1
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Wang D, Li H, Chandel NS, Dou Y, Yi R. MOF-mediated histone H4 Lysine 16 acetylation governs mitochondrial and ciliary functions by controlling gene promoters. Nat Commun 2023; 14:4404. [PMID: 37479688 PMCID: PMC10362062 DOI: 10.1038/s41467-023-40108-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 07/11/2023] [Indexed: 07/23/2023] Open
Abstract
Histone H4 lysine 16 acetylation (H4K16ac), governed by the histone acetyltransferase MOF, orchestrates gene expression regulation and chromatin interaction. However, the roles of MOF and H4K16ac in controlling cellular function and regulating mammalian tissue development remain unclear. Here we show that conditional deletion of Mof in the skin, but not Kansl1, causes severe defects in the self-renewal of basal epithelial progenitors, epidermal differentiation, and hair follicle growth, resulting in barrier defects and perinatal lethality. MOF-regulated genes are highly enriched for essential functions in the mitochondria and cilia. Genetic deletion of Uqcrq, an essential subunit for the electron transport chain (ETC) Complex III, in the skin, recapitulates the defects in epidermal differentiation and hair follicle growth observed in MOF knockout mouse. Together, this study reveals the requirement of MOF-mediated epigenetic mechanism for regulating mitochondrial and ciliary gene expression and underscores the important function of the MOF/ETC axis for mammalian skin development.
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Affiliation(s)
- Dongmei Wang
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Haimin Li
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Navdeep S Chandel
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Yali Dou
- Department of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Rui Yi
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
- Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
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2
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Mohan S, Mayers M, Weaver M, Baudet H, De Biase I, Goldstein J, Mao R, McGlaughon J, Moser A, Pujol A, Suchy S, Yuzyuk T, Braverman NE. Evaluating the strength of evidence for genes implicated in peroxisomal disorders using the ClinGen clinical validity framework and providing updates to the peroxisomal disease nomenclature. Mol Genet Metab 2023; 139:107604. [PMID: 37236006 PMCID: PMC10484331 DOI: 10.1016/j.ymgme.2023.107604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 03/09/2023] [Accepted: 05/01/2023] [Indexed: 05/28/2023]
Abstract
Peroxisomal disorders are heterogeneous in nature, with phenotypic overlap that is indistinguishable without molecular testing. Newborn screening and gene sequencing for a panel of genes implicated in peroxisomal diseases are critical tools for the early and accurate detection of these disorders. It is therefore essential to evaluate the clinical validity of the genes included in sequencing panels for peroxisomal disorders. The Peroxisomal Gene Curation Expert Panel (GCEP) assessed genes frequently included on clinical peroxisomal testing panels using the Clinical Genome Resource (ClinGen) gene-disease validity curation framework and classified gene-disease relationships as Definitive, Strong, Moderate, Limited, Disputed, Refuted, or No Known Disease Relationship. Subsequent to gene curation, the GCEP made recommendations to update the disease nomenclature and ontology in the Monarch Disease Ontology (Mondo) database. Thirty-six genes were assessed for the strength of evidence supporting their role in peroxisomal disease, leading to 36 gene-disease relationships, after two genes were removed for their lack of a role in peroxisomal disease and two genes were curated for two different disease entities each. Of these, 23 were classified as Definitive (64%), one as Strong (3%), eight as Moderate (23%), two as Limited (5%), and two as No known disease relationship (5%). No contradictory evidence was found to classify any relationships as Disputed or Refuted. The gene-disease relationship curations are publicly available on the ClinGen website (https://clinicalgenome.org/affiliation/40049/). The changes to peroxisomal disease nomenclature are displayed on the Mondo website (http://purl.obolibrary.org/obo/MONDO_0019053). The Peroxisomal GCEP-curated gene-disease relationships will inform clinical and laboratory diagnostics and enhance molecular testing and reporting. As new data will emerge, the gene-disease classifications asserted by the Peroxisomal GCEP will be re-evaluated periodically.
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Affiliation(s)
- Shruthi Mohan
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, NC, USA
| | - Megan Mayers
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, NC, USA
| | - Meredith Weaver
- American College of Medical Genetics and Genomics, Bethesda, MD, USA
| | - Heather Baudet
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, NC, USA
| | | | - Jennifer Goldstein
- Department of Genetics, School of Medicine, University of North Carolina at Chapel Hill, NC, USA
| | - Rong Mao
- ARUP Laboratories, Salt Lake City, UT, USA
| | | | - Ann Moser
- Kennedy Krieger Institute, Baltimore, MD, USA
| | - Aurora Pujol
- Bellvitge Biomedical Research Institute (IDIBELL Instituto de Investigación Biomédica de Bellvitge), Barcelona, Spain
| | | | | | - Nancy E Braverman
- Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
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3
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Landowski M, Bhute VJ, Grindel S, Haugstad Z, Gyening YK, Tytanic M, Brush RS, Moyer LJ, Nelson DW, Davis CR, Yen CLE, Ikeda S, Agbaga MP, Ikeda A. Transmembrane protein 135 regulates lipid homeostasis through its role in peroxisomal DHA metabolism. Commun Biol 2023; 6:8. [PMID: 36599953 PMCID: PMC9813353 DOI: 10.1038/s42003-022-04404-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 12/23/2022] [Indexed: 01/05/2023] Open
Abstract
Transmembrane protein 135 (TMEM135) is thought to participate in the cellular response to increased intracellular lipids yet no defined molecular function for TMEM135 in lipid metabolism has been identified. In this study, we performed a lipid analysis of tissues from Tmem135 mutant mice and found striking reductions of docosahexaenoic acid (DHA) across all Tmem135 mutant tissues, indicating a role of TMEM135 in the production of DHA. Since all enzymes required for DHA synthesis remain intact in Tmem135 mutant mice, we hypothesized that TMEM135 is involved in the export of DHA from peroxisomes. The Tmem135 mutation likely leads to the retention of DHA in peroxisomes, causing DHA to be degraded within peroxisomes by their beta-oxidation machinery. This may lead to generation or alteration of ligands required for the activation of peroxisome proliferator-activated receptor a (PPARa) signaling, which in turn could result in increased peroxisomal number and beta-oxidation enzymes observed in Tmem135 mutant mice. We confirmed this effect of PPARa signaling by detecting decreased peroxisomes and their proteins upon genetic ablation of Ppara in Tmem135 mutant mice. Using Tmem135 mutant mice, we also validated the protective effect of increased peroxisomes and peroxisomal beta-oxidation on the metabolic disease phenotypes of leptin mutant mice which has been observed in previous studies. Thus, we conclude that TMEM135 has a role in lipid homeostasis through its function in peroxisomes.
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Affiliation(s)
- Michael Landowski
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Vijesh J Bhute
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- Department of Chemical Engineering, Imperial College London, South Kensington, London, UK
| | - Samuel Grindel
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - Zachary Haugstad
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - Yeboah K Gyening
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Dean A. McGee Eye Institute, Oklahoma City, OK, USA
| | - Madison Tytanic
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Dean A. McGee Eye Institute, Oklahoma City, OK, USA
| | - Richard S Brush
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Dean A. McGee Eye Institute, Oklahoma City, OK, USA
| | - Lucas J Moyer
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - David W Nelson
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Christopher R Davis
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Chi-Liang Eric Yen
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Sakae Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Martin-Paul Agbaga
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Dean A. McGee Eye Institute, Oklahoma City, OK, USA
| | - Akihiro Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA.
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA.
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4
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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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5
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Role of STAR and SCP2/SCPx in the Transport of Cholesterol and Other Lipids. Int J Mol Sci 2022; 23:ijms232012115. [PMID: 36292972 PMCID: PMC9602805 DOI: 10.3390/ijms232012115] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 09/30/2022] [Accepted: 10/08/2022] [Indexed: 11/21/2022] Open
Abstract
Cholesterol is a lipid molecule essential for several key cellular processes including steroidogenesis. As such, the trafficking and distribution of cholesterol is tightly regulated by various pathways that include vesicular and non-vesicular mechanisms. One non-vesicular mechanism is the binding of cholesterol to cholesterol transport proteins, which facilitate the movement of cholesterol between cellular membranes. Classic examples of cholesterol transport proteins are the steroidogenic acute regulatory protein (STAR; STARD1), which facilitates cholesterol transport for acute steroidogenesis in mitochondria, and sterol carrier protein 2/sterol carrier protein-x (SCP2/SCPx), which are non-specific lipid transfer proteins involved in the transport and metabolism of many lipids including cholesterol between several cellular compartments. This review discusses the roles of STAR and SCP2/SCPx in cholesterol transport as model cholesterol transport proteins, as well as more recent findings that support the role of these proteins in the transport and/or metabolism of other lipids.
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6
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Galano M, Ezzat S, Papadopoulos V. SCP2 variant is associated with alterations in lipid metabolism, brainstem neurodegeneration, and testicular defects. Hum Genomics 2022; 16:32. [PMID: 35996156 PMCID: PMC9396802 DOI: 10.1186/s40246-022-00408-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 08/11/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND The detoxification of very long-chain and branched-chain fatty acids and the metabolism of cholesterol to form bile acids occur largely through a process called peroxisomal β-oxidation. Mutations in several peroxisomal proteins involved in β-oxidation have been reported, resulting in diseases characterized by neurological defects. The final step of the peroxisomal β-oxidation pathway is catalyzed by sterol carrier protein-x (SCPx), which is encoded by the SCP2 gene. Previously, there have been two reports of SCPx deficiency, which resulted from a homozygous or compound heterozygous SCP2 mutation. We report herein the first patient with a heterozygous SCP2 mutation leading to SCPx deficiency. RESULTS Clinical presentations of the patient included progressive brainstem neurodegeneration, cardiac dysrhythmia, muscle wasting, and azoospermia. Plasma fatty acid analysis revealed abnormal values of medium-, long-, and very long-chain fatty acids. Protein expression of SCPx and other enzymes involved in β-oxidation were altered between patient and normal fibroblasts. RNA sequencing and lipidomic analyses identified metabolic pathways that were altered between patient and normal fibroblasts including PPAR signaling, serotonergic signaling, steroid biosynthesis, and fatty acid degradation. Treatment with fenofibrate or 4-hydroxytamoxifen increased SCPx levels, and certain fatty acid levels in patient fibroblasts. CONCLUSIONS These findings suggest that the patient's SCP2 mutation resulted in decreased protein levels of SCPx, which may be associated with many metabolic pathways. Increasing SCPx levels through pharmacological interventions may reverse some effects of SCPx deficiency. Collectively, this work provides insight into many of the clinical consequences of SCPx deficiency and provides evidence for potential treatment strategies.
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Affiliation(s)
- Melanie Galano
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Ave, Los Angeles, CA, 90089, USA
| | - Shereen Ezzat
- Department of Medicine, University of Toronto and Princess Margaret Cancer Center, Toronto, ON, M5G 2C1, Canada
| | - Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Ave, Los Angeles, CA, 90089, USA.
