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Carvalho S, Zea-Redondo L, Tang TCC, Stachel-Braum P, Miller D, Caldas P, Kukalev A, Diecke S, Grosswendt S, Grosso AR, Pombo A. SRRM2 splicing factor modulates cell fate in early development. Biol Open 2024; 13:bio060415. [PMID: 38656788 PMCID: PMC11070786 DOI: 10.1242/bio.060415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 03/20/2024] [Indexed: 04/26/2024] Open
Abstract
Embryo development is an orchestrated process that relies on tight regulation of gene expression to guide cell differentiation and fate decisions. The Srrm2 splicing factor has recently been implicated in developmental disorders and diseases, but its role in early mammalian development remains unexplored. Here, we show that Srrm2 dosage is critical for maintaining embryonic stem cell pluripotency and cell identity. Srrm2 heterozygosity promotes loss of stemness, characterised by the coexistence of cells expressing naive and formative pluripotency markers, together with extensive changes in gene expression, including genes regulated by serum-response transcription factor (SRF) and differentiation-related genes. Depletion of Srrm2 by RNA interference in embryonic stem cells shows that the earliest effects of Srrm2 heterozygosity are specific alternative splicing events on a small number of genes, followed by expression changes in metabolism and differentiation-related genes. Our findings unveil molecular and cellular roles of Srrm2 in stemness and lineage commitment, shedding light on the roles of splicing regulators in early embryogenesis, developmental diseases and tumorigenesis.
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Affiliation(s)
- Silvia Carvalho
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Epigenetic Regulation and Chromatin Structure Group, 10115 Berlin, Germany
- Associate Laboratory i4HB – Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO – Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-313 Porto, Portugal
- Graduate Program in Areas of Basic and Applied Biology (GABBA), ICBAS, University of Porto, 4050-313 Porto, Portugal
| | - Luna Zea-Redondo
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Epigenetic Regulation and Chromatin Structure Group, 10115 Berlin, Germany
- Humboldt-Universität zu Berlin, Institute of Biology, 10115 Berlin, Germany
| | - Tsz Ching Chloe Tang
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Epigenetic Regulation and Chromatin Structure Group, 10115 Berlin, Germany
| | - Philipp Stachel-Braum
- Humboldt-Universität zu Berlin, Institute of Biology, 10115 Berlin, Germany
- Berlin Institute of Health (BIH) at Charité – Universitätsmedizin Berlin, Exploratory Diagnostic Sciences (EDS) 10178 Berlin, Germany
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), From Cell State to Function Group, 10115 Berlin, Germany
| | - Duncan Miller
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Pluripotent Stem Cells Platform, 13125 Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Berlin, 10785 Berlin, Germany
| | - Paulo Caldas
- Associate Laboratory i4HB – Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO – Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Alexander Kukalev
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Epigenetic Regulation and Chromatin Structure Group, 10115 Berlin, Germany
| | - Sebastian Diecke
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Pluripotent Stem Cells Platform, 13125 Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Berlin, 10785 Berlin, Germany
| | - Stefanie Grosswendt
- Berlin Institute of Health (BIH) at Charité – Universitätsmedizin Berlin, Exploratory Diagnostic Sciences (EDS) 10178 Berlin, Germany
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), From Cell State to Function Group, 10115 Berlin, Germany
| | - Ana Rita Grosso
- Associate Laboratory i4HB – Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
- UCIBIO – Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Ana Pombo
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin Institute for Medical Systems Biology (BIMSB), Epigenetic Regulation and Chromatin Structure Group, 10115 Berlin, Germany
- Humboldt-Universität zu Berlin, Institute of Biology, 10115 Berlin, Germany
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2
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Christen M, Oevermann A, Rupp S, Vaz FM, Wever EJM, Braus BK, Jagannathan V, Kehl A, Hytönen MK, Lohi H, Leeb T. PCYT2 deficiency in Saarlooswolfdogs with progressive retinal, central, and peripheral neurodegeneration. Mol Genet Metab 2024; 141:108149. [PMID: 38277988 DOI: 10.1016/j.ymgme.2024.108149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/19/2024] [Accepted: 01/19/2024] [Indexed: 01/28/2024]
Abstract
We investigated a syndromic disease comprising blindness and neurodegeneration in 11 Saarlooswolfdogs. Clinical signs involved early adult onset retinal degeneration and adult-onset neurological deficits including gait abnormalities, hind limb weakness, tremors, ataxia, cognitive decline and behavioral changes such as aggression towards the owner. Histopathology in one affected dog demonstrated cataract, retinal degeneration, central and peripheral axonal degeneration, and severe astroglial hypertrophy and hyperplasia in the central nervous system. Pedigrees indicated autosomal recessive inheritance. We mapped the suspected genetic defect to a 15 Mb critical interval by combined linkage and autozygosity analysis. Whole genome sequencing revealed a private homozygous missense variant, PCYT2:c.4A>G, predicted to change the second amino acid of the encoded ethanolamine-phosphate cytidylyltransferase 2, XP_038402224.1:(p.Ile2Val). Genotyping of additional Saarlooswolfdogs confirmed the homozygous genotype in all eleven affected dogs and demonstrated an allele frequency of 9.9% in the population. This experiment also identified three additional homozygous mutant young dogs without overt clinical signs. Subsequent examination of one of these dogs revealed early-stage progressive retinal atrophy (PRA) and expansion of subarachnoid CSF spaces in MRI. Dogs homozygous for the pathogenic variant showed ether lipid accumulation, confirming a functional PCYT2 deficiency. The clinical and metabolic phenotype in affected dogs shows some parallels with human patients, in whom PCYT2 variants lead to a rare form of spastic paraplegia or axonal motor and sensory polyneuropathy. Our results demonstrate that PCYT2:c.4A>G in dogs cause PCYT2 deficiency. This canine model with histopathologically documented retinal, central, and peripheral neurodegeneration further deepens the knowledge of PCYT2 deficiency.
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Affiliation(s)
- Matthias Christen
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern 3001, Switzerland
| | - Anna Oevermann
- Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, Bern 3001, Switzerland
| | - Stefan Rupp
- Neurology Department, Tierklinik Hofheim, IVC Evidensia, Hofheim am Taunus 65719, Germany
| | - Frédéric M Vaz
- Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Gastroenterology Endocrinology Metabolism, Inborn Errors of Metabolism, Amsterdam, the Netherlands; Core Facility Metabolomics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Eric J M Wever
- Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Gastroenterology Endocrinology Metabolism, Inborn Errors of Metabolism, Amsterdam, the Netherlands; Core Facility Metabolomics, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands; Bioinformatics Laboratory, Department of Epidemiology & Data Science, Amsterdam Public Health Research Institute, University of Amsterdam, 1100 DE Amsterdam UMC, the Netherlands
| | - Barbara K Braus
- Ophthalmology Department, Tierklinik Hofheim, IVC Evidensia, Hofheim am Taunus 65719, Germany
| | - Vidhya Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern 3001, Switzerland
| | - Alexandra Kehl
- Laboklin GmbH & Co. KG, Steubenstraße 4, Bad Kissingen 97688, Germany; Comparative Experimental Pathology, School of Medicine, Technical University of Munich (TUM), Munich, Germany
| | - Marjo K Hytönen
- Department of Medical and Clinical Genetics, University of Helsinki, Helsinki 00014, Finland; Department of Veterinary Biosciences, University of Helsinki, Helsinki 00014, Finland; Folkhälsan Research Center, Helsinki 00290, Finland
| | - Hannes Lohi
- Department of Medical and Clinical Genetics, University of Helsinki, Helsinki 00014, Finland; Department of Veterinary Biosciences, University of Helsinki, Helsinki 00014, Finland; Folkhälsan Research Center, Helsinki 00290, Finland
| | - Tosso Leeb
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bern 3001, Switzerland.
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3
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Sun M, Zhang F, Lu F, Yu D, Wang Y, Chen P, Liu S. Integrating fecal metabolomics and intestinal microbiota to study the mechanism of cannabidiol in the treatment of idiopathic pulmonary fibrosis. Front Pharmacol 2024; 15:1358626. [PMID: 38379898 PMCID: PMC10877013 DOI: 10.3389/fphar.2024.1358626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 01/08/2024] [Indexed: 02/22/2024] Open
Abstract
Introduction: Idiopathic pulmonary fibrosis is a chronic interstitial lung disease characterized by excessive deposition of extracellular matrix. Cannabidiol, a natural component extracted from plant cannabis, has been shown to have therapeutic effects on lung diseases, but its exact mechanism of action is unknown, hindering its therapeutic effectiveness. Methods: To establish a pulmonary fibrosis model, combined with UPLC-Q-TOF/MS metabolomics and 16S rDNA sequencing, to explore cannabidiol's mechanism in treating pulmonary fibrosis. The rats were randomly divided into the control group, pulmonary fibrosis model group, prednisone treatment group, and cannabidiol low, medium, and high dose groups. The expression levels of HYP, SOD, and MDA in lung tissue and the expression levels of TNF-α, IL-1β, and IL-6 in serum were detected. Intestinal microbiota was detected using UPLC-QTOF/MS analysis of metabolomic properties and 16S rDNA sequencing. Results: Pathological studies and biochemical indexes showed that cannabidiol treatment could significantly alleviate IPF symptoms, significantly reduce the levels of TNF-α, IL-1β, IL-6, MDA, and HYP, and increase the expression level of SOD (p < 0.05). CBD-H can regulate Lachnospiraceae_NK4A136_group, Pseudomonas, Clostridia_UCG-014, Collinsella, Prevotella, [Eubacterium]_coprostanoligenes_group, Fusobacterium, Ruminococcus, and Streptococcus, it can restore intestinal microbiota function and reverse fecal metabolism trend. It also plays the role of fibrosis through the metabolism of linoleic acid, glycerol, linolenic acid, and sphingolipid. Discussion: Cannabidiol reverses intestinal microbiota imbalance and attenuates pulmonary fibrosis in rats through anti-inflammatory, antioxidant, and anti-fibrotic effects. This study lays the foundation for future research on the pathological mechanisms of IPF and the development of new drug candidates.
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Affiliation(s)
| | | | | | | | | | | | - Shumin Liu
- Institute of Traditional Chinese Medicine, Heilongjiang University of Chinese Medicine, Harbin, Heilongjiang, China
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4
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Basu S, Pawlowic MC, Hsu FF, Thomas G, Zhang K. Ethanolaminephosphate cytidylyltransferase is essential for survival, lipid homeostasis and stress tolerance in Leishmania major. PLoS Pathog 2023; 19:e1011112. [PMID: 37506172 PMCID: PMC10411802 DOI: 10.1371/journal.ppat.1011112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 08/09/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Glycerophospholipids including phosphatidylethanolamine (PE) and phosphatidylcholine (PC) are vital components of biological membranes. Trypanosomatid parasites of the genus Leishmania can acquire PE and PC via de novo synthesis and the uptake/remodeling of host lipids. In this study, we investigated the ethanolaminephosphate cytidylyltransferase (EPCT) in Leishmania major, which is the causative agent for cutaneous leishmaniasis. EPCT is a key enzyme in the ethanolamine branch of the Kennedy pathway which is responsible for the de novo synthesis of PE. Our results demonstrate that L. major EPCT is a cytosolic protein capable of catalyzing the formation of CDP-ethanolamine from ethanolamine-phosphate and cytidine triphosphate. Genetic manipulation experiments indicate that EPCT is essential in both the promastigote and amastigote stages of L. major as the chromosomal null mutants cannot survive without the episomal expression of EPCT. This differs from our previous findings on the choline branch of the Kennedy pathway (responsible for PC synthesis) which is required only in promastigotes but not amastigotes. While episomal EPCT expression does not affect promastigote proliferation under normal conditions, it leads to reduced production of ethanolamine plasmalogen or plasmenylethanolamine, the dominant PE subtype in Leishmania. In addition, parasites with episomal EPCT exhibit heightened sensitivity to acidic pH and starvation stress, and significant reduction in virulence. In summary, our investigation demonstrates that proper regulation of EPCT expression is crucial for PE synthesis, stress response, and survival of Leishmania parasites throughout their life cycle.
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Affiliation(s)
- Somrita Basu
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, United States of America
| | - Mattie C. Pawlowic
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, United States of America
- Wellcome Centre for Anti-Infectives Research (WCAIR), Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Geoff Thomas
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, United States of America
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, Texas, United States of America
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5
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Grapentine S, Singh RK, Bakovic M. Skeletal Muscle Consequences of Phosphatidylethanolamine Synthesis Deficiency. FUNCTION 2023; 4:zqad020. [PMID: 37342414 PMCID: PMC10278983 DOI: 10.1093/function/zqad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 06/22/2023] Open
Abstract
The maintenance of phospholipid homeostasis is increasingly being implicated in metabolic health. Phosphatidylethanolamine (PE) is the most abundant phospholipid on the inner leaflet of cellular membranes, and we have previously shown that mice with a heterozygous ablation of the PE synthesizing enzyme, Pcyt2 (Pcyt2+/-), develop obesity, insulin resistance, and NASH. Skeletal muscle is a major determinant of systemic energy metabolism, making it a key player in metabolic disease development. Both the total PE levels and the ratio of PE to other membrane lipids in skeletal muscle are implicated in insulin resistance; however, the underlying mechanisms and the role of Pcyt2 regulation in this association remain unclear. Here, we show how reduced phospholipid synthesis due to Pcyt2 deficiency causes Pcyt2+/- skeletal muscle dysfunction and metabolic abnormalities. Pcyt2+/- skeletal muscle exhibits damage and degeneration, with skeletal muscle cell vacuolization, disordered sarcomeres, mitochondria ultrastructure irregularities and paucity, inflammation, and fibrosis. There is intramuscular adipose tissue accumulation, and major disturbances in lipid metabolism with impaired FA mobilization and oxidation, elevated lipogenesis, and long-chain fatty acyl-CoA, diacylglycerol, and triacylglycerol accumulation. Pcyt2+/- skeletal muscle exhibits perturbed glucose metabolism with elevated glycogen content, impaired insulin signaling, and reduced glucose uptake. Together, this study lends insight into the critical role of PE homeostasis in skeletal muscle metabolism and health with broad implications on metabolic disease development.
