Effect of Maternal Obesity and Preconceptional Weight Loss on Male and Female Offspring Metabolism and Olfactory Performance in Mice

Breastfeeding: science and knowledge in pediatric obesity prevention

The increasing prevalence of childhood obesity worldwide is a significant concern due to its link to severe health issues in adulthood, such as non-communicable diseases (NCDs). To address this issue, this review evaluates the effectiveness of various preventive measures for childhood obesity, focusing on maternal nutrition and breastfeeding. The study underscores the criticality of the periconceptional period, where the diets of both parents can influence epigenetic modifications that impact the child's metabolic pathways and obesity risks. Breastfeeding is a potent protective mechanism against early-onset obesity, significantly enhancing the infant's metabolic and immune health by modifying DNA methylation and gene expression. Furthermore, the perspective underscores the significance of the Mediterranean diet during the periconceptional period and lactation. This diet can effectively prevent gestational complications and improve breast milk quality, fostering optimal infant development. Recognizing that obesity results from genetic, epigenetic, environmental, and social factors, the paper advocates for a comprehensive, multidisciplinary approach from the earliest stages of life. This approach champions a balanced maternal diet, exclusive breastfeeding, and timely introduction to complementary foods. In conclusion, addressing pediatric obesity requires a multifaceted strategy emphasizing improving prenatal and postnatal nutrition. Further research is necessary to understand the epigenetic mechanisms influenced by nutrition and their long-term effects on children's health. This will help refine interventions that curb the obesity epidemic among future generations.

Preconception Diet Interventions in Obese Outbred Mice and the Impact on Female Offspring Metabolic Health and Oocyte Quality

Obese individuals often suffer from metabolic health disorders and reduced oocyte quality. Preconception diet interventions in obese outbred mice restore metabolic health and oocyte quality and mitochondrial ultrastructure. Also, studies in inbred mice have shown that maternal obesity induces metabolic alterations and reduces oocyte quality in offspring (F1). Until now, the effect of maternal high-fat diet on F1 metabolic health and oocyte quality and the potential beneficial effects of preconception dietary interventions have not been studied together in outbred mice. Therefore, we fed female mice a high-fat/high-sugar (HF/HS) diet for 7 weeks and switched them to a control (CONT) or caloric-restriction (CR) diet or maintained them on the HF/HS diet for 4 weeks before mating, resulting in three treatment groups: diet normalization (DN), CR, and HF/HS. In the fourth group, mice were fed CONT diet for 11 weeks (CONT). HF/HS mice were fed an HF/HS diet from conception until weaning, while all other groups were then fed a CONT diet. After weaning, offspring were kept on chow diet and sacrificed at 11 weeks. We observed significantly elevated serum insulin concentrations in female HF/HS offspring and a slightly increased percentage of mitochondrial ultrastructural abnormalities, mitochondrial size, and mitochondrial mean gray intensity in HF/HS F1 oocytes. Also, global DNA methylation was increased and cellular stress-related proteins were downregulated in HF/HS F1 oocytes. Mostly, these alterations were prevented in the DN group, while, in CR, this was only the case for a few parameters. In conclusion, this research has demonstrated for the first time that a maternal high-fat diet in outbred mice has a moderate impact on female F1 metabolic health and oocyte quality and that preconception DN is a better strategy to alleviate this compared to CR.

The effect of chronic, non-pathogenic maternal immune activation on offspring postnatal muscle and immune outcomes

