Activation of peroxisome proliferator-activated receptor alpha in human peripheral blood mononuclear cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE11289 | GEO | 2008/06/06
SECONDARY ACCESSION(S): PRJNA106703
REPOSITORIES: GEO
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Project description:Background: Peripheral blood mononuclear cells (PBMCs) are relatively easily obtainable cells in humans. Gene expression profiles of PBMCs have been shown to reflect the pathological and physiological state of a person. Recently, we showed that the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARα) has a functional role in human PBMCs during fasting. However, the extent of the role of PPARα in human PBMCs remains unclear. In this study, we therefore performed gene expression profiling of PBMCs incubated with the specific PPARα ligand WY14,643. Results: Incubation of PBMCs with WY14,643 for 12 hours resulted in a differential expression of 1,373 of the 13,080 genes expressed in the PBMCs. Gene expression profiles showed a clear individual response to PPARα activation between six healthy human blood donors, which was not the result of the nutritional status of the donors. Pathway analysis showed that genes in fatty acid metabolism, primarily in β-oxidation were up-regulated upon activation of PPARα with WY14,643, and genes in several amino acid metabolism pathways were down-regulated. Conclusions: This study shows that PPARα in human PBMCs regulates fatty acid and amino acid metabolism. In addition, PBMC gene expression profiles show individual responses to WY14,643 activation. We show that PBMCs are a suitable model to study changes in PPARα activation in healthy humans. Keywords: metabolic state analysis PBMCs from six healthy Caucasian male blood donors, aged between 30 and 48 yr, were isolated directly after arrival of the buffy coat (max. 8 hours after donation) by Ficol-paque Plus density gradient centrifugation (Amersham Biosciences, Roosendaal, the Netherlands). PBMCs were incubated in RPMI1640 medium with 2 mmol/L L-glutamine, 10% fetal bovine serum and antibiotics (penicillin and streptomycin) in the presence of 5% CO2 at 37°C. at 1.0 x 106 cells per ml with either WY14,643 (50 μM) or vehicle (DMSO, 0.1%) for 12 hours. Total RNA from PBMCs was labeled using a one-cycle cDNA labeling kit (Affymetrix Inc, Santa Clara, CA) and hybridized to Affymetrix Human whole genome U133 plus 2.0 arrays (Affymetrix). Sample labeling, hybridization to chips and image scanning was performed according to the manufacturer’s GeneChip Expression Analysis Technical Manual (Affymetrix).
2008-06-06 | E-GEOD-11289 | biostudies-arrayexpress
Project description:Fatty acids comprise the primary energy source for the heart and are mainly taken up via hydrolysis of circulating triglyceride-rich lipoproteins. While most of the fatty acids entering the cardiomyocyte are oxidized, a small portion is involved in altering gene transcription to modulate cardiometabolic functions. So far, no in vivo model has been developed enabling study of the transcriptional effects of specific fatty acids in the intact heart. In the present study, mice were given a single oral dose of synthetic triglycerides composed of one single fatty acid. Hearts were collected 6h thereafter and used for whole genome gene expression profiling. Experiments were conducted in wild-type and PPARα−/− mice to allow exploration of the specific contribution of PPARα. It was found that: 1) linolenic acid (C18:3) had the most pronounced effect on cardiac gene expression. 2) The largest similarity in gene regulation was observed between linoleic acid (C18:2) and C18:3. Large similarity was also observed between the synthetic PPARα agonist Wy14,643 and docosahexaenoic acid (C22:6). 3) Many genes were regulated by one particular treatment only. Genes regulated by one particular treatment showed large functional divergence. 4) The majority of genes responding to fatty acid treatment were regulated in a PPARα-dependent manner, emphasizing the importance of PPARα in mediating transcriptional regulation by fatty acids in the heart. 5) Several genes were robustly regulated by all or many of the fatty acids studied, mostly representing well-described targets of PPARs (e.g. Acot1, Angptl4, Ucp3). 6) Deletion and activation of PPARα had a major effect on expression of numerous genes involved in metabolism and immunity. Our analysis demonstrates the marked impact of dietary fatty acids on gene regulation in the heart via PPARα.
