespan. The prenatal, perinatal, and later postnatal effects of leptin on systems regulating body energy stores and on the energy stores themselves are heavily influenced by the nutritional environment which leptin exposure occurs. This review discusses the prenatal and perinatal roles of leptin in establishing the neuronal circuitry and other systems relevant to the adiposity set-point (or “threshold”) and the role of leptin in maintaining weight homeostasis in adulthood. Therapeutic manipulation of the intrauterine environment, use of leptin sensitizing agents, and identification of specific cohorts who may be more responsive to leptin or other means of activating the leptin signaling pathway are ripe areas for future research.

Early life nutrition and neuroendocrine programming

Alterations in the nutritional environment in early life can significantly increase the risk for obesity and a range of development of metabolic disorders in offspring in later life, effects that can be passed onto future generations. This process, termed development programming, provides the framework of the developmental origins of health and disease (DOHaD) paradigm. Early life nutritional compromise including undernutrition, overnutrition or specific macro/micronutrient deficiencies, results in a range of adverse health outcomes in offspring that can be further exacerbated by a poor postnatal nutritional environment. Although the mechanisms underlying programming remain poorly defined, a common feature across the phenotypes displayed in preclinical models is that of altered wiring of neuroendocrine circuits that regulate satiety and energy balance. As such, altered maternal nutritional exposures during critical early periods of developmental plasticity can result in aberrant hardwiring of these circuits with lasting adverse consequences for the offspring. There is also increasing evidence around the role of an altered epigenome and the gut-brain axis in mediating some of the central programming effects observed. Further, although such programming was once considered to result in a permanent change in developmental trajectory, there is evidence, at least from preclinical models, that programming can be reversed via targeted nutritional manipulations during early development. Further work is required at a mechanistic level to allow for identification for early markers of later disease risk, delineation of sex-specific effects and pathways to implementation of strategies aimed at breaking the transgenerational transmission of disease.

Infant body composition relationship to maternal adipokines and fat mass: the PONCH study

BACKGROUND

Infant adiposity is linked to both high maternal fat mass (FM) and excessive gestational FM gain, whereas the association with maternal adipokines is less clear. The aim was to determine how levels of maternal leptin, the soluble leptin receptor (sOB-R), adiponectin, and FM during pregnancy were linked to infant FM in normal-weight (NW) women and women with obesity (OB).

METHODS

Body composition and serum levels of leptin, adiponectin, and sOB-R were determined three times during pregnancy in 80 NW and 46 OB women. For infants, body composition was measured at 1 and 12 weeks of age.

RESULTS

Maternal leptin and sOB-R levels increased during pregnancy. For NW women, infant FM at 1 week was inversely associated with changes in maternal leptin and at 12 weeks inversely associated with absolute maternal sOB-R levels throughout pregnancy, as well as changes in sOB-R levels in early pregnancy. For OB women, infant FM at both 1 and 12 weeks were best explained by maternal FM.

CONCLUSIONS

Leptin and sOB-R, thought to regulate leptin bioavailability, are associated with fat accumulation in infants born to NW women. In OB women, maternal FM in early pregnancy is more important than leptin in determining infant fat accumulation.

IMPACT

In normal-weight women, the regulation of maternal leptin bioavailability during pregnancy has a role in infant fat mass accumulation. In women with obesity, however, pre-pregnancy maternal fat mass seems more important for infant fat mass. This is the first study of maternal adipokines and fat mass including longitudinal measurements in both mothers and their children. Understanding the relationship between maternal factors and infant fat mass is of great importance as obesity is programmed over the generations, and it is important to learn what regulates this programming.

