MicroRNA signature in skeletal muscle in insulin resistant rats
Ontology highlight
ABSTRACT: The current study aimed to address the hypothesis that programmed expression of key miRNAs in skeletal muscle mediates the development of insulin resistance, and consequently long-term health. We thus examined microRNA signatures in skeletal muscle of programmed insulin resistant rats offspring from high fat-fed dams vs control offspring from chow fed dams. Skeletal muscle (soleus) was collected from the hind limb of 1 year old male offspring (6 from control dams, 6 from high fat-fed dams) . Ramaciotti Centre for Genomics (UNSW, sydney, Australia)
Project description:The current study aimed to address the hypothesis that programmed expression of key miRNAs in skeletal muscle mediates the development of insulin resistance, and consequently long-term health. We thus examined microRNA signatures in skeletal muscle of programmed insulin resistant rats offspring from high fat-fed dams vs control offspring from chow fed dams.
Project description:Maternal obesity can program metabolic syndrome in offspring but the mechanisms are not well characterized. Moreover, the consequences of maternal overnutrition in the absence of frank obesity remain poorly understood. This study aimed to determine the effects of maternal consumption of a high fat-sucrose diet on the skeletal muscle metabolic and transcriptional profiles of adult offspring. Female Sprague Dawley rats were fed either a diet rich in saturated fat and sucrose (HFD, 23.5% fat, 20% sucrose wt/wt) or a standard chow diet (NFD, 7% fat, 10% sucrose w/w) for the 3 weeks prior to mating and throughout pregnancy and lactation. Although maternal weights were not different between groups at conception or weaning, HFD dams were ~22% heavier than chow fed dams from mid-pregnancy until 4 days post-partum. Adult male offspring of HFD dams were not heavier than controls but demonstrated features of insulin resistance including elevated plasma insulin concentration (+40%, P<0.05). Next Generation mRNA Sequencing was used to identify differentially expressed genes in the soleus muscle of offspring, and Gene Set Enrichment Analysis (GSEA) to detect coordinated changes that are characteristic of a biological function. GSEA identified 15 pathways enriched for up-regulated genes, including cytokine signaling (P<0.005), starch and sucrose metabolism (P<0.017), and inflammatory response (P<0.024). A further 8 pathways were significantly enriched for down-regulated genes including oxidative phosphorylation (P<0.004) and electron transport (P<0.022). Western blots confirmed a ~60% reduction in the phosphorylation of the insulin signaling protein Akt (P<0.05) and ~70% reduction in mitochondrial complexes II (P<0.05) and V expression (P<0.05). On a normal diet, offspring of HFD dams developed an insulin resistant phenotype, with transcriptional evidence of muscle cytokine activation, inflammation and mitochondrial dysfunction. These data indicate that maternal overnutrition, even in the absence of pre-pregnancy obesity can promote metabolic dysregulation and predispose offspring to type 2 diabetes. Messenger RNA profile of skeletal muscle of male offspring from female Sprague Dawley rats fed either a diet rich in saturated fat and sucrose (HFD, 23.5% fat, 20% sucrose wt/wt) or a standard chow diet (NFD, 7% fat, 10% sucrose w/w) for the 3 weeks prior to mating and throughout pregnancy and lactation. There were 5 HFD samples compared to 6 NFD control samples.
Project description:Taurine is known to be important for fetal well being and to be able to prevent effects of a low birthweight phenotype when supplemented to pregnant dams. We hypothesized that gestational taurine supplementation would affect gene expression level in 4w offspring liver and skeletal muscle. Pregnant mouse dams were subjected to different diet schemes from day 1 of pregnancy until birth. Pups were killed at 4 weeks of age and liver and quadriceps skeletal muscle taken out and frozen at -80C until analysis. Diet schemes: Normal Protein (20% casein; NP), Normal Protein + taurine (1% taurine supplementation in water ad libitum; NP+tau). The liver and muscle samples were normalized separately.