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Affiliation(s)
- Sophie Grapentine
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph N1G 2W1, Canada
| | - Rathnesh K Singh
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph N1G 2W1, Canada
| | - Marica Bakovic
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph N1G 2W1, Canada
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6
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Wang Y, Jiang Z, Qin A, Wang F, Chang E, Liu Y, Nie W, Tan C, Yuan Y, Dong Y, Huang R, Jia Z, Wang J. Population Structure, Genetic Diversity and Candidate Genes for the Adaptation to Environmental Stress in Picea koraiensis. PLANTS (BASEL, SWITZERLAND) 2023; 12:1266. [PMID: 36986954 PMCID: PMC10055018 DOI: 10.3390/plants12061266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 06/19/2023]
Abstract
Picea koraiensis is major silvicultural and timber species in northeast China, and its distribution area is an important transition zone for genus spruce migration. The degree of intraspecific differentiation of P. koraiensis is high, but population structure and differentiation mechanisms are not clear. In this study, 523,761 single nucleotide polymorphisms (SNPs) were identified in 113 individuals from 9 populations of P. koraiensis by genotyping-by-sequencing (GBS). Population genomic analysis showed that P. koraiensis was divided into three geoclimatic regions: Great Khingan Mountains climatic region, Lesser Khingan Mountains climatic region, and Changbai Mountain climatic region. Mengkeshan (MKS) population on the northern edge of the distribution area and Wuyiling (WYL) population located in the mining area are two highly differentiated groups. Selective sweep analysis showed that MKS and WYL populations had 645 and 1126 selected genes, respectively. Genes selected in the MKS population were associated with flowering and photomorphogenesis, cellular response to water deficit, and glycerophospholipid metabolism; genes selected in the WYL population were associated with metal ion transport, biosynthesis of macromolecules, and DNA repair. Climatic factors and heavy metal stress drives divergence in MKS and WYL populations, respectively. Our findings provide insights into adaptive divergence mechanisms in Picea and will contribute to molecular breeding studies.
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Affiliation(s)
- Ya Wang
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Zeping Jiang
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Aili Qin
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Fude Wang
- Forestry Research Institute in Heilongjiang Province, Harbin 150081, China
| | - Ermei Chang
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Yifu Liu
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Wen Nie
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Cancan Tan
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Yanchao Yuan
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Yao Dong
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Ruizhi Huang
- Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration, Ecology and Nature Conservation Institute, Chinese Academy of Forestry, Beijing 100091, China
| | - Zirui Jia
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
| | - Junhui Wang
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
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7
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Cikes D, Elsayad K, Sezgin E, Koitai E, Torma F, Orthofer M, Yarwood R, Heinz LX, Sedlyarov V, Miranda ND, Taylor A, Grapentine S, Al-Murshedi F, Abot A, Weidinger A, Kutchukian C, Sanchez C, Cronin SJF, Novatchkova M, Kavirayani A, Schuetz T, Haubner B, Haas L, Hagelkruys A, Jackowski S, Kozlov AV, Jacquemond V, Knauf C, Superti-Furga G, Rullman E, Gustafsson T, McDermot J, Lowe M, Radak Z, Chamberlain JS, Bakovic M, Banka S, Penninger JM. PCYT2-regulated lipid biosynthesis is critical to muscle health and ageing. Nat Metab 2023; 5:495-515. [PMID: 36941451 DOI: 10.1038/s42255-023-00766-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 02/10/2023] [Indexed: 03/23/2023]
Abstract
Muscle degeneration is the most prevalent cause for frailty and dependency in inherited diseases and ageing. Elucidation of pathophysiological mechanisms, as well as effective treatments for muscle diseases, represents an important goal in improving human health. Here, we show that the lipid synthesis enzyme phosphatidylethanolamine cytidyltransferase (PCYT2/ECT) is critical to muscle health. Human deficiency in PCYT2 causes a severe disease with failure to thrive and progressive weakness. pcyt2-mutant zebrafish and muscle-specific Pcyt2-knockout mice recapitulate the participant phenotypes, with failure to thrive, progressive muscle weakness and accelerated ageing. Mechanistically, muscle Pcyt2 deficiency affects cellular bioenergetics and membrane lipid bilayer structure and stability. PCYT2 activity declines in ageing muscles of mice and humans, and adeno-associated virus-based delivery of PCYT2 ameliorates muscle weakness in Pcyt2-knockout and old mice, offering a therapy for individuals with a rare disease and muscle ageing. Thus, PCYT2 plays a fundamental and conserved role in vertebrate muscle health, linking PCYT2 and PCYT2-synthesized lipids to severe muscle dystrophy and ageing.
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Affiliation(s)
- Domagoj Cikes
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria.
| | - Kareem Elsayad
- Division of Anatomy, Center for Anatomy and Cell Biology and Medical Imaging Cluster (MIC), Vienna, Austria.
| | - Erdinc Sezgin
- MRC Weatherall Institute of Molecular Medicine, MRC Human Immunology Unit, University of Oxford, Oxford, UK
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden
| | - Erika Koitai
- Research Institute of Sport Science, University of Physical Education, Budapest, Hungary
| | - Ferenc Torma
- Research Institute of Sport Science, University of Physical Education, Budapest, Hungary
| | - Michael Orthofer
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Rebecca Yarwood
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Leonhard X Heinz
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Vitaly Sedlyarov
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | | | - Adrian Taylor
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Sophie Grapentine
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Fathiya Al-Murshedi
- Department of Genetics, College of Medicine, Sultan Qaboos University, Muscat, Sultanate of Oman
| | - Anne Abot
- Enterosys SAS, Prologue Biotech, Labège, France
| | - Adelheid Weidinger
- Ludwig Boltzmann Institute for Traumatology, The Research Center in Cooperation with AUVA, Vienna, Austria
| | - Candice Kutchukian
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Villeurbanne, France
| | - Colline Sanchez
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Villeurbanne, France
| | - Shane J F Cronin
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Maria Novatchkova
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Anoop Kavirayani
- VBCF, Vienna BioCenter Core Facilities, Vienna BioCenter, Vienna, Austria
| | - Thomas Schuetz
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Bernhard Haubner
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Lisa Haas
- IMP Research Institute of Molecular Pathology, Vienna, Austria
| | - Astrid Hagelkruys
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | | | - Andrey V Kozlov
- Ludwig Boltzmann Institute for Traumatology, The Research Center in Cooperation with AUVA, Vienna, Austria
| | - Vincent Jacquemond
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Villeurbanne, France
| | - Claude Knauf
- INSERM U1220 Institut de Recherche en Santé Digestive, CHU Purpan, Université Toulouse III Paul Sabatier Toulouse, Toulouse, France
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Eric Rullman
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
- Cardiovascular Theme, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Thomas Gustafsson
- Division of Clinical Physiology, Department of Laboratory Medicine, Karolinska Institutet, and Unit of Clinical Physiology, Karolinska University Hospital, Stockholm, Sweden
| | - John McDermot
- Manchester Centre for Genomics Medicine, St Mary's Hospital, Manchester University Hospital Foundation Trust, Manchester, UK
| | - Martin Lowe
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Zsolt Radak
- Research Institute of Sport Science, University of Physical Education, Budapest, Hungary
| | - Jeffrey S Chamberlain
- Department of Neurology, University of Washington, Seattle, WA, USA
- Senator Paul D. Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, WA, USA
| | - Marica Bakovic
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Siddharth Banka
- Manchester Centre for Genomics Medicine, St Mary's Hospital, Manchester University Hospital Foundation Trust, Manchester, UK
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Josef M Penninger
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria.
- Department of Medical Genetics, Life Science Institute, University of British Columbia, Vancouver, British Columbia, Canada.
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8
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Xu H, Li W, Huang L, He X, Xu B, He X, Chen W, Wang Y, Xu W, Wang S, Kong Q, Xu Y, Lu W. Phosphoethanolamine cytidylyltransferase ameliorates mitochondrial function and apoptosis in hepatocytes in T2DM in vitro. J Lipid Res 2023; 64:100337. [PMID: 36716821 PMCID: PMC10033998 DOI: 10.1016/j.jlr.2023.100337] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 12/22/2022] [Accepted: 12/22/2022] [Indexed: 01/29/2023] Open
Abstract
Liver function indicators are often impaired in patients with type 2 diabetes mellitus (T2DM), who present higher concentrations of aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase than individuals without diabetes. However, the mechanism of liver injury in patients with T2DM has not been clearly elucidated. In this study, we performed a lipidomics analysis on the liver of T2DM mice, and we found that phosphatidylethanolamine (PE) levels were low in T2DM, along with an increase in diglyceride, which may be due to a decrease in the levels of phosphoethanolamine cytidylyltransferase (Pcyt2), thus likely affecting the de novo synthesis of PE. The phosphatidylserine decarboxylase pathway did not change significantly in the T2DM model, although both pathways are critical sources of PE. Supplementation with CDP-ethanolamine (CDP-etn) to increase the production of PE from the CDP-etn pathway reversed high glucose and FFA (HG&FFA)-induced mitochondrial damage including increased apoptosis, decreased ATP synthesis, decreased mitochondrial membrane potential, and increased reactive oxygen species, whereas supplementation with lysophosphatidylethanolamine, which can increase PE production in the phosphatidylserine decarboxylase pathway, did not. Additionally, we found that overexpression of PCYT2 significantly ameliorated ATP synthesis and abnormal mitochondrial morphology induced by HG&FFA. Finally, the BAX/Bcl-2/caspase3 apoptosis pathway was activated in hepatocytes of the T2DM model, which could also be reversed by CDP-etn supplements and PCYT2 overexpression. In summary, in the liver of T2DM mice, Pcyt2 reduction may lead to a decrease in the levels of PE, whereas CDP-etn supplementation and PCYT2 overexpression ameliorate partial mitochondrial function and apoptosis in HG&FFA-stimulated L02 cells.
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Affiliation(s)
- Hu Xu
- Basic Medical College, Anhui Medical University, Hefei, China
| | - Weizu Li
- Basic Medical College, Anhui Medical University, Hefei, China
| | - Lei Huang
- Basic Medical College, Anhui Medical University, Hefei, China
| | - Xinyu He
- Basic Medical College, Anhui Medical University, Hefei, China
| | - Bei Xu
- Basic Medical College, Anhui Medical University, Hefei, China
| | - Xueqing He
- Basic Medical College, Anhui Medical University, Hefei, China
| | - Wentong Chen
- Basic Medical College, Anhui Medical University, Hefei, China
| | - Yaoxing Wang
- Basic Medical College, Anhui Medical University, Hefei, China
| | - Wenjun Xu
- Basic Medical College, Anhui Medical University, Hefei, China
| | - Sheng Wang
- Center for Scientific Research, Anhui Medical University, Hefei, China
| | - Qin Kong
- Basic Medical College, Anhui Medical University, Hefei, China
| | - Youzhi Xu
- Basic Medical College, Anhui Medical University, Hefei, China.
| | - Wenjie Lu
- Basic Medical College, Anhui Medical University, Hefei, China.
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9
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Basu S, Pawlowic M, Hsu FF, Thomas G, Zhang K. Ethanolaminephosphate cytidyltransferase is essential for survival, lipid homeostasis and stress tolerance in Leishmania major. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.10.523530. [PMID: 36712124 PMCID: PMC9882048 DOI: 10.1101/2023.01.10.523530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Glycerophospholipids including phosphatidylethanolamine (PE) and phosphatidylcholine (PC) are vital components of biological membranes. Trypanosomatid parasites of the genus Leishmania can acquire PE and PC via de novo synthesis and the uptake/remodeling of host lipids. In this study, we investigated the ethanolaminephosphate cytidyltransferase (EPCT) in Leishmania major , which is the causative agent for cutaneous leishmaniasis. EPCT is a key enzyme in the ethanolamine branch of the Kennedy pathway which is responsible for the de novo synthesis of PE. Our results demonstrate that L. major EPCT is a cytosolic protein capable of catalyzing the formation of CDP-ethanolamine from ethanolamine-phosphate and cytidine triphosphate. Genetic manipulation experiments indicate that EPCT is essential in both the promastigote and amastigote stages of L. major as the chromosomal null mutants cannot survive without the episomal expression of EPCT. This differs from our previous findings on the choline branch of the Kennedy pathway (responsible for PC synthesis) which is required only in promastigotes but not amastigotes. While episomal EPCT expression does not affect promastigote proliferation under normal conditions, it leads to reduced production of ethanolamine plasmalogen or plasmenylethanolamine, the dominant PE subtype in Leishmania . In addition, parasites with epsiomal EPCT exhibit heightened sensitivity to acidic pH and starvation stress, and significant reduction in virulence. In summary, our investigation demonstrates that proper regulation of EPCT expression is crucial for PE synthesis, stress response, and survival of Leishmania parasites throughout their life cycle. AUTHOR SUMMARY In nature, Leishmania parasites alternate between fast replicating, extracellular promastigotes in sand fly gut and slow growing, intracellular amastigotes in macrophages. Previous studies suggest that promastigotes acquire most of their lipids via de novo synthesis whereas amastigotes rely on the uptake and remodeling of host lipids. Here we investigated the function of ethanolaminephosphate cytidyltransferase (EPCT) which catalyzes a key step in the de novo synthesis of phosphatidylethanolamine (PE) in Leishmania major . Results showed that EPCT is indispensable for both promastigotes and amastigotes, indicating that de novo PE synthesis is still needed at certain capacity for the intracellular form of Leishmania parasites. In addition, elevated EPCT expression alters overall PE synthesis and compromises parasite’s tolerance to adverse conditions and is deleterious to the growth of intracellular amastigotes. These findings provide new insight into how Leishmania acquire essential phospholipids and how disturbance of lipid metabolism can impact parasite fitness.
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Affiliation(s)
- Somrita Basu
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - Mattie Pawlowic
- Wellcome Centre for Anti-Infectives Research (WCAIR), Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Fong-Fu Hsu
- Mass Spectrometry Resource, Division of Endocrinology, Diabetes, Metabolism, and Lipid Research, Department of Internal Medicine, Washington University School of Medicine, 660S. Euclid Ave., Saint Louis, MO 63110, USA
| | - Geoff Thomas
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - Kai Zhang
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
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10
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St Germain M, Iraji R, Bakovic M. Phosphatidylethanolamine homeostasis under conditions of impaired CDP-ethanolamine pathway or phosphatidylserine decarboxylation. Front Nutr 2023; 9:1094273. [PMID: 36687696 PMCID: PMC9849821 DOI: 10.3389/fnut.2022.1094273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 12/14/2022] [Indexed: 01/07/2023] Open
Abstract
Phosphatidylethanolamine is the major inner-membrane lipid in the plasma and mitochondrial membranes. It is synthesized in the endoplasmic reticulum from ethanolamine and diacylglycerol (DAG) by the CDP-ethanolamine pathway and from phosphatidylserine by decarboxylation in the mitochondria. Recently, multiple genetic disorders that impact these pathways have been identified, including hereditary spastic paraplegia 81 and 82, Liberfarb syndrome, and a new type of childhood-onset neurodegeneration-CONATOC. Individuals with these diseases suffer from multisystem disorders mainly affecting neuronal function. This indicates the importance of maintaining proper phospholipid homeostasis when major biosynthetic pathways are impaired. This study summarizes the current knowledge of phosphatidylethanolamine metabolism in order to identify areas of future research that might lead to the development of treatment options.
