Adipose tissue gene expression profiling reveals distinct molecular pathways that define visceral adiposity in offspring of maternal protein-restricted rats

Interplay between maternal nutrition and epigenetic programming on offspring hypertension

Recent human and animal studies have delineated hypertension can develop in the earliest stage of life. A lack or excess of particular nutrients in the maternal diet may impact the expression of genes associated with BP, leading to an increased risk of hypertension in adulthood. Modulations in gene expression could be caused by epigenetic mechanisms through aberrant DNA methylation, histone modification, and microRNAs (miRNAs). Several molecular mechanisms for the developmental programming of hypertension, including oxidative stress, dysregulated nutrient-sensing signal, aberrant renin-angiotensin system, and dysbiotic gut microbiota have been associated with epigenetic programming. Conversely, maternal nutritional interventions such as amino acids, melatonin, polyphenols, resveratrol or short chain fatty acids may work as epigenetic modifiers to trigger protective epigenetic modifications and prevent offspring hypertension. We present a current perspective of maternal malnutrition that can cause fetal programming and the potential of epigenetic mechanisms lead to offspring hypertension. We also discuss the opportunities of dietary nutrients or nutraceuticals as epigenetic modifiers to counteract those adverse programming actions for hypertension prevention. The extent to which aberrant epigenetic changes can be reprogrammed or reversed by maternal dietary interventions in order to prevent human hypertension remains to be established. Continued research is necessary to evaluate the interaction between maternal malnutrition and epigenetic programming, as well as a greater focus on nutritional interventions for hypertension prevention towards their use in clinical translation.

Visceral fat and cardiometabolic future in children and adolescents: a critical update

Cardiovascular disease (CVD) is a process whose pathogenetic mechanisms start very early in life. Recently, the importance of visceral adipose tissue (VAT) has been highlighted in the development of CVD. VAT does not always depend on body mass index (BMI) and has been implicated in unfavorable metabolic activity and cardiovascular adverse events. Abnormally high deposition of VAT is associated with metabolic syndrome, obesity-associated phenotype, and cardiometabolic risk factors. Although the importance of visceral fat has not been studied broadly or extensively in long-term studies in children and adolescents, it appears that it does not have the same behavior as in adults, it is related to the appearance of cardiac risk factors. In adolescents, it plays a role in the pathogenesis of CVD that occur later in adulthood. Excess body weight and adiposity may lead to the development of early myocardial and pathological coronary changes in childhood. The purpose of this review is to summarize the risk factors, the clinical significance, and the prognostic role of visceral obesity in children and adolescents. In addition, extensive reference is made to the most commonly used techniques for the evaluation of VAT in clinical settings. IMPACT: Visceral obesity, plays an important role in cardiovascular health from very early in an individual's life. Visceral adipose tissue (VAT) distribution is not entirely related to body mass index (BMI) and provides additional prognostic information. There is a need to pay more attention to the assessment of VAT in young people, to develop methods that would go beyond the measurement of only BMI in clinical practice and to identify individuals with excess visceral adiposity and perhaps to monitor its changes.

Birth weight concerning obesity and diabetes gene expression in healthy infants; a case-control study

Background

Since obesity and diabetes are prevalent worldwide, identifying the factors affecting these two conditions can effectively alter them. We decided to investigate the expression of obesity and diabetes genes in infants with birth weights lower than 2500 g in comparison with infants with normal birth weights.

Methods

215 healthy infants between the ages of 5–6 months were used in the current case-control research, which was conducted at health and treatment facilities in Kermanshah. Infants who were healthy were chosen for the research after their weight and height were measured and compared to the WHO diagram to ensure that they were well-grown and in good health. There were 137 infants in the control group and 78 infants in the case group. All newborns had 5 cc of blood drawn intravenously. To assess the expression of the genes MC4R, MTNR1B, PTEN, ACACB, PPAR-γ, PPAR-α, NRXN3, NTRK2, PCSK1, A2BP1, TMEM18, LXR, BDNF, TCF7L2, FTO and CPT1A, blood samples were gathered in EDTA-coated vials. Chi-square, Mann-Whitney U, and Spearman analyses were used to examine the data.

Results

A significant inverse correlation between birth weight and obesity and diabetes genes, including MTNR1B, NTRK2, PCSK1, and PTEN genes (r= -0.221, -0.235, -0.246, and − 0.418, respectively). In addition, the LBW infant’s expression level was significantly up-regulated than the normal-weight infants (P = 0.001, 0.007, 0.001, and < 0.001, respectively). The expression level of the PPAR-a gene had a significantly positive correlation with birth weight (r = 0.19, P = 0.005). The expression level of the PPAR-a gene in the normal-weight infants was significantly up-regulated than the LBW infants (P = 0.049).

Conclusion

The expression levels of MTNR1B, NTRK2, PCSK1, and PTEN genes were up-regulated in the LBW infants; however, the expression level of PPAR-a gene was significantly down-regulated in the LBW infants compared to the infants with normal birth weight.

Catch-up growth in juvenile rats, fat expansion, and dysregulation of visceral adipose tissue

BACKGROUND

Accelerated catch-up growth following intrauterine restriction increases the risk of developing visceral adiposity and metabolic abnormalities. However, the underlying molecular mechanisms of such metabolic programming are still poorly understood.

METHODS

A Wistar rat model of catch-up growth following intrauterine restriction was used. A gene expression array was performed in the retroperitoneal adipose tissue sampled at postnatal day (PD) 42.

RESULTS

Five hundred and forty-six differentially expressed genes (DEGs) were identified (adjusted p value < 0.05). Gene ontology enrichment analysis identified pathways related to immune and lipid metabolic processes, brown fat cell differentiation, and regulation of PI3K. Ccl21, Npr3, Serpina3n, Pnpla3, Slc2a4, and Serpina12 were validated to be upregulated in catch-up pups (all p < 0.01) and related to several fat expansion and metabolic parameters, including body weight at PD42, postnatal body weight gain, white and brown adipose tissue mass, plasma triglycerides, and insulin resistance index (all p < 0.05).

CONCLUSIONS

Genes related to immune and metabolic processes were upregulated in retroperitoneal adipose tissue following catch-up growth in juvenile rats and were found to be associated with fat expansion and metabolic parameters. Our results provide evidence for several dysregulated genes in white adipose tissue that could help develop novel strategies to prevent the metabolic abnormalities associated with catch-up growth.

IMPACT

Catch-up growth presents several dysregulated genes in white adipose tissue related to metabolic abnormalities. Ccl21, Npr3, Serpina3n, Pnpla3, Slc2a4, and Serpina12 were validated to be upregulated in catch-up pups and related to visceral fat expansion and metabolic parameters. Profiling and validation of these dysregulated genes in visceral adipose tissue could help develop novel strategies to prevent the metabolic abnormalities associated with catch-up growth.

Animal Foetal Models of Obesity and Diabetes - From Laboratory to Clinical Settings

The prenatal period, during which a fully formed newborn capable of surviving outside its mother's body is built from a single cell, is critical for human development. It is also the time when the foetus is particularly vulnerable to environmental factors, which may modulate the course of its development. Both epidemiological and animal studies have shown that foetal programming of physiological systems may alter the growth and function of organs and lead to pathology in adulthood. Nutrition is a particularly important environmental factor for the pregnant mother as it affects the condition of offspring. Numerous studies have shown that an unbalanced maternal metabolic status (under- or overnutrition) may cause long-lasting physiological and behavioural alterations, resulting in metabolic disorders, such as obesity and type 2 diabetes (T2DM). Various diets are used in laboratory settings in order to induce maternal obesity and metabolic disorders, and to alter the offspring development. The most popular models are: high-fat, high-sugar, high-fat-high-sugar, and cafeteria diets. Maternal undernutrition models are also used, which results in metabolic problems in offspring. Similarly to animal data, human studies have shown the influence of mothers' diets on the development of children. There is a strong link between the maternal diet and the birth weight, metabolic state, changes in the cardiovascular and central nervous system of the offspring. The mechanisms linking impaired foetal development and adult diseases remain under discussion. Epigenetic mechanisms are believed to play a major role in prenatal programming. Additionally, sexually dimorphic effects on offspring are observed. Therefore, further research on both sexes is necessary.

