Maternal obesity upregulates fatty acid and glucose transporters and increases expression of enzymes mediating fatty acid biosynthesis in fetal adipose tissue depots

The Impact of Maternal Obesity on Adipose Progenitor Cells

The concept of Developmental Origin of Health and Disease (DOHaD) postulates that adult-onset metabolic disorders may originate from suboptimal conditions during critical embryonic and fetal programming windows. In particular, nutritional disturbance during key developmental stages may program the set point of adiposity and its associated metabolic diseases later in life. Numerous studies in mammals have reported that maternal obesity and the resulting accelerated growth in neonates may affect adipocyte development, resulting in persistent alterations in adipose tissue plasticity (i.e., adipocyte proliferation and storage) and adipocyte function (i.e., insulin resistance, impaired adipokine secretion, reduced thermogenesis, and higher inflammation) in a sex- and depot-specific manner. Over recent years, adipose progenitor cells (APCs) have been shown to play a crucial role in adipose tissue plasticity, essential for its development, maintenance, and expansion. In this review, we aim to provide insights into the developmental timeline of lineage commitment and differentiation of APCs and their role in predisposing individuals to obesity and metabolic diseases. We present data supporting the possible implication of dysregulated APCs and aberrant perinatal adipogenesis through epigenetic mechanisms as a primary mechanism responsible for long-lasting adipose tissue dysfunction in offspring born to obese mothers.

Developmental Programming in Animal Models: Critical Evidence of Current Environmental Negative Changes

The Developmental Origins of Health and Disease (DOHaD) approach answers questions surrounding the early events suffered by the mother during reproductive stages that can either partially or permanently influence the developmental programming of children, predisposing them to be either healthy or exhibit negative health outcomes in adulthood. Globally, vulnerable populations tend to present high obesity rates, including among school-age children and women of reproductive age. In addition, adults suffer from high rates of diabetes, hypertension, cardiovascular, and other metabolic diseases. The increase in metabolic outcomes has been associated with the combination of maternal womb conditions and adult lifestyle-related factors such as malnutrition and obesity, smoking habits, and alcoholism. However, to date, "new environmental changes" have recently been considered negative factors of development, such as maternal sedentary lifestyle, lack of maternal attachment during lactation, overcrowding, smog, overurbanization, industrialization, noise pollution, and psychosocial stress experienced during the current SARS-CoV-2 pandemic. Therefore, it is important to recognize how all these factors impact offspring development during pregnancy and lactation, a period in which the subject cannot protect itself from these mechanisms. This review aims to introduce the importance of studying DOHaD, discuss classical programming studies, and address the importance of studying new emerging programming mechanisms, known as actual lifestyle factors, during pregnancy and lactation.

Adult mice offspring of obese mothers supplemented with melatonin show lessened liver steatosis, inflammation, oxidative stress, and endoplasmic reticulum stress

AIMS

To investigate, in the liver of adult offspring, the possible effects of melatonin supplementation in the obese mother during pregnancy and lactation.

MAIN METHODS

C57BL/6 females were fed with a control (C) or a high-fat (HF) diet and supplemented with melatonin (Mel) during the pregnancy and lactation, forming the groups: C, CMel, HF, and HFMel. After weaning until three months old, the offspring only received the C diet.

KEY FINDINGS

The HF mothers and their offspring showed higher body weight (BW) than the C mothers and offspring. However, at 3-mo-old, BW was reduced in HFMel vs. HF offspring. Also, plasmatic and liver lipid markers increased in HF vs. C offspring but were reduced in HFMel vs. HF offspring. Liver lipid content was lessened in HFMel vs. HF offspring by 50 %. Also, lipid metabolism, pro-inflammatory and endoplasmic reticulum (ER) stress genes were higher expressed in HF vs. C offspring but reduced in HFMel vs. HF offspring. Contrarily, beta-oxidation and antioxidant enzyme genes were less expressed in HF vs. C offspring but improved in HFMel vs. HF offspring. Finally, AMPK/mTOR pathway genes, initially dysregulated in the HF, were restored in the HFMel offspring.

SIGNIFICANCE

The obese mother leads to liver alterations in the offspring. Current findings demonstrated the maternal melatonin supplementation during pregnancy and lactation in adult offspring's liver. Consequently, the effects were seen in mitigating the liver's AMPK/mTOR pathway genes, lipogenesis, beta-oxidation, inflammation, oxidative stress, and ER stress, preventing liver disease progression in the offspring.

Programming by maternal obesity: a pathway to poor cardiometabolic health in the offspring

There is an ever increasing prevalence of maternal obesity worldwide such that in many populations over half of women enter pregnancy either overweight or obese. This review aims to summarise the impact of maternal obesity on offspring cardiometabolic outcomes. Maternal obesity is associated with increased risk of adverse maternal and pregnancy outcomes. However, beyond this exposure to maternal obesity during development also increases the risk of her offspring developing long-term adverse cardiometabolic outcomes throughout their adult life. Both human studies and those in experimental animal models have shown that maternal obesity can programme increased risk of offspring developing obesity and adipose tissue dysfunction; type 2 diabetes with peripheral insulin resistance and β-cell dysfunction; CVD with impaired cardiac structure and function and hypertension via impaired vascular and kidney function. As female offspring themselves are therefore likely to enter pregnancy with poor cardiometabolic health this can lead to an inter-generational cycle perpetuating the transmission of poor cardiometabolic health across generations. Maternal exercise interventions have the potential to mitigate some of the adverse effects of maternal obesity on offspring health, although further studies into long-term outcomes and how these translate to a clinical context are still required.

Use of Agriculturally Important Animals as Models in Biomedical Research

Livestock have contributed significantly to advances in biomedicine and offer unique advantages over rodent models. The human is the ideal biomedical model; however, ethical reasons limit the testing of hypotheses and treatments in humans. Rodent models are frequently used as alternatives to humans due to size, low cost, and ease of genetic manipulation, and have contributed tremendously to our understanding of human health and disease. However, the use of rodents in translational research pose challenges for researchers due to physiological differences to humans. The use of livestock species as biomedical models can address these challenges as livestock have several similarities to human anatomy, physiology, genetics, and metabolism and their larger size permits collection of more frequent and often larger samples. Additionally, recent advances in genetics in livestock species allow for studies in genomics, proteomics, and metabolomics, which have the added benefit of applications to both humans in biomedical research and livestock in improving production. In this review, we provide an overview of scientific findings using livestock and benefits of each model to the livestock industry and to biomedical research.

Maternal Nutrition and Developmental Programming of Male Progeny

Simple Summary

The objective of the following review is to describe available literature on the interaction between maternal nutrition and developmental programming in male offspring. The majority of current research focuses on female offspring or fails to take offspring sex into account, though sexual dimorphisms in response to maternal diet are well-recognized. This leaves a large gap in the understanding of male developmental programming. This review will specifically discuss the impacts of maternal dietary energy and protein on bull and ram growth, development, and reproductive capacity in later life.

Abstract

Poor maternal nutrition can cause several maladaptive phenotypes in exposed offspring. While non-sex-specific and female-specific adaptations are well-documented, male-specific outcomes are still poorly understood. Of particular interest are the outcomes in bulls and rams, as developmental programming directly impacts long-term productivity of the animal as well as human food security. The following review discusses the impact of poor maternal dietary energy and protein on bull and ram developmental programming as it relates to growth, development, and reproductive capacity. The review also highlights the importance of the timing of maternal dietary insult, as early-, mid-, and late-gestational insults can all have varying effects on offspring.