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11
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Cancer Malignancy Is Correlated with Upregulation of PCYT2-Mediated Glycerol Phosphate Modification of α-Dystroglycan. Int J Mol Sci 2022; 23:ijms23126662. [PMID: 35743105 PMCID: PMC9223686 DOI: 10.3390/ijms23126662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/09/2022] [Accepted: 06/11/2022] [Indexed: 12/10/2022] Open
Abstract
The dystrophin–glycoprotein complex connects the cytoskeleton with base membrane components such as laminin through unique O-glycans displayed on α-dystroglycan (α-DG). Genetic impairment of elongation of these glycans causes congenital muscular dystrophies. We previously identified that glycerol phosphate (GroP) can cap the core part of the α-DG O-glycans and terminate their further elongation. This study examined the possible roles of the GroP modification in cancer malignancy, focusing on colorectal cancer. We found that the GroP modification critically depends on PCYT2, which serves as cytidine 5′-diphosphate-glycerol (CDP-Gro) synthase. Furthermore, we identified a significant positive correlation between cancer progression and GroP modification, which also correlated positively with PCYT2 expression. Moreover, we demonstrate that GroP modification promotes the migration of cancer cells. Based on these findings, we propose that the GroP modification by PCYT2 disrupts the glycan-mediated cell adhesion to the extracellular matrix and thereby enhances cancer metastasis. Thus, the present study suggests the possibility of novel approaches for cancer treatment by targeting the PCYT2-mediated GroP modification.
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12
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Yang Y, Zhang X, Lei Y, Chang G, Zou Y, Yu S, Wu H, Rong H, Lei Z, Xu C. The effects of H22 tumor on the quality of oocytes and the development of early embryos from host mice: A single-cell RNA sequencing approach. Theriogenology 2022; 179:45-59. [PMID: 34826707 DOI: 10.1016/j.theriogenology.2021.11.006] [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: 06/19/2021] [Revised: 10/30/2021] [Accepted: 11/13/2021] [Indexed: 10/19/2022]
Abstract
The association between cancer and female reproduction remains largely unknown. Here we investigated the quality of oocytes and the developmental potential of zygotes using H22 tumor-bearing mice model. The results showed that the number of oocytes was decreased in tumor-bearing mice compared with the control mice, and accompanied scattered chromosomes was observed. Further study revealed an abnormal epigenetic reprogramming occurred in the zygotes from the H22 tumor-bearing mice, as exemplified by the aberrant 5hmC/5mC modifications in the pronuclei. Finally, single-cell RNA sequencing was performed on the oocytes collected from the H22 tumor-bearing mice. Our data showed that 45 of the 202 differentially expressed genes in tumor-bearing group were closely associated with oocyte quality. Protein interaction analysis indicated that the potential interaction among these 45 genes. Collectively, our study uncovered that the quality of oocytes and early embryonic development were affected by H22 tumor bearing via the altered expression patterns of genes related with reproduction, providing new insights into the reproductive capability of female cancer patients.
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Affiliation(s)
- Yanhong Yang
- The First Affiliated Hospital (School of Clinical Medicine), Guangdong Pharmaceutical University, Nong-Lin-Xia Road 19#, Yue-Xiu District, Guangzhou, 510080, PR China
| | - Xueying Zhang
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou, 510006, PR China; School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Guangzhou, 510006, PR China
| | - Yuting Lei
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou, 510006, PR China
| | - Gang Chang
- Department of Biochemistry and Molecular Biology, Shenzhen University Health Science Center, Shenzhen, 518060, PR China
| | - Yan Zou
- The Reproductive Medical Center of Nanning Second People's Hospital, Nanning, 530031, PR China
| | - Siping Yu
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou, 510006, PR China; School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Guangzhou, 510006, PR China
| | - Huijuan Wu
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou, 510006, PR China; School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Guangzhou, 510006, PR China
| | - Hedong Rong
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou, 510006, PR China; School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou Higher Education Mega Center, Guangzhou, 510006, PR China
| | - Zili Lei
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Institute of Chinese Medicine, Guangdong Pharmaceutical University, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou, 510006, PR China.
| | - Changlong Xu
- The Reproductive Medical Center of Nanning Second People's Hospital, Nanning, 530031, PR China.
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13
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Grapentine S, Singh RK, Basu P, Sivanesan S, Mattos G, Oresajo O, Cheema J, Demeke W, Dolinsky VW, Bakovic M. Pcyt2 deficiency causes age-dependant development of nonalcoholic steatohepatitis and insulin resistance that could be attenuated with phosphoethanolamine. Sci Rep 2022; 12:1048. [PMID: 35058529 PMCID: PMC8776951 DOI: 10.1038/s41598-022-05140-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 01/06/2022] [Indexed: 12/19/2022] Open
Abstract
The mechanisms of NASH development in the context of age and genetics are not fully elucidated. This study investigates the age-dependent liver defects during NASH development in mice with heterozygous deletion of Pcyt2 (Pcyt2+/−), the rate limiting enzyme in phosphatidylethanolamine (PE) synthesis. Further, the therapeutic potential of Pcyt2 substrate, phosphoethanolamine (PEtn), is examined. Pcyt2+/− were investigated at 2 and 6–8 months (mo) of age and in addition, 6-mo old Pcyt2+/− with developed NASH were supplemented with PEtn for 8 weeks and glucose and fatty acid metabolism, insulin signaling, and inflammation were examined. Heterozygous ablation of Pcyt2 causes changes in liver metabolic regulators from young age, prior to the development of liver disease which does not occur until adulthood. Only older Pcyt2+/− experiences perturbed glucose and fatty acid metabolism. Older Pcyt2+/− liver develops NASH characterized by increased glucose production, accumulation of TAG and glycogen, and increased inflammation. Supplementation with PEtn reverses Pcyt2+/− steatosis, inflammation, and other aspects of NASH, showing that was directly caused by Pcyt2 deficiency. Pcyt2 deficiency is a novel mechanism of metabolic dysregulation due to reduced membrane ethanolamine phospholipid synthesis, and the metabolite PEtn offers therapeutic potential for NASH reversion.
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14
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Biosynthetic Mechanisms and Biological Significance of Glycerol Phosphate-Containing Glycan in Mammals. Molecules 2021; 26:molecules26216675. [PMID: 34771084 PMCID: PMC8587909 DOI: 10.3390/molecules26216675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/01/2021] [Accepted: 11/02/2021] [Indexed: 11/25/2022] Open
Abstract
Bacteria contain glycerol phosphate (GroP)-containing glycans, which are important constituents of cell-surface glycopolymers such as the teichoic acids of Gram-positive bacterial cell walls. These glycopolymers comprising GroP play crucial roles in bacterial physiology and virulence. Recently, the first identification of a GroP-containing glycan in mammals was reported as a variant form of O-mannosyl glycan on α-dystroglycan (α-DG). However, the biological significance of such GroP modification remains largely unknown. In this review, we provide an overview of this new discovery of GroP-containing glycan in mammals and then outline the recent progress in elucidating the biosynthetic mechanisms of GroP-containing glycans on α-DG. In addition, we discuss the potential biological role of GroP modification along with the challenges and prospects for further research. The progress in this newly identified glycan modification will provide insights into the phylogenetic implications of glycan.
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15
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Taylor A, Grapentine S, Ichhpuniani J, Bakovic M. Choline transporter-like proteins 1 and 2 are newly identified plasma membrane and mitochondrial ethanolamine transporters. J Biol Chem 2021; 296:100604. [PMID: 33789160 PMCID: PMC8081925 DOI: 10.1016/j.jbc.2021.100604] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 12/31/2022] Open
Abstract
The membrane phospholipids phosphatidylcholine and phosphatidylethanolamine (PE) are synthesized de novo by the CDP-choline and CDP-ethanolamine (Kennedy) pathway, in which the extracellular substrates choline and ethanolamine are transported into the cell, phosphorylated, and coupled with diacylglycerol to form the final phospholipid product. Although multiple transport systems have been established for choline, ethanolamine transport is poorly characterized and there is no single protein assigned a transport function for ethanolamine. The solute carriers 44A (SLC44A) known as choline transporter-like proteins-1 and -2 (CTL1 and CTL2) are choline transporter at the plasma membrane and mitochondria. We report a novel function of CTL1 and CTL2 in ethanolamine transport. Using the lack or the gain of gene function in combination with specific antibodies and transport inhibitors we established two distinct ethanolamine transport systems of a high affinity, mediated by CTL1, and of a low affinity, mediated by CTL2. Both transporters are Na+-independent ethanolamine/H+ antiporters. Primary human fibroblasts with separate frameshift mutations in the CTL1 gene (M1= SLC44A1ΔAsp517 and M2= SLC44A1ΔSer126) are devoid of CTL1 ethanolamine transport but maintain unaffected CTL2 transport. The lack of CTL1 in M2 cells reduced the ethanolamine transport, the flux through the CDP-ethanolamine Kennedy pathway, and PE synthesis. In contrast, overexpression of CTL1 in M2 cells improved ethanolamine transport and PE synthesis. These data firmly establish that CTL1 and CTL2 are the first identified ethanolamine transporters in whole cells and mitochondria, with intrinsic roles in de novo PE synthesis by the Kennedy pathway and intracellular redistribution of ethanolamine.
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Affiliation(s)
- Adrian Taylor
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada
| | - Sophie Grapentine
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada
| | - Jasmine Ichhpuniani
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada
| | - Marica Bakovic
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada.
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16
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Acoba MG, Senoo N, Claypool SM. Phospholipid ebb and flow makes mitochondria go. J Cell Biol 2021; 219:151918. [PMID: 32614384 PMCID: PMC7401802 DOI: 10.1083/jcb.202003131] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 01/19/2023] Open
Abstract
Mitochondria, so much more than just being energy factories, also have the capacity to synthesize macromolecules including phospholipids, particularly cardiolipin (CL) and phosphatidylethanolamine (PE). Phospholipids are vital constituents of mitochondrial membranes, impacting the plethora of functions performed by this organelle. Hence, the orchestrated movement of phospholipids to and from the mitochondrion is essential for cellular integrity. In this review, we capture recent advances in the field of mitochondrial phospholipid biosynthesis and trafficking, highlighting the significance of interorganellar communication, intramitochondrial contact sites, and lipid transfer proteins in maintaining membrane homeostasis. We then discuss the physiological functions of CL and PE, specifically how they associate with protein complexes in mitochondrial membranes to support bioenergetics and maintain mitochondrial architecture.
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Affiliation(s)
- Michelle Grace Acoba
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Nanami Senoo
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
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17
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Sam PN, Calzada E, Acoba MG, Zhao T, Watanabe Y, Nejatfard A, Trinidad JC, Shutt TE, Neal SE, Claypool SM. Impaired phosphatidylethanolamine metabolism activates a reversible stress response that detects and resolves mutant mitochondrial precursors. iScience 2021; 24:102196. [PMID: 33718843 PMCID: PMC7921845 DOI: 10.1016/j.isci.2021.102196] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/27/2021] [Accepted: 02/10/2021] [Indexed: 02/06/2023] Open
Abstract
Phosphatidylethanolamine (PE) made in mitochondria has long been recognized as an important precursor for phosphatidylcholine production that occurs in the endoplasmic reticulum (ER). Recently, the strict mitochondrial localization of the enzyme that makes PE in the mitochondrion, phosphatidylserine decarboxylase 1 (Psd1), was questioned. Since a dual localization of Psd1 to the ER would have far-reaching implications, we initiated our study to independently re-assess the subcellular distribution of Psd1. Our results support the unavoidable conclusion that the vast majority, if not all, of functional Psd1 resides in the mitochondrion. Through our efforts, we discovered that mutant forms of Psd1 that impair a self-processing step needed for it to become functional are dually localized to the ER when expressed in a PE-limiting environment. We conclude that severely impaired cellular PE metabolism provokes an ER-assisted adaptive response that is capable of identifying and resolving nonfunctional mitochondrial precursors.
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Affiliation(s)
- Pingdewinde N. Sam
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Elizabeth Calzada
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Michelle Grace Acoba
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Tian Zhao
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Yasunori Watanabe
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Anahita Nejatfard
- Division of Biological Sciences, The Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | | | - Timothy E. Shutt
- Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata, Yamagata 990-8560, Japan
| | - Sonya E. Neal
- Division of Biological Sciences, The Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Steven M. Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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18
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Tavasoli M, Lahire S, Reid T, Brodovsky M, McMaster CR. Genetic diseases of the Kennedy pathways for membrane synthesis. J Biol Chem 2020; 295:17877-17886. [PMID: 33454021 PMCID: PMC7762932 DOI: 10.1074/jbc.rev120.013529] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 10/20/2020] [Indexed: 11/06/2022] Open
Abstract
The two branches of the Kennedy pathways (CDP-choline and CDP-ethanolamine) are the predominant pathways responsible for the synthesis of the most abundant phospholipids, phosphatidylcholine and phosphatidylethanolamine, respectively, in mammalian membranes. Recently, hereditary diseases associated with single gene mutations in the Kennedy pathways have been identified. Interestingly, genetic diseases within the same pathway vary greatly, ranging from muscular dystrophy to spastic paraplegia to a childhood blinding disorder to bone deformations. Indeed, different point mutations in the same gene (PCYT1; CCTα) result in at least three distinct diseases. In this review, we will summarize and review the genetic diseases associated with mutations in genes of the Kennedy pathway for phospholipid synthesis. These single-gene disorders provide insight, indeed direct genotype-phenotype relationships, into the biological functions of specific enzymes of the Kennedy pathway. We discuss potential mechanisms of how mutations within the same pathway can cause disparate disease.