Epigenetic Modifications at the Center of the Barker Hypothesis and Their Transgenerational Implications

Embryo/fetal nutrition and the environment in the reproductive tract influence the subsequent risk of developing adult diseases and disorders, as formulated in the Barker hypothesis. Metabolic syndrome, obesity, heart disease, and hypertension in adulthood have all been linked to unwanted epigenetic programing in embryos and fetuses. Multiple studies support the conclusion that environmental challenges, such as a maternal low-protein diet, can change one-carbon amino acid metabolism and, thus, alter histone and DNA epigenetic modifications. Since histones influence gene expression and the program of embryo development, these epigenetic changes likely contribute to the risk of adult disease onset not just in the directly affected offspring, but for multiple generations to come. In this paper, we hypothesize that the effects of parental nutritional status on fetal epigenetic programming are transgenerational and warrant further investigation. Numerous studies supporting this hypothesis are reviewed, and potential research techniques to study these transgenerational epigenetic effects are offered.

Depot and sex-specific implications for adipose tissue expandability and functional traits in adulthood of late prenatal and early postnatal malnutrition in a precocial sheep model

The aim was to investigate long‐term, tissue and sex‐specific impacts of pre and postnatal malnutrition on expandability and functional traits of different adipose tissues. Twin‐pregnant ewes were fed NORM (~requirements), LOW (50% of NORM) or HIGH (150%/110% of energy/protein) diets the last 6 weeks prepartum (term ~147‐days). Lambs received moderate, low‐fat (CONV) or high‐carbohydrate‐high‐fat (HCHF) diets from 3 days until 6 months of age, and thereafter CONV diet. At 2½ years of age (adulthood), histomorphometric and gene expression patterns were characterized in subcutaneous (SUB), perirenal (PER), mesenteric (MES), and epicardial (EPI) adipose tissues. SUB had sex‐specific (♂<♀) upper‐limits for adipocyte size and cell‐number indices, irrespective of early life nutrition. PER mass and contents of adipocytes were highest in females and HIGH♂, whereas adipocyte cross‐sectional area was lowest in LOW♂. Pre/postnatal nutrition affected gene expression sex‐specifically in SUB + PER, but unrelated to morphological changes. In PER, LOW/LOW♂ were specific targets of gene expression changes. EPI was affected by postnatal nutrition, and HCHF sheep had enlarged adipocytes and upregulated expressions for adipogenic and lipogenic genes. Conclusion: upper‐limits for SUB expandability were markedly lower in males. Major targets for prenatal malnutrition were PER and males. LOW♂ had the lowest PER expandability, whereas HIGH♂ had an adaptive advantage due to increased hypertrophic ability equivalent to females. Fixed expandability in SUB meant PER became a determining factor for MES and ectopic fat deposition, rendering LOW♂ particularly predisposed for obesity‐associated metabolic risks. EPI, in contrast to other tissues, was targeted particularly by early postnatal obesity, resulting in adipocyte hypertrophy in adulthood.

In Utero Exposure to Δ9-Tetrahydrocannabinol Leads to Postnatal Catch-Up Growth and Dysmetabolism in the Adult Rat Liver

The rates of gestational cannabis use have increased despite limited evidence for its safety in fetal life. Recent animal studies demonstrate that prenatal exposure to Δ9-tetrahydrocannabinol (Δ9-THC, the psychoactive component of cannabis) promotes intrauterine growth restriction (IUGR), culminating in postnatal metabolic deficits. Given IUGR is associated with impaired hepatic function, we hypothesized that Δ9-THC offspring would exhibit hepatic dyslipidemia. Pregnant Wistar rat dams received daily injections of vehicular control or 3 mg/kg Δ9-THC i.p. from embryonic day (E) 6.5 through E22. Exposure to Δ9-THC decreased the liver to body weight ratio at birth, followed by catch-up growth by three weeks of age. At six months, Δ9-THC-exposed male offspring exhibited increased visceral adiposity and higher hepatic triglycerides. This was instigated by augmented expression of enzymes involved in triglyceride synthesis (ACCα, SCD, FABP1, and DGAT2) at three weeks. Furthermore, the expression of hepatic DGAT1/DGAT2 was sustained at six months, concomitant with mitochondrial dysfunction (i.e., elevated p66shc) and oxidative stress. Interestingly, decreases in miR-203a-3p and miR-29a/b/c, both implicated in dyslipidemia, were also observed in these Δ9-THC-exposed offspring. Collectively, these findings indicate that prenatal Δ9-THC exposure results in long-term dyslipidemia associated with enhanced hepatic lipogenesis. This is attributed by mitochondrial dysfunction and epigenetic mechanisms.

Developmental programming of offspring adipose tissue biology and obesity risk

Obesity is reaching epidemic proportions and imposes major negative health crises and an economic burden in both high and low income countries. The multifaceted nature of obesity represents a major health challenge, with obesity affecting a variety of different organs and increases the risk of many other noncommunicable diseases, such as type 2 diabetes, fatty liver disease, dementia, cardiovascular diseases, and even cancer. The defining organ of obesity is the adipose tissue, highlighting the need to more comprehensively understand the development and biology of this tissue to understand the pathogenesis of obesity. Adipose tissue is a miscellaneous and highly plastic endocrine organ. It comes in many different sizes and shades and is distributed throughout many different locations in the body. Though its development begins prenatally, quite uniquely, it has the capacity for unlimited growth throughout adulthood. Adipose tissue is also a highly sexually dimorphic tissue, patterning men and women in different ways, which means the risks associated with obesity are also sexually dimorphic. Recent studies show that environmental factors during prenatal and early stages of postnatal development have the capacity to programme the structure and function of adipose tissue, with implications for the development of obesity. This review summarizes the evidence for a role for early environmental factors, such as maternal malnutrition, hypoxia, and exposure to excess hormones and endocrine disruptors during gestation in the programming of adipose tissue and obesity in the offspring. We will also discuss the complexity of studying adipose tissue biology and the importance of appreciating nuances in adipose tissue, such as sexual dimorphism and divergent responses to metabolic and endocrine stimuli. Given the rising levels of obesity worldwide, understanding how environmental conditions in early life affects adipose tissue phenotype and the subsequent development of obesity is of absolute importance.

Molecular mechanisms governing offspring metabolic programming in rodent models of in utero stress

The results of different human epidemiological datasets provided the impetus to introduce the now commonly accepted theory coined as 'developmental programming', whereby the presence of a stressor during gestation predisposes the growing fetus to develop diseases, such as metabolic dysfunction in later postnatal life. However, in a clinical setting, human lifespan and inaccessibility to tissue for analysis are major limitations to study the molecular mechanisms governing developmental programming. Subsequently, studies using animal models have proved indispensable to the identification of key molecular pathways and epigenetic mechanisms that are dysregulated in metabolic organs of the fetus and adult programmed due to an adverse gestational environment. Rodents such as mice and rats are the most used experimental animals in the study of developmental programming. This review summarises the molecular pathways and epigenetic mechanisms influencing alterations in metabolic tissues of rodent offspring exposed to in utero stress and subsequently programmed for metabolic dysfunction. By comparing molecular mechanisms in a variety of rodent models of in utero stress, we hope to summarise common themes and pathways governing later metabolic dysfunction in the offspring whilst identifying reasons for incongruencies between models so to inform future work. With the continued use and refinement of such models of developmental programming, the scientific community may gain the knowledge required for the targeted treatment of metabolic diseases that have intrauterine origins.

In utero nutritional stress as a cause of obesity: Altered relationship between body fat, leptin levels and caloric intake in offspring into adulthood

AIMS

Emerging evidence suggests that during gestation the in utero environment programs metabolism and can increase risk of obesity in adult offspring. Our aim was to study how alterations in maternal diets during gestation might alter body weight evolution, circulating leptin levels and caloric intake in offspring, leading to changes in body composition.

