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Haynes PR, Pyfrom ES, Li Y, Stein C, Cuddapah VA, Jacobs JA, Yue Z, Sehgal A. A neuron-glia lipid metabolic cycle couples daily sleep to mitochondrial homeostasis. Nat Neurosci 2024; 27:666-678. [PMID: 38360946 PMCID: PMC11001586 DOI: 10.1038/s41593-023-01568-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 12/29/2023] [Indexed: 02/17/2024]
Abstract
Sleep is thought to be restorative to brain energy homeostasis, but it is not clear how this is achieved. We show here that Drosophila glia exhibit a daily cycle of glial mitochondrial oxidation and lipid accumulation that is dependent on prior wake and requires the Drosophila APOE orthologs NLaz and GLaz, which mediate neuron-glia lipid transfer. In turn, a full night of sleep is required for glial lipid clearance, mitochondrial oxidative recovery and maximal neuronal mitophagy. Knockdown of neuronal NLaz causes oxidative stress to accumulate in neurons, and the neuronal mitochondrial integrity protein, Drp1, is required for daily glial lipid accumulation. These data suggest that neurons avoid accumulation of oxidative mitochondrial damage during wake by using mitophagy and passing damage to glia in the form of lipids. We propose that a mitochondrial lipid metabolic cycle between neurons and glia reflects a fundamental function of sleep relevant for brain energy homeostasis.
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Affiliation(s)
- Paula R Haynes
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, USA
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Elana S Pyfrom
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Yongjun Li
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Carly Stein
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Vishnu Anand Cuddapah
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA, USA
| | - Jack A Jacobs
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Zhifeng Yue
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
- Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Amita Sehgal
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, USA.
- Chronobiology and Sleep Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
- Howard Hughes Medical Institute, University of Pennsylvania, Philadelphia, PA, USA.
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2
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Wang X, Zhai Y, Zheng H. Deciphering the cellular heterogeneity of the insect brain with single-cell RNA sequencing. INSECT SCIENCE 2024; 31:314-327. [PMID: 37702319 DOI: 10.1111/1744-7917.13270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/27/2023] [Accepted: 07/31/2023] [Indexed: 09/14/2023]
Abstract
Insects show highly complicated adaptive and sophisticated behaviors, including spatial orientation skills, learning ability, and social interaction. These behaviors are controlled by the insect brain, the central part of the nervous system. The tiny insect brain consists of millions of highly differentiated and interconnected cells forming a complex network. Decades of research has gone into an understanding of which parts of the insect brain possess particular behaviors, but exactly how they modulate these functional consequences needs to be clarified. Detailed description of the brain and behavior is required to decipher the complexity of cell types, as well as their connectivity and function. Single-cell RNA-sequencing (scRNA-seq) has emerged recently as a breakthrough technology to understand the transcriptome at cellular resolution. With scRNA-seq, it is possible to uncover the cellular heterogeneity of brain cells and elucidate their specific functions and state. In this review, we first review the basic structure of insect brains and the links to insect behaviors mainly focusing on learning and memory. Then the scRNA applications on insect brains are introduced by representative studies. Single-cell RNA-seq has allowed researchers to classify cell subpopulations within different insect brain regions, pinpoint single-cell developmental trajectories, and identify gene regulatory networks. These developments empower the advances in neuroscience and shed light on the intricate problems in understanding insect brain functions and behaviors.
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Affiliation(s)
- Xiaofei Wang
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Yifan Zhai
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
- Key Laboratory of Natural Enemies Insects, Ministry of Agriculture and Rural Affairs, Jinan, China
- Shandong Provincial Engineering Technology Research Center on Biocontrol of Crops Diseases and In-sect Pests, Jinan, China
| | - Hao Zheng
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan, China
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
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3
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Panyushev N, Selitskiy M, Melnichenko V, Lebedev E, Okorokova L, Adonin L. Dynamic Evolution of Repetitive Elements and Chromatin States in Apis mellifera Subspecies. Genes (Basel) 2024; 15:89. [PMID: 38254978 PMCID: PMC10815273 DOI: 10.3390/genes15010089] [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: 12/15/2023] [Revised: 01/07/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
In this study, we elucidate the contribution of repetitive DNA sequences to the establishment of social structures in honeybees (Apis mellifera). Despite recent advancements in understanding the molecular mechanisms underlying the formation of honeybee castes, primarily associated with Notch signaling, the comprehensive identification of specific genomic cis-regulatory sequences remains elusive. Our objective is to characterize the repetitive landscape within the genomes of two honeybee subspecies, namely A. m. mellifera and A. m. ligustica. An observed recent burst of repeats in A. m. mellifera highlights a notable distinction between the two subspecies. After that, we transitioned to identifying differentially expressed DNA elements that may function as cis-regulatory elements. Nevertheless, the expression of these sequences showed minimal disparity in the transcriptome during caste differentiation, a pivotal process in honeybee eusocial organization. Despite this, chromatin segmentation, facilitated by ATAC-seq, ChIP-seq, and RNA-seq data, revealed a distinct chromatin state associated with repeats. Lastly, an analysis of sequence divergence among elements indicates successive changes in repeat states, correlating with their respective time of origin. Collectively, these findings propose a potential role of repeats in acquiring novel regulatory functions.
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Affiliation(s)
- Nick Panyushev
- Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, 625003 Tyumen, Russia; (N.P.); (M.S.)
- Bioinformatics Institute, 197342 St. Petersburg, Russia;
| | - Max Selitskiy
- Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, 625003 Tyumen, Russia; (N.P.); (M.S.)
| | - Vasilina Melnichenko
- International Scientific and Research Institute of Bioengineering, ITMO University, 197101 St. Petersburg, Russia;
| | - Egor Lebedev
- Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, 625003 Tyumen, Russia; (N.P.); (M.S.)
| | | | - Leonid Adonin
- Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, 625003 Tyumen, Russia; (N.P.); (M.S.)
- Institute of Biomedical Chemistry, Group of Mechanisms for Nanosystems Targeted Delivery, 119121 Moscow, Russia
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4
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Fernandes VM, Auld V, Klämbt C. Glia as Functional Barriers and Signaling Intermediaries. Cold Spring Harb Perspect Biol 2024; 16:a041423. [PMID: 38167424 PMCID: PMC10759988 DOI: 10.1101/cshperspect.a041423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Glia play a crucial role in providing metabolic support to neurons across different species. To do so, glial cells isolate distinct neuronal compartments from systemic signals and selectively transport specific metabolites and ions to support neuronal development and facilitate neuronal function. Because of their function as barriers, glial cells occupy privileged positions within the nervous system and have also evolved to serve as signaling intermediaries in various contexts. The fruit fly, Drosophila melanogaster, has significantly contributed to our understanding of glial barrier development and function. In this review, we will explore the formation of the glial sheath, blood-brain barrier, and nerve barrier, as well as the significance of glia-extracellular matrix interactions in barrier formation. Additionally, we will delve into the role of glia as signaling intermediaries in regulating nervous system development, function, and response to injury.
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Affiliation(s)
- Vilaiwan M Fernandes
- Department of Cell and Developmental Biology, University College London, London UC1E 6DE, United Kingdom
| | - Vanessa Auld
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Christian Klämbt
- Institute for Neuro- and Behavioral Biology, University of Münster, Münster 48149, Germany
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5
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Ciani C, Ayub M, Falcone C. Evolution of Astrocyte-Neuron Interactions Across Species. ADVANCES IN NEUROBIOLOGY 2024; 39:1-17. [PMID: 39190069 DOI: 10.1007/978-3-031-64839-7_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/28/2024]
Abstract
Proper functioning of the central nervous system depends on various tightly regulated phenomena, among which astrocyte-neuron interactions are of critical importance. Various studies across the species have highlighted the diverse yet crucial roles of astrocytes in regulating the nervous system development and functions. In simpler organisms like worms or insects, astrocyte-like cells govern basic functions such as structural support to neurons or regulation of extracellular ions. As the species complexity increases, so does the functional and morphological complexity of astrocytes. For example, in fish and amphibians, these cells are involved in synaptic development and ion homeostasis, while in reptiles and birds, astrocytes regulate synaptic transmission and plasticity and are reported to be involved in complex behaviors. Other species like those belonging to mammals and, in particular, primates have a heterogeneous population of astrocytes, exhibiting region-specific functional properties. In primates, these cells are responsible for proper synaptic transmission, neurotransmitter release and metabolism, and higher cognitive functions like learning, memory, or information processing. This chapter highlights the well-established and somewhat conserved roles of astrocytes and astrocyte-neuron interactions across the evolution of both invertebrates and vertebrates.
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Affiliation(s)
- Caterina Ciani
- Neuroscience Department, Scuola Internazionale di Studi Avanzati (SISSA), Trieste, Italy
| | - Maria Ayub
- Neuroscience Department, Scuola Internazionale di Studi Avanzati (SISSA), Trieste, Italy
| | - Carmen Falcone
- Neuroscience Department, Scuola Internazionale di Studi Avanzati (SISSA), Trieste, Italy.
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6
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Tremblay MÈ, Verkhratsky A. General Pathophysiology of Microglia. ADVANCES IN NEUROBIOLOGY 2024; 37:3-14. [PMID: 39207683 DOI: 10.1007/978-3-031-55529-9_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Microglia, which are the resident innate immune cells of the central nervous system (CNS), have emerged as critical for maintaining health by not only ensuring proper development, activity, and plasticity of neurones and glial cells but also maintaining and restoring homeostasis when faced with various challenges across the lifespan. This chapter is dedicated to the current understanding of microglia, including their beneficial versus detrimental roles, which are highly complex, rely on various microglial states, and intimately depend on their spatiotemporal context. Microglia are first contextualized within the perspective of finding therapeutic strategies to cure diseases in the twenty-first century-the overall functions of neuroglia with relation one to another and to neurones, and their shared CNS environment. A historical framework is provided, and the main principles of glial neuropathology are enunciated. The current view of microglial nomenclature is then covered, notably by discussing the rejected concepts of microglial activation, their polarisation into M1 and M2 phenotypes, and neuroinflammation. The transformation of the microglial population through the addition, migration, and elimination of individual members, as well as their dynamic metamorphosis between a wide variety of structural and functional states, based on the experienced physiological and pathological stimuli, is subsequently discussed. Lastly, the perspective of microglia as a cell type endowed with a health status determining their outcomes on adaptive CNS plasticity as well as disease pathology is proposed for twenty-first-century approaches to disease prevention and treatment.
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Affiliation(s)
- Marie-Ève Tremblay
- Division of Medical Sciences, Medical Sciences Building, University of Victoria, Victoria, BC, Canada.
- Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec City, QC, Canada.
- Neurology and Neurosurgery Department, McGill University, Montreal, QC, Canada.
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada.
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Life Sciences Center, Vancouver, BC, Canada.
| | - Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester, Manchester, UK.
- Department of Neurosciences,University of the Basque Country,, Leioa, Spain.
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania.
