Maternal diet-induced obesity programmes cardiac dysfunction in male mice independently of post-weaning diet.
ABSTRACT: Aims:Obesity during pregnancy increases risk of cardiovascular disease (CVD) in the offspring and individuals exposed to over-nutrition during fetal life are likely to be exposed to a calorie-rich environment postnatally. Here, we established the consequences of combined exposure to a maternal and post-weaning obesogenic diet on offspring cardiac structure and function using an established mouse model of maternal diet-induced obesity. Methods and results:The impact of the maternal and postnatal environment on the offspring metabolic profile, arterial blood pressure, cardiac structure, and function was assessed in 8-week-old C57BL/6 male mice. Measurement of cardiomyocyte cell area, the transcriptional re-activation of cardiac fetal genes as well as genes involved in the regulation of contractile function and matrix remodelling in the adult heart were determined as potential mediators of effects on cardiac function. In the adult offspring: a post-weaning obesogenic diet coupled with exposure to maternal obesity increased serum insulin (P?
Project description:Previous studies have shown that maternal diet-induced obesity leads to increased risk of type 2 diabetes in offspring. The current study investigated if weaning onto an obesogenic diet exaggerated the detrimental effects of maternal diet-induced obesity in adipose tissue. Maternal obesity and offspring obesity led to reduced expression of key insulin signalling proteins, including insulin receptor substrate-1 (IRS-1). The effects of maternal obesity and offspring obesity were, generally, independent and additive. Irs1 mRNA levels were similar between all four groups of offspring, suggesting that in both cases post-transcriptional regulation was involved. Maternal diet-induced obesity increased miR-126 expression however levels of this miR were not influenced by a post-weaning obesogenic diet. In contrast, a post-weaning obesogenic diet was associated with increased levels of suppressor of cytokine signaling-1, implicating increased degradation of IRS-1 as an underlying mechanism. Our results suggest that whilst programmed reductions in IRS-1 are associated with increased levels of miR-126 and consequently reduced translation of Irs1 mRNA, the effects of a post-weaning obesogenic diet on IRS-1 are mediated by miR-126 independent mechanisms, including increased IRS-1 protein degradation. These divergent mechanisms explain why the combination of maternal obesity and offspring obesity leads to the most pronounced effects on offspring metabolism.
Project description:Maternal obesity increases the risk of metabolic dysregulation in rodent offspring, especially when offspring are exposed to a high-fat (HF), obesogenic diet later in life. We previously demonstrated that maternal choline supplementation (MCS) in HF-fed mouse dams during gestation prevents fetal overgrowth and excess adiposity. In this study, we examined the long-term metabolic influence of MCS. C57BL/6J mice were fed a HF diet with or without choline supplementation prior to and during gestation. After weaning, their pups were exposed to either a HF or control diet for 6 weeks before measurements. Prenatal and post-weaning dietary treatments led to sexually dimorphic responses. In male offspring, while post-weaning HF led to impaired fasting glucose and worse glucose tolerance (p < 0.05), MCS in HF dams (HFCS) attenuated these changes. HFCS (versus maternal normal fat control) appeared to improve metabolic functioning of visceral adipose tissue during post-weaning HF feeding, preventing the elevation in leptin and increasing (p < 0.05) mRNA expression of insulin receptor substrate 1 (Irs1) that promotes peripheral insulin signaling in male offspring. In contrast, MCS had minimal effects on metabolic outcomes of female offspring. In conclusion, MCS during HF feeding in mice improves long-term blood glucose homeostasis in male offspring when they are faced with a postnatal obesogenic environment.