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Affiliation(s)
- Mahtab Tavasoli
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Sarah Lahire
- University of Reims Champagne-Ardenne, Reims, France
| | - Taryn Reid
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Maren Brodovsky
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
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19
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Zhao H, Wang T. PE homeostasis rebalanced through mitochondria-ER lipid exchange prevents retinal degeneration in Drosophila. PLoS Genet 2020; 16:e1009070. [PMID: 33064773 PMCID: PMC7592913 DOI: 10.1371/journal.pgen.1009070] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/28/2020] [Accepted: 08/21/2020] [Indexed: 02/06/2023] Open
Abstract
The major glycerophospholipid phosphatidylethanolamine (PE) in the nervous system is essential for neural development and function. There are two major PE synthesis pathways, the CDP-ethanolamine pathway in the endoplasmic reticulum (ER) and the phosphatidylserine decarboxylase (PSD) pathway in mitochondria. However, the role played by mitochondrial PE synthesis in maintaining cellular PE homeostasis is unknown. Here, we show that Drosophila pect (phosphoethanolamine cytidylyltransferase) mutants lacking the CDP-ethanolamine pathway, exhibited alterations in phospholipid composition, defective phototransduction, and retinal degeneration. Induction of the PSD pathway fully restored levels and composition of cellular PE, thus rescued the retinal degeneration and defective visual responses in pect mutants. Disrupting lipid exchange between mitochondria and ER blocked the ability of PSD to rescue pect mutant phenotypes. These findings provide direct evidence that the synthesis of PE in mitochondria contributes to cellular PE homeostasis, and suggest the induction of mitochondrial PE synthesis as a promising therapeutic approach for disorders associated with PE deficiency.
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Affiliation(s)
- Haifang Zhao
- National Institute of Biological Sciences, Beijing, China
| | - Tao Wang
- National Institute of Biological Sciences, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
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20
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Osawa T, Shimamura T, Saito K, Hasegawa Y, Ishii N, Nishida M, Ando R, Kondo A, Anwar M, Tsuchida R, Hino S, Sakamoto A, Igarashi K, Saitoh K, Kato K, Endo K, Yamano S, Kanki Y, Matsumura Y, Minami T, Tanaka T, Anai M, Wada Y, Wanibuchi H, Hayashi M, Hamada A, Yoshida M, Yachida S, Nakao M, Sakai J, Aburatani H, Shibuya M, Hanada K, Miyano S, Soga T, Kodama T. Phosphoethanolamine Accumulation Protects Cancer Cells under Glutamine Starvation through Downregulation of PCYT2. Cell Rep 2020; 29:89-103.e7. [PMID: 31577958 DOI: 10.1016/j.celrep.2019.08.087] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/02/2019] [Accepted: 08/27/2019] [Indexed: 01/01/2023] Open
Abstract
Tolerance to severe tumor microenvironments, including hypoxia and nutrient starvation, is a common feature of aggressive cancer cells and can be targeted. However, metabolic alterations that support cancer cells upon nutrient starvation are not well understood. Here, by comprehensive metabolome analyses, we show that glutamine deprivation leads to phosphoethanolamine (PEtn) accumulation in cancer cells via the downregulation of PEtn cytidylyltransferase (PCYT2), a rate-limiting enzyme of phosphatidylethanolamine biosynthesis. PEtn accumulation correlated with tumor growth under nutrient starvation. PCYT2 suppression was partially mediated by downregulation of the transcription factor ELF3. Furthermore, PCYT2 overexpression reduced PEtn levels and tumor growth. In addition, PEtn accumulation and PCYT2 downregulation in human breast tumors correlated with poor prognosis. Thus, we show that glutamine deprivation leads to tumor progression by regulating PE biosynthesis via the ELF3-PCYT2 axis. Furthermore, manipulating glutamine-responsive genes could be a therapeutic approach to limit cancer progression.
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Affiliation(s)
- Tsuyoshi Osawa
- Division of Integrative Nutriomics and Oncology, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.
| | - Teppei Shimamura
- Department of Systems Biology, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
| | - Kyoko Saito
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Yoko Hasegawa
- Division of Integrative Nutriomics and Oncology, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Naoko Ishii
- Division of Integrative Nutriomics and Oncology, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Miyuki Nishida
- Division of Integrative Nutriomics and Oncology, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Ritsuko Ando
- Division of Integrative Nutriomics and Oncology, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Ayano Kondo
- Division of Genome Science, RCAST, The University of Tokyo, Tokyo 153-8904, Japan
| | - Muyassar Anwar
- Division of Genome Science, RCAST, The University of Tokyo, Tokyo 153-8904, Japan
| | - Rika Tsuchida
- Division of Integrative Nutriomics and Oncology, RCAST, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Shinjiro Hino
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan
| | - Akihisa Sakamoto
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan
| | - Kaori Igarashi
- Institute for Advanced Biosciences, Keio University, Tsuruoka 997-0052, Japan
| | - Kaori Saitoh
- Institute for Advanced Biosciences, Keio University, Tsuruoka 997-0052, Japan
| | - Keiko Kato
- Institute for Advanced Biosciences, Keio University, Tsuruoka 997-0052, Japan
| | - Keiko Endo
- Institute for Advanced Biosciences, Keio University, Tsuruoka 997-0052, Japan
| | - Shotaro Yamano
- Department of Molecular Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan
| | - Yasuharu Kanki
- Isotope Science Center, The University of Tokyo, Tokyo 113-0032, Japan
| | - Yoshihiro Matsumura
- Division of Metabolic Medicine, RCAST, The University of Tokyo, Tokyo 153-8904, Japan
| | - Takashi Minami
- Division of Molecular and Vascular Biology, IRDA, Kumamoto University, Kumamoto 860-0811, Japan
| | - Toshiya Tanaka
- Laboratory for Systems Biology and Medicine, RCAST, The University of Tokyo, Tokyo 153-8904, Japan
| | - Motonobu Anai
- Laboratory for Systems Biology and Medicine, RCAST, The University of Tokyo, Tokyo 153-8904, Japan
| | - Youichiro Wada
- Isotope Science Center, The University of Tokyo, Tokyo 113-0032, Japan
| | - Hideki Wanibuchi
- Department of Molecular Pathology, Osaka City University Graduate School of Medicine, 1-4-3 Asahimachi, Abeno-ku, Osaka 545-8585, Japan
| | - Mitsuhiro Hayashi
- Division of Clinical Pharmacology and Translational Research, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Akinobu Hamada
- Division of Molecular Pharmacology, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - Masayuki Yoshida
- Department of Pathology and Clinical Laboratories, National Cancer Center Hospital, Tokyo 104-0045, Japan
| | - Shinichi Yachida
- Department of Cancer Genome Informatics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Mitsuyoshi Nakao
- Department of Medical Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Chuo-ku, Kumamoto 860-0811, Japan
| | - Juro Sakai
- Division of Metabolic Medicine, RCAST, The University of Tokyo, Tokyo 153-8904, Japan; Division of Molecular Physiology and Metabolism, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan
| | - Hiroyuki Aburatani
- Division of Genome Science, RCAST, The University of Tokyo, Tokyo 153-8904, Japan
| | - Masabumi Shibuya
- Institute of Physiology and Medicine, Jobu University, 634-1 Toyazuka-machi, Isesaki, Gunma 372-8588, Japan
| | - Kentaro Hanada
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Satoru Miyano
- Human Genome Center, Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Tsuruoka 997-0052, Japan.
| | - Tatsuhiko Kodama
- Laboratory for Systems Biology and Medicine, RCAST, The University of Tokyo, Tokyo 153-8904, Japan.
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21
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Avery JC, Yamazaki Y, Hoffmann FW, Folgelgren B, Hoffmann PR. Selenoprotein I is essential for murine embryogenesis. Arch Biochem Biophys 2020; 689:108444. [PMID: 32502470 PMCID: PMC7363539 DOI: 10.1016/j.abb.2020.108444] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/12/2020] [Accepted: 05/28/2020] [Indexed: 12/13/2022]
Abstract
Selenoprotein I (SELENOI) is an ethanolamine phosphotransferase that catalyzes the third reaction of the Kennedy pathway for the synthesis of phosphatidylethanolamine. Since the role of SELENOI in murine embryogenesis has not been investigated, SELENOI-/+ mating pairs were used to generate global KO offspring. Of 323 weanling pups, no homozygous KO genotypes were found. E6.5-E18.5 embryos (165 total) were genotyped, and only two E18.5 KO embryos were detected with no discernable anatomical defects. To screen embryos prior to uterine implantation that occurs ~ E6, blastocyst embryos (E3.5-E4.4) were flushed from uteruses of pregnant females and analyzed for morphology and genotype. KO embryos were detected in 5 of 6 pregnant females, and 7 of the 32 genotyped embryos were found to be SELENOI KO that exhibited no overt pathological features. Overall, these results demonstrate that, except for rare cases (2/490 = 0.4%), global SELENOI deletion leads to early embryonic lethality.
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Affiliation(s)
- Joseph C Avery
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| | - Yukiko Yamazaki
- Institute for Biogenesis Research, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| | - FuKun W Hoffmann
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| | - Benjamin Folgelgren
- Department of Anatomy, Biochemistry and Physiology, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Peter R Hoffmann
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA.
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22
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Vaz FM, McDermott JH, Alders M, Wortmann SB, Kölker S, Pras-Raves ML, Vervaart MAT, van Lenthe H, Luyf ACM, Elfrink HL, Metcalfe K, Cuvertino S, Clayton PE, Yarwood R, Lowe MP, Lovell S, Rogers RC, van Kampen AHC, Ruiter JPN, Wanders RJA, Ferdinandusse S, van Weeghel M, Engelen M, Banka S. Mutations in PCYT2 disrupt etherlipid biosynthesis and cause a complex hereditary spastic paraplegia. Brain 2020; 142:3382-3397. [PMID: 31637422 PMCID: PMC6821184 DOI: 10.1093/brain/awz291] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 06/07/2019] [Accepted: 07/16/2019] [Indexed: 11/14/2022] Open
Abstract
CTP:phosphoethanolamine cytidylyltransferase (ET), encoded by PCYT2, is the rate-limiting enzyme for phosphatidylethanolamine synthesis via the CDP-ethanolamine pathway. Phosphatidylethanolamine is one of the most abundant membrane lipids and is particularly enriched in the brain. We identified five individuals with biallelic PCYT2 variants clinically characterized by global developmental delay with regression, spastic para- or tetraparesis, epilepsy and progressive cerebral and cerebellar atrophy. Using patient fibroblasts we demonstrated that these variants are hypomorphic, result in altered but residual ET protein levels and concomitant reduced enzyme activity without affecting mRNA levels. The significantly better survival of hypomorphic CRISPR-Cas9 generated pcyt2 zebrafish knockout compared to a complete knockout, in conjunction with previously described data on the Pcyt2 mouse model, indicates that complete loss of ET function may be incompatible with life in vertebrates. Lipidomic analysis revealed profound lipid abnormalities in patient fibroblasts impacting both neutral etherlipid and etherphospholipid metabolism. Plasma lipidomics studies also identified changes in etherlipids that have the potential to be used as biomarkers for ET deficiency. In conclusion, our data establish PCYT2 as a disease gene for a new complex hereditary spastic paraplegia and confirm that etherlipid homeostasis is important for the development and function of the brain.
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Affiliation(s)
- Frédéric M Vaz
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry, Amsterdam Gastroenterology and Metabolism, Meibergdreef 9, AZ Amsterdam, The Netherlands
| | - John H McDermott
- Manchester Centre for Genomics Medicine, St Mary's Hospital, Manchester University Hospital Foundation Trust, Health Innovation Manchester, Oxford Road, Manchester, UK
| | - Mariëlle Alders
- Laboratory Genome Diagnostics, Amsterdam UMC, University of Amsterdam, Department of Clinical Genetics, Amsterdam Reproduction and Development, Meibergdreef 9, AZ Amsterdam, The Netherlands
| | - Saskia B Wortmann
- Institute of Human Genetics, Technical University München, Munich, Germany.,Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,University Children's Hospital, Paracelsus Medical University, Salzburg, Austria
| | - Stefan Kölker
- Division of Pediatric Neurology and Metabolic Medicine, Centre for Pediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Mia L Pras-Raves
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry, Amsterdam Gastroenterology and Metabolism, Meibergdreef 9, AZ Amsterdam, The Netherlands.,Bioinformatics Laboratory, Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Amsterdam Public Health research institute, Amsterdam UMC, University of Amsterdam, Amsterdam AZ, The Netherlands
| | - Martin A T Vervaart
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry, Amsterdam Gastroenterology and Metabolism, Meibergdreef 9, AZ Amsterdam, The Netherlands
| | - Henk van Lenthe
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry, Amsterdam Gastroenterology and Metabolism, Meibergdreef 9, AZ Amsterdam, The Netherlands
| | - Angela C M Luyf
- Bioinformatics Laboratory, Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Amsterdam Public Health research institute, Amsterdam UMC, University of Amsterdam, Amsterdam AZ, The Netherlands
| | - Hyung L Elfrink
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry, Amsterdam Gastroenterology and Metabolism, Meibergdreef 9, AZ Amsterdam, The Netherlands
| | - Kay Metcalfe
- Manchester Centre for Genomics Medicine, St Mary's Hospital, Manchester University Hospital Foundation Trust, Health Innovation Manchester, Oxford Road, Manchester, UK
| | - Sara Cuvertino
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Peter E Clayton
- Department of Pediatric Endocrinology, Royal Manchester Children's Hospital, Manchester University Hospital Foundation Trust, Oxford Road, Manchester, UK
| | - Rebecca Yarwood
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Martin P Lowe
- Division of Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Simon Lovell
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Richard C Rogers
- Greenwood Genetic Center, 14 Edgewood Drive, Greenville, SC, USA
| | | | - Antoine H C van Kampen
- Bioinformatics Laboratory, Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Amsterdam Public Health research institute, Amsterdam UMC, University of Amsterdam, Amsterdam AZ, The Netherlands.,Biosystems Data Analysis, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, XH Amsterdam, The Netherlands
| | - Jos P N Ruiter
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry, Amsterdam Gastroenterology and Metabolism, Meibergdreef 9, AZ Amsterdam, The Netherlands
| | - Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry, Amsterdam Gastroenterology and Metabolism, Meibergdreef 9, AZ Amsterdam, The Netherlands
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry, Amsterdam Gastroenterology and Metabolism, Meibergdreef 9, AZ Amsterdam, The Netherlands
| | - Michel van Weeghel
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Department of Clinical Chemistry, Amsterdam Gastroenterology and Metabolism, Meibergdreef 9, AZ Amsterdam, The Netherlands
| | - Marc Engelen
- Department of (Pediatric) Neurology, Emma Children's Hospital, Amsterdam UMC, Amsterdam, The Netherlands
| | - Siddharth Banka
- Manchester Centre for Genomics Medicine, St Mary's Hospital, Manchester University Hospital Foundation Trust, Health Innovation Manchester, Oxford Road, Manchester, UK.,Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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23
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O'Dwyer C, Yaworski R, Katsumura S, Ghorbani P, Gobeil Odai K, Nunes JRC, LeBlond ND, Sanjana S, Smith TTK, Han S, Margison KD, Alain T, Morita M, Fullerton MD. Hepatic Choline Transport Is Inhibited During Fatty Acid-Induced Lipotoxicity and Obesity. Hepatol Commun 2020; 4:876-889. [PMID: 32490323 PMCID: PMC7262319 DOI: 10.1002/hep4.1516] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/25/2020] [Accepted: 03/11/2020] [Indexed: 01/11/2023] Open
Abstract
Choline is an essential nutrient and a critical component of the membrane phospholipid phosphatidylcholine (PC), the neurotransmitter acetylcholine, while also contributing to the methylation pathway. In the liver specifically, PC is the major membrane constituent and can be synthesized by the cytidine diphosphate-choline or the phosphatidylethanolamine N-methyltransferase pathway. With the continuing global rise in the rates of obesity and nonalcoholic fatty liver disease, we sought to explore how excess fatty acids on primary hepatocytes and diet-induced obesity affect choline uptake and metabolism. Our results demonstrate that hepatocytes chronically treated with palmitate, but not oleate or a mixture, had decreased choline uptake, which was associated with lower choline incorporation into PC and lower expression of choline transport proteins. Interestingly, a reduction in the rate of degradation spared PC levels in response to palmitate when compared with control. The effects of palmitate treatment were independent of endoplasmic reticulum stress, which counterintuitively augmented choline transport and transporter expression. In a model of obesity-induced hepatic steatosis, male mice fed a 60% high-fat diet for 10 weeks had significantly diminished hepatic choline uptake compared with lean mice fed a control diet. Although the transcript and protein expression of various choline metabolic enzymes fluctuated slightly, we observed reduced protein expression of choline transporter-like 1 (CTL1) in the liver of mice fed a high-fat diet. Polysome profile analyses revealed that in livers of obese mice, the CTL1 transcript, despite being more abundant, was translated to a lesser extent compared with lean controls. Finally, human liver cells demonstrated a similar response to palmitate treatment. Conclusion: Our results suggest that the altered fatty acid milieu seen in obesity-induced fatty liver disease progression may adversely affect choline metabolism, potentially through CTL1, but that compensatory mechanisms work to maintain phospholipid homeostasis.