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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7
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Son W, Jeong HS, Nam DE, Lee AJ, Nam SH, Lee JE, Choi BO, Chung KW. Peripheral Neuropathy and Decreased Locomotion of a RAB40B Mutation in Human and Model Animals. Exp Neurobiol 2023; 32:410-422. [PMID: 38196136 PMCID: PMC10789172 DOI: 10.5607/en23027] [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: 08/30/2023] [Revised: 12/13/2023] [Accepted: 12/15/2023] [Indexed: 01/11/2024] Open
Abstract
Rab40 proteins are an atypical subgroup of Rab GTPases containing a unique suppressor of the cytokine signaling (SOCS) domain that is recruited to assemble the CRL5 E3 ligase complex for proteolytic regulation in various biological processes. A nonsense mutation deleting the C-terminal SOCS box in the RAB40B gene was identified in a family with axonal peripheral neuropathy (Charcot-Marie-Tooth disease type 2), and pathogenicity of the mutation was assessed in model organisms of zebrafish and Drosophila. Compared to control fish, zebrafish larvae transformed by the human mutant hRAB40B-Y83X showed a defective swimming pattern of stalling with restricted localization and slower motility. We were consistently able to observe reduced labeling of synaptic markers along neuromuscular junctions of the transformed larvae. In addition to the neurodevelopmental phenotypes, compared to normal hRAB40B expression, we further examined ectopic expression of hRAB40B-Y83X in Drosophila to show a progressive decline of locomotion ability. Decreased ability of locomotion by ubiquitous expression of the human mutation was reproduced not with GAL4 drivers for neuron-specific expression but only when a pan-glial GAL4 driver was applied. Using the ectopic expression model of Drosophila, we identified a genetic interaction in which Cul5 down regulation exacerbated the defective motor performance, showing a consistent loss of SOCS box of the pathogenic RAB40B. Taken together, we could assess the possible gain-of-function of the human RAB40B mutation by comparing behavioral phenotypes in animal models; our results suggest that the mutant phenotypes may be associated with CRL5-mediated proteolytic regulation.
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Affiliation(s)
- Wonseok Son
- Department of Biological Sciences and BK21 Team for Field-oriented BioCore Human Resources Development, Kongju National University, Gongju 32588, Korea
| | - Hui Su Jeong
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University, Seoul 06351, Korea
| | - Da Eun Nam
- Department of Biological Sciences and BK21 Team for Field-oriented BioCore Human Resources Development, Kongju National University, Gongju 32588, Korea
| | - Ah Jin Lee
- Department of Biological Sciences and BK21 Team for Field-oriented BioCore Human Resources Development, Kongju National University, Gongju 32588, Korea
| | - Soo Hyun Nam
- Cell and Gene Therapy Institute, Samsung Medical Center, Seoul 06351, Korea
| | - Ji Eun Lee
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University, Seoul 06351, Korea
- Samsung Biomedical Research Institute, Samsung Medical Center, Seoul 06351, Korea
| | - Byung-Ok Choi
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology, Sungkyunkwan University, Seoul 06351, Korea
- Cell and Gene Therapy Institute, Samsung Medical Center, Seoul 06351, Korea
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
| | - Ki Wha Chung
- Department of Biological Sciences and BK21 Team for Field-oriented BioCore Human Resources Development, Kongju National University, Gongju 32588, Korea
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8
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Lago-Baldaia I, Cooper M, Seroka A, Trivedi C, Powell GT, Wilson SW, Ackerman SD, Fernandes VM. A Drosophila glial cell atlas reveals a mismatch between transcriptional and morphological diversity. PLoS Biol 2023; 21:e3002328. [PMID: 37862379 PMCID: PMC10619882 DOI: 10.1371/journal.pbio.3002328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 11/01/2023] [Accepted: 09/08/2023] [Indexed: 10/22/2023] Open
Abstract
Morphology is a defining feature of neuronal identity. Like neurons, glia display diverse morphologies, both across and within glial classes, but are also known to be morphologically plastic. Here, we explored the relationship between glial morphology and transcriptional signature using the Drosophila central nervous system (CNS), where glia are categorised into 5 main classes (outer and inner surface glia, cortex glia, ensheathing glia, and astrocytes), which show within-class morphological diversity. We analysed and validated single-cell RNA sequencing data of Drosophila glia in 2 well-characterised tissues from distinct developmental stages, containing distinct circuit types: the embryonic ventral nerve cord (VNC) (motor) and the adult optic lobes (sensory). Our analysis identified a new morphologically and transcriptionally distinct surface glial population in the VNC. However, many glial morphological categories could not be distinguished transcriptionally, and indeed, embryonic and adult astrocytes were transcriptionally analogous despite differences in developmental stage and circuit type. While we did detect extensive within-class transcriptomic diversity for optic lobe glia, this could be explained entirely by glial residence in the most superficial neuropil (lamina) and an associated enrichment for immune-related gene expression. In summary, we generated a single-cell transcriptomic atlas of glia in Drosophila, and our extensive in vivo validation revealed that glia exhibit more diversity at the morphological level than was detectable at the transcriptional level. This atlas will serve as a resource for the community to probe glial diversity and function.
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Affiliation(s)
- Inês Lago-Baldaia
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Maia Cooper
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Austin Seroka
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, Oregon, United States of America
| | - Chintan Trivedi
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Gareth T. Powell
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Stephen W. Wilson
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Sarah D. Ackerman
- Department of Pathology and Immunology, Brain Immunology and Glia Center, Washington University School of Medicine, Saint Louis, Missouri, United States of America
- Department of Developmental Biology, Washington University School of Medicine, Saint Louis, Missouri, United States of America
| | - Vilaiwan M. Fernandes
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
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9
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Ferreira AAG, Desplan C. An Atlas of the Developing Drosophila Visual System Glia and Subcellular mRNA Localization of Transcripts in Single Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.06.552169. [PMID: 37609218 PMCID: PMC10441313 DOI: 10.1101/2023.08.06.552169] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Glial cells are essential for proper nervous system development and function. To understand glial development and function, we comprehensively annotated glial cells in a single-cell mRNA-sequencing (scRNAseq) atlas of the developing Drosophila visual system. This allowed us to study their developmental trajectories, from larval to adult stages, and to understand how specific types of glia diversify during development. For example, neuropil glia that are initially transcriptionally similar in larvae, split into ensheathing and astrocyte-like glia during pupal stages. Other glial types, such as chiasm glia change gradually during development without splitting into two cell types. The analysis of scRNA-seq allowed us to discover that the transcriptome of glial cell bodies can be distinguished from that of their broken processes. The processes contain distinct enriched mRNAs that were validated in vivo. Therefore, we have identified most glial types in the developing optic lobe and devised a computational approach to identify mRNA species that are localized to cell bodies or cellular processes.
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Affiliation(s)
| | - Claude Desplan
- Department of Biology, New York University, New York, NY, USA
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10
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Li Y, Haynes P, Zhang SL, Yue Z, Sehgal A. Ecdysone acts through cortex glia to regulate sleep in Drosophila. eLife 2023; 12:e81723. [PMID: 36719183 PMCID: PMC9928426 DOI: 10.7554/elife.81723] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 01/30/2023] [Indexed: 02/01/2023] Open
Abstract
Steroid hormones are attractive candidates for transmitting long-range signals to affect behavior. These lipid-soluble molecules derived from dietary cholesterol easily penetrate the brain and act through nuclear hormone receptors (NHRs) that function as transcription factors. To determine the extent to which NHRs affect sleep:wake cycles, we knocked down each of the 18 highly conserved NHRs found in Drosophila adults and report that the ecdysone receptor (EcR) and its direct downstream NHR Eip75B (E75) act in glia to regulate the rhythm and amount of sleep. Given that ecdysone synthesis genes have little to no expression in the fly brain, ecdysone appears to act as a long-distance signal and our data suggest that it enters the brain more at night. Anti-EcR staining localizes to the cortex glia in the brain and functional screening of glial subtypes revealed that EcR functions in adult cortex glia to affect sleep. Cortex glia are implicated in lipid metabolism, which appears to be relevant for actions of ecdysone as ecdysone treatment mobilizes lipid droplets (LDs), and knockdown of glial EcR results in more LDs. In addition, sleep-promoting effects of exogenous ecdysone are diminished in lsd-2 mutant flies, which are lean and deficient in lipid accumulation. We propose that ecdysone is a systemic secreted factor that modulates sleep by stimulating lipid metabolism in cortex glia.
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Affiliation(s)
- Yongjun Li
- Howard Hughes Medical Institute and Chronobiology and Sleep Institute, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Department of Biology, University of PennsylvaniaPhiladelphiaUnited States
| | - Paula Haynes
- Howard Hughes Medical Institute and Chronobiology and Sleep Institute, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
- Department of Pharmacology, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - Shirley L Zhang
- Howard Hughes Medical Institute and Chronobiology and Sleep Institute, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - Zhifeng Yue
- Howard Hughes Medical Institute and Chronobiology and Sleep Institute, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
| | - Amita Sehgal
- Howard Hughes Medical Institute and Chronobiology and Sleep Institute, Perelman School of Medicine at the University of PennsylvaniaPhiladelphiaUnited States
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11
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Gu Z, Chen H, Zhao H, Yang W, Song Y, Li X, Wang Y, Du D, Liao H, Pan W, Li X, Gao Y, Han H, Tong Z. New insight into brain disease therapy: nanomedicines-crossing blood-brain barrier and extracellular space for drug delivery. Expert Opin Drug Deliv 2022; 19:1618-1635. [PMID: 36285632 DOI: 10.1080/17425247.2022.2139369] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
INTRODUCTION Brain diseases including brain tumor, Alzheimer's disease, Parkinson's disease, etc. are difficult to treat. The blood-brain barrier (BBB) is a major obstacle for drug delivery into the brain. Although nano-package and receptor-mediated delivery of nanomedicine markedly increases BBB penetration, it yet did not extensively improve clinical cure rate. Recently, brain extracellular space (ECS) and interstitial fluid (ISF) drainage in ECS have been found to determine whether a drug dissolved in ISF can reach its target cells. Notably, an increase in tortuosity of ECS associated with slower ISF drainage induced by the accumulated harmful substances, such as: amyloid-beta (Aβ), α-synuclein, and metabolic wastes, causes drug delivery failure. AREAS COVERED The methods of nano-package and receptor-mediated drug delivery and the penetration efficacy of nanomedicines across BBB and ECS are assessed. EXPERT OPINION Invasive delivering drug via ECS and noninvasive near-infrared photo-sensitive nanomedicines may provide a promising benefit to patients with brain disease.