Project description:Background: It is well established that maternal exercise during pregnancy improves metabolic outcomes associated with obesity in mothers and offspring, however, its effects on the gut microbiota of both mother and offspring, are unknown. Here, we investigated whether wheel running exercise prior to and during pregnancy and prolonged feeding of an obesogenic diet were associated with changes in the gut microbiomes of Sprague-Dawley rat dams and their offspring. Female rats were fed either chow or obesogenic diet, and half of each diet group were given access to a running wheel 10 days before mating until delivery, while others remained sedentary. 16S rRNA gene amplicon sequencing was used to assess gut microbial communities in dams and their male and female offspring around the time of weaning. Results: Statistical analyses at the operational taxonomic unit (OTU) level revealed that maternal obesogenic diet decreased gut microbial alpha diversity and altered abundances of bacterial taxa previously associated with obesity such as Bacteroides and Blautia in dams, and their offspring of both sexes. Distance based linear modeling revealed that the relative abundances of Bacteroides OTUs were associated with adiposity measures in both dams and offspring. We identified no marked effects of maternal exercise on the gut microbiota of obesogenic diet dams or their offspring. In contrast, maternal exercise decreased gut microbial alpha diversity and altered the abundance of 88 microbial taxa in offspring of control dams. Thirty of these taxa were altered in a similar direction in offspring of sedentary obesogenic vs. control diet dams. In particular, the relative abundances of Oscillibacter OTUs were decreased in offspring of both exercised control dams and sedentary obesogenic diet dams, and associated with blood glucose concentrations and adiposity measures. Analyses of predicted bacterial metabolic pathways inferred decreased indole alkaloid biosynthesis in offspring of both obesogenic diet and exercised control dams. Conclusions: Our data suggest that maternal exercise prior to and during pregnancy resulted in gut dysbiosis in offspring of control dams. Importantly, alterations in the maternal gut microbiota by obesogenic diet or obesity were transferred to their offspring.
Project description:Human and animal studies show that suboptimal intrauterine environments lead to fetal programming, predisposing offspring to disease in later life. Maternal obesity has been shown to program offspring for cardiovascular disease (CVD), diabetes, and obesity. MicroRNAs (miRNAs) are small, noncoding RNA molecules that act as key regulators of numerous cellular processes. Compelling evidence links miRNAs to the control of cardiac development and etiology of cardiac pathology; however, little is known about their role in the fetal cardiac response to maternal obesity. Our aim was to sequence and profile the cardiac miRNAs that are dysregulated in the hearts of baboon fetuses born to high fat/high fructose-diet (HFD) fed mothers for comparison with fetal hearts from mothers eating a regular diet. Eighty miRNAs were differentially expressed. Of those, 55 miRNAs were upregulated and 25 downregulated with HFD. Twenty-two miRNAs were mapped to human; 14 of these miRNAs were previously reported to be dysregulated in experimental or human CVD. We used an Ingenuity Pathway Analysis to integrate miRNA profiling and bioinformatics predictions to determine miRNA-regulated processes and genes potentially involved in fetal programming. We found a correlation between miRNA expression and putative gene targets involved in developmental disorders and CVD. Cellular death, growth, and proliferation were the most affected cellular functions in response to maternal obesity. Thus, the current study reveals significant alterations in cardiac miRNA expression in the fetus of obese baboons. The epigenetic modifications caused by adverse prenatal environment may represent one of the mechanisms underlying fetal programming of CVD.
