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Xiong A, Richmond JE, Kim H. Presynaptic neurons self-tune by inversely coupling neurotransmitter release with the abundance of CaV2 voltage-gated Ca 2+ channels. Proc Natl Acad Sci U S A 2024; 121:e2404969121. [PMID: 39172783 PMCID: PMC11363341 DOI: 10.1073/pnas.2404969121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Accepted: 07/12/2024] [Indexed: 08/24/2024] Open
Abstract
The abundance of CaV2 voltage-gated calcium channels is linked to presynaptic homeostatic plasticity (PHP), a process that recalibrates synaptic strength to maintain the stability of neural circuits. However, the molecular and cellular mechanisms governing PHP and CaV2 channels are not completely understood. Here, we uncover a previously not described form of PHP in Caenorhabditis elegans, revealing an inverse regulatory relationship between the efficiency of neurotransmitter release and the abundance of UNC-2/CaV2 channels. Gain-of-function unc-2SL(S240L) mutants, which carry a mutation analogous to the one causing familial hemiplegic migraine type 1 in humans, showed markedly reduced channel abundance despite increased channel functionality. Reducing synaptic release in these unc-2SL(S240L) mutants restored channel levels to those observed in wild-type animals. Conversely, loss-of-function unc-2DA(D726A) mutants, which harbor the D726A mutation in the channel pore, exhibited a marked increase in channel abundance. Enhancing synaptic release in unc-2DA mutants reversed this increase in channel levels. Importantly, this homeostatic regulation of UNC-2 channel levels is accompanied by the structural remodeling of the active zone (AZ); specifically, unc-2DA mutants, which exhibit increased channel abundance, showed parallel increases in select AZ proteins. Finally, our forward genetic screen revealed that WWP-1, a HECT family E3 ubiquitin ligase, is a key homeostatic mediator that removes UNC-2 from synapses. These findings highlight a self-tuning PHP regulating UNC-2/CaV2 channel abundance along with AZ reorganization, ensuring synaptic strength and stability.
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Affiliation(s)
- Ame Xiong
- Discipline of Cell Biology & Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL60064
| | - Janet E. Richmond
- Department of Biological Sciences, University of Illinois, Chicago, IL60607
| | - Hongkyun Kim
- Discipline of Cell Biology & Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL60064
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2
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Rathor L, Curry S, Park Y, McElroy T, Robles B, Sheng Y, Chen WW, Min K, Xiao R, Lee MH, Han SM. Mitochondrial stress in GABAergic neurons non-cell autonomously regulates organismal health and aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.20.585932. [PMID: 38585797 PMCID: PMC10996468 DOI: 10.1101/2024.03.20.585932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Mitochondrial stress within the nervous system can trigger non-cell autonomous responses in peripheral tissues. However, the specific neurons involved and their impact on organismal aging and health have remained incompletely understood. Here, we demonstrate that mitochondrial stress in γ-aminobutyric acid-producing (GABAergic) neurons in Caenorhabditis elegans ( C. elegans ) is sufficient to significantly alter organismal lifespan, stress tolerance, and reproductive capabilities. This mitochondrial stress also leads to significant changes in mitochondrial mass, energy production, and levels of reactive oxygen species (ROS). DAF-16/FoxO activity is enhanced by GABAergic neuronal mitochondrial stress and mediates the induction of these non-cell-autonomous effects. Moreover, our findings indicate that GABA signaling operates within the same pathway as mitochondrial stress in GABAergic neurons, resulting in non-cell-autonomous alterations in organismal stress tolerance and longevity. In summary, these data suggest the crucial role of GABAergic neurons in detecting mitochondrial stress and orchestrating non-cell-autonomous changes throughout the organism.
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3
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Buckley M, Jacob WP, Bortey L, McClain M, Ritter AL, Godfrey A, Munneke AS, Ramachandran S, Kenis S, Kolnik JC, Olofsson S, Adkins R, Kutoloski T, Rademacher L, Heinecke O, Alva A, Beets I, Francis MM, Kowalski JR. Cell non-autonomous signaling through the conserved C. elegans glycopeptide hormone receptor FSHR-1 regulates cholinergic neurotransmission. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.10.578699. [PMID: 38405708 PMCID: PMC10888917 DOI: 10.1101/2024.02.10.578699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Modulation of neurotransmission is key for organismal responses to varying physiological contexts such as during infection, injury, or other stresses, as well as in learning and memory and for sensory adaptation. Roles for cell autonomous neuromodulatory mechanisms in these processes have been well described. The importance of cell non-autonomous pathways for inter-tissue signaling, such as gut-to-brain or glia-to-neuron, has emerged more recently, but the cellular mechanisms mediating such regulation remain comparatively unexplored. Glycoproteins and their G protein-coupled receptors (GPCRs) are well-established orchestrators of multi-tissue signaling events that govern diverse physiological processes through both cell-autonomous and cell non-autonomous regulation. Here, we show that follicle stimulating hormone receptor, FSHR-1, the sole Caenorhabditis elegans ortholog of mammalian glycoprotein hormone GPCRs, is important for cell non-autonomous modulation of synaptic transmission. Inhibition of fshr-1 expression reduces muscle contraction and leads to synaptic vesicle accumulation in cholinergic motor neurons. The neuromuscular and locomotor defects in fshr-1 loss-of-function mutants are associated with an underlying accumulation of synaptic vesicles, build-up of the synaptic vesicle priming factor UNC-10/RIM, and decreased synaptic vesicle release from cholinergic motor neurons. Restoration of FSHR-1 to the intestine is sufficient to restore neuromuscular activity and synaptic vesicle localization to fshr-1- deficient animals. Intestine-specific knockdown of FSHR-1 reduces neuromuscular function, indicating FSHR-1 is both necessary and sufficient in the intestine for its neuromuscular effects. Re-expression of FSHR-1 in other sites of endogenous expression, including glial cells and neurons, also restored some neuromuscular deficits, indicating potential cross-tissue regulation from these tissues as well. Genetic interaction studies provide evidence that downstream effectors gsa-1 / Gα S , acy-1 /adenylyl cyclase and sphk-1/ sphingosine kinase and glycoprotein hormone subunit orthologs, GPLA-1/GPA2 and GPLB-1/GPB5, are important for FSHR-1 modulation of the NMJ. Together, our results demonstrate that FSHR-1 modulation directs inter-tissue signaling systems, which promote synaptic vesicle release at neuromuscular synapses.
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4
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Hulsey-Vincent H, McClain M, Buckley M, Kowalski JR, Dahlberg CL. Comparison and agreement between two image analysis tools for quantifying GFP::SNB-1 puncta in fshr-1 mutants of C. elegans. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.001005. [PMID: 38162412 PMCID: PMC10755584 DOI: 10.17912/micropub.biology.001005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/16/2023] [Accepted: 12/12/2023] [Indexed: 01/03/2024]
Abstract
Quantitative imaging of synaptic vesicle localization and abundance using fluorescently labeled synaptic vesicle associated proteins like GFP::SNB-1 is a well-established method for measuring changes in synapse structure at neuromuscular junctions (NMJ) in C. elegans . To date, however, the ability to easily and reproducibly measure key parameters at the NMJ - maximum intensity, size of GFP::SNB-1 puncta, density of puncta - has relied on the use of expensive, customizable software that requires coding skills to modify, precluding widespread access and thus preventing standardization within the field. We carried out a comparative evaluation of a new, open-source Fiji puncta plugin versus traditional Igor-based analysis of GFP::SNB-1 imaging data taken of cholinergic motor neurons in the dorsal nerve cord of loss of function mutants in fshr-1 , which encodes a G protein-coupled receptor known to impact GFP::SNB-1 accumulation. We analyzed images taken on a widefield fluorescence microscope, as well as on a spinning disk confocal microscope. Our data demonstrate strong concordance between the differences in GFP::SNB-1 localization in fshr-1 mutants compared to wild type worms across both analysis platforms (Fiji and Igor), as well as across microscope types (widefield and confocal). These data also agree with previously published observations related to synapse number and GFP::SNB-1 intensity in fshr-1 and wild type worms. Based on these findings, we conclude that the Fiji platform is viable as a method for analyzing synaptic vesicle localization and abundance at cholinergic dorsal nerve cord motor NMJs and expect the Fiji puncta plugin to be of broad utility in imaging across a variety of imaging platforms and synaptic markers.