The Importance of Leptin to Reproduction

A healthy nutritional state is required for all aspects of reproduction and is signaled by the adipokine leptin. Leptin acts in a relatively narrow concentration range: too much or too little will compromise fertility. The leptin signal timing is important to prepubertal development in both sexes. In the brain, leptin acts on ventral premammillary neurons which signal kisspeptin (Kiss1) neurons to stimulate gonadotropin releasing hormone (GnRH) neurons. Suppression of Kiss1 neurons occurs when agouti-related peptide neurons are activated by reduced leptin, because leptin normally suppresses these orexigenic neurons. In the pituitary, leptin stimulates production of GnRH receptors (GnRHRs) and follicle-stimulating hormone at midcycle, by activating pathways that derepress actions of the messenger ribonucleic acid translational regulatory protein Musashi. In females, rising estrogen stimulates a rise in serum leptin, which peaks at midcycle, synchronizing with nocturnal luteinizing hormone pulses. The normal range of serum leptin levels (10-20 ng/mL) along with gonadotropins and growth factors promote ovarian granulosa and theca cell functions and oocyte maturation. In males, the prepubertal rise in leptin promotes testicular development. However, a decline in leptin levels in prepubertal boys reflects inhibition of leptin secretion by rising androgens. In adult males, leptin levels are 10% to 50% of those in females, and high leptin inhibits testicular function. The obesity epidemic has elucidated leptin resistance pathways, with too much leptin in either sex leading to infertility. Under conditions of balanced nutrition, however, the secretion of leptin is timed and regulated within a narrow level range that optimizes its trophic effects.

Maternal tadalafil therapy for fetal growth restriction prevents non-alcoholic fatty liver disease and adipocyte hypertrophy in the offspring

We aimed to investigate the effects of maternal tadalafil therapy on fetal programming of metabolic function in a mouse model of fetal growth restriction (FGR). Pregnant C57BL6 mice were divided into the control, L-NG-nitroarginine methyl ester (L-NAME), and tadalafil + L-NAME groups. Six weeks after birth, the male pups in each group were given a high-fat diet. A glucose tolerance test (GTT) was performed at 15 weeks and the pups were euthanized at 20 weeks. We then assessed the histological changes in the liver and adipose tissue, and the adipocytokine production. We found that the non-alcoholic fatty liver disease activity score was higher in the L-NAME group than in the control group (p < 0.05). Although the M1 macrophage numbers were significantly higher in the L-NAME/high-fat diet group (p < 0.001), maternal tadalafil administration prevented this change. Moreover, the epididymal adipocyte size was significantly larger in the L-NAME group than in the control group. This was also improved by maternal tadalafil administration (p < 0.05). Further, we found that resistin levels were significantly lower in the L-NAME group compared to the control group (p < 0.05). The combination of exposure to maternal L-NAME and a high-fat diet induced glucose impairment and non-alcoholic fatty liver disease. However, maternal tadalafil administration prevented these complications. Thus, deleterious fetal programming caused by FGR might be modified by in utero intervention with tadalafil.

Early life overnutrition impairs plasticity of non-neuronal brainstem cells and drives obesity in offspring across development in rats

BACKGROUND

The prevalence of adolescent obesity has increased dramatically, becoming a serious public health concern. While previous evidence suggests that in utero- and early postnatal overnutrition increases adult-onset obesity risk, the neurobiological mechanisms underlying this outcome are not well understood. Non-neuronal cells play an underestimated role in the physiological responses to metabolic/nutrient signals. Hypothalamic glial-mediated inflammation is now considered a contributing factor in the development and perpetuation of obesity; however, attention on the role of gliosis and microglia activation in other nuclei is still needed.

METHODS/RESULTS

Here, we demonstrate that early life consumption of high-fat/sucrose diet (HFSD) is sufficient to increase offspring body weight, hyperleptinemia and potentially maladaptive cytoarchitectural changes in the brainstem dorsal-vagal-complex (DVC), an essential energy balance processing hub, across postnatal development. Our data demonstrate that pre- and postnatal consumption of HFSD result in increased body weight, hyperleptinemia and dramatically affects the non-neuronal landscape, and therefore the plasticity of the DVC in the developing offspring.

CONCLUSIONS

Current findings are very provocative, considering the importance of the DVC in appetite regulation, suggesting that HFSD-consumption during early life may contribute to subsequent obesity risk via DVC cytoarchitectural changes.

A potential role of fatty acid binding protein 4 in the pathophysiology of autism spectrum disorder

