1
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Ohm H, Rey S, Klämbt C. Clustering of voltage-gated ion channels as an evolutionary trigger of myelin formation. Neural Regen Res 2024; 19:1631-1632. [PMID: 38103215 PMCID: PMC10960306 DOI: 10.4103/1673-5374.389636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/12/2023] [Accepted: 10/26/2023] [Indexed: 12/18/2023] Open
Affiliation(s)
- Henrike Ohm
- Institut für Neuro- und Verhaltensbiologie, Münster, Germany
| | - Simone Rey
- Institut für Neuro- und Verhaltensbiologie, Münster, Germany
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2
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Chang YC, Peng YJ, Lee JY, Chag KT. Peripheral glia and neurons jointly regulate activity-induced synaptic remodeling at the Drosophila neuromuscular junction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.27.600908. [PMID: 39005352 PMCID: PMC11244886 DOI: 10.1101/2024.06.27.600908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
In the nervous system, reliable communication depends on the ability of neurons to adaptively remodel their synaptic structure and function in response to changes in neuronal activity. While neurons are the main drivers of synaptic plasticity, glial cells are increasingly recognized for their roles as active modulators. However, the underlying molecular mechanisms remain unclear. Here, using Drosophila neuromuscular junction as a model system for a tripartite synapse, we show that peripheral glial cells collaborate with neurons at the NMJ to regulate activity-induced synaptic remodeling, in part through a protein called shriveled (Shv). Shv is an activator of integrin signaling previously shown to be released by neurons during intense stimulation at the fly NMJ to regulate activity-induced synaptic remodeling. We demonstrate that Shv is also present in peripheral glia, and glial Shv is both necessary and sufficient for synaptic remodeling. However, unlike neuronal Shv, glial Shv does not activate integrin signaling at the NMJ. Instead, it regulates synaptic plasticity in two ways: 1) maintaining the extracellular balance of neuronal Shv proteins to regulate integrin signaling, and 2) controlling ambient extracellular glutamate concentration to regulate postsynaptic glutamate receptor abundance. Loss of glial cells showed the same phenotype as loss of Shv in glia. Together, these results reveal that neurons and glial cells homeostatically regulate extracellular Shv protein levels to control activity-induced synaptic remodeling. Additionally, peripheral glia maintains postsynaptic glutamate receptor abundance and contribute to activity-induced synaptic remodeling by regulating ambient glutamate concentration at the fly NMJ.
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3
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Clayworth K, Gilbert M, Auld V. Cell Biology Techniques for Studying Drosophila Peripheral Glial Cells. Cold Spring Harb Protoc 2024; 2024:pdb.top108159. [PMID: 37399179 DOI: 10.1101/pdb.top108159] [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: 07/05/2023]
Abstract
Glial cells are essential for the proper development and functioning of the peripheral nervous system (PNS). The ability to study the biology of glial cells is therefore critical for our ability to understand PNS biology and address PNS maladies. The genetic and proteomic pathways underlying vertebrate peripheral glial biology are understandably complex, with many layers of redundancy making it sometimes difficult to study certain facets of PNS biology. Fortunately, many aspects of vertebrate peripheral glial biology are conserved with those of the fruit fly, Drosophila melanogaster With simple and powerful genetic tools and fast generation times, Drosophila presents an accessible and versatile model for studying the biology of peripheral glia. We introduce here three techniques for studying the cell biology of peripheral glia of Drosophila third-instar larvae. With fine dissection tools and common laboratory reagents, third-instar larvae can be dissected, with extraneous tissues removed, revealing the central nervous system (CNS) and PNS to be processed using a standard immunolabeling protocol. To improve the resolution of peripheral nerves in the z-plane, we describe a cryosectioning method to achieve 10- to 20-µm thick coronal sections of whole larvae, which can then be immunolabeled using a modified version of standard immunolabeling techniques. Finally, we describe a proximity ligation assay (PLA) for detecting close proximity between two proteins-thus inferring protein interaction-in vivo in third-instar larvae. These methods, further described in our associated protocols, can be used to improve our understanding of Drosophila peripheral glia biology, and thus our understanding of PNS biology.
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Affiliation(s)
- Katherine Clayworth
- Department of Zoology, Cell and Developmental Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Mary Gilbert
- Department of Zoology, Cell and Developmental Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Vanessa Auld
- Department of Zoology, Cell and Developmental Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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4
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Contreras EG, Kautzmann S, Klämbt C. The Drosophila blood-brain barrier invades the nervous system in a GPCR-dependent manner. Front Cell Neurosci 2024; 18:1397627. [PMID: 38846639 PMCID: PMC11153769 DOI: 10.3389/fncel.2024.1397627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 05/07/2024] [Indexed: 06/09/2024] Open
Abstract
The blood-brain barrier (BBB) represents a crucial interface between the circulatory system and the brain. In Drosophila melanogaster, the BBB is composed of perineurial and subperineurial glial cells. The perineurial glial cells are small mitotically active cells forming the outermost layer of the nervous system and are engaged in nutrient uptake. The subperineurial glial cells form occluding septate junctions to prevent paracellular diffusion of macromolecules into the nervous system. To address whether the subperineurial glia just form a simple barrier or whether they establish specific contacts with both the perineurial glial cells and inner central nervous system (CNS) cells, we undertook a detailed morphological analysis. Using genetically encoded markers alongside with high-resolution laser scanning confocal microscopy and transmission electron microscopy, we identified thin cell processes extending into the perineurial layer and into the CNS cortex. Interestingly, long cell processes were observed reaching the glia ensheathing the neuropil of the central brain. GFP reconstitution experiments highlighted multiple regions of membrane contacts between subperineurial and ensheathing glia. Furthermore, we identify the G-protein-coupled receptor (GPCR) Moody as negative regulator of the growth of subperineurial cell processes. Loss of moody triggered a massive overgrowth of subperineurial cell processes into the CNS cortex and, moreover, affected the polarized localization of the xenobiotic transporter Mdr65. Finally, we found that GPCR signaling, but not septate junction formation, is responsible for controlling membrane overgrowth. Our findings support the notion that the Drosophila BBB is able to bridge the communication gap between circulation and synaptic regions of the brain by long cell processes.
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Affiliation(s)
| | | | - Christian Klämbt
- Multiscale Imaging Center, Institute of Neuro- and Behavioral Biology, University of Münster, Münster, Germany
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5
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Park K, Choi H, Han IJ, Asefa WR, Jeong C, Yu S, Jeong H, Choi M, Yoon SE, Kim YJ, Choi MS, Kwon JY. Molecular and cellular organization of odorant binding protein genes in Drosophila. Heliyon 2024; 10:e29358. [PMID: 38694054 PMCID: PMC11058302 DOI: 10.1016/j.heliyon.2024.e29358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/01/2024] [Accepted: 04/05/2024] [Indexed: 05/03/2024] Open
Abstract
Chemosensation is important for the survival and reproduction of animals. The odorant binding proteins (OBPs) are thought to be involved in chemosensation together with chemosensory receptors. While OBPs were initially considered to deliver hydrophobic odorants to olfactory receptors in the aqueous lymph solution, recent studies suggest more complex roles in various organs. Here, we use GAL4 transgenes to systematically analyze the expression patterns of all 52 members of the Obp gene family and 3 related chemosensory protein genes in adult Drosophila, focusing on chemosensory organs such as the antenna, maxillary palp, pharynx, and labellum, and other organs such as the brain, ventral nerve cord, leg, wing, and intestine. The OBPs were observed to express in diverse organs and in multiple cell types, suggesting that these proteins can indeed carry out diverse functional roles. Also, we constructed 10 labellar-expressing Obp mutants, and obtained behavioral evidence that these OBPs may be involved in bitter sensing. The resources we constructed should be useful for future Drosophila OBP gene family research.
