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Smith T, Knudsen KJ, Ritchie SA. A novel inducible animal model for studying chronic plasmalogen deficiency associated with Alzheimer's disease. Brain Res 2024; 1843:149132. [PMID: 39053687 DOI: 10.1016/j.brainres.2024.149132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/15/2024] [Accepted: 07/22/2024] [Indexed: 07/27/2024]
Abstract
Plasmalogens are vinyl-ether glycerophospholipids critical for the structure and function of neuronal membranes. Deficient plasmalogen levels are associated with neurodegenerative diseases, particularly Alzheimer's disease (AD), which has led to the hypothesis that plasmalogen deficiency might drive disease onset and progression. However, the lack of a suitable animal model with late-onset plasmalogen deficiency has prevented testing of this hypothesis. The goal of this project was therefore to develop and characterize a mouse model capable of undergoing a plasmalogen deficiency only in adulthood, mirroring the chronic decline thought to occur in AD. We report here the creation of a novel animal model containing a tamoxifen-inducible knockout of the Gnpat gene encoding the first step in the plasmalogen biosynthetic pathway. Tamoxifen treatment in adult animals resulted in a significant reduction of plasmalogens in both the circulation and tissues as early as four weeks. By four months, changes in behavior and nerve function were observed, with strong correlations between residual brain plasmalogen levels, hyperactivity, and latency. The model will be useful for further elucidating the role of plasmalogens in AD and evaluating plasmalogen therapies.
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Affiliation(s)
- Tara Smith
- Med-Life Discoveries LP, Saskatoon, SK, Canada.
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2
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Honsho M, Fujiki Y. Asymmetric Distribution of Plasmalogens and Their Roles-A Mini Review. MEMBRANES 2023; 13:764. [PMID: 37755186 PMCID: PMC10534842 DOI: 10.3390/membranes13090764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/03/2023] [Accepted: 08/25/2023] [Indexed: 09/28/2023]
Abstract
Plasmalogens are a unique family of cellular glycerophospholipids that contain a vinyl-ether bond. The synthesis of plasmalogens is initiated in peroxisomes and completed in the endoplasmic reticulum. Plasmalogens are transported to the post-Golgi compartment, including endosomes and plasma membranes, in a manner dependent on ATP, but not vesicular transport. Plasmalogens are preferentially localized in the inner leaflet of the plasma membrane in a manner dependent on P4-type ATPase ATP8B2, that associates with the CDC50 subunit. Plasmalogen biosynthesis is spatiotemporally regulated by a feedback mechanism that senses the amount of plasmalogens in the inner leaflet of the plasma membrane and controls the stability of fatty acyl-CoA reductase 1 (FAR1), the rate-limiting enzyme for plasmalogen biosynthesis. The physiological consequences of such asymmetric localization and homeostasis of plasmalogens are discussed in this review.
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Affiliation(s)
- Masanori Honsho
- Department of Neuroinflammation and Brain Fatigue Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8581, Japan
| | - Yukio Fujiki
- Institute of Rheological Functions of Food-Kyushu University Collaboration Program, Kyushu University, Fukuoka 811-2501, Japan
- Graduate School of Science, University of Hyogo, Himeji 671-2280, Japan
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3
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Gerami R, Barkhordari S. Antenatal ultrasonographic diagnosis of rhizomelic chondrodysplasia punctata. J Ultrasound 2023; 26:539-542. [PMID: 36315400 PMCID: PMC10247581 DOI: 10.1007/s40477-022-00737-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 09/23/2022] [Indexed: 06/08/2023] Open
Abstract
BACKGROUND Rhizomelic chondrodysplasia punctata (RCDP) is a rare autosomal recessive inherited subtype of a family of congenital anomalies known as chondrodysplasia calcificans punctate (CCP). Given their low rate of occurrence, these cases are highly challenging to diagnose, and because the presence of chondrodysplasia is an indication for legal abortion in Iran, such diagnosis is extremely critical. CASE PRESENTATION A 27-year-old white multipara was referred for obstetric ultrasonography at 17 weeks and 6 days of gestation because an ultrasonographic study performed at an outside institution revealed a short femur length. Given the patient's positive family history of chondrodysplasia, she underwent targeted sonography to check the anomaly of the bone and cartilage. The key finding in the sonography was short bones for gestational age. CONCLUSION The important clue in this finding was the patient's family history, which made the gynaecologist request an ultrasound to prevent the birth of a child with a congenital disorder. Genetic tests are usually performed on amniocentesis samples. Because the presence of chondrodysplasia is an indication for legal abortion in Iran, finally, the patient underwent legal abortion after amniocentesis and genetic tests.
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Affiliation(s)
- Reza Gerami
- Department of Radiology, Faculty of Medicine, Army University of Medical Science (AJA University of Medical Science), Tehran, Iran
| | - Shoresh Barkhordari
- School of Medicine, Army University of Medical Science (AJA University of Medical Science), Tehran, Iran
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4
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Honsho M, Fujiki Y. Regulation of plasmalogen biosynthesis in mammalian cells and tissues. Brain Res Bull 2023; 194:118-123. [PMID: 36720320 DOI: 10.1016/j.brainresbull.2023.01.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 01/08/2023] [Accepted: 01/27/2023] [Indexed: 01/29/2023]
Abstract
Plasmalogens are a unique family of cellular glycerophospholipids that contain a vinyl-ether bond. Synthesis of plasmalogens is initiated in peroxisomes and completed in the endoplasmic reticulum. The absence of plasmalogens in several organs of patients with deficiency in peroxisome biogenesis suggests that de novo synthesis of plasmalogens contributes significantly to plasmalogen homeostasis in humans. Plasmalogen biosynthesis is spatiotemporally regulated by a feedback mechanism that senses the amount of plasmalogens in the inner leaflet of the plasma membrane and regulates the stability of fatty acyl-CoA reductase 1 (FAR1), the rate-limiting enzyme for plasmalogen biosynthesis. Dysregulation of plasmalogen synthesis impairs cholesterol synthesis in cells and brain, resulting in the reduced expression of genes such as mRNA encoding myelin basic protein, a phenotype found in the cerebellum of plasmalogen-deficient mice. In this review, we summarize the current knowledge of molecular mechanisms underlying the regulation of plasmalogen biosynthesis and the link between plasmalogen homeostasis and cholesterol biosynthesis, and address the pathogenesis of impaired plasmalogen homeostasis in rodent and humans.
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Affiliation(s)
- Masanori Honsho
- Department of Neuroinflammation and Brain Fatigue Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Yukio Fujiki
- Institute of Rheological Functions of Food-Kyushu University Collaboration Program, Kyushu University, Fukuoka, Japan; Graduate School of Science, University of Hyogo, Hyogo, Japan.
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5
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Dorninger F, Kiss A, Rothauer P, Stiglbauer-Tscholakoff A, Kummer S, Fallatah W, Perera-Gonzalez M, Hamza O, König T, Bober MB, Cavallé-Garrido T, Braverman NE, Forss-Petter S, Pifl C, Bauer J, Bittner RE, Helbich TH, Podesser BK, Todt H, Berger J. Overlapping and Distinct Features of Cardiac Pathology in Inherited Human and Murine Ether Lipid Deficiency. Int J Mol Sci 2023; 24:1884. [PMID: 36768204 PMCID: PMC9914995 DOI: 10.3390/ijms24031884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/10/2023] [Accepted: 01/11/2023] [Indexed: 01/21/2023] Open
Abstract
Inherited deficiency in ether lipids, a subgroup of glycerophospholipids with unique biochemical and biophysical properties, evokes severe symptoms in humans resulting in a multi-organ syndrome. Mouse models with defects in ether lipid biosynthesis have widely been used to understand the pathophysiology of human disease and to study the roles of ether lipids in various cell types and tissues. However, little is known about the function of these lipids in cardiac tissue. Previous studies included case reports of cardiac defects in ether-lipid-deficient patients, but a systematic analysis of the impact of ether lipid deficiency on the mammalian heart is still missing. Here, we utilize a mouse model of complete ether lipid deficiency (Gnpat KO) to accomplish this task. Similar to a subgroup of human patients with rhizomelic chondrodysplasia punctata (RCDP), a fraction of Gnpat KO fetuses present with defects in ventricular septation, presumably evoked by a developmental delay. We did not detect any signs of cardiomyopathy but identified increased left ventricular end-systolic and end-diastolic pressure in middle-aged ether-lipid-deficient mice. By comprehensive electrocardiographic characterization, we consistently found reduced ventricular conduction velocity, as indicated by a prolonged QRS complex, as well as increased QRS and QT dispersion in the Gnpat KO group. Furthermore, a shift of the Wenckebach point to longer cycle lengths indicated depressed atrioventricular nodal function. To complement our findings in mice, we analyzed medical records and performed electrocardiography in ether-lipid-deficient human patients, which, in contrast to the murine phenotype, indicated a trend towards shortened QT intervals. Taken together, our findings demonstrate that the cardiac phenotype upon ether lipid deficiency is highly heterogeneous, and although the manifestations in the mouse model only partially match the abnormalities in human patients, the results add to our understanding of the physiological role of ether lipids and emphasize their importance for proper cardiac development and function.
