Sex-dependent vulnerability of fetal nonhuman primate cardiac mitochondria to moderate maternal nutrient reduction.

Poor maternal nutrition in pregnancy affects fetal development, predisposing offspring to cardiometabolic diseases. The role of mitochondria during fetal development on later-life cardiac dysfunction caused by maternal nutrient reduction (MNR) remains unexplored. We hypothesized that MNR during gestation causes fetal cardiac bioenergetic deficits, compromising cardiac mitochondrial metabolism and reserve capacity. To enable human translation, we developed a primate baboon model (Papio spp.) of moderate MNR in which mothers receive 70% of control nutrition during pregnancy, resulting in intrauterine growth restriction (IUGR) offspring and later exhibiting myocardial remodeling and heart failure at human equivalent ∼25 years. Term control and MNR baboon offspring were necropsied following cesarean-section, and left ventricle (LV) samples were collected. MNR adversely impacted fetal cardiac LV mitochondria in a sex-dependent fashion. Increased maternal plasma aspartate aminotransferase, creatine phosphokinase (CPK), and elevated cortisol levels in MNR concomitant with decreased blood insulin in male fetal MNR were measured. MNR resulted in a two-fold increase in fetal LV mitochondrial DNA (mtDNA). MNR resulted in increased transcripts for several respiratory chain (NDUFB8, UQCRC1, and cytochrome c) and adenosine triphosphate (ATP) synthase proteins. However, MNR fetal LV mitochondrial complex I and complex II/III activities were significantly decreased, possibly contributing to the 73% decreased ATP content and increased lipid peroxidation. MNR fetal LV showed mitochondria with sparse and disarranged cristae dysmorphology. Conclusion: MNR disruption of fetal cardiac mitochondrial fitness likely contributes to the documented developmental programming of adult cardiac dysfunction, indicating a programmed mitochondrial inability to deliver sufficient energy to cardiac tissues as a chronic mechanism for later-life heart failure.

Maternal malnourishment induced upregulation of fetuin-B blunts nephrogenesis in the low birth weight neonate.

Maternal undernutrition during pregnancy (MUN) often leads to low birth weight (LBW) neonates that have a reduced total nephron endowment, leaving these neonates susceptible to kidney disease throughout their lives. For reasons unknown, these LBW neonates have impaired kidney development due to a severe reduction in renal SIX2+ stem cells during nephrogenesis. Using a mouse model of MUN, we investigated SIX2+ stem cell reduction in the LBW neonate. Significant upregulation of the protein fetuin-B (measured by PCR and immunoblotting) in the MUN mother's placenta, organs and circulation yielded a 3-fold increase of this protein in the embryonic kidney. Recombinant fetuin-B, administered to healthy pregnant mothers at the concentration equivalent to that in the MUN mother, crossed the placenta and reduced both SIX2+ stem cells by 50% and nephron formation by 66% in embryonic kidneys (measured by immunofluorescence and the physical dissector/fractionator stereological method). Administration of fetuin-B to kidney explants yielded similar reductions in renal SIX2+ stem cells and nephron formation. Fetuin-B treatment of isolated embryonic renal SIX2+ stem cell primary cultures 1) increased NF-kB activity and apoptosis, 2) reduced cell proliferation due to upregulated p21 nuclear activity and subsequent cell cycle arrest, and 3) enhanced generation of reactive oxygen species (measured by fluorescence microscopy). In conclusion, MUN increases fetuin-B in the developing embryonic kidney. The increase in fetuin-B blunts nephrogenesis by reducing SIX2+ stem cells by promoting their apoptosis (via NF-kB upregulation), blunting their proliferative renewal (via p21 upregulation) and enhancing oxidative stress.

Oral leptin supplementation throughout lactation in rats prevents later metabolic alterations caused by gestational calorie restriction.

