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Burgoon LD, Kluxen FM, Hüser A, Frericks M. The database makes the poison: How the selection of datasets in QSAR models impacts toxicant prediction of higher tier endpoints. Regul Toxicol Pharmacol 2024; 151:105663. [PMID: 38871173 DOI: 10.1016/j.yrtph.2024.105663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 05/10/2024] [Accepted: 06/10/2024] [Indexed: 06/15/2024]
Abstract
As the United States and the European Union continue their steady march towards the acceptance of new approach methodologies (NAMs), we need to ensure that the available tools are fit for purpose. Critics will be well-positioned to caution against NAMs acceptance and adoption if the tools turn out to be inadequate. In this paper, we focus on Quantitative Structure Activity-Relationship (QSAR) models and highlight how the training database affects quality and performance of these models. Our analysis goes to the point of asking, "are the endpoints extracted from the experimental studies in the database trustworthy, or are they false negatives/positives themselves?" We also discuss the impacts of chemistry on QSAR models, including issues with 2-D structure analyses when dealing with isomers, metabolism, and toxicokinetics. We close our analysis with a discussion of challenges associated with translational toxicology, specifically the lack of adverse outcome pathways/adverse outcome pathway networks (AOPs/AOPNs) for many higher tier endpoints. We recognize that it takes a collaborate effort to build better and higher quality QSAR models especially for higher tier toxicological endpoints. Hence, it is critical to bring toxicologists, statisticians, and machine learning specialists together to discuss and solve these challenges to get relevant predictions.
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An J, Jiang J, Tang W, Zhong Y, Ren G, Shang Y, Yu Z. Lipid metabolic disturbance induced by triphenyl phosphate and hydroxy metabolite in HepG2 cells. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 262:115160. [PMID: 37356402 DOI: 10.1016/j.ecoenv.2023.115160] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 06/12/2023] [Accepted: 06/17/2023] [Indexed: 06/27/2023]
Abstract
Triphenyl phosphate (TPHP) has been widely used as flame retardants and been detected with increasing frequency in environment. TPHP can transform into mono-hydroxylated phosphate (OH-TPHP) and diester diphenyl phosphate (DPHP) through biotransformation. So far, information on the cytotoxicity and molecular regulatory mechanisms of TPHP metabolites are still limit. This study investigated the adverse effects of TPHP, OH-TPHP, and DPHP in HepG2 cells in terms of cell proliferation, lactate dehydrogenase release, reactive oxygen species generation, and mitochondrial membrane potential. The transcriptomic changes were measured using RNA sequencing, and bioinformatics characteristics including biological functions, signal pathways and protein-protein interaction were analyzed to explore the potential molecular mechanisms. Results displayed that the order of cytotoxicity was OH-TPHP> TPHP> DPHP. The prioritized biological functions changes induced by TPHP and OH-TPHP were correlated with lipid metabolism. Significant lipid accumulation was observed as confirmed by increased total cholesterol and triglycerides contents, and enhanced oil red O staining. Enrichment of PPARα/γ and down-stream genes suggested the participation of PPARs signal pathway in lipid metabolism disorder. In addition, TPHP and OH-TPHP induced endoplasmic reticulum stress (ERS), which was further confirmed by the ERS inhibitor experiment. In general, TPHP and OH-TPHP had obvious cytotoxic effects in HepG2 cells. PPARs signal pathway and endoplasmic reticulum stress may be involved in the lipid metabolism disorder induced by TPHP and OH-TPHP.
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Affiliation(s)
- Jing An
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Jingjing Jiang
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Waner Tang
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Yufang Zhong
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Guofa Ren
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Yu Shang
- Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Zhiqiang Yu
- State Key Laboratory of Organic Geochemistry, Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China.
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3
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Liu HY, Hu P, Li Y, Sun MA, Qu H, Zong Q, Gu H, Chen X, Bao W, Cai D. Targeted inhibition of PPARα ameliorates CLA-induced hypercholesterolemia via hepatic cholesterol biosynthesis reprogramming. Liver Int 2022; 42:1449-1466. [PMID: 35184357 DOI: 10.1111/liv.15199] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/10/2022] [Accepted: 02/14/2022] [Indexed: 02/13/2023]
Abstract
BACKGROUND & AIMS Disruption of lipid metabolism is largely linked to metabolic disorders, such as hypercholesterolemia (HCL) and liver steatosis. While cholesterol metabolic re-programmers can serve as targets for relevant interventions. Here we explored the dietary conjugated linoleic acids (CLA)-induced HCL in mice and the molecular regulation behind it. METHODS A high dose of CLA supplementation in the diet was used to induce HCL in mice and was found to cause a hyper-activated cholesterol biosynthesis programme in the liver, leading to cholesterol metabolism dysregulation. The effects of a small-molecule drug targeting PPARα, i.e., GW6471 were studied in vivo in mice fed diets with CLA supplementation for 28 days, and in primary hepatocytes derived from HCL-mice in vitro. RESULTS We demonstrate that CLA induced HCL and liver steatosis through multiple pathways. Among which was the PPARα-mediated cholesterogenesis. It was found to cooperate with SREBP2 via binding to Hmgcr and Dhcr7 (genes encoding key enzymes of the cholesterol biosynthetic pathway) and recruits the histone marks H3K27ac and H3K4me1 and cofactors. PPARα inhibition disrupts its physical association with SREBP2 by blocking cobinding of PPARα and SREBP2 to the genomic DNA response element. We showed that NR RORγ functions as an essential mediator that facilitates the interaction of PPARα and SREBP2 to modulate the cholesterol biosynthesis genes expression. CONCLUSIONS Our study unravels that the small-molecule compound GW6471 exerts an attractive therapeutic effect for CLA-induced HCL, involving multiple pathways with the "PPARα-RORγ-SREBP2" being a potential complex player in this hepatic cholesterol biosynthesis programming.
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Affiliation(s)
- Hao-Yu Liu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Ping Hu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Yanwei Li
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Ming-An Sun
- College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Huan Qu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Qiufang Zong
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Haotian Gu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Xiaobo Chen
- Centre for Environment and Sustainability, University of Surrey, Surrey, UK
| | - Wenbin Bao
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
| | - Demin Cai
- College of Animal Science and Technology, Yangzhou University, Yangzhou, China
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4
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Ranea-Robles P, Chen H, Stauffer B, Yu C, Bhattacharya D, Friedman SL, Puchowicz M, Houten SM. The peroxisomal transporter ABCD3 plays a major role in hepatic dicarboxylic fatty acid metabolism and lipid homeostasis. J Inherit Metab Dis 2021; 44:1419-1433. [PMID: 34564857 PMCID: PMC8578467 DOI: 10.1002/jimd.12440] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 09/02/2021] [Accepted: 09/24/2021] [Indexed: 01/02/2023]
Abstract
Peroxisomes metabolize a specific subset of fatty acids, which include dicarboxylic fatty acids (DCAs) generated by ω-oxidation. Data obtained in vitro suggest that the peroxisomal transporter ABCD3 (also known as PMP70) mediates the transport of DCAs into the peroxisome, but in vivo evidence to support this role is lacking. In this work, we studied an Abcd3 KO mouse model generated by CRISPR-Cas9 technology using targeted and untargeted metabolomics, histology, immunoblotting, and stable isotope tracing technology. We show that ABCD3 functions in hepatic DCA metabolism and uncover a novel role for this peroxisomal transporter in lipid homeostasis. The Abcd3 KO mouse presents with increased hepatic long-chain DCAs, increased urine medium-chain DCAs, lipodystrophy, enhanced hepatic cholesterol synthesis and decreased hepatic de novo lipogenesis. Moreover, our study suggests that DCAs are metabolized by mitochondrial fatty acid β-oxidation when ABCD3 is not functional, reflecting the importance of the metabolic compartmentalization and communication between peroxisomes and mitochondria. In summary, this study provides data on the role of the peroxisomal transporter ABCD3 in hepatic lipid homeostasis and DCA metabolism, and the consequences of peroxisomal dysfunction for the liver.
