Effects of preoperative fasting on renal ischemia-reperfusion injury in young-lean and aged overweight mice
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ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Jeroen Pennings
PROVIDER: E-GEOD-52982 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Metabolic homeostasis in mammals critically depends on the regulation of fasting-induced genes by CREB in the liver. Previous genome-wide analysis has shown that only a small percentage of CREB target genes are induced in response to fasting-associated signaling pathways. The precise molecular mechanisms by which CREB specifically targets these genes in response to alternating hormonal cues remain to be elucidated. We performed chromatin immunoprecipitation coupled to high-throughput sequencing of CREB in livers from both fasted and re-fed mice. In order to quantitatively compare the extent of CREB-DNA interactions genome-wide between these two physiological conditions we developed a novel, robust analysis method, termed the ‘single sample independence’ (SSI) test that greatly reduced the number of false positive peaks. We found that CREB remains constitutively bound to its target genes in the liver regardless of the metabolic state. Integration of the CREB cistrome with expression microarrays of fasted and re-fed mouse livers and ChIP-seq data for additional transcription factors revealed that the gene expression switches between the fasted and fed states are associated with co-localization of additional transcription factors at CREB sites. Our results support a model in which CREB is constitutively bound to thousands of potential target genes and combinatorial interactions between DNA-binding factors are necessary to achieve the specific transcriptional response of the liver to fasting. Furthermore, our genome-wide analysis identifies thousands of novel CREB target genes in liver, including a previously unknown role for CREB in regulating ER stress genes in response to nutrient influx. Individual livers were collected from 24hr fasted and re-fed mice, with 4 biological replicates per condition. Extracted RNA was hybridized to Agilent two-color arrays, using randomly paired fasted/re-fed replicates.
2013-05-01 | E-GEOD-45731 | biostudies-arrayexpress
Project description:The aim of this study was to investigate whether the differences in memory decline associated with aging are a result of differences in gene expression. We first categorized age-unimpaired and age-impaired rats based on their performance in the Morris water maze, when compared to young rats. Then we isolated messenger RNA from the dentate gyrus of the hippocampus of each animal to interrogate Affymetrix RAE 230A rat genome microarrays. Supervised statistical analysis of the different groups of aged animals recognized 85 genes (p<0.005) that were significantly different in the dentate gyrus of aged rats that had learned the Morris water maze (MWM) paradigm when compared to learning impaired and a number of controls for stress, exercise and non-spatial learning. In addition, statistical analysis of the microarray data that included young and aged rats identified 1129 genes (p<0.005) that were differentially expressed between aged and young rats independent of behavior, but due to aging alone. Experiment Overall Design: a total of 80 samples were analyzed including aged and young rats for aged versus young comparisons. One chip was interrogated per animal. Supervised analysis of aged rat data (aged unimpaired (HID U) versus controls : HID I, VIS, YOKE, SIT includes 39 samples (intermediate learners were not included in the analysis). Controls include cage controls, yoke controls (no platform), visible platform controls.
2008-06-13 | E-GEOD-4821 | biostudies-arrayexpress
Project description:Metabolic homeostasis in mammals critically depends on the regulation of fasting-induced genes by CREB in the liver. Previous genome-wide analysis has shown that only a small percentage of CREB target genes are induced in response to fasting-associated signaling pathways. The precise molecular mechanisms by which CREB specifically targets these genes in response to alternating hormonal cues remain to be elucidated. We performed chromatin immunoprecipitation coupled to high-throughput sequencing of CREB in livers from both fasted and re-fed mice. In order to quantitatively compare the extent of CREB-DNA interactions genome-wide between these two physiological conditions we developed a novel, robust analysis method, termed the M-bM-^@M-^Xsingle sample independenceM-bM-^@M-^Y (SSI) test that greatly reduced the number of false positive peaks. We found that CREB remains constitutively bound to its target genes in the liver regardless of the metabolic state. Integration of the CREB cistrome with expression microarrays of fasted and re-fed mouse livers and ChIP-seq data for additional transcription factors revealed that the gene expression switches between the fasted and fed states are associated with co-localization of additional transcription factors at CREB sites. Our results support a model in which CREB is constitutively bound to thousands of potential target genes and combinatorial interactions between DNA-binding factors are necessary to achieve the specific transcriptional response of the liver to fasting. Furthermore, our genome-wide analysis identifies thousands of novel CREB target genes in liver, including a previously unknown role for CREB in regulating ER stress genes in response to nutrient influx. CREB ChIP-seq was performed on mouse liver from fasted and re-fed mice, using 5 separate biological replicates for each condition. GR and C/EBP(beta) ChIP-seq were performed as single replicates on ad-lib fed mice.