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Affiliation(s)
- Ziqi Gu
- Key Laboratory of Alzheimer's Disease of Zhejiang Province, Institute of Aging, Oujiang Laboratory, School of Mental Health, Wenzhou Medical University, Wenzhou, China
| | - Haishu Chen
- Key Laboratory of Alzheimer's Disease of Zhejiang Province, Institute of Aging, Oujiang Laboratory, School of Mental Health, Wenzhou Medical University, Wenzhou, China
| | - Han Zhao
- Key Laboratory of Alzheimer's Disease of Zhejiang Province, Institute of Aging, Oujiang Laboratory, School of Mental Health, Wenzhou Medical University, Wenzhou, China
| | - Wanting Yang
- Key Laboratory of Alzheimer's Disease of Zhejiang Province, Institute of Aging, Oujiang Laboratory, School of Mental Health, Wenzhou Medical University, Wenzhou, China
| | - Yilan Song
- Key Laboratory of Alzheimer's Disease of Zhejiang Province, Institute of Aging, Oujiang Laboratory, School of Mental Health, Wenzhou Medical University, Wenzhou, China
| | - Xiang Li
- Key Laboratory of Alzheimer's Disease of Zhejiang Province, Institute of Aging, Oujiang Laboratory, School of Mental Health, Wenzhou Medical University, Wenzhou, China
| | - Yang Wang
- Institute of Medical Technology, Peking University Health Science Center, Beijing, China.,Department of Radiology, Peking University Third Hospital, Beijing, China
| | - Dan Du
- Department of Radiology, Peking University Third Hospital, Beijing, China.,Department of Magnetic Resonance Imaging, Qinhuangdao Municipal No. 1 Hospital, Qinhuangdao, China.,Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China
| | - Haikang Liao
- Key Laboratory of Alzheimer's Disease of Zhejiang Province, Institute of Aging, Oujiang Laboratory, School of Mental Health, Wenzhou Medical University, Wenzhou, China
| | - Wenhao Pan
- Key Laboratory of Alzheimer's Disease of Zhejiang Province, Institute of Aging, Oujiang Laboratory, School of Mental Health, Wenzhou Medical University, Wenzhou, China
| | - Xi Li
- The Affiliated Kangning Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yajuan Gao
- Department of Radiology, Peking University Third Hospital, Beijing, China.,NMPA key Laboratory for Evaluation of Medical Imaging Equipment and Technique, Beijing, China
| | - Hongbin Han
- Institute of Medical Technology, Peking University Health Science Center, Beijing, China.,Department of Radiology, Peking University Third Hospital, Beijing, China.,Beijing Key Laboratory of Magnetic Resonance Imaging Devices and Technology, Peking University Third Hospital, Beijing, China.,Peking University Shenzhen Graduate School, Shenzhen, China
| | - Zhiqian Tong
- Key Laboratory of Alzheimer's Disease of Zhejiang Province, Institute of Aging, Oujiang Laboratory, School of Mental Health, Wenzhou Medical University, Wenzhou, China.,The Affiliated Kangning Hospital of Wenzhou Medical University, Wenzhou, China
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12
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Verkhratsky A, Arranz AM, Ciuba K, Pękowska A. Evolution of neuroglia. Ann N Y Acad Sci 2022; 1518:120-130. [PMID: 36285711 DOI: 10.1111/nyas.14917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The evolution of the nervous system progressed through cellular diversification and specialization of functions. Conceptually, the nervous system is composed of electrically excitable neuronal networks connected by chemical synapses and nonexcitable glial cells that provide for homeostasis and defense. The evolution of neuroglia began with the emergence of the centralized nervous system and proceeded through a continuous increase in their complexity. In the primate brain, especially in the brain of humans, the astrocyte lineage is exceedingly complex, with the emergence of new types of astroglial cells possibly involved in interlayer communication and integration.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,Achucarro Basque Center for Neuroscience, Leioa, Spain.,IKERBASQUE Basque Foundation for Science, Bilbao, Spain.,Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China.,Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Amaia M Arranz
- Achucarro Basque Center for Neuroscience, Leioa, Spain.,IKERBASQUE Basque Foundation for Science, Bilbao, Spain
| | - Katarzyna Ciuba
- Dioscuri Centre of Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
| | - Aleksandra Pękowska
- Dioscuri Centre of Chromatin Biology and Epigenomics, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, Poland
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13
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Lin WY, Liu CH, Cheng J, Liu HP. Alterations of RNA-binding protein found in neurons in Drosophila neurons and glia influence synaptic transmission and lifespan. Front Mol Neurosci 2022; 15:1006455. [DOI: 10.3389/fnmol.2022.1006455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/24/2022] [Indexed: 11/13/2022] Open
Abstract
The found in neurons (fne), a paralog of the RNA-binding protein ELAV gene family in Drosophila, is required for post-transcriptional regulation of neuronal development and differentiation. Previous explorations into the functions of the FNE protein have been limited to neurons. The function of fne in Drosophila glia remains unclear. We induced the knockdown or overexpression of fne in Drosophila neurons and glia to determine how fne affects different types of behaviors, neuronal transmission and the lifespan. Our data indicate that changes in fne expression impair associative learning, thermal nociception, and phototransduction. Examination of synaptic transmission at presynaptic and postsynaptic terminals of the larval neuromuscular junction (NMJ) revealed that loss of fne in motor neurons and glia significantly decreased excitatory junction currents (EJCs) and quantal content, while flies with glial fne knockdown facilitated short-term synaptic plasticity. In muscle cells, overexpression of fne reduced both EJC and quantal content and increased short-term synaptic facilitation. In both genders, the lifespan could be extended by the knockdown of fne in neurons and glia; the overexpression of fne shortened the lifespan. Our results demonstrate that disturbances of fne in neurons and glia influence the function of the Drosophila nervous system. Further explorations into the physiological and molecular mechanisms underlying neuronal and glial fne and elucidation of how fne affects neuronal activity may clarify certain brain functions.
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14
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Panov AA. Giant Cortical Glial Cells in the Central Nervous System of Insects. BIOL BULL+ 2022. [DOI: 10.1134/s106235902205017x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Damulewicz M, Doktór B, Baster Z, Pyza E. The Role of Glia Clocks in the Regulation of Sleep in Drosophila melanogaster. J Neurosci 2022; 42:6848-6860. [PMID: 35906073 PMCID: PMC9463985 DOI: 10.1523/jneurosci.2340-21.2022] [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: 11/26/2021] [Revised: 05/08/2022] [Accepted: 06/06/2022] [Indexed: 11/21/2022] Open
Abstract
In Drosophila melanogaster, the pacemaker located in the brain plays the main role in maintaining circadian rhythms; however, peripheral oscillators including glial cells, are also crucial components of the circadian network. In the present study, we investigated an impact of oscillators located in astrocyte-like glia, the chiasm giant glia of the optic lobe, epithelial and subperineurial glia on sleep of Drosophila males. We described that oscillators located in astrocyte-like glia and chiasm giant glia are necessary to maintain daily changes in clock neurons arborizations, while those located in epithelial glia regulate amplitude of these changes. Finally, we showed that communication between glia and neurons through tripartite synapses formed by epithelial glia and, in effect, neurotransmission regulation plays important role in wake-promoting during the day.SIGNIFICANCE STATEMENT Circadian clock or pacemaker regulates many aspects of animals' physiology and behavior. The pacemaker is located in the brain and is composed of neurons. However, there are also additional oscillators, called peripheral clocks, which synchronize the main clock. Despite the critical role of glia in the clock machinery, little is known which type of glia houses peripheral oscillators and how they affect neuronal clocks. This study using Drosophila shows that oscillators in specific glia types maintain awakeness during the day by regulating the daily plasticity of clock neurons.
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Affiliation(s)
- Milena Damulewicz
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow 30-387, Poland
| | - Bartosz Doktór
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow 30-387, Poland
| | - Zbigniew Baster
- Department of Molecular and Interfacial Biophysics, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Krakow 30-387, Poland
| | - Elzbieta Pyza
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Krakow 30-387, Poland
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16
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Falcone C. Evolution of astrocytes: From invertebrates to vertebrates. Front Cell Dev Biol 2022; 10:931311. [PMID: 36046339 PMCID: PMC9423676 DOI: 10.3389/fcell.2022.931311] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/12/2022] [Indexed: 11/13/2022] Open
Abstract
The central nervous system (CNS) shows incredible diversity across evolution at the anatomical, cellular, molecular, and functional levels. Over the past decades, neuronal cell number and heterogeneity, together with differences in the number and types of neuro-active substances, axonal conduction, velocity, and modes of synaptic transmission, have been rigorously investigated in comparative neuroscience studies. However, astrocytes, a specific type of glial cell in the CNS, play pivotal roles in regulating these features and thus are crucial for the brain's development and evolution. While special attention has been paid to mammalian astrocytes, we still do not have a clear definition of what an astrocyte is from a broader evolutionary perspective, and there are very few studies on astroglia-like structures across all vertebrates. Here, I elucidate what we know thus far about astrocytes and astrocyte-like cells across vertebrates. This information expands our understanding of how astrocytes evolved to become more complex and extremely specialized cells in mammals and how they are relevant to the structure and function of the vertebrate brain.
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Affiliation(s)
- Carmen Falcone
- Department of Neuroscience, International School for Advanced Studies (SISSA), Trieste, Italy
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17
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Chen X, Li J, Gao Z, Yang Y, Kuang W, Dong Y, Chua GH, Huang X, Jiang B, Tian H, Wang Y, Huang X, Li Y, Lam SM, Shui G. Endogenous ceramide phosphoethanolamine modulates circadian rhythm via neural-glial coupling in Drosophila. Natl Sci Rev 2022; 9:nwac148. [PMID: 36713590 PMCID: PMC9875363 DOI: 10.1093/nsr/nwac148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 06/08/2022] [Accepted: 07/13/2022] [Indexed: 02/01/2023] Open
Abstract
While endogenous lipids are known to exhibit rhythmic oscillations, less is known about how specific lipids modulate circadian behavior. Through a series of loss-of-function and gain-of-function experiments on ceramide phosphoethanolamine (CPE) synthase of Drosophila, we demonstrated that pan-glial-specific deficiency in membrane CPE, the structural analog of mammalian sphingomyelin (SM), leads to arrhythmic locomotor behavior and shortens lifespan, while the reverse is true for increasing CPE. Comparative proteomics uncovered dysregulated synaptic glutamate utilization and transport in CPE-deficient flies. An extensive genetic screen was conducted to verify the role of differentially expressed proteins in circadian regulation. Arrhythmic locomotion under cpes1 mutant background was rescued only by restoring endogenous CPE or SM through expressing their respective synthases. Our results underscore the essential role of CPE in maintaining synaptic glutamate homeostasis and modulating circadian behavior in Drosophila. The findings suggest that region-specific elevations of functional membrane lipids can benefit circadian regulation.
