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Abstract
Spaceflight affects numerous organ systems in the body, leading to metabolic dysfunction that may have long-term consequences. Microgravity-induced alterations in liver metabolism, particularly with respect to lipids, remain largely unexplored. Here we utilize a novel systems biology approach, combining metabolomics and transcriptomics with advanced Raman microscopy, to investigate altered hepatic lipid metabolism in mice following short duration spaceflight. Mice flown aboard Space Transportation System -135, the last Shuttle mission, lose weight but redistribute lipids, particularly to the liver. Intriguingly, spaceflight mice lose retinol from lipid droplets. Both mRNA and metabolite changes suggest the retinol loss is linked to activation of PPARα-mediated pathways and potentially to hepatic stellate cell activation, both of which may be coincident with increased bile acids and early signs of liver injury. Although the 13-day flight duration is too short for frank fibrosis to develop, the retinol loss plus changes in markers of extracellular matrix remodeling raise the concern that longer duration exposure to the space environment may result in progressive liver damage, increasing the risk for nonalcoholic fatty liver disease.
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Long-chain acylcarnitines determine ischaemia/reperfusion-induced damage in heart mitochondria. Biochem J 2016; 473:1191-202. [PMID: 26936967 DOI: 10.1042/bcj20160164] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 03/02/2016] [Indexed: 11/17/2022]
Abstract
The accumulation of long-chain fatty acids (FAs) and their CoA and carnitine esters is observed in the ischaemic myocardium after acute ischaemia/reperfusion. The aim of the present study was to identify harmful FA intermediates and their detrimental mechanisms of action in mitochondria and the ischaemic myocardium. In the present study, we found that the long-chain acyl-CoA and acylcarnitine content is increased in mitochondria isolated from an ischaemic area of the myocardium. In analysing the FA derivative content, we discovered that long-chain acylcarnitines, but not acyl-CoAs, accumulate at concentrations that are harmful to mitochondria. Acylcarnitine accumulation in the mitochondrial intermembrane space is a result of increased carnitine palmitoyltransferase 1 (CPT1) and decreased carnitine palmitoyltransferase 2 (CPT2) activity in ischaemic myocardium and it leads to inhibition of oxidative phosphorylation, which in turn induces mitochondrial membrane hyperpolarization and stimulates the production of reactive oxygen species (ROS) in cardiac mitochondria. Thanks to protection mediated by acyl-CoA-binding protein (ACBP), the heart is much better guarded against the damaging effects of acyl-CoAs than against acylcarnitines. Supplementation of perfusion buffer with palmitoylcarnitine (PC) before occlusion resulted in a 2-fold increase in the acylcarnitine content of the heart and increased the infarct size (IS) by 33%. A pharmacologically induced decrease in the mitochondrial acylcarnitine content reduced the IS by 44%. Long-chain acylcarnitines are harmful FA intermediates, accumulating in ischaemic heart mitochondria and inducing inhibition of oxidative phosphorylation. Therefore, decreasing the acylcarnitine content via cardioprotective drugs may represent a novel treatment strategy.
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Ritchie MK, Johnson LC, Clodfelter JE, Pemble CW, Fulp BE, Furdui CM, Kridel SJ, Lowther WT. Crystal Structure and Substrate Specificity of Human Thioesterase 2: INSIGHTS INTO THE MOLECULAR BASIS FOR THE MODULATION OF FATTY ACID SYNTHASE. J Biol Chem 2015; 291:3520-30. [PMID: 26663084 DOI: 10.1074/jbc.m115.702597] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Indexed: 01/12/2023] Open
Abstract
The type I fatty acid synthase (FASN) is responsible for the de novo synthesis of palmitate. Chain length selection and release is performed by the C-terminal thioesterase domain (TE1). FASN expression is up-regulated in cancer, and its activity levels are controlled by gene dosage and transcriptional and post-translational mechanisms. In addition, the chain length of fatty acids produced by FASN is controlled by a type II thioesterase called TE2 (E.C. 3.1.2.14). TE2 has been implicated in breast cancer and generates a broad lipid distribution within milk. The molecular basis for the ability of the TE2 to compete with TE1 for the acyl chain attached to the acyl carrier protein (ACP) domain of FASN is unknown. Herein, we show that human TE1 efficiently hydrolyzes acyl-CoA substrate mimetics. In contrast, TE2 prefers an engineered human acyl-ACP substrate and readily releases short chain fatty acids from full-length FASN during turnover. The 2.8 Å crystal structure of TE2 reveals a novel capping domain insert within the α/β hydrolase core. This domain is reminiscent of capping domains of type II thioesterases involved in polyketide synthesis. The structure also reveals that the capping domain had collapsed onto the active site containing the Ser-101-His-237-Asp-212 catalytic triad. This observation suggests that the capping domain opens to enable the ACP domain to dock and to place the acyl chain and 4'-phosphopantetheinyl-linker arm correctly for catalysis. Thus, the ability of TE2 to prematurely release fatty acids from FASN parallels the role of editing thioesterases involved in polyketide and non-ribosomal peptide synthase synthases.
