1
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Crawford BI, Talley MJ, Russman J, Riddle J, Torres S, Williams T, Longworth MS. Condensin-mediated restriction of retrotransposable elements facilitates brain development in Drosophila melanogaster. Nat Commun 2024; 15:2716. [PMID: 38548759 PMCID: PMC10978865 DOI: 10.1038/s41467-024-47042-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/18/2024] [Indexed: 04/01/2024] Open
Abstract
Neural stem and progenitor cell (NSPC) maintenance is essential for ensuring that organisms are born with proper brain volumes and head sizes. Microcephaly is a disorder in which babies are born with significantly smaller head sizes and cortical volumes. Mutations in subunits of the DNA organizing complex condensin have been identified in microcephaly patients. However, the molecular mechanisms by which condensin insufficiency causes microcephaly remain elusive. We previously identified conserved roles for condensins in repression of retrotransposable elements (RTEs). Here, we show that condensin subunit knockdown in NSPCs of the Drosophila larval central brain increases RTE expression and mobility which causes cell death, and significantly decreases adult head sizes and brain volumes. These findings suggest that unrestricted RTE expression and activity may lead to improper brain development in condensin insufficient organisms, and lay the foundation for future exploration of causative roles for RTEs in other microcephaly models.
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Affiliation(s)
- Bert I Crawford
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Mary Jo Talley
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Joshua Russman
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - James Riddle
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Sabrina Torres
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Troy Williams
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA
| | - Michelle S Longworth
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, 44195, USA.
- Cleveland Clinic Lerner College of Medicine, Case Western Reserve University School of Medicine, Cleveland, OH, 44195, USA.
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2
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Eberwein AE, Kulkarni SS, Rushton E, Broadie K. Glycosphingolipids are linked to elevated neurotransmission and neurodegeneration in a Drosophila model of Niemann Pick type C. Dis Model Mech 2023; 16:dmm050206. [PMID: 37815467 PMCID: PMC10581387 DOI: 10.1242/dmm.050206] [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: 03/24/2023] [Accepted: 09/27/2023] [Indexed: 10/11/2023] Open
Abstract
The lipid storage disease Niemann Pick type C (NPC) causes neurodegeneration owing primarily to loss of NPC1. Here, we employed a Drosophila model to test links between glycosphingolipids, neurotransmission and neurodegeneration. We found that Npc1a nulls had elevated neurotransmission at the glutamatergic neuromuscular junction (NMJ), which was phenocopied in brainiac (brn) mutants, impairing mannosyl glucosylceramide (MacCer) glycosylation. Npc1a; brn double mutants had the same elevated synaptic transmission, suggesting that Npc1a and brn function within the same pathway. Glucosylceramide (GlcCer) synthase inhibition with miglustat prevented elevated neurotransmission in Npc1a and brn mutants, further suggesting epistasis. Synaptic MacCer did not accumulate in the NPC model, but GlcCer levels were increased, suggesting that GlcCer is responsible for the elevated synaptic transmission. Null Npc1a mutants had heightened neurodegeneration, but no significant motor neuron or glial cell death, indicating that dying cells are interneurons and that elevated neurotransmission precedes neurodegeneration. Glycosphingolipid synthesis mutants also had greatly heightened neurodegeneration, with similar neurodegeneration in Npc1a; brn double mutants, again suggesting that Npc1a and brn function in the same pathway. These findings indicate causal links between glycosphingolipid-dependent neurotransmission and neurodegeneration in this NPC disease model.
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Affiliation(s)
- Anna E. Eberwein
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Swarat S. Kulkarni
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Emma Rushton
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
- Kennedy Center for Research on Human Development, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
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3
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Kulkarni A, Ewen-Campen B, Terao K, Matsumoto Y, Li Y, Watanabe T, Kao JA, Parhad SS, Ylla G, Mizunami M, Extavour CG. oskar acts with the transcription factor Creb to regulate long-term memory in crickets. Proc Natl Acad Sci U S A 2023; 120:e2218506120. [PMID: 37192168 PMCID: PMC10214185 DOI: 10.1073/pnas.2218506120] [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: 10/29/2022] [Accepted: 03/28/2023] [Indexed: 05/18/2023] Open
Abstract
Novel genes have the potential to drive the evolution of new biological mechanisms, or to integrate into preexisting regulatory circuits and contribute to the regulation of older, conserved biological functions. One such gene, the novel insect-specific gene oskar, was first identified based on its role in establishing the Drosophila melanogaster germ line. We previously showed that this gene likely arose through an unusual domain transfer event involving bacterial endosymbionts and played a somatic role before evolving its well-known germ line function. Here, we provide empirical support for this hypothesis in the form of evidence for a neural role for oskar. We show that oskar is expressed in the adult neural stem cells of a hemimetabolous insect, the cricket Gryllus bimaculatus. In these stem cells, called neuroblasts, oskar is required together with the ancient animal transcription factor Creb to regulate long-term (but not short-term) olfactory memory. We provide evidence that oskar positively regulates Creb, which plays a conserved role in long-term memory across animals, and that oskar in turn may be a direct target of Creb. Together with previous reports of a role for oskar in nervous system development and function in crickets and flies, our results are consistent with the hypothesis that oskar's original somatic role may have been in the insect nervous system. Moreover, its colocalization and functional cooperation with the conserved pluripotency gene piwi in the nervous system may have facilitated oskar's later co-option to the germ line in holometabolous insects.
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Affiliation(s)
- Arpita Kulkarni
- Department of Organismic and Evolutionary Biology, Faculty of Arts and Sciences, Harvard University, Cambridge, MA02138
| | - Ben Ewen-Campen
- Department of Organismic and Evolutionary Biology, Faculty of Arts and Sciences, Harvard University, Cambridge, MA02138
| | - Kanta Terao
- Graduate School of Life Science, Hokkaido University, Sapporo060-0810, Japan
| | | | - Yaolong Li
- Graduate School of Life Science, Hokkaido University, Sapporo060-0810, Japan
| | - Takayuki Watanabe
- Faculty of Science, Hokkaido University, Sapporo060-0810, Japan
- Research Center for Integrative Evolutionary Science, School of Advanced Sciences, Sokendai-Hayama, Kanagawa240-0193, Japan
| | - Jonchee A. Kao
- Department of Molecular and Cellular Biology, Faculty of Arts and Sciences, Harvard University, Cambridge, MA02138
| | - Swapnil S. Parhad
- University of Massachusetts Chan Medical School, Program in Molecular Medicine, Worcester, MA01655
| | - Guillem Ylla
- Department of Organismic and Evolutionary Biology, Faculty of Arts and Sciences, Harvard University, Cambridge, MA02138
| | - Makoto Mizunami
- Faculty of Science, Hokkaido University, Sapporo060-0810, Japan
| | - Cassandra G. Extavour
- Department of Organismic and Evolutionary Biology, Faculty of Arts and Sciences, Harvard University, Cambridge, MA02138
- Department of Molecular and Cellular Biology, Faculty of Arts and Sciences, Harvard University, Cambridge, MA02138
- HHMI, Chevy Chase, MD20815
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4
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Markey KM, Saunders JC, Smuts J, von Reyn CR, Garcia ADR. Astrocyte development—More questions than answers. Front Cell Dev Biol 2023; 11:1063843. [PMID: 37051466 PMCID: PMC10083403 DOI: 10.3389/fcell.2023.1063843] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 03/14/2023] [Indexed: 03/28/2023] Open
Abstract
The past 15–20 years has seen a remarkable shift in our understanding of astrocyte contributions to central nervous system (CNS) function. Astrocytes have emerged from the shadows of neuroscience and are now recognized as key elements in a broad array of CNS functions. Astrocytes comprise a substantial fraction of cells in the human CNS. Nevertheless, fundamental questions surrounding their basic biology remain poorly understood. While recent studies have revealed a diversity of essential roles in CNS function, from synapse formation and function to blood brain barrier maintenance, fundamental mechanisms of astrocyte development, including their expansion, migration, and maturation, remain to be elucidated. The coincident development of astrocytes and synapses highlights the need to better understand astrocyte development and will facilitate novel strategies for addressing neurodevelopmental and neurological dysfunction. In this review, we provide an overview of the current understanding of astrocyte development, focusing primarily on mammalian astrocytes and highlight outstanding questions that remain to be addressed. We also include an overview of Drosophila glial development, emphasizing astrocyte-like glia given their close anatomical and functional association with synapses. Drosophila offer an array of sophisticated molecular genetic tools and they remain a powerful model for elucidating fundamental cellular and molecular mechanisms governing astrocyte development. Understanding the parallels and distinctions between astrocyte development in Drosophila and vertebrates will enable investigators to leverage the strengths of each model system to gain new insights into astrocyte function.