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Affiliation(s)
| | | | - Zhongbao Gao
- University of Chinese Academy of Sciences, Beijing 100049, China,State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yang Yang
- University of Chinese Academy of Sciences, Beijing 100049, China,State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Wenqing Kuang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing100101, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Dong
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing100101, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gek Huey Chua
- LipidALL Technologies Company Limited, Changzhou213022, China
| | - Xiahe Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing100101, China
| | - Binhua Jiang
- LipidALL Technologies Company Limited, Changzhou213022, China
| | - He Tian
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing100101, China
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing100101, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xun Huang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing100101, China,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Li
- University of Chinese Academy of Sciences, Beijing 100049, China,State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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18
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Single-cell transcriptomic analysis of honeybee brains identifies vitellogenin as caste differentiation-related factor. iScience 2022; 25:104643. [PMID: 35800778 PMCID: PMC9254125 DOI: 10.1016/j.isci.2022.104643] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 03/31/2022] [Accepted: 06/14/2022] [Indexed: 11/22/2022] Open
Abstract
The honeybee (Apis mellifera) is a well-known eusocial insect. In honeybee colonies, thousands of sterile workers, including nurse and forager bees, perform various tasks within or outside the hive, respectively. The queen is the only fertile female and is responsible for reproduction. The queen and workers share similar genomes but occupy different caste statuses. We established single-cell transcriptomic atlases of brains from queens and worker subcastes and identified five major cell groups: Kenyon, optic lobe, olfactory projection, glial, and hemocyte cells. By dividing Kenyon and glial cells into multiple subtypes based on credible markers, we observed that vitellogenin (vg) was highly expressed in specific glial-cell subtypes in brains of queens. Knockdown of vg at the early larval stage significantly suppressed the development into adult queens. We demonstrate vg expression as a "molecular signature" for the queen caste and suggest involvement of vg in regulating caste differentiation. scRNA-seq revealed distinct gene expression in the brains of queens and workers Vitellogenin (vg) may represent a "molecular signature" of the queen caste Knockdown of vg at early larval stage suppressed development into adult queens Vg may be involved in regulating caste differentiation
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19
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Leboulle G, Gehne N, Froese A, Menzel R. In-vivo egfp expression in the honeybee Apis mellifera induced by electroporation and viral expression vector. PLoS One 2022; 17:e0263908. [PMID: 35653376 PMCID: PMC9162312 DOI: 10.1371/journal.pone.0263908] [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: 01/27/2022] [Accepted: 05/02/2022] [Indexed: 11/18/2022] Open
Abstract
In this study we describe egfp expression induced by two techniques: in vivo electroporation and viral transduction in several cell types of the adult honeybee brain. Non-neuronal and neuronal cell types were identified and the expression persisted at least during three days. Kenyon cells, optic lobe neurons and protocerebral lobe neurons were electroporated. Astrocyte-like glia cells, fibrous lamellar glia cells and cortex glia cells were identified. Viral transduction targeted one specific type of glia cells that could not be identified. EGFP positive cells types were rather variable after electroporation, and viral transduction resulted in more homogenous groups of positive cells. We propose that these techniques remain a good alternative to transgenic animals because they potentially target only somatic cells.
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Affiliation(s)
- Gérard Leboulle
- Neurobiologie, Freie Universität Berlin, Berlin, Germany
- * E-mail:
| | - Nora Gehne
- Neurobiologie, Freie Universität Berlin, Berlin, Germany
| | - Anja Froese
- Neurobiologie, Freie Universität Berlin, Berlin, Germany
| | - Randolf Menzel
- Neurobiologie, Freie Universität Berlin, Berlin, Germany
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20
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Fölsz O, Lin CC, Task D, Riabinina O, Potter CJ. The Q-system: A Versatile Repressible Binary Expression System. Methods Mol Biol 2022; 2540:35-78. [PMID: 35980572 DOI: 10.1007/978-1-0716-2541-5_2] [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] [Indexed: 06/15/2023]
Abstract
Binary expression systems are useful genetic tools for experimentally labeling or manipulating the function of defined cells. The Q-system is a repressible binary expression system that consists of a transcription factor QF (and the recently improved QF2/QF2w), the inhibitor QS, a QUAS-geneX effector, and a drug that inhibits QS (quinic acid). The Q-system can be used alone or in combination with other binary expression systems, such as GAL4/UAS and LexA/LexAop. In this review chapter, we discuss the past, present, and future of the Q-system for applications in Drosophila and other organisms. We discuss the in vivo application of the Q-system for transgenic labeling, the modular nature of QF that allows chimeric or split transcriptional activators to be developed, its temporal control by quinic acid, new methods to generate QF2 reagents, intersectional expression labeling, and its recent adoption into many emerging experimental species.
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Affiliation(s)
- Orsolya Fölsz
- Department of Biosciences, Durham University, Durham, UK
| | - Chun-Chieh Lin
- Department of Pathology and Laboratory Medicine, Giesel School of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | - Darya Task
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | | | - Christopher J Potter
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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21
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Scheffer LK, Meinertzhagen IA. A connectome is not enough - what is still needed to understand the brain of Drosophila? J Exp Biol 2021; 224:272599. [PMID: 34695211 DOI: 10.1242/jeb.242740] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Understanding the structure and operation of any nervous system has been a subject of research for well over a century. A near-term opportunity in this quest is to understand the brain of a model species, the fruit fly Drosophila melanogaster. This is an enticing target given its relatively small size (roughly 200,000 neurons), coupled with the behavioral richness that this brain supports, and the wide variety of techniques now available to study both brain and behavior. It is clear that within a few years we will possess a connectome for D. melanogaster: an electron-microscopy-level description of all neurons and their chemical synaptic connections. Given what we will soon have, what we already know and the research that is currently underway, what more do we need to know to enable us to understand the fly's brain? Here, we itemize the data we will need to obtain, collate and organize in order to build an integrated model of the brain of D. melanogaster.
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Affiliation(s)
- Louis K Scheffer
- Howard Hughes Medical Institute, 19741 Smith Circle, Ashburn, VA 20147, USA
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22
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Phosphatidylserine synthase plays an essential role in glia and affects development, as well as the maintenance of neuronal function. iScience 2021; 24:102899. [PMID: 34401677 PMCID: PMC8358705 DOI: 10.1016/j.isci.2021.102899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 06/14/2021] [Accepted: 07/21/2021] [Indexed: 01/05/2023] Open
Abstract
Phosphatidylserine (PS) is an integral component of eukaryotic cell membranes and organelles. The Drosophila genome contains a single PS synthase (PSS)-encoding gene (Pss) homologous to mammalian PSSs. Flies with Pss loss-of-function alleles show a reduced life span, increased bang sensitivity, locomotor defects, and vacuolated brain, which are the signs associated with neurodegeneration. We observed defective mitochondria in mutant adult brain, as well as elevated production of reactive oxygen species, and an increase in autophagy and apoptotic cell death. Intriguingly, glial-specific knockdown or overexpression of Pss alters synaptogenesis and axonal growth in the larval stage, causes developmental arrest in pupal stages, and neurodegeneration in adults. This is not observed with pan-neuronal up- or down-regulation. These findings suggest that precisely regulated expression of Pss in glia is essential for the development and maintenance of brain function. We propose a mechanism that underlies these neurodegenerative phenotypes triggered by defective PS metabolism. Loss of Pss leads to developmental defects and neurodegeneration Loss of Pss causes a mitochondrial defect, elevated ROS, and secondary necrosis Pss functions in glia are essential for synaptogenesis and neuronal maintenance Glial Pss expression level must be tightly regulated to maintain a healthy nervous system
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23
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Mamon L, Yakimova A, Kopytova D, Golubkova E. The RNA-Binding Protein SBR (Dm NXF1) Is Required for the Constitution of Medulla Boundaries in Drosophila melanogaster Optic Lobes. Cells 2021; 10:1144. [PMID: 34068524 PMCID: PMC8151460 DOI: 10.3390/cells10051144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 11/17/2022] Open
Abstract
Drosophila melanogaster sbr (small bristles) is an orthologue of the Nxf1 (nuclear export factor 1) genes in different Opisthokonta. The known function of Nxf1 genes is the export of various mRNAs from the nucleus to the cytoplasm. The cytoplasmic localization of the SBR protein indicates that the nuclear export function is not the only function of this gene in Drosophila. RNA-binding protein SBR enriches the nucleus and cytoplasm of specific neurons and glial cells. In sbr12 mutant males, the disturbance of medulla boundaries correlates with the defects of photoreceptor axons pathfinding, axon bundle individualization, and developmental neurodegeneration. RNA-binding protein SBR participates in processes allowing axons to reach and identify their targets.
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Affiliation(s)
- Ludmila Mamon
- Department of Genetics and Biotechnology, Saint-Petersburg State University, Universitetskaya Emb. 7/9, 199034 St. Petersburg, Russia; or
| | - Anna Yakimova
- A. Tsyb Medical Radiological Research Center—Branch of the National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Koroleva Str. 4, 249036 Obninsk, Russia;
| | - Daria Kopytova
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov St. 34/5, 119334 Moscow, Russia;
| | - Elena Golubkova
- Department of Genetics and Biotechnology, Saint-Petersburg State University, Universitetskaya Emb. 7/9, 199034 St. Petersburg, Russia; or
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24
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Parallel Synaptic Acetylcholine Signals Facilitate Large Monopolar Cell Repolarization and Modulate Visual Behavior in Drosophila. J Neurosci 2021; 41:2164-2176. [PMID: 33468565 DOI: 10.1523/jneurosci.2388-20.2021] [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: 09/13/2020] [Revised: 12/03/2020] [Accepted: 01/03/2021] [Indexed: 11/21/2022] Open
Abstract
Appropriate termination of the photoresponse in image-forming photoreceptors and downstream neurons is critical for an animal to achieve high temporal resolution. Although the cellular and molecular mechanisms of termination in image-forming photoreceptors have been extensively studied in Drosophila, the underlying mechanism of termination in their downstream large monopolar cells remains less explored. Here, we show that synaptic ACh signaling, from both amacrine cells (ACs) and L4 neurons, facilitates the rapid repolarization of L1 and L2 neurons. Intracellular recordings in female flies show that blocking synaptic ACh output from either ACs or L4 neurons leads to slow repolarization of L1 and L2 neurons. Genetic and electrophysiological studies in both male and female flies determine that L2 neurons express ACh receptors and directly receive ACh signaling. Moreover, our results demonstrate that synaptic ACh signaling from both ACs and L4 neurons simultaneously facilitates ERG termination. Finally, visual behavior studies in both male and female flies show that synaptic ACh signaling, from either ACs or L4 neurons to L2 neurons, is essential for the optomotor response of the flies in high-frequency light stimulation. Our study identifies parallel synaptic ACh signaling for repolarization of L1 and L2 neurons and demonstrates that synaptic ACh signaling facilitates L1 and L2 neuron repolarization to maintain the optomotor response of the fly on high-frequency light stimulation.SIGNIFICANCE STATEMENT The image-forming photoreceptor downstream neurons receive multiple synaptic inputs from image-forming photoreceptors and various types of interneurons. It remains largely unknown how these synaptic inputs modulate the neural activity and function of image-forming photoreceptor downstream neurons. We show that parallel synaptic ACh signaling from both amacrine cells and L4 neurons facilitates rapid repolarization of large monopolar cells in Drosophila and maintains the optomotor response of the fly on high-frequency light stimulation. This work is one of the first reports showing how parallel synaptic signaling modulates the activity of large monopolar cells and motion vision simultaneously.
