Maternal obesity accelerates fetal pancreatic beta-cell but not alpha-cell development in sheep: prenatal consequences

Poor maternal nutrition during gestation in sheep alters key hormonal systems involved in energy homeostasis and appetite in the offspring

Disturbances in maternal nutrient availability through increased or decreased abundance of specific or total nutrients during pre-natal development can have negative impacts on offspring growth. These changes are likely mediated, at least in part, by hormonal systems that control energy homeostasis and appetite. Regulation of insulin signaling is critical to ensuring appropriate glucose homeostasis. Poor maternal nutrition during gestation impacts circulating glucose and insulin concentration in both the dam and offspring, reducing circulating insulin and glucose in offspring of restricted-fed dams and increased circulating insulin and glucose in the offspring of over-fed dams. Leptin and ghrelin are key regulators of appetite and feed intake. Offspring of over-fed ewes often exhibit leptin resistance, which may lead to changes in adiposity. Leptin responses in offspring of restricted-fed ewes are not well defined, although restricted-fed ewes themselves exhibit decreased circulating leptin concentrations. Little is known about the effects of poor maternal nutrition on offspring ghrelin. Glucocorticoids and thyroid hormones are required for appropriate fetal development. Poor maternal nutrition during gestation alters the development of the hypothalamic-pituitary-adrenal and thyroid axes in the offspring, although the effects vary according to the type, duration, timing, and severity of the nutritional insult. The relationships between insulin, leptin, ghrelin, glucocorticoids, and thyroid hormones can result in synergistic effects, exacerbating negative outcomes for the offspring. The impacts of poor maternal nutrition are multi-faceted, and the resulting alterations in body composition can continue to impact hormone regulation beyond the initial insult caused by poor maternal nutrition during gestation.

High-Fat Diets Fed during Pregnancy Cause Changes to Pancreatic Tissue DNA Methylation and Protein Expression in the Offspring: A Multi-Omics Approach

Maternal obesity, caused by diets rich in fats and sugars during pregnancy, can predispose offspring to metabolic diseases such as diabetes. We hypothesized that obesity during pregnancy leads to increased DNA methylation and reduced protein expression in factors regulating β-cell function and apoptosis. Female C57BL/6J mice were fed a high-fat diet (HFD; 42% fat content; n = 3) or a control diet (CON; 16% fat content; n = 3) for fourteen weeks before and during pregnancy. Offspring were euthanized at 8 weeks and pancreatic tissue was collected. Isolated DNA was analyzed using whole-genome bisulfite sequencing. Protein expression was quantified using LC-MS. No significant differences in body weight were observed between HFD and control pups (p = 0.10). Whole-genome bisulfite sequencing identified 91,703 and 88,415 differentially methylated regions (DMRs) in CON vs. HFD male and female offspring. A total of 34 and 4 proteins were determined to have changes in expression that correlated with changes in DNA methylation in CON vs. HFD males and females, respectively. The majority of these factors were grouped into the metabolic function category via pathway analyses. This study illustrates the complex relationship between epigenetics, diet, and sex-specific responses, therefore offering insights into potential therapeutic targets and areas for further research.

Developmental programming: Testosterone excess masculinizes female pancreatic transcriptome and function in sheep

Hyperandrogenic disorders, such as polycystic ovary syndrome, are often associated with metabolic disruptions such as insulin resistance and hyperinsulinemia. Studies in sheep, a precocial model of translational relevance, provide evidence that in utero exposure to excess testosterone during days 30-90 of gestation (the sexually dimorphic window where males naturally experience elevated androgens) programs insulin resistance and hyperinsulinemia in female offspring. Extending earlier findings that adverse effects of testosterone excess are evident in fetal day 90 pancreas, the end of testosterone treatment, the present study provides evidence that transcriptomic and phenotypic effects of in utero testosterone excess on female pancreas persist after cessation of treatment, suggesting lasting organizational changes, and induce a male-like phenotype in female pancreas. These findings demonstrate that the female pancreas is susceptible to programmed masculinization during the sexually dimorphic window of fetal development and shed light on underlying connections between hyperandrogenism and metabolic homeostasis.

Maternal-placental axis and its impact on fetal outcomes, metabolism, and development

Maternal obesity could impact offspring's health. During "critical period" such as pregnancy insults have a significant role in developing chronic diseases later in life. Literature has shown that diet can play a major role in essential metabolic and development processes on fetal outcomes. Moreover, the placenta, an essential organ developed in pregnancy, seems to have its functions impaired based on pre-gestational and gestational nutritional status. Specifically, a high-fat diet has been shown as a potential nutritional insult that also affects the maternal-placental axis, which is involved in offspring development and outcome. Moreover, some classes of nutrients are associated with pregnancy complications such as reduced intake of micronutrients and diabetes, preeclampsia, and preterm delivery. Thus, we will summarize the current literature on maternal environment factors that impacts the placental development and consequently the fetal an offspring health, or the maternal-placental axis, and this on fetal outcomes, metabolism, and development.

RISING STARS: Mechanistic insights into maternal-fetal cross talk and islet beta-cell development

The metabolic health trajectory of an individual is shaped as early as prepregnancy, during pregnancy, and lactation period. Both maternal nutrition and metabolic health status are critical factors in the programming of offspring toward an increased propensity to developing type 2 diabetes in adulthood. Pancreatic beta-cells, part of the endocrine islets, which are nutrient-sensitive tissues important for glucose metabolism, are primed early in life (the first 1000 days in humans) with limited plasticity later in life. This suggests the high importance of the developmental window of programming in utero and early in life. This review will focus on how changes to the maternal milieu increase offspring's susceptibility to diabetes through changes in pancreatic beta-cell mass and function and discuss potential mechanisms by which placental-driven nutrient availability, hormones, exosomes, and immune alterations that may impact beta-cell development in utero, thereby affecting susceptibility to type 2 diabetes in adulthood.

Placental dysfunction in obese women and antenatal surveillance

Obesity is a significant health concern worldwide and is associated with numerous health complications, including placental dysfunction during pregnancy. Placental dysfunction can lead to adverse outcomes for both the mother and the foetus, such as preeclampsia, gestational diabetes, preterm birth, and foetal growth restriction. Studies have shown that maternal obesity can lead to placental dysfunction through various mechanisms, including chronic inflammation, oxidative stress, and dysregulation of metabolic pathways. These factors can contribute to changes in the placenta's structure and function, impairing nutrient and oxygen exchange between the mother and foetus. Recent research has also suggested that alteration of gene expression in the placenta due to epigenetic changes, such as DNA methylation, may play a role in placental dysfunction associated with maternal obesity. These changes can affect altering foetal growth and development. Prevention and management of maternal obesity are crucial in reducing the risk of placental dysfunction and associated adverse outcomes during pregnancy. This can be achieved through lifestyle modifications, such as diet and exercise, and early detection and management of underlying health conditions. In conclusion, maternal obesity is a significant risk factor for placental dysfunction during pregnancy, which can lead to adverse outcomes for both the mother and the foetus. Further research is needed to understand the relationship and mechanisms to develop effective interventions to prevent and manage placental dysfunction in obese pregnant women.

Maternal restricted- and over- feeding during gestation perturb offspring sperm epigenome in sheep

IN BRIEF

Inadequate maternal nutrition during gestation can have immediate and lifelong effects on offspring. This study shows that maternal restricted - and over- nutrition during gestation do not affect semen characteristics in F1 male offspring but alters offspring sperm sncRNA profiles and DNA methylome in sheep.