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Affiliation(s)
- Melissa K Ritchie
- From the Center for Structural Biology and Department of Biochemistry
| | | | - Jill E Clodfelter
- From the Center for Structural Biology and Department of Biochemistry
| | - Charles W Pemble
- From the Center for Structural Biology and Department of Biochemistry
| | - Brian E Fulp
- Comprehensive Cancer Center of Wake Forest Baptist Medical Center, Winston-Salem, North Carolina 27157
| | - Cristina M Furdui
- Comprehensive Cancer Center of Wake Forest Baptist Medical Center, Winston-Salem, North Carolina 27157 Department of Internal Medicine, Section on Molecular Medicine, and
| | - Steven J Kridel
- Comprehensive Cancer Center of Wake Forest Baptist Medical Center, Winston-Salem, North Carolina 27157 Department of Cancer Biology, Wake Forest School of Medicine and
| | - W Todd Lowther
- From the Center for Structural Biology and Department of Biochemistry, Comprehensive Cancer Center of Wake Forest Baptist Medical Center, Winston-Salem, North Carolina 27157
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Farr RL, Lismont C, Terlecky SR, Fransen M. Peroxisome biogenesis in mammalian cells: The impact of genes and environment. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:1049-60. [PMID: 26305119 DOI: 10.1016/j.bbamcr.2015.08.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 08/13/2015] [Accepted: 08/18/2015] [Indexed: 01/16/2023]
Abstract
The initiation and progression of many human diseases are mediated by a complex interplay of genetic, epigenetic, and environmental factors. As all diseases begin with an imbalance at the cellular level, it is essential to understand how various types of molecular aberrations, metabolic changes, and environmental stressors function as switching points in essential communication networks. In recent years, peroxisomes have emerged as important intracellular hubs for redox-, lipid-, inflammatory-, and nucleic acid-mediated signaling pathways. In this review, we focus on how nature and nurture modulate peroxisome biogenesis and function in mammalian cells. First, we review emerging evidence that changes in peroxisome activity can be linked to the epigenetic regulation of cell function. Next, we outline how defects in peroxisome biogenesis may directly impact cellular pathways involved in the development of disease. In addition, we discuss how changes in the cellular microenvironment can modulate peroxisome biogenesis and function. Finally, given the importance of peroxisome function in multiple aspects of health, disease, and aging, we highlight the need for more research in this still understudied field.
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Affiliation(s)
- Rebecca L Farr
- Laboratory of Lipid Biochemistry and Protein Interactions, Department of Cellular and Molecular Medicine, KU Leuven-University of Leuven, Herestraat 49 box 601, B-3000 Leuven, Belgium; Department of Pharmacology, Wayne State University School of Medicine, 540 E. Canfield Ave., Detroit, MI 48201, USA
| | - Celien Lismont
- Laboratory of Lipid Biochemistry and Protein Interactions, Department of Cellular and Molecular Medicine, KU Leuven-University of Leuven, Herestraat 49 box 601, B-3000 Leuven, Belgium
| | - Stanley R Terlecky
- Department of Pharmacology, Wayne State University School of Medicine, 540 E. Canfield Ave., Detroit, MI 48201, USA
| | - Marc Fransen
- Laboratory of Lipid Biochemistry and Protein Interactions, Department of Cellular and Molecular Medicine, KU Leuven-University of Leuven, Herestraat 49 box 601, B-3000 Leuven, Belgium.