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Affiliation(s)
| | - Makenzi McClain
- Biological Sciences, Butler University, Indianapolis, Indiana, United States
| | - Morgan Buckley
- Biological Sciences, Butler University, Indianapolis, Indiana, United States
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5
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Yamamoto KK, Savage-Dunn C. TGF-β pathways in aging and immunity: lessons from Caenorhabditis elegans. Front Genet 2023; 14:1220068. [PMID: 37732316 PMCID: PMC10507863 DOI: 10.3389/fgene.2023.1220068] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/23/2023] [Indexed: 09/22/2023] Open
Abstract
The Transforming Growth Factor-β (TGF-β) superfamily of signaling molecules plays critical roles in development, differentiation, homeostasis, and disease. Due to the conservation of these ligands and their signaling pathways, genetic studies in invertebrate systems including the nematode Caenorhabditis elegans have been instrumental in identifying signaling mechanisms. C. elegans is also a premier organism for research in longevity and healthy aging. Here we summarize current knowledge on the roles of TGF-β signaling in aging and immunity.
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Affiliation(s)
| | - Cathy Savage-Dunn
- Department of Biology, Queens College, and PhD Program in Biology, The Graduate Center, City University of New York, New York City, NY, United States
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6
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Guerrero-Rubio MA, Hernández-García S, García-Carmona F, Gandía-Herrero F. Consumption of commonly used artificial food dyes increases activity and oxidative stress in the animal model Caenorhabditis elegans. Food Res Int 2023; 169:112925. [PMID: 37254351 DOI: 10.1016/j.foodres.2023.112925] [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: 01/18/2023] [Revised: 04/13/2023] [Accepted: 04/26/2023] [Indexed: 06/01/2023]
Abstract
In recent decades, the consumption of artificial colorants in foods and beverages has increased despite of concerns in the general population raised by studies that have shown possible injurious effects. In this study, tartrazine, sunset yellow, quinoline yellow, ponceau 4R, carmoisine and allura red were employed as pure compounds to explore their effects in vivo in the animal model Caenorhabditis elegans. The exposition of C. elegans to these artificial dyes produced damage related with aging such as oxidative stress and lipofuscin accumulation, as well as a heavy shortening of lifespan, alterations in movement patterns and alterations in the production of dopamine receptors. Besides, microarray analysis performed with worms treated with tartrazine and ponceau 4R showed how the consumption of synthetic colorants is able to alter the expression of genes involved in resistance to oxidative stress and neurodegeneration.
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Affiliation(s)
- M Alejandra Guerrero-Rubio
- Departamento de Bioquímica y Biología Molecular A, Unidad Docente de Biología, Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia, Spain
| | - Samanta Hernández-García
- Departamento de Bioquímica y Biología Molecular A, Unidad Docente de Biología, Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia, Spain
| | - Francisco García-Carmona
- Departamento de Bioquímica y Biología Molecular A, Unidad Docente de Biología, Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia, Spain
| | - Fernando Gandía-Herrero
- Departamento de Bioquímica y Biología Molecular A, Unidad Docente de Biología, Facultad de Veterinaria, Regional Campus of International Excellence "Campus Mare Nostrum", Universidad de Murcia, Murcia, Spain.
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7
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Pannone L, Muto V, Nardecchia F, Di Rocco M, Marchei E, Tosato F, Petrini S, Onorato G, Lanza E, Bertuccini L, Manti F, Folli V, Galosi S, Di Schiavi E, Leuzzi V, Tartaglia M, Martinelli S. The recurrent pathogenic Pro890Leu substitution in CLTC causes a generalized defect in synaptic transmission in Caenorhabditis elegans. Front Mol Neurosci 2023; 16:1170061. [PMID: 37324589 PMCID: PMC10264582 DOI: 10.3389/fnmol.2023.1170061] [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: 02/20/2023] [Accepted: 05/09/2023] [Indexed: 06/17/2023] Open
Abstract
De novo CLTC mutations underlie a spectrum of early-onset neurodevelopmental phenotypes having developmental delay/intellectual disability (ID), epilepsy, and movement disorders (MD) as major clinical features. CLTC encodes the widely expressed heavy polypeptide of clathrin, a major component of the coated vesicles mediating endocytosis, intracellular trafficking, and synaptic vesicle recycling. The underlying pathogenic mechanism is largely unknown. Here, we assessed the functional impact of the recurrent c.2669C > T (p.P890L) substitution, which is associated with a relatively mild ID/MD phenotype. Primary fibroblasts endogenously expressing the mutated protein show reduced transferrin uptake compared to fibroblast lines obtained from three unrelated healthy donors, suggesting defective clathrin-mediated endocytosis. In vitro studies also reveal a block in cell cycle transition from G0/G1 to the S phase in patient's cells compared to control cells. To demonstrate the causative role of the p.P890L substitution, the pathogenic missense change was introduced at the orthologous position of the Caenorhabditis elegans gene, chc-1 (p.P892L), via CRISPR/Cas9. The resulting homozygous gene-edited strain displays resistance to aldicarb and hypersensitivity to PTZ, indicating defective release of acetylcholine and GABA by ventral cord motor neurons. Consistently, mutant animals show synaptic vesicle depletion at the sublateral nerve cords, and slightly defective dopamine signaling, highlighting a generalized deficit in synaptic transmission. This defective release of neurotransmitters is associated with their secondary accumulation at the presynaptic membrane. Automated analysis of C. elegans locomotion indicates that chc-1 mutants move slower than their isogenic controls and display defective synaptic plasticity. Phenotypic profiling of chc-1 (+/P892L) heterozygous animals and transgenic overexpression experiments document a mild dominant-negative behavior for the mutant allele. Finally, a more severe phenotype resembling that of chc-1 null mutants is observed in animals harboring the c.3146 T > C substitution (p.L1049P), homologs of the pathogenic c.3140 T > C (p.L1047P) change associated with a severe epileptic phenotype. Overall, our findings provide novel insights into disease mechanisms and genotype-phenotype correlations of CLTC-related disorders.