ABSTRACT

There is a growing body of evidence that inadequate maternal nutrition during gestation can have immediate and lifelong effects on offspring. However, little is known about the effects of maternal nutrition during gestation on male offspring reproduction. Here, using a sheep model of maternal restricted - and over - nutrition (60 or 140% of the National Research Council requirements) during gestation, we found that maternal restricted - and over - nutrition do not affect semen characteristics (i.e. volume, sperm concentration, pH, sperm motility, sperm morphology) or scrotal circumference in male F1 offspring. However, using small RNA sequencing analysis, we demonstrated that both restricted - and over - nutrition during gestation induced marked changes in composition and expression of sperm small noncoding RNAs (sncRNAs) subpopulations including in male F1 offspring. Whole-genome bisulfite sequencing analysis further identified specific genomic loci where poor maternal nutrition resulted in alterations in DNA methylation. These findings indicate that maternal restricted - and over - nutrition during gestation induce epigenetic modifications in sperm of F1 offspring sperm in sheep, which may contribute to environmentally influenced phenotypes in ruminants.

The Impact of Obesity on Reproductive Health and Pregnancy Outcomes

Women carry the majority of the burden of our obesogenic surroundings, with a larger prevalence of obesity than males, a greater impact on fertility and treatment success, and increased maternal and perinatal morbidity and death. Obesity and its associated morbidity are now among our most pressing global health concerns. Women are more susceptible to gaining weight, which has reproductive, coronary, and emotional consequences. The current data on the negative consequences of obesity before conception (fertility issues, assisted reproductive treatment, polycystic ovary disease, overweight and obesity preventative measures, and emotional well-being), pregnancy (preventing excess gestational body weight, gestational diabetes, and preeclampsia, as well as labor and newborn health), and following delivery (the lactation process and breastfeeding, postnatal weight retention, and depressive symptoms) health is summarized. in this review. Along with this, underlying factors, consequences, and solutions to the obesity pandemic are investigated, as well as the mechanisms of obesity's effect on women and men, the epigenetic consequences of masculine obesity, its significant effects on reproductive results, and the implications of the loss of weight preceding to pregnancy as well as during pregnancy. This review suggests study methodologies that might assist in guiding attempts to enhance reproductive health and neonatal health in obese or overweight women.

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

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

Maternal obesity and offspring health: Adapting metabolic changes through autophagy and mitophagy

Maternal obesity leads to obstetric complications and a high prevalence of metabolic anomalies in the offspring. Among various contributing factors for maternal obesity-evoked health sequelae, developmental programming is considered as one of the leading culprit factors for maternal obesity-associated chronic comorbidities. Although a unified theory is still lacking to systematically address multiple unfavorable postnatal health sequelae, a cadre of etiological machineries have been put forward, including lipotoxicity, inflammation, oxidative stress, autophagy/mitophagy defect, and cell death. Hereinto, autophagy and mitophagy play an essential housekeeping role in the clearance of long-lived, damaged, and unnecessary cell components to maintain and restore cellular homeostasis. Defective autophagy/mitophagy has been reported in maternal obesity and negatively impacts fetal development and postnatal health. This review will provide an update on metabolic disorders in fetal development and postnatal health issues evoked by maternal obesity and/or intrauterine overnutrition and discuss the possible contribution of autophagy/mitophagy in metabolic diseases. Moreover, relevant mechanisms and potential therapeutic strategies will be discussed in an effort to target autophagy/mitophagy and metabolic disturbances in maternal obesity.

Multi-Omics Analysis Reveals the Potential Effects of Maternal Dietary Restriction on Fetal Muscle Growth and Development

In terms of fetal muscle growth, development, and health, maternal nutrition is a crucial influence, although the exact biochemical mechanism by which this occurs is still not fully understood. To examine the potential impacts of maternal dietary restriction on fetal muscle development, the sheep maternal dietary restriction model was developed for this study. In our study, 12 pregnant ewes were evenly split into two experimental groups and fed either 75% or 100% of a maternal nutrient. In addition, a multi-omics analysis was used to study the embryonic longissimus dorsis on gestational days (GD) 85 and 135. The fetal weight at GD 135 was significantly below normal due to the maternal restricted diet (p < 0.01). When fetuses were exposed to the dietary deficit, 416 mRNAs and 40 proteins were significantly changed. At GD 85, the multi-omics analysis revealed that maternal dietary restriction led to a significant up-regulation of the cell cycle regulator CDK2 gene in the cellular senescence signaling pathway, and the results of the qRT-PCR were similar to the multi-omics analysis, which showed that SIX1, PAX7, the cell cycle factors CDK4 and CDK6, and the BCL-2 apoptosis factor were up-regulated and several skeletal muscle marker genes, such as MYF5 and MyoD were down-regulated. At GD 135, maternal dietary restriction blocks the muscle fiber differentiation and maturation. The multi-omics analysis revealed that the TEAD1 gene was in the Hippo signaling pathway, the muscle marker genes MYF5 and MyoG were significantly down-regulated, and the TEAD1 binding of the down-regulated VGLL3 gene might be potential mechanisms affecting myofiber differentiation and maturation. Knocking down the CDK2 gene could inhibit the proliferation of primary embryonic myoblasts, and the expression levels of cell cycle regulatory factors CDK4 and CDK6 were significantly changed. Under low nutrient culture conditions, the number of myoblasts decreased and the expression of CDK2, CDK6, MYF5, PAX7 and BCL-2 changed, which was in perfect agreement with the multi-omics analysis. All of the findings from our study helped to clarify the potential effects of maternal dietary restriction on fetal muscle growth and development. They also provided a molecular foundation for understanding the molecular regulatory mechanisms of maternal nutrition on fetal muscle growth and development, as well as for the development of new medications and the management of related metabolic diseases.

Large animal models in the study of gynecological diseases

Gynecological diseases are a series of diseases caused by abnormalities in the female reproductive organs or breast, which endanger women's fertility and even their lives. Therefore, it is important to investigate the mechanism of occurrence and treatment of gynecological diseases. Animal models are the main objects for people to study the development of diseases and explore treatment options. Large animals, compared to small rodents, have reproductive organs with structural and physiological characteristics closer to those of humans, and are also better suited for long-term serial examinations for gynecological disease studies. This review gives examples of large animal models in gynecological diseases and provides a reference for the selection of animal models for gynecological diseases.

Role of Obesity in Female Reproduction

Contemporary scientists need no "p value" and "relative risk" statistics to be exquisitely aware of the increasing prevalence of obesity and complications posed by obesity. It is now well recognized that obesity is strongly associated with type 2 diabetes, hypertension, vascular disease, tumors and reproductive disorders. Obese women show lower levels of gonadotropin hormones, reduced fecundity, higher miscarriage rates and poorer outcomes of in vitro fertilization, revealing that obesity affects female reproduction. In addition, adipose tissue contains special immune cells and obesity-induced inflammation is a chronic, low-grade inflammatory response. Herein, we mainly review detrimental influences of obesity in the complete process of female reproduction, including hypothalamic-pituitary-ovarian axis, oocyte maturation, embryo and fetal development. In the latter part, we view obesity-induced inflammation and discuss related epigenetic impact on female reproduction.

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.

