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Musselman LP, Truong HG, DiAngelo JR. Transcriptional Control of Lipid Metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024. [PMID: 38782870 DOI: 10.1007/5584_2024_808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Transcriptional control of lipid metabolism uses a framework that parallels the control of lipid metabolism at the protein or enzyme level, via feedback and feed-forward mechanisms. Increasing the substrates for an enzyme often increases enzyme gene expression, for example. A paucity of product can likewise potentiate transcription or stability of the mRNA encoding the enzyme or enzymes needed to produce it. In addition, changes in second messengers or cellular energy charge can act as on/off switches for transcriptional regulators to control transcript (and protein) abundance. Insects use a wide range of DNA-binding transcription factors (TFs) that sense changes in the cell and its environment to produce the appropriate change in transcription at gene promoters. These TFs work together with histones, spliceosomes, and additional RNA processing factors to ultimately regulate lipid metabolism. In this chapter, we will first focus on the important TFs that control lipid metabolism in insects. Next, we will describe non-TF regulators of insect lipid metabolism such as enzymes that modify acetylation and methylation status, transcriptional coactivators, splicing factors, and microRNAs. To conclude, we consider future goals for studying the mechanisms underlying the control of lipid metabolism in insects.
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Affiliation(s)
- Laura Palanker Musselman
- Department of Biological Sciences, Binghamton University, State University of New York, Binghamton, NY, USA
| | - Huy G Truong
- Division of Science, Pennsylvania State University, Berks Campus, Reading, PA, USA
| | - Justin R DiAngelo
- Division of Science, Pennsylvania State University, Berks Campus, Reading, PA, USA.
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2
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Vaughen JP, Theisen E, Rivas-Serna IM, Berger AB, Kalakuntla P, Anreiter I, Mazurak VC, Rodriguez TP, Mast JD, Hartl T, Perlstein EO, Reimer RJ, Clandinin MT, Clandinin TR. Glial control of sphingolipid levels sculpts diurnal remodeling in a circadian circuit. Neuron 2022; 110:3186-3205.e7. [PMID: 35961319 PMCID: PMC10868424 DOI: 10.1016/j.neuron.2022.07.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/21/2022] [Accepted: 07/14/2022] [Indexed: 11/19/2022]
Abstract
Structural plasticity in the brain often necessitates dramatic remodeling of neuronal processes, with attendant reorganization of the cytoskeleton and membranes. Although cytoskeletal restructuring has been studied extensively, how lipids might orchestrate structural plasticity remains unclear. We show that specific glial cells in Drosophila produce glucocerebrosidase (GBA) to locally catabolize sphingolipids. Sphingolipid accumulation drives lysosomal dysfunction, causing gba1b mutants to harbor protein aggregates that cycle across circadian time and are regulated by neural activity, the circadian clock, and sleep. Although the vast majority of membrane lipids are stable across the day, a specific subset that is highly enriched in sphingolipids cycles daily in a gba1b-dependent fashion. Remarkably, both sphingolipid biosynthesis and degradation are required for the diurnal remodeling of circadian clock neurites, which grow and shrink across the day. Thus, dynamic sphingolipid regulation by glia enables diurnal circuit remodeling and proper circadian behavior.
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Affiliation(s)
- John P Vaughen
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - Emma Theisen
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA
| | - Irma Magaly Rivas-Serna
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Andrew B Berger
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA
| | - Prateek Kalakuntla
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - Ina Anreiter
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA
| | - Vera C Mazurak
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | | | - Joshua D Mast
- Perlara PBC, 2625 Alcatraz Ave #435, Berkeley, CA 94705, USA
| | - Tom Hartl
- Perlara PBC, 2625 Alcatraz Ave #435, Berkeley, CA 94705, USA
| | | | - Richard J Reimer
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - M Thomas Clandinin
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Thomas R Clandinin
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA.