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7
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Sharma S, Shen T, Chitranshi N, Gupta V, Basavarajappa D, Mirzaei M, You Y, Krezel W, Graham SL, Gupta V. Retinoid X Receptor: Cellular and Biochemical Roles of Nuclear Receptor with a Focus on Neuropathological Involvement. Mol Neurobiol 2022; 59:2027-2050. [PMID: 35015251 PMCID: PMC9015987 DOI: 10.1007/s12035-021-02709-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 12/21/2021] [Indexed: 12/13/2022]
Abstract
Retinoid X receptors (RXRs) present a subgroup of the nuclear receptor superfamily with particularly high evolutionary conservation of ligand binding domain. The receptor exists in α, β, and γ isotypes that form homo-/heterodimeric complexes with other permissive and non-permissive receptors. While research has identified the biochemical roles of several nuclear receptor family members, the roles of RXRs in various neurological disorders remain relatively under-investigated. RXR acts as ligand-regulated transcription factor, modulating the expression of genes that plays a critical role in mediating several developmental, metabolic, and biochemical processes. Cumulative evidence indicates that abnormal RXR signalling affects neuronal stress and neuroinflammatory networks in several neuropathological conditions. Protective effects of targeting RXRs through pharmacological ligands have been established in various cell and animal models of neuronal injury including Alzheimer disease, Parkinson disease, glaucoma, multiple sclerosis, and stroke. This review summarises the existing knowledge about the roles of RXR, its interacting partners, and ligands in CNS disorders. Future research will determine the importance of structural and functional heterogeneity amongst various RXR isotypes as well as elucidate functional links between RXR homo- or heterodimers and specific physiological conditions to increase drug targeting efficiency in pathological conditions.
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Affiliation(s)
- Samridhi Sharma
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia.
| | - Ting Shen
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Nitin Chitranshi
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Veer Gupta
- School of Medicine, Deakin University, Melbourne, VIC, Australia
| | - Devaraj Basavarajappa
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Mehdi Mirzaei
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Yuyi You
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia.,Save Sight Institute, University of Sydney, Sydney, NSW, Australia
| | - Wojciech Krezel
- Institut de Génétique Et de Biologie Moléculaire Et Cellulaire, INSERM U1258, CNRS UMR 7104, Unistra, 67404, Illkirch-Graffenstaden, France
| | - Stuart L Graham
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia.,Save Sight Institute, University of Sydney, Sydney, NSW, Australia
| | - Vivek Gupta
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia.
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8
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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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9
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Zhao CS, Wei W, Luo SW, Yang P, Ren YH, Liu Y, Wang WN. FABP regulates fatty acid metabolism and oxidative response via PPARα/RXR signaling in Litopenaeus vannamei following environmental exposure of clofibric acid. ECOTOXICOLOGY (LONDON, ENGLAND) 2021; 30:954-965. [PMID: 33864550 DOI: 10.1007/s10646-021-02408-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/28/2021] [Indexed: 06/12/2023]
Abstract
Clofibric acid (CFA), a drug and personal care product, has been identified as ubiquitous in the aquatic system and surface water, causing pollution to the environment. In this study, after environmental (4 µg/L) levels of CFA challenge, the LvFABP, LvACS gene expressions, total haemocyte count (THC), relative enzymes (SOD1 and GST) activities in Litopenaeus vannamei were observed to decrease. In the meantime LvFATP, LvRXR expression and the level of NEFA were upregulated in L. vannamei body. LvFABP expression in vivo was knocked down by dsRNA-mediated RNA interference (RNAi), which led to significantly decreased levels of PPARα (including LvFATP, LvRXR and LvACS). When exposed to environmental CFA after 4 days, LvFABP knocked down group had a sharp upregulation of LvFATP, LvRXR, LvACS expression, GST activity and NEFA amount, following decreased THC and SOD1 activity. These results suggested that environmental concentration CFA may have some toxicological effect on L. vannamei, following fatty acids metabolism and oxidative stress responses by LvFABP via the PPARα/RXR signaling pathway, including LvFATP, LvRXR and LvACS.
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Affiliation(s)
- Chang-Sheng Zhao
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Wei Wei
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Sheng-Wei Luo
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Ping Yang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Ying-Hao Ren
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Yuan Liu
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China
| | - Wei-Na Wang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou, 510631, PR China.
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10
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Neurodegeneration with Brain Iron Accumulation and a Brief Report of the Disease in Iran. Can J Neurol Sci 2021; 49:338-351. [PMID: 34082843 DOI: 10.1017/cjn.2021.124] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Neurodegeneration with brain iron accumulation (NBIA) is a term used for a group of hereditary neurological disorders with abnormal accumulation of iron in basal ganglia. It is clinically and genetically heterogeneous with symptoms such as dystonia, dysarthria, Parkinsonism, intellectual disability, and spasticity. The age at onset and rate of progression are variable among individuals. Current therapies are exclusively symptomatic and unable to hinder the disease progression. Approximately 16 genes have been identified and affiliated to such condition with different functions such as iron metabolism (only two genes: Ferritin Light Chain (FTL) Ceruloplasmin (CP)), lipid metabolism, lysosomal functions, and autophagy process, but some functions have remained unknown so far. Subgroups of NBIA are categorized based on the mutant genes. Although in the last 10 years, the development of whole-exome sequencing (WES) technology has promoted the identification of disease-causing genes, there seem to be some unknown genes and our knowledge about the molecular aspects and pathogenesis of NBIA is not complete yet. There is currently no comprehensive study about the NBIA in Iran; however, one of the latest discovered NBIA genes, GTP-binding protein 2 (GTPBP2), has been identified in an Iranian family, and there are some patients who have genetically remained unknown.
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11
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Gianotti AR, Klinke S, Ermácora MR. The structure of unliganded sterol carrier protein 2 from Yarrowia lipolytica unveils a mechanism for binding site occlusion. J Struct Biol 2020; 213:107675. [PMID: 33278583 DOI: 10.1016/j.jsb.2020.107675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/21/2020] [Accepted: 11/27/2020] [Indexed: 11/19/2022]
Abstract
Isolated or as a part of multidomain proteins, Sterol Carrier Protein 2 (SCP2) exhibits high affinity and broad specificity for different lipidic and hydrophobic compounds. A wealth of structural information on SCP2 domains in all forms of life is currently available; however, many aspects of its ligand binding activity are poorly understood. ylSCP2 is a well-characterized single domain SCP2 from the yeast Yarrowia lipolytica. Herein, we report the X-ray structure of unliganded ylSCP2 refined to 2.0 Å resolution. Comparison with the previously solved liganded ylSCP2 structure unveiled a novel mechanism for binding site occlusion. The liganded ylSCP2 binding site is a large cavity with a volume of more than 800 Å3. In unliganded ylSCP2 the binding site is reduced to about 140 Å3. The obliteration is caused by a swing movement of the C-terminal α helix 5 and a subtle compaction of helices 2-4. Previous pairwise comparisons were between homologous SCP2 domains with a uncertain binding status. The reported unliganded ylSCP2 structure allows for the first time a fully controlled comparative analysis of the conformational effects of ligand occupation dispelling several doubts regarding the architecture of SCP2 binding site.
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Affiliation(s)
- Alejo R Gianotti
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Argentina; Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Argentina
| | - Sebastián Klinke
- Fundación Instituto Leloir, IIBBA-CONICET, and Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Buenos Aires, Argentina
| | - Mario R Ermácora
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Argentina; Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes, Argentina.
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Cerebellar and hepatic alterations in ACBD5-deficient mice are associated with unexpected, distinct alterations in cellular lipid homeostasis. Commun Biol 2020; 3:713. [PMID: 33244184 PMCID: PMC7691522 DOI: 10.1038/s42003-020-01442-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 10/31/2020] [Indexed: 11/27/2022] Open
Abstract
ACBD5 deficiency is a novel peroxisome disorder with a largely uncharacterized pathology. ACBD5 was recently identified in a tethering complex mediating membrane contacts between peroxisomes and the endoplasmic reticulum (ER). An ACBD5-deficient mouse was analyzed to correlate ACBD5 tethering functions with the disease phenotype. ACBD5-deficient mice exhibit elevated very long-chain fatty acid levels and a progressive cerebellar pathology. Liver did not exhibit pathologic changes but increased peroxisome abundance and drastically reduced peroxisome-ER contacts. Lipidomics of liver and cerebellum revealed tissue-specific alterations in distinct lipid classes and subspecies. In line with the neurological pathology, unusual ultra-long chain fatty acids (C > 32) were elevated in phosphocholines from cerebelli but not liver indicating an organ-specific imbalance in fatty acid degradation and elongation pathways. By contrast, ether lipid formation was perturbed in liver towards an accumulation of alkyldiacylglycerols. The alterations in several lipid classes suggest that ACBD5, in addition to its acyl-CoA binding function, might maintain peroxisome-ER contacts in order to contribute to the regulation of anabolic and catabolic cellular lipid pathways. Darwisch, von Spangenberg et al. show that ACBD5‐deficient mice exhibit elevated levels of very long‐chain fatty acids and a progressive cerebellar pathology. A complex metabolic phenotype suggests that ACBD5 with its acyl‐CoA binding and peroxisome‐ER tethering functions might contribute to the regulation of anabolic and catabolic cellular lipid pathways.
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Jiang M, Wang S, Li F, Geng J, Ji Y, Li K, Jiang X. A novel 1p33p32.2 deletion involving SCP2, ORC1, and DAB1 genes in a patient with craniofacial dysplasia, short stature, developmental delay, and leukoencephalopathy: A case report. Medicine (Baltimore) 2020; 99:e23033. [PMID: 33157955 PMCID: PMC7647596 DOI: 10.1097/md.0000000000023033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
INTRODUCTION Microdeletion syndromes occur from deletion of 5Mb of a chromosome in approximately 5% of patients with unexplained intellectual disability. Interstitial microdeletions at bands 1p33 and 1p32.2 of the short arm of chromosome 1 are rare and have not been previously reported in relation to disease. PATIENT CONCERNS We present a case of a 39-month boy with Pierre Robin sequence, development delay/intellectual disability, growth retardation, short stature, leukoencephalopathy, craniofacial dysplasia, and speech delay. The child was referred to the Child health care department in October 2014 for his delayed language development and aggravated aggression. DIAGNOSIS Molecular diagnostic testing with G-band karyotyping was normal but clinical microarray analysis detected a 10 Mb microdeletion at 1p33p32.2. INTERVENTIONS The patient received rehabilitation. OUTCOMES Three candidate genes were pinpointed to the deleted area, including ORC1, SCP2, and DAB1. Phenotype-genotype analysis suggested that these three genes are likely to be responsible for the main phenotypes observed in the patient, such as microcephaly, growth retardation, short stature, leukoencephalopathy, and development delay/intellectual disability. CONCLUSIONS The spectrum of phenotypes this case presented with are likely to be caused by 1p33p32.2 deletion which could represent a new microdeletion syndrome.