Programming of cardiometabolic health: the role of maternal and fetal hyperinsulinaemia

Obesity and gestational diabetes during pregnancy have multiple short- and long-term consequences for both mother and child. One common feature of pregnancies complicated by maternal obesity and gestational diabetes is maternal hyperinsulinaemia, which has effects on the mother and her adaptation to pregnancy. Even though insulin does not cross the placenta insulin can act on the placenta as well affecting placental growth, angiogenesis and lipid metabolism. Obese and gestational diabetic pregnancies are often characterised by maternal hyperglycaemia resulting in exposure of the fetus to high levels of glucose, which freely crosses the placenta. This leads to stimulation of fetal ß-cells and insulin secretion in the fetus. Fetal hyperglycaemia/hyperinsulinaemia has been shown to cause multiple complications in fetal development, such as altered growth trajectories, impaired neuronal and cardiac development and early exhaustion of the pancreas. These changes could increase the susceptibility of the offspring to develop cardiometabolic diseases later in life. In this review, we aim to summarize and review the mechanisms by which maternal and fetal hyperinsulinaemia impact on (i) maternal health during pregnancy; (ii) placental and fetal development; (iii) offspring energy homeostasis and long-term cardiometabolic health; (iv) how interventions can alleviate these effects.

Maternal Under- and Over-Nutrition during Gestation Causes Islet Hypertrophy and Sex-Specific Changes to Pancreas DNA Methylation in Fetal Sheep

The mechanisms by which fetal programming predisposes offspring to reduced β-cell function later in life are poorly understood. We hypothesized that maternal under- and over-nutrition during gestation would negatively affect offspring pancreas development and alter DNA methylation patterns. Pregnant ewes (n = 78) were fed 100, 60, or 140% of NRC requirements beginning at d 30.2 ± 0.2 of gestation. The fetuses are referred to as CON, RES, and OVER, respectively. Fetal pancreas tissue was collected at d 90 or 135 of gestation or within 24 h of birth. Tissue was preserved for histological (n = 8 to 9 offspring per treatment per time point) and DNA methylation analyses (n = 3 to 4 fetuses per treatment per sex). At d 135, OVER exhibited an increased islet size, reduced islet number, and greater insulin positive area compared with CON (p ≤ 0.03). An increased islet size was also observed at d 135 in RES (p ≤ 0.03) compared with CON. Cellular proliferation was reduced at birth in OVER vs. CON (p = 0.01). In the RES vs. CON females, 62% of the differentially methylated regions (DMRs) were hypomethylated (p ≤ 0.001). In the RES vs. CON males, 93% of the DMRs were hypermethylated (p ≤ 0.001). In OVER, 66 and 80% of the DMRs were hypermethylated in the female and male offspring compared with CON (p ≤ 0.001). In conclusion, changes to maternal diet during pregnancy affects the islet hypertrophy and cellular proliferation of the offspring at early post-natal time points. Additionally, changes in DNA methylation patterns appear to be in a diet-specific and sex-dependent manner.

Understanding the Long-Lasting Effects of Fetal Nutrient Restriction versus Exposure to an Obesogenic Diet on Islet-Cell Mass and Function

Early life represents a window of phenotypic plasticity. Thus, exposure of the developing fetus to a compromised nutritional environment can have long term consequences for their health. Indeed, undernutrition or maternal intake of an obesogenic diet during pregnancy leads to a heightened risk of type 2 diabetes (T2D) and obesity in her offspring in adult life. Given that abnormalities in beta-cell function are crucial in delineating the risk of T2D, studies have investigated the impact of these exposures on islet morphology and beta-cell function in the offspring in a bid to understand why they are more at risk of T2D. Interestingly, despite the contrasting maternal metabolic phenotype and, therefore, intrauterine environment associated with undernutrition versus high-fat feeding, there are a number of similarities in the genes/biological pathways that are disrupted in offspring islets leading to changes in function. Looking to the future, it will be important to define the exact mechanisms involved in mediating changes in the gene expression landscape in islet cells to determine whether the road to T2D development is the same or different in those exposed to different ends of the nutritional spectrum.

Mismatch between obesogenic intrauterine environment and low-fat postnatal diet may confer offspring metabolic advantage

OBJECTIVE

Mismatch between a depleted intrauterine environment and a substrate-rich postnatal environment confers an increased risk of offspring obesity and metabolic syndrome. Maternal diet-induced obesity (MATOB) is associated with the same outcomes. These experiments tested the hypothesis that a mismatch between a nutrient-rich intrauterine environment and a low-fat postnatal environment would ameliorate offspring metabolic morbidity.

METHODS

C57BL6/J female mice were fed either a 60% high-fat diet (HFD) or a 10% fat control diet (CD) for 14-week pre-breeding and during pregnancy/lactation. Offspring were weaned to CD. Weight was evaluated weekly; body composition was determined using EchoMRI. Serum fasting lipids and glucose and insulin tolerance tests were performed. Metabolic rate, locomotor, and sleep behavior were evaluated with indirect calorimetry.

RESULTS

MATOB-exposed/CD-weaned offspring of both sexes had improved glucose tolerance and insulin sensitivity compared to controls. Males had improved fasting lipids. Females had significantly increased weight and body fat percentage in adulthood compared to sex-matched controls. Females also had significantly increased sleep duration and reduced locomotor activity compared to males.

CONCLUSIONS

Reduced-fat dietary switch following intrauterine and lactational exposure to MATOB was associated with improved glucose handling and lipid profiles in adult offspring, more pronounced in males. A mismatch between a high-fat prenatal and low-fat postnatal environment may confer a metabolic advantage. The amelioration of deleterious metabolic programming by strict offspring adherence to a low-fat diet may have translational potential.

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.

Effects of maternal obesity in an ovine model on metabolic outcomes in F2 adults and F3 neonates

Accumulating evidence suggests that indications of metabolic syndrome can be inherited through the germline as a result of maternal obesity. We hypothesized that diet-induced maternal obesity during gestation would program metabolic consequences for multiple generations of offspring, even when first, second, and third generation offspring (F1, F2, F3, respectively) were fed only to requirements. Control (CON) and obese (OB) ewes (generation 0; F0) were bred to a single ram to produce the first generation of offspring (F1). From 60 d prior to conception through term, CONF0 ate 100% National Research Council recommendations (NRC), while OBF0 ewes ate 150% NRC. All F1, F2, and F3 ate 100% NRC after weaning. All mature F1 ewes were bred to a single ram to generate CONF2 (n = 6) and OBF2 (n = 10). All mature F2 ewes were bred to a single ram to produce CONF3 (n = 6) and OBF3 (n = 10). OBF2 ewes exhibited greater (P < 0.0001) plasma cortisol than CONF2 throughout gestation. A glucose tolerance test at 90% gestation revealed OBF2 ewes had higher (P < 0.05) insulin response with similar glucose, resulting in greater (P < 0.05) insulin resistance. OBF3 neonates had similar weight, lean mass, and body fat mass to CONF3 neonates. These data suggest that multigenerational programming of adverse metabolic phenotypes occur in association with F0 maternal obesity, yet adiposity may return to CON levels in F3 neonates.

Strategies to improve neurodevelopmental outcomes in babies at risk of neonatal hypoglycaemia

Neonatal hypoglycaemia is associated with adverse development, particularly visual-motor and executive function impairment, in childhood. As neonatal hypoglycaemia is common and frequently asymptomatic in at-risk babies-ie, those born preterm, small or large for gestational age, or to mothers with diabetes, it is recommended that these babies are screened for hypoglycaemia in the first 1-2 days after birth with frequent blood glucose measurements. Neonatal hypoglycaemia can be prevented and treated with buccal dextrose gel, and it is also common to treat babies with hypoglycaemia with infant formula and intravenous dextrose. However, it is uncertain if screening, prophylaxis, or treatment improves long-term outcomes of babies at risk of neonatal hypoglycaemia. This narrative review assesses the latest evidence for screening, prophylaxis, and treatment of neonates at risk of hypoglycaemia to improve long-term neurodevelopmental outcomes.