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Affiliation(s)
- Kathryn M. Markey
- Department of Biology, Drexel University, Philadelphia, PA, United States
| | | | - Jana Smuts
- Department of Neurobiology and Anatomy, Drexel University, Philadelphia, PA, United States
| | - Catherine R. von Reyn
- Department of Neurobiology and Anatomy, Drexel University, Philadelphia, PA, United States
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA, United States
| | - A. Denise R. Garcia
- Department of Biology, Drexel University, Philadelphia, PA, United States
- Department of Neurobiology and Anatomy, Drexel University, Philadelphia, PA, United States
- *Correspondence: A. Denise R. Garcia,
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5
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Anosike NL, Adejuwon JF, Emmanuel GE, Adebayo OS, Etti-Balogun H, Nathaniel JN, Omotosho OI, Aschner M, Ijomone OM. Necroptosis in the developing brain: role in neurodevelopmental disorders. Metab Brain Dis 2023; 38:831-837. [PMID: 36964816 DOI: 10.1007/s11011-023-01203-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 03/17/2023] [Indexed: 03/26/2023]
Abstract
Cell death is vital to various organismal developmental processes including brain development. Apoptosis, the most recognized programmed cell death, has been linked to several developmental processes and implicated in pruning cells to provide the ultimate tissue integrity. However, more recently, other forms of non-apoptotic programmed cell death have been identified, of which necroptosis is of predominant interest. Necroptosis is a regulated form of necrosis, activated under apoptotic-deficient conditions. Tumour necrosis factor (TNF) is a major activator of necroptosis, and the process is mediated by several kinases including receptor-interacting protein kinase (RIPK) and mixed lineage kinase domain-like protein (MLKL). Potential roles for necroptosis during brain development have been muted. Necroptosis has been implicated in mediating neurological disorders, and contributing to the severity of these disorders. Here we will review the literature on the role of necroptosis in neurodevelopment, summarizing its molecular mechanisms and highlighting potential implications for disorders of the developing brain.
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Affiliation(s)
- Nnenna Loveth Anosike
- The Neuro- Lab, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
| | - Joy Funsho Adejuwon
- The Neuro- Lab, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
- Department of Human Anatomy, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
| | - Godslove Emeka Emmanuel
- The Neuro- Lab, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
- Department of Human Anatomy, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
| | - Oluwatosin Samuel Adebayo
- The Neuro- Lab, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
- Department of Human Anatomy, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
| | - Hassanat Etti-Balogun
- The Neuro- Lab, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
- Department of Human Anatomy, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
| | - Jannie Nathaniel Nathaniel
- The Neuro- Lab, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
- Department of Physiology, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
| | - Omolabake Ifeoluwa Omotosho
- The Neuro- Lab, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
- Department of Human Anatomy, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Neurosciences, Albert Einstein College of Medicine, Bronx, NY, USA
- Department of Paediatrics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Omamuyovwi Meashack Ijomone
- The Neuro- Lab, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria.
- Department of Human Anatomy, School of Basic Medical Sciences, Federal University of Technology Akure, Akure, Nigeria.
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA.
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6
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Truman JW, Riddiford LM. Drosophila postembryonic nervous system development: a model for the endocrine control of development. Genetics 2023; 223:iyac184. [PMID: 36645270 PMCID: PMC9991519 DOI: 10.1093/genetics/iyac184] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 12/13/2022] [Indexed: 01/17/2023] Open
Abstract
During postembryonic life, hormones, including ecdysteroids, juvenile hormones, insulin-like peptides, and activin/TGFβ ligands act to transform the larval nervous system into an adult version, which is a fine-grained mosaic of recycled larval neurons and adult-specific neurons. Hormones provide both instructional signals that make cells competent to undergo developmental change and timing cues to evoke these changes across the nervous system. While touching on all the above hormones, our emphasis is on the ecdysteroids, ecdysone and 20-hydroxyecdysone (20E). These are the prime movers of insect molting and metamorphosis and are involved in all phases of nervous system development, including neurogenesis, pruning, arbor outgrowth, and cell death. Ecdysteroids appear as a series of steroid peaks that coordinate the larval molts and the different phases of metamorphosis. Each peak directs a stereotyped cascade of transcription factor expression. The cascade components then direct temporal programs of effector gene expression, but the latter vary markedly according to tissue and life stage. The neurons read the ecdysteroid titer through various isoforms of the ecdysone receptor, a nuclear hormone receptor. For example, at metamorphosis the pruning of larval neurons is mediated through the B isoforms, which have strong activation functions, whereas subsequent outgrowth is mediated through the A isoform through which ecdysteroids play a permissive role to allow local tissue interactions to direct outgrowth. The major circulating ecdysteroid can also change through development. During adult development ecdysone promotes early adult patterning and differentiation while its metabolite, 20E, later evokes terminal adult differentiation.
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Affiliation(s)
- James W Truman
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA
| | - Lynn M Riddiford
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
- Department of Biology, University of Washington, Box 351800, Seattle, WA 98195, USA
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7
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Gil M, Gama V. Emerging mitochondrial-mediated mechanisms involved in oligodendrocyte development. J Neurosci Res 2023; 101:354-366. [PMID: 36461887 PMCID: PMC9851982 DOI: 10.1002/jnr.25151] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 10/19/2022] [Accepted: 11/22/2022] [Indexed: 12/05/2022]
Abstract
Oligodendrocytes are the myelinating glia of the central nervous system and are generated after oligodendrocyte progenitor cells (OPCs) transition into pre-oligodendrocytes and then into myelinating oligodendrocytes. Myelin is essential for proper signal transmission within the nervous system and axonal metabolic support. Although the intrinsic and extrinsic factors that support the differentiation, survival, integration, and subsequent myelination of appropriate axons have been well investigated, little is known about how mitochondria-related pathways such as mitochondrial dynamics, bioenergetics, and apoptosis finely tune these developmental events. Previous findings suggest that changes to mitochondrial morphology act as an upstream regulatory mechanism of neural stem cell (NSC) fate decisions. Whether a similar mechanism is engaged during OPC differentiation has yet to be elucidated. Maintenance of mitochondrial dynamics is vital for regulating cellular bioenergetics, functional mitochondrial networks, and the ability of cells to distribute mitochondria to subcellular locations, such as the growing processes of oligodendrocytes. Myelination is an energy-consuming event, thus, understanding the interplay between mitochondrial dynamics, metabolism, and apoptosis will provide further insight into mechanisms that mediate oligodendrocyte development in healthy and disease states. Here we will provide a concise overview of oligodendrocyte development and discuss the potential contribution of mitochondrial mitochondrial-mediated mechanisms to oligodendrocyte bioenergetics and development.
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Affiliation(s)
- M Gil
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
- Neuroscience Graduate Program, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
| | - V Gama
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
- Neuroscience Graduate Program, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, USA
- Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, USA
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8
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Liu W, Liang W, Xiong XP, Li JL, Zhou R. A circular RNA Edis-Relish-castor axis regulates neuronal development in Drosophila. PLoS Genet 2022; 18:e1010433. [PMID: 36301831 PMCID: PMC9612563 DOI: 10.1371/journal.pgen.1010433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 09/19/2022] [Indexed: 11/16/2022] Open
Abstract
Circular RNAs (circRNAs) are a new group of noncoding/regulatory RNAs that are particularly abundant in the nervous system, however, their physiological functions are underexplored. Here we report that the brain-enriched circular RNA Edis (Ect4-derived immune suppressor) plays an essential role in neuronal development in Drosophila. We show that depletion of Edis in vivo causes defects in axonal projection patterns of mushroom body (MB) neurons in the brain, as well as impaired locomotor activity and shortened lifespan of adult flies. In addition, we find that the castor gene, which encodes a transcription factor involved in neurodevelopment, is upregulated in Edis knockdown neurons. Notably, castor overexpression phenocopies Edis knockdown, and reducing castor levels suppresses the neurodevelopmental phenotypes in Edis-depleted neurons. Furthermore, chromatin immunoprecipitation analysis reveals that the transcription factor Relish, which plays a key role in regulating innate immunity signaling, occupies a pair of sites at the castor promoter, and that both sites are required for optimal castor gene activation by either immune challenge or Edis depletion. Lastly, Relish mutation and/or depletion can rescue both the castor gene hyperactivation phenotype and neuronal defects in Edis knockdown animals. We conclude that the circular RNA Edis acts through Relish and castor to regulate neuronal development.