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

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

Ovine prenatal growth-restriction and sex influence fetal adipose tissue phenotype and impact postnatal lipid metabolism and adiposity in vivo from birth until adulthood

Adipose tissue development begins in utero and is a key target of developmental programming. Here the influence of nutritionally-mediated prenatal growth-restriction on perirenal adipose tissue (PAT) gene expression and adipocyte phenotype in late fetal life was investigated in both sexes in an ovine model. Likewise circulating leptin concentrations and non-esterified fatty acid (NEFA) and glycerol responses to glucose challenge were determined in relation to offspring adiposity at key stages from birth to mid-adult life. In both studies' singleton-bearing adolescent sheep were fed control or high nutrient intakes to induce normal or growth-restricted pregnancies, respectively. Fetal growth-restriction at day 130 of gestation (32% lighter) was characterised by greater body-weight-specific PAT mass and higher PAT expression of peroxisome proliferator-activated receptor gamma (PPARɤ), glycerol-3-phosphate dehydrogenase, hormone sensitive lipase (HSL), insulin-like growth factor 1 receptor, and uncoupling protein 1. Independent of prenatal growth, females had a greater body-weight-specific PAT mass, more multilocular adipocytes, higher leptin and lower insulin-like growth factor 1 mRNA than males. Growth-restricted offspring of both sexes (42% lighter at birth) were characterised by higher plasma NEFA concentrations across the life-course (post-fasting and after glucose challenge at 7, 32, 60, 85 and 106 weeks of age) consistent with reduced adipose tissue insulin sensitivity. Circulating plasma leptin correlated with body fat percentage (females>males) and restricted compared with normal females had more body fat and increased abundance of PPARɤ, HSL, leptin and adiponectin mRNA in PAT at necropsy (109 weeks). Therefore, prenatal nutrient supply and sex both influence adipose tissue development with consequences for lipid metabolism and body composition persisting throughout the life-course.

Obesity in mares promotes uterine inflammation and alters embryo lipid fingerprints and homeostasis

Maternal body composition can be an important determinant for development of obesity and metabolic syndrome in adult offspring. Obesity-related outcomes in offspring may include epigenetic alterations; however, mechanisms of fetal programming remain to be fully elucidated. This study was conducted to determine the impact of maternal obesity in the absence of a high fat diet on equine endometrium and preimplantation embryos. Embryos were collected from normal and obese mares at 8 and 16 days and a uterine biopsy at 16 days (0 day = ovulation). With the exception of 8 day embryos, each sample was divided into two pieces. One piece was analyzed for gene expression markers related to carbohydrate metabolism, lipid homeostasis, inflammation, endoplasmic reticulum stress, oxidative stress, mitochondrial stress, and components of the insulin-like growth factor (IGF) system. The second piece was analyzed for lipid content using matrix-assisted laser desorption/ionization mass spectrometry. Obese mares had elevated concentrations of insulin, leptin, and total cholesterol, and they tended to have increased triglycerides and decreased insulin sensitivity. Embryos from obese mares had altered transcript abundance in genes for inflammation and lipid homeostasis, as well as endoplasmic reticulum, oxidative and mitochondrial stress and altered lipid fingerprints. Endometrium from obese mares had increased expression of inflammatory cytokines, lipid homeostasis regulation, mitochondrial stress, and the IGF2 system. This study demonstrates that increased adiposity in mares alters the uterine environment, transcript abundance of genes for cellular functions, and lipid profiles of embryos. These alterations could affect prenatal programming, with potential long-term effects in offspring.

The relationship between maternal adiposity during pregnancy and fetal kidney development and kidney function in infants: the Gomeroi gaaynggal study

Maternal obesity during pregnancy has a detrimental impact on offspring renal development and function. This is pertinent to Indigenous Australians as they are twice as likely as non-Indigenous Australians to develop chronic kidney disease (CKD). The aim of this study was to examine whether there was an association between maternal adiposity and fetal kidney growth in late gestation (>28 weeks) and kidney function in infants, <2.5 years of age, from the Gomeroi gaaynggal cohort. Pre-pregnancy body mass index (BMI) was recorded at the first prenatal visit and maternal adiposity indicators (percent body fat and visceral fat area) measured at >28 weeks gestation by bioelectrical impedance analysis. Fetal kidney structure was assessed by ultrasound. Renal function indicators (urinary albumin:creatinine and protein:creatinine) were measured in infants from a spot urine collection from nappies. Multiple linear regression and multi-level mixed effects linear regression models with clustering were used to account for repeated measures of urine. 147 mother-child pairs were examined. Estimated fetal weight (EFW), but not fetal kidney size, was positively associated with maternal adiposity and pre-pregnancy BMI. When adjusted for smoking, combined kidney volume relative to EFW was negatively associated with maternal percentage body fat. Infant kidney function was not influenced by maternal adiposity and pre-pregnancy BMI (n = 84 observations). Current findings show that Indigenous babies born to obese mothers have reduced kidney size relative to EFW. We suggest that these babies are experiencing a degree of glomerular hyperfiltration in utero, and therefore are at risk of developing CKD in later life, especially if their propensity for obesity is maintained. Although no impact on renal function was observed at <2.5 years of age, long-term follow-up of offspring is required to evaluate potential later life impacts.

Developmental Programming and Growth of Livestock Tissues for Meat Production

Maternal regulation of fetal development has consequences for growth and development of carcass tissues. Severely restricted fetal growth can reduce postnatal growth capacity, resulting in smaller-for-age animals that take longer to reach market weights but has little effect on feedlot efficiency or carcass and meat quality. Specific nutritional supplementation, particularly during later pregnancy, may limit fetal growth retardation and enhance postnatal growth capacity and carcass characteristics, and may improve development of intramuscular fat. Continued improvements in understanding developmental processes and their regulation will increase future capacity to improve growth, efficiency, carcasses, and meat quality through developmental programming.

Primate fetal hepatic responses to maternal obesity: epigenetic signalling pathways and lipid accumulation

KEY POINTS

Maternal obesity (MO) and exposure to a high-fat, high-simple-carbohydrate diet during pregnancy predisposes offspring to obesity, metabolic and cardiovascular disorders in later life. Underlying molecular pathways and potential epigenetic factors that are dysregulated in MO were identified using unbiased transcriptomic methods. There was increased lipid accumulation and severe steatosis in the MO baboon fetal liver suggesting that these offspring are on an early trajectory of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis.

ABSTRACT

Maternal obesity (MO) increases offspring cardiometabolic disease risk. Altered fetal liver development in response to the challenge of MO has metabolic consequences underlying adverse offspring life-course health outcomes. Little is known about the molecular pathways and potential epigenetic changes regulating primate fetal liver responses to MO. We hypothesized that MO would induce fetal baboon liver epigenetic changes resulting in dysregulation of key metabolic pathways that impact lipid metabolism. MO was induced prior to pregnancy by a high-fat, high-fructose diet. Unbiased gene and microRNA (small RNA Seq) abundance analyses were performed on fetal baboon livers at 0.9 gestation and subjected to pathway analyses to identify fetal liver molecular responses to MO. Fetal baboon liver lipid and glycogen content were quantified by the Computer Assisted Stereology Toolbox. In response to MO, fetal livers revealed dysregulation of TCA cycle, proteasome, oxidative phosphorylation, glycolysis and Wnt/β-catenin signalling pathways together with marked lipid accumulation supporting our hypothesis that multiple pathway dysregulation detrimentally impacts lipid management. This is the first study of MO programming of the non-human primate fetal liver using unbiased transcriptome analysis to detect changes in hepatic gene expression levels and identify potential microRNA epigenetic regulators of metabolic disruption.