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Affiliation(s)
- Keehyun Park
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Hyungjun Choi
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - I Joon Han
- Sungkyunkwan University School of Medicine, Seoul, 06351, Republic of Korea
| | - Wayessa Rahel Asefa
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Chaiyoung Jeong
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Seungyun Yu
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Hanhee Jeong
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Minkook Choi
- Department of Oral Biology, Yonsei University College of Dentistry, Seoul, 03722, Republic of Korea
| | - Sung-Eun Yoon
- Korea Drosophila Resource Center, Gwangju, 61005, Republic of Korea
| | - Young-Joon Kim
- Korea Drosophila Resource Center, Gwangju, 61005, Republic of Korea
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea
| | - Min Sung Choi
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Jae Young Kwon
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, Republic of Korea
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6
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Pan X, Huang W, Nie G, Wang C, Wang H. Ultrasound-Sensitive Intelligent Nanosystems: A Promising Strategy for the Treatment of Neurological Diseases. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2303180. [PMID: 37871967 DOI: 10.1002/adma.202303180] [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: 04/05/2023] [Revised: 09/26/2023] [Indexed: 10/25/2023]
Abstract
Neurological diseases are a major global health challenge, affecting hundreds of millions of people worldwide. Ultrasound therapy plays an irreplaceable role in the treatment of neurological diseases due to its noninvasive, highly focused, and strong tissue penetration capabilities. However, the complexity of brain and nervous system and the safety risks associated with prolonged exposure to ultrasound therapy severely limit the applicability of ultrasound therapy. Ultrasound-sensitive intelligent nanosystems (USINs) are a novel therapeutic strategy for neurological diseases that bring greater spatiotemporal controllability and improve safety to overcome these challenges. This review provides a detailed overview of therapeutic strategies and clinical advances of ultrasound in neurological diseases, focusing on the potential of USINs-based ultrasound in the treatment of neurological diseases. Based on the physical and chemical effects induced by ultrasound, rational design of USINs is a prerequisite for improving the efficacy of ultrasound therapy. Recent developments of ultrasound-sensitive nanocarriers and nanoagents are systemically reviewed. Finally, the challenges and developing prospects of USINs are discussed in depth, with a view to providing useful insights and guidance for efficient ultrasound treatment of neurological diseases.
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Affiliation(s)
- Xueting Pan
- CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Wenping Huang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- School of Nanoscience and Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guangjun Nie
- CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- School of Nanoscience and Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Changyong Wang
- Beijing Institute of Basic Medical Sciences, 27 Taiping Road, Beijing, 100850, China
| | - Hai Wang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing, 100190, China
- School of Nanoscience and Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
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7
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Karashchuk L, Li JS(L, Chou GM, Walling-Bell S, Brunton SL, Tuthill JC, Brunton BW. Sensorimotor delays constrain robust locomotion in a 3D kinematic model of fly walking. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.18.589965. [PMID: 38712226 PMCID: PMC11071299 DOI: 10.1101/2024.04.18.589965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Walking animals must maintain stability in the presence of external perturbations, despite significant temporal delays in neural signaling and muscle actuation. Here, we develop a 3D kinematic model with a layered control architecture to investigate how sensorimotor delays constrain robustness of walking behavior in the fruit fly, Drosophila. Motivated by the anatomical architecture of insect locomotor control circuits, our model consists of three component layers: a neural network that generates realistic 3D joint kinematics for each leg, an optimal controller that executes the joint kinematics while accounting for delays, and an inter-leg coordinator. The model generates realistic simulated walking that matches real fly walking kinematics and sustains walking even when subjected to unexpected perturbations, generalizing beyond its training data. However, we found that the model's robustness to perturbations deteriorates when sensorimotor delay parameters exceed the physiological range. These results suggest that fly sensorimotor control circuits operate close to the temporal limit at which they can detect and respond to external perturbations. More broadly, we show how a modular, layered model architecture can be used to investigate physiological constraints on animal behavior.
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Affiliation(s)
- Lili Karashchuk
- Neuroscience Graduate Program, University of Washington, Seattle
| | - Jing Shuang (Lisa) Li
- Dept of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor
| | - Grant M. Chou
- Dept of Physiology & Biophysics, University of Washington, Seattle
| | | | | | - John C. Tuthill
- Dept of Physiology & Biophysics, University of Washington, Seattle
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8
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Hewson L, Choo A, Webber DL, Trim PJ, Snel MF, Fedele AO, Hopwood JJ, Hemsley KM, O'Keefe LV. Drosophila melanogaster models of MPS IIIC (Hgsnat-deficiency) highlight the role of glia in disease presentation. J Inherit Metab Dis 2024; 47:340-354. [PMID: 38238109 DOI: 10.1002/jimd.12712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/18/2023] [Accepted: 12/21/2023] [Indexed: 03/16/2024]
Abstract
Sanfilippo syndrome (Mucopolysaccharidosis type III or MPS III) is a recessively inherited neurodegenerative lysosomal storage disorder. Mutations in genes encoding enzymes in the heparan sulphate degradation pathway lead to the accumulation of partially degraded heparan sulphate, resulting ultimately in the development of neurological deficits. Mutations in the gene encoding the membrane protein heparan-α-glucosaminide N-acetyltransferase (HGSNAT; EC2.3.1.78) cause MPS IIIC (OMIM#252930), typified by impaired cognition, sleep-wake cycle changes, hyperactivity and early death, often before adulthood. The precise disease mechanism that causes symptom emergence remains unknown, posing a significant challenge in the development of effective therapeutics. As HGSNAT is conserved in Drosophila melanogaster, we now describe the creation and characterisation of the first Drosophila models of MPS IIIC. Flies with either an endogenous insertion mutation or RNAi-mediated knockdown of hgsnat were confirmed to have a reduced level of HGSNAT transcripts and age-dependent accumulation of heparan sulphate leading to engorgement of the endo/lysosomal compartment. This resulted in abnormalities at the pre-synapse, defective climbing and reduced overall activity. Altered circadian rhythms (shift in peak morning activity) were seen in hgsnat neuronal knockdown lines. Further, when hgsnat was knocked down in specific glial subsets (wrapping, cortical, astrocytes or subperineural glia), impaired climbing or reduced activity was noted, implying that hgsnat function in these specific glial subtypes contributes significantly to this behaviour and targeting treatments to these cell groups may be necessary to ameliorate or prevent symptom onset. These novel models of MPS IIIC provide critical research tools for delineating the key cellular pathways causal in the onset of neurodegeneration in this presently untreatable disorder.
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Affiliation(s)
- Laura Hewson
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Amanda Choo
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Dani L Webber
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Paul J Trim
- Proteomics, Metabolomics & MS-Imaging Core, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Marten F Snel
- Proteomics, Metabolomics & MS-Imaging Core, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Anthony O Fedele
- Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - John J Hopwood
- Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Kim M Hemsley
- Childhood Dementia Research Group, Flinders Health and Medical Research Institute, Flinders University, Bedford Park, South Australia, Australia
| | - Louise V O'Keefe
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
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9
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Ghosh T, Almeida RG, Zhao C, Mannioui A, Martin E, Fleet A, Chen CZ, Assinck P, Ellams S, Gonzalez GA, Graham SC, Rowitch DH, Stott K, Adams I, Zalc B, Goldman N, Lyons DA, Franklin RJM. A retroviral link to vertebrate myelination through retrotransposon-RNA-mediated control of myelin gene expression. Cell 2024; 187:814-830.e23. [PMID: 38364788 DOI: 10.1016/j.cell.2024.01.011] [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: 12/12/2022] [Revised: 10/12/2023] [Accepted: 01/07/2024] [Indexed: 02/18/2024]
Abstract
Myelin, the insulating sheath that surrounds neuronal axons, is produced by oligodendrocytes in the central nervous system (CNS). This evolutionary innovation, which first appears in jawed vertebrates, enabled rapid transmission of nerve impulses, more complex brains, and greater morphological diversity. Here, we report that RNA-level expression of RNLTR12-int, a retrotransposon of retroviral origin, is essential for myelination. We show that RNLTR12-int-encoded RNA binds to the transcription factor SOX10 to regulate transcription of myelin basic protein (Mbp, the major constituent of myelin) in rodents. RNLTR12-int-like sequences (which we name RetroMyelin) are found in all jawed vertebrates, and we further demonstrate their function in regulating myelination in two different vertebrate classes (zebrafish and frogs). Our study therefore suggests that retroviral endogenization played a prominent role in the emergence of vertebrate myelin.
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Affiliation(s)
- Tanay Ghosh
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK.
| | - Rafael G Almeida
- Centre for Discovery Brain Sciences, MS society Edinburgh Centre for MS Research, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - Chao Zhao
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK
| | - Abdelkrim Mannioui
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), Aquatic Facility, 75005 Paris, France
| | - Elodie Martin
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Alex Fleet
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK
| | - Civia Z Chen
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK
| | - Peggy Assinck
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK
| | - Sophie Ellams
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK
| | - Ginez A Gonzalez
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK
| | - Stephen C Graham
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - David H Rowitch
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - Katherine Stott
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - Ian Adams
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Bernard Zalc
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Nick Goldman
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome, Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - David A Lyons
- Centre for Discovery Brain Sciences, MS society Edinburgh Centre for MS Research, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - Robin J M Franklin
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK.