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25
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Walkowicz L, Krzeptowski W, Krzeptowska E, Warzecha K, Sałek J, Górska-Andrzejak J, Pyza E. Glial expression of DmMANF is required for the regulation of activity, sleep and circadian rhythms in the visual system of Drosophila melanogaster. Eur J Neurosci 2021; 54:5785-5797. [PMID: 33666288 DOI: 10.1111/ejn.15171] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 01/31/2021] [Accepted: 02/22/2021] [Indexed: 12/12/2022]
Abstract
DmMANF, Drosophila melanogaster mesencephalic astrocyte-derived neurotrophic factor (DmMANF) is an evolutionarily conserved orthologue of mammalian MANF. This neurotrophic factor exerts many functions in the Drosophila brain, particularly those dependent on glial cells. As we found in our earlier study, downregulation of DmMANF in glia induces degeneration of glial cells in the first optic neuropil (lamina) where DmMANF abundance is especially high. In the present study, we observed that changes in the level of DmMANF in two types of glia, astrocyte-like glia (AlGl) and ensheathing glia (EnGl), affect activity and sleep of flies. Interestingly, a proper level of DmMANF in AlGl seems to be important in guiding processes of pigment dispersing factor (PDF)-expressing clock neurons. This is supported by our finding that DmMANF overexpression in AlGl leads to structural changes in the architecture of the PDF-positive arborization in the brain. Finally, we detected that DmMANF also affects rhythms in glia themselves, as circadian oscillations in expression of the catalytic α subunit of the sodium pump in the lamina epithelial glia were abolished after DmMANF silencing. DmMANF expressed in AlGl and EnGl seems to affect the activity of neurons leading to changes in behaviour.
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Affiliation(s)
- Lucyna Walkowicz
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Wojciech Krzeptowski
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Ewelina Krzeptowska
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Karolina Warzecha
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Joanna Sałek
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Jolanta Górska-Andrzejak
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
| | - Elżbieta Pyza
- Department of Cell Biology and Imaging, Institute of Zoology and Biomedical Research, Jagiellonian University, Kraków, Poland
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26
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Ismail NIB, Kato Y, Matsuura T, Gómez-Canela C, Barata C, Watanabe H. Reduction of histamine and enhanced spinning behavior of Daphnia magna caused by scarlet mutant. Genesis 2020; 59:e23403. [PMID: 33348442 DOI: 10.1002/dvg.23403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 11/09/2022]
Abstract
The ABC transporter, Scarlet, and its binding partner, White are involved in pigment synthesis in the insect eye and mutations in these genes are used as genetic markers. Recent studies have suggested that these transporters also have additional functions in the neuronal system. In our previous study, we generated scarlet mutant in the small crustacean, Daphnia magna and showed that the mutant lacked the eye pigment in the mutant. Here, we show that the scarlet mutant exhibits spinning behavior. This phenotype is partly associated with the presence of light. Metabolomic analysis of a juvenile mutant revealed that the scarlet mutant has approximately one-tenth of the histamine content of the wild type. Application of histamine to the scarlet mutant rescued the spinning behavior in juveniles, suggesting that the spinning behavior of the mutant is caused by the reduction of histamine. However, the altered behavior was not rescued in the adult mutant by the addition of histamine, suggesting that Scarlet plays an irreversible role in the development of histaminergic neurons. These results suggest that Scarlet plays an important role in histaminergic signaling, which might be related to control the spinning behavior, in addition to its role in eye pigmentation.
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Affiliation(s)
| | - Yasuhiko Kato
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan.,Frontier Research Base for Global Young Researchers, Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Tomoaki Matsuura
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan
| | - Cristian Gómez-Canela
- Department of Analytical Chemistry and Applied (Chromatography Section), School of Engineering, Institut Químic de Sarrià-Universitat Ramon Llull, Barcelona, Spain
| | - Carlos Barata
- Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Barcelona, Spain
| | - Hajime Watanabe
- Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan
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Vesicular neurotransmitter transporters in Drosophila melanogaster. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183308. [PMID: 32305263 DOI: 10.1016/j.bbamem.2020.183308] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 04/09/2020] [Accepted: 04/10/2020] [Indexed: 12/11/2022]
Abstract
Drosophila melanogaster express vesicular transporters for the storage of neurotransmitters acetylcholine, biogenic amines, GABA, and glutamate. The large array of powerful molecular-genetic tools available in Drosophila enhances the use of this model organism for studying transporter function and regulation.
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28
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Tsao CK, Huang YF, Sun YH. Early lineage segregation of the retinal basal glia in the Drosophila eye disc. Sci Rep 2020; 10:18522. [PMID: 33116242 PMCID: PMC7595039 DOI: 10.1038/s41598-020-75581-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 10/16/2020] [Indexed: 11/09/2022] Open
Abstract
The retinal basal glia (RBG) is a group of glia that migrates from the optic stalk into the third instar larval eye disc while the photoreceptor cells (PR) are differentiating. The RBGs are grouped into three major classes based on molecular and morphological characteristics: surface glia (SG), wrapping glia (WG) and carpet glia (CG). The SGs migrate and divide. The WGs are postmitotic and wraps PR axons. The CGs have giant nucleus and extensive membrane extension that each covers half of the eye disc. In this study, we used lineage tracing methods to determine the lineage relationships among these glia subtypes and the temporal profile of the lineage decisions for RBG development. We found that the CG lineage segregated from the other RBG very early in the embryonic stage. It has been proposed that the SGs migrate under the CG membrane, which prevented SGs from contacting with the PR axons lying above the CG membrane. Upon passing the front of the CG membrane, which is slightly behind the morphogenetic furrow that marks the front of PR differentiation, the migrating SG contact the nascent PR axon, which in turn release FGF to induce SGs' differentiation into WG. Interestingly, we found that SGs are equally distributed apical and basal to the CG membrane, so that the apical SGs are not prevented from contacting PR axons by CG membrane. Clonal analysis reveals that the apical and basal RBG are derived from distinct lineages determined before they enter the eye disc. Moreover, the basal SG lack the competence to respond to FGFR signaling, preventing its differentiation into WG. Our findings suggest that this novel glia-to-glia differentiation is both dependent on early lineage decision and on a yet unidentified regulatory mechanism, which can provide spatiotemporal coordination of WG differentiation with the progressive differentiation of photoreceptor neurons.
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Affiliation(s)
- Chia-Kang Tsao
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, ROC.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Yu Fen Huang
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, ROC.,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.,, 64 Marvin Lane, Piscataway, NJ, 08854, USA
| | - Y Henry Sun
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, ROC. .,Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC.
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29
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Bostock MP, Prasad AR, Chaouni R, Yuen AC, Sousa-Nunes R, Amoyel M, Fernandes VM. An Immobilization Technique for Long-Term Time-Lapse Imaging of Explanted Drosophila Tissues. Front Cell Dev Biol 2020; 8:590094. [PMID: 33117817 PMCID: PMC7576353 DOI: 10.3389/fcell.2020.590094] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/15/2020] [Indexed: 01/19/2023] Open
Abstract
Time-lapse imaging is an essential tool to study dynamic biological processes that cannot be discerned from fixed samples alone. However, imaging cell- and tissue-level processes in intact animals poses numerous challenges if the organism is opaque and/or motile. Explant cultures of intact tissues circumvent some of these challenges, but sample drift remains a considerable obstacle. We employed a simple yet effective technique to immobilize tissues in medium-bathed agarose. We applied this technique to study multiple Drosophila tissues from first-instar larvae to adult stages in various orientations and with no evidence of anisotropic pressure or stress damage. Using this method, we were able to image fine features for up to 18 h and make novel observations. Specifically, we report that fibers characteristic of quiescent neuroblasts are inherited by their basal daughters during reactivation; that the lamina in the developing visual system is assembled roughly 2-3 columns at a time; that lamina glia positions are dynamic during development; and that the nuclear envelopes of adult testis cyst stem cells do not break down completely during mitosis. In all, we demonstrate that our protocol is well-suited for tissue immobilization and long-term live imaging, enabling new insights into tissue and cell dynamics in Drosophila.
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Affiliation(s)
- Matthew P. Bostock
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Anadika R. Prasad
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Rita Chaouni
- Centre for Developmental Neurobiology, King’s College London, London, United Kingdom
| | - Alice C. Yuen
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Rita Sousa-Nunes
- Centre for Developmental Neurobiology, King’s College London, London, United Kingdom
| | - Marc Amoyel
- 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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30
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Serotonergic modulation of visual neurons in Drosophila melanogaster. PLoS Genet 2020; 16:e1009003. [PMID: 32866139 PMCID: PMC7485980 DOI: 10.1371/journal.pgen.1009003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/11/2020] [Accepted: 07/22/2020] [Indexed: 02/06/2023] Open
Abstract
Sensory systems rely on neuromodulators, such as serotonin, to provide flexibility for information processing as stimuli vary, such as light intensity throughout the day. Serotonergic neurons broadly innervate the optic ganglia of Drosophila melanogaster, a widely used model for studying vision. It remains unclear whether serotonin modulates the physiology of interneurons in the optic ganglia. To address this question, we first mapped the expression patterns of serotonin receptors in the visual system, focusing on a subset of cells with processes in the first optic ganglion, the lamina. Serotonin receptor expression was found in several types of columnar cells in the lamina including 5-HT2B in lamina monopolar cell L2, required for spatiotemporal luminance contrast, and both 5-HT1A and 5-HT1B in T1 cells, whose function is unknown. Subcellular mapping with GFP-tagged 5-HT2B and 5-HT1A constructs indicated that these receptors localize to layer M2 of the medulla, proximal to serotonergic boutons, suggesting that the medulla neuropil is the primary site of serotonergic regulation for these neurons. Exogenous serotonin increased basal intracellular calcium in L2 terminals in layer M2 and modestly decreased the duration of visually induced calcium transients in L2 neurons following repeated dark flashes, but otherwise did not alter the calcium transients. Flies without functional 5-HT2B failed to show an increase in basal calcium in response to serotonin. 5-HT2B mutants also failed to show a change in amplitude in their response to repeated light flashes but other calcium transient parameters were relatively unaffected. While we did not detect serotonin receptor expression in L1 neurons, they, like L2, underwent serotonin-induced changes in basal calcium, presumably via interactions with other cells. These data demonstrate that serotonin modulates the physiology of interneurons involved in early visual processing in Drosophila. Serotonergic neurons innervate the Drosophila melanogaster eye, but it was not known whether serotonin signaling could induce acute physiological responses in visual interneurons. We found serotonin receptors expressed in all neuropils of the optic lobe and identified specific neurons involved in visual information processing that express serotonin receptors. Activation of these receptors increased intracellular calcium in first order interneurons L1 and L2 and may enhance visually induced calcium transients in L2 neurons. These data support a role for the serotonergic neuromodulation of interneurons in the Drosophila visual system.