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Affiliation(s)
- Maoying Jiang
- Hangzhou Children's Hospital, Behavioral Pediatric Department &Child Primary Care Department, Hangzhou
| | - Shanlin Wang
- Hangzhou Children's Hospital, Behavioral Pediatric Department &Child Primary Care Department, Hangzhou
| | - Fei Li
- Developmental and Behavioral Pediatric Department & Child Primary Care Department, MOE-Shanghai Key Lab for Children's Enviromental Health, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai
| | - Juan Geng
- Hangzhou Joingenome Diagnostics, Hangzhou
| | - Yiting Ji
- Developmental and Behavioral Pediatric Department, Shanghai Children's Hospital, Affiliated To Shanghai Jiaotong University School of Medicine& MOE-Shanghai Key Lab for Children's Environmental Health, Shanghai, China
| | - Ke Li
- Developmental and Behavioral Pediatric Department, Shanghai Children's Hospital, Affiliated To Shanghai Jiaotong University School of Medicine& MOE-Shanghai Key Lab for Children's Environmental Health, Shanghai, China
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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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15
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Martin GG, Seeger DR, McIntosh AL, Milligan S, Chung S, Landrock D, Dangott LJ, Golovko MY, Murphy EJ, Kier AB, Schroeder F. Sterol Carrier Protein-2/Sterol Carrier Protein-x/Fatty Acid Binding Protein-1 Ablation Impacts Response of Brain Endocannabinoid to High-Fat Diet. Lipids 2019; 54:583-601. [PMID: 31487051 DOI: 10.1002/lipd.12192] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 08/16/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022]
Abstract
Brain endocannabinoids (EC) such as arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) primarily originate from serum arachidonic acid (ARA), whose level is regulated in part by a cytosolic ARA-binding protein, that is, liver fatty acid binding protein-1 (FABP1), not expressed in the brain. Ablation of the Fabp1 gene (LKO) increases brain AEA and 2-AG by decreasing hepatic uptake of ARA to increase serum ARA, thereby increasing ARA availability for uptake by the brain. The brain also expresses sterol carrier protein-2 (SCP-2), which is also a cytosolic ARA-binding protein. To further resolve the role of SCP-2 independent of FABP1, mice ablated in the Scp-2/Scp-x gene (DKO) were crossed with mice ablated in the Fabp1 gene (LKO) mice to generate triple knock out (TKO) mice. TKO impaired the ability of LKO to increase brain AEA and 2-AG. While a high-fat diet (HFD) alone increased brain AEA, TKO impaired this effect. Overall, these TKO-induced blocks were not attributable to altered expression of brain proteins in ARA uptake, AEA/2-AG synthesis, or AEA/2-AG degrading enzymes. Instead, TKO reduced serum levels of free ARA and/or total ARA and thereby decreased ARA availability for uptake to the brain and downstream synthesis of AEA and 2-AG therein. In summary, Scp-2/Scp-x gene ablation in Fabp1 null (LKO) mice antagonized the impact of LKO and HFD on brain ARA and, subsequently, EC levels. Thus, both FABP1 and SCP-2 participate in regulating the EC system in the brain.
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA
| | - Drew R Seeger
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, 58202-9037, USA
| | - Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA
| | - Sherrelle Milligan
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Sarah Chung
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Lawrence J Dangott
- Protein Chemistry Laboratory, Texas A&M University, College Station, TX, 77843-2128, USA
| | - Mikhail Y Golovko
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, 58202-9037, USA
| | - Eric J Murphy
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, 58202-9037, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA
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16
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Shumar SA, Kerr EW, Fagone P, Infante AM, Leonardi R. Overexpression of Nudt7 decreases bile acid levels and peroxisomal fatty acid oxidation in the liver. J Lipid Res 2019; 60:1005-1019. [PMID: 30846528 PMCID: PMC6495166 DOI: 10.1194/jlr.m092676] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 03/04/2019] [Indexed: 12/14/2022] Open
Abstract
Lipid metabolism requires CoA, an essential cofactor found in multiple subcellular compartments, including the peroxisomes. In the liver, CoA levels are dynamically adjusted between the fed and fasted states. Elevated CoA levels in the fasted state are driven by increased synthesis; however, this also correlates with decreased expression of Nudix hydrolase (Nudt)7, the major CoA-degrading enzyme in the liver. Nudt7 resides in the peroxisomes, and we overexpressed this enzyme in mouse livers to determine its effect on the size and composition of the hepatic CoA pool in the fed and fasted states. Nudt7 overexpression did not change total CoA levels, but decreased the concentration of short-chain acyl-CoAs and choloyl-CoA in fasted livers, when endogenous Nudt7 activity was lowest. The effect on these acyl-CoAs correlated with a significant decrease in the hepatic bile acid content and in the rate of peroxisomal fatty acid oxidation, as estimated by targeted and untargeted metabolomics, combined with the measurement of fatty acid oxidation in intact hepatocytes. Identification of the CoA species and metabolic pathways affected by the overexpression on Nudt7 in vivo supports the conclusion that the nutritionally driven modulation of Nudt7 activity could contribute to the regulation of the peroxisomal CoA pool and peroxisomal lipid metabolism.
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Affiliation(s)
- Stephanie A Shumar
- Department of Biochemistry, West Virginia University, Morgantown, WV 26506
| | - Evan W Kerr
- Department of Biochemistry, West Virginia University, Morgantown, WV 26506
| | - Paolo Fagone
- Department of Biochemistry, West Virginia University, Morgantown, WV 26506; Protein Core Facility West Virginia University, Morgantown, WV 26506
| | - Aniello M Infante
- Genomics Core Facility West Virginia University, Morgantown, WV 26506
| | - Roberta Leonardi
- Department of Biochemistry, West Virginia University, Morgantown, WV 26506.
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17
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Wanders RJA, Vaz FM, Ferdinandusse S, van Kuilenburg ABP, Kemp S, van Karnebeek CD, Waterham HR, Houtkooper RH. Translational Metabolism: A multidisciplinary approach towards precision diagnosis of inborn errors of metabolism in the omics era. J Inherit Metab Dis 2019; 42:197-208. [PMID: 30723938 DOI: 10.1002/jimd.12008] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 09/27/2018] [Accepted: 10/11/2018] [Indexed: 12/19/2022]
Abstract
The laboratory diagnosis of inborn errors of metabolism has been revolutionized in recent years, thanks to the amazing developments in the field of DNA sequencing including whole exome and whole genome sequencing (WES and WGS). Interpretation of the results coming from WES and/or WGS analysis is definitely not trivial especially since the biological relevance of many of the variants identified by WES and/or WGS, have not been tested experimentally and prediction programs like POLYPHEN-2 and SIFT are far from perfect. Correct interpretation of WES and/or WGS results can only be achieved by performing functional studies at multiple levels (different metabolomics platforms, enzymology, in vitro and in vivo flux analysis), often requires studies in model organisms like zebra fish, Caenorhabditis elegans, Saccharomyces cerevisiae, mutant mice and others, and also requires the input of many different disciplines to make this Translational Metabolism approach effective.
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Affiliation(s)
- Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory Genetic Metabolic Diseases, Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Frederic M Vaz
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory Genetic Metabolic Diseases, Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory Genetic Metabolic Diseases, Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - André B P van Kuilenburg
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory Genetic Metabolic Diseases, Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Stephan Kemp
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory Genetic Metabolic Diseases, Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Clara D van Karnebeek
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory Genetic Metabolic Diseases, Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory Genetic Metabolic Diseases, Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Riekelt H Houtkooper
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
- Laboratory Genetic Metabolic Diseases, Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
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Neurodegeneration with Brain Iron Accumulation Disorders: Valuable Models Aimed at Understanding the Pathogenesis of Iron Deposition. Pharmaceuticals (Basel) 2019; 12:ph12010027. [PMID: 30744104 PMCID: PMC6469182 DOI: 10.3390/ph12010027] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 01/25/2019] [Accepted: 01/29/2019] [Indexed: 02/07/2023] Open
Abstract
Neurodegeneration with brain iron accumulation (NBIA) is a set of neurodegenerative disorders, which includes very rare monogenetic diseases. They are heterogeneous in regard to the onset and the clinical symptoms, while the have in common a specific brain iron deposition in the region of the basal ganglia that can be visualized by radiological and histopathological examinations. Nowadays, 15 genes have been identified as causative for NBIA, of which only two code for iron-proteins, while all the other causative genes codify for proteins not involved in iron management. Thus, how iron participates to the pathogenetic mechanism of most NBIA remains unclear, essentially for the lack of experimental models that fully recapitulate the human phenotype. In this review we reported the recent data on new models of these disorders aimed at highlight the still scarce knowledge of the pathogenesis of iron deposition.
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The peroxisomal zebrafish SCP2-thiolase (type-1) is a weak transient dimer as revealed by crystal structures and native mass spectrometry. Biochem J 2019; 476:307-332. [PMID: 30573650 DOI: 10.1042/bcj20180788] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/12/2018] [Accepted: 12/20/2018] [Indexed: 12/19/2022]
Abstract
The SCP2 (sterol carrier protein 2)-thiolase (type-1) functions in the vertebrate peroxisomal, bile acid synthesis pathway, converting 24-keto-THC-CoA and CoA into choloyl-CoA and propionyl-CoA. This conversion concerns the β-oxidation chain shortening of the steroid fatty acyl-moiety of 24-keto-THC-CoA. This class of dimeric thiolases has previously been poorly characterized. High-resolution crystal structures of the zebrafish SCP2-thiolase (type-1) now reveal an open catalytic site, shaped by residues of both subunits. The structure of its non-dimerized monomeric form has also been captured in the obtained crystals. Four loops at the dimer interface adopt very different conformations in the monomeric form. These loops also shape the active site and their structural changes explain why a competent active site is not present in the monomeric form. Native mass spectrometry studies confirm that the zebrafish SCP2-thiolase (type-1) as well as its human homolog are weak transient dimers in solution. The crystallographic binding studies reveal the mode of binding of CoA and octanoyl-CoA in the active site, highlighting the conserved geometry of the nucleophilic cysteine, the catalytic acid/base cysteine and the two oxyanion holes. The dimer interface of SCP2-thiolase (type-1) is equally extensive as in other thiolase dimers; however, it is more polar than any of the corresponding interfaces, which correlates with the notion that the enzyme forms a weak transient dimer. The structure comparison of the monomeric and dimeric forms suggests functional relevance of this property. These comparisons provide also insights into the structural rearrangements that occur when the folded inactive monomers assemble into the mature dimer.
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20
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Huang K, Chen W, Zhu F, Li PWL, Kapahi P, Bai H. RiboTag translatomic profiling of Drosophila oenocytes under aging and induced oxidative stress. BMC Genomics 2019; 20:50. [PMID: 30651069 PMCID: PMC6335716 DOI: 10.1186/s12864-018-5404-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 12/20/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Aging is accompanied with loss of tissue homeostasis and accumulation of cellular damages. As one of the important metabolic centers, liver shows age-related dysregulation of lipid metabolism, impaired detoxification pathway, increased inflammation and oxidative stress response. However, the mechanisms for these age-related changes still remain unclear. In the fruit fly, Drosophila melanogaster, liver-like functions are controlled by two distinct tissues, fat body and oenocytes. Compared to fat body, little is known about how oenocytes age and what are their roles in aging regulation. To characterize age- and stress-regulated gene expression in oenocytes, we performed cell-type-specific ribosome profiling (RiboTag) to examine the impacts of aging and oxidative stress on oenocyte translatome in Drosophila. RESULTS We show that aging and oxidant paraquat significantly increased the levels of reactive oxygen species (ROS) in adult oenocytes of Drosophila, and aged oenocytes exhibited reduced sensitivity to paraquat treatment. Through RiboTag sequencing, we identified 3324 and 949 differentially expressed genes in oenocytes under aging and paraquat treatment, respectively. Aging and paraquat exhibit both shared and distinct regulations on oenocyte translatome. Among all age-regulated genes, oxidative phosphorylation, ribosome, proteasome, fatty acid metabolism, and cytochrome P450 pathways were down-regulated, whereas DNA replication and immune response pathways were up-regulated. In addition, most of the peroxisomal genes were down-regulated in aged oenocytes, including genes involved in peroxisomal biogenesis factors and fatty acid beta-oxidation. Many age-related mRNA translational changes in oenocytes are similar to aged mammalian liver, such as up-regulation of innate immune response and Ras/MAPK signaling pathway and down-regulation of peroxisome and fatty acid metabolism. Furthermore, oenocytes highly expressed genes involving in liver-like processes (e.g., ketogenesis). CONCLUSIONS Our oenocyte-specific translatome analysis identified many genes and pathways that are shared between Drosophila oenocytes and mammalian liver, highlighting the molecular and functional similarities between the two tissues. Many of these genes were altered in both oenocytes and liver during aging. Thus, our translatome analysis provide important genomic resource for future dissection of oenocyte function and its role in lipid metabolism, stress response and aging regulation.