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Stuecker TN, Bramhacharya S, Hodge-Hanson KM, Suen G, Escalante-Semerena JC. Phylogenetic and amino acid conservation analyses of bacterial L-aspartate-α-decarboxylase and of its zymogen-maturation protein reveal a putative interaction domain. BMC Res Notes 2015; 8:354. [PMID: 26276430 PMCID: PMC4537548 DOI: 10.1186/s13104-015-1314-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 08/03/2015] [Indexed: 11/16/2022] Open
Abstract
Background All organisms must synthesize the enzymatic cofactor coenzyme A (CoA) from the precursor pantothenate. Most bacteria can synthesize pantothenate de novo by the condensation of pantoate and β-alanine. The synthesis of β-alanine is catalyzed by l-aspartate-α-decarboxylase (PanD), a pyruvoyl enzyme that is initially synthesized as a zymogen (pro-PanD). Active PanD is generated by self-cleavage of pro-PanD at Gly24-Ser25 creating the active-site pyruvoyl moiety. In Salmonella enterica, this cleavage requires PanM, an acetyl-CoA sensor related to the Gcn5-like N-acetyltransferases. PanM does not acetylate pro-PanD, but the recent publication of the three-dimensional crystal structure of the PanM homologue PanZ in complex with the PanD zymogen of Escherichia coli provides validation to our predictions and provides a framework in which to further examine the cleavage mechanism. In contrast, PanD from bacteria lacking PanM efficiently cleaved in the absence of PanM in vivo. Results Using phylogenetic analyses combined with in vivo phenotypic investigations, we showed that two classes of bacterial l-aspartate-α-decarboxylases exist. This classification is based on their posttranslational activation by self-cleavage of its zymogen. Class I l-aspartate-α-decarboxylase zymogens require the acetyl-CoA sensor PanM to be cleaved into active PanD. This class is found exclusively in the Gammaproteobacteria. Class II l-aspartate-α-decarboxylase zymogens self cleave efficiently in the absence of PanM, and are found in a wide number of bacterial phyla. Several members of the Euryarchaeota and Crenarchaeota also contain Class II l-aspartate-α-decarboxylases. Phylogenetic and amino acid conservation analyses of PanM revealed a conserved region of PanM distinct from conserved regions found in related Gcn5-related acetyltransferase enzymes (Pfam00583). This conserved region represents a putative domain for interactions with l-aspartate-α-decarboxylase zymogens. This work may inform future biochemical and structural studies of pro-PanD-PanM interactions. Conclusions Experimental results indicate that S. enterica and C. glutamicuml-aspartate-α-decarboxylases represent two different classes of homologues of these enzymes. Class I homologues require PanM for activation, while Class II self cleave in the absence of PanM. Computer modeling of conserved amino acids using structure coordinates of PanM and l-aspartate-α-decarboxylase available in the protein data bank (RCSB PDB) revealed a putative site of interactions, which may help generate models to help understand the molecular details of the self-cleavage mechanism of l-aspartate-α-decarboxylases. Electronic supplementary material The online version of this article (doi:10.1186/s13104-015-1314-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tara N Stuecker
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA. .,Department of Biological Sciences, University of Arkansas, 850 W. Dickson St., SCEN 601, Fayettevile, AR, 72701, USA.
| | - Shanti Bramhacharya
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA. .,Microsoft Corporation, 7000 State Highway 161, Irving, TX, 75039, USA.
| | - Kelsey M Hodge-Hanson
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA. .,Department of Microbiology, University of Georgia, Biological Sciences Building, 120 Cedar Street, Athens, GA, 30602, USA.
| | - Garret Suen
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Jorge C Escalante-Semerena
- Department of Microbiology, University of Georgia, 212C, Biological Sciences Building, 120 Cedar Street, Athens, GA, 30602, USA.