Associations between maternal physical activity and fitness during pregnancy and infant birthweight

Prenatal physical activity (PA) reduces the risk of delivering infants with a birthweight ≥4000 g among normal-weight pregnant women, but evidence on the impact of maternal cardiorespiratory fitness (CRF) on birthweight remains equivocal among overweight or obese (OW/OB) pregnant women. The purpose of this study was to evaluate the relationship between maternal prenatal PA and CRF and birthweight in OW/OB pregnant women. Data from a randomized controlled exercise intervention trial in sedentary, OW/OB pregnant women were used. Women with complete data (n = 89) on birthweight, peak oxygen consumption (at 17 weeks), and daily PA were selected for analyses. Multiple linear regression models were performed to determine the independent and joint associations of maternal PA and CRF with birthweight while adjusting for gestational age, weight gain, and group allocation. On average, participants were 32 years old, OW/OB (BMI 29.97 ± 7.14 kg/m2), unfit (VO2peak: 19.85 ± 3.35 ml O2 kg-1 min-1), and led low active lifestyles (6579.91 ± 2379.17 steps/day). Analyses showed that maternal PA (steps·day-1·month-1) (β = 0.03 g, 95% CI: -0.03, 0.08 g) and CRF (ml O2·kg-1·min-1) (β = -8.8 g, 95%CI: -42.2, 24.5 g) were neither independently nor jointly (β = 0.006 g, 95%CI: -0.005, 0.02 g) associated with birthweight. Maternal PA and CRF during pregnancy were not related to birthweight in OW/OB pregnant women. The limited variability in maternal PA and CRF and low dose of PA may explain the null findings of this study. Given the paucity of studies examining these relationships in OW/OB pregnant women, more research is warranted.

Effects of maternal obesity on maternal and fetal plasma concentrations of adiponectin and expression of adiponectin and its receptor genes in cotyledonary and adipose tissues at mid- and late-gestation in sheep

Adiponectin potentially influences fetal weight by altering insulin signaling and trans-placental amino acid and glucose transporters. The objective of this study was to determine how maternal obesity influences maternal and fetal plasma concentrations of adiponectin, expression of fetal adiponectin, its receptors, and adipogenic genes at mid- and late-gestation. Blood samples and tissues were collected from obese and control multiparous pregnant ewes at day 75 or 135 of gestation. Although day of gestation or maternal obesity did not influence (P >  0.6) maternal plasma concentrations of adiponectin, fetal weight was increased (P <  0.001) and adiponectin tended to decrease (P =  0.10) at mid-gestation in fetuses from obese ewes. Differences were not apparent at late-gestation (P > 0.70). Relative abundance of adiponectin (P =  0.01), AdipoR2 (P =  0.04) and PPARγ (P =  0.01) mRNA was less at mid-gestation in fetal adipose tissue from obese mothers. By late gestation, maternal obesity tended to associated with a decrease in relative abundance of adiponectin (P =  0.09) and SREBF1 (P =  0.10) mRNA in fetal adipose tissue. Maternal obesity did not influence (P ≥  0.20) the relative abundance of adiponectin, AdipoR1 and AdipoR2 mRNA in cotyledonary tissue at mid or late- gestation. In conclusion, maternal obesity in sheep influences relative abundance of fetal adipose tissue mRNA for adiponectin and adipogenic, as well as plasma concentrations of total adiponectin. Although adiposity in pregnant ewes did not influence maternal adiponectin, maternal obesity potentially influenced fetal adipogenesis by altering the abundance of adiponectin, PPARγ and SREBF1 mRNA in fetal adipose tissue.

Cell-Specific "Competition for Calories" Drives Asymmetric Nutrient-Energy Partitioning, Obesity, and Metabolic Diseases in Human and Non-human Animals

The mammalian body is a complex physiologic “ecosystem” in which cells compete for calories (i.e., nutrient-energy). Axiomatically, cell-types with competitive advantages acquire a greater number of consumed calories, and when possible, increase in size and/or number. Thus, it is logical and parsimonious to posit that obesity is the competitive advantages of fat-cells (adipocytes) driving a disproportionate acquisition and storage of nutrient-energy. Accordingly, we introduce two conceptual frameworks. Asymmetric Nutrient-Energy Partitioning describes the context-dependent, cell-specific competition for calories that determines the partitioning of nutrient-energy to oxidation, anabolism, and/or storage; and Effective Caloric Intake which describes the number of calories available to constrain energy-intake via the inhibition of the sensorimotor appetitive cells in the liver and brain that govern ingestive behaviors. Inherent in these frameworks is the independence and dissociation of the energetic demands of metabolism and the neuro-muscular pathways that initiate ingestive behaviors and energy intake. As we demonstrate, if the sensorimotor cells suffer relative caloric deprivation via asymmetric competition from other cell-types (e.g., skeletal muscle- or fat-cells), energy-intake is increased to compensate for both real and merely apparent deficits in energy-homeostasis (i.e., true and false signals, respectively). Thus, we posit that the chronic positive energy balance (i.e., over-nutrition) that leads to obesity and metabolic diseases is engendered by apparent deficits (i.e., false signals) driven by the asymmetric inter-cellular competition for calories and concomitant differential partitioning of nutrient-energy to storage. These frameworks, in concert with our previous theoretic work, the Maternal Resources Hypothesis, provide a parsimonious and rigorous explanation for the rapid rise in the global prevalence of increased body and fat mass, and associated metabolic dysfunctions in humans and other mammals inclusive of companion, domesticated, laboratory, and feral animals.

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.

Effect of maternal high-fat diet on key components of the placental and hepatic endocannabinoid system

Maternal obesity in pregnancy has been linked to a spectrum of adverse developmental changes. Involvement of eCBs in obesity is well characterized. However, information regarding eCB physiology in obesity associated with pregnancy is sparse. This study evaluated fetomaternal hepatic, systemic, and placental eCB molecular changes in response to maternal consumption of a HFD. From ≥9 mo before conception, nonpregnant baboons ( Papio spp.) were fed a diet of either 45 (HFD; n = 11) or 12% fat or a control diet (CTR; n = 11), and dietary intervention continued through pregnancy. Maternal and fetal venous plasma samples were evaluated using liquid chromatography-mass spectrometry to quantify AEA and 2-AG. Placental, maternal and fetal hepatic tissues were analyzed using RT-PCR, Western blot, and immunohistochemistry. mRNA and protein expression of endocannabinoid receptors (CB1R and CB2R), FAAH, DAGL, MAGL, and COX-2 were determined. Statistical analyses were performed with the nonparametric Scheirer-Ray-Hare extension of the Kruskal-Wallis test to analyze the effects of diet (HFD vs. CTR), fetal sex (male vs. female), and the diet × sex interaction. Fetal weight was influenced by fetal sex but not by maternal diet. The increase in maternal weight in animals fed the HFD vs. the CTR diet approached significance ( P = 0.055). Maternal circulating 2-AG concentrations increased, and fetal circulating concentrations decreased in the HFD group, independently of fetal sex. CB1R receptor expression was detected in syncytiotrophoblasts (HFD) and the fetal endothelium (CTR and HFD). Placental CB2R protein expression was higher in males and lower in female fetuses in the HFD group. Fetal hepatic CB2R, FAAH, COX-2 (for both fetal sexes), and DAGLα (in male fetuses) protein expression decreased in the HFD group compared with the CTR group. We conclude that consumption of a HFD during pregnancy results in fetal systemic 2-AG and hepatic eCB deficiency.

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.