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10
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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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11
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Baldenius M, Kautzmann S, Nanda S, Klämbt C. Signaling Pathways Controlling Axonal Wrapping in Drosophila. Cells 2023; 12:2553. [PMID: 37947631 PMCID: PMC10647682 DOI: 10.3390/cells12212553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/24/2023] [Accepted: 10/27/2023] [Indexed: 11/12/2023] Open
Abstract
The rapid transmission of action potentials is an important ability that enables efficient communication within the nervous system. Glial cells influence conduction velocity along axons by regulating the radial axonal diameter, providing electrical insulation as well as affecting the distribution of voltage-gated ion channels. Differentiation of these wrapping glial cells requires a complex set of neuron-glia interactions involving three basic mechanistic features. The glia must recognize the axon, grow around it, and eventually arrest its growth to form single or multiple axon wraps. This likely depends on the integration of numerous evolutionary conserved signaling and adhesion systems. Here, we summarize the mechanisms and underlying signaling pathways that control glial wrapping in Drosophila and compare those to the mechanisms that control glial differentiation in mammals. This analysis shows that Drosophila is a beneficial model to study the development of even complex structures like myelin.
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Affiliation(s)
| | | | | | - Christian Klämbt
- Institute for Neuro- and Behavioral Biology, Faculty of Biology, University of Münster, Röntgenstraße 16, D-48149 Münster, Germany; (M.B.)
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12
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Srivastava S, Shaked HM, Gable K, Gupta SD, Pan X, Somashekarappa N, Han G, Mohassel P, Gotkine M, Doney E, Goldenberg P, Tan QKG, Gong Y, Kleinstiver B, Wishart B, Cope H, Pires CB, Stutzman H, Spillmann RC, Sadjadi R, Elpeleg O, Lee CH, Bellen HJ, Edvardson S, Eichler F, Dunn TM, Dai H, Dhar SU, Emrick LT, Goldman AM, Hanchard NA, Jamal F, Karaviti L, Lalani SR, Lee BH, Lewis RA, Marom R, Moretti PM, Murdock DR, Nicholas SK, Orengo JP, Posey JE, Potocki L, Rosenfeld JA, Samson SL, Scott DA, Tran AA, Vogel TP, Wangler MF, Yamamoto S, Eng CM, Liu P, Ward PA, Behrens E, Deardorff M, Falk M, Hassey K, Sullivan K, Vanderver A, Goldstein DB, Cope H, McConkie-Rosell A, Schoch K, Shashi V, Smith EC, Spillmann RC, Sullivan JA, Tan QKG, Walley NM, Agrawal PB, Beggs AH, Berry GT, Briere LC, Cobban LA, Coggins M, Cooper CM, Fieg EL, High F, Holm IA, Korrick S, Krier JB, Lincoln SA, Loscalzo J, Maas RL, MacRae CA, Pallais JC, Rao DA, Rodan LH, Silverman EK, Stoler JM, Sweetser DA, Walker M, Walsh CA, Esteves C, Kelley EG, Kohane IS, LeBlanc K, McCray AT, Nagy A, Dasari S, Lanpher BC, Lanza IR, Morava E, Oglesbee D, Bademci G, Barbouth D, Bivona S, Carrasquillo O, Chang TCP, Forghani I, Grajewski A, Isasi R, Lam B, Levitt R, Liu XZ, McCauley J, Sacco R, Saporta M, Schaechter J, Tekin M, Telischi F, Thorson W, Zuchner S, Colley HA, Dayal JG, Eckstein DJ, Findley LC, Krasnewich DM, Mamounas LA, Manolio TA, Mulvihill JJ, LaMoure GL, Goldrich MP, Urv TK, Doss AL, Acosta MT, Bonnenmann C, D’Souza P, Draper DD, Ferreira C, Godfrey RA, Groden CA, Macnamara EF, Maduro VV, Markello TC, Nath A, Novacic D, Pusey BN, Toro C, Wahl CE, Baker E, Burke EA, Adams DR, Gahl WA, Malicdan MCV, Tifft CJ, Wolfe LA, Yang J, Power B, Gochuico B, Huryn L, Latham L, Davis J, Mosbrook-Davis D, Rossignol F, Solomon B, MacDowall J, Thurm A, Zein W, Yousef M, Adam M, Amendola L, Bamshad M, Beck A, Bennett J, Berg-Rood B, Blue E, Boyd B, Byers P, Chanprasert S, Cunningham M, Dipple K, Doherty D, Earl D, Glass I, Golden-Grant K, Hahn S, Hing A, Hisama FM, Horike-Pyne M, Jarvik GP, Jarvik J, Jayadev S, Lam C, Maravilla K, Mefford H, Merritt JL, Mirzaa G, Nickerson D, Raskind W, Rosenwasser N, Scott CR, Sun A, Sybert V, Wallace S, Wener M, Wenger T, Ashley EA, Bejerano G, Bernstein JA, Bonner D, Coakley TR, Fernandez L, Fisher PG, Fresard L, Hom J, Huang Y, Kohler JN, Kravets E, Majcherska MM, Martin BA, Marwaha S, McCormack CE, Raja AN, Reuter CM, Ruzhnikov M, Sampson JB, Smith KS, Sutton S, Tabor HK, Tucker BM, Wheeler MT, Zastrow DB, Zhao C, Byrd WE, Crouse AB, Might M, Nakano-Okuno M, Whitlock J, Brown G, Butte MJ, Dell’Angelica EC, Dorrani N, Douine ED, Fogel BL, Gutierrez I, Huang A, Krakow D, Lee H, Loo SK, Mak BC, Martin MG, Martínez-Agosto JA, McGee E, Nelson SF, Nieves-Rodriguez S, Palmer CGS, Papp JC, Parker NH, Renteria G, Signer RH, Sinsheimer JS, Wan J, Wang LK, Perry KW, Woods JD, Alvey J, Andrews A, Bale J, Bohnsack J, Botto L, Carey J, Pace L, Longo N, Marth G, Moretti P, Quinlan A, Velinder M, Viskochi D, Bayrak-Toydemir P, Mao R, Westerfield M, Bican A, Brokamp E, Duncan L, Hamid R, Kennedy J, Kozuira M, Newman JH, PhillipsIII JA, Rives L, Robertson AK, Solem E, Cogan JD, Cole FS, Hayes N, Kiley D, Sisco K, Wambach J, Wegner D, Baldridge D, Pak S, Schedl T, Shin J, Solnica-Krezel L, Sadjadi R, Elpeleg O, Lee CH, Bellen HJ, Edvardson S, Eichler F, Dunn TM. SPTSSA variants alter sphingolipid synthesis and cause a complex hereditary spastic paraplegia. Brain 2023; 146:1420-1435. [PMID: 36718090 PMCID: PMC10319774 DOI: 10.1093/brain/awac460] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 11/03/2022] [Accepted: 11/19/2022] [Indexed: 02/01/2023] Open
Abstract
Sphingolipids are a diverse family of lipids with critical structural and signalling functions in the mammalian nervous system, where they are abundant in myelin membranes. Serine palmitoyltransferase, the enzyme that catalyses the rate-limiting reaction of sphingolipid synthesis, is composed of multiple subunits including an activating subunit, SPTSSA. Sphingolipids are both essential and cytotoxic and their synthesis must therefore be tightly regulated. Key to the homeostatic regulation are the ORMDL proteins that are bound to serine palmitoyltransferase and mediate feedback inhibition of enzymatic activity when sphingolipid levels become excessive. Exome sequencing identified potential disease-causing variants in SPTSSA in three children presenting with a complex form of hereditary spastic paraplegia. The effect of these variants on the catalytic activity and homeostatic regulation of serine palmitoyltransferase was investigated in human embryonic kidney cells, patient fibroblasts and Drosophila. Our results showed that two different pathogenic variants in SPTSSA caused a hereditary spastic paraplegia resulting in progressive motor disturbance with variable sensorineural hearing loss and language/cognitive dysfunction in three individuals. The variants in SPTSSA impaired the negative regulation of serine palmitoyltransferase by ORMDLs leading to excessive sphingolipid synthesis based on biochemical studies and in vivo studies in Drosophila. These findings support the pathogenicity of the SPTSSA variants and point to excessive sphingolipid synthesis due to impaired homeostatic regulation of serine palmitoyltransferase as responsible for defects in early brain development and function.