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Affiliation(s)
- Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Attila Kiss
- Center for Biomedical Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Peter Rothauer
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Währingerstrasse 13a, 1090 Vienna, Austria
| | - Alexander Stiglbauer-Tscholakoff
- Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Structural Preclinical Imaging, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Stefan Kummer
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Währinger Straße 13, 1090 Vienna, Austria
| | - Wedad Fallatah
- Department of Genetic Medicine, King AbdulAziz University, Jeddah 21589, Saudi Arabia
- Department of Human Genetics and Pediatrics, Montreal Children’s Hospital, McGill University, 1001 Décarie Blvd, Montreal, QC H4A 3J1, Canada
| | - Mireia Perera-Gonzalez
- Center for Biomedical Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Ouafa Hamza
- Center for Biomedical Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Theresa König
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Michael B. Bober
- Skeletal Dysplasia Program, Nemours Children’s Hospital, 1600 Rockland Road, Wilmington, DE 19803, USA
| | - Tiscar Cavallé-Garrido
- Department of Pediatrics, Division of Cardiology, Montreal Children’s Hospital, McGill University, 1001 Décarie Blvd, Montreal, QC H4A 3J1, Canada
| | - Nancy E. Braverman
- Department of Human Genetics and Pediatrics, Montreal Children’s Hospital, McGill University, 1001 Décarie Blvd, Montreal, QC H4A 3J1, Canada
| | - Sonja Forss-Petter
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Christian Pifl
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Jan Bauer
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
| | - Reginald E. Bittner
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Währinger Straße 13, 1090 Vienna, Austria
| | - Thomas H. Helbich
- Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Structural Preclinical Imaging, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Bruno K. Podesser
- Center for Biomedical Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - Hannes Todt
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Währingerstrasse 13a, 1090 Vienna, Austria
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
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6
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Chen CT, Shao Z, Fu Z. Dysfunctional peroxisomal lipid metabolisms and their ocular manifestations. Front Cell Dev Biol 2022; 10:982564. [PMID: 36187472 PMCID: PMC9524157 DOI: 10.3389/fcell.2022.982564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Retina is rich in lipids and dyslipidemia causes retinal dysfunction and eye diseases. In retina, lipids are not only important membrane component in cells and organelles but also fuel substrates for energy production. However, our current knowledge of lipid processing in the retina are very limited. Peroxisomes play a critical role in lipid homeostasis and genetic disorders with peroxisomal dysfunction have different types of ocular complications. In this review, we focus on the role of peroxisomes in lipid metabolism, including degradation and detoxification of very-long-chain fatty acids, branched-chain fatty acids, dicarboxylic acids, reactive oxygen/nitrogen species, glyoxylate, and amino acids, as well as biosynthesis of docosahexaenoic acid, plasmalogen and bile acids. We also discuss the potential contributions of peroxisomal pathways to eye health and summarize the reported cases of ocular symptoms in patients with peroxisomal disorders, corresponding to each disrupted peroxisomal pathway. We also review the cross-talk between peroxisomes and other organelles such as lysosomes, endoplasmic reticulum and mitochondria.
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Affiliation(s)
- Chuck T Chen
- Department of Nutritional Sciences, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Zhuo Shao
- Post-Graduate Medical Education, University of Toronto, Toronto, ON, Canada
- Division of Clinical and Metabolic Genetics, the Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
- The Genetics Program, North York General Hospital, University of Toronto, Toronto, ON, Canada
| | - Zhongjie Fu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
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7
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Fallatah W, Cui W, Di Pietro E, Carter GT, Pounder B, Dorninger F, Pifl C, Moser AB, Berger J, Braverman NE. A Pex7 Deficient Mouse Series Correlates Biochemical and Neurobehavioral Markers to Genotype Severity—Implications for the Disease Spectrum of Rhizomelic Chondrodysplasia Punctata Type 1. Front Cell Dev Biol 2022; 10:886316. [PMID: 35898397 PMCID: PMC9310236 DOI: 10.3389/fcell.2022.886316] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/19/2022] [Indexed: 12/31/2022] Open
Abstract
Rhizomelic chondrodysplasia punctata type 1 (RCDP1) is a peroxisome biogenesis disorder caused by defects in PEX7 leading to impairment in plasmalogen (Pls) biosynthesis and phytanic acid (PA) oxidation. Pls deficiency is the main pathogenic factor that determines the severity of RCDP. Severe (classic) RCDP patients have negligible Pls levels, congenital cataracts, skeletal dysplasia, growth and neurodevelopmental deficits, and cerebral hypomyelination and cerebellar atrophy on brain MRI. Individuals with milder or nonclassic RCDP have higher Pls levels, better growth and cognitive outcomes. To better understand the pathophysiology of RCDP disorders, we generated an allelic series of Pex7 mice either homozygous for the hypomorphic allele, compound heterozygous for the hypomorphic and null alleles or homozygous for the null allele. Pex7 transcript and protein were almost undetectable in the hypomorphic model, and negligible in the compound heterozygous and null mice. Pex7 deficient mice showed a graded reduction in Pls and increases in C26:0-LPC and PA in plasma and brain according to genotype. Neuropathological evaluation showed significant loss of cerebellar Purkinje cells over time and a decrease in brain myelin basic protein (MBP) content in Pex7 deficient models, with more severe effects correlating with Pex7 genotype. All Pex7 deficient mice exhibited a hyperactive behavior in the open field environment. Brain neurotransmitters analysis of Pex7 deficient mice showed a significant reduction in levels of dopamine, norepinephrine, serotonin and GABA. Also, a significant correlation was found between brain neurotransmitter levels, the hyperactivity phenotype, Pls level and the severity of Pex7 genotype. In conclusion, our study showed evidence of a genotype-phenotype correlation between the severity of Pex7 deficiency and several clinical and neurobiochemical phenotypes in RCDP1 mouse models. We propose that PA accumulation may underlie the cerebellar atrophy seen in older RCDP1 patients, as even relatively low tissue levels were strongly associated with Purkinje cells loss over time in the murine models. Also, our data demonstrate the interrelation between Pls, brain neurotransmitter deficiencies and the neurobehavioral phenotype, which could be further used as a valuable clinical endpoint for therapeutic interventions. Finally, these models show that incremental increases in Pex7 levels result in dramatic improvements in phenotype.
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Affiliation(s)
- Wedad Fallatah
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- Department of Medical Genetics, King Abdul-Aziz University, Jeddah, Saudi Arabia
- *Correspondence: Wedad Fallatah, ; Nancy E. Braverman,
| | - Wei Cui
- Child Health and Human Development Program, Peroxisome Disease Laboratory, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Erminia Di Pietro
- Child Health and Human Development Program, Peroxisome Disease Laboratory, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Grace T. Carter
- Child Health and Human Development Program, Peroxisome Disease Laboratory, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Brittany Pounder
- Child Health and Human Development Program, Peroxisome Disease Laboratory, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Christian Pifl
- Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Ann B. Moser
- Hugo W Moser Research Institute, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Nancy E. Braverman
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- Child Health and Human Development Program, Peroxisome Disease Laboratory, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- *Correspondence: Wedad Fallatah, ; Nancy E. Braverman,
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8
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Honsho M, Mawatari S, Fujiki Y. ATP8B2-Mediated Asymmetric Distribution of Plasmalogens Regulates Plasmalogen Homeostasis and Plays a Role in Intracellular Signaling. Front Mol Biosci 2022; 9:915457. [PMID: 35832735 PMCID: PMC9271795 DOI: 10.3389/fmolb.2022.915457] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 05/23/2022] [Indexed: 12/21/2022] Open
Abstract
Plasmalogens are a subclass of glycerophospholipid containing vinyl-ether bond at the sn-1 position of glycerol backbone. Ethanolamine-containing plasmalogens (plasmalogens) are major constituents of cellular membranes in mammalian cells and de novo synthesis of plasmalogens largely contributes to the homeostasis of plasmalogens. Plasmalogen biosynthesis is regulated by a feedback mechanism that senses the plasmalogen level in the inner leaflet of the plasma membrane and regulates the stability of fatty acyl-CoA reductase 1 (Far1), a rate-limiting enzyme for plasmalogen biosynthesis. However, the molecular mechanism underlying the localization of plasmalogens in cytoplasmic leaflet of plasma membrane remains unknown. To address this issue, we attempted to identify a potential transporter of plasmalogens from the outer to the inner leaflet of plasma membrane by focusing on phospholipid flippases, type-IV P-type adenosine triphosphatases (P4-ATPase), localized in the plasma membranes. We herein show that knockdown of ATP8B2 belonging to the class-1 P4-ATPase enhances localization of plasmalogens but not phosphatidylethanolamine in the extracellular leaflet and impairs plasmalogen-dependent degradation of Far1. Furthermore, phosphorylation of protein kinase B (AKT) is downregulated by lowering the expression of ATP8B2, which leads to suppression of cell growth. Taken together, these results suggest that enrichment of plasmalogens in the cytoplasmic leaflet of plasma membranes is mediated by ATP8B2 and this asymmetric distribution of plasmalogens is required for sensing plasmalogens as well as phosphorylation of AKT.
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Affiliation(s)
- Masanori Honsho
- Department of Neuroinflammation and Brain Fatigue Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
- Institute of Rheological Functions of Food-Kyushu University Collaboration Program, Kyushu University, Fukuoka, Japan
- *Correspondence: Masanori Honsho, ; Yukio Fujiki,
| | - Shiro Mawatari
- Institute of Rheological Functions of Food, Fukuoka, Japan
| | - Yukio Fujiki
- Institute of Rheological Functions of Food-Kyushu University Collaboration Program, Kyushu University, Fukuoka, Japan
- Graduate School of Science, University of Hyogo, Hyogo, Japan
- *Correspondence: Masanori Honsho, ; Yukio Fujiki,
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9
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Smith T, Knudsen KJ, Ritchie SA. Pharmacokinetics, Mass Balance, Excretion, and Tissue Distribution of Plasmalogen Precursor PPI-1011. Front Cell Dev Biol 2022; 10:867138. [PMID: 35547803 PMCID: PMC9081329 DOI: 10.3389/fcell.2022.867138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/03/2022] [Indexed: 11/19/2022] Open
Abstract
PPI-1011 is a synthetic plasmalogen precursor in development as a treatment for multiple plasmalogen-deficiency disorders. Previous work has demonstrated the ability of PPI-1011 to augment plasmalogens and its effects in vitro and in vivo, however, the precise uptake and distribution across tissues in vivo has not been investigated. The purpose of this study was to evaluate the pharmacokinetics, mass balance, and excretion of [14C]PPI-1011 following a single oral administration at 100 mg/kg in Sprague-Dawley rats. Further tissue distribution was examined using quantitative whole-body autoradiography after both single and repeat daily doses at 100 mg/kg/day. Non-compartmental analysis showed that following a single dose, PPI-1011 exhibited peak levels between 6 and 12 h but also a long half-life with mean t1/2 of 40 h. Mass balance showed that over 50% of the compound-associated radioactivity was absorbed by the body, while approximately 40% was excreted in the feces, 2.5% in the urine, and 10% in expired air within the first 24 h. Quantitative whole-body autoradiography following a single dose showed uptake to nearly all tissues, with the greatest initial uptake in the intestines, liver, and adipose tissue, which decreased time-dependently throughout 168 h post-dose. Following 15 consecutive daily doses, uptake was significantly higher across the entire body at 24 h compared to single dose and remained high out to 96 h where 75% of the initially-absorbed compound-associated radioactivity was still present. The adipose tissue remained particularly high, suggesting a possible reserve of either plasmalogens or alkyl diacylglycerols that the body can pull from for plasmalogen biosynthesis. Uptake to the brain was also definitively confirmed, proving PPI-1011’s ability to cross the blood-brain barrier. In conclusion, our results suggest that oral administration of PPI-1011 results in high uptake across the body, and that repeated dosing over time represents a viable therapeutic strategy for treating plasmalogen deficiencies.