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3
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Dabelsteen S, Pallesen EMH, Marinova IN, Nielsen MI, Adamopoulou M, Rømer TB, Levann A, Andersen MM, Ye Z, Thein D, Bennett EP, Büll C, Moons SJ, Boltje T, Clausen H, Vakhrushev SY, Bagdonaite I, Wandall HH. Essential Functions of Glycans in Human Epithelia Dissected by a CRISPR-Cas9-Engineered Human Organotypic Skin Model. Dev Cell 2020; 54:669-684.e7. [PMID: 32710848 PMCID: PMC7497784 DOI: 10.1016/j.devcel.2020.06.039] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 04/07/2020] [Accepted: 06/29/2020] [Indexed: 12/26/2022]
Abstract
The glycome undergoes characteristic changes during histogenesis and organogenesis, but our understanding of the importance of select glycan structures for tissue formation and homeostasis is incomplete. Here, we present a human organotypic platform that allows genetic dissection of cellular glycosylation capacities and systematic interrogation of the roles of distinct glycan types in tissue formation. We used CRISPR-Cas9 gene targeting to generate a library of 3D organotypic skin tissues that selectively differ in their capacity to produce glycan structures on the main types of N- and O-linked glycoproteins and glycolipids. This tissue library revealed distinct changes in skin formation associated with a loss of features for all tested glycoconjugates. The organotypic skin model provides phenotypic cues for the distinct functions of glycoconjugates and serves as a unique resource for further genetic dissection and identification of the specific structural features involved. The strategy is also applicable to other organotypic tissue models.
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Affiliation(s)
- Sally Dabelsteen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark; Department of Oral Pathology, School of Dentistry, University of Copenhagen, Denmark
| | - Emil M H Pallesen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Irina N Marinova
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Mathias I Nielsen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Maria Adamopoulou
- Department of Oral Pathology, School of Dentistry, University of Copenhagen, Denmark
| | - Troels B Rømer
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Asha Levann
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Mikkel M Andersen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Zilu Ye
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - David Thein
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Eric P Bennett
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Christian Büll
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Sam J Moons
- Institute for Molecules and Materials, Nijmegen 6525 AJ, the Netherlands
| | - Thomas Boltje
- Institute for Molecules and Materials, Nijmegen 6525 AJ, the Netherlands
| | - Henrik Clausen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Sergey Y Vakhrushev
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Ieva Bagdonaite
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Hans H Wandall
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark.
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4
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Abstract
Glycosylation refers to the covalent attachment of sugar residues to a protein or lipid, and the biological importance of this modification has been widely recognized. While glycosylation in mammals is being extensively investigated, lower level animals such as invertebrates have not been adequately interrogated for their glycosylation. The rich diversity of invertebrate species, the increased database of sequenced invertebrate genomes and the time and cost efficiency of raising and experimenting on these species have enabled a handful of the species to become excellent model organisms, which have been successfully used as tools for probing various biologically interesting problems. Investigation on invertebrate glycosylation, especially on model organisms, not only expands the structural and functional knowledgebase, but also can facilitate deeper understanding on the biological functions of glycosylation in higher organisms. Here, we reviewed the research advances in invertebrate glycosylation, including N- and O-glycosylation, glycosphingolipids and glycosaminoglycans. The aspects of glycan biosynthesis, structures and functions are discussed, with a focus on the model organisms Drosophila and Caenorhabditis. Analytical strategies for the glycans and glycoconjugates are also summarized.