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Affiliation(s)
- Luca Pannone
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Valentina Muto
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | | | - Martina Di Rocco
- Department of Human Neuroscience, “Sapienza” University of Rome, Rome, Italy
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Emilia Marchei
- National Centre on Addiction and Doping, Istituto Superiore di Sanità, Rome, Italy
| | - Federica Tosato
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Stefania Petrini
- Confocal Microscopy Core Facility, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Giada Onorato
- Institute of Biosciences and Bioresources, National Research Council, Naples, Italy
- Department of Environmental, Biological and Pharmaceutical Science and Technologies, Università degli Studi della Campania “Luigi Vanvitelli”, Caserta, Italy
| | - Enrico Lanza
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome, Italy
- D-Tails s.r.l., Rome, Italy
| | | | - Filippo Manti
- Department of Human Neuroscience, “Sapienza” University of Rome, Rome, Italy
| | - Viola Folli
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome, Italy
- D-Tails s.r.l., Rome, Italy
| | - Serena Galosi
- Department of Human Neuroscience, “Sapienza” University of Rome, Rome, Italy
| | - Elia Di Schiavi
- Institute of Biosciences and Bioresources, National Research Council, Naples, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, “Sapienza” University of Rome, Rome, Italy
| | - Marco Tartaglia
- Molecular Genetics and Functional Genomics, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome, Italy
| | - Simone Martinelli
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
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8
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Mattison KA, Tossing G, Mulroe F, Simmons C, Butler KM, Schreiber A, Alsadah A, Neilson DE, Naess K, Wedell A, Wredenberg A, Sorlin A, McCann E, Burghel GJ, Menendez B, Hoganson GE, Botto LD, Filloux FM, Aledo-Serrano Á, Gil-Nagel A, Tatton-Brown K, Verbeek NE, van der Zwaag B, Aleck KA, Fazenbaker AC, Balciuniene J, Dubbs HA, Marsh ED, Garber K, Ek J, Duno M, Hoei-Hansen CE, Deardorff MA, Raca G, Quindipan C, van Hirtum-Das M, Breckpot J, Hammer TB, Møller RS, Whitney A, Douglas AGL, Kharbanda M, Brunetti-Pierri N, Morleo M, Nigro V, May HJ, Tao JX, Argilli E, Sherr EH, Dobyns WB, Baines RA, Warwicker J, Parker JA, Banka S, Campeau PM, Escayg A. ATP6V0C variants impair V-ATPase function causing a neurodevelopmental disorder often associated with epilepsy. Brain 2023; 146:1357-1372. [PMID: 36074901 PMCID: PMC10319782 DOI: 10.1093/brain/awac330] [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: 02/14/2022] [Revised: 07/29/2022] [Accepted: 08/14/2022] [Indexed: 11/14/2022] Open
Abstract
The vacuolar H+-ATPase is an enzymatic complex that functions in an ATP-dependent manner to pump protons across membranes and acidify organelles, thereby creating the proton/pH gradient required for membrane trafficking by several different types of transporters. We describe heterozygous point variants in ATP6V0C, encoding the c-subunit in the membrane bound integral domain of the vacuolar H+-ATPase, in 27 patients with neurodevelopmental abnormalities with or without epilepsy. Corpus callosum hypoplasia and cardiac abnormalities were also present in some patients. In silico modelling suggested that the patient variants interfere with the interactions between the ATP6V0C and ATP6V0A subunits during ATP hydrolysis. Consistent with decreased vacuolar H+-ATPase activity, functional analyses conducted in Saccharomyces cerevisiae revealed reduced LysoSensor fluorescence and reduced growth in media containing varying concentrations of CaCl2. Knockdown of ATP6V0C in Drosophila resulted in increased duration of seizure-like behaviour, and the expression of selected patient variants in Caenorhabditis elegans led to reduced growth, motor dysfunction and reduced lifespan. In summary, this study establishes ATP6V0C as an important disease gene, describes the clinical features of the associated neurodevelopmental disorder and provides insight into disease mechanisms.
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Affiliation(s)
- Kari A Mattison
- Genetics and Molecular Biology Graduate Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, GA, USA
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Gilles Tossing
- Department of Neuroscience, University of Montreal, Montreal, QC, Canada
| | - Fred Mulroe
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Center, Manchester, UK
| | - Callum Simmons
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Center, Manchester, UK
| | - Kameryn M Butler
- Department of Human Genetics, Emory University, Atlanta, GA, USA
- Greenwood Genetics Center, Greenwood, SC, USA
| | - Alison Schreiber
- Center for Personalized Genetic Healthcare, Cleveland Clinic, Cleveland, OH, USA
| | - Adnan Alsadah
- Center for Personalized Genetic Healthcare, Cleveland Clinic, Cleveland, OH, USA
| | - Derek E Neilson
- Division of Genetics and Metabolism, Department of Child Health, The University of Arizona College of Medicine, Phoenix, AZ, USA
- Department of Genetics and Metabolism, Phoenix Children’s Hospital, Phoenix Children’s Medical Group, Phoenix, AZ, USA
| | - Karin Naess
- Center for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Anna Wedell
- Center for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
- Deparment of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden
| | - Anna Wredenberg
- Center for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Arthur Sorlin
- National Center of Genetics, Laboratoire National de Santé, Dudelange, Luxembourg
| | - Emma McCann
- Liverpool Center for Genomic Medicine, Liverpool Women’s Hospital, Liverpool, UK
| | - George J Burghel
- Genomic Diagnostic Laboratory, St. Mary’s Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | | | - George E Hoganson
- Division of Genetics, Department of Pediatrics, University of Illinois College of Medicine, Chicago, IL, USA
| | - Lorenzo D Botto
- Division of Medical Genetics, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Francis M Filloux
- Division of Pediatric Neurology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Ángel Aledo-Serrano
- Genetic Epilepsy Program, Department of Neurology, Ruber International Hospital, Madrid, Spain
| | - Antonio Gil-Nagel
- Genetic Epilepsy Program, Department of Neurology, Ruber International Hospital, Madrid, Spain
| | - Katrina Tatton-Brown
- Medical Genetics, St. George’s University Hospitals NHS Foundation Trust and Institute for Molecular and Cell Sciences, St. George’s, University of London, London, UK
| | - Nienke E Verbeek
- Department of Genetics, University Medical Center Utrecht, Member of the ERN EpiCARE, Utrecht, The Netherlands
| | - Bert van der Zwaag
- Department of Genetics, University Medical Center Utrecht, Member of the ERN EpiCARE, Utrecht, The Netherlands
| | - Kyrieckos A Aleck
- Division of Genetics and Metabolism, Department of Child Health, The University of Arizona College of Medicine, Phoenix, AZ, USA
- Department of Genetics and Metabolism, Phoenix Children’s Hospital, Phoenix Children’s Medical Group, Phoenix, AZ, USA
| | - Andrew C Fazenbaker
- Department of Genetics and Metabolism, Phoenix Children’s Hospital, Phoenix Children’s Medical Group, Phoenix, AZ, USA
| | - Jorune Balciuniene
- Divison of Genomic Diagnostics, Department of Pathology and Laboratory Medicine, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
- PerkinElmer Genomics, Pittsburgh, PA, USA
| | - Holly A Dubbs
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Eric D Marsh
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kathryn Garber
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Jakob Ek
- Department of Clinical Genetics, University Hospital of Copenhagen, Copenhagen, Denmark
| | - Morten Duno
- Department of Clinical Genetics, University Hospital of Copenhagen, Copenhagen, Denmark
| | - Christina E Hoei-Hansen
- Department of Pediatrics, University Hospital of Copenhagen, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Matthew A Deardorff
- Department of Pathology and Laboratory Medicine, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Department of Pediatrics, Division of Medical Genetics, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Gordana Raca
- Department of Pathology and Laboratory Medicine, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Catherine Quindipan
- Center for Personalized Medicine, Children’s Hospital Los Angeles, Los Angeles, CA, USA
| | - Michele van Hirtum-Das