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10
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Wells KM, Baumel M, McCusker CD. The Regulation of Growth in Developing, Homeostatic, and Regenerating Tetrapod Limbs: A Minireview. Front Cell Dev Biol 2022; 9:768505. [PMID: 35047496 PMCID: PMC8763381 DOI: 10.3389/fcell.2021.768505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 11/19/2021] [Indexed: 01/29/2023] Open
Abstract
The size and shape of the tetrapod limb play central roles in their functionality and the overall physiology of the organism. In this minireview we will discuss observations on mutant animal models and humans, which show that the growth and final size of the limb is most impacted by factors that regulate either limb bud patterning or the elongation of the long bones. We will also apply the lessons that have been learned from embryos to how growth could be regulated in regenerating limb structures and outline the challenges that are unique to regenerating animals.
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11
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Luisman T, Smith T, Ritchie S, Malone KE. Genetic epidemiology approach to estimating birth incidence and current disease prevalence for rhizomelic chondrodysplasia punctata. Orphanet J Rare Dis 2021; 16:300. [PMID: 34229749 PMCID: PMC8258949 DOI: 10.1186/s13023-021-01889-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/24/2021] [Indexed: 11/17/2022] Open
Abstract
Background Rhizomelic chondrodysplasia punctata (RCDP) is an inherited ultra-rare disease which results in severely impaired physical and mental development. Mutations in one of five genes involved in plasmalogen biosynthesis have been reported to drive disease pathology. Estimates of disease incidence have been extremely challenging due to the rarity of the disorder, preventing an understanding of the unmet medical need. To address this, we have prepared a disease incidence and prevalence model based on genetic epidemiology approaches to estimate the total number of RCDP patients affected, and their demographic characteristics. Results Extraction of allelic frequencies for known and predicted pathogenic variants in PEX7, GNPAT, AGPS, FAR1, PEX5 (limited to the PTS2 domain encoding region) genes, from large-scale human genetic diversity datasets (TopMed and gnomAD) revealed the mutational landscape contributing to the RCDP patient population in the US and Europe. We computed genetic prevalence to derive birth incidence for RCDP and modeled the impact to life expectancy to obtain high confidence estimates of disease prevalence. Our population genetics-based model indicates PEX7 variants are expected to contribute to the majority of RCDP cases in both the US and Europe; closely aligning with clinical reports. Furthermore, this model provides estimates for RCDP subtypes due to mutations in other genes, including exceedingly rare subtypes. Conclusion In total, the estimated number of RCDP patients in the US and the five largest European countries (UK, Germany, France, Italy and Spain) is between 516 and 847 patients, all under the age of 35 years old. This model provides a quantitative framework for better understanding the unmet medical need in RCDP, to help guide disease awareness and diagnosis efforts for this specific patient group. Supplementary Information The online version contains supplementary material available at 10.1186/s13023-021-01889-z.
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Affiliation(s)
| | - Tara Smith
- Med-Life Discoveries, Saskatoon, SK, Canada.
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12
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Xiao C, Rossignol F, Vaz FM, Ferreira CR. Inherited disorders of complex lipid metabolism: A clinical review. J Inherit Metab Dis 2021; 44:809-825. [PMID: 33594685 DOI: 10.1002/jimd.12369] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 02/04/2021] [Accepted: 02/09/2021] [Indexed: 02/06/2023]
Abstract
Over 80 human diseases have been attributed to defects in complex lipid metabolism. A majority of them have been reported recently in the setting of rapid advances in genomic technology and their increased use in clinical settings. Lipids are ubiquitous in human biology and play roles in many cellular and intercellular processes. While inborn errors in lipid metabolism can affect every organ system with many examples of genetic heterogeneity and pleiotropy, the clinical manifestations of many of these disorders can be explained based on the disruption of the metabolic pathway involved. In this review, we will discuss the physiological function of major pathways in complex lipid metabolism, including nonlysosomal sphingolipid metabolism, acylceramide metabolism, de novo phospholipid synthesis, phospholipid remodeling, phosphatidylinositol metabolism, mitochondrial cardiolipin synthesis and remodeling, and ether lipid metabolism as well as common clinical phenotypes associated with each.
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Affiliation(s)
- Changrui Xiao
- National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Francis Rossignol
- National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Frédéric M Vaz
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry and Pediatrics, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, The Netherlands
- Core Facility Metabolomics, Amsterdam UMC, Amsterdam, The Netherlands
| | - Carlos R Ferreira
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
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13
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Fallatah W, Schouten M, Yergeau C, Di Pietro E, Engelen M, Waterham HR, Poll-The BT, Braverman N. Clinical, biochemical, and molecular characterization of mild (nonclassic) rhizomelic chondrodysplasia punctata. J Inherit Metab Dis 2021; 44:1021-1038. [PMID: 33337545 DOI: 10.1002/jimd.12349] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/27/2020] [Accepted: 12/08/2020] [Indexed: 01/12/2023]
Abstract
Rhizomelic chondrodysplasia punctata (RCDP) is a heterogenous group of disorders due to defects in genes encoding peroxisomal proteins required for plasmalogen (PL) biosynthesis, specifically PEX7 and PEX5 receptors, or GNPAT, AGPS and FAR1 enzymes. Most patients have congenital cataract and skeletal dysplasia. In the classic form, there is profound growth restriction and psychomotor delays, with most patients not advancing past infantile developmental milestones. Disease severity correlates to erythrocyte PL levels, which are almost undetectable in severe (classic) RCDP. In milder (nonclassic) forms, residual PL levels are associated with improved growth and development. However, the clinical course of this milder group remains largely unknown as only a few cases were reported. Using as inclusion criteria the ability to communicate and walk, we identified 16 individuals from five countries, ages 5-37 years, and describe their clinical, biochemical and molecular profiles. The average age at diagnosis was 2.6 years and most had cataract, growth deficiency, joint contractures, and developmental delays. Other major symptoms were learning disability (87%), behavioral issues (56%), seizures (43%), and cardiac defects (31%). All patients had decreased C16:0 PL levels that were higher than in classic RCDP, and up to 43% of average controls. Plasma phytanic acid levels were elevated in most patients. There were several common, and four novel, PEX7, and GNPAT hypomorphic alleles in this cohort. These results can be used to support earlier diagnosis and improve management in patients with mild RCDP.
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Affiliation(s)
- Wedad Fallatah
- Department of Human Genetics, McGill University, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
- Department of Medical Genetics, King Abdul-Aziz University, Jeddah, Saudi Arabia
| | - Monica Schouten
- Department of Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC - location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Christine Yergeau
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
| | - Erminia Di Pietro
- Child Health and Human Development Program, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
| | - Marc Engelen
- Department of Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC - location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC - location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Bwee Tien Poll-The
- Department of Pediatric Neurology, Emma Children's Hospital, Amsterdam UMC - location AMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Nancy Braverman
- Department of Human Genetics and Pediatrics, Child Health and Human Development Program, McGill University, Research Institute of the McGill University Health Centre, Montreal, Québec, Canada
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14
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A missense allele of PEX5 is responsible for the defective import of PTS2 cargo proteins into peroxisomes. Hum Genet 2021; 140:649-666. [PMID: 33389129 DOI: 10.1007/s00439-020-02238-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 11/07/2020] [Indexed: 11/27/2022]
Abstract
Peroxisomes, single-membrane intracellular organelles, play an important role in various metabolic pathways. The translocation of proteins from the cytosol to peroxisomes depends on peroxisome import receptor proteins and defects in peroxisome transport result in a wide spectrum of peroxisomal disorders. Here, we report a large consanguineous family with autosomal recessive congenital cataracts and developmental defects. Genome-wide linkage analysis localized the critical interval to chromosome 12p with a maximum two-point LOD score of 4.2 (θ = 0). Next-generation exome sequencing identified a novel homozygous missense variant (c.653 T > C; p.F218S) in peroxisomal biogenesis factor 5 (PEX5), a peroxisome import receptor protein. This missense mutation was confirmed by bidirectional Sanger sequencing. It segregated with the disease phenotype in the family and was absent in ethnically matched control chromosomes. The lens-specific knockout mice of Pex5 recapitulated the cataractous phenotype. In vitro import assays revealed a normal capacity of the mutant PEX5 to enter the peroxisomal Docking/Translocation Module (DTM) in the presence of peroxisome targeting signal 1 (PTS1) cargo protein, be monoubiquitinated and exported back into the cytosol. Importantly, the mutant PEX5 protein was unable to form a stable trimeric complex with peroxisomal biogenesis factor 7 (PEX7) and a peroxisome targeting signal 2 (PTS2) cargo protein and, therefore, failed to promote the import of PTS2 cargo proteins into peroxisomes. In conclusion, we report a novel missense mutation in PEX5 responsible for the defective import of PTS2 cargo proteins into peroxisomes resulting in congenital cataracts and developmental defects.
