Maternal high-fat diet and obesity impact palatable food intake and dopamine signaling in nonhuman primate offspring

Cannabidiol improves maternal obesity-induced behavioral, neuroinflammatory and neurochemical dysfunctions in the juvenile offspring

Maternal obesity is associated with an increased risk of psychiatric disorders such as anxiety, depression, schizophrenia and autism spectrum disorder in the offspring. While numerous studies focus on preventive measures targeting the mothers, only a limited number provide practical approaches for addressing the damages once they are already established. We have recently demonstrated the interplay between maternal obesity and treatment with cannabidiol (CBD) on hypothalamic inflammation and metabolic disturbances, however, little is known about this relationship on behavioral manifestations and neurochemical imbalances in other brain regions. Therefore, here we tested whether CBD treatment could mitigate anxiety-like and social behavioral alterations, as well as neurochemical disruptions in both male and female offspring of obese dams. Female Wistar rats were fed a cafeteria diet for 12 weeks prior to mating, and during gestation and lactation. Offspring received CBD (50 mg/kg) from weaning for 3 weeks. Behavioral tests assessed anxiety-like manifestations and social behavior, while neuroinflammatory and neurochemical markers were evaluated in the prefrontal cortex (PFC) and hippocampus. CBD treatment attenuated maternal obesity-induced anxiety-like and social behavioral alterations, followed by rescuing effects on imbalanced neurotransmitter and endocannabinoid concentrations and altered expression of glial markers, CB1, oxytocin and dopamine receptors, with important differences between sexes. Overall, the findings of this study provide insight into the signaling pathways for the therapeutic benefits of CBD on neuroinflammation and neurochemical imbalances caused by perinatal maternal obesity in the PFC and the hippocampus, which translates into the behavioral manifestations, highlighting the sexual dimorphism encompassing both the transgenerational effect of obesity and the endocannabinoid system.

Hofbauer cells and fetal brain microglia share transcriptional profiles and responses to maternal diet-induced obesity

Maternal immune activation is associated with adverse offspring neurodevelopmental outcomes, many mediated by in utero microglial programming. As microglia remain inaccessible throughout development, identification of noninvasive biomarkers reflecting fetal brain microglial programming could permit screening and intervention. We used lineage tracing to demonstrate the shared ontogeny between fetal brain macrophages (microglia) and fetal placental macrophages (Hofbauer cells) in a mouse model of maternal diet-induced obesity, and single-cell RNA-seq to demonstrate shared transcriptional programs. Comparison with human datasets demonstrated conservation of placental resident macrophage signatures between mice and humans. Single-cell RNA-seq identified common alterations in fetal microglial and Hofbauer cell gene expression induced by maternal obesity, as well as sex differences in these alterations. We propose that Hofbauer cells, which are easily accessible at birth, provide insights into fetal brain microglial programs and may facilitate the early identification of offspring vulnerable to neurodevelopmental disorders.

Maternal obesity increases hypothalamic miR-505-5p expression in mouse offspring leading to altered fatty acid sensing and increased intake of high-fat food

In utero exposure to maternal obesity programs increased obesity risk. Animal models show that programmed offspring obesity is preceded by hyperphagia, but the mechanisms that mediate these changes are unknown. Using a mouse model of maternal obesity, we observed increased intake of a high-fat diet (HFD) in offspring of obese mothers that precedes the development of obesity. Through small RNA sequencing, we identified programmed overexpression of hypothalamic miR-505-5p that is established in the fetus, lasts to adulthood and is maintained in hypothalamic neural progenitor cells cultured in vitro. Metabolic hormones and long-chain fatty acids associated with obesity increase miR-505-5p expression in hypothalamic neurons in vitro. We demonstrate that targets of miR-505-5p are enriched in fatty acid metabolism pathways and overexpression of miR-505-5p decreased neuronal fatty acid metabolism in vitro. miR-505-5p targets are associated with increased BMI in human genetic studies. Intra-cerebroventricular injection of miR-505-5p in wild-type mice increased HFD intake, mimicking the phenotype observed in offspring exposed to maternal obesity. Conversely, maternal exercise intervention in an obese mouse pregnancy rescued the programmed increase of hypothalamic miR-505-5p in offspring of obese dams and reduced HFD intake to control offspring levels. This study identifies a novel mechanism by which maternal obesity programs obesity in offspring via increased intake of high-fat foods.

Palm oil as part of a high-fat diet: advances and challenges, or possible risks of pathology?

Nutritional status disorders have the most significant impact on the development of cardiovascular and oncologic diseases; therefore, the interest in the study of palm oil as among the leading components of nutrition has been increasing. The data examined in this review were sourced from the Scopus, SCIE (Web of Science), PubMed and PubMed Central, MEDLINE, CAPlus/SciFinder, and Embase databases; experts in the field; bibliographies; and abstracts from review analyses from the past 15 years. This review summarizes recent research data focusing on the quantitative and qualitative composition of nutrition of modern humans; concepts of the relationship between high-fat diets and disorders of insulin functioning and transport and metabolism of fatty acids; analyses of data regarding the palmitic acid (16:0) to oleic acid (18:1) ratio; and the effect of diet based on palm oil consumption on cardiovascular risk factors and lipid and lipoprotein levels. Several studies suggest a potential vector contributing to the transmission of maternal, high-fat-diet-induced, addictive-like behaviors and obesogenic phenotypes across generations. The relationship between cholesterol accumulation in lysosomes that may lead to lysosome dysfunction and inhibition of the autophagy process is analyzed, as is the progression of inflammatory diseases, atherosclerosis, nonalcoholic liver inflammation, and obesity with associated complications. Data are discussed from analyses of differences between rodent models and human population studies in the investigated different effects of palm oil consumption as a high-fat diet component. A conclusion is reached that the results cannot be generalized in human population studies because no similar effects were observed. Although there are numerous published reports, more studies are necessary to elucidate the complex regulatory mechanisms in digestive and nutrition processes, because there are great differences in lipoprotein profiles between rodents and humans, which makes it difficult to reproduce the pathology of many diseases caused by different types of the high-fat diet.

Maternal Phlorizin Intake Protects Offspring from Maternal Obesity-Induced Metabolic Disorders in Mice via Targeting Gut Microbiota to Activate the SCFA-GPR43 Pathway

Maternal obesity increases the risk of obesity and metabolic disorders (MDs) in offspring, which can be mediated by the gut microbiota. Phlorizin (PHZ) can improve gut dysbiosis and positively affect host health; however, its transgenerational metabolic benefits remain largely unclear. This study aimed to investigate the potential of maternal PHZ intake in attenuating the adverse impacts of a maternal high-fat diet on obesity-related MDs in dams and offspring. The results showed that maternal PHZ reduced HFD-induced body weight gain and fat accumulation and improved glucose intolerance and abnormal lipid profiles in both dams and offspring. PHZ improved gut dysbiosis by promoting expansion of SCFA-producing bacteria, Akkermansia and Blautia, while inhibiting LPS-producing and pro-inflammatory bacteria, resulting in significantly increased fecal SCFAs, especially butyric acid, and reduced serum lipopolysaccharide levels and intestinal inflammation. PHZ also promoted intestinal GLP-1/2 secretion and intestinal development and enhanced gut barrier function by activating G protein-coupled receptor 43 (GPR43) in the offspring. Antibiotic-treated mice receiving FMT from PHZ-regulated offspring could attenuate MDs induced by receiving FMT from HFD offspring through the gut microbiota to activate the GPR43 pathway. It can be regarded as a promising functional food ingredient for preventing intergenerational transmission of MDs and breaking the obesity cycle.

Perinatal Western-style diet exposure associated with decreased microglial counts throughout the arcuate nucleus of the hypothalamus in Japanese macaques

Perinatal exposure to a high-fat, high-sugar Western-style diet (WSD) is associated with altered neural circuitry in the melanocortin system. This association may have an underlying inflammatory component, as consumption of a WSD during pregnancy can lead to an elevated inflammatory environment. Our group previously demonstrated that prenatal WSD exposure was associated with increased markers of inflammation in the placenta and fetal hypothalamus in Japanese macaques. In this follow-up study, we sought to determine whether this heightened inflammatory state persisted into the postnatal period, as prenatal exposure to inflammation has been shown to reprogram offspring immune function and long-term neuroinflammation would present a potential means for prolonged disruptions to microglia-mediated neuronal circuit formation. Neuroinflammation was approximated in 1-yr-old offspring by counting resident microglia and peripherally derived macrophages in the region of the hypothalamus examined in the fetal study, the arcuate nucleus (ARC). Microglia and macrophages were immunofluorescently stained with their shared marker, ionized calcium-binding adapter molecule 1 (Iba1), and quantified in 11 regions along the rostral-caudal axis of the ARC. A mixed-effects model revealed main effects of perinatal diet (P = 0.011) and spatial location (P = 0.003) on Iba1-stained cell count. Perinatal WSD exposure was associated with a slight decrease in the number of Iba1-stained cells, and cells were more densely located in the center of the ARC. These findings suggest that the heightened inflammatory state experienced in utero does not persist postnatally. This inflammatory response trajectory could have important implications for understanding how neurodevelopmental disorders progress.NEW & NOTEWORTHY Prenatal Western-style diet exposure is associated with increased microglial activity in utero. However, we found a potentially neuroprotective reduction in microglia count during early postnatal development. This trajectory could inform the timing of disruptions to microglia-mediated neuronal circuit formation. Additionally, this is the first study in juvenile macaques to characterize the distribution of microglia along the rostral-caudal axis of the arcuate nucleus of the hypothalamus. Nearby neuronal populations may be greater targets during inflammatory insults.

