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Kocherlakota S, Swinkels D, Van Veldhoven PP, Baes M. Mouse Models to Study Peroxisomal Functions and Disorders: Overview, Caveats, and Recommendations. Methods Mol Biol 2023; 2643:469-500. [PMID: 36952207 DOI: 10.1007/978-1-0716-3048-8_34] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
During the last three decades many mouse lines were created or identified that are deficient in one or more peroxisomal functions. Different methodologies were applied to obtain global, hypomorph, cell type selective, inducible, and knockin mice. Whereas some models closely mimic pathologies in patients, others strongly deviate or no human counterpart has been reported. Often, mice, apparently endowed with a stronger transcriptional adaptation, have to be challenged with dietary additions or restrictions in order to trigger phenotypic changes. Depending on the inactivated peroxisomal protein, several approaches can be taken to validate the loss-of-function. Here, an overview is given of the available mouse models and their most important characteristics.
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Affiliation(s)
- Sai Kocherlakota
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Daniëlle Swinkels
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Paul P Van Veldhoven
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium.
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2
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Enoyl-CoA hydratase/3-hydroxyacyl CoA dehydrogenase is essential for the production of DHA in zebrafish. J Lipid Res 2022; 64:100326. [PMID: 36592657 PMCID: PMC9974443 DOI: 10.1016/j.jlr.2022.100326] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 12/01/2022] [Accepted: 12/12/2022] [Indexed: 01/01/2023] Open
Abstract
Compared with other species, freshwater fish are more capable of synthesizing DHA via same biosynthetic pathways. Freshwater fish have a "Sprecher" pathway to biosynthesize DHA in a peroxisome-dependent manner. Enoyl-CoA hydratase/3-hydroxyacyl CoA dehydrogenase (Ehhadh) is involved in the hydration and dehydrogenation reactions of fatty acid β-oxidation in peroxisomes. However, the role of Ehhadh in the synthesis of DHA in freshwater fish remains largely unclear. In this study, the knockout of Ehhadh significantly inhibited DHA synthesis in zebrafish. Liver transcriptome analysis showed that Ehhadh deletion significantly inhibited SREBF and PPAR signaling pathways and decreased the expression of PUFA synthesis-related genes. Our results from the analysis of transgenic zebrafish (Tg:Ehhadh) showed that Ehhadh overexpression significantly increased the DHA content in the liver and significantly upregulated the expression of genes related to PUFA synthesis. In addition, the DHA content in the liver of Tg:Ehhadh fed with linseed oil was significantly higher than that of wildtype, but the expression of PUFA synthesis-related genes fads2 and elovl2 were significantly lower, indicating that Ehhadh had a direct effect on DHA synthesis. In conclusion, our results showed that Ehhadh was essential for DHA synthesis in the "Sprecher" pathway, and Ehhadh overexpression could promote DHA synthesis. This study provides insight into the role of Ehhadh in freshwater fish.
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3
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Zhang Y, Chen Y, Zhang Z, Tao X, Xu S, Zhang X, Zurashvili T, Lu Z, Bayascas JR, Jin L, Zhao J, Zhou X. Acox2 is a regulator of lysine crotonylation that mediates hepatic metabolic homeostasis in mice. Cell Death Dis 2022; 13:279. [PMID: 35351852 PMCID: PMC8964741 DOI: 10.1038/s41419-022-04725-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/22/2022] [Accepted: 03/11/2022] [Indexed: 11/13/2022]
Abstract
Acyl-CoA oxidase 2 (Acox2) is an enzyme involved in peroxisomal bile acid synthesis and branched-chain fatty acid degradation. Acox2 knockout (−/−) mice spontaneously developed liver cancer with marked lymphocytic infiltrate. Tandem-affinity purification coupled with mass spectrometry analysis revealed that Acox2 interacted with methylcrotonoyl-CoA carboxylase followed by co-immunoprecipitation confirmation. Here we reported that non-histone lysine crotonylation (Kcr) levels were downregulated in Acox2−/− mice livers. Interestingly, Kcr signals were concentrated in the nucleus of tumor cells but mostly located in the cytoplasm of adjacent normal liver cells of Acox2−/− mice. Quantitative analysis of the global crotonylome further revealed that 54% (27/50) of downregulated non-histone Kcr sites were located in mitochondrial (11/50) and peroxisomal (17/50) enzymes including Ehhadh, Scp2, Hsd17b4, Crot, Etfa, Cpt1a, Eci1/2, Hadha, Etfdh, and Idh2. Subsequent site-directed mutagenesis and transcriptome analysis revealed that Ehhadh K572cr might have site-specific regulatory roles by downregulating TOP3B expression that lead to increased DNA damage in vitro. Our findings suggested Acox2 is a regulator of Kcr that might play critical role on hepatic metabolic homeostasis.
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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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Dalwani S, Lampela O, Leprovost P, Schmitz W, Juffer A, Wierenga RK, Venkatesan R. Substrate specificity and conformational flexibility properties of the Mycobacterium tuberculosis β-oxidation trifunctional enzyme. J Struct Biol 2021; 213:107776. [PMID: 34371166 DOI: 10.1016/j.jsb.2021.107776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/30/2021] [Accepted: 08/04/2021] [Indexed: 10/20/2022]
Abstract
The Mycobacterium tuberculosis trifunctional enzyme (MtTFE) is an α2β2 tetrameric enzyme. The α -chain harbors the 2E-enoyl-CoA hydratase (ECH) and 3S-hydroxyacyl-CoA dehydrogenase (HAD) activities and the β -chain provides the 3-ketoacyl-CoA thiolase (KAT) activity. Enzyme kinetic data reported here show that medium and long chain enoyl-CoA molecules are preferred substrates for MtTFE. Modelling studies indicate how the linear medium and long chain acyl chains of these substrates can bind to each of the active sites. In addition, crystallographic binding studies have identified three new CoA binding sites which are different from the previously known CoA binding sites of the three TFE active sites. Structure comparisons provide new insights into the properties of ECH, HAD and KAT active sites of MtTFE. The interactions of the adenine moiety of CoA with loop-2 of the ECH active site cause a conformational change of this loop by which a competent ECH active site is formed. The NAD+ binding domain (domain C) of the HAD part of MtTFE has only a few interactions with the rest of the complex and adopts a range of open conformations, whereas the A-domain of the ECH part is rigidly fixed with respect to the HAD part. Two loops, the CB1-CA1 region and the catalytic CB4-CB5 loop, near the thiolase active site and the thiolase dimer interface, have high B-factors. Structure comparisons suggest that a competent and stable thiolase dimer is formed only when complexed with the α -chains, highlighting the importance of the assembly for the proper functioning of the complex.
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Affiliation(s)
- Subhadra Dalwani
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Outi Lampela
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Pierre Leprovost
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Werner Schmitz
- Theoder-Boveri-Institut für Biowissenschaften der Universität Würzburg, Würzburg, Germany
| | - Andre Juffer
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Rik K Wierenga
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Rajaram Venkatesan
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.
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Van Veldhoven PP, de Schryver E, Young SG, Zwijsen A, Fransen M, Espeel M, Baes M, Van Ael E. Slc25a17 Gene Trapped Mice: PMP34 Plays a Role in the Peroxisomal Degradation of Phytanic and Pristanic Acid. Front Cell Dev Biol 2020; 8:144. [PMID: 32266253 PMCID: PMC7106852 DOI: 10.3389/fcell.2020.00144] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 02/20/2020] [Indexed: 12/04/2022] Open
Abstract
Mice lacking PMP34, a peroxisomal membrane transporter encoded by Slc25a17, did not manifest any obvious phenotype on a Swiss Webster genetic background, even with various treatments designed to unmask impaired peroxisomal functioning. Peroxisomal α- and β-oxidation rates in PMP34 deficient fibroblasts or liver slices were not or only modestly affected and in bile, no abnormal bile acid intermediates were detected. Peroxisomal content of cofactors like CoA, ATP, NAD+, thiamine-pyrophosphate and pyridoxal-phosphate, based on direct or indirect data, appeared normal as were tissue plasmalogen and very long chain fatty acid levels. However, upon dietary phytol administration, the knockout mice displayed hepatomegaly, liver inflammation, and an induction of peroxisomal enzymes. This phenotype was partially mediated by PPARα. Hepatic triacylglycerols and cholesterylesters were elevated and both phytanic acid and pristanic acid accumulated in the liver lipids, in females to higher extent than in males. In addition, pristanic acid degradation products were detected, as wells as the CoA-esters of all these branched fatty acids. Hence, PMP34 is important for the degradation of phytanic/pristanic acid and/or export of their metabolites. Whether this is caused by a shortage of peroxisomal CoA affecting the intraperoxisomal formation of pristanoyl-CoA (and perhaps of phytanoyl-CoA), or the SCPx-catalyzed thiolytic cleavage during pristanic acid β-oxidation, could not be proven in this model, but the phytol-derived acyl-CoA profile is compatible with the latter possibility. On the other hand, the normal functioning of other peroxisomal pathways, and especially bile acid formation, seems to exclude severe transport problems or a shortage of CoA, and other cofactors like FAD, NAD(P)+, TPP. Based on our findings, PMP34 deficiency in humans is unlikely to be a life threatening condition but could cause elevated phytanic/pristanic acid levels in older adults.
