Activation of peroxisome proliferator-activated receptor alpha in human peripheral blood mononuclear cells reveals an individual gene expression profile response.
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ABSTRACT: 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 (PPARalpha) has a functional role in human PBMCs during fasting. However, the extent of the role of PPARalpha in human PBMCs remains unclear. In this study, we therefore performed gene expression profiling of PBMCs incubated with the specific PPARalpha 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 PPARalpha activation between six healthy human blood donors. Pathway analysis showed that genes in fatty acid metabolism, primarily in beta-oxidation were up-regulated upon activation of PPARalpha with WY14,643, and genes in several amino acid metabolism pathways were down-regulated.Conclusion
This study shows that PPARalpha in human PBMCs regulates fatty acid and amino acid metabolism. In addition, PBMC gene expression profiles show individual responses to WY14,643 activation. We showed that PBMCs are a suitable model to study changes in PPARalpha activation in healthy humans.
SUBMITTER: Bouwens M
PROVIDER: S-EPMC2430976 | biostudies-literature |
REPOSITORIES: biostudies-literature
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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
2008-06-06 | GSE11289 | GEO
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:ObjectivePeripheral atherosclerosis that accumulates in the extracranial carotid and lower extremity arteries can lead to significant morbidity and mortality. However, atherosclerotic disease progression is often not homogenous and is accelerated by diabetes. We previously observed increased phospholipid content in minimally (Min)-diseased arterial segments compared to maximally (Max)-diseased segments. Since Peroxisome Proliferator-Activated Receptor alpha (PPARα) is a key regulator of lipid metabolism, we hypothesized that it may have differential expression and signaling in Min vs. Max-diseased peripheral arterial segments.MethodsEighteen patients who underwent carotid endarterectomy (CEA), and 34 patients who underwent major lower extremity amputation were prospectively enrolled into a vascular tissue biobank. Min and Max-diseased segments were obtained in real-time from CEA plaque and amputated lower extremity arterial segments. mRNA and protein were isolated from specimens and the relative expression of ppara, and its downstream genes Acyl-CoA Oxidase 1 (acox1) and Carnitine Palmitoyltransferase 1A (cpt1a) were also evaluated. We evaluated gene expression and protein content relative to atherosclerotic disease severity and clinical diabetes status. Gene expression was also evaluated relative to Hemoglobin A1c and serum lipid profiles.ResultsIn CEA segments of patients with diabetes, we observed significantly higher ppara and acox1 gene expression (p < 0.01 and p < 0.001 respectively), and higher PPARα protein content (p < 0.05). Hemoglobin A1c significantly correlated with expression of ppara (R2 = 0.66, p < 0.001), acox1 (R2 = 0.31, p < 0.05), and cpt1a (R2 = 0.4, p < 0.05). There was no significant difference in gene expression between Min vs. Max-diseased CEA plaque segments. Conversely, in lower extremity arterial segments of patients with diabetes, we observed significantly lower ppara, acox1, and cpt1a expression (p < 0.05, p < 0.001, and p < 0.0001 respectively). Interestingly, CPT1A content was lower in arterial segments of patients with diabetes (p < 0.05). Hemoglobin A1c and HDL-cholesterol had negative correlations with ppara (R2 = 0.44, p < 0.05; R2 = 0.42, p < 0.05; respectively).ConclusionThis study demonstrates the significant differential expression of ppara and its immediate downstream genes in human carotid and lower extremity arteries relative to disease severity and diabetes. These findings highlight that mechanisms that influence atheroprogression in the carotid and lower extremities peripheral arteries are not homogenous and can be impacted by patient diabetes status and serum cholesterol profiles. Further elucidating these differential molecular mechanisms can help improve targeted therapy of atherosclerosis in different peripheral arterial beds.