Hofbauer cells and fetal brain microglia share transcriptional profiles and responses to maternal diet-induced obesity

Maternal immune activation is associated with adverse offspring neurodevelopmental outcomes, many mediated by in utero microglial programming. As microglia remain inaccessible throughout development, identification of noninvasive biomarkers reflecting fetal brain microglial programming could permit screening and intervention. We used lineage tracing to demonstrate the shared ontogeny between fetal brain macrophages (microglia) and fetal placental macrophages (Hofbauer cells) in a mouse model of maternal diet-induced obesity, and single-cell RNA-seq to demonstrate shared transcriptional programs. Comparison with human datasets demonstrated conservation of placental resident macrophage signatures between mice and humans. Single-cell RNA-seq identified common alterations in fetal microglial and Hofbauer cell gene expression induced by maternal obesity, as well as sex differences in these alterations. We propose that Hofbauer cells, which are easily accessible at birth, provide novel insights into fetal brain microglial programs, and may facilitate the early identification of offspring vulnerable to neurodevelopmental disorders in the setting of maternal exposures.

A Maternal Western-Style Diet Impairs Skeletal Muscle Lipid Metabolism in Adolescent Japanese Macaques

Maternal consumption of a Western-style diet (mWD) during pregnancy alters fatty acid metabolism and reduces insulin sensitivity in fetal skeletal muscle. The long-term impact of these fetal adaptations and the pathways underlying disordered lipid metabolism are incompletely understood. Therefore, we tested whether a mWD chronically fed to lean, insulin-sensitive adult Japanese macaques throughout pregnancy and lactation would impact skeletal muscle oxidative capacity and lipid metabolism in adolescent offspring fed a postweaning (pw) Western-style diet (WD) or control diet (CD). Although body weight was not different, retroperitoneal fat mass and subscapular skinfold thickness were significantly higher in pwWD offspring consistent with elevated fasting insulin and glucose. Maximal complex I (CI)-dependent respiration in muscle was lower in mWD offspring in the presence of fatty acids, suggesting that mWD impacts muscle integration of lipid with nonlipid oxidation. Abundance of all five oxidative phosphorylation complexes and VDAC, but not ETF/ETFDH, were reduced with mWD, partially explaining the lower respiratory capacity with lipids. Muscle triglycerides increased with pwWD; however, the fold increase in lipid saturation, 1,2-diacylglycerides, and C18 ceramide compared between pwCD and pwWD was greatest in mWD offspring. Reductions in CI abundance and VDAC correlated with reduced markers of oxidative stress, suggesting that these reductions may be an early-life adaptation to mWD to mitigate excess reactive oxygen species. Altogether, mWD, independent of maternal obesity or insulin resistance, results in sustained metabolic reprogramming in offspring muscle despite a healthy diet intervention.

ARTICLE HIGHLIGHTS

In lean, active adolescent offspring, a postweaning Western-style diet (pwWD) leads to shifts in body fat distribution that are associated with poorer insulin sensitivity. Fatty acid-linked oxidative metabolism was reduced in skeletal muscles from offspring exposed to maternal Western-style diet (mWD) even when weaned to a healthy control diet for years. Reduced oxidative phosphorylation complex I-V and VDAC1 abundance partially explain decreased skeletal muscle respiration in mWD offspring. Prior exposure to mWD results in greater fold increase with pwWD in saturated lipids and bioactive lipid molecules (i.e. ceramide and sphingomyelin) associated with insulin resistance.

Brain Dopamine-Clock Interactions Regulate Cardiometabolic Physiology: Mechanisms of the Observed Cardioprotective Effects of Circadian-Timed Bromocriptine-QR Therapy in Type 2 Diabetes Subjects

Despite enormous global efforts within clinical research and medical practice to reduce cardiovascular disease(s) (CVD), it still remains the leading cause of death worldwide. While genetic factors clearly contribute to CVD etiology, the preponderance of epidemiological data indicate that a major common denominator among diverse ethnic populations from around the world contributing to CVD is the composite of Western lifestyle cofactors, particularly Western diets (high saturated fat/simple sugar [particularly high fructose and sucrose and to a lesser extent glucose] diets), psychosocial stress, depression, and altered sleep/wake architecture. Such Western lifestyle cofactors are potent drivers for the increased risk of metabolic syndrome and its attendant downstream CVD. The central nervous system (CNS) evolved to respond to and anticipate changes in the external (and internal) environment to adapt survival mechanisms to perceived stresses (challenges to normal biological function), including the aforementioned Western lifestyle cofactors. Within the CNS of vertebrates in the wild, the biological clock circuitry surveils the environment and has evolved mechanisms for the induction of the obese, insulin-resistant state as a survival mechanism against an anticipated ensuing season of low/no food availability. The peripheral tissues utilize fat as an energy source under muscle insulin resistance, while increased hepatic insulin resistance more readily supplies glucose to the brain. This neural clock function also orchestrates the reversal of the obese, insulin-resistant condition when the low food availability season ends. The circadian neural network that produces these seasonal shifts in metabolism is also responsive to Western lifestyle stressors that drive the CNS clock into survival mode. A major component of this natural or Western lifestyle stressor-induced CNS clock neurophysiological shift potentiating the obese, insulin-resistant state is a diminution of the circadian peak of dopaminergic input activity to the pacemaker clock center, suprachiasmatic nucleus. Pharmacologically preventing this loss of circadian peak dopaminergic activity both prevents and reverses existing metabolic syndrome in a wide variety of animal models of the disorder, including high fat-fed animals. Clinically, across a variety of different study designs, circadian-timed bromocriptine-QR (quick release) (a unique formulation of micronized bromocriptine-a dopamine D2 receptor agonist) therapy of type 2 diabetes subjects improved hyperglycemia, hyperlipidemia, hypertension, immune sterile inflammation, and/or adverse cardiovascular event rate. The present review details the seminal circadian science investigations delineating important roles for CNS circadian peak dopaminergic activity in the regulation of peripheral fuel metabolism and cardiovascular biology and also summarizes the clinical study findings of bromocriptine-QR therapy on cardiometabolic outcomes in type 2 diabetes subjects.

Maternal Western-style diet in nonhuman primates leads to offspring islet adaptations including altered gene expression and insulin hypersecretion

Maternal overnutrition is associated with increased susceptibility to type 2 diabetes in the offspring. Rodent models have shown that maternal overnutrition influences islet function in offspring. To determine whether maternal Western-style diet (WSD) alters prejuvenile islet function in a model that approximates that of human offspring, we utilized a well-characterized Japanese macaque model. We compared islet function from offspring exposed to WSD throughout pregnancy and lactation and weaned to WSD (WSD/WSD) compared with islets from offspring exposed only to postweaning WSD (CD/WSD) at 1 yr of age. WSD/WSD offspring islets showed increased basal insulin secretion and an exaggerated increase in glucose-stimulated insulin secretion, as assessed by dynamic ex vivo perifusion assays, relative to CD/WSD-exposed offspring. We probed potential mechanisms underlying insulin hypersecretion using transmission electron microscopy to evaluate β-cell ultrastructure, qRT-PCR to quantify candidate gene expression, and Seahorse assay to assess mitochondrial function. Insulin granule density, mitochondrial density, and mitochondrial DNA ratio were similar between groups. However, islets from WSD/WSD male and female offspring had increased expression of transcripts known to facilitate stimulus-secretion coupling and changes in the expression of cell stress genes. Seahorse assay revealed increased spare respiratory capacity in islets from WSD/WSD male offspring. Overall, these results show that maternal WSD feeding confers changes to genes governing insulin secretory coupling and results in insulin hypersecretion as early as the postweaning period. The results suggest a maternal diet leads to early adaptation and developmental programming in offspring islet genes that may underlie future β-cell dysfunction.NEW & NOTEWORTHY Programed adaptations in islets in response to maternal WSD exposure may alter β-cell response to metabolic stress in offspring. We show that islets from maternal WSD-exposed offspring hypersecrete insulin, possibly due to increased components of stimulus-secretion coupling. These findings suggest that islet hyperfunction is programed by maternal diet, and changes can be detected as early as the postweaning period in nonhuman primate offspring.

Maternal high fat diets: impacts on offspring obesity and epigenetic hypothalamic programming

Maternal high-fat diet (HFD) during pregnancy is associated with rapid weight gain and fetal fat mass increase at an early stage. Also, HFD during pregnancy can cause the activation of proinflammatory cytokines. Maternal insulin resistance and inflammation lead to increased adipose tissue lipolysis, and also increased free fatty acid (FFA) intake during pregnancy (˃35% of energy from fat) cause a significant increase in FFA levels in the fetus. However, both maternal insulin resistance and HFD have detrimental effects on adiposity in early life. As a result of these metabolic alterations, excess fetal lipid exposure may affect fetal growth and development. On the other hand, increase in blood lipids and inflammation can adversely affect the development of the liver, adipose tissue, brain, skeletal muscle, and pancreas in the fetus, increasing the risk for metabolic disorders. In addition, maternal HFD is associated with changes in the hypothalamic regulation of body weight and energy homeostasis by altering the expression of the leptin receptor, POMC, and neuropeptide Y in the offspring, as well as altering methylation and gene expression of dopamine and opioid-related genes which cause changes in eating behavior. All these maternal metabolic and epigenetic changes may contribute to the childhood obesity epidemic through fetal metabolic programming. Dietary interventions, such as limiting dietary fat intake <35% with appropriate fatty acid intake during the gestation period are the most effective type of intervention to improve the maternal metabolic environment during pregnancy. Appropriate nutritional intake during pregnancy should be the principal goal in reducing the risks of obesity and metabolic disorders.

Potential mechanisms and modulators of food intake during pregnancy

Dietary choice during pregnancy is crucial not only for fetal development, but also for long-term health outcomes of both mother and child. During pregnancy, dramatic changes in endocrine, cognitive, and reward systems have been shown to take place. Interestingly, in different contexts, many of these mechanisms play a key role in guiding food intake. Here, we review how food intake may be impacted as a function of pregnancy-induced changes across species. We first summarize changes in endocrine and metabolic signaling in the course of pregnancy. Then, we show how these may be related to cognitive function and reward processing in humans. Finally, we link these to potential drivers of change in eating behavior throughout the course of pregnancy.