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Affiliation(s)
| | - Evelyn de Schryver
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Stephen G. Young
- Departments of Medicine and Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - An Zwijsen
- Laboratory of Developmental Signaling, Department Human Genetics, VIB-KU Leuven, Leuven, Belgium
| | - Marc Fransen
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Marc Espeel
- Department of Anatomy, Embryology, Histology and Medical Physics, Ghent University, Ghent, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Faculty of Pharmaceutical Sciences, KU Leuven, Leuven, Belgium
| | - Elke Van Ael
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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7
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Zhang X, Yang H, Zhang J, Gao F, Dai L. HSD17B4, ACAA1, and PXMP4 in Peroxisome Pathway Are Down-Regulated and Have Clinical Significance in Non-small Cell Lung Cancer. Front Genet 2020; 11:273. [PMID: 32265992 PMCID: PMC7103649 DOI: 10.3389/fgene.2020.00273] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 03/06/2020] [Indexed: 12/25/2022] Open
Abstract
To explore the potential functions and clinical significances of peroxisomes during lung cancer development and progression, we investigated the expressional profiles of peroxisome pathway genes and their correlations with clinical features in non-small cell lung cancer (NSCLC). The RNA-seq data of NSCLC including lung squamous carcinoma (LUSC) and lung adenocarcinoma (LUAD) patients with their clinical information were downloaded from The Cancer Genome Atlas (TCGA). Gene expression comparisons between tumor and normal samples were performed with edgeR package in R software and the results of the 83 peroxisome pathway genes were extracted. Through Venn diagram analysis, 38 common differentially expressed peroxisome pathway genes (C-DEPGs) in NSCLC were identified. Principal components analysis (PCA) was performed and the 38 C-DEPGs could discriminate NSCLC tumors from the non-tumor controls well. Through Kaplan-Meier survival and Cox regression analyses, 11 of the C-DEPGs were shown to have prognostic effects on NSCLC overall survival (OS) and were considered as key C-DEPGs (K-DEPGs). Through Oncomine, Human Protein Atlas (HPA) and the Clinical Proteomic Tumor Analysis Consortium (CPTAC), three K-DEPGs (HSD17B4, ACAA1, and PXMP4) were confirmed to be down-regulated in NSCLC at both mRNA and protein level. Their dy-regulation mechanisms were revealed through their correlations with their copy number variations and methylation status. Their potential functions in NSCLC were explored through their NSCLC-specific co-expression network analysis, their correlations with immune infiltrations, immunomodulator gene expressions, MKI67 expression and their associations with anti-cancer drug sensitivity. Our findings suggested that HSD17B4, ACAA1, and PXMP4 might be new markers for NSCLC diagnosis and prognosis and might provide new clues for NSCLC treatment.
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Affiliation(s)
- Xiuzhi Zhang
- Department of Pathology, Henan Medical College, Zhengzhou, China.,Institute of Cancer Research, Henan Medical College, Zhengzhou, China.,Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Hongmei Yang
- Department of Pathology, Henan Medical College, Zhengzhou, China.,Institute of Cancer Research, Henan Medical College, Zhengzhou, China
| | - Jinzhong Zhang
- Institute of Cancer Research, Henan Medical College, Zhengzhou, China
| | - Fenglan Gao
- Department of Pathology, Henan Medical College, Zhengzhou, China
| | - Liping Dai
- Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
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8
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Crick PJ, Yutuc E, Abdel-Khalik J, Saeed A, Betsholtz C, Genove G, Björkhem I, Wang Y, Griffiths WJ. Formation and metabolism of oxysterols and cholestenoic acids found in the mouse circulation: Lessons learnt from deuterium-enrichment experiments and the CYP46A1 transgenic mouse. J Steroid Biochem Mol Biol 2019; 195:105475. [PMID: 31541728 PMCID: PMC6880786 DOI: 10.1016/j.jsbmb.2019.105475] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/16/2019] [Accepted: 09/18/2019] [Indexed: 12/31/2022]
Abstract
While the presence and abundance of the major oxysterols and cholestenoic acids in the circulation is well established, minor cholesterol metabolites may also have biological importance and be of value to investigate. In this study by observing the metabolism of deuterium-labelled cholesterol in the pdgfbret/ret mouse, a mouse model with increased vascular permeability in brain, and by studying the sterol content of plasma from the CYP46A1 transgenic mouse overexpressing the human cholesterol 24S-hydroxylase enzyme we have been able to identify a number of minor cholesterol metabolites found in the circulation, make approximate-quantitative measurements and postulate pathways for their formation. These "proof of principle" data may have relevance when using mouse models to mimic human disease and in respect of the increasing possibility of treating human neurodegenerative diseases with pharmaceuticals designed to enhance the activity of CYP46A1 or by adeno-associated virus delivery of CYP46A1.
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Affiliation(s)
- Peter J Crick
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, Wales, UK
| | - Eylan Yutuc
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, Wales, UK
| | - Jonas Abdel-Khalik
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, Wales, UK
| | - Ahmed Saeed
- Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska University Hospital, Karolinska Institutet, 141 86 Huddinge, Sweden
| | | | - Guillem Genove
- ICMC Karolinska Institutet, Novum, 141 57 Huddinge, Sweden
| | - Ingemar Björkhem
- Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska University Hospital, Karolinska Institutet, 141 86 Huddinge, Sweden
| | - Yuqin Wang
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, Wales, UK.
| | - William J Griffiths
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, Wales, UK.
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Griffiths WJ, Wang Y. Oxysterols as lipid mediators: Their biosynthetic genes, enzymes and metabolites. Prostaglandins Other Lipid Mediat 2019; 147:106381. [PMID: 31698146 PMCID: PMC7081179 DOI: 10.1016/j.prostaglandins.2019.106381] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/29/2019] [Accepted: 09/09/2019] [Indexed: 02/07/2023]
Abstract
Pathways of oxysterol biosynthesis. Pathways of oxysterol metabolism. Oxysterols as bioactive molecules. Disorders of oxysterol metabolism.
There is growing evidence that oxysterols are more than simple metabolites in the pathway from cholesterol to bile acids. Recent data has shown oxysterols to be ligands to nuclear receptors and to G protein-coupled receptors, modulators of N-methyl-d-aspartate receptors and regulators of cholesterol biosynthesis. In this mini-review we will discuss the biosynthetic mechanisms for the formation of different oxysterols and the implication of disruption of these mechanisms in health and disease.
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Affiliation(s)
- William J Griffiths
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP Wales, UK.
| | - Yuqin Wang
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP Wales, UK.
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Chong CS, Kunze M, Hochreiter B, Krenn M, Berger J, Maurer-Stroh S. Rare Human Missense Variants can affect the Function of Disease-Relevant Proteins by Loss and Gain of Peroxisomal Targeting Motifs. Int J Mol Sci 2019; 20:E4609. [PMID: 31533369 PMCID: PMC6770196 DOI: 10.3390/ijms20184609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/06/2019] [Accepted: 09/14/2019] [Indexed: 12/30/2022] Open
Abstract
Single nucleotide variants (SNVs) resulting in amino acid substitutions (i.e., missense variants) can affect protein localization by changing or creating new targeting signals. Here, we studied the potential of naturally occurring SNVs from the Genome Aggregation Database (gnomAD) to result in the loss of an existing peroxisomal targeting signal 1 (PTS1) or gain of a novel PTS1 leading to mistargeting of cytosolic proteins to peroxisomes. Filtering down from 32,985 SNVs resulting in missense mutations within the C-terminal tripeptide of 23,064 human proteins, based on gene annotation data and computational prediction, we selected six SNVs for experimental testing of loss of function (LoF) of the PTS1 motif and five SNVs in cytosolic proteins for gain in PTS1-mediated peroxisome import (GoF). Experimental verification by immunofluorescence microscopy for subcellular localization and FRET affinity measurements for interaction with the receptor PEX5 demonstrated that five of the six predicted LoF SNVs resulted in loss of the PTS1 motif while three of five predicted GoF SNVs resulted in de novo PTS1 generation. Overall, we showed that a complementary approach incorporating bioinformatics methods and experimental testing was successful in identifying SNVs capable of altering peroxisome protein import, which may have implications in human disease.
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Affiliation(s)
- Cheng-Shoong Chong
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore 138671, Singapore.