Manipulation of the Growth Hormone-Insulin-Like Growth Factor (GH-IGF) Axis: A Treatment Strategy to Reverse the Effects of Early Life Developmental Programming

Evidence from human clinical, epidemiological, and experimental animal models has clearly highlighted a link between the early life environment and an increased risk for a range of cardiometabolic disorders in later life. In particular, altered maternal nutrition, including both undernutrition and overnutrition, spanning exposure windows that cover the period from preconception through to early infancy, clearly highlight an increased risk for a range of disorders in offspring in later life. This process, preferentially termed “developmental programming” as part of the developmental origins of health and disease (DOHaD) framework, leads to phenotypic outcomes in offspring that closely resemble those of individuals with untreated growth hormone (GH) deficiency, including increased adiposity and cardiovascular disorders. As such, the use of GH as a potential intervention strategy to mitigate the effects of developmental malprogramming has received some attention in the DOHaD field. In particular, experimental animal models have shown that early GH treatment in the setting of poor maternal nutrition can partially rescue the programmed phenotype, albeit in a sex-specific manner. Although the mechanisms remain poorly defined, they include changes to endothelial function, an altered inflammasome, changes in adipogenesis and cardiovascular function, neuroendocrine effects, and changes in the epigenetic regulation of gene expression. Similarly, GH treatment to adult offspring, where an adverse metabolic phenotype is already manifest, has shown efficacy in reversing some of the metabolic disorders arising from a poor early life environment. Components of the GH-insulin-like growth factor (IGF)-IGF binding protein (GH-IGF-IGFBP) system, including insulin-like growth factor 1 (IGF-1), have also shown promise in ameliorating programmed metabolic disorders, potentially acting via epigenetic processes including changes in miRNA profiles and altered DNA methylation. However, as with the use of GH in the clinical setting of short stature and GH-deficiency, the benefits of treatment are also, in some cases, associated with potential unwanted side effects that need to be taken into account before effective translation as an intervention modality in the DOHaD context can be undertaken.

Conjugated Linoleic Acid Supplementation Improves Maternal High Fat Diet-Induced Programming of Metabolic Dysfunction in Adult Male Rat Offspring

The developmental origins of health and disease hypothesis proposes that an adverse early life environment, including in utero exposure to a maternal obesogenic environment, can lead to an increased long-term risk of obesity and related metabolic complications in offspring. We assessed whether maternal supplementation with conjugated linoleic acid (CLA) could prevent some of these adverse effects in offspring exposed to a maternal high fat diet. Sprague-Dawley dams consumed either a: control (CD), control with CLA (CLA), high fat (HF) or high fat with CLA (HFCLA) diet 10 days prior to mating and throughout pregnancy/lactation. Male offspring were weaned onto a standard chow diet. Body composition was quantified by DXA and oral glucose tolerance tests conducted on adult offspring. Gene/protein expression and histological analysis were conducted in adipose tissue. Offspring from HF dams had increased body weight, body fat deposition, impaired insulin sensitivity and adipocyte hypertrophy; all of which were rescued in HFCLA offspring. Molecular and histological analyses of the adipose tissue suggest that disturbances in adipogenesis may mediate the metabolic dysfunction observed in HF offspring. Therefore, CLA supplementation to a maternal obesogenic diet may be a promising strategy to prevent adverse programming outcomes.

Effects of maternal nutrient restriction during early or mid-gestation without realimentation on maternal physiology and foetal growth and development in beef cattle

The aim of this study is to determine the effects of early and mid-gestation nutrient restriction on maternal metabolites and foetal growth. Primiparous Angus cows were synchronized and inseminated with semen from one sire. Dietary treatments were: control to gain 1 kg/week (CON) or 0.55% maintenance energy and CP requirements (nutrient restricted; NR). A subset of dams was fed NR (n=8) or CON (n=8) from days 30 to 110 of gestation. Another group was fed CON (n=8), days 30 to 190; NR (n=7), days 30 to 110 followed by CON days 110 to 190; or CON, (n=7) days 30 to 110 followed by NR days 110 to 190. Cows were harvested at days 110 or 190 of gestation, when foetal measurements and samples were collected. Cows that were NR during days 30 to 110 or 110 to 190 of gestation lost significant BW and body condition score (P<0.001), this was associated with reduced plasma glucose during NR (P<0.002). Foetal weights, empty foetal weights, abdominal and thoracic circumferences were all reduced (P<0.03) in day 110 NR animals. Foetal perirenal adipose as a percentage of empty foetal weight was increased (P=0.01) in NR day 110 female foetuses compared with CON foetus. Maternal serum triglycerides at day 110 of gestation were decreased (P<0.05) in NR dams, whereas foetal serum triglycerides were increased (P<0.05) in response to maternal NR. Foetal weights tended to be reduced (P=0.08) in NR/CON and CON/NR v. CON/CON cattle at day 190 of gestation. Empty foetal weights, abdominal and thoracic circumferences were reduced (P⩽0.03) in NR/CON and CON/NR v. CON/CON cattle. Brain weight as a percentage of empty foetal weight was increased (P<0.001) in NR/CON and CON/NR v. CON/CON cattle. Foetal perirenal adipose as a percentage of empty foetal weight was increased (P=0.003) in NR/CON and CON/NR v. CON/CON cattle. Maternal serum triglycerides at day 190 of gestation were decreased (P<0.05) in association with maternal NR. Foetal serum triglycerides at day 190 of gestation were increased (P<0.05) in response to maternal NR during early gestation but decreased by NR in mid gestation compared with CON foetuses. The data show that maternal nutrient restriction during early or mid-gestation cause's asymmetrical foetal growth restriction, regardless if the restriction is preceded or followed by a period of non-restriction.

Experimental Models of Maternal Obesity and Neuroendocrine Programming of Metabolic Disorders in Offspring

Evidence from epidemiological, clinical, and experimental studies have clearly shown that disease risk in later life is increased following a poor early life environment, a process preferentially termed developmental programming. In particular, this work clearly highlights the importance of the nutritional environment during early development with alterations in maternal nutrition, including both under- and overnutrition, increasing the risk for a range of cardiometabolic and neurobehavioral disorders in adult offspring characterized by both adipokine resistance and obesity. Although the mechanistic basis for such developmental programming is not yet fully defined, a common feature derived from experimental animal models is that of alterations in the wiring of the neuroendocrine pathways that control energy balance and appetite regulation during early stages of developmental plasticity. The adipokine leptin has also received significant attention with clear experimental evidence that normal regulation of leptin levels during the early life period is critical for the normal development of tissues and related signaling pathways that are involved in metabolic and cardiovascular homeostasis. There is also increasing evidence that alterations in the epigenome and other underlying mechanisms including an altered gut-brain axis may contribute to lasting cardiometabolic dysfunction in offspring. Ongoing studies that further define the mechanisms between these associations will allow for identification of early risk markers and implementation of strategies around interventions that will have obvious beneficial implications in breaking a programmed transgenerational cycle of metabolic disorders.

Persistent influence of maternal obesity on offspring health: Mechanisms from animal models and clinical studies

The consequences of excessive maternal weight and adiposity at conception for the offspring are now well recognized. Maternal obesity increases the risk of overweight and obesity even in children born with appropriate-for-gestational age (AGA) birth weights. Studies in animal models have employed both caloric excess and manipulation of macronutrients (especially high-fat) to mimic hypercaloric intake present in obesity. Findings from these studies show transmission of susceptibility to obesity, metabolic dysfunction, alterations in glucose homeostasis, hepatic steatosis, skeletal muscle metabolism and neuroendocrine changes in the offspring. This review summarizes the essential literature in this area in both experimental and clinical domains and focuses on the translatable aspects of these experimental studies. Moreover this review highlights emerging mechanisms broadly explaining maternal obesity-associated developmental programming. The roles of early developmental alterations and placental adaptations are also reviewed. Increasing evidence also points to changes in the epigenome and other emerging mechanisms such as alterations in the microbiome that may contribute to persistent changes in the offspring. Finally, we examine potential interventions that have been employed in clinical cohorts.