The Role of Prenatal Psychosocial Stress in the Associations of a Proinflammatory Diet in Pregnancy With Child Adiposity and Growth Trajectories

Importance

Prenatal psychosocial stress and nutrition may each program offspring adiposity, an important predictor of lifelong cardiometabolic health. Although increased stress and poor nutrition have been found to co-occur in pregnancy, little is known about their combined longitudinal associations in the offspring.

Objective

To investigate whether the associations of the Dietary Inflammatory Index (DII) with offspring adiposity differ by prenatal stress levels and whether these associations change with age.

Design, Setting, and Participants

Project Viva, a prospective prebirth cohort study of mother-child dyads in Massachusetts, included singleton children of mothers enrolled between April 1999 and July 2002, with follow-up visits at early childhood, midchildhood, and early adolescence. Data analysis was performed from October 31, 2020, to October 31, 2022.

Exposures

Food frequency-derived DII score in pregnancy was the exposure. Effect modifiers included stress-related measures in pregnancy; depressive symptoms assessed using the Edinburgh Postnatal Depression Scale (EPDS), dichotomized at scores greater than or equal to 13 vs less than 13; and census tract-level social vulnerability (overall Social Vulnerability Index and its 4 main subindices), dichotomized at the 75th percentile.

Main Outcomes and Measures

Overall adiposity, comprising sex- and age-standardized body mass index (BMI z), sum of subscapular and triceps skinfolds, fat mass index (FMI), and body fat percentage estimated using bioelectrical impedance analysis (BIA) and dual x-ray absorptiometry (DXA); and central adiposity, comprising waist circumference, ratio of subscapular to triceps skinfolds, and DXA-derived trunk FMI.

Results

Among 1060 mother-child dyads, mean (SD) maternal age was 32.6 (4.6) years, and 811 (77%) mothers were non-Hispanic White. Mean (SD) DII score was -2.7 (1.3) units, Social Vulnerability Index level was 38th (27th) percentile, and 8% of mothers had depressive symptoms. Mean (SD) age of the children was 3.3 (0.3) years at the early childhood visit, 7.9 (0.8) years at the midchildhood visit, and 13.2 (0.9) years at the early adolescence visit. In adjusted analyses, children born to mothers in the highest (vs lowest) quartile of DII had slower decrease in BMI z scores (β, 0.03 SD units/y; 95% CI, 0.01-0.05 SD units/y), and faster adiposity gain (eg, BIA total FMI β, 0.11 kg/m2/y; 95% CI, 0.03-0.19 kg/m2/y) over time. Associations of prenatal DII quartiles with childhood adiposity were stronger (eg, BIA total FMI quartile 4 vs quartile 1 change in β, 1.40 kg/m2; 95% CI, 0.21-2.59 kg/m2) among children of mothers with high vs low EPDS scores in pregnancy, although EPDS scores did not modify the change over time. Associations of prenatal DII with adiposity change over time, however, were greater among children whose mothers lived in neighborhoods with a high (BIA percentage body fat: β, 0.55% per year; 95% CI, 0.04%-1.07% per year) vs low (β, 0.13% per year; 95% CI, -0.20 to 0.46% per year), percentage of racial and ethnic minorities, and residents with limited English-language proficiency.

Conclusions and Relevance

The findings of this cohort study suggest that it may be useful to simultaneously evaluate prenatal diet and psychosocial stress in women as targets for interventions intended to prevent excess childhood adiposity.

Maternal high-fat diet decreases milk endocannabinoids with sex-specific changes in the cannabinoid and dopamine signaling and food preference in rat offspring

INTRODUCTION

Maternal high-fat (HF) diet during gestation and lactation programs obesity in rat offspring associated with sex-dependent and tissue-specific changes of the endocannabinoid system (ECS). The ECS activation induces food intake and preference for fat as well as lipogenesis. We hypothesized that maternal HF diet would increase the lipid endocannabinoid levels in breast milk programming cannabinoid and dopamine signaling and food preference in rat offspring.

METHODS

Female Wistar rats were assigned into two experimental groups: control group (C), which received a standard diet (10% fat), or HF group, which received a high-fat diet (29% fat) for 8 weeks before mating and during gestation and lactation. Milk samples were collected to measure endocannabinoids and fatty acids by mass spectrometry. Cannabinoid and dopamine signaling were evaluated in the nucleus accumbens (NAc) of male and female weanling offspring. C and HF offspring received C diet after weaning and food preference was assessed in adolescence.

RESULTS

Maternal HF diet reduced the milk content of anandamide (AEA) (p<0.05) and 2-arachidonoylglycerol (2-AG) (p<0.05). In parallel, maternal HF diet increased adiposity in male (p<0.05) and female offspring (p<0.05) at weaning. Maternal HF diet increased cannabinoid and dopamine signaling in the NAc only in male offspring (p<0.05), which was associated with higher preference for fat in adolescence (p<0.05).

CONCLUSION

Contrary to our hypothesis, maternal HF diet reduced AEA and 2-AG in breast milk. We speculate that decreased endocannabinoid exposure during lactation may induce sex-dependent adaptive changes of the cannabinoid-dopamine crosstalk signaling in the developing NAc, contributing to alterations in neurodevelopment and programming of preference for fat in adolescent male offspring.

Dipeptidyl peptidase IV inhibition delays developmental programming of obesity and metabolic disease in male offspring of obese mothers

Maternal obesity programs the offspring to metabolic diseases later in life; however, the mechanisms of programming are yet unclear, and no strategies exist for addressing its detrimental transgenerational effects. Obesity has been linked to dipeptidyl peptidase IV (DPPIV), an adipokine, and treatment of obese individuals with DPPIV inhibitors has been reported to prevent weight gain and improve metabolism. We hypothesized that DPPIV plays a role in maternal obesity-mediated programming. We measured plasma DPPIV activity in human maternal and cord blood samples from normal-weight and obese mothers at term. We found that maternal obesity increases maternal and cord blood plasma DPPIV activity but only in male offspring. Using two non-human primate models of maternal obesity, we confirmed the activation of DPPIV in the offspring of obese mothers. We then created a mouse model of maternal high-fat diet (HFD)-induced obesity, and found an early-life increase in plasma DPPIV activity in male offspring. Activation of DPPIV preceded the progression of obesity, glucose intolerance and insulin resistance in male offspring of HFD-fed mothers. We then administered sitagliptin, DPPIV inhibitor, to regular diet (RD)- and HFD-fed mothers, starting a week prior to breeding and continuing throughout pregnancy and lactation. We found that sitagliptin treatment of HFD-fed mothers delayed the progression of obesity and metabolic diseases in male offspring and had no effects on females. Our findings reveal that maternal obesity dysregulates plasma DPPIV activity in males and provide evidence that maternal inhibition of DPPIV has potential for addressing the transgenerational effects of maternal obesity.

Maternal Western-style diet reduces social engagement and increases idiosyncratic behavior in Japanese macaque offspring

Recent evidence in humans and animals indicates an association between maternal obesity and offspring behavioral outcomes. In humans, increased maternal body mass index has been linked to an increased risk of children receiving a diagnosis of early-emerging neurodevelopmental disorders such as Attention Deficit/Hyperactivity Disorder (ADHD) and/or Autism Spectrum Disorder (ASD). However, a limited number of preclinical studies have examined associations between maternal Western-Style Diet (mWSD) exposure and offspring social behavior. To our knowledge, this is the first study to investigate relationships between mWSD exposure and social behavior in non-human primates. Since aberrant social behavior is a diagnostic criterion for several neurodevelopmental disorders, the current study focuses on examining the influence of maternal nutrition and metabolic state on offspring social behavior in Japanese macaques (Macaca fuscata). We found that mWSD offspring initiated less affiliative social behaviors as well as proximity to a peer. Using path analysis, we found that the association between mWSD consumption and reduced offspring social engagement was statistically mediated by increased maternal interleukin (IL)-12 during the third trimester of pregnancy. Additionally, mWSD offspring displayed increased idiosyncratic behavior, which was related to alterations in maternal adiposity and leptin in the third trimester. Together, these results suggest that NHP offspring exposed to mWSD exhibit behavioral phenotypes similar to what is described in some early-emerging neurodevelopmental disorders. These results provide evidence that mWSD exposure during gestation may be linked to increased risk of neurodevelopmental disorders and provides targets for prevention and intervention efforts.

Maternal obesity and the impact of associated early-life inflammation on long-term health of offspring

The prevalence of obesity is increasingly common in the United States, with ~25% of women of reproductive age being overweight or obese. Metaflammation, a chronic low grade inflammatory state caused by altered metabolism, is often present in pregnancies complicated by obesity. As a result, the fetuses of mothers who are obese are exposed to an in-utero environment that has altered nutrients and cytokines. Notably, both human and preclinical studies have shown that children born to mothers with obesity have higher risks of developing chronic illnesses affecting various organ systems. In this review, the authors sought to present the role of cytokines and inflammation during healthy pregnancy and determine how maternal obesity changes the inflammatory landscape of the mother, leading to fetal reprogramming. Next, the negative long-term impact on offspring’s health in numerous disease contexts, including offspring’s risk of developing neuropsychiatric disorders (autism, attention deficit and hyperactive disorder), metabolic diseases (obesity, type 2 diabetes), atopy, and malignancies will be discussed along with the potential of altered immune/inflammatory status in offspring as a contributor of these diseases. Finally, the authors will list critical knowledge gaps in the field of developmental programming of health and diseases in the context of offspring of mothers with obesity, particularly the understudied role of hematopoietic stem and progenitor cells.

