Abstract-Maternal obesity is increasingly prevalent and may affect the long-term health of the child. We investigated the effects of maternal diet-induced obesity in mice on offspring metabolic and cardiovascular function. Female C57BL/6J mice were fed either a standard chow (3% fat, 7% sugar) or a palatable obesogenic diet (16% fat, 33% sugar) for 6 weeks before mating and throughout pregnancy and lactation. Offspring of control (OC) and obese dams (OO) were weaned onto standard chow and studied at 3 and 6 months of age. OO were hyperphagic from 4 to 6 weeks of age compared with OC and at 3 months locomotor activity was reduced and adiposity increased (abdominal fat pad mass; PϽ0.01). OO were heavier than OC at 6 months (body weight, PϽ0.05). OO abdominal obesity was associated with adipocyte hypertrophy and altered mRNA expression of ␤-adrenoceptor 2 and 3, 11␤HSD-1, and PPAR-␥ 2. OO showed resistance artery endothelial dysfunction at 3 months, and were hypertensive, as assessed by radiotelemetry (nighttime systolic blood pressure at 6 months [ Key Words: obesity Ⅲ pregnancy Ⅲ developmental programming Ⅲ metabolic syndrome Ⅲ appetite Ⅲ blood pressure Ⅲ mouse O besity among women of reproductive age is presenting a critical challenge to health care. 29% of USA women aged 20 to 39 years are reported to be clinically obese 1 and there is serious concern in many European countries over the increasing obesity among young women. 2 While obesity is associated with increased risk of almost every common complication of pregnancy, obesity in the mother may play a direct role in transmission of an obesogenic and diabetogenic trait from generation to generation. Increasing evidence suggests that children born of pregnancies complicated by either obesity or related gestational diabetes mellitus (GDM) are at increased risk of obesity, impaired glucose tolerance, and other facets of the metabolic syndrome. 3 Animal models have proven invaluable in interrogation of associations between maternal diet and body composition and offspring phenotype. 4 Those studies which have addressed effects of maternal calorific excess, including several from our laboratory, have generally fed rats diets rich in animal fat. 4 -7 Because young women of reproductive age often consume excessive amounts of sugars as well as fats, 8 the relevance of a diet rich in fat alone is limited. In this study, we induced obesity by feeding mice a highly palatable diet rich in sugars and animal fat, and addressed the hypothesis that diet-induced obesity during pregnancy can transmit a propensity for adiposity, glucose intolerance, and cardiovascular dysfunction to the offspring. Obesity was induced in female mice and offspring cardiovascular and metabolic function

Hypothalamic systems which regulate appetite may be permanently modified during early development. We have previously reported hyperphagia and increased adiposity in the adult offspring of rodents fed an obesogenic diet prior to and throughout pregnancy and lactation. We now report that offspring of obese (OffOb) rats display an amplified and prolonged neonatal leptin surge, which is accompanied by elevated leptin mRNA expression in their abdominal white adipose tissue. At postnatal Day 30, before the onset of hyperphagia in these animals, serum leptin is normal, but leptin-induced appetite suppression and phosphorylation of STAT3 in the arcuate nucleus (ARC) are attenuated; the level of AgRP-immunoreactivity in the hypothalamic paraventricular nucleus (PVH), which derives from neurones in the ARC and is developmentally dependent on leptin, is also diminished. We hypothesise that prolonged release of abnormally high levels of leptin by neonatal OffOb rats leads to leptin resistance and permanently affects hypothalamic functions involving the ARC and PVH. Such effects may underlie the developmental programming of hyperphagia and obesity in these rats.

Nonalcoholic fatty liver disease (NAFLD) describes an increasingly prevalent spectrum of liver disorders associated with obesity and metabolic syndrome. It is uncertain why steatosis occurs in some individuals, whereas nonalcoholic steatohepatitis (NASH) occurs in others. We have generated a novel mouse model to test our hypothesis: that maternal fat intake contributes to the development of NAFLD in adult offspring. Female mice were fed either a high-fat (HF) or control chow (C) diet before and during gestation and lactation. Resulting offspring were fed either a C or a HF diet after weaning, to generate four offspring groups; HF/HF, HF/C, C/HF, C/C. At 15 weeks of age, liver histology was normal in both the C/C and HF/C offspring. Kleiner scoring showed that although the C/HF offspring developed nonalcoholic fatty liver, the HF/HF offspring developed NASH. At 30 weeks, histological analysis and Kleiner scoring showed that both the HF/C and C/HF groups had NAFLD, whereas the HF/HF had a more severe form of NASH. Therefore, exposure to a HF diet in utero and during lactation contributes toward NAFLD progression. We investigated the mechanisms by which this developmental priming is mediated. At 15 weeks of age, hepatic mitochondrial electron transport chain (ETC) enzyme complex activity (I, II/III, and IV) was reduced in both groups of offspring from HF-fed mothers (HF/C and HF/HF). In addition, measurement of hepatic gene expression indicated that lipogenesis, oxidative stress, and inflammatory pathways were up-regulated in the 15-week-old HF/C and HF/HF offspring. Conclusion: Maternal fat intake contributes toward the NAFLD progression in adult offspring, which is mediated through impaired hepatic mitochondrial metabolism and up-regulated hepatic lipogenesis.

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