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15
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Fallatah W, Smith T, Cui W, Jayasinghe D, Di Pietro E, Ritchie SA, Braverman N. Oral administration of a synthetic vinyl-ether plasmalogen normalizes open field activity in a mouse model of rhizomelic chondrodysplasia punctata. Dis Model Mech 2020; 13:dmm.042499. [PMID: 31862688 PMCID: PMC6994958 DOI: 10.1242/dmm.042499] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 12/13/2019] [Indexed: 01/06/2023] Open
Abstract
Rhizomelic chondrodysplasia punctata (RCDP) is a rare genetic disorder caused by mutations in peroxisomal genes essential for plasmalogen biosynthesis. Plasmalogens are a class of membrane glycerophospholipids containing a vinyl-ether-linked fatty alcohol at the sn-1 position that affect functions including vesicular transport, membrane protein function and free radical scavenging. A logical rationale for the treatment of RCDP is therefore the therapeutic augmentation of plasmalogens. The objective of this work was to provide a preliminary characterization of a novel vinyl-ether synthetic plasmalogen, PPI-1040, in support of its potential utility as an oral therapeutic option for RCDP. First, wild-type mice were treated with 13C6-labeled PPI-1040, which showed that the sn-1 vinyl-ether and the sn-3 phosphoethanolamine groups remained intact during digestion and absorption. Next, a 4-week treatment of adult plasmalogen-deficient Pex7hypo/null mice with PPI-1040 showed normalization of plasmalogen levels in plasma, and variable increases in plasmalogen levels in erythrocytes and peripheral tissues (liver, small intestine, skeletal muscle and heart). Augmentation was not observed in brain, lung and kidney. Functionally, PPI-1040 treatment normalized the hyperactive behavior observed in the Pex7hypo/null mice as determined by open field test, with a significant inverse correlation between activity and plasma plasmalogen levels. Parallel treatment with an equal amount of ether plasmalogen precursor, PPI-1011, did not effectively augment plasmalogen levels or reduce hyperactivity. Our findings show, for the first time, that a synthetic vinyl-ether plasmalogen is orally bioavailable and can improve plasmalogen levels in an RCDP mouse model. Further exploration of its clinical utility is warranted. This article has an associated First Person interview with the joint first authors of the paper. Summary: This article shows, for the first time, that a synthetic vinyl-ether plasmalogen is orally bioavailable and bioactive in vivo following administration in animals.
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Affiliation(s)
- Wedad Fallatah
- Department of Human Genetics and Pediatrics, Research Institute of the McGill University Health Center and McGill University, Montreal, QC H4A3J1, Canada.,Department of Medical Genetics, King Abdul-Aziz University, Jeddah, 21589 Saudi Arabia
| | - Tara Smith
- Med-Life Discoveries LP, Saskatoon, SK S7N2X8, Canada
| | - Wei Cui
- Department of Human Genetics and Pediatrics, Research Institute of the McGill University Health Center and McGill University, Montreal, QC H4A3J1, Canada
| | | | - Erminia Di Pietro
- Department of Human Genetics and Pediatrics, Research Institute of the McGill University Health Center and McGill University, Montreal, QC H4A3J1, Canada
| | | | - Nancy Braverman
- Department of Human Genetics and Pediatrics, Research Institute of the McGill University Health Center and McGill University, Montreal, QC H4A3J1, Canada
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16
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Abe Y, Tamura S, Honsho M, Fujiki Y. A Mouse Model System to Study Peroxisomal Roles in Neurodegeneration of Peroxisome Biogenesis Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1299:119-143. [PMID: 33417212 DOI: 10.1007/978-3-030-60204-8_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Fourteen PEX genes are currently identified as genes responsible for peroxisome biogenesis disorders (PBDs). Patients with PBDs manifest as neurodegenerative symptoms such as neuronal migration defect and malformation of the cerebellum. To address molecular mechanisms underlying the pathogenesis of PBDs, mouse models for the PBDs have been generated by targeted disruption of Pex genes. Pathological phenotypes and metabolic abnormalities in Pex-knockout mice well resemble those of the patients with PBDs. The mice with tissue- or cell type-specific inactivation of Pex genes have also been established by using a Cre-loxP system. The genetically modified mice reveal that pathological phenotypes of PBDs are mediated by interorgan and intercellular communications. Despite the illustrations of detailed pathological phenotypes in the mutant mice, mechanistic insights into pathogenesis of PBDs are still underway. In this chapter, we overview the phenotypes of Pex-inactivated mice and the current understanding of the pathogenesis underlying PBDs.
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Affiliation(s)
- Yuichi Abe
- Faculty of Arts and Science, Kyushu University, Fukuoka, Japan
| | | | | | - Yukio Fujiki
- Institute of Rheological Functions of Food, Fukuoka, Japan. .,Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
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17
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Schrader M, Kamoshita M, Islinger M. Organelle interplay-peroxisome interactions in health and disease. J Inherit Metab Dis 2020; 43:71-89. [PMID: 30864148 PMCID: PMC7041636 DOI: 10.1002/jimd.12083] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 02/28/2019] [Accepted: 03/06/2019] [Indexed: 01/04/2023]
Abstract
Peroxisomes are multifunctional, dynamic, membrane-bound organelles with important functions in cellular lipid metabolism, rendering them essential for human health and development. Important roles for peroxisomes in signaling and the fine-tuning of cellular processes are emerging, which integrate them in a complex network of interacting cellular compartments. Like many other organelles, peroxisomes communicate through membrane contact sites. For example, peroxisomal growth, positioning, and lipid metabolism involves contacts with the endoplasmic reticulum (ER). Here, we discuss the most recent findings on peroxisome-organelle interactions including peroxisome-ER interplay at membrane contacts sites, and functional interplay with mitochondria, lysosomes, and lipid droplets in mammalian cells. We address tether proteins, metabolic cooperation, and the impact of peroxisome interactions on human health and disease.
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Affiliation(s)
- Michael Schrader
- College of Life and Environmental Sciences, BiosciencesUniversity of ExeterExeterUK
| | - Maki Kamoshita
- College of Life and Environmental Sciences, BiosciencesUniversity of ExeterExeterUK
| | - Markus Islinger
- Institute of Neuroanatomy, Center for Biomedicine and Medical Technology Mannheim, Medical Faculty ManheimUniversity of HeidelbergMannheimGermany
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18
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Honsho M, Okumoto K, Tamura S, Fujiki Y. Peroxisome Biogenesis Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1299:45-54. [PMID: 33417206 DOI: 10.1007/978-3-030-60204-8_4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Peroxisomes are presented in all eukaryotic cells and play essential roles in many of lipid metabolic pathways, including β-oxidation of fatty acids and synthesis of ether-linked glycerophospholipids, such as plasmalogens. Impaired peroxisome biogenesis, including defects of membrane assembly, import of peroxisomal matrix proteins, and division of peroxisome, causes peroxisome biogenesis disorders (PBDs). Fourteen complementation groups of PBDs are found, and their complementing genes termed PEXs are isolated. Several new mutations in peroxins from patients with mild PBD phenotype or patients with phenotypes unrelated to the commonly observed impairments of PBD patients are found by next-generation sequencing. Exploring a dysfunctional step(s) caused by the mutation is important for unveiling the pathogenesis of novel mutation by means of cellular and biochemical analyses.
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Affiliation(s)
| | - Kanji Okumoto
- Department of Biology, Faculty of Sciences, Kyushu University Graduate School, Fukuoka, Japan
| | | | - Yukio Fujiki
- Institute of Rheological Functions of Food, Fukuoka, Japan. .,Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
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19
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Takahashi T, Honsho M, Abe Y, Fujiki Y. Plasmalogen mediates integration of adherens junction. J Biochem 2019; 166:423-432. [PMID: 31236591 DOI: 10.1093/jb/mvz049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 06/19/2019] [Indexed: 11/13/2022] Open
Abstract
Ether glycerolipids, plasmalogens are found in various mammalian cells and tissues. However, physiological role of plasmalogens in epithelial cells remains unknown. We herein show that synthesis of ethanolamine-containing plasmalogens, plasmenylethanolamine (PlsEtn), is deficient in MCF7 cells, an epithelial cell line, with severely reduced expression of alkyl-dihydroxyacetonephosphate synthase (ADAPS), the second enzyme in the PlsEtn biosynthesis. Moreover, expression of ADAPS or supplementation of PlsEtn containing C18-alkenyl residue delays the migration of MCF7 cells as compared to that mock-treated MCF7 and C16-alkenyl-PlsEtn-supplemented MCF7 cells. Localization of E-cadherin to cell-cell junctions is highly augmented in cells containing C18-alkenyl-PlsEtn. Together, these results suggest that PlsEtn containing C18-alkenyl residue plays a distinct role in the integrity of E-cadherin-mediated adherens junction.
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Affiliation(s)
- Takanori Takahashi
- Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, Japan
| | - Masanori Honsho
- Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Yuichi Abe
- Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
| | - Yukio Fujiki
- Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan
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20
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Alshenaifi J, Ewida N, Anazi S, Shamseldin HE, Patel N, Maddirevula S, Al-Sheddi T, Alomar R, Alobeid E, Ibrahim N, Hashem M, Abdulwahab F, Jacob M, Alhashem A, Alzaidan HI, Seidahmed MZ, Alhashemi N, Rawashdeh R, Eyaid W, Al-Hassnan ZN, Rahbeeni Z, Alswaid A, Hadid A, Qari A, Mohammed DA, El Khashab HY, Alfadhel M, Abanemai M, Sunbul R, Al Tala S, Alkhalifi S, Alkharfi T, Abouelhoda M, Monies D, Al Tassan N, AlDubayan SH, Kurdi W, Al-Owain M, Dasouki MJ, Kentab AY, Atyani S, Makhseed N, Faqeih E, Shaheen R, Alkuraya FS. The many faces of peroxisomal disorders: Lessons from a large Arab cohort. Clin Genet 2018; 95:310-319. [PMID: 30561787 DOI: 10.1111/cge.13481] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 11/01/2018] [Accepted: 11/16/2018] [Indexed: 01/28/2023]
Abstract
Defects in the peroxisomes biogenesis and/or function result in peroxisomal disorders. In this study, we describe the largest Arab cohort to date (72 families) of clinically, biochemically and molecularly characterized patients with peroxisomal disorders. At the molecular level, we identified 43 disease-causing variants, half of which are novel. The founder nature of many of the variants allowed us to calculate the minimum disease burden for these disorders in our population ~1:30 000, which is much higher than previous estimates in other populations. Clinically, we found an interesting trend toward genotype/phenotype correlation in terms of long-term survival. Nearly half (40/75) of our peroxisomal disorders patients had documented survival beyond 1 year of age. Most unusual among the long-term survivors was a multiplex family in which the affected members presented as adults with non-specific intellectual disability and epilepsy. Other unusual presentations included the very recently described peroxisomal fatty acyl-CoA reductase 1 disorder as well as CRD, spastic paraparesis, white matter (CRSPW) syndrome. We conclude that peroxisomal disorders are highly heterogeneous in their clinical presentation. Our data also confirm the demonstration that milder forms of Zellweger spectrum disorders cannot be ruled out by the "gold standard" very long chain fatty acids assay, which highlights the value of a genomics-first approach in these cases.