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Affiliation(s)
- Pablo Ranea-Robles
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Hongjie Chen
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Mount Sinai Genomics, Inc, Stamford, Connecticut, USA
| | - Brandon Stauffer
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Mount Sinai Genomics, Inc, Stamford, Connecticut, USA
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Mount Sinai Genomics, Inc, Stamford, Connecticut, USA
| | - Dipankar Bhattacharya
- Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Scott L Friedman
- Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Michelle Puchowicz
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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5
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Ranea-Robles P, Violante S, Argmann C, Dodatko T, Bhattacharya D, Chen H, Yu C, Friedman SL, Puchowicz M, Houten SM. Murine deficiency of peroxisomal L-bifunctional protein (EHHADH) causes medium-chain 3-hydroxydicarboxylic aciduria and perturbs hepatic cholesterol homeostasis. Cell Mol Life Sci 2021; 78:5631-5646. [PMID: 34110423 PMCID: PMC8263512 DOI: 10.1007/s00018-021-03869-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/29/2021] [Accepted: 05/29/2021] [Indexed: 02/07/2023]
Abstract
Peroxisomes play an essential role in the β-oxidation of dicarboxylic acids (DCAs), which are metabolites formed upon ω-oxidation of fatty acids. Genetic evidence linking transporters and enzymes to specific DCA β-oxidation steps is generally lacking. Moreover, the physiological functions of DCA metabolism remain largely unknown. In this study, we aimed to characterize the DCA β-oxidation pathway in human cells, and to evaluate the biological role of DCA metabolism using mice deficient in the peroxisomal L-bifunctional protein (Ehhadh KO mice). In vitro experiments using HEK-293 KO cell lines demonstrate that ABCD3 and ACOX1 are essential in DCA β-oxidation, whereas both the bifunctional proteins (EHHADH and HSD17B4) and the thiolases (ACAA1 and SCPx) have overlapping functions and their contribution may depend on expression level. We also show that medium-chain 3-hydroxydicarboxylic aciduria is a prominent feature of EHHADH deficiency in mice most notably upon inhibition of mitochondrial fatty acid oxidation. Using stable isotope tracing methodology, we confirmed that products of peroxisomal DCA β-oxidation can be transported to mitochondria for further metabolism. Finally, we show that, in liver, Ehhadh KO mice have increased mRNA and protein expression of cholesterol biosynthesis enzymes with decreased (in females) or similar (in males) rate of cholesterol synthesis. We conclude that EHHADH plays an essential role in the metabolism of medium-chain DCAs and postulate that peroxisomal DCA β-oxidation is a regulator of hepatic cholesterol biosynthesis.
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Affiliation(s)
- Pablo Ranea-Robles
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY, 10029, USA
| | - Sara Violante
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY, 10029, USA
- The Donald B. and Catherine C. Marron Cancer Metabolism Center, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Carmen Argmann
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY, 10029, USA
| | - Tetyana Dodatko
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY, 10029, USA
| | - Dipankar Bhattacharya
- Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Hongjie Chen
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY, 10029, USA
- Mount Sinai Genomics, Inc, Stamford, CT, 06902, USA
| | - Chunli Yu
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY, 10029, USA
- Mount Sinai Genomics, Inc, Stamford, CT, 06902, USA
| | - Scott L Friedman
- Division of Liver Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Michelle Puchowicz
- Department of Nutrition, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY, 10029, USA.
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6
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Houten SM, Wanders RJA, Ranea-Robles P. Metabolic interactions between peroxisomes and mitochondria with a special focus on acylcarnitine metabolism. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165720. [PMID: 32057943 DOI: 10.1016/j.bbadis.2020.165720] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/03/2020] [Accepted: 02/05/2020] [Indexed: 12/13/2022]
Abstract
Carnitine plays an essential role in mitochondrial fatty acid β-oxidation as a part of a cycle that transfers long-chain fatty acids across the mitochondrial membrane and involves two carnitine palmitoyltransferases (CPT1 and CPT2). Two distinct carnitine acyltransferases, carnitine octanoyltransferase (COT) and carnitine acetyltransferase (CAT), are peroxisomal enzymes, which indicates that carnitine is not only important for mitochondrial, but also for peroxisomal metabolism. It has been demonstrated that after peroxisomal metabolism, specific intermediates can be exported as acylcarnitines for subsequent and final mitochondrial metabolism. There is also evidence that peroxisomes are able to degrade fatty acids that are typically handled by mitochondria possibly after transport as acylcarnitines. Here we review the biochemistry and physiological functions of metabolite exchange between peroxisomes and mitochondria with a special focus on acylcarnitines.
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Affiliation(s)
- Sander M Houten
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA.
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry, Amsterdam Gastroenterology & Metabolism, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
| | - Pablo Ranea-Robles
- Department of Genetics and Genomic Sciences, Icahn Institute for Data Science and Genomic Technology, Icahn School of Medicine at Mount Sinai, 1425 Madison Avenue, Box 1498, New York, NY 10029, USA
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7
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Kunze M. The type-2 peroxisomal targeting signal. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1867:118609. [PMID: 31751594 DOI: 10.1016/j.bbamcr.2019.118609] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/08/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022]
Abstract
The type-2 peroxisomal targeting signal (PTS2) is one of two peptide motifs destining soluble proteins for peroxisomes. This signal acts as amphiphilic α-helix exposing the side chains of all conserved residues to the same side. PTS2 motifs are recognized by a bipartite protein complex consisting of the receptor PEX7 and a co-receptor. Cargo-loaded receptor complexes are translocated across the peroxisomal membrane by a transient pore and inside peroxisomes, cargo proteins are released and processed in many, but not all species. The components of the bipartite receptor are re-exported into the cytosol by a ubiquitin-mediated and ATP-driven export mechanism. Structurally, PTS2 motifs resemble other N-terminal targeting signals, whereas the functional relation to the second peroxisomal targeting signal (PTS1) is unclear. Although only a few PTS2-carrying proteins are known in humans, subjects lacking a functional import mechanism for these proteins suffer from the severe inherited disease rhizomelic chondrodysplasia punctata.
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Affiliation(s)
- Markus Kunze
- Medical University of Vienna, Center for Brain Research, Department of Pathobiology of the Nervous System, Spitalgasse 4, 1090 Vienna, Austria.