Maternal High-Fat diet During Pregnancy and Lactation Disrupts NMDA Receptor Expression and Spatial Memory in the Offspring

The problem of an unbalanced diet, overly rich in fats, affects a significant proportion of the population, including women of childbearing age. Negative metabolic and endocrine outcomes for offspring associated with maternal high-fat diet during pregnancy and/or lactation are well documented in the literature. In this paper, we present our findings on the little-studied effects of this diet on NMDA receptors and cognitive functions in offspring. The subject of the study was the rat offspring born from dams fed a high-fat diet before mating and throughout pregnancy and lactation. Using a novel object location test, spatial memory impairment was detected in adolescent offspring as well as in young adult female offspring. The recognition memory of the adolescent and young adult offspring remained unaltered. We also found multiple alterations in the expression of the NMDA receptor subunits, NMDA receptor-associated scaffolding proteins, and selected microRNAs that regulate the activity of the NMDA receptor in the medial prefrontal cortex and the hippocampus of the offspring. Sex-dependent changes in glutamate levels were identified in extracellular fluid obtained from the medial prefrontal cortex and the hippocampus of the offspring. The obtained results indicate that a maternal high-fat diet during pregnancy and lactation can induce in the offspring memory disturbances accompanied by alterations in NMDA receptor expression.

Disruption of Glutamate Homeostasis in the Brain of Rat Offspring Induced by Prenatal and Early Postnatal Exposure to Maternal High-Sugar Diet

A high-calorie diet has contributed greatly to the prevalence of overweight and obesity worldwide for decades. These conditions also affect pregnant women and have a negative impact on the health of both the woman and the fetus. Numerous studies indicate that an unbalanced maternal diet, rich in sugars and fats, can influence the in utero environment and, therefore, the future health of the child. It has also been shown that prenatal exposure to an unbalanced diet might permanently alter neurotransmission in offspring. In this study, using a rat model, we evaluated the effects of a maternal high-sugar diet on the level of extracellular glutamate and the expression of key transporters crucial for maintaining glutamate homeostasis in offspring. Glutamate concentration was assessed in extracellular fluid samples collected from the medial prefrontal cortex and hippocampus of male and female offspring. Analysis showed significantly increased glutamate levels in both brain structures analyzed, regardless of the sex of the offspring. These changes were accompanied by altered expression of the EAAT1, VGLUT1, and x_c⁻ proteins in these brain structures. This animal study further confirms our previous findings that a maternal high-sugar diet has a detrimental effect on the glutamatergic system.

Maternal diet and obesity shape offspring central and peripheral inflammatory outcomes in juvenile non-human primates

The obesity epidemic affects 40% of adults in the US, with approximately one-third of pregnant women classified as obese. Previous research suggests that children born to obese mothers are at increased risk for a number of health conditions. The mechanisms behind this increased risk are poorly understood. Increased exposure to in-utero inflammation induced by maternal obesity is proposed as an underlying mechanism for neurodevelopmental alterations in offspring. Utilizing a non-human primate model of maternal obesity, we hypothesized that maternal consumption of an obesogenic diet will predict offspring peripheral (e.g., cytokines and chemokines) and central (microglia number) inflammatory outcomes via the diet's effects on maternal adiposity and maternal inflammatory state during the third trimester. We used structural equation modeling to simultaneously examine the complex associations among maternal diet, metabolic state, adiposity, inflammation, and offspring central and peripheral inflammation. Four latent variables were created to capture maternal chemokines and pro-inflammatory cytokines, and offspring cytokine and chemokines. Model results showed that offspring microglia counts in the basolateral amygdala were associated with maternal diet (β = -0.622, p < 0.01), adiposity (β = 0.593, p < 0.01), and length of gestation (β = 0.164, p < 0.05) but not with maternal chemokines (β = 0.135, p = 0.528) or maternal pro-inflammatory cytokines (β = 0.083, p = 0.683). Additionally, we found that juvenile offspring peripheral cytokines (β = -0.389, p < 0.01) and chemokines (β = -0.298, p < 0.05) were associated with a maternal adiposity-induced decrease in maternal circulating chemokines during the third trimester (β = -0.426, p < 0.01). In summary, these data suggest that maternal diet and adiposity appear to directly predict offspring amygdala microglial counts while maternal adiposity influences offspring peripheral inflammatory outcomes via maternal inflammatory state.

The Influence of Maternal Metabolic State and Nutrition on Offspring Neurobehavioral Development: A Focus on Preclinical Models

The prevalence of both obesity and neurodevelopmental disorders has increased substantially over the last several decades. Early environmental factors, including maternal nutrition and metabolic state during gestation, influence offspring neurodevelopment. Both human and preclinical models demonstrate a link between poor maternal nutrition, altered metabolic state, and risk of behavioral abnormalities in offspring. This review aims to highlight evidence from the current literature connecting maternal nutrition and the associated metabolic changes with neural and behavioral outcomes in the offspring, as well as identify possible mechanisms underlying these neurodevelopmental outcomes. Owing to the highly correlated nature of poor nutrition and obesity in humans, preclinical animal models are important in distinguishing the unique effects of maternal nutrition and metabolic state on offspring brain development. We use a translational lens to highlight results from preclinical animal models of maternal obesogenic diet related to alterations in behavioral and neurodevelopmental outcomes in offspring. Specifically, we aim to highlight results that resemble behavioral phenotypes described in the diagnostic criteria of neurodevelopmental conditions in humans. Finally, we examine the proinflammatory nature of maternal obesity and consumption of a high-fat diet as a mechanism for neurodevelopmental alterations that may alter offspring behavior later in life. It is important that future studies examine potential therapeutic interventions and prevention strategies to interrupt the transgenerational transmission of the disease. Given the tremendous risk to the next generation, changes need to be made to ensure that all pregnant people have access to nutritious food and are informed about the optimal diet for their developing child.

Integrative Analysis of the Gut Microbiota and Metabolome in Obese Mice with Electroacupuncture by 16S rRNA Gene Sequencing and HPLC-MS-based Metabolic Profiling

Acupuncture has been used to treat numerous diseases such as obesity in China for thousands of years. Several mechanisms of acupuncture on obesity have been surveyed based on metabolomics, but the effects of acupuncture on the alterations in the gut flora are still unclear. In this study, an integrated approach based on 16S rRNA gene sequencing combined with high-performance liquid chromatography-mass spectrometry (HPLC-MS) metabolic profiling was conducted to investigate the effects of acupuncture on high-fat-diet-induced obesity through the regulation of the relative abundances of gut microbiota and their relationships with biomarker candidates. A total of 10 significantly altered bacterial genera and 11 metabolites were recognized, which recovered to normal levels after electroacupuncture treatment. The relative abundances of the bacterial families Muribaculaceae,Lachnospiraceae,Desulfovibrionaceae,Helicobacteraceae, Prevotellaceae,Ruminococcaceae,Rikenellaceae,Deferribacteraceae,Bacteroidaceae andTannerellaceaewere remarkedly changed among the three groups. Potential biomarkers, including LysoPC(0:0/16:0) ([Formula: see text]1),PC(0:0/18:0) ([Formula: see text]2),Cholic acid([Formula: see text]3),LysoPC(16:0) ([Formula: see text]4), 3[Formula: see text],6[Formula: see text],7[Formula: see text]-Trihydroxy-5[Formula: see text]-cholanoic acid([Formula: see text]5), 5beta-Cyprinolsulfate([Formula: see text]6),PC(18:0/0:0) ([Formula: see text]7), 1-Nitro-5-hydroxy-6-glutathionyl-5,6-dihydronaphthalene([Formula: see text]8),Glycocholic acid([Formula: see text]9),[Formula: see text]-Arginine([Formula: see text]10) andGulonic acid([Formula: see text]11), were involved in several metabolic pathways, such as the glycerophospholipid metabolism and primary bile acid biosynthesis. Interestingly, there was a strong correlation between the perturbed gut flora in Bilophila and Bifidobacterium and the altered intestinal metabolite of 3[Formula: see text],6[Formula: see text],7[Formula: see text]-Trihydroxy-5[Formula: see text]-cholanoic acid and Cholanoic acid and [Formula: see text]-Arginine. This finding suggested that the effects of electroacupuncture might change the proportions of Bilophila and Bifidobacterium by regulating the constituents of the functional metabolite of 3[Formula: see text],6[Formula: see text],7[Formula: see text]-Trihydroxy-5[Formula: see text]-cholanoic acid and Cholanoic acid and [Formula: see text]-Arginine. These results indicated that the effects of electroacupuncture focused on custom metabolic pathways as well as depend on the changes in the gut microbiota in obesity. These findings suggest that the 16S rRNA gene sequencing and HPLC-MS-based metabolomics approach can be applied to comprehensively assess the effects of traditional Chinese medicines.