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Affiliation(s)
- Kerui Huang
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, 50011, USA.
| | - Wenhao Chen
- Department of Electrical and Computer Engineering, Iowa State University, Ames, IA, 50011, USA
| | - Fang Zhu
- Department of Entomology, Pennsylvania State University, University Park, PA, 16802, USA
| | | | - Pankaj Kapahi
- Buck Institute for Research on Aging, Novato, CA, 94945, USA
| | - Hua Bai
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, 50011, USA.
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Sharma V, Hiller M. Loss of Enzymes in the Bile Acid Synthesis Pathway Explains Differences in Bile Composition among Mammals. Genome Biol Evol 2018; 10:3211-3217. [PMID: 30388264 PMCID: PMC6296402 DOI: 10.1093/gbe/evy243] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2018] [Indexed: 12/11/2022] Open
Abstract
Bile acids are important for absorbing nutrients. Most mammals produce cholic and chenodeoxycholic bile acids. Here, we investigated genes in the bile acid synthesis pathway in four mammals that deviate from the usual mammalian bile composition. First, we show that naked-mole rats, elephants, and manatees repeatedly inactivated CYP8B1, an enzyme uniquely required for cholic acid synthesis, which explains the absence of cholic acid in these species. Second, no gene-inactivating mutations were found in any pathway gene in the rhinoceros, a species that lacks bile acids, indicating an evolutionarily recent change in its bile composition. Third, elephants and/or manatees that also lack bile acids altogether have lost additional nonessential enzymes (SLC27A5, ACOX2). Apart from uncovering genomic differences explaining deviations in bile composition, our analysis of bile acid enzymes in bile acid-lacking species suggests that essentiality prevents gene loss, while loss of pleiotropic genes is permitted if their other functions are compensated by functionally related proteins.
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Affiliation(s)
- Virag Sharma
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Systems Biology Dresden, Dresden, Germany.,CRTD-DFG Center for Regenerative Therapies Dresden, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Dresden; Paul Langerhans Institute Dresden (PLID) of the Helmholtz Center Munich at University Hospital Carl Gustav Carus and Faculty of Medicine, Technische Universität Dresden, Dresden; and German Center for Diabetes Research (DZD), Munich, Neuherberg, Germany
| | - Michael Hiller
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Systems Biology Dresden, Dresden, Germany
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Gianotti AR, Ferreyra RG, Ermácora MR. Binding properties of sterol carrier protein 2 (SCP2) characterized using Laurdan. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1866:1143-1152. [DOI: 10.1016/j.bbapap.2018.08.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/14/2018] [Accepted: 08/20/2018] [Indexed: 12/23/2022]
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Selvaraj V, Stocco DM, Clark BJ. Current knowledge on the acute regulation of steroidogenesis. Biol Reprod 2018; 99:13-26. [PMID: 29718098 PMCID: PMC6044331 DOI: 10.1093/biolre/ioy102] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/23/2018] [Accepted: 04/26/2018] [Indexed: 12/31/2022] Open
Abstract
How rapid induction of steroid hormone biosynthesis occurs in response to trophic hormone stimulation of steroidogenic cells has been a subject of intensive investigation for approximately six decades. A key observation made very early was that acute regulation of steroid biosynthesis required swift and timely synthesis of a new protein whose role appeared to be involved in the delivery of the substrate for all steroid hormones, cholesterol, from the outer to the inner mitochondrial membrane where the process of steroidogenesis begins. It was quickly learned that this transfer of cholesterol to the inner mitochondrial membrane was the regulated and rate-limiting step in steroidogenesis. Following this observation, the quest for this putative regulator protein(s) began in earnest in the late 1950s. This review provides a history of this quest, the candidate proteins that arose over the years and facts surrounding their rise or decline. Only two have persisted-translocator protein (TSPO) and the steroidogenic acute regulatory protein (StAR). We present a detailed summary of the work that has been published for each of these two proteins, the specific data that has appeared in support of their role in cholesterol transport and steroidogenesis, and the ensuing observations that have arisen in recent years that have refuted the role of TSPO in this process. We believe that the only viable candidate that has been shown to be indispensable is the StAR protein. Lastly, we provide our view on what may be the most important questions concerning the acute regulation of steroidogenesis that need to be asked in future.
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Affiliation(s)
- Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, USA
| | - Douglas M Stocco
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas, USA
| | - Barbara J Clark
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, Kentucky, USA
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Di Meo I, Tiranti V. Classification and molecular pathogenesis of NBIA syndromes. Eur J Paediatr Neurol 2018; 22:272-284. [PMID: 29409688 DOI: 10.1016/j.ejpn.2018.01.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 12/06/2017] [Accepted: 01/08/2018] [Indexed: 12/14/2022]
Abstract
Brain iron accumulation is the hallmark of a group of seriously invalidating and progressive rare diseases collectively denominated Neurodegeneration with Brain Iron Accumulation (NBIA), characterized by movement disorder, painful dystonia, parkinsonism, mental disability and early death. Currently there is no established therapy available to slow down or reverse the progression of these conditions. Several genes have been identified as responsible for NBIA but only two encode for proteins playing a direct role in iron metabolism. The other genes encode for proteins either with various functions in lipid metabolism, lysosomal activity and autophagic processes or with still unknown roles. The different NBIA subtypes have been classified and denominated on the basis of the mutated genes and, despite genetic heterogeneity, some of them code for proteins, which share or converge on common metabolic pathways. In the last ten years, the implementation of genetic screening based on Whole Exome Sequencing has greatly accelerated gene discovery, nevertheless our knowledge of the pathogenic mechanisms underlying the NBIA syndromes is still largely incomplete.
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Affiliation(s)
- Ivano Di Meo
- Unit of Molecular Neurogenetics, Pierfranco and Luisa Mariani Centre for the Study of Mitochondrial Disorders in Children, Foundation IRCCS Neurological Institute C. Besta, Via Temolo 4, 20126, Milan, Italy
| | - Valeria Tiranti
- Unit of Molecular Neurogenetics, Pierfranco and Luisa Mariani Centre for the Study of Mitochondrial Disorders in Children, Foundation IRCCS Neurological Institute C. Besta, Via Temolo 4, 20126, Milan, Italy.
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Tracey TJ, Steyn FJ, Wolvetang EJ, Ngo ST. Neuronal Lipid Metabolism: Multiple Pathways Driving Functional Outcomes in Health and Disease. Front Mol Neurosci 2018; 11:10. [PMID: 29410613 PMCID: PMC5787076 DOI: 10.3389/fnmol.2018.00010] [Citation(s) in RCA: 215] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Accepted: 01/08/2018] [Indexed: 12/12/2022] Open
Abstract
Lipids are a fundamental class of organic molecules implicated in a wide range of biological processes related to their structural diversity, and based on this can be broadly classified into five categories; fatty acids, triacylglycerols (TAGs), phospholipids, sterol lipids and sphingolipids. Different lipid classes play major roles in neuronal cell populations; they can be used as energy substrates, act as building blocks for cellular structural machinery, serve as bioactive molecules, or a combination of each. In amyotrophic lateral sclerosis (ALS), dysfunctions in lipid metabolism and function have been identified as potential drivers of pathogenesis. In particular, aberrant lipid metabolism is proposed to underlie denervation of neuromuscular junctions, mitochondrial dysfunction, excitotoxicity, impaired neuronal transport, cytoskeletal defects, inflammation and reduced neurotransmitter release. Here we review current knowledge of the roles of lipid metabolism and function in the CNS and discuss how modulating these pathways may offer novel therapeutic options for treating ALS.
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Affiliation(s)
- Timothy J Tracey
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Frederik J Steyn
- Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
| | - Ernst J Wolvetang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Shyuan T Ngo
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia.,Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
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26
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Milligan S, Martin GG, Landrock D, McIntosh AL, Mackie JT, Schroeder F, Kier AB. Ablating both Fabp1 and Scp2/Scpx (TKO) induces hepatic phospholipid and cholesterol accumulation in high fat-fed mice. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:323-338. [PMID: 29307784 DOI: 10.1016/j.bbalip.2017.12.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 12/13/2017] [Accepted: 12/31/2017] [Indexed: 01/16/2023]
Abstract
Although singly ablating Fabp1 or Scp2/Scpx genes may exacerbate the impact of high fat diet (HFD) on whole body phenotype and non-alcoholic fatty liver disease (NAFLD), concomitant upregulation of the non-ablated gene, preference for ad libitum fed HFD, and sex differences complicate interpretation. Therefore, these issues were addressed in male and female mice ablated in both genes (Fabp1/Scp2/Scpx null or TKO) and pair-fed HFD. Wild-type (WT) males gained more body weight as fat tissue mass (FTM) and exhibited higher hepatic lipid accumulation than WT females. The greater hepatic lipid accumulation in WT males was associated with higher hepatic expression of enzymes in glyceride synthesis, higher hepatic bile acids, and upregulation of transporters involved in hepatic reuptake of serum bile acids. While TKO had little effect on whole body phenotype and hepatic bile acid accumulation in either sex, TKO increased hepatic accumulation of lipids in both, specifically phospholipid and cholesteryl esters in males and females and free cholesterol in females. TKO-induced increases in glycerides were attributed not only to complete loss of FABP1, SCP2 and SCPx, but also in part to sex-dependent upregulation of hepatic lipogenic enzymes. These data with WT and TKO mice pair-fed HFD indicate that: i) Sex significantly impacted the ability of HFD to increase body weight, induce hepatic lipid accumulation and increase hepatic bile acids; and ii) TKO exacerbated the HFD ability to induce hepatic lipid accumulation, regardless of sex, but did not significantly alter whole body phenotype in either sex.
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Affiliation(s)
- Sherrelle Milligan
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Gregory G Martin
- Department of Physiology/Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA
| | - Danilo Landrock
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Avery L McIntosh
- Department of Physiology/Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA
| | - John T Mackie
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology/Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA
| | - Ann B Kier
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA.
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27
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Abstract
Triglyceride molecules represent the major form of storage and transport of fatty acids within cells and in the plasma. The liver is the central organ for fatty acid metabolism. Fatty acids accrue in liver by hepatocellular uptake from the plasma and by de novo biosynthesis. Fatty acids are eliminated by oxidation within the cell or by secretion into the plasma within triglyceride-rich very low-density lipoproteins. Notwithstanding high fluxes through these pathways, under normal circumstances the liver stores only small amounts of fatty acids as triglycerides. In the setting of overnutrition and obesity, hepatic fatty acid metabolism is altered, commonly leading to the accumulation of triglycerides within hepatocytes, and to a clinical condition known as nonalcoholic fatty liver disease (NAFLD). In this review, we describe the current understanding of fatty acid and triglyceride metabolism in the liver and its regulation in health and disease, identifying potential directions for future research. Advances in understanding the molecular mechanisms underlying the hepatic fat accumulation are critical to the development of targeted therapies for NAFLD. © 2018 American Physiological Society. Compr Physiol 8:1-22, 2018.