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Affiliation(s)
- Feifei Zhu
- 1 Institute of Life Sciences, Jiangsu University , Zhenjiang 212013 , People's Republic of China.,2 School of Food and Biological Engineering, Jiangsu University , Zhenjiang 212013 , People's Republic of China
| | - Dong Li
- 1 Institute of Life Sciences, Jiangsu University , Zhenjiang 212013 , People's Republic of China
| | - Keping Chen
- 1 Institute of Life Sciences, Jiangsu University , Zhenjiang 212013 , People's Republic of China
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5
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Functional analysis of glycosylation using Drosophila melanogaster. Glycoconj J 2019; 37:1-14. [DOI: 10.1007/s10719-019-09892-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/13/2019] [Accepted: 09/25/2019] [Indexed: 12/15/2022]
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6
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Roles of forkhead box O (FoxO) transcription factors in neurodegenerative diseases: A panoramic view. Prog Neurobiol 2019; 181:101645. [PMID: 31229499 DOI: 10.1016/j.pneurobio.2019.101645] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 06/03/2019] [Accepted: 06/18/2019] [Indexed: 12/11/2022]
Abstract
Neurodegenerative diseases (NDDs), which are among the most important aging-related diseases, are typically characterized by neuronal damage and a progressive impairment in neurological function during aging. Few effective therapeutic targets for NDDs have been revealed; thus, an understanding of the pathogenesis of NDDs is important. Forkhead box O (FoxO) transcription factors have been implicated in the mechanisms regulating aging and longevity. The functions of FoxOs are regulated by diverse post-translational modifications (e.g., phosphorylation, acetylation, ubiquitination, methylation and glycosylation). FoxOs exert both detrimental and protective effects on NDDs. Therefore, an understanding of the precise function of FoxOs in NDDs will be helpful for developing appropriate treatment strategies. In this review, we first introduce the post-translational modifications of FoxOs. Next, the regulation of FoxO expression and post-translational modifications in the central nervous system (CNS) is described. Afterwards, we analyze and address the important roles of FoxOs in NDDs. Finally, novel potential directions of future FoxO research in NDDs are discussed. This review recapitulates essential facts and questions about the promise of FoxOs in treating NDDs, and it will likely be important for the design of further basic studies and to realize the potential for FoxOs as therapeutic targets in NDDs.
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7
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Yildirim K, Petri J, Kottmeier R, Klämbt C. Drosophila glia: Few cell types and many conserved functions. Glia 2018; 67:5-26. [DOI: 10.1002/glia.23459] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/25/2018] [Accepted: 05/04/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Kerem Yildirim
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
| | - Johanna Petri
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
| | - Rita Kottmeier
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
| | - Christian Klämbt
- Institute for Neuro and Behavioral Biology; University of Münster; Badestraße 9, 48149 Münster Germany
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8
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Huang Y, Huang S, Di Scala C, Wang Q, Wandall HH, Fantini J, Zhang YQ. The glycosphingolipid MacCer promotes synaptic bouton formation in Drosophila by interacting with Wnt. eLife 2018; 7:38183. [PMID: 30355446 PMCID: PMC6202054 DOI: 10.7554/elife.38183] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 09/09/2018] [Indexed: 01/05/2023] Open
Abstract
Lipids are structural components of cellular membranes and signaling molecules that are widely involved in development and diseases, but the underlying molecular mechanisms are poorly understood, partly because of the vast variety of lipid species and complexity of synthetic and turnover pathways. From a genetic screen, we identify that mannosyl glucosylceramide (MacCer), a species of glycosphingolipid (GSL), promotes synaptic bouton formation at the Drosophila neuromuscular junction (NMJ). Pharmacological and genetic analysis shows that the NMJ growth-promoting effect of MacCer depends on normal lipid rafts, which are known to be composed of sphingolipids, sterols and select proteins. MacCer positively regulates the synaptic level of Wnt1/Wingless (Wg) and facilitates presynaptic Wg signaling, whose activity is raft-dependent. Furthermore, a functional GSL-binding motif in Wg exhibiting a high affinity for MacCer is required for normal NMJ growth. These findings reveal a novel mechanism whereby the GSL MacCer promotes synaptic bouton formation via Wg signaling.