| S-EPMC9248745 | biostudies-literature
Project description:Peroxisome proliferator-activated receptor alpha (PPARalpha) is important in the induction of cell-specific pleiotropic responses, including the development of liver tumors, when it is chronically activated by structurally diverse synthetic ligands such as Wy-14,643 or by unmetabolized endogenous ligands resulting from the disruption of the gene encoding acyl coenzyme A (CoA) oxidase (AOX). Alterations in gene expression patterns in livers with PPARalpha activation were delineated by using a proteomic approach to analyze liver proteins of Wy-14,643-treated and AOX(-/-) mice. We identified 46 differentially expressed proteins in mouse livers with PPARalpha activation. Up-regulated proteins, including acetyl-CoA acetyltransferase, farnesyl pyrophosphate synthase, and carnitine O-octanoyltransferase, are involved in fatty acid metabolism, whereas down-regulated proteins, including ketohexokinase, formiminotransferase-cyclodeaminase, fructose-bisphosphatase aldolase B, sarcosine dehydrogenase, and cysteine sulfinic acid decarboxylase, are involved in carbohydrate and amino acid metabolism. Among stress response and xenobiotic metabolism proteins, selenium-binding protein 2 and catalase showed a dramatic approximately 18-fold decrease in expression and a modest approximately 6-fold increase in expression, respectively. In addition, glycine N-methyltransferase, pyrophosphate phosphohydrolase, and protein phosphatase 1D were down-regulated with PPARalpha activation. These observations establish proteomic profiles reflecting a common and predictable pattern of differential protein expression in livers with PPARalpha activation. We conclude that livers with PPARalpha activation are transcriptionally geared towards fatty acid combustion.
| S-EPMC434239 | biostudies-literature
Project description:α-Chlorofatty aldehydes are generated from myeloperoxidase-derived HOCl targeting plasmalogens, and are subsequently oxidized to α-chlorofatty acids (α-ClFAs). The catabolic pathway for α-ClFA is initiated by ω-oxidation. Here, we examine PPAR-α activation as a mechanism to increase α-ClFA catabolism. Pretreating both HepG2 cells and primary mouse hepatocytes with the PPAR-α agonist, pirinixic acid (Wy 14643), increased the production of α-chlorodicarboxylic acids (α-ClDCAs) in cells treated with exogenous α-ClFA. Additionally, α-ClDCA production in Wy 14643-pretreated wild-type mouse hepatocytes was accompanied by a reduction in cellular free α-ClFA. The dependence of PPAR-α-accelerated α-ClFA catabolism was further demonstrated by both impaired metabolism in mouse PPAR-α-/- hepatocytes and decreased clearance of plasma α-ClFA in PPAR-α-/- mice. Furthermore, Wy 14643 treatments decreased plasma 2-chlorohexadecanoic acid levels in wild-type mice. Additional studies showed that α-ClFA increases PPAR-α, PPAR-δ, and PPAR-γ activities, as well as mRNA expression of the PPAR-α target genes, CD36, CPT1a, Cyp4a10, and CIDEC. Collectively, these results indicate that PPAR-α accelerates important pathways for the clearance of α-ClFA, and α-ClFA may, in part, accelerate its catabolism by serving as a ligand for PPAR-α.
| S-EPMC5282948 | biostudies-literature
Project description:Background and Objective: Retinal ischemia-reperfusion (IR) leads to massive loss of retinal ganglion cells (RGC) and characterizes several blind-causing ophthalmic diseases. However, the mechanism related to retinal IR is controversial, and a drug that could prevent the RGC loss caused by IR is still lacking. This study aimed to investigate the role of endogenous retinal peroxisome proliferator-activated receptor (PPAR)α and the therapeutic effect of its agonist, fenofibric acid (FA), in IR-related retinopathy. Materials and Methods: Fenofibric acid treatment was applied to the Sprague-Dawley rats with IR and retinal cell line 28 cells with oxygen-glucose deprivation (OGD) (an in vitro model of IR). Western blotting, real-time PCR, and immunofluorescence were used to examine the expression levels of PPARα, glial fibrillary acidic protein (GFAP), and cyclooxygenase-2 (COX2). Hematoxylin and eosin (HE) staining, propidium iodide (PI) staining, retrograde tracing, and flash visual-evoked potential (FVEP) were applied to assess RGC injury and visual function. Results: Retinal IR down-regulated PPARα expression in vitro and in vivo. Peroxisome proliferator-activated receptor α activation by FA promoted survival of RGCs, mitigated thinning of the ganglion cell complex, and decreased the latency of positive waves of FVEPs after IR injury. Further, FA treatment enhanced the expression of endogenous PPARα and suppressed the expression of GFAP and COX2 significantly. Conclusion: Peroxisome proliferator-activated receptor α activation by FA is protective against RGC loss in retinal IR condition, which may occur by restoring PPARα expression, inhibiting activation of glial cells, and suppressing retinal inflammation. All these findings indicate the translational potential of FA in treating IR-related retinopathy.
