Impairment of rat fetal beta-cell development by maternal exposure to dexamethasone during different time-windows.

Aim: Glucocorticoids (GCs) take part in the direct control of cell lineage during the late phase of pancreas development when endocrine and exocrine cell differentiation occurs. However, other tissues such as the vasculature exert a critical role before that phase. This study aims to investigate the consequences of overexposure to exogenous glucocorticoids during different time-windows of gestation for the development of the fetal endocrine pancreas.

Alteration of mitochondrial function in adult rat offspring of malnourished dams.

Under-nutrition as well as over-nutrition during pregnancy has been associated with the development of adult diseases such as diabetes and obesity. Both epigenetic modifications and programming of the mitochondrial function have been recently proposed to explain how altered intrauterine metabolic environment may produce such a phenotype. This review aims to report data reported in several animal models of fetal malnutrition due to maternal low protein or low calorie diet, high fat diet as well as reduction in placental blood flow.

Maternal malnutrition programs the endocrine pancreas in progeny.

Type 2 diabetes arises when the endocrine pancreas fails to secrete sufficient insulin to cope with metabolic demands resulting from β cell secretory dysfunction, decreased β cell mass, or both. Epidemiologic studies have shown strong relations between poor fetal and early postnatal nutrition and susceptibility to diabetes later in life. Animal models have been established, and studies have shown that a reduction in the availability of nutrients during fetal development programs the endocrine pancreas and insulin-sensitive tissues.

Developmental programming of adult obesity and cardiovascular disease in rodents by maternal nutrition imbalance.

Studies on fetal undernutrition have generated the hypothesis that fetal programming corresponds to an attempt of the fetus to adapt to adverse conditions encountered in utero. These adaptations would be beneficial if these conditions prevail later in life, but they become detrimental in the case of normal or plentiful nutrition and favor the appearance of the metabolic syndrome. In this article, the discussion is limited to the developmental programming of obesity and cardiovascular disorders caused by an early mismatched nutrition, particularly intrauterine growth retardation followed by postnatal catch-up growth.

Sex- and diet-specific changes of imprinted gene expression and DNA methylation in mouse placenta under a high-fat diet.

Background: Changes in imprinted gene dosage in the placenta may compromise the prenatal control of nutritional resources. Indeed monoallelic behaviour and sensitivity to changes in regional epigenetic state render imprinted genes both vulnerable and adaptable.

Methods And Findings: We investigated whether a high-fat diet (HFD) during pregnancy modified the expression of imprinted genes and local and global DNA methylation patterns in the placenta.

Maternal malnutrition programs pancreatic islet mitochondrial dysfunction in the adult offspring.

Accumulating evidence has shown that maternal malnutrition increases the risk of metabolic disease in the progeny. We previously reported that prenatal exposure to a low-protein diet (LP) leads to mitochondrial dysfunction in pancreatic islets from adult rodent offspring that could relate physiological and cellular alterations due to early diet. We aim to determine whether mitochondrial dysfunction could be a common consequence of prenatal nutritional unbalances.

Does early mismatched nutrition predispose to hypertension and atherosclerosis, in male mice?

Background: A link between early mismatched nutritional environment and development of components of the metabolic syndrome later in life has been shown in epidemiological and animal data. The aim of this study was to investigate whether an early mismatched nutrition produced by catch-up growth after fetal protein restriction could induce the appearance of hypertension and/or atherosclerosis in adult male mice.

Methodology/principal Findings: Wild-type C57BL6/J or LDLr-/- dams were fed a low protein (LP) or a control (C) diet during gestation.

Maternal low-protein diet alters pancreatic islet mitochondrial function in a sex-specific manner in the adult rat.

Mitochondrial dysfunction may be a long-term consequence of a poor nutritional environment during early life. Our aim was to investigate whether a maternal low-protein (LP) diet may program mitochondrial dysfunction in islets of adult progeny before glucose intolerance ensues. To address this, pregnant Wistar rats were fed isocaloric diets containing either 20% protein (control) or 8% protein (LP diet) throughout gestation.

Early low protein diet aggravates unbalance between antioxidant enzymes leading to islet dysfunction.

Background: Islets from adult rat possess weak antioxidant defense leading to unbalance between superoxide dismutase (SOD) and hydrogen peroxide-inactivating enzymatic activities, catalase (CAT) and glutathione peroxidase (GPX) rending them susceptible to oxidative stress. We have shown that this vulnerability is influenced by maternal diet during gestation and lactation.

Methodology/principal Findings: The present study investigated if low antioxidant activity in islets is already observed at birth and if maternal protein restriction influences the development of islet antioxidant defenses.

Programming of impaired insulin secretion versus sensitivity: cause or effect?

A substantial body of evidence suggests that a poor intrauterine milieu elicited by maternal nutritional disturbance, including maternal diabetes or placental insufficiency, may programme susceptibility in the fetus to later development of glucose intolerance and diabetes. Numerous data in animals have allowed possible mechanisms for programming to be proposed. This review of work in several animal models attempts to identify the cellular and molecular mechanisms at the level of the beta-cell and in the insulin sensitive tissues that are involved in the process of events leading to the pathology later in life.

