Filters
Technology
Platform
GSE8316
Mus musculus, Rattus norvegicus, Homo sapiens
8 Downloadable Samples
Description
PPARalpha is a ligand-activated transcription factor involved in the regulation of nutrient metabolism and inflammation. Although much is already known about the function of PPARalpha in hepatic lipid metabolism, many PPARalpha-dependent pathways and genes have yet to be discovered. In order to obtain an overview of PPARalpha-regulated genes relevant to lipid metabolism, and to probe for novel candidate PPARalpha target genes, livers from several animal studies in which PPARalpha was activated and/or disabled were analyzed by Affymetrix GeneChips. Numerous novel PPARalpha-regulated genes relevant to lipid metabolism were identified. Out of this set of genes, eight genes were singled out for study of PPARalpha-dependent regulation in mouse liver and in mouse, rat, and human primary hepatocytes, including thioredoxin interacting protein (Txnip), electron-transferring-flavoprotein beta polypeptide (Etfb), electron-transferring-flavoprotein dehydrogenase (Etfdh), phosphatidylcholine transfer protein (Pctp), endothelial lipase (EL, Lipg), adipose triglyceride lipase (Pnpla2), hormone-sensitive lipase (HSL, Lipe), and monoglyceride lipase (Mgll). Using an in silico screening approach, one or more PPAR response elements (PPREs) were identified in each of these genes. Regulation of Pnpla2, Lipe, and Mgll, which are involved in triglyceride hydrolysis, was studied under conditions of elevated hepatic lipids. In wild-type mice fed a high fat diet, the decrease in hepatic lipids following treatment with the PPARalpha agonist Wy14643 was paralleled by significant up-regulation of Pnpla2, Lipe, and Mgll, suggesting that induction of triglyceride hydrolysis may contribute to the anti-steatotic role of PPARalpha. Our study illustrates the power of transcriptional profiling to uncover novel PPARalpha-regulated genes and pathways in liver.
Publication Title
Comprehensive analysis of PPARalpha-dependent regulation of hepatic lipid metabolism by expression profiling.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 18 Downloadable Samples
Description
Objective: Nonalcoholic fatty liver disease (NAFLD) is linked to obesity and diabetes, suggesting an important role of adipose tissue in the pathogenesis of NAFLD. Here we aim to investigate the interaction between adipose tissue and liver in NAFLD, and identify potential early plasma markers that predict NASH. Research Design and Methods: C57Bl/6 mice were chronically fed a high fat diet to induce NAFLD and compared with mice fed low fat diet. Extensive histological and phenotypical analyses coupled with a time-course study of plasma proteins using multiplex assay was performed. Results: Mice exhibited pronounced heterogeneity in liver histological scoring, leading to classification into 4 subgroups: LF-low (LFL) responders displaying normal liver morphology, LF-high (LFH) responders showing benign hepatic steatosis, HF-low (HFL) responders displaying pre-NASH with macrovesicular lipid droplets, and HF-high (HFH) responders exhibiting overt NASH characterized by ballooning of hepatocytes, presence of Mallory bodies, and activated inflammatory cells. Compared to HFL responders, HFH mice gained weight more rapidly and exhibited adipose tissue dysfunction characterized by decreased final fat mass, enhanced macrophage infiltration and inflammation, and adipose tissue remodelling. Plasma haptoglobin, IL-1, TIMP-1, adiponectin and leptin were significantly changed in HFH mice. Multivariate analysis indicated that in addition to leptin, plasma CRP, haptoglobin, eotaxin and MIP-1 early in the intervention were positively associated with liver triglycerides. Intermediate prognostic markers of liver triglycerides included IL-18, IL-1, MIP-1 and MIP-2, whereas insulin, TIMP-1, GCP-2 and MPO emerged as late markers. Conclusions: Our data support the existence of a tight relationship between adipose tissue dysfunction and NASH pathogenesis and point to several novel potential predictive biomarkers for NASH.
Publication Title
Adipose tissue dysfunction signals progression of hepatic steatosis towards nonalcoholic steatohepatitis in C57BL/6 mice.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus, Homo sapiens
- 5 Downloadable Samples
Description
The p53 family is known as a family of transcription factors with functions in tumor suppression and development. Whereas the central DNA binding domain is highly conserved among the three family members p53, p63 and p73, the C-terminal domains (CTDs) are diverse and subject to alternative splicing and post-translational modification. Here we demonstrate that the CTDs strongly influence DNA binding and transcriptional activity. While p53 and the p73 isoform p73gamma have basic CTDs and form weak sequence-specific protein-DNA complexes, the major p73 isoforms alpha, beta and delta have neutral CTDs and bind DNA strongly. A basic CTD has been previously shown to enable sliding along the DNA backbone and to facilitate the search for binding sites in the complex genome. Our experiments, however, reveal that a basic CTD also reduces protein-DNA complex stability, intranuclear mobility, promoter occupancy in vivo, transgene activation and induction of cell cycle arrest or apoptosis. A basic CTD in p53 and p73gamma therefore provides both positive and negative regulatory functions presumably to enable rapid switching of protein activity in response to stress. In contrast, most p73 isoforms exhibit constitutive DNA binding activity consistent with a predominant role in developmental control.