Project description:Though obesity is a global epidemic, the physiological mechanisms involved are little understood. Recent advances reveal that susceptibility to obesity can be programmed by maternal and neonatal nutrition. Specifically, a maternal low protein diet during pregnancy causes decreased intrauterine growth, rapid postnatal catch-up growth and increased risk for diet-induced obesity. Given that the synthesis of the neurotransmitter 5-hydroxytryptamine (5-HT) is nutritionally regulated and 5-HT is a trophic factor, we hypothesized that maternal diet influences fetal 5-HT exposure, which then influences central appetite network development and the subsequent efficacy of 5-HT to control energy balance in later life. Consistent with our hypothesis, pregnant low protein fed rat mothers exhibited elevated serum 5-HT, which was also evident in the placenta and fetal brains at E16.5. This increase was associated with reduced hypothalamic expression of 5-HT2CR - the primary 5-HT receptor influencing appetite. As expected, reduced 5-HT2CR expression was associated with impaired sensitivity to 5-HT-mediated appetite suppression. 5-HT primarily achieves effects on appetite via 5-HT2CR stimulation of pro-opiomelanocortin (POMC) peptides within the arcuate nucleus of the hypothalamus (ARC). We reveal that 5-HT2ARs are also anatomically positioned to influence the activity of ARC POMC and that 5-HT2AR mRNA is increased in the hypothalamus of in utero growth restricted offspring that underwent rapid postnatal catch-up growth. Furthermore, these animals are more sensitive to 5-HT2AR agonist-induced appetite suppression. These findings may not only reveal a 5-HT-mediated mechanism underlying programming of obesity susceptibility but also provide a promising means to correct it, via a 5-HT2AR agonist treatment. The study was carried out using male Wistar rats (Rattus norvegicus). On postnatal day 3, two experimental groups of offspring were established: controls (offspring of control dams) and recuperated (offspring of dams fed a low-protein diet (8% protein, w/v), but nursed by control dams. The animals were fed with standard chow until 3 months of age where the brains were collected for transcriptomic profiling
Project description:Adult female Wistar rats (about 220g) obtained from a breeding colony were mated and fed either a protein sufficient (PS) or protein restricted (PR) diet (n = 6 per dietary group) during F0 pregnancy which provided an increase in energy of approximately 25% compared to the diet fed to the breeding colony (2018S). During lactation dams were fed AIN93G and litters were standardisied to 8 offspring within 24 hours of birth with a bias towards females. Offpsring were weaned onto AIN93M at postnatal day 28 and F1 and F2 females were mated on postnatal day 70 (n = 6 per F0 dietary group). F1 and F2 dams were fed the PS diet during pregnancy and AIN93G during lactation. Offspring were weaned onto AIN93M. On postnatal day 70 unmated female offspring were fasted for 12 hours then sacrificed for hepatic transcritpome analysis by microarray. Expression of 1,684 genes differed by at least 2 fold between adult female F1 offspring of F0 dams from both dietary groups. 1680 genes were altered in F2 offspring and 2,065 genes altered in F3 offspring. Expression of 113 genes was altered in all three generations. Of these, 47% showed directionally opposite differences between generations. Gene ontology analysis revealed clear differences in the pathways altered in each generation. F1 and F2 offspring of F0 dams fed a PR diet showed impaired fasting glucose homeostasis. Hepatic phosphoenolpyruvate carboxykinase (PEPCK) expression was elevated in F1 and F2 offspring from F0 PR dams, but decreased in F3, compared to PS offspring
Project description:Objective: Procyanidins are polyphenolic bioactive compounds that exert beneficial effects against obesity and its related diseases. The aim of this study was to evaluate whether the supplementation with low doses of a grape seed procyanidin extract (GSPE) to dams during pre and postnatal periods has biological effects on their offspring at youth. Design: The metabolic imprinting effect of GSPE was evaluated in 30 days-old male offspring of four groups of rats that were fed either a standard diet (STD) or a high-fat diet (HFD) and supplemented with either GSPE at 25 mg per kg of body weight/day or vehicle during pregnancy and lactation. Results: A significant increase in the adiposity index and in the weight of all the white adipose tissue depots studied (retroperitoneal â??RWAT-, mesenteric â??MWAT-, epididymal â??EWAT- and inguinal â??IWAT-) was observed in offspring of dams fed with a HFD and treated with GSPE (HFT group), compared to the offspring of dams fed with the same diet and that do not received procyanidins (HF group). HFT animals also showed a higher number of cells in the EWAT, a sharply decrease of the circulating levels of monocyte chemoattractant protein-1 (MCP-1) as well as a moderate, but significant, decrease of plasma glycerol levels. The transcriptomic analysis performed in the EWAT showed 238 genes differentially expressed between HF and HFT animals, covering an entire range of processes related with the immune function and the inflammatory response (the metabolic pathway mainly reflected in the EWAT), adipose tissue remodeling and function, lipid and glucose homeostasis and metabolism of methyl groups. Conclusion: GSPE treatment to dams fed a HFD during pregnancy and lactation increases adiposity, decreases the circulating levels of MCP-1 and modulates the expression of key genes involved in the adipose tissue metabolism of their offspring. The microarray study was performed with the EWAT RNA samples of rats from the HF and the HFT groups (n=8 animals each).
Project description:In utero undernutrition is associated with obesity and insulin resistance, although its effect on skeletal muscle remains poorly defined. We report that, in mice, adult offspring from undernourished dams have decreased energy expenditure, decreased skeletal muscle mitochondrial content, and altered energetics in isolated mitochondria and permeabilized muscle fibers. Strikingly, when these mice are put on a 40% calorie restricted diet they lose half as much weight as calorie restricted controls. Our results reveal for the first time that in utero undernutrition alters metabolic physiology having a profound effect on skeletal muscle energetics and response to calorie restriction in adulthood. We have used a mouse model of low birth weight generated through 50% food restriction of mouse dams during the third week of gestation. We have studied in utero food restricted offspring and control offspring that were not food restricted in utero in both the ad libitum and calorie restricted states. Gene expression profiling was performed on tibialis anterior muscle from 8 mice per group, pooled in pairs.
