Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that induces a battery of cytoprotective genes in response to oxidative/electrophilic stress. Kelch-like ECH associating protein 1 (Keap1) sequesters Nrf2 in the cytosol. The purpose of this study was to investigate the role of Nrf2 in regulating the mRNA of genes encoding drug metabolizing enzymes and xenobiotic transporters. Microarray analysis was performed in livers of Nrf2-null, wild-type, Keap1-knockdown mice with increased Nrf2 activation, and Keap1-hepatocyte knockout mice with maximum Nrf2 activation. In general, Nrf2 did not have a marked effect on uptake transporters, but the mRNAs of organic anion transporting polypeptide 1a1, sodium taurocholate cotransporting polypeptide, and organic anion transporter 2 were decreased with Nrf2 activation. The effect of Nrf2 on cytochrome P450 (Cyp) genes was minimal, with only Cyp2a5, Cyp2c50, Cyp2c54, and Cyp2g1 increased, and Cyp2u1 decreased with enhanced Nrf2 activation. However, Nrf2 increased mRNA of many other phase-I enzymes, such as aldo-keto reductases, carbonyl reductases, and aldehyde dehydrogenase 1. Many genes involved in phase-II drug metabolism were induced by Nrf2, including glutathione S -transferases, UDP- glucuronosyltransferases, and UDP-glucuronic acid synthesis enzymes. Efflux transporters, such as multidrug resistance-associated proteins, breast cancer resistant protein, as well as ATP-binding cassette g5 and g8 were induced by Nrf2. In conclusion, Nrf2 markedly alters hepatic mRNA of a large number of drug metabolizing enzymes and xenobiotic transporters, and thus Nrf2 plays a central role in xenobiotic metabolism and detoxification.
Effect of graded Nrf2 activation on phase-I and -II drug metabolizing enzymes and transporters in mouse liver.
Sex, Age, Specimen part
View SamplesThe goal of this study was to investigate the effects of vairous diets on the expression of genes involved in intermediary metabolism in liver. Adult wild type male mice (3 for each group) were fed with the corresponding diet for two weeks, and then liver samples were collected. Total RNA was isolated by the RNAzol B reagent, and pellet was disolved in DEPC-treated water. Total RNA was isolated using RNA Bee reagent (Tel-Test Inc., Friendswood, TX) per the manufacturers protocol. RNA concentrations were quantified using a NanoDrop Spectrophotometer (NanoDrop Technologies, Wilmington, DE) at a wavelength of 260 nm. The integrity of the total RNA samples was evaluated by formaldehyde-agarose gel electrophoresis, and confirmed by visualization of 18S and 28S rRNA bands. The gene expression was determined by Affymetrix Mouse 430 2.0 Gene Expression Microarray. Nine different diets were used: Diet 1. TD.84224. EFA Deficient diet; Diet 2. TD 97070. High fat diet: Diet 3. TD.88137. Adjusted Calories Diet (42% from fat) (Western Diet); Diet 4. TD.02028. Atherogenic Rodent Diet; Diet 5. TD.89247. 60% Fructose Diet; Diet 6. TD.94048. AIN-93M Purified Diet, Diet 7. Current rodent diet used in LAR; Diet 8. DHA-supplemented diet; Diet 9. Diet-restriction: 75% of the diet consumed by ad lib feeding. Mice (n=3/diet) were fed one of these diets (Harlan Laboratories) for 3 weeks. All mice were euthanized in the morning (8:0010:00 A.M.) and blood and tissue samples were collected. All procedures were approved in accordance with Institutional Animal Care and Use Committee guidelines.
Effect of diet on expression of genes involved in lipid metabolism, oxidative stress, and inflammation in mouse liver-insights into mechanisms of hepatic steatosis.
Sex, Age, Specimen part
View SamplesCells with slow proliferation kinetics that retain the nuclear label over long time periods – the label-retaining cells (LRCs) – represent multipotent stem cells in a number of adult tissues. Since the identity of liver LRCs (LLRCs) had remained elusive we utilized a genetic approach to reveal LLRCs in normal non-injured livers and characterized their regenerative properties in vivo and in culture. We found that LLRCs were located in biliary vessels and participated in the regeneration of biliary but not hepatocyte injury. In culture experiments the sorted LLRCs displayed an enhanced self-renewal capacity but a unipotent biliary differentiation potential. Transcriptome analysis revealed a unique set of tumorigenesis- and nervous system-related genes upregulated in LLRCs when compared to non-LRC cholangiocytes. We conclude that the LLRCs established during the normal morphogenesis of the liver do not represent a multipotent primitive somatic stem cell population but act as unipotent biliary progenitor cells. Overall design: Transcriptome comparison of label-retaining biliary epithelial cells and non-label-retaining biliary epithelial cells (cells with GFP expression were compared to the cells without GFP). Illumina HiSeq 2000 was used to analyze 8 RNA samples from 4 mice.