Maternal, fetal and perinatal alterations associated with obesity, overweight and gestational diabetes: an observational cohort study (PREOBE)

Background

Maternal overweight, obesity, and gestational diabetes (GD) have been negatively associated with offspring development. Further knowledge regarding metabolic and nutritional alterations in these mother and their offspring are warranted.

Methods

In an observational cohort study we included 331 pregnant women from Granada, Spain. The mothers were categorized into four groups according to BMI and their GD status; overweight (n:56), obese (n:64), GD (n:79), and healthy normal weight controls (n:132). We assessed maternal growth and nutritional biomarkers at 24 weeks (n = 269), 34 weeks (n = 310) and at delivery (n = 310) and the perinatal characteristics including cord blood biomarkers.

Results

Obese and GD mothers had significantly lower weight gain during pregnancy and infant birth weight, waist circumference, and placental weight were higher in the obese group, including a significantly increased prevalence of macrosomia. Except for differences in markers of glucose metabolism (glucose, HbA1c, insulin and uric acid) we found at some measures that overweight and/or obese mothers had lower levels of transferrin saturation, hemoglobin, Vitamin B12 and folate and higher levels of C-reactive protein, erythrocyte sedimentation rate, ferritin, and cortisol. GD mothers had similar differences in hemoglobin and C-reactive protein but higher levels of folate. The latter was seen also in cord blood.

Conclusions

We identified several metabolic alterations in overweight, obese and GD mothers compared to controls. Together with the observed differences in infant anthropometrics, these may be important biomarkers in future research regarding the programming of health and disease in children.

Trial registration

The trial was registered at clinicaltrials.gov, identifier (NCT01634464).

The early origins of obesity and insulin resistance: timing, programming and mechanisms

Maternal obesity is associated with an increased risk of developing gestational diabetes mellitus and it also results in an increased risk of giving birth to a large baby with increased fat mass. Furthermore, it is also contributes to an increased risk of obesity and insulin resistance in the offspring in childhood, adolescence and adult life. It has been proposed that exposure to maternal obesity may therefore result in an 'intergenerational cycle' of obesity and insulin resistance. There is significant interest in whether exposure to maternal obesity around the time of conception alone contributes directly to poor metabolic outcomes in the offspring and whether dieting in the obese mother before pregnancy or around the time of conception has metabolic benefits for the offspring. This review focusses on experimental and clinical studies that have investigated the specific impact of exposure to maternal obesity during the periconceptional period alone or extending beyond conception on adipogenesis, lipogenesis and on insulin signalling pathways in the fat, liver and muscle of the offspring. Findings from these studies highlight the need for a better evidence base for the development of dietary interventions in obese women before pregnancy and around the time of conception to maximize the metabolic benefits and minimize the metabolic costs for the next generation.

The effect of maternal nutrition level during mid-gestation on postnatal muscle fibre composition and meat quality in lambs

Maternal nutrient intake during early- and mid-gestation can alter fetal growth and development with long-term consequences on the postnatal productivity and health of offspring. The aim of this study was to investigate the effects of maternal nutrition level during mid-gestation on postnatal growth rate, carcass composition, muscle fibre characteristics and meat quality in lambs. Ewes were fed from Days 30 to 80 of gestation as follows: 100% (control group, C), 50% (undernutrition, UN) or 175% (overnutrition, ON) of their daily requirement. During the rest of the gestation, the ewes in all groups were fed 100% of their daily requirements. Birth and weaning (at Day 90) weights of lambs born to ewes in nutritional groups were similar, but slaughter weights (at Day 150) and daily weight gain during finishing period of lambs born to the UN group were lower (P < 0.05). Similarly, a decrease in weights of semitendinosus (ST), semimembranosus and gastrocnemius muscles was observed in the lambs born to the UN group (P < 0.05). Lambs born to the ON group had a higher (P < 0.05) concentration of DNA in longissimus dorsi (LD) and ST muscles than UN groups, but they had a lower (P < 0.05) total protein and other proteins concentrations in LD and ST muscles than those to C and UN groups. Protein to DNA ratio in LD and ST muscles of lambs born to ON group were lower than those to C and UN groups (P < 0.05). However, lambs born to the ON group had a higher number of Type IIA and IIB muscle fibres in ST muscles but not in LD muscles than those in the C and UN groups (P < 0.05). Additionally an increase in the number of fibres/mm2 muscle area in lambs born to the ON group was observed in LD and ST muscles (P < 0.05). There were no significant differences between treatment groups in terms of meat quality parameters studied. This study confirms that maternal nutrition level during mid-gestation alters the postnatal growth and muscle fibre development of lambs.

Prenatal origins of postnatal variation in growth, development and productivity of ruminants

This review provides an update on recent research into the effects of maternal nutrition on fetal biology and the growth, development and productivity of progeny in postnatal life of ruminant livestock. Evidence is summarised for effects on postnatal growth and body composition, feed intake and efficiency, carcass characteristics and meat quality, wool production, reproduction and lactation performance. In general, these demonstrated effects are not large in relation to the effects of postnatal nutrition and other environmental influences. The mechanisms underpinning the above production outcomes are briefly discussed in terms of systemic endocrine and metabolic responses, and cellular and molecular effects in skeletal muscle, bone, adipose tissue, wool follicles and brain of fetal, neonatal and adult progeny. Treatments observed to elicit tissue responses include maternal under- and overnutrition at various stages of pregnancy and placental insufficiency caused by increased litter size, chronic maternal heat stress and premating carunclectomy in sheep. The as yet meagre evidence for epigenetic mediation of intergenerational effects in ruminants is considered, as is the likelihood that other, more conventional explanations may suffice in some cases. Finally, evidence is summarised for the proposition that the placenta is not merely a passive conduit for nutrient transfer from dam to fetus, but plays an active role in buffering the effects of variations in maternal nutrition on fetal growth and development, and thence, postnatal outcomes.

Maternal obesity disrupts the methionine cycle in baboon pregnancy

Maternal intake of dietary methyl-micronutrients (e.g. folate, choline, betaine and vitamin B-12) during pregnancy is essential for normal maternal and fetal methionine metabolism, and is critical for important metabolic processes including those involved in developmental programming. Maternal obesity and nutrient excess during pregnancy influence developmental programming potentially predisposing adult offspring to a variety of chronic health problems. In the present study, we hypothesized that maternal obesity would dysregulate the maternal and fetal methionine cycle. To test this hypothesis, we developed a nulliparous baboon obesity model fed a high fat, high energy diet (HF-HED) prior to and during gestation, and examined methionine cycle biomarkers (e.g., circulating concentrations of homocysteine, methionine, choline, betaine, key amino acids, folate, and vitamin B-12). Animals were group housed allowing full physical activity and social interaction. Maternal prepregnancy percent body fat was 5% in controls and 19% in HF-HED mothers, while fetal weight was 16% lower in offspring of HF-HED mothers at term. Maternal and fetal homocysteine were higher, while maternal and fetal vitamin B-12 and betaine were lower in the HF-HED group. Elevations in circulating maternal folate were evident in the HF-HED group indicating impaired folate metabolism (methyl-trap) as a consequence of maternal vitamin B-12 depletion. Finally, fetal methionine, glycine, serine, and taurine were lower in the HF-HED fetuses. These data show that maternal obesity disturbs the methionine cycle in primate pregnancy, providing a mechanism for the epigenetic changes observed among obese pregnant women and suggesting diagnostic and therapeutic opportunities in human pregnancies complicated by obesity.