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Affiliation(s)
- Jumanah Alshenaifi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nour Ewida
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Shams Anazi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nisha Patel
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Sateesh Maddirevula
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Tarfa Al-Sheddi
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Rana Alomar
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Eman Alobeid
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Niema Ibrahim
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais Hashem
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Firdous Abdulwahab
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Minnie Jacob
- The Newborn Screening and Biochemical Genetics Laboratory, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Amal Alhashem
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Hamad I Alzaidan
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | | | | | - Rifaat Rawashdeh
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Wafaa Eyaid
- Medical Genetic Division, Department of Pediatrics, King Abdullah International Medical Research Centre, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Zuhair N Al-Hassnan
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Zuhair Rahbeeni
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Abdulrahman Alswaid
- Medical Genetic Division, Department of Pediatrics, King Abdullah International Medical Research Centre, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Adnan Hadid
- Department of Pediatrics College of Medicine and King Saud University Medical City, King Saud University, Riyadh, Saudi Arabia
| | - Alya Qari
- Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Dia A Mohammed
- Department of Pediatrics, Makkah Maternity and Children's Hospital, Makkah, Saudi Arabia
| | - Heba Y El Khashab
- Department of Pediatrics Dr. Sulimann AL Habib Medical Group, Riyadh, Saudi Arabia.,Department of Pediatrics, Division of Pediatric Neurology Children Hospital, Ain Shams University, Cairo, Egypt
| | - Majid Alfadhel
- Medical Genetic Division, Department of Pediatrics, King Abdullah International Medical Research Centre, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Mohammad Abanemai
- Pediatrics Department, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Rawda Sunbul
- Pediatrics Medical Genetic Unit (PMGU), Pediatrics Department, Qatif Central Hospital, Qatif, Saudi Arabia
| | - Saeed Al Tala
- Armed Forces Hospital Southern Region, Pediatric Directorate and Genetic Unit Khamis Mushayt, Khamis Mushait, Saudi Arabia
| | | | - Turki Alkharfi
- Department of Pediatrics, Sanad Hospital, Riyadh, Saudi Arabia
| | - Mohamed Abouelhoda
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Nada Al Tassan
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Saud H AlDubayan
- Department of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,Division of Genetics, Brigham and Women's Hospital, Boston, Massachusetts
| | - Wesam Kurdi
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Department of Obstetrics and Gynecology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mohammed Al-Owain
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Department of Medical Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Majed J Dasouki
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,The Newborn Screening and Biochemical Genetics Laboratory, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Amal Y Kentab
- Department of Pediatrics College of Medicine and King Saud University Medical City, King Saud University, Riyadh, Saudi Arabia
| | - Suha Atyani
- Department of Pediatrics, Mubarak Al-Kabeer Hospital, Kuwait, Kuwait
| | - Nawal Makhseed
- Pediatric Department, Al-Jahra Hospital, Ministry of Health, Kuwait, Kuwait
| | - Eissa Faqeih
- Department of Pediatric Subspecialties, Children's Hospital, Riyadh, Saudi Arabia
| | - Ranad Shaheen
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
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21
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Lopez DH, Bestard-Escalas J, Garate J, Maimó-Barceló A, Fernández R, Reigada R, Khorrami S, Ginard D, Okazaki T, Fernández JA, Barceló-Coblijn G. Tissue-selective alteration of ethanolamine plasmalogen metabolism in dedifferentiated colon mucosa. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:928-938. [PMID: 29709709 DOI: 10.1016/j.bbalip.2018.04.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 04/12/2018] [Accepted: 04/21/2018] [Indexed: 01/09/2023]
Abstract
Human colon lipid analysis by imaging mass spectrometry (IMS) demonstrates that the lipid fingerprint is highly sensitive to a cell's pathophysiological state. Along the colon crypt axis, and concomitant to the differentiation process, certain lipid species tightly linked to signaling (phosphatidylinositols and arachidonic acid (AA)-containing diacylglycerophospholipids), change following a rather simple mathematical expression. We extend here our observations to ethanolamine plasmalogens (PlsEtn), a unique type of glycerophospholipid presenting a vinyl ether linkage at sn-1 position. PlsEtn distribution was studied in healthy, adenomatous, and carcinomatous colon mucosa sections by IMS. In epithelium, 75% of PlsEtn changed in a highly regular manner along the crypt axis, in clear contrast with diacyl species (67% of which remained constant). Consistently, AA-containing PlsEtn species were more abundant at the base, where stem cells reside, and decreased while ascending the crypt. In turn, mono-/diunsaturated species experienced the opposite change. These gradients were accompanied by a gradual expression of ether lipid synthesis enzymes. In lamina propria, 90% of stromal PlsEtn remained unchanged despite the high content of AA and the gradient in AA-containing diacylglycerophospholipids. Finally, both lipid and protein gradients were severely affected in polyps and carcinoma. These results link PlsEtn species regulation to cell differentiation for the first time and confirm that diacyl and ether species are differently regulated. Furthermore, they reaffirm the observations on cell lipid fingerprint image sensitivity to predict cell pathophysiological status, reinforcing the translational impact both lipidome and IMS might have in clinical research.
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Affiliation(s)
- Daniel H Lopez
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain.
| | - Joan Bestard-Escalas
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain.
| | - Jone Garate
- Dep. of Physical Chemistry, University of the Basque Country (UPV/EHU), Leioa, Biscay, Spain.
| | - Albert Maimó-Barceló
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain.
| | - Roberto Fernández
- Dep. of Physical Chemistry, University of the Basque Country (UPV/EHU), Leioa, Biscay, Spain.
| | - Rebeca Reigada
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain.
| | - Sam Khorrami
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain; Gastroenterology Unit, Hospital Universitari Son Espases, Palma, Balearic Islands, Spain.
| | - Daniel Ginard
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain; Gastroenterology Unit, Hospital Universitari Son Espases, Palma, Balearic Islands, Spain.
| | - Toshiro Okazaki
- Department of Hematology/Immunity, Kanazawa Medical University, Uchinada-machi, Kahoku-gun, Ishikawa 920-0293, Japan.
| | - José A Fernández
- Dep. of Physical Chemistry, University of the Basque Country (UPV/EHU), Leioa, Biscay, Spain.
| | - Gwendolyn Barceló-Coblijn
- Institut d'Investigació Sanitària Illes Balears (IdISBa, Health Research Institute of the Balearic Islands), Palma, Balearic Islands, Spain.
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Wanders RJA, Waterham HR, Ferdinandusse S. Peroxisomes and Their Central Role in Metabolic Interaction Networks in Humans. Subcell Biochem 2018; 89:345-365. [PMID: 30378031 DOI: 10.1007/978-981-13-2233-4_15] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Peroxisomes catalyze a number of essential metabolic functions and impairments in any of these are usually associated with major clinical signs and symptoms. In contrast to mitochondria which are autonomous organelles that can catalyze the degradation of fatty acids, certain amino acids and other compounds all by themselves, peroxisomes are non-autonomous organelles which are highly dependent on the interaction with other organelles and compartments to fulfill their role in metabolism. This includes mitochondria, the endoplasmic reticulum, lysosomes, and the cytosol. In this paper we will discuss the central role of peroxisomes in different metabolic interaction networks in humans, including fatty acid oxidation, ether phospholipid biosynthesis, bile acid synthesis, fatty acid alpha-oxidation and glyoxylate metabolism.
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Affiliation(s)
- Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Departments Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands.
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Departments Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Departments Clinical Chemistry and Pediatrics, Emma Children's Hospital, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands
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Dorninger F, Forss-Petter S, Berger J. From peroxisomal disorders to common neurodegenerative diseases - the role of ether phospholipids in the nervous system. FEBS Lett 2017; 591:2761-2788. [PMID: 28796901 DOI: 10.1002/1873-3468.12788] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 07/26/2017] [Accepted: 08/07/2017] [Indexed: 01/01/2023]
Abstract
The emerging diverse roles of ether (phospho)lipids in nervous system development and function in health and disease are currently attracting growing interest. Plasmalogens, a subgroup of ether lipids, are important membrane components involved in vesicle fusion and membrane raft composition. They store polyunsaturated fatty acids and may serve as antioxidants. Ether lipid metabolites act as precursors for the formation of glycosyl-phosphatidyl-inositol anchors; others, like platelet-activating factor, are implicated in signaling functions. Consolidating the available information, we attempt to provide molecular explanations for the dramatic neurological phenotype in ether lipid-deficient human patients and mice by linking individual functional properties of ether lipids with pathological features. Furthermore, recent publications have identified altered ether lipid levels in the context of many acquired neurological disorders including Alzheimer's disease (AD) and autism. Finally, current efforts to restore ether lipids in peroxisomal disorders as well as AD are critically reviewed.
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Affiliation(s)
- Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Austria
| | - Sonja Forss-Petter
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Austria
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Austria
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Honsho M, Fujiki Y. Plasmalogen homeostasis - regulation of plasmalogen biosynthesis and its physiological consequence in mammals. FEBS Lett 2017; 591:2720-2729. [PMID: 28686302 DOI: 10.1002/1873-3468.12743] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 06/28/2015] [Accepted: 06/29/2016] [Indexed: 11/06/2022]
Abstract
Plasmalogens, mostly ethanolamine-containing alkenyl ether phospholipids, are a major subclass of glycerophospholipids. Plasmalogen synthesis is initiated in peroxisomes and completed in the endoplasmic reticulum. The absence of plasmalogens in several organs of peroxisome biogenesis-defective patients suggests that the de novo synthesis of plasmalogens plays a pivotal role in its homeostasis in tissues. Plasmalogen synthesis is regulated by modulating the stability of fatty acyl-CoA reductase 1 on peroxisomal membranes, a rate-limiting enzyme in plasmalogen synthesis, by sensing plasmalogens in the inner leaflet of plasma membranes. Dysregulation of plasmalogen homeostasis impairs cholesterol biosynthesis by altering the stability of squalene monooxygenase, a key enzyme in cholesterol biosynthesis, implying physiological consequences of plasmalogen homeostasis with respect to cholesterol metabolism in cells, as well as in organs such as the liver.