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Affiliation(s)
- Wei Liu
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Cancer and Blood Disorders Institute, Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, United States of America
- Institute for Fundamental Biomedical Research, Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, United States of America
| | - Weihong Liang
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Cancer and Blood Disorders Institute, Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, United States of America
- Institute for Fundamental Biomedical Research, Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, United States of America
| | - Xiao-Peng Xiong
- Tumor Initiation and Maintenance Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
| | - Jian-Liang Li
- Tumor Initiation and Maintenance Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- National Institute of Environmental Health Sciences, Durham, North Carolina, United States of America
| | - Rui Zhou
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Cancer and Blood Disorders Institute, Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, United States of America
- Institute for Fundamental Biomedical Research, Johns Hopkins All Children’s Hospital, St. Petersburg, Florida, United States of America
- Tumor Initiation and Maintenance Program, NCI-Designated Cancer Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, United States of America
- * E-mail:
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9
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Prasad AR, Lago-Baldaia I, Bostock MP, Housseini Z, Fernandes VM. Differentiation signals from glia are fine-tuned to set neuronal numbers during development. eLife 2022; 11:78092. [PMID: 36094172 PMCID: PMC9507125 DOI: 10.7554/elife.78092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 09/11/2022] [Indexed: 11/13/2022] Open
Abstract
Neural circuit formation and function require that diverse neurons are specified in appropriate numbers. Known strategies for controlling neuronal numbers involve regulating either cell proliferation or survival. We used the Drosophila visual system to probe how neuronal numbers are set. Photoreceptors from the eye-disc induce their target field, the lamina, such that for every unit eye there is a corresponding lamina unit (column). Although each column initially contains ~6 post-mitotic lamina precursors, only 5 differentiate into neurons, called L1-L5; the 'extra' precursor, which is invariantly positioned above the L5 neuron in each column, undergoes apoptosis. Here, we showed that a glial population called the outer chiasm giant glia (xgO), which resides below the lamina, secretes multiple ligands to induce L5 differentiation in response to EGF from photoreceptors. By forcing neuronal differentiation in the lamina, we uncovered that though fated to die, the 'extra' precursor is specified as an L5. Therefore, two precursors are specified as L5s but only one differentiates during normal development. We found that the row of precursors nearest to xgO differentiate into L5s and, in turn, antagonise differentiation signalling to prevent the 'extra' precursors from differentiating, resulting in their death. Thus, an intricate interplay of glial signals and feedback from differentiating neurons defines an invariant and stereotyped pattern of neuronal differentiation and programmed cell death to ensure that lamina columns each contain exactly one L5 neuron.
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Affiliation(s)
- Anadika R Prasad
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Inês Lago-Baldaia
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Matthew P Bostock
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Zaynab Housseini
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Vilaiwan M Fernandes
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
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10
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Gebreegziabher Amare M, Westrick NM, Keller NP, Kabbage M. The conservation of IAP-like proteins in fungi, and their potential role in fungal programmed cell death. Fungal Genet Biol 2022; 162:103730. [PMID: 35998750 DOI: 10.1016/j.fgb.2022.103730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/07/2022] [Indexed: 11/30/2022]
Abstract
Programmed cell death (PCD) is a tightly regulated process which is required for survival and proper development of all cellular life. Despite this ubiquity, the precise molecular underpinnings of PCD have been primarily characterized in animals. Attempts to expand our understanding of this process in fungi have proven difficult as core regulators of animal PCD are apparently absent in fungal genomes, with the notable exception of a class of proteins referred to as inhibitors of apoptosis proteins (IAPs). These proteins are characterized by the conservation of a distinct Baculovirus IAP Repeat (BIR) domain and animal IAPs are known to regulate a number of processes, including cellular death, development, organogenesis, immune system maturation, host-pathogen interactions and more. IAP homologs are broadly conserved throughout the fungal kingdom, but our understanding of both their mechanism and role in fungal development/virulence is still unclear. In this review, we provide a broad and comparative overview of IAP function across taxa, with a particular focus on fungal processes regulated by IAPs. Furthermore, their putative modes of action in the absence of canonical interactors will be discussed.
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Affiliation(s)
| | - Nathaniel M Westrick
- Department of Plant Pathology, University of Wisconsin - Madison, Madison, WI, USA
| | - Nancy P Keller
- Department of Plant Pathology, University of Wisconsin - Madison, Madison, WI, USA
| | - Mehdi Kabbage
- Department of Plant Pathology, University of Wisconsin - Madison, Madison, WI, USA.
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11
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Pfeifer K, Wolfstetter G, Anthonydhason V, Masudi T, Arefin B, Bemark M, Mendoza-Garcia P, Palmer RH. Patient-associated mutations in Drosophila Alk perturb neuronal differentiation and promote survival. Dis Model Mech 2022; 15:dmm049591. [PMID: 35972154 PMCID: PMC9403751 DOI: 10.1242/dmm.049591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 06/27/2022] [Indexed: 12/13/2022] Open
Abstract
Activating anaplastic lymphoma kinase (ALK) receptor tyrosine kinase (RTK) mutations occur in pediatric neuroblastoma and are associated with poor prognosis. To study ALK-activating mutations in a genetically controllable system, we employed CRIPSR/Cas9, incorporating orthologs of the human oncogenic mutations ALKF1174L and ALKY1278S in the Drosophila Alk locus. AlkF1251L and AlkY1355S mutant Drosophila exhibited enhanced Alk signaling phenotypes, but unexpectedly depended on the Jelly belly (Jeb) ligand for activation. Both AlkF1251L and AlkY1355S mutant larval brains displayed hyperplasia, represented by increased numbers of Alk-positive neurons. Despite this hyperplasic phenotype, no brain tumors were observed in mutant animals. We showed that hyperplasia in Alk mutants was not caused by significantly increased rates of proliferation, but rather by decreased levels of apoptosis in the larval brain. Using single-cell RNA sequencing, we identified perturbations during temporal fate specification in AlkY1355S mutant mushroom body lineages. These findings shed light on the role of Alk in neurodevelopmental processes and highlight the potential of Alk-activating mutations to perturb specification and promote survival in neuronal lineages. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Kathrin Pfeifer
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Georg Wolfstetter
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Vimala Anthonydhason
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Tafheem Masudi
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Badrul Arefin
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Mats Bemark
- Department of Microbiology and Immunology, Mucosal Immunobiology and Vaccine Center, Institute of Biomedicine, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Patricia Mendoza-Garcia
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Ruth H. Palmer
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-405 30 Gothenburg, Sweden
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12
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Pérez E, Venkatanarayan A, Lundell MJ. Hunchback prevents notch-induced apoptosis in the serotonergic lineage of Drosophila Melanogaster. Dev Biol 2022; 486:109-120. [PMID: 35381219 DOI: 10.1016/j.ydbio.2022.03.012] [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: 12/21/2021] [Revised: 03/16/2022] [Accepted: 03/30/2022] [Indexed: 11/19/2022]
Abstract
The serotonergic lineage (NB7-3) in the Drosophila ventral nerve cord produces six cells during neurogenesis. Four of the cells differentiate into neurons: EW1, EW2, EW3 and GW. The other two cells undergo apoptosis. This simple lineage provides an opportunity to examine genes that are required to induce or repress apoptosis during cell specification. Previous studies have shown that Notch signaling induces apoptosis within the NB7-3 lineage. The three EW neurons are protected from Notch-induced apoptosis by asymmetric distribution of Numb protein, an inhibitor of Notch signaling. In a numb1 mutant EW2 and EW3 undergo apoptosis. The EW1 and GW neurons survive even in a numb1 mutant background suggesting that these cells are protected from Notch-induced apoptosis by some factor other than Numb. The EW1 and GW neurons are mitotic sister cells, and uniquely express the transcription factor Hunchback. We present evidence that Hunchback prevents apoptosis in the NB7-3 lineage during normal CNS development and can rescue the two apoptotic cells in the lineage when it is ectopically expressed. We show that hunchback overexpression produces ectopic cells that express markers similar to the EW2 neuron and changes the expression pattern of the EW3 neuron to a EW2 neuron In addition we show that hunchback overexpression can override apoptosis that is genetically induced by the pro-apoptotic genes grim and hid.
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Affiliation(s)
- Ernesto Pérez
- Department of Biology, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
| | | | - Martha J Lundell
- Department of Biology, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA.