Neonatal streptozotocin-induced diabetes in mothers promotes metabolic programming of adipose tissue in male rat offspring

AIMS

Maternal hyperglycemia during pregnancy can lead to fetal changes, like macrosomia or obesity in adultlife. Experimentalmodels of diabetes have been studied to evaluate the consequences of offspring lipidmetabolism. This study aimed to investigate the metabolic changes in adipose tissue of offspring of streptozotocininduced diabetic mothers during neonatal period.

MAIN METHODS

Diabetes was induced in female rats by streptozotocin administration on 5th day of life. In adulthood, female rats were bred with control male rats. Male puppies were sacrificed on 12th week of life and epididymal (EP) and subcutaneous (SC) adipose fat pads were excised and weighted. Adipocytes were isolated and evaluated for basal and insulin-stimulated 2-deoxyglucose uptake, oxidation of glucose into CO2, and incorporationof glucose into lipids and lipolytic capacity.

KEY FINDINGS

Bodyweight, EP fat padweight and diameter of adipocytes fromoffspring of diabeticmothers were increased in comparison to offspring of control mothers. EP adipocytes from offspring of diabetic mothers presented increased basal and insulin stimulated glucose uptake in comparison to control ones. Similar pattern was observed for glucose oxidation into CO2 and incorporation into lipids. However, significant difference in lipolytic capacity in vitrowas not observed. Protein content of GLUT4, insulin receptor and acetyl-CoA carboxylase was significantly increased in EP fat pad of offspring of diabetic mothers in relation to control group.

SIGNIFICANCE

Metabolic programming occurred in the adipose tissue of offspring of diabetic mothers, increasing its capacity to store lipids with no changes in lipolytic capacity.

Programming of obesity and comorbidities in the progeny: lessons from a model of diet-induced obese parents

Aim

To determine the impact of paternal obesity, maternal obesity or the combination of two obese parents on markers of adult offspring metabolism, with a focus on body mass (BM), lipid and carbohydrate, components of lipogenesis and beta-oxidation in the liver, sex dimorphism in the offspring that received a SC diet during the postnatal period.

Materials and Methods

Male and female C57BL/6 mice were fed a high-fat diet (HF; 49% lipids) or standard chow (SC; 17% lipids) for 8 weeks before mating until lactation. The offspring were labeled according to sex, maternal diet (first letters), paternal diet (second letters), and received a SCdiet until 12-weeks of age when they were sacrificed. BM, eating behavior, glucose tolerance, plasma analysis, gene and protein expression of the components of lipogenesis and beta-oxidation in the liver of offspring were evaluated.

Results

HF diet-fed mothers and fathers were overweight, hyperglycemic and glucose intolerant and had a deteriorating lipid profile. The adult male and female offspring of HF-mothers were overweight, with an increased adiposity index, hyperphagic, had an impaired glucose metabolism, increased total cholesterol and triacylglycerol levels, increased lipogenesis concomitant with decreased beta-oxidation resulting in liver steatosis. The male and female offspring of HF-father had impaired glucose metabolism, exacerbated lipogenesis without influencing beta-oxidation and enhanced hepatic steatosis. These findings are independent of BM. Male and female offspring of a mother and father that received a HF diet demonstrated these effects most prominently in adult life.

Conclusion

Paternal obesity leads to alterations in glucose metabolism, increase in components of lipogenesis and liver steatosis. In contrast, maternal obesity leads to overweight and changes in the metabolic profile and liver resulting from activation of hepatic lipogenesis with impaired beta-oxidation. When both parents are obese, the effects observed in the male and female offspring are exacerbated.

Maternal obesity in sheep increases fatty acid synthesis, upregulates nutrient transporters, and increases adiposity in adult male offspring after a feeding challenge

Maternal obesity in women is increasing worldwide. The objective of this study was to evaluate differences in adipose tissue metabolism and function in adult male offspring from obese and control fed mothers subjected to an ad libitum feeding challenge. We developed a model in which obese ewes were fed 150% of feed provided for controls from 60 days before mating to term. All ewes were fed to requirements during lactation. After weaning, F1 male offspring were fed only to maintenance requirements until adulthood (control = 7, obese = 6), when they were fed ad libitum for 12 weeks with intake monitored. At the end of the feeding challenge offspring were given an intravenous glucose tolerance test (IVGTT), necropsied, and adipose tissue collected. During the feeding trial F1obese males consumed more (P < 0.01), gained more weight (P < 0.01) and became heavier (P < 0.05) than F1control males. During IVGTT, Obese F1 offspring were hyperglycemic and hypoinsulinemic (P < 0.01) compared to F1 control F1. At necropsy perirenal and omental adipose depots weights were 47% and 58% greater respectively and subcutaneous fat thickness 41% greater in F1obese vs F1control males (P < 0.05). Adipocyte diameters were greater (P ≤ 0.04) in perirenal, omental and subcutaneous adipose depots in F1obese males (11, 8 and 7% increase vs. control, respectively). When adipose tissue was incubated for 2 hrs with C-14 labeled acetate, subcutaneous, perirenal, and omental adipose tissue of F1 obese males exhibited greater incorporation (290, 83, and 90% increase vs. control, respectively P < 0.05) of acetate into lipids. Expression of fatty acid transporting, binding, and syntheses mRNA and protein was increased (P < 0.05) compared to F1 control offspring. Maternal obesity increased appetite and adiposity associated with increased adipocyte diameters and increased fatty acid synthesis in over-nourished adult male offspring.

Offspring subcutaneous adipose markers are sensitive to the timing of maternal gestational weight gain

BACKGROUND

Excessive maternal weight gain during pregnancy impacts on offspring health. This study focused on the timing of maternal gestational weight gain, using a porcine model with mothers of normal pre-pregnancy weight.

METHODS

Trial design ensured the trajectory of maternal gestational weight gain differed across treatments in early, mid and late gestation. Diet composition did not differ. On day 25 gestation, sows were assigned to one of five treatments: Control sows received a standard gestation diet of 2.3 kg/day (30 MJ DE/day) from early to late gestation (day 25-110 gestation). E sows received 4.6 kg food/day in early gestation (day 25-50 gestation). M sows doubled their food intake in mid gestation (day 50-80 gestation). EM sows doubled their food intake during both early and mid gestation (day 25-80 gestation). L sows consumed 3.5 kg food/day in late gestation (day 80-110 gestation). Offspring body weight and food intake levels were measured from birth to adolescence. Markers of lipid metabolism, hypertrophy and inflammation were investigated in subcutaneous adipose tissue of adolescent offspring.

RESULTS

The trajectory of gestational weight gain differed across treatments. However total gestational weight gain did not differ except for EM sows who were the heaviest and fattest mothers at parturition. Offspring birth weight did not differ across treatments. Subcutaneous adipose tissue from EM offspring differed significantly from controls, with elevated mRNA levels of lipogenic (CD36, ACACB and LPL), nutrient transporters (FABP4 and GLUT4), lipolysis (HSL and ATGL), adipocyte size (MEST) and inflammation (PAI-1) indicators. The subcutaneous adipose depot from L offspring exhibited elevated levels of CD36, ACACB, LPL, GLUT4 and FABP4 mRNA transcripts compared to control offspring.

CONCLUSIONS

Increasing gestational weight gain in early gestation had the greatest impact on offspring postnatal growth rate. Increasing maternal food allowance in late gestation appeared to shift the offspring adipocyte focus towards accumulation of fat. Mothers who gained the most weight during gestation (EM mothers) gave birth to offspring whose subcutaneous adipose tissue, at adolescence, appeared hyperactive compared to controls. This study concluded that mothers, who gained more than the recommended weight gain in mid and late gestation, put their offspring adipose tissue at risk of dysfunction.