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Affiliation(s)
- Yan Huang
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, CAS Center for Excellence in Brain Science and Intelligence Technology, Beijing, China
| | - Sheng Huang
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, CAS Center for Excellence in Brain Science and Intelligence Technology, Beijing, China.,Sino-Danish College, Sino-Danish Center for Education and Research, Chinese Academy of Sciences, Beijing, China
| | | | - Qifu Wang
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, CAS Center for Excellence in Brain Science and Intelligence Technology, Beijing, China
| | - Hans H Wandall
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jacques Fantini
- UNIS UMR_S 1072, INSERM, Aix-Marseille Université, Marseille, France
| | - Yong Q Zhang
- Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, CAS Center for Excellence in Brain Science and Intelligence Technology, Beijing, China
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9
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Itonori S, Hashimoto K, Nakagawa M, Harada M, Suzuki T, Kojima H, Ito M, Sugita M. Structural analysis of neutral glycosphingolipids from the silkworm Bombyx mori and the difference in ceramide composition between larvae and pupae. J Biochem 2018; 163:201-214. [PMID: 29069405 DOI: 10.1093/jb/mvx072] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 09/08/2017] [Indexed: 01/06/2023] Open
Abstract
Glycosphingolipids (GSLs) from the silkworm Bombyx mori were identified and GSL expression patterns between larvae and pupae were compared. The structural analysis of neutral GSLs from dried pupae revealed the following predominant species: Glcβ1Cer, Manβ4Glcβ1Cer, GlcNAcβ3Manβ4Glcβ1Cer, Galβ3Manβ4Glcβ1Cer, GalNAcα4Galβ3Manβ4Glcβ1Cer, GlcNAcβ3Galβ3Manβ4Glcβ1Cer, Galα4Galβ3Manβ4Glcβ1Cer and (GalNAcα4)1-4 GalNAcα4Galβ3Manβ4Glcβ1Cer. Lin-ear elongation of α4-GalNAc was observed at the non-reducing end of Galβ3Manβ4Glcβ1Cer with up to five GalNAc repeats. The arthro-series GSL GlcNAcβ3Manβ4Glcβ1Cer, a characteristic GSL-glycan sequence of other Arthropoda, was detected in silkworms. The main ceramide species in each purified GSL fraction were h20:0-d14:1 and h22:0-d14:1. GSL expression patterns in larvae and pupae were compared using thin-layer chromatography, which demonstrated differences among acidic, polar and neutral GSL fractions, while the zwitterionic fraction showed no difference. Neutral GSLs such as ceramides di-, tri- and tetrasaccharides in larvae showed less abundant than those in pupae. MALDI-TOF MS analysis revealed that larval GSLs contained four types of ceramide species, whereas pupal GSLs contained only two types. The structural analysis of neutral GSLs from silkworms revealed a novel series of GSLs. The comparison of GSL expression patterns between larvae and pupae demonstrated differences in several fractions. Alterations in GSL ceramide composition between larvae and pupae were observed by MALDI-TOF MS analysis.