Project description:Obesity during pregnancy is associated with increased risk of non-alcoholic fatty liver disease in the offspring. We used RNA next generation sequencing analysis (HiSeq2000) to have a snapshot of the liver transcriptome in twelve week-old male offspring exposed to maternal obesity and weaned onto an obesogenic diet. Overall design: Thirty-five female C57BL/6J mice were fed either a standard control diet, RM1 [7% simple carbohydrates/3% lipids (w/w)] or an energy-rich obesogenic diet [10% simple carbohydrates/20% lipids (w/w)] plus sweetened condensed milk [55% simple carbohydrates, 8% lipids, 8% protein (w/w), supplemented with mineral and vitamin mix AIN93G]. Female mice were mated, and maintained on their diets until weaning. On post-natal day 21, male offspring were weaned onto either standard chow (RM1) or the obesogenic diet, generating 4 experimental groups: maternal and offspring control diet (CC), maternal control diet and offspring obesogenic diet (CO), maternal obesogenic diet and offspring control diet (OC), maternal and offspring obesogenic diet (OO). At 12 weeks of age, mice were killed by raising on a fasted state. Liver were dissected, and snap frozen. Three high quality RNA samples from each group were randomly selected and subjected to a cDNA library preparation for further mRNA sequencing using TruSeq RNA Library Preparation kit
Project description:Obesity during pregnancy is associated with increased risk of non-alcoholic fatty liver disease in the offspring. We used RNA next generation sequencing analysis (HiSeq2000) to have a glance at the miRNome in twelve week-old male offspring exposed to maternal obesity and weaned onto an obesogenic diet. Overall design: Thirty-five female C57BL/6J mice were fed either a standard control diet, RM1 [7% simple carbohydrates/3% lipids (w/w)] or an energy-rich obesogenic diet [10% simple carbohydrates/20% lipids (w/w)] plus sweetened condensed milk [55% simple carbohydrates, 8% lipids, 8% protein (w/w), supplemented with mineral and vitamin mix AIN93G]. Female mice were mated, and maintained on their diets until weaning. On post-natal day 21, male offspring were weaned onto either standard chow (RM1) or the obesogenic diet, generating 4 experimental groups: maternal and offspring control diet (CC), maternal control diet and offspring obesogenic diet (CO), maternal obesogenic diet and offspring control diet (OC), maternal and offspring obesogenic diet (OO). At 12 weeks of age, mice were killed by raising on a fasted state. Liver were dissected, and snap frozen. Three high quality RNA samples from each group were randomly selected and subjected to a cDNA library preparation for further sRNA sequencing using TruSeq RNA Library Preparation kit
Project description:Maternal obesity in pregnancy predisposes offspring to insulin resistance and associated cardiovascular disease. Here, we used a well-established sheep model to investigate the effects of maternal obesity on cardiac functions. Multiparous ewes were assigned to a control (CON) diet [100% of National Research Council (NRC) recommendations] or an obesogenic (OB) diet (150% of NRC recommendations) from 60 d before conception to necropsy on d 135 of pregnancy. Fetal blood glucose and insulin were increased (P<0.01, n=8) in OB (35.09+/-2.03 mg/dl and 3.40+/-1.43 microU/ml, respectively) vs. CON ewes (23.80+/-1.38 mg/dl and 0.769+/-0.256 microU/ml). Phosphorylation of AMP-activated protein kinase (AMPK), a cardioprotective signaling pathway, was reduced (P<0.05), while the stress signaling pathway, p38 MAPK, was up-regulated (P<0.05) in OB maternal and fetal hearts. Phosphorylation of c-Jun N-terminal kinase (JNK) and insulin receptor substrate-1 (IRS-1) at Ser-307 were increased (P<0.05) in OB fetal heart associated with lower downstream PI3K-Akt activity (P<0.05), indicating impaired cardiac insulin signaling. Although OB fetal hearts exhibited a normal contractile function vs. CON fetal hearts during basal perfusion, they developed an impaired heart-rate-left-ventricular-developed pressure product in response to high workload stress. Taken together, fetuses of OB mothers demonstrate alterations in cardiac PI3K-Akt, AMPK, and JNK-IRS-1 signaling pathways that would predispose them to insulin resistance and cardiac dysfunction.
Project description:Although a pre-pregnancy dietary intervention is believed to be able to prevent offspring obesity, research evidence is absent. We hypothesize that a long period of pre-pregnancy maternal diet transition from a high-fat (HF) diet to a normal-fat (NF) diet effectively prevents offspring obesity, and this preventive effect is independent of maternal body weight change. In our study, female mice were either continued on an NF diet (NF group) or an HF diet (HF group) until weaning, or switched from an HF to an NF for 1 week (H1N group), 5 weeks (H5N group) or 9 weeks (H9N group) before pregnancy. After weaning, the offspring were given the HF diet for 12 weeks to promote obesity. The mothers, regardless of which group, did not display maternal body weight change and glucose intolerance either before pregnancy or after weaning. Compared to the HF group, the H1N and H5N, but not the H9N, offspring developed glucose intolerance earlier, with more severely imbalanced glucose homeostasis. These offspring also displayed hepatocyte degeneration and significant adipocyte hypertrophy associated with higher expression of lipogenesis genes. The molecular mechanistic study showed blunted insulin signaling, overactivated adipocyte Akt signaling and hepatic AMPK signaling with enhanced lipogenesis genes in the H1N and H5N versus the NF offspring. However, maternal H9N diets normalized glucose and lipid metabolism of the offspring via resensitized insulin signaling and normalized Akt and AMPK signaling. In summary, we showed that a long-term maternal diet intervention effectively released the intergenerational obesogenic effect of maternal HF diet independent of maternal weight management.