- National University of Singapore Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore 119077, Singapore.
| | - Markus Kunze
- Medical University of Vienna, Center for Brain Research, Department of Pathobiology of the Nervous System, 1090 Vienna, Austria.
| | - Bernhard Hochreiter
- Medical University of Vienna, Center for Physiology and Pharmacology, Institute for Vascular Biology and Thrombosis Research, 1090 Vienna, Austria.
| | - Martin Krenn
- Department of Neurology, Medical University of Vienna, 1090 Vienna, Austria.
- Institute of Human Genetics, Technical University Munich, 81675 Munich, Germany.
| | - Johannes Berger
- Medical University of Vienna, Center for Brain Research, Department of Pathobiology of the Nervous System, 1090 Vienna, Austria.
| | - Sebastian Maurer-Stroh
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore 138671, Singapore.
- National University of Singapore Graduate School for Integrative Sciences and Engineering (NGS), National University of Singapore, Singapore 119077, Singapore.
- Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore.
- Innovations in Food and Chemical Safety Programme (IFCS), Agency for Science, Technology and Research (A*STAR), Singapore 138671, Singapore.
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11
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Griffiths WJ, Abdel-Khalik J, Yutuc E, Roman G, Warner M, Gustafsson JÅ, Wang Y. Concentrations of bile acid precursors in cerebrospinal fluid of Alzheimer's disease patients. Free Radic Biol Med 2019; 134:42-52. [PMID: 30578919 PMCID: PMC6597949 DOI: 10.1016/j.freeradbiomed.2018.12.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Revised: 11/20/2018] [Accepted: 12/17/2018] [Indexed: 01/19/2023]
Abstract
Using liquid chromatography - mass spectrometry in combination with derivatisation chemistry we profiled the oxysterol and cholestenoic acid content of cerebrospinal fluid from patients with Alzheimer's disease (n = 21), vascular dementia (n = 11), other neurodegenerative diseases (n = 15, Lewy bodies dementia, n = 3, Frontotemporal dementia, n = 11) and controls (n = 15). Thirty different sterols were quantified and the bile acid precursor 7α,25-dihydroxy-3-oxocholest-4-en-26-oic acid found to be reduced in abundance in cerebrospinal fluid of Alzheimer's disease patient-group. This was the only sterol found to be changed amongst the different groups.
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Affiliation(s)
- William J Griffiths
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK.
| | - Jonas Abdel-Khalik
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK
| | - Eylan Yutuc
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK
| | - Gustavo Roman
- Methodist Neurological Institute, Methodist Hospital, Houston, TX 77030, USA
| | - Margaret Warner
- Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signaling, University of Houston, 3517 Cullen Blvd, Houston, TX 77204, USA
| | - Jan-Åke Gustafsson
- Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signaling, University of Houston, 3517 Cullen Blvd, Houston, TX 77204, USA
| | - Yuqin Wang
- Swansea University Medical School, ILS1 Building, Singleton Park, Swansea SA2 8PP, UK.
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12
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Abdel-Khalik J, Crick PJ, Yutuc E, DeBarber AE, Duell PB, Steiner RD, Laina I, Wang Y, Griffiths WJ. Identification of 7α,24-dihydroxy-3-oxocholest-4-en-26-oic and 7α,25-dihydroxy-3-oxocholest-4-en-26-oic acids in human cerebrospinal fluid and plasma. Biochimie 2018; 153:86-98. [PMID: 29960034 PMCID: PMC6171785 DOI: 10.1016/j.biochi.2018.06.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 06/25/2018] [Indexed: 01/08/2023]
Abstract
Dihydroxyoxocholestenoic acids are intermediates in bile acid biosynthesis. Here, using liquid chromatography – mass spectrometry, we confirm the identification of 7α,24-dihydroxy-3-oxocholest-4-en-26-oic and 7α,25-dihydroxy-3-oxocholest-4-en-26-oic acids in cerebrospinal fluid (CSF) based on comparisons to authentic standards and of 7α,12α-dihydroxy-3-oxocholest-4-en-26-oic and 7α,x-dihydroxy-3-oxocholest-4-en-26-oic (where hydroxylation is likely on C-22 or C-23) based on exact mass measurement and multistage fragmentation. Surprisingly, patients suffering from the inborn error of metabolism cerebrotendinous xanthomatosis, where the enzyme CYP27A1, which normally introduces the (25 R)26-carboxylic acid group to the sterol side-chain, is defective still synthesise 7α,24-dihydroxy-3-oxocholest-4-en-26-oic acid and also both 25 R- and 25 S-epimers of 7α,12α-dihydroxy-3-oxocholest-4-en-26-oic acid. We speculate that the enzymes CYP46A1 and CYP3A4 may have C-26 carboxylase activity to generate these acids. In patients suffering from hereditary spastic paraplegia type 5 the CSF concentrations of the 7α,24- and 7α,25-dihydroxy acids are reduced, suggesting an involvement of CYP7B1 in their biosynthesis in brain. Dihydroxy-3-oxocholest-5-en-26-oic are found in human CSF and plasma. Hydroxy groups may be at 7α,24, 7α,25, or 7α,12α. Another acid is hydroxylated at 7α and in the side-chain probably at C-22 or C-23. In patients with CTX acids with 25 R or 25 S stereochemistry are found. In patients with SPG5 the concentrations of acids in CSF are reduced.
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Affiliation(s)
- Jonas Abdel-Khalik
- Institute of Life Science, Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK
| | - Peter J Crick
- Institute of Life Science, Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK
| | - Eylan Yutuc
- Institute of Life Science, Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK
| | - Andrea E DeBarber
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, OR, USA
| | - P Barton Duell
- Knight Cardiovascular Institute, Oregon Health and Sciences University, Portland, OR, USA
| | - Robert D Steiner
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Ioanna Laina
- Athens Medical Group, Athens Medical Center, Marousi Athens, Greece
| | - Yuqin Wang
- Institute of Life Science, Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK.
| | - William J Griffiths
- Institute of Life Science, Swansea University Medical School, ILS1 Building, Singleton Park, Swansea, SA2 8PP, UK.
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Shinde AB, Baboota RK, Denis S, Loizides-Mangold U, Peeters A, Espeel M, Malheiro AR, Riezman H, Vinckier S, Vaz FM, Brites P, Ferdinandusse S, Van Veldhoven PP, Baes M. Mitochondrial disruption in peroxisome deficient cells is hepatocyte selective but is not mediated by common hepatic peroxisomal metabolites. Mitochondrion 2018; 39:51-59. [DOI: 10.1016/j.mito.2017.08.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 08/25/2017] [Indexed: 01/06/2023]
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14
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Impaired Bile Acid Homeostasis in Children with Severe Acute Malnutrition. PLoS One 2016; 11:e0155143. [PMID: 27163928 PMCID: PMC4862637 DOI: 10.1371/journal.pone.0155143] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 03/25/2016] [Indexed: 02/08/2023] Open
Abstract
Objective Severe acute malnutrition (SAM) is a major cause of mortality in children under 5 years and is associated with hepatic steatosis. Bile acids are synthesized in the liver and participate in dietary fat digestion, regulation of energy expenditure, and immune responses. The aim of this work was to investigate whether SAM is associated with clinically relevant changes in bile acid homeostasis. Design An initial discovery cohort with 5 healthy controls and 22 SAM-patients was used to identify altered bile acid homeostasis. A follow up cohort of 40 SAM-patients were then studied on admission and 3 days after clinical stabilization to assess recovery in bile acid metabolism. Recruited children were 6–60 months old and admitted for SAM in Malawi. Clinical characteristics, feces and blood were collected on admission and prior to discharge. Bile acids, 7α-hydroxy-4-cholesten-3-one (C4) and FGF-19 were quantified. Results On admission, total serum bile acids were higher in children with SAM than in healthy controls and glycine-conjugates accounted for most of this accumulation with median and interquartile range (IQR) of 24.6 μmol/L [8.6–47.7] compared to 1.9 μmol/L [1.7–3.3] (p = 0.01) in controls. Total serum bile acid concentrations did not decrease prior to discharge. On admission, fecal conjugated bile acids were lower and secondary bile acids higher at admission compared to pre- discharge, suggesting increased bacterial conversion. FGF19 (Fibroblast growth factor 19), a marker of intestinal bile acid signaling, was higher on admission and was associated with decreased C4 concentrations as a marker of bile acid synthesis. Upon recovery, fecal calprotectin, a marker of intestinal inflammation, was lower. Conclusion SAM is associated with increased serum bile acid levels despite reduced synthesis rates. In SAM, there tends to be increased deconjugation of bile acids and conversion from primary to secondary bile acids, which may contribute to the development of liver disease.