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Affiliation(s)
- Saki Itonori
- Department of Chemistry, Faculty of Liberal Arts and Education, Shiga University, 2-5-1, Hiratsu, Otsu, Shiga 520-0862, Japan
| | - Kyouhei Hashimoto
- Department of Chemistry, Faculty of Liberal Arts and Education, Shiga University, 2-5-1, Hiratsu, Otsu, Shiga 520-0862, Japan
| | - Mika Nakagawa
- Department of Chemistry, Faculty of Liberal Arts and Education, Shiga University, 2-5-1, Hiratsu, Otsu, Shiga 520-0862, Japan
| | - Masashi Harada
- Department of Chemistry, Faculty of Liberal Arts and Education, Shiga University, 2-5-1, Hiratsu, Otsu, Shiga 520-0862, Japan
| | - Takae Suzuki
- Department of Chemistry, Faculty of Liberal Arts and Education, Shiga University, 2-5-1, Hiratsu, Otsu, Shiga 520-0862, Japan
| | - Hisao Kojima
- Department of Bioinformatics, Institute of Science and Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan
| | - Masahiro Ito
- Department of Bioinformatics, Institute of Science and Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577, Japan
| | - Mutsumi Sugita
- Department of Chemistry, Faculty of Liberal Arts and Education, Shiga University, 2-5-1, Hiratsu, Otsu, Shiga 520-0862, Japan
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10
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Gerdøe-Kristensen S, Lund VK, Wandall HH, Kjaerulff O. Mactosylceramide prevents glial cell overgrowth by inhibiting insulin and fibroblast growth factor receptor signaling. J Cell Physiol 2017; 232:3112-3127. [PMID: 28019653 DOI: 10.1002/jcp.25762] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 12/22/2016] [Accepted: 12/22/2016] [Indexed: 12/13/2022]
Abstract
Receptor tyrosine kinase (RTK) signaling controls key aspects of cellular differentiation, proliferation, survival, metabolism, and migration. Deregulated RTK signaling also underlies many cancers. Glycosphingolipids (GSL) are essential elements of the plasma membrane. By affecting clustering and activity of membrane receptors, GSL modulate signal transduction, including that mediated by the RTK. GSL are abundant in the nervous system, and glial development in Drosophila is emerging as a useful model for studying how GSL modulate RTK signaling. Drosophila has a simple GSL biosynthetic pathway, in which the mannosyltransferase Egghead controls conversion of glucosylceramide (GlcCer) to mactosylceramide (MacCer). Lack of elongated GSL in egghead (egh) mutants causes overgrowth of subperineurial glia (SPG), largely due to aberrant activation of phosphatidylinositol 3-kinase (PI3K). However, to what extent this effect involves changes in upstream signaling events is unresolved. We show here that glial overgrowth in egh is strongly linked to increased activation of Insulin and fibroblast growth factor receptors (FGFR). Glial hypertrophy is phenocopied when overexpressing gain-of-function mutants of the Drosophila insulin receptor (InR) and the FGFR homolog Heartless (Htl) in wild type SPG, and is suppressed by inhibiting Htl and InR activity in egh. Knockdown of GlcCer synthase in the SPG fails to suppress glial overgrowth in egh nerves, and slightly promotes overgrowth in wild type, suggesting that RTK hyperactivation is caused by absence of MacCer and not by GlcCer accumulation. We conclude that an early product in GSL biosynthesis, MacCer, prevents inappropriate activation of insulin and fibroblast growth factor receptors in Drosophila glia.
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Affiliation(s)
- Stine Gerdøe-Kristensen
- Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark.,Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Viktor K Lund
- Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Hans H Wandall
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Ole Kjaerulff
- Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen N, Denmark
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11
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Ghosh A, Kling T, Snaidero N, Sampaio JL, Shevchenko A, Gras H, Geurten B, Göpfert MC, Schulz JB, Voigt A, Simons M. A global in vivo Drosophila RNAi screen identifies a key role of ceramide phosphoethanolamine for glial ensheathment of axons. PLoS Genet 2013; 9:e1003980. [PMID: 24348263 PMCID: PMC3861124 DOI: 10.1371/journal.pgen.1003980] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 10/12/2013] [Indexed: 01/08/2023] Open
Abstract
Glia are of vital importance for all complex nervous system. One of the many functions of glia is to insulate and provide trophic and metabolic support to axons. Here, using glial-specific RNAi knockdown in Drosophila, we silenced 6930 conserved genes in adult flies to identify essential genes and pathways. Among our screening hits, metabolic processes were highly represented, and genes involved in carbohydrate and lipid metabolic pathways appeared to be essential in glia. One critical pathway identified was de novo ceramide synthesis. Glial knockdown of lace, a subunit of the serine palmitoyltransferase associated with hereditary sensory and autonomic neuropathies in humans, resulted in ensheathment defects of peripheral nerves in Drosophila. A genetic dissection study combined with shotgun high-resolution mass spectrometry of lipids showed that levels of ceramide phosphoethanolamine are crucial for axonal ensheathment by glia. A detailed morphological and functional analysis demonstrated that the depletion of ceramide phosphoethanolamine resulted in axonal defasciculation, slowed spike propagation, and failure of wrapping glia to enwrap peripheral axons. Supplementing sphingosine into the diet rescued the neuropathy in flies. Thus, our RNAi study in Drosophila identifies a key role of ceramide phosphoethanolamine in wrapping of axons by glia.