| S-EPMC8732875 | biostudies-literature
Project description: Not available
| S-EPMC2884686 | biostudies-literature
Project description:Peroxisome proliferator-activated receptor-alpha (PPARalpha) belongs to the nuclear receptor (NR) family of transcription factors and regulates lipid and glucose metabolism. Like other NRs, the regulation of gene expression by PPARalpha depends on cofactor recruitment to the transcription complex and multiple protein-protein interactions. In this study, Murine Double Minute 2 (MDM2), an E3 ubiquitin ligase, is identified as a PPARalpha-interacting protein that regulates PPARalpha transcriptional activity. MDM2 modulated the transcriptional activity of PPARalpha and PPARbeta/delta, but not PPARgamma in reporter assays. Knockdown of MDM2 by small interfering RNA in rat hepatoma cells inhibited ligand-induced mRNA levels of several PPARalpha target genes involved in lipid metabolism. MDM2 associated with PPARalpha on target gene promoters, and this association increased in response to Wy14,643 treatment. MDM2 interacted with PPARalpha and this interaction occurred with the A/B domain of PPARalpha. Coexpression of MDM2 increased PPARalpha ubiquitination and the E3 ubiquitin ligase activity of MDM2 affected PPARalpha protein expression and transcriptional activity. MDM2 expression was decreased in response to clofibrate in wild-type (WT), but not in PPARalpha null mice, indicating a PPARalpha-dependent regulation. These studies identify a role for MDM2 in regulating PPARalpha-mediated pathways of lipid metabolism.
| S-EPMC2644403 | biostudies-literature
Project description:To identify the potential functions of peroxisome proliferator-activated receptor alpha (PPARalpha) in skin development, transgenic mice were generated to target constitutively activated PPARalpha (VP16PPARalpha) to the stratified epithelia by use of the keratin K5 promoter. In addition to marked alterations in epidermal development, the transgenic mice had a severe defect in lactation during pregnancy resulting in 100% pup mortality. In this study, the alteration of mammary gland development in these transgenic mice was investigated. The results showed that expression of the VP16PPARalpha transgene during pregnancy resulted in impaired development of lobuloalveoli, which is associated with reduced proliferation and increased apoptosis of mammary epithelia. Mammary epithelia from transgenic mice also showed a significant reduction in the expression of beta-catenin and a down-regulation of one of its target genes, cyclin D1, which is thought to be required for lobuloalveolar development. Furthermore, upon PPARalpha ligand treatment, similar effects on lobuloalveolar development were observed in wild-type mice, but not in PPARalpha-null mice. These findings suggest that PPARalpha activation has a marked influence in mammary lobuloalveolar development.
| S-EPMC1570154 | biostudies-literature
Project description:Peroxisome proliferator-activated receptor alpha (PPARalpha) is a nuclear receptor with manifold effects on intermediary metabolism. To define a set of urinary biomarkers that could be used to determine the efficacy of PPARalpha agonists, a metabolomic investigation was undertaken in wild-type and Pparalpha-null mice fed for 2 wk either a regular diet or a diet containing the PPARalpha ligand Wy-14,643 ([4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio] acetic acid), and their urine was analyzed by ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry. Principal components analysis of 6393 accurate mass positive ions revealed clustering as a single phenotype of the treated and untreated Pparalpha (-/-) mice plus two additional discrete phenotypes for the treated and untreated Pparalpha (+/+) mice. Biomarkers of PPARalpha activation were identified from their accurate masses and confirmed by tandem mass spectrometry of authentic compounds. Biomarkers were quantitated from raw chromatographic data using appropriate calibration curves. PPARalpha urinary biomarkers highly statistically significantly elevated by Wy-14,643 treatment included 11beta-hydroxy-3,20-dioxopregn-4-en-21-oic acid (>3700-fold), 11beta,20-dihydroxy-3-oxopregn-4-en-21-oic acid (50-fold), nicotinamide (>2-fold), nicotinamide 1-oxide (5-fold), 1-methylnicotinamide (1.5-fold), hippuric acid (2-fold), and 2,8-dihydroxyquinoline-beta-d-glucuronide (3-fold). PPARalpha urinary biomarkers highly statistically significantly attenuated by Wy-14,643 treatment included xanthurenic acid (1.3-fold), hexanoylglycine (20-fold), phenylpropionylglycine (4-fold), and cinnamoylglycine (9-fold). These biomarkers arise from PPARalpha effects on tryptophan, corticosterone, and fatty acid metabolism and on glucuronidation. This study underscores the power of mass spectrometry-based metabolomics combined with genetically modified mice in the definition of monogenic metabolic phenotypes.
| S-EPMC2084472 | biostudies-literature