2013-05-01 | E-GEOD-45674 | biostudies-arrayexpress
Project description:Pathenogenesis of atherosclerosis results from the interactions between disrupted lipid homeostasis and immune response, but the molecular bridges between the major players are still a matter of controversy. We performed a systemic study of the imflammatory cytokine tumor necrosis factor alpha (TNF alpha), a well established anorexia agent, in the livers of the mice exposed to 20h-cytokine/starvation. We show that treatment with TNF-alpha reverses adaptations to fasting. Moreover, it up-regulates cholesterol biosynthesis and down-regulates bile acids synthesis, which leads to disrupted cholesterol homeostasis and pro-atherogenic changes. Interestingly, we found that TNF alpha also interferes with gene regulation of the xenobiotic metabolism. Keywords: treatment and diet effects Mice have been either saline treated (nontreated group), saline treated and fasted for 20h (fasted group), and TNF-alpha treated (30 mikrograms per animal) and fasted for 20h (TNF-alpha group). 3 biological replicas from fasted and TNF-alpha groups were co-hybridized with pool of nontreated group. No dye-swaps were performed.
2010-05-25 | E-GEOD-6423 | biostudies-arrayexpress
Project description:Because most human stroke victims are elderly, studies of experimental stroke in the aged rather than the young rat model may be optimal for identifying clinically relevant cellular responses, as well for pinpointing beneficial interventions. We employed the Affymetrix platform to analyze the whole-gene transcriptome following temporary ligation of the middle cerebral artery in aged and young rats. Expression profiling of periinfarcted brain areas of young and aged rats, as well as healthy tissue from naive animals.
2014-04-22 | E-GEOD-55260 | biostudies-arrayexpress
Project description:In addition to gaining knowledge on in vivo miRNA responses to formaldehyde, we set out to relate these miRNA responses to transcriptional profiles modified by formaldehyde. Rats were exposed by inhalation to either 0 or 2 ppm formaldehyde (6 hours/day) for 28 days. Genome-wide transcriptional profiles and associated signaling pathways were assessed within the nasal respiratory mucosa and circulating mononuclear white blood cells (WBC). Male Fischer rats received nose-only inhalation exposures of 2 ppm formaldehyde for 7 days or 28 days (6 hours/day). Control (unexposed) rats were placed in nose-only exposure tubes containing room air for the same duration. After the last exposure period, animals were euthanized. RNA were assessed from sampes collected from the nasal epithelium and circulating white blood cells. Genome-wide mRNA expression profiles were evaluated using microarrays.
2014-01-07 | E-GEOD-42394 | biostudies-arrayexpress
Project description:Decay of mRNAs initiates with shortening of the poly(A) tail. Although the CCR4-NOT complex participates in deadenylation, how it becomes activates remain obscure. We show that complete deficiency in CNOT3, subunit 3 of this complex, is lethal in mice, but that heterozygotes survive as lean mice with hepatic and adipose tissues containing reduced lipid levels. Cnot3+/- mice have enhanced metabolic rates and remain lean on high-fat diets. We further provide evidence suggesting that CNOT3, by changing its level in response to feeding conditions, affects the activity of the CCR4-NOT deadenylase against poly(A) tails of specific mRNAs coding for proteins involved in metabolism of carbohydrates and fats. Because the levels of CNOT3 protein were decreased under fasting conditions and increased upon refeeding and because CNOT3 could be a positive regulator of the CCR4-NOT deadenylase, we hypothesized that the levels of CCR4-NOT target mRNAs would be lower in fed mice than in fasted mice. We compared the gene expression profiles of fed and fasted wild-type mice. Microarray analysis revealed that approximately 1,200 mRNA transcripts were down-regulated in the livers of fed mice. Of these mRNAs, 68 corresponded to the genes up-regulated in the livers of Cnot3+/- mice and fasted wild-type mice. A large number of the 68 identified genes encoded proteins involved in metabolism, especially lipid metabolism and growth. The livers were isolated from 8-week-old fed wild-type, fasted wild-type and fasted Cnot3+/- mice (n = 2 for each genotype).
