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Aims/hypothesis Levels of the microRNA (miRNA) miR-126-3p are programmed cell-autonomously in visceral adipose tissue of adult offspring born to obese female C57BL/6J mice. The spectrum of miR-126-3p targets and thus the consequences of its dysregulation for adipocyte metabolism are unknown. Therefore, the aim of the current study was to identify novel targets of miR-126-3p in vitro and then establish the outcomes of their dysregulation on adipocyte metabolism in vivo using a well-established maternal obesity mouse model. Methods miR-126-3p overexpression in 3T3-L1 pre-adipocytes followed by pulsed stable isotope labelling by amino acids in culture (pSILAC) was performed to identify novel targets of the miRNA. Well-established bioinformatics algorithms and luciferase assays were then employed to confirm those that were direct targets of miR-126-3p. Selected knockdown experiments were performed in vitro to define the consequences of target dysregulation. Quantitative real-time PCR, immunoblotting, histology, euglycaemic–hyperinsulinaemic clamps and glucose tolerance tests were performed to determine the phenotypic and functional outcomes of maternal programmed miR-126-3p levels in offspring adipose tissue. Results The proteomic approach confirmed the identity of known targets of miR-126-3p (including IRS-1) and identified Lunapark, an endoplasmic reticulum (ER) protein, as a novel one. We confirmed by luciferase assay that Lunapark was a direct target of miR-126-3p. Overexpression of miR-126-3p in vitro led to a reduction in Lunapark protein levels and increased Perk (also known as Eif2ak3) mRNA levels and small interference-RNA mediated knockdown of Lunapark led to increased Xbp1, spliced Xbp1, Chop (also known as Ddit3) and Perk mRNA levels and an ER stress transcriptional response in 3T3-L1 pre-adipocytes. Consistent with the results found in vitro, increased miR-126-3p expression in adipose tissue from adult mouse offspring born to obese dams was accompanied by decreased Lunapark and IRS-1 protein levels and increased markers of ER stress. At the whole-body level the animals displayed glucose intolerance. Conclusions/interpretation Concurrently targeting IRS-1 and Lunapark, a nutritionally programmed increase in miR-126-3p causes adipose tissue insulin resistance and an ER stress response, both of which may contribute to impaired glucose tolerance. These findings provide a novel mechanism by which obesity during pregnancy leads to increased risk of type 2 diabetes in the offspring and therefore identify miR-126-3p as a potential therapeutic target. Graphical abstract

In the present study we investigated the participation of hepatic peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) in the metabolic programming of newborn rats exposed in utero to dexamethasone (DEX). On the 21st day of life, fasted offspring born to DEX-treated mothers displayed increased conversion of pyruvate into glucose with simultaneous upregulation of PEPCK (phosphoenolpyruvate carboxykinase) and G6Pase (glucose-6-phosphatase). Increased oxidative phosphorylation, higher ATP/ADP ratio and mitochondrial biogenesis and lower pyruvate levels were also found in the progeny of DEX-treated mothers. On the other hand, the 21-day-old progeny of DEX-treated mothers had increased hepatic triglycerides (TAG) and lower CPT-1 activity when subjected to short-term fasting. At the mechanistic level, rats exposed in utero to DEX exhibited increased hepatic PGC-1α protein content with lower miR-29a-c expression. Increased PGC-1α content was concurrent with increased association to HNF-4α and NRF1 and reduced PPARα expression. The data presented herein reveal that changes in the transcription machinery in neonatal liver of rats born to DEX-treated mothers leads to an inflexible metabolic response to fasting. Such programming is hallmarked by increased oxidative phosphorylation of pyruvate with impaired FFA oxidation and hepatic TAG accumulation.

Maternal obesity during pregnancy has immediate and long-term detrimental effects on the offspring heart. In this study, we characterized the cardiac and circulatory lipid profiles in fetuses of diet-induced obese pregnant mice and established the changes in lipid abundance and fetal cardiac transcriptomics. We used untargeted and targeted lipidomics and transcriptomics to define changes in the serum and cardiac lipid composition and fatty acid metabolism in male and female fetuses. From these analyses we observed: (1) maternal obesity affects the maternal and fetal serum lipidome distinctly; (2) female heart lipidomes are more sensitive to maternal obesity than male fetuses; (3) changes in lipid supply might contribute to early expression of lipolytic genes in mouse hearts exposed to maternal obesity. These results highlight the existence of sexually dimorphic responses of the fetal heart to the same in utero obesogenic environment and identify lipids species that might mediate programming of cardiovascular health.

