Gender-specific gene repression of PPAR-alpha KO mice in liver and heart
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE14395 | GEO | 2009/09/11
SECONDARY ACCESSION(S): PRJNA111369
REPOSITORIES: GEO
Similar Datasets
Project description:Most metabolic studies are conducted in male animals; thus, the molecular mechanism controlling gender-specific pathways has been neglected, including sex-dependent responses to peroxisome proliferator-activated receptors (PPARs). Here we show that PPARalpha has broad female-dependent repressive actions on hepatic genes involved in steroid metabolism and inflammation. In males, this effect is reproduced by the administration of synthetic PPARalpha ligand. Using the steroid hydroxylase gene Cyp7b1 as a model, we elucidated the molecular mechanism of this PPARalpha-dependent repression. Initial sumoylation of the ligand-binding domain of PPARalpha triggers the interaction of PPARalpha with the GA-binding protein alpha bound to the target promoter. Histone deacetylase is then recruited, and histones and adjacent Sp1-binding site are methylated. These events result in the loss of Sp1-stimulated expression, and thus the down-regulation of Cyp7b1. Physiologically, this repression confers protection against estrogen-induced intrahepatic cholestasis, paving the way for a novel therapy against the most common hepatic disease during pregnancy. Experiment Overall Design: Expression profile difference between male and female PPARalpha wild-type and knock-out mice in liver and heart (3 pools of 4 animals in each group). Wild-type (12 males and 12 females) and knock-out PPARalpha SV129 mice (12 males and 12 females) approximately 10 to 12 weeks of age were killed at ZT14 and their livers and hearts quickly removed and frozen.
2009-11-16 | E-GEOD-14395 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series:; GSE8290: Comprehensive analysis of PPARα-dependent regulation of hepatic lipid metabolism by expression profiling - 1; GSE8291: Comprehensive analysis of PPARα-dependent regulation of hepatic lipid metabolism by expression profiling - 2; GSE8292: Comprehensive analysis of PPARα-dependent regulation of hepatic lipid metabolism by expression profiling - 3; GSE8295: Comprehensive analysis of PPARα-dependent regulation of hepatic lipid metabolism by expression profiling - 4; GSE8302: Comprehensive analysis of PPARα-dependent regulation of hepatic lipid metabolism by expression profiling - 5; 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. Experiment Overall Design: Refer to individual Series
2008-06-16 | E-GEOD-8316 | biostudies-arrayexpress
Project description:A functional interaction between peroxisome proliferator-activated receptor alpha (PPARalpha) and components of the circadian clock has been suggested; however, it remains to be clarified whether those transcriptional factors interact with each other to regulate the expression of their target genes. In this study, we used a ligand of PPARalpha, bezafibrate, to search the PPARalpha-regulated genes that express in a CLOCK-dependent circadian manner. Microarrays analyses using hepatic RNA isolated from bezafibrate treated-wild type, Clock mutant (Clk/Clk), and PPARalpha-null mice revealed that 136 genes are transcriptionally regulated by PPARalpha in a CLOCK-dependent manner.
2010-06-15 | GSE20513 | GEO
Project 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. This SuperSeries is composed of the SubSeries listed below.
2007-07-24 | GSE8316 | GEO
Project description:A functional interaction between peroxisome proliferator-activated receptor alpha (PPARalpha) and components of the circadian clock has been suggested; however, it remains to be clarified whether those transcriptional factors interact with each other to regulate the expression of their target genes. In this study, we used a ligand of PPARalpha, bezafibrate, to search the PPARalpha-regulated genes that express in a CLOCK-dependent circadian manner. Microarrays analyses using hepatic RNA isolated from bezafibrate treated-wild type, Clock mutant (Clk/Clk), and PPARalpha-null mice revealed that 136 genes are transcriptionally regulated by PPARalpha in a CLOCK-dependent manner. Clk/Clk mutant mice with Jcl:ICR background, wild-type mice with the same strain, and PPARalpha-null mice aged 6-12 weeks were housed under a 12 h light-12 h dark cycle [LD 12:12; lights on at Zeitgeber time (ZT) 0]. For chronic treatment of bezafibrate, mice were provided with either a normal diet or the same diet containing 0.5% w/w bezafibrate for 5 days. A white fluorescent lamp provided light (300 - 500 lux at cage level) during the day. To examine the transient effect of bezafibrate injection on hepatic gene expression, bezafibrate was dissolved in warm (~40 C) sterile corn oil (Sigma) at a concentration of 10 mg/ml and administered intraperitoneally (i.p.) in a single dose of 100 mg/kg body weight at ZT2. To examine the PPARalpha-regulated genes that express in a CLOCK-dependent manner in mice, we performed oligonucleotide microarray analysis at ZT14, when CLOCK/BMAL1 transcriptional activity is maximal, using RNA isolated from wild-type (n = 3), Clock mutant (n = 3), and PPARalpha-null mice (n = 3) treated with bezafibrate for 5 days, and control wild-type mice (n = 3). Livers were collected and frozen in liquid nitrogen. Total RNA (250 ng) was extracted using RNAiso.