MATERIALS AND METHODS

We fed gestating rats either a control diet (CD), high fat diet (HFD) or an isocaloric low protein diet (LPD), and examined the repercussions in offspring fed similar diets post-weaning on birth weight, body weight evolution, body composition, insulin sensitivity, glucose tolerance and in the relationship between plasma leptin concentration and caloric intake in offspring during growth and development.

KEY FINDS

Offspring from dams fed LPD maintained reduced body weight with greater % lean mass and consumed fewer calories despite having leptin levels similar to controls. On the other hand, offspring from dams fed a HFD were insulin resistant and maintained increased body weight and % fat mass, while consuming more calories than controls despite elevated leptin concentrations. Therefore the uterine environment, modulated primarily through maternal nutrition, modified the relationship between circulating leptin levels, body fat, and caloric intake in the offspring, and dams fed a HFD produced offspring with excess adiposity, insulin resistance, and leptin resistance into adulthood.

SIGNIFICANCE

Our data indicates that in utero environmental factors affected by maternal diet program alterations in the set point around which leptin regulates body weight in offspring into adulthood contributing to obesity.

Nonnutritive sweetener consumption during pregnancy, adiposity, and adipocyte differentiation in offspring: evidence from humans, mice, and cells

BACKGROUND

Obesity often originates in early life, and is linked to excess sugar intake. Nonnutritive sweeteners (NNS) are widely consumed as "healthier" alternatives to sugar, yet recent evidence suggests NNS may adversely influence weight gain and metabolic health. The impact of NNS during critical periods of early development has rarely been studied. We investigated the effect of prenatal NNS exposure on postnatal adiposity and adipocyte development.

METHODS

In the CHILD birth cohort (N = 2298), we assessed maternal NNS beverage intake during pregnancy and child body composition at 3 years, controlling for maternal BMI and other potential confounders. To investigate causal mechanisms, we fed NNS to pregnant C57BL6J mice at doses relevant to human consumption (42 mg/kg/day aspartame or 6.3 mg/kg/day sucralose), and assessed offspring until 12 weeks of age for: body weight, adiposity, adipose tissue morphology and gene expression, glucose and insulin tolerance. We also studied the effect of sucralose on lipid accumulation and gene expression in cultured 3T3-L1 pre-adipocyte cells.

RESULTS

In the CHILD cohort, children born to mothers who regularly consumed NNS beverages had elevated body mass index (mean z-score difference +0.23, 95% CI 0.05-0.42 for daily vs. no consumption, adjusted for maternal BMI). In mice, maternal NNS caused elevated body weight, adiposity, and insulin resistance in offspring, especially in males (e.g., 47% and 15% increase in body fat for aspartame and sucralose vs. controls, p < 0.001). In cultured adipocytes, sucralose exposure at early stages of differentiation caused increased lipid accumulation and expression of adipocyte differentiation genes (e.g., C/EBP-α, FABP4, and FASN). These genes were also upregulated in adipose tissue of male mouse offspring born to sucralose-fed dams.

CONCLUSION

By triangulating evidence from humans, mice, and cultured adipocytes, this study provides new evidence that maternal NNS consumption during pregnancy may program obesity risk in offspring through effects on adiposity and adipocyte differentiation.

Early-life programming of adipose tissue

Worldwide obesity is increasing at an alarming rate in children and adolescents, with the consequent emergence of co-morbidities. Moreover, the maternal environment during pregnancy plays an important role in obesity, contributing to transgenerational transmission of the same and metabolic dysfunction. White adipose tissue represents a prime target of metabolic programming induced by maternal milieu. In this article, we review adipose tissue physiology and development, as well as maternal influences during the perinatal period that may lead to obesity in early postnatal life and adulthood. First, we describe the adipose tissue cell composition, distribution and hormonal action, together with the evidence of hormonal factors participating in fetal/postnatal programming. Subsequently, we describe the critical periods of adipose tissue development and the relationship of gestational and early postnatal life with healthy fetal adipose tissue expansion. Furthermore, we discuss the evidence showing that adipose tissue is an important target for nutritional, hormonal and epigenetic signals to modulate fetal growth. Finally, we describe nutritional, hormonal, epigenetic and microbiome changes observed in maternal obesity, and whether their disruption alters fetal growth and adiposity. The presented evidence supports the developmental origins of health and disease concept, which proposes that the homeostatic system is affected during gestational and postnatal development, impeding the ability to regulate body weight after birth, thereby resulting in adult obesity. Consequently, we anticipate that promoting a healthy early-life programming of adipose tissue and increasing the knowledge of the mechanisms by which maternal factors affect the health of future generations may offer novel strategies for explaining and addressing worldwide health problems such as obesity.

Differential impacts of late gestational over-and undernutrition on adipose tissue traits and associated visceral obesity risk upon exposure to a postnatal high-fat diet in adolescent sheep

We hypothesized that late gestation malnutrition differentially affects expandability of adipose tissues to predispose for early postnatal visceral adiposity. Twin-lambs born to dams fed HIGH (150%/110% of required energy/protein, respectively), NORM (100% of requirements) or LOW (50% of NORM) diets during the last trimester were used. Postnatally, lambs were raised on moderate (CONV) or high-carbohydrate-high-fat (HCHF) diets. Adipose tissues were sampled at autopsy at 6 months of age (~puberty) to characterize cellularity, adipocyte cross-sectional area and gene expression patterns. HIGH and LOW compared to NORM lambs had reduced intrinsic (under CONV diet) cellularity in subcutaneous and mesenteric (particularly LOW), and reduced obesity-induced (under HCHF diet) hyperplasia in subcutaneous, mesenteric and perirenal (particularly HIGH) adipose tissues. This corresponded with more pronounced HCHF diet-induced hypertrophy in mesenteric (particularly LOW), perirenal (particularly HIGH) and subcutaneous (particularly HIGH) adipose tissues, and tissue-specific reductions in mRNA expressions for lipid metabolism, angiogenesis and adipose development. Gene expression for inflammation and lipid metabolism markers were increased and decreased, respectively, in HCHF lambs (HCHF lambs became obese) in all tissues. Both prenatal over- and undernutrition predisposed for abdominal adiposity and extreme perirenal hypertrophy due to reduced intrinsic (observed under CONV diet) cellularity and impaired ability of subcutaneous, mesenteric and perirenal adipose tissues to expand by hyperplasia rather than hypertrophy on an obesogenic (HCHF) diet.

Transcription profiling in the liver of undernourished male rat offspring reveals altered lipid metabolism pathways and predisposition to hepatic steatosis

Clinical and animal studies have reported an association between low birth weight and the development of nonalcoholic fatty liver disease (NAFLD) in offspring. Using a model of prenatal maternal 70% food restriction diet (FR30) in the rat, we previously showed that maternal undernutrition predisposes offspring to altered lipid metabolism in adipose tissue, especially on a high-fat (HF) diet. Here, using microarray-based expression profiling combined with metabolic, endocrine, biochemical, histological, and lipidomic approaches, we assessed whether FR30 procedure sensitizes adult male offspring to impaired lipid metabolism in the liver. No obvious differences were noted in the concentrations of triglycerides, cholesterol, and bile acids in the liver of 4-mo-old FR30 rats whichever postweaning diet was used. However, several clues suggest that offspring's lipid metabolism and steatosis are modified by maternal undernutrition. First, lipid composition was changed (i.e., higher total saturated fatty acids and lower elaidic acid) in the liver, whereas larger triglyceride droplets were observed in hepatocytes of undernourished rats. Second, FR30 offspring exhibited long-term impact on hepatic gene expression and lipid metabolism pathways on a chow diet. Although the transcriptome profile was globally modified by maternal undernutrition, cholesterol and bile acid biosynthesis pathways appear to be key targets, indicating that FR30 animals were predisposed to impaired hepatic cholesterol metabolism. Third, the FR30 protocol markedly modifies hepatic gene transcription profiles in undernourished offspring in response to postweaning HF. Overall, FR30 offspring may exhibit impaired metabolic flexibility, which does not enable them to properly cope with postweaning nutritional challenges influencing the development of nonalcoholic fatty liver.