Autism spectrum disorder is a neurodevelopmental disorder characterized by difficulties in social communication and interaction, as well as repetitive and characteristic patterns of behaviour. Although the pathogenesis of autism spectrum disorder is unknown, being overweight or obesity during infancy and low weight at birth are known as risks, suggesting a metabolic aspect. In this study, we investigated adipose tissue development as a pathophysiological factor of autism spectrum disorder by examining the serum levels of adipokines and other metabolic markers in autism spectrum disorder children (n = 123) and typically developing children (n = 92) at 4–12 years of age. Among multiple measures exhibiting age-dependent trajectories, the leptin levels displayed different trajectory patterns between autism spectrum disorder and typically developing children, supporting an adipose tissue-dependent mechanism of autism spectrum disorder. Of particular interest, the levels of fatty acid binding protein 4 (FABP4) were significantly lower in autism spectrum disorder children than in typically developing subjects, at preschool age (4–6 years old: n = 21 for autism spectrum disorder and n = 26 for typically developing). The receiver operating characteristic curve analysis discriminated autism spectrum disorder children from typically developing children with a sensitivity of 94.4% and a specificity of 75.0%. We re-sequenced the exons of the FABP4 gene in a Japanese cohort comprising 659 autism spectrum disorder and 1000 control samples, and identified two rare functional variants in the autism spectrum disorder group. The Trp98Stop, one of the two variants, was transmitted to the proband from his mother with a history of depression. The disruption of the Fabp4 gene in mice evoked autism spectrum disorder-like behavioural phenotypes and increased spine density on apical dendrites of pyramidal neurons, which has been observed in the postmortem brains of autism spectrum disorder subjects. The Fabp4 knockout mice had an altered fatty acid composition in the cortex. Collectively, these results suggest that an ‘adipo-brain axis’ may underlie the pathophysiology of autism spectrum disorder, with FABP4 as a potential molecule for use as a biomarker.

Involvement of the GHSR in the developmental programming and metabolic disturbances induced by maternal undernutrition

The mismatch between maternal undernutrition and adequate nutrition after birth increases the risk of developing metabolic diseases. We aimed to investigate whether the hyperghrelinemia during maternal undernourishment rewires the hypothalamic development of the offspring and contributes to the conversion to an obese phenotype when fed a high-fat diet (HFD). Pregnant C57BL/6 J, wild type (WT) and ghrelin receptor (GHSR)^-/- mice were assigned to either a normal nourished (NN) group, or an undernutrition (UN) (30% food restricted) group. All pups were fostered by NN Swiss mice. After weaning, pups were fed a normal diet, followed by a HFD from week 9. Plasma ghrelin levels peaked at postnatal day 15 (P15) in both C57BL/6 J UN and NN pups. Hypothalamic Ghsr mRNA expression was upregulated at P15 in UN pups compared to NN pups and inhibited agouti-related peptide (AgRP) projections. Adequate lactation increased body weight of UN WT but not of GHSR^-/- pups compared to NN littermates. After weaning with a HFD, body weight and food intake was higher in WT UN pups but lower in GHSR^-/- UN pups than in NN controls. The GHSR prevented a decrease in ambulatory activity and oxygen consumption in UN offspring during ad libitum feeding. Maternal undernutrition triggers developmental changes in the hypothalamus in utero which were further affected by adequate feeding after birth during the postnatal period by affecting GHSR signaling. The GHSR contributes to the hyperphagia and the increase in body weight when maternal undernutrition is followed by an obesity prone life environment.

Leptin and Nutrition in Gestational Diabetes

Leptin is highly expressed in the placenta, mainly by trophoblastic cells, where it has an important autocrine trophic effect. Moreover, increased leptin levels are found in the most frequent pathology of pregnancy: gestational diabetes, where leptin may mediate the increased size of the placenta and the fetus, which becomes macrosomic. In fact, leptin mediates the increased protein synthesis, as observed in trophoblasts from gestational diabetic subjects. In addition, leptin seems to facilitate nutrients transport to the fetus in gestational diabetes by increasing the expression of the glycerol transporter aquaporin-9. The high plasma leptin levels found in gestational diabetes may be potentiated by leptin resistance at a central level, and obesity-associated inflammation plays a role in this leptin resistance. Therefore, the importance of anti-inflammatory nutrients to modify the pathology of pregnancy is clear. In fact, nutritional intervention is the first-line approach for the treatment of gestational diabetes mellitus. However, more nutritional intervention studies with nutraceuticals, such as polyphenols or polyunsaturated fatty acids, or nutritional supplementation with micronutrients or probiotics in pregnant women, are needed in order to achieve a high level of evidence. In this context, the Mediterranean diet has been recently found to reduce the risk of gestational diabetes in a multicenter randomized trial. This review will focus on the impact of maternal obesity on placental inflammation and nutrients transport, considering the mechanisms by which leptin may influence maternal and fetal health in this setting, as well as its role in pregnancy pathologies.