The childhood obesity epidemic as a result of nongenetic evolution: the maternal resources hypothesis

Over the past century, socioenvironmental evolution (eg, reduced pathogenic load, decreased physical activity, and improved nutrition) led to cumulative increments in maternal energy resources (ie, body mass and adiposity) and decrements in energy expenditure and metabolic control. These decrements reduced the competition between maternal and fetal energy demands and increased the availability of energy substrates to the intrauterine milieu. This perturbation of mother-conceptus energy partitioning stimulated fetal pancreatic β-cell and adipocyte hyperplasia, thereby inducing an enduring competitive dominance of adipocytes over other tissues in the acquisition and sequestering of nutrient energy via intensified insulin secretion and hyperplastic adiposity. At menarche, the competitive dominance of adipocytes was further amplified via hormone-induced adipocyte hyperplasia and weight-induced decrements in physical activity. These metabolic and behavioral effects were propagated progressively when obese, inactive, metabolically compromised women produced progressively larger, more inactive, metabolically compromised children. Consequently, the evolution of human energy metabolism was markedly altered. This phenotypic evolution was exacerbated by increments in the use of cesarean sections, which allowed both the larger fetuses and the metabolically compromised mothers who produced them to survive and reproduce. Thus, natural selection was iatrogenically rendered artificial selection, and the frequency of obese, inactive, metabolically compromised phenotypes increased in the global population. By the late 20th century, a metabolic tipping point was reached at which the postprandial insulin response was so intense, the relative number of adipocytes so large, and inactivity so pervasive that the competitive dominance of adipocytes in the sequestering of nutrient energy was inevitable and obesity was unavoidable.

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.

Interventions to prevent adverse fetal programming due to maternal obesity during pregnancy

Maternal obesity is a global epidemic affecting both developed and developing countries. Human and animal studies indicate that maternal obesity adversely programs the development of offspring, predisposing them to chronic diseases later in life. Several mechanisms act together to produce these adverse health effects. There is a consequent need for effective interventions that can be used in the management of human pregnancy to prevent these outcomes. The present review analyzes the dietary and exercise intervention studies performed to date in both altricial and precocial animals, rats and sheep, with the aim of preventing adverse offspring outcomes. The results of these interventions present exciting opportunities to prevent, at least in part, adverse metabolic and other outcomes in obese mothers and their offspring.

Maternal nutritional history modulates the hepatic IGF-IGFBP axis in adult male rat offspring

Alterations in early life nutrition lead to an increased risk of obesity and metabolic syndrome in offspring. We have shown that both relative maternal undernutrition (UN) and maternal obesity result in metabolic derangements in offspring, independent of the postnatal dietary environment. Since insulin-like growth factor binding protein 2 (IGFBP2) has been shown to be independently associated with obesity and diabetes risk, we examined the IGF-IGFBP axis in male rat offspring following either maternal UN or maternal obesity to explain possible common pathways in the development of metabolic disorders. Wistar rats were time-mated and fed either a control diet (CONT), 50 % of CONT (UN) or a high-fat (HF) diet throughout pregnancy. Male offspring were weaned onto a standard chow diet and blood and tissues were collected at postnatal day 160. Plasma and hepatic tissue samples were analysed for key players in the IGF-IGFBP system. Both maternal UN and HF resulted in increased fat mass, hyperinsulinemia, hyperleptinemia and altered blood lipid profiles in offspring compared to CONT. Circulating IGF-1 and IGFBP3 levels and hepatic mRNA expression of IGFBP1 and IGFBP2 were significantly decreased in UN and HF offspring compared to CONT. DNA methylation of the IGFBP2 promotor region was similar between maternal dietary groups. Although chaperone gene heat-shock protein 90 and hepatic IGFBP1 were significantly correlated in CONT offspring this effect was absent in both UN and HF offspring. In conclusion, this study is one of the first to directly compare two experimental models of developmental programming representing both ends of the maternal dietary spectrum. Our data suggest that two disparate nutritional models that elicit similar adverse metabolic phenotypes in offspring are characterised by common alterations in the IGF-IGFBP pathway.

Early metabolic imprinting events increase marbling scores in fed cattle

Early weaning of calves to a high concentrate diet results in greater fat deposition and suggests early postnatal metabolic imprinting events may be exploited as a management tool to improve cattle value. Our objective was to implement a short, high energy dietary intervention before a typical grazing period to manipulate intramuscular fat deposition in finishing cattle. Fall-born, Angus-sired steer calves (n = 24) were stratified by sire and randomly assigned to normal weaned (NW) or metabolic-imprinted (MIP) treatments. At 105 ± 6d (135kg), MIP calves were transitioned to a diet containing 20% CP and 1.26 Mcal/kg NEg. Metabolic-imprinted calves were fed ad libitum as a group. Normal weaned calves remained on their dam until 253 ± 6 d of age. At this time, treatment groups were combined and grazed for 156 d on a mixed summer pasture. Following the grazing phase, steers were adapted to a corn silage-based feedlot diet and performance was monitored on 28-d intervals. Calves were staged for harvest based on backfat endpoint (target 1.0 to 1.2 cm). Metabolic-imprinted calves were heavier (P < 0.05) than NW calves (341 vs. 265 ± 4.2 kg) at normal weaning age. During the grazing phase, NW steers gained more weight than (P < 0.05) MIP steers (0.69 vs. 0.35 ± 0.03 kg/d). Feedlot performance and USDA yield grade were similar (P > 0.20) between treatments. However, MIP steers produced heavier (P < 0.05) carcasses (564 vs. 524 ± 5.6 kg) with higher (P < 0.001) marbling scores (645 vs. 517 ± 23). Therefore, calves consuming a high concentrate diet for 148 d after early weaning produced higher quality carcasses. This suggests early weaning and feeding a high concentrate before grazing is a viable strategy to increase marbling deposition compared with a traditional production system.

Maternal obesity enhances white adipose tissue differentiation and alters genome-scale DNA methylation in male rat offspring

The risk of obesity (OB) in adulthood is strongly influenced by maternal body composition. Here we examined the hypothesis that maternal OB influences white adipose tissue (WAT) transcriptome and increases propensity for adipogenesis in the offspring, prior to the development of OB, using an established model of long-term metabolic programming. Employing an overfeeding-based rat model, in which exposure to OB is limited to preconception and gestation alone, we conducted global transcriptomic profiling in WAT, and gene/protein expression analysis of lipogenic and adipogenic pathways and examined adipogenic differentiation of WAT stromal-vascular cells ex vivo. Using reduced representation bisulfite sequencing we also evaluated genome-scale changes in DNA methylation in offspring WAT. Maternal OB led to extensive changes in expression of genes (± 1.8-fold, P ≤ .05), revealing a distinct up-regulation of lipogenic pathways in WAT. mRNA expression of a battery of sterol regulatory element-binding protein-1-regulated genes was increased in OB-dam offspring, which were confirmed by immunoblotting. In conjunction with lipogenic gene expression, OB-dam offspring showed increased glucose transporter-4 mRNA/protein expression and greater AKT phosphorylation following acute insulin challenge, suggesting sensitization of insulin signaling in WAT. Offspring of OB dams also exhibited increased in vivo expression of adipogenic regulators (peroxisome proliferator-activated receptor-γ, CCAAT enhancer binding protein α [C/EBP-α] and C/EBP-β), associated with greater ex vivo differentiation of WAT stromal-vascular cells. These transcriptomic changes were associated with alterations in DNA methylation of CpG sites and CGI shores, proximal to developmentally important genes, including key pro-adipogenic factors (Zfp423 and C/EBP-β). Our findings strongly suggest that the maternal OB in utero alters adipocyte commitment and differentiation via epigenetic mechanisms.