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Affiliation(s)
- Siddharth Srivastava
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, BostonChildren's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Hagar Mor Shaked
- Department of Genetics, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Kenneth Gable
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Sita D Gupta
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Xueyang Pan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Niranjanakumari Somashekarappa
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Gongshe Han
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Payam Mohassel
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20814, USA
| | - Marc Gotkine
- Department of Genetics, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | | | - Paula Goldenberg
- Department of Pediatrics, Section on Medical Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Queenie K G Tan
- Department of Pediatrics, Division of Medical Genetics, Duke University School of Medicine, Durham, NC 27710, USA
| | - Yi Gong
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.,Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Benjamin Kleinstiver
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.,Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA.,Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - Brian Wishart
- Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Heidi Cope
- Department of Pediatrics, Division of Medical Genetics, Duke University School of Medicine, Durham, NC 27710, USA
| | - Claudia Brito Pires
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.,Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Hannah Stutzman
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.,Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Rebecca C Spillmann
- Department of Pediatrics, Division of Medical Genetics, Duke University School of Medicine, Durham, NC 27710, USA
| | | | - Reza Sadjadi
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Orly Elpeleg
- Department of Genetics, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Chia-Hsueh Lee
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA
| | - Simon Edvardson
- Pediatric Neurology Unit, Hadassah University Hospital, Mount Scopus, Jerusalem 91240, Israel
| | - Florian Eichler
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.,Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Teresa M Dunn
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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- Department of Neurology, Massachusetts General Hospital, Harvard Medical School , Boston, MA 02114 , USA
| | - Orly Elpeleg
- Department of Genetics, Hadassah Medical Center and Faculty of Medicine, Hebrew University of Jerusalem , Jerusalem 91120 , Israel
| | - Chia-Hsueh Lee
- Department of Structural Biology, St. Jude Children’s Research Hospital , Memphis, TN 38105 , USA
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine , Houston, TX 77030 , USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital , Houston, TX 77030 , USA
| | - Simon Edvardson
- Pediatric Neurology Unit, Hadassah University Hospital, Mount Scopus , Jerusalem 91240 , Israel
| | - Florian Eichler
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School , Boston, MA 02114 , USA
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School , Boston, MA 02114 , USA
| | - Teresa M Dunn
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences , Bethesda, MD 20814 , USA
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Corty MM, Coutinho-Budd J. Drosophila glia take shape to sculpt the nervous system. Curr Opin Neurobiol 2023; 79:102689. [PMID: 36822142 PMCID: PMC10023329 DOI: 10.1016/j.conb.2023.102689] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 12/19/2022] [Accepted: 01/10/2023] [Indexed: 02/23/2023]
Abstract
The importance of glial cells has become increasingly apparent over the past 20 years, yet compared to neurons we still know relatively little about these essential cells. Most critical glial cell functions are conserved in Drosophila glia, often using the same key molecular players as their vertebrate counterparts. The relative simplicity of the Drosophila nervous system, combined with a vast array of powerful genetic tools, allows us to further dissect the molecular composition and functional roles of glia in ways that would be much more cumbersome or not possible in higher vertebrate systems. Importantly, Drosophila genetics allow for in vivo manipulation, and their transparent body wall enables in vivo imaging of glia in intact animals throughout early development. Here we discuss recent advances in Drosophila glial development detailing how these cells take on their mature morphologies and interact with neurons to perform their important functional roles in the nervous system.
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Affiliation(s)
- Megan M Corty
- Vollum Institute, Oregon Health & Science University, Portland, OR, USA. https://twitter.com/@megancphd
| | - Jaeda Coutinho-Budd
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA.
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14
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Das M, Cheng D, Matzat T, Auld VJ. Innexin-Mediated Adhesion between Glia Is Required for Axon Ensheathment in the Peripheral Nervous System. J Neurosci 2023; 43:2260-2276. [PMID: 36801823 PMCID: PMC10072304 DOI: 10.1523/jneurosci.1323-22.2023] [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: 07/05/2022] [Revised: 01/03/2023] [Accepted: 02/09/2023] [Indexed: 02/19/2023] Open
Abstract
Glia are essential to protecting and enabling nervous system function and a key glial function is the formation of the glial sheath around peripheral axons. Each peripheral nerve in the Drosophila larva is ensheathed by three glial layers, which structurally support and insulate the peripheral axons. How peripheral glia communicate with each other and between layers is not well established and we investigated the role of Innexins in mediating glial function in the Drosophila periphery. Of the eight Drosophila Innexins, we found two (Inx1 and Inx2) are important for peripheral glia development. In particular loss of Inx1 and Inx2 resulted in defects in the wrapping glia leading to disruption of the glia wrap. Of interest loss of Inx2 in the subperineurial glia also resulted in defects in the neighboring wrapping glia. Inx plaques were observed between the subperineurial glia and the wrapping glia suggesting that gap junctions link these two glial cell types. We found Inx2 is key to Ca2+ pulses in the peripheral subperineurial glia but not in the wrapping glia, and we found no evidence of gap junction communication between subperineurial and wrapping glia. Rather we have clear evidence that Inx2 plays an adhesive and channel-independent role between the subperineurial and wrapping glia to ensure the integrity of the glial wrap.SIGNIFICANCE STATEMENT Gap junctions are critical for glia communication and formation of myelin in myelinating glia. However, the role of gap junctions in non-myelinating glia is not well studied, yet non-myelinating glia are critical for peripheral nerve function. We found the Innexin gap junction proteins are present between different classes of peripheral glia in Drosophila. Here Innexins form junctions to facilitate adhesion between the different glia but do so in a channel-independent manner. Loss of adhesion leads to disruption of the glial wrap around axons and leads to fragmentation of the wrapping glia membranes. Our work points to an important role for gap junction proteins in mediating insulation by non-myelinating glia.
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Affiliation(s)
- Mriga Das
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Duo Cheng
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Till Matzat
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Vanessa J Auld
- Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
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15
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Vaughen JP, Theisen E, Clandinin TR. From seconds to days: Neural plasticity viewed through a lipid lens. Curr Opin Neurobiol 2023; 80:102702. [PMID: 36965206 DOI: 10.1016/j.conb.2023.102702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 01/31/2023] [Accepted: 02/16/2023] [Indexed: 03/27/2023]
Abstract
Many adult neurons are dynamically remodeled across timescales ranging from the rapid addition and removal of specific synaptic connections, to largescale structural plasticity events that reconfigure circuits over hours, days, and months. Membrane lipids, including brain-enriched sphingolipids, play crucial roles in these processes. In this review, we summarize progress at the intersection of neuronal activity, lipids, and structural remodeling. We highlight how brain activity modulates lipid metabolism to enable adaptive structural plasticity, and showcase glia as key players in membrane remodeling. These studies reveal that lipids act as critical signaling molecules that instruct the dynamic architecture of the brain.
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Affiliation(s)
- John P Vaughen
- Department of Neurobiology, Stanford University, Stanford, CA, 94305, United States; Department of Developmental Biology, Stanford University, Stanford, CA, 94305, United States. https://twitter.com/gliaful
| | - Emma Theisen
- Department of Neurobiology, Stanford University, Stanford, CA, 94305, United States. https://twitter.com/emmaktheisen
| | - Thomas R Clandinin
- Department of Neurobiology, Stanford University, Stanford, CA, 94305, United States.
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16
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Contreras EG, Klämbt C. The Drosophila blood-brain barrier emerges as a model for understanding human brain diseases. Neurobiol Dis 2023; 180:106071. [PMID: 36898613 DOI: 10.1016/j.nbd.2023.106071] [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: 12/29/2022] [Revised: 02/24/2023] [Accepted: 03/07/2023] [Indexed: 03/12/2023] Open
Abstract
The accurate regulation of the microenvironment within the nervous system is one of the key features characterizing complex organisms. To this end, neural tissue has to be physically separated from circulation, but at the same time, mechanisms must be in place to allow controlled transport of nutrients and macromolecules into and out of the brain. These roles are executed by cells of the blood-brain barrier (BBB) found at the interface of circulation and neural tissue. BBB dysfunction is observed in several neurological diseases in human. Although this can be considered as a consequence of diseases, strong evidence supports the notion that BBB dysfunction can promote the progression of brain disorders. In this review, we compile the recent evidence describing the contribution of the Drosophila BBB to the further understanding of brain disease features in human patients. We discuss the function of the Drosophila BBB during infection and inflammation, drug clearance and addictions, sleep, chronic neurodegenerative disorders and epilepsy. In summary, this evidence suggests that the fruit fly, Drosophila melanogaster, can be successfully employed as a model to disentangle mechanisms underlying human diseases.
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Affiliation(s)
- Esteban G Contreras
- University of Münster, Institute of Neuro- and Behavioral Biology, Badestr. 9, Münster, Germany.
| | - Christian Klämbt
- University of Münster, Institute of Neuro- and Behavioral Biology, Badestr. 9, Münster, Germany.