Maternal obesity-induced endoplasmic reticulum stress causes metabolic alterations and abnormal hypothalamic development in the offspring

The steady increase in the prevalence of obesity and associated type II diabetes mellitus is a major health concern, particularly among children. Maternal obesity represents a risk factor that contributes to metabolic perturbations in the offspring. Endoplasmic reticulum (ER) stress has emerged as a critical mechanism involved in leptin resistance and type 2 diabetes in adult individuals. Here, we used a mouse model of maternal obesity to investigate the importance of early life ER stress in the nutritional programming of this metabolic disease. Offspring of obese dams developed glucose intolerance and displayed increased body weight, adiposity, and food intake. Moreover, maternal obesity disrupted the development of melanocortin circuits associated with neonatal hyperleptinemia and leptin resistance. ER stress-related genes were up-regulated in the hypothalamus of neonates born to obese mothers. Neonatal treatment with the ER stress-relieving drug tauroursodeoxycholic acid improved metabolic and neurodevelopmental deficits and reversed leptin resistance in the offspring of obese dams.

Developmental origins of health and disease theory in cardiology

Numerous epidemiological and animal studies disclosed that birth weight is inversely associated with the incidence of the lifestyle-related disorders in adult life, such as cardiovascular disease, diabetes, and /or chronic kidney disease. Lower birth weight occurs in numerous undesired intrauterine environments including malnutrition, smoking, alcohol consumption, or stress.　The Developmental Origin of Health and Disease (DOHaD) theory is based on the concept that the origins of lifestyle-related disease is formed at the time of fertilization, embryonic, fetal, and neonatal stages by the interrelation between genes and the environments (nutrition, stress, or environmental chemicals). Adult disease develops after delivery facing to abnormal environments such as over-nutrition, much stress, or lack of exercise. Disease develops through these two insults. This concept was first proposed as the "Barker Hypothesis." David Barker had discovered the relation between the lower birth weight and the higher prevalence of ischemic heart disease mortality. Previous epidemiologic studies have found the people exposed to famine during early life had higher risks of cardiovascular diseases in adulthood. Yet, the exact mechanisms that permanently change the structure, physiology, and endocrine status of an individual across their lifespan following altered growth during fetal life are not entirely clear. Epidemiological studies including prospective cohort and observational analysis of the people exposed to malnutrition during fetal or infancy have disclosed the strong relation between the lower birth weight and the higher cardiovascular risks in adults. Recent progress of epigenetic studies unveiled strong genetic association. Hormonal regulation and epigenetic modifications have an important role for proper organ development and physiological functions. The molecular mechanism of predisposition is supposed to be the epigenetics modifications.　Their dysregulation is related to the acquisition of the disease-susceptible trait. In this review, we overview the concept of DOHaD and introduce related clinical and basic research.

Epigenetics: Linking Early Postnatal Nutrition to Obesity Programming?

Despite constant research and public policy efforts, the obesity epidemic continues to be a major public health threat, and new approaches are urgently needed. It has been shown that nutrient imbalance in early life, from conception to infancy, influences later obesity risk, suggesting that obesity could result from "developmental programming". In this review, we evaluate the possibility that early postnatal nutrition programs obesity risk via epigenetic mechanisms, especially DNA methylation, focusing on four main topics: (1) the dynamics of epigenetic processes in key metabolic organs during the early postnatal period; (2) the epigenetic effects of alterations in early postnatal nutrition in animal models or breastfeeding in humans; (3) current limitations and remaining outstanding questions in the field of epigenetic programming; (4) candidate pathways by which early postnatal nutrition could epigenetically program adult body weight set point. A particular focus will be given to the potential roles of breast milk fatty acids, neonatal metabolic and hormonal milieu, and gut microbiota. Understanding the mechanisms by which early postnatal nutrition can promote lifelong metabolic modifications is essential to design adequate recommendations and interventions to "de-program" the obesity epidemic.

Plasticity of histone modifications around Cidea and Cidec genes with secondary bile in the amelioration of developmentally-programmed hepatic steatosis

We recently reported that a treatment with tauroursodeoxycholic acid (TUDCA), a secondary bile acid, improved developmentally-deteriorated hepatic steatosis in an undernourishment (UN, 40% caloric restriction) in utero mouse model after a postnatal high-fat diet (HFD). We performed a microarray analysis and focused on two genes (Cidea and Cidec) because they are enhancers of lipid droplet (LD) sizes in hepatocytes and showed the greatest up-regulation in expression by UN that were completely recovered by TUDCA, concomitant with parallel changes in LD sizes. TUDCA remodeled developmentally-induced histone modifications (dimethylation of H3K4, H3K27, or H3K36), but not DNA methylation, around the Cidea and Cidec genes in UN pups only. Changes in these histone modifications may contribute to the markedly down-regulated expression of Cidea and Cidec genes in UN pups, which was observed in the alleviation of hepatic fat deposition, even under HFD. These results provide an insight into the future of precision medicine for developmentally-programmed hepatic steatosis by targeting histone modifications.