Western diet-induced shifts in the maternal microbiome are associated with altered microRNA expression in baboon placenta and fetal liver

Maternal consumption of a high-fat, Western-style diet (WD) disrupts the maternal/infant microbiome and contributes to developmental programming of the immune system and nonalcoholic fatty liver disease (NAFLD) in the offspring. Epigenetic changes, including non-coding miRNAs in the fetus and/or placenta may also underlie this risk. We previously showed that obese nonhuman primates fed a WD during pregnancy results in the loss of beneficial maternal gut microbes and dysregulation of cellular metabolism and mitochondrial dysfunction in the fetal liver, leading to a perturbed postnatal immune response with accelerated NAFLD in juvenile offspring. Here, we investigated associations between WD-induced maternal metabolic and microbiome changes, in the absence of obesity, and miRNA and gene expression changes in the placenta and fetal liver. After ~8-11 months of WD feeding, dams were similar in body weight but exhibited mild, systemic inflammation (elevated CRP and neutrophil count) and dyslipidemia (increased triglycerides and cholesterol) compared with dams fed a control diet. The maternal gut microbiome was mainly comprised of Lactobacillales and Clostridiales, with significantly decreased alpha diversity (P = 0.0163) in WD-fed dams but no community-wide differences (P = 0.26). At 0.9 gestation, mRNA expression of IL6 and TNF in maternal WD (mWD) exposed placentas trended higher, while increased triglycerides, expression of pro-inflammatory CCR2, and histological evidence for fibrosis were found in mWD-exposed fetal livers. In the mWD-exposed fetus, hepatic expression levels of miR-204-5p and miR-145-3p were significantly downregulated, whereas in mWD-exposed placentas, miR-182-5p and miR-183-5p were significantly decreased. Notably, miR-1285-3p expression in the liver and miR-183-5p in the placenta were significantly associated with inflammation and lipid synthesis pathway genes, respectively. Blautia and Ruminococcus were significantly associated with miR-122-5p in liver, while Coriobacteriaceae and Prevotellaceae were strongly associated with miR-1285-3p in the placenta; both miRNAs are implicated in pathways mediating postnatal growth and obesity. Our findings demonstrate that mWD shifts the maternal microbiome, lipid metabolism, and inflammation prior to obesity and are associated with epigenetic changes in the placenta and fetal liver. These changes may underlie inflammation, oxidative stress, and fibrosis patterns that drive NAFLD and metabolic disease risk in the next generation.

Maternal obesity reverses the resistance to LPS-induced adverse pregnancy outcome and increases female offspring metabolic alterations in cannabinoid receptor 1 knockout mice

Maternal overnutrition negatively impacts the offspring's health leading to an increased risk of developing chronic diseases or metabolic syndrome in adulthood. What we eat affects the endocannabinoid system (eCS) activity, which in turn modulates lipogenesis and fatty acids utilization in hepatic, muscle, and adipose tissues. This study aimed to evaluate the transgenerational effect of maternal obesity on cannabinoid receptor 1 knock-out (CB1 KO) animals in combination with a postnatal obesogenic diet on the development of metabolic disturbances on their offspring. CB1 KO mice were fed a control diet (CD) or a high-fat diet (HFD; 33% more energy from fat) for 3 months. Offspring born to control and obese mothers were also fed with CD or HFD. We observed that pups born to an HFD-fed mother presented higher postnatal weight, lower hepatic fatty acid amide hydrolase activity, and increased blood cholesterol levels when compared to the offspring born to CD-fed mothers. When female mice born to HFD-fed CB1 KO mothers were exposed to an HFD, they gained more weight, presented elevated blood cholesterol levels, and more abdominal adipose tissue accumulation than control-fed adult offspring. The eCS is involved in several reproductive physiological processes. Interestingly, we showed that CB1 KO mice in gestational day 15 presented resistance to LPS-induced deleterious effects on pregnancy outcome, which was overcome when these mice were obese. Our results suggest that an HFD in CB1 receptor-deficient mice contributes to a "nutritional programming" of the offspring resulting in increased susceptibility to metabolic challenges both perinatally and during adulthood.

An examination of maternal prenatal BMI and human fetal brain development

BACKGROUND

Prenatal development is a time when the brain is acutely vulnerable to insult and alteration by environmental factors (e.g., toxins, maternal health). One important risk factor is maternal obesity (Body Mass Index > 30). Recent research indicates that high maternal BMI during pregnancy is associated with increased risk for numerous physical health, cognitive, and mental health problems in offspring across the lifespan. It is possible that heightened maternal prenatal BMI influences the developing brain even before birth.

METHODS

The present study examines this possibility at the level of macrocircuitry in the human fetal brain. Using a data-driven strategy for parcellating the brain into subnetworks, we test whether MRI functional connectivity within or between fetal neural subnetworks varies with maternal prenatal BMI in 109 fetuses between the ages of 26 and 39weeks.

RESULTS

We discovered that strength of connectivity between two subnetworks, left anterior insula/inferior frontal gyrus (aIN/IFG) and bilateral prefrontal cortex (PFC), varied with maternal BMI. At the level of individual aIN/IFG-PFC connections, we observed both increased and decreased between-network connectivity with a tendency for increased within-hemisphere connectivity and reduced cross-hemisphere connectivity in higher BMI pregnancies. Maternal BMI was not associated with global differences in network topography based on network-based statistical analyses.

CONCLUSIONS

Overall effects were localized in regions that will later support behavioral regulation and integrative processes, regions commonly associated with obesity-related deficits. By establishing onset in neural differences prior to birth, this study supports a model in which maternal BMI-related risk is associated with fetal connectome-level brain organization with implications for offspring long-term cognitive development and mental health.

Reducing intergenerational obesity and diabetes risk

To address the intergenerational transmission of obesity and diabetes, strategies promoting the health of women of reproductive age appear to be urgently needed. In this narrative review, we summarise what has been learned from many prenatal clinical trials, discuss the emerging evidence from preconception clinical trials and highlight persistent gaps and critical future directions. Most trials tested prenatal interventions that resulted in a limited gestational weight gain of ~1 kg and reduced gestational diabetes by 20-30%. These interventions also reduced macrosomia by 20-40% but had little-to-no impact on other offspring outcomes at birth or beyond. Far fewer trials tested preconception interventions, with almost all designed to improve conception or live-birth rates in overweight or obese women with infertility rather than reduce intergenerational risks in diverse populations. Preconception trials have successfully reduced weight by 3-9 kg and improved markers of glucose homeostasis and insulin resistance by the end of the intervention but whether effects were sustained to conception is unclear. Very few studies have reported offspring outcomes at birth and beyond, with no evidence thus far of beneficial effects on offspring obesity or diabetes risks. Further efforts to develop effective and scalable strategies to reduce risk of obesity and diabetes before conception should be prioritised, especially for diverse and under-resourced populations at disparately high risk of obesity and diabetes. Future clinical trials should include interventions with high potential for dissemination, diverse populations, thorough maternal phenotyping from enrolment through to conception and pregnancy, and rigorous assessment of offspring obesity and diabetes risks from birth onwards, including into the third generation.

Maternal high-fat diet during lactation reprograms the dopaminergic circuitry in mice

The maternal perinatal environment modulates brain formation, and altered maternal nutrition has been linked to the development of metabolic and psychiatric disorders in the offspring. Here, we showed that maternal high-fat diet (HFD) feeding during lactation in mice elicits long-lasting changes in gene expression in the offspring's dopaminergic circuitry. This translated into silencing of dopaminergic midbrain neurons, reduced connectivity to their downstream targets, and reduced stimulus-evoked dopamine (DA) release in the striatum. Despite the attenuated activity of DA midbrain neurons, offspring from mothers exposed to HFD feeding exhibited a sexually dimorphic expression of DA-related phenotypes, i.e., hyperlocomotion in males and increased intake of palatable food and sucrose in females. These phenotypes arose from concomitantly increased spontaneous activity of D1 medium spiny neurons (MSNs) and profoundly decreased D2 MSN projections. Overall, we have unraveled a fundamental restructuring of dopaminergic circuitries upon time-restricted altered maternal nutrition to induce persistent behavioral changes in the offspring.

Differential Effects of Maternal High Fat Diet During Pregnancy and Lactation on Taste Preferences in Rats

Maternal intake of high fat diet (HFD) increases risk for obesity and metabolic disorders in offspring. Developmental programming of taste preference is a potential mechanism by which this occurs. Whether maternal HFD during pregnancy, lactation, or both, imposes greater risks for altered taste preferences in adult offspring remains a question, and in turn, was investigated in the present study. Four groups of offspring were generated based on maternal HFD access: (1) HFD during pregnancy and lactation (HFD); (2) HFD during pregnancy (HFD-pregnancy); (3) HFD during lactation (HFD-lactation); and (4) normal diet (ND) during pregnancy and lactation (ND). Adult offspring 70 days of age underwent sensory and motivational taste preference testing with various concentrations of sucrose and Intralipid solutions using brief-access automated gustometers (Davis-rigs) and 24 h two-bottle choice tests, respectively. To control for post-gestational diet effects, offspring in all experimental groups were weaned on ND, and did not differ in body weight or glucose tolerance at the time of testing. Offspring exposed to maternal HFD showed increased sensory taste responses for 0.3, 0.6, 1.2 M sucrose solutions in HFD and 0.6 M in HFD-pregnancy groups, compared to animals exposed to ND. Similar effects were noted for lower concentrations of Intralipid in HFD (0.05, 0.10%) and HFD-pregnancy (0.05, 0.10, 0.5%) groups. The HFD-lactation group showed an opposite, diminished responsiveness for sucrose at the highest concentrations (0.9, 1.2, 1.5 M), but not for Intralipid, compared to ND animals. Extended-access two-bottle tests did not reveal major difference across the groups. Our study shows that maternal HFD during pregnancy and lactation has markedly different effects on preferences for palatable sweet and fatty solutions in adult offspring and suggests that such developmental programing may primarily affect gustatory mechanisms. Future studies are warranted for determining the impact of taste changes on development of obesity and metabolic disorders in a “real” food environment with food choices available, as well as to identify specific underlying mechanisms.

Offspring of obese mice display enhanced intake and sensitivity for palatable stimuli, with altered expression of taste signaling elements

Maternal body mass index and gestational weight gain predict future obesity status of the offspring. In studies of both rodents and non-human primates, maternal obesity also predicts a preference for palatable foods in the offspring. In this study, we used C57BL/6J mice to investigate whether an underlying cause for an increase in palatable food consumption in the offspring of obese mice was a change in taste function. Adult female mice were fed a normal chow (NC) or a high fat diet (HFD) for 5 weeks before mating, then also during the gestation (3 weeks) and lactation (3 weeks) periods, with offspring always maintained on a normal chow diet; thus the only experience offspring had with high fat food was via maternal exposure. Offspring exhibited similar weight, blood glucose levels and baseline water and chow intake in adulthood. Taste response was assessed after reaching maturity, using brief-access taste testing, with female offspring of obese dams showing an enhanced response to sucrose, and both sexes consuming more sucrose, sucralose and high fat diet if from obese mothers. Offspring also exhibited increased taste bud expression of mRNA for sweet receptor subunits T1R (Taste receptor type) 2 and 3, as well as other markers associated with taste signaling. Taste morphology in both groups appeared similar. Results indicate that obesity in the mother may lead to unhealthy feeding behavior in the offspring, correlating with altered expression of taste signaling elements, which likely drive increased avidity for palatable foods.