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17
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Schwann cell functions in peripheral nerve development and repair. Neurobiol Dis 2023; 176:105952. [PMID: 36493976 DOI: 10.1016/j.nbd.2022.105952] [Citation(s) in RCA: 36] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/23/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022] Open
Abstract
The glial cell of the peripheral nervous system (PNS), the Schwann cell (SC), counts among the most multifaceted cells of the body. During development, SCs secure neuronal survival and participate in axonal path finding. Simultaneously, they orchestrate the architectural set up of the developing nerves, including the blood vessels and the endo-, peri- and epineurial layers. Perinatally, in rodents, SCs radially sort and subsequently myelinate individual axons larger than 1 μm in diameter, while small calibre axons become organised in non-myelinating Remak bundles. SCs have a vital role in maintaining axonal health throughout life and several specialized SC types perform essential functions at specific locations, such as terminal SC at the neuromuscular junction (NMJ) or SC within cutaneous sensory end organs. In addition, neural crest derived satellite glia maintain a tight communication with the soma of sensory, sympathetic, and parasympathetic neurons and neural crest derivatives are furthermore an indispensable part of the enteric nervous system. The remarkable plasticity of SCs becomes evident in the context of a nerve injury, where SC transdifferentiate into intriguing repair cells, which orchestrate a regenerative response that promotes nerve repair. Indeed, the multiple adaptations of SCs are captivating, but remain often ill-resolved on the molecular level. Here, we summarize and discuss the knowns and unknowns of the vast array of functions that this single cell type can cover in peripheral nervous system development, maintenance, and repair.
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18
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Corty MM, Hulegaard AL, Hill JQ, Sheehan AE, Aicher SA, Freeman MR. Discoidin domain receptor regulates ensheathment, survival and caliber of peripheral axons. Development 2022; 149:281293. [PMID: 36355066 PMCID: PMC10112903 DOI: 10.1242/dev.200636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 10/27/2022] [Indexed: 11/12/2022]
Abstract
Most invertebrate axons and small-caliber axons in mammalian peripheral nerves are unmyelinated but still ensheathed by glia. Here, we use Drosophila wrapping glia to study the development and function of non-myelinating axon ensheathment, which is poorly understood. Selective ablation of these glia from peripheral nerves severely impaired larval locomotor behavior. In an in vivo RNA interference screen to identify glial genes required for axon ensheathment, we identified the conserved receptor tyrosine kinase Discoidin domain receptor (Ddr). In larval peripheral nerves, loss of Ddr resulted in severely reduced ensheathment of axons and reduced axon caliber, and we found a strong dominant genetic interaction between Ddr and the type XV/XVIII collagen Multiplexin (Mp), suggesting that Ddr functions as a collagen receptor to drive axon wrapping. In adult nerves, loss of Ddr decreased long-term survival of sensory neurons and significantly reduced axon caliber without overtly affecting ensheathment. Our data establish essential roles for non-myelinating glia in nerve development, maintenance and function, and identify Ddr as a key regulator of axon-glia interactions during ensheathment and establishment of axon caliber.
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Affiliation(s)
- Megan M Corty
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | | | - Jo Q Hill
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
| | - Amy E Sheehan
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Sue A Aicher
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
| | - Marc R Freeman
- Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA
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19
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Styfhals R, Zolotarov G, Hulselmans G, Spanier KI, Poovathingal S, Elagoz AM, De Winter S, Deryckere A, Rajewsky N, Ponte G, Fiorito G, Aerts S, Seuntjens E. Cell type diversity in a developing octopus brain. Nat Commun 2022; 13:7392. [PMID: 36450803 PMCID: PMC9712504 DOI: 10.1038/s41467-022-35198-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 11/22/2022] [Indexed: 12/02/2022] Open
Abstract
Octopuses are mollusks that have evolved intricate neural systems comparable with vertebrates in terms of cell number, complexity and size. The brain cell types that control their sophisticated behavioral repertoire are still unknown. Here, we profile the cell diversity of the paralarval Octopus vulgaris brain to build a cell type atlas that comprises mostly neural cells, but also multiple glial subtypes, endothelial cells and fibroblasts. We spatially map cell types to the vertical, subesophageal and optic lobes. Investigation of cell type conservation reveals a shared gene signature between glial cells of mouse, fly and octopus. Genes related to learning and memory are enriched in vertical lobe cells, which show molecular similarities with Kenyon cells in Drosophila. We construct a cell type taxonomy revealing transcriptionally related cell types, which tend to appear in the same brain region. Together, our data sheds light on cell type diversity and evolution in the octopus brain.
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Affiliation(s)
- Ruth Styfhals
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Grygoriy Zolotarov
- Laboratory for Systems Biology of Gene Regulatory Elements, Berlin Institute for Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Hannoversche Str. 28, 10115, Berlin, Germany
| | - Gert Hulselmans
- Department of Human Genetics, KU Leuven, Leuven, 3000, Belgium
- VIB Center for Brain & Disease Research, KU Leuven, Leuven, 3000, Belgium
| | - Katina I Spanier
- Department of Human Genetics, KU Leuven, Leuven, 3000, Belgium
- VIB Center for Brain & Disease Research, KU Leuven, Leuven, 3000, Belgium
| | | | - Ali M Elagoz
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
| | - Seppe De Winter
- Department of Human Genetics, KU Leuven, Leuven, 3000, Belgium
- VIB Center for Brain & Disease Research, KU Leuven, Leuven, 3000, Belgium
| | - Astrid Deryckere
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
- Department of Biological Sciences, Columbia University, New York, US
| | - Nikolaus Rajewsky
- Laboratory for Systems Biology of Gene Regulatory Elements, Berlin Institute for Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Hannoversche Str. 28, 10115, Berlin, Germany
- Department of Pediatric Oncology/Hematology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Giovanna Ponte
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Graziano Fiorito
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Stein Aerts
- Department of Human Genetics, KU Leuven, Leuven, 3000, Belgium
- VIB Center for Brain & Disease Research, KU Leuven, Leuven, 3000, Belgium
| | - Eve Seuntjens
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium.
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20
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Reed CB, Feltri ML, Wilson ER. Peripheral glia diversity. J Anat 2022; 241:1219-1234. [PMID: 34131911 PMCID: PMC8671569 DOI: 10.1111/joa.13484] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/20/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022] Open
Abstract
Recent years have seen an evolving appreciation for the role of glial cells in the nervous system. As we move away from the typical neurocentric view of neuroscience, the complexity and variability of central nervous system glia is emerging, far beyond the three main subtypes: astrocytes, oligodendrocytes, and microglia. Yet the diversity of the glia found in the peripheral nervous system remains rarely discussed. In this review, we discuss the developmental origin, morphology, and function of the different populations of glia found in the peripheral nervous system, including: myelinating Schwann cells, Remak Schwann cells, repair Schwann cells, satellite glia, boundary cap-derived glia, perineurial glia, terminal Schwann cells, glia found in the skin, olfactory ensheathing cells, and enteric glia. The morphological and functional heterogeneity of glia found in the periphery reflects the diverse roles the nervous system performs throughout the body. Further, it highlights a complexity that should be appreciated and considered when it comes to a complete understanding of the peripheral nervous system in health and disease.
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Affiliation(s)
- Chelsey B Reed
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences State, University of New York at Buffalo, Buffalo, New York, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - M Laura Feltri
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences State, University of New York at Buffalo, Buffalo, New York, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Emma R Wilson
- Hunter James Kelly Research Institute, Jacobs School of Medicine and Biomedical Sciences State, University of New York at Buffalo, Buffalo, New York, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
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21
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Delta/Notch signaling in glia maintains motor nerve barrier function and synaptic transmission by controlling matrix metalloproteinase expression. Proc Natl Acad Sci U S A 2022; 119:e2110097119. [PMID: 35969789 PMCID: PMC9407389 DOI: 10.1073/pnas.2110097119] [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] [Indexed: 11/18/2022] Open
Abstract
We have made a surprising discovery linking Delta/Notch signaling in subperineurial glia (SPG) to the regulation of nerve ensheathment and neurotransmitter release at the Drosophila neuromuscular junction (NMJ). SPG, the counterpart of the endothelial layer in the vertebrate blood–brain barrier, form the key cellular layer that is critical for axonal ensheathment and the blood–brain barrier in Drosophila. Our findings demonstrate that Delta/Notch signaling exerts a constitutive negative inhibition on JNK signaling in SPG, thereby limiting the expression of Mmp1, a matrix metalloproteinase. SPG-specific and temporally regulated knockdown of Delta leads to breakdown of barrier function and compromises neurotransmitter release at the NMJ. Our results provide a mechanistic insight into the biology of barrier function and glia–neuron interactions. While the role of barrier function in establishing a protective, nutrient-rich, and ionically balanced environment for neurons has been appreciated for some time, little is known about how signaling cues originating in barrier-forming cells participate in maintaining barrier function and influence synaptic activity. We have identified Delta/Notch signaling in subperineurial glia (SPG), a crucial glial type for Drosophila motor axon ensheathment and the blood–brain barrier, to be essential for controlling the expression of matrix metalloproteinase 1 (Mmp1), a major regulator of the extracellular matrix (ECM). Our genetic analysis indicates that Delta/Notch signaling in SPG exerts an inhibitory control on Mmp1 expression. In the absence of this inhibition, abnormally enhanced Mmp1 activity disrupts septate junctions and glial ensheathment of peripheral motor nerves, compromising neurotransmitter release at the neuromuscular junction (NMJ). Temporally controlled and cell type–specific transgenic analysis shows that Delta/Notch signaling inhibits transcription of Mmp1 by inhibiting c-Jun N-terminal kinase (JNK) signaling in SPG. Our results provide a mechanistic insight into the regulation of neuronal health and function via glial-initiated signaling and open a framework for understanding the complex relationship between ECM regulation and the maintenance of barrier function.