2012-02-21 | GSE30553 | GEO
Project description:Nuclear receptor activation in liver leads to coordinated alteration of the expression of multiple gene products with attendant phenotypic changes of hepatocytes. Peroxisome proliferators including endogenous fatty acids, environmental chemicals, and drugs induce a multi-enzyme metabolic response that affects lipid and fatty acid processing. We studied the signaling network for the peroxisome proliferator-associated receptor alpha (PPARα) in primary human hepatocytes using the selective PPARα ligand, GW7647. We measured gene expression over multiple concentrations and times and conducted ChIP-seq studies at 2 and 24 hours to assess genomic binding of PPARα. Over all treatments there were 192 genes differentially expressed. Of these only 51% showed evidence of PPARα binding – either directly at PPARα response elements or via alternative mechanisms. Almost half of regulated genes had no PPARα binding. We then developed two novel bioinformatics methods to visualize the dose-dependent activation of both the transcription factor circuitry for PPARα and the downstream metabolic network in relation to functional annotation categories. Available databases identified several key transcription factors involved with the non-genomic targets after GW7647 treatment, including SP1, STAT1, ETS1, ERα, and HNF4α. The linkage from PPARα binding through gene expression likely requires intermediate protein kinases to activate these transcription factors. We found enrichment of functional annotation categories for organic acid metabolism and cell lipid metabolism among the differentially expressed genes. Lipid transport processes showed enrichment at the highest concentration of GW7647 (10μM). While our strategy for mapping transcriptional networks is evolving, these approaches are necessary in moving from toxicogenomic methods that derive signatures of activity to methods that establish pathway structure, showing the coordination of the activated nuclear receptor with other signaling pathways. Primary hepatocytes from four donors were exposed to 0, 0.001, 0.01, 0.1, 1.0, or 10.0μM GW7647 for 2, 6, 12, 24, or 72 hours.
2013-12-18 | E-GEOD-53399 | biostudies-arrayexpress
Project description:To identify the CAR-, PXR- and PPARα-specific genome-wide expression changes, hepatocyte cultures from six individual donors were treated with the prototypical ligands for CAR (CITCO), PXR (rifampicin) and PPARα (WY14,643) as well as DMSO (vehicle control). Afterwards, the mRNA expression in these samples was determined utilizing Affymetrix® microarrays.
2016-03-24 | GSE76148 | GEO
Project description:Background: The selective absorption of nutrients and other food constituents in the small intestine is mediated by a group of transport proteins and metabolic enzymes, often collectively called ‘intestinal barrier proteins’. An important receptor that mediates the effects of dietary lipids on gene expression is the peroxisome proliferator-activated receptor alpha (PPARα), which is abundantly expressed in enterocytes. In this study we examined the effects of acute nutritional activation of PPARα on expression of genes encoding intestinal barrier proteins. To this end we used triacylglycerols composed of identical fatty acids in combination with gene expression profiling in wild-type and PPARα-null mice. Treatment with the synthetic PPARα agonist WY14643 served as reference. Results: We identified 74 barrier genes that were PPARα-dependently regulated 6 hours after activation with WY14643. For eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and oleic acid (OA) these numbers were 46, 41, and 19, respectively. The overlap between EPA-, DHA-, and WY14643-regulated genes was considerable, whereas OA treatment showed limited overlap. Functional implications inferred form our data suggested that nutrient-activated PPARα regulated transporters and phase I/II metabolic enzymes were involved in a) fatty acid oxidation, b) cholesterol, glucose, and amino acid transport and metabolism, c) intestinal motility, and d) oxidative stress defense. Conclusion: We identified intestinal barrier genes that were PPARα-dependently regulated after acute activation by fatty acids.This knowledge provides a better understanding of the impact dietary fat has on the barrier function of the gut, identifies PPARα as an important factor controlling this key function, and underscores the importance of PPARα for nutrient-mediated gene regulation in intestine. Keywords: metabolic state analysis
2008-05-22 | GSE9533 | GEO