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15
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Baes M, Van Veldhoven PP. Hepatic dysfunction in peroxisomal disorders. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:956-70. [PMID: 26453805 DOI: 10.1016/j.bbamcr.2015.09.035] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/25/2015] [Accepted: 09/28/2015] [Indexed: 12/18/2022]
Abstract
The peroxisomal compartment in hepatocytes hosts several essential metabolic conversions. These are defective in peroxisomal disorders that are either caused by failure to import the enzymes in the organelle or by mutations in the enzymes or in transporters needed to transfer the substrates across the peroxisomal membrane. Hepatic pathology is one of the cardinal features in disorders of peroxisome biogenesis and peroxisomal β-oxidation although it only rarely determines the clinical fate. In mouse models of these diseases liver pathologies also occur, although these are not always concordant with the human phenotype which might be due to differences in diet, expression of enzymes and backup mechanisms. Besides the morphological changes, we overview the impact of peroxisome malfunction on other cellular compartments including mitochondria and the ER. We further focus on the metabolic pathways that are affected such as bile acid formation, and dicarboxylic acid and branched chain fatty acid degradation. It appears that the association between deregulated metabolites and pathological events remains unclear.
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Affiliation(s)
- Myriam Baes
- Laboratory for Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, B-3000 Leuven, Belgium.
| | - Paul P Van Veldhoven
- Laboratory for Lipid Biochemistry and Protein Interactions, Department of Cellular and Molecular Medicine, KU Leuven, B-3000 Leuven, Belgium.
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16
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Fattah S, Augustijns P, Annaert P. Age-dependent activity of the uptake transporters Ntcp and Oatp1b2 in male rat hepatocytes: from birth till adulthood. Drug Metab Dispos 2014; 43:1-8. [PMID: 25305012 DOI: 10.1124/dmd.114.059212] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Recognition of the role of hepatic drug transporters in elimination of xenobiotics continues to grow. Hepatic uptake transporters, such as hepatic isoforms of the organic anion-transporting polypeptide (Oatp) family as well as the bile acid transporter Na(+)-taurocholate cotransporting polypeptide (Ntcp) have been studied extensively both at the mRNA and protein expression levels in adults. However, in pediatric/juvenile populations, there continues to be a knowledge gap about the functional activity of these transporters. Therefore, the aim of this study was to examine the functional maturation of Ntcp and Oatp isoforms as major hepatic transporters. Hepatocytes were freshly isolated from rats aged between birth and 8 weeks. Transporter activities were assessed by measuring the initial uptake rates of known substrates: taurocholate (TCA) for Ntcp and sodium fluorescein (NaFluo) for Oatp. Relative to adult values, uptake clearance of TCA in hepatocytes from rats aged 0, 1, 2, 3, and 4 weeks reached 19, 43, 22, 46, and 63%, respectively. In contrast, Oatp-mediated NaFluo uptake showed a considerably slower developmental pattern: uptake clearance of NaFluo in hepatocytes from rats aged 0, 1, 2, 3, 4, and 6 weeks were 24, 20, 19, 8, 19, and 64%, respectively. Maturation of NaFluo uptake activity correlated with the previously reported ontogeny of Oatp1b2 mRNA expression, confirming the role of Oatp1b2 for NaFluo uptake in rat liver. The outcome of this project will help in understanding and predicting age-dependent drug exposure in juvenile animals and will eventually support safe and more effective drug therapies for children.
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Affiliation(s)
- Sarinj Fattah
- Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, Leuven, Belgium
| | - Patrick Augustijns
- Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, Leuven, Belgium
| | - Pieter Annaert
- Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, Leuven, Belgium
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17
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Baptissart M, Vega A, Martinot E, Pommier AJ, Houten SM, Marceau G, de Haze A, Baron S, Schoonjans K, Lobaccaro JMA, Volle DH. Bile acids alter male fertility through G-protein-coupled bile acid receptor 1 signaling pathways in mice. Hepatology 2014; 60:1054-65. [PMID: 24798773 DOI: 10.1002/hep.27204] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 05/01/2014] [Indexed: 12/12/2022]
Abstract
UNLABELLED Bile acids (BAs) are signaling molecules that are involved in many physiological functions, such as glucose and energy metabolism. These effects are mediated through activation of the nuclear and membrane receptors, farnesoid X receptor (FXR-α) and TGR5 (G-protein-coupled bile acid receptor 1; GPBAR1). Although both receptors are expressed within the testes, the potential effect of BAs on testis physiology and male fertility has not been explored thus far. Here, we demonstrate that mice fed a diet supplemented with cholic acid have reduced fertility subsequent to testicular defects. Initially, germ cell sloughing and rupture of the blood-testis barrier occur and are correlated with decreased protein accumulation of connexin-43 (Cx43) and N-cadherin, whereas at later stages, apoptosis of spermatids is observed. These abnormalities are associated with increased intratesticular BA levels in general and deoxycholic acid, a TGR5 agonist, in particular. We demonstrate here that Tgr5 is expressed within the germ cell lineage, where it represses Cx43 expression through regulation of the transcriptional repressor, T-box transcription factor 2 gene. Consistent with this finding, mice deficient for Tgr5 are protected against the deleterious testicular effects of BA exposure. CONCLUSIONS These data identify the testis as a new target of BAs and emphasize TGR5 as a critical element in testicular pathophysiology. This work may open new perspectives on the potential effect of BAs on testis physiology during liver dysfunction.
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Affiliation(s)
- Marine Baptissart
- INSERM U 1103, Génétique Reproduction et Développement (GReD), Aubière, France; Clermont Université, Université Blaise, Pascal, GReD, BP 80026, Aubière, France; CNRS, UMR 6293, GReD, Aubière, France; Centre de Recherche en Nutrition Humaine d'Auvergne, Clermont-Ferrand, France
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18
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Ferdinandusse S, Jimenez-Sanchez G, Koster J, Denis S, Van Roermund CW, Silva-Zolezzi I, Moser AB, Visser WF, Gulluoglu M, Durmaz O, Demirkol M, Waterham HR, Gökcay G, Wanders RJ, Valle D. A novel bile acid biosynthesis defect due to a deficiency of peroxisomal ABCD3. Hum Mol Genet 2014; 24:361-70. [DOI: 10.1093/hmg/ddu448] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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19
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Role of AMACR (α-methylacyl-CoA racemase) and MFE-1 (peroxisomal multifunctional enzyme-1) in bile acid synthesis in mice. Biochem J 2014; 461:125-35. [DOI: 10.1042/bj20130915] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Bile acid analysis of wild-type, Mfe-1−/−, Amacr−/− and Amacr−/−Mfe-1−/− mouse models shows that peroxisomal multifunctional enzyme 1 can participate in bile acid synthesis in both AMACR-dependent and AMACR-independent pathways.
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20
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Verheijden S, Beckers L, De Munter S, Van Veldhoven PP, Baes M. Central nervous system pathology in MFP2 deficiency: Insights from general and conditional knockout mouse models. Biochimie 2014; 98:119-26. [DOI: 10.1016/j.biochi.2013.08.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 08/03/2013] [Indexed: 12/22/2022]
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21
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Vlaardingerbroek H, Ng K, Stoll B, Benight N, Chacko S, Kluijtmans LAJ, Kulik W, Squires EJ, Olutoye O, Schady D, Finegold ML, van Goudoever JB, Burrin DG. New generation lipid emulsions prevent PNALD in chronic parenterally fed preterm pigs. J Lipid Res 2014; 55:466-77. [PMID: 24478031 DOI: 10.1194/jlr.m044545] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Total parenteral nutrition (TPN) is associated with the development of parenteral nutrition-associated liver disease (PNALD) in infants. Fish oil-based lipid emulsions can reverse PNALD, yet it is unknown if they can prevent PNALD. We studied preterm pigs administered TPN for 14 days with either 100% soybean oil (IL), 100% fish oil (OV), or a mixture of soybean oil, medium chain triglycerides (MCTs), olive oil, and fish oil (SL); a group was fed formula enterally (ENT). In TPN-fed pigs, serum direct bilirubin, gamma glutamyl transferase (GGT), and plasma bile acids increased after the 14 day treatment but were highest in IL pigs. All TPN pigs had suppressed hepatic expression of farnesoid X receptor (FXR), cholesterol 7-hydroxylase (CYP7A1), and plasma 7α-hydroxy-4-cholesten-3-one (C4) concentrations, yet hepatic CYP7A1 protein abundance was increased only in the IL versus ENT group. Organic solute transporter alpha (OSTα) gene expression was the highest in the IL group and paralleled plasma bile acid levels. In cultured hepatocytes, bile acid-induced bile salt export pump (BSEP) expression was inhibited by phytosterol treatment. We show that TPN-fed pigs given soybean oil developed cholestasis and steatosis that was prevented with both OV and SL emulsions. Due to the presence of phytosterols in the SL emulsion, the differences in cholestasis and liver injury among lipid emulsion groups in vivo were weakly correlated with plasma and hepatic phytosterol content.