Beyond the bone: Bone morphogenetic protein signaling in adipose tissue

The bone morphogenetic proteins (BMPs) belong to the same superfamily as related to transforming growth factor β (TGFβ), growth and differentiation factors (GDFs), and activins. They were initially described as inducers of bone formation but are now known to be involved in morphogenetic activities and cell differentiation throughout the body, including the development of adipose tissue and adipogenic differentiation. BMP4 and BMP7 are the most studied BMPs in adipose tissue, with major roles in white adipogenesis and brown adipogenesis, respectively, but other BMPs such as BMP2, BMP6, and BMP8b as well as some inhibitors and modulators have been shown to also affect adipogenesis. It has become ever more important to understand adipose regulation, including the BMP pathways, in light of the strong links between obesity and metabolic and cardiovascular disease. In this review, we summarize the available information on BMP signaling in adipose tissue using preferentially articles that have appeared in the last decade, which together demonstrate the importance of BMP signaling in adipose biology.

The Good, the Bad, and the Ugly of Pregnancy Nutrients and Developmental Programming of Adult Disease

Maternal nutrition plays a decisive role in developmental programming of many non-communicable diseases (NCDs). A variety of nutritional insults during gestation can cause programming and contribute to the development of adult-onset diseases. Nutritional interventions during pregnancy may serve as reprogramming strategies to reverse programming processes and prevent NCDs. In this review, firstly we summarize epidemiological evidence for nutritional programming of human disease. It will also discuss evidence from animal models, for the common mechanisms underlying nutritional programming, and potential nutritional interventions used as reprogramming strategies.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Mitochondrial inefficiency in infants born to overweight African-American mothers

Background

Currently 20–35% of pregnant women are obese, posing a major health risk for mother and fetus. It is postulated that an abnormal maternal-fetal nutritional environment leads to adverse metabolic programming, resulting in altered substrate metabolism in the offspring and predisposing to risks of obesity and diabetes later in life. Data indicate that oocytes from overweight animals have abnormal mitochondria. We hypothesized that maternal obesity is associated with altered mitochondrial function in healthy neonatal offspring.

Methods

Overweight and obese (Body mass index, (BMI) ≥ 25 kg/m², n=14) and lean (BMI < 25 kg/m², n=8), African American pregnant women carrying male fetuses were recruited from the Barnes Jewish Hospital obstetric clinic. Maternal and infant data were extracted from medical records. Infants underwent body composition testing in the first days of life. Circumcision skin was collected for isolation of fibroblasts. Fibroblast cells were evaluated for mitochondrial function, metabolic gene expression, nutrient uptake and oxidative stress.

Results

Skin fibroblasts of infants born to overweight mothers had significantly higher mitochondrial respiration without a concurrent increase in ATP production, indicating mitochondrial inefficiency. These fibroblasts had higher levels of reactive oxygen species and evidence of oxidative stress. Evaluation of gene expression in offspring fibroblasts revealed altered expression of multiple genes involved in fatty acid and glucose metabolism and mitochondrial respiration in infants of overweight mothers.

Conclusion

This study demonstrates altered mitochondrial function and oxidative stress in skin fibroblasts of infants born to overweight mothers. Future studies are needed to determine the long-term impact of this finding on the metabolic health of these children.

Decreased insulin secretion in pregnant rats fed a low protein diet

Low protein (LP) diet during pregnancy leads to reduced plasma insulin levels in rodents, but the underlying mechanisms remain unclear. Glucose is the primary insulin secretagogue, and enhanced glucose-stimulated insulin secretion (GSIS) in beta cells contributes to compensation for insulin resistance and maintenance of glucose homeostasis during pregnancy. In this study, we hypothesized that plasma insulin levels in pregnant rats fed LP diet are reduced due to disrupted GSIS of pancreatic islets. We first confirmed reduced plasma insulin levels, then investigated in vivo insulin secretion by glucose tolerance test and ex vivo GSIS of pancreatic islets in the presence of glucose at different doses, and KCl, glibenclamide, and L-arginine. Main findings include (1) plasma insulin levels were unaltered on day 10, but significantly reduced on days 14-22 of pregnancy in rats fed LP diet compared to those of control (CT) rats; (2) insulin sensitivity was unchanged, but glucose intolerance was more severe in pregnant rats fed LP diet; (3) GSIS in pancreatic islets was lower in LP rats compared to CT rats in the presence of glucose, KCl, and glibenclamide, and the response to L-arginine was abolished in LP rats; and (4) the total insulin content in pancreatic islets and expression of Ins2 were reduced in LP rats, but expression of Gcg was unaltered. These studies demonstrate that decreased GSIS in beta cells of LP rats contributes to reduced plasma insulin levels, which may lead to placental and fetal growth restriction and programs hypertension and other metabolic diseases in offspring.

Post implantation fate of adipogenic induced mesenchymal stem cells on Type I collagen scaffold in a rat model

Regenerative medicine via its application in soft tissue reconstruction through novel methods in adipose tissue engineering (ATE) has gained remarkable attention and investment despite simultaneous reports on clinical incidence of graft resorption and impaired vascularization. The underlying malaise here once identified may play a critical role in optimizing implant function. Our work attempts to determine the fate of donor cells and the implant in recipient micro environment using adipose-derived mesenchymal stem cells (ASCs) on a type I collagen sponge, an established scaffold for ATE. Cell components within the construct were identified 21 days post implantation to delineate cell survival, proliferation & terminal roles in vivo. ASC's are multipotent, while collagen type I is a natural extra cellular matrix component. Commercially available bovine type I collagen was characterized for its physiochemical properties and cyto-compatibility. Nile red staining of induced ASCs identified red globular structures in cell cytoplasm indicating oil droplet accumulation. Similarly, in vivo implantation of the cell seeded collagen construct in rat model for 21 days in the dorsal muscle, showed genesis of chicken wire network of fat-like cells, which was demonstrated histologically using a variety of staining techniques. Furthermore, fluorescent in situ hybridization (FISH) technique established the efficiency of transplantation wherein the male donor cells with labeled Y chromosome was identified 21 days post implantation from female rat model. Retrieved samples at 21 days indicated adipogenesis in situ, with donor cells highlighted via FISH. The study provides an insight to stem cells in ATE from genesis to functionalization.

Effects of prenatal low protein and postnatal high fat diets on visceral adipose tissue macrophage phenotypes and IL-6 expression in Sprague Dawley rat offspring

Adipose tissue macrophages (ATM) are implicated in adipose tissue inflammation and obesity-related insulin resistance. Maternal low protein models result in fetal programming of obesity. The study aims to answer whether maternal undernutrition by protein restriction affects the ATM M1 or M2 phenotype under postnatal high fat diet in F1 offspring. Using a rat model of prenatal low protein (LP, 8% protein) diet followed by a postnatal high fat energy diet (HE, 45% fat) or low fat normal energy diet (NE, 10% fat) for 12 weeks, we investigated the effects of these diets on adiposity, programming of the offspring ATM phenotype, and the associated inflammatory response in adipose tissue. Fat mass in newborn and 12-week old LP fed offspring was lower than that of normal protein (20%; NP) fed offspring; however, the adipose tissue growth rate was higher compared to the NP fed offspring. While LP did not affect the number of CD68⁺ or CD206⁺ cells in adipose tissue of NE offspring, it attenuated the number of these cells in offspring fed HE. In offspring fed HE, LP offspring had a lower percentage of CD11c⁺CD206⁺ ATMs, whose abundancy was correlated with the size of the adipocytes. Noteworthy, similar to HE treatment, LP increased gene expression of IL-6 within ATMs. Two-way ANOVA showed an interaction of prenatal LP and postnatal HE on IL-6 and IL-1β transcription. Overall, both LP and HE diets impact ATM phenotype by affecting the ratio of CD11c⁺CD206⁺ ATMs and the expression of IL-6.

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

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

Characterization of visceral and subcutaneous adipose tissue transcriptome in pregnant women with and without spontaneous labor at term: implication of alternative splicing in the metabolic adaptations of adipose tissue to parturition

OBJECTIVE

The aim of this study was to determine gene expression and splicing changes associated with parturition and regions (visceral vs. subcutaneous) of the adipose tissue of pregnant women.