Postnatal administration of leptin antagonist mitigates susceptibility to obesity under high-fat diet in male αMUPA mice

Perturbations in postnatal leptin signaling have been associated with altered susceptibility to diet-induced obesity (DIO) under high-fat-diet (HFD), albeit with contradicting evidence. Previous studies have shown that alpha murine urokinase-type plasminogen activator (αMUPA) mice have a higher and longer postnatal leptin surge compared with their wild types (WTs) as well as lower body weight and food intake under regular diet (RD). Here we explored αMUPA's propensity for DIO and the effect of attenuating postnatal leptin signaling with leptin antagonist (LA) on energy homeostasis under both RD and HFD. Four-day-old αMUPA pups were treated on alternate days until postnatal day 18 with either vehicle or LA (10 or 20 mg·day^-1·kg^-1) and weaned into RD or HFD. Compared with RD-fed αMUPA males, HFD-fed αMUPA males showed higher energy intake, even when corrected for body weight difference, and became hyperinsulinemic and obese. Additionally, HFD-fed αMUPA males gained body weight at a higher rate than their WTs mainly because of strain differences in energy expenditure. LA administration did not affect strain differences under RD but attenuated αMUPA's hyperinsulinemia and DIO under HFD, most likely by mediating energy expenditure. Together with our previous findings, these results suggest that αMUPA's leptin surge underlies its higher susceptibility to obesity under HFD, highlighting the role of leptin-related developmental processes in inducing obesity in a postweaning obesogenic environment, at least in αMUPA males. This study therefore supports the use of αMUPA mice for elucidating developmental mechanisms of obesity and the efficacy of early-life manipulations via leptin surge axis in attenuating DIO.

Gestational caloric restriction with micronutrients supplementation does not delay development and promotes feeding behavior benefits

Introduction: Caloric restriction (CR) has been proven to promote a series of health benefits from yeast to primates. Nowadays, increasing rates of obesity certainly encourage researchers to evaluate CR effects and establish it as a therapeutic approach. Maternal obesity is also a concern, and studies in the developmental origins of health and disease (DOHaD) have shown the importance of interventions during pregnancy, especially those involving maternal nutrition. On the other hand, undernutrition during pregnancy leads to increased weight gain, disturbed feeding behavior and dysfunctional metabolism in adulthood.Methods: In this way, we utilized moderate CR (20% compared to control consumption) in pregnant Wistar rats as intervention, with malnutrition control by micronutrients supplementation. We assessed CR effects on offspring's developmental milestones, feeding behavior, exploratory behavior, and memory on adolescence (PND21) and adulthood (PND60).Results: We did not find alterations on litter size or birth weight, although CR pups were leaner at adult ages. Importantly, no delay in development was observed. Besides, female pups showed earlier suction reflex and male pups showed earlier response to the negative geotaxis. CR pups also showed less preference for palatable food (Froot Loops®) at adult age, which could be decisive on obesity tendency. Locomotor activity was increased by CR on PND60 and there was no effect on memory at all.Discussion: Our results on development and behavior demonstrate that gestational CR may be a helpful health strategy if malnutrition is well controlled, with potential clinical impact.

DNA methylation of the Rtl1 promoter in the placentas with fetal growth restriction

BACKGROUND

Small for gestational age (SGA) babies experience fetal growth restriction because of placental insufficiency, and aberrant fetal growth has been linked to DNA methylation in the placenta. An imprinted gene encoding retrotransposon-like protein 1 (RTL1) is regulated by DNA methylation in the promoter region and plays a key role in placental development. We therefore investigated the DNA methylation status of RTL1 in the placenta of infants with severe SGA.