Background In utero exposure to obesity is consistently associated with increased risk of metabolic disease, obesity and cardiovascular dysfunction in later life despite the divergence of birth weight outcomes. The placenta plays a critical role in offspring development and long-term health, as it mediates the crosstalk between the maternal and fetal environments. However, its phenotypic and molecular modifications in the context of maternal obesity associated with fetal growth restriction (FGR) remain poorly understood. Methods Using a mouse model of maternal diet-induced obesity, we investigated changes in the placental transcriptome through RNA sequencing (RNA-seq) and Ingenuity Pathway Analysis (IPA) at embryonic day (E) 19. The most differentially expressed genes (FDR Results RNA-seq and IPA analyses revealed differential expression of transcripts and pathway interactions related to placental vascular development and tissue morphology in obese placentae at term, including downregulation of Muc15, Cnn1, and Acta2. Pdgfb, which is implicated in labyrinthine layer development, was downregulated in obese placentae at E13. This was consistent with the morphological evidence of reduced labyrinth zone (LZ) size, as well as lower fetal weight at both timepoints irrespective of offspring sex. Conclusions Maternal obesity results in abnormal placental LZ development and impaired vascularization, which may mediate the observed FGR through reduced transfer of nutrients across the placenta.

Obesity during pregnancy is associated with increased risk of nonalcoholic fatty liver disease (NAFLD) in the offspring; however, the underlying molecular mechanisms remain largely unknown. The aim of the current study was to explore the contribution of microRNAs (miRs) as mediators of programming by maternal obesity. To achieve this, we used a mouse model of maternal-diet induced obesity where dams develop gestational diabetes and offspring demonstrate increased hepatic triglyceride content. We carried out small RNA next generation sequencing analysis of liver from twelve-week-old male offspring and identified miR-582-5p as the most dysregulated, showing a threefold increase. Binding site prediction (TargetScan 7.2) and pathway enrichment analysis (Reactome v67) suggested a number of miR-582-5p target genes related to lipid metabolism including Insulin Induced Gene 2 (INSIG2) and Translocase of Inner Mitochondrial Membrane 23 (TIMM23). Overexpression of miR-582-5p in AML12 (mouse) and HEPG2 (human) cell lines caused increased triglyceride accumulation, downregulation of INSIG2 and TIMM23, increased nuclear localization of Sterol Regulatory Element-Binding Protein 1 (SREBP-1), and overexpression of lipogenic genes. These findings suggest that overexpression of miR-582-5p induces hepatic intracellular lipid accumulation through mechanisms that involve mitochondrial malfunction and activation of de novo lipogenesis. We therefore conclude that an epigenetically programmed increase in hepatic miR-582 is a likely contributing mechanism underlying the programming of fatty liver disease in the offspring of obese gestational diabetic mothers. Disclosure L. Pantaleao: None. D. Fernandez-Twinn: None. A. Carpenter: None. E. Loche: None. L. Dearden: None. D. Duque Guimaraes: None. N.C. Penfold: None. T.J. Ashmore: None. M. Bushell: None. S. Ozanne: Advisory Panel; Self; Nestlé. Funding Brazilian National Council for the Improvement of Higher Education (BEX 10594/13-2); Brazilian National Council for Scientific and Technological Development (PDE/204416/2014-0)