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Affiliation(s)
- Michele Alves-Bezerra
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, USA
| | - David E Cohen
- Joan & Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, USA
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28
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Colasante C, Chen J, Ahlemeyer B, Baumgart-Vogt E. Peroxisomes in cardiomyocytes and the peroxisome / peroxisome proliferator-activated receptor-loop. Thromb Haemost 2017; 113:452-63. [DOI: 10.1160/th14-06-0497] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 12/18/2014] [Indexed: 01/29/2023]
Abstract
SummaryIt is well established that the heart is strongly dependent on fatty acid metabolism. In cardiomyocytes there are two distinct sites for the β-oxidisation of fatty acids: the mitochondrion and the peroxisome. Although the metabolism of these two organelles is believed to be tightly coupled, the nature of this relationship has not been fully investigated. Recent research has established the significant contribution of mitochondrial function to cardiac ATP production under normal and pathological conditions. In contrast, limited information is available on peroxisomal function in the heart. This is despite these organelles harbouring metabolic pathways that are potentially cardioprotective, and findings that patients with peroxisomal diseases, such as adult Refsum’s disease, can develop heart failure. In this article, we provide a comprehensive overview on the current knowledge of peroxisomes and the regulation of lipid metabolism by PPARs in cardiomyocytes. We also present new experimental evidence on the differential expression of peroxisome-related genes in the heart chambers and demonstrate that even a mild peroxisomal biogenesis defect (Pex11α-/- ) can induce profound alterations in the cardiomyocyte’s peroxisomal compartment and related gene expression, including the concomitant deregulation of specific PPARs. The possible impact of peroxisomal dysfunction in the heart is discussed and a model for the modulation of myocardial metabolism via a peroxisome/PPAR-loop is proposed.
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29
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McIntosh AL, Storey SM, Huang H, Kier AB, Schroeder F. Sex-dependent impact of Scp-2/Scp-x gene ablation on hepatic phytol metabolism. Arch Biochem Biophys 2017; 635:17-26. [PMID: 29051070 DOI: 10.1016/j.abb.2017.10.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/10/2017] [Accepted: 10/14/2017] [Indexed: 12/19/2022]
Abstract
While prior studies focusing on male mice suggest a role for sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x; DKO) on hepatic phytol metabolism, its role in females is unresolved. This issue was addressed using female and male wild-type (WT) and DKO mice fed a phytoestrogen-free diet without or with 0.5% phytol. GC/MS showed that hepatic: i) phytol was absent and its branched-chain fatty acid (BCFA) metabolites were barely detectable in WT control-fed mice; ii) accumulation of phytol as well as its peroxisomal metabolite BCFAs (phytanic acid » pristanic and 2,3-pristenic acids) was increased by dietary phytol in WT females, but only slightly in WT males; iii) accumulation of phytol and BCFA was further increased by DKO in phytol-fed females, but much more markedly in males. Livers of phytol-fed WT female mice as well as phytol-fed DKO female and male mice also accumulated increased proportion of saturated straight-chain fatty acids (LCFA) at the expense of unsaturated LCFA. Liver phytol accumulation was not due to increased SCP-2 binding/transport of phytol since SCP-2 bound phytanic acid, but not its precursor phytol. Thus, the loss of Scp-2/Scp-x contributed to a sex-dependent hepatic accumulation of dietary phytol and BCFA.
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Affiliation(s)
- Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, United States
| | - Stephen M Storey
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, United States
| | - Huan Huang
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, United States
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX 77843-4467, United States
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, United States.
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Mezzar S, De Schryver E, Asselberghs S, Meyhi E, Morvay PL, Baes M, Van Veldhoven PP. Phytol-induced pathology in 2-hydroxyacyl-CoA lyase (HACL1) deficient mice. Evidence for a second non-HACL1-related lyase. Biochim Biophys Acta Mol Cell Biol Lipids 2017. [PMID: 28629946 DOI: 10.1016/j.bbalip.2017.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
2-Hydroxyacyl-CoA lyase (HACL1) is a key enzyme of the peroxisomal α-oxidation of phytanic acid. To better understand its role in health and disease, a mouse model lacking HACL1 was investigated. Under normal conditions, these mice did not display a particular phenotype. However, upon dietary administration of phytol, phytanic acid accumulated in tissues, mainly in liver and serum of KO mice. As a consequence of phytanic acid (or a metabolite) toxicity, KO mice displayed a significant weight loss, absence of abdominal white adipose tissue, enlarged and mottled liver and reduced hepatic glycogen and triglycerides. In addition, hepatic PPARα was activated. The central nervous system of the phytol-treated mice was apparently not affected. In addition, 2OH-FA did not accumulate in the central nervous system of HACL1 deficient mice, likely due to the presence in the endoplasmic reticulum of an alternate HACL1-unrelated lyase. The latter may serve as a backup system in certain tissues and account for the formation of pristanic acid in the phytol-fed KO mice. As the degradation of pristanic acid is also impaired, both phytanoyl- and pristanoyl-CoA levels are increased in liver, and the ω-oxidized metabolites are excreted in urine. In conclusion, HACL1 deficiency is not associated with a severe phenotype, but in combination with phytanic acid intake, the normal situation in man, it might present with phytanic acid elevation and resemble a Refsum like disorder.
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Affiliation(s)
- Serena Mezzar
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Evelyn De Schryver
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Stanny Asselberghs
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Els Meyhi
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Petruta L Morvay
- LIPIT, Department of Cellular and Molecular Medicine, KU Leuven, Belgium
| | - Myriam Baes
- Laboratory for Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Belgium
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31
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A structural appraisal of sterol carrier protein 2. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:565-577. [DOI: 10.1016/j.bbapap.2017.03.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/03/2017] [Accepted: 03/07/2017] [Indexed: 11/19/2022]
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Landrock D, Milligan S, Martin GG, McIntosh AL, Landrock KK, Schroeder F, Kier AB. Effect of Fabp1/Scp-2/Scp-x Ablation on Whole Body and Hepatic Phenotype of Phytol-Fed Male Mice. Lipids 2017; 52:385-397. [PMID: 28382456 PMCID: PMC5500168 DOI: 10.1007/s11745-017-4249-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/28/2017] [Indexed: 11/29/2022]
Abstract
Liver fatty acid binding protein (Fabp1) and sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x) genes encode proteins that enhance hepatic uptake, cytosolic transport, and peroxisomal oxidation of toxic branched-chain fatty acids derived from dietary phytol. Since male wild-type (WT) mice express markedly higher levels of these proteins than females, the impact of ablating both genes (TKO) was examined in phytol-fed males. In WT males, high phytol diet alone had little impact on whole body weight and did not alter the proportion of lean tissue mass (LTM) versus fat tissue mass (FTM). TKO conferred on dietary phytol the ability to induce weight loss as well as reduce liver weight, FTM, and even more so LTM. Concomitantly TKO induced hepatic lipid accumulation, preferentially threefold increased phospholipid (PL) at the expense of decreased triacylglycerol (TG) and total cholesterol. Increased PL was associated with upregulation of membrane fatty acid transport/translocase proteins (FATP 2,4), cytosolic fatty acid/fatty acyl-CoA binding proteins (FABP2, ACBP), and the rate limiting enzyme in PL synthesis (Gpam). Decreased TG and cholesterol levels were not attributable to altered levels in respective synthetic enzymes or nuclear receptors. These data suggest that the higher level of Fabp1 and Scp2/Scpx gene products in WT males was protective against deleterious effects of dietary phytol, but TKO significantly exacerbated phytol effects in males.
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Affiliation(s)
- Danilo Landrock
- Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, TVMC, College Station, TX, 77843-4467, USA
| | - Sherrelle Milligan
- Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, TVMC, College Station, TX, 77843-4467, USA
| | - Gregory G Martin
- Department of Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Avery L McIntosh
- Department of Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Kerstin K Landrock
- Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, TVMC, College Station, TX, 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Ann B Kier
- Department of Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, TVMC, College Station, TX, 77843-4467, USA.
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Storey SM, Huang H, McIntosh AL, Martin GG, Kier AB, Schroeder F. Impact of Fabp1/Scp-2/Scp-x gene ablation (TKO) on hepatic phytol metabolism in mice. J Lipid Res 2017; 58:1153-1165. [PMID: 28411199 DOI: 10.1194/jlr.m075457] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/07/2017] [Indexed: 01/19/2023] Open
Abstract
Studies in vitro have suggested that both sterol carrier protein-2/sterol carrier protein-x (Scp-2/Scp-x) and liver fatty acid binding protein [Fabp1 (L-FABP)] gene products facilitate hepatic uptake and metabolism of lipotoxic dietary phytol. However, interpretation of physiological function in mice singly gene ablated in the Scp-2/Scp-x has been complicated by concomitant upregulation of FABP1. The work presented herein provides several novel insights: i) An 8-anilino-1-naphthalenesulfonic acid displacement assay showed that neither SCP-2 nor L-FABP bound phytol, but both had high affinity for its metabolite, phytanic acid; ii) GC-MS studies with phytol-fed WT and Fabp1/Scp-2/SCP-x gene ablated [triple KO (TKO)] mice showed that TKO exacerbated hepatic accumulation of phytol metabolites in vivo in females and less so in males. Concomitantly, dietary phytol increased hepatic levels of total long-chain fatty acids (LCFAs) in both male and female WT and TKO mice. Moreover, in both WT and TKO female mice, dietary phytol increased hepatic ratios of saturated/unsaturated and polyunsaturated/monounsaturated LCFAs, while decreasing the peroxidizability index. However, in male mice, dietary phytol selectively increased the saturated/unsaturated ratio only in TKO mice, while decreasing the peroxidizability index in both WT and TKO mice. These findings suggested that: 1) SCP-2 and FABP1 both facilitated phytol metabolism after its conversion to phytanic acid; and 2) SCP-2/SCP-x had a greater impact on hepatic phytol metabolism than FABP1.
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Affiliation(s)
- Stephen M Storey
- Departments of Physiology and Pharmacology Texas A&M Veterinary Medical Center, Texas A&M University, College Station, TX 77843
| | - Huan Huang
- Departments of Physiology and Pharmacology Texas A&M Veterinary Medical Center, Texas A&M University, College Station, TX 77843
| | - Avery L McIntosh
- Departments of Physiology and Pharmacology Texas A&M Veterinary Medical Center, Texas A&M University, College Station, TX 77843
| | - Gregory G Martin
- Departments of Physiology and Pharmacology Texas A&M Veterinary Medical Center, Texas A&M University, College Station, TX 77843
| | - Ann B Kier
- Pathobiology, Texas A&M Veterinary Medical Center, Texas A&M University, College Station, TX 77843
| | - Friedhelm Schroeder
- Departments of Physiology and Pharmacology Texas A&M Veterinary Medical Center, Texas A&M University, College Station, TX 77843
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34
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Milligan S, Martin GG, Landrock D, McIntosh AL, Mackie JT, Schroeder F, Kier AB. Impact of dietary phytol on lipid metabolism in SCP2/SCPX/L-FABP null mice. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:291-304. [PMID: 27940000 PMCID: PMC5266609 DOI: 10.1016/j.bbalip.2016.12.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/15/2016] [Accepted: 12/04/2016] [Indexed: 12/20/2022]
Abstract
In vitro studies suggest that liver fatty acid binding protein (L-FABP) and sterol carrier protein-2/sterol carrier protein-x (SCP2/SCPx) gene products facilitate uptake and metabolism and detoxification of dietary-derived phytol in mammals. However, concomitant upregulation of L-FABP in SCP2/SCPx null mice complicates interpretation of their physiological phenotype. Therefore, the impact of ablating both the L-FABP gene and SCP2/SCPx gene (L-FABP/SCP2/SCPx null or TKO) was examined in phytol-fed female wild-type (WT) and TKO mice. TKO increased hepatic total lipid accumulation, primarily phospholipid, by mechanisms involving increased hepatic levels of proteins in the phospholipid synthetic pathway. Concomitantly, TKO reduced expression of proteins in targeting fatty acids towards the triacylglycerol synthetic pathway. Increased hepatic lipid accumulation was not associated with any concomitant upregulation of membrane fatty acid transport/translocase proteins involved in fatty acid uptake (FATP2, FATP4, FATP5 or GOT) or cytosolic proteins involved in fatty acid intracellular targeting (ACBP). In addition, TKO exacerbated dietary phytol-induced whole body weight loss, especially lean tissue mass. Since individually ablating SCPx or SCP2/SCPx elicited concomitant upregulation of L-FABP, these findings with TKO mice help to resolve the contributions of SCP2/SCPx gene ablation on dietary phytol-induced whole body and hepatic lipid phenotype independent of concomitant upregulation of L-FABP.