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8
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2-Phenyl-8-(1-phenylallyl)-chromenone compounds have a pan-PPAR modulator pharmacophore. Bioorg Med Chem 2019; 27:2948-2958. [PMID: 31128991 DOI: 10.1016/j.bmc.2019.05.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/15/2019] [Accepted: 05/17/2019] [Indexed: 12/30/2022]
Abstract
Adiponectin is an adipocytokine with insulin-sensitizing, anti-atherogenic, and anti-inflammatory properties. Adiponectin secretion-inducing compounds have therapeutic potential in a variety of metabolic diseases. Phenotypic screening led to the discovery that 5,7-dihydroxy-8-(1-(4-hydroxy-3-methoxyphenyl)allyl)-2-phenyl-4H-chromen-4-one (compound 1) had adiponectin secretion-inducing activity during adipogenesis in human bone marrow mesenchymal stem cells (hBM-MSCs). Compound 1 was originally reported to be an anti-cancer chemical isolated from natural honeybee propolis, and its adiponectin secretion-inducing activity was found in non-cytotoxic concentrations. In a target identification study, compound 1 and its potent synthetic derivative compound 5 were shown to be novel pan-peroxisome proliferator-activator receptor (PPAR) modulators. Molecular docking models with PPARs have indicated that the binding modes of chromenone compounds preferentially interacted with the hydrophobic ligand binding pocket of PPARs. In addition, chromenone compounds have been shown to result in different phenotypic outcomes in the transcriptional regulation of lipid metabolic enzymes than those of selective PPAR mono-agonists for PPARα, PPARγ, and PPARδ. In line with the pharmacology of adiponectin and PPAR pan-modulators, compounds 1 and 5 may have diverse therapeutic potentials to treat cancer and metabolic diseases.
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9
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Mezzar S, De Schryver E, Asselberghs S, Meyhi E, Morvay PL, Baes M, Van Veldhoven PP. Phytol-induced pathology in 2-hydroxyacyl-CoA lyase (HACL1) deficient mice. Evidence for a second non-HACL1-related lyase. Biochim Biophys Acta Mol Cell Biol Lipids 2017. [PMID: 28629946 DOI: 10.1016/j.bbalip.2017.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
2-Hydroxyacyl-CoA lyase (HACL1) is a key enzyme of the peroxisomal α-oxidation of phytanic acid. To better understand its role in health and disease, a mouse model lacking HACL1 was investigated. Under normal conditions, these mice did not display a particular phenotype. However, upon dietary administration of phytol, phytanic acid accumulated in tissues, mainly in liver and serum of KO mice. As a consequence of phytanic acid (or a metabolite) toxicity, KO mice displayed a significant weight loss, absence of abdominal white adipose tissue, enlarged and mottled liver and reduced hepatic glycogen and triglycerides. In addition, hepatic PPARα was activated. The central nervous system of the phytol-treated mice was apparently not affected. In addition, 2OH-FA did not accumulate in the central nervous system of HACL1 deficient mice, likely due to the presence in the endoplasmic reticulum of an alternate HACL1-unrelated lyase. The latter may serve as a backup system in certain tissues and account for the formation of pristanic acid in the phytol-fed KO mice. As the degradation of pristanic acid is also impaired, both phytanoyl- and pristanoyl-CoA levels are increased in liver, and the ω-oxidized metabolites are excreted in urine. In conclusion, HACL1 deficiency is not associated with a severe phenotype, but in combination with phytanic acid intake, the normal situation in man, it might present with phytanic acid elevation and resemble a Refsum like disorder.
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Affiliation(s)
- Serena Mezzar
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Evelyn De Schryver
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Stanny Asselberghs
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Els Meyhi
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Petruta L Morvay
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Myriam Baes
- Laboratory for Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Belgium
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Ashikawa Y, Nishimura Y, Okabe S, Sasagawa S, Murakami S, Yuge M, Kawaguchi K, Kawase R, Tanaka T. Activation of Sterol Regulatory Element Binding Factors by Fenofibrate and Gemfibrozil Stimulates Myelination in Zebrafish. Front Pharmacol 2016; 7:206. [PMID: 27462272 PMCID: PMC4939524 DOI: 10.3389/fphar.2016.00206] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 06/28/2016] [Indexed: 01/01/2023] Open
Abstract
Oligodendrocytes are major myelin-producing cells and play essential roles in the function of a healthy nervous system. However, they are also one of the most vulnerable neural cell types in the central nervous system (CNS), and myelin abnormalities in the CNS are found in a wide variety of neurological disorders, including multiple sclerosis, adrenoleukodystrophy, and schizophrenia. There is an urgent need to identify small molecular weight compounds that can stimulate myelination. In this study, we performed comparative transcriptome analysis to identify pharmacodynamic effects common to miconazole and clobetasol, which have been shown to stimulate myelination by mouse oligodendrocyte progenitor cells (OPCs). Of the genes differentially expressed in both miconazole- and clobetasol-treated mouse OPCs compared with untreated cells, we identified differentially expressed genes (DEGs) common to both drug treatments. Gene ontology analysis revealed that these DEGs are significantly associated with the sterol biosynthetic pathway, and further bioinformatics analysis suggested that sterol regulatory element binding factors (SREBFs) might be key upstream regulators of the DEGs. In silico screening of a public database for chemicals associated with SREBF activation identified fenofibrate, a peroxisome proliferator-activated receptor α (PPARα) agonist, as a drug that increases the expression of known SREBF targets, raising the possibility that fenofibrate may also stimulate myelination. To test this, we performed in vivo imaging of zebrafish expressing a fluorescent reporter protein under the control of the myelin basic protein (mbp) promoter. Treatment of zebrafish with fenofibrate significantly increased expression of the fluorescent reporter compared with untreated zebrafish. This increase was attenuated by co-treatment with fatostatin, a specific inhibitor of SREBFs, confirming that the fenofibrate effect was mediated via SREBFs. Furthermore, incubation of zebrafish with another PPARα agonist, gemfibrozil, also increased expression of the mbp promoter-driven fluorescent reporter in an SREBF-dependent manner. These results suggest that activation of SREBFs by small molecular weight compounds may be a feasible therapeutic approach to stimulate myelination.
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Affiliation(s)
- Yoshifumi Ashikawa
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine Tsu, Japan
| | - Yuhei Nishimura
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of MedicineTsu, Japan; Department of Systems Pharmacology, Mie University Graduate School of MedicineTsu, Japan; Mie University Medical Zebrafish Research CenterTsu, Japan; Department of Omics Medicine, Mie University Industrial Technology Innovation InstituteTsu, Japan; Department of Bioinformatics, Mie University Life Science Research CenterTsu, Japan
| | - Shiko Okabe
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine Tsu, Japan
| | - Shota Sasagawa
- Department of Systems Pharmacology, Mie University Graduate School of Medicine Tsu, Japan
| | - Soichiro Murakami
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine Tsu, Japan
| | - Mizuki Yuge
- Department of Molecular and Cellular Pharmacology, Pharmacogenomics and Pharmacoinformatics, Mie University Graduate School of Medicine Tsu, Japan
| | - Koki Kawaguchi
- Department of Systems Pharmacology, Mie University Graduate School of Medicine Tsu, Japan
| | - Reiko Kawase
- Department of Systems Pharmacology, Mie University Graduate School of Medicine Tsu, Japan
| | - Toshio Tanaka
- Department of Systems Pharmacology, Mie University Graduate School of MedicineTsu, Japan; Mie University Medical Zebrafish Research CenterTsu, Japan; Department of Omics Medicine, Mie University Industrial Technology Innovation InstituteTsu, Japan; Department of Bioinformatics, Mie University Life Science Research CenterTsu, Japan
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11
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Mitochondria in peroxisome-deficient hepatocytes exhibit impaired respiration, depleted DNA, and PGC-1α independent proliferation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:285-98. [PMID: 25450972 DOI: 10.1016/j.bbamcr.2014.11.017] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 11/04/2014] [Accepted: 11/13/2014] [Indexed: 02/01/2023]
Abstract
The tight interrelationship between peroxisomes and mitochondria is illustrated by their cooperation in lipid metabolism, antiviral innate immunity and shared use of proteins executing organellar fission. In addition, we previously reported that disruption of peroxisome biogenesis in hepatocytes severely impacts on mitochondrial integrity, primarily damaging the inner membrane. Here we investigated the molecular impairments of the dysfunctional mitochondria in hepatocyte selective Pex5 knockout mice. First, by using blue native electrophoresis and in-gel activity stainings we showed that the respiratory complexes were differentially affected with reduction of complexes I and III and incomplete assembly of complex V, whereas complexes II and IV were normally active. This resulted in impaired oxygen consumption in cultured Pex5(-/-) hepatocytes. Second, mitochondrial DNA was depleted causing an imbalance in the expression of mitochondrial- and nuclear-encoded subunits of the respiratory chain complexes. Third, mitochondrial membranes showed increased permeability and fluidity despite reduced content of the polyunsaturated fatty acid docosahexaenoic acid. Fourth, the affected mitochondria in peroxisome deficient hepatocytes displayed increased oxidative stress. Acute deletion of PEX5 in vivo using adeno-Cre virus phenocopied these effects, indicating that mitochondrial perturbations closely follow the loss of functional peroxisomes in time. Likely to compensate for the functional impairments, the volume of the mitochondrial compartment was increased several folds. This was not driven by PGC-1α but mediated by activation of PPARα, possibly through c-myc overexpression. In conclusion, loss of peroxisomal metabolism in hepatocytes perturbs the mitochondrial inner membrane, depletes mitochondrial DNA and causes mitochondrial biogenesis independent of PGC-1α.
