Transcriptomic response to 24-hour food deprivation in four hypothalamic nuclei
Ontology highlight
ABSTRACT: The hypothalamus has an established role in the central control of energy homeostasis. In this study, we examine the gene expression changes in four discrete hypothalamic nuclei across 24-hour food deprived versus ad libitum fed mice.
Project description:Mice with a congenital Snord116 deletion model aspects of the Prader-Willi Syndrome. In this study, we examine the gene expression changes in four hypothalamic nuclei across 24-hour food deprived versus ad libitum fed mice.
Project description:Nutrition affects milk composition influencing its nutritional properties. Nutrition also modifies the expression of mammary genes, whose regulation is not completely known. MicroRNAs (miRNA) are small non-coding RNA that work as important post-transcriptional gene expression regulators by targeting messenger RNAs. Our goal was to characterize miRNA whose expression is regulated by nutrition in the lactating goat mammary gland, and which may give clues to decipher the regulations of milk components biosynthesis and secretion. Using high-throughput sequencing technology, miRNomes of the lactating mammary gland have been established from 4 goats fed ad libitum and 6 goats food deprived during 48h. Food deprivation affected the expression of 30 miRNA (padj<0.1), 16 were downregulated and 14 were upregulated. Prediction tools Diana-microT suggests a potential role of several nutriregulated miRNA in the lipid metabolism. Among putative targets 19 differently expressed genes (DEG) previously identified in the same sample, were found. Functions of these 19 DEG revealed their involvement in tissue remodeling. This study constitutes the first evidence of nutriregulated miRNA in the ruminant mammary gland. The characterization of these 30 miRNA could contribute to a better understanding of genes regulations in the mammary gland in response to nutrition.
Project description:Nutrition affects milk composition influencing its nutritional properties. Nutrition also modifies the expression of mammary genes, whose regulation is not completely known. MicroRNAs (miRNA) are small non-coding RNA that work as important post-transcriptional gene expression regulators by targeting messenger RNAs. Our goal was to characterize miRNA whose expression is regulated by nutrition in the lactating goat mammary gland, and which may give clues to decipher the regulations of milk components biosynthesis and secretion. Using high-throughput sequencing technology, miRNomes of the lactating mammary gland have been established from 4 goats fed ad libitum and 6 goats food deprived during 48h. Food deprivation affected the expression of 30 miRNA (padj<0.1), 16 were downregulated and 14 were upregulated. Prediction tools Diana-microT suggests a potential role of several nutriregulated miRNA in the lipid metabolism. Among putative targets 19 differently expressed genes (DEG) previously identified in the same sample, were found. Functions of these 19 DEG revealed their involvement in tissue remodeling. This study constitutes the first evidence of nutriregulated miRNA in the ruminant mammary gland. The characterization of these 30 miRNA could contribute to a better understanding of genes regulations in the mammary gland in response to nutrition. MicroRNA profiles of mammary glands from 10 Alpine goats at the peak of lactation (48 ± 2 days post-partum) generated by a HiSeq 2500 using Illumina Solexa technic.
Project description:BackgroundMonitoring salt consumption in children is essential for informing and implementing public health interventions to reduce children's salt intake. However, collection of 24-hour urines, considered as the most reliable approach, can be especially challenging to school children. This study aimed to assess the agreement between 24-hour urine (24hrU) and 24-hour food recall (24hrFR) in: (1) estimating salt intake in children; (2) classifying salt intakes above the recommended upper level set for children, and; (3) estimating change in mean salt intake over time.MethodsThis study utilised data from two cross-sectional surveys of school children aged 8 to 12 years living in the state of Victoria, Australia. A single 24hrU and 24hrFR were collected from each participant. Suspected inaccurate urine collections and implausible energy intakes were excluded based on pre-defined criteria. The agreement between the two methods was assessed using Bland-Altman methodology, the intraclass correlation coefficient (ICC), and the kappa statistic. The difference between the measured change in salt intake over time using 24hrU and 24hrFR was derived using mixed effects linear regression analysis.ResultsA total of 588 participants provided a 24hrU and 24hrFR. Overall, there was no meaningful difference in mean estimated salt intake between the two methods (- 0.2 g/day, 95% CI - 0.5 to 0.1). The Bland-Altman plot showed wide 95% limits of agreement (- 7.2 to 6.8). The ICC between the two methods was 0.13 (95% CI 0.05 to 0.21). There was poor interrater reliability in terms of classifying salt intake above the recommended upper level for children, with an observed agreement of 63% and kappa statistic of 0.11. The change in mean salt intake over time was 0.2 g/day (- 0.4 to 0.7) based on 24hrU, and 0.5 g/day (- 0.0 to 1.1) based on 24hrFR, with a difference-in-differences of 0.4 g/day (- 0.3 to 1.1).Conclusions24hrFR appears to provide a reasonable estimate of mean salt intake as measured by 24hrU in Australian school children. However, similar to previous observations in adults, and of studies exploring other alternative methods for estimating salt intake, 24hrFR is a poor predictor of individual-level salt intake in children.