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13
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Liu KE, Raymond MH, Ravichandran KS, Kucenas S. Clearing Your Mind: Mechanisms of Debris Clearance After Cell Death During Neural Development. Annu Rev Neurosci 2022; 45:177-198. [PMID: 35226828 PMCID: PMC10157384 DOI: 10.1146/annurev-neuro-110920-022431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Neurodevelopment and efferocytosis have fascinated scientists for decades. How an organism builds a nervous system that is precisely tuned for efficient behaviors and survival and how it simultaneously manages constant somatic cell turnover are complex questions that have resulted in distinct fields of study. Although neurodevelopment requires the overproduction of cells that are subsequently pruned back, very few studies marry these fields to elucidate the cellular and molecular mechanisms that drive nervous system development through the lens of cell clearance. In this review, we discuss these fields to highlight exciting areas of future synergy. We first review neurodevelopment from the perspective of overproduction and subsequent refinement and then discuss who clears this developmental debris and the mechanisms that control these events. We then end with how a more deliberate merger of neurodevelopment and efferocytosis could reframe our understanding of homeostasis and disease and discuss areas of future study. Expected final online publication date for the Annual Review of Neuroscience, Volume 45 is July 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Kendra E Liu
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA; .,Program in Fundamental Neuroscience, University of Virginia, Charlottesville, Virginia, USA
| | - Michael H Raymond
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA; .,Center for Clearance, University of Virginia, Charlottesville, Virginia, USA
| | - Kodi S Ravichandran
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA; .,Center for Clearance, University of Virginia, Charlottesville, Virginia, USA.,Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, USA.,VIB-UGent Center for Inflammation Research and the Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Sarah Kucenas
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA; .,Program in Fundamental Neuroscience, University of Virginia, Charlottesville, Virginia, USA.,Department of Biology, University of Virginia, Charlottesville, Virginia, USA
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14
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Tiwari P, Rengarajan H, Saunders TE. Scaling of internal organs during Drosophila embryonic development. Biophys J 2021; 120:4264-4276. [PMID: 34087212 PMCID: PMC8516638 DOI: 10.1016/j.bpj.2021.05.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 05/04/2021] [Accepted: 05/27/2021] [Indexed: 11/20/2022] Open
Abstract
Many species show a diverse range of sizes; for example, domestic dogs have large variation in body mass. Yet, the internal structure of the organism remains similar, i.e., the system scales to organism size. Drosophila melanogaster has been a powerful model system for exploring scaling mechanisms. In the early embryo, gene expression boundaries scale very precisely to embryo length. Later in development, the adult wings grow with remarkable symmetry and scale well with animal size. Yet, our knowledge of whether internal organs initially scale to embryo size remains largely unknown. Here, we utilize artificially small Drosophila embryos to explore how three critical internal organs-the heart, hindgut, and ventral nerve cord (VNC)-adapt to changes in embryo morphology. We find that the heart scales precisely with embryo length. Intriguingly, reduction in cardiac cell length, rather than number, appears to be important in controlling heart length. The hindgut, which is the first chiral organ to form, displays scaling with embryo size under large-scale changes in the artificially smaller embryos but shows few hallmarks of scaling within wild-type size variation. Finally, the VNC only displays weak scaling behavior; even large changes in embryo geometry result in only small shifts in VNC length. This suggests that the VNC may have an intrinsic minimal length that is largely independent of embryo length. Overall, our work shows that internal organs can adapt to embryo size changes in Drosophila, but the extent to which they scale varies significantly between organs.
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Affiliation(s)
- Prabhat Tiwari
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | | | - Timothy E Saunders
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore, Singapore; Institute of Molecular and Cell Biology, A(∗)Star, Singapore, Singapore; Warwick Medical School, University of Warwick, Coventry, United Kingdom.
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15
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Simon F, Konstantinides N. Single-cell transcriptomics in the Drosophila visual system: Advances and perspectives on cell identity regulation, connectivity, and neuronal diversity evolution. Dev Biol 2021; 479:107-122. [PMID: 34375653 DOI: 10.1016/j.ydbio.2021.08.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 07/10/2021] [Accepted: 08/03/2021] [Indexed: 11/17/2022]
Abstract
The Drosophila visual system supports complex behaviors and shares many of its anatomical and molecular features with the vertebrate brain. Yet, it contains a much more manageable number of neurons and neuronal types. In addition to the extensive Drosophila genetic toolbox, this relative simplicity has allowed decades of work to yield a detailed account of its neuronal type diversity, morphology, connectivity and specification mechanisms. In the past three years, numerous studies have applied large scale single-cell transcriptomic approaches to the Drosophila visual system and have provided access to the complete gene expression profile of most neuronal types throughout development. This makes the fly visual system particularly well suited to perform detailed studies of the genetic mechanisms underlying the evolution and development of neuronal systems. Here, we highlight how these transcriptomic resources allow exploring long-standing biological questions under a new light. We first present the efforts made to characterize neuronal diversity in the Drosophila visual system and suggest ways to further improve this description. We then discuss current advances allowed by the single-cell datasets, and envisage how these datasets can be further leveraged to address fundamental questions regarding the regulation of neuronal identity, neuronal circuit development and the evolution of neuronal diversity.
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Affiliation(s)
- Félix Simon
- Department of Biology, New York University, New York, NY, 10003, USA.
| | - Nikolaos Konstantinides
- Department of Biology, New York University, New York, NY, 10003, USA; Institut Jacques Monod, Centre National de la Recherche Scientifique-UMR 7592, Université Paris Diderot, Paris, France.
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16
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Wu B, He L, Xiao Y, Du J, Wang X, Zhao Z. Juvenile hormone receptor MET regulates sleep and neuronal morphology via glial-neuronal crosstalk. J Genet Genomics 2021; 48:706-715. [PMID: 34376377 DOI: 10.1016/j.jgg.2021.04.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/05/2021] [Accepted: 04/14/2021] [Indexed: 11/24/2022]
Abstract
Juvenile hormone (JH) is one of the most important hormones in insects since it is essential for insect development. The mechanism by which JH affects the central nervous system still remains a mystery. In this study, we demonstrate that one of the JH receptors, Methoprene-tolerant (Met), is important for the control of neurite development and sleep behavior in Drosophila. With the identification of Met-expressing glial cells, the mechanism that Met negatively controls the mushroom body (MB) β lobes fusion and positively maintains pigment-dispersing factor sLNvs projection pruning has been established. Furthermore, despite the developmental effects, Met can also maintain nighttime sleep in a development-independent manner through the α/β lobe of MB. Combining analyses of neuronal morphology and entomological behavior, this study advances our understanding of how the JH receptor regulates the nervous system.
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Affiliation(s)
- Binbin Wu
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Lei He
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Yutong Xiao
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Juan Du
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Xiaoxiao Wang
- College of Life Sciences, Hebei University, Baoding 071002, China.
| | - Zhangwu Zhao
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China.
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17
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Guntur AR, Venkatanarayan A, Gangula S, Lundell MJ. Zfh-2 facilitates Notch-induced apoptosis in the CNS and appendages of Drosophila melanogaster. Dev Biol 2021; 475:65-79. [PMID: 33705738 DOI: 10.1016/j.ydbio.2021.02.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/22/2021] [Accepted: 02/22/2021] [Indexed: 12/26/2022]
Abstract
Apoptosis is a fundamental remodeling process for most tissues during development. In this manuscript we examine a pro-apoptotic function for the Drosophila DNA binding protein Zfh-2 during development of the central nervous system (CNS) and appendages. In the CNS we find that a loss-of-function zfh-2 allele gives an overall reduction of apoptotic cells in the CNS, and an altered pattern of expression for the axonal markers 22C10 and FasII. This same loss-of-function zfh-2 allele causes specific cells in the NB7-3 lineage of the CNS that would normally undergo apoptosis to be inappropriately maintained, whereas a gain-of-function zfh-2 allele has the opposite effect, resulting in a loss of normal NB 7-3 progeny. We also demonstrate that Zfh-2 and Hunchback reciprocally repress each other's gene expression which limits apoptosis to later born progeny of the NB7-3 lineage. Apoptosis is also required for proper segmentation of the fly appendages. We find that Zfh-2 co-localizes with apoptotic cells in the folds of the imaginal discs and presumptive cuticular joints. A reduction of Zfh-2 levels with RNAi inhibits expression of the pro-apoptotic gene reaper, and produces abnormal joints in the leg, antenna and haltere. Apoptosis has previously been shown to be activated by Notch signaling in both the NB7-3 CNS lineage and the appendage joints. Our results indicate that Zfh-2 facilitates Notch-induced apoptosis in these structures.
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Affiliation(s)
- Ananya R Guntur
- Department of Biology, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
| | | | - Sindhura Gangula
- Department of Biology, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA
| | - Martha J Lundell
- Department of Biology, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249, USA.