- Department of Pediatrics, Division of Medical Genetics, Children’s Hospital Los Angeles, Los Angeles, CA, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Jeroen Breckpot
- Center for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Trine Bjørg Hammer
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Fildelfia, Dianalund, Denmark
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Center, Fildelfia, Dianalund, Denmark
- Insititue for Regional Health Services Research, University of Southern Denmark, Odense, Denmark
| | - Andrea Whitney
- Pediatric Neurology, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Andrew G L Douglas
- Wessex Clinical Genetics Service, University of Southampton, Southampton, UK
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Mira Kharbanda
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Nicola Brunetti-Pierri
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Translational Medicine, Federico II University of Naples, Naples, Italy
| | - Manuela Morleo
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Precision Medicine, University of Campania ‘Luigi Vanvitelli’, Naples, Italy
| | - Vincenzo Nigro
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Italy
- Department of Precision Medicine, University of Campania ‘Luigi Vanvitelli’, Naples, Italy
| | - Halie J May
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | - James X Tao
- Department of Neurology, University of Chicago, Chicago, IL, USA
| | - Emanuela Argilli
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
- Pediatrics Institute of Human Genetics and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Elliot H Sherr
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
- Pediatrics Institute of Human Genetics and Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - William B Dobyns
- Department of Pediatrics, Division of Genetics and Metabolism, University of Minnesota, Minneapolis, MN, USA
| | | | - Richard A Baines
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Center, Manchester, UK
| | - Jim Warwicker
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Institute of Biotechnology, University of Manchester, Manchester, UK
| | - J Alex Parker
- Department of Neuroscience, University of Montreal, Montreal, QC, Canada
| | - Siddharth Banka
- Division of Evolution, Infection, and Genomics, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | | | - Andrew Escayg
- Department of Human Genetics, Emory University, Atlanta, GA, USA
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9
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Hao Y, Liu H, Zeng XT, Wang Y, Zeng WX, Qian KY, Li L, Chi MX, Gao S, Hu Z, Tong XJ. UNC-43/CaMKII-triggered anterograde signals recruit GABA ARs to mediate inhibitory synaptic transmission and plasticity at C. elegans NMJs. Nat Commun 2023; 14:1436. [PMID: 36918518 PMCID: PMC10015018 DOI: 10.1038/s41467-023-37137-0] [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: 07/17/2022] [Accepted: 02/28/2023] [Indexed: 03/16/2023] Open
Abstract
Disturbed inhibitory synaptic transmission has functional impacts on neurodevelopmental and psychiatric disorders. An essential mechanism for modulating inhibitory synaptic transmission is alteration of the postsynaptic abundance of GABAARs, which are stabilized by postsynaptic scaffold proteins and recruited by presynaptic signals. However, how GABAergic neurons trigger signals to transsynaptically recruit GABAARs remains elusive. Here, we show that UNC-43/CaMKII functions at GABAergic neurons to recruit GABAARs and modulate inhibitory synaptic transmission at C. elegans neuromuscular junctions. We demonstrate that UNC-43 promotes presynaptic MADD-4B/Punctin secretion and NRX-1α/Neurexin surface delivery. Together, MADD-4B and NRX-1α recruit postsynaptic NLG-1/Neuroligin and stabilize GABAARs. Further, the excitation of GABAergic neurons potentiates the recruitment of NLG-1-stabilized-GABAARs, which depends on UNC-43, MADD-4B, and NRX-1. These data all support that UNC-43 triggers MADD-4B and NRX-1α, which act as anterograde signals to recruit postsynaptic GABAARs. Thus, our findings elucidate a mechanism for pre- and postsynaptic communication and inhibitory synaptic transmission and plasticity.
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Affiliation(s)
- Yue Hao
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Haowen Liu
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Xian-Ting Zeng
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Ya Wang
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Wan-Xin Zeng
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Kang-Ying Qian
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
- Institute of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, 200031, China
- University of Chinese Academy of Sciences, Beijing, 100190, China
| | - Lei Li
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Ming-Xuan Chi
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Shangbang Gao
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Zhitao Hu
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Xia-Jing Tong
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
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10
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Caenorhabditis elegans as a Model System to Study Human Neurodegenerative Disorders. Biomolecules 2023; 13:biom13030478. [PMID: 36979413 PMCID: PMC10046667 DOI: 10.3390/biom13030478] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/18/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
In recent years, advances in science and technology have improved our quality of life, enabling us to tackle diseases and increase human life expectancy. However, longevity is accompanied by an accretion in the frequency of age-related neurodegenerative diseases, creating a growing burden, with pervasive social impact for human societies. The cost of managing such chronic disorders and the lack of effective treatments highlight the need to decipher their molecular and genetic underpinnings, in order to discover new therapeutic targets. In this effort, the nematode Caenorhabditis elegans serves as a powerful tool to recapitulate several disease-related phenotypes and provides a highly malleable genetic model that allows the implementation of multidisciplinary approaches, in addition to large-scale genetic and pharmacological screens. Its anatomical transparency allows the use of co-expressed fluorescent proteins to track the progress of neurodegeneration. Moreover, the functional conservation of neuronal processes, along with the high homology between nematode and human genomes, render C. elegans extremely suitable for the study of human neurodegenerative disorders. This review describes nematode models used to study neurodegeneration and underscores their contribution in the effort to dissect the molecular basis of human diseases and identify novel gene targets with therapeutic potential.
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11
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Kropp PA, Rogers P, Kelly SE, McWhirter R, Goff WD, Levitan IM, Miller DM, Golden A. Patient-specific variants of NFU1/NFU-1 disrupt cholinergic signaling in a model of multiple mitochondrial dysfunctions syndrome 1. Dis Model Mech 2023; 16:286662. [PMID: 36645076 PMCID: PMC9922734 DOI: 10.1242/dmm.049594] [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: 04/04/2022] [Accepted: 01/05/2023] [Indexed: 01/17/2023] Open
Abstract
Neuromuscular dysfunction is a common feature of mitochondrial diseases and frequently presents as ataxia, spasticity and/or dystonia, all of which can severely impact individuals with mitochondrial diseases. Dystonia is one of the most common symptoms of multiple mitochondrial dysfunctions syndrome 1 (MMDS1), a disease associated with mutations in the causative gene (NFU1) that impair iron-sulfur cluster biogenesis. We have generated Caenorhabditis elegans strains that recreated patient-specific point variants in the C. elegans ortholog (nfu-1) that result in allele-specific dysfunction. Each of these mutants, Gly147Arg and Gly166Cys, have altered acetylcholine signaling at neuromuscular junctions, but opposite effects on activity and motility. We found that the Gly147Arg variant was hypersensitive to acetylcholine and that knockdown of acetylcholine release rescued nearly all neuromuscular phenotypes of this variant. In contrast, we found that the Gly166Cys variant caused predominantly postsynaptic acetylcholine hypersensitivity due to an unclear mechanism. These results are important for understanding the neuromuscular conditions of MMDS1 patients and potential avenues for therapeutic intervention.