Project description:To determine the impact of maternal and post-weaning consumption of a high fat diet on endothelium-dependent vasorelaxation and redox regulation in adult male mouse offspring.Female C57BL6J mice were fed an obesogenic high fat diet (HF, 45% kcal fat) or standard chow (C, 21% kcal fat) pre-conception and throughout pregnancy and lactation. Post-weaning, male offspring were continued on the same diet as their mothers or placed on the alternative diet to give 4 dietary groups (C/C, HF/C, C/HF and HF/HF) which were studied at 15 or 30 weeks of age.There were significant effects of maternal diet on offspring body weight (p<0.004), systolic blood pressure (p = 0.026) and endothelium-dependent relaxation to ACh (p = 0.004) and NO production (p = 0.005) measured in the femoral artery. With control for maternal diet there was also an effect of offspring post-weaning dietary fat to increase systolic blood pressure (p<0.0001) and reduce endothelium-dependent relaxation (p = 0.022) and ACh-mediated NO production (p = 0.007). There was also a significant impact of age (p<0.005). Redox balance was perturbed, with altered regulation of vascular enzymes involved in ROS/NO signalling.Maternal consumption of a HF diet is associated with changes in vascular function and oxidative balance in the offspring of similar magnitude to those seen with consumption of a high fat diet post-weaning. Further, this disadvantageous vascular phenotype is exacerbated by age to influence the risk of developing obesity, raised blood pressure and endothelial dysfunction in adult life.
Project description:Maternal obesity (MO) impairs maternal and offspring health. Mechanisms and interventions to prevent adverse maternal and offspring outcomes need to be determined. Human studies are confounded by socio-economic status providing the rationale for controlled animal data on effects of maternal exercise (MEx) intervention on maternal (F0) and offspring (F1) outcomes in MO.MO produces metabolic and endocrine dysfunction, increases maternal and offspring glucocorticoid exposure, oxidative stress and adverse offspring outcomes by postnatal day (PND) 36. MEx in part prevents these outcomes.F0 female rats ate either control or obesogenic diet from weaning through lactation. Half of each group wheel ran (from day 90 of life through pregnancy beginning day 120) providing four groups (n=8/group)--(i) controls, (ii) obese, (iii) exercised controls and (iv) exercised obese. After weaning, PND 21, F1 offspring ate a control diet. Metabolic parameters of F0 prepregnancy and end of lactation and F1 offspring at PND 36 were analyzed.Exercise did not change maternal weight. Before breeding, MO elevated F0 glucose, insulin, triglycerides, cholesterol, leptin, fat and oxidative stress. Exercise completely prevented the triglyceride rise and partially increases glucose, insulin, cholesterol and oxidative stress. MO decreased fertility, recovered by exercise. At the end of lactation, exercise returned all metabolic variables except leptin to control levels. Exercise partially prevented MO elevated corticosterone. F1 offspring weights were similar at birth. At PND 36, MO increased F1 male but not female offspring leptin, triglycerides and fat mass. In controls, exercise reduced male and female offspring glucose, prevented the offspring leptin increase and partially the triglyceride rise.MEx before and during pregnancy has beneficial effects on the maternal and offspring metabolism and endocrine function occurring with no weight change in mothers and offspring indicating the importance of body composition rather than weight in evaluations of metabolic status.