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Affiliation(s)
- Aniket Ghosh
- Max Planck Institute for Experimental Medicine, Göttingen, Germany
- Department of Neurology, University of Göttingen, Göttingen, Germany
| | - Tina Kling
- Max Planck Institute for Experimental Medicine, Göttingen, Germany
- Department of Neurology, University of Göttingen, Göttingen, Germany
| | - Nicolas Snaidero
- Max Planck Institute for Experimental Medicine, Göttingen, Germany
- Department of Neurology, University of Göttingen, Göttingen, Germany
| | - Julio L. Sampaio
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Andrej Shevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Heribert Gras
- Department of Cellular Neurobiology, University of Göttingen, Göttingen, Germany
| | - Bart Geurten
- Department of Cellular Neurobiology, University of Göttingen, Göttingen, Germany
| | - Martin C. Göpfert
- Department of Cellular Neurobiology, University of Göttingen, Göttingen, Germany
| | - Jörg B. Schulz
- Department of Neurology, University Medical Center, RWTH Aachen, Aachen, Germany
| | - Aaron Voigt
- Department of Neurology, University Medical Center, RWTH Aachen, Aachen, Germany
| | - Mikael Simons
- Max Planck Institute for Experimental Medicine, Göttingen, Germany
- Department of Neurology, University of Göttingen, Göttingen, Germany
- * E-mail:
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12
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Jennemann R, Gröne HJ. Cell-specific in vivo functions of glycosphingolipids: lessons from genetic deletions of enzymes involved in glycosphingolipid synthesis. Prog Lipid Res 2013; 52:231-48. [PMID: 23473748 DOI: 10.1016/j.plipres.2013.02.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 02/20/2013] [Accepted: 02/25/2013] [Indexed: 11/16/2022]
Abstract
Glycosphingolipids (GSLs) are believed to be involved in many cellular events including trafficking, signaling and cellular interactions. Over the past decade considerable progress was made elucidating the function of GSLs by generating and exploring animal models with GSL-deficiency. Initial studies focused on exploring the role of complex sialic acid containing GSLs (gangliosides) in neuronal tissue. Although complex gangliosides were absent, surprisingly, the phenotype observed was rather mild. In subsequent studies, several mouse models with combinations of gene-deletions encoding GSL-synthesizing enzymes were developed. The results indicated that reduction of GSL-complexity correlated with severity of phenotypes. However, in these mice, accumulation of precursor GSLs or neobiosynthesized GSL-series seemed to partly compensate the loss of GSLs. Thus, UDP-glucose:ceramide glucosyltransferase (Ugcg), catalyzing the basic step of the glucosylceramide-based GSL-biosynthesis, was genetically disrupted. A total systemic deletion of Ugcg caused early embryonic lethality. Therefore, Ugcg was eliminated in a cell-specific manner using the cre/loxP-system. New insights into the cellular function of GSLs were gained. It was demonstrated that neurons require GSLs for differentiation and maintenance. In keratinocytes, preservation of the skin barrier depends on GSL synthesis and in enterocytes of the small intestine GSLs are involved in endocytosis and vesicular transport.
