The rising prevalence of obesity and its associated metabolic abnormalities have become global diseases that carry considerable morbidity and mortality. While there is certainly an important genetic component, extensive human epidemiologic and animal model data suggest an epigenetic component to obesity. Nevertheless, the cellular and molecular underpinnings of these pathways and how they contribute to the development of obesity remain to be elucidated. Suv420h1 and h2 are histone methyltransferases responsible for chromatin compaction and gene repression. Through in vivo, ex-vivo and in vitro studies, we found that Suv420h1 and h2 respond to environmental stimuli and regulate metabolism by downregulating PPAR-?, a master transcriptional regulator of lipid storage and glucose metabolism. Accordingly, mice lacking Suv420h proteins activate PPAR-? target genes in brown adipose tissue to increase mitochondria respiration, improve glucose tolerance and reduce adipose tissue to fight obesity. We conclude that Suv420h proteins are key epigenetic regulator of PPAR-? and the pathways controlling metabolism and weight balance in response to environmental stimuli. Overall design: For experiment 1, total RNA was isolated from males and females control- and Suv420h dKO-derived BAT. For experiment 2, total RNA was isolated from BAT collected from females control and Suv420h dKO mice after both diet regimes (nd = normal diet, hfd = high fat diet).
The Suv420h histone methyltransferases regulate PPAR-γ and energy expenditure in response to environmental stimuli.
Sex, Specimen part, Treatment, Subject
View SamplesWe devised a novel insertional mutagenesis approach based on lentiviral vectors to induce hepatocellular carcinoma in three mouse models and identified four novel cancer initiating genes. Two genes are the well characterized Braf and Sos1, while the other two are Fign, encoding an AAA ATPase whose functions are poorly understood, and the complex Dlk1-Dio3 imprinted region which has been recently implicated in cancer and stemness. Activation of Fign or Braf and upregulation of the Dlk1-Dio3 imprinted region are functionally interconnected and may altogether control cell transformation, stemness and energy metabolism. Moreover, all the genes identified play a relevant role in human hepatocarcinogenesis as their expression levels and/or transcriptional signatures induced by their deregulation predict a different clinical outcome in hepatocellular carcinoma patients. These series consists of mRNA expression microarray data (The GeneChip Mouse Gene 1.0 ST Array, Affymetrix) from 8 non-tumoral liver and 21 hepatocellular carcinoma induced by insertional mutagenesis.
Lentiviral vector-based insertional mutagenesis identifies genes associated with liver cancer.
Specimen part
View SamplesThe gastrointestinal (GI) tract can have significant impact on the regulation of the whole body metabolism and may contribute to the development of obesity and diabetes. To systemically elucidate the role of the GI tract in obesity, we performed a transcriptomic analyses in different parts of the GI tract of two obese mouse models: ob/ob and high-fat diet (HFD) fed mice. Compared to their lean controls, both obese mouse groups had significant amount of gene expression changes in the stomach (ob/ob: 959; HFD: 542), much more than the number of changes in the intestine. Despite the difference in genetic background, the two mouse models shared 296 similar gene expression changes in the stomach. Among those genes, some had known associations to obesity, diabetes and insulin resistance. In addition, the gene expression profile strongly suggested an increased gastric acid secretion in both obese mouse models, probably through an activation of the gastrin pathway. In conclusion, our data reveal a previously unknown dominant connection between the stomach and obesity.
Significant obesity-associated gene expression changes occur in the stomach but not intestines in obese mice.
Specimen part
View SamplesBACKGROUND: p53 is an important tumor suppressor with a known role in the later stages of colorectal cancer, but its relevance to the early stages of neoplastic initiation remains somewhat unclear. Although p53-dependent regulation of Wnt signalling activity is known to occur, the importance of these regulatory mechanisms during the early stages of intestinal neoplasia has not been demonstrated.
A limited role for p53 in modulating the immediate phenotype of Apc loss in the intestine.
Specimen part
View SamplesTo characterize how symbiotic bacteria affect the lolecular and cellular mechanisms of epithelial homeostasis, human colonic Caco-2 cells
Epithelial cell proliferation arrest induced by lactate and acetate from Lactobacillus casei and Bifidobacterium breve.
No sample metadata fields
View SamplesWe sought to find a gene-expression multigene predictor of response to infliximab therapy in Rheumatoid Arthritis patients. Using internal and external cross-validation systems we have built and validated an 8-gene predictor for response to infliximab.
An eight-gene blood expression profile predicts the response to infliximab in rheumatoid arthritis.
Sex, Specimen part, Disease, Disease stage
View SamplesIn order to identify the developmental changes controlling the switch from disease susceptibility to resistance, we performed global gene expression analysis on non-infected and infected intestinal tissues taken from 4-day- and 7-day-old animals.
Maturation of paneth cells induces the refractory state of newborn mice to Shigella infection.
Age
View SamplesPlants have developed complex mechanisms to respond and adapt to abiotic stresses, coupling elaborate modulation of gene expression together with the preservation of genome stability. Epigenetic mechanisms - DNA methylation, chromatin modifications and non coding RNAs - were shown to play a fundamental role in stress-induced gene regulation and may also result in genome destabilization, with the activation and/or the transcription of silenced transposons and retroelements, causing genome rearrangements and novel gene expression patterns. Maize leaf transcriptome was analyzed by total RNA-Seq in both B73 and rmr6 (PolIV mutant involved in siRNA biogenesis and in the RdDM pathway) after drought and salt stress application. Reference annotation based transcript assembly allowed the identification both of new expressed loci and splicing variants, improving the current maize transcriptome annotation. Many antisense transcripts matching on the opposite strand of annotated loci were also identified, while more than the 20% of transcripts represent non coding RNA belonging to four classes: siRNAs, shRNAs, lncRNAs and transposable elements (or their relics). Several lncRNAs are modulated by stress application while TE-related sequences are mainly expressed in rmr6 and up-regulated by the stress. Overall design: Total RNA-Seq analysis of maize leaves from wt and rmr6-1 mutant plants grown under 1) control conditions, 2) drought stress, 3) salt stress, 4) salt+drought stress. Each condition was investigated in triplicate after 10 days of treatment and after 7 days of recovery. Samples derived from replicates 2 and 3 were pooled and sequenced together
Maize RNA PolIV affects the expression of genes with nearby TE insertions and has a genome-wide repressive impact on transcription.
Treatment, Subject, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The long non-coding RNA Dali is an epigenetic regulator of neural differentiation.
Specimen part, Cell line
View SamplesGenes specific to Sox9+ pancreatic progenitors were identified by comparing the gene expression in embryonic and adult Sox9+ cells.
A Notch-dependent molecular circuitry initiates pancreatic endocrine and ductal cell differentiation.
Specimen part
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