Project description:The offspring of older fathers have an increased risk of neurodevelopmental disorders such as schizophrenia and autism. It has been proposed that de novo point mutations and copy number variants (CNVs) in the continually dividing spermatogonia underlie this association. In light of the evidence implicating CNVs with schizophrenia and autism, here we use a mouse model to test the hypothesis that the offspring of older males have an increased risk of de novo CNVs. Three-month-old and fourteen- to sixteen-month-old C57BL/6J sires were mated with three-month-old dams to create control offspring and offspring of old sires, respectively. Applying genome-wide microarray screening technology, seven distinct CNVs were identified in a discovery set of twelve offspring and their parents. Competitive quantitative PCR was employed to confirm the variants and establish their frequency in a replication set of 77 offspring and their parents. Six de novo CNVs were detected in the offspring of older sires, while none were detected in the control group. One of the de novo CNVs involved Auts2 (autism susceptibility candidate 2), and other CNVs included genes linked to schizophrenia, autism and brain development. Two of the CNVs were associated with behavioural and/or neuroanatomical phenotypic features. This is the first experimental demonstration that the offspring of older males have more de novo CNVs. The results suggest that offspring of older fathers may be at increased risk of neurodevelopmental disorders such as schizophrenia and autism via the generation of de novo CNV in the male germline. In light of the trends for delayed parenthood in many societies, and in light of the potential for these CNVs to accumulate over subsequent generations, the impact of these mechanisms on the health of future generations warrants closer scrutiny. 2 sires of advanced paternal age (12-16 months of age) and 2 control (3 months of age) sires were mated to dams (3 months of age) to create 6 offspring of advanced paternal age (APA) and 6 control offspring (C), respectively, with an even number of sexes within each group of offspring. A commerical aCGH and a custom CNV array (both supplied by Agilent) were used in combination to detect copy number variations in the genomes of the offspring and their parents. DNA from all male animals was hybridized against a male reference animal and that from all female animals against a female reference animal.
Project description:The offspring of older fathers have an increased risk of neurodevelopmental disorders such as schizophrenia and autism. It has been proposed that de novo point mutations and copy number variants (CNVs) in the continually dividing spermatogonia underlie this association. In light of the evidence implicating CNVs with schizophrenia and autism, here we use a mouse model to test the hypothesis that the offspring of older males have an increased risk of de novo CNVs. Three-month-old and fourteen- to sixteen-month-old C57BL/6J sires were mated with three-month-old dams to create control offspring and offspring of old sires, respectively. Applying genome-wide microarray screening technology, seven distinct CNVs were identified in a discovery set of twelve offspring and their parents. Competitive quantitative PCR was employed to confirm the variants and establish their frequency in a replication set of 77 offspring and their parents. Six de novo CNVs were detected in the offspring of older sires, while none were detected in the control group. One of the de novo CNVs involved Auts2 (autism susceptibility candidate 2), and other CNVs included genes linked to schizophrenia, autism and brain development. Two of the CNVs were associated with behavioural and/or neuroanatomical phenotypic features. This is the first experimental demonstration that the offspring of older males have more de novo CNVs. The results suggest that offspring of older fathers may be at increased risk of neurodevelopmental disorders such as schizophrenia and autism via the generation of de novo CNV in the male germline. In light of the trends for delayed parenthood in many societies, and in light of the potential for these CNVs to accumulate over subsequent generations, the impact of these mechanisms on the health of future generations warrants closer scrutiny. 2 sires of advanced paternal age (12-16 months of age) and 2 control (3 months of age) sires were mated to dams (3 months of age) to create 6 offspring of advanced paternal age (APA) and 6 control offspring (C), respectively, with an even number of sexes within each group of offspring. A commerical aCGH and a custom CNV array (both supplied by Agilent) were used in combination to detect copy number variations in the genomes of the offspring and their parents. DNA from all male animals was hybridized against a male reference animal and that from all female animals against a female reference animal.
Project description:Analysis of glucose and Lipid metabolism in male and female offspring after protein restriction of the mother Male offspring showed features of metabolic syndrome after receiving a high fat diet, regardless of the diet of the dam. Glucose and lipid metabolism in male offspring was unaltered. Insulin sensitivity and hepatic fatty acid storage in female offspring of low-protein-fed dams changed in such a way that it resembled the male pattern of insulin sensitivity and hepatic fatty acid storage. Microarray analysis on hepatic gene expression patterns confirmed these findings. We therefore conclude that in mice, maternal protein restriction does not change the response of glucose and fatty acid metabolism to a high fat diet in male offspring, but does program metabolism in female offspring in such a way that it resembles male metabolism. Our findings might have implications for potential future gender-specific treatment of the features of metabolic diseases. Total RNA obtained from liver (16 samples per gender) were compared in the different groups. In total, 4 groups per gender, each group consisting of 4 biological replicates.