Early Life Stress and the Onset of Obesity: Proof of MicroRNAs' Involvement Through Modulation of Serotonin and Dopamine Systems' Homeostasis

Healthy persons hold a very complex system for controlling energy homeostasis. The system functions on the interconnected way between the nutritional, endocrine, neural, and epigenetic regulation, which includes the microRNAs (miRNAs). Currently, it is well accepted that experiences of early life stress (ELS) carry modification of the central control of feeding behavior, one of the factors controlling energy homeostasis. Recently, studies give us a clue on the modulation of eating behavior, which is one of the main factors associated with the development of obesity. This clue connected the neural control through the serotonin (5HT) and dopamine (DA) systems with the fine regulation of miRNAs. The first pieces of evidence highlight the presence of the miR-16 in the regulation of the serotonin transporter (SERT) as well as the receptors 1a (5HT1A) and 2a (5HT2A). On the other hand, miR-504 is related to the dopamine receptor D2 (DRD2). As our knowledge advance, we expected to discover other important pathways for the regulation of the energy homeostasis. As both neurotransmission systems and miRNAs seem to be sensible to ELS, the aim of this review is to bring new insight about the involvement of miRNAs with a central role in the control of eating behavior focusing on the influences of ELS and regulation of neurotransmission systems.

Butyrate, but not propionate, reverses maternal diet-induced neurocognitive deficits in offspring

BACKGROUND

Maternal diet plays a beneficial role in the health, including the neurodevelopment, of offspring. Insufficient fibre consumption among the general population has increased concern about neurocognitive diseases. However, the association between maternal low-fibre diet (MLFD) and neurocognitive function in offspring is still unclear.

METHODS

Mice were fed diets containing diverse levels of fibre or administered short-chain fatty acids (SCFAs) during gestation. The neurocognitive functions of the offspring and synaptic plasticity-related protein levels were measured. Gene expression was disrupted by siRNA interference. Samples from pregnant women and paired umbilical cord blood (UCB) samples were analysed by the general linear model.

RESULTS

We found that MLFD impaired cognitive function and synaptic plasticity in offspring and that the impairments were reversed by butyrate intake but not propionate intake. Mechanistic studies showed that histone deacetylase (HDAC)-4 is the most likely mediator of butyrate-dependent neurocognitive improvement. In addition, using human maternal serum and paired UCB samples, we demonstrated that SCFA levels in offspring were positively correlated with levels in the maternal serum.

CONCLUSION

These results provide solid evidence that fibre in the maternal diet regulates neurocognitive functions in offspring through altering SCFA levels and supports the use of SCFA-dependent perinatal intervention for improving offspring health in the clinic.

Strength of nonhuman primate studies of developmental programming: review of sample sizes, challenges, and steps for future work

Nonhuman primate (NHP) studies are crucial to biomedical research. NHPs are the species most similar to humans in lifespan, body size, and hormonal profiles. Planning research requires statistical power evaluation, which is difficult to perform when lacking directly relevant preliminary data. This is especially true for NHP developmental programming studies, which are scarce. We review the sample sizes reported, challenges, areas needing further work, and goals of NHP maternal nutritional programming studies. The literature search included 27 keywords, for example, maternal obesity, intrauterine growth restriction, maternal high-fat diet, and maternal nutrient reduction. Only fetal and postnatal offspring studies involving tissue collection or imaging were included. Twenty-eight studies investigated maternal over-nutrition and 33 under-nutrition; 23 involved macaques and 38 baboons. Analysis by sex was performed in 19; minimum group size ranged from 1 to 8 (mean 4.7 ± 0.52, median 4, mode 3) and maximum group size from 3 to 16 (8.3 ± 0.93, 8, 8). Sexes were pooled in 42 studies; minimum group size ranged from 2 to 16 (mean 5.3 ± 0.35, median 6, mode 6) and maximum group size from 4 to 26 (10.2 ± 0.92, 8, 8). A typical study with sex-based analyses had group size minimum 4 and maximum 8 per sex. Among studies with sexes pooled, minimum group size averaged 6 and maximum 8. All studies reported some significant differences between groups. Therefore, studies with group sizes 3-8 can detect significance between groups. To address deficiencies in the literature, goals include increasing age range, more frequently considering sex as a biological variable, expanding topics, replicating studies, exploring intergenerational effects, and examining interventions.

Fetal brain and placental programming in maternal obesity: A review of human and animal model studies

Both human epidemiologic and animal model studies demonstrate that prenatal and lactational exposure to maternal obesity and high-fat diet are associated with adverse neurodevelopmental outcomes in offspring. Neurodevelopmental outcomes described in offspring of obese women include cognitive impairment, autism spectrum disorder (ASD), attention deficit hyperactivity disorder, anxiety and depression, disordered eating, and propensity for reward-driven behavior, among others. This review synthesizes human and animal data linking maternal obesity and high-fat diet consumption to abnormal fetal brain development, and neurodevelopmental and psychiatric morbidity in offspring. It highlights key mechanisms by which maternal obesity and maternal diet impact fetal and offspring development, and sex differences in offspring programming. In addition, we review placental effects of maternal obesity, and the role the placenta might play as an indicator vs mediator of fetal programming.

Caregiver Influences on Eating Behaviors in Young Children: A Scientific Statement From the American Heart Association

A substantial body of research suggests that efforts to prevent pediatric obesity may benefit from targeting not just what a child eats, but how they eat. Specifically, child obesity prevention should include a component that addresses reasons why children have differing abilities to start and stop eating in response to internal cues of hunger and satiety, a construct known as eating self‐regulation. This review summarizes current knowledge regarding how caregivers can be an important influence on children's eating self‐regulation during early childhood. First, we discuss the evidence supporting an association between caregiver feeding and child eating self‐regulation. Second, we discuss what implications the current evidence has for actions caregivers may be able to take to support children's eating self‐regulation. Finally, we consider the broader social, economic, and cultural context around the feeding environment relationship and how this intersects with the implementation of any actions. As far as we are aware, this is the first American Heart Association (AHA) scientific statement to focus on a psychobehavioral approach to reducing obesity risk in young children. It is anticipated that the timely information provided in this review can be used not only by caregivers within the immediate and extended family but also by a broad range of community‐based care providers.

Maternal exercise during gestation and lactation decreases high-fat diet preference by altering central reward system gene expression in adult female offspring from high-fat fed dams

Exposure to maternal high-fat (HF) diet during gestation and lactation alters adult offspring's feeding behavior and diet preference. However, the impact of maternal exercise on offspring's diet preference and reward system development is less studied. In this study, we investigate the effect of perinatal maternal exercise on the development of diet preference, dopamine- and opioid-related gene expression in the central reward system in female offspring from HF-fed Sprague-Dawley rat dams. We found maternal HF diet did not alter adult offspring HF preference, but influenced offspring's dopamine and opioid system both at weaning and in adulthood, and these offspring retained higher body weight in adulthood. However, offspring from dams exposed to both HF diet and exercise during gestation and lactation had normalized body weight, decreased fat mass and lower HF-diet preference but increased energy intake in adulthood. The dopamine- and opioid-related gene expression in central reward system and POMC expression in hypothalamus was elevated in these adult offspring. We conclude that maternal exercise during gestation and lactation can potentially overcome the negative effects of perinatal exposure to HF diet in female offspring by altering their diet preference, central reward system signaling and hypothalamus neuropeptide expression.

From the Outside In: Biological Mechanisms Linking Social and Environmental Exposures to Chronic Disease and to Health Disparities

The ongoing epidemic of chronic diseases involves a spectrum of clinical entities now understood to represent late manifestations of progressive metabolic dysfunction initiated in early life. These diseases disproportionately affect disadvantaged populations, exacerbating health disparities that persist despite public health efforts. Excessive exposure to stressful psychosocial and environmental forces is 1 factor known to contribute to population-level disparities in at-risk settings. Yet increasing evidence reveals that even a single adverse environmental exposure-especially during very early developmental years-can become literally biologically embedded, inducing long-lasting disease-promoting pathways that amplify responses (e.g., cortisol, immune, inflammatory) to all future adverse stressors, thus enhancing their disease-promoting impacts. The same pathways may also interact with ancestrally linked genetic variants to modify chronic disease risk. We address how, in at-risk populations, environmentally activated disease-promoting pathways can contribute to a biologically based disease-susceptible phenotype; this is likely to be uniquely damaging in populations with multiple adverse exposures and is capable of cross-generational transmission. Intended to complement existing models, this biological perspective highlights key research opportunities and life-stage priorities with potential to enhance the reduction of health disparities.