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Schrader M, Costello J, Godinho LF, Islinger M. Peroxisome-mitochondria interplay and disease. J Inherit Metab Dis 2015; 38:681-702. [PMID: 25687155 DOI: 10.1007/s10545-015-9819-7] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 01/21/2015] [Accepted: 01/26/2015] [Indexed: 12/16/2022]
Abstract
Peroxisomes and mitochondria are ubiquitous, highly dynamic organelles with an oxidative type of metabolism in eukaryotic cells. Over the years, substantial evidence has been provided that peroxisomes and mitochondria exhibit a close functional interplay which impacts on human health and development. The so-called "peroxisome-mitochondria connection" includes metabolic cooperation in the degradation of fatty acids, a redox-sensitive relationship, an overlap in key components of the membrane fission machineries and cooperation in anti-viral signalling and defence. Furthermore, combined peroxisome-mitochondria disorders with defects in organelle division have been revealed. In this review, we present the latest progress in the emerging field of peroxisomal and mitochondrial interplay in mammals with a particular emphasis on cooperative fatty acid β-oxidation, redox interplay, organelle dynamics, cooperation in anti-viral signalling and the resulting implications for disease.
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Affiliation(s)
- Michael Schrader
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK,
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Jin Z, Bian F, Tomcik K, Kelleher JK, Zhang GF, Brunengraber H. Compartmentation of Metabolism of the C12-, C9-, and C5-n-dicarboxylates in Rat Liver, Investigated by Mass Isotopomer Analysis: ANAPLEROSIS FROM DODECANEDIOATE. J Biol Chem 2015; 290:18671-7. [PMID: 26070565 DOI: 10.1074/jbc.m115.651737] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Indexed: 12/14/2022] Open
Abstract
We investigated the compartmentation of the catabolism of dodecanedioate (DODA), azelate, and glutarate in perfused rat livers, using a combination of metabolomics and mass isotopomer analyses. Livers were perfused with recirculating or nonrecirculating buffer containing one fully (13)C-labeled dicarboxylate. Information on the peroxisomal versus mitochondrial catabolism was gathered from the labeling patterns of acetyl-CoA proxies, i.e. total acetyl-CoA, the acetyl moiety of citrate, C-1 + 2 of β-hydroxybutyrate, malonyl-CoA, and acetylcarnitine. Additional information was obtained from the labeling patterns of citric acid cycle intermediates and related compounds. The data characterize the partial oxidation of DODA and azelate in peroxisomes, with terminal oxidation in mitochondria. We did not find evidence of peroxisomal oxidation of glutarate. Unexpectedly, DODA contributes a substantial fraction to anaplerosis of the citric acid cycle. This opens the possibility to use water-soluble DODA in nutritional or pharmacological anaplerotic therapy when other anaplerotic substrates are impractical or contraindicated, e.g. in propionic acidemia and methylmalonic acidemia.
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Affiliation(s)
- Zhicheng Jin
- From the Department of Nutrition, Case Western Reserve University, Cleveland, Ohio 44106 and
| | - Fang Bian
- From the Department of Nutrition, Case Western Reserve University, Cleveland, Ohio 44106 and
| | - Kristyen Tomcik
- From the Department of Nutrition, Case Western Reserve University, Cleveland, Ohio 44106 and
| | - Joanne K Kelleher
- the Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Guo-Fang Zhang
- From the Department of Nutrition, Case Western Reserve University, Cleveland, Ohio 44106 and
| | - Henri Brunengraber
- From the Department of Nutrition, Case Western Reserve University, Cleveland, Ohio 44106 and
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Raza-Iqbal S, Tanaka T, Anai M, Inagaki T, Matsumura Y, Ikeda K, Taguchi A, Gonzalez FJ, Sakai J, Kodama T. Transcriptome Analysis of K-877 (a Novel Selective PPARα Modulator (SPPARMα))-Regulated Genes in Primary Human Hepatocytes and the Mouse Liver. J Atheroscler Thromb 2015; 22:754-72. [PMID: 26040752 DOI: 10.5551/jat.28720] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
AIM Selective PPARα modulators (SPPARMα) are under development for use as next-generation lipid lowering drugs. In the current study, to predict the pharmacological and toxicological effects of a novel SPPARMα K-877, comprehensive transcriptome analyses of K-877-treated primary human hepatocytes and mouse liver tissue were carried out. METHODS Total RNA was extracted from the K-877 treated primary human hepatocytes and mouse liver and adopted to the transcriptome analysis. Using a cluster analysis, commonly and species specifically regulated genes were identified. Also, the profile of genes regulated by K-877 and fenofibrate were compared to examine the influence of different SPPARMα on the liver gene expression. RESULTS Consequently, a cell-based transactivation assay showed that K-877 activates PPARα with much greater potency and selectivity than fenofibric acid, the active metabolite of clinically used fenofibrate. K-877 upregulates the expression of several fatty acid β-oxidative genes in human hepatocytes and the mouse liver. Almost all genes up- or downregulated by K-877 treatment in the mouse liver were also regulated by fenofibrate treatment. In contrast, the K-877-regulated genes in the mouse liver were not affected by K-877 treatment in the Ppara-null mouse liver. Depending on the species, the peroxisomal biogenesis-related gene expression was robustly induced in the K-877-treated mouse liver, but not human hepatocytes, thus suggesting that the clinical dose of K-877 may not induce peroxisome proliferation or liver toxicity in humans. Notably, K-877 significantly induces the expression of clinically beneficial target genes (VLDLR, FGF21, ABCA1, MBL2, ENPEP) in human hepatocytes. CONCLUSION These results indicate that changes in the gene expression induced by K-877 treatment are mainly mediated through PPARα activation. K-877 regulates the hepatic gene expression as a SPPARMα and thus may improve dyslipidemia as well as metabolic disorders, such as metabolic syndrome and type 2 diabetes, without untoward side effects.