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Affiliation(s)
- Hester Vlaardingerbroek
- Department of Pediatrics, Division of Neonatology, Erasmus MC - Sophia Children's Hospital, Rotterdam, The Netherlands
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22
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Kim YI, Bhandari S, Lee JN, Yoo KW, Kim SJ, Oh GS, Kim HJ, Cho M, Kwak JY, So HS, Park R, Choe SK. Developmental roles of D-bifunctional protein-A zebrafish model of peroxisome dysfunction. Mol Cells 2014; 37:74-80. [PMID: 24552713 PMCID: PMC3907007 DOI: 10.14348/molcells.2014.2300] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 11/08/2013] [Accepted: 11/08/2013] [Indexed: 12/17/2022] Open
Abstract
The peroxisome is an intracellular organelle that responds dynamically to environmental changes. Various model organisms have been used to study the roles of peroxisomal proteins in maintaining cellular homeostasis. By taking advantage of the zebrafish model whose early stage of embryogenesis is dependent on yolk components, we examined the developmental roles of the D-bifunctional protein (Dbp), an essential enzyme in the peroxisomal β-oxidation. The knockdown of dbp in zebrafish phenocopied clinical manifestations of its deficiency in human, including defective craniofacial morphogenesis, growth retardation, and abnormal neuronal development. Overexpression of murine Dbp rescued the morphological phenotypes induced by dbp knockdown, indicative of conserved roles of Dbp during zebrafish and mammalian development. Knockdown of dbp impaired normal development of blood, blood vessels, and most strikingly, endoderm-derived organs including the liver and pancreas - a phenotype not reported elsewhere in connection with peroxisome dysfunction. Taken together, our results demonstrate for the first time that zebrafish might be a useful model animal to study the role of peroxisomes during vertebrate development.
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Affiliation(s)
- Yong-Il Kim
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Sushil Bhandari
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Joon No Lee
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Kyeong-Won Yoo
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
- Immune-network Pioneer Research Center, Department of Biochemistry, College of Medicine, Dong-A University, Busan 602-714,
Korea
| | - Se-Jin Kim
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Gi-Su Oh
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Hyung-Jin Kim
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Meyoung Cho
- Department of Internal Medicine, Gunsan Medical Center, Gunsan 573-713
Korea
| | - Jong-Young Kwak
- Immune-network Pioneer Research Center, Department of Biochemistry, College of Medicine, Dong-A University, Busan 602-714,
Korea
| | - Hong-Seob So
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Raekil Park
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
| | - Seong-Kyu Choe
- Center for Metabolic Function Regulation, and Department of Microbiology, School of Medicine, Wonkwang University, Iksan 570-749,
Korea
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23
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Richert S, Kleinecke S, Günther J, Schaumburg F, Edgar J, Nienhaus GU, Nave KA, Kassmann CM. In vivo labeling of peroxisomes by photoconvertible mEos2 in myelinating glia of mice. Biochimie 2013; 98:127-34. [PMID: 24262602 DOI: 10.1016/j.biochi.2013.10.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 10/31/2013] [Indexed: 02/06/2023]
Abstract
Mutations of several genes encoding peroxisomal proteins have been associated with human diseases. Some of these display specific white matter abnormalities in the brain, although the affected proteins are ubiquitously expressed. To better understand the etiology of peroxisomal myelin diseases, we aimed to label these organelles in vivo and in a cell type specific fashion. We had previously shown that in oligodendrocytes and Schwann cells numerous peroxisomes reside in the cytoplasmic channels of "non-compacted" myelin. These organelles are smaller and biochemically distinct from non-myelin peroxisomes. Targeting peroxisomal functions in various cell types of the brain has demonstrated that oligodendroglial peroxisomes are specifically important for long-term integrity of the CNS. To visualize myelin peroxisomes in intact cells and tissues by live imaging, we have generated a novel line of transgenic mice for the expression of fluorescently tagged peroxisomes specifically in myelinating glia. This was achieved by modifying the gene for a photoconvertible mEos2 with a peroxisomal targeting signal type 1 (PTS1) and generating a fusion gene with the myelin-specific Cnp1 promoter. In the brain of resulting transgenic mice, peroxisomes are selectively labeled in oligodendrocytes. In this novel genetic tool, photoconversion of single peroxisomes from green to red fluorescence can be used to monitor the fate of single organelles and to determine the dynamics of PTS1-mediated protein import in the context of myelin diseases that affect peroxisomal functions.
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Affiliation(s)
- Sarah Richert
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
| | - Sandra Kleinecke
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
| | - Jenniffer Günther
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
| | - Florian Schaumburg
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
| | - Julia Edgar
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
| | - Gerd Ulrich Nienhaus
- Institute of Applied Physics (APH) and Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany.
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
| | - Celia M Kassmann
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
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Kassmann CM. Myelin peroxisomes - essential organelles for the maintenance of white matter in the nervous system. Biochimie 2013; 98:111-8. [PMID: 24120688 DOI: 10.1016/j.biochi.2013.09.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Accepted: 09/20/2013] [Indexed: 12/29/2022]
Abstract
Peroxisomes are cellular compartments primarily associated with lipid metabolism. Most cell types, including nervous system cells, harbor several hundred of these organelles. The importance of peroxisomes for central nervous system white matter is evidenced by a variety of human peroxisomal disorders with neurological impairment frequently involving the white matter. Moreover, the most frequent childhood white matter disease, X-linked adrenoleukodystrophy, is a peroxisomal disorder. During the past decade advances in imaging techniques have enabled the identification of peroxisomes within the myelin sheath, especially close to nodes of Ranvier. Although the function of myelin peroxisomes is not solved yet on molecular level, recently acquired knowledge suggests a central role for these organelles in axo-glial metabolism. This review focuses on the biology of myelin peroxisomes as well as on the pathology of myelin and myelinated axons that is observed as a consequence of partial or complete peroxisomal dysfunction in the brain.
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Affiliation(s)
- Celia M Kassmann
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany.
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25
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Verheijden S, Bottelbergs A, Krysko O, Krysko DV, Beckers L, De Munter S, Van Veldhoven PP, Wyns S, Kulik W, Nave KA, Ramer MS, Carmeliet P, Kassmann CM, Baes M. Peroxisomal multifunctional protein-2 deficiency causes neuroinflammation and degeneration of Purkinje cells independent of very long chain fatty acid accumulation. Neurobiol Dis 2013; 58:258-69. [PMID: 23777740 DOI: 10.1016/j.nbd.2013.06.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/27/2013] [Accepted: 06/07/2013] [Indexed: 01/03/2023] Open
Abstract
Although peroxisome biogenesis and β-oxidation disorders are well known for their neurodevelopmental defects, patients with these disorders are increasingly diagnosed with neurodegenerative pathologies. In order to investigate the cellular mechanisms of neurodegeneration in these patients, we developed a mouse model lacking multifunctional protein 2 (MFP2, also called D-bifunctional protein), a central enzyme of peroxisomal β-oxidation, in all neural cells (Nestin-Mfp2(-/-)) or in oligodendrocytes (Cnp-Mfp2(-/-)) and compared these models with an already established general Mfp2 knockout. Nestin-Mfp2 but not Cnp-Mfp2 knockout mice develop motor disabilities and ataxia, similar to the general mutant. Deterioration of motor performance correlates with the demise of Purkinje cell axons in the cerebellum, which precedes loss of Purkinje cells and cerebellar atrophy. This closely mimics spinocerebellar ataxias of patients affected with mild peroxisome β-oxidation disorders. However, general knockouts have a much shorter life span than Nestin-Mfp2 knockouts which is paralleled by a disparity in activation of the innate immune system. Whereas in general mutants a strong and chronic proinflammatory reaction proceeds throughout the brain, elimination of MFP2 from neural cells results in minor neuroinflammation. Neither the extent of the inflammatory reaction nor the cerebellar degeneration could be correlated with levels of very long chain fatty acids, substrates of peroxisomal β-oxidation. In conclusion, MFP2 has multiple tasks in the adult brain, including the maintenance of Purkinje cells and the prevention of neuroinflammation but this is not mediated by its activity in oligodendrocytes nor by its role in very long chain fatty acid degradation.
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Affiliation(s)
- Simon Verheijden
- Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Belgium.