Strong evidence suggests that an adverse in utero and/or early postnatal environment impacts on long-term risk of developing type 2 diabetes. We showed previously that miR-126 is increased in adipose tissue of mouse offspring born to obese mothers which leads to impaired insulin signaling pathway by silencing IRS-1 at the translational level. However, the full spectrum of targets of miR-126 and consequently the consequences of its overexpression for adipose tissue function are unknown. The aim of the current study was therefore to identify novel targets of miR-126 using the proteomic technique, known as Pulsed Stable Isotope Labeling by Amino Acids (pSILAC). 3T3-L1-cells were transfected with miR-126 and their proteome compared to those transfected with a scrambled sequence. We detected 4567 proteins that were translated in adipocytes and of these 401 demonstrated a >1.3 fold decrease following over-expression of miR-126. Bioinformatic analysis revealed that 43 of these contained a miR-126 seed sequence in their 3’un-translated region. This included known miR-126 targets such as IRS-1 and VCAM-1 as well as novel targets. One of the largest changes in expression was observed for Lunapark and through the use of luciferase assays and western blotting we independently confirmed this was a direct target of miR-126. Lunapark is a key component for stabilization of nascent three-way junctions in the endoplasmic reticulum (ER). Consistent with this role we observed altered levels of mTOR and XBP1 in cells treated with miR-126, reflecting the presence of ER stress. Together, the results suggest that overexpression of miR-126 can lead to both ER stress and Insulin Resistance and therefore represent a novel link between two pathways that contribute to development and progression to T2DM. Disclosure J.A. Faria: None. D. Duque Guimaraes: None. L. Pantaleao: None. T.P. Ong: None. A. Ozanne: None.

Identifying microRNA (miRNA) signatures in animal tissues is an essential first step in studies assessing post-transcriptional regulation of gene expression in health or disease. Small RNA sequencing (sRNA-Seq) is a next-generation sequencing-based technology that is currently considered the most powerful and versatile tool for miRNA profiling. Here, we describe a sRNA-Seq protocol including RNA purification from mammalian tissues, library preparation, and raw data analysis.

Identifying microRNA (miRNA) signatures in animal tissues is an essential first step in studies assessing post-transcriptional regulation of gene expression in health or disease. Small RNA sequencing (sRNA-Seq) is a next-generation sequencing-based technology that is currently considered the most powerful and versatile tool for miRNA profiling. Here, we describe a sRNA-Seq protocol including RNA purification from mammalian tissues, library preparation, and raw data analysis.

We investigated the effect of dexamethasone during the last week of pregnancy on glucose and lipid metabolism in male offspring. Twelve-week old offspring were evaluated after fasting for 12-hours (physiological) and 60-hours (prolonged). Physiological fasting resulted in glucose intolerance, decreased glucose clearance after pyruvate load and increased PEPCK expression in rats born to dexamethasone-treated mothers (DEX). Prolonged fasting resulted in increased glucose tolerance and increased glucose clearance after pyruvate load in DEX. These modulations were accompanied by accumulation of hepatic triglycerides (TG). Sixty-hour fasted DEX also showed increased citrate synthase (CS) activity, ATP citrate lyase (ACLY) content, and pyruvate kinase 2 (pkm2), glucose transporter 1 (slc2a1) and lactate dehydrogenase-a (ldha) expressions. Hepatic AKT2 was increased in 60-hour fasted DEX, in parallel with reduced miRNAs targeting the AKT2 gene. Altogether, we show that metabolic programming by prenatal dexamethasone is characterized by an unexpected hepatic TG accumulation during prolonged fasting. The underlying mechanism may depend on increased hepatic glycolytic flux due to increased pkm2 expression and consequent conversion of pyruvate to non-esterified fatty acid synthesis due to increased CS activity and ACLY levels. Upregulation of AKT2 due to reduced miRNAs may serve as a permanent mechanism leading to increased pkm2 expression.