Project description:2,4-dinitrotoluene (2,4-DNT), a nitroaromatic used in industrial and explosive manufacturing processes, is known to contaminate artillery ranges, demilitarization areas and munitions manufacturing facilities. Previous transcriptomic and lipidomic studies identified energy metabolism as a principle biochemical process affected by 2,4-DNT where up-stream effects on PPARα signaling were hypothesized as themolecular initiating event for these effects. Here, the validity of this hypothetical adverse outcome pathway (AOP) was assessed by testing the hypothesis that 2,4-DNT-induced perturbations in PPARα signaling and resultant downstream deficits in energy metabolism, especially from lipids, would result in organism-level impacts on exercise endurance. PPARα knock-out (-/-) and wild-type (WT) mice were exposed for 14 days to vehicle or 2,4-DNT at a dose (134 mg/kg/day) that did not exhibit overt systemic toxicity. Mice performed an exercise challenge (forced swim) 1 day after the last dose. 2,4-DNT decreased swim times in WT and PPARα (-/-) mice, but the effect was significantly less in PPARα (-/-) mice indicating the critical of PPARα in mediating 2,4-DNT-induced energy metabolism deficits. 2,4-DNT caused down-regulation of transcripts involved in fatty acid metabolism, gluconeogenesis, triacylglycerol catabolism, and the pentose phosphate pathway, and 2,4-DNT treated wild-type mice had decreased serum trigylcerides and increased serum glucose versus 2,4-DNT treated PPARα (-/-) mice. Our results support the hypothesis that 2,4-DNT perturbs PPARα signaling as a molecular initiating event therefore impacting energy metabolism, especially lipid metabolism, producing reduced exercise endurance in mice. RNA was isolated from liver tissue of vehicle or 2,4-DNT treated wild-type or PPARα (-/-) mice (n=6) and RT-PCR performed to analyze genes involved in fatty acid metabolism
2014-06-30 | E-GEOD-50167 | biostudies-arrayexpress
Project description:2,4-dinitrotoluene (2,4-DNT), a nitroaromatic used in industrial and explosive manufacturing processes, is known to contaminate artillery ranges, demilitarization areas and munitions manufacturing facilities. Previous transcriptomic and lipidomic studies identified energy metabolism as a principle biochemical process affected by 2,4-DNT where up-stream effects on PPARα signaling were hypothesized as themolecular initiating event for these effects. Here, the validity of this hypothetical adverse outcome pathway (AOP) was assessed by testing the hypothesis that 2,4-DNT-induced perturbations in PPARα signaling and resultant downstream deficits in energy metabolism, especially from lipids, would result in organism-level impacts on exercise endurance. PPARα knock-out (-/-) and wild-type (WT) mice were exposed for 14 days to vehicle or 2,4-DNT at a dose (134 mg/kg/day) that did not exhibit overt systemic toxicity. Mice performed an exercise challenge (forced swim) 1 day after the last dose. 2,4-DNT decreased swim times in WT and PPARα (-/-) mice, but the effect was significantly less in PPARα (-/-) mice indicating the critical of PPARα in mediating 2,4-DNT-induced energy metabolism deficits. 2,4-DNT caused down-regulation of transcripts involved in fatty acid metabolism, gluconeogenesis, triacylglycerol catabolism, and the pentose phosphate pathway, and 2,4-DNT treated wild-type mice had decreased serum trigylcerides and increased serum glucose versus 2,4-DNT treated PPARα (-/-) mice. Our results support the hypothesis that 2,4-DNT perturbs PPARα signaling as a molecular initiating event therefore impacting energy metabolism, especially lipid metabolism, producing reduced exercise endurance in mice. RNA was isolated from liver tissue of vehicle or 2,4-DNT treated wild-type or PPARα (-/-) mice (n=6) and RT-PCR performed to analyze genes involved in fatty acid metabolism
2014-06-30 | E-GEOD-50169 | biostudies-arrayexpress
Project description:Elevated circulating triglycerides, which are considered a risk factor for cardiovascular disease, can be targeted by treatment with fenofibrate or fish oil. To gain insight into underlying mechanisms, we carried out a comparative transcriptomics and metabolomics analysis of the effect of 2 week treatment withfenofibrate and fish oil in mice. Plasma triglycerides were significantly decreased byfenofibrate (-49.1%) and fish oil (-21.8%), whereas plasma cholesterol was increased by fenofibrate (+29.9%) and decreased by fish oil (-32.8%). Levels of various phospholipid species were specifically decreased by fish oil, while levels of Krebs cycle intermediates were increased specifically by fenofibrate. Plasma levels of many amino acids were altered by fenofibrate and to a lesser extent by fish oil. Both fenofibrate and fish oil upregulated genes involved in fatty acid metabolism, and downregulated genes involved in blood coagulation and fibrinolysis. Significant overlap in gene regulation by fenofibrate and fish oil was observed, reflecting their property as high or low affinity agonist for PPARα, respectively. Fenofibrate specifically downregulated genes involved in complement cascade and inflammatory response. Fish oil specifically downregulated genes involved in cholesterol and fatty acid biosynthesis, and upregulated genes involved in amino acid and arachidonic acid metabolism. Taken together, the data indicate that despite being similarly potent towards modulating plasma free fatty acids, cholesterol and triglyceride levels, fish oil causes modest changes in gene expression likely via activation of multiple mechanistic pathways, whereas fenofibrate causes pronounced gene expression changes via a single pathway, reflecting the key difference between nutritional and pharmacological intervention. Expression profiling of liver from mice fed control diet, fish oil or fenofibrate for 2 weeks.