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Affiliation(s)
- Peter A Kropp
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,Biology Department, Kenyon College, Gambier, OH 43022, USA
| | - Philippa Rogers
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sydney E Kelly
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rebecca McWhirter
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37235, USA
| | - Willow D Goff
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.,Biology Department, Colgate University, Hamilton, NY 13346, USA
| | - Ian M Levitan
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - David M Miller
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37235, USA.,Neuroscience Graduate Program, Vanderbilt University, Nashville, TN 37235, USA
| | - Andy Golden
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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12
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Parrales-Macias V, Harfouche A, Ferrié L, Haïk S, Michel PP, Raisman-Vozari R, Figadère B, Bizat N, Maciuk A. Effects of a New Natural Catechol- O-methyl Transferase Inhibitor on Two In Vivo Models of Parkinson's Disease. ACS Chem Neurosci 2022; 13:3303-3313. [PMID: 36347018 DOI: 10.1021/acschemneuro.2c00356] [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: 11/10/2022] Open
Abstract
A tetrahydroisoquinoline identified in Mucuna pruriens ((1R,3S)-6,7-dihydroxy-1-methyl-1,2,3,4-tetrahydroisoquinoline-1,3-dicarboxylic acid, compound 4) was synthesized and assessed for its in vitro pharmacological profile and in vivo effects in two animal models of Parkinson's disease. Compound 4 inhibits catechol-O-methyltransferase (COMT) with no affinity for the dopaminergic receptors or the dopamine transporter. It restores dopamine-mediated motor behavior when it is co-administered with L-DOPA to C. elegans worms with 1-methyl-4-phenylpyridinium-damaged dopaminergic neurons. In a 6-hydroxydopamine rat model of Parkinson's disease, its co-administration at 30 mg/kg with L-DOPA enhances the effect of L-DOPA with an intensity similar to that of tolcapone 1 at 30 mg/kg but for a shorter duration. The effect is not dose-dependent. Compound 4 seems not to cross the blood-brain barrier and thus acts as a peripheral COMT inhibitor. COMT inhibition by compound 4 further validates the traditional use of M. pruriens for the treatment of Parkinson's disease, and compound 4 can thus be considered as a promising drug candidate for the development of safe, peripheral COMT inhibitors.
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Affiliation(s)
- Valeria Parrales-Macias
- Paris Brain Institute - ICM, Inserm, CNRS, Hôpital Pitié Salpêtrière, Sorbonne Université, Paris 75013, France
| | - Abha Harfouche
- CNRS, BioCIS, Université Paris-Saclay, Orsay 91400, France
| | - Laurent Ferrié
- CNRS, BioCIS, Université Paris-Saclay, Orsay 91400, France
| | - Stéphane Haïk
- Paris Brain Institute - ICM, Inserm, CNRS, Hôpital Pitié Salpêtrière, Sorbonne Université, Paris 75013, France
| | - Patrick P Michel
- Paris Brain Institute - ICM, Inserm, CNRS, Hôpital Pitié Salpêtrière, Sorbonne Université, Paris 75013, France
| | - Rita Raisman-Vozari
- Paris Brain Institute - ICM, Inserm, CNRS, Hôpital Pitié Salpêtrière, Sorbonne Université, Paris 75013, France
| | - Bruno Figadère
- CNRS, BioCIS, Université Paris-Saclay, Orsay 91400, France
| | - Nicolas Bizat
- Paris Brain Institute - ICM, Inserm, CNRS, Hôpital Pitié Salpêtrière, Sorbonne Université, Paris 75013, France
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13
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Lo WS, Roca M, Dardiry M, Mackie M, Eberhardt G, Witte H, Hong R, Sommer RJ, Lightfoot JW. Evolution and Diversity of TGF-β Pathways are Linked with Novel Developmental and Behavioral Traits. Mol Biol Evol 2022; 39:msac252. [PMID: 36469861 PMCID: PMC9733428 DOI: 10.1093/molbev/msac252] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 10/19/2022] [Accepted: 11/07/2022] [Indexed: 12/12/2022] Open
Abstract
Transforming growth factor-β (TGF-β) signaling is essential for numerous biologic functions. It is a highly conserved pathway found in all metazoans including the nematode Caenorhabditis elegans, which has also been pivotal in identifying many components. Utilizing a comparative evolutionary approach, we explored TGF-β signaling in nine nematode species and revealed striking variability in TGF-β gene frequency across the lineage. Of the species analyzed, gene duplications in the DAF-7 pathway appear common with the greatest disparity observed in Pristionchus pacificus. Specifically, multiple paralogues of daf-3, daf-4 and daf-7 were detected. To investigate this additional diversity, we induced mutations in 22 TGF-β components and generated corresponding double, triple, and quadruple mutants revealing both conservation and diversification in function. Although the DBL-1 pathway regulating body morphology appears highly conserved, the DAF-7 pathway exhibits functional divergence, notably in some aspects of dauer formation. Furthermore, the formation of the phenotypically plastic mouth in P. pacificus is partially influenced through TGF-β with the strongest effect in Ppa-tag-68. This appears important for numerous processes in P. pacificus but has no known function in C. elegans. Finally, we observe behavioral differences in TGF-β mutants including in chemosensation and the establishment of the P. pacificus kin-recognition signal. Thus, TGF-β signaling in nematodes represents a stochastic genetic network capable of generating novel functions through the duplication and deletion of associated genes.
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Affiliation(s)
- Wen-Sui Lo
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Marianne Roca
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior—Caesar, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
| | - Mohannad Dardiry
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Marisa Mackie
- Department of Biology, California State University, Northridge, CA
| | - Gabi Eberhardt
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Hanh Witte
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - Ray Hong
- Department of Biology, California State University, Northridge, CA
| | - Ralf J Sommer
- Department for Integrative Evolutionary Biology, Max-Planck Institute for Biology Tübingen, Max-Planck Ring 9, 72076 Tübingen, Germany
| | - James W Lightfoot
- Max Planck Research Group Genetics of Behavior, Max Planck Institute for Neurobiology of Behavior—Caesar, Ludwig-Erhard-Allee 2, 53175, Bonn, Germany
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14
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Di Rocco M, Galosi S, Lanza E, Tosato F, Caprini D, Folli V, Friedman J, Bocchinfuso G, Martire A, Di Schiavi E, Leuzzi V, Martinelli S. Caenorhabditis elegans provides an efficient drug screening platform for GNAO1-related disorders and highlights the potential role of caffeine in controlling dyskinesia. Hum Mol Genet 2021; 31:929-941. [PMID: 34622282 PMCID: PMC8947233 DOI: 10.1093/hmg/ddab296] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 12/12/2022] Open
Abstract
Dominant GNAO1 mutations cause an emerging group of childhood-onset neurological disorders characterized by developmental delay, intellectual disability, movement disorders, drug-resistant seizures and neurological deterioration. GNAO1 encodes the α-subunit of an inhibitory GTP/GDP-binding protein regulating ion channel activity and neurotransmitter release. The pathogenic mechanisms underlying GNAO1-related disorders remain largely elusive and there are no effective therapies. Here, we assessed the functional impact of two disease-causing variants associated with distinct clinical features, c.139A > G (p.S47G) and c.662C > A (p.A221D), using Caenorhabditis elegans as a model organism. The c.139A > G change was introduced into the orthologous position of the C. elegans gene via CRISPR/Cas9, whereas a knock-in strain carrying the p.A221D variant was already available. Like null mutants, homozygous knock-in animals showed increased egg laying and were hypersensitive to aldicarb, an inhibitor of acetylcholinesterase, suggesting excessive neurotransmitter release by different classes of motor neurons. Automated analysis of C. elegans locomotion indicated that goa-1 mutants move faster than control animals, with more frequent body bends and a higher reversal rate and display uncoordinated locomotion. Phenotypic profiling of heterozygous animals revealed a strong hypomorphic effect of both variants, with a partial dominant-negative activity for the p.A221D allele. Finally, caffeine was shown to rescue aberrant motor function in C. elegans harboring the goa-1 variants; this effect is mainly exerted through adenosine receptor antagonism. Overall, our findings establish a suitable platform for drug discovery, which may assist in accelerating the development of new therapies for this devastating condition, and highlight the potential role of caffeine in controlling GNAO1-related dyskinesia.