The liver plays an essential role in maternal metabolic adaptation during late pregnancy. With regard to lipid metabolism, increased secretion of very low-density lipoprotein (VLDL) is characteristic of late pregnancy. Despite this well-described metabolic plasticity, the molecular changes underlying the hepatic adaptation to pregnancy remain unclear. As AMPK is a key intracellular energy sensor, we investigated whether this protein assumes a causal role in the hepatic adaptation to pregnancy. Pregnant Wistar rats were treated with vehicle or AICAR (5-aminoimidazole-4-carboxamide ribonucleotide) for 5 days starting at gestational day 14. At the end of treatment, the rats were subjected to an intraperitoneal pyruvate tolerance test and in situ liver perfusion with pyruvate. The livers were processed for Western blot analysis, quantitative PCR, thin-layer chromatography, enzymatic activity, and glycogen content measurements. Blood biochemical profiles were also assessed. We found that AMPK and ACC phosphorylation were reduced in the livers of pregnant rats in parallel with a reduced level of hepatic gluconeogenesis of pyruvate. This effect was accompanied by both a reduction in the levels of hepatic triglycerides (TG) and an increase in circulating levels of TG. Treatment with AICAR restored hepatic levels of TG to those observed in nonpregnant rats. Additionally, AMPK activation reduced the upregulation of genes related to VLDL synthesis and secretion observed in the livers of pregnant rats. We conclude that the increased secretion of hepatic TG in late pregnancy is concurrent with a transcriptional profile that favors VLDL production. This transcriptional profile results from the reduction in hepatic AMPK activity. ispartof: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology vol:307 issue:9 pages:R1146-R1156 ispartof: location:United States status: published

The positive regulation of insulin pathway in skeletal muscle results in increased activity of the mammalian target of rapamycin (mTOR), a positive effector of mRNA translation rate and protein synthesis. Studies that assess the activity of this protein in response to chronic high-fat diet (HFD) are scarce and controversial, and to date, there are no studies evaluating the mTOR pathway in infants exposed to gestational and postgestational HFD. This study investigated the effect of maternal HFD on skeletal muscle morphology and on phosphorylation of proteins that comprise the intracellular mTOR signaling pathway in soleus muscle of offspring at weaning. For this purpose, 10 days prior to conception, 39 female Wistar rats were randomly assigned to either control diet (CTL) or HFD. Later, rats were distributed into four groups according to gestational and postpregnancy diet: CTL/CTL (n=10), CTL/HF (n=11), HF/HF (n=10) and HF/CTL (n=8). After 21 days of lactation, pups were killed, and blood samples and soleus and gastrocnemius skeletal muscle were collected for analysis. We observed an influence of maternal postgestational diet, rather than gestational diet, in promoting an obese phenotype, characterized by body fat accumulation, insulin resistance and high serum leptin, glucose, triglycerides and cholesterol levels (P.05). We have also detected alterations on skeletal muscle morphology--with reduced myofiber density--and impairment on S6 kinase 1 and 4E binding protein-1 phosphorylation (P.05). These results emphasize the importance of maternal diet during lactation on muscle morphology and on physiological adaptations of infant rats.

Position statement: The Brazilian Society for Food and Nutrition (SBAN) bases the following position statement on a critical analysis of the literature on the indications of a gluten-free (GF) diet. (1) There is insufficient evidence to assume that healthy individuals would experience any benefits from the consumption of a GF diet. (2) Recent studies suggest that gluten sensitivity may be confounded by sensitivity to low-fermentable, poorly absorbed, short-chain carbohydrates known as fermentable oligo-, di-, and mono-saccharides and polyols (FODMAPs). (3) Epidemiological data supports that even overweight celiac disease (CD) individuals fail to achieve weight loss under a GF diet. (4) Recent experimental data showed possible deleterious effects of GF feeding on the intestinal microbiota of healthy individuals. (5) GF diets can be healthy for the general population, as long as GF-processed foods are avoided, and the ingestion of other whole grains, and low-energy-density vegetables is assured. This position statement has been externally reviewed and approved by the board of the Brazilian Society for Food and Nutrition, and has not gone through the journal’s standard peer review process.