OBJECTIVES: Calorie-restriction during gestation in rats has been seen to produce lasting detrimental effects in the offspring, affecting energy balance control and other related metabolic functions. Our aim was to assess whether leptin supplementation throughout lactation may prevent the dysmetabolic phenotype in adulthood associated with gestational calorie restriction. METHODS: Three groups of male Wistar rats were followed: the offspring of ad libitum fed dams (controls); the offspring of 20% calorie-restricted dams during gestation (CR); and CR rats supplemented with physiological doses of leptin throughout lactation (CR-Leptin). Pups were weaned with a standard diet (SD) until 4 months of age, and then half of the animals of each group were moved to a Western diet (WD) until 6 months of age. Body weight and food intake were recorded. Energy expenditure, locomotive activity, blood parameters, liver triglycerides (TG), and gene expression and specific proteins in liver and white adipose tissue (WAT) were measured in adulthood. RESULTS: Adult CR rats, but not CR-Leptin rats, displayed greater adiposity index and feed efficiency (both under SD) than controls, along with lower locomotive activity and energy expenditure, higher HOMA-IR index and greater circulating TG and leptin levels. CR animals also exhibited increased values of the respiratory exchange ratio and more severe signs of hepatic steatosis under WD than CR-Leptin animals. Gene expression analysis revealed that CR, but not CR-Leptin, animals displayed indicators of lower capacity for WAT expansion, along with decreased lipogenesis and lipolytic capacity under SD, and impaired lipogenic response of the liver to WD feeding, in accordance with diminished insulin sensitivity and WAT leptin signaling. CONCLUSIONS: Oral leptin supplementation in physiological doses throughout lactation in rats prevents most of the detrimental effects on energy homeostasis and metabolic alterations in adulthood caused by inadequate fetal nutrition.

Nutritional models of foetal programming and nutrigenomic and epigenomic dysregulations of fatty acid metabolism in the liver and heart.

Barker's concept of 'foetal programming' proposes that intrauterine growth restriction (IUGR) predicts complex metabolic diseases through relationships that may be further modified by the postnatal environment. Dietary restriction and deficit in methyl donors, folate, vitamin B12, and choline are used as experimental conditions of foetal programming as they lead to IUGR and decreased birth weight. Overfeeding and deficit in methyl donors increase central fat mass and lead to a dramatic increase of plasma free fatty acids (FFA) in offspring. Conversely, supplementing the mothers under protein restriction with folic acid reverses metabolic and epigenomic phenotypes of offspring. High-fat diet or methyl donor deficiency (MDD) during pregnancy and lactation produce liver steatosis and myocardium hypertrophy that result from increased import of FFA and impaired fatty acid ß-oxidation, respectively. The underlying molecular mechanisms show dysregulations related with similar decreased expression and activity of sirtuin 1 (SIRT1) and hyperacetylation of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α). High-fat diet and overfeeding impair AMPK-dependent phosphorylation of PGC-1α, while MDD decreases PGC-1α methylation through decreased expression of PRMT1 and cellular level of S-adenosyl methionine. The visceral manifestations of metabolic syndrome are under the influence of endoplasmic reticulum (ER) stress in overnourished animal models. These mechanisms should also deserve attention in the foetal programming effects of MDD since vitamin B12 influences ER stress through impaired SIRT1 deacetylation of HSF1. Taken together, similarities and synergies of high-fat diet and MDD suggest, therefore, considering their consecutive or contemporary influence in the mechanisms of complex metabolic diseases.

Thrifty metabolic programming in rats is induced by both maternal undernutrition and postnatal leptin treatment, but masked in the presence of both: implications for models of developmental programming.

BACKGROUND: Maternal undernutrition leads to an increased risk of metabolic disorders in offspring including obesity and insulin resistance, thought to be due to a programmed thrifty phenotype which is inappropriate for a subsequent richer nutritional environment. In a rat model, both male and female offspring of undernourished mothers are programmed to become obese, however postnatal leptin treatment gives discordant results between males and females. Leptin treatment is able to rescue the adverse programming effects in the female offspring of undernourished mothers, but not in their male offspring. Additionally, in these rats, postnatal leptin treatment of offspring from normally-nourished mothers programmes their male offspring to develop obesity in later life, while there is no comparable effect in their female offspring. RESULTS: We show by microarray analysis of the female liver transcriptome that both maternal undernutrition and postnatal leptin treatment independently induce a similar thrifty transcriptional programme affecting carbohydrate metabolism, amino acid metabolism and oxidative stress genes. Paradoxically, however, the combination of both stimuli restores a more normal transcriptional environment. This demonstrates that "leptin reversal" is a global phenomenon affecting all genes involved in fetal programming by maternal undernourishment and leptin treatment. The thrifty transcriptional programme was associated with pro-inflammatory markers and downregulation of adaptive immune mediators, particularly MHC class I genes, suggesting a deficit in antigen presentation in these offspring. CONCLUSIONS: We propose a revised model of developmental programming reconciling the male and female observations, in which there are two competing programmes which collectively drive liver transcription. The first element is a thrifty metabolic phenotype induced by early life growth restriction independently of leptin levels. The second is a homeostatic set point calibrated in response to postnatal leptin surge, which is able to over-ride the metabolic programme. This "calibration model" for the postnatal leptin surge, if applicable in humans, may have implications for understanding responses to catch-up growth in infants. Additionally, the identification of an antigen presentation deficit associated with metabolic thriftiness may relate to a previously observed correlation between birth season (a proxy for gestational undernutrition) and infectious disease mortality in rural African communities.