METHODS

We extracted DNA from the placenta of appropriate for gestational age (AGA; gestational age 35 ± 6 weeks, birthweight 2292 ± 1006 g; n = 12), SGA (birthweight z-score ≤-2 SD, 33 ± 5 weeks, 1373 ± 580 g; n = 11), and severe SGA (birthweight z-score ≤-3 SD, 33 ± 4 weeks, 1145 g ± 423 g; n = 7) infants, and we determined the methylation rates of five CpG sites in the CG4 (82,275,427-82,275,737 in NT_026437 sequence, NCBI database) region of the RTL1 promoter by pyrosequencing. We defined hypermethylation (>75.5%) and hypomethylation (<45.6%) based on the average methylation rate exceeding ± two standard deviations (SD) in the AGA group, respectively, and compared these among groups.

RESULTS

There was no significant difference in the average methylation of CpG1-5 (control 59%, SGA 60%, severe SGA 63%), but abnormal methylation (hyper-/hypo-methylation) in CpG1 differed significantly among the groups (control 0%, SGA 36%, severe SGA 71%).

CONCLUSION

Infants with severe SGA have abnormal placental DNA methylation of CpG1 in the CG4 region of RTL1, suggesting the existence of disturbed epigenetic control in utero.

Leptin as a breast milk component for the prevention of obesity

Leptin ingested as a component of breast milk is increasingly recognized to play a role in the postnatal programming of a healthy phenotype in adulthood. Besides its primary function in controlling body weight, leptin may be an essential nutrient required during lactation to ensure that the system controlling fat accumulation and body composition is well organized from the early stages of development. This review delves into the following topics: (1) the imprinted protective function of adequate leptin intake during lactation in future metabolic health; (2) the consequences of a lack of leptin intake or of alterations in leptin levels; and (3) the mechanisms described for the effects of leptin on postnatal programming. Furthermore, it highlights the importance of breastfeeding and the need to establish optimal or reference intake values for leptin during lactation to design patterns of personalized nutrition from early childhood.

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.

Feeding circuit development and early-life influences on future feeding behaviour

A wide range of maternal exposures - undernutrition, obesity, diabetes, stress and infection - are associated with an increased risk of metabolic disease in offspring. Developmental influences can cause persistent structural changes in hypothalamic circuits regulating food intake in the service of energy balance. The physiological relevance of these alterations has been called into question because maternal impacts on daily caloric intake do not persist to adulthood. Recent behavioural and epidemiological studies in humans provide evidence that the relative contribution of appetitive traits related to satiety, reward and the emotional aspects of food intake regulation changes across the lifespan. This Opinion article outlines a neurodevelopmental framework to explore the possibility that crosstalk between developing circuits regulating different modalities of food intake shapes future behavioural responses to environmental challenges.

Obesity after neonatal overfeeding is independent of hypothalamic microgliosis

The early-life environment is important in programming brain development, and metabolic disruptions at this time can have long-lasting effects. Previously, we have shown that rats overfed for the first 3 weeks of their neonatal life maintain obesity into adulthood. Neonatal overfeeding also leads to primed hypothalamic and hippocampal microglia that are hyper-responsive to an immune challenge in adulthood. However, whether this microglial priming contributes to the obese phenotype and whether it is possible to reverse either the obesity or the microglial priming are not clear. In the present study, we hypothesised that an intervention with minocycline during the juvenile period (postnatal day 21-42) would normalise both the microglial priming and obesity. To induce obesity in neonatal Wistar rats, we manipulated the litter sizes in which they were suckled, yielding litters of 12 (control-fed) or four (neonatally overfed). After weaning, we administered minocycline i.p. every second day for a 3-week period and examined body composition and microglial profiles 24 hours following an immune challenge with lipopolysaccharide. As demonstrated previously, neonatal overfeeding resulted in prolonged weight gain. However, minocycline failed to reverse this effect. Minocycline did reverse microglial priming in feeding-related regions of the hypothalamus, with minimal effects on pro-inflammatory cytokines and on microglial number and morphology in the hippocampus. Thus, the programming effect of neonatal overfeeding on microglial priming can be ameliorated by minocycline later in life. However, the persistent obesity seen after neonatal overfeeding is likely not driven by changes in hypothalamic inflammation and microglial activity.

The Perinatal Condition Around Birth and Cardiovascular Risk Factors in the Japanese General Population: The Suita Study

Aim: To investigate the relationship between perinatal condition around birth and cardiovascular risk in later life.