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Affiliation(s)
- Conor O'Dwyer
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada
| | - Rebecca Yaworski
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada
| | - Sakie Katsumura
- Department of Molecular Medicine University of Texas Health Science Center at San Antonio San Antonio TX
| | - Peyman Ghorbani
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada
| | - Kaelan Gobeil Odai
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada
| | - Julia R C Nunes
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada
| | - Nicholas D LeBlond
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada
| | - Sabrin Sanjana
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada
| | - Tyler T K Smith
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada
| | - Shauna Han
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada
| | - Kaitlyn D Margison
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada
| | - Tommy Alain
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada.,Children's Hospital of Eastern Ontario Research Institute Ottawa ON Canada
| | - Masahiro Morita
- Department of Molecular Medicine University of Texas Health Science Center at San Antonio San Antonio TX.,Barshop Institute for Longevity and Aging Studies University of Texas Health Science Center at San Antonio San Antonio TX.,Institute of Resource Development and Analysis Kumamoto University Kumamoto Japan
| | - Morgan D Fullerton
- Department of Biochemistry, Microbiology and Immunology Faculty of Medicine University of Ottawa Ottawa ON Canada.,Centre for Infection Immunity and Inflammation and Centre for Catalysis Research and Innovation University of Ottawa Ottawa ON Canada
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24
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Guan Y, Chen X, Wu M, Zhu W, Arslan A, Takeda S, Nguyen MH, Majeti R, Thomas D, Zheng M, Peltz G. The phosphatidylethanolamine biosynthesis pathway provides a new target for cancer chemotherapy. J Hepatol 2020; 72:746-760. [PMID: 31760071 PMCID: PMC7085447 DOI: 10.1016/j.jhep.2019.11.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/01/2019] [Accepted: 11/01/2019] [Indexed: 12/25/2022]
Abstract
BACKGROUND & AIMS Since human induced pluripotent stem cells (iPSCs) develop into hepatic organoids through stages that resemble human embryonic liver development, they can be used to study developmental processes and disease pathology. Therefore, we examined the early stages of hepatic organoid formation to identify key pathways affecting early liver development. METHODS Single-cell RNA-sequencing and metabolomic analysis was performed on developing organoid cultures at the iPSC, hepatoblast (day 9) and mature organoid stage. The importance of the phosphatidylethanolamine biosynthesis pathway to early liver development was examined in developing organoid cultures using iPSC with a CRISPR-mediated gene knockout and an over the counter medication (meclizine) that inhibits the rate-limiting enzyme in this pathway. Meclizine's effect on the growth of a human hepatocarcinoma cell line in a xenotransplantation model and on the growth of acute myeloid leukemia cells in vitro was also examined. RESULTS Transcriptomic and metabolomic analysis of organoid development indicated that the phosphatidylethanolamine biosynthesis pathway is essential for early liver development. Unexpectedly, early hepatoblasts were selectively sensitive to the cytotoxic effect of meclizine. We demonstrate that meclizine could be repurposed for use in a new synergistic combination therapy for primary liver cancer: a glycolysis inhibitor reprograms cancer cell metabolism to make it susceptible to the cytotoxic effect of meclizine. This combination inhibited the growth of a human liver carcinoma cell line in vitro and in a xenotransplantation model, without causing significant side effects. This drug combination was also highly active against acute myeloid leukemia cells. CONCLUSION Our data indicate that phosphatidylethanolamine biosynthesis is a targetable pathway for cancer; meclizine may have clinical efficacy as a repurposed anti-cancer drug when used as part of a new combination therapy. LAY SUMMARY The early stages of human liver development were modeled using human hepatic organoids. We identified a pathway that was essential for early liver development. Based upon this finding, a novel combination drug therapy was identified that could be used to treat primary liver cancer and possibly other types of cancer.
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Affiliation(s)
- Yuan Guan
- Department of Anesthesia, Stanford University School of
Medicine, Stanford CA 94305
| | - Xinyu Chen
- Department of Anesthesia, Stanford University School of
Medicine, Stanford CA 94305
| | - Manhong Wu
- Department of Anesthesia, Stanford University School of
Medicine, Stanford CA 94305
| | - Wan Zhu
- Department of Anesthesia, Stanford University School of
Medicine, Stanford CA 94305
| | - Ahmed Arslan
- Department of Anesthesia, Stanford University School of
Medicine, Stanford CA 94305
| | - Saori Takeda
- Department of Anesthesia, Stanford University School of
Medicine, Stanford CA 94305
| | - Mindie H. Nguyen
- Department of Medicine, Division of Gastroenterology and
Hepatology, Stanford University School of Medicine, Stanford CA 94305
| | - Ravindra Majeti
- Department of Medicine, Division of Hematology, Cancer
Institute, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford
University School of Medicine
| | - Dan Thomas
- Department of Medicine, Division of Hematology, Cancer
Institute, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford
University School of Medicine
| | - Ming Zheng
- Department of Anesthesia, Stanford University School of
Medicine, Stanford CA 94305
| | - Gary Peltz
- Department of Anesthesia, Stanford University School of Medicine, Stanford, CA 94305.
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25
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Walsh SC, Miles JR, Yao L, Broeckling CD, Rempel LA, Wright-Johnson EC, Pannier AK. Metabolic compounds within the porcine uterine environment are unique to the type of conceptus present during the early stages of blastocyst elongation. Mol Reprod Dev 2019; 87:174-190. [PMID: 31840336 PMCID: PMC7003770 DOI: 10.1002/mrd.23306] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 12/02/2019] [Indexed: 12/13/2022]
Abstract
The objective of this study was to identify metabolites within the porcine uterine milieu during the early stages of blastocyst elongation. At Days 9, 10, or 11 of gestation, reproductive tracts of White cross‐bred gilts (n = 38) were collected immediately following harvest and flushed with Roswell Park Memorial Institute‐1640 medium. Conceptus morphologies were assessed from each pregnancy and corresponding uterine flushings were assigned to one of five treatment groups based on these morphologies: (a) uniform spherical (n = 8); (b) heterogeneous spherical and ovoid (n = 8); (c) uniform ovoid (n = 8); (d) heterogeneous ovoid and tubular (n = 8); and (e) uniform tubular (n = 6). Uterine flushings from these pregnancies were submitted for nontargeted profiling by gas chromatography–mass spectrometry (GC–MS) and ultra performance liquid chromatography (UPLC)–MS techniques. Unsupervised multivariate principal component analysis (PCA) was performed using pcaMethods and univariate analysis of variance was performed in R with false discovery rate (FDR) adjustment. PCA analysis of the GC–MS and UPLC–MS data identified 153 and 104 metabolites, respectively. After FDR adjustment of the GC–MS and UPLC–MS data, 38 and 59 metabolites, respectively, differed (p < .05) in uterine flushings from pregnancies across the five conceptus stages. Some metabolites were greater (p < .05) in abundance for uterine flushings containing earlier stage conceptuses (i.e., spherical), such as uric acid, tryptophan, and tyrosine. In contrast, some metabolites were greater (p < .05) in abundance for uterine flushings containing later stage conceptuses (i.e., tubular), such as creatinine, serine, and urea. These data illustrate several putative metabolites that change within the uterine milieu during early porcine blastocyst elongation.
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Affiliation(s)
- Sophie C Walsh
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Jeremy R Miles
- United States Department of Agriculture, U.S. Meat Animal Research Center, Clay Center, Nebraska
| | - Linxing Yao
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, Colorado
| | - Corey D Broeckling
- Proteomics and Metabolomics Facility, Colorado State University, Fort Collins, Colorado
| | - Lea A Rempel
- United States Department of Agriculture, U.S. Meat Animal Research Center, Clay Center, Nebraska
| | - Elane C Wright-Johnson
- United States Department of Agriculture, U.S. Meat Animal Research Center, Clay Center, Nebraska
| | - Angela K Pannier
- Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska
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26
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Naef V, Mero S, Fichi G, D'Amore A, Ogi A, Gemignani F, Santorelli FM, Marchese M. Swimming in Deep Water: Zebrafish Modeling of Complicated Forms of Hereditary Spastic Paraplegia and Spastic Ataxia. Front Neurosci 2019; 13:1311. [PMID: 31920481 PMCID: PMC6914767 DOI: 10.3389/fnins.2019.01311] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/22/2019] [Indexed: 12/13/2022] Open
Abstract
Hereditary spastic paraplegia (HSP) and hereditary ataxia (HA) are two groups of disorders characterized, respectively, by progressive dysfunction or degeneration of the pyramidal tracts (HSP) and of the Purkinje cells and spinocerebellar tracts (HA). Although HSP and HA are generally shown to have distinct clinical-genetic profiles, in several cases the clinical presentation, the causative genes, and the cellular pathways and mechanisms involved overlap between the two forms. Genetic analyses in humans in combination with in vitro and in vivo studies using model systems have greatly expanded our knowledge of spinocerebellar degenerative disorders. In this review, we focus on the zebrafish (Danio rerio), a vertebrate model widely used in biomedical research since its overall nervous system organization is similar to that of humans. A critical analysis of the literature suggests that zebrafish could serve as a powerful experimental tool for molecular and genetic dissection of both HA and HSP. The zebrafish, found to be very useful for demonstrating the causal relationship between defect and mutation, also offers a useful platform to exploit for the development of therapies.
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Affiliation(s)
- Valentina Naef
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy
| | - Serena Mero
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy.,Department of Biology, University of Pisa, Pisa, Italy
| | - Gianluca Fichi
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy.,Struttura Complessa Toscana Sud (Sede Grosseto), Istituto Zooprofilattico Sperimentale del Lazio e Toscana M. Aleandri, Grosseto, Italy
| | - Angelica D'Amore
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy.,Department of Biology, University of Pisa, Pisa, Italy.,Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Asahi Ogi
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy.,Department of Veterinary Sciences, University of Pisa, Pisa, Italy
| | | | | | - Maria Marchese
- Neurobiology and Molecular Medicine, IRCCS Stella Maris, Pisa, Italy
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Ando H, Horibata Y, Aoyama C, Shimizu H, Shinohara Y, Yamashita S, Sugimoto H. Side-chain oxysterols suppress the transcription of CTP: Phosphoethanolamine cytidylyltransferase and 3-hydroxy-3-methylglutaryl-CoA reductase by inhibiting the interaction of p300 and NF-Y, and H3K27 acetylation. J Steroid Biochem Mol Biol 2019; 195:105482. [PMID: 31580889 DOI: 10.1016/j.jsbmb.2019.105482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 09/10/2019] [Accepted: 09/18/2019] [Indexed: 10/25/2022]
Abstract
CTP: phosphoethanolamine cytidylyltransferase (Pcyt2) is the rate-limiting enzyme in mammalian phosphatidylethanolamine (PE) biosynthesis. Previously, we reported that increasedPcyt2 mRNA levels after serum starvation are suppressed by 25-hydroxycholesterol (HC) (25-HC), and that nuclear factor-Y (NF-Y) is involved in the inhibitory effects. Transcription of Hmgcr, which encodes 3-hydroxy-3-methylglutaryl-CoA reductase, is suppressed in the same manner. However, no typical sterol regulatory element (SRE) was detected in the Pcyt2 promoter. We were therefore interested in the effect of 25-HC on the modification of histones and thus treated cells with histone acetyltransferase inhibitor (anacardic acid) or histone deacetylase inhibitor (trichostatin A). The suppressive effect of 25-HC on Pcyt2 and Hmgcr mRNA transcription was ameliorated by trichostatin A. Anacardic acid, 25-HC and 24(S)-HC suppressed their transcription by inhibiting H3K27 acetylation in their promoters as evaluated by chromatin immunoprecipitation (ChIP) assays. 27-HC, 22(S)-HC and 22(R)-HC also suppressed their transcription, but 7α-HC, 7β-HC, the synthetic LXR agonist T0901317 and cholesterol did not. Furthermore, 25-HC inhibited p300 recruitment to the Pcyt2 and Hmgcr promoters, and suppressed H3K27 acetylation. 25-HC in the medium was easily conducted into cells. Based on these results, we concluded that 25-HC (and other side-chain oxysterols) in the medium was easily transferred into cells, suppressed H3K27 acetylation via p300 recruitment on the NF-Y complex in the Pcyt2 and Hmgcr promoters, and then suppressed transcription of these genes although LXR is not involved.