Effect of fetal and infant malnutrition on metabolism in older age.

BACKGROUND: While malnutrition is an important concern in the developing world, Western countries are experiencing a pandemic of obesity and metabolic diseases. OBJECTIVE: This work reviews the current state of knowledge of the effects of malnutrition during early life on metabolism in older age. METHODS: The impact of early-life determinants on diabetes and related metabolic diseases in later life is elucidated by three different methodological approaches. First, results from animal studies in dietary manipulation models are reviewed. Second, findings from epidemiological studies that often use natural experiments to determine the effects of famines on the health status of the population are discussed. Finally, the relation between maternal or childhood malnutrition and diabetes in adulthood is explored in a big-data study using the entire population of a country across a century. RESULTS: We present overwhelming evidence that the maternal or early childhood nutritional status negatively affects both the short- and long-term health status and development of the offspring, thereby providing starting points to formulate intervention and prevention strategies. In particular, it was found that in the case of early-life exposure to famine, the risk of the offspring to develop type 2 diabetes in older age is up to 125% higher than without famine exposure. CONCLUSION: Due to its inherent complexity, an understanding of the long-term effects of maternal and childhood malnutrition on metabolism in older age necessitates interdisciplinary and big-data approaches. Only then can we hope to prevent chronic diseases at their earliest beginning.

Gestational undernourishment modifies the composition of skeletal muscle transverse tubule membranes and the mechanical properties of muscles in newborn rats.

BACKGROUND/AIMS: [corrected] Skeletal muscle (SM) constitutes more than 40% of the body weight in adulthood. Transports dietary glucose mainly through the insulin-dependent glucose transporter (Glut-4) located in the Transverse tubule membrane system (TT). The TT development ends shortly after birth. The TT membrane hosts the proteins involved in excitation-contraction coupling and glucose uptake. Glycaemic regulation through movement is a key function of fully developed skeletal muscle. In this study, we aimed to characterize the effect of gestational undernourishment (GUN) in rats GLUT-4 expression and on the protein/lipid content of the TT membranes. We also examined the effect of GUN on the mechanical properties of muscles as an indication of the metabolic condition of the SM at birth. METHODS: Isolated TT membrane from SM of GUN rats were used to study lipid/protein content and protein stability by differential scanning calorimetry. The effect of GUN on the SM mechanical properties was determined in isolated Extensor Digitorum Longus (EDL) muscle. RESULTS: We demonstrate that compared to control, GUN in the new-born produces; i) decreases body weight; ii) diminution in SM mass; iii) decreases the formation of TT membranes; iv) expresses TT membrane proteins with higher thermal stability. The TT membrane expression of GLUT-4 in GUN offspring was twice that of controls. The isolated EDL of GUN offspring was 20% stronger as measured by contractile force and more resistant to fatigue relative to controls. CONCLUSION: These results provide the first evidence of adaptive changes of the SM in new-borns exposed to severe gestational food restriction. The effects of GUN on muscle at birth are the first step toward detrimental SM metabolic function, contributing to the physiopathology of metabolic diseases in adulthood.

Role of placental nutrient sensing in developmental programming.

Altered maternal nutrition and metabolism, restricted utero-placental blood flow, and other perturbations in the maternal compartment may disturb critical periods of fetal development resulting in increased susceptibility to develop disease in childhood and adult life. In response to these perturbations, changes in placental structure and function occur, which influence the supply of nutrients, oxygen, and methyl donors and alter the secretion of hormones and other signaling molecules into the fetal circulation. Thus, the placenta plays a critical role in modulating maternal-fetal resource allocation, thereby affecting fetal growth and the long-term health of the offspring.

Metabolomics and fetal-neonatal nutrition: between "not enough" and "too much".