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31
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Muliyil S, Levet C, Düsterhöft S, Dulloo I, Cowley SA, Freeman M. ADAM17-triggered TNF signalling protects the ageing Drosophila retina from lipid droplet-mediated degeneration. EMBO J 2020; 39:e104415. [PMID: 32715522 PMCID: PMC7459420 DOI: 10.15252/embj.2020104415] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 06/26/2020] [Accepted: 06/29/2020] [Indexed: 12/15/2022] Open
Abstract
Animals have evolved multiple mechanisms to protect themselves from the cumulative effects of age‐related cellular damage. Here, we reveal an unexpected link between the TNF (tumour necrosis factor) inflammatory pathway, triggered by the metalloprotease ADAM17/TACE, and a lipid droplet (LD)‐mediated mechanism of protecting retinal cells from age‐related degeneration. Loss of ADAM17, TNF and the TNF receptor Grindelwald in pigmented glial cells of the Drosophila retina leads to age‐related degeneration of both glia and neurons, preceded by an abnormal accumulation of glial LDs. We show that the glial LDs initially buffer the cells against damage caused by glial and neuronally generated reactive oxygen species (ROS), but that in later life the LDs dissipate, leading to the release of toxic peroxidated lipids. Finally, we demonstrate the existence of a conserved pathway in human iPS‐derived microglia‐like cells, which are central players in neurodegeneration. Overall, we have discovered a pathway mediated by TNF signalling acting not as a trigger of inflammation, but as a cytoprotective factor in the retina.
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Affiliation(s)
- Sonia Muliyil
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Clémence Levet
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Stefan Düsterhöft
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Iqbal Dulloo
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Sally A Cowley
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Matthew Freeman
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
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32
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Kim T, Song B, Lee IS. Drosophila Glia: Models for Human Neurodevelopmental and Neurodegenerative Disorders. Int J Mol Sci 2020; 21:E4859. [PMID: 32660023 PMCID: PMC7402321 DOI: 10.3390/ijms21144859] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 06/27/2020] [Accepted: 07/07/2020] [Indexed: 12/12/2022] Open
Abstract
Glial cells are key players in the proper formation and maintenance of the nervous system, thus contributing to neuronal health and disease in humans. However, little is known about the molecular pathways that govern glia-neuron communications in the diseased brain. Drosophila provides a useful in vivo model to explore the conserved molecular details of glial cell biology and their contributions to brain function and disease susceptibility. Herein, we review recent studies that explore glial functions in normal neuronal development, along with Drosophila models that seek to identify the pathological implications of glial defects in the context of various central nervous system disorders.
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Affiliation(s)
| | | | - Im-Soon Lee
- Department of Biological Sciences, Center for CHANS, Konkuk University, Seoul 05029, Korea; (T.K.); (B.S.)
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33
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Bittern J, Pogodalla N, Ohm H, Brüser L, Kottmeier R, Schirmeier S, Klämbt C. Neuron-glia interaction in the Drosophila nervous system. Dev Neurobiol 2020; 81:438-452. [PMID: 32096904 DOI: 10.1002/dneu.22737] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/11/2020] [Accepted: 02/24/2020] [Indexed: 12/14/2022]
Abstract
Animals are able to move and react in manifold ways to external stimuli. Thus, environmental stimuli need to be detected, information must be processed, and, finally, an output decision must be transmitted to the musculature to get the animal moving. All these processes depend on the nervous system which comprises an intricate neuronal network and many glial cells. Glial cells have an equally important contribution in nervous system function as their neuronal counterpart. Manifold roles are attributed to glia ranging from controlling neuronal cell number and axonal pathfinding to regulation of synapse formation, function, and plasticity. Glial cells metabolically support neurons and contribute to the blood-brain barrier. All of the aforementioned aspects require extensive cell-cell interactions between neurons and glial cells. Not surprisingly, many of these processes are found in all phyla executed by evolutionarily conserved molecules. Here, we review the recent advance in understanding neuron-glia interaction in Drosophila melanogaster to suggest that work in simple model organisms will shed light on the function of mammalian glial cells, too.
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Affiliation(s)
- Jonas Bittern
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Nicole Pogodalla
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Henrike Ohm
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Lena Brüser
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Rita Kottmeier
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Stefanie Schirmeier
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
| | - Christian Klämbt
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Münster, Germany
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34
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Traniello IM, Bukhari SA, Kevill J, Ahmed AC, Hamilton AR, Naeger NL, Schroeder DC, Robinson GE. Meta-analysis of honey bee neurogenomic response links Deformed wing virus type A to precocious behavioral maturation. Sci Rep 2020; 10:3101. [PMID: 32080242 PMCID: PMC7033282 DOI: 10.1038/s41598-020-59808-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 02/04/2020] [Indexed: 02/06/2023] Open
Abstract
Crop pollination by the western honey bee Apis mellifera is vital to agriculture but threatened by alarmingly high levels of colony mortality, especially in Europe and North America. Colony loss is due, in part, to the high viral loads of Deformed wing virus (DWV), transmitted by the ectoparasitic mite Varroa destructor, especially throughout the overwintering period of a honey bee colony. Covert DWV infection is commonplace and has been causally linked to precocious foraging, which itself has been linked to colony loss. Taking advantage of four brain transcriptome studies that unexpectedly revealed evidence of covert DWV-A infection, we set out to explore whether this effect is due to DWV-A mimicking naturally occurring changes in brain gene expression that are associated with behavioral maturation. Consistent with this hypothesis, we found that brain gene expression profiles of DWV-A infected bees resembled those of foragers, even in individuals that were much younger than typical foragers. In addition, brain transcriptional regulatory network analysis revealed a positive association between DWV-A infection and transcription factors previously associated with honey bee foraging behavior. Surprisingly, single-cell RNA-Sequencing implicated glia, not neurons, in this effect; there are relatively few glial cells in the insect brain and they are rarely associated with behavioral plasticity. Covert DWV-A infection also has been linked to impaired learning, which together with precocious foraging can lead to increased occurrence of infected bees from one colony mistakenly entering another colony, especially under crowded modern apiary conditions. These findings provide new insights into the mechanisms by which DWV-A affects honey bee health and colony survival.
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Affiliation(s)
- Ian M Traniello
- Neuroscience Program, University of Illinois at Urbana-Champaign, (UIUC), Urbana, IL, USA.
- Carl R. Woese Institute for Genomic Biology, UIUC, Urbana, USA.
| | - Syed Abbas Bukhari
- Carl R. Woese Institute for Genomic Biology, UIUC, Urbana, USA
- Department of Animal Biology, UIUC, Urbana, USA
| | - Jessica Kevill
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN, USA
| | - Amy Cash Ahmed
- Carl R. Woese Institute for Genomic Biology, UIUC, Urbana, USA
| | - Adam R Hamilton
- Carl R. Woese Institute for Genomic Biology, UIUC, Urbana, USA
| | - Nicholas L Naeger
- Department of Entomology, Washington State University, Pullman, WA, USA
| | - Declan C Schroeder
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN, USA
- School of Biological Sciences, University of Reading, Reading, UK
| | - Gene E Robinson
- Neuroscience Program, University of Illinois at Urbana-Champaign, (UIUC), Urbana, IL, USA
- Carl R. Woese Institute for Genomic Biology, UIUC, Urbana, USA
- Department of Entomology, UIUC, Urbana, USA
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35
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Shetty AK, Zanirati G. The Interstitial System of the Brain in Health and Disease. Aging Dis 2020; 11:200-211. [PMID: 32010493 PMCID: PMC6961771 DOI: 10.14336/ad.2020.0103] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 01/03/2020] [Indexed: 12/13/2022] Open
Abstract
The brain interstitial fluid (ISF) and the cerebrospinal fluid (CSF) cushion and support the brain cells. The ISF occupies the brain interstitial system (ISS), whereas the CSF fills the brain ventricles and the subarachnoid space. The brain ISS is an asymmetrical, tortuous, and exceptionally confined space between neural cells and the brain microvasculature. Recently, with a newly developed in vivo measuring technique, a series of discoveries have been made in the brain ISS and the drainage of ISF. The goal of this review is to confer recent advances in our understanding of the brain ISS, including its structure, function, and the various processes mediating or disrupting ISF drainage in physiological and pathological conditions. The brain ISF in the deep brain regions has recently been demonstrated to drain in a compartmentalized ISS instead of a highly connected system, together with the drainage of ISF into the cerebrospinal fluid (CSF) at the surface of the cerebral cortex and the transportation from CSF into cervical lymph nodes. Besides, accumulation of tau in the brain ISS in conditions such as Alzheimer’s disease and its link to the sleep-wake cycle and sleep deprivation, clearance of ISF in a deep sleep via increased CSF flow, novel approaches to remove beta-amyloid from the brain ISS, and obstruction to the ISF drainage in neurological conditions are deliberated. Moreover, the role of ISS in the passage of extracellular vesicles (EVs) released from neural cells and the rapid targeting of therapeutic EVs into neural cells in the entire brain following an intranasal administration, and the promise and limitations of ISS based drug delivery approaches are discussed
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Affiliation(s)
- Ashok K Shetty
- 1Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX 77843, USA
| | - Gabriele Zanirati
- 2Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil
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36
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George J, Tuomela T, Kemppainen E, Nurminen A, Braun S, Yalgin C, Jacobs HT. Mitochondrial dysfunction generates a growth-restraining signal linked to pyruvate in Drosophila larvae. Fly (Austin) 2019; 13:12-28. [PMID: 31526131 PMCID: PMC6988875 DOI: 10.1080/19336934.2019.1662266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The Drosophila bang-sensitive mutant tko25t, manifesting a global deficiency in oxidative phosphorylation due to a mitochondrial protein synthesis defect, exhibits a pronounced delay in larval development. We previously identified a number of metabolic abnormalities in tko25t larvae, including elevated pyruvate and lactate, and found the larval gut to be a crucial tissue for the regulation of larval growth in the mutant. Here we established that expression of wild-type tko in any of several other tissues of tko25t also partially alleviates developmental delay. The effects appeared to be additive, whilst knockdown of tko in a variety of specific tissues phenocopied tko25t, producing developmental delay and bang-sensitivity. These findings imply the existence of a systemic signal regulating growth in response to mitochondrial dysfunction. Drugs and RNAi-targeted on pyruvate metabolism interacted with tko25t in ways that implicated pyruvate or one of its metabolic derivatives in playing a central role in generating such a signal. RNA-seq revealed that dietary pyruvate-induced changes in transcript representation were mostly non-coherent with those produced by tko25t or high-sugar, consistent with the idea that growth regulation operates primarily at the translational and/or metabolic level.
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Affiliation(s)
- Jack George
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Tea Tuomela
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Esko Kemppainen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Antti Nurminen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Samuel Braun
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Cagri Yalgin
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Howard T Jacobs
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.,Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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37
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Traniello IM, Chen Z, Bagchi VA, Robinson GE. Valence of social information is encoded in different subpopulations of mushroom body Kenyon cells in the honeybee brain. Proc Biol Sci 2019; 286:20190901. [PMID: 31506059 DOI: 10.1098/rspb.2019.0901] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Over 600 Myr of evolutionary divergence between vertebrates and invertebrates is associated with considerable neuroanatomical variation both across and within these lineages. By contrast, valence encoding is an important behavioural trait that is evolutionarily conserved across vertebrates and invertebrates, and enables individuals to distinguish between positive (potentially beneficial) and negative (potentially harmful) situations. We tested the hypothesis that social interactions of positive and negative valence are modularly encoded in the honeybee brain (i.e. encoded in different cellular subpopulations) as in vertebrate brains. In vertebrates, neural activation patterns are distributed across distinct parts of the brain, suggesting that discrete circuits encode positive or negative stimuli. Evidence for this hypothesis would suggest a deep homology of neural organization between insects and vertebrates for valence encoding, despite vastly different brain sizes. Alternatively, overlapping localization of valenced social information in the brain would imply a 're-use' of circuitry in response to positive and negative social contexts, potentially to overcome the energetic constraints of a tiny brain. We used immediate early gene expression to map positively and negatively valenced social interactions in the brain of the western honeybee Apis mellifera. We found that the valence of a social signal is represented by distinct anatomical subregions of the mushroom bodies, an invertebrate sensory neuropil associated with social behaviour, multimodal sensory integration, learning and memory. Our results suggest that the modularization of valenced social information in the brain is a fundamental property of neuroanatomical organization.