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Affiliation(s)
- Hiromi Ando
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Mibu 321-0293, Japan
| | - Yasuhiro Horibata
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Mibu 321-0293, Japan
| | - Chieko Aoyama
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Mibu 321-0293, Japan
| | - Hiroaki Shimizu
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Mibu 321-0293, Japan
| | - Yasutake Shinohara
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Mibu 321-0293, Japan
| | - Satoko Yamashita
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Mibu 321-0293, Japan
| | - Hiroyuki Sugimoto
- Department of Biochemistry, Dokkyo Medical University School of Medicine, Mibu 321-0293, Japan.
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28
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The Liberfarb syndrome, a multisystem disorder affecting eye, ear, bone, and brain development, is caused by a founder pathogenic variant in thePISD gene. Genet Med 2019; 21:2734-2743. [PMID: 31263216 PMCID: PMC6892740 DOI: 10.1038/s41436-019-0595-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 06/17/2019] [Indexed: 01/24/2023] Open
Abstract
Purpose We observed four individuals in two unrelated but consanguineous
families from Portugal and Brazil affected by early-onset retinal degeneration,
sensorineural hearing loss, microcephaly, intellectual disability, and skeletal
dysplasia with scoliosis and short stature. The phenotype precisely matched that
of an individual of Azorean descent published in 1986 by Liberfarb and
coworkers. Methods Patients underwent specialized clinical examinations (including
ophthalmological, audiological, orthopedic, radiological, and developmental
assessment). Exome and targeted sequencing was performed on selected
individuals. Minigene constructs were assessed by quantitative polymerase chain
reaction (qPCR) and Sanger sequencing. Results Affected individuals shared a 3.36-Mb region of autozygosity on
chromosome 22q12.2, including a 10-bp deletion
(NM_014338.3:c.904-12_904-3delCTATCACCAC), immediately upstream of the last exon
of the PISD (phosphatidylserine
decarboxylase) gene. Sequencing of PISD from
paraffin-embedded tissue from the 1986 case revealed the identical homozygous
variant. In HEK293T cells, this variant led to aberrant splicing of PISD transcripts. Conclusion We have identified the genetic etiology of the Liberfarb syndrome,
affecting brain, eye, ear, bone, and connective tissue. Our work documents the
migration of a rare Portuguese founder variant to two continents and highlights
the link between phospholipid metabolism and bone formation, sensory defects,
and cerebral development, while raising the possibility of therapeutic
phospholipid replacement.
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29
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Calzada E, Avery E, Sam PN, Modak A, Wang C, McCaffery JM, Han X, Alder NN, Claypool SM. Phosphatidylethanolamine made in the inner mitochondrial membrane is essential for yeast cytochrome bc 1 complex function. Nat Commun 2019; 10:1432. [PMID: 30926815 PMCID: PMC6441012 DOI: 10.1038/s41467-019-09425-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 03/11/2019] [Indexed: 12/18/2022] Open
Abstract
Of the four separate PE biosynthetic pathways in eukaryotes, one occurs in the mitochondrial inner membrane (IM) and is executed by phosphatidylserine decarboxylase (Psd1). Deletion of Psd1 is lethal in mice and compromises mitochondrial function. We hypothesize that this reflects inefficient import of non-mitochondrial PE into the IM. Here, we test this by re-wiring PE metabolism in yeast by re-directing Psd1 to the outer mitochondrial membrane or the endomembrane system and show that PE can cross the IMS in both directions. Nonetheless, PE synthesis in the IM is critical for cytochrome bc1 complex (III) function and mutations predicted to disrupt a conserved PE-binding site in the complex III subunit, Qcr7, impair complex III activity similar to PSD1 deletion. Collectively, these data challenge the current dogma of PE trafficking and demonstrate that PE made in the IM by Psd1 support the intrinsic functionality of complex III. Phosphatidylethanolamine (PE) is synthesized by four separate pathways, although surprisingly, perturbing mitochondrial PE synthesis compromises mitochondrial function. Here, the authors show that mitochondrial PE synthesis is required for Complex III function and challenge PE trafficking dogma.
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Affiliation(s)
- Elizabeth Calzada
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Erica Avery
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Pingdewinde N Sam
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Arnab Modak
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Chunyan Wang
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - J Michael McCaffery
- Integrated Imaging Center, Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Nathan N Alder
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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30
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Sivanesan S, Taylor A, Zhang J, Bakovic M. Betaine and Choline Improve Lipid Homeostasis in Obesity by Participation in Mitochondrial Oxidative Demethylation. Front Nutr 2018; 5:61. [PMID: 30042948 PMCID: PMC6048254 DOI: 10.3389/fnut.2018.00061] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/21/2018] [Indexed: 01/01/2023] Open
Abstract
We investigated the metabolic effects of betaine (Bet) supplementation on CTP:phosphoethanolamine cytidylyltransferase/Pcyt2 heterozygous mice (HET). HET received either no treatment or were allowed access to 1% Bet supplemented water for 8 weeks. As we previously showed with choline (Cho), Bet improved hypertriglyceridemia, and hepatic steatosis in HET. The protection from obesity associated with reduced hepatic steatosis and increased lipid breakdown in adipocytes was attributed to increased energy requirements for metabolism and elimination of supplemented Bet and Cho. 1H-NMR-based profiling revealed metabolic changes caused by Bet and Cho supplementation. Cho increased the citric acid cycle intermediate succinic acid while reducing isoleucine, valine, threonine, and lysine. Bet increased α-ketoglutaric acid and did not stimulate catabolism of amino acids. Increased histidine and alanine are specific biomarkers for Bet treatment. Cho and Bet caused glycerol accumulation and reduced sarcosine, taurine, acetate, and β-hydroxybutyrate levels. These data provide new insights on how Cho and Bet supplementation can aid in treatment of obesity related disorders due to their positive effects on lipolysis, the citric acid cycle, and mitochondrial oxidative demethylation.
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Affiliation(s)
- Sugashan Sivanesan
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Adrian Taylor
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Junzeng Zhang
- Aquatic and Crop Resource Development, National Research Council Canada, Halifax, NS, Canada
| | - Marica Bakovic
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
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31
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Vance JE. Historical perspective: phosphatidylserine and phosphatidylethanolamine from the 1800s to the present. J Lipid Res 2018; 59:923-944. [PMID: 29661786 DOI: 10.1194/jlr.r084004] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/12/2018] [Indexed: 12/17/2022] Open
Abstract
This article provides a historical account of the discovery, chemistry, and biochemistry of two ubiquitous phosphoglycerolipids, phosphatidylserine (PS) and phosphatidylethanolamine (PE), including the ether lipids. In addition, the article describes the biosynthetic pathways for these phospholipids and how these pathways were elucidated. Several unique functions of PS and PE in mammalian cells in addition to their ability to define physical properties of membranes are discussed. For example, the translocation of PS from the inner to the outer leaflet of the plasma membrane of cells occurs during apoptosis and during some other specific physiological processes, and this translocation is responsible for profound life-or-death events. Moreover, mitochondrial function is severely impaired when the PE content of mitochondria is reduced below a threshold level. The discovery and implications of the existence of membrane contact sites between the endoplasmic reticulum and mitochondria and their relevance for PS and PE metabolism, as well as for mitochondrial function, are also discussed. Many of the recent advances in these fields are due to the use of isotope labeling for tracing biochemical pathways. In addition, techniques for disruption of specific genes in mice are now widely used and have provided major breakthroughs in understanding the roles and metabolism of PS and PE in vivo.
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Affiliation(s)
- Jean E Vance
- Department of Medicine and Group on the Molecular and Cell Biology of Lipids, University of Alberta, Edmonton, Alberta T6G 2S2, Canada.
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32
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Basu Ball W, Neff JK, Gohil VM. The role of nonbilayer phospholipids in mitochondrial structure and function. FEBS Lett 2017; 592:1273-1290. [PMID: 29067684 DOI: 10.1002/1873-3468.12887] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 10/17/2017] [Accepted: 10/18/2017] [Indexed: 12/18/2022]
Abstract
Mitochondrial structure and function are influenced by the unique phospholipid composition of its membranes. While mitochondria contain all the major classes of phospholipids, recent studies have highlighted specific roles of the nonbilayer-forming phospholipids phosphatidylethanolamine (PE) and cardiolipin (CL) in the assembly and activity of mitochondrial respiratory chain (MRC) complexes. The nonbilayer phospholipids are cone-shaped molecules that introduce curvature stress in the bilayer membrane and have been shown to impact mitochondrial fusion and fission. In addition to their overlapping roles in these mitochondrial processes, each nonbilayer phospholipid also plays a unique role in mitochondrial function; for example, CL is specifically required for MRC supercomplex formation. Recent discoveries of mitochondrial PE- and CL-trafficking proteins and prior knowledge of their biosynthetic pathways have provided targets for precisely manipulating nonbilayer phospholipid levels in the mitochondrial membranes in vivo. Thus, the genetic mutants of these pathways could be valuable tools in illuminating molecular functions and biophysical properties of nonbilayer phospholipids in driving mitochondrial bioenergetics and dynamics.
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Affiliation(s)
- Writoban Basu Ball
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - John K Neff
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Vishal M Gohil
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
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33
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Multitiered and Cooperative Surveillance of Mitochondrial Phosphatidylserine Decarboxylase 1. Mol Cell Biol 2017; 37:MCB.00049-17. [PMID: 28606933 DOI: 10.1128/mcb.00049-17] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 06/08/2017] [Indexed: 11/20/2022] Open
Abstract
Phosphatidylserine decarboxylase 1 (Psd1p), an ancient enzyme that converts phosphatidylserine to phosphatidylethanolamine in the inner mitochondrial membrane, must undergo an autocatalytic self-processing event to gain activity. Autocatalysis severs the protein into a large membrane-anchored β subunit that noncovalently associates with the small α subunit on the intermembrane space side of the inner membrane. Here, we determined that a temperature sensitive (ts) PSD1 allele is autocatalytically impaired and that its fidelity is closely monitored throughout its life cycle by multiple mitochondrial quality control proteases. Interestingly, the proteases involved in resolving misfolded Psd1ts vary depending on its autocatalytic status. Specifically, the degradation of a Psd1ts precursor unable to undergo autocatalysis requires the unprecedented cooperative and sequential actions of two inner membrane proteases, Oma1p and Yme1p. In contrast, upon heat exposure postautocatalysis, Psd1ts β subunits accumulate in protein aggregates that are resolved by Yme1p acting alone, while the released α subunit is degraded in parallel by an unidentified protease. Importantly, the stability of endogenous Psd1p is also influenced by Yme1p. We conclude that Psd1p, the key enzyme required for the mitochondrial pathway of phosphatidylethanolamine production, is closely monitored at several levels and by multiple mitochondrial quality control mechanisms present in the intermembrane space.
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34
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Ethanolamine and Phosphatidylethanolamine: Partners in Health and Disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:4829180. [PMID: 28785375 PMCID: PMC5529665 DOI: 10.1155/2017/4829180] [Citation(s) in RCA: 193] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 06/01/2017] [Indexed: 12/18/2022]
Abstract
Phosphatidylethanolamine (PE) is the second most abundant phospholipid in mammalian cells. PE comprises about 15–25% of the total lipid in mammalian cells; it is enriched in the inner leaflet of membranes, and it is especially abundant in the inner mitochondrial membrane. PE has quite remarkable activities: it is a lipid chaperone that assists in the folding of certain membrane proteins, it is required for the activity of several of the respiratory complexes, and it plays a key role in the initiation of autophagy. In this review, we focus on PE's roles in lipid-induced stress in the endoplasmic reticulum (ER), Parkinson's disease (PD), ferroptosis, and cancer.
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35
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Singh RK, Lui E, Wright D, Taylor A, Bakovic M. Alcohol extract of North American ginseng (Panax quinquefolius) reduces fatty liver, dyslipidemia, and other complications of metabolic syndrome in a mouse model. Can J Physiol Pharmacol 2017; 95:1046-1057. [PMID: 28666094 DOI: 10.1139/cjpp-2016-0510] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We investigated whether North American ginseng (Panax quinquefolius) could reduce development of the metabolic syndrome phenotype in a mouse model (ETKO) of the disease. Young ETKO mice have no disease but similar to humans start to develop the fatty liver, hypertriglyceridemia, obesity, and insulin resistance at 25-30 weeks of age, and the disease continues to progress with ageing. ETKO mice were orally given an ethanol extract of ginseng roots at 4 and 32 weeks of age. Treatments with ginseng eliminated the ETKO fatty liver, reduced hepatic and intestinal lipoprotein secretion, and reduced the level of circulating lipids. Improvements by ginseng treatments were manifested as a reduction in the expression of genes involved in the regulation of fatty acid and triglyceride (fat) synthesis and secretion by the lipoproteins on one hand, and the stimulation of fatty acid oxidation and triglyceride degradation by lipolysis on the other hand. These processes altogether improved glucose, fatty acid, and triglyceride metabolism, reduced liver fat load, and reversed the progression of metabolic syndrome. These data confirm that treatments with North American ginseng could alleviate metabolic syndrome through the maintenance of a better balance between glucose and fatty acid metabolism, lipoprotein secretion, and energy homeostasis in disease-prone states.