Metabolomics is a new analytical technique defined as the study of the complex system of metabolites that is capable of describing the biochemical phenotype of a biological system. In recent years the literature has shown an increasing interest in paediatric obesity and the onset of diabetes and the metabolic syndrome in adulthood. Some studies show that fetal malnutrition, both excessive and insufficient, may permanently alter the metabolic processes of the fetus and increase the risk of future chronic pathologies. At present then, attention is being focused mainly on the formulation of new hypotheses, by means of metabolomics, concerning the biological mechanisms to departure from fetal-neonatal life that may predispose to the development of these diseases.

Proteomic analysis of the maternal protein restriction rat model for schizophrenia: identification of translational changes in hormonal signaling pathways and glutamate neurotransmission.

Previous studies have found that some first onset schizophrenia patients show signs of impaired insulin signaling. Also, epidemiological studies have shown that periods of suboptimal nutrition including protein deficiencies during pregnancy can lead to increased incidence of metabolic conditions and psychiatric disorders in the offspring. For these reasons, we have carried out a molecular profiling analysis of blood serum and brain tissues from adult offspring produced by the maternal low protein (LP) rat model. The results showed similar changes to those seen in schizophrenia. Multiplex immunoassay profiling identified changes in the levels of insulin, adiponectin, and leptin along with alterations in inflammatory and vascular system-related proteins such as osteopontin, macrophage colony-stimulating factor 1, and vascular cell adhesion molecule 1. LC-MS(E) proteomic profiling showed that glutamatergic pathways were altered in frontal cortex, while signaling pathways and cytoskeletal proteins involved in hormonal secretion and synaptic remodeling were altered in the hypothalamus. Taken together, these studies indicate that the LP rat model recapitulates several pathophysiological attributes seen in schizophrenia patients. We propose that the LP model may have utility for drug discovery efforts, especially to identify compounds that modulate the metabolic and glutamatergic systems.

Placental expression of myostatin and follistatin-like-3 protein in a model of developmental programming.

Maternal undernutrition during gestation is known to be detrimental to fetal development, leading to a propensity for metabolic disorders later in the adult lives of the offspring. Identifying possible mediators and physiological processes involved in modulating nutrient transport within the placenta is essential to prevent and/or develop treatments for the effects of aberrant nutrition, nutrient transfer, and detrimental changes to fetal development. A potential role for myostatin as a mediator of nutrient uptake and transport from the mother to the fetus was shown through the recent finding that myostatin acts within the human placenta to modulate glucose uptake and therefore homeostasis. The mRNA and protein expression of myostatin and its inhibitor, follistatin-like-3 (FSTL3), was studied in the placenta and skeletal muscle of a transgenerational Wistar rat model of gestational maternal undernutrition in which the F2 offspring postweaning consumed a high-fat (HF) diet. Alterations in placental characteristics and offspring phenotype, specifically glucose homeostasis, were evident in the transgenerationally undernourished (UNAD) group. Myostatin and FSTL3 protein expression were also higher (P < 0.05) in the placentae of the UNAD compared with the control group. At maturity, UNAD HF-fed animals had higher (P < 0.05) skeletal muscle expression of FSTL3 than control animals. In summary, maternal undernutrition during gestation results in the aberrant regulation of myostatin and FSTL3 in the placenta and skeletal muscle of subsequent generations. Myostatin, through the disruption of maternal nutrient supply to the fetus, may thus be a potential mediator of offspring phenotype.

Perinatal copper deficiency alters rat cerebellar purkinje cell size and distribution.

Copper is required for activity of several key enzymes and for optimal mammalian development, especially within the central nervous system. Copper-deficient (CuD) animals are visibly ataxic, and previous studies in rats have demonstrated impaired motor function through behavioral experiments consistent with altered cerebellar development. Perinatal copper deficiency was produced in Holtzman rat dams by restricting dietary copper during the last two thirds of gestation and lactation. Male offspring were evaluated at postnatal day 25. Compared to cerebella from copper-adequate pups, the CuD pups had larger Purkinje cell (PC) size and irregularities in the Purkinje cell monolayer. These results suggest that the ataxic behavioral phenotype of CuD rats may result from disrupted inhibitory pathways in the cerebellum. A similar PC phenotype is seen in Menkes disease and in mottled mouse mutants with genetic copper deficiency, suggesting that copper deficiency and not just specific loss of ATP7A function is responsible.

The effects of intrauterine malnutrition on maternal-fetal cholesterol transport and fetal lipid synthesis in mice.