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13
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Eraly SA. Striking differences between knockout and wild-type mice in global gene expression variability. PLoS One 2014; 9:e97734. [PMID: 24830645 PMCID: PMC4022672 DOI: 10.1371/journal.pone.0097734] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 04/23/2014] [Indexed: 12/16/2022] Open
Abstract
Microarray analyses of gene knockouts have traditionally focused on the identification of genes whose mean expression is different in knockout and wild-type mice. However, recent work suggests that changes in the variability of gene expression can have important phenotypic consequences as well. Here, in an unbiased sample of publicly available microarray data on gene expression in various knockouts, highly significant differences from wild-type (either increases or decreases) are noted in the gene expression coefficients of variation (CVs) of virtually every knockout considered. Examination of the distribution of gene-by-gene CV differences indicates that these findings are not attributable to a few outlier genes, but rather to broadly increased or decreased CV in the various knockouts over all the (tens of thousands of) transcripts assayed. These global differences in variability may reflect either authentic biological effects of the knockouts or merely experimental inconsistencies. However, regardless of the underlying explanation, the variability differences are of importance as they will influence both the statistical detection of gene expression changes and, potentially, the knockout phenotype itself.
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Affiliation(s)
- Satish A. Eraly
- Department of Medicine, University of California San Diego, School of Medicine, La Jolla, California, United States of America
- * E-mail:
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14
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Vapola MH, Rokka A, Sormunen RT, Alhonen L, Schmitz W, Conzelmann E, Wärri A, Grunau S, Antonenkov VD, Hiltunen JK. Peroxisomal membrane channel Pxmp2 in the mammary fat pad is essential for stromal lipid homeostasis and for development of mammary gland epithelium in mice. Dev Biol 2014; 391:66-80. [PMID: 24726525 DOI: 10.1016/j.ydbio.2014.03.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 03/25/2014] [Accepted: 03/26/2014] [Indexed: 12/28/2022]
Abstract
To understand the functional role of the peroxisomal membrane channel Pxmp2, mice with a targeted disruption of the Pxmp2 gene were generated. These mice were viable, grew and bred normally. However, Pxmp2(-/-) female mice were unable to nurse their pups. Lactating mammary gland epithelium displayed secretory lipid droplets and milk proteins, but the size of the ductal system was greatly reduced. Examination of mammary gland development revealed that retarded mammary ductal outgrowth was due to reduced proliferation of epithelial cells during puberty. Transplantation experiments established the Pxmp2(-/-) mammary stroma as a tissue responsible for suppression of epithelial growth. Morphological and biochemical examination confirmed the presence of peroxisomes in the mammary fat pad adipocytes, and functional Pxmp2 was detected in the stroma of wild-type mammary glands. Deletion of Pxmp2 led to an elevation in the expression of peroxisomal proteins in the mammary fat pad but not in liver or kidney of transgenic mice. Lipidomics of Pxmp2(-/-)mammary fat pad showed a decrease in the content of myristic acid (C14), a principal substrate for protein myristoylation and a potential peroxisomal β-oxidation product. Analysis of complex lipids revealed a reduced concentration of a variety of diacylglycerols and phospholipids containing mostly polyunsaturated fatty acids that may be caused by activation of lipid peroxidation. However, an antioxidant-containing diet did not stimulate mammary epithelial proliferation in Pxmp2(-/-) mice. The results point to disturbances of lipid metabolism in the mammary fat pad that in turn may result in abnormal epithelial growth. The work reveals impaired mammary gland development as a new category of peroxisomal disorders.
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Affiliation(s)
- Miia H Vapola
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, P.O Box 3000, FI-90014 Oulu, Finland
| | - Aare Rokka
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, P.O Box 3000, FI-90014 Oulu, Finland
| | - Raija T Sormunen
- Department of Pathology and Biocenter Oulu, University of Oulu, FI-90014 Oulu, Finland
| | - Leena Alhonen
- A.I. Virtanen Institute for Molecular Sciences, University of Kuopio, FI-70211 Kuopio, Finland
| | - Werner Schmitz
- Theodor-Boveri-Institut fȕr Biowissenschaften (Biocentrum) der Universität Wurzburg, D-97074 Wurzburg, Germany
| | - Ernst Conzelmann
- Theodor-Boveri-Institut fȕr Biowissenschaften (Biocentrum) der Universität Wurzburg, D-97074 Wurzburg, Germany
| | - Anni Wärri
- Georgetown University Medical Center, Department of Oncology, Washington, DC 20057, USA
| | - Silke Grunau
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, P.O Box 3000, FI-90014 Oulu, Finland
| | - Vasily D Antonenkov
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, P.O Box 3000, FI-90014 Oulu, Finland.
| | - J Kalervo Hiltunen
- Faculty of Biochemistry and Molecular Medicine and Biocenter Oulu, University of Oulu, P.O Box 3000, FI-90014 Oulu, Finland.