The objective was to determine the effects of maternal inflammation on offspring muscle development and postnatal innate immune response. Sixteen first-parity gilts were randomly allotted to repeated intravenous injections with lipopolysaccharide (LPS; n = 8, treatment code INFLAM) or comparable volume of phosphate buffered saline (CON, n = 8). Injections took place every other day from gestational day (GD) 70 to GD 84 with an initial dose of 10 μg LPS/kg body weight (BW) increasing by 12% each time to prevent endotoxin tolerance. On GD 70, 76, and 84, blood was collected at 0 and 4 h postinjection via jugular or ear venipuncture to determine tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β concentrations. After farrowing, litter mortality was recorded, and the pig closest to litter BW average was used for dissection and muscle fiber characterization. On weaning (postnatal day [PND] 21), pigs were weighed individually and 2 barrows closest to litter BW average were selected for another study. The third barrow closest to litter BW average was selected for the postnatal LPS challenge. On PND 52, pigs were given 5 μg LPS/kg BW via intraperitoneal injection, and blood was collected at 0, 4, and 8 h postinjection to determine TNF-α concentration. INFLAM gilt TNF-α concentration increased (P < 0.01) 4 h postinjection compared to 0 h postinjection, while CON gilt TNF-α concentration did not differ between time points. INFLAM gilt IL-6 and IL-1β concentrations increased (P = 0.03) 4 h postinjection compared to 0 h postinjection on GD 70, but did not differ between time points on GD 76 and 84. There were no differences between INFLAM and CON gilts litter mortality outcomes (P ≥ 0.13), but INFLAM pigs were smaller (P = 0.04) at birth and tended (P = 0.09) to be smaller at weaning. Muscle and organ weights did not differ (P ≥ 0.17) between treatments, with the exception of semitendinosus, which was smaller (P < 0.01) in INFLAM pigs. INFLAM pigs tended (P = 0.06) to have larger type I fibers. INFLAM pig TNF-α concentration did not differ across time, while CON pig TNF-α concentration peaked (P = 0.01) 4 h postinjection. TNF-α concentration did not differ between treatments at 0 and 8 h postinjection, but CON pigs had increased (P = 0.01) TNF-α compared to INFLAM pigs 4 h postinjection. Overall, maternal immune activation did not alter pig muscle development, but resulted in suppressed innate immune activation.

The Effect of Maternal Exposure to a Diet High in Fats and Cholesterol on the Placental Function and Phenotype of the Offspring in a Rabbit Model: A Summary Review of About 15 Years of Research

The rates of obesity and being overweight are increasing all around the world, especially among women of childbearing age, in part due to overconsumption of lipids. The aim of this summary review was to present the cellular and molecular effects of a hyperlipidic high-cholesterol (H) diet on the maternal and offspring phenotype at the early embryonic, neonatal, weaning and adult stages while considering the effects of sex and to identify the window(s) of vulnerability linked to this exposure in a rabbit model. Before breeding, the H diet induced dyslipidemia and aortic atherosclerosis lesions and increased the number of atretic follicles. In the offspring, the H diet disrupted the embryonic phenotype and induced fetal hypotrophy associated with sex-specific disturbances of the feto-placental unit. In adulthood, the offspring of the H dams were heavier and hyperphagic and had increased blood pressure associated with disturbed gonadal development in both sexes. Vulnerability windows were explored via embryo transfers. The maternal gestational diet was shown to play a key role in the feto-placental phenotype, and preconception programming was unquestionably also observed. These two periods could represent windows of intervention in the context of obesity or being overweight to limit fetal and placental consequences.

The Legacy of Parental Obesity: Mechanisms of Non-Genetic Transmission and Reversibility

While a dramatic increase in obesity and related comorbidities is being witnessed, the underlying mechanisms of their spread remain unresolved. Epigenetic and other non-genetic mechanisms tend to be prominent candidates involved in the establishment and transmission of obesity and associated metabolic disorders to offspring. Here, we review recent findings addressing those candidates, in the context of maternal and paternal influences, and discuss the effectiveness of preventive measures.