Project description:Obesity occurs when energy expenditure is outweighed by food intake. Tuberal hypothalamic nuclei, including the arcuate nucleus (ARC), ventromedial nucleus (VMH), and dorsomedial nucleus (DMH), regulate feeding amount as well as energy expenditure. Here we report that mice lacking circadian nuclear receptors REV-ERBa and b in the tuberal hypothalamus (HDKO) gain excessive weight on an obesogenic diet due both to decreased energy expenditure and increased food consumption during the light phase. Moreover, rebound food intake after fasting is markedly increased in HDKO mice. Integrative transcriptomic and cistromic analyses revealed that such disruption in feeding behavior is due to perturbed REV-ERB-dependent leptin signaling in the ARC. Indeed, in vivo leptin sensitivity is impaired in HDKO mice on an obesogenic diet in a circadian manner. Thus, REV-ERBs play a crucial role in hypothalamic regulation of food intake and circadian leptin sensitivity in diet-induced obesity.
Project description:Obesity occurs when energy expenditure is outweighed by food intake. Tuberal hypothalamic nuclei, including the arcuate nucleus (ARC), ventromedial nucleus (VMH), and dorsomedial nucleus (DMH), regulate feeding amount as well as energy expenditure. Here we report that mice lacking circadian nuclear receptors REV-ERBa and b in the tuberal hypothalamus (HDKO) gain excessive weight on an obesogenic diet due both to decreased energy expenditure and increased food consumption during the light phase. Moreover, rebound food intake after fasting is markedly increased in HDKO mice. Integrative transcriptomic and cistromic analyses revealed that such disruption in feeding behavior is due to perturbed REV-ERB-dependent leptin signaling in the ARC. Indeed, in vivo leptin sensitivity is impaired in HDKO mice on an obesogenic diet in a circadian manner. Thus, REV-ERBs play a crucial role in hypothalamic regulation of food intake and circadian leptin sensitivity in diet-induced obesity.
Project description:Anorexia is frequently observed during cancer and associated with increased morbidity and mortality. Our previous work has shown the presence of transcription factors in the hypothalamus of anorectic tumor-bearing rats. The aim of the present study was, therefore, to assess expression of neuropeptides, neurotransmitter-synthesizing enzymes and receptors in this structure. Morris hepatoma 7777 cells injected subcutaneously in Buffalo rats provoked a 15% reduction in food intake and 10% lower body weight when the tumor represented 1-2% of body mass. Real-time PCR showed that tumor-bearing rats did not display the increase in hypothalamic agouti-related peptide mRNA observed in food-restricted weight-matched animals. These findings indicate that blunted hypothalamic AgRp mRNA expression underlies cancer-associated anorexia.
Project description:The hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei are important integrative structures that regulate co-ordinated responses to perturbations in cardiovascular homeostasis. Through descending projections from parvocellular neurons to the brainstem, the PVN acts as an autonomic 'premotor nucleus', regulating reflex changes in sympathetic nerve activity that are involved in blood pressure and blood volume regulation. Endocrine responses are mediated through axonal projections from SON and PVN magnocellular neurons (MCNs) to the capillaries of the posterior pituitary neural lobe. In response to dehydration, a massive release of the antidiuretic peptide hormone vasopressin (VP) into the circulation is accompanied by a dramatic functional remodelling of the HNS. We have used microarrays to comprehensively catalogue the genes expressed in the PVN, the SON and the neurointermediate lobe (NIL) of the pituitary gland. Further, we have identified transcripts that are regulated as a consequence of dehydration, as well as RNAs that are enriched in either the PVN or the SON. We suggest that these differentially expressed genes represent candidate regulators and effectors of HNS activity and remodelling. Experiment Overall Design: In total, 10 Affymetrix Genechip Rat Genome 230 2.0 were used. The experiment compared hypothalamic supraoptic nucleus from 3 day dehydrated and control male Sprague Dawley rats (10-12 weeks). For each chip, tissue from 5 animals was pooled prior to extraction of total RNA and in total 5 chips were used for each condition using independently prepared RNA samples from separate groups of animals.
Project description:Animal nutrition considerably affects milk composition that influences its nutritional quality. Milk component synthesis and secretion by the mammary gland involve expression of a large number of genes whose nutritional regulation remains poorly defined. In this study, we examined the effect of food deprivation (FD) on the expression of 8379 genes in caprine mammary gland using a bovine oligonucleotide microarray. Twelve lactating goats were assigned to 2 groups based on their feeding level (control diet ad libitum vs. 48-h FD). We identified 161 genes whose expression was altered by FD. Most of these genes (88%) were downregulated, suggesting a stress response by the mammary gland. In particular, the decrease in expression of genes involved in milk protein, lactose, and lipid metabolism could contribute together with the shortage of nutrients to the drop in milk protein, lactose, and fat secretion. In addition, this study highlights modification of the expression of at least 14 genes that could be responsible for a slowdown in mammary cell proliferation and differentiation and/or an increase in programmed cell death in response to 48-h FD in goats. Keywords: Response to nutritional factor
Project description:These studies adress differential changes in gene expression between 6h sleep deprived and control mice in the brain and the liver. We profiled gene expression in three different inbred strains to understand the influence of genetic background. Experiment Overall Design: Experiments were performed on male mice (C57BL/6J (B6), AKR/J (AK), DBA/2J (D2)), 12-13 weeks of aged, purchased from Jackson Laboratory. Animals were housed in a light/dark cycle of 24 hrs with water and food available ad libitum. Mice of the 3 inbred strains were sleep deprived for 6h starting at light onset (ZT0) and sacrificed together with their home-cage controls at ZT6 (n=9 / strain =3 / condition =2 / tissues =2; total = 108 mice).