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18
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Zhang L, Li D, Zhang J, Yan P, Liu X, Wang L, Khan A, Liu Z, Mu J, Xu J, Niu B, Xie J. Excessive apoptosis and ROS induced by ethionine affect neural cell viability and differentiation. Acta Biochim Biophys Sin (Shanghai) 2020; 52:1156-1165. [PMID: 33083831 PMCID: PMC7751163 DOI: 10.1093/abbs/gmaa093] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/01/2020] [Accepted: 06/05/2020] [Indexed: 12/24/2022] Open
Abstract
The central nervous system (CNS) diseases are still a major cause of morbidity and mortality throughout the world, which imposes heavy burden on the development of society. Ethionine is a non-proteinogenic amino acid having similar chemical structure and activity to that of methionine, with which it competes. Previous studies have confirmed that ethionine affects various cellular functions by inhibiting the biosynthesis of proteins, RNA, DNA, and phospholipids, or all of them. The relationship of ethionine with some CNS diseases, including neural tube defects, has been investigated recently. However, the detailed effects of ethionine on the nerve cell bioactivities and the underlying mechanisms have not been fully explored. Herein, we systematically investigated the influences of ethionine on the proliferation, differentiation, and apoptosis of neural stem cells (NSCs) and post-mitotic nerve cells. We demonstrated that ethionine inhibited cell viability by disrupting the balance between proliferation and apoptosis, prevented NSCs from differentiating into neurons and astrocytes, and blocked cell progression from G1 to S phase via reducing cyclin D1 function in nerve cells including NSCs, a mouse hippocampal neuron cell line (HT-22), and a mouse brain neuroma cell line (Neuro-2a). We speculated that the inhibitory effect of ethionine on cell viability and differentiation are associated with increased reactive oxygen species production. Our results also supported the concept that ethionine may be an underlying cause of abnormal folate metabolism-induced CNS diseases. Our findings may provide important direction for the application of abnormal folate metabolism-induced CNS diseases in future NSC-based therapies.
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Affiliation(s)
- Li Zhang
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
- Department of General Surgery, The First Affiliated Hospital of Shanxi Medical University, Taiyuan 030001, China
| | - Dandan Li
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
| | - Juan Zhang
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
| | - Ping Yan
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
| | - Xueqin Liu
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
| | - Lei Wang
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
| | - Ajab Khan
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
| | - Zhizhen Liu
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
| | - Jianbing Mu
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852, USA
| | - Jun Xu
- Department of General Surgery, The First Affiliated Hospital of Shanxi Medical University, Taiyuan 030001, China
| | - Bo Niu
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
- Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing 100020, China
| | - Jun Xie
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan 030001, China
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19
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Pop S, Chen CL, Sproston CJ, Kondo S, Ramdya P, Williams DW. Extensive and diverse patterns of cell death sculpt neural networks in insects. eLife 2020; 9:59566. [PMID: 32894223 PMCID: PMC7535934 DOI: 10.7554/elife.59566] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/06/2020] [Indexed: 11/20/2022] Open
Abstract
Changes to the structure and function of neural networks are thought to underlie the evolutionary adaptation of animal behaviours. Among the many developmental phenomena that generate change programmed cell death (PCD) appears to play a key role. We show that cell death occurs continuously throughout insect neurogenesis and happens soon after neurons are born. Mimicking an evolutionary role for increasing cell numbers, we artificially block PCD in the medial neuroblast lineage in Drosophila melanogaster, which results in the production of ‘undead’ neurons with complex arborisations and distinct neurotransmitter identities. Activation of these ‘undead’ neurons and recordings of neural activity in behaving animals demonstrate that they are functional. Focusing on two dipterans which have lost flight during evolution we reveal that reductions in populations of flight interneurons are likely caused by increased cell death during development. Our findings suggest that the evolutionary modulation of death-based patterning could generate novel network configurations. Just like a sculptor chips away at a block of granite to make a statue, the nervous system reaches its mature state by eliminating neurons during development through a process known as programmed cell death. In vertebrates, this mechanism often involves newly born neurons shrivelling away and dying if they fail to connect with others during development. Most studies in insects have focused on the death of neurons that occurs at metamorphosis, during the transition between larva to adult, when cells which are no longer needed in the new life stage are eliminated. Pop et al. harnessed a newly designed genetic probe to point out that, in fruit flies, programmed cell death of neurons at metamorphosis is not the main mechanism through which cells die. Rather, the majority of cell death takes place as soon as neurons are born throughout all larval stages, when most of the adult nervous system is built. To gain further insight into the role of this ‘early’ cell death, the neurons were stopped from dying, showing that these cells were able to reach maturity and function. Together, these results suggest that early cell death may be a mechanism fine-tuned by evolution to shape the many and varied nervous systems of insects. To explore this, Pop et al. looked for hints of early cell death in relatives of fruit flies that are unable to fly: the swift lousefly and the bee lousefly. This analysis showed that early cell death is likely to occur in these two insects, but it follows different patterns than in the fruit fly, potentially targeting the neurons that would have controlled flight in these flies’ ancestors. Brains are the product of evolution: learning how neurons change their connections and adapt could help us understand how the brain works in health and disease. This knowledge may also be relevant to work on artificial intelligence, a discipline that often bases the building blocks and connections in artificial ‘brains’ on how neurons communicate with one another.
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Affiliation(s)
- Sinziana Pop
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Chin-Lin Chen
- Neuroengineering Laboratory, Brain Mind Institute and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Connor J Sproston
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
| | - Shu Kondo
- Genetic Strains Research Center, National Institute of Genetics, Shizuoka, Japan
| | - Pavan Ramdya
- Neuroengineering Laboratory, Brain Mind Institute and Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Darren W Williams
- Centre for Developmental Neurobiology, King's College London, London, United Kingdom
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20
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Abstract
Development encapsulates the morphogenesis of an organism from a single fertilized cell to a functional adult. A critical part of development is the specification of organ forms. Beyond the molecular control of morphogenesis, shape in essence entails structural constraints and thus mechanics. Revisiting recent results in biophysics and development, and comparing animal and plant model systems, we derive key overarching principles behind the formation of organs across kingdoms. In particular, we highlight how growing organs are active rather than passive systems and how such behavior plays a role in shaping the organ. We discuss the importance of considering different scales in understanding how organs form. Such an integrative view of organ development generates new questions while calling for more cross-fertilization between scientific fields and model system communities.
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Affiliation(s)
- O Hamant
- Laboratoire de Reproduction et Développement des Plantes, École normale supérieure (ENS) de Lyon, Université Claude Bernard Lyon (UCBL), Institut national de recherche pour l'agriculture, l'alimentation et l'environnement (INRAE), CNRS, Université de Lyon, 69364 Lyon, France;
| | - T E Saunders
- Mechanobiology Institute and Department of Biological Sciences, National University of Singapore, Singapore 117411; .,Institute of Molecular and Cell Biology, A*Star, Proteos, Singapore 138673
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21
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Hailstone M, Waithe D, Samuels TJ, Yang L, Costello I, Arava Y, Robertson E, Parton RM, Davis I. CytoCensus, mapping cell identity and division in tissues and organs using machine learning. eLife 2020; 9:e51085. [PMID: 32423529 PMCID: PMC7237217 DOI: 10.7554/elife.51085] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 03/17/2020] [Indexed: 01/16/2023] Open
Abstract
A major challenge in cell and developmental biology is the automated identification and quantitation of cells in complex multilayered tissues. We developed CytoCensus: an easily deployed implementation of supervised machine learning that extends convenient 2D 'point-and-click' user training to 3D detection of cells in challenging datasets with ill-defined cell boundaries. In tests on such datasets, CytoCensus outperforms other freely available image analysis software in accuracy and speed of cell detection. We used CytoCensus to count stem cells and their progeny, and to quantify individual cell divisions from time-lapse movies of explanted Drosophila larval brains, comparing wild-type and mutant phenotypes. We further illustrate the general utility and future potential of CytoCensus by analysing the 3D organisation of multiple cell classes in Zebrafish retinal organoids and cell distributions in mouse embryos. CytoCensus opens the possibility of straightforward and robust automated analysis of developmental phenotypes in complex tissues.