2011-10-07 | E-GEOD-32706 | biostudies-arrayexpress
Project description:The class 3 phosphoinositide 3-kinase (PI3K) is required for the lysosomal degradation by autophagy and vesicular trafficking, assuring adaptation to energy shortages. Mitochondrial lipid catabolism is another important energy source. Autophagy and mitochondrial metabolism are transcriptionally controlled by nutrient sensing nuclear receptors. However, it is not known whether the class 3 PI3K contributes to this regulation. Here we show that hepatocyte-specific inactivation of Vps15, the essential regulatory subunit of the class 3 PI3K, results in mitochondrial depletion and a failure to oxidize fatty acids. Mechanistically, the transcriptional activity of Peroxisome Proliferator Activated Receptor alpha (PPARα), a nuclear receptor that orchestrates fatty acid catabolism, is blunted in Vps15-deficient livers. We find PPARα transcriptional repressors Histone Deacetylase 3 (Hdac3) and Nuclear receptor co-repressor 1 (NCoR1) accumulated in Vps15-deficient livers due to defective autophagic flux. Pharmacologic activation of PPARα with a synthetic ligand, re-expression of its co-activator Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha (PGC-1α) or inhibition of Hdac3 restored mitochondrial biogenesis and lipid oxidation in Vps15-deficient hepatocytes. These findings reveal a role for the class 3 PI3K and autophagy in transcriptional coordination of mitochondrial metabolism.
2020-02-06 | E-MTAB-7685 | biostudies-arrayexpress
Project description:Fatty acids comprise the primary energy source for the heart and are mainly taken up via hydrolysis of circulating triglyceride-rich lipoproteins. While most of the fatty acids entering the cardiomyocyte are oxidized, a small portion is involved in altering gene transcription to modulate cardiometabolic functions. So far, no in vivo model has been developed enabling study of the transcriptional effects of specific fatty acids in the intact heart. In the present study, mice were given a single oral dose of synthetic triglycerides composed of one single fatty acid. Hearts were collected 6h thereafter and used for whole genome gene expression profiling. Experiments were conducted in wild-type and PPARα−/− mice to allow exploration of the specific contribution of PPARα. It was found that: 1) linolenic acid (C18:3) had the most pronounced effect on cardiac gene expression. 2) The largest similarity in gene regulation was observed between linoleic acid (C18:2) and C18:3. Large similarity was also observed between the synthetic PPARα agonist Wy14643 and docosahexaenoic acid (C22:6). 3) Many genes were regulated by one particular treatment only. Genes regulated by one particular treatment showed large functional divergence. 4) The majority of genes responding to fatty acid treatment were regulated in a PPARα-dependent manner, emphasizing the importance of PPARα in mediating transcriptional regulation by fatty acids in the heart. 5) Several genes were robustly regulated by all or many of the fatty acids studied, mostly representing well-described targets of PPARs (e.g. Acot1, Angptl4, Ucp3). 6) Deletion and activation of PPARα had a major effect on expression of numerous genes involved in metabolism and immunity. Our analysis demonstrates the marked impact of dietary fatty acids on gene regulation in the heart via PPARα.
2012-02-21 | GSE30495 | GEO