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Affiliation(s)
- Ratnesh K Singh
- a Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Edmund Lui
- b Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON N6A 5C1, Canada
| | - David Wright
- a Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Adrian Taylor
- a Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Marica Bakovic
- a Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
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36
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Chénard T, Guénard F, Vohl MC, Carpentier A, Tchernof A, Najmanovich RJ. Remodeling adipose tissue through in silico modulation of fat storage for the prevention of type 2 diabetes. BMC SYSTEMS BIOLOGY 2017; 11:60. [PMID: 28606124 PMCID: PMC5468946 DOI: 10.1186/s12918-017-0438-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 06/05/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND Type 2 diabetes is one of the leading non-infectious diseases worldwide and closely relates to excess adipose tissue accumulation as seen in obesity. Specifically, hypertrophic expansion of adipose tissues is related to increased cardiometabolic risk leading to type 2 diabetes. Studying mechanisms underlying adipocyte hypertrophy could lead to the identification of potential targets for the treatment of these conditions. RESULTS We present iTC1390adip, a highly curated metabolic network of the human adipocyte presenting various improvements over the previously published iAdipocytes1809. iTC1390adip contains 1390 genes, 4519 reactions and 3664 metabolites. We validated the network obtaining 92.6% accuracy by comparing experimental gene essentiality in various cell lines to our predictions of biomass production. Using flux balance analysis under various test conditions, we predict the effect of gene deletion on both lipid droplet and biomass production, resulting in the identification of 27 genes that could reduce adipocyte hypertrophy. We also used expression data from visceral and subcutaneous adipose tissues to compare the effect of single gene deletions between adipocytes from each compartment. CONCLUSIONS We generated a highly curated metabolic network of the human adipose tissue and used it to identify potential targets for adipose tissue metabolic dysfunction leading to the development of type 2 diabetes.
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Affiliation(s)
- Thierry Chénard
- Department of Biochemistry, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Canada
| | - Frédéric Guénard
- Institute of Nutrition and Functional Foods, Université Laval, Quebec City, Canada
| | - Marie-Claude Vohl
- Institute of Nutrition and Functional Foods, Université Laval, Quebec City, Canada.,School of Nutrition, Université Laval, Quebec City, Canada
| | - André Carpentier
- Division of Endocrinology, Department of Medicine, Centre de recherche du CHUS, Université de Sherbrooke, Sherbrooke, Canada
| | - André Tchernof
- School of Nutrition, Université Laval, Quebec City, Canada.,Centre de Recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, QC, Canada
| | - Rafael J Najmanovich
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada.
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37
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van der Veen JN, Kennelly JP, Wan S, Vance JE, Vance DE, Jacobs RL. The critical role of phosphatidylcholine and phosphatidylethanolamine metabolism in health and disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1558-1572. [PMID: 28411170 DOI: 10.1016/j.bbamem.2017.04.006] [Citation(s) in RCA: 870] [Impact Index Per Article: 124.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/27/2017] [Accepted: 04/09/2017] [Indexed: 12/11/2022]
Abstract
Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) are the most abundant phospholipids in all mammalian cell membranes. In the 1950s, Eugene Kennedy and co-workers performed groundbreaking research that established the general outline of many of the pathways of phospholipid biosynthesis. In recent years, the importance of phospholipid metabolism in regulating lipid, lipoprotein and whole-body energy metabolism has been demonstrated in numerous dietary studies and knockout animal models. The purpose of this review is to highlight the unappreciated impact of phospholipid metabolism on health and disease. Abnormally high, and abnormally low, cellular PC/PE molar ratios in various tissues can influence energy metabolism and have been linked to disease progression. For example, inhibition of hepatic PC synthesis impairs very low density lipoprotein secretion and changes in hepatic phospholipid composition have been linked to fatty liver disease and impaired liver regeneration after surgery. The relative abundance of PC and PE regulates the size and dynamics of lipid droplets. In mitochondria, changes in the PC/PE molar ratio affect energy production. We highlight data showing that changes in the PC and/or PE content of various tissues are implicated in metabolic disorders such as atherosclerosis, insulin resistance and obesity. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá.
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Affiliation(s)
- Jelske N van der Veen
- Group on the Molecular and Cell Biology of Lipids, Canada; Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - John P Kennelly
- Group on the Molecular and Cell Biology of Lipids, Canada; Department of Agricultural, Food and Nutritional Science, 4-002 Li Ka Shing Centre for Heath Research Innovations, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Sereana Wan
- Group on the Molecular and Cell Biology of Lipids, Canada; Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Jean E Vance
- Group on the Molecular and Cell Biology of Lipids, Canada; Department of Medicine, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Dennis E Vance
- Group on the Molecular and Cell Biology of Lipids, Canada; Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - René L Jacobs
- Group on the Molecular and Cell Biology of Lipids, Canada; Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2S2, Canada; Department of Agricultural, Food and Nutritional Science, 4-002 Li Ka Shing Centre for Heath Research Innovations, University of Alberta, Edmonton, AB T6G 2E1, Canada.
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38
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Taylor A, Schenkel LC, Yokich M, Bakovic M. Adaptations to excess choline in insulin resistant and Pcyt2 deficient skeletal muscle. Biochem Cell Biol 2016; 95:223-231. [PMID: 28068143 DOI: 10.1139/bcb-2016-0105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
It was hypothesized that choline supplementation in insulin resistant (IR) CTP:phosphoethanolamine cytidylyltransferase deficient (Pcyt2+/-) mice would ameliorate muscle function by remodeling glucose and fatty acid (FA) metabolism. Pcyt2+/- mice either received no treatment or were allowed access to 2 mg/mL choline in drinking water for 4 weeks. Skeletal muscle was harvested from choline treated and untreated mice. Lipid analysis and metabolic gene expression and signaling pathways were compared between untreated Pcyt2+/- mice, treated Pcyt2+/- mice, and Pcyt2+/+ mice. The major positive effect of choline supplementation on IR muscle was the reduction of glucose utilization for FA and triglyceride (TAG) synthesis and increased muscle glucose storage as glycogen. Choline reduced the expression of genes for FA and TAG formation (Scd1, Fas, Srebp1c, Dgat1/2), upregulated the genes for FA oxidation (Cpt1, Pparα, Pgc1α), and had minor effects on phospholipid and lipolysis genes. Pcyt2+/- muscle had reduced insulin signaling (IRS1), autophagy (LC3), and choline transport (CTL1) proteins that were restored by choline treatment. Additionally, choline activated AMPK and Akt while inhibiting mTORC1 phosphorylation. These data established that choline supplementation could restore muscle glucose metabolism by reducing lipogenesis and improving mitochondrial and intracellular signaling for protein and energy metabolism in insulin resistant Pcyt2 deficient mice.
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Affiliation(s)
- Adrian Taylor
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.,Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Laila Cigana Schenkel
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.,Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Maiya Yokich
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.,Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Marica Bakovic
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.,Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
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Heden TD, Neufer PD, Funai K. Looking Beyond Structure: Membrane Phospholipids of Skeletal Muscle Mitochondria. Trends Endocrinol Metab 2016; 27:553-562. [PMID: 27370525 PMCID: PMC4958499 DOI: 10.1016/j.tem.2016.05.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 05/23/2016] [Accepted: 05/26/2016] [Indexed: 12/21/2022]
Abstract
Skeletal muscle mitochondria are highly dynamic and are capable of tremendous expansion to meet cellular energetic demands. Such proliferation in mitochondrial mass requires a synchronized supply of enzymes and structural phospholipids. While transcriptional regulation of mitochondrial enzymes has been extensively studied, there is limited information on how mitochondrial membrane lipids are generated in skeletal muscle. Herein we describe how each class of phospholipids that constitute mitochondrial membranes are synthesized and/or imported, and summarize genetic evidence indicating that membrane phospholipid composition represents a significant modulator of skeletal muscle mitochondrial respiratory function. We also discuss how skeletal muscle mitochondrial phospholipids may mediate the effect of diet and exercise on oxidative metabolism.
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Affiliation(s)
- Timothy D Heden
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Physiology, East Carolina University, Greenville, NC, USA
| | - Katsuhiko Funai
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, USA; Department of Kinesiology, East Carolina University, Greenville, NC, USA; Department of Physiology, East Carolina University, Greenville, NC, USA.
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40
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He J, Li G, Chen J, Lin J, Zeng C, Chen J, Deng J, Xie P. Prolonged exposure to low-dose microcystin induces nonalcoholic steatohepatitis in mice: a systems toxicology study. Arch Toxicol 2016; 91:465-480. [PMID: 26984711 DOI: 10.1007/s00204-016-1681-3] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 02/09/2016] [Indexed: 12/20/2022]
Abstract
Microcystin-LR (MCLR), a cyanotoxin widely present in freshwater, has been shown to have potent acute hepatotoxicity. However, the chronic toxicity of low-dose MCLR remains confusing by traditional measurements of toxicity. This has impeded understanding of the chronic liver damage of low-dose MCLR and corresponding safety risks of the human exposure guideline value. Here, iTRAQ-based proteomics and NMR-based metabonomics were used to decipher the molecular toxicological signatures of low doses of MCLR in mice exposed to this agent for 90 days. Low levels of MCLR, even under the reported no observed adverse effect level, significantly altered hepatic protein expression, especially of proteins associated with lipid metabolism, transport, immune and proteolysis. Coherently, MCLR induced marked perturbations in lipid metabolites in both liver and serum. Integrated analysis of proteomic, metabolic, histological and cytokine profiles revealed that MCLR significantly inhibited fatty acid β-oxidation and hepatic lipoprotein secretion and promoted hepatic inflammation, resulting in nonalcoholic steatohepatitis disease (NASH). These findings for the first time provide compelling evidence that chronic exposure to low-level MCLR can induce NASH. These results also indicate that current guidelines for MCs in drinking water may be inadequate and associated with risks to human health.
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Affiliation(s)
- Jun He
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan, 430072, People's Republic of China
| | - Guangyu Li
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jun Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan, 430072, People's Republic of China
| | - Juan Lin
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan, 430072, People's Republic of China
| | - Cheng Zeng
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
| | - Jing Chen
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan, 430072, People's Republic of China
| | - Junliang Deng
- Shanghai Biotree Biotech Co., Ltd, Shanghai, 200433, People's Republic of China
| | - Ping Xie
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Donghu South Road 7, Wuhan, 430072, People's Republic of China.
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41
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Calzada E, Onguka O, Claypool SM. Phosphatidylethanolamine Metabolism in Health and Disease. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 321:29-88. [PMID: 26811286 DOI: 10.1016/bs.ircmb.2015.10.001] [Citation(s) in RCA: 240] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Phosphatidylethanolamine (PE) is the second most abundant glycerophospholipid in eukaryotic cells. The existence of four only partially redundant biochemical pathways that produce PE, highlights the importance of this essential phospholipid. The CDP-ethanolamine and phosphatidylserine decarboxylase pathways occur in different subcellular compartments and are the main sources of PE in cells. Mammalian development fails upon ablation of either pathway. Once made, PE has diverse cellular functions that include serving as a precursor for phosphatidylcholine and a substrate for important posttranslational modifications, influencing membrane topology, and promoting cell and organelle membrane fusion, oxidative phosphorylation, mitochondrial biogenesis, and autophagy. The importance of PE metabolism in mammalian health has recently emerged following its association with Alzheimer's disease, Parkinson's disease, nonalcoholic liver disease, and the virulence of certain pathogenic organisms.
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Affiliation(s)
- Elizabeth Calzada
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ouma Onguka
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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42
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Schenkel LC, Sivanesan S, Zhang J, Wuyts B, Taylor A, Verbrugghe A, Bakovic M. Choline supplementation restores substrate balance and alleviates complications of Pcyt2 deficiency. J Nutr Biochem 2015; 26:1221-34. [PMID: 26242921 DOI: 10.1016/j.jnutbio.2015.05.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 05/24/2015] [Accepted: 05/27/2015] [Indexed: 02/07/2023]
Abstract
Choline plays a critical role in systemic lipid metabolism and hepatic function. Here we conducted a series of experiments to investigate the effect of choline supplementation on metabolically altered Pcyt2(+/-) mice. In Pcyt2(+/-) mice, the membrane phosphatidylethanolamine (PE) turnover is reduced and the formation of fatty acids (FA) and triglycerides (TAG) increased, resulting in hypertriglyceridemia, liver steatosis and obesity. One month of choline supplementation reduced the incorporation of FA into TAG and facilitated TAG degradation in Pcyt2(+/-) adipocytes, plasma and liver. Choline particularly stimulated adipocyte and liver TAG lipolysis by specific lipases (ATGL, LPL and HSL) and inhibited TAG formation by DGAT1 and DGAT2. Choline also activated the liver AMPK and mitochondrial FA oxidation gene PPARα and reduced the FA synthesis genes SREBP1, SCD1 and FAS. Liver (HPLC) and plasma (tandem mass spectroscopy and (1)H-NMR) metabolite profiling established that Pcyt2(+/-) mice have reduced membrane cholesterol/sphingomyelin ratio and the homocysteine/methionine cycle that were improved by choline supplementation. These data suggest that supplementary choline is beneficial for restoring FA and TAG homeostasis under conditions of obesity caused by impaired PE synthesis.
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Affiliation(s)
- Laila C Schenkel
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada N1G 2W1
| | - Sugashan Sivanesan
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada N1G 2W1
| | - Junzeng Zhang
- Aquatic and Crop Resource Development, National Research Council Canada, Halifax, NS, Canada B3H 3Z1
| | - Birgitte Wuyts
- Department of Clinical Chemistry, Laboratory of Metabolic Disorders, University Hospital Ghent, 9000 Ghent, Belgium
| | - Adrian Taylor
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada N1G 2W1
| | - Adronie Verbrugghe
- University of Guelph, Ontario Veterinary College, Dep. Clinical Studies, Guelph, Canada
| | - Marica Bakovic
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada N1G 2W1.
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43
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Male-Specific Cardiac Dysfunction in CTP:Phosphoethanolamine Cytidylyltransferase (Pcyt2)-Deficient Mice. Mol Cell Biol 2015; 35:2641-57. [PMID: 25986609 DOI: 10.1128/mcb.00380-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 05/14/2015] [Indexed: 12/15/2022] Open
Abstract
Phosphatidylethanolamine (PE) is the most abundant inner membrane phospholipid. PE synthesis from ethanolamine and diacylglycerol is regulated primarily by CTP:phosphoethanolamine cytidylyltransferase (Pcyt2). Pcyt2(+/-) mice have reduced PE synthesis and, as a consequence, perturbed glucose and fatty acid metabolism, which gradually leads to the development of hyperlipidemia, obesity, and insulin resistance. Glucose and fatty acid uptake and the corresponding transporters Glut4 and Cd36 are similarly impaired in male and female Pcyt2(+/-) hearts. These mice also have similarly reduced phosphatidylinositol 3-kinase (PI3K)/Akt1 signaling and increased reactive oxygen species (ROS) production in the heart. However, only Pcyt2(+/-) males develop hypertension and cardiac hypertrophy. Pcyt2(+/-) males have upregulated heart AceI expression, heart phospholipids enriched in arachidonic acid and other n-6 polyunsaturated fatty acids, and dramatically increased ROS production in the aorta. In contrast, Pcyt2(+/-) females have unmodified heart phospholipids but have reduced heart triglyceride levels and altered expression of the structural genes Acta (low) and Myh7 (high). These changes together protect Pcyt2(+/-) females from cardiac dysfunction under conditions of reduced glucose and fatty acid uptake and heart insulin resistance. Our data identify Pcyt2 and membrane PE biogenesis as important determinants of gender-specific differences in cardiac lipids and heart function.