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Affiliation(s)
- Ian M Traniello
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Zhenqing Chen
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Vikram A Bagchi
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Gene E Robinson
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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38
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Nakano R, Iwamura M, Obikawa A, Togane Y, Hara Y, Fukuhara T, Tomaru M, Takano-Shimizu T, Tsujimura H. Cortex glia clear dead young neurons via Drpr/dCed-6/Shark and Crk/Mbc/dCed-12 signaling pathways in the developing Drosophila optic lobe. Dev Biol 2019; 453:68-85. [PMID: 31063730 DOI: 10.1016/j.ydbio.2019.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 04/25/2019] [Accepted: 05/02/2019] [Indexed: 02/06/2023]
Abstract
The molecular and cellular mechanism for clearance of dead neurons was explored in the developing Drosophila optic lobe. During development of the optic lobe, many neural cells die through apoptosis, and corpses are immediately removed in the early pupal stage. Most of the cells that die in the optic lobe are young neurons that have not extended neurites. In this study, we showed that clearance was carried out by cortex glia via a phagocytosis receptor, Draper (Drpr). drpr expression in cortex glia from the second instar larval to early pupal stages was required and sufficient for clearance. Drpr that was expressed in other subtypes of glia did not mediate clearance. Shark and Ced-6 mediated clearance of Drpr. The Crk/Mbc/dCed-12 pathway was partially involved in clearance, but the role was minor. Suppression of the function of Pretaporter, CaBP1 and phosphatidylserine delayed clearance, suggesting a possibility for these molecules to function as Drpr ligands in the developing optic lobe.
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Affiliation(s)
- Ryosuke Nakano
- Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Department of Drosophila Genomics and Genetic Resources, Center for Advanced Insect Research Promotion, Kyoto Institute of Technology, Saga Ippongi-cho, Ukyo-ku, Kyoto 616-8354, Japan
| | - Masashi Iwamura
- Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Akiko Obikawa
- Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan; Department of Drosophila Genomics and Genetic Resources, Center for Advanced Insect Research Promotion, Kyoto Institute of Technology, Saga Ippongi-cho, Ukyo-ku, Kyoto 616-8354, Japan
| | - Yu Togane
- Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Yusuke Hara
- Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Toshiyuki Fukuhara
- Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
| | - Masatoshi Tomaru
- Department of Drosophila Genomics and Genetic Resources, Center for Advanced Insect Research Promotion, Kyoto Institute of Technology, Saga Ippongi-cho, Ukyo-ku, Kyoto 616-8354, Japan
| | - Toshiyuki Takano-Shimizu
- Department of Drosophila Genomics and Genetic Resources, Center for Advanced Insect Research Promotion, Kyoto Institute of Technology, Saga Ippongi-cho, Ukyo-ku, Kyoto 616-8354, Japan
| | - Hidenobu Tsujimura
- Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan.
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39
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Split-QF System for Fine-Tuned Transgene Expression in Drosophila. Genetics 2019; 212:53-63. [PMID: 30862621 PMCID: PMC6499530 DOI: 10.1534/genetics.119.302034] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 03/03/2019] [Indexed: 11/18/2022] Open
Abstract
The Q-system is a binary expression system that works well across species. Here, we report the development and demonstrate the applications of a split-QF system that drives strong expression in Drosophila, is repressible by QS, and is inducible by a small nontoxic molecule (quinic acid). The split-QF system is fully compatible with existing split-GAL4 and split-LexA lines, thus greatly expanding the range of possible advanced intersectional experiments and anatomical, physiological, and behavioral assays in Drosophila, and in other organisms.
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Stenesen D, Moehlman AT, Schellinger JN, Rodan AR, Krämer H. The glial sodium-potassium-2-chloride cotransporter is required for synaptic transmission in the Drosophila visual system. Sci Rep 2019; 9:2475. [PMID: 30792494 PMCID: PMC6385505 DOI: 10.1038/s41598-019-38850-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 01/08/2019] [Indexed: 02/07/2023] Open
Abstract
The Drosophila Ncc69 gene encodes a Na+-K+-2Cl−-cotransporter (NKCC) that is critical for regulating intra- and extracellular ionic conditions in different tissues. Here, we show that the Ncc69 transporter is necessary for fly vision and that its expression is required non-autonomously in glia to maintain visual synaptic transmission. Flies mutant for Ncc69 exhibit normal photoreceptor depolarization in response to a light pulse but lack the ON and OFF-transients characteristic of postsynaptic responses of lamina neurons, indicating a failure in synaptic transmission. We also find that synaptic transmission requires the Ncc69 regulatory kinases WNK and Fray in glia. The ERG phenotype is associated with a defect in the recycling of the histamine neurotransmitter. Ncc69 mutants exhibit higher levels of the transport metabolite carcinine in lamina cartridges, with its accumulation most intense in the extracellular space. Our work reveals a novel role of glial NKCC transporters in synaptic transmission, possibly through regulating extracellular ionic conditions.
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Affiliation(s)
- Drew Stenesen
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.,Biology Department, University of Dallas, Irving, TX, 75062, USA
| | - Andrew T Moehlman
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jeffrey N Schellinger
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Aylin R Rodan
- Department of Internal Medicine, Division of Nephrology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA. .,Department of Internal Medicine, Division of Nephrology and Hypertension and Molecular Medicine Program, University of Utah, Salt Lake City, UT, 84112, USA. .,Medical Service, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah, USA.
| | - Helmut Krämer
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA. .,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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Abstract
Neuroglia represent a diverse population of non-neuronal cells in the nervous systems, be that peripheral, central, enteric or autonomic nervous system. Arguably, these cells represent about half of the volume of the human brain. This volumetric ratio, and by extension glia to neurone ratio, not only widely differ depending on the size of the animal species brain and its positioning on the phylogenetic tree, but also vary between the regions of an individual brain. Neuroglia derived from a dual origin (ectoderm and mesodermal) and in an assorted morphology, yet their functional traits can be mainly classified into being keepers of homeostasis (water, ions, neurotransmitters, metabolites, fuels, etc.) and defenders (e.g., against microbial organisms, etc.) of the nervous system. As these capabilities go awry, neuroglia ultimately define their fundamental role in most, if not, all neuropathologies. This concept presented in this chapter serves as a general introduction into the world of neuroglia and subsequent topics covered by this book.
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Abstract
As the nervous system evolved from the diffused to centralised form, the neurones were joined by the appearance of the supportive cells, the neuroglia. Arguably, these non-neuronal cells evolve into a more diversified cell family than the neurones are. The first ancestral neuroglia appeared in flatworms being mesenchymal in origin. In the nematode C. elegans proto-astrocytes/supportive glia of ectodermal origin emerged, albeit the ensheathment of axons by glial cells occurred later in prawns. The multilayered myelin occurred by convergent evolution of oligodendrocytes and Schwann cells in vertebrates above the jawless fishes. Nutritive partitioning of the brain from the rest of the body appeared in insects when the hemolymph-brain barrier, a predecessor of the blood-brain barrier was formed. The defensive cellular mechanism required specialisation of bona fide immune cells, microglia, a process that occurred in the nervous system of leeches, bivalves, snails, insects and above. In ascending phylogeny, new type of glial cells, such as scaffolding radial glia, appeared and as the bran sizes enlarged, the glia to neurone ratio increased. Humans possess some unique glial cells not seen in other animals.
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Yang Y, Jackson R. Astrocyte identity: evolutionary perspectives on astrocyte functions and heterogeneity. Curr Opin Neurobiol 2018; 56:40-46. [PMID: 30529823 DOI: 10.1016/j.conb.2018.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 11/18/2018] [Accepted: 11/21/2018] [Indexed: 10/27/2022]
Abstract
The development of new animal models, in vivo isolation approaches, and improvements in genome-wide RNA expression methods have greatly propelled molecular profiling of astrocytes and the characterization of astrocyte heterogeneity in the central nervous system (CNS). Several recent reviews have comprehensively discussed the molecular and functional diversity of mammalian astrocytes. In this brief review, we emphasize interspecies comparisons and an evolutionary perspective regarding the astro(glia) of vertebrates and invertebrates which are similar in form and function. This analysis has revealed conserved astrocyte transcriptomes in the fly, mouse and human. We also offer opinions about the pattern and origin of astrocyte heterogeneity in the CNS.
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Affiliation(s)
- Yongjie Yang
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Ave, Boston, MA, 02111, United States; Sackler School of Biomedical Sciences, Tufts University, 145 Harrison Ave, Boston, MA, 02111, United States.
| | - Rob Jackson
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Ave, Boston, MA, 02111, United States; Sackler School of Biomedical Sciences, Tufts University, 145 Harrison Ave, Boston, MA, 02111, United States.
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Artiushin G, Zhang SL, Tricoire H, Sehgal A. Endocytosis at the Drosophila blood-brain barrier as a function for sleep. eLife 2018; 7:e43326. [PMID: 30475209 PMCID: PMC6255390 DOI: 10.7554/elife.43326] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 11/09/2018] [Indexed: 12/18/2022] Open
Abstract
Glia are important modulators of neural activity, yet few studies link glia to sleep regulation. We find that blocking activity of the endocytosis protein, dynamin, in adult Drosophila glia increases sleep and enhances sleep need, manifest as resistance to sleep deprivation. Surface glia comprising the fly equivalent of the blood-brain barrier (BBB) mediate the effect of dynamin on sleep. Blocking dynamin in the surface glia causes ultrastructural changes, albeit without compromising the integrity of the barrier. Supporting a role for endocytic trafficking in sleep, a screen of Rab GTPases identifies sleep-modulating effects of the recycling endosome Rab11 in surface glia. We also find that endocytosis is increased in BBB glia during sleep and reflects sleep need. We propose that endocytic trafficking through the BBB represents a function of sleep.