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Affiliation(s)
- Sana Raza-Iqbal
- Laboratory for Systems Biology and Medicine (LSBM), Research Center for Advanced Science and Technology (RCAST), University of Tokyo
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Coenzyme A and its derivatives: renaissance of a textbook classic. Biochem Soc Trans 2015; 42:1025-32. [PMID: 25109997 DOI: 10.1042/bst20140176] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In 1945, Fritz Lipmann discovered a heat-stable cofactor required for many enzyme-catalysed acetylation reactions. He later determined the structure for this acetylation coenzyme, or coenzyme A (CoA), an achievement for which he was awarded the Nobel Prize in 1953. CoA is now firmly embedded in the literature, and in students' minds, as an acyl carrier in metabolic reactions. However, recent research has revealed diverse and important roles for CoA above and beyond intermediary metabolism. As well as participating in direct post-translational regulation of metabolic pathways by protein acetylation, CoA modulates the epigenome via acetylation of histones. The organization of CoA biosynthetic enzymes into multiprotein complexes with different partners also points to close linkages between the CoA pool and multiple signalling pathways. Dysregulation of CoA biosynthesis or CoA thioester homoeostasis is associated with various human pathologies and, although the biochemistry of CoA biosynthesis is highly conserved, there are significant sequence and structural differences between microbial and human biosynthetic enzymes. Therefore the CoA biosynthetic pathway is an attractive target for drug discovery. The purpose of the Coenzyme A and Its Derivatives in Cellular Metabolism and Disease Biochemical Society Focused Meeting was to bring together researchers from around the world to discuss the most recent advances on the influence of CoA, its biosynthetic enzymes and its thioesters in cellular metabolism and diseases and to discuss challenges and opportunities for the future.
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Neess D, Bek S, Engelsby H, Gallego SF, Færgeman NJ. Long-chain acyl-CoA esters in metabolism and signaling: Role of acyl-CoA binding proteins. Prog Lipid Res 2015; 59:1-25. [PMID: 25898985 DOI: 10.1016/j.plipres.2015.04.001] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 03/11/2015] [Accepted: 04/09/2015] [Indexed: 02/03/2023]
Abstract
Long-chain fatty acyl-CoA esters are key intermediates in numerous lipid metabolic pathways, and recognized as important cellular signaling molecules. The intracellular flux and regulatory properties of acyl-CoA esters have been proposed to be coordinated by acyl-CoA-binding domain containing proteins (ACBDs). The ACBDs, which comprise a highly conserved multigene family of intracellular lipid-binding proteins, are found in all eukaryotes and ubiquitously expressed in all metazoan tissues, with distinct expression patterns for individual ACBDs. The ACBDs are involved in numerous intracellular processes including fatty acid-, glycerolipid- and glycerophospholipid biosynthesis, β-oxidation, cellular differentiation and proliferation as well as in the regulation of numerous enzyme activities. Little is known about the specific roles of the ACBDs in the regulation of these processes, however, recent studies have gained further insights into their in vivo functions and provided further evidence for ACBD-specific functions in cellular signaling and lipid metabolic pathways. This review summarizes the structural and functional properties of the various ACBDs, with special emphasis on the function of ACBD1, commonly known as ACBP.