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22
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Rey S, Ohm H, Klämbt C. Axonal ion homeostasis and glial differentiation. FEBS J 2022. [PMID: 35943294 DOI: 10.1111/febs.16594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 07/26/2022] [Accepted: 08/08/2022] [Indexed: 11/27/2022]
Abstract
The brain is the ultimate control unit of the body. It conducts accurate, fast and reproducible calculations to control motor actions affecting mating, foraging and flight or fight decisions. Therefore, during evolution, better and more efficient brains have emerged. However, even simple brains are complex organs. They are formed by glial cells and neurons that establish highly intricate networks to enable information collection, processing and eventually, a precise motor control. Here, we review and connect some well-established and some hidden pieces of information to set the focus on ion homeostasis as a driving force in glial differentiation promoting signalling speed and accuracy.
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Affiliation(s)
- Simone Rey
- Institut für Neuro‐ und Verhaltensbiologie Münster Germany
| | - Henrike Ohm
- Institut für Neuro‐ und Verhaltensbiologie Münster Germany
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23
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Gu X, Jouandin P, Lalgudi PV, Binari R, Valenstein ML, Reid MA, Allen AE, Kamitaki N, Locasale JW, Perrimon N, Sabatini DM. Sestrin mediates detection of and adaptation to low-leucine diets in Drosophila. Nature 2022; 608:209-216. [PMID: 35859173 PMCID: PMC10112710 DOI: 10.1038/s41586-022-04960-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 06/09/2022] [Indexed: 12/28/2022]
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) regulates cell growth and metabolism in response to multiple nutrients, including the essential amino acid leucine1. Recent work in cultured mammalian cells established the Sestrins as leucine-binding proteins that inhibit mTORC1 signalling during leucine deprivation2,3, but their role in the organismal response to dietary leucine remains elusive. Here we find that Sestrin-null flies (Sesn-/-) fail to inhibit mTORC1 or activate autophagy after acute leucine starvation and have impaired development and a shortened lifespan on a low-leucine diet. Knock-in flies expressing a leucine-binding-deficient Sestrin mutant (SesnL431E) have reduced, leucine-insensitive mTORC1 activity. Notably, we find that flies can discriminate between food with or without leucine, and preferentially feed and lay progeny on leucine-containing food. This preference depends on Sestrin and its capacity to bind leucine. Leucine regulates mTORC1 activity in glial cells, and knockdown of Sesn in these cells reduces the ability of flies to detect leucine-free food. Thus, nutrient sensing by mTORC1 is necessary for flies not only to adapt to, but also to detect, a diet deficient in an essential nutrient.
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Affiliation(s)
- Xin Gu
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Patrick Jouandin
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
| | - Pranav V Lalgudi
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Rich Binari
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA
| | - Max L Valenstein
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Michael A Reid
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Annamarie E Allen
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Nolan Kamitaki
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Jason W Locasale
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC, USA
| | - Norbert Perrimon
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA, USA.
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24
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Wang Y, Lobb-Rabe M, Ashley J, Chatterjee P, Anand V, Bellen HJ, Kanca O, Carrillo RA. Systematic expression profiling of Dpr and DIP genes reveals cell surface codes in Drosophila larval motor and sensory neurons. Development 2022; 149:dev200355. [PMID: 35502740 PMCID: PMC9188756 DOI: 10.1242/dev.200355] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 04/20/2022] [Indexed: 07/26/2023]
Abstract
In complex nervous systems, neurons must identify their correct partners to form synaptic connections. The prevailing model to ensure correct recognition posits that cell-surface proteins (CSPs) in individual neurons act as identification tags. Thus, knowing what cells express which CSPs would provide insights into neural development, synaptic connectivity, and nervous system evolution. Here, we investigated expression of Dpr and DIP genes, two CSP subfamilies belonging to the immunoglobulin superfamily, in Drosophila larval motor neurons (MNs), muscles, glia and sensory neurons (SNs) using a collection of GAL4 driver lines. We found that Dpr genes are more broadly expressed than DIP genes in MNs and SNs, and each examined neuron expresses a unique combination of Dpr and DIP genes. Interestingly, many Dpr and DIP genes are not robustly expressed, but are found instead in gradient and temporal expression patterns. In addition, the unique expression patterns of Dpr and DIP genes revealed three uncharacterized MNs. This study sets the stage for exploring the functions of Dpr and DIP genes in Drosophila MNs and SNs and provides genetic access to subsets of neurons.
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Affiliation(s)
- Yupu Wang
- Department of Molecular Genetics & Cellular Biology, University of Chicago, Chicago, IL 60637, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60637, USA
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL 60637, USA
| | - Meike Lobb-Rabe
- Department of Molecular Genetics & Cellular Biology, University of Chicago, Chicago, IL 60637, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60637, USA
- Program in Cell and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - James Ashley
- Department of Molecular Genetics & Cellular Biology, University of Chicago, Chicago, IL 60637, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60637, USA
| | - Purujit Chatterjee
- Department of Molecular Genetics & Cellular Biology, University of Chicago, Chicago, IL 60637, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60637, USA
| | - Veera Anand
- Department of Molecular Genetics & Cellular Biology, University of Chicago, Chicago, IL 60637, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60637, USA
| | - Hugo J. Bellen
- Department of Molecular and Human Genetics and Jan and Dan Duncan Neurobiological Research Institute, Baylor College of Medicine (BCM), Houston, TX 77030, USA
- Department of Neuroscience and Howard Hughes Medical Institute, Baylor College of Medicine (BCM), Houston, TX 77030, USA
| | - Oguz Kanca
- Department of Molecular and Human Genetics and Jan and Dan Duncan Neurobiological Research Institute, Baylor College of Medicine (BCM), Houston, TX 77030, USA
| | - Robert A. Carrillo
- Department of Molecular Genetics & Cellular Biology, University of Chicago, Chicago, IL 60637, USA
- Neuroscience Institute, University of Chicago, Chicago, IL 60637, USA
- Committee on Development, Regeneration, and Stem Cell Biology, University of Chicago, Chicago, IL 60637, USA
- Program in Cell and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
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25
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Salazar G, Ross G, Maserejian AE, Coutinho-Budd J. Quantifying Glial-Glial Tiling Using Automated Image Analysis in Drosophila. Front Cell Neurosci 2022; 16:826483. [PMID: 35401121 PMCID: PMC8987577 DOI: 10.3389/fncel.2022.826483] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/31/2022] [Indexed: 11/20/2022] Open
Abstract
Not only do glia form close associations with neurons throughout the central nervous system (CNS), but glial cells also interact closely with other glial cells. As these cells mature, they undergo a phenomenon known as glial tiling, where they grow to abut one another, often without invading each other’s boundaries. Glial tiling occurs throughout the animal kingdom, from fruit flies to humans; however, not much is known about the glial-glial interactions that lead to and maintain this tiling. Drosophila provide a strong model to investigate glial-glial tiling, where tiling occurs both among individual glial cells of the same subtype, as well as between those of different subtypes. Furthermore, the spatial segregation of the CNS allows for the unique ability to visualize and manipulate inter-subtype interactions. Previous work in Drosophila has suggested an interaction between cortex glia and astrocytes, where astrocytes cross the normal neuropil-cortex boundary in response to dysfunctional cortex glia. Here, we further explore this interaction by implementing an automated pipeline to more fully characterize this astrocyte-cortex glial relationship. By quantifying and correlating the extent of cortex glial dysfunction and aberrant astrocyte infiltration using automated analysis, we maximize the size of the quantified dataset to reveal subtle patterns in astrocyte-cortex glial interactions. We provide a guide for creating and validating a fully-automated image analysis pipeline for exploring these interactions, and implement this pipeline to describe a significant correlation between cortex glial dysfunction and aberrant astrocyte infiltration, as well as demonstrate variations in their relationship across different regions of the CNS.