Publication Title
C-terminal diversity within the p53 family accounts for differences in DNA binding and transcriptional activity.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 5 Downloadable Samples
Description
Background
Publication Title
Similar inflammatory DC maturation signatures induced by TNF or Trypanosoma brucei antigens instruct default Th2-cell responses.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Mus musculus
- 6 Downloadable Samples
Description
Recent studies have reported that glycosphingolipids (GSL) might be involved in obesity induced insulin resistance. Those reports suggested that inhibition of GSL biosynthesis in animals ameliorated insulin sensitivity accompanied with improved glycemic control leading to decreased liver steatosis in obese mice. In addition, GSL depletion altered hepatic secretory function. In those studies, ubiquitously acting inhibitors for GSL-biosynthesis have been used to inhibit function of the enzyme Ugcg (UDP-glucose:ceramide glucosyltransferase), catalyzing the first step of the glucosylceramide based GSL-synthesis pathway. In the present study, a genetic approach for GSL deletion in hepatocytes was chosen to achieve full inhibition of GSL synthesis and to prevent possible adverse effects caused by Ugcg-inhibitors. Using the Cre/loxP system under control of the albumin promoter, GSL biosynthesis in hepatocytes and their release into the plasma could be effectively blocked. Deletion of GSL in hepatocytes did not change quantity of bile excretion through the biliary duct. Total bile salt content in bile-, feces- and plasma from mutant mice showed no difference as compared to control animals. Cholesterol concentration in liver-, bile-, feces- and plasma-samples remained unaffected. Lipoprotein concentration in plasma-samples in mutant animals reached similar levels as in their control littermates. No alteration in glucose tolerance after intraperitoneal application of glucose and insulin appeared in mutant animals. A preventive effect of GSL-deficiency on development of liver steatosis after high fat diet feeding could not be observed.
Publication Title
Hepatic glycosphingolipid deficiency and liver function in mice.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 4 Downloadable Samples
Description
The human cytomegalovirus (HCMV) encodes the chemokine receptor US28 that exhibits constitutive activity. NIH-3T3 cells stably transfected with US28 present a pro-angiogenic and transformed phenotype both in vitro and in vivo.
Publication Title
The human cytomegalovirus-encoded chemokine receptor US28 promotes angiogenesis and tumor formation via cyclooxygenase-2.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 14 Downloadable Samples
Description
CD38, a multi-functional membrane receptor and enzyme, consumes NAD+ to generate products such as cyclic-ADP-ribose. CD38 knockout mice show elevated tissue and blood NAD+ level. Chronic feeding of high-fat, high-sucrose diet to wild type mice leads to exercise intolerance and reduced metabolic flexibility. Loss of CD38 by genetic mutation protects mice from diet-induced metabolic deficit. These animal model results suggest that elevation of tissue NAD+ through genetic ablation of CD38 can profoundly alter energy homeostasis in animals that are maintained on a calorically-excessive Western diet.
Publication Title
Genetic Ablation of CD38 Protects against Western Diet-Induced Exercise Intolerance and Metabolic Inflexibility.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus, Homo sapiens
- 10 Downloadable Samples
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
GATA4-dependent organ-specific endothelial differentiation controls liver development and embryonic hematopoiesis.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 6 Downloadable Samples
Description
Hearts of Myh6-MeCP2 transgenic mice and wildtype littermates were rapidly dissected and flash frozen.
Publication Title
Adrenergic Repression of the Epigenetic Reader MeCP2 Facilitates Cardiac Adaptation in Chronic Heart Failure.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 4 Downloadable Samples
Illumina HiSeq 2000
Description
Autophagy selectively degrades aggregation-prone misfolded proteins caused by defective cellular proteostasis. However, the complexity of autophagy may prevent the full appreciation of how its modulation could be used as a therapeutic strategy in disease management. Here we define a molecular pathway through which recombinant interleukin-1 receptor antagonist (IL-1Ra, anakinra) affects cellular proteostasis independently from the IL-1 receptor (IL-1R1). Anakinra promoted H2O2-driven autophagy through a xenobiotic sensing pathway involving the aryl hydrocarbon receptor that, activated through the indoleamine 2,3-dioxygenase 1-kynurenine pathway, transcriptionally activates NADPH Oxidase 4 independent of the IL-1R1. By coupling the mitochondrial redox balance to autophagy, anakinra improved the dysregulated proteostasis network in murine and human cystic fibrosis. We anticipate that anakinra may represent a therapeutic option in addition to its IL-1R1 dependent anti-inflammatory properties by acting at the intersection of mitochondrial oxidative stress and autophagy with the capacity to restore conditions in which defective proteostasis leads to human disease. Overall design: mRNA profiles of alveolar macrophages purified from C57BL/6 and Il1r1-/- mice treated or not with Anakinra
Publication Title
Anakinra restores cellular proteostasis by coupling mitochondrial redox balance to autophagy.
Sample Metadata Fields
Specimen part, Genotype, Subject
View Samples