β-Glucan-Rich Extract of Gray Oyster Mushroom, Pleurotus pulmonarius, Improves Object Recognition Memory and Hippocampus Morphology in Mice Fed a High-Fat Diet

Obesity may cause behavioral alterations, while maternal obesity can contribute to metabolic disorders in subsequent generations. The effect of β-glucan-rich Pleurotus pulmonarius (βgPp) was investigated on mouse neurobehavior and hippocampus and its offspring's hippocampus development. Female ICR mice were fed with normal diet (ND), ND with βgPp, high-fat diet (HFD), or HFD with βgPp for 3 months followed by behavioral test and mating. Immunohistochemistry for the expression of neuronal nuclear protein (NeuN) and ionized calcium binding adaptor molecule-1 (Iba-1) in the hippocampus was carried out. βgPp significantly enhanced short-term object recognition memory in HFD-fed mice. βgPp also ameliorated the histological alterations and neuronal loss and increased Iba-1-positive microglia in the hippocampus regions of HFD-fed mice and their male offspring. These findings demonstrated that βgPp supplementation attenuated the effects of HFD on object recognition memory and the alterations on the hippocampal regions of maternal mice and their male offspring.

Importance of Windows of Exposure to Maternal High-Fat Diet and Feto-Placental Effects: Discrimination Between Pre-conception and Gestational Periods in a Rabbit Model

Context and Aim: Lipid overnutrition in female rabbits, from prepuberty, leads to impaired metabolism (dyslipidemia and increased adiposity) and follicular atresia, and, when continued during gestation, affects offspring phenotype with intrauterine growth retardation (IUGR) and leads to placental and lipid metabolism abnormalities. Growth retardation is already observed in embryo stage, indicating a possible implication of periconceptional exposure. The objective of this study was to discriminate the effects of preconception and gestational exposures on feto-placental development.

Materials and Methods: Rabbit 1-day zygotes were collected from female donors under control (CD) or high-fat-high-cholesterol (HD) diet and surgically transferred to the left and right uterus, respectively, of each H (n = 6) or C (n = 7) synchronized recipients. Close to term, four combinations, CC (n = 10), CH (n = 13), HC (n = 13), and HH (n = 6), of feto-placental units were collected, for biometry analyses. Fatty acid (FA) profiles were determined in placental labyrinth, decidua, fetal plasma, and fetal liver by gas chromatography and explored further by principal component analysis (PCA). Candidate gene expression was also analyzed by RT-qPCR in the placenta and fetal liver. Data were analyzed by Kruskal–Wallis followed by Dunn’s pairwise comparison test. Combinations of different data sets were combined and explored by multifactorial analysis (MFA).

Results: Compared to controls, HH fetuses were hypotrophic with reduced placental efficiency and altered organogenesis, CH presented heavier placenta but less efficient, whereas HC presented a normal biometry. However, the MFA resulted in a good separation of the four groups, discriminating the effects of each period of exposure. HD during gestation led to reduced gene expression (nutrient transport and metabolism) and big changes in FA profiles in both tissues with increased membrane linoleic acid, lipid storage, and polyunsaturated-to-saturated FA ratios. Pre-conception exposure had a major effect on fetal biometry and organogenesis in HH, with specific changes in FA profiles (increased MUFAs and decreased LCPUFAs).

Conclusion: Embryo origin left traces in end-gestation feto-placental unit; however, maternal diet during gestation played a major role, either negative (HD) or positive (control). Thus, an H embryo developed favorably when transferred to a C recipient (HC) with normal biometry at term, despite disturbed and altered FA profiles.

The role of sperm and oocyte in fetal programming: Is Lamarck making a comeback?

Compelling evidence has shown that parental experiences and age at conception may potentially shape the future health of the next generation(s). Certain factors may affect both the female and, strikingly, the male gametes potentially causing the transmission of acquired traits, which was strongly defended by Jean-Baptiste Lamarck. Neurodevelopmental psychiatric disorders, trinucleotide repeat-associated diseases, cardiovascular pathologies, diabetes, obesity and cancer in the offspring, among others, have now been associated with events occurring at the preconception level. The potential implications of a (trans)generational inheritance of parental disease and exposure effects should be taken into account in counselling and public policy. Further research into how exactly gametes apparently deliver more than DNA to a new generation is warranted.