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Affiliation(s)
- Masanori Honsho
- Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Yukio Fujiki
- Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
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Yagita Y, Shinohara K, Abe Y, Nakagawa K, Al-Owain M, Alkuraya FS, Fujiki Y. Deficiency of a Retinal Dystrophy Protein, Acyl-CoA Binding Domain-containing 5 (ACBD5), Impairs Peroxisomal β-Oxidation of Very-long-chain Fatty Acids. J Biol Chem 2016; 292:691-705. [PMID: 27899449 DOI: 10.1074/jbc.m116.760090] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 11/11/2016] [Indexed: 12/22/2022] Open
Abstract
Acyl-CoA binding domain-containing 5 (ACBD5) is a peroxisomal protein that carries an acyl-CoA binding domain (ACBD) at its N-terminal region. The recent identification of a mutation in the ACBD5 gene in patients with a syndromic form of retinal dystrophy highlights the physiological importance of ACBD5 in humans. However, the underlying pathogenic mechanisms and the precise function of ACBD5 remain unclear. We herein report that ACBD5 is a peroxisomal tail-anchored membrane protein exposing its ACBD to the cytosol. Using patient-derived fibroblasts and ACBD5 knock-out HeLa cells generated via genome editing, we demonstrate that ACBD5 deficiency causes a moderate but significant defect in peroxisomal β-oxidation of very-long-chain fatty acids (VLCFAs) and elevates the level of cellular phospholipids containing VLCFAs without affecting peroxisome biogenesis, including the import of membrane and matrix proteins. Both the N-terminal ACBD and peroxisomal localization of ACBD5 are prerequisite for efficient VLCFA β-oxidation in peroxisomes. Furthermore, ACBD5 preferentially binds very-long-chain fatty acyl-CoAs (VLC-CoAs). Together, these results suggest a direct role of ACBD5 in peroxisomal VLCFA β-oxidation. Based on our findings, we propose that ACBD5 captures VLC-CoAs on the cytosolic side of the peroxisomal membrane so that the transport of VLC-CoAs into peroxisomes and subsequent β-oxidation thereof can proceed efficiently. Our study reclassifies ACBD5-related phenotype as a novel peroxisomal disorder.
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Affiliation(s)
- Yuichi Yagita
- From the Department of Biology and Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan
| | - Kyoko Shinohara
- From the Department of Biology and Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan
| | - Yuichi Abe
- the Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan, and
| | - Keiko Nakagawa
- From the Department of Biology and Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan
| | - Mohammed Al-Owain
- the King Faisal Specialist Hospital and Research Center, MBC-03 P. O. Box 3354, Riyadh 11211, Saudi Arabia
| | - Fowzan S Alkuraya
- the King Faisal Specialist Hospital and Research Center, MBC-03 P. O. Box 3354, Riyadh 11211, Saudi Arabia
| | - Yukio Fujiki
- the Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan, and
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Human disorders of peroxisome metabolism and biogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:922-33. [DOI: 10.1016/j.bbamcr.2015.11.015] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 12/22/2022]
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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: 197] [Impact Index Per Article: 24.6] [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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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: 120] [Impact Index Per Article: 13.3] [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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Barøy T, Koster J, Strømme P, Ebberink MS, Misceo D, Ferdinandusse S, Holmgren A, Hughes T, Merckoll E, Westvik J, Woldseth B, Walter J, Wood N, Tvedt B, Stadskleiv K, Wanders RJ, Waterham HR, Frengen E. A novel type of rhizomelic chondrodysplasia punctata, RCDP5, is caused by loss of the PEX5 long isoform. Hum Mol Genet 2015. [DOI: 10.1093/hmg/ddv305] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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30
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Dorninger F, Brodde A, Braverman NE, Moser AB, Just WW, Forss-Petter S, Brügger B, Berger J. Homeostasis of phospholipids - The level of phosphatidylethanolamine tightly adapts to changes in ethanolamine plasmalogens. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:117-28. [PMID: 25463479 PMCID: PMC4331674 DOI: 10.1016/j.bbalip.2014.11.005] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 11/04/2014] [Accepted: 11/10/2014] [Indexed: 01/19/2023]
Abstract
Ethanolamine plasmalogens constitute a group of ether glycerophospholipids that, due to their unique biophysical and biochemical properties, are essential components of mammalian cellular membranes. Their importance is emphasized by the consequences of defects in plasmalogen biosynthesis, which in humans cause the fatal disease rhizomelic chondrodysplasia punctata (RCDP). In the present lipidomic study, we used fibroblasts derived from RCDP patients, as well as brain tissue from plasmalogen-deficient mice, to examine the compensatory mechanisms of lipid homeostasis in response to plasmalogen deficiency. Our results show that phosphatidylethanolamine (PE), a diacyl glycerophospholipid, which like ethanolamine plasmalogens carries the head group ethanolamine, is the main player in the adaptation to plasmalogen insufficiency. PE levels were tightly adjusted to the amount of ethanolamine plasmalogens so that their combined levels were kept constant. Similarly, the total amount of polyunsaturated fatty acids (PUFAs) in ethanolamine phospholipids was maintained upon plasmalogen deficiency. However, we found an increased incorporation of arachidonic acid at the expense of docosahexaenoic acid in the PE fraction of plasmalogen-deficient tissues. These data show that under conditions of reduced plasmalogen levels, the amount of total ethanolamine phospholipids is precisely maintained by a rise in PE. At the same time, a shift in the ratio between ω-6 and ω-3 PUFAs occurs, which might have unfavorable, long-term biological consequences. Therefore, our findings are not only of interest for RCDP but may have more widespread implications also for other disease conditions, as for example Alzheimer's disease, that have been associated with a decline in plasmalogens. PE accurately compensates for the lack of plasmalogens in vitro and in vivo. PE levels decrease to adapt to excess of ethanolamine plasmalogens (PlsEtn). Plasmalogen deficiency favors incorporation of arachidonic acid into PE. Docosahexaenoic acid in ethanolamine phospholipids decreases upon PlsEtn depletion.
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Affiliation(s)
- Fabian Dorninger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| | - Alexander Brodde
- Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
| | - Nancy E Braverman
- Department of Human Genetics and Pediatrics, McGill University-Montreal Children's Hospital, 4060 Ste-Catherine West, PT-406.2, Montreal, QC H3Z 2Z3, Canada.
| | - Ann B Moser
- Peroxisomal Diseases Laboratory, The Hugo W Moser Research Institute, The Kennedy Krieger Institute, 707 N. Broadway, Baltimore, MD 21205, USA.
| | - Wilhelm W Just
- Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
| | - Sonja Forss-Petter
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
| | - Britta Brügger
- Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria.
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Buchert R, Tawamie H, Smith C, Uebe S, Innes AM, Al Hallak B, Ekici AB, Sticht H, Schwarze B, Lamont RE, Parboosingh JS, Bernier FP, Abou Jamra R. A peroxisomal disorder of severe intellectual disability, epilepsy, and cataracts due to fatty acyl-CoA reductase 1 deficiency. Am J Hum Genet 2014; 95:602-10. [PMID: 25439727 DOI: 10.1016/j.ajhg.2014.10.003] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 10/02/2014] [Indexed: 11/18/2022] Open
Abstract
Rhizomelic chondrodysplasia punctata (RCDP) is a group of disorders with overlapping clinical features including rhizomelia, chondrodysplasia punctata, coronal clefts, cervical dysplasia, congenital cataracts, profound postnatal growth retardation, severe intellectual disability, and seizures. Mutations in PEX7, GNPAT, and AGPS, all involved in the plasmalogen-biosynthesis pathway, have been described in individuals with RCDP. Here, we report the identification of mutations in another gene in plasmalogen biosynthesis, fatty acyl-CoA reductase 1 (FAR1), in two families affected by severe intellectual disability, early-onset epilepsy, microcephaly, congenital cataracts, growth retardation, and spasticity. Exome analyses revealed a homozygous in-frame indel mutation (c.495_507delinsT [p.Glu165_Pro169delinsAsp]) in two siblings from a consanguineous family and compound-heterozygous mutations (c.[787C>T];[1094A>G], p.[Arg263(∗)];[Asp365Gly]) in a third unrelated individual. FAR1 reduces fatty acids to their respective fatty alcohols for the plasmalogen-biosynthesis pathway. To assess the pathogenicity of the identified mutations, we transfected human embryonic kidney 293 cells with plasmids encoding FAR1 with either wild-type or mutated constructs and extracted the lipids from the cells. We screened the lipids with gas chromatography and mass spectrometry and found that all three mutations abolished the reductase activity of FAR1, given that no fatty alcohols could be detected. We also observed reduced plasmalogens in red blood cells in one individual to a range similar to that seen in individuals with RCDP, further supporting abolished FAR1 activity. We thus expand the spectrum of clinical features associated with defects in plasmalogen biosynthesis to include FAR1 deficiency as a cause of syndromic severe intellectual disability with cataracts, epilepsy, and growth retardation but without rhizomelia.
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Affiliation(s)
- Rebecca Buchert
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Hasan Tawamie
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Christopher Smith
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Steffen Uebe
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - A Micheil Innes
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | | | - Arif B Ekici
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Heinrich Sticht
- Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Bernd Schwarze
- Department of Forensic Medicine, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Ryan E Lamont
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Jillian S Parboosingh
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Francois P Bernier
- Department of Medical Genetics, University of Calgary, Calgary, AB T2N 4N1, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Rami Abou Jamra
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany.
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Waterham HR, Ebberink MS. Genetics and molecular basis of human peroxisome biogenesis disorders. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1430-41. [PMID: 22871920 DOI: 10.1016/j.bbadis.2012.04.006] [Citation(s) in RCA: 189] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 03/30/2012] [Accepted: 04/11/2012] [Indexed: 10/28/2022]
Abstract
Human peroxisome biogenesis disorders (PBDs) are a heterogeneous group of autosomal recessive disorders comprised of two clinically distinct subtypes: the Zellweger syndrome spectrum (ZSS) disorders and rhizomelic chondrodysplasia punctata (RCDP) type 1. PBDs are caused by defects in any of at least 14 different PEX genes, which encode proteins involved in peroxisome assembly and proliferation. Thirteen of these genes are associated with ZSS disorders. The genetic heterogeneity among PBDs and the inability to predict from the biochemical and clinical phenotype of a patient with ZSS which of the currently known 13 PEX genes is defective, has fostered the development of different strategies to identify the causative gene defects. These include PEX cDNA transfection complementation assays followed by sequencing of the thus identified PEX genes, and a PEX gene screen in which the most frequently mutated exons of the different PEX genes are analyzed. The benefits of DNA testing for PBDs include carrier testing of relatives, early prenatal testing or preimplantation genetic diagnosis in families with a recurrence risk for ZSS disorders, and insight in genotype-phenotype correlations, which may eventually assist to improve patient management. In this review we describe the current status of genetic analysis and the molecular basis of PBDs.