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Affiliation(s)
- Gabriela Salazar
- Department of Biology, The University of Vermont, Burlington, VT, United States.,Vermont Complex Systems Center, The University of Vermont, Burlington, VT, United States
| | - Grace Ross
- Department of Biology, The University of Vermont, Burlington, VT, United States
| | - Ariana E Maserejian
- Department of Biology, The University of Vermont, Burlington, VT, United States
| | - Jaeda Coutinho-Budd
- Department of Biology, The University of Vermont, Burlington, VT, United States
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26
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Bittern J, Praetz M, Baldenius M, Klämbt C. Long-Term Observation of Locomotion of Drosophila Larvae Facilitates Feasibility of Food-Choice Assays. Adv Biol (Weinh) 2022; 6:e2100938. [PMID: 34365739 DOI: 10.1002/adbi.202100938] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 07/20/2021] [Indexed: 01/27/2023]
Abstract
Animal behavior is reflected by locomotor patterns. To decipher the underlying neural circuitry locomotion has to be monitored over often longer time periods. Here a simple adaptation is described to constrain movement of third instar Drosophila larvae to a defined area and use Frustrated total internal reflection based imaging method (FIM) imaging to monitor larval movements up to 1 h. It is demonstrated that the combination of FIM imaging and long analysis periods facilitates the conduction of food choice assays and provides the means to easily quantify food preferences.
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Affiliation(s)
- Jonas Bittern
- Institut für Neuro-und Verhaltensbiologie, Badestr. 9, 48149, Münster, Germany
| | - Marit Praetz
- Institut für Neuro-und Verhaltensbiologie, Badestr. 9, 48149, Münster, Germany
| | - Marie Baldenius
- Institut für Neuro-und Verhaltensbiologie, Badestr. 9, 48149, Münster, Germany
| | - Christian Klämbt
- Institut für Neuro-und Verhaltensbiologie, Badestr. 9, 48149, Münster, Germany
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27
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Tzou FY, Wen JK, Yeh JY, Huang SY, Chen GC, Chan CC. Drosophila as a model to study autophagy in neurodegenerative diseases and digestive tract. IUBMB Life 2021; 74:339-360. [PMID: 34874101 DOI: 10.1002/iub.2583] [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: 10/10/2021] [Revised: 11/08/2021] [Accepted: 11/15/2021] [Indexed: 12/20/2022]
Abstract
Autophagy regulates cellular homeostasis by degrading and recycling cytosolic components and damaged organelles. Disruption of autophagic flux has been shown to induce or facilitate neurodegeneration and accumulation of autophagic vesicles is overt in neurodegenerative diseases. The fruit fly Drosophila has been used as a model system to identify new factors that regulate physiology and disease. Here we provide a historical perspective of how the fly models have offered mechanistic evidence to understand the role of autophagy in neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, Charcot-Marie-Tooth neuropathy, and polyglutamine disorders. Autophagy also plays a pivotal role in maintaining tissue homeostasis and protecting organism health. The gastrointestinal tract regulates organism health by modulating food intake, energy balance, and immunity. Growing evidence is strengthening the link between autophagy and digestive tract health in recent years. Here, we also discuss how the fly models have advanced the understanding of digestive physiology regulated by autophagy.
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Affiliation(s)
- Fei-Yang Tzou
- Graduate Institute of Physiology, National Taiwan University, Taipei, Taiwan
| | - Jung-Kun Wen
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Jui-Yu Yeh
- Graduate Institute of Physiology, National Taiwan University, Taipei, Taiwan
| | - Shu-Yi Huang
- Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan
| | - Guang-Chao Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Chih-Chiang Chan
- Graduate Institute of Physiology, National Taiwan University, Taipei, Taiwan
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28
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Developing the Concepts of Homeostasis, Homeorhesis, Allostasis, Elasticity, Flexibility and Plasticity of Brain Function. NEUROSCI 2021. [DOI: 10.3390/neurosci2040027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
I discuss some concepts advanced for the understanding of the complex dynamics of brain functions, and relate them to approaches in affective, cognitive and action neurosciences. These functions involve neuro-glial interactions in a dynamic system that receives sensory signals from the outside of the central nervous system, processes information in frequency, amplitude and phase-modulated electrochemical waves, and control muscles and glands to generate behavioral patterns. The astrocyte network is in charge of controlling global electrochemical homeostasis, and Hodgkin–Huxley dynamics drive the bioelectric homeostasis of single neurons. In elastic processes, perturbations cause instability, but the system returns to the basal equilibrium. In allostatic processes, perturbations elicit a response from the system, reacting to the deviation and driving the system to stable states far from the homeostatic equilibrium. When the system does not return to a fixed point or region of the state space, the process is called homeorhetic, and may present two types of evolution: (a) In flexible processes, there are previously existing “attractor” stable states that may be achieved after the perturbation, depending on context; (b) In plastic processes, the homeostatic set point(s) is(are) changed; the system is in a process of adaptation, in which the allostatic forces do not drive it back to the previous set point, but project to the new one. In the temporal phase from the deviant state to the recovery of stability, the system generates sensations that indicate if the recovery is successful (pleasure-like sensations) or if there is a failure (pain-like sensations).
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29
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Winkler B, Funke D, Benmimoun B, Spéder P, Rey S, Logan MA, Klämbt C. Brain inflammation triggers macrophage invasion across the blood-brain barrier in Drosophila during pupal stages. SCIENCE ADVANCES 2021; 7:eabh0050. [PMID: 34705495 PMCID: PMC8550232 DOI: 10.1126/sciadv.abh0050] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The nervous system is shielded from circulating immune cells by the blood-brain barrier (BBB). During infections and autoimmune diseases, macrophages can enter the brain where they participate in pathogen elimination but can also cause tissue damage. Here, we establish a Drosophila model to study macrophage invasion into the inflamed brain. We show that the immune deficiency (Imd) pathway, but not the Toll pathway, is responsible for attraction and invasion of hemolymph-borne macrophages across the BBB during pupal stages. Macrophage recruitment is mediated by glial, but not neuronal, induction of the Imd pathway through expression of Pvf2. Within the brain, macrophages can phagocytose synaptic material and reduce locomotor abilities and longevity. Similarly, we show that central nervous system infection by group B Streptococcus elicits macrophage recruitment in an Imd-dependent manner. This suggests that evolutionarily conserved inflammatory responses require a delicate balance between beneficial and detrimental activities.
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Affiliation(s)
- Bente Winkler
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
| | - Dominik Funke
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
| | - Billel Benmimoun
- Brain Plasticity in response to the Environment, Institut Pasteur, UMR3738 CNRS, 75015 Paris, France
| | - Pauline Spéder
- Brain Plasticity in response to the Environment, Institut Pasteur, UMR3738 CNRS, 75015 Paris, France
| | - Simone Rey
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
| | - Mary A. Logan
- Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR 97239, USA
| | - Christian Klämbt
- Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestr. 9, 48149 Münster, Germany
- Corresponding author.
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30
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Ding YQ, Qi JG. Sensory root demyelination: Transforming touch into pain. Glia 2021; 70:397-413. [PMID: 34549463 DOI: 10.1002/glia.24097] [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: 05/24/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 11/12/2022]
Abstract
The normal feeling of touch is vital for nearly every aspect of our daily life. However, touching is not always felt as touch, but also abnormally as pain under numerous diseased conditions. For either mechanistic understanding of the faithful feeling of touch or clinical management of chronic pain, there is an essential need to thoroughly dissect the neuropathological changes that lead to painful touch or tactile allodynia and their corresponding cellular and molecular underpinnings. In recent years, we have seen remarkable progress in our understanding of the neural circuits for painful touch, with an increasing emphasis on the upstream roles of non-neuronal cells. As a highly specialized form of axon ensheathment by glial cells in jawed vertebrates, myelin sheaths not only mediate their outstanding neural functions via saltatory impulse propagation of temporal and spatial precision, but also support long-term neuronal/axonal integrity via metabolic and neurotrophic coupling. Therefore, myelinopathies have been implicated in diverse neuropsychiatric diseases, which are traditionally recognized as a result of the dysfunctions of neural circuits. However, whether myelinopathies can transform touch into pain remains a long-standing question. By summarizing and reframing the fragmentary but accumulating evidence so far, the present review indicates that sensory root demyelination represents a hitherto underappreciated neuropathological change for most neuropathic conditions of painful touch and offers an insightful window into faithful tactile sensation as well as a potential therapeutic target for intractable painful touch.
