Shared PPARα/γ target genes regulate brown adipocyte thermogenic function (RNA-Seq)
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ABSTRACT: Purpose: To study the role of PPAR nuclear receptors in brown fat. Methods: mRNA-sequencing was performed on brown adipose tissue from mice on diets with or without added rosiglitazone or fenofibrate. Sequence reads that passed quality filters were analyzed at the transcript isoform level with RNA-Seq Unified Mapper. Results: We identified genes that were induced or repressed by either PPAR agonist, and approximately three-fold more genes were significantly regulated by rosiglitazone (rosi, a PPARg agonist) than by fenofibrate (feno, a PPARa agonist). Those genes induced by either drug were enriched for expected lipid metabolic pathways, while down-regulated genes fell in pathways of uncertain relevance. Most genes were selectively regulated by one of the two PPAR agonists, with few regulated by both. Only 34 genes were induced by both PPAR agonists (~10% of rosi-induced genes and ~25% of feno-induced genes), and these were enriched for mitochondrial functionrelated pathways, including fatty acid β-oxidation. Conclusions: These data suggest that PPARγ agonists have stronger effects on BAT than PPARα agonists, yet those genes activated by both PPAR agonists may be particularly relevant to BAT function.
Project description:Cardiac hypertrophy is characterized by increase in the size of the cardiomyocytes which is initially triggered as an adaptive response due to various kinds of stimuli but ultimately becomes maladaptive with chronic exposure. Peroxisome proliferator activated receptor alpha (PPAR α), which is critical for mitochondrial biogenesis and fatty acid oxidation, is known to be down regulated in hypertrophied cardiomyocytes. The aim of the study was to unveil the role of PPAR α in the mechanism that drives myocardium towards maladaptation in chronic hypertrophy. Wild-type C57BL/6 and PPAR α-/- mice were subjected to isoproterenol treatment for 2 weeks (n=8). Proteomic analysis using Orbitrap mass spectrometer revealed an unexpected down regulation of apoptotic markers, Annexin V and p53. PPAR α regulated and non-regulated genes were validated using RT-PCR. Specificity for α isoform was confirmed using PPAR α agonist, fenofibrate and pan-agonist bezafibrate. Fenofibrate failed to restore PPAR α target genes, whereas bezafibrate managed to ameliorate the effects of isoproterenol for a subset of genes even in the absence of PPAR α. Autophagy markers like p62, Beclin1 and LC3 A/B were up regulated in PPAR α-/-mice therefore indicating an upsurge in autophagy. The results demonstrate hindrance to intrinsic apoptotic pathway and activation of autophagy in the absence of PPAR α in hypertrophic cardiomyocytes. Therefore, PPAR α signalling might act as a molecular switch between apoptosis and autophagy thereby playing a critical role in adaptive process in stress induced cardiomyocytes.
Project description:Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors that act as ligand-activated transcription factors. Although prescribed for dyslipidemia and type-II diabetes, PPAR agonists have demonstrated therapeutic properties for several brain disorders, including alcohol dependence. PPAR agonists decrease ethanol consumption and reduce withdrawal severity and susceptibility to stress-induced relapse in rodents. However, the cellular and molecular mechanisms facilitating these properties have yet to be investigated and little is known about their effects in the brain. We tested three PPAR agonists in a continuous access two-bottle choice (2BC) drinking paradigm and found that tesaglitazar and fenofibrate decreased ethanol consumption in male C57BL/6J mice while bezafibrate did not. Hypothesizing that fenofibrate and tesaglitazar are causing brain gene expression changes that precipitate the reduction in ethanol drinking, we gave daily oral injections of fenofibrate, tesaglitazar and bezafibrate to mice for eight consecutive days and collected liver, prefrontal cortex and amygdala 24 hours after last injection. RNA was isolated and purified using MagMAX-96 Total RNA Isolation Kit. Biotinylated, amplified cRNA was generated using Illumina TotalPrep RNA Amplification Kit and hybridized to Illumina MouseWG-6 v2.0 Expression microarrays. Mice were divided into four groups (N=10 per group): fenofibrate, tesaglitazar, bezafibrate and saline. See summary and protocols for details.
Project description:To better understand what genes are regulated by PPAR gamma, an experimental dataset was generated by microarray analysis, in duplicate, of pooled aortic mRNA isolated from adult male mice (C57BL/6J strain) treated for 21 days with a PPAR gamma agonist (rosiglitazone) or vehicle.