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Affiliation(s)
- Martina Di Rocco
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome 00161, Italy.,Department of Human Neuroscience, "Sapienza" University of Rome, Rome 00185, Italy
| | - Serena Galosi
- Department of Human Neuroscience, "Sapienza" University of Rome, Rome 00185, Italy
| | - Enrico Lanza
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome 00161, Italy
| | - Federica Tosato
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Davide Caprini
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome 00161, Italy
| | - Viola Folli
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome 00161, Italy
| | - Jennifer Friedman
- UCSD Department of Neuroscience and Pediatrics, Rady Children's Hospital Division of Neurology; Rady Children's Institute for Genomic Medicine, San Diego, USA
| | - Gianfranco Bocchinfuso
- Department of Chemical Sciences and Technologies, University of Rome "Tor Vergata", Rome, 00133, Italy
| | - Alberto Martire
- National Center for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Elia Di Schiavi
- Institute of Biosciences and BioResources, National Research Council, Naples 80131, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, "Sapienza" University of Rome, Rome 00185, Italy
| | - Simone Martinelli
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome 00161, Italy
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15
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Labarre A, Tossing G, Maios C, Doyle JJ, Parker JA. A single copy transgenic mutant FUS strain reproduces age-dependent ALS phenotypes in C. elegans. MICROPUBLICATION BIOLOGY 2021; 2021. [PMID: 34568776 PMCID: PMC8459179 DOI: 10.17912/micropub.biology.000473] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 08/31/2021] [Accepted: 09/15/2021] [Indexed: 11/29/2022]
Abstract
Mutations in the human DNA/RNA binding protein FUS are associated with amyotrophic lateral sclerosis and frontotemporal lobar degeneration, including some aggressive and juvenile onset forms. Cytoplasmic inclusions of human FUS proteins are observed in various neurodegenerative disorders, such as Huntington’s disease or spinocerebellar ataxia, suggesting that FUS proteinopathy may be a key player in neurodegeneration. To better understand the pathogenic mechanisms of FUS, we created single copy transgenic Caenorhabditis elegans strains expressing full-length, untagged human FUS in the worm’s GABAergic neurons. These transgenic worms expressing human mutant FUS (mFUS) display the same ALS-associated phenotypes than our previous multiple copy transgenic model, including adult-onset age-dependent loss of motility, progressive paralysis and GABAergic neurodegeneration. These phenotypes are distinct from the transgenic worms expressing human wild-type FUS (wtFUS). We introduce here our C. elegans single copy transgenic for human mutant FUS motor neuron toxicity that may be used for rapid genetic and pharmacological suppressor screening.
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Affiliation(s)
- Audrey Labarre
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada.,Department of Neuroscience, Université de Montréal, Montreal, Canada
| | - Gilles Tossing
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada.,Department of Neuroscience, Université de Montréal, Montreal, Canada
| | - Claudia Maios
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - James J Doyle
- Division of Experimental Medicine, Faculty of Medicine, McGill University, Montreal, Canada.,Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada.,Metabolic Disorders and Complications, Research Institute of the McGill University Health Centre , Montreal, Canada
| | - J Alex Parker
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada.,Department of Neuroscience, Université de Montréal, Montreal, Canada
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16
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Chaya T, Patel S, Smith EM, Lam A, Miller EN, Clupper M, Kervin K, Tanis JE. A C. elegans genome-wide RNAi screen for altered levamisole sensitivity identifies genes required for muscle function. G3-GENES GENOMES GENETICS 2021; 11:6169532. [PMID: 33713125 PMCID: PMC8049432 DOI: 10.1093/g3journal/jkab047] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 02/09/2021] [Indexed: 01/17/2023]
Abstract
At the neuromuscular junction (NMJ), postsynaptic ionotropic acetylcholine receptors (AChRs) transduce a chemical signal released from a cholinergic motor neuron into an electrical signal to induce muscle contraction. To identify regulators of postsynaptic function, we conducted a genome-wide RNAi screen for genes required for proper response to levamisole, a pharmacological agonist of ionotropic L-AChRs at the Caenorhabditis elegans NMJ. A total of 117 gene knockdowns were found to cause levamisole hypersensitivity, while 18 resulted in levamisole resistance. Our screen identified conserved genes important for muscle function including some that are mutated in congenital myasthenic syndrome, congenital muscular dystrophy, congenital myopathy, myotonic dystrophy, and mitochondrial myopathy. Of the genes found in the screen, we further investigated those predicted to play a role in endocytosis of cell surface receptors. Loss of the Epsin homolog epn-1 caused levamisole hypersensitivity and had opposing effects on the levels of postsynaptic L-AChRs and GABAA receptors, resulting in increased and decreased abundance, respectively. We also examined other genes that resulted in a levamisole-hypersensitive phenotype when knocked down including gas-1, which functions in Complex I of the mitochondrial electron transport chain. Consistent with altered ATP synthesis impacting levamisole response, treatment of wild-type animals with levamisole resulted in L-AChR–dependent depletion of ATP levels. These results suggest that the paralytic effects of levamisole ultimately lead to metabolic exhaustion.
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Affiliation(s)
- Timothy Chaya
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shrey Patel
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Erin M Smith
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Andy Lam
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Elaine N Miller
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Michael Clupper
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Kirsten Kervin
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Jessica E Tanis
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
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17
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Qian KY, Zeng WX, Hao Y, Zeng XT, Liu H, Li L, Chen L, Tian FM, Chang C, Hall Q, Song CX, Gao S, Hu Z, Kaplan JM, Li Q, Tong XJ. Male pheromones modulate synaptic transmission at the C. elegans neuromuscular junction in a sexually dimorphic manner. eLife 2021; 10:e67170. [PMID: 33787493 PMCID: PMC8051947 DOI: 10.7554/elife.67170] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/30/2021] [Indexed: 12/24/2022] Open
Abstract
The development of functional synapses in the nervous system is important for animal physiology and behaviors, and its disturbance has been linked with many neurodevelopmental disorders. The synaptic transmission efficacy can be modulated by the environment to accommodate external changes, which is crucial for animal reproduction and survival. However, the underlying plasticity of synaptic transmission remains poorly understood. Here we show that in Caenorhabditis elegans, the male environment increases the hermaphrodite cholinergic transmission at the neuromuscular junction (NMJ), which alters hermaphrodites' locomotion velocity and mating efficiency. We identify that the male-specific pheromones mediate this synaptic transmission modulation effect in a developmental stage-dependent manner. Dissection of the sensory circuits reveals that the AWB chemosensory neurons sense those male pheromones and further transduce the information to NMJ using cGMP signaling. Exposure of hermaphrodites to the male pheromones specifically increases the accumulation of presynaptic CaV2 calcium channels and clustering of postsynaptic acetylcholine receptors at cholinergic synapses of NMJ, which potentiates cholinergic synaptic transmission. Thus, our study demonstrates a circuit mechanism for synaptic modulation and behavioral flexibility by sexual dimorphic pheromones.