A label-retaining but unipotent cell population resides in biliary compartment of mammalian liver.
Subject
View SamplesCharacterization of Peroxisome Proliferator-Activated Receptor alpha (PPAR(alpha)) - Independent Effects of PPAR(alpha) Activators in the Rodent Liver: Di-(2-ethylhexyl) phthalate Activates the Constitutive Activated Receptor
Characterization of peroxisome proliferator-activated receptor alpha--independent effects of PPARalpha activators in the rodent liver: di-(2-ethylhexyl) phthalate also activates the constitutive-activated receptor.
Sex, Age, Treatment
View SamplesThe functional shift of quiescent endothelial cells into tip cells that migrate and stalk cells that proliferate is a key event during sprouting angiogenesis. We previously showed that the sialomucin CD34 is expressed in a small subset of cultured endothelial cells and that these cells extend filopodia: a hallmark of tip cells in vivo. In the present study, we characterized endothelial cells expressing CD34 in endothelial monolayers in vitro. We found that CD34-positive human umbilical vein endothelial cells show low proliferation activity and increased mRNA expression of all known tip cell markers, as compared to CD34- negative cells. Genome-wide mRNA profiling analysis of CD34-positive endothelial cells demonstrated enrichment for biological functions related to angiogenesis and migration, whereas CD34-negative cells were enriched for functions related to proliferation. In addition, we found an increase or decrease of CD34-positive cells in vitro upon exposure to stimuli that enhance or limit the number of tip cells in vivo, respectively. Our findings suggest cells with virtually all known properties of tip cells are present in vascular endothelial cell cultures and that they can be isolated based on expression of CD34. This novel strategy may open alternative avenues for future studies of molecular processes and functions in tip cells in angiogenesis.
CD34 marks angiogenic tip cells in human vascular endothelial cell cultures.
Specimen part, Subject
View SamplesAnalysis of livers of male and female B6C3F1 mice exposed to prototype treatments from five classes of model hepatotoxicants. These hepatotoxicants include compounds that activate the peroxisome proliferator-activated receptor (PPAR), induce the inflammatory response, activate the constitutive androstane receptor (CAR), stimulate the hypoxia signal transduction pathway, and activate the aryl-hydrocarbon receptor (AHR). The results provide insights into the shared and unique pathways that are activated across these model hepatotoxicants.
Screening a mouse liver gene expression compendium identifies modulators of the aryl hydrocarbon receptor (AhR).
Sex, Age, Compound, Time
View SamplesPPAR-null and wild-type male mice treated with PFHxS or PFNA
Screening a mouse liver gene expression compendium identifies modulators of the aryl hydrocarbon receptor (AhR).
Sex, Specimen part, Compound
View SamplesMany environmentally-relevant chemicals and drugs activate the nuclear receptor pregnane X receptor (PXR). Activation of PXR can lead to increases in liver weight in part through hepatocyte replication similar to a large number of compounds that activate other nuclear receptors such as the peroxisome proliferator-activated receptor alpha and the constitutive activated receptor (CAR). PXR controls the expression of a large battery of genes involved in xenobiotic metabolism. Identification of genes that are accurate predictors of PXR activation would be useful in high-throughput screens to assess potential toxicity and drug-drug interactions. Here, we identified PXR-dependent genes in the mouse liver after exposure to pregnenolone 16alpha-carbinonitrile (PCN), a chemical that is often used as a model PXR agonist.
Screening a mouse liver gene expression compendium identifies modulators of the aryl hydrocarbon receptor (AhR).
Sex, Specimen part, Compound
View SamplesThe biological tumor samples (ie, breast tumor specimens) consisted of freshly frozen breast tumors from a population-based cohort of 315 women representing 65% of all breast cancers resected in Uppsala County, Sweden, from January 1, 1987 to December 31, 1989. Estrogen receptor status was determined by biochemical assay as part of the routine clinical procedure. An experienced pathologist determined the Elston-Ellis grades of the tumors, classifying the tumors into low, medium and high-grade tumors. The clinico-pathological characteristics accompanying each tumor include p53 status, ER status, tumor grade, lymph node status and patient age.
An expression signature for p53 status in human breast cancer predicts mutation status, transcriptional effects, and patient survival.
No sample metadata fields
View SamplesTitle: Transcriptome analysis of human endometrial tissues from healthy post-menoupausal women reflecting the endometrial response to 3-weeks treatment with tibolone, E2 and E2+MPA.
Molecular analysis of human endometrium: short-term tibolone signaling differs significantly from estrogen and estrogen + progestagen signaling.
No sample metadata fields
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