The aim of this study was to investigate the effect of isocaloric intake from a high-fat diet (HFD) on insulin resistance and inflammation in rats. Male Wistar rats were fed on an HFD (n = 12) or control diet (n = 12) for 12 weeks. Subsequently, all animals were euthanized, and blood glucose, insulin, free fatty acids, C-reactive protein, lipid profile, cytokines and hepatic-enzyme activity were determined. Carcass chemical composition was also analyzed. During the first and the twelfth weeks of the experimental protocol, the oral glucose tolerance test and insulin tolerance test were performed and demonstrated insulin resistance (P

OBJECTIVE: Aging is characterized by alterations in body composition such as an increase in body fat and decreases in muscle mass (sarcopenia) and bone density (osteopenia). Leucine supplementation has been shown to acutely stimulate protein synthesis and to decrease body fat. However, the long-term effect of consistent leucine supplementation is not well defined. This study investigated the effect of leucine supplementation during aging. METHODS: Six-month-old rats were divided into three groups: an adult group (n = 10) euthanized at 6 mo of age, a leucine group (n = 16) that received a diet supplemented with 4% leucine for 40 wk, and a control group (n = 19) that received the control diet for 40 wk. The following parameters were evaluated: body weight, food intake, chemical carcass composition, indicators of acquired chronic diseases, and indicators of protein nutritional status. RESULTS: Body weight and fat were lower in the leucine group after 40 wk of supplementation compared with the control group but still higher than in the adult group. The lipid and glycemic profiles were equally altered in the control and leucine groups because of aging. In addition, leucine supplementation did not affect the changes in protein status parameters associated with aging, such as decreases in body and muscle protein and total serum protein. CONCLUSION: The results indicate that leucine supplementation attenuates body fat gain during aging but does not affect risk indicators of acquired chronic diseases. Furthermore, supplemented animals did not show signs of a prevention of the decrease in lean mass associated with aging.

Avaliamos o efeito da RCIU induzida por glicocorticoides sobre a regulação da expressão de miRNAs no fígado de ratos albinos. Animais expostos intrauterinamente à dexametasona apresentaram menor peso ao nascer, fígados relativamente menores dos que os observados em animais controle e menores concentrações hepáticas de PCNA. Em longo prazo, os animais DEX desenvolveram distúrbios metabólicos caracterizados por intolerância à glicose e maior potencial gliconeogênico no desmame e na vida adulta. Ao avaliarmos o perfil de miRNAs no fígado, detectamos aumento da expressão de todo o cluster do miR-322 no período perinatal, com menor conteúdo de alvos preditos desses transcritos (AKT3, CCND1 e INSR). A superexposição ao miR-322-5P reduz a taxa de proliferação em linhagens celulares de hepatocarcinoma e a expressão dos alvos observados no fígado dos animais estudados. Propomos um link entre a expressão aberrante do miR-322-5P e a reduzida taxa de proliferação detectada no tecido hepático em desenvolvimento, contribuindo para o estabelecimento do fenótipo em longo prazo. We evaluated the effects of glucocorticoid induced IUGR on the expression of miRNA on Wistar rat livers. Dexamethasone (DEX) treated animals were lighter and had smaller liver weight:body weight ratio when compared to control animals. Furthermore, liver PCNA expression was downregulated, sugesting a reduction on cell proliferation rate. In the long term, DEX animals developed metabolic disturbances such as glucose intolerance e increased gluconeogenesis rate in a fast state. The analysis of miRNA expression profile showed an upregulation of miR-322 cluster on perinatal period, together with a downregulation of three putative targets: Akt3, CCND1 and INSR. Later, we used in vitro studies to prove that overexpression of miR-322-5P arrests cell cycle and impairs proliferation of HEPG2 cells as well as it downregulates the predicted targets. Based on this data, we suggest a link between overexpression of miR-322-5P and impaired proliferation rate on the developing liver, which affects the phenotype in the long term.

Maternal nutrition is directly related to the growth and development of the fetus. However, epidemiological studies have demonstrated the consequences of poor maternal nutrition on the development of diseases in later life, such as obesity, cardiovascular diseases associated with a high incidence of myocardial infarction, insulin resistance, diabetes, hypertension, and dyslipidemias. On the basis of these observations, Barker formulated the hypothesis of the fetal origin of diseases, which proposes that fetuses exposed to a limited supply of nutrients adapt to this situation by altering their metabolic processes. Fetal programming can therefore be defined as an adaptive process to an adverse intrauterine environment which redefines developmental processes, guaranteeing fetal survival.