Effects of Maternal Exercise During Pregnancy on Perinatal Growth and Childhood Obesity Outcomes: A Meta-analysis and Meta-regression

BACKGROUND

Perinatal growth abnormalities program susceptibility to childhood obesity, which is further exaggerated by maternal overweight and obesity (MO) during pregnancy. Exercise is highly accessible, but reports about the benefits of maternal exercise on fetal growth and childhood obesity outcomes are inconsistent, reducing the incentives for pregnant women to participate in exercise to improve children's perinatal growth.

OBJECTIVE

This systematic review and meta-analysis aims to establish evidence-based efficacy of exercise in mothers with normal weight (MNW) and MO during pregnancy in reducing the risks of perinatal growth abnormalities and childhood obesity. In addition, the impacts of exercise volume are also assessed.

METHODS

The PubMed, ScienceDirect, Web of Science, and Cochrane Library databases were searched from inception to February 15, 2020. We included randomized controlled trials with exercise-only intervention or exercise with other confounders in pregnant MNW (body mass index, BMI 18.5-24.9 kg/m²) and MO (BMI ≥ 25 kg/m²), which were further subgrouped in the meta-analysis. Primary outcomes included birth weight, preterm birth, small for gestational age (SGA), large for gestational age (LGA), infant and childhood weight, and childhood obesity. A linear meta-regression analysis was also used to explore the effects of exercise volume on outcomes.

RESULTS

99 studies were included in the meta-analysis (n = 596,876), and individual study quality ranged from fair to good according to the Newcastle-Ottawa scale assessment. Exercise only interventions in MNW reduced preterm birth by 15% (26 studies, n = 76,132; odds ratio [OR] 0.85; 95% CI 0.72, 1.01; I² = 83.3%), SGA by 17% (33 studies, n = 92,351; OR 0.83; 95% CI 0.71, 0.98; I² = 74.5%) and LGA by 17% (29 studies, n = 84,310; OR 0.83; 95% CI 0.74, 0.95; I² = 60.4%). Exercise only interventions in MO reduced preterm birth by 33% (2 studies, n = 3,050; OR 0.67; 95% CI 0.70, 0.96; I² = 0%), SGA by 27% (8 studies, n = 3,909; OR 0.73; 95% CI 0.50, 1.05; I² = 40.4%) and LGA by 55% (9 studies, n = 81,581; OR 0.45; 95% CI 0.18, 1.11; I² = 98.3%). Exercise only interventions in MNW reduced childhood obesity by 53% (3 studies, n = 6,920; OR 0.47; 95% CI 0.36, 0.63; I² = 77.0%). However, no significant effect was observed in outcomes from exercise confounders in either MNW or MO. In the meta-regression, the volume of exercise-only intervention in MNW was negatively associated with birth weight, greatly driven by volumes more than 810 metabolic equivalents (MET)-min per week. Other outcomes were not associated with exercise volume.

CONCLUSIONS

This systematic review and meta-analysis suggests that exercise during pregnancy in both MNW and MO safely and effectively reduce the risks of preterm birth, SGA, and LGA. Furthermore, MNW exercise also reduces the risk of childhood obesity. Overall, regardless of prepregnancy BMI, maternal exercise during pregnancy provides an excellent opportunity to mitigate the high prevalence of adverse birth outcomes and childhood obesity.

Modelling gestational diabetes mellitus: large animals hold great promise

Gestational diabetes mellitus (GDM) characterized by hyperglycemia during pregnancy is a risk factor for various maternal and fetal complications. The key pathophysiological mechanisms underlying its development have not been elucidated, largely due to the lack of a model that accurately simulates the major clinical and pathological features of human GDM. In this review, we discuss the refined criteria for an ideal animal model of GDM, focusing on the key clinical and pathophysiological characteristics of human GDM. We provide a comprehensive overview of different models and currently used species for GDM research. In general, insulin insufficiency consequent to pancreatic β-cell death represents the current leading strategy to mimic human GDM-like hyperglycemia in animals. Nonetheless, these models have a limited capacity to mimic the natural history of GDM, the marked alteration in circulating estrogen/ progestogen, obesity and its related metabolic complications. We discuss emerging evidence of the increased susceptibility to GDM in rodents and large animals with genetic modifications in pregnancy-related hormones. An appraisal of current GDM models suggests that a combination strategy involving dietary stress, pregnancy-related hormones, insulin resistance and metabolic disorders might enable the development of better GDM models and expedite the translation of basic research findings to GDM treatment.

Prolonged transitional neonatal hypoglycaemia: characterisation of a clinical syndrome

BACKGROUND

We performed a case-control study to characterise infants with "prolonged transitional hypoglycaemia".

METHODS

Cases were born ≥36 weeks' gestation; had ≥1 hypoglycaemic episode <72 h and ≥72 h; received ongoing treatment for hypoglycaemia ≥72 h; and were without congenital disorders or acute illness. Cases were compared to controls born ≥36 weeks' with brief transitional hypoglycaemia, resolving <72 h.

RESULTS

39/471 infants screened met case definition: 71.8% were male, 61.5% were small-for-gestational-age (SGA), and most were admitted <6 h. Compared to controls (N = 75), key risk factors for prolonged transitional hypoglycaemia were SGA (OR = 6.4, 95%CI 2.7-15.1), severe/recurrent hypoglycaemia <24 h (OR = 16.7, 95%CI 4.5-16.1), intravenous glucose bolus <24 h (OR = 26.6, 95%CI 9.4-75.1) and maximum glucose delivery rate <48 h of ≥8 mg/kg/min (OR = 25.5, 95%CI 7.7-84.1).

CONCLUSIONS

Infants with prolonged transitional hypoglycaemia are predominantly male, SGA and have early severe/recurrent hypoglycaemia requiring glucose boluses and high glucose delivery rates in the first 24-48 h.

Effect of maternal overnutrition on predisposition to insulin resistance in the foal: Maternal parameters and foal pancreas histoarchitecture

Results from previous studies indicate that maternal overnutrition during late gestation predisposes foals to metabolic disease, however, specific mechanisms resulting in disease remain unknown. Quarter Horse mares (n = 16), were randomly assigned to dietary treatments, beginning on gestational day 235, and consisted of a control group (CON- diet meeting nutrient requirement; n = 8) or an overfed diet (HIGH; n = 8) where mares received an additional 40 % above CON. On gestational days 285 and 315, an intravenous glucose tolerance test (FSIGTT) was conducted. Following parturition, foals were separated from the mare, prohibited from nursing, and an FSIGTT was conducted at 2 h postpartum. Foals were immediately euthanized and tissues preserved for analyses. There was no effect of treatment on foal BW (P = 0.50), pancreas weight (P = 0.60), or FSIGTT area under the curve for glucose (P = 0.80) and insulin (P = 0.70). Colocalization of α-amylase to isolate pancreatic islets of Langerhans indicated increased islet number and size in foals from HIGH mares (P < 0.01). Immunofluoresent analysis of insulin, glucagon, and somatostatin indicate no difference in intensity of staining (P> 0.10). Foals exposed to overnutrition during peak fetal growth had altered pancreatic islet development that may lead to adult-onset metabolic disease.