Intrauterine malnutrition is associated with increased susceptibility to chronic diseases in adulthood. Growth-restricted infants display a less favorable lipid profile already shortly postnatal. Maternal low protein diet (LPD) during gestation is a well-defined model of fetal programming in rodents and affects lipid metabolism of the offspring. Effects of LPD throughout gestation on physiologic relevant parameters of lipid metabolism are unclear. We aimed to determine effects of LPD on maternal-fetal cholesterol fluxes and fetal lipid synthesis in mice. Pregnant mice (dams) were fed with a control (18% casein) or an LPD (9% casein) from E0.5 onward. We quantified maternal-fetal cholesterol transport and maternal cholesterol absorption at E19.5 using stable isotopes. We determined fetal lipid biosynthesis at E19.5, after administration of (1-C)-acetate from E17.5 onward. LPD did not change fetal and maternal plasma and hepatic concentrations of cholesterol and triglycerides. LPD affected neither the magnitudes of maternal-fetal cholesterol flux, maternal cholesterol absorption, nor fetal synthesis of cholesterol and palmitate (both groups, approximately 14% and approximately 13%, respectively). We conclude that LPD throughout gestation in mice does not affect maternal-fetal cholesterol transport, fetal cholesterol or fatty acid synthesis, indicating that programming effects of LPD are not mediated by short-term changes in maternal-fetal lipid metabolism.

Differential impacts of late gestational over-and undernutrition on adipose tissue traits and associated visceral obesity risk upon exposure to a postnatal high-fat diet in adolescent sheep.

We hypothesized that late gestation malnutrition differentially affects expandability of adipose tissues to predispose for early postnatal visceral adiposity. Twin-lambs born to dams fed HIGH (150%/110% of required energy/protein, respectively), NORM (100% of requirements) or LOW (50% of NORM) diets during the last trimester were used. Postnatally, lambs were raised on moderate (CONV) or high-carbohydrate-high-fat (HCHF) diets. Adipose tissues were sampled at autopsy at 6 months of age (~puberty) to characterize cellularity, adipocyte cross-sectional area and gene expression patterns. HIGH and LOW compared to NORM lambs had reduced intrinsic (under CONV diet) cellularity in subcutaneous and mesenteric (particularly LOW), and reduced obesity-induced (under HCHF diet) hyperplasia in subcutaneous, mesenteric and perirenal (particularly HIGH) adipose tissues. This corresponded with more pronounced HCHF diet-induced hypertrophy in mesenteric (particularly LOW), perirenal (particularly HIGH) and subcutaneous (particularly HIGH) adipose tissues, and tissue-specific reductions in mRNA expressions for lipid metabolism, angiogenesis and adipose development. Gene expression for inflammation and lipid metabolism markers were increased and decreased, respectively, in HCHF lambs (HCHF lambs became obese) in all tissues. Both prenatal over- and undernutrition predisposed for abdominal adiposity and extreme perirenal hypertrophy due to reduced intrinsic (observed under CONV diet) cellularity and impaired ability of subcutaneous, mesenteric and perirenal adipose tissues to expand by hyperplasia rather than hypertrophy on an obesogenic (HCHF) diet.

Behavioral Feeding Circuit: Dietary Fat-Induced Effects of Inflammatory Mediators in the Hypothalamus.

Excessive dietary fat intake has extensive impacts on several physiological systems and can lead to metabolic and nonmetabolic disease. In animal models of ingestion, exposure to a high fat diet during pregnancy predisposes offspring to increase intake of dietary fat and causes increase in weight gain that can lead to obesity, and without intervention, these physiological and behavioral consequences can persist for several generations. The hypothalamus is a region of the brain that responds to physiological hunger and fullness and contains orexigenic neuropeptide systems that have long been associated with dietary fat intake. The past fifteen years of research show that prenatal exposure to a high fat diet increases neurogenesis of these neuropeptide systems in offspring brain and are correlated to behavioral changes that induce a pro-consummatory and obesogenic phenotype. Current research has uncovered several potential molecular mechanisms by which excessive dietary fat alters the hypothalamus and involve dietary fatty acids, the immune system, gut microbiota, and transcriptional and epigenetic changes. This review will examine the current knowledge of dietary fat-associated changes in the hypothalamus and the potential pathways involved in modifying the development of orexigenic peptide neurons that lead to changes in ingestive behavior, with a special emphasis on inflammation by chemokines.