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Affiliation(s)
- Richard Jennemann
- Department of Cellular and Molecular Pathology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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13
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Hua D, Qin F, Shen L, Jiang Z, Zou ST, Xu L, Cheng ZH, Wu SL. β3GnT8 regulates laryngeal carcinoma cell proliferation via targeting MMPs/TIMPs and TGF-β1. Asian Pac J Cancer Prev 2013; 13:2087-93. [PMID: 22901175 DOI: 10.7314/apjcp.2012.13.5.2087] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Previous evidence showed β1, 3-N-acetylglucosaminyltransferase 8 (β3GnT8), which can extend polylactosamine on N-glycans, to be highly expressed in some cancer cell lines and tissues, indicating roles in tumorigenesis. However, so far, the function of β3GnT8 in laryngeal carcinoma has not been characterized. To test any contribution, Hep-2 cells were stably transfected with sense or interference vectors to establish cell lines that overexpressed or were deficient in β3GnT8. Here we showed that cell proliferation was increased in β3GnT8 overexpressed cells but decreased in β3GnT8 knockdown cells using MTT. Furthermore, we demonstrated that change in β3GnT8 expression had significant effects on tumor growth in nude mice.We further provided data suggesting that overexpression of β3GnT8 enhanced the expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) at both the mRNA and protein levels, associated with shedding of tissue inhibitors of metalloproteinase TIMP-2. In addition, it caused increased production of transforming growth factor beta 1 (TGF-β1), whereas β3GnT8 gene knockdown caused the reverse effect. The results may indicate a novel mechanism by which effects of β3GnT8 in regulating cellular proliferation are mediated, at least in partvia targeting MMPs/TIMPs and TGF-β1 in laryngeal carcinoma Hep-2 cells. The finding may lay a foundation for further investigations into the β3GnT8 as a potential target for therapy of laryngeal carcinoma.
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Affiliation(s)
- Dong Hua
- The Fourth Affiliated Hospital of Soochow University, Wuxi, China
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14
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Park SH, Lee S, Hong YK, Hwang S, Lee JH, Bang SM, Kim YK, Koo BS, Lee IS, Cho KS. Suppressive Effects of SuHeXiang Wan on Amyloid-β42-Induced Extracellular Signal-Regulated Kinase Hyperactivation and Glial Cell Proliferation in a Transgenic Drosophila Model of Alzheimer’s Disease. Biol Pharm Bull 2013; 36:390-8. [DOI: 10.1248/bpb.b12-00792] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Soojin Lee
- Department of Biological Sciences, Konkuk University
| | - Yoon Ki Hong
- Department of Biological Sciences, Konkuk University
| | - Soojin Hwang
- Department of Biological Sciences, Konkuk University
| | - Jang Ho Lee
- Department of Biological Sciences, Konkuk University
| | - Se Min Bang
- Department of Biological Sciences, Konkuk University
| | - Young-Kyoon Kim
- Department of Forest Products & Biotechnology, Kookmin University
| | - Byung-Soo Koo
- Department of Neuropsychiatry, Graduate School of Oriental Medicine, Dongguk University
| | - Im-Soon Lee
- Department of Biological Sciences, Konkuk University
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15
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Katoh T, Tiemeyer M. The N's and O's of Drosophila glycoprotein glycobiology. Glycoconj J 2012; 30:57-66. [PMID: 22936173 DOI: 10.1007/s10719-012-9442-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 08/13/2012] [Indexed: 11/28/2022]
Abstract
The past 25 years have seen significant advances in understanding the diversity and functions of glycoprotein glycans in Drosophila melanogaster. Genetic screens have captured mutations that reveal important biological activities modulated by glycans, including protein folding and trafficking, as well as cell signaling, tissue morphogenesis, fertility, and viability. Many of these glycan functions have parallels in vertebrate development and disease, providing increasing opportunities to dissect pathologic mechanisms using Drosophila genetics. Advances in the sensitivity of structural analytic techniques have allowed the glycan profiles of wild-type and mutant tissues to be assessed, revealing novel glycan structures that may be functionally analogous to vertebrate glycans. This review describes a selected set of recent advances in understanding the functions of N-linked and O-linked (non-glycosaminoglycan) glycoprotein glycans in Drosophila with emphasis on their relatedness to vertebrate organisms.
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Affiliation(s)
- Toshihiko Katoh
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
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