STUDY DESIGN

The transcriptome of visceral and abdominal subcutaneous adipose tissue from pregnant women at term with (n=15) and without (n=25) spontaneous labor was profiled with the Affymetrix GeneChip Human Exon 1.0 ST array. Overall gene expression changes and the differential exon usage rate were compared between patient groups (unpaired analyses) and adipose tissue regions (paired analyses). Selected genes were tested by quantitative reverse transcription-polymerase chain reaction.

RESULTS

Four hundred and eighty-two genes were differentially expressed between visceral and subcutaneous fat of pregnant women with spontaneous labor at term (q-value <0.1; fold change >1.5). Biological processes enriched in this comparison included tissue and vasculature development as well as inflammatory and metabolic pathways. Differential splicing was found for 42 genes [q-value <0.1; differences in Finding Isoforms using Robust Multichip Analysis scores >2] between adipose tissue regions of women not in labor. Differential exon usage associated with parturition was found for three genes (LIMS1, HSPA5, and GSTK1) in subcutaneous tissues.

CONCLUSION

We show for the first time evidence of implication of mRNA splicing and processing machinery in the subcutaneous adipose tissue of women in labor compared to those without labor.

Maternal Macronutrient Intake during Pregnancy Is Associated with Neonatal Abdominal Adiposity: The Growing Up in Singapore Towards healthy Outcomes (GUSTO) Study

BACKGROUND

Infant body composition has been associated with later metabolic disease risk, but few studies have examined the association between maternal macronutrient intake and neonatal body composition. Furthermore, most of those studies have used proxy measures of body composition that may not reflect body fat distribution, particularly abdominal internal adiposity.

OBJECTIVE

We investigated the relation between maternal macronutrient intake and neonatal abdominal adiposity measured by using MRI in a multiethnic Asian mother-offspring cohort.

METHODS

The macronutrient intake of mothers was ascertained by using a 24-h dietary recall at 26-28 wk gestation. Neonatal abdominal adiposity was assessed by using MRI in week 2 of life. Mother-offspring dyads with complete macronutrient intake and adiposity information (n = 320) were included in the analysis. Associations were assessed by both substitution and addition models with the use of multivariable linear regressions.

RESULTS

Mothers (mean age: 30 y) consumed (mean ± SD) 15.5% ± 4.3% of their energy from protein, 32.4% ± 7.7% from fat, and 52.1% ± 9.0% from carbohydrate. A higher-protein, lower-carbohydrate or -fat diet during pregnancy was associated with lower abdominal internal adipose tissue (IAT) in the neonates [β (95% CI): -0.18 mL (-0.35, -0.001 mL) per 1% protein-to-carbohydrate substitution and -0.25 mL (-0.46, -0.04 mL) per 1% protein-to-fat substitution]. These associations were stronger in boys than in girls (P-interaction < 0.05). Higher maternal intake of animal protein, but not plant protein, was associated with lower offspring IAT. In contrast, maternal macronutrient intake was not associated consistently with infant anthropometric measurements, including abdominal circumference and subscapular skinfold thickness.

CONCLUSIONS

Higher maternal protein intake at the expense of carbohydrate or fat intake at 26-28 wk gestation was associated with lower abdominal internal adiposity in neonates. Optimizing maternal dietary balance might be a new approach to improve offspring body composition. This trial was registered at clinicaltrials.gov as NCT01174875.

Maternal high fructose and low protein consumption during pregnancy and lactation share some but not all effects on early-life growth and metabolic programming of rat offspring

Maternal nutritional stress during pregnancy acts to program offspring metabolism. We hypothesized that the nutritional stress caused by maternal fructose or low protein intake during pregnancy would program the offspring to develop metabolic aberrations that would be exacerbated by a diet rich in fructose or fat during adult life. The objective of this study was to characterize and compare the fetal programming effects of maternal fructose with the established programming model of a low-protein diet on offspring. Male offspring from Sprague-Dawley dams fed a 60% starch control diet, a 60% fructose diet, or a low-protein diet throughout pregnancy and lactation were weaned onto either a 60% starch control diet, 60% fructose diet, or a 30% fat diet for 15 weeks. Offspring from low-protein and fructose-fed dam showed retarded growth (P<.05) at weaning (50.3, 29.6 vs 59.1±0.8 g) and at 18 weeks of age (420, 369 vs 464±10.9 g). At 18 weeks of age, offspring from fructose dams expressed greater quantities (P<.05) of intestinal Pgc1a messenger RNA compared with offspring from control or low-protein dams (1.31 vs 0.89, 0.85; confidence interval, 0.78-1.04). Similarly, maternal fructose (P=.09) and low-protein (P<.05) consumption increased expression of Pgc1a in offspring liver (7.24, 2.22 vs 1.22; confidence interval, 2.11-3.45). These data indicate that maternal fructose feeding is a programming model that shares some features of maternal protein restriction such as retarded growth, but is unique in programming of selected hepatic and intestinal transcripts.

Low birth weight leads to obesity, diabetes and increased leptin levels in adults: the CoLaus study

BACKGROUND

Low birth weight is associated with increased rates of obesity, insulin resistance and type 2 diabetes, but the precise mechanisms for this association remain unclear. We aimed to assess the relationships between birth weight and markers of glucose homeostasis or obesity in adults.

METHODS

Cross-sectional population-based study on 1458 women and 1088 men aged 35-75 years living in Lausanne, Switzerland. Birth weight was self-reported and categorized into ≤ 2.5, 2.6-3.5, 3.6-4.0 and >4.0 kg. Body composition was assessed by bioimpedance. Leptin and adiponectin levels were measured by ELISA.

RESULTS

Women with low birth weight (≤ 2.5 kg) had higher levels of fasting plasma glucose, insulin, HOMA, diabetes and metabolic syndrome; a non significant similar trend was seen in men. In both genders, height increased with birth weight, whereas a U-shaped association was found between birth weight and body mass index, waist circumference and body fat percentage. After adjusting for age, smoking status, physical activity and fat mass, an inverse association was found between leptin and birth weight categories: adjusted mean ± standard error 17.3 ± 0.7, 16.2 ± 0.3, 15.6 ± 0.5 and 14.0 ± 0.8 ng/dL for birth weight categories ≤ 2.5, 2.6-3.5, 3.6-4.0 and >4.0 kg, respectively, in women (p < 0.05) and 9.8 ± 0.8, 9.1 ± 03, 7.8 ± 0.4 and 7.7 ± 0.5 ng/dL in men (p < 0.05). An inverse association was also found between reported birth weight and leptin to fat mass ratio: mean ± standard error 0.77 ± 0.04, 0.73 ± 0.02, 0.69 ± 0.03 and 0.62 ± 0.04 in women (p < 0.05); 0.46 ± 0.05, 0.45 ± 0.02, 0.39 ± 0.02 and 0.38 ± 0.03 in men (p < 0.05). No differences in adiponectin levels were found between birth weight groups.

CONCLUSIONS

Middle-aged adults born with a low weight present a higher prevalence of diabetes and obesity and also higher leptin levels and leptin to fat mass ratio than adults born with a normal weight. The higher leptin levels and leptin to fat mass ratio among adults born with a low weight might be related to nutritional factors during childhood or to the development of leptin resistance and/or higher leptin production by body fat unit. Subjects born with a low weight should be counselled regarding the risks of developing diabetes and/or cardiovascular disease.