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Kanzawa N, Shimozawa N, Wanders RJA, Ikeda K, Murakami Y, Waterham HR, Mukai S, Fujita M, Maeda Y, Taguchi R, Fujiki Y, Kinoshita T. Defective lipid remodeling of GPI anchors in peroxisomal disorders, Zellweger syndrome, and rhizomelic chondrodysplasia punctata. J Lipid Res 2012; 53:653-63. [PMID: 22253471 DOI: 10.1194/jlr.m021204] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Many cell surface proteins in mammalian cells are anchored to the plasma membrane via glycosylphosphatidylinositol (GPI). The predominant form of mammalian GPI contains 1-alkyl-2-acyl phosphatidylinositol (PI), which is generated by lipid remodeling from diacyl PI. The conversion of diacyl PI to 1-alkyl-2-acyl PI occurs in the ER at the third intermediate in the GPI biosynthetic pathway. This lipid remodeling requires the alkyl-phospholipid biosynthetic pathway in peroxisome. Indeed, cells defective in dihydroxyacetone phosphate acyltransferase (DHAP-AT) or alkyl-DHAP synthase express only the diacyl form of GPI-anchored proteins. A defect in the alkyl-phospholipid biosynthetic pathway causes a peroxisomal disorder, rhizomelic chondrodysplasia punctata (RCDP), and defective biogenesis of peroxisomes causes Zellweger syndrome, both of which are lethal genetic diseases with multiple clinical phenotypes such as psychomotor defects, mental retardation, and skeletal abnormalities. Here, we report that GPI lipid remodeling is defective in cells from patients with Zellweger syndrome having mutations in the peroxisomal biogenesis factors PEX5, PEX16, and PEX19 and in cells from patients with RCDP types 1, 2, and 3 caused by mutations in PEX7, DHAP-AT, and alkyl-DHAP synthase, respectively. Absence of the 1-alkyl-2-acyl form of GPI-anchored proteins might account for some of the complex phenotypes of these two major peroxisomal disorders.
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Affiliation(s)
- Noriyuki Kanzawa
- Department of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
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Wanders RJA, Brites P. Biosynthesis of ether-phospholipids including plasmalogens, peroxisomes and human disease: new insights into an old problem. ACTA ACUST UNITED AC 2010. [DOI: 10.2217/clp.10.16] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
Chondrodysplasia punctata (CDP) is associated with a number of disorders, including inborn errors of metabolism, involving peroxisomal and cholesterol pathways, embryopathy and chromosomal abnormalities. Several classification systems of the different types of CDP have been suggested earlier. More recently, the biochemical and molecular basis of a number of CDP syndromes has recently been elucidated and a new aetiological classification has emerged. Here we provide an updated version with an overview of the different types of CDP, a discussion of the aetiology and a description of the clinical and radiographic findings. An investigative guideline to help determine the exact diagnosis in new cases is also presented.
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Wanders RJA, Waterham HR. Peroxisomal disorders: the single peroxisomal enzyme deficiencies. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1707-20. [PMID: 17055078 DOI: 10.1016/j.bbamcr.2006.08.010] [Citation(s) in RCA: 175] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Accepted: 08/18/2006] [Indexed: 01/02/2023]
Abstract
Peroxisomal disorders are a group of inherited diseases in man in which either peroxisome biogenesis or one or more peroxisomal functions are impaired. The peroxisomal disorders identified to date are usually classified in two groups including: (1) the disorders of peroxisome biogenesis, and (2) the single peroxisomal enzyme deficiencies. This review is focused on the second group of disorders, which currently includes ten different diseases in which the mutant gene affects a protein involved in one of the following peroxisomal functions: (1) ether phospholipid (plasmalogen) biosynthesis; (2) fatty acid beta-oxidation; (3) peroxisomal alpha-oxidation; (4) glyoxylate detoxification, and (5) H2O2 metabolism.
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Başbuğ M, Serin IS, Ozçelik B, Guneş T, Akçakuş M, Tayyar M. Prenatal Ultrasonographic Diagnosis of Rhizomelic Chondrodysplasia punctata by Detection of Rhizomelic Shortening and Bilateral Cataracts. Fetal Diagn Ther 2005; 20:171-4. [PMID: 15824492 DOI: 10.1159/000083899] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2003] [Accepted: 02/13/2004] [Indexed: 11/19/2022]
Abstract
Antenatal sonographic diagnosis of rhizomelic chondrodysplasia punctata depends on recognization of the combination of rhizomelic bone shortening and epiphyseal stippling. This is the only report of prenatal ultrasonographic diagnosis of bilateral cataracts in a fetus with rhizomelic chondrodysplasia punctata (type 1). Also, this is the first report of severe rhizomelic limb shortening, and bilateral cataracts prior to the recognization of epiphyseal stippling.
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Affiliation(s)
- Mustafa Başbuğ
- Department of Obstetrics and Gynecology, Erciyes University Medical Faculty, Kayseri, Turkey.
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39
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Abstract
The group of peroxisomal disorders now includes 17 different disorders with Zellweger syndrome as prototype. Thanks to the explosion of new information about the functions and biogenesis of peroxisomes, the metabolic and molecular basis of most of the peroxisomal disorders has been resolved. A review of peroxisomal disorders is provided in this paper.
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Affiliation(s)
- Ronald J A Wanders
- University of Amsterdam, Academic Medical Centre, Department of Clinical Chemistry, Emma Children's Hospital, Laboratory of Genetic Metabolic Diseases, Amsterdam, The Netherlands.
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Wanders RJA. Peroxisomes, lipid metabolism, and peroxisomal disorders. Mol Genet Metab 2004; 83:16-27. [PMID: 15464416 DOI: 10.1016/j.ymgme.2004.08.016] [Citation(s) in RCA: 152] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2004] [Accepted: 08/30/2004] [Indexed: 10/26/2022]
Abstract
Peroxisomes catalyse a large variety of different cellular functions of which most have to do with lipid metabolism. This paper deals with the role of peroxisomes in three key pathways of lipid metabolism, including: (1) etherphospholipid biosynthesis, (2) fatty acid beta-oxidation, and (3) fatty acid alpha-oxidation. Apart from a brief description of the peroxisomal enzymes involved in each of these pathways, the interaction between peroxisomes and other subcellular organelles, notably microsomes and peroxisomes, will be discussed. Finally, the current state of knowledge with respect to the different disorders of peroxisomal lipid metabolism will be described.
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Affiliation(s)
- R J A Wanders
- Laboratory for Genetic Metabolic Diseases, Department of Clinical Chemistry and Pediatrics, Academic Medical Center, University of Amsterdam, Emma Children's Hospital, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
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41
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Braverman N, Chen L, Lin P, Obie C, Steel G, Douglas P, Chakraborty PK, Clarke JTR, Boneh A, Moser A, Moser H, Valle D. Mutation analysis of PEX7 in 60 probands with rhizomelic chondrodysplasia punctata and functional correlations of genotype with phenotype. Hum Mutat 2002; 20:284-97. [PMID: 12325024 DOI: 10.1002/humu.10124] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PEX7 encodes the cytosolic receptor for the set of peroxisomal matrix enzymes targeted to the organelle by the peroxisome targeting signal 2 (PTS2). Mutations in PEX7 cause rhizomelic chondrodysplasia punctata (RCDP), a distinct peroxisome biogenesis disorder. In previous work we described three novel PEX7 mutant alleles, including one, L292X, with a high frequency due to a founder effect. We have now extended our analysis to 60 RCDP probands and identified a total of 24 PEX7 alleles, accounting for 95% of the mutant PEX7 genes in our sample. Of these, 50% are L292X, 13% are IVS9+1G>C, and the remainder are mostly private. IVS9+1G>C occurs on at least three different haplotypes and thus appears to result from recurrent mutation. The phenotypic spectrum of RCDP is broader than commonly recognized and includes minimally affected individuals at the mild end of the spectrum. To relate PEX7 genotype and phenotype, we evaluated the consequence of the disease mutation on PEX7 RNA by Northern analysis and RT/PCR. We evaluated the function of the encoded Pex7 protein (Pex7p) by expressing selected alleles in fibroblasts from RCDP patients and assaying their ability to restore import of a PTS2 marker protein. We find that residual activity of mutant Pex7p and reduced amounts of normal Pex7p are associated with milder and variant phenotypes.
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Affiliation(s)
- Nancy Braverman
- McKusick-Nathans Institute of Genetic Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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42
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Abstract
Peroxisomes are subcellular organelles catalyzing a number of indispensable functions in cellular metabolism. The importance of peroxisomes is stressed by the existence of an expanding number of genetic diseases in which there is an impairment of one or more peroxisomal functions. The prototype of this group of diseases is the cerebro-hepato-renal syndrome of Zellweger (ZS), first described as a familial syndrome of multiple congenital defects in 1964. ZS is characterized by the presence of dysmorphias and polymalformative syndrome, severe neurologic abnormalities including neurosensory defects and hepato-intestinal dysfunction with failure to thrive and usually early death. Other peroxisomal disorders share some of these symptoms, but with varying degrees of organ involvement, severity of dysfunction and duration of survival. This paper provides an overview of the peroxisomal disorders including their clinical, biochemical and molecular characteristics with particular emphasis on the clinical presentation in neonates.