2011-12-09 | E-GEOD-18925 | biostudies-arrayexpress
Project description:Gene-environment interactions mediated at the epigenetic level may provide an initial step in delivering an appropriate response to environmental changes. 5-hydroxymethylcytosine (5hmC), a DNA base derived from 5-methylcytosine (5mC), accounts for ~40% of modified cytosine in brain and has been implicated in DNA methylation-related plasticity. To identify the role of 5hmC in gene-environment interactions, we exposed both young (6-week-old) and aged (18-month-old) mice to both an enriched environment and a standard environment. Exposure to EE significantly improves learning and memory in aged mice and reduces 5hmC abundance in mouse hippocampus. Furthermore, we mapped the genome-wide distribution of 5hmC and found that the alteration of 5hmC modification occurred mainly at gene bodies. In particular, genes involved in axon guidance are enriched among the genes with altered 5hmC modification. These results together suggest that environmental enrichment could modulate the dynamics of 5hmC in hippocampus, which could potentially contribute to improved learning and memory in aged animals. To identify the role of 5hmC in gene-environment interactions, we exposed both young (6-week-old) and aged (18-month-old) C57B/6 mice to both an enriched environment (EE) and a standard environment. Exposure of mice to EE was achieved by keeping a group of mice in the EE chamber, which is larger than the standard cage, includes novel objects, such as toys of varied color and texture, tunnels, an exercise wheel for voluntary exercise, and extra bedding material, along with free access to food and water. Daily exposure to EE was kept at 5 hours during the daylight cycle for 4 consecutive weeks. Control animals were kept in their small cages that are used as standard housing cages (CE) containing bedding, food and access to water. YC, young mice exposing to control environment, YE, young mice exposing to enriched environment, AC, aged mice exposing to control environment, AE, aged mice exposed to enriched environment. Please note that 5hmC-containing DNA enrichment method was inspired by a unique character of beta-glucotransferase that can specifically add glucose to 5hmC modification. With a modified glucose conjugated with biotin, we are able to purify the 5hmC-containing DNA by biotin-streptavidin-based immunoprecipitation.
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2009-11-16 | E-GEOD-16725 | biostudies-arrayexpress
Project description:Peroxisome proliferator-activated receptor alpha (PPARα) is a key regulator of hepatic fat oxidation that serves as an energy source during starvation. Vanin-1 has been described as a putative PPARα target gene in liver, but its function in hepatic lipid metabolism is unknown. We investigated the regulation of vanin-1, and total vanin activity, by PPARα in mice and humans. Furthermore, the function of vanin-1 in the development of hepatic steatosis in response to starvation was examined in Vnn1 deficient mice, and in rats treated with an inhibitor of vanin activity. Liver microarray analyses reveals that Vnn1 is the most prominently regulated gene after modulation of PPARα activity. In addition, activation of mouse PPARα regulates hepatic- and plasma vanin activity. In humans, consistent with regulation by PPARα, plasma vanin activity increases in all subjects after prolonged fasting, as well as after treatment with the PPARα agonist fenofibrate. In mice, absence of vanin-1 exacerbates the fasting-induced increase in hepatic triglyceride levels. Similarly, inhibition of vanin activity in rats induces accumulation of hepatic triglycerides upon fasting. Microarray analysis reveal that the absence of vanin-1 associates with gene sets involved in liver steatosis, and reduces pathways involved in oxidative stress and inflammation. We show that hepatic vanin-1 is under extremely sensitive regulation by PPARα and that plasma vanin activity could serve as a readout of changes in PPARα activity in human subjects. In addition, our data propose a role for vanin-1 in regulation of hepatic TG levels during fasting. Livers of wild type and vanin-1 knockout mice that were fed or fasted for 24h were subjected to gene expression analysis
2014-04-24 | E-GEOD-51712 | biostudies-arrayexpress