Effects of pre- and postnatal protein restriction on maternal and offspring metabolism in the nonhuman primate

Women in low- and middle-income countries frequently consume a protein-deficient diet during pregnancy and breastfeeding. The effects of gestational malnutrition on fetal and early postnatal development can have lasting adverse effects on offspring metabolism. Expanding on previous studies in rodent models, we utilized a nonhuman primate model of gestational and early-life protein restriction (PR) to evaluate effects on the organ development and glucose metabolism of juvenile offspring. Offspring were born to dams that had consumed a control diet containing 26% protein or a PR diet containing 13% protein. Offspring were maintained on the PR diet and studied [body and serum measurements, intravenous glucose tolerance tests (ivGTTs), and dual-energy X-ray absorptiometry scans] up to 7 mo of age, at which time tissues were collected for analysis. PR offspring had age-appropriate body weight and were euglycemic but exhibited elevated fasting insulin and reduced initial, but increased total, insulin secretion during an ivGTT at 6 mo of age. No changes were detected in pancreatic islets of PR juveniles; however, PR did induce changes, including reduced kidney size, and changes in liver, adipose tissue, and muscle gene expression in other peripheral organs. Serum osteocalcin was elevated and bone mineral content and density were reduced in PR juveniles, indicating a significant impact of PR on early postnatal bone development.

Maternal obesogenic diet combined with postnatal exposure to high-fat diet induces metabolic alterations in offspring

Maternal obesity has been shown to impact the offspring health during childhood and adult life. This study aimed to evaluate whether maternal obesity combined with postnatal exposure to an obesogenic diet could induce metabolic alterations in offspring. Female CD1 mice were fed a control diet (CD, 11.1% of energy from fat) or with a high-fat diet (HFD, 44.3% of energy from fat) for 3 months. After weaning, pups born from control and obese mothers were fed with CD or HFD for 3 months. Both mothers and offspring were weighted weekly and several blood metabolic parameters levels were evaluated. Here, we present evidence that the offspring from mothers exposed to a HFD showed increased acetylation levels of histone 3 on lysine 9 (H3K9) in the liver at postnatal Day 1, whereas the levels of acetylation of H4K16, dimethylation of H3K27, and trimethylation of H3K9 showed no change. We also observed a higher perinatal weight and increased blood cholesterol levels when compared to the offspring on postnatal Day 1 born from CD-fed mothers. When mice born from obese mothers were fed with HFD, we observed that they gained more weight, presented higher blood cholesterol levels, and abdominal adipose tissue than mice born to the same mothers but fed with CD. Collectively, our results point toward maternal obesity and HFD consumption as a risk factor for epigenetic changes in the liver of the offspring, higher perinatal weight, increased weight gain, and altered blood cholesterol levels.

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.

The role of adipokines in developmental programming: evidence from animal models

Alterations in the environment during critical periods of development, including altered maternal nutrition, can increase the risk for the development of a range of metabolic, cardiovascular and reproductive disorders in offspring in adult life. Following the original epidemiological observations of David Barker that linked perturbed fetal growth to adult disease, a wide range of experimental animal models have provided empirical support for the developmental programming hypothesis. Although the mechanisms remain poorly defined, adipose tissue has been highlighted as playing a key role in the development of many disorders that manifest in later life. In particular, adipokines, including leptin and adiponectin, primarily secreted by adipose tissue, have now been shown to be important mediators of processes underpinning several phenotypic features associated with developmental programming including obesity, insulin sensitivity and reproductive disorders. Moreover, manipulation of adipokines in early life has provided for potential strategies to ameliorate or reverse the adverse sequalae that are associated with aberrant programming and provided insight into some of the mechanisms involved in the development of chronic disease across the lifecourse.

Relationship between maternal global nutrient restriction during pregnancy and offspring kidney structure and function: a systematic review of animal studies

Maternal undernutrition during pregnancy is prevalent across the globe, and the origins of many chronic diseases can be traced back to in utero conditions. This systematic review considers the current evidence in animal models regarding the relationship between maternal global nutrient restriction during pregnancy and offspring kidney structure and function. CINAHL, Cochrane, EMBASE, MEDLINE, and Scopus were searched to November 2017. Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines were followed, and articles were screened by two independent reviewers. Twenty-eight studies met the inclusion criteria: 16 studies were on rats, 9 on sheep, 2 on baboons, and 1 on goats. The majority of the rat studies had maternal global nutrient restriction during pregnancy at 50% of ad libitum while restriction for sheep and baboon studies ranged from 50% to 75%. Because of the heterogeneity of outcome measures and the large variation in the age of offspring at followup, no meta-analysis was possible. Common outcome measures included kidney weight, nephron number, glomerular size, glomerular filtration rate, and creatinine clearance. To date, there have been no studies assessing kidney function in large animal models. Most studies were rated as having a high or unknown risk of bias. The current body of evidence in animals suggests that exposure to maternal global nutrient restriction during pregnancy has detrimental effects on offspring kidney structure and function, such as lower kidney weight, lower nephron endowment, larger glomerular size, and lower glomerular filtration rate. Further long-term followup of studies in large animal models investigating kidney function through to adulthood are warranted.

Chronic hyperandrogenemia and western-style diet beginning at puberty reduces fertility and increases metabolic dysfunction during pregnancy in young adult, female macaques

STUDY QUESTION

What are the impacts of elevated testosterone (T) and an obesogenic western-style diet (WSD), either independently or together, on fertility and metabolic adaptations of pregnancy in primates?

SUMMARY ANSWER

Testosterone increases the time to achieve pregnancy, while a WSD reduces overall fertility, and the combination of testosterone and WSD additionally impairs glucose tolerance and causes pregnancy loss.

WHAT IS KNOWN ALREADY

Both hyperandrogenemia and obesity are hallmarks of polycystic ovary syndrome, which is a leading cause of infertility among women worldwide. Female macaques receiving T and WSD beginning at puberty show increased metabolic, ovarian and uterine dysfunction in the non-pregnant state by 3 years of treatment.

STUDY DESIGN, SIZE, DURATION

The same cohort of female rhesus macaques continued treatments from the time of puberty (2.5 years) to 4 years, including this fertility trial. There were four groups (n = 9-10/group): controls (C), T-treated (T; average total serum level 1.35 ng/ml), WSD-treated, and combined T and WSD-treated (T + WSD) females.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Females, which were typically having menstrual cycles, were paired for 4 days with a proven male breeder following the late follicular rise in circulating estradiol (≥100 pg/ml). The presence of sperm in the reproductive tract was used to confirm mating. Animals went through up to three successive rounds of mating until they became pregnant, as confirmed by a rise in circulating mCG during the late luteal phase and ultrasound evidence of a gestational sac at Day 30 post-mating (GD30). Placental vascular parameters were also measured at GD30. Metabolic measurements consisted of fasting levels of blood glucose and insulin at approximately GD30, 60, 90 and 115, as well as an intravenous (iv) glucose tolerance test (GTT) at GD115.

MAIN RESULTS AND THE ROLE OF CHANCE

While all animals in the C and T groups eventually became pregnant, T-treated females on average had a greater interval to achieve pregnancy (P < 0.05). However, only ~70% of animals in the WSD and T + WSD groups became pregnant (P < 0.004). One pregnancy in T + WSD group resulted in an anembryonic pregnancy which miscarried around GD60, while another T + WSD female conceived with a rare identical twin pregnancy which required cessation due to impending fetal loss at GD106. Thus, the number of viable fetuses was less in the T + WSD group, compared to C, T or WSD. Placental blood volume at GD30 was reduced in all treatments compared to the C group (P < 0.05). Maternal P4 levels were elevated in the WSD (P < 0.03) group and E2 levels were elevated in T + WSD animals (P < 0.05). An increase in serum A4 levels throughout gestation was observed in all groups (P < 0.03) except WSD (P = 0.3). All groups displayed increased insulin resistance with pregnancy, as measured from the ivGTT during pregnancy. However, only the T + WSD group had a significant increase in fasting glucose levels and glucose clearance during the GTT indicating a worsened glucose tolerance. WSD treatment decreased female fetuses third trimester weights, but there was an interaction between WSD and T to increase female fetal weight when normalized to maternal weight.

LARGE SCALE DATA

N/A.

LIMITATIONS REASONS FOR CAUTION

The small number of pregnancies in the WSD and T + WSD groups hampers the ability to make definitive conclusions on effects during gestation. Also, the high fertility rate in the controls indicates the cohort was at their breeding prime age, which may impair the ability to observe subtle fertility defects. The low number of fetuses used for male and female analysis requires additional studies.

WIDER IMPLICATIONS OF THE FINDINGS

The current findings strongly suggest that both hyperandrogenemia and obesity have detrimental effects on fertility and gestation in primates, which may be directly relevant to women with polycystic ovary syndrome.

STUDY FUNDING/COMPETING INTEREST(S)

All ONPRC Cores and Units were supported by NIH Grant P51 OD011092 awarded to ONPRC. Research reported in this publication was supported by the Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD) of the National Institutes of Health (NIH) under Award Number P50HD071836 (to R.L.S.). The authors have no competing conflict of interests to disclose.

Developmental Programming of Obesity and Diabetes in Mouse, Monkey, and Man in 2018: Where Are We Headed?

Childhood obesity and its comorbidities continue to accelerate across the globe. Two-thirds of pregnant women are obese/overweight, as are 20% of preschoolers. Gestational diabetes mellitus (GDM) is escalating, affecting up to 1 in 5 pregnant women. The field of developmental origins of health and disease has begun to move beyond associations to potential causal mechanisms for developmental programming. Evidence across species compellingly demonstrates that maternal obesity, diabetes, and Western-style diets create a long-lasting signature on multiple systems, including infant stem cells, the early immune system, and gut microbiota. Such exposures accelerate adipogenesis, disrupt mitochondrial metabolism, and impair energy sensing, affecting neurodevelopment, liver, pancreas, and skeletal muscle. Attempts to prevent developmental programming have met with very limited success. A challenging level of complexity is involved in how the host genome, metabolome, and microbiome throughout pregnancy and lactation increase the offspring's risk of metabolic diseases across the life span. Considerable gaps in knowledge include the timing of exposure(s) and permanence or plasticity of the response, encompassing effects from both maternal and paternal dysmetabolism. Basic, translational, and human intervention studies targeting pathways that connect diet, microbiota, and metabolism in mothers with obesity/GDM and their infants are a critical unmet need and present new challenges for disease prevention in the next generation.