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26
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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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Denk GU, Maitz S, Wimmer R, Rust C, Invernizzi P, Ferdinandusse S, Kulik W, Fuchsbichler A, Fickert P, Trauner M, Hofmann AF, Beuers U. Conjugation is essential for the anticholestatic effect of NorUrsodeoxycholic acid in taurolithocholic acid-induced cholestasis in rat liver. Hepatology 2010; 52:1758-68. [PMID: 21038414 DOI: 10.1002/hep.23911] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
UNLABELLED NorUDCA (24-norursodeoxycholic acid), the C₂₃-homolog of ursodeoxycholic acid (UDCA), showed remarkable therapeutic effects in cholestatic Mdr2 (Abcb4) (multidrug resistance protein 2/ATP-binding cassette b4) knockout mice with sclerosing/fibrosing cholangitis. In contrast to UDCA, norUDCA is inefficiently conjugated in human and rodent liver, and conjugation has been discussed as a key step for the anticholestatic action of UDCA in cholestasis. We compared the choleretic, anticholestatic, and antiapoptotic properties of unconjugated and taurine-conjugated UDCA (C₂₄) and norUDCA (C₂₃) in isolated perfused rat liver (IPRL) and in natrium/taurocholate cotransporting polypeptide (Ntcp)-transfected human hepatoma (HepG2) cells. Taurolithocholic acid (TLCA) was used to induce a predominantly hepatocellular cholestasis in IPRL. Bile flow was determined gravimetrically; bile acids determined by gas chromatography and liquid chromatography/tandem mass spectrometry; the Mrp2 model substrate, 2,4-dinitrophenyl-S-glutathione (GS-DNP) was determined spectrophotometrically; and apoptosis was determined immunocytochemically. The choleretic effect of C₂₃-bile acids was comparable to their C₂₄-homologs in IPRL. In contrast, TnorUDCA, but not norUDCA antagonized the cholestatic effect of TLCA. Bile flow (percent of controls) was 8% with TLCA-induced cholestasis, and unchanged by coinfusion of norUDCA (14%). However, it was increased by TnorUDCA (83%), UDCA (73%) and TUDCA (136%). Secretion of GS-DNP was markedly reduced by TLCA (5%), unimproved by norUDCA (4%) or UDCA (17%), but was improved modestly by TnorUDCA (26%) or TUDCA (58%). No apoptosis was observed in IPRL exposed to low micromolar TLCA, but equivalent antiapoptotic effects of TUDCA and TnorUDCA were observed in Ntcp-HepG2 cells exposed to TLCA. CONCLUSION Conjugation is essential for the anticholestatic effect of norUDCA in a model of hepatocellular cholestasis. Combined therapy with UDCA and norUDCA may be superior to UDCA or norUDCA monotherapy in biliary disorders in which hepatocyte as well as cholangiocyte dysfunction contribute to disease progression.
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Affiliation(s)
- Gerald U Denk
- Department of Medicine II, Klinikum Großhadern, University of Munich, Munich, Germany
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Van Veldhoven PP. Biochemistry and genetics of inherited disorders of peroxisomal fatty acid metabolism. J Lipid Res 2010; 51:2863-95. [PMID: 20558530 DOI: 10.1194/jlr.r005959] [Citation(s) in RCA: 247] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In humans, peroxisomes harbor a complex set of enzymes acting on various lipophilic carboxylic acids, organized in two basic pathways, alpha-oxidation and beta-oxidation; the latter pathway can also handle omega-oxidized compounds. Some oxidation products are crucial to human health (primary bile acids and polyunsaturated FAs), whereas other substrates have to be degraded in order to avoid neuropathology at a later age (very long-chain FAs and xenobiotic phytanic acid and pristanic acid). Whereas total absence of peroxisomes is lethal, single peroxisomal protein deficiencies can present with a mild or severe phenotype and are more informative to understand the pathogenic factors. The currently known single protein deficiencies equal about one-fourth of the number of proteins involved in peroxisomal FA metabolism. The biochemical properties of these proteins are highlighted, followed by an overview of the known diseases.
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Affiliation(s)
- Paul P Van Veldhoven
- Katholieke Universiteit Leuven, Department of Molecular Cell Biology, LIPIT, Campus Gasthuisberg, Herestraat, Leuven, Belgium.
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Krysko O, Bottelbergs A, Van Veldhoven P, Baes M. Combined deficiency of peroxisomal beta-oxidation and ether lipid synthesis in mice causes only minor cortical neuronal migration defects but severe hypotonia. Mol Genet Metab 2010; 100:71-6. [PMID: 20202875 DOI: 10.1016/j.ymgme.2010.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 02/05/2010] [Accepted: 02/05/2010] [Indexed: 12/01/2022]
Abstract
The metabolic factors causing cortical neuronal migration defects, hypotonia and malformation of cerebellum in patients and mice with severe peroxisome biogenesis disorders are still not identified. In the present investigation, we tested the hypothesis that the combined inactivity of peroxisomal beta-oxidation and ether lipid biosynthesis could be at the origin of these pathologies. Double MFP2/DAPAT knockout mice were generated and their postnatal phenotypes were compared with single knockouts and control mice. Cortical neuronal migration was not affected in DAPAT knockouts and only mildly in double MFP2/DAPAT knockout mice. The latter mice were severely hypotonic and usually died in the postnatal period. Both DAPAT and MFP2 single knockout mice exhibited delays in the formation of cerebellar folia. We conclude that the combined defect of peroxisomal beta-oxidation and ether lipid synthesis does not solely account for the typical cortical neuronal migration defect of mice with peroxisome biogenesis disorders but contributes to their hypotonia.
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Affiliation(s)
- Olga Krysko
- Laboratory of Cell Metabolism, Department of Pharmaceutical Sciences, K.U.Leuven, B-3000 Leuven, Belgium
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30
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Peroxisomes, lipid metabolism and lipotoxicity. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:272-80. [DOI: 10.1016/j.bbalip.2010.01.001] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 01/07/2010] [Accepted: 01/07/2010] [Indexed: 12/26/2022]
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Ferdinandusse S, Denis S, Faust PL, Wanders RJA. Bile acids: the role of peroxisomes. J Lipid Res 2009; 50:2139-47. [PMID: 19357427 DOI: 10.1194/jlr.r900009-jlr200] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
It is well established that peroxisomes play a crucial role in de novo bile acid synthesis. Studies in patients with a peroxisomal disorder have been indispensable for the elucidation of the precise role of peroxisomes. Several peroxisomal disorders are associated with distinct bile acid abnormalities and each disorder has a characteristic pattern of abnormal bile acids that accumulate, which is often used for diagnostic purposes. The patients have also been important for determining the pathophysiological consequences of defects in bile acid biosynthesis. In this review, we will discuss all the peroxisomal steps involved in bile acid synthesis and the bile acid abnormalities in patients with peroxisomal disorders. We will show the results of bile acid measurements in several tissues from patients, including brain, and we will discuss the toxicity and the pathological effects of the abnormal bile acids.
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Affiliation(s)
- Sacha Ferdinandusse
- Laboratory of Genetic Metabolic Diseases, Academic Medical Center at the University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
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32
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Ferdinandusse S, Denis S, Dacremont G, Wanders RJA. Toxicity of peroxisomal C27-bile acid intermediates. Mol Genet Metab 2009; 96:121-8. [PMID: 19136287 DOI: 10.1016/j.ymgme.2008.11.165] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Accepted: 11/27/2008] [Indexed: 12/20/2022]
Abstract
Peroxisomes play an important role in bile acid biosynthesis because the last steps of the synthesis pathway are performed by the beta-oxidation system located inside peroxisomes. As a consequence, C(27)-bile acid intermediates accumulate in several peroxisomal disorders. It has been suggested that C(27)-bile acids are especially toxic and contribute to the liver disease associated with peroxisomal disorders. For this reason, we investigated the toxicity of C(27)-bile acids and the underlying mechanisms. We studied the effects of conjugated and unconjugated C(27)-bile acids on cell viability, mitochondrial respiratory chain function and production of oxygen radicals in the rat hepatoma cell line McA-RH7777. Cell viability decreased progressively after incubation with increasing concentrations of different bile acids with dihydroxycholestanoic acid (DHCA) being clearly the most cytotoxic bile acid. In addition, the different bile acids caused a dose-dependent decrease in ATP synthesis by isolated mitochondria oxidizing malate and glutamate. Finally, there was a dose-dependent stimulation of ROS generation in the presence of C(27)-bile acids. In conclusion, our studies showed that C(27)-bile acids are more cytotoxic than mature C(24)-bile acids. In addition, C(27)-bile acids are potent inhibitors of oxidative phosphorylation and enhance mitochondrial ROS production by inhibiting the respiratory chain.
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Affiliation(s)
- Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Academic Medical Center at the University of Amsterdam, Amsterdam, The Netherlands.