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Affiliation(s)
- You-Quan Ding
- Department of Histology, Embryology and Neurobiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
| | - Jian-Guo Qi
- Department of Histology, Embryology and Neurobiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, Sichuan, China
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31
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Krill JL, Dawson-Scully K. Characterization of a novel stimulus-induced glial calcium wave in Drosophila larval peripheral segmental nerves and its role in PKG-modulated thermoprotection. J Neurogenet 2021; 35:221-235. [PMID: 34309496 DOI: 10.1080/01677063.2021.1941945] [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: 10/20/2022]
Abstract
Insects, as poikilotherms, have adaptations to deal with wide ranges in temperature fluctuation. Allelic variations in the foraging gene that encodes a cGMP dependent protein kinase, were discovered to have effects on behavior in Drosophila by Dr. Marla Sokolowski in 1980. This single gene has many pleiotropic effects and influences feeding behavior, metabolic storage, learning and memory and has been shown to affect stress tolerance. PKG regulation affects motoneuronal thermotolerance in Drosophila larvae as well as adults. While the focus of thermotolerance studies has been on the modulation of neuronal function, other cell types have been overlooked. Because glia are vital to neuronal function and survival, we wanted to determine if glia play a role in thermotolerance as well. In our investigation, we discovered a novel calcium wave at the larval NMJ and set out to characterize the wave's dynamics and the potential mechanism underlying the wave prior to determining what effect, if any, PKG modulation has on the thermotolerance of glia cells. Using pharmacology, we determined that calcium buffering mechanisms of the mitochondria and endoplasmic reticulum play a role in the propagation of our novel glial calcium wave. By coupling pharmacology with genetic manipulation using RNA interference (RNAi), we found that PKG modulation in glia alters thermoprotection of function as well as glial calcium wave dynamics.
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Affiliation(s)
- Jennifer L Krill
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida
| | - Ken Dawson-Scully
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida
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32
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Böhme MA, McCarthy AW, Blaum N, Berezeckaja M, Ponimaskine K, Schwefel D, Walter AM. Glial Synaptobrevin mediates peripheral nerve insulation, neural metabolic supply, and is required for motor function. Glia 2021; 69:1897-1915. [PMID: 33811396 DOI: 10.1002/glia.24000] [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: 09/18/2020] [Revised: 03/12/2021] [Accepted: 03/17/2021] [Indexed: 01/10/2023]
Abstract
Peripheral nerves contain sensory and motor neuron axons coated by glial cells whose interplay ensures function, but molecular details are lacking. SNARE-proteins mediate the exchange and secretion of cargo by fusing vesicles with target organelles, but how glial SNAREs contribute to peripheral nerve function is largely unknown. We, here, identify non-neuronal Synaptobrevin (Syb) as the essential vesicular SNARE in Drosophila peripheral glia to insulate and metabolically supply neurons. We show that tetanus neurotoxin light chain (TeNT-LC), which potently inhibits SNARE-mediated exocytosis from neurons, also impairs peripheral nerve function when selectively expressed in glia, causing nerve disintegration, defective axonal transport, tetanic muscle hyperactivity, impaired locomotion, and lethality. While TeNT-LC disrupts neural function by cleaving neuronal Synaptobrevin (nSyb), it targets non-neuronal Synaptobrevin (Syb) in glia, which it cleaves at low rates: Glial knockdown of Syb (but not nSyb) phenocopied glial TeNT-LC expression whose effects were reverted by a TeNT-LC-insensitive Syb mutant. We link Syb-necessity to two distinct glial subtypes: Impairing Syb function in subperineurial glia disrupted nerve morphology, axonal transport, and locomotion, likely, because nerve-isolating septate junctions (SJs) could not form as essential SJ components (like the cell adhesion protein Neurexin-IV) were mistargeted. Interference with Syb in axon-encircling wrapping glia left nerve morphology and locomotion intact but impaired axonal transport, likely because neural metabolic supply was disrupted due to the mistargeting of metabolite shuffling monocarboxylate transporters. Our study identifies crucial roles of Syb in various glial subtypes to ensure glial-glial and glial-neural interplay needed for proper nerve function, animal motility, and survival.
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Affiliation(s)
- Mathias A Böhme
- Molecular and Theoretical Neuroscience, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), FMP im CharitéCrossOver, Berlin, Germany.,Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Anthony W McCarthy
- Molecular and Theoretical Neuroscience, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), FMP im CharitéCrossOver, Berlin, Germany
| | - Natalie Blaum
- Molecular and Theoretical Neuroscience, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), FMP im CharitéCrossOver, Berlin, Germany
| | - Monika Berezeckaja
- Molecular and Theoretical Neuroscience, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), FMP im CharitéCrossOver, Berlin, Germany
| | - Kristina Ponimaskine
- Molecular and Theoretical Neuroscience, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), FMP im CharitéCrossOver, Berlin, Germany
| | - David Schwefel
- Institute of Medical Physics and Biophysics, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Alexander M Walter
- Molecular and Theoretical Neuroscience, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), FMP im CharitéCrossOver, Berlin, Germany.,Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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33
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Abstract
Myelination of axons provides the structural basis for rapid saltatory impulse propagation along vertebrate fiber tracts, a well-established neurophysiological concept. However, myelinating oligodendrocytes and Schwann cells serve additional functions in neuronal energy metabolism that are remarkably similar to those of axon-ensheathing glial cells in unmyelinated invertebrates. Here we discuss myelin evolution and physiological glial functions, beginning with the role of ensheathing glia in preventing ephaptic coupling, axoglial metabolic support, and eliminating oxidative radicals. In both vertebrates and invertebrates, axoglial interactions are bidirectional, serving to regulate cell fate, nerve conduction, and behavioral performance. One key step in the evolution of compact myelin in the vertebrate lineage was the emergence of the open reading frame for myelin basic protein within another gene. Several other proteins were neofunctionalized as myelin constituents and help maintain a healthy nervous system. Myelination in vertebrates became a major prerequisite of inhabiting new ecological niches.
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Affiliation(s)
- Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, D-37075 Göttingen, Germany; ,
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, D-37075 Göttingen, Germany; ,
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34
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Morpho-Functional Consequences of Swiss Cheese Knockdown in Glia of Drosophila melanogaster. Cells 2021; 10:cells10030529. [PMID: 33801404 PMCID: PMC7998100 DOI: 10.3390/cells10030529] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/18/2021] [Accepted: 02/24/2021] [Indexed: 01/15/2023] Open
Abstract
Glia are crucial for the normal development and functioning of the nervous system in many animals. Insects are widely used for studies of glia genetics and physiology. Drosophila melanogaster surface glia (perineurial and subperineurial) form a blood–brain barrier in the central nervous system and blood–nerve barrier in the peripheral nervous system. Under the subperineurial glia layer, in the cortical region of the central nervous system, cortex glia encapsulate neuronal cell bodies, whilst in the peripheral nervous system, wrapping glia ensheath axons of peripheral nerves. Here, we show that the expression of the evolutionarily conserved swiss cheese gene is important in several types of glia. swiss cheese knockdown in subperineurial glia leads to morphological abnormalities of these cells. We found that the number of subperineurial glia nuclei is reduced under swiss cheese knockdown, possibly due to apoptosis. In addition, the downregulation of swiss cheese in wrapping glia causes a loss of its integrity. We reveal transcriptome changes under swiss cheese knockdown in subperineurial glia and in cortex + wrapping glia and show that the downregulation of swiss cheese in these types of glia provokes reactive oxygen species acceleration. These results are accompanied by a decline in animal mobility measured by the negative geotaxis performance assay.
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35
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Abstract
One in three epilepsy cases is drug resistant, and seizures often begin in infancy, when they are life-threatening and when therapeutic options are highly limited. An important tool for prioritizing and validating genes associated with epileptic conditions, which is suitable for large-scale screening, is disease modeling in Drosophila. Approximately two-thirds of disease genes are conserved in Drosophila, and gene-specific fly models exhibit behavioral changes that are related to symptoms of epilepsy. Models are based on behavior readouts, seizure-like attacks and paralysis following stimulation, and neuronal, cell-biological readouts that are in the majority based on changes in nerve cell activity or morphology. In this review, we focus on behavioral phenotypes. Importantly, Drosophila modeling is independent of, and complementary to, other approaches that are computational and based on systems analysis. The large number of known epilepsy-associated gene variants indicates a need for efficient research strategies. We will discuss the status quo of epilepsy disease modelling in Drosophila and describe promising steps towards the development of new drugs to reduce seizure rates and alleviate other epileptic symptoms.
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Affiliation(s)
- Paul Lasko
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, Netherlands
- Department of Biology, McGill University, Montréal, Québec, Canada
| | - Kevin Lüthy
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, Netherlands
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