Postnatal catch-up growth after fetal protein restriction programs proliferation of rat preadipocytes.

We studied the in vitro proliferation and differentiation of rat preadipocytes to investigate whether catch-up growth after prenatal protein restriction may program adipose precursor cells leading to development of increased adipose tissue mass. Pregnant rat dams were fed either an isocaloric low-protein diet (LP-8%) or control diet (C-20%). During lactation, in order to induce catch-up growth, dams from LP group were fed with the C diet and litter size was reduced to four pups instead of eight.

Fetal determinants of type 2 diabetes.

Type 2 diabetes, which has dramatically increased during the last decade normally results from a combination of pancreatic beta cell dysfunction and insulin resistance. One of the most recent risk factors identified for type 2 diabetes is a sub-optimal fetal and neonatal environment. Numerous human epidemiological studies worldwide have highlighted that a disturbed nutritional environment of the fetus, either poor or too abundant will compromise the health of the offspring by increasing the susceptibility to insulin resistance, to glucose intolerance and to diabetes in later life.

Is taurine a functional nutrient?

Purpose Of Review: Taurine, a free amino acid, is found in millimolar concentrations in most mammalian tissues. Mammals are able to synthesize taurine endogenously, but some species such as humans are more dependent on dietary sources of taurine. A growing body of evidence suggests that taurine plays a preponderant role in many physiological processes, which will be summarized in this review.

The importance of catch-up growth after early malnutrition for the programming of obesity in male rat.

Objective: To investigate whether catch-up growth after maternal malnutrition would favor the development of obesity in adulthood.

Research Methods And Procedures: Pregnant rats were submitted to protein or calorie restriction during the course of gestation. During lactation, pups were protein-restricted, normally fed, or overfed [reduced litter size, control (C) diet].

The regulation of IGFs and IGFBPs by prolactin in primary culture of fetal rat hepatocytes is influenced by maternal malnutrition.

During perinatal development, the regulation of IGF system appears to be growth hormone (GH) independent. By using highly purified primary fetal hepatocytes, we investigated the role of prolactin (PRL) in the regulation of IGF system and hepatocyte proliferation. We also analyzed the consequence of a maternal low-protein (LP) diet on the regulation of IGF, IGF-binding protein (IGFBP), and hepatocyte proliferation by prolactin.

Maternal protein intake in the pregnant rat programs the insulin axis and body composition in the offspring.

Evidence to support an association between early nutrition and the development of obesity in the rat is equivocal. In this study we have investigated the postnatal growth, glucose tolerance, and adipocyte function of the offspring from pregnant rats fed with diets containing either 20% or 8% protein during gestation. By 25 weeks of age, the female offspring of dams fed with the diet containing 8% protein had a significantly lower adult body weight due in part to a decrease in body fat.

Programming of the endocrine pancreas by the early nutritional environment.

A substantial body of evidence now suggests that poor intrauterine milieu elicited by maternal nutritional disturbance or placental insufficiency may programme susceptibility in the foetus to later develop chronic degenerative diseases, such as obesity, hypertension, cardiovascular diseases and diabetes. Further data showing the developmental programming of the metabolic syndrome are now available thanks to animal studies in which the foetal environment has been manipulated. This review examines the developmental programming of glucose intolerance by disturbed intrauterine metabolic condition in rats.

Involvement of endogenous glucagon-like peptide-1(7-36) amide on glycaemia-lowering effect of oligofructose in streptozotocin-treated rats.

We have evaluated the influence of oligofructose (OFS), a fermentable dietary fibre, on glucose homeostasis, insulin production and intestinal glucagon-like peptide-1 (GLP-1) in streptozotocin-treated diabetic rats. Male Wistar rats received either i.v.

Prenatal protein restriction does not affect the proliferation and differentiation of rat preadipocytes.

Poor development in utero may favor the development of obesity in adulthood. Animal studies showed that embryo manipulation in vitro or nutritional insults during the embryonic and fetal stages of development may lead to obesity in adult life. We studied the in vitro proliferation and differentiation of adipocytes to investigate whether early protein restriction may program cell growth and development.

Taurine supplementation of a low protein diet fed to rat dams normalizes the vascularization of the fetal endocrine pancreas.

In rats, an isoenergetic low protein diet (LP) given throughout gestation perturbs the development of the endocrine pancreas by reducing beta-cell mass and islet vascularization at birth. Taurine, an important amino acid during development, has been found to be low in fetal and maternal plasma. When added to a LP diet, taurine normalizes beta-cell mass.

Isocaloric maternal low-protein diet alters IGF-I, IGFBPs, and hepatocyte proliferation in the fetal rat.

We investigated the effect of an isocaloric maternal low-protein diet during pregnancy in rats on the proliferative capacity of cultured fetal hepatocytes. The potential roles of these changes on the IGF-IGF-binding protein (IGFBP) axis, and the role of insulin and glucocorticoids in liver growth retardation, were also evaluated. Pregnant Wistar rats were fed a control (C) diet (20% protein) or a low-protein (LP) diet (8%) throughout gestation.