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33
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Alnouti Y, Csanaky IL, Klaassen CD. Quantitative-profiling of bile acids and their conjugates in mouse liver, bile, plasma, and urine using LC-MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci 2008; 873:209-17. [PMID: 18801708 PMCID: PMC2582521 DOI: 10.1016/j.jchromb.2008.08.018] [Citation(s) in RCA: 207] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 06/24/2008] [Accepted: 08/26/2008] [Indexed: 12/30/2022]
Abstract
The differences among individual bile acids (BAs) in eliciting different physiological and pathological responses are largely unknown because of the lack of valid and simple analytical methods for the quantification of individual BAs and their taurine and glycine conjugates. Therefore, a simple and sensitive LC-MS/MS method for the simultaneous quantification of 6 major BAs, their glycine, and taurine conjugates in mouse liver, bile, plasma, and urine was developed and validated. One-step sample preparation using solid-phase extraction (for bile and urine) or protein precipitation (for plasma and liver) was used to extract BAs. This method is valid and sensitive with a limit of quantification ranging from 10 to 40 ng/ml for the various analytes, has a large dynamic range (2500), and a short run time (20 min). Detailed BA profiles were obtained from mouse liver, plasma, bile, and urine using this method. Muricholic acid (MCA) and cholic acid (CA) taurine conjugates constituted more than 90% of BAs in liver and bile. BA concentrations in liver were about 300-fold higher than in plasma, and about 180-fold higher in bile than in liver. In summary, a reliable and simple LC-MS/MS method to quantify major BAs and their metabolites was developed and applied to quantify BAs in mouse tissues and fluids.
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Affiliation(s)
- Yazen Alnouti
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE 68198, United States.
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34
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Coordinate induction of PPAR alpha and SREBP2 in multifunctional protein 2 deficient mice. Biochim Biophys Acta Mol Cell Biol Lipids 2008; 1781:694-702. [PMID: 18773970 DOI: 10.1016/j.bbalip.2008.07.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Revised: 07/08/2008] [Accepted: 07/28/2008] [Indexed: 01/19/2023]
Abstract
Mice with inactivation of the D-specific multifunctional protein 2 (MFP2), a crucial enzyme of peroxisomal beta-oxidation, develop multiple pathologies in diverse tissues already starting in the postnatal period. Gene expression profiling performed on liver of 2-day-old pups revealed up-regulation of PPAR alpha responsive genes in knockout mice. Surprisingly, also genes involved in cholesterol biosynthesis were markedly induced. Real-time PCR confirmed the induction of PPAR alpha target genes and of HMGCR and SREBP2, both involved in cholesterol synthesis, in lactating and in adult MFP2 knockout mice. In accordance, the rate of cholesterol biosynthesis was significantly increased in liver of knockout mice but the hepatic cholesterol concentration was unaltered. In MFP2/PPAR alpha double knockout mice, up-regulations of SREBP2 and HMGCR were markedly attenuated. These data demonstrate a tight interrelationship between induction of PPAR alpha by endogenous ligands and up-regulation of genes of cholesterol biosynthesis through increased expression of SREBP2.
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35
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Chan J, Donalson LM, Kushwaha RS, Ferdinandusse S, VandeBerg JF, VandeBerg JL. Differential expression of hepatic genes involved in cholesterol homeostasis in high- and low-responding strains of laboratory opossums. Metabolism 2008; 57:718-24. [PMID: 18442639 PMCID: PMC2465809 DOI: 10.1016/j.metabol.2008.01.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Accepted: 01/07/2008] [Indexed: 10/22/2022]
Abstract
Plasma very low-density lipoprotein and low-density lipoprotein (VLDL+LDL) cholesterol levels of 2 partially inbred strains of opossums (Monodelphis domestica) differ markedly when they are fed a high-cholesterol and low-fat (HCLF) diet. High-responding opossums exhibit a dramatic increase (>10-fold) in VLDL+LDL cholesterol, whereas low-responding opossums exhibit a minimal increase (<2-fold) in VLDL+LDL cholesterol. The genes responsible for the accumulation of high levels of plasma VLDL+LDL cholesterol in high-responding opossums have not yet been identified. In this study, we analyzed the expression of genes encoding for (1) 4 bile acid synthesis enzymes (CYP7A1, CYP27A1, CYP8B1, and CYP7B1); (2) 3 cholesterol synthesis enzymes (HMGCR, HMGCS1, and SQLE); (3) the LDL receptor (LDLR); (4) 2 sterol transporters (ABCG5 and ABCG8); and (5) 2 bile acid transporters (ABCB11 and SLC10A1) to determine how the expression of these genes was affected by dietary cholesterol in the 2 strains of opossums. We found differences between high and low responders in the expression of cholesterol synthesis genes on the basal diet, as well as differences in the expression of the CYP27A1, ABCG5, ABCG8, and SLC10A1 genes on the HCLF diet. CYP27A1 messenger RNA levels were lower in the livers of high responders compared with low responders, whereas CYP27A1 messenger RNA levels in extrahepatic tissues were similar in high and low responders on the HCLF diet. Low levels of CYP27A1, ABCG5, and ABCG8 expression in the liver may contribute to hypercholesterolemia in high-responding opossums.
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Affiliation(s)
- Jeannie Chan
- Southwest National Primate Research Center, Department of Genetics, Southwest Foundation for Biomedical Research, PO Box 760549, San Antonio, TX 78245-0549, USA.
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36
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Keane MH, Overmars H, Wikander TM, Ferdinandusse S, Duran M, Wanders RJA, Faust PL. Bile acid treatment alters hepatic disease and bile acid transport in peroxisome-deficient PEX2 Zellweger mice. Hepatology 2007; 45:982-97. [PMID: 17393522 DOI: 10.1002/hep.21532] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
UNLABELLED The marked deficiency of peroxisomal organelle assembly in the PEX2(-/-) mouse model for Zellweger syndrome provides a unique opportunity to developmentally and biochemically characterize hepatic disease progression and bile acid products. The postnatal survival of homozygous mutants enabled us to evaluate the response to bile acid replenishment in this disease state. PEX2 mutant liver has severe but transient intrahepatic cholestasis that abates in the early postnatal period and progresses to steatohepatitis by postnatal day 36. We confirmed the expected reduction of mature C24 bile acids, accumulation of C27-bile acid intermediates, and low total bile acid level in liver and bile from these mutant mice. Treating the PEX2(-/-) mice with bile acids prolonged postnatal survival, alleviated intrahepatic cholestasis and intestinal malabsorption, reduced C27-bile acid intermediate production, and prevented older mutants from developing severe steatohepatitis. However, this therapy exacerbated the degree of hepatic steatosis and worsened the already severe mitochondrial and cellular damage in peroxisome-deficient liver. Both untreated and bile acid-fed PEX2(-/-) mice accumulated high levels of predominantly unconjugated bile acids in plasma because of altered expression of hepatocyte bile acid transporters. Significant amounts of unconjugated bile acids were also found in the liver and bile of PEX2 mutants, indicating a generalized defect in bile acid conjugation. CONCLUSION Peroxisome deficiency widely disturbs bile acid homeostasis and hepatic functioning in mice, and the high sensitivity of the peroxisome-deficient liver to bile acid toxicity limits the effectiveness of bile acid therapy for preventing hepatic disease.
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Affiliation(s)
- Megan H Keane
- Department of Pathology, Columbia University, New York, NY 10032, USA
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37
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Ferdinandusse S, Houten SM. Peroxisomes and bile acid biosynthesis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1427-40. [PMID: 17034878 DOI: 10.1016/j.bbamcr.2006.09.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Revised: 08/24/2006] [Accepted: 09/01/2006] [Indexed: 01/11/2023]
Abstract
Peroxisomes play an important role in the biosynthesis of bile acids because a peroxisomal beta-oxidation step is required for the formation of the mature C24-bile acids from C27-bile acid intermediates. In addition, de novo synthesized bile acids are conjugated within the peroxisome. In this review, we describe the current state of knowledge about all aspects of peroxisomal function in bile acid biosynthesis in health and disease. The peroxisomal enzymes involved in the synthesis of bile acids have been identified, and the metabolic and pathologic consequences of a deficiency of one of these enzymes are discussed, including the potential role of nuclear receptors therein.
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Affiliation(s)
- Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, F0-224 Academic Medical Center at the University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands.
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38
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Huyghe S, Schmalbruch H, Hulshagen L, Veldhoven PV, Baes M, Hartmann D. Peroxisomal multifunctional protein-2 deficiency causes motor deficits and glial lesions in the adult central nervous system. THE AMERICAN JOURNAL OF PATHOLOGY 2006; 168:1321-34. [PMID: 16565505 PMCID: PMC1606565 DOI: 10.2353/ajpath.2006.041220] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In humans, mutations inactivating multifunctional protein-2 (MFP-2), and thus peroxisomal beta-oxidation, cause neuronal heterotopia and demyelination, which is clinically reflected by hypotonia, seizures, and death within the first year of life. In contrast, our recently generated MFP-2-deficient mice did not show neurodevelopmental abnormalities but exhibited aberrations in bile acid metabolism and one of three of them died early postnatally. In the postweaning period, all survivors developed progressive motor deficits, including abnormal cramping reflexes of the limbs and loss of mobility, with death at 6 months. Motor impairment was not accompanied by lesions of peripheral nerves or muscles. However, in the central nervous system MFP-2-deficient mice overexpressed catalase in glial cells, accumulated lipids in ependymal cells and in the molecular layer of the cerebellum, exhibited severe astrogliosis and reactive microglia predominantly within the gray matter of the brain and the spinal cord, whereas synaptic and myelin markers were not affected. This culminated in degenerative changes of astroglia cells but not in overt neuronal lesions. Neither the motor deficits nor the brain lesions were aggravated by increasing the branched-chain fatty acid concentration through dietary supplementation. These data indicate that MFP-2 deficiency in mice causes a neurological phenotype in adulthood that is manifested primarily by astroglial damage.