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Affiliation(s)
- Gregory Artiushin
- Neuroscience Graduate GroupPerelman School of Medicine, University of PennsylvaniaPhiladelphiaUnited States
| | - Shirley L Zhang
- Howard Hughes Medical InstitutePerelman School of Medicine, University of PennsylvaniaPhiladelphiaUnited States
| | - Hervé Tricoire
- Laboratory of Degenerative Processes, Stress and AgingUMR8251, Université Paris DiderotParisFrance
| | - Amita Sehgal
- Neuroscience Graduate GroupPerelman School of Medicine, University of PennsylvaniaPhiladelphiaUnited States
- Howard Hughes Medical InstitutePerelman School of Medicine, University of PennsylvaniaPhiladelphiaUnited States
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Chen P, Matsushita A, Wakakuwa M, Arikawa K. Immunolocalization suggests a role of the histamine‐gated chloride channel PxHCLB in spectral opponent processing in butterfly photoreceptors. J Comp Neurol 2018; 527:753-766. [DOI: 10.1002/cne.24558] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Revised: 08/31/2018] [Accepted: 10/04/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Pei‐Ju Chen
- Department of Evolutionary Studies of BiosystemsSOKENDAI (The Graduate University for Advanced Studies) Hayama Japan
| | - Atsuko Matsushita
- Department of Evolutionary Studies of BiosystemsSOKENDAI (The Graduate University for Advanced Studies) Hayama Japan
| | - Motohiro Wakakuwa
- Department of Evolutionary Studies of BiosystemsSOKENDAI (The Graduate University for Advanced Studies) Hayama Japan
| | - Kentaro Arikawa
- Department of Evolutionary Studies of BiosystemsSOKENDAI (The Graduate University for Advanced Studies) Hayama Japan
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Regulation of Circadian Behavior by Astroglial MicroRNAs in Drosophila. Genetics 2018; 208:1195-1207. [PMID: 29487148 DOI: 10.1534/genetics.117.300342] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 01/08/2018] [Indexed: 11/18/2022] Open
Abstract
We describe a genome-wide microRNA (miRNA)-based screen to identify brain glial cell functions required for circadian behavior. To identify glial miRNAs that regulate circadian rhythmicity, we employed a collection of "miR-sponges" to inhibit miRNA function in a glia-specific manner. Our initial screen identified 20 glial miRNAs that regulate circadian behavior. We studied two miRNAs, miR-263b and miR-274, in detail and found that both function in adult astrocytes to regulate behavior. Astrocyte-specific inhibition of miR-263b or miR-274 in adults acutely impairs circadian locomotor activity rhythms with no effect on glial or clock neuronal cell viability. To identify potential RNA targets of miR-263b and miR-274, we screened 35 predicted miRNA targets, employing RNA interference-based approaches. Glial knockdown of two putative miR-274 targets, CG4328 and MESK2, resulted in significantly decreased rhythmicity. Homology of the miR-274 targets to mammalian counterparts suggests mechanisms that might be relevant for the glial regulation of rhythmicity.
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Allen AM, Anreiter I, Vesterberg A, Douglas SJ, Sokolowski MB. Pleiotropy of the Drosophila melanogaster foraging gene on larval feeding-related traits. J Neurogenet 2018; 32:256-266. [PMID: 30303018 PMCID: PMC6309726 DOI: 10.1080/01677063.2018.1500572] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 07/09/2018] [Indexed: 10/28/2022]
Abstract
Little is known about the molecular underpinning of behavioral pleiotropy. The Drosophila melanogaster foraging gene is highly pleiotropic, affecting many independent larval and adult phenotypes. Included in foraging's multiple phenotypes are larval foraging path length, triglyceride levels, and food intake. foraging has a complex structure with four promoters and 21 transcripts that encode nine protein isoforms of a cGMP dependent protein kinase (PKG). We examined if foraging's complex molecular structure underlies the behavioral pleiotropy associated with this gene. Using a promotor analysis strategy, we cloned DNA fragments upstream of each of foraging's transcription start sites and generated four separate forpr-Gal4s. Supporting our hypothesis of modular function, they had discrete, restricted expression patterns throughout the larva. In the CNS, forpr1-Gal4 and forpr4-Gal4 were expressed in neurons while forpr2-Gal4 and forpr3-Gal4 were expressed in glia cells. In the gastric system, forpr1-Gal4 and forpr3-Gal4 were expressed in enteroendocrine cells of the midgut while forpr2-Gal4 was expressed in the stem cells of the midgut. forpr3-Gal4 was expressed in the midgut enterocytes, and midgut and hindgut visceral muscle. forpr4-Gal4's gastric system expression was restricted to the hindgut. We also found promoter specific expression in the larval fat body, salivary glands, and body muscle. The modularity of foraging's molecular structure was also apparent in the phenotypic rescues. We rescued larval path length, triglyceride levels (bordered on significance), and food intake of for0 null larvae using different forpr-Gal4s to drive UAS-forcDNA. In a foraging null genetic background, forpr1-Gal4 was the only promoter driven Gal4 to rescue larval path length, forpr3-Gal4 altered triglyceride levels, and forpr4-Gal4 rescued food intake. Our results refine the spatial expression responsible for foraging's associated phenotypes, as well as the sub-regions of the locus responsible for their expression. foraging's pleiotropy arises at least in part from the individual contributions of its four promoters.
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Affiliation(s)
- A. M. Allen
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada, M5S 3G5
- Current address: Centre for Neural Circuits and Behaviour, University of Oxford, Oxford, UK, OX1 3SR
| | - I. Anreiter
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada, M5S 3B2
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, West Tower, 661 University Ave., Suite 505, Toronto, Ontario, Canada, M5G 1M1
| | - A. Vesterberg
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada, M5S 3B2
| | - S. J. Douglas
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada, M5S 3G5
| | - M. B. Sokolowski
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada, M5S 3G5
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, Canada, M5S 3B2
- Child and Brain Development Program, Canadian Institute for Advanced Research (CIFAR), MaRS Centre, West Tower, 661 University Ave., Suite 505, Toronto, Ontario, Canada, M5G 1M1
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Borycz J, Ziegler A, Borycz JA, Uhlenbrock G, Tapken D, Caceres L, Hollmann M, Hovemann BT, Meinertzhagen IA. Location and functions of Inebriated in the Drosophila eye. Biol Open 2018; 7:7/7/bio034926. [PMID: 30037884 PMCID: PMC6078345 DOI: 10.1242/bio.034926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Histamine (HA) is a neurotransmitter in arthropod photoreceptors. It is recycled via conjugation to β-alanine to form β-alanylhistamine (carcinine). Conjugation occurs in epithelial glia that surround photoreceptor terminals in the first optic neuropil, and carcinine (CA) is then transported back to photoreceptors and cleaved to liberate HA and β-alanine. The gene Inebriated (Ine) encodes an Na+/Cl--dependent SLC6 family transporter translated as two protein isoforms, long (P1) and short (P2). Photoreceptors specifically express Ine-P2 whereas Ine-P1 is expressed in non-neuronal cells. Both ine1 and ine3 have significantly reduced head HA contents compared with wild type, and a smaller increase in head HA after drinking 1% CA. Similarly, uptake of 0.1% CA was reduced in ine1 and ine3 mutant synaptosomes, but increased by 90% and 84% respectively for fractions incubated in 0.05% β-Ala, compared with wild type. Screening potential substrates in Ine expressing Xenopus oocytes revealed very little response to carcinine and β-Ala but increased conductance with glycine. Both ine1 and ine3 mutant responses in light-dark phototaxis did not differ from wild-type. Collectively our results suggest that Inebriated functions in an adjunct role as a transporter to the previously reported carcinine transporter CarT.
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Affiliation(s)
- Janusz Borycz
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Anna Ziegler
- Receptor Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, 44780 Bochum, Germany
| | - Jolanta A Borycz
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Guido Uhlenbrock
- Receptor Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, 44780 Bochum, Germany
| | - Daniel Tapken
- Receptor Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, 44780 Bochum, Germany
| | - Lucia Caceres
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Michael Hollmann
- Molecular Cell Biochemistry, Ruhr University of Bochum, 44780 Bochum, Germany
| | - Bernhard T Hovemann
- Receptor Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University of Bochum, 44780 Bochum, Germany
| | - Ian A Meinertzhagen
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada .,Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
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Abstract
In the field of neuroscience and, more specifically glial cell biology, one of the most fundamentally intriguing and enduring questions has been “how many neuronal cells—neurones and glia—are there in the human brain?”. From the outset, the driving force behind this question was undoubtedly the scientific quest for knowledge of why humans are more intelligent than even our nearest relatives; the ‘neuronal doctrine’ dictated we must have more neurones than other animals. The early histological studies indicated a vast space between neurones that was filled by ‘nervenkitt’, later identified as neuroglia; arguably, this was the origin of the myth that glia massively outnumber neurones in the human brain. The myth eventually became embedded in ideology when later studies seemed to confirm that glia outnumber neurones in the human cortex—the seat of humanity—and that there was an inevitable rise in the glia-to-neurone ratio (GNR) as we climbed the evolutionary tree. This could be described as the ‘glial doctrine’—that the rise of intelligence and the rise of glia go hand-in-hand. In many ways, the GNR became a mantra for working on glial cells at a time when the neuronal doctrine ruled the world. However, the work of Suzana Herculano-Houzel which she reviews in this first volume of Neuroglia has led the way in demonstrating that neurones and glia are almost equal in number in the human cortex and there is no inexorable phylogenetic rise in the GNR. In this commentary we chart the fall and decline of the mythology of the GNR.
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Shah AK, Kreibich CD, Amdam GV, Münch D. Metabolic enzymes in glial cells of the honeybee brain and their associations with aging, starvation and food response. PLoS One 2018; 13:e0198322. [PMID: 29927967 PMCID: PMC6013123 DOI: 10.1371/journal.pone.0198322] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 05/17/2018] [Indexed: 12/03/2022] Open
Abstract
The honey bee has been extensively studied as a model for neuronal circuit and memory function and more recently has emerged as an unconventional model in biogerontology. Yet, the detailed knowledge of neuronal processing in the honey bee brain contrasts with the very sparse information available on glial cells. In other systems glial cells are involved in nutritional homeostasis, detoxification, and aging. These glial functions have been linked to metabolic enzymes, such as glutamine synthetase and glycogen phosphorylase. As a step in identifying functional roles and potential differences among honey bee glial types, we examined the spatial distribution of these enzymes and asked if enzyme abundance is associated with aging and other processes essential for survival. Using immunohistochemistry and confocal laser microscopy we demonstrate that glutamine synthetase and glycogen phosphorylase are abundant in glia but appear to co-localize with different glial sub-types. The overall spatial distribution of both enzymes was not homogenous and differed markedly between different neuropiles and also within each neuropil. Using semi-quantitative Western blotting we found that rapid aging, typically observed in shortest-lived worker bees (foragers), was associated with declining enzyme levels. Further, we found enzyme abundance changes after severe starvation stress, and that glutamine synthetase is associated with food response. Together, our data indicate that aging and nutritional physiology in bees are linked to glial specific metabolic enzymes. Enzyme specific localization patterns suggest a functional differentiation among identified glial types.
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Affiliation(s)
- Ashish K. Shah
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Aas, Norway
| | - Claus D. Kreibich
- Faculty of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Aas, Norway
| | - Gro V. Amdam
- Faculty of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Aas, Norway
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Daniel Münch
- Faculty of Ecology and Natural Resource Management, Norwegian University of Life Sciences, Aas, Norway
- * E-mail:
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