Maternal food restriction is associated with the development of obesity in offspring. This study examined how maternal undernutrition in sheep affects the fetal hypothalamic glucocorticoid receptor (GR) and the appetite-regulating neuropeptides, proopiomelanocortin (POMC) and neuropeptide Y, which it regulates. In fetuses from ewes undernourished from -60 to +30 d around conception, there was increased histone H3K9 acetylation (1.63-fold) and marked hypomethylation (62% decrease) of the POMC gene promoter but no change in POMC expression. In the same group, acetylation of histone H3K9 associated with the hypothalamic GR gene was increased 1.60-fold and the GR promoter region was hypomethylated (53% decrease). In addition, there was a 4.7-fold increase in hypothalamic GR expression but no change in methylation of GR gene expression in the anterior pituitary or hippocampus. Interestingly, hypomethylation of both POMC and GR promoter markers in fetal hypothalami was also identified after maternal undernutrition from -60 to 0 d and -2 to +30 d. In comparison, the Oct4 gene, was hypermethylated in both control and underfed groups. Periconceptional undernutrition is therefore associated with marked epigenetic changes in hypothalamic genes. Increase in GR expression in the undernourished group may contribute to fetal programming of a predisposition to obesity, via altered GR regulation of POMC and neuropeptide Y. These epigenetic changes in GR and POMC in the hypothalamus may also predispose the offspring to altered regulation of food intake, energy expenditure, and glucose homeostasis later in life.

Vascular endothelial growth factor (VEGF) is a potent mitogen and cytoprotective factor for vascular endothelial cells. Although VEGF is ubiquitously expressed, its role in nonvascular tissues is poorly understood. VEGF interacts with various cell surface receptors to mediate its cellular effects. It previously has been thought that the VEGF receptor Flk-1/KDR, its main signaling receptor, was expressed exclusively by endothelial cells. However, in the present study using bovine and rodent models, we demonstrate that VEGF and Flk-1/KDR are coexpressed in ovarian granulosa cells. VEGF and Flk-1/KDR mRNA and protein were both detectable in follicle tissue sections and in vitro cultured granulosa cells. Expression of both ligand and receptor increased in healthy follicles throughout follicular development. VEGF treatment of serum-starved and cytokine-exposed granulosa cells resulted in enhanced survival, and this cytoprotection was ameliorated when Flk-1/KDR signaling was inhibited. Reduced expression of Flk-1/KDR was also associated with the onset and progression of follicle atresia, suggesting involvement in follicular health in vivo. The results of this study demonstrate for the first time expression of Flk-1/KDR in ovarian granulosa cells and identify a novel extravascular role for VEGF and its receptor in ovarian function.

The association between an adverse early life environment and increased susceptibility to later-life metabolic disorders such as obesity, type 2 diabetes and cardiovascular disease is described by the developmental origins of health and disease hypothesis. Employing a rat model of maternal high fat (MHF) nutrition, we recently reported that offspring born to MHF mothers are small at birth and develop a postnatal phenotype that closely resembles that of the human metabolic syndrome. Livers of offspring born to MHF mothers also display a fatty phenotype reflecting hepatic steatosis and characteristics of non-alcoholic fatty liver disease. In the present study we hypothesised that a MHF diet leads to altered regulation of liver development in offspring; a derangement that may be detectable during early postnatal life. Livers were collected at postnatal days 2 (P2) and 27 (P27) from male offspring of control and MHF mothers (n = 8 per group). Cell cycle dynamics, measured by flow cytometry, revealed significant G0/G1 arrest in the livers of P2 offspring born to MHF mothers, associated with an increased expression of the hepatic cell cycle inhibitor Cdkn1a. In P2 livers, Cdkn1a was hypomethylated at specific CpG dinucleotides and first exon in offspring of MHF mothers and was shown to correlate with a demonstrable increase in mRNA expression levels. These modifications at P2 preceded observable reductions in liver weight and liver∶brain weight ratio at P27, but there were no persistent changes in cell cycle dynamics or DNA methylation in MHF offspring at this time. Since Cdkn1a up-regulation has been associated with hepatocyte growth in pathologic states, our data may be suggestive of early hepatic dysfunction in neonates born to high fat fed mothers. It is likely that these offspring are predisposed to long-term hepatic dysfunction.

Key points• Maternal high fat nutrition during pregnancy and lactation significantly reduced maternal care during the early neonatal period; but reduced maternal care was not associated with an offspring phenotype.• Maternal high fat nutrition resulted in maternal obesity characterized by increased fat mass, hyperleptinaemia, hyperinsulinaemia.• Maternal high fat nutrition resulted in fatter offspring before puberty and advanced pubertal onset.• Adult female offspring of high fat-fed mothers have altered reproductive function, reflected in an increased likelihood of prolonged or persistent oestrus.• These phenotypic effects were not related to maternal care suggesting that poor maternal nutrition, rather than inadequate maternal care, could be the primary driver of the observed alterations in offspring development and reproductive function. AbstractWe have previously reported that offspring of mothers fed a high fat (HF) diet during pregnancy and lactation enter puberty early and are hyperleptinaemic, hyperinsulinaemic and obese as adults. Poor maternal care and bonding can also impact offspring development and disease risk. We therefore hypothesized that prenatal nutrition would affect maternal care and that an interaction may exist between a maternal HF diet and maternal care, subsequently impacting on offspring phenotype. Wistar rats were mated and randomized to control dams fed a control diet (CON) or dams fed a HF diet from conception until the end of lactation (HF). Maternal care was assessed by observing maternal licking and grooming of pups between postnatal day (P)3 and P8. Postweaning (P22), offspring were fed a control (-con) or HF (-hf) diet. From P27, pubertal onset was assessed. At ∼P105 oestrous cyclicity was investigated. Maternal HF diet reduced maternal care; HF-fed mothers licked and groomed pups less than CON dams. Maternal fat:lean ratio was higher in HF dams at weaning and was associated with higher maternal plasma leptin and insulin concentrations, but there was no effect of maternal care on fat:lean ratio or maternal hormone levels. Both female and male offspring of HF dams were lighter from birth to P11 than offspring of CON dams, but by P19, HF offspring were heavier than controls. Prepubertal retroperitoneal fat mass was greater in pups from HF-fed dams compared to CON and was associated with elevated circulating leptin concentrations in females only, but there was neither an effect of maternal care, nor an interaction between maternal diet and care on prepubertal fat mass. Pups from HF-fed dams went into puberty early and this effect was exacerbated by a postweaning HF diet. HF-fed mothers were more likely to have prolonged or persistent oestrus, whilst female offspring fed a HF diet postweaning were more likely to have irregular oestrous cycles and were more likely to have prolonged or persistent oestrus. These data indicate that maternal HF nutrition during pregnancy and lactation results in a maternal obese phenotype and has significant impact on maternal care during lactation. Mat...