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Affiliation(s)
- Steven Huyghe
- Laboratory of Clinical Chemistry, Campus Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium
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Makkar RS, Contreras MA, Paintlia AS, Smith BT, Haq E, Singh I. Molecular organization of peroxisomal enzymes: protein-protein interactions in the membrane and in the matrix. Arch Biochem Biophys 2006; 451:128-40. [PMID: 16781659 DOI: 10.1016/j.abb.2006.05.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Revised: 05/03/2006] [Accepted: 05/04/2006] [Indexed: 11/30/2022]
Abstract
The beta-oxidation of fatty acids in peroxisomes produces hydrogen peroxide (H2O2), a toxic metabolite, as a bi-product. Fatty acids beta-oxidation activity is deficient in X-linked adrenoleukodystrophy (X-ALD) because of mutation in ALD-gene resulting in loss of very long chain acyl-CoA synthetase (VLCS) activity. It is also affected in disease with catalase negative peroxisomes as a result of inactivation by H2O2. Therefore, the following studies were undertaken to delineate the molecular interactions between both the ALD-gene product (adrenoleukodystrophy protein, ALDP) and VLCS as well as H2O2 degrading enzyme catalase and proteins of peroxisomal beta-oxidation. Studies using a yeast two hybrid system and surface plasmon resonance techniques indicate that ALDP, a peroxisomal membrane protein, physically interacts with VLCS. Loss of these interactions in X-ALD cells may result in a deficiency in VLCS activity. The yeast two-hybrid system studies also indicated that catalase physically interacts with L-bifunctional enzyme (L-BFE). Interactions between catalase and L-BFE were further supported by affinity purification, using a catalase-linked resin. The affinity bound 74-kDa protein, was identified as L-BFE by Western blot with specific antibodies and by proteomic analysis. Additional support for their interaction comes from immunoprecipitation of L-BFE with antibodies against catalase as a catalase- L-BFE complex. siRNA for L-BFE decreased the specific activity and protein levels of catalase without changing its subcellular distribution. These observations indicate that L-BFE might help in oligomerization and possibly in the localization of catalase at the site of H2O2 production in the peroxisomal beta-oxidation pathway.
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Affiliation(s)
- Randhir S Makkar
- The Charles Darby Children's Research Institute, Department of Pediatrics, Medical University of South Carolina, Charleston, SC 29425, USA
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40
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Huyghe S, Mannaerts GP, Baes M, Van Veldhoven PP. Peroxisomal multifunctional protein-2: the enzyme, the patients and the knockout mouse model. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:973-94. [PMID: 16766224 DOI: 10.1016/j.bbalip.2006.04.006] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2006] [Revised: 04/04/2006] [Accepted: 04/10/2006] [Indexed: 10/24/2022]
Abstract
The mammalian multifunctional protein-2 (MFP-2, also called multifunctional enzyme 2, D-bifunctional enzyme or 17-beta-estradiol dehydrogenase type IV) was identified by several groups about a decade ago. It plays a central role in peroxisomal beta-oxidation as it handles most, if not all, peroxisomal beta-oxidation substrates. Deficiency of this enzyme in man causes a severe developmental syndrome with abnormalities in several organs but in particular in the brain, leading to death within the first year of life. Accumulation of branched-long-chain fatty acids and very-long-chain fatty acids and a disturbed synthesis of bile acids were documented in these patients. A mouse model with MFP-2 deficiency only partly phenocopies the human disease. Although the expected metabolic abnormalities are present, no neurodevelopmental aberrations are observed. However, the survival of these mice into adulthood allowed to document the importance of this enzyme for the normal functioning of the brain, eyes and testis. In the present review, the identification and biochemical characteristics of MFP-2, and the consequences of MFP-2 dysfunction in humans and in mice will be discussed.
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Affiliation(s)
- Steven Huyghe
- Laboratory of Cell Metabolism, Department of Pharmaceutical Sciences, Katholieke Universiteit Leuven, Campus Gasthuisberg, Onderwijs en Navorsing II, bus 823, Herestraat 49, B-3000 Leuven, Belgium
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41
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Huyghe S, Schmalbruch H, De Gendt K, Verhoeven G, Guillou F, Van Veldhoven PP, Baes M. Peroxisomal multifunctional protein 2 is essential for lipid homeostasis in Sertoli cells and male fertility in mice. Endocrinology 2006; 147:2228-36. [PMID: 16484321 DOI: 10.1210/en.2005-1571] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Inactivation of peroxisomal beta-oxidation in mice, by knocking out multifunctional protein-2 (MFP-2; also called d-bifunctional enzyme), causes male infertility. In the testis, extensive accumulations of neutral lipids were observed in Sertoli cells, beginning in prepubertal mice and evolving in complete testicular atrophy by the age of 4 months. Spermatogenesis was already severely affected at the age of 5 wk, and pre- and postmeiotic germ cells gradually disappeared from the tubuli seminiferi. Based on cytochemical stainings and biochemical analyses, the lipid droplets consisted of cholesteryl esters and neutral glycerolipids. Furthermore, peroxisomal beta-oxidation substrates, such as very-long-chain fatty acids and pristanic acid, accumulated in the testis, whereas the concentration of docosapentaenoic acid, a polyunsaturated fatty acid and peroxisomal beta-oxidation product, was reduced. The testicular defects were also present in double MFP-2/peroxisome proliferator-activated receptor-alpha knockout mice, ruling out the possibility that they were mediated through the activation of this nuclear receptor. Immunoreactivity for peroxisomal proteins, including MFP-2, was detected in Sertoli cells as well as in germ cells and Leydig cells. The pivotal role of peroxisomal metabolism in Sertoli cells was also demonstrated by generating mice with a Sertoli cell-selective elimination of peroxisomes through cell type-specific inactivation of the peroxin 5 gene. These mice also developed lipid inclusions and were infertile, and their testes fully degenerated by the age of 4 months. In conclusion, the present data demonstrate that peroxisomal beta-oxidation is essential for lipid homeostasis in the testis and for male fertility.
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Affiliation(s)
- Steven Huyghe
- Laboratory of Clinical Chemistry, Faculty of Pharmacy, Katholieke Universiteit, Leuven, Belgium
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42
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Taskinen JP, Kiema TR, Hiltunen JK, Wierenga RK. Structural Studies of MFE-1: the 1.9Å Crystal Structure of the Dehydrogenase Part of Rat Peroxisomal MFE-1. J Mol Biol 2006; 355:734-46. [PMID: 16330050 DOI: 10.1016/j.jmb.2005.10.085] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Revised: 10/26/2005] [Accepted: 10/26/2005] [Indexed: 10/25/2022]
Abstract
The 1.9 A structure of the C-terminal dehydrogenase part of the rat peroxisomal monomeric multifunctional enzyme type 1 (MFE-1) has been determined. In this construct (residues 260-722 and referred to as MFE1-DH) the N-terminal hydratase part of MFE-1 has been deleted. The structure of MFE1-DH shows that it consists of an N-terminal helix, followed by a Rossmann-fold domain (domain C), followed by two tightly associated helical domains (domains D and E), which have similar topology. The structure of MFE1-DH is compared with the two known homologous structures: human mitochondrial 3-hydroxyacyl-CoA dehydrogenase (HAD; sequence identity is 33%) (which is dimeric and monofunctional) and with the dimeric multifunctional alpha-chain (alphaFOM; sequence identity is 28%) of the bacterial fatty acid beta-oxidation alpha2beta2-multienzyme complex. Like MFE-1, alphaFOM has an N-terminal hydratase part and a C-terminal dehydrogenase part, and the structure comparisons show that the N-terminal helix of MFE1-DH corresponds to the alphaFOM linker helix, located between its hydratase and dehydrogenase part. It is also shown that this helix corresponds to the C-terminal helix-10 of the hydratase/isomerase superfamily, suggesting that functionally it belongs to the N-terminal hydratase part of MFE-1.
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Affiliation(s)
- Jukka P Taskinen
- Biocenter Oulu and Department of Biochemistry, University of Oulu, P.O. Box 3000, FIN-90014, Finland
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