Methods: Retrospective data were examined from 1241 city dwellers (521 men, 720 women; age 41–69 years) who had undergone medical examination at a single institution including blood tests and physical measurements from 2007 to 2008. The questionnaire was conducted to determine how perinatal factors affect their lives later. We also selected and studied a total of 28 individuals (12 men and 16 women) specifically about the conformity rate of the breastfeeding method between participants' memories and what was written in the maternal and child health handbooks.

Results: The conformity rate of the breastfeeding method between a self-questionnaire and his/her maternal and child health handbook was well correlated (r = 0.73; p < 0.025). Among the data in women who were born at home, HbA1C levels (5.36 ± 0.03 vs. 5.25 ± 0.05 mg/dL, p = 0.03) and low-density lipoprotein cholesterol (136.0 ± 1.4 vs. 129.3 ± 2.5 mg/dL, p = 0.04) were higher than women who were born at the hospital. Women raised by formula showed higher low-density lipoprotein cholesterol levels than women fed breast milk or a mixture of breast milk and formula (150.2 ± 4.8 vs. 138.7 ± 3.7, 142.5 ± 2.6 mg/dL, p = 0.04). Fasting blood glucose levels at an adult time in men and women born through breech presentation were higher than those by the cephalic presentation (123.2 ± 7.8 vs. 106.8 ± 1.2 mg/dL, p = 0.03).

Conclusion: The study proposed that some perinatal conditions around birth such as delivery place, presenting part, and lactation affected especially Japanese women's cardiovascular risks between ages 41 and 69 years.

Nutritional adversity, sex and reproduction: 30 years of DOHaD and what have we learned?

It is well established that early life environmental signals, including nutrition, set the stage for long-term health and disease risk - effects that span multiple generations. This relationship begins early, in the periconceptional period and extends into embryonic, fetal and early infant phases of life. Now known as the Developmental Origins of Health and Disease (DOHaD), this concept describes the adaptations that a developing organism makes in response to early life cues, resulting in adjustments in homeostatic systems that may prove maladaptive in postnatal life, leading to an increased risk of chronic disease and/or the inheritance of risk factors across generations. Reproductive maturation and function is similarly influenced by early life events. This should not be surprising, since primordial germ cells are established early in life and thus vulnerable to early life adversity. A multitude of 'modifying' cues inducing developmental adaptations have been identified that result in changes in reproductive development and impairments in reproductive function. Many types of nutritional challenges including caloric restriction, macronutrient excess and micronutrient insufficiencies have been shown to induce early life adaptations that produce long-term reproductive dysfunction. Many pathways have been suggested to underpin these associations, including epigenetic reprogramming of germ cells. While the mechanisms still remain to be fully investigated, it is clear that a lifecourse approach to understanding lifetime reproductive function is necessary. Furthermore, investigations of the impacts of early life adversity must be extended to include the paternal environment, especially in epidemiological and clinical studies of offspring reproductive function.

The role of epigenetics in hypothalamic energy balance control: implications for obesity

Despite enormous social and scientific efforts, obesity rates continue to increase worldwide. While genetic factors contribute to obesity development, genetics alone cannot explain the current epidemic. Obesity is essentially the consequence of complex genetic-environmental interactions. Evidence suggests that contemporary lifestyles trigger epigenetic changes, which can dysregulate energy balance and thus contribute to obesity. The hypothalamus plays a pivotal role in the regulation of body weight, through a sophisticated network of neuronal systems. Alterations in the activity of these neuronal pathways have been implicated in the pathophysiology of obesity. Here, we review the current knowledge on the central control of energy balance with a focus on recent studies linking epigenetic mechanisms in the hypothalamus to the development of obesity and metabolic disorders.

Perinatal free-choice of a high-calorie low-protein diet affects leptin signaling through IRS1 and AMPK dephosphorylation in the hypothalami of female rat offspring in adulthood

AIM

We aimed to investigate whether a dysregulated maternal diet during gestation and lactation induces long-lasting changes in the hypothalamic control of feeding behavior in the offspring and whether this effect is sex specific.

METHODS

The study included an analysis of appetite-regulating metabolic hormones and hypothalamic signaling in male and female offspring in adulthood after exposure to a free-choice high-calorie palatable low-protein (P) diet or standard chow (C) during (pre)gestation/lactation (maternal) and/or postweaning (offspring).