To investigate the effect of Yerba Mate (YM) aqueous extract intake on the NF-kB pathway and AKT expression in the liver, muscle, and adipose tissue of rats submitted to a high-fat diet (HFD). Male Wistar rats were fed a control (CON) (n = 24) or a HFD (n = 24) for 12 weeks. Afterwards, rats received YM daily (1 g/kg body weight) for 4 weeks. Intake of YM aqueous extract reduced body weight gain (p

Excess of glucocorticoids (GCs) during pregnancy is strongly associated with the programming of glucose intolerance in the offspring. However, the impact of high GC levels on maternal metabolism is not clearly documented. This study aimed to test the hypothesis that mothers exposed to elevated levels of GCs might also display long-term disturbances in glucose homeostasis. Dexamethasone (DEX) was administered noninvasively to the mothers via drinking water between the 14th and the 19th days of pregnancy. Mothers were subjected to glucose and insulin tolerance tests at 1, 2, 3, 6, and 12 mo postweaning. Pregnant rats not treated with DEX and age-matched virgin rats were used as controls. Pancreatic islets were isolated at the 20th day of pregnancy and 12 mo postweaning in order to evaluate glucose-stimulated insulin secretion. The expression of the miR-29 family was also studied due to its responsiveness to GCs and its well-documented role in the regulation of pancreatic β-cell function. Rats treated with DEX during pregnancy presented long-term glucose intolerance and impaired insulin secretion. These changes correlated with 1) increased expression of miR-29 and its regulator p53, 2) reduced expression of syntaxin-1a, a direct target of miR-29, and 3) altered expression of genes related to cellular senescence. Our data demonstrate that the use of DEX during pregnancy results in deleterious outcomes to the maternal metabolism, hallmarked by reduced insulin secretion and glucose intolerance. This maternal metabolic programming might be a consequence of time-sustained upregulation of miR-29s in maternal pancreatic islets.

Sepsis is a leading cause of death in intensive care units worldwide. Low availability of glutamine contributes to the catabolic state of sepsis. L-Glutamine supplementation has antioxidant properties and modulates the expression of heat shock proteins (HSPs). This study investigated the effects of oral supplementation with L-glutamine plus L-alanine (GLN+ALA), both in the free form and L-alanyl-L-glutamine dipeptide (DIP), on glutamine-glutathione (GSH) axis and HSPs expression in endotoxemic mice. B6.129F2/J mice were subjected to endotoxemia (lipopolysaccharides from Escherichia coli, 5 mg.kg(-1), LPS group) and orally supplemented for 48 h with either L-glutamine (1 g.kg(-1)) plus L-alanine (0.61 g.kg(-1)) (GLN+ALA-LPS group) or 1.49 g.kg(-1) of DIP (DIP-LPS group). Endotoxemia reduced plasma and muscle glutamine concentrations [relative to CTRL group] which were restored in both GLN+ALA-LPS and DIP-LPS groups (P

The aim of this study was to investigate the effect of isocaloric intake from a high-fat diet (HFD) on insulin resistance and inflammation in rats. Male Wistar rats were fed on an HFD (n = 12) or control diet (n = 12) for 12 weeks. Subsequently, all animals were euthanized, and blood glucose, insulin, free fatty acids, C-reactive protein, lipid profile, cytokines and hepatic-enzyme activity were determined. Carcass chemical composition was also analyzed. During the first and the twelfth weeks of the experimental protocol, the oral glucose tolerance test and insulin tolerance test were performed and demonstrated insulin resistance (P0.05) in the HFD group. Although food intake (g) was lower (P0.05) in the HFD group compared with the control group, the concentration of total cholesterol, low-density lipoprotein, C-reactive protein and liver weight were all significantly higher. The kinase inhibitor of κB, c-Jun N-terminal kinase and protein kinase B expressions were determined in the liver and skeletal muscle. After an insulin stimulus, the HFD group demonstrated decreased (P = 0.05) hepatic protein kinase B expression, whereas the kinase inhibitor of κB phospho/total ratio was elevated in the HFD muscle (P = 0.02). In conclusion, the isocaloric intake from the HFD induced insulin resistance, associated with impaired insulin signalling in the liver and an inflammatory response in the muscle.