Maternal High-Fat Diet During Pre-Conception and Gestation Predisposes Adult Female Offspring to Metabolic Dysfunction in Mice

The risk of obesity in adulthood is subject to programming in the womb. Maternal obesity contributes to programming of obesity and metabolic disease risk in the adult offspring. With the increasing prevalence of obesity in women of reproductive age there is a need to understand the ramifications of maternal high-fat diet (HFD) during pregnancy on offspring's metabolic heath trajectory. In the present study, we determined the long-term metabolic outcomes on adult male and female offspring of dams fed with HFD during pregnancy. C57BL/6J dams were fed either Ctrl or 60% Kcal HFD for 4 weeks before and throughout pregnancy, and we tested glucose homeostasis in the adult offspring. Both Ctrl and HFD-dams displayed increased weight during pregnancy, but HFD-dams gained more weight than Ctrl-dams. Litter size and offspring birthweight were not different between HFD-dams or Ctrl-dams. A significant reduction in random blood glucose was evident in newborns from HFD-dams compared to Ctrl-dams. Islet morphology and alpha-cell fraction were normal but a reduction in beta-cell fraction was observed in newborns from HFD-dams compared to Ctrl-dams. During adulthood, male offspring of HFD-dams displayed comparable glucose tolerance under normal chow. Male offspring re-challenged with HFD displayed glucose intolerance transiently. Adult female offspring of HFD-dams demonstrated normal glucose tolerance but displayed increased insulin resistance relative to controls under normal chow diet. Moreover, adult female offspring of HFD-dams displayed increased insulin secretion in response to high-glucose treatment, but beta-cell mass were comparable between groups. Together, these data show that maternal HFD at pre-conception and during gestation predisposes the female offspring to insulin resistance in adulthood.

Preconceptional diet manipulation and fetus number can influence placenta endocrine function in sheep

Changes in maternal nutrition during pregnancy can result in profound effects on placental function and fetal development. Although the preconceptional period holds the potential to reprogram embryonic and placental development, little is known regarding the effects of premating nutritional manipulation on placental function and fetal and postnatal offspring growth. To test this, Polypay-Dorset sheep (n = 99) were assigned to 1 of 3 nutritional treatments (n = 33/treatment) receiving 50% (UN: undernutrition), 100% (C: control), or 200% (ON: overnutrition) of maintenance energy requirements for 21 d before mating during April-May (increasing photoperiod). Thereafter, diets were the same across groups. We evaluated maternal reproductive variables and maternal and offspring weight and body mass index through weaning. Maternal plasma was collected through pregnancy until postnatal day 1 to assay pregnancy-associated glycoproteins (PAGs) and progesterone. Fertility rate was similar among treatments, but ON females had a higher reproductive rate (UN: 82%; C: 100%, ON: 145%). When correcting by total birth weight, twin pregnancies had lower PAGs and progesterone versus singleton pregnancies (P < 0.001). At birth, UN lambs were heavier than C lambs regardless of birth type (P < 0.01). Growth velocity, daily gain, and weaning weight were similar, but UN and ON females grew faster and were heavier at weaning versus C females. We demonstrated that a 3-wk preconceptional maternal undernutrition or overnutrition, when correcting by total birth weight, results in lower endocrine capacity in twin pregnancies. Preconceptional maternal undernutrition and overnutrition increased postnatal female lamb growth, suggestive of reprogramming of pathways regulating growth before conception. This highlights how preconceptional nutrition can result in marked sex-specific differences.

Research Progress on the Experimental Animal Model of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) refers to different degrees of abnormal glucose metabolism during pregnancy, where blood glucose levels do not reach the level of overt diabetes, accounting for 80-90% of pregnancy with hyperglycemia. Hyperglycemia affects the pregnancy process, leading to a series of adverse maternal outcomes that have a profound impact on the future of the offspring. The establishing of an appropriate GDM model will provide theoretical basis for study GDM pathogenesis involves, the choice of resonable drugs and the observation the disease trends and outcomes. At present, there are many methods for establishing experimental GDM animal models and animal choices. This paper examines the different GDM models and their induction methods.

Developmental origins of ovarian disorder: impact of maternal lean gestational diabetes on the offspring ovarian proteome in mice†

Gestational diabetes mellitus (GDM) is an obstetric disorder affecting approximately 10% of pregnancies. The four high-fat, high-sucrose (HFHS) mouse model emulates GDM in lean women. Dams are fed a HFHS diet 1 week prior to mating and throughout gestation resulting in inadequate insulin response to glucose in mid-late pregnancy. The offspring of HFHS dams have increased adiposity, thus, we hypothesized that maternal metabolic alterations during lean GDM would compromise ovarian function in offspring both basally and in response to a control or HFHS diet in adulthood. Briefly, DLPL were lean dams and control diet pups; DLPH were lean dams and HFHS pups; DHPL were HFHS dams and control diet pups; and DHPH were HFHS dams and HFHS pups. A HFHS challenge in the absence of maternal GDM (DLPL vs. DLPH) increased 3 and decreased 30 ovarian proteins. Maternal GDM in the absence of a dietary stress (DLPL vs. DHPL) increased abundance of 4 proteins and decreased abundance of 85 proteins in the offspring ovary. Finally, 87 proteins increased, and 4 proteins decreased in offspring ovaries due to dietary challenge and exposure to maternal GDM in utero (DLPL vs. DHPH). Canopy FGF signaling regulator 2, deleted in azoospermia-associated protein 1, septin 7, and serine/arginine-rich splicing factor 2 were altered across multiple offspring groups. Together, these findings suggest a possible impact on fertility and oocyte quality in relation to GDM exposure in utero as well as in response to a western diet in later life.

A Review of Maternal Nutrition during Pregnancy and Impact on the Offspring through Development: Evidence from Animal Models of Over- and Undernutrition

Similarities in offspring phenotype due to maternal under- or over-nutrition during gestation have been observed in studies conducted at University of Wyoming. In these studies, ewes were either nutrient-restricted (NR) from early to mid-gestation, or fed an obesogenic diet (MO) from preconception through term. Offspring necropsies occurred at mid-gestation, late-gestation, and after parturition. At mid gestation, body weights of NR fetuses were ~30% lighter than controls, whereas MO fetuses were ~30% heavier than those of controls. At birth, lambs born to NR, MO, and control ewes exhibited similar weights. This was a consequence of accelerated fetal growth rates in NR ewes, and reduced fetal growth rates in MO ewes in late gestation, when compared to their respective controls. These fetal growth patterns resulted in remarkably similar effects of increased susceptibility to obesity, cardiovascular disease, and glucose intolerance in offspring programmed mostly during fetal stages of development. These data provide evidence that maternal under- and over-nutrition similarly induce the development of the same cadre of physical and metabolic problems in postnatal life.

Maternal arginine supplementation enhances thermogenesis in the newborn lamb

Body temperature maintenance is one of the most important physiological processes initiated after birth. Brown adipose tissue (BAT) is an essential mediator of thermogenesis in many species and is responsible for 50% of the heat generated in the newborn lamb. To determine if maternal arginine supplementation could enhance thermogenesis in the neonate, we randomly assigned 31 multiparous Suffolk ewes, gestating singletons or twins, to receive intravenous injections of either l-arginine (27 mg/kg body weight; n = 17) or sterile saline (n = 14) three times daily from day 75 to 125 of gestation (term = 147). Following parturition, lambs were removed from their mothers and subjected to 0 °C cold challenges at 4 and 22 h of age. Rectal temperatures were higher for the duration of the cold challenges in lambs from arginine-treated ewes compared with lambs from saline-treated ewes (P < 0.05). Elevated rectal temperatures were associated with increased (P < 0.05) circulating glycine and serine concentrations in lambs. The mRNA expression of genes related to BAT function changed over time, but not between lambs from arginine-treated vs. saline-treated ewes. Results indicate that maternal arginine treatment increases neonatal thermogenesis after birth. Although the underlying mechanisms remain to be elucidated, these data are a first step in improving neonatal survival in response to cold.