Maternal high-sugar diet results in NMDA receptors abnormalities and cognitive impairment in rat offspring

Cognitive impairment affects patients suffering from various neuropsychiatric diseases, which are often accompanied by changes in the glutamatergic system. Epidemiological studies indicate that predispositions to the development of neuropsychiatric diseases may be programmed prenatally. Mother's improper diet during pregnancy and lactation may cause fetal abnormalities and, consequently, predispose to diseases in childhood and even adulthood. Considering the prevalence of obesity in developed countries, it seems important to examine the effects of diet on the behavior and physiology of future generations. We hypothesized that exposure to sugar excess in a maternal diet during pregnancy and lactation would affect memory as the NMDA receptor-related processes. Through the manipulation of the sugar amount in the maternal diet in rats, we assessed its effect on offspring's memory. Then, we evaluated if memory alterations were paralleled by molecular changes in NMDA receptors and related modulatory pathways in the prefrontal cortex and the hippocampus of adolescent and young adult female and male offspring. Behavioral studies have shown sex-related changes like impaired recognition memory in adolescent males and spatial memory in females. Molecular results confirmed an NMDA receptor hypofunction along with subunit composition abnormalities in the medial prefrontal cortex of adolescent offspring. In young adults, GluN2A-containing receptors were dominant in the medial prefrontal cortex, while in the hippocampus the GluN2B subunit contribution was elevated. In conclusion, we demonstrated that a maternal high-sugar diet can affect the memory processes in the offspring by disrupting the NMDA receptor composition and regulation in the medial prefrontal cortex and the hippocampus.

Reducing intergenerational obesity and diabetes risk

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

Maternal dietary patterns are associated with susceptibility to a depressive-like phenotype in rat offspring

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Modified maternal diet influences offspring behavior and the brain transcriptome.

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Maternal HFD provokes depressive-like behavior in male and female offspring.

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In utero exposure to HFD leads to transcriptomics alterations within the offspring’s frontal cortex.

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Maternal HFD changes expression of markers specific to excitatory and inhibitory cortical neurons.

Environmental factors such as maternal diet, determine the pathologies that appear early in life and can persist in adulthood. Maternally modified diets provided through pregnancy and lactation increase the predisposition of offspring to the development of many diseases, including obesity, diabetes, and neurodevelopmental and mental disorders such as depression. Fetal and early postnatal development are sensitive periods in the offspring’s life in which maternal nutrition influences epigenetic modifications, which results in changes in gene expression and affects molecular phenotype. This study aimed to evaluate the impact of maternal modified types of diet, including a high-fat diet (HFD), high-carbohydrate diet (HCD) and mixed diet (MD) during pregnancy and lactation on phenotypic changes in rat offspring with respect to anhedonia, depressive- and anxiety-like behavior, memory impairment, and gene expression profile in the frontal cortex. Behavioral results indicate that maternal HFD provokes depressive-like behavior and molecular findings showed that HFD leads to persistent transcriptomics alterations. Moreover, a HFD significantly influences the expression of neuronal markers specific to excitatory and inhibitory cortical neurons. Collectively, these experiments highlight the complexity of the impact of maternal modified diet during fetal programming. Undoubtedly, maternal HFD affects brain development and our findings suggest that nutrition exerts significant changes in brain function that may be associated with depression.

Differential Effects of Post-Weaning Diet and Maternal Obesity on Mouse Liver and Brain Metabolomes

Nutritional changes during developmental windows are of particular concern in offspring metabolic disease. Questions are emerging concerning the role of maternal weight changes before conception, particularly for weight loss, in the development of diet-related disorders. Understanding the physiological pathways affected by the maternal trajectories in the offspring is therefore essential, but a broad overview is still lacking. We recently reported both metabolic and behavioral negative outcomes in offspring born to obese or weight-loss mothers and fed a control of high-fat diet, suggesting long-term modeling of metabolic pathways needing to be further characterized. Using non-targeted LC–HRMS, we investigated the impact of maternal and post-weaning metabolic status on the adult male offspring’s metabolome in three tissues involved in energy homeostasis: liver, hypothalamus and olfactory bulb. We showed that post-weaning diet interfered with the abundance of several metabolites, including 1,5-anhydroglucitol, saccharopine and β-hydroxybutyrate, differential in the three tissues. Moreover, maternal diet had a unique impact on the abundance of two metabolites in the liver. Particularly, anserine abundance, lowered by maternal obesity, was normalized by a preconceptional weight loss, whatever the post-weaning diet. This study is the first to identify a programming long-term effect of maternal preconception obesity on the offspring metabolome.