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Affiliation(s)
- Martin Hailstone
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
| | - Dominic Waithe
- Wolfson Imaging Center & MRC WIMM Centre for Computational Biology MRC Weather all Institute of Molecular Medicine University of OxfordOxfordUnited Kingdom
| | - Tamsin J Samuels
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
| | - Lu Yang
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
| | - Ita Costello
- The Dunn School of Pathology,University of OxfordOxfordUnited Kingdom
| | - Yoav Arava
- Department of Biology, Technion - Israel Institute of TechnologyHaifaIsrael
| | | | - Richard M Parton
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
- Micron Advanced Bioimaging Unit, Department of Biochemistry, University of OxfordOxfordUnited Kingdom
| | - Ilan Davis
- Department of Biochemistry, University of OxfordOxfordUnited Kingdom
- Micron Advanced Bioimaging Unit, Department of Biochemistry, University of OxfordOxfordUnited Kingdom
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22
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Kuzmicz-Kowalska K, Kicheva A. Regulation of size and scale in vertebrate spinal cord development. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 10:e383. [PMID: 32391980 PMCID: PMC8244110 DOI: 10.1002/wdev.383] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/25/2020] [Accepted: 04/16/2020] [Indexed: 12/13/2022]
Abstract
All vertebrates have a spinal cord with dimensions and shape specific to their species. Yet how species‐specific organ size and shape are achieved is a fundamental unresolved question in biology. The formation and sculpting of organs begins during embryonic development. As it develops, the spinal cord extends in anterior–posterior direction in synchrony with the overall growth of the body. The dorsoventral (DV) and apicobasal lengths of the spinal cord neuroepithelium also change, while at the same time a characteristic pattern of neural progenitor subtypes along the DV axis is established and elaborated. At the basis of these changes in tissue size and shape are biophysical determinants, such as the change in cell number, cell size and shape, and anisotropic tissue growth. These processes are controlled by global tissue‐scale regulators, such as morphogen signaling gradients as well as mechanical forces. Current challenges in the field are to uncover how these tissue‐scale regulatory mechanisms are translated to the cellular and molecular level, and how regulation of distinct cellular processes gives rise to an overall defined size. Addressing these questions will help not only to achieve a better understanding of how size is controlled, but also of how tissue size is coordinated with the specification of pattern. This article is categorized under:Establishment of Spatial and Temporal Patterns > Regulation of Size, Proportion, and Timing Signaling Pathways > Global Signaling Mechanisms Nervous System Development > Vertebrates: General Principles
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23
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Lee G, Sehgal R, Wang Z, Park JH. Ultraspiracle-independent anti-apoptotic function of ecdysone receptors is required for the survival of larval peptidergic neurons via suppression of grim expression in Drosophila melanogaster. Apoptosis 2020; 24:256-268. [PMID: 30637539 DOI: 10.1007/s10495-019-01514-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In Drosophila melanogaster a significant number of heterogenous larval neurons in the central nervous system undergo metamorphosis-associated programmed cell death, termed metamorphoptosis. Interestingly distinct groups of doomed larval neurons are eliminated at different metamorphic phases. Although ecdysone hormonal signaling via nuclear ecdysone receptors (EcRs) is known to orchestrate the neuronal metamorphoptosis, little is known about how this signaling controls such diverse neuronal responses. Crustacean cardioactive peptide (CCAP)-producing neurons in the ventral nerve cord are developmentally programmed to die shortly after adult emergence. In this study, we show that disruption of endogenous EcR function by ectopic expression of dominant negative forms of EcRs (EcRDN) causes premature death of larval CCAP neurons in a caspase-dependent manner. This event is rescued by co-expression of individual EcR isoforms. Furthermore, larval CCAP neurons are largely normal in ecr mutants lacking either EcR-A or EcR-B isoforms, suggesting that EcR isoforms redundantly function to protect larval CCAP neurons. Of surprise, a role of Ultraspiracle (Usp), a canonical partner of EcR, is dispensable in the protection of CCAP neurons, whereas both EcR and Usp are required for inducing metamorphoptosis of vCrz neurons shortly after prepupal formation. As a downstream, grim is an essential cell death gene for the EcRDN-mediated CCAP neuronal death, while either hid or rpr function is dispensable. Together, our results suggest that Usp-independent EcR actions protect CCAP neurons from their premature death by repressing grim expression until their normally scheduled apoptosis at post-emergence. Our studies highlight two opposite roles played by EcR function for metamorphoptosis of two different peptidergic neuronal groups, proapoptotic (vCrz) versus antiapoptotic (CCAP), and propose that distinct death timings of doomed larval neurons are determined by differential signaling mechanisms involving EcR.
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Affiliation(s)
- Gyunghee Lee
- Department of Biochemistry and Cellular and Molecular Biology and NeuroNet Research Center, University of Tennessee, Knoxville, TN, 37996, USA
| | - Ritika Sehgal
- Department of Biochemistry and Cellular and Molecular Biology and NeuroNet Research Center, University of Tennessee, Knoxville, TN, 37996, USA
| | - Zixing Wang
- UT-ORNL Graduate School of Genome Science and Technology Program, University of Tennessee, Knoxville, TN, 37996, USA
| | - Jae H Park
- Department of Biochemistry and Cellular and Molecular Biology and NeuroNet Research Center, University of Tennessee, Knoxville, TN, 37996, USA. .,UT-ORNL Graduate School of Genome Science and Technology Program, University of Tennessee, Knoxville, TN, 37996, USA.
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Prieto-Godino LL, Silbering AF, Khallaf MA, Cruchet S, Bojkowska K, Pradervand S, Hansson BS, Knaden M, Benton R. Functional integration of "undead" neurons in the olfactory system. SCIENCE ADVANCES 2020; 6:eaaz7238. [PMID: 32195354 PMCID: PMC7065876 DOI: 10.1126/sciadv.aaz7238] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 12/03/2019] [Indexed: 05/05/2023]
Abstract
Programmed cell death (PCD) is widespread during neurodevelopment, eliminating the surpluses of neuronal production. Using the Drosophila olfactory system, we examined the potential of cells fated to die to contribute to circuit evolution. Inhibition of PCD is sufficient to generate new cells that express neural markers and exhibit odor-evoked activity. These "undead" neurons express a subset of olfactory receptors that is enriched for relatively recent receptor duplicates and includes some normally found in different chemosensory organs and life stages. Moreover, undead neuron axons integrate into the olfactory circuitry in the brain, forming novel receptor/glomerular couplings. Comparison of homologous olfactory lineages across drosophilids reveals natural examples of fate change from death to a functional neuron. Last, we provide evidence that PCD contributes to evolutionary differences in carbon dioxide-sensing circuit formation in Drosophila and mosquitoes. These results reveal the remarkable potential of alterations in PCD patterning to evolve new neural pathways.
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Affiliation(s)
- Lucia L. Prieto-Godino
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
- The Francis Crick Institute, London NW1 1BF, UK
| | - Ana F. Silbering
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Mohammed A. Khallaf
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
| | - Steeve Cruchet
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Karolina Bojkowska
- Genomic Technologies Facility, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Sylvain Pradervand
- Genomic Technologies Facility, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
- Vital-IT Group, Swiss Institute of Bioinformatics, CH-1015 Lausanne, Switzerland
| | - Bill S. Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
| | - Markus Knaden
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
| | - Richard Benton
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
- Corresponding author.
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25
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Crews ST. Drosophila Embryonic CNS Development: Neurogenesis, Gliogenesis, Cell Fate, and Differentiation. Genetics 2019; 213:1111-1144. [PMID: 31796551 PMCID: PMC6893389 DOI: 10.1534/genetics.119.300974] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 09/26/2019] [Indexed: 01/04/2023] Open
Abstract
The Drosophila embryonic central nervous system (CNS) is a complex organ consisting of ∼15,000 neurons and glia that is generated in ∼1 day of development. For the past 40 years, Drosophila developmental neuroscientists have described each step of CNS development in precise molecular genetic detail. This has led to an understanding of how an intricate nervous system emerges from a single cell. These studies have also provided important, new concepts in developmental biology, and provided an essential model for understanding similar processes in other organisms. In this article, the key genes that guide Drosophila CNS development and how they function is reviewed. Features of CNS development covered in this review are neurogenesis, gliogenesis, cell fate specification, and differentiation.