Perinatal exposure to maternal obesity: Lasting cardiometabolic impact on offspring

Evidence from epidemiological, clinical, and animal model studies clearly demonstrates that prenatal and lactational maternal obesity and high-fat diet consumption are associated with cardiometabolic morbidity in offspring. Fetal and offspring sex may be an important effect modifier. Adverse offspring cardiometabolic outcomes observed in the setting of maternal obesity include an increased risk for obesity, features of metabolic syndrome (hypertension, hyperglycemia and insulin resistance, hyperlipidemia, increased adiposity), and non-alcoholic fatty liver disease. This review article synthesizes human and animal data linking maternal obesity and high-fat diet consumption in pregnancy and lactation to adverse cardiometabolic outcomes in offspring. We review key mechanisms underlying skeletal muscle, adipose tissue, pancreatic, liver, and central brain reward programming in obesity-exposed offspring, and how such malprogramming contributes to offspring cardiometabolic morbidity.

Maternal obesity: focus on offspring cardiometabolic outcomes

Several human and animal studies have demonstrated that cardiometabolic parameters in infancy, childhood, adolescence and even adulthood are negatively influenced by many factors besides energy imbalance. Interestingly, maternal weight excess both before and during pregnancy seems to be a negative determinant of metabolic and cardiovascular outcomes in the offspring. This review includes both human and animal studies and finally highlights the link between maternal obesity and cardiometabolic disorders in offspring.

Maternal stressors and the developmental origins of neuropsychiatric risk

The maternal environment during pregnancy is critical for fetal development and perinatal perturbations can prime offspring disease risk. Here, we briefly review evidence linking two well-characterized maternal stressors - psychosocial stress and infection - to increased neuropsychiatric risk in offspring. In the current climate of increasing obesity and globalization of the Western-style diet, maternal overnutrition emerges as a pressing public health concern. We focus our attention on recent epidemiological and animal model evidence showing that, like psychosocial stress and infection, maternal overnutrition can also increase offspring neuropsychiatric risk. Using lessons learned from the psychosocial stress and infection literature, we discuss how altered maternal and placental physiology in the setting of overnutrition may contribute to abnormal fetal development and resulting neuropsychiatric outcomes. A better understanding of converging pathophysiological pathways shared between stressors may enable development of interventions against neuropsychiatric illnesses that may be beneficial across stressors.

A heretical view: rather than a solely placental protective function, placental 11β hydroxysteroid dehydrogenase 2 also provides substrate for fetal peripheral cortisol synthesis in obese pregnant ewes

Exposure to glucocorticoid levels higher than appropriate for current developmental stages induces offspring metabolic dysfunction. Overfed/obese (OB) ewes and their fetuses display elevated blood cortisol, while fetal Adrenocorticotropic hormone (ACTH) remains unchanged. We hypothesized that OB pregnancies would show increased placental 11β hydroxysteroid dehydrogenase 2 (11β-HSD2) that converts maternal cortisol to fetal cortisone as it crosses the placenta and increased 11β-HSD system components responsible for peripheral tissue cortisol production, providing a mechanism for ACTH-independent increase in circulating fetal cortisol. Control ewes ate 100% National Research Council recommendations (CON) and OB ewes ate 150% CON diet from 60 days before conception until necropsy at day 135 gestation. At necropsy, maternal jugular and umbilical venous blood, fetal liver, perirenal fat, and cotyledonary tissues were harvested. Maternal plasma cortisol and fetal cortisol and cortisone were measured. Fetal liver, perirenal fat, cotyledonary 11β-HSD1, hexose-6-phosphate dehydrogenase (H6PD), and 11β-HSD2 protein abundance were determined by Western blot. Maternal plasma cortisol, fetal plasma cortisol, and cortisone were higher in OB vs. CON (p < 0.01). 11β-HSD2 protein was greater (p < 0.05) in OB cotyledonary tissue than CON. 11β-HSD1 abundance increased (p < 0.05) in OB vs. CON fetal liver and perirenal fat. Fetal H6PD, an 11β-HSD1 cofactor, also increased (p < 0.05) in OB vs. CON perirenal fat and tended to be elevated in OB liver (p < 0.10). Our data provide evidence for increased 11β-HSD system components responsible for peripheral tissue cortisol production in fetal liver and adipose tissue, thereby providing a mechanism for an ACTH-independent increase in circulating fetal cortisol in OB fetuses.

The effects of early- or mid-gestation nutrient restriction on bovine fetal pancreatic development

Research on the effects of nutrient restriction in beef cows on fetal pancreatic development is limited. To address this, multiparous Angus-cross cows (n = 22) were fed either control (CON; to gain 1 kg/wk) or nutrient-restricted (NR; 0.55% NE_m) diets based on NRC requirements. On d 30 of gestation, cows were blocked by body condition and randomly assigned to one of three nutritional regimes: CON fed from d 30 to 190 (n = 8), or NR/C (n = 7) or C/NR (n = 7) fed either the CON or NR diet from d 30 to 110 followed by CON or NR from d 110 to 190 of gestation. Cows were harvested on d 190 of gestation, and blood samples, fetal weights, and fetal tissue weights and samples were collected. Pancreas samples were embedded in paraffin and sectioned for standard immunohistochemistry procedures to quantify insulin-positive β cells and number of apoptotic β cells using TUNEL staining. Data were analyzed via ANOVA using the general linear model procedure of SAS. At harvest, empty carcass weights were decreased (P = 0.036) in fetuses of C/NR and NR/C fed dams compared to fetuses of CON fed dams. Pancreas weight was decreased (P = 0.028) in fetuses of C/NR fed dams compared to CON fetuses; however, fetuses of NR/C fed dams were not different (P > 0.05) from fetuses of CON fed dams. Maternal and fetal serum insulin concentrations were not different (P > 0.05) in NR/C fed compared to CON fed; however, concentrations of insulin were decreased (P = 0.036 and P = 0.40, respectively) in C/NR fed compared to CON fed. Beta cell number was decreased (P = 0.009) in fetuses of NR/C and C/NR fed dams compared to fetuses of CON fed dams. Percentage of apoptotic cells was increased (P < 0.0001) in fetuses of NR/C and C/NR fetuses than fetuses of CON fed dams. This evidence suggests that nutrient restriction either during early- or mid-gestation can negatively impact fetal pancreatic development. However, mid-gestational nutritional insult is potentially recovered by reacclimation to a diet that meets requirements of the dam, thus reducing negative outcomes in fetal offspring.

Stimulatory effects of nano-selenium and conjugated linoleic acid ‎ on antioxidant activity, trace minerals, and gene expression response of growing male Moghani lambs

Sheep keepers need suitable strategies to improve animal immunity and the quality of their products. This study was aimed to evaluate the effect of nano-selenium (nano-Se) and conjugated linoleic acid (CLA) on an antioxidant statue, trace minerals, and mRNA expression of glutathione peroxidase 1 (GPX1) and selenoprotein W1 (SEPW1) genes in the liver and peroxisome proliferator-activated receptor-gamma (PPARγ) and stearoyl COA desaturase 1 (SCD1) genes in fat- tail of male Moghani lambs. Thirty male Moghani lambs, three months old and average weight 30.00 ± 0.25 kg, were assigned to a completely randomized design in a 2×3 factorial arrangement with dietary supplementation of nano-Se (0, 1.00 and 2.00 mg kg^-1 dry matter) and CLA (0.00 and 15.00 g kg^-1 dry matter). The lambs were slaughtered at the end of the experiment, on day 90 of the experiment. Results showed that dietary inclusion of nano-Se significantly improved antioxidant enzymes glutathione peroxidase and superoxide dismutase in blood, however, did not show any differences in trace mineral treatments. The analysis of qPCR showed that nano-Se inclusion at the highest level (2.00 g kg^-1 dry matter) enhanced gene expression of GPX1 (0.64 vs 0.34) and SEPW1 (0.72 vs 0.35) in the liver. Dietary inclusion of CLA increased the expression of PPARγ (0.63 vs 0.38) and decreased SCD1 (0.63 vs 0.33) genes in fat- tail. It could be concluded that selenium inclusion in the growing lamb's diet could improve antioxidant status, however, no synergistic interaction was observed along with CLA on the mentioned parameters.