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Affiliation(s)
- Kang-Ying Qian
- School of Life Science and Technology, ShanghaiTech UniversityShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
- Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of SciencesShanghaiChina
| | - Wan-Xin Zeng
- School of Life Science and Technology, ShanghaiTech UniversityShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
- Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of SciencesShanghaiChina
| | - Yue Hao
- School of Life Science and Technology, ShanghaiTech UniversityShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
- Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of SciencesShanghaiChina
| | - Xian-Ting Zeng
- School of Life Science and Technology, ShanghaiTech UniversityShanghaiChina
| | - Haowen Liu
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), The University of QueenslandBrisbaneAustralia
| | - Lei Li
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), The University of QueenslandBrisbaneAustralia
| | - Lili Chen
- College of Life Science and Technology, Huazhong University of Science and TechnologyWuhanChina
| | - Fu-min Tian
- School of Life Science and Technology, ShanghaiTech UniversityShanghaiChina
- University of Chinese Academy of SciencesBeijingChina
| | - Cindy Chang
- Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Qi Hall
- Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Chun-Xue Song
- Center for Brain Science, Shanghai Children's Medical CenterShanghaiChina
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Shangbang Gao
- College of Life Science and Technology, Huazhong University of Science and TechnologyWuhanChina
| | - Zhitao Hu
- Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research (CJCADR), The University of QueenslandBrisbaneAustralia
| | - Joshua M Kaplan
- Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Qian Li
- Center for Brain Science, Shanghai Children's Medical CenterShanghaiChina
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Research Center for Brain Science and Brain-Inspired IntelligenceShanghaiChina
| | - Xia-Jing Tong
- School of Life Science and Technology, ShanghaiTech UniversityShanghaiChina
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18
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Park L, Luth ES, Jones K, Hofer J, Nguyen I, Watters KE, Juo P. The Snail transcription factor CES-1 regulates glutamatergic behavior in C. elegans. PLoS One 2021; 16:e0245587. [PMID: 33529210 PMCID: PMC7853468 DOI: 10.1371/journal.pone.0245587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 01/04/2021] [Indexed: 11/18/2022] Open
Abstract
Regulation of AMPA-type glutamate receptor (AMPAR) expression and function alters synaptic strength and is a major mechanism underlying synaptic plasticity. Although transcription is required for some forms of synaptic plasticity, the transcription factors that regulate AMPA receptor expression and signaling are incompletely understood. Here, we identify the Snail family transcription factor ces-1 in an RNAi screen for conserved transcription factors that regulate glutamatergic behavior in C. elegans. ces-1 was originally discovered as a selective cell death regulator of neuro-secretory motor neuron (NSM) and I2 interneuron sister cells in C. elegans, and has almost exclusively been studied in the NSM cell lineage. We found that ces-1 loss-of-function mutants have defects in two glutamatergic behaviors dependent on the C. elegans AMPA receptor GLR-1, the mechanosensory nose-touch response and spontaneous locomotion reversals. In contrast, ces-1 gain-of-function mutants exhibit increased spontaneous reversals, and these are dependent on glr-1 consistent with these genes acting in the same pathway. ces-1 mutants have wild type cholinergic neuromuscular junction function, suggesting that they do not have a general defect in synaptic transmission or muscle function. The effect of ces-1 mutation on glutamatergic behaviors is not due to ectopic cell death of ASH sensory neurons or GLR-1-expressing neurons that mediate one or both of these behaviors, nor due to an indirect effect on NSM sister cell deaths. Rescue experiments suggest that ces-1 may act, in part, in GLR-1-expressing neurons to regulate glutamatergic behaviors. Interestingly, ces-1 mutants suppress the increased reversal frequencies stimulated by a constitutively-active form of GLR-1. However, expression of glr-1 mRNA or GFP-tagged GLR-1 was not decreased in ces-1 mutants suggesting that ces-1 likely promotes GLR-1 function. This study identifies a novel role for ces-1 in regulating glutamatergic behavior that appears to be independent of its canonical role in regulating cell death in the NSM cell lineage.
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Affiliation(s)
- Lidia Park
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Graduate Program in Cell, Developmental and Molecular Biology, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Eric S. Luth
- Department of Biology, Simmons University, Boston, Massachusetts, United States of America
| | - Kelsey Jones
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Julia Hofer
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Irene Nguyen
- Department of Biology, Simmons University, Boston, Massachusetts, United States of America
| | - Katherine E. Watters
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Peter Juo
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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19
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Pandey P, Singh A, Kaur H, Ghosh-Roy A, Babu K. Increased dopaminergic neurotransmission results in ethanol dependent sedative behaviors in Caenorhabditis elegans. PLoS Genet 2021; 17:e1009346. [PMID: 33524034 PMCID: PMC7877767 DOI: 10.1371/journal.pgen.1009346] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 02/11/2021] [Accepted: 01/06/2021] [Indexed: 12/19/2022] Open
Abstract
Ethanol is a widely used drug, excessive consumption of which could lead to medical conditions with diverse symptoms. Ethanol abuse causes dysfunction of memory, attention, speech and locomotion across species. Dopamine signaling plays an essential role in ethanol dependent behaviors in animals ranging from C. elegans to humans. We devised an ethanol dependent assay in which mutants in the dopamine autoreceptor, dop-2, displayed a unique sedative locomotory behavior causing the animals to move in circles while dragging the posterior half of their body. Here, we identify the posterior dopaminergic sensory neuron as being essential to modulate this behavior. We further demonstrate that in dop-2 mutants, ethanol exposure increases dopamine secretion and functions in a DVA interneuron dependent manner. DVA releases the neuropeptide NLP-12 that is known to function through cholinergic motor neurons and affect movement. Thus, DOP-2 modulates dopamine levels at the synapse and regulates alcohol induced movement through NLP-12.
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Affiliation(s)
- Pratima Pandey
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Anuradha Singh
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Harjot Kaur
- National Brain Research Centre, Gurgaon, India
| | | | - Kavita Babu
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
- Centre for Neuroscience, Indian Institute of Science (IISc), Bangalore, India
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20
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Kreyden VA, Mawi EB, Rush KM, Kowalski JR. UBC-9 Acts in GABA Neurons to Control Neuromuscular Signaling in C. elegans. Neurosci Insights 2020; 15:2633105520962792. [PMID: 33089216 PMCID: PMC7543134 DOI: 10.1177/2633105520962792] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 09/10/2020] [Indexed: 11/20/2022] Open
Abstract
Regulation of excitatory to inhibitory signaling balance is essential to nervous system health and is maintained by numerous enzyme systems that modulate the activity, localization, and abundance of synaptic proteins. SUMOylation is a key post-translational regulator of protein function in diverse cells, including neurons. There, its role in regulating synaptic transmission through pre- and postsynaptic effects has been shown primarily at glutamatergic central nervous system synapses, where the sole SUMO-conjugating enzyme Ubc9 is a critical player. However, whether Ubc9 functions globally at other synapses, including inhibitory synapses, has not been explored. Here, we investigated the role of UBC-9 and the SUMOylation pathway in controlling the balance of excitatory cholinergic and inhibitory GABAergic signaling required for muscle contraction in Caenorhabditis elegans. We found inhibition or overexpression of UBC-9 in neurons modestly increased muscle excitation. Similar and even stronger phenotypes were seen with UBC-9 overexpression specifically in GABAergic neurons, but not in cholinergic neurons. These effects correlated with accumulation of synaptic vesicle-associated proteins at GABAergic presynapses, where UBC-9 and the C. elegans SUMO ortholog SMO-1 localized, and with defects in GABA-dependent behaviors. Experiments involving expression of catalytically inactive UBC-9 [UBC-9(C93S)], as well as co-expression of UBC-9 and SMO-1, suggested wild type UBC-9 overexpressed alone may act via substrate sequestration in the absence of sufficient free SUMO, underscoring the importance of tightly regulated SUMO enzyme function. Similar effects on muscle excitation, GABAergic signaling, and synaptic vesicle localization occurred with overexpression of the SUMO activating enzyme subunit AOS-1. Together, these data support a model in which UBC-9 and the SUMOylation system act at presynaptic sites in inhibitory motor neurons to control synaptic signaling balance in C. elegans. Future studies will be important to define UBC-9 targets at this synapse, as well as mechanisms by which UBC-9 and the SUMO pathway are regulated.