Maternal high-fat diet and fetal programming: increased proliferation of hypothalamic peptide-producing neurons that increase risk for overeating and obesity.

Recent studies in adult and weanling rats show that dietary fat, in close association with circulating lipids, can stimulate expression of hypothalamic peptides involved in controlling food intake and body weight. In the present study, we examined the possibility that a fat-rich diet during pregnancy alters the development of these peptide systems in utero, producing neuronal changes in the offspring that persist postnatally in the absence of the diet and have long-term consequences. The offspring of dams on a high-fat diet (HFD) versus balanced diet (BD), from embryonic day 6 to postnatal day 15 (P15), showed increased expression of orexigenic peptides, galanin, enkephalin, and dynorphin, in the paraventricular nucleus and orexin and melanin-concentrating hormone in the perifornical lateral hypothalamus. The increased density of these peptide-expressing neurons, evident in newborn offspring as well as P15 offspring cross-fostered at birth to dams on the BD, led us to examine events that might be occurring in utero. During gestation, the HFD stimulated the proliferation of neuroepithelial and neuronal precursor cells of the embryonic hypothalamic third ventricle. It also stimulated the proliferation and differentiation of neurons and their migration toward hypothalamic areas where ultimately a greater proportion of the new neurons expressed the orexigenic peptides. This increase in neurogenesis, closely associated with a marked increase in lipids in the blood, may have a role in producing the long-term behavioral and physiological changes observed in offspring after weaning, including an increase in food intake, preference for fat, hyperlipidemia, and higher body weight.

Maternal perinatal undernutrition drastically reduces postnatal leptin surge and affects the development of arcuate nucleus proopiomelanocortin neurons in neonatal male rat pups.

A growing body of evidence suggests that maternal undernutrition sensitizes the offspring to the development of energy balance metabolic disorders such as type 2 diabetes, dyslipidemia, and obesity. The present study aimed at examining the impact of maternal undernutrition on leptin plasma levels in newborn male rats and on the arcuate nucleus proopiomelanocortin (POMC) and neuropeptide Y (NPY) neurons that are major leptin targets. Using a model of perinatal maternal 50% food-restricted diet (FR50) in the rat, we evaluated leptin plasma levels and hypothalamic POMC and NPY gene expression from postnatal day (PND) 4 to PND30 in both control and FR50 offspring. In control rats, a postnatal peak of plasma leptin was observed between PND4 and PND14 that reached a maximal value at PND10 (5.17 +/- 0.53 ng/ml), whereas it was dramatically reduced in FR50 pups with the higher concentration at PND7 (0.93 +/- 0.23 ng/ml). In FR50 animals, using semiquantitative RT-PCR and in situ hybridization, we showed that the hypothalamic POMC mRNA level was decreased from PND14 until PND30, whereas NPY gene expression was not significantly modified. In PND21 FR50 animals, we observed strikingly reduced immunoreactive beta-endorphin nerve fibers projecting to the hypothalamic paraventricular nucleus without affecting NPY projections. Our data showed that maternal undernutrition drastically reduces the postnatal surge of plasma leptin, disturbing particularly the hypothalamic wiring as well as the gene expression of the anorexigenic POMC neurons in male rat pups. These alterations might contribute to the adult metabolic disorders resulting from perinatal growth retardation.

Impact of abnormal nutrition during pregnancy on the offspring hormone resistance.

OBJECTIVE: To investigate the impact of abnormal nutrition during pregnancy on the insulin and leptin resistance of adult offsprings. METHODS: The model of abnormal nutrition during pregnancy was established, and these rats were fed whole-course low-protein or high-nutrition. After natural childbirth, the birth weight of each newborn rat was measured. According to the determining birth weights, the newborn rats were assigned into the small for gestational age (SGA) and large for gestational age (LGA) groups as well as the healthy control group, respectively. There was a total of 36 randomly selected rats in each group. The levels of insulin and leptin and the insulin sensitivity index (ISI) were determined by enzymelinked immunosorbent assay 4 and 12 weeks post birth, respectively. RESULTS: In the low-protein group, the birth weight was significantly lower than in the control group (p<0.01) and 68.97% of the newborn rats were SGA; in the high-energy group, the birth weight of the newborn rats was significantly larger than in the control group (p<0.01), and 37.98% of the newborn were LGA. The body weights (BW) of the SGA 4 weeks post birth had no significant difference from that of the controls, while the perirenal fat weight (FW) and the FW/BW ratio were significantly larger than those of the controls (p<0.01 and p<0.05, respectively); however, the FW/BW of the LGA had no significant difference from that of the controls. Twelve weeks after birth, the BW of both SGA and LGA rats increased significantly compared to the controls (p<0.05 and p<0.01, respectively), and the FW/BW ratios of both were significantly larger than that of the controls (p<0.01). For the SGA rats 4 weeks post birth, the insulin and leptin level increased significantly (both p<0.05), while the ISI decreased significantly (p<0.05), with the occurrence of insulin resistance. For both SGA and LGA 12 weeks post birth, the insulin and leptin level significantly increased (both p<0.01). CONCLUSION: Abnormal nutrition during pregnancy could lead to abnormal birth weight, and both low and high birth weight could cause abdominal obesity as well as insulin and leptin resistance in adulthood, although through different mechanisms.