Exposure to a Highly Caloric Palatable Diet During Pregestational and Gestational Periods Affects Hypothalamic and Hippocampal Endocannabinoid Levels at Birth and Induces Adiposity and Anxiety-Like Behaviors in Male Rat Offspring

Exposure to unbalanced diets during pre-gestational and gestational periods may result in long-term alterations in metabolism and behavior. The contribution of the endocannabinoid system to these long-term adaptive responses is unknown. In the present study, we investigated the impact of female rat exposure to a hypercaloric-hypoproteic palatable diet during pre-gestational, gestational and lactational periods on the development of male offspring. In addition, the hypothalamic and hippocampal endocannabinoid contents at birth and the behavioral performance in adulthood were investigated. Exposure to a palatable diet resulted in low weight offspring who exhibited low hypothalamic contents of arachidonic acid and the two major endocannabinoids (anandamide and 2-arachidonoylglycerol) at birth. Palmitoylethanolamide, but not oleoylethanolamide, also decreased. Additionally, pups from palatable diet-fed dams displayed lower levels of anandamide and palmitoylethanolamide in the hippocampus. The low-weight male offspring, born from palatable diet exposed mothers, gained less weight during lactation and although they recovered weight during the post-weaning period, they developed abdominal adiposity in adulthood. These animals exhibited anxiety-like behavior in the elevated plus-maze and open field test and a low preference for a chocolate diet in a food preference test, indicating that maternal exposure to a hypercaloric diet induces long-term behavioral alterations in male offspring. These results suggest that maternal diet alterations in the function of the endogenous cannabinoid system can mediate the observed phenotype of the offspring, since both hypothalamic and hippocampal endocannabinoids regulate feeding, metabolic adaptions to caloric diets, learning, memory, and emotions.

Wisp1 mediates Bmp3-stimulated mesenchymal stem cell proliferation

Adipose tissue expansion, resulting from adipocyte hyperplasia and/or hypertrophy, is a hallmark of obesity. Adipocytes are derived from mesenchymal stem cells (MSCs) through adipogenesis, a process involving three key steps: proliferation, commitment and differentiation. Although studies have elaborated on the mechanisms regulating adipocyte commitment and differentiation, the factors that control MSC proliferation remain largely unknown. Previously, we demonstrated that bone morphogenetic protein 3 (Bmp3), the expression of which was upregulated in our rat model of hyperplasic visceral adiposity, potently stimulated MSC proliferation. In the present study, we investigate the molecular target of Bmp3. We conducted DNA microarray analysis on MSCs treated with and without Bmp3 and identified WNT1-inducible signaling pathway protein 1 (Wisp1) as a differentially expressed gene, whose expression was upregulated 3.7-fold by Bmp3. Wisp1 is a proliferative agent in various non-adipose cell types and is implicated in adipogenesis. Therefore, we tested the hypothesis that Wisp1 mediates Bmp3 stimulation of MSC proliferation. We showed that Bmp3 increased the expression of Wisp1 as early as 3 h following Bmp3 treatment in MSCs. Importantly, the upregulated Wisp1 expression preceded Bmp3-induced MSC proliferation, as determined by [(3)H]-thymidine incorporation. Furthermore, treatment of MSCs with recombinant Wisp1 led to a concentration-dependent increase in [(3)H]-thymidine incorporation with a maximal increase of 300%. In addition, siRNA-mediated knockdown of Wisp1 expression attenuated Bmp3-induced MSC proliferation. Taken together, our present findings reveal Wisp1 as a novel target of Bmp3 and suggest that the Bmp3/Wisp1 signaling pathway play a key role in MSC proliferation, and consequently adipogenesis.

Characterization of Visceral and Subcutaneous Adipose Tissue Transcriptome and Biological Pathways in Pregnant and Non-Pregnant Women: Evidence for Pregnancy-Related Regional-Specific Differences in Adipose Tissue

Objective

The purpose of this study was to compare the transcriptome of visceral and subcutaneous adipose tissues between pregnant and non-pregnant women.

Study Design

The transcriptome of paired visceral and abdominal subcutaneous adipose tissues from pregnant women at term and matched non-pregnant women (n = 11) was profiled with the Affymetrix Human Exon 1.0 ST array. Differential expression of selected genes was validated with the use of quantitative reverse transcription–polymerase chain reaction.

Results

Six hundred forty-four transcripts from 633 known genes were differentially expressed (false discovery rate (FDR) <0.1; fold-change >1.5), while 42 exons from 36 genes showed differential usage (difference in FIRMA scores >2 and FDR<0.1) between the visceral and subcutaneous fat of pregnant women. Fifty-six known genes were differentially expressed between pregnant and non-pregnant subcutaneous fat and three genes in the visceral fat. Enriched biological processes in the subcutaneous adipose tissue of pregnant women were mostly related to inflammation.

Conclusion

The transcriptome of visceral and subcutaneous fat depots reveals pregnancy-related gene expression and splicing differences in both visceral and subcutaneous adipose tissue. Furthermore, for the first time, alternative splicing in adipose tissue has been associated with regional differences and human parturition.

Intrauterine Programming of Diabetes and Adiposity

The prevalence of diabetes and adiposity has increased at an alarming rate and together they contribute to the rise in morbidity and mortality worldwide. Genetic studies till date have succeeded in explaining only a proportion of heritability, while a major component remains unexplained. Early life determinants of future risk of these diseases are likely contributors to the missing heritability and thus have a significant potential in disease prevention. Epidemiological and animal studies show the importance of intrauterine and early postnatal environment in programming of the fetus to adverse metabolic outcomes and support the notion of Developmental Origins of Health and Disease (DOHaD). Emerging evidence highlights the role of epigenetic mechanisms in mediating effects of environmental exposures, which in certain instances may exhibit intergenerational transmission even in the absence of exposure. In this article, we will discuss the complexity of diabetes and increased adiposity and mechanisms of programming of these adverse metabolic conditions.

Maternal nutritional manipulations program adipose tissue dysfunction in offspring

Based on the concept of Developmental Origin of Health and Disease, both human and animal studies have demonstrated a close link between nutrient supply perturbations in the fetus or neonate (i.e., maternal undernutrition, obesity, gestational diabetes and/or rapid catch-up growth) and increased risk of adult-onset obesity. Indeed, the adipose tissue has been recognized as a key target of developmental programming in a sex-and depot-specific manner. Despite different developmental time windows, similar mechanisms of adipose tissue programming have been described in rodents and in bigger mammals (sheep, primates). Maternal nutritional manipulations reprogram offspring's adipose tissue resulting in series of alterations: enhanced adipogenesis and lipogenesis, impaired sympathetic activity with reduced noradrenergic innervations and thermogenesis as well as low-grade inflammation. These changes affect adipose tissue development, distribution and composition predisposing offspring to fat accumulation. Modifications of hormonal tissue sensitivity (i.e., leptin, insulin, glucocorticoids) and/or epigenetic mechanisms leading to persistent changes in gene expression may account for long-lasting programming across generations.

Early pharmacological inhibition of angiotensin-I converting enzyme activity induces obesity in adulthood

We have investigated early programming of body mass in order to understand the multifactorial etiology of obesity. Considering that the renin-angiotensin system (RAS) is expressed and functional in the white adipose tissue (WAT) and modulates its development, we reasoned whether early transitory inhibition of angiotensin-I converting enzyme activity after birth could modify late body mass development. Therefore, newborn Wistar rats were treated with enalapril (10 mg/kg of body mass) or saline, starting at the first day of life until the age of 16 days. Between days ninetieth and hundred and eightieth, a group of these animals received high fat diet (HFD). Molecular, biochemical, histological, and physiological data were collected. Enalapril treated animals presented hyperphagia, overweight, and increased serum level of triglycerides, total cholesterol and leptin, in adult life. Body composition analyses revealed higher fat mass with increased adipocyte size in these animals. Molecular analyses revealed that enalapril treatment increases neuropeptide Y (NPY) and cocaine- and amphetamine-regulated transcript (CART) gene expression in hypothalamus, fatty acid synthase (FAS), and hormone-sensitive lipase (HSL) gene expression in retroperitoneal WAT, and decreases peroxixome proliferators-activated receptor (PPAR)γ, PPARα, uncoupling protein (UCP)2, and UCP3 gene expression in WAT. The results of the current study indicate that enalapril administration during early postnatal development increases body mass, adiposity and serum lipids in adulthood associated with enhanced food intake and decreased metabolic activity in WAT, predisposing to obesity in adulthood.