Project description:To better understand what genes are regulated by PPAR gamma, an experimental dataset was generated by microarray analysis, in duplicate, of pooled aortic mRNA isolated from adult male mice (C57BL/6J strain) treated for 21 days with a PPAR gamma agonist (rosiglitazone) or vehicle. Keywords: other
Project description:Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors that act as ligand-activated transcription factors. Although prescribed for dyslipidemia and type-II diabetes, PPAR agonists have demonstrated therapeutic properties for several brain disorders, including alcohol dependence. PPAR agonists decrease ethanol consumption and reduce withdrawal severity and susceptibility to stress-induced relapse in rodents. However, the cellular and molecular mechanisms facilitating these properties have yet to be investigated and little is known about their effects in the brain. We tested three PPAR agonists in a continuous access two-bottle choice (2BC) drinking paradigm and found that tesaglitazar and fenofibrate decreased ethanol consumption in male C57BL/6J mice while bezafibrate did not. Hypothesizing that fenofibrate and tesaglitazar are causing brain gene expression changes that precipitate the reduction in ethanol drinking, we gave daily oral injections of fenofibrate, tesaglitazar and bezafibrate to mice for eight consecutive days and collected liver, prefrontal cortex and amygdala 24 hours after last injection. RNA was isolated and purified using MagMAX-96 Total RNA Isolation Kit. Biotinylated, amplified cRNA was generated using Illumina TotalPrep RNA Amplification Kit and hybridized to Illumina MouseWG-6 v2.0 Expression microarrays.
Project description:Reprograming of 'white' to 'brite' adipocytes with higher oxidative capacity and improved endocrine function represents a potentially important approach to address the dysfunctional adipocyte phenotypes in obesity. We find that chronic treatment with the PPAR? agonist (rosiglitazone, 1 uM for 7days in vitro) in white human adipose tissue induced metabolic changes. Our trancriptome analysis showed that higher mitochondrial and peroxisomal fatty acid oxidation pathways and other genes involved in lipid metabolism including (re)esterification are induced by rosiglitazone treatment. To understand the biochemical basis of brite vs. white human adipocytes, we will perform comprehensive metabolomic profiling of control and rosiglitazone treated tissues using unbiased lipidomics approach.
Project description:Robust identification of placental PPARg target genes via mutliple PPARg-dependence criteria. Integration of differential expression data from Pparg-null, Rxra-null, Med1-nul and Ncoa6-null placentas and from WT and Pparg-null Trophoblast stem cells (TSC) differentiated for 2 or 4 days in the presence or absence of the PPARg agonist Rosiglitazone (Rosi).
Project description:Objective : This work aimed at characterizing PPARα involvement in metabolism regulation and at comparing PPARα and PPARγ roles in human white adipocytes. Research Design and Methods : Profiling of gene expression alterations was assessed with microarrays and RT-qPCR. Primary cultures of human adipocytes were treated with PPARα agonist GW7647 or PPARγ agonist Rosiglitazone. Western blot were used to determine protein level modifications. Metabolic changes were evaluated with palmitate and glucose oxidation studies and with metabolite measurements. Results : GW7647 induces an upregulation of β-oxidation gene expression and increases palmitate oxidation. Unexpectedly glycolysis was strongly reduced at transcriptional and functional levels by GW7647 while the overall glucose oxidation remains unaltered, leading to a decrease in pyruvate and lactate production. Moreover lipogenesis was downregulated by GW7647 inhibiting triglyceride esterification and de novo lipogenesis. GW7647 induced alterations were abolished by a PPARα antagonist treatment and were clearly different from Rosiglitazone effects. Rosiglitazone had no major impact on glycolysis and β-oxidation but increased glucose incorporation into glycerol backbone of triglycerides. Conclusions : Altogether these results show that PPARα can upregulate β-oxidation in human white adipocytes. Its pharmacological activation may be used to oxidize fatty acids in situ when lipolysis is activated thus preventing their release into systemic circulation. We treated four adipocyte cultures, each one coming from different subjects, with GW7647, Rosiglitazone (ROSI) or DMSO. DMSO treated cells are control samples. Thus we have four paired sample groups for each treatment (GW7647 and ROSI).
Project description:Reprograming of 'white' to 'brite' adipocytes with higher oxidative capacity and improved endocrine function represents a potentially important approach to address the dysfunctional adipocyte phenotypes in obesity. We find that chronic treatment with the PPAR? agonist (rosiglitazone, 1 uM for 7days in vitro) in white human adipose tissue induced metabolic changes. Our trancriptome analysis showed that higher mitochondrial and peroxisomal fatty acid oxidation pathways and other genes involved in lipid metabolism including (re)esterification are induced by rosiglitazone treatment. To understand the biochemical basis of brite vs. white human adipocytes, we will perform comprehensive metabolomic profiling of control and rosiglitazone treated tissues using unbiased lipidomics approach.
Project description:We examined the alternation of gene expression by MCC-555, rosiglitazone (RGZ) and 15-deoxy-Δ12, 14-prostaglandin J2 (PGJ2) in human colorectal adenocarcinoma HCT-116 cells. Keywords: effects of PPAR-gamma agonists