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Affiliation(s)
- Stephen T Crews
- Department of Biochemistry and Biophysics, Integrative Program for Biological and Genome Sciences, School of Medicine, The University of North Carolina at Chapel Hill, North Carolina 27599
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26
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Dulovic-Mahlow M, Trinh J, Kandaswamy KK, Braathen GJ, Di Donato N, Rahikkala E, Beblo S, Werber M, Krajka V, Busk ØL, Baumann H, Al-Sannaa NA, Hinrichs F, Affan R, Navot N, Al Balwi MA, Oprea G, Holla ØL, Weiss ME, Jamra RA, Kahlert AK, Kishore S, Tveten K, Vos M, Rolfs A, Lohmann K. De Novo Variants in TAOK1 Cause Neurodevelopmental Disorders. Am J Hum Genet 2019; 105:213-220. [PMID: 31230721 DOI: 10.1016/j.ajhg.2019.05.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 05/08/2019] [Indexed: 02/08/2023] Open
Abstract
De novo variants represent a significant cause of neurodevelopmental delay and intellectual disability. A genetic basis can be identified in only half of individuals who have neurodevelopmental disorders (NDDs); this indicates that additional causes need to be elucidated. We compared the frequency of de novo variants in patient-parent trios with (n = 2,030) versus without (n = 2,755) NDDs. We identified de novo variants in TAOK1 (thousand and one [TAO] amino acid kinase 1), which encodes the serine/threonine-protein kinase TAO1, in three individuals with NDDs but not in persons who did not have NDDs. Through further screening and the use of GeneMatcher, five additional individuals with NDDs were found to have de novo variants. All eight variants were absent from gnomAD (Genome Aggregation Database). The variant carriers shared a non-specific phenotype of developmental delay, and six individuals had additional muscular hypotonia. We established a fibroblast line of one mutation carrier, and we demonstrated that reduced mRNA levels of TAOK1 could be increased upon cycloheximide treatment. These results indicate nonsense-mediated mRNA decay. Further, there was neither detectable phosphorylated TAO1 kinase nor phosphorylated tau in these cells, and mitochondrial morphology was altered. Knockdown of the ortholog gene Tao1 (Tao, CG14217) in Drosophila resulted in delayed early development. The majority of the Tao1-knockdown flies did not survive beyond the third instar larval stage. When compared to control flies, Tao1 knockdown flies revealed changed morphology of the ventral nerve cord and the neuromuscular junctions as well as a decreased number of endings (boutons). Furthermore, mitochondria in mutant flies showed altered distribution and decreased size in axons of motor neurons. Thus, we provide compelling evidence that de novo variants in TAOK1 cause NDDs.
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27
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Effects of norfloxacin exposure on neurodevelopment of zebrafish (Danio rerio) embryos. Neurotoxicology 2019; 72:85-94. [DOI: 10.1016/j.neuro.2019.02.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 01/21/2019] [Accepted: 02/08/2019] [Indexed: 12/11/2022]
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28
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Miyares RL, Lee T. Temporal control of Drosophila central nervous system development. Curr Opin Neurobiol 2018; 56:24-32. [PMID: 30500514 DOI: 10.1016/j.conb.2018.10.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 10/30/2018] [Indexed: 12/19/2022]
Abstract
A complex nervous system requires precise numbers of various neuronal types produced with exquisite spatiotemporal control. This striking diversity is generated by a limited number of neural stem cells (NSC), where spatial and temporal patterning intersect. Drosophila is a genetically tractable model system that has significant advantages for studying stem cell biology and neuronal fate specification. Here we review the latest findings in the rich literature of temporal patterning of neuronal identity in the Drosophila central nervous system. Rapidly changing consecutive transcription factors expressed in NSCs specify short series of neurons with considerable differences. More slowly progressing changes are orchestrated by NSC intrinsic temporal factor gradients which integrate extrinsic signals to coordinate nervous system and organismal development.
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Affiliation(s)
- Rosa Linda Miyares
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Tzumin Lee
- Howard Hughes Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA.
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29
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Yalonetskaya A, Mondragon AA, Elguero J, McCall K. I Spy in the Developing Fly a Multitude of Ways to Die. J Dev Biol 2018; 6:E26. [PMID: 30360387 PMCID: PMC6316796 DOI: 10.3390/jdb6040026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 12/11/2022] Open
Abstract
Cell proliferation and cell death are two opposing, yet complementary fundamental processes in development. Cell proliferation provides new cells, while developmental programmed cell death adjusts cell numbers and refines structures as an organism grows. Apoptosis is the best-characterized form of programmed cell death; however, there are many other non-apoptotic forms of cell death that occur throughout development. Drosophila is an excellent model for studying these varied forms of cell death given the array of cellular, molecular, and genetic techniques available. In this review, we discuss select examples of apoptotic and non-apoptotic cell death that occur in different tissues and at different stages of Drosophila development. For example, apoptosis occurs throughout the nervous system to achieve an appropriate number of neurons. Elsewhere in the fly, non-apoptotic modes of developmental cell death are employed, such as in the elimination of larval salivary glands and midgut during metamorphosis. These and other examples discussed here demonstrate the versatility of Drosophila as a model organism for elucidating the diverse modes of programmed cell death.
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Affiliation(s)
- Alla Yalonetskaya
- Cell and Molecular Biology Program, Department of Biology, 5 Cummington Mall, Boston University, Boston, MA 02215, USA.
| | - Albert A Mondragon
- Molecular Biology, Cell Biology, and Biochemistry Program, 5 Cummington Mall, Boston University, Boston, MA 02215, USA.
| | - Johnny Elguero
- Cell and Molecular Biology Program, Department of Biology, 5 Cummington Mall, Boston University, Boston, MA 02215, USA.
| | - Kimberly McCall
- Cell and Molecular Biology Program, Department of Biology, 5 Cummington Mall, Boston University, Boston, MA 02215, USA.
- Molecular Biology, Cell Biology, and Biochemistry Program, 5 Cummington Mall, Boston University, Boston, MA 02215, USA.
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30
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Harding K, White K. Drosophila as a Model for Developmental Biology: Stem Cell-Fate Decisions in the Developing Nervous System. J Dev Biol 2018; 6:E25. [PMID: 30347666 PMCID: PMC6315890 DOI: 10.3390/jdb6040025] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 10/16/2018] [Accepted: 10/17/2018] [Indexed: 12/25/2022] Open
Abstract
Stem cells face a diversity of choices throughout their lives. At specific times, they may decide to initiate cell division, terminal differentiation, or apoptosis, or they may enter a quiescent non-proliferative state. Neural stem cells in the Drosophila central nervous system do all of these, at stereotypical times and anatomical positions during development. Distinct populations of neural stem cells offer a unique system to investigate the regulation of a particular stem cell behavior, while comparisons between populations can lead us to a broader understanding of stem cell identity. Drosophila is a well-described and genetically tractable model for studying fundamental stem cell behavior and the mechanisms that underlie cell-fate decisions. This review will focus on recent advances in our understanding of the factors that contribute to distinct stem cell-fate decisions within the context of the Drosophila nervous system.
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Affiliation(s)
- Katherine Harding
- Massachusetts General Hospital Cutaneous Biology Research Center, Harvard Medical School, Boston, MA 02129, USA
| | - Kristin White
- Massachusetts General Hospital Cutaneous Biology Research Center, Harvard Medical School, Boston, MA 02129, USA.
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31
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Konstantinides N, Degabriel S, Desplan C. Neuro-evo-devo in the single cell sequencing era. CURRENT OPINION IN SYSTEMS BIOLOGY 2018; 11:32-40. [PMID: 30886939 PMCID: PMC6419771 DOI: 10.1016/j.coisb.2018.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The nervous system represents the most complex tissue in animals. How this complexity evolved has been a challenging question to address. The explosion in single cell sequencing techniques, the development of new algorithms to cluster single cells into cell types, along with powerful tools for drawing developmental trajectories offer a unique opportunity to compare homologous cell types between species. They further permit the identification of key developmental points and transcription factors that can lead to the evolution of new cell types. At the same time, the ease of use and efficiency of CRISPR genome editing technology allow validation of predicted regulators. This promises exciting developments in the next few years in the field of neuronal evolution and development.
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Affiliation(s)
| | - Sophie Degabriel
- Department of Biology, New York University, New York, NY 10003, USA
| | - Claude Desplan
- Department of Biology, New York University, New York, NY 10003, USA
- New York University Abu Dhabi, Saadiyat Island, Abu Dhabi, UAE
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32
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Konstantinides N, Kapuralin K, Fadil C, Barboza L, Satija R, Desplan C. Phenotypic Convergence: Distinct Transcription Factors Regulate Common Terminal Features. Cell 2018; 174:622-635.e13. [PMID: 29909983 PMCID: PMC6082168 DOI: 10.1016/j.cell.2018.05.021] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 03/28/2018] [Accepted: 05/09/2018] [Indexed: 12/25/2022]
Abstract
Transcription factors regulate the molecular, morphological, and physiological characteristics of neurons and generate their impressive cell-type diversity. To gain insight into the general principles that govern how transcription factors regulate cell-type diversity, we used large-scale single-cell RNA sequencing to characterize the extensive cellular diversity in the Drosophila optic lobes. We sequenced 55,000 single cells and assigned them to 52 clusters. We validated and annotated many clusters using RNA sequencing of FACS-sorted single-cell types and cluster-specific genes. To identify transcription factors responsible for inducing specific terminal differentiation features, we generated a "random forest" model, and we showed that the transcription factors Apterous and Traffic-jam are required in many but not all cholinergic and glutamatergic neurons, respectively. In fact, the same terminal characters often can be regulated by different transcription factors in different cell types, arguing for extensive phenotypic convergence. Our data provide a deep understanding of the developmental and functional specification of a complex brain structure.