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Affiliation(s)
- Ditte Neess
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Signe Bek
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Hanne Engelsby
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Sandra F Gallego
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Nils J Færgeman
- Villum Center for Bioanalytical Sciences, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark.
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Valença I, Pértega-Gomes N, Vizcaino JR, Henrique RM, Lopes C, Baltazar F, Ribeiro D. Localization of MCT2 at peroxisomes is associated with malignant transformation in prostate cancer. J Cell Mol Med 2015; 19:723-33. [PMID: 25639644 PMCID: PMC4395187 DOI: 10.1111/jcmm.12481] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 10/06/2014] [Indexed: 12/14/2022] Open
Abstract
Previous studies on monocarboxylate transporters expression in prostate cancer (PCa) have shown that monocarboxylate transporter 2 (MCT2) was clearly overexpressed in prostate malignant glands, pointing it out as a putative biomarker for PCa. However, its localization and possible role in PCa cells remained unclear. In this study, we demonstrate that MCT2 localizes mainly at peroxisomes in PCa cells and is able to take advantage of the peroxisomal transport machinery by interacting with Pex19. We have also shown an increase in MCT2 expression from non-malignant to malignant cells that was directly correlated with its peroxisomal localization. Upon analysis of the expression of several peroxisomal β-oxidation proteins in PIN lesions and PCa cells from a large variety of human prostate samples, we suggest that MCT2 presence at peroxisomes is related to an increase in β -oxidation levels which may be crucial for malignant transformation. Our results present novel evidence that may not only contribute to the study of PCa development mechanisms but also pinpoint novel targets for cancer therapy.
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Affiliation(s)
- Isabel Valença
- Centre for Cell Biology and Department of Biology, University of Aveiro, Aveiro, Portugal
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Leclerc D, Dejgaard K, Mazur A, Deng L, Wu Q, Nilsson T, Rozen R. Quantitative proteomics reveals differentially expressed proteins in murine preneoplastic intestine in a model of intestinal tumorigenesis induced by low dietary folate and MTHFR deficiency. Proteomics 2014; 14:2558-65. [PMID: 25081070 DOI: 10.1002/pmic.201400280] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 07/14/2014] [Accepted: 07/29/2014] [Indexed: 12/19/2022]
Abstract
Colorectal cancer risk is increased when dietary folate intake is low, with or without a deficiency in methylenetetrahydrofolate reductase (MTHFR). We have observed that intestinal tumors are induced in mice fed low-folate diets, and that tumor incidence is increased when these mice also have MTHFR deficiency. This study was undertaken to identify differentially expressed proteins in conditions favoring initial steps of murine carcinogenesis in normal preneoplastic intestine. We compared the proteome of BALB/c normal intestine in Mthfr(+/+) mice fed control diets for 1 year (low susceptibility to tumorigenesis) with the proteome of Mthfr(+/-) animals fed low folate diets (higher tumor susceptibility). Our data suggest that the NuRD complex, KRAS-related proteins, the protein synthetic machinery, and fatty acid-related metabolic proteins are upregulated in the early stages of tumorigenesis. These proteins may serve as biomarkers or targets for colorectal cancer diagnosis or therapy.