Impact of periconceptional undernutrition on adrenal growth and adrenal insulin-like growth factor and steroidogenic enzyme expression in the sheep fetus during early pregnancy.

Periconceptional undernutrition (PCUN) results in an earlier prepartum activation of the pituitary-adrenal axis in twin compared with singleton fetuses. We have tested the hypotheses that the functional development of the fetal sheep adrenal is delayed in twins compared with singletons in early gestation and that PCUN accelerates adrenal growth and increases the expression of intraadrenal IGF-I and -II and cytochrome P450 17-hydroxylase (CYP17) as early as 55 d gestation. We have investigated the effect of PCUN in the ewe (restricted at 70% of control allowance, n=21; control, n=24) from at least 45 d before mating until d 7 after mating on maternal cortisol and progesterone concentrations, fetal adrenal weight, adrenal IGF-I, IGF-I receptor (IGF-IR), IGF-II, IGF-IIR, and CYP17 mRNA expression and placental 11beta-hydroxysteroid dehydrogenase-1 and -2 mRNA and protein expression at d 53-56 pregnancy. The relative weight of the fetal adrenal and adrenal IGF-I, IGF-IR, IGF-II, IGF-IIR, and CYP17 mRNA expression were lower in twin compared with singleton fetuses. In singleton fetuses of PCUN ewes, there was a loss of the relationship between adrenal IGF-II/IGF-IIR expression and either adrenal weight or CYP17 mRNA, which was present in controls. Similarly in twin fetuses, PCUN resulted in the loss of the relationships between adrenal weight and IGF-I expression and between adrenal CYP17 and IGF-II expression, which were present in controls. Our findings suggest that differences in the timing of the prepartum activation of the fetal adrenal in twins and singletons have their origins in early gestation and highlight the importance of the interaction between the periconceptional environment and embryo number in setting the growth trajectory of the fetal adrenal.

Prenatal and postnatal pathways to obesity: different underlying mechanisms, different metabolic outcomes.

Obesity and type 2 diabetes are worldwide health issues. The present paper investigates prenatal and postnatal pathways to obesity, identifying different metabolic outcomes with different effects on insulin sensitivity and different underlying mechanisms involving key components of insulin receptor signaling pathways. Pregnant Wistar rats either were fed chow ad libitum or were undernourished throughout pregnancy, generating either control or intrauterine growth restricted (IUGR) offspring. Male offspring were fed either standard chow or a high-fat diet from weaning. At 260 d of age, whole-body insulin sensitivity was assessed by hyperinsulinemic-euglycemic clamp, and other metabolic parameters were measured. As expected, high-fat feeding caused diet-induced obesity (DIO) and insulin resistance. Importantly, the insulin sensitivity of IUGR offspring was similar to that of control offspring, despite fasting insulin hypersecretion and increased adiposity, irrespective of postnatal nutrition. Real-time PCR and Western blot analyses of key markers of insulin sensitivity and metabolic regulation showed that IUGR offspring had increased hepatic levels of atypical protein kinase C zeta (PKC zeta) and increased expression of fatty acid synthase mRNA. In contrast, DIO led to decreased expression of fatty acid synthase mRNA and hepatic steatosis. The decrease in hepatic PKC zeta with DIO may explain, at least in part, the insulin resistance. Our data suggest that the mechanisms of obesity induced by prenatal events are fundamentally different from those of obesity induced by postnatal high-fat nutrition. The origin of insulin hypersecretion in IUGR offspring may be independent of the mechanistic events that trigger the insulin resistance commonly observed in DIO.