Regulation of postnatal pancreatic Pdx1 and downstream target genes after gestational exposure to protein restriction in rats

The study carried out in our laboratory demonstrated that protein restriction (low protein, LP) during fetal and neonatal life alters pancreatic development and impairs glucose tolerance later in life. In this study, we examined the role of the transcription factorPdx1, a master regulator of β-cell differentiation and function along with its downstream target genes insulin,Glut2and glucokinase (GK). The role(s) of these genes and protein products on the pancreata of male offspring from mothers exposed to LP diets were assessed during gestation, weaning, and adult life. Pregnant rats were allocated to two dietary treatments: control (C) 20% protein diet or LP, 8% protein diet. At birth, offspring were divided into four groups: C received control diet all life, LP1 received LP diet all life, LP2 changed the LP diet to C at weaning, and LP3 switched to C after being exposed to LP during gestation only. Body weights (bw) were significantly (P<0.001) decreased in all LP groups at birth. At weaning, only the LP3 offspring had their body weight restored to control levels.Pdx1or any of thePdx1-target genes were similar in all diets at day 21. However, at d130Pdx1mRNA expression and protein abundance were significantly decreased (P<0.05) in all LP groups. In addition, insulin mRNA and protein were decreased in LP1 and LP3 groups compared with C,Glut2mRNA and GLUT2 protein levels were decreased in LP3 and GK did not change between groups. Intraperitoneal glucose tolerance test revealed impaired glucose tolerance in LP3 males, concomitant with decreased β-cell mass, islet area, and PDX1 nuclear protein localization. Collectively, this study suggests that restoring proteins in the diet after birth in LP offspring dramatically impairs glucose homeostasis in early adulthood, by alteringPdx1expression and downstream-target genes increasing the risk to develop type 2 diabetes.

Developmental programming: the role of growth hormone

Developmental programming of the fetus has consequences for physiologic responses in the offspring as an adult and, more recently, is implicated in the expression of altered phenotypes of future generations. Some phenotypes, such as fertility, bone strength, and adiposity are highly relevant to food animal production and in utero factors that impinge on those traits are vital to understand. A key systemic regulatory hormone is growth hormone (GH), which has a developmental role in virtually all tissues and organs. This review catalogs the impact of GH on tissue programming and how perturbations early in development influence GH function.

Sex-specific effects of low protein diet on in utero programming of renal G-protein coupled receptors

Intrauterine growth restriction (IUGR) is an important risk factor for development of hypertension, diabetes and the metabolic syndrome. Maternal low protein (LP) intake during rat pregnancy leads to IUGR in male and female offspring, although females may be resistant to the development of effect. Current evidence suggests that changes in the renin-angiotensin system (RAS) in utero contribute to this programmed hypertension, via sex-specific mechanisms. The previously orphaned G-protein coupled receptor (GPR91) was identified as a central player in the development of hypertension in adult mice, through a RAS-dependent pathway. However, whether the GPR91 pathway contributes to fetal programming is unknown. Furthermore, the nature of involvement of downstream modulators of the RAS including Gqα/11α and GαS has not been investigated in IUGR-LP rats. Therefore, we postulated that renal GPR91, in conjunction with RAS, is differentially impacted in a sex-specific manner from LP-induced IUGR rats. Pregnant Wistar rats were fed control (C, 20% protein) or LP (8% protein) diet until embryonic day 19 (E19) or postnatal d21. At E19, GPR91 protein and mRNA were increased in both male and female LP kidneys (P<0.05), whereas renin and angiotensin converting enzyme (ACE) were only increased in males (P=0.06 and P<0.05, respectively). On d21, AT1R and Gqα/11α were increased in LP males, while in LP females, AT2R protein was elevated and renin expression was decreased (P<0.05). This study demonstrates that in IUGR-LP rats, up regulation of GPR91 in fetal kidney is mirrored by increased ACE and renin in males. These in utero alterations, when combined with postnatal increases in AT1R-Gqα/11α specifically in male offspring, may predispose to the development of hypertension.

Diet, behavior and immunity across the lifespan

It is increasingly appreciated that perinatal events can set an organism on a life-long trajectory for either health or disease, resilience or risk. One early life variable that has proven critical for optimal development is the nutritional environment in which the organism develops. Extensive research has documented the effects of both undernutrition and overnutrition, with strong links evident for an increased risk for obesity and metabolic disorders, as well as adverse mental health outcomes. Recent work has highlighted a critical role of the immune system, in linking diet with long term health and behavioral outcomes. The present review will summarize the recent literature regarding the interactions of diet, immunity, and behavior.

Maternal protein intake during pregnancy and offspring overweight 20 y later

BACKGROUND

Animal studies have shown that protein intake in pregnancy may influence offspring fat metabolism and adiposity. The macronutrient ratio in human pregnancy appears to be important for offspring glucose tolerance; however, less is known about the influence on offspring adiposity.

OBJECTIVE

We examined the relation between maternal dietary protein intake during pregnancy and offspring anthropometric measures and biomarkers of adiposity and glucose metabolism.

DESIGN

We used a prospective cohort of 965 Danish pregnant women recruited in 1988-1989 with offspring follow-up at 19-21 y. Macronutrient intake was collected in gestational week 30, and we divided protein according to its source (animal and vegetable including cereals). Offspring body mass index (BMI; in kg/m(2)) and waist circumference were recorded at follow-up (n = 695-697), and biomarkers were quantified in a subset (n = 443) of participants. We used multivariable linear and log-binomial regression to calculate effect estimates and 95% CIs for a 1:1-g substitution of carbohydrates for protein.

RESULTS

Offspring mean (±SD) BMI was 22.1 ± 3.3 and 22.8 ± 2.9 for women and men, respectively. The prevalence of overweight (BMI ≥25) was 16.9% for women and 19.1% for men. We showed that a 1:1-g substitution of animal protein for carbohydrates increased risk of BMI ≥25 in female [quartile 4 compared with quartile 1: risk ratio (RR): 3.36; 95% CI: 1.52, 7.42] and male (quartile 4 compared with quartile 1: RR: 2.22; 95% CI: 0.92, 5.35) offspring. These results appeared to be accounted for by protein from meat sources. The results could not be explained by postnatal risk factors.

CONCLUSIONS

Protein from animal sources, primarily meat products, consumed during pregnancy may increase risk of overweight in offspring; this association appeared to be stronger for female offspring. Because of the lack of information on postnatal exposure in this cohort, these results are hypothesis-generating and need to be replicated in other cohorts.

The cellularity of offspring's adipose tissue is programmed by maternal nutritional manipulations

Epidemiological studies initially demonstrated that maternal undernutrition leads to low birth weight with increased risk of adult-onset obesity. Maternal obesity and diabetes associated with high birth weight, excessive nutrition in neonates, and rapid catch-up growth also predispose offspring to fat accumulation. As stated by the Developmental Origin of Health and Disease concept, nutrient supply perturbations in the fetus or neonate result in long-term programming of individual body weight set-point. Adipose tissue is a key fuel storage unit mainly involved in the maintenance of energy homeostasis. Studies in numerous animal models have demonstrated that the adipose tissue is the focus of developmental programming events in a gender- and depot-specific manner. This review summarizes the impact of maternal nutritional manipulations on cellularity (i.e., cell number, size, and type) of adipose tissue in programmed offspring. In rodents, adipose tissue development is particularly active during the perinatal period, especially during the last week of gestation and during early postnatal life. In contrast to rodents, this process essentially takes place before birth in bigger mammals. Despite these different developmental time windows, altricial and precocial species share several mechanisms of adipose tissue programming. Maternal nutritional manipulations result in increased adipogenesis and modified fat distribution and composition. Inflammation changes such as infiltration of macrophages and increased inflammatory markers are also observed. Overall, it may predispose offspring to fat accumulation and obesity. Inappropriate hormone levels, modified tissue sensitivity, and epigenetic mechanisms are key factors involved in the programming of adipose tissue's cellularity during the perinatal period.