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Affiliation(s)
- Daniel Leclerc
- Department of Human Genetics, Montreal Children's Hospital, The Research Institute of the McGill University Health Centre, McGill University, Montreal, Canada; Department of Pediatrics, Montreal Children's Hospital, The Research Institute of the McGill University Health Centre, McGill University, Montreal, Canada
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Snyder NW, Basu SS, Zhou Z, Worth AJ, Blair IA. Stable isotope dilution liquid chromatography/mass spectrometry analysis of cellular and tissue medium- and long-chain acyl-coenzyme A thioesters. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:1840-1848. [PMID: 25559454 PMCID: PMC4286313 DOI: 10.1002/rcm.6958] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 05/28/2014] [Accepted: 06/02/2014] [Indexed: 06/04/2023]
Abstract
RATIONALE Acyl-Coenzyme A (CoA) thioesters are the principal form of activated carboxylates in cells and tissues. They are employed as acyl carriers that facilitate the transfer of acyl groups to lipids and proteins. Quantification of medium- and long-chain acyl-CoAs represents a significant bioanalytical challenge because of their instability. METHODS Stable isotope dilution liquid chromatography/selected reaction monitoring-mass spectrometry (LC/SRM-MS) provides the most specific and sensitive method for the analysis of CoA species. However, relevant heavy isotope standards are not available and they are challenging to prepare by chemical synthesis. Stable isotope labeling by essential nutrients in cell culture (SILEC), developed originally for the preparation of stable isotope labeled short-chain acyl-CoA thioester standards, has now been extended to medium-chain and long-chain acyl-CoAs and used for LC/SRM-MS analyses. RESULTS Customized SILEC standards with >98% isotopic purity were prepared using mouse Hepa 1c1c7 cells cultured in pantothenic-free media fortified with [(13) C3 (15) N1 ]-pantothenic acid and selected fatty acids. A SILEC standard in combination with LC/SRM-MS was employed to quantify cellular concentrations of arachidonoyl-CoA (a representative long-chain acyl-CoA) in two human colon cancer cell lines. A panel of SILEC standards was also employed in combination LC/SRM-MS to quantify medium- and long-chain acyl-CoAs in mouse liver. CONCLUSIONS This new SILEC-based method in combination with LC/SRM-MS will make it possible to rigorously quantify medium- and long-chain acyl-CoAs in cells and tissues. The method will facilitate studies of medium- and long-chain acyl-CoA dehydrogenase deficiencies as well as studies on the role of medium- and long-chain acyl-CoAs in cellular metabolism.
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Affiliation(s)
| | | | | | | | - Ian A. Blair
- Correspondence to Ian A. Blair, PhD, Center for Cancer Pharmacology, 854 BRB II/III, 421 Curie Blvd, University of Pennsylvania, Philadelphia PA 19104-6160, USA. Phone: 215-573-9880, Fax: 215-573-9889,
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Meng W, Hsiao AS, Gao C, Jiang L, Chye ML. Subcellular localization of rice acyl-CoA-binding proteins (ACBPs) indicates that OsACBP6::GFP is targeted to the peroxisomes. THE NEW PHYTOLOGIST 2014; 203:469-482. [PMID: 24738983 DOI: 10.1111/nph.12809] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 03/12/2014] [Indexed: 05/08/2023]
Abstract
Acyl-CoA-binding proteins (ACBPs) show conservation at the acyl-CoA-binding (ACB) domain which facilitates binding to acyl-CoA esters. In Arabidopsis thaliana, six ACBPs participate in development and stress responses. Rice (Oryza sativa) also contains six genes encoding ACBPs. We investigated differences in subcellular localization between monocot rice and eudicot A. thaliana ACBPs. The subcellular localization of the six OsACBPs was achieved via transient expression of green fluorescence protein (GFP) fusions in tobacco (Nicotiana tabacum) epidermal cells, and stable transformation of A. thaliana. As plant ACBPs had not been reported in the peroxisomes, OsACBP6::GFP localization was confirmed by transient expression in rice sheath cells. The function of OsACBP6 was investigated by overexpressing 35S::OsACBP6 in the peroxisomal abc transporter1 (pxa1) mutant defective in peroxisomal fatty acid β-oxidation. As predicted, OsACBP1::GFP and OsACBP2::GFP were localized to the cytosol, and OsACBP4::GFP and OsACBP5::GFP to the endoplasmic reticulum (ER). However, OsACBP3::GFP displayed subcellular multi-localization while OsACBP6::GFP was localized to the peroxisomes. 35S::OsACBP6-OE/pxa1 lines showed recovery in indole-3-butyric acid (IBA) peroxisomal β-oxidation, wound-induced VEGETATIVE STORAGE PROTEIN1 (VSP1) expression and jasmonic acid (JA) accumulation. These findings indicate a role for OsACBP6 in peroxisomal β-oxidation, and suggest that rice ACBPs are involved in lipid degradation in addition to lipid biosynthesis.
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Affiliation(s)
- Wei Meng
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China
- College of Life Science, Northeast Forestry University, Harbin, China
| | - An-Shan Hsiao
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Caiji Gao
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Liwen Jiang
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Mee-Len Chye
- School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China
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