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Cholesterol biosynthesis and ER stress in peroxisome deficiency. Biochimie 2014; 98:75-85. [DOI: 10.1016/j.biochi.2013.10.019] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 10/22/2013] [Indexed: 12/27/2022]
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16
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Disturbances in cholesterol, bile acid and glucose metabolism in peroxisomal 3-ketoacylCoA thiolase B deficient mice fed diets containing high or low fat contents. Biochimie 2013; 98:86-101. [PMID: 24287293 DOI: 10.1016/j.biochi.2013.11.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 11/15/2013] [Indexed: 12/29/2022]
Abstract
The peroxisomal 3-ketoacyl-CoA thiolase B (ThB) catalyzes the thiolytic cleavage of straight chain 3-ketoacyl-CoAs. Up to now, the ability of ThB to interfere with lipid metabolism was studied in mice fed a laboratory chow enriched or not with the synthetic agonist Wy14,643, a pharmacological activator of the nuclear hormone receptor PPARα. The aim of the present study was therefore to determine whether ThB could play a role in obesity and lipid metabolism when mice are chronically fed a synthetic High Fat Diet (HFD) or a Low Fat Diet (LFD) as a control diet. To investigate this possibility, wild-type (WT) mice and mice deficient for Thb (Thb(-/-)) were subjected to either a synthetic LFD or a HFD for 25 weeks, and their responses were compared. First, when fed a normal regulatory laboratory chow, Thb(-/-) mice displayed growth retardation as well as a severe reduction in the plasma level of Growth Hormone (GH) and Insulin Growth Factor-I (IGF-I), suggesting alterations in the GH/IGF-1 pathway. When fed the synthetic diets, the corrected energy intake to body mass was significantly higher in Thb(-/-) mice, yet those mice were protected from HFD-induced adiposity. Importantly, Thb(-/-) mice also suffered from hypoglycemia, exhibited reduction in liver glycogen stores and circulating insulin levels under the LFD and the HFD. Thb deficiency was also associated with higher levels of plasma HDL (High Density Lipoproteins) cholesterol and increased liver content of cholesterol under both the LFD and the HFD. As shown by the plasma lathosterol to cholesterol ratio, a surrogate marker for cholesterol biosynthesis, whole body cholesterol de novo synthesis was increased in Thb(-/-) mice. By comparing liver RNA from WT mice and Thb(-/-) mice using oligonucleotide microarray and RT-qPCR, a coordinated decrease in the expression of critical cholesterol synthesizing genes and an increased expression of genes involved in bile acid synthesis (Cyp7a1, Cyp17a1, Akr1d1) were observed in Thb(-/-) mice. In parallel, the elevation of the lathosterol to cholesterol ratio as well as the increased expression of cholesterol synthesizing genes were observed in the kidney of Thb(-/-) mice fed the LFD and the HFD. Overall, the data indicate that ThB is not fully interchangeable with the thiolase A isoform. The present study also reveals that modulating the expression of the peroxisomal ThB enzyme can largely reverberate not only throughout fatty acid metabolism but also cholesterol, bile acid and glucose metabolism.
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Conservation of lipid metabolic gene transcriptional regulatory networks in fish and mammals. Gene 2013; 534:1-9. [PMID: 24177230 DOI: 10.1016/j.gene.2013.10.040] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 10/01/2013] [Accepted: 10/21/2013] [Indexed: 01/04/2023]
Abstract
Lipid content and composition in aquafeeds have changed rapidly as a result of the recent drive to replace ecologically limited marine ingredients, fishmeal and fish oil (FO). Terrestrial plant products are the most economic and sustainable alternative; however, plant meals and oils are devoid of physiologically important cholesterol and long-chain polyunsaturated fatty acids (LC-PUFA), eicosapentaenoic (EPA), docosahexaenoic (DHA) and arachidonic (ARA) acids. Although replacement of dietary FO with vegetable oil (VO) has little effect on growth in Atlantic salmon (Salmo salar), several studies have shown major effects on the activity and expression of genes involved in lipid homeostasis. In vertebrates, sterols and LC-PUFA play crucial roles in lipid metabolism by direct interaction with lipid-sensing transcription factors (TFs) and consequent regulation of target genes. The primary aim of the present study was to elucidate the role of key TFs in the transcriptional regulation of lipid metabolism in fish by transfection and overexpression of TFs. The results show that the expression of genes of LC-PUFA biosynthesis (elovl and fads2) and cholesterol metabolism (abca1) are regulated by Lxr and Srebp TFs in salmon, indicating highly conserved regulatory mechanism across vertebrates. In addition, srebp1 and srebp2 mRNA respond to replacement of dietary FO with VO. Thus, Atlantic salmon adjust lipid metabolism in response to dietary lipid composition through the transcriptional regulation of gene expression. It may be possible to further increase efficient and effective use of sustainable alternatives to marine products in aquaculture by considering these important molecular interactions when formulating diets.
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Selkälä EM, Kuusisto SM, Salonurmi T, Savolainen MJ, Jauhiainen M, Pirilä PL, Kvist AP, Conzelmann E, Schmitz W, Alexson SE, Kotti TJ, Hiltunen JK, Autio KJ. Metabolic adaptation allows Amacr-deficient mice to remain symptom-free despite low levels of mature bile acids. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1335-43. [DOI: 10.1016/j.bbalip.2013.05.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 04/30/2013] [Accepted: 05/06/2013] [Indexed: 10/26/2022]
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Naville D, Pinteur C, Vega N, Menade Y, Vigier M, Le Bourdais A, Labaronne E, Debard C, Luquain‐Costaz C, Bégeot M, Vidal H, Le Magueresse‐Battistoni B. Low‐dose food contaminants trigger sex‐specific, hepatic metabolic changes in the progeny of obese mice. FASEB J 2013; 27:3860-70. [DOI: 10.1096/fj.13-231670] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Danielle Naville
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
| | - Claudie Pinteur
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
| | - Nathalie Vega
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
| | - Yoan Menade
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
| | - Michèle Vigier
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
| | - Alexandre Le Bourdais
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
| | - Emmanuel Labaronne
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
| | - Cyrille Debard
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
| | - Céline Luquain‐Costaz
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
- Institut National des Sciences Appliquées (INSA)‐LyonInstitut Multidisciplinaire de Biochimie des Lipides (IMBL)VilleurbanneFrance
| | - Martine Bégeot
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
| | - Hubert Vidal
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
- Institut National des Sciences Appliquées (INSA)‐LyonInstitut Multidisciplinaire de Biochimie des Lipides (IMBL)VilleurbanneFrance
| | - Brigitte Le Magueresse‐Battistoni
- Institut National de la Santé et de la Recherche Médicale (INSERM)U1060Cardiovasculaire, Métabolisme, Diabétologie, et Nutrition (CarMeN) LaboratoryOullinsFrance
- Institut National de la Recherche Agronomique (INRA) U1362OullinsFrance
- Université Lyon 1VilleurbanneFrance
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Azimzadeh O, Sievert W, Sarioglu H, Yentrapalli R, Barjaktarovic Z, Sriharshan A, Ueffing M, Janik D, Aichler M, Atkinson MJ, Multhoff G, Tapio S. PPAR alpha: a novel radiation target in locally exposed Mus musculus heart revealed by quantitative proteomics. J Proteome Res 2013; 12:2700-14. [PMID: 23560462 DOI: 10.1021/pr400071g] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Radiation exposure of the thorax is associated with a markedly increased risk of cardiac morbidity and mortality with a latency period of decades. Although many studies have confirmed the damaging effect of ionizing radiation on the myocardium and cardiac endothelial structure and function, the molecular mechanism behind this damage is not yet elucidated. Peroxisome proliferator-activated receptor alpha (PPAR alpha), a transcriptional regulator of lipid metabolism in heart tissue, has recently received great attention in the development of cardiovascular disease. The goal of this study was to investigate radiation-induced cardiac damage in general and the role of PPAR alpha in this process in particular. C57BL/6 mice received local heart irradiation with X-ray doses of 8 and 16 gray (Gy) at the age of 8 weeks. The mice were sacrificed 16 weeks later. Radiation-induced changes in the cardiac proteome were quantified using the Isotope Coded Protein Label (ICPL) method followed by mass spectrometry and software analysis. Significant alterations were observed in proteins involved in lipid metabolism and oxidative phosphorylation. Ionizing radiation markedly changed the phosphorylation and ubiquitination status of PPAR alpha. This was reflected as decreased expression of its target genes involved in energy metabolism and mitochondrial respiratory chain confirming the proteomics data. This study suggests that persistent alteration of cardiac metabolism due to impaired PPAR alpha activity contributes to the heart pathology after radiation.