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Selathurai A, Kowalski GM, Burch ML, Sepulveda P, Risis S, Lee-Young RS, Lamon S, Meikle PJ, Genders AJ, McGee SL, Watt MJ, Russell AP, Frank M, Jackowski S, Febbraio MA, Bruce CR. The CDP-Ethanolamine Pathway Regulates Skeletal Muscle Diacylglycerol Content and Mitochondrial Biogenesis without Altering Insulin Sensitivity. Cell Metab 2015; 21:718-30. [PMID: 25955207 DOI: 10.1016/j.cmet.2015.04.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 02/20/2015] [Accepted: 03/28/2015] [Indexed: 01/20/2023]
Abstract
Accumulation of diacylglycerol (DG) in muscle is thought to cause insulin resistance. DG is a precursor for phospholipids, thus phospholipid synthesis could be involved in regulating muscle DG. Little is known about the interaction between phospholipid and DG in muscle; therefore, we examined whether disrupting muscle phospholipid synthesis, specifically phosphatidylethanolamine (PtdEtn), would influence muscle DG content and insulin sensitivity. Muscle PtdEtn synthesis was disrupted by deleting CTP:phosphoethanolamine cytidylyltransferase (ECT), the rate-limiting enzyme in the CDP-ethanolamine pathway, a major route for PtdEtn production. While PtdEtn was reduced in muscle-specific ECT knockout mice, intramyocellular and membrane-associated DG was markedly increased. Importantly, however, this was not associated with insulin resistance. Unexpectedly, mitochondrial biogenesis and muscle oxidative capacity were increased in muscle-specific ECT knockout mice and were accompanied by enhanced exercise performance. These findings highlight the importance of the CDP-ethanolamine pathway in regulating muscle DG content and challenge the DG-induced insulin resistance hypothesis.
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Affiliation(s)
- Ahrathy Selathurai
- Centre for Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, 3125 VIC, Australia
| | - Greg M Kowalski
- Centre for Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, 3125 VIC, Australia
| | - Micah L Burch
- Department of Physiology, Monash University, Clayton, 3800 VIC, Australia
| | - Patricio Sepulveda
- Department of Physiology, Monash University, Clayton, 3800 VIC, Australia
| | - Steve Risis
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, Prahran, 3004 VIC, Australia
| | - Robert S Lee-Young
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, Prahran, 3004 VIC, Australia
| | - Severine Lamon
- Centre for Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, 3125 VIC, Australia
| | - Peter J Meikle
- Metabolomics Laboratory, Baker IDI Heart and Diabetes Institute, Prahran, 3004 VIC, Australia
| | - Amanda J Genders
- Metabolic Research Unit, Deakin University, Waurn Ponds, 3216 VIC, Australia
| | - Sean L McGee
- Metabolic Research Unit, Deakin University, Waurn Ponds, 3216 VIC, Australia
| | - Matthew J Watt
- Department of Physiology, Monash University, Clayton, 3800 VIC, Australia
| | - Aaron P Russell
- Centre for Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, 3125 VIC, Australia
| | - Matthew Frank
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Suzanne Jackowski
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Mark A Febbraio
- Cellular and Molecular Metabolism Laboratory, Baker IDI Heart and Diabetes Institute, Prahran, 3004 VIC, Australia
| | - Clinton R Bruce
- Centre for Physical Activity and Nutrition (C-PAN) Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, 3125 VIC, Australia.
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45
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Onguka O, Calzada E, Ogunbona OB, Claypool SM. Phosphatidylserine decarboxylase 1 autocatalysis and function does not require a mitochondrial-specific factor. J Biol Chem 2015; 290:12744-52. [PMID: 25829489 DOI: 10.1074/jbc.m115.641118] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Indexed: 11/06/2022] Open
Abstract
Phosphatidylethanolamine (PE) is a major cellular phospholipid that can be made by four separate pathways, one of which resides in the mitochondrion. The mitochondrial enzyme that generates PE is phosphatidylserine decarboxylase 1 (Psd1p). The pool of PE produced by Psd1p, which cannot be compensated for by the other cellular PE metabolic pathways, is important for numerous mitochondrial functions, including oxidative phosphorylation and mitochondrial dynamics and morphology, and is essential for murine development. To become catalytically active, Psd1p undergoes an autocatalytic processing step involving a conserved LGST motif that separates the enzyme into α and β subunits that remain non-covalently attached and are anchored to the inner membrane by virtue of the membrane-embedded β subunit. It was speculated that Psd1p autocatalysis requires a mitochondrial-specific factor and that for Psd1p to function in vivo, it had to be embedded with the correct topology in the mitochondrial inner membrane. However, the identity of the mitochondrial factor required for Psd1p autocatalysis has not been identified. With the goal of defining molecular requirements for Psd1p autocatalysis, we demonstrate that: 1) despite the conservation of the LGST motif from bacteria to humans, only the serine residue is absolutely required for Psd1p autocatalysis and function; 2) yeast Psd1p does not require its substrate phosphatidylserine for autocatalysis; and 3) contrary to a prior report, yeast Psd1p autocatalysis does not require mitochondrial-specific phospholipids, proteins, or co-factors, because Psd1p re-directed to the secretory pathway undergoes autocatalysis normally and is fully functional in vivo.
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Affiliation(s)
- Ouma Onguka
- From the Department of Physiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Elizabeth Calzada
- From the Department of Physiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Oluwaseun B Ogunbona
- From the Department of Physiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
| | - Steven M Claypool
- From the Department of Physiology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205
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46
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Fullerton MD, Ford RJ, McGregor CP, LeBlond ND, Snider SA, Stypa SA, Day EA, Lhoták Š, Schertzer JD, Austin RC, Kemp BE, Steinberg GR. Salicylate improves macrophage cholesterol homeostasis via activation of Ampk. J Lipid Res 2015; 56:1025-33. [PMID: 25773887 PMCID: PMC4409279 DOI: 10.1194/jlr.m058875] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Indexed: 02/02/2023] Open
Abstract
Atherosclerosis stems from imbalances in lipid metabolism and leads to maladaptive inflammatory responses. The AMP-activated protein kinase (Ampk) is a highly conserved serine/threonine kinase that regulates many aspects of lipid and energy metabolism, although its specific role in controlling macrophage cholesterol homeostasis remains unclear. We sought to address this question by testing the effects of direct Ampk activators in primary bone marrow-derived macrophages from Ampk β1-deficient (β1−/−) mice. Macrophages from Ampk β1−/− mice had enhanced lipogenic capacity and diminished cholesterol efflux, although cholesterol uptake was unaffected. Direct activation of Ampk β1 via salicylate (the unacetylated form of aspirin) or A-769662 (a small molecule activator), decreased the synthesis of FAs and sterols in WT but not Ampk β1−/− macrophages. In lipid-laden macrophages, Ampk activation decreased cholesterol content (foam cell formation) and increased cholesterol efflux to HDL and apoA-I, effects that occurred in an Ampk β1-dependent manner. Increased cholesterol efflux was also associated with increased gene expression of the ATP binding cassette transporters, Abcg1 and Abca1. Moreover, in vivo reverse cholesterol transport was suppressed in mice that received Ampk β1−/− macrophages compared with the WT control. Our data highlight the therapeutic potential of targeting macrophage Ampk with new or existing drugs for the possible reduction in foam cell formation during the early stages of atherosclerosis.
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Affiliation(s)
- Morgan D Fullerton
- Divisions of Endocrinology and Metabolism McMaster University, Hamilton, Canada Department of Medicine, and Departments of Biochemistry and Biomedical Sciences McMaster University, Hamilton, Canada Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Canada
| | - Rebecca J Ford
- Divisions of Endocrinology and Metabolism McMaster University, Hamilton, Canada
| | - Chelsea P McGregor
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Canada
| | - Nicholas D LeBlond
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Canada
| | - Shayne A Snider
- Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, Canada
| | - Stephanie A Stypa
- Divisions of Endocrinology and Metabolism McMaster University, Hamilton, Canada
| | - Emily A Day
- Divisions of Endocrinology and Metabolism McMaster University, Hamilton, Canada
| | - Šárka Lhoták
- Hamilton Centre for Kidney Research, St. Joseph's Healthcare Hamilton, Hamilton, Canada Nephrology, McMaster University, Hamilton, Canada
| | - Jonathan D Schertzer
- Department of Medicine, and Departments of Biochemistry and Biomedical Sciences McMaster University, Hamilton, Canada Pediatrics, McMaster University, Hamilton, Canada
| | - Richard C Austin
- Hamilton Centre for Kidney Research, St. Joseph's Healthcare Hamilton, Hamilton, Canada Nephrology, McMaster University, Hamilton, Canada
| | - Bruce E Kemp
- St. Vincent's Institute of Medical Research and Department of Medicine, University of Melbourne, Fitzroy, Australia
| | - Gregory R Steinberg
- Divisions of Endocrinology and Metabolism McMaster University, Hamilton, Canada Department of Medicine, and Departments of Biochemistry and Biomedical Sciences McMaster University, Hamilton, Canada
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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: 73] [Impact Index Per Article: 7.3] [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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48
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Vance JE. Phospholipid Synthesis and Transport in Mammalian Cells. Traffic 2014; 16:1-18. [DOI: 10.1111/tra.12230] [Citation(s) in RCA: 376] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 09/17/2014] [Accepted: 09/18/2014] [Indexed: 01/18/2023]
Affiliation(s)
- Jean E. Vance
- Department of Medicine and Group on Molecular and Cell Biology of Lipids; University of Alberta; Edmonton AB Canada
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49
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Tian S, Ohtsuka J, Wang S, Nagata K, Tanokura M, Ohta A, Horiuchi H, Fukuda R. Human CTP:phosphoethanolamine cytidylyltransferase: enzymatic properties and unequal catalytic roles of CTP-binding motifs in two cytidylyltransferase domains. Biochem Biophys Res Commun 2014; 449:26-31. [PMID: 24802409 DOI: 10.1016/j.bbrc.2014.04.131] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 04/25/2014] [Indexed: 10/25/2022]
Abstract
CTP:phosphoethanolamine cytidylyltransferase (ECT) is a key enzyme in the CDP-ethanolamine branch of the Kennedy pathway, which is the primary pathway of phosphatidylethanolamine (PE) synthesis in mammalian cells. Here, the enzymatic properties of recombinant human ECT (hECT) were characterized. The catalytic reaction of hECT obeyed Michaelis-Menten kinetics with respect to both CTP and phosphoethanolamine. hECT is composed of two tandem cytidylyltransferase (CT) domains as ECTs of other organisms. The histidines, especially the first histidine, in the CTP-binding motif HxGH in the N-terminal CT domain were critical for its catalytic activity in vitro, while those in the C-terminal CT domain were not. Overexpression of the wild-type hECT and hECT mutants containing amino acid substitutions in the HxGH motif in the C-terminal CT domain suppressed the growth defect of the Saccharomyces cerevisiae mutant of ECT1 encoding ECT in the absence of a PE supply via the decarboxylation of phosphatidylserine, but overexpression of hECT mutants of the N-terminal CT domain did not. These results suggest that the N-terminal CT domain of hECT contributes to its catalytic reaction, but C-terminal CT domain does not.
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Affiliation(s)
- Siqi Tian
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Jun Ohtsuka
- Department of Applied Biological Chemistry, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Shipeng Wang
- Department of Applied Biological Chemistry, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Koji Nagata
- Department of Applied Biological Chemistry, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Masaru Tanokura
- Department of Applied Biological Chemistry, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Akinori Ohta
- Department of Biological Chemistry, College of Bioscience and Biotechnology, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501, Japan
| | - Hiroyuki Horiuchi
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ryouichi Fukuda
- Department of Biotechnology, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
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Pavlovic Z, Zhu L, Pereira L, Singh RK, Cornell RB, Bakovic M. Isoform-specific and protein kinase C-mediated regulation of CTP:phosphoethanolamine cytidylyltransferase phosphorylation. J Biol Chem 2014; 289:9053-64. [PMID: 24519946 DOI: 10.1074/jbc.m113.544932] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CTP:phosphoethanolamine cytidylyltransferase (Pcyt2) is the main regulatory enzyme for de novo biosynthesis of phosphatidylethanolamine by the CDP-ethanolamine pathway. There are two isoforms of Pcyt2, -α and -β; however, very little is known about their specific roles in this important metabolic pathway. We previously demonstrated increased phosphatidylethanolamine biosynthesis subsequent to elevated activity and phosphorylation of Pcyt2α and -β in MCF-7 breast cancer cells grown under conditions of serum deficiency. Mass spectroscopy analyses of Pcyt2 provided evidence for isoform-specific as well as shared phosphorylations. Pcyt2β was specifically phosphorylated at the end of the first cytidylyltransferase domain. Pcyt2α was phosphorylated within the α-specific motif that is spliced out in Pcyt2β and on two PKC consensus serine residues, Ser-215 and Ser-223. Single and double mutations of PKC consensus sites reduced Pcyt2α phosphorylation, activity, and phosphatidylethanolamine synthesis by 50-90%. The phosphorylation and activity of endogenous Pcyt2 were dramatically increased with phorbol esters and reduced by specific PKC inhibitors. In vitro translated Pcyt2α was phosphorylated by PKCα, PKCβI, and PKCβII. Pcyt2α Ser-215 was also directly phosphorylated with PKCα. Mapping of the Pcyt2α- and -β-phosphorylated sites to the solved structure of a human Pcyt2β showed that they clustered within and flanking the central linker region that connects the two catalytic domains and is a novel regulatory segment not present in other cytidylyltransferases. This study is the first to demonstrate differences in phosphorylation between Pcyt2 isoforms and to uncover the role of the PKC-regulated phosphorylation.
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Affiliation(s)
- Zvezdan Pavlovic
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Ontario N1G 2W1 and
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