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: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:We examined global gene expression profiles in amygdala (AMY), nucleus accumbens (NAC), prefrontal cortex (PFC) and Liver of male C57BL/6J mice exposed to 4 cycles of chronic intermittent ethanol (CIE) vapor. Animals were sacrificed at 0, 8, and 120 hr following the last ethanol exposure.
Project description:We examined global gene expression profiles in amygdala (AMY), nucleus accumbens (NAC), prefrontal cortex (PFC) and Liver of male C57BL/6J mice exposed to 4 cycles of chronic intermittent ethanol (CIE) vapor. Animals were sacrificed at 0, 8, and 120 hr following the last ethanol exposure. Mice were exposed to 4 cycles of intermittent vapor [4 days of 16 hours vapor/ 8 hours air] with a week between each cycle. Before entry into the vapor chambers, animals were injected with pyrazole (1 mMol/kg) and either ethanol (1.6 g/kg) or saline (controls). Animals were sacrificed at 0, 8, and 120 hr following the last ethanol exposure. The liver 0 hr control group contained 7 animals. Otherwise there were 8 animals per group (treated, control) at each time point.
Project description:Metabolic challenges experienced by dairy cows during the transition between pregnancy and lactation (also known as peripartum), are of considerable interest from a nutrigenomic perspective. The mobilization of large amounts of non-esterified fatty acids (NEFA) leads to an increase in NEFA uptake in the liver, the excess of which can cause hepatic accumulation of lipids and ultimately fatty liver. Interestingly, peripartum NEFA activate the peroxisome proliferator-activated receptor (PPAR), a transcriptional regulator with known nutrigenomic properties. The study of PPAR activation in the liver of periparturient dairy cows is thus crucial; however, current in vitro models of the bovine liver are inadequate, and the isolation of primary hepatocytes is prohibitive and error-prone. The objective of the current study was to evaluate the use of precision-cut liver slices (PCLS) from liver biopsies as a model for PPAR activation in periparturient dairy cows. Four cows were enrolled in the experiment, and PCLS from each were prepared prepartum (-10 DIM) and postpartum (+10 DIM) and treated with a variety of PPAR agonists and antagonist. Gene expression was assayed through RT-qPCR and RNAseq, and intracellular triglyceride concentration was measured. PCLS treated with PPARγ agonist rosiglitazone displayed upregulation of canonical PPAR targets ACADVL and LIPC in the postpartum, while a PPARδ agonists increased expression of PPAR target PDK4; no gene expression changes were detected in the prepartum, and triglyceride concentrations were unchanged between treatments. Transcriptome sequencing revealed considerable differences in response to PPAR agonist, mainly related to pathways involved with lipid metabolism and the immune response. Among differentially expressed genes, a subset of 91 genes were identified as novel putative PPAR targets in the bovine liver, by cross-referencing our results with a publicly-available dataset of predicted PPAR target genes, and supplementing our finding with prior literature. Our results provide important insights on the use of PCLS as a model for assaying PPAR activation in the peripartum.
Project description: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.