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Affiliation(s)
- Sherrelle Milligan
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Gregory G Martin
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Danilo Landrock
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Avery L McIntosh
- Department of Physiology/Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA
| | - John T Mackie
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology/Pharmacology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4466, USA
| | - Ann B Kier
- Department of Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-4467, USA.
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35
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Stocco DM, Zhao AH, Tu LN, Morohaku K, Selvaraj V. A brief history of the search for the protein(s) involved in the acute regulation of steroidogenesis. Mol Cell Endocrinol 2017; 441:7-16. [PMID: 27484452 PMCID: PMC5929480 DOI: 10.1016/j.mce.2016.07.036] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/26/2016] [Accepted: 07/26/2016] [Indexed: 12/14/2022]
Abstract
The synthesis of steroid hormones occurs in specific cells and tissues in the body in response to trophic hormones and other signals. In order to synthesize steroids de novo, cholesterol, the precursor of all steroid hormones, must be mobilized from cellular stores to the inner mitochondrial membrane (IMM) to be converted into the first steroid formed, pregnenolone. This delivery of cholesterol to the IMM is the rate-limiting step in this process, and has long been known to require the rapid synthesis of a new protein(s) in response to stimulation. Although several possibilities for this protein have arisen over the past few decades, most of the recent attention to fill this role has centered on the candidacies of the proteins the Translocator Protein (TSPO) and the Steroidogenic Acute Regulatory Protein (StAR). In this review, the process of regulating steroidogenesis is briefly described, the characteristics of the candidate proteins and the data supporting their candidacies summarized, and some recent findings that propose a serious challenge for the role of TSPO in this process are discussed.
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Affiliation(s)
- Douglas M Stocco
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | - Amy H Zhao
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Lan N Tu
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Kanako Morohaku
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA
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Martin GG, Landrock D, Chung S, Dangott LJ, Seeger DR, Murphy EJ, Golovko MY, Kier AB, Schroeder F. Fabp1 gene ablation inhibits high-fat diet-induced increase in brain endocannabinoids. J Neurochem 2017; 140:294-306. [PMID: 27861894 PMCID: PMC5225076 DOI: 10.1111/jnc.13890] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 10/28/2016] [Accepted: 11/03/2016] [Indexed: 01/03/2023]
Abstract
The endocannabinoid system shifts energy balance toward storage and fat accumulation, especially in the context of diet-induced obesity. Relatively little is known about factors outside the central nervous system that may mediate the effect of high-fat diet (HFD) on brain endocannabinoid levels. One candidate is the liver fatty acid binding protein (FABP1), a cytosolic protein highly prevalent in liver, but not detected in brain, which facilitates hepatic clearance of fatty acids. The impact of Fabp1 gene ablation (LKO) on the effect of high-fat diet (HFD) on brain and plasma endocannabinoid levels was examined and data expressed for each parameter as the ratio of high-fat diet/control diet. In male wild-type mice, HFD markedly increased brain N-acylethanolamides, but not 2-monoacylglycerols. LKO blocked these effects of HFD in male mice. In female wild-type mice, HFD slightly decreased or did not alter these endocannabinoids as compared with male wild type. LKO did not block the HFD effects in female mice. The HFD-induced increase in brain arachidonic acid-derived arachidonoylethanolamide in males correlated with increased brain-free and total arachidonic acid. The ability of LKO to block the HFD-induced increase in brain arachidonoylethanolamide correlated with reduced ability of HFD to increase brain-free and total arachidonic acid in males. In females, brain-free and total arachidonic acid levels were much less affected by either HFD or LKO in the context of HFD. These data showed that LKO markedly diminished the impact of HFD on brain endocannabinoid levels, especially in male mice.
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Affiliation(s)
- Gregory G. Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Sarah Chung
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Lawrence J. Dangott
- Protein Chemistry Laboratory, Texas A&M University, College Station, TX 77843-2128
| | - Drew R. Seeger
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Eric J. Murphy
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Mikhail Y. Golovko
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Ann B. Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
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Martin GG, Chung S, Landrock D, Landrock KK, Dangott LJ, Peng X, Kaczocha M, Murphy EJ, Kier AB, Schroeder F. Female Mice are Resistant to Fabp1 Gene Ablation-Induced Alterations in Brain Endocannabinoid Levels. Lipids 2016; 51:1007-20. [PMID: 27450559 PMCID: PMC5418128 DOI: 10.1007/s11745-016-4175-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/14/2016] [Indexed: 10/21/2022]
Abstract
Although liver fatty acid binding protein (FABP1, L-FABP) is not detectable in the brain, Fabp1 gene ablation (LKO) markedly increases endocannabinoids (EC) in brains of male mice. Since the brain EC system of females differs significantly from that of males, it was important to determine if LKO differently impacted the brain EC system. LKO did not alter brain levels of arachidonic acid (ARA)-containing EC, i.e. arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG), but decreased non-ARA-containing N-acylethanolamides (OEA, PEA) and 2-oleoylglycerol (2-OG) that potentiate the actions of AEA and 2-AG. These changes in brain potentiating EC levels were not associated with: (1) a net decrease in levels of brain membrane proteins associated with fatty acid uptake and EC synthesis; (2) a net increase in brain protein levels of cytosolic EC chaperones and enzymes in EC degradation; or (3) increased brain protein levels of EC receptors (CB1, TRVP1). Instead, the reduced or opposite responsiveness of female brain EC levels to loss of FABP1 (LKO) correlated with intrinsically lower FABP1 level in livers of WT females than males. These data show that female mouse brain endocannabinoid levels were unchanged (AEA, 2-AG) or decreased (OEA, PEA, 2-OG) by complete loss of FABP1 (LKO).
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA
| | - Sarah Chung
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Kerstin K Landrock
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA
| | - Lawrence J Dangott
- Protein Chemistry Laboratory, Texas A&M University, College Station, TX, 77843-2128, USA
| | - Xiaoxue Peng
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Martin Kaczocha
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Eric J Murphy
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND, 58202-9037, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX, 77843-4466, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, 4466 TAMU, College Station, TX, 77843-4466, USA.
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Martin GG, Chung S, Landrock D, Landrock KK, Huang H, Dangott LJ, Peng X, Kaczocha M, Seeger DR, Murphy EJ, Golovko MY, Kier AB, Schroeder F. FABP-1 gene ablation impacts brain endocannabinoid system in male mice. J Neurochem 2016; 138:407-22. [PMID: 27167970 PMCID: PMC4961623 DOI: 10.1111/jnc.13664] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/14/2016] [Accepted: 04/26/2016] [Indexed: 12/15/2022]
Abstract
Liver fatty acid-binding protein (FABP1, L-FABP) has high affinity for and enhances uptake of arachidonic acid (ARA, C20:4, n-6) which, when esterified to phospholipids, is the requisite precursor for synthesis of endocannabinoids (EC) such as arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG). The brain derives most of its ARA from plasma, taking up ARA and transporting it intracellularly via cytosolic fatty acid-binding proteins (FABPs 3,5, and 7) localized within the brain. In contrast, the much more prevalent cytosolic FABP1 is not detectable in the brain but is instead highly expressed in the liver. Therefore, the possibility that FABP1 outside the central nervous system may regulate brain AEA and 2-AG was examined in wild-type (WT) and FABP1 null (LKO) male mice. LKO increased brain levels of AA-containing EC (AEA, 2-AG), correlating with increased free and total ARA in brain and serum. LKO also increased brain levels of non-ARA that contain potentiating endocannabinoids (EC*) such as oleoyl ethanolamide (OEA), PEA, 2-OG, and 2-PG. Concomitantly, LKO decreased serum total ARA-containing EC, but not non-ARA endocannabinoids. LKO did not elicit these changes in the brain EC and EC* as a result of compensatory up-regulation of brain protein levels of enzymes in EC synthesis (NAPEPLD, DAGLα) or cytosolic EC chaperone proteins (FABPs 3, 5, 7, SCP-2, HSP70), or cannabinoid receptors (CB1, TRVP1). These data show for the first time that the non-CNS fatty acid-binding protein FABP1 markedly affected brain levels of both ARA-containing endocannabinoids (AEA, 2-AG) as well as their non-ARA potentiating endocannabinoids. Fatty acid-binding protein-1 (FABP-1) is not detectable in brain but instead is highly expressed in liver. The possibility that FABP1 outside the central nervous system may regulate brain endocannabinoids arachidonoylethanolamide (AEA) and 2-arachidonoylglycerol (2-AG) was examined in wild-type (WT) and FABP-1 null (LKO) male mice. LKO increased brain levels of arachidonic acid-containing endocannabinoids (AEA, 2-AG), correlating with increased free and total arachidonic acid in brain and serum. Read the Editorial Highlight for this article on page 371.
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Affiliation(s)
- Gregory G. Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
| | - Sarah Chung
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Kerstin K. Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Huan Huang
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
| | - Lawrence J. Dangott
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843-2128
| | - Xiaoxue Peng
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY 11794
| | - Martin Kaczocha
- Department of Anesthesiology, Stony Brook University, Stony Brook, NY 11794
| | - Drew R. Seeger
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Eric J. Murphy
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Mikhail Y. Golovko
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202-9037 USA
| | - Ann B. Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466
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Guo X, Zhang H, Zheng X, Zhou Q, Yang Y, Chen X, Du A. Structural and functional characterization of a novel gene, Hc-daf-22, from the strongylid nematode Haemonchus contortus. Parasit Vectors 2016; 9:422. [PMID: 27472920 PMCID: PMC4966567 DOI: 10.1186/s13071-016-1704-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 07/14/2016] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND The strongylid nematode Haemonchus contortus is a parasite of major concern for modern livestock husbandry because hostile environmental conditions may induce diapause in the early fourth-stage larvae. METHODS A new gene Hc-daf-22 was identified which is the homologue of Ce-daf-22 and human SCPx. Genome walking and RACE were performed to obtain the whole cDNA and genomic sequence of this gene. Using qRT-PCR with all developmental stages as templates to explore the transcription level and micro-injection was applied to confirm the promoter activity of the 5'-flanking region. Overexpression, rescue and RNA interference experiments were performed in N2, daf-22 mutant (ok 693) strains of C. elegans to study the gene function of Hc-daf-22. RESULTS The full length gene of Hc-daf-22 (6,939 bp) contained 16 exons separated by 15 introns, and encoded a cDNA of 1,602 bp (533 amino acids, estimated at about 59.3 kDa) with a peak in L3 and L4 in transcriptional level. The Hc-DAF-22 protein was consisted of a 3-oxoacyl-CoA thiolase domain and a SCP2 domain and evolutionarily conserved. The 1,548 bp fragment upstream of the 5'-flanking region was confirmed to have promoter activity compared with 5'-flanking region of Ce-daf-22. The rescue experiment by micro-injection of daf-22 (ok693) mutant strain showed significant increase in body size and brood size in the rescued worms with significantly reduced or completely absent fat granules confirmed by Oil red O staining, indicating that Hc-daf-22 could partially rescue the function of Ce-daf-22. Furthermore, RNAi with Hc-daf-22 could partially silence the endogenous Ce-daf-22 in N2 worms and mimic the phenotype of daf-22 (ok693) mutants. CONCLUSION The gene Hc-daf-22 was isolated and its function identified using C. elegans as a model organism. Our results indicate that Hc-daf-22 shared similar characteristics and function with Ce-daf-22 and may play an important role in peroxisomal β-oxidation and the development in H. contortus.