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Affiliation(s)
- Omid Azimzadeh
- Helmholtz Zentrum München - German Research Center for Environmental Health, Institute of Radiation Biology, Neuherberg, Germany.
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Martens K, Bottelbergs A, Peeters A, Jacobs F, Espeel M, Carmeliet P, Van Veldhoven PP, Baes M. Peroxisome deficient aP2-Pex5 knockout mice display impaired white adipocyte and muscle function concomitant with reduced adrenergic tone. Mol Genet Metab 2012; 107:735-47. [PMID: 23141464 DOI: 10.1016/j.ymgme.2012.10.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 10/16/2012] [Accepted: 10/16/2012] [Indexed: 12/21/2022]
Abstract
Peroxisomes are essential for intermediary lipid metabolism, but the role of these organelles has been primarily studied in the liver. We recently generated aP2-Pex5 conditional knockout mice that due to the nonselectivity of the aP2 promoter, not only had dysfunctional peroxisomes in the adipose tissue but also in the central and peripheral nervous system, besides some other tissues. Peroxisomes were however intact in the liver, heart, pancreas and muscle. Surprisingly, these mice not only showed dysfunctional white adipose tissue with increased fat mass and reduced lipolysis but also the skeletal muscle was affected including impaired shivering thermogenesis, reduced motor performance and increased insulin resistance. Non-shivering thermogenesis by brown adipose tissue was not altered. Strongly reduced levels of plasma adrenaline and to a lesser extent noradrenaline, impaired expression of catecholamine synthesizing enzymes in the adrenal medulla and reversal of all pathologies after administration of the β-agonist isoproterenol indicated that β-adrenergic signaling was reduced. Based on normal white adipose and muscle function in Nestin-Pex5 and Wnt-Pex5 knockout mice respectively, it is unlikely that peroxisome absence from the central and peripheral nervous system caused the phenotype. We conclude that peroxisomal metabolism is necessary to maintain the adrenergic tone in mice, which in turn determines metabolic homeostasis.
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Affiliation(s)
- Katrin Martens
- Laboratory of Cell Metabolism, Department of Pharmaceutical Sciences, KU Leuven, Leuven, Belgium
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Baes M, Van Veldhoven PP. Mouse models for peroxisome biogenesis defects and β-oxidation enzyme deficiencies. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1489-500. [DOI: 10.1016/j.bbadis.2012.03.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Revised: 02/22/2012] [Accepted: 03/06/2012] [Indexed: 12/26/2022]
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Bottelbergs A, Verheijden S, Van Veldhoven PP, Just W, Devos R, Baes M. Peroxisome deficiency but not the defect in ether lipid synthesis causes activation of the innate immune system and axonal loss in the central nervous system. J Neuroinflammation 2012; 9:61. [PMID: 22458306 PMCID: PMC3419640 DOI: 10.1186/1742-2094-9-61] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 03/29/2012] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Mice with peroxisome deficiency in neural cells (Nestin-Pex5-/-) develop a neurodegenerative phenotype leading to motor and cognitive disabilities and early death. Major pathologies at the end stage of disease include severe demyelination, axonal degeneration and neuroinflammation. We now investigated the onset and progression of these pathological processes, and their potential interrelationship. In addition, the putative role of oxidative stress, the impact of plasmalogen depletion on the neurodegenerative phenotype, and the consequences of peroxisome elimination in the postnatal period were studied. METHODS Immunohistochemistry in association with gene expression analysis was performed on Nestin-Pex5-/- mice to document demyelination, axonal damage and neuroinflammation. Also Gnpat-/- mice, with selective plasmalogen deficiency and CMV-Tx-Pex5-/- mice, with tamoxifen induced generalized loss of peroxisomes were analysed. RESULTS Activation of the innate immune system is a very early event in the pathological process in Nestin-Pex5-/- mice which evolves in chronic neuroinflammation. The complement factor C1q, one of the earliest up regulated transcripts, was expressed on neurons and oligodendrocytes but not on microglia. Transcripts of other pro- and anti-inflammatory genes and markers of phagocytotic activity were already significantly induced before detecting pathologies with immunofluorescent staining. Demyelination, macrophage activity and axonal loss co-occurred throughout the brain. As in patients with mild peroxisome biogenesis disorders who develop regressive changes, demyelination in cerebellum and brain stem preceded major myelin loss in corpus callosum of both Nestin-Pex5-/- and CMV-Tx-Pex5-/- mice. These lesions were not accompanied by generalized oxidative stress throughout the brain. Although Gnpat-/- mice displayed dysmyelination and Purkinje cell axon damage in cerebellum, confirming previous observations, no signs of inflammation or demyelination aggravating with age were observed. CONCLUSIONS Peroxisome inactivity triggers a fast neuroinflammatory reaction, which is not solely due to the depletion of plasmalogens. In association with myelin abnormalities this causes axon damage and loss.
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Affiliation(s)
- Astrid Bottelbergs
- Laboratory of Cell Metabolism, Department of Pharmaceutical Sciences, K.U. Leuven, Leuven, Belgium
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24
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Kovacs WJ, Charles KN, Walter KM, Shackelford JE, Wikander TM, Richards MJ, Fliesler SJ, Krisans SK, Faust PL. Peroxisome deficiency-induced ER stress and SREBP-2 pathway activation in the liver of newborn PEX2 knock-out mice. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:895-907. [PMID: 22441164 DOI: 10.1016/j.bbalip.2012.02.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 01/20/2012] [Accepted: 02/29/2012] [Indexed: 12/26/2022]
Abstract
Disruption of the Pex2 gene leads to peroxisome deficiency and widespread metabolic dysfunction. We previously demonstrated that peroxisomes are critical for maintaining cholesterol homeostasis, using peroxisome-deficient Pex2(-/-) mice on a hybrid Swiss Webster×129S6/SvEv (SW/129) genetic background. Peroxisome deficiency activates hepatic endoplasmic reticulum (ER) stress pathways, leading to dysregulation of the endogenous sterol response mechanism. Herein, we demonstrate a more profound dysregulation of cholesterol homeostasis in newborn Pex2(-/-) mice congenic on a 129S6/SvEv (129) genetic background, and substantial differences between newborn versus postnatal Pex2(-/-) mice in factors that activate ER stress. These differences extend to relationships between activation of genes regulated by SREBP-2 versus PPARα. The SREBP-2 pathway is induced in neonatal Pex2(-/-) livers from 129 and SW/129 strains, despite normal hepatic cholesterol levels. ER stress markers are increased in newborn 129 Pex2(-/-) livers, which occurs in the absence of hepatic steatosis or accumulation of peroxins in the ER. Moreover, the induction of SREBP-2 and ER stress pathways is independent of PPARα activation in livers of newborn 129 and SW/129 Pex2(-/-) mice. Two-week-old wild-type mice treated with the peroxisome proliferator WY-14,643 show strong induction of PPARα-regulated genes and decreased expression of SREBP-2 and its target genes, further demonstrating that SREBP-2 pathway induction is not dependent on PPARα activation. Lastly, there is no activation of either SREBP-2 or ER stress pathways in kidney and lung of newborn Pex2(-/-) mice, suggesting a parallel induction of these pathways in peroxisome-deficient mice. These findings establish novel associations between SREBP-2, ER stress and PPARα pathway inductions.