Perinatal protein malnutrition affects mitochondrial function in adult and results in a resistance to high fat diet-induced obesity

Epidemiological findings indicate that transient environmental influences during perinatal life, especially nutrition, may have deleterious heritable health effects lasting for the entire life. Indeed, the fetal organism develops specific adaptations that permanently change its physiology/metabolism and that persist even in the absence of the stimulus that initiated them. This process is termed "nutritional programming". We previously demonstrated that mothers fed a Low-Protein-Diet (LPD) during gestation and lactation give birth to F1-LPD animals presenting metabolic consequences that are different from those observed when the nutritional stress is applied during gestation only. Compared to control mice, adult F1-LPD animals have a lower body weight and exhibit a higher food intake suggesting that maternal protein under-nutrition during gestation and lactation affects the energy metabolism of F1-LPD offspring. In this study, we investigated the origin of this apparent energy wasting process in F1-LPD and demonstrated that minimal energy expenditure is increased, due to both an increased mitochondrial function in skeletal muscle and an increased mitochondrial density in White Adipose Tissue. Importantly, F1-LPD mice are protected against high-fat-diet-induced obesity. Clearly, different paradigms of exposure to malnutrition may be associated with differences in energy expenditure, food intake, weight and different susceptibilities to various symptoms associated with metabolic syndrome. Taken together these results demonstrate that intra-uterine environment is a major contributor to the future of individuals and disturbance at a critical period of development may compromise their health. Consequently, understanding the molecular mechanisms may give access to useful knowledge regarding the onset of metabolic diseases.

Altered adipocyte structure and function in nutritionally programmed microswine offspring

Adipose tissue (AT) dysfunction links obesity of any cause with cardiometabolic disease, but whether early-life nutritional deficiency can program adipocyte dysfunction independently of obesity is untested. In 3-5-month-old juvenile microswine offspring exposed to isocaloric perinatal maternal protein restriction (MPR) and exhibiting accelerated prepubertal fat accrual without obesity, we assessed markers of acquired obesity: adiponectin and tumor necrosis factor (TNF)-α messenger ribonucleic acid (mRNA) levels and adipocyte size in intra-abdominal (ABD-AT) and subcutaneous (SC-AT) adipose tissues. Plasma cortisol, leptin and insulin levels were measured in fetal, neonatal and juvenile offspring. In juvenile low-protein offspring (LPO), adipocyte size in ABD-AT was reduced 22% (P = 0.011 v. controls), whereas adipocyte size in SC-AT was increased in female LPO (P = 0.05) and normal in male LPO; yet, adiponectin mRNA in LPO was low in both sexes and in both depots (P < 0.001). Plasma leptin (P = 0.004) and cortisol (P < 0.05) were reduced only in neonatal LPO during MPR. In juveniles, correlations between % body fat and adiponectin mRNA, TNF-α mRNA or plasma leptin were significant in normal-protein offspring (NPO) but absent in LPO. Plasma glucose in juvenile LPO was increased in males but decreased in females (interaction, P = 0.023); plasma insulin levels and insulin sensitivity were unaffected. Findings support nutritional programming of adipocyte size and gene expression and subtly altered glucose homeostasis. Reduced adiponectin mRNA and adipokine dysregulation in juvenile LPO following accelerated growth occurred independently of obesity, adipocyte hypertrophy or inflammatory markers; thus, perinatal MPR and/or growth acceleration can alter adipocyte structure and disturb adipokine homeostasis in metabolically adverse patterns predictive of enhanced disease risk.

Influence of birth weight and gender on lipid status and adipose tissue gene expression in lambs

Intrauterine growth restriction (IUGR) is a risk factor for obesity, particularly when offspring are born into an unrestricted nutritional environment. In this study, we investigated the impact of IUGR and gender on circulating lipids and on expression of adipogenic, lipogenic and adipokine genes in perirenal adipose tissue. Singleton lambs born to overnourished adolescent dams were normal birth weight (N) or IUGR (32% lower birth weight due to placental insufficiency). IUGR lambs exhibited increased fractional growth rates but remained smaller than N lambs at necropsy (d77). At 48 days, fasting plasma triglycerides, non-esterified fatty acids and glycerol were elevated predominantly in IUGR males. Body fat content was independent of prenatal growth but higher in females than in males. In perirenal fat, relative to male lambs, females had larger adipocytes; higher lipoprotein lipase, fatty acid synthase and leptin and lower IGF1, IGF2, IGF1R, IGF2R and hormone-sensitive lipase mRNA expression levels, and all were independent of prenatal growth category; peroxisome proliferator-activated receptor gamma and glycerol-3-phosphate dehydrogenase (G3PDH) mRNA expression were not affected by IUGR or gender. Adiposity indices were inversely related to G3PDH mRNA expression, and for the population as a whole the expression of IGF system genes in perirenal fat was negatively correlated with plasma leptin, fat mass and adipocyte size, and positively correlated with circulating IGF1 levels. Higher plasma lipid levels in IUGR males may predict later adverse metabolic health and obesity, but in early postnatal life gender has the dominant influence on adipose tissue gene expression, reflecting the already established sexual dimorphism in body composition.

Effect of photoperiod on the feline adipose transcriptome as assessed by RNA sequencing

Background

Photoperiod is known to cause physiological changes in seasonal mammals, including changes in body weight, physical activity, reproductive status, and adipose tissue gene expression in several species. The objective of this study was to determine the effects of day length on the adipose transcriptome of cats as assessed by RNA sequencing. Ten healthy adult neutered male domestic shorthair cats were used in a randomized crossover design study. During two 12-wk periods, cats were exposed to either short days (8 hr light:16 hr dark) or long days (16 hr light:8 hr dark). Cats were fed a commercial diet to maintain baseline body weight to avoid weight-related bias. Subcutaneous adipose biopsies were collected at wk 12 of each period for RNA isolation and sequencing.

Results

A total of 578 million sequences (28.9 million/sample) were generated by Illumina sequencing. A total of 170 mRNA transcripts were differentially expressed between short day- and long day-housed cats. 89 annotated transcripts were up-regulated by short days, while 24 annotated transcripts were down-regulated by short days. Another 57 un-annotated transcripts were also different between groups. Adipose tissue of short day-housed cats had greater expression of genes involved with cell growth and differentiation (e.g., myostatin; frizzled-related protein), cell development and structure (e.g., cytokeratins), and protein processing and ubiquitination (e.g., kelch-like proteins). In contrast, short day-housed cats had decreased expression of genes involved with immune function (e.g., plasminogen activator inhibitor 1; chemokine (C-C motif) ligand 2; C-C motif chemokine 5; T-cell activators), and altered expression of genes associated with carbohydrate and lipid metabolism.

Conclusions

Collectively, these gene expression changes suggest that short day housing may promote adipogenesis, minimize inflammation and oxidative stress, and alter nutrient metabolism in feline adipose tissue, even when fed to maintain body weight. Although this study has highlighted molecular mechanisms contributing to the seasonal metabolic changes observed in cats, future research that specifically targets and studies these biological pathways, and the physiological outcomes that are affected by them, is justified.

Early-life nutritional programming of longevity

Available data from both experimental and epidemiological studies suggest that inadequate diet in early life can permanently change the structure and function of specific organs or homoeostatic pathways, thereby ‘programming’ the individual’s health status and longevity. Sufficient evidence has accumulated showing significant impact of epigenetic regulation mechanisms in nutritional programming phenomenon. The essential role of early-life diet in the development of aging-related chronic diseases is well established and described in many scientific publications. However, the programming effects on lifespan have not been extensively reviewed systematically. The aim of the review is to provide a summary of research findings and theoretical explanations that indicate that longevity can be influenced by early nutrition.

Transgenerational effects of caloric restriction on appetite: a meta-analysis

Maternal undernutrition can result in significant alterations to the post-natal offspring phenotype, including body size and behaviour. For example, maternal food restriction has been implicated in offspring hyperphagia, potentially causing increased weight gain and fat accumulation. This could result in obesity and other adverse long-term health effects in offspring. We investigated the link between maternal caloric restriction during gestation and offspring appetite by conducting the first meta-analysis on this topic using experimental data from mammalian laboratory models (i.e. rats and mice). We collected 89 effect sizes from 35 studies, together with relevant moderators. Our analysis revealed weak and statistically non-significant overall effect on offspring's appetite. However, we found that lower protein content of restricted diets is associated with higher food intake in female offspring. Importantly, we show that a main source of variation among studies arises from whether, and how, food intake was adjusted for body mass. This probably explains many of the contradictory results in the field. Based on our results, we recommend using allometric scaling of food intake to body mass in future studies.