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Affiliation(s)
- Xiaolu Guo
- College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou, 310058 China
| | - Hongli Zhang
- Zhejiang Center of Animal Disease Control, Hangzhou, 310020 China
| | - Xiuping Zheng
- College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou, 310058 China
| | - Qianjin Zhou
- Faculty of Life Science and Biotechnology, Ningbo University, Ningbo, 315211 China
| | - Yi Yang
- College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou, 310058 China
| | - Xueqiu Chen
- College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou, 310058 China
| | - Aifang Du
- College of Animal Sciences, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Zhejiang University, Hangzhou, 310058 China
- Present address: Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058 China
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Jouffe C, Gobet C, Martin E, Métairon S, Morin-Rivron D, Masoodi M, Gachon F. Perturbed rhythmic activation of signaling pathways in mice deficient for Sterol Carrier Protein 2-dependent diurnal lipid transport and metabolism. Sci Rep 2016; 6:24631. [PMID: 27097688 PMCID: PMC4838911 DOI: 10.1038/srep24631] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 03/29/2016] [Indexed: 01/22/2023] Open
Abstract
Through evolution, most of the living species have acquired a time keeping system to anticipate daily changes caused by the rotation of the Earth. In all of the systems this pacemaker is based on a molecular transcriptional/translational negative feedback loop able to generate rhythmic gene expression with a period close to 24 hours. Recent evidences suggest that post-transcriptional regulations activated mostly by systemic cues play a fundamental role in the process, fine tuning the time keeping system and linking it to animal physiology. Among these signals, we consider the role of lipid transport and metabolism regulated by SCP2. Mice harboring a deletion of the Scp2 locus present a modulated diurnal accumulation of lipids in the liver and a perturbed activation of several signaling pathways including PPARα, SREBP, LRH-1, TORC1 and its upstream regulators. This defect in signaling pathways activation feedbacks upon the clock by lengthening the circadian period of animals through post-translational regulation of core clock regulators, showing that rhythmic lipid transport is a major player in the establishment of rhythmic mRNA and protein expression landscape.
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Affiliation(s)
- Céline Jouffe
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, CH-1011, Switzerland.,Department of Diabetes and Circadian Rhythms, Nestlé Institute of Health Sciences, CH-1015 Lausanne, Switzerland
| | - Cédric Gobet
- Department of Diabetes and Circadian Rhythms, Nestlé Institute of Health Sciences, CH-1015 Lausanne, Switzerland.,Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Eva Martin
- Department of Diabetes and Circadian Rhythms, Nestlé Institute of Health Sciences, CH-1015 Lausanne, Switzerland
| | - Sylviane Métairon
- Functional Genomic, Nestlé Institute of Health Sciences, CH-1015 Lausanne, Switzerland
| | - Delphine Morin-Rivron
- Department of Gastro-Intestinal Health &Microbiome, Nestlé Institute of Health Sciences, CH-1015 Lausanne, Switzerland
| | - Mojgan Masoodi
- Department of Gastro-Intestinal Health &Microbiome, Nestlé Institute of Health Sciences, CH-1015 Lausanne, Switzerland.,Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 3E2, Canada
| | - Frédéric Gachon
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, CH-1011, Switzerland.,Department of Diabetes and Circadian Rhythms, Nestlé Institute of Health Sciences, CH-1015 Lausanne, Switzerland.,Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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Sterol Carrier Protein-2, a Nonspecific Lipid-Transfer Protein, in Intracellular Cholesterol Trafficking in Testicular Leydig Cells. PLoS One 2016; 11:e0149728. [PMID: 26901662 PMCID: PMC4762939 DOI: 10.1371/journal.pone.0149728] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 01/26/2016] [Indexed: 11/19/2022] Open
Abstract
Sterol carrier protein-2 (SCP2), also called nonspecific lipid-transfer protein, is thought to play a major role in intracellular lipid transport and metabolism, and it has been associated with diseases involving abnormalities in lipid trafficking, such as Zellweger syndrome. The Scp2 gene encodes the 58 kDa sterol carrier protein-x (SCPX) and 15 kDa pro-SCP2 proteins, both of which contain a 13 kDa SCP2 domain in their C-termini. We found that 22-NBD-cholesterol, a fluorescent analog of cholesterol and a preferred SCP2 ligands, was not localized in the peroxisomes. This raises questions about previous reports on the localization of the SCPX and SCP2 proteins and their relationship to peroxisomes and mitochondria in intracellular cholesterol transport. Immunofluorescent staining of cryosections of mouse testis and of MA-10 mouse tumor Leydig cells showed that SCPX and SCP2 are present in both mouse testicular interstitial tissue and in MA-10 cells. Fluorescent fusion proteins of SCPX and SCP2, as well as confocal live-cell imaging, were used to investigate the subcellular targeting of these proteins and the function of the putative mitochondrial targeting sequence. The results showed that SCPX and SCP2 are targeted to the peroxisomes by the C-terminal PTS1 domain, but the putative N-terminal mitochondrial targeting sequence alone is not potent enough to localize SCPX and SCP2 to the mitochondria. Homology modeling and molecular docking studies indicated that the SCP2 domain binds cholesterol, but lacks specificity of the binding and/or transport. These findings further our understanding of the role of SCPX and SCP2 in intracellular cholesterol transport, and present a new point of view on the role of these proteins in cholesterol trafficking.
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Wanders RJA, Waterham HR, Ferdinandusse S. Metabolic Interplay between Peroxisomes and Other Subcellular Organelles Including Mitochondria and the Endoplasmic Reticulum. Front Cell Dev Biol 2016; 3:83. [PMID: 26858947 PMCID: PMC4729952 DOI: 10.3389/fcell.2015.00083] [Citation(s) in RCA: 195] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 12/10/2015] [Indexed: 01/02/2023] Open
Abstract
Peroxisomes are unique subcellular organelles which play an indispensable role in several key metabolic pathways which include: (1.) etherphospholipid biosynthesis; (2.) fatty acid beta-oxidation; (3.) bile acid synthesis; (4.) docosahexaenoic acid (DHA) synthesis; (5.) fatty acid alpha-oxidation; (6.) glyoxylate metabolism; (7.) amino acid degradation, and (8.) ROS/RNS metabolism. The importance of peroxisomes for human health and development is exemplified by the existence of a large number of inborn errors of peroxisome metabolism in which there is an impairment in one or more of the metabolic functions of peroxisomes. Although the clinical signs and symptoms of affected patients differ depending upon the enzyme which is deficient and the extent of the deficiency, the disorders involved are usually (very) severe diseases with neurological dysfunction and early death in many of them. With respect to the role of peroxisomes in metabolism it is clear that peroxisomes are dependent on the functional interplay with other subcellular organelles to sustain their role in metabolism. Indeed, whereas mitochondria can oxidize fatty acids all the way to CO2 and H2O, peroxisomes are only able to chain-shorten fatty acids and the end products of peroxisomal beta-oxidation need to be shuttled to mitochondria for full oxidation to CO2 and H2O. Furthermore, NADH is generated during beta-oxidation in peroxisomes and beta-oxidation can only continue if peroxisomes are equipped with a mechanism to reoxidize NADH back to NAD+, which is now known to be mediated by specific NAD(H)-redox shuttles. In this paper we describe the current state of knowledge about the functional interplay between peroxisomes and other subcellular compartments notably the mitochondria and endoplasmic reticulum for each of the metabolic pathways in which peroxisomes are involved.
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Affiliation(s)
- Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Laboratory Division, Departments of Paediatrics and Clinical Chemistry, Academic Medical Center, Emma Children's Hospital, University of Amsterdam Amsterdam, Netherlands
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Laboratory Division, Departments of Paediatrics and Clinical Chemistry, Academic Medical Center, Emma Children's Hospital, University of Amsterdam Amsterdam, Netherlands
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Laboratory Division, Departments of Paediatrics and Clinical Chemistry, Academic Medical Center, Emma Children's Hospital, University of Amsterdam Amsterdam, Netherlands
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Martin GG, Landrock D, Landrock KK, Howles PN, Atshaves BP, Kier AB, Schroeder F. Relative contributions of L-FABP, SCP-2/SCP-x, or both to hepatic biliary phenotype of female mice. Arch Biochem Biophys 2015; 588:25-32. [PMID: 26541319 PMCID: PMC4683591 DOI: 10.1016/j.abb.2015.10.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 10/20/2015] [Accepted: 10/28/2015] [Indexed: 01/01/2023]
Abstract
Both sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x) and liver fatty acid binding protein (L-FABP) have been proposed to function in hepatobiliary bile acid metabolism/accumulation. To begin to address this issue, the impact of ablating L-FABP (LKO) or SCP-2/SCP-x (DKO) individually or both together (TKO) was examined in female mice. Biliary bile acid levels were decreased in LKO, DKO, and TKO mice; however, hepatic bile acid concentration was decreased in LKO mice only. In contrast, biliary phospholipid level was decreased only in TKO mice, while biliary cholesterol levels were unaltered regardless of phenotype. The loss of either or both genes increased hepatic expression of the major bile acid synthetic enzymes (CYP7A1 and/or CYP27A1). Loss of L-FABP and/or SCP-2/SCP-x genes significantly altered the molecular composition of biliary bile acids, but not the proportion of conjugated/unconjugated bile acids or overall bile acid hydrophobicity index. These data suggested that L-FABP was more important in hepatic retention of bile acids, while SCP-2/SCP-x more broadly affected biliary bile acid and phospholipid levels.
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA
| | - Kerstin K Landrock
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, USA
| | - Philip N Howles
- Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, OH 45219, USA
| | - Barbara P Atshaves
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, USA.