2010-06-14 | E-GEOD-20513 | biostudies-arrayexpress
Project description:Lipid metabolism is essential in maintaining energy homeostasis in multicellular organisms. In vertebrates, a group of nuclear receptor transcription factors named peroxisome proliferator-activated receptors (PPARs, NR1C) regulate the expression of many genes involved in these processes. We have recently cloned the four Ppars in Atlantic cod (Gadus morhua), including Ppara1 and Ppara2, Pparb/d, and Pparg, and studied their tissue specific transcription and ligand activation characteristics. However, the downstream regulative role of Ppars in cod lipid metabolism is not well understood or described. In this study, activation of Atlantic cod Ppar by the fibrate drug WY-14,643 (pirinixic acid) and the performance enhancing drug GW501516 (Cardarine) were first studied using ligand-binding luciferase reporter assays in vitro. Based on the agonist activities found in vitro, juvenile Atlantic cod was injected twice over four days with WY-14,643 and GW501516 in vivo, and sampled seven days after the last injection. Using multiple omics methods, including RNA sequencing, quantitative proteomics, and lipidomics, liver and plasma samples from male cod were analyzed. The resulting multi-omics dataset provides novel insights into the systemic regulation of lipid metabolism in Atlantic cod.
2022-02-28 | MTBLS2131 | MetaboLights
Project description:The liver X receptors (LXRs) are nuclear receptors that form permissive heterodimers with retinoid X receptor (RXR) and are important regulators of lipid metabolism in the liver. We have recently shown that RXR agonist-induced hypertriglyceridemia and hepatic steatosis in mice is dependent on LXR and correlates with an LXR-dependent hepatic induction of lipogenic genes. To further investigate the role of RXR and LXR in the regulation of hepatic gene expression, we have mapped the ligand-regulated genome-wide binding of these factors in mouse liver. We find that the RXR agonist bexarotene primarily increases the genomic binding of RXR, whereas the LXR agonist T0901317 greatly increases both LXR and RXR binding. Functional annotation of putative direct LXR target genes revealed a significant association with classical LXR-regulated pathways as well as PPAR signaling pathways, and subsequent ChIP-seq mapping of PPARM-NM-1 binding demonstrated binding of PPARM-NM-1 to 71-88% of the identified LXR:RXR binding sites. Sequence analysis of shared binding regions combined with sequential ChIP on selected sites indicate that LXR:RXR and PPARM-NM-1:RXR bind to degenerate response elements in a mutually exclusive manner. Together our findings suggest extensive and unexpected cross-talk between hepatic LXR and PPARM-NM-1 at the level of binding to shared genomic sites LXR, RXR, PPARalpha and RNA Polymerase II ChIP-seq on livers from female C57BL/6 wild-type and/or LXRM-NM-1/M-NM-2-deficient mice (13 weeks of age, n=1) treated by oral gavage once daily for 14 days with the RXR agonist bexarotene (100 mg/kg body weight [mpk], in 1% carboxymethylcellulose), the LXR agonist T0901317 (T09, 30 mpk) or vehicle alone.