Gestational Diabetes Triggers Oxidative Stress in Hippocampus and Cerebral Cortex and Cognitive Behavior Modifications in Rat Offspring: Age- and Sex-Dependent Effects

Gestational diabetes (GD) has been linked with an increased risk of developing metabolic disorders and behavioral abnormalities in the offspring. Oxidative stress is strongly associated with neurodegeneration and cognitive disruption. In the offspring brains in a GD experimental rat model, increased oxidative stress in the prenatal and postnatal stages was reported. However, long-term alterations to offspring behavior and oxidative stress, caused by changes in the cerebral cortex and hippocampus, remain unclear. In this study, we evaluated the effect of GD on young and adult male and female rat offspring in metabolic parameters, cognitive behavior, and oxidative stress. GD was induced using streptozotocin in dams. Next, the offspring were evaluated at two and six months of age. Anxiety-like behavior was evaluated using the elevated plus maze and open field maze; spatial learning and short-term memory were evaluated using the Morris water maze and radial maze, respectively. We determined oxidative stress biomarkers (reactive oxygen species (ROS), lipid peroxidation and glutathione status) and antioxidant enzymes (superoxide dismutase and catalase) in the brain of offspring. We observed that male GD offspring showed a reduced level of anxiety at both ages as they spent less time in the closed arms of the elevated plus maze at adult age ((P = 0.019, d = 1.083 ( size effect)) and spent more time in the open area of an open field (P = 0.0412, d = 0.743) when young and adult age (P = 0.018, d = 0.65). Adult female GD offspring showed a reduced level of anxiety (P = 0.036; d = 0.966), and young female GD offspring showed a deficiency in spatial learning (P = 0.0291 vs. control, d = 3.207). Adult male GD offspring showed a deficiency in short-term memory (P = 0.017, d = 1.795). We found an increase in ROS and lipid peroxidation, a disruption in the glutathione status, and decreased activity of catalase and superoxide dismutase (P < 0.05 vs. control, d > 1.0), in the cerebral cortex and hippocampus of male and female GD offspring. GD altered metabolism; male offspring of both ages and adult females showed a high level of triglycerides and a lower level of high-density lipoprotein-cholesterol (P < 0.05 vs. control, d > 1.0). Young and adult female offspring displayed higher insulin levels (P < 0.05, d > 1.0). These results suggest that gestational diabetes modifies oxidative stress and cognitive behavior in an age- and sex-dependent manner.

Epigenetics and the Developmental Origins of Health and Disease: Parental environment signalling to the epigenome, critical time windows and sculpting the adult phenotype

The literature about Developmental Origins of Health and Disease (DOHaD) studies is considerably growing. Maternal and paternal environment, during all the development of the individual from gametogenesis to weaning and beyond, as well as the psychosocial environment in childhood and teenage, can shape the adult and the elderly person's susceptibility to her/his own environment and diseases. This non-conventional, non-genetic, inheritance is underlain by several mechanisms among which epigenetics is obviously central, due to the notion of memory of early decisional events during development even when this stimulus is gone, that is implied in Waddington's developmental concept. This review first summarizes the different mechanisms by which the environment can model the epigenome: receptor signalling, energy metabolism and signal mechanotransduction from extracellular matrix to chromatin. Then an overview of the epigenetic changes in response to maternal environment during the vulnerability time windows, gametogenesis, early development, placentation and foetal growth, and postnatal period, is described, with the specific example of overnutrition and food deprivation. The implication of epigenetics in DOHaD is obvious, however the precise causal chain from early environment to the epigenome modifications to the phenotype still needs to be deciphered.