Regulating Gut Flora Dysbiosis in Obese Mice by Electroacupuncture

Recently, gut flora has been linked to the onset of obesity and has been shown to influence the host's metabolism. Acupuncture is a well-known agent used for the treatment of numerous diseases such as obesity. This study aimed to explore the impacts of electroacupuncture treatment on gut microbiota composition and function in obese mice. Pyrosequencing of 16S rRNA genes and Metagenomic analysis of the fecal microbiota were used for this purpose. The basic parameters of body weight, Lee's index, serum lipid and epididymal adipose weight were ameliorated significantly after introducing an electroacupuncture intervention. Acidobacteria, Cyanobacteria and Basidiomycota (Normal group) and Fusobacteria, Firmicutes and Spirochmycetes (Model group) were remarkably affluent at the phylum level. Bacteroides sp. CAG: 927 and Prevotella sp. CAG: 1031 (Normal group), Lachnospiraceae bacterium and Helicobacter rodentium (Model group) at the species level were distinctly enriched. The structures and functions of the intestinal flora were significantly different between healthy and obese mice, and animals in the acupuncture group gradually tended towards healthy controls. Moreover, electroacupuncture altered the bacterial diversity and metabolic genes to establish new balance, observed the obvious change from 7[Formula: see text]d and stabilized gradually through 21[Formula: see text]d. These findings suggested gut flora could be a novel target of electroacupuncture treatment against obesity.

Early High-Fat Diet Exposure Causes Dysregulation of the Orexin and Dopamine Neuronal Populations in Nonhuman Primates

Maternal obesity and consumption of a high-fat diet (HFD) during pregnancy has a negative impact on offspring, including an increased risk for the development of obesity in adolescence. The mechanism for this transferred metabolic risk is unclear, but many studies have focused on the brain due to its important role in appetite and body-weight regulation. Two main pathways regulate appetite in the brain; homeostatic regulation that occurs predominantly in hypothalamic circuits and hedonic regulation of feeding that occurs via dopaminergic pathways. The current proposal examined the impact of early HFD exposure on the dopaminergic control of hedonic feeding pathways in a translational nonhuman primate model. Japanese macaque offspring from mothers consuming a control (CTR) or HFD were weaned onto control or HFD at an average 8 months of age yielding four groups: maternal and post-weaning control diet (mCTRpCTR), maternal control diet and post-weaning HFD (mCTRpHFD), maternal HFD and post-weaning control diet (mHFDpCTR) and maternal and post-weaning HFD (mHFDpHFD). Brains from 13-month-old offspring were evaluated for expression of neuropeptides that regulate dopaminergic pathways including orexin, melanin-concentrating hormone (MCH) in the lateral hypothalamus (LH), and tyrosine hydroxylase expression in the ventral tegmental area (VTA). Orexin cell numbers in the LH were significantly increased in animals exposed to a post-weaning HFD, while no difference was observed for orexin mRNA content or MCH cell numbers. Orexin fiber projections to the rostral VTA were significantly reduced in mCTRpHFD, mHFDpCTR, and mHFDpHFD groups, but these differences were not significant in the caudal VTA. There was no difference in the percentage of dopamine neurons receiving close appositions from orexin fibers in either the rostral or caudal VTA, nor was there any difference between groups in the number of orexin contacts per TH cell. In conclusion, the current study finds that prolonged early exposure to HFD during the in utero and postnatal period causes alterations at several levels in the dopaminergic circuits regulating reward.

Maternal High-Fat Diet Effects on Adaptations to Metabolic Challenges in Male and Female Juvenile Nonhuman Primates

OBJECTIVE

This study aimed to determine whether maternal high-fat diet (HFD) consumption in nonhuman primates alters the ability of offspring to adapt metabolically to nutrient and caloric challenges.

METHODS

Offspring from Japanese macaque dams fed either a control (CTR) diet or HFD were weaned onto a CTR diet creating two groups: maternal HFD (mHFD, n = 18) and maternal CTR (mCTR) diet (n = 12). Male and female offspring were exposed to a 5-day 30% calorie restriction and to a 35-day HFD challenge (HFDC), at 16 and 24 months of age, respectively. Caloric intake, body weight, and energy expenditure were measured.

RESULTS

Offspring from both groups showed similar body weight, food intake, and metabolic adaptations to a 5-day calorie restriction. mHFD offspring demonstrated increased food intake and early weight gain in response to a 35-day HFDC; however, group differences in weight dissipated during the challenge. Unlike mCTR animals, the mHFD group had a significant increase in fasting insulin after acute HFD exposure.

CONCLUSIONS

The current findings indicate that offspring exposed to an mHFD show metabolic adaptations to calorie restriction that are largely similar to those of offspring exposed to a mCTR diet but show delayed adaptation upon exposure to an acute HFDC.

Persistent effects of obesity: a neuroplasticity hypothesis

The obesity epidemic is a leading cause of health problems in the United States, increasing the risk of cardiovascular, endocrine, and psychiatric diseases. Although many people lose weight through changes in diet and lifestyle, keeping the weight off remains a challenge. Here, we discuss a hypothesis that seeks to explain why obesity is so persistent. There is a great degree of overlap in the circuits implicated in substance use disorder and obesity, and neural plasticity of these circuits in response to drugs of abuse is well documented. We hypothesize that obesity is also associated with neural plasticity in these circuits, and this may underlie persistent changes in behavior, energy balance, and body weight. Here, we discuss how obesity-associated reductions in motivation and physical activity may be rooted in neurophysiological alterations in these circuits. Such plasticity may alter how humans and animals use, expend, and store energy, even after weight loss.

Maternal obesity increases the risk of metabolic disease and impacts renal health in offspring

Obesity, together with insulin resistance, promotes multiple metabolic abnormalities and is strongly associated with an increased risk of chronic disease including type 2 diabetes (T2D), hypertension, cardiovascular disease, non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD). The incidence of obesity continues to rise in astronomical proportions throughout the world and affects all the different stages of the lifespan. Importantly, the proportion of women of reproductive age who are overweight or obese is increasing at an alarming rate and has potential ramifications for offspring health and disease risk. Evidence suggests a strong link between the intrauterine environment and disease programming. The current review will describe the importance of the intrauterine environment in the development of metabolic disease, including kidney disease. It will detail the known mechanisms of fetal programming, including the role of epigenetic modulation. The evidence for the role of maternal obesity in the developmental programming of CKD is derived mostly from our rodent models which will be described. The clinical implication of such findings will also be discussed.

Hypothalamic circuits regulating appetite and energy homeostasis: pathways to obesity

The ‘obesity epidemic’ represents a major global socioeconomic burden that urgently calls for a better understanding of the underlying causes of increased weight gain and its associated metabolic comorbidities, such as type 2 diabetes mellitus and cardiovascular diseases. Improving our understanding of the cellular basis of obesity could set the stage for the development of new therapeutic strategies. The CNS plays a pivotal role in the regulation of energy and glucose homeostasis. Distinct neuronal cell populations, particularly within the arcuate nucleus of the hypothalamus, sense the nutrient status of the organism and integrate signals from peripheral hormones including pancreas-derived insulin and adipocyte-derived leptin to regulate calorie intake, glucose metabolism and energy expenditure. The arcuate neurons are tightly connected to other specialized neuronal subpopulations within the hypothalamus, but also to various extrahypothalamic brain regions, allowing a coordinated behavioral response. This At a Glance article gives an overview of the recent knowledge, mainly derived from rodent models, regarding the CNS-dependent regulation of energy and glucose homeostasis, and illustrates how dysregulation of the neuronal networks involved can lead to overnutrition and obesity. The potential impact of recent research findings in the field on therapeutic treatment strategies for human obesity is also discussed.

Summary: This at a glance article gives an overview of the recent knowledge mainly derived from rodent models regarding the CNS-dependent regulation of energy and glucose homeostasis, and depicts how dysregulation of the involved neuronal networks promotes overnutrition and obesity.

Circadian peak dopaminergic activity response at the biological clock pacemaker (suprachiasmatic nucleus) area mediates the metabolic responsiveness to a high-fat diet

Among vertebrate species of the major vertebrate classes in the wild, a seasonal rhythm of whole body fuel metabolism, oscillating from a lean to obese condition, is a common biological phenomenon. This annual cycle is driven in part by annual changes in the circadian dopaminergic signalling at the suprachiasmatic nuclei (SCN), with diminution of circadian peak dopaminergic activity at the SCN facilitating development of the seasonal obese insulin-resistant condition. The present study investigated whether such an ancient circadian dopamine-SCN activity system for expression of the seasonal obese, insulin-resistant phenotype may be operative in animals made obese amd insulin resistant by high-fat feeding and, if so, whether reinstatement of the circadian dopaminergic peak at the SCN would be sufficient to reverse the adverse metabolic impact of the high-fat diet without any alteration of caloric intake. First, we identified the supramammillary nucleus as a novel site providing the majority of dopaminergic neuronal input to the SCN. We further identified dopamine D2 receptors within the peri-SCN region as being functional in mediating SCN responsiveness to local dopamine. In lean, insulin-sensitive rats, the peak in the circadian rhythm of dopamine release at the peri-SCN coincided with the daily peak in SCN electrophysiological responsiveness to local dopamine administration. However, in rats made obese and insulin resistant by high-fat diet (HFD) feeding, these coincident circadian peak activities were both markedly attenuated or abolished. Reinstatement of the circadian peak in dopamine level at the peri-SCN by its appropriate circadian-timed daily microinjection to this area (but not outside this circadian time-interval) abrogated the obese, insulin-resistant condition without altering the consumption of the HFD. These findings suggest that the circadian peak of dopaminergic activity at the peri-SCN/SCN is a key modulator of metabolism and the responsiveness to adverse metabolic consequences of HFD consumption.