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Affiliation(s)
- Werner J Kovacs
- Institute of Cell Biology, ETH Zuerich, CH-8093 Zuerich, Switzerland.
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De Bruyn T, Fattah S, Stieger B, Augustijns P, Annaert P. Sodium fluorescein is a probe substrate for hepatic drug transport mediated by OATP1B1 and OATP1B3. J Pharm Sci 2011; 100:5018-30. [DOI: 10.1002/jps.22694] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 06/10/2010] [Accepted: 06/14/2011] [Indexed: 01/11/2023]
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Peeters A, Fraisl P, van den Berg S, Ver Loren van Themaat E, Van Kampen A, Rider MH, Takemori H, van Dijk KW, Van Veldhoven PP, Carmeliet P, Baes M. Carbohydrate metabolism is perturbed in peroxisome-deficient hepatocytes due to mitochondrial dysfunction, AMP-activated protein kinase (AMPK) activation, and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) suppression. J Biol Chem 2011; 286:42162-42179. [PMID: 22002056 DOI: 10.1074/jbc.m111.299727] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Hepatic peroxisomes are essential for lipid conversions that include the formation of mature conjugated bile acids, the degradation of branched chain fatty acids, and the synthesis of docosahexaenoic acid. Through unresolved mechanisms, deletion of functional peroxisomes from mouse hepatocytes (L-Pex5(-/-) mice) causes severe structural and functional abnormalities at the inner mitochondrial membrane. We now demonstrate that the peroxisomal and mitochondrial anomalies trigger energy deficits, as shown by increased AMP/ATP and decreased NAD(+)/NADH ratios. This causes suppression of gluconeogenesis and glycogen synthesis and up-regulation of glycolysis. As a consequence, L-Pex5(-/-) mice combust more carbohydrates resulting in lower body weights despite increased food intake. The perturbation of carbohydrate metabolism does not require a long term adaptation to the absence of functional peroxisomes as similar metabolic changes were also rapidly induced by acute elimination of Pex5 via adenoviral administration of Cre. Despite its marked activation, peroxisome proliferator-activated receptor α (PPARα) was not causally involved in these metabolic perturbations, because all abnormalities still manifested when peroxisomes were eliminated in a peroxisome proliferator-activated receptor α null background. Instead, AMP-activated kinase activation was responsible for the down-regulation of glycogen synthesis and induction of glycolysis. Remarkably, PGC-1α was suppressed despite AMP-activated kinase activation, a paradigm not previously reported, and they jointly contributed to impaired gluconeogenesis. In conclusion, lack of functional peroxisomes from hepatocytes results in marked disturbances of carbohydrate homeostasis, which are consistent with adaptations to an energy deficit. Because this is primarily due to impaired mitochondrial ATP production, these L-Pex5-deficient livers can also be considered as a model for secondary mitochondrial hepatopathies.
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Affiliation(s)
- Annelies Peeters
- Laboratory of Cell Metabolism, Department of Pharmaceutical Sciences, University of Leuven, B-3000 Leuven, Belgium
| | - Peter Fraisl
- Laboratory of Angiogenesis and Neurovascular Link, Vesalius Research Center, Flanders Institute of Biotechnology, B-3000 Leuven, Belgium; Department of Human Genetics, Leiden University Medical Center, NL-2333 ZA Leiden, The Netherlands
| | - Sjoerd van den Berg
- Department of Human Genetics, Leiden University Medical Center, NL-2333 ZA Leiden, The Netherlands
| | | | - Antoine Van Kampen
- Laboratory of Bioinformatics, Academic Medical Center, NL-1105 AZ Amsterdam, The Netherlands
| | - Mark H Rider
- Université Catholique de Louvain and de Duve Institute, B-1200 Brussels, Belgium
| | - Hiroshi Takemori
- Laboratory of Cell Signaling and Metabolism, National Institute of Biomedical Innovation, Osaka 567-0085, Japan
| | - Ko Willems van Dijk
- Department of Human Genetics, Leiden University Medical Center, NL-2333 ZA Leiden, The Netherlands
| | - Paul P Van Veldhoven
- Laboratory of Lipid Biochemistry and Protein Interactions, Department of Molecular Cell Biology, University of Leuven, B-3000 Leuven, Belgium
| | - Peter Carmeliet
- Laboratory of Angiogenesis and Neurovascular Link, Vesalius Research Center, University of Leuven, B-3000 Leuven, Belgium; Laboratory of Angiogenesis and Neurovascular Link, Vesalius Research Center, Flanders Institute of Biotechnology, B-3000 Leuven, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical Sciences, University of Leuven, B-3000 Leuven, Belgium.
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Du R, Xue J, Wang HB, Zhang Y, Xie ML. Osthol ameliorates fat milk-induced fatty liver in mice by regulation of hepatic sterol regulatory element-binding protein-1c/2-mediated target gene expression. Eur J Pharmacol 2011; 666:183-8. [DOI: 10.1016/j.ejphar.2011.05.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 04/23/2011] [Accepted: 05/11/2011] [Indexed: 12/19/2022]
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Peeters A, Swinnen JV, Van Veldhoven PP, Baes M. Hepatosteatosis in peroxisome deficient liver despite increased β-oxidation capacity and impaired lipogenesis. Biochimie 2011; 93:1828-38. [PMID: 21756965 DOI: 10.1016/j.biochi.2011.06.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 06/27/2011] [Indexed: 11/26/2022]
Abstract
Peroxisome deficiency in liver causes hepatosteatosis both in patients and in mice. Here, we studied the mechanisms that contribute to this lipid accumulation and to activation of peroxisome proliferator activated receptor α (PPARα) by using liver-specific Pex5(-/-) mice (L-Pex5(-/-) mice). Surprisingly, steatosis was accompanied both by increased mitochondrial β-oxidation capacity, confirming previous observations, and by impaired de novo lipid synthesis mediated by reduced expression of sterol regulatory element binding protein 1c and its targets. As a consequence, when challenged with a high fat diet, L-Pex5(-/-) mice were protected from adiposity. Hepatic fatty acid uptake was strongly increased whereas the expression of apolipoproteins and the lipoprotein assembly factor microsomal triglyceride transfer protein were markedly reduced resulting in reduced secretion of very low density lipoproteins. Most of these changes seemed to be orchestrated by the endogenous activation of PPARα, challenging the assumption that PPARα activation in hepatocytes requires fatty acid synthase dependent de novo fatty acid synthesis. Expression of cholesterol synthesizing enzymes and cholesterol levels were not affected in peroxisome deficient liver. In conclusion, increased fatty acid uptake driven by endogenous PPARα activation and reduced fatty acid secretion cause hepatosteatosis in peroxisome deficient livers.