Certain amino acids, such as leucine (Leu) are not only substrates for protein synthesis but also are important regulators of protein metabolism. Moreover, it is known that alterations in intrauterine growth favor the development of chronic diseases in adulthood. Therefore, we investigated the role of Leu in combination with other BCAA on effects that are induced by maternal protein restriction on fetal growth. Wistar rats were divided into 4 groups according to the diet provided during pregnancy: control (C; 20% casein); V+I [5% casein + 2% L-valine (Val) + 2% L-isoleucine (Ile)]; KYT [5% casein + 1.8% L-lysine (Lys) + 1.2% L-tyrosine (Tyr) + 1% L-threonine (Thr)]; and BCAA (5% casein + 1.8% L-Leu + 1.2% L-Val + 1% L-Ile). Maternal protein restriction reduced the growth and organ weight of the offspring of dams receiving the V+I and KYT diets compared with the C group. Supplementation with BCAA reversed this growth deficit, minimizing the difference or restoring the mass of organs and carcass fat, the liver and muscle protein, and the RNA concentrations compared with newborns in the C group (P < 0.05). These effects could be explained by the activation of the mTOR signaling pathway, because phosphorylation of 4E-BP1 in the liver of offspring of the BCAA group was greater than that in the C, V+I, and KYT groups. The present results identify a critical role for Leu in association with other BCAA in the activation of the mTOR signaling pathway for the control of altered intrauterine growth induced by a maternal low-protein diet.

The present investigation was undertaken to test whether exercise training (ET) associated with AMPK/PPAR agonists (EM) would improve skeletal muscle function in mdx mice. These drugs have the potential to improve oxidative metabolism. This is of particular interest because oxidative muscle fibers are less affected in the course of the disease than glycolitic counterparts. Therefore, a cohort of 34 male congenic C57Bl/10J mdx mice included in this study was randomly assigned into four groups: vehicle solution (V), EM [AICAR (AMPK agonist, 50 mg/Kg-1.day-1, ip) and GW 1516 (PPARδ agonist, 2.5 mg/Kg-1.day-1, gavage)], ET (voluntary running on activity wheel) and EM+ET. Functional performance (grip meter and rotarod), aerobic capacity (running test), muscle histopathology, serum creatine kinase (CK), levels of ubiquitined proteins, oxidative metabolism protein expression (AMPK, PPAR, myoglobin and SCD) and intracellular calcium handling (DHPR, SERCA and NCX) protein expression were analyzed. Treatments started when the animals were two months old and were maintained for one month. A significant functional improvement (p

Background Studies suggest that leucine supplementation (LS) has a therapeutic potential to prevent obesity and to promote glucose homeostasis. Furthermore, regular physical exercise is a widely accepted strategy for body weight maintenance and also for the prevention of obesity. The aim of this study was to determine the effect of chronic LS alone or combined with endurance training (ET) as potential approaches for reversing the insulin resistance and obesity induced by a high-fat diet (HFD) in rats. Methods Forty-seven rats were randomly divided into two groups. Animals were fed a control diet-low fat (n = 10) or HFD (n = 37). After 15 weeks on HFD, all rats received the control diet-low fat and were randomly divided according to treatment: reference (REF), LS, ET, and LS+ET (n = 7-8 rats per group). After 6 weeks of treatment, the animals were sacrificed and body composition, fat cell volume, and serum concentrations of total cholesterol, HDL-cholesterol, triacylglycerol, glucose, adiponectin, leptin and tumor necrosis factor-alpha (TNF-α) were analyzed. Results At the end of the sixth week of treatment, there was no significant difference in body weight between the REF, LS, ET and LS+ET groups. However, ET increased lean body mass in rats (P = 0.019). In addition, ET was more effective than LS in reducing adiposity (P = 0.019), serum insulin (P = 0.022) and TNF-α (P = 0.044). Conversely, LS increased serum adiponectin (P = 0.021) levels and reduced serum total cholesterol concentration (P = 0.042). Conclusions The results showed that LS had no beneficial effects on insulin sensitivity or adiposity in previously obese rats. On the other hand, LS was effective in increasing adiponectin levels and in reducing total cholesterol concentration.