Diet reduction to requirements in obese/overfed ewes from early gestation prevents glucose/insulin dysregulation and returns fetal adiposity and organ development to control levels

Obesity at conception and excess gestational weight gain pose significant risks for adverse health consequences in human offspring. This study evaluated the effects of reducing dietary intake of obese/overfed ewes beginning in early gestation on fetal development. Sixty days prior to conception, ewes were assigned to a control diet [CON: 100% of National Research Council (NRC) recommendations], a diet inducing maternal obesity (MO: 150% of NRC recommendations), or a maternal obesity intervention diet (MOI: 150% of NRC recommendations to day 28 of gestation, then 100% NRC) until necropsy at midgestation (day 75) or late (day 135) gestation. Fetal size and weight, as well as fetal organ weights, were greater (P < 0.05) at midgestation in MO ewes than those of CON and MOI ewes. By late gestation, whereas fetal size and weight did not differ among dietary groups, cardiac ventricular weights and wall thicknesses as well as liver and perirenal fat weights remained elevated in fetuses from MO ewes compared with those from CON and MOI ewes. MO ewes and fetuses exhibited elevated (P < 0.05) plasma concentrations of triglycerides, cholesterol, insulin, glucose, and cortisol at midgestation compared with CON and MOI ewes and fetuses. In late gestation, whereas plasma triglycerides and cholesterol, insulin, and cortisol remained elevated in MO vs. CON and MOI ewes and fetuses, glucose concentrations were elevated in both MO and MOI fetuses compared with CON fetuses, which was associated with elevated placental GLUT3 expression in both groups. These data are consistent with the concept that reducing maternal diet of obese/overfed ewes to requirements from early gestation can prevent subsequent alterations in fetal growth, adiposity, and glucose/insulin dynamics.

Transgenic increase in N-3/n-6 Fatty Acid ratio reduces maternal obesity-associated inflammation and limits adverse developmental programming in mice

Maternal and pediatric obesity has risen dramatically over recent years, and is a known predictor of adverse long-term metabolic outcomes in offspring. However, which particular aspects of obese pregnancy promote such outcomes is less clear. While maternal obesity increases both maternal and placental inflammation, it is still unknown whether this is a dominant mechanism in fetal metabolic programming. In this study, we utilized the Fat-1 transgenic mouse to test whether increasing the maternal n-3/n-6 tissue fatty acid ratio could reduce the consequences of maternal obesity-associated inflammation and thereby mitigate downstream developmental programming. Eight-week-old WT or hemizygous Fat-1 C57BL/6J female mice were placed on a high-fat diet (HFD) or control diet (CD) for 8 weeks prior to mating with WT chow-fed males. Only WT offspring from Fat-1 mothers were analyzed. WT-HFD mothers demonstrated increased markers of infiltrating adipose tissue macrophages (P<0.02), and a striking increase in 12 serum pro-inflammatory cytokines (P<0.05), while Fat1-HFD mothers remained similar to WT-CD mothers, despite equal weight gain. E18.5 Fetuses from WT-HFD mothers had larger placentas (P<0.02), as well as increased placenta and fetal liver TG deposition (P<0.01 and P<0.02, respectively) and increased placental LPL TG-hydrolase activity (P<0.02), which correlated with degree of maternal insulin resistance (r = 0.59, P<0.02). The placentas and fetal livers from Fat1-HFD mothers were protected from this excess placental growth and fetal-placental lipid deposition. Importantly, maternal protection from excess inflammation corresponded with improved metabolic outcomes in adult WT offspring. While the offspring from WT-HFD mothers weaned onto CD demonstrated increased weight gain (P<0.05), body and liver fat (P<0.05 and P<0.001, respectively), and whole body insulin resistance (P<0.05), these were prevented in WT offspring from Fat1-HFD mothers. Our results suggest that reducing excess maternal inflammation may be a promising target for preventing adverse fetal metabolic outcomes in pregnancies complicated by maternal obesity.

Maternal obesity: how big an impact does it have on offspring prenatally and during postnatal life?

Obesity is increasing at an epidemic rate in women of reproductive age. Not only does obesity during pregnancy lead to increased maternal health concerns, it is also linked to an increase in adiposity and components of the metabolic syndrome in the children and grandchildren of obese women. The potential transgenerational impact of maternal obesity on the health of future generations will undoubtedly result in increasing healthcare costs for society. This review will describe what is known about the specific impacts of maternal obesity on offspring in the human population as well as discuss how controlled animal experiments have shed light on the specific physiological mechanisms involved. Furthermore, preliminary experiments are presented describing potential dietary methods for preventing obesity-induced programming of offspring health concerns in postnatal life.

Developmental origins of obesity: programmed adipogenesis

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

In utero programming of later adiposity: the role of fetal growth restriction

Intrauterine growth restriction (IUGR) is strongly associated with obesity in adult life. The mechanisms contributing to the onset of IUGR-associated adult obesity have been studied in animal models and humans, where changes in fetal adipose tissue development, hormone levels and epigenome have been identified as principal areas of alteration leading to later life obesity. Following an adverse in utero development, IUGR fetuses display increased lipogenic and adipogenic capacity in adipocytes, hypoleptinemia, altered glucocorticoid signalling, and chromatin remodelling, which subsequently all contribute to an increased later life obesity risk. Data suggest that many of these changes result from an enhanced activity of the adipose master transcription factor regulator, peroxisome proliferator-activated receptor-γ (PPARγ) and its coregulators, increased lipogenic fatty acid synthase (FAS) expression and activity, and upregulation of glycolysis in fetal adipose tissue. Increased expression of fetal hypothalamic neuropeptide Y (NPY), altered hypothalamic leptin receptor expression and partitioning, reduced adipose noradrenergic sympathetic innervations, enhanced adipose glucocorticoid action, and modifications in methylation status in the promoter of hepatic and adipose adipogenic and lipogenic genes in the fetus also contribute to obesity following IUGR. Therefore, interventions that inhibit these fetal developmental changes will be beneficial for modulation of adult body fat accumulation.

Maternal obesity, lipotoxicity and cardiovascular diseases in offspring

Maternal obesity has risen dramatically over the past 20 years, by nearly 42% in African-Americans and 29% in Caucasians. Maternal obesity is afflicted with many maternal obstetric complications in the offspring including high blood pressure, obesity, gestational diabetes and increased perinatal morbidity. Maternal nutritional environment plays a rather important role in the programming of the health set-points in the offspring such as glucose and insulin metabolism, energy balance and predisposition to metabolic disorders. In particular, maternal obesity is associated with elevated prevalence of cardiovascular diseases in the offspring. Evidence from human and experimental studies including rodents and nonhuman primates has indicated that maternal obesity or overnutrition programs offspring for an increased risk of adult obesity. Maternal obesity or fat diet exposure predisposes the onset and development of obesity, insulin resistance, cardiac hypertrophy and myocardial contractile anomalies in the offspring. A number of mechanisms including elevated hormones (leptin, insulin), nutrients (fatty acids, triglycerides and glucose) and inflammatory cytokines have been postulated to play a key role in maternal obesity-induced postnatal cardiovascular sequelae. In addition, lipotoxicity (accumulation of lipid metabolites) resulting from maternal obesity is capable of activating a number of stress signaling cascades including pro-inflammatory cytokines and oxidative stress to exacerbate maternal obesity-induced cardiovascular complications later on in adult life. This mini-review summarizes the recent knowledge with regard to the role of lipotoxicity in maternal obesity-induced change in cardiovascular function in the offspring. This article is part of a Special Issue entitled "Focus on Cardiac Metabolism".