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Affiliation(s)
- Annelies Peeters
- Laboratory of Cell Metabolism, Department of Pharmaceutical Sciences, K.U.Leuven, B-3000 Leuven, Belgium
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Determination of OATP-, NTCP- and OCT-mediated substrate uptake activities in individual and pooled batches of cryopreserved human hepatocytes. Eur J Pharm Sci 2011; 43:297-307. [DOI: 10.1016/j.ejps.2011.05.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 04/01/2011] [Accepted: 05/07/2011] [Indexed: 01/11/2023]
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Fidaleo M, Arnauld S, Clémencet MC, Chevillard G, Royer MC, De Bruycker M, Wanders RJA, Athias A, Gresti J, Clouet P, Degrace P, Kersten S, Espeel M, Latruffe N, Nicolas-Francès V, Mandard S. A role for the peroxisomal 3-ketoacyl-CoA thiolase B enzyme in the control of PPARα-mediated upregulation of SREBP-2 target genes in the liver. Biochimie 2011; 93:876-91. [PMID: 21352884 DOI: 10.1016/j.biochi.2011.02.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Accepted: 02/11/2011] [Indexed: 11/16/2022]
Abstract
Peroxisomal 3-ketoacyl-CoA thiolase B (Thb) catalyzes the final step in the peroxisomal β-oxidation of straight-chain acyl-CoAs and is under the transcription control of the nuclear hormone receptor PPARα. PPARα binds to and is activated by the synthetic compound Wy14,643 (Wy). Here, we show that the magnitude of Wy-mediated induction of peroxisomal β-oxidation of radiolabeled (1-(14)C) palmitate was significantly reduced in mice deficient for Thb. In contrast, mitochondrial β-oxidation was unaltered in Thb(-/-) mice. Given that Wy-treatment induced Acox1 and MFP-1/-2 activity at a similar level in both genotypes, we concluded that the thiolase step alone was responsible for the reduced peroxisomal β-oxidation of fatty acids. Electron microscopic analysis and cytochemical localization of catalase indicated that peroxisome proliferation in the liver after Wy-treatment was normal in Thb(-/-) mice. Intriguingly, micro-array analysis revealed that mRNA levels of genes encoding cholesterol biosynthesis enzymes were upregulated by Wy in Wild-Type (WT) mice but not in Thb(-/-) mice, which was confirmed at the protein level for the selected genes. The non-induction of genes encoding cholesterol biosynthesis enzymes by Wy in Thb(-/-) mice appeared to be unrelated to defective SREBP-2 or PPARα signaling. No difference was observed in the plasma lathosterol/cholesterol ratio (a marker for de novo cholesterol biosynthesis) between Wy-treated WT and Thb(-/-) mice, suggesting functional compensation. Overall, we conclude that ThA and SCPx/SCP2 thiolases cannot fully compensate for the absence of ThB. In addition, our data indicate that ThB is involved in the regulation of genes encoding cholesterol biosynthesis enzymes in the liver, suggesting that the peroxisome could be a promising candidate for the correction of cholesterol imbalance in dyslipidemia.
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Affiliation(s)
- Marco Fidaleo
- Centre de recherche INSERM U866, Dijon F-21000, France; Université de Bourgogne, Faculté des Sciences Gabriel, Equipe Biochimie Métabolique et Nutritionnelle, Dijon F-21000, France
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Pyper SR, Viswakarma N, Yu S, Reddy JK. PPARalpha: energy combustion, hypolipidemia, inflammation and cancer. NUCLEAR RECEPTOR SIGNALING 2010; 8:e002. [PMID: 20414453 PMCID: PMC2858266 DOI: 10.1621/nrs.08002] [Citation(s) in RCA: 291] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Accepted: 03/04/2010] [Indexed: 12/11/2022]
Abstract
The peroxisome proliferator-activated receptor alpha (PPARalpha, or NR1C1) is a nuclear hormone receptor activated by a structurally diverse array of synthetic chemicals known as peroxisome proliferators. Endogenous activation of PPARalpha in liver has also been observed in certain gene knockout mouse models of lipid metabolism, implying the existence of enzymes that either generate (synthesize) or degrade endogenous PPARalpha agonists. For example, substrates involved in fatty acid oxidation can function as PPARalpha ligands. PPARalpha serves as a xenobiotic and lipid sensor to regulate energy combustion, hepatic steatosis, lipoprotein synthesis, inflammation and liver cancer. Mainly, PPARalpha modulates the activities of all three fatty acid oxidation systems, namely mitochondrial and peroxisomal beta-oxidation and microsomal omega-oxidation, and thus plays a key role in energy expenditure. Sustained activation of PPARalpha by either exogenous or endogenous agonists leads to the development of hepatocellular carcinoma resulting from sustained oxidative and possibly endoplasmic reticulum stress and liver cell proliferation. PPARalpha requires transcription coactivator PPAR-binding protein (PBP)/mediator subunit 1(MED1) for its transcriptional activity.
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Affiliation(s)
| | | | | | - Janardan K. Reddy
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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Benedetti E, Galzio R, Laurenti G, D'Angelo B, Melchiorre E, Cifone M, Fanelli F, Muzi P, Coletti G, Alecci M, Sotgiu A, Cerù M, Cimini A. Lipid Metabolism Impairment in Human Gliomas: Expression of Peroxisomal Proteins in Human Gliomas at Different Grades of Malignancy. Int J Immunopathol Pharmacol 2010; 23:235-46. [DOI: 10.1177/039463201002300121] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Gliomas are histologically graded by cellularity, cytological atypia, necrosis, mitotic figures, and vascular proliferation, features associated with biologically aggressive behaviour. However, abundant evidence suggests the presence of unrecognized, clinically relevant subclasses of the diffuse gliomas, both in respect to their underlying molecular phenotype and their clinical response to therapy. It is well-known that patient prognosis and therapeutic decisions rely on accurate pathological grading. Recently, it was reported that human gliomas accumulate lipid droplets during progression, suggesting a lipid metabolism impairment. Considering the crucial role of peroxisomes in lipid metabolism, in the present work we studied the expression profiles of proteins either exclusively localized to peroxisomes, such as peroxin14 (PEX14), peroxisomal membrane protein 70Kda (PMP70), acyl-CoA oxidase, thiolase, or partially associated to peroxisomes such as Hydroxymethylglutaryl-CoA reductase (HMGCoA-red) and peroxisomal-related proteins, namely PPARa, in human glioma specimens at different grades of malignancy. Moreover, Nile red staining of lipid droplets, thin layer chromatography (TLC) and proton nuclear magnetic resonance spectroscopy (NMR) were carried out in order to correlate the biochemical results with the lipid content of tumor tissues. The results obtained indicate that correlating the malignancy grade with the expression of peroxisomal genes and proteins, may constitute a sensitive tool to highlight possible subtypes not recognized by the classical histological techniques.
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Affiliation(s)
| | - R. Galzio
- Department of Health Sciences, University of L'Aquila
| | | | | | - E. Melchiorre
- Department of Health Sciences, University of L'Aquila
| | - M.G. Cifone
- Department of Health Sciences, University of L'Aquila
| | - F. Fanelli
- Department of Biology, University of Rome3
| | - P. Muzi
- Department of Experimental Medicine, University of L'Aquila
| | - G. Coletti
- San Salvatore Hospital, Division of Anatomopathology, L'Aquila, Italy
| | - M. Alecci
- Department of Health Sciences, University of L'Aquila
| | - A. Sotgiu
- Department of Health Sciences, University of L'Aquila
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Arnauld S, Fidaleo M, Clémencet MC, Chevillard G, Athias A, Gresti J, Wanders RJ, Latruffe N, Nicolas-Francès V, Mandard S. Modulation of the hepatic fatty acid pool in peroxisomal 3-ketoacyl-CoA thiolase B-null mice exposed to the selective PPARalpha agonist Wy14,643. Biochimie 2009; 91:1376-86. [DOI: 10.1016/j.biochi.2009.09.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Accepted: 09/14/2009] [Indexed: 11/16/2022]
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