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Berger J, Dorninger F, Forss-Petter S, Kunze M. Peroxisomes in brain development and function. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:934-55. [PMID: 26686055 PMCID: PMC4880039 DOI: 10.1016/j.bbamcr.2015.12.005] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/04/2015] [Accepted: 12/09/2015] [Indexed: 12/26/2022]
Abstract
Peroxisomes contain numerous enzymatic activities that are important for mammalian physiology. Patients lacking either all peroxisomal functions or a single enzyme or transporter function typically develop severe neurological deficits, which originate from aberrant development of the brain, demyelination and loss of axonal integrity, neuroinflammation or other neurodegenerative processes. Whilst correlating peroxisomal properties with a compilation of pathologies observed in human patients and mouse models lacking all or individual peroxisomal functions, we discuss the importance of peroxisomal metabolites and tissue- and cell type-specific contributions to the observed brain pathologies. This enables us to deconstruct the local and systemic contribution of individual metabolic pathways to specific brain functions. We also review the recently discovered variability of pathological symptoms in cases with unexpectedly mild presentation of peroxisome biogenesis disorders. Finally, we explore the emerging evidence linking peroxisomes to more common neurological disorders such as Alzheimer’s disease, autism and amyotrophic lateral sclerosis. This article is part of a Special Issue entitled: Peroxisomes edited by Ralf Erdmann.
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Affiliation(s)
- Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| | - Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| | - Sonja Forss-Petter
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| | - Markus Kunze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
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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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46
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Klipsic D, Landrock D, Martin GG, McIntosh AL, Landrock KK, Mackie JT, Schroeder F, Kier AB. Impact of SCP-2/SCP-x gene ablation and dietary cholesterol on hepatic lipid accumulation. Am J Physiol Gastrointest Liver Physiol 2015; 309:G387-99. [PMID: 26113298 PMCID: PMC4556946 DOI: 10.1152/ajpgi.00460.2014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 06/22/2015] [Indexed: 01/31/2023]
Abstract
While a high-cholesterol diet induces hepatic steatosis, the role of intracellular sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x) proteins is unknown. We hypothesized that ablating SCP-2/SCP-x [double knockout (DKO)] would impact hepatic lipids (cholesterol and cholesteryl ester), especially in high-cholesterol-fed mice. DKO did not alter food consumption, and body weight (BW) gain decreased especially in females, concomitant with hepatic steatosis in females and less so in males. DKO-induced steatosis in control-fed wild-type (WT) mice was associated with 1) loss of SCP-2; 2) upregulation of liver fatty acid binding protein (L-FABP); 3) increased mRNA and/or protein levels of sterol regulatory element binding proteins (SREBP1 and SREBP2) as well as increased expression of target genes of cholesterol synthesis (Hmgcs1 and Hmgcr) and fatty acid synthesis (Acc1 and Fas); and 4) cholesteryl ester accumulation was also associated with increased acyl-CoA cholesterol acyltransferase-2 (ACAT2) in males. DKO exacerbated the high-cholesterol diet-induced hepatic cholesterol and glyceride accumulation, without further increasing SREBP1, SREBP2, or target genes. This exacerbation was associated both with loss of SCP-2 and concomitant downregulation of Ceh/Hsl, apolipoprotein B (ApoB), MTP, and/or L-FABP protein expression. DKO diminished the ability to secrete excess cholesterol into bile and oxidize cholesterol to bile acid for biliary excretion, especially in females. This suggested that SCP-2/SCP-x affects cholesterol transport to particular intracellular compartments, with ablation resulting in less to the endoplasmic reticulum for SREBP regulation, making more available for cholesteryl ester synthesis, for cholesteryl-ester storage in lipid droplets, and for bile salt synthesis and/or secretion. These alterations are significant findings, since they affect key processes in regulation of sterol metabolism.
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Affiliation(s)
- Devon Klipsic
- Department of Pathobiology, Texas A&M University, College Station, Texas; and
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, Texas; and
| | - Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, Texas
| | - Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, College Station, Texas
| | - Kerstin K Landrock
- Department of Physiology and Pharmacology, Texas A&M University, College Station, Texas
| | - John T Mackie
- Department of Pathobiology, Texas A&M University, College Station, Texas; and
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, Texas
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, Texas; and
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De Munter S, Verheijden S, Régal L, Baes M. Peroxisomal Disorders: A Review on Cerebellar Pathologies. Brain Pathol 2015. [PMID: 26201894 DOI: 10.1111/bpa.12290] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Peroxisomes are organelles with diverse metabolic tasks including essential roles in lipid metabolism. They are of utmost importance for the normal functioning of the nervous system as most peroxisomal disorders are accompanied with neurological symptoms. Remarkably, the cerebellum exquisitely depends on intact peroxisomal function both during development and adulthood. In this review, we cover all aspects of cerebellar pathology that were reported in peroxisome biogenesis disorders and in diseases caused by dysfunction of the peroxisomal α-oxidation, β-oxidation or ether lipid synthesis pathways. We also discuss the phenotypes of mouse models in which cerebellar pathologies were recapitulated and search for connections with the metabolic abnormalities. It becomes increasingly clear that besides the most severe forms of peroxisome dysfunction that are associated with developmental cerebellar defects, milder impairments can give rise to ataxia later in life.
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Affiliation(s)
- Stephanie De Munter
- Department of Pharmaceutical and Pharmacological Sciences, Cell Metabolism, KU Leuven-University of Leuven, B-3000, Leuven, Belgium
| | - Simon Verheijden
- Department of Clinical and Experimental Medicine, TARGID, KU Leuven-University of Leuven, B-3000, Leuven, Belgium
| | - Luc Régal
- Department of Pediatric Neurology and Metabolic Disorders, UZ Brussel-University Hospital Brussels, 1000, Brussels, Belgium
| | - Myriam Baes
- Department of Pharmaceutical and Pharmacological Sciences, Cell Metabolism, KU Leuven-University of Leuven, B-3000, Leuven, Belgium
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48
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Selkälä EM, Nair RR, Schmitz W, Kvist AP, Baes M, Hiltunen JK, Autio KJ. Phytol is lethal for Amacr-deficient mice. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1394-405. [PMID: 26248199 DOI: 10.1016/j.bbalip.2015.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 07/08/2015] [Accepted: 07/31/2015] [Indexed: 01/22/2023]
Abstract
α-Methylacyl-CoA racemase (Amacr) catalyzes the racemization of the 25-methyl group in C27-intermediates in bile acid synthesis and in methyl-branched fatty acids such as pristanic acid, a metabolite derived from phytol. Consequently, patients with Amacr deficiency accumulate C27-bile acid intermediates, pristanic and phytanic acid and display sensorimotor neuropathy, seizures and relapsing encephalopathy. In contrast to humans, Amacr-deficient mice are clinically symptomless on a standard laboratory diet, but failed to thrive when fed phytol-enriched chow. In this study, the effect and the mechanisms behind the development of the phytol-feeding associated disease state in Amacr-deficient mice were investigated. All Amacr-/- mice died within 36weeks on a phytol diet, while wild-type mice survived. Liver failure was the main cause of death accompanied by kidney and brain abnormalities. Histological analysis of liver showed inflammation, fibrotic and necrotic changes, Kupffer cell proliferation and fatty changes in hepatocytes, and serum analysis confirmed the hepatic disease. Pristanic and phytanic acids accumulated in livers of Amacr-/- mice after a phytol diet. Microarray analysis also revealed changes in the expression levels of numerous genes in wild-type mouse livers after two weeks of the phytol diet compared to a control diet. This indicates that detoxification of phytol metabolites in liver is accompanied by activation of multiple pathways at the molecular level and Amacr-/- mice are not able to respond adequately. Phytol causes primary failure in liver leading to death of Amacr-/- mice thus emphasizing the indispensable role of Amacr in detoxification of α-methyl-branched fatty acids.
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Affiliation(s)
- Eija M Selkälä
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, P.O. Box 5400, FI-90014, Finland; Biocenter Oulu, University of Oulu, Finland
| | - Remya R Nair
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, P.O. Box 5400, FI-90014, Finland; Biocenter Oulu, University of Oulu, Finland
| | - Werner Schmitz
- Theodor-Boveri-Institut für Biowissenschaften, Lehrstuhl für Biochemie und Molekularbiologie der Universität Würzburg, Am Hubland, 97974 Würzburg, Germany
| | - Ari-Pekka Kvist
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, P.O. Box 5400, FI-90014, Finland; Biocenter Oulu, University of Oulu, Finland
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Herestraat 49 O&N 2, 3000 Leuven, Belgium
| | - J Kalervo Hiltunen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, P.O. Box 5400, FI-90014, Finland; Biocenter Oulu, University of Oulu, Finland
| | - Kaija J Autio
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, P.O. Box 5400, FI-90014, Finland; Biocenter Oulu, University of Oulu, Finland.
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Martin GG, Atshaves BP, Landrock KK, Landrock D, Schroeder F, Kier AB. Loss of L-FABP, SCP-2/SCP-x, or both induces hepatic lipid accumulation in female mice. Arch Biochem Biophys 2015; 580:41-9. [PMID: 26116377 DOI: 10.1016/j.abb.2015.06.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Revised: 06/08/2015] [Accepted: 06/17/2015] [Indexed: 02/06/2023]
Abstract
Although roles for both sterol carrier protein-2/sterol carrier protein-x (SCP-2/SCP-x) and liver fatty acid binding protein (L-FABP) have been proposed in hepatic lipid accumulation, individually ablating these genes has been complicated by concomitant alterations in the other gene product(s). For example, ablating SCP2/SCP-x induces upregulation of L-FABP in female mice. Therefore, the impact of ablating SCP-2/SCP-x (DKO) or L-FABP (LKO) individually or both together (TKO) was examined in female mice. Loss of SCP-2/SCP-x (DKO, TKO) more so than loss of L-FABP alone (LKO) increased hepatic total lipid and total cholesterol content, especially cholesteryl ester. Hepatic accumulation of nonesterified long chain fatty acids (LCFA) and phospholipids occurred only in DKO and TKO mice. Loss of SCP-2/SCP-x (DKO, TKO) increased serum total lipid primarily by increasing triglycerides. Altered hepatic level of proteins involved in cholesterol uptake, efflux, and/or secretion was observed, but did not compensate for the loss of L-FABP, SCP-2/SCP-x or both. However, synergistic responses were not seen with the combinatorial knock out animals-suggesting that inhibiting SCP-2/SCP-x is more correlative with hepatic dysfunction than L-FABP. The DKO- and TKO-induced hepatic accumulation of cholesterol and long chain fatty acids shared significant phenotypic similarities with non-alcoholic fatty liver disease (NAFLD).
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Affiliation(s)
- Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, United States
| | - Barbara P Atshaves
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, United States
| | - Kerstin K Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, College Station, TX 77843-4466, United States
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, College Station, TX 77843-4467, United States.
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50
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"Role of peroxisomes in human lipid metabolism and its importance for neurological development". Neurosci Lett 2015; 637:11-17. [PMID: 26095698 DOI: 10.1016/j.neulet.2015.06.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 06/07/2015] [Indexed: 11/23/2022]
Abstract
Peroxisomes play a crucial role in normal neurological development as exemplified by the devastating neurological consequences of a defect in the biogenesis of peroxisomes as in Zellweger syndrome. The underlying basis for the important role of peroxisomes in neurological development resides in the fact that peroxisomes catalyze a number of physiological functions, notably involving the metabolism of different lipids. Indeed, peroxisomes catalyse the beta-oxidative breakdown of certain fatty acids including: (1.) the very long-chain fatty acids C22:0, C24:0, and C26:0; (2.) pristanic acid and (3.) the bile acid intermediates di- and trihydroxycholestanoic acid which cannot be oxidized in mitochondria. Furthermore, peroxisomes catalyze the synthesis of a particular type of lipids, i.e. ether-linked phospholipids, which are highly abundant in brain, especially in myelin. The current state of knowledge with respect to the metabolic role of peroxisomes will be described in this paper with particular emphasis on the role of peroxisomes in brain.
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