The impact of maternal weight in pregnancy on glucose metabolism in non-diabetic offspring in late adulthood

AIMS

We aimed to examine the association between maternal adiposity and glucose metabolism in adult offspring without diabetes, simultaneous taking offspring own adiposity into account.

METHODS

This longitudinal birth cohort study (Helsinki Birth Cohort Study) included 1,440 non-diabetic subjects examined at a mean age of 62 years. Subjects were divided into quartiles according to maternal body mass index (BMI). The impact of maternal BMI on offspring body composition was also studied.

RESULTS

There were no differences in fasting glucose between the groups. In men, maternal BMI was inversely associated with mean 2-hour glucose concentration after a 75 g oral glucose tolerance test (p < 0.001) and mean homeostatic model assessment of insulin resistance (HOMA-IR) (p = 0.049). According to the subjects' own BMI, high maternal BMI was associated with lower 2-hour glucose concentrations only in non-obese men and with lower HOMA-IR only in obese men. Maternal BMI was not associated with glucose concentrations nor with HOMA-IR in women. In addition, maternal BMI was positively associated with a higher offspring lean body mass in men.

CONCLUSIONS

High maternal BMI was associated with lower 2-hour plasma glucose concentration, especially in non-obese men. Offspring lean body mass may be a mediating factor for the association.

Effects of feeding a high- or moderate-starch prepartum diet to cows on newborn dairy heifer calf responses to intravenous glucose tolerance tests early in life

The objective of this study was to evaluate the effect of feeding a prepartum diet with a high or moderate starch content on growth and insulin sensitivity of female offspring early in life. Thirty-eight Holstein heifer calves were born to dams fed either a high-starch (26% starch on a DM basis, HI; n = 20) or moderate-starch (14% starch on a DM basis, MOD; n = 18) prepartum diet commencing at 28 ± 3 d before expected parturition date. Following birth, all calves were housed individually and fed three 2-L meals of colostrum within the first 24 h of life and offered 10 L/d of milk replacer (26% CP, 18% fat, mixed to 130 g/L). Body weight of calves was measured at birth and on d 2 (after colostrum feeding but before milk feeding), 10 ± 2, and 20 ± 2. A glucose tolerance test was performed at a minimum of 6 h after their last colostrum or milk meal to evaluate insulin sensitivity on d 2, 10 ± 2 and 20 ± 2. Body weight did not differ throughout between HI and MOD calves; however, calves born to primiparous dams were smaller compared with those born to multiparous dams. Glucose or insulin concentrations were not different before the glucose tolerance test. Following the glucose tolerance test, maximum glucose concentrations were not different between treatments at any time point. However, HI calves had greater insulin area under the curve, and HI calves had greater maximum insulin concentrations on d 2. Glucose or insulin clearance rates were not different nor was the calculated insulin sensitivity index between treatments. These findings suggest that feeding a HI prepartum diet may reduce some insulin sensitivity indicators of female offspring early in life.

Prolonged Prepregnant Maternal High-Fat Feeding Reduces Fetal and Neonatal Blood Glucose Concentrations by Enhancing Fetal β-Cell Development in C57BL/6 Mice

The main objective of this study was to investigate the effect of maternal obesity on offspring's glucose metabolism during the perinatal period. Maternal obesity was established by feeding C57BL/6 mice with a high-fat (HF) diet before or during pregnancy. Our results showed that prolonged prepregnant HF feeding but not HF feeding during pregnancy significantly reduced fetal and neonatal blood glucose concentrations. Remarkably, elevated blood insulin concentrations and increased activation of insulin signaling were observed in fetuses and neonates from prepregnant HF-fed dams. In addition, significantly larger β-cell areas were observed in pancreases of fetuses and neonates from prepregnant HF-fed dams. Although there was no significant change in placental cross-sectional area or GLUT 1 expression, prepregnant HF feeding significantly enhanced the expression of genes that control placental fatty acid supply. Interestingly, reducing fatty acid supply to the placenta and fetus by placental-specific knockout of adipose triglyceride lipase not only reduced fetal β-cell area and blood insulin concentration but also attenuated prepregnant HF feeding-induced reduction in offspring blood glucose concentrations during the perinatal period. Together, these results indicate that placental and fetal fatty acid supply plays an important role in fetal β-cell development, insulin secretion, and glucose metabolism. Prolonged prepregnant maternal HF feeding resembles pregravid maternal obesity in mice, which reduces fetal and neonatal blood glucose concentrations by enhancing fetal β-cell development and insulin secretion.

CELL BIOLOGY SYMPOSIUM: METABOLIC RESPONSES TO STRESS: FROM ANIMAL TO CELL: Poor maternal nutrition during gestation: effects on offspring whole-body and tissue-specific metabolism in livestock species1,2

Poor maternal nutrition, both restricted-feeding and overfeeding, during gestation can negatively affect offspring growth, body composition, and metabolism. The effects are observed as early as the prenatal period and often persist through postnatal growth and adulthood. There is evidence of multigenerational effects demonstrating the long-term negative impacts on livestock production. We and others have demonstrated that poor maternal nutrition impairs muscle growth, increases adipose tissue, and negatively affects liver function. In addition to altered growth, changes in key metabolic factors, increased glucose concentrations, insulin insensitivity, and hyperleptinemia are observed during the postnatal period. Furthermore, there is recent evidence of altered metabolism in specific tissues (e.g., muscle, adipose, and liver) and stem cells. The systemic and local changes in metabolism demonstrate the importance of determining the mechanism(s) by which maternal diet programs offspring growth and metabolism in an effort to develop novel management practices to improve the efficiency of growth and health in these offspring.

Maternal obesity in pregnancy impacts offspring cardiometabolic health: Systematic review and meta-analysis of animal studies

Obesity before and during pregnancy leads to reduced offspring cardiometabolic health. Here, we systematically reviewed animal experimental evidence of maternal obesity before and during pregnancy and offspring anthropometry and cardiometabolic health. We systematically searched Embase and Medline from inception until January 2018. Eligible publications compared offspring of mothers with obesity to mothers with a normal weight. We performed meta-analyses and subgroup analyses. We also examined methodological quality and publication bias. We screened 2543 publications and included 145 publications (N = 21 048 animals, five species). Essential methodological details were not reported in the majority of studies. We found evidence of publication bias for birth weight. Offspring of mothers with obesity had higher body weight (standardized mean difference (SMD) 0.76 [95% CI 0.60;0.93]), fat percentage (0.99 [0.64;1.35]), systolic blood pressure (1.33 [0.75;1.91]), triglycerides (0.64 [0.42;0.86], total cholesterol (0.46 [0.18;0.73]), glucose level (0.43 [0.24;0.63]), and insulin level (0.81 [0.61;1.02]) than offspring of control mothers, but similar birth weight. Sex, age, or species did not influence the effect of maternal obesity on offspring's cardiometabolic health. Obesity before and during pregnancy reduces offspring cardiometabolic health in animals. Future intervention studies should investigate whether reducing obesity prior to conception could prevent these detrimental programming effects and improve cardiometabolic health of future generations.