RESULTS

Maternal exposure to the P diet resulted in decreased protein intake and body weight gain in dams and decreased body weight gain in offspring during lactation. The maternal P diet (PC) specifically increased feed efficacy and decreased body weight and cholesterol levels in the female offspring in adulthood, but no changes in adiposity or leptin levels were found. In contrast, P diet exposure after weaning (CP and PP) increased caloric intake, adiposity and circulating levels of leptin in the male and female offspring in adulthood. The hypothalami of the female offspring exposed to the maternal P diet (PC and PP) expressed high levels of the phospho-leptin receptor and low levels of SOCS3, phospho-IRS1 and phospho-AMPK, regardless of the postweaning diet. The hypothalami of the female rats in the PC group also showed increased levels of STAT3 and the orexigenic neuropeptide Agrp.

CONCLUSIONS

Maternal exposure to a free-choice high-calorie low-protein diet induces a long-term feed efficacy associated with changes in leptin signaling through IRS-1 and AMPK dephosphorylation in the hypothalami of female offspring in adulthood.

Short communication: Manipulation of neonatal leptin profile via exogenous glucocorticoids in beef calves

The link between circulating glucocorticoids and leptin in beef calves has not been explored but has been noted in several studies. The aim of this study is to determine the effects of exogenous glucocorticoids given at birth and 1 day of age on serum leptin concentrations in beef calves. Ruminant animals secrete leptin, which is thought to be important for the programming of the hypothalamic appetite centers. Angus crossbred cows (n = 31) bred via natural service were utilized for this experiment. At parturition (day 0), calf BW was recorded and each calf was infused intravenously with either a hydrocortisol sodium succinate solution (HC, 8 males and 8 females) at a dosage of 3.5 μg/kg of BW or a similar volume of saline solution (CONT, 7 males and 8 females). Each calf was given a second infusion of its respective treatment 24 h postpartum at 1.5 μg/kg of BW for HC treatment. Calf treatment was blocked by sex, dam body condition score (BCS), and dam age. Blood samples were taken via jugular venipuncture before infusion, daily from days 0 to 5, then every other day up to day 17. Serum leptin and cortisol concentrations were analyzed via radioimmunoassay. Dam age, dam BCS, calf BW, and serum leptin and cortisol concentrations were analyzed using MIXED procedure of SAS. Dam age was not different (P = 0.81) among HC and CONT calves (4.9±0.5 and 4.7±0.5, respectively). Dam BCS was not different between treatments (5.7±0.2 and 5.6±0.2 HC and CONT, respectively; P = 0.66). There was no difference in calf birth BW between treatments (P = 0.87) and averaged 38.3±1.4 kg. Cortisol concentrations were not different between both treatments (P = 0.23) from birth to day 4 of age. Calves that received the HC treatment showed significantly reduced (P = 0.03) leptin concentrations on days 1 to 13. Calf BW from 60 to 150 days of age was not different between CONT and HC treated calves (P = 0.65). These data indicate that exogenous glucocorticoids can be used to suppress neonatal leptin levels in calves. This could lead to changes in voluntary feed intake of treated calves.

Sex differences in major depression and comorbidity of cardiometabolic disorders: impact of prenatal stress and immune exposures

Major depressive disorder topped ischemic heart disease as the number one cause of disability worldwide in 2012, and women have twice the risk of men. Further, the comorbidity of depression and cardiometabolic disorders will be one of the primary causes of disability worldwide by 2020, with women at twice the risk. Thus, understanding the sex-dependent comorbidities has public health consequences worldwide. We propose here that sex differences in MDD-cardiometabolic comorbidity originate, in part, from pathogenic processes initiated in fetal development that involve sex differences in shared pathophysiology between the brain, the vascular system, the CNS control of the heart and associated hormonal, immune, and metabolic physiology. Pathways implicate neurotrophic and angiogenic growth factors, gonadal hormone receptors, and neurotransmitters such as gamma amino butyric acid (GABA) on neuronal and vascular development of HPA axis regions, such as the paraventricular nucleus (PVN), in addition to blood pressure, in part through the renin-angiotensin system, and insulin and glucose metabolism. We show that the same prenatal exposures have consequences for sex differences across multiple organ systems that, in part, share common pathophysiology. Thus, we believe that applying a sex differences lens to understanding shared biologic substrates underlying these comorbidities will provide novel insights into the development of sex-dependent therapeutics. Further, taking a lifespan perspective beginning in fetal development provides the opportunity to target abnormalities early in the natural history of these disorders in a sex-dependent way.