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Affiliation(s)
- N Nagan
- Department of Laboratory Medicine and Pathology, Division of Clinical Biochemistry and Immunology, Mayo Foundation Clinic, Rochester, MN 55905, USA
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44
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Farooqui AA, Horrocks LA. Plasmalogens, phospholipase A2, and docosahexaenoic acid turnover in brain tissue. J Mol Neurosci 2001; 16:263-72; discussion 279-84. [PMID: 11478381 DOI: 10.1385/jmn:16:2-3:263] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Plasmalogens are glycerophospholipids of neural membranes containing vinyl ether bonds. Their synthetic pathway is located in peroxisomes and endoplasmic reticulum. The rate-limiting enzymes are in the peroxisomes and are induced by docosahexaenoic acid (DHA). Plasmalogens often contain arachidonic acid (AA) or DHA at the sn-2 position of the glycerol moiety. The receptor-mediated hydrolysis of plasmalogens by cytosolic plasmalogen-selective phospholipase A2 generates AA or DHA and lysoplasmalogens. AA is metabolized to eicosanoids. The mechanism of signaling with DHA is not known. The plasmalogen-selective phospholipase A2 differs from other intracellular phospholipases A2 in molecular mass, kinetic properties, substrate specificity, and response to glycosaminoglycans, gangliosides, and sialoglycoproteins. A major portion of [3H]DHA incorporated into neural membranes is found at the sn-2 position of ethanolamine glycerophospholipids. Studies with a mutant cell line defective in plasmalogen biosynthesis indicate that the incorporation of DHA is reduced in this RAW 264.7 cell line by 50%. In contrast, the incorporation of AA remains unaffected. This is reversed completely when the growth medium is supplemented with sn-1-hexadecylglycerol, suggesting that DHA can be selectively targeted for incorporation into plasmalogens. We suggest that deficiencies of DHA and plasmalogens in peroxisomal disorders, Alzheimer's disease (AD), depression, and attention deficit hyperactivity disorders (ADHD) may be responsible for abnormal signal transduction associated with learning disability, cognitive deficit, and visual dysfunction. These abnormalities in the signal-transduction process can be partially corrected by supplementation with a diet enriched with DHA.
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Affiliation(s)
- A A Farooqui
- Department of Molecular and Cellular Biochemistry The Ohio State University, Columbus 43210, USA
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45
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Ofman R, Lajmir S, Wanders RJ. Etherphospholipid biosynthesis and dihydroxyactetone-phosphate acyltransferase: resolution of the genomic organization of the human gnpat gene and its use in the identification of novel mutations. Biochem Biophys Res Commun 2001; 281:754-60. [PMID: 11237722 DOI: 10.1006/bbrc.2001.4407] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Etherphospholipids are characterised by the occurrence of an alkyl- or alkenyl-group at the sn-1 position of the glycerol backbone. Peroxisomes play an essential role in the formation of etherphospholipids since the first two enzymes of the biosynthetic pathway are strictly peroxisomal. The function of plasmalogens is still an enigma but the recent identification of patients suffering from an isolated defect in either dihydroxyacetone phosphate acyltransferase (GNPAT) or alkyldihydroxyacetone phosphate synthase provides conclusive evidence that plasmalogens play an essential role for human survival and functioning. In this paper we report the complete genomic organisation of the GNPAT gene coding for the peroxisomal dihydroxyacetone phosphate acyltransferase. The gene is located on chromosome 1q42.12-43. It spans approximately 28 kb and consists of 16 exons and 15 introns. This information was used to analyse the GNPAT gene in 12 patients with GNPAT deficiency. All patients analysed were found to have mutations in their GNPAT gene. Of the 9 different mutations found, 2 were missense mutations, 2 small deletions, 1 insertion and 3 mutations were within splice donor/acceptor-sites. Another mutation created an alternative splice donor-site causing the partial deletion of an exon. The data obtained provide conclusive evidence for the major role of GNPAT in etherphospholipid biosynthesis.
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Affiliation(s)
- R Ofman
- Department of Clinical Chemistry and Pediatrics, Academic Medical Centre, Amsterdam, 1100 DE, The Netherlands
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Kumada S, Hayashi M, Kenmochi J, Kurosawa S, Shimozawa N, Kratz LE, Kelley RI, Taki K, Okaniwa M. Lethal form of chondrodysplasia punctata with normal plasmalogen and cholesterol biosynthesis. AMERICAN JOURNAL OF MEDICAL GENETICS 2001; 98:250-5. [PMID: 11169563 DOI: 10.1002/1096-8628(20010122)98:3<250::aid-ajmg1087>3.0.co;2-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We present a male autopsied case of chondrodysplasia punctata with abnormal face, symmetrical proximal limb shortness, severe psychomotor developmental delay, respiratory muscle weakness, and death at the age of 2 years. Although his clinical manifestations were similar to those of rhizomelic chondrodysplasia punctata (RCDP), biochemical studies using skin fibroblasts did not document the peroxisomal dysfunction described in RCDP. In addition, the sterol profile, for which abnormalities have recently been reported in cases of X-linked dominant form chondrodysplasia punctata (CDPX2), was normal both in the liver and in the fibroblasts. This patient may represent a new lethal form of chondrodysplasia punctata.
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Affiliation(s)
- S Kumada
- Department of Pediatrics, Musashino Red Cross Hospital, Tokyo, Japan.
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47
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Vreken P, Valianpour F, Overmars H, Barth PG, Selhorst JJ, van Gennip AH, Wanders RJ. Analysis of plasmenylethanolamines using electrospray tandem mass spectrometry and its application in screening for peroxisomal disorders. J Inherit Metab Dis 2000; 23:429-33. [PMID: 10896311 DOI: 10.1023/a:1005676507682] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- P Vreken
- Academic Medical Center, University of Amsterdam, Department of Clinical Chemistry and Emma Children's Hospital, The Netherlands.
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48
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Braverman N, Steel G, Lin P, Moser A, Moser H, Valle D. PEX7 gene structure, alternative transcripts, and evidence for a founder haplotype for the frequent RCDP allele, L292ter. Genomics 2000; 63:181-92. [PMID: 10673331 DOI: 10.1006/geno.1999.6080] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We recently reported cloning a cDNA encoding Pex7p, the peroxisomal PTS2 receptor. PEX7 mutations cause the peroxisome biogenesis disorder (PBD) rhizomelic chondrodysplasia punctata (RCDP). In a survey of 44 RCDP probands, we found that one PEX7 allele, L292ter, accounted for 50% of mutant PEX7 genes. Here we report the characterization of the PEX7 structural gene, which spans 102 kb on chromosome 6q21-q22.2 and contains at least 10 exons. In addition to the predominant full-length transcript, we identified eight smaller PEX7 transcripts generated by alternative exon splicing in several tissues. However, none of these splice forms was able to restore PTS2 protein import into peroxisomes when expressed in RCDP fibroblasts nor did they inhibit PTS2 protein import when expressed in normal fibroblasts. To determine whether the high frequency of the L292ter allele is due to a founder effect, we identified five polymorphic markers (four diallelic markers and one CA repeat) spanning the PEX7 gene. We show that all 12 L292ter homozygotes in our patient sample have an identical haplotype at these five sites, consistent with the hypothesis that the L292ter mutation arose once on an ancestral chromosome in the Caucasian population.
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Affiliation(s)
- N Braverman
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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49
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Zomer AW, Michels PA, Opperdoes FR. Molecular characterisation of Trypanosoma brucei alkyl dihydroxyacetone-phosphate synthase. Mol Biochem Parasitol 1999; 104:55-66. [PMID: 10589981 DOI: 10.1016/s0166-6851(99)00141-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Alkyl dihydroxyacetone-phosphate synthase is the second enzyme of the ether-lipid biosynthetic pathway which is responsible for the introduction of the ether linkage between a fatty alcohol and a glycerol present in a subclass of phospholipids, the plasmalogens and possibly in glycolipid membrane anchors. In this study the gene coding for alkyl dihydroxyacetone-phosphate synthase was isolated from Trypanosoma brucei. Southern blot analysis of total genomic DNA suggested the presence of a single copy gene. The analysis, together with sequencing of different cDNA clones showed that the two alleles of the gene differ in only one nucleotide. The gene encodes a protein of 612 amino acids with a calculated molecular mass of 68,891, not counting the initiator methionine. It carries a type-1 peroxisomal targeting signal (a C-terminal tripeptide--AHL) and a calculated overall positive charge of +10. The gene was expressed in a bacterial system and the corresponding protein carrying a His-tag was purified. The recombinant alkyl dihydroxyacetone-phosphate synthase and the enzyme isolated directly from the glycosomes of bloodstream-form trypanosomes have comparable kinetics. The Km for hexadecanol was 42 microM, while approximately 100 microM of palmitoyl dihydroxyacetone phosphate (DHAP) was necessary for optimal activity. Sodium chloride inhibited both the His-tagged protein and the enzyme isolated from the glycosomes of bloodstream-form and insect stage T. brucei.
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Affiliation(s)
- A W Zomer
- Research Unit for Tropical Diseases, Christian de Duve Institute of Cellular Pathology and Laboratory of Biochemistry, Catholic University of Louvain, Brussels, Belgium
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50
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Abstract
Genetically determined human peroxisomal disorders are subdivided into two major categories: disorders of peroxisome biogenesis (PBD), in which the organelle is not formed normally, and those that involve a single peroxisomal enzyme. Twelve PBD have been identified, and the molecular defects have been defined in 10. All involve defects in the import of proteins into the organelle. Factors required for this import are now referred to as peroxins (PEX) and form the basis of a new and preferred classification system. The PBD are associated with four clinical phenotypes, named before their association with the organelle was recognized: Zellweger syndrome (ZS), neonatal adrenoleukodystrophy (NALD), infantile Refsum disease (IRD), and rhizomelic chondrodysplasia punctata (RCDP). The first three are associated with 9 of the 10 PEX defects that have been defined so far, and represent a clinical continuum with variant severity, with ZS the most severe, NALD intermediate, and IRD the least severe. RCDP is associated with PEX7. Genotype-phenotype correlations are complicated by the fact that the clinical manifestations of the ZS-NALD-IRD continuum can be mimicked by disorders that affect single enzymes of peroxisomal fatty acid oxidation, and PEX7 by disorders of plasmalogen synthesis enzymes. Furthermore, clinical manifestations of each of the PEX disorders may vary. Phenotypic expression varies with the nature of the mutation, the milder phenotypes being associated with mutations that do not abolish function completely, or with mosaicism. Definition of the molecular defects is of great value for genetic counseling and may be of aid in establishing prognosis.
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Affiliation(s)
- H W Moser
- Department of Neurogenetics, Kennedy Krieger Institute, Johns Hopkins University, 707 North Broadway, Baltimore, Maryland, 21205, USA
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