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Affiliation(s)
| | - Katarina Kapuralin
- New York University Abu Dhabi, Saadiyat Island, Abu Dhabi, United Arab Emirates
| | - Chaimaa Fadil
- Department of Biology, New York University, New York, NY 10003, USA; New York University Abu Dhabi, Saadiyat Island, Abu Dhabi, United Arab Emirates
| | - Luendreo Barboza
- Department of Biology, New York University, New York, NY 10003, USA; Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA; New York Genome Center, New York, NY 10013, USA
| | - Rahul Satija
- Department of Biology, New York University, New York, NY 10003, USA; New York Genome Center, New York, NY 10013, USA
| | - Claude Desplan
- Department of Biology, New York University, New York, NY 10003, USA; New York University Abu Dhabi, Saadiyat Island, Abu Dhabi, United Arab Emirates.
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33
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Hara Y, Sudo T, Togane Y, Akagawa H, Tsujimura H. Cell death in neural precursor cells and neurons before neurite formation prevents the emergence of abnormal neural structures in the Drosophila optic lobe. Dev Biol 2018; 436:28-41. [PMID: 29447906 DOI: 10.1016/j.ydbio.2018.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 01/15/2018] [Accepted: 02/07/2018] [Indexed: 11/30/2022]
Abstract
Programmed cell death is a conserved strategy for neural development both in vertebrates and invertebrates and is recognized at various developmental stages in the brain from neurogenesis to adulthood. To understand the development of the central nervous system, it is essential to reveal not only molecular mechanisms but also the role of neural cell death (Pinto-Teixeira et al., 2016). To understand the role of cell death in neural development, we investigated the effect of inhibition of cell death on optic lobe development. Our data demonstrate that, in the optic lobe of Drosophila, cell death occurs in neural precursor cells and neurons before neurite formation and functions to prevent various developmental abnormalities. When neuronal cell death was inhibited by an effector caspase inhibitor, p35, multiple abnormal neuropil structures arose during optic lobe development-e.g., enlarged or fused neuropils, misrouted neurons and abnormal neurite lumps. Inhibition of cell death also induced morphogenetic defects in the lamina and medulla development-e.g., failures in the separation of the lamina and medulla cortices and the medulla rotation. These defects were reproduced in the mutant of an initiator caspase, dronc. If cell death was a mechanism for removing the abnormal neuropil structures, we would also expect to observe them in mutants defective for corpse clearance. However, they were not observed in these mutants. When dead cell-membranes were visualized with Apoliner, they were observed only in cortices and not in neuropils. These results suggest that the cell death occurs before mature neurite formation. Moreover, we found that inhibition of cell death induced ectopic neuroepithelial cells, neuroblasts and ganglion mother cells in late pupal stages, at sites where the outer and inner proliferation centers were located at earlier developmental stages. Caspase-3 activation was observed in the neuroepithelial cells and neuroblasts in the proliferation centers. These results indicate that cell death is required for elimination of the precursor cells composing the proliferation centers. This study substantiates an essential role of early neural cell death for ensuring normal development of the central nervous system.
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Affiliation(s)
- Yusuke Hara
- Developmental Biology, Tokyo University of Agriculture and Technology, Japan; Graduate School of Life Sciences, Tohoku University, Japan.
| | - Tatsuya Sudo
- Developmental Biology, Tokyo University of Agriculture and Technology, Japan
| | - Yu Togane
- Developmental Biology, Tokyo University of Agriculture and Technology, Japan
| | - Hiromi Akagawa
- Developmental Biology, Tokyo University of Agriculture and Technology, Japan
| | - Hidenobu Tsujimura
- Developmental Biology, Tokyo University of Agriculture and Technology, Japan
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34
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Novel Triazole linked 2-phenyl benzoxazole derivatives induce apoptosis by inhibiting miR-2, miR-13 and miR-14 function in Drosophila melanogaster. Apoptosis 2018; 22:786-799. [PMID: 28401354 DOI: 10.1007/s10495-017-1367-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Apoptosis is an important phenomenon in multi cellular organisms for maintaining tissue homeostasis and embryonic development. Defect in apoptosis leads to a number of disorders like- autoimmune disorder, immunodeficiency and cancer. 21-22 nucleotides containing micro RNAs (miRNAs/miRs) function as a crucial regulator of apoptosis alike other cellular pathways. Recently, small molecules have been identified as a potent inducer of apoptosis. In this study, we have identified novel Triazole linked 2-phenyl benzoxazole derivatives (13j and 13h) as a negative regulator of apoptosis inhibiting micro RNAs (miR-2, miR-13 and miR-14) in a well established in vivo model Drosophila melanogaster where the process of apoptosis is very similar to human apoptosis. These compounds inhibit miR-2, miR-13 and miR-14 activity at their target sites, which induce an increased caspase activity, and in turn influence the caspase dependent apoptotic pathway. These two compounds also increase the mitochondrial reactive oxygen species (ROS) level to trigger apoptotic cell death.
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35
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Torroglosa A, Villalba-Benito L, Fernández RM, Moya-Jiménez MJ, Antiñolo G, Borrego S. Dnmt3b knock-down in enteric precursors reveals a possible mechanism by which this de novo methyltransferase is involved in the enteric nervous system development and the onset of Hirschsprung disease. Oncotarget 2017; 8:106443-106453. [PMID: 29290961 PMCID: PMC5739746 DOI: 10.18632/oncotarget.22473] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/27/2017] [Indexed: 12/30/2022] Open
Abstract
Hirschsprung disease (HSCR, OMIM 142623) is a pathology that shows a lack of enteric ganglia along of the distal gastrointestinal tract. This aganglionosis is attributed to an abnormal proliferation, migration, differentiation and/or survival of enteric precursor cells (EPCs) derived from neural crest cells (NCCs) during the enteric nervous system (ENS) embryogenesis. DNMT3b de novo methyltransferase is associated with NCCs development and has been shown to be implicated in ENS formation as well as in HSCR. In this study we have aimed to elucidate the specific mechanism underlying the DNMT3b role in such processes. We have performed the knockdown of Dnmt3b expression (Dnmt3b-KD) in enteric precursor cells (EPCs) to clarify its role on these cells in vitro. Moreover, we have analyzed several signaling pathways to determine the mechanisms responsible for the effect caused by Dnmt3b-KD in EPCs. Our results seem to support that Dnmt3b-KD promotes an increase EPCs proliferation that may be mediated by P53 and P21 activity, since both proteins were observed to be down-regulated in our Dnmt3b-KD cultures. Moreover, we observed a down-regulation of P53 and P21 in HSCR patients. These results lead us to propose that DNMT3b could be involved in HSCR through P53 and P21 activity.
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Affiliation(s)
- Ana Torroglosa
- Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío, CSIC, University of Seville, Seville 41013, Spain.,Center for Biomedical Network Research on Rare Diseases, Seville 41013, Spain
| | - Leticia Villalba-Benito
- Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío, CSIC, University of Seville, Seville 41013, Spain.,Center for Biomedical Network Research on Rare Diseases, Seville 41013, Spain
| | - Raquel María Fernández
- Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío, CSIC, University of Seville, Seville 41013, Spain.,Center for Biomedical Network Research on Rare Diseases, Seville 41013, Spain
| | | | - Guillermo Antiñolo
- Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío, CSIC, University of Seville, Seville 41013, Spain.,Center for Biomedical Network Research on Rare Diseases, Seville 41013, Spain
| | - Salud Borrego
- Department of Genetics, Reproduction and Fetal Medicine, Institute of Biomedicine of Seville, University Hospital Virgen del Rocío, CSIC, University of Seville, Seville 41013, Spain.,Center for Biomedical Network Research on Rare Diseases, Seville 41013, Spain
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36
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Just W. . FEBS Lett 2016; 590:2325-6. [DOI: 10.1002/1873-3468.12305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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