2012-01-31 | E-GEOD-35262 | biostudies-arrayexpress
Project description:Findings suggest that PPARalpha plays a decisive role in the development of hypertrophy, affecting the functional outcome of the heart. Unfortunately, information on the nature of PPARalpha-dependent processes in cardiac hypertrophy is fragmentary and incomplete. The primary aim of this study was to identify the processes and signaling pathways regulated by PPARalpha in hearts challenged by a chronic pressure overload by means of whole genome transcriptomic analysis. Second, we wanted to gain insight how PPARalpha modulates the identified processes, e.g. by trans-activation or by trans-repression. Keywords: 28 days of TAC
2008-08-06 | GSE12337 | GEO
Project description:Kupffer cells have been implicated in the pathogenesis of various liver diseases. However, their involvement in metabolic disorders of the liver, including fatty liver disease, remains unclear. The present study sought to determine the impact of Kupffer cells on hepatic triglyceride storage and to explore the possible mechanisms involved. To that end, C57Bl/6 mice rendered obese and steatotic by chronic high-fat feeding were treated for 1 week with clodronate liposomes, which cause depletion of Kupffer cells. Loss of expression of marker genes Cd68, F4/80, and Clec4f, and loss of Cd68 immunostaining verified almost complete removal of Kupffer cells from the liver. Also, expression of complement components C1, the chemokine (C-C motif) ligand 6 (Ccl6), and cytokines interleukin-15 (IL-15) and IL-1beta were markedly reduced. Importantly, Kupffer cell depletion significantly decreased liver triglyceride and glucosylceramide levels concurrent with increased expression of genes involved in fatty acid oxidation including peroxisome proliferator-activated receptor alpha (PPARalpha), carnitine palmitoyltransferase 1A (Cpt1alpha), and fatty acid transport protein 2 (Fatp2). Treatment of mice with IL-1beta decreased expression of PPARalpha and its target genes, which was confirmed in primary hepatocytes. Consistent with these data, IL-1beta suppressed human and mouse PPARalpha promoter activity. Suppression of PPARalpha promoter activity was recapitulated by overexpression of nuclear factor kappaB (NF-kappaB) subunit p50 and p65, and was abolished upon deletion of putative NF-kappaB binding sites. Finally, IL-1beta and NF-kappaB interfered with the ability of PPARalpha to activate gene transcription. CONCLUSION: Our data point toward important cross-talk between Kupffer cells and hepatocytes in the regulation of hepatic triglyceride storage. The effect of Kupffer cells on liver triglycerides are at least partially mediated by IL-1beta, which suppresses PPARalpha expression and activity. Expression profiling of livers from mice fed control, low-fat diet diet or high-fat diet for 20weeks with or without knockdown of Kupffer cells.
2011-10-17 | E-GEOD-33044 | biostudies-arrayexpress
Project description:Kupffer cells have been implicated in the pathogenesis of various liver diseases. However, their involvement in metabolic disorders of the liver, including fatty liver disease, remains unclear. The present study sought to determine the impact of Kupffer cells on hepatic triglyceride storage and to explore the possible mechanisms involved. To that end, C57Bl/6 mice rendered obese and steatotic by chronic high-fat feeding were treated for 1 week with clodronate liposomes, which cause depletion of Kupffer cells. Loss of expression of marker genes Cd68, F4/80, and Clec4f, and loss of Cd68 immunostaining verified almost complete removal of Kupffer cells from the liver. Also, expression of complement components C1, the chemokine (C-C motif) ligand 6 (Ccl6), and cytokines interleukin-15 (IL-15) and IL-1beta were markedly reduced. Importantly, Kupffer cell depletion significantly decreased liver triglyceride and glucosylceramide levels concurrent with increased expression of genes involved in fatty acid oxidation including peroxisome proliferator-activated receptor alpha (PPARalpha), carnitine palmitoyltransferase 1A (Cpt1alpha), and fatty acid transport protein 2 (Fatp2). Treatment of mice with IL-1beta decreased expression of PPARalpha and its target genes, which was confirmed in primary hepatocytes. Consistent with these data, IL-1beta suppressed human and mouse PPARalpha promoter activity. Suppression of PPARalpha promoter activity was recapitulated by overexpression of nuclear factor kappaB (NF-kappaB) subunit p50 and p65, and was abolished upon deletion of putative NF-kappaB binding sites. Finally, IL-1beta and NF-kappaB interfered with the ability of PPARalpha to activate gene transcription. CONCLUSION: Our data point toward important cross-talk between Kupffer cells and hepatocytes in the regulation of hepatic triglyceride storage. The effect of Kupffer cells on liver triglycerides are at least partially mediated by IL-1beta, which suppresses PPARalpha expression and activity.
2011-10-18 | GSE33044 | GEO