Effect of maternal obesity on fetal and postnatal baboon (Papio species) early life phenotype

BACKGROUND

Non-human primate models of developmental programming by maternal obesity (MO) are needed for translation to human programming outcomes. We present baboon offspring (F1) morphometry, blood cortisol, and adrenocorticotropic hormone (ACTH) from 0.9 gestation to 0-2 years.

METHODS

Control mothers ate chow; MO mothers ate high-fat high-energy diet pre-pregnancy through lactation.

RESULTS

Maternal obesity mothers weighed more than controls pre-pregnancy. Maternal obesity gestational weight gain was lower with no correlation with fetal or placenta weights. At 0.9 gestation, MO and control F1 morphometry and ACTH were similar. MO-F1 0.9 gestation male cortisol was lower, rising slower from 0-2 years vs control-F1. At birth, male MO-F1 and control-F1 weights were similar, but growth from 0-2 years was steeper in MO-F1; newborn female MO-F1 weighed more than control-F1 but growth from 0-2 years was similar. ACTH did not change in either sex.

CONCLUSIONS

Maternal obesity produced sexually dimorphic fetal and postnatal growth and hormonal phenotypes.

Embryonic programming of heart disease in response to obesity during pregnancy

Obesity during pregnancy programs adult-onset heart disease in the offspring. Clinical studies indicate that exposure to an adverse environment in utero during early, as compared to late, gestation leads to a higher prevalence of adult-onset heart disease. This suggests that the early developing heart is particularly sensitive to an adverse environment. Accordingly, growing evidence from clinical studies and animal models demonstrates that obesity during pregnancy alters the function of the fetal heart, programming a higher risk of cardiovascular disease later in life. Moreover, gene expression patterns and signaling pathways that promote initiation and progression of cardiovascular disease are altered in the hearts in offspring born to obese mothers. However, the mechanisms mediating the long-term effects of an adverse environment in utero on the developing heart leading to adult-onset disease are not clear. Here, we review clinical and experimental evidence documenting the effects of maternal obesity during pregnancy on the fetal and post-natal heart and emphasize on the potential mechanisms of disease programming.

Rapid Communication: Reduced maternal nutrition during early- to mid-gestation elevates newborn lamb plasma cortisol concentrations and eliminates the neonatal leptin surge

Human epidemiological and animal studies show that maternal nutrient reduction (MNR) and maternal overnutrition/obesity (MO) alter fetal growth and development, predisposing offspring (F1) to endocrine and appetite dysregulation. Compared to F1 of control-fed ewes, F1 of MO ewes display hypercortisolemia at birth and fail to exhibit the neonatal leptin surge implicated in lifelong appetite regulation. Here, we determined if MNR also elevates newborn lamb plasma cortisol and eliminates the neonatal leptin surge. Starting 30 d prior to conception, nulliparous control (CON, n = 6) ewes ate 100% NRC recommendations through parturition. Nutrient-reduced (NR, n = 6) ewes ate a CON diet through day 27 of gestation. From gestational days 28 to 78, NR ewes ate 50% of the CON diet before realimentation to 100% NRC recommendations. Jugular blood was collected daily from lambs from birth (day 0) through postnatal day 10, to determine plasma cortisol and leptin. Newborn NR plasma cortisol concentrations were increased (P < 0.0001) vs. CON and were similar to concentrations in MO lambs. Plasma leptin concentrations were similar between groups through postnatal day 7. The leptin surge, seen in CON lambs on postnatal days 8 to 10 was not present in NR lambs. These data show that, similar to MO lambs, early pregnancy MNR elevates newborn lamb plasma cortisol and eliminates the neonatal leptin surge. In the light of the similar elevation of neonatal cortisol in MNR and MO lambs, we conclude that cortisol plays a central role in regulating the neonatal lamb leptin surge.

Maternal obesity impairs fetal cardiomyocyte contractile function in sheep

Obesity is a major public health problem worldwide. In the United States, one-third of women of reproductive age are obese. Human studies show that maternal obesity (MO) predisposes offspring to cardiovascular disease. However, the underlying mechanisms remain unclear. Given the similarities between pregnancy in sheep and humans, we studied sheep to examine the impact of MO on fetal cardiomyocyte contractility at term. We observed that MO impaired cardiomyocyte contractility by reducing peak shortening and shortening/relengthening velocity, prolonging time to relengthening. MO disrupted Ca²⁺ homeostasis in fetal cardiomyocytes, increasing intracellular Ca²⁺ and inducing cellular Ca²⁺ insensitivity. The Ca²⁺-release channel was impaired, but Ca²⁺ uptake was unaffected by MO. The upstream kinases that phosphorylate the Ca²⁺-release channel-ryanodine receptor-2, PKA, and calmodulin-dependent protein kinase II-were activated in MO fetuses. Contractile dysfunction was associated with an increased ratio of myosin heavy chain (MHC)-β to MHC-α and upregulated cardiac troponin (cTn)-T and tropomyosin, as well as cTn-I phosphorylation. In summary, this is the first characterization of the effects of MO on fetal cardiomyocyte contractility. Our findings indicate that MO impairs fetal cardiomyocyte contractility through altered intracellular Ca²⁺ handling, overloading fetal cardiomyocyte intracellular Ca²⁺ and aberrant myofilament protein composition. These mechanisms may contribute to developmental programming by MO of offspring cardiac function and predisposition to later life cardiovascular disease in the offspring.-Wang, Q., Zhu, C., Sun, M., Maimaiti, R., Ford, S. P., Nathanielsz, P. W., Ren, J., Guo, W. Maternal obesity impairs fetal cardiomyocyte contractile function in sheep.

Epigenetic Mechanisms Link Maternal Diets and Gut Microbiome to Obesity in the Offspring

Nutrition is the most important environmental factor that can influence early developmental processes through regulation of epigenetic mechanisms during pregnancy and neonatal periods. Maternal diets or nutritional compositions contribute to the establishment of the epigenetic profiles in the fetus that have a profound impact on individual susceptibility to certain diseases or disorders in the offspring later in life. Obesity is considered a global epidemic that impairs human life quality and also increases risk of development of many human diseases such as diabetes and cardiovascular diseases. Studies have shown that maternal nutrition status is closely associated with obesity in progenies indicating obesity has a developmental origin. Maternal diets may also impact the early establishment of the fetal and neonatal microbiome leading to specific epigenetic signatures that may potentially predispose to the development of late-life obesity. This article will review the association of different maternal dietary statuses including essential nutritional quantity and specific dietary components with gut microbiome in determining epigenetic impacts on offspring susceptibility to obesity.

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.

Fetal pancreatic Langerhans islets size in pregnancies with metabolic disorders

Objective: Metabolic disorders are a pandemic and increasing health problem. Women of childbearing age may also be affected, thus an abnormal metabolism may interfere with pregnancy short- and long-term outcomes, harming both mother and child. In the context of an abnormal maternal and intrauterine metabolic milieu the development of fetal organs, including pancreas, may be affected. Aim: To investigate the effects of pregnancy metabolic disorders on the morphology of pancreatic Langerhans islets in human late-third trimester stillborn fetuses. Methods: Samples from fetal pancreas underwent a quantitative histological evaluation to detect differences between pregnancy with (cases, n = 9) or without (controls, n = 6) abnormal metabolism. Results: Results show that the islets size increases in fetuses from dysmetabolic pregnancies and that this increment is related to both beta-cell hyperplasia and hypertrophy. Moreover, according to pregnancy and fetal metabolic disorders, a threshold of abnormal size of the islets has been identified. Above this threshold the size of fetal pancreatic Langerhans islets should be considered excessively increased. Conclusion: The study suggests that an accurate fetal pancreas analysis supplies an important tool in stillborn fetus, to discover metabolic disturbances that should be kept in mind and managed in future pregnancies.