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Affiliation(s)
- Victoria A Kreyden
- Department of Biological Sciences, Butler University, Indianapolis, IN, USA
| | - Elly B Mawi
- Department of Biological Sciences, Butler University, Indianapolis, IN, USA
| | - Kristen M Rush
- Department of Biological Sciences, Butler University, Indianapolis, IN, USA
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21
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Park KT, Han JK, Kim SJ, Lim YH. Gamma-Aminobutyric Acid Increases Erythropoietin by Activation of Citrate Cycle and Stimulation of Hypoxia-Inducible Factors Expression in Rats. Biomolecules 2020; 10:E595. [PMID: 32290638 PMCID: PMC7226430 DOI: 10.3390/biom10040595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 04/04/2020] [Accepted: 04/09/2020] [Indexed: 02/07/2023] Open
Abstract
Erythropoietin (EPO) is the primary regulator of erythropoiesis in the mammalian fetus and adult. Deficiency of EPO induces anemia. In this study, we investigated the effect of gamma-aminobutyric acid (GABA) on serum EPO levels and erythropoiesis in rats. Expression levels of Epo-related genes were measured by quantitative real-time PCR (qPCR) and expression of Epo and Epo receptor (Epor) proteins were measured by immunohistochemistry. The gene and protein expression profiles of kidney tissue in GABA-treated rats were evaluated by ribonucleic acid (RNA) sequencing and two-dimensional electrophoresis (2-DE), respectively. GABA significantly increased serum EPO levels and expression levels of Epo and Epor. GABA increased expression levels of hypoxia-inducible factor (Hif)-1 and Hif-2. Seven proteins with expression levels showing >2-fold change were identified by 2-DE followed by MALDI-TOF MS in GABA-treated rat kidney. The top KEGG pathway from the identified proteins was the tricarboxylic acid cycle, and nicotinamide adenine dinucleotide (NADH) dehydrogenase, succinate dehydrogenase, and isocitrate dehydrogenase were identified as key proteins. GABA treatment significantly increased ATP levels and NADH dehydrogenase activity in a dose-dependent manner. In conclusion, GABA shows a new physiological role in EPO production, and it can thus can contribute to the prevention of anemia when used alone or in combination with other anemia treating drugs.
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Affiliation(s)
- Keun-Tae Park
- Research and Development Center, Milae Bioresources Co., Ltd., Seoul 05836, Korea; (K.-T.P.); (J.-K.H.); (S.J.K.)
- Department of Integrated Biomedical and Life Sciences, College of Health Science, Korea University, Seoul 02841, Korea
| | - Jong-Kwon Han
- Research and Development Center, Milae Bioresources Co., Ltd., Seoul 05836, Korea; (K.-T.P.); (J.-K.H.); (S.J.K.)
| | - Seong Jin Kim
- Research and Development Center, Milae Bioresources Co., Ltd., Seoul 05836, Korea; (K.-T.P.); (J.-K.H.); (S.J.K.)
| | - Young-Hee Lim
- Department of Integrated Biomedical and Life Sciences, College of Health Science, Korea University, Seoul 02841, Korea
- Department of Public Health Science (BK21 PLUS Program), Graduate School, Korea University, Seoul 02841, Korea
- Department of Laboratory Medicine, Korea University Guro Hospital, Seoul 08308, Korea
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22
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Zhou X, Bessereau JL. Molecular Architecture of Genetically-Tractable GABA Synapses in C. elegans. Front Mol Neurosci 2019; 12:304. [PMID: 31920535 PMCID: PMC6920096 DOI: 10.3389/fnmol.2019.00304] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 11/26/2019] [Indexed: 12/18/2022] Open
Abstract
Inhibitory synapses represent a minority of the total chemical synapses in the mammalian brain, yet proper tuning of inhibition is fundamental to shape neuronal network properties. The neurotransmitter γ-aminobutyric acid (GABA) mediates rapid synaptic inhibition by the activation of the type A GABA receptor (GABAAR), a pentameric chloride channel that governs major inhibitory neuronal transduction in the nervous system. Impaired GABA transmission leads to a variety of neuropsychiatric diseases, including schizophrenia, autism, epilepsy or anxiety. From an evolutionary perspective, GABAAR shows remarkable conservations, and are found in all eukaryotic clades and even in bacteria and archaea. Specifically, bona fide GABAARs are found in the nematode Caenorhabditis elegans. Because of the anatomical simplicity of the nervous system and its amenability to genetic manipulations, C. elegans provide a powerful system to investigate the molecular and cellular biology of GABA synapses. In this mini review article, we will introduce the structure of the C. elegans GABAergic system and describe recent advances that have identified novel proteins controlling the localization of GABAARs at synapses. In particular, Ce-Punctin/MADD-4 is an evolutionarily-conserved extracellular matrix protein that behaves as an anterograde synaptic organizer to instruct the excitatory or inhibitory identity of postsynaptic domains.
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Affiliation(s)
- Xin Zhou
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, Institut NeuroMyoGène, Lyon, France
| | - Jean-Louis Bessereau
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U 1217, Institut NeuroMyoGène, Lyon, France
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Câmara DF, Machado ML, Arantes LP, Silva TC, Silveira TL, Leal JG, Dornelles L, Stefanello ST, Soares FAA. MPMT-OX up-regulates GABAergic transmission and protects against seizure-like behavior in Caenorhabditis elegans. Neurotoxicology 2019; 74:272-281. [PMID: 31415799 DOI: 10.1016/j.neuro.2019.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 08/02/2019] [Accepted: 08/02/2019] [Indexed: 11/17/2022]
Abstract
The signal transmission in the nervous system operates through a sensitive balance between excitatory (E) inputs and inhibitory (I) responses. Imbalances in this system contribute to the development of pathologies such as seizures. In Caenorhabditis elegans, the locomotor circuit operates via the coordinated activity of cholinergic excitatory (E) and GABAergic inhibitory (I) transmission. Changes in E/I inputs can cause uncontrolled electrical discharges, mimicking the physiology of seizures. Molecules derived from 1,3,4-oxadiazole have been found to exhibit diverse biological activities, including anticonvulsant effect. In this work, we study the activity of the compound 2-[(4-methoxyphenylselenyl)methylthio]-5-phenyl-1,3,4-oxadiazole (MPMT-OX) in the GABAergic and cholinergic systems. We demonstrate that MPMT-OX reduced the locomotor activity of C. elegans with a normal balance between the E/I systems and increased the resistance to paralysis in worms exposed to pentylenetetrazol and aldicarb. MPMT-OX increased seizure resistance and assisted in the recovery of locomotor activity in worms with deletions in the genes unc-46, which regulates the transport of GABA into vesicles, and unc-49, which encodes the GABAA receptor. C. elegans with deletions in the unc-25 and unc-47 genes did not respond to treatment. Therefore, we suggest that the compound MPMT-OX upregulates GABAergic signaling in a manner dependent on the unc-25 gene, which is responsible for GABA synthesis, and unc-47, which encodes the vesicular GABA transporter.
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Affiliation(s)
- Daniela F Câmara
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, CEP 97.105-900 Santa Maria, RS, Brazil
| | - Marina L Machado
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, CEP 97.105-900 Santa Maria, RS, Brazil
| | - Leticia P Arantes
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, CEP 97.105-900 Santa Maria, RS, Brazil
| | - Thayanara C Silva
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, CEP 97.105-900 Santa Maria, RS, Brazil
| | - Tássia L Silveira
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, CEP 97.105-900 Santa Maria, RS, Brazil
| | - Julliano G Leal
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, CEP 97.105-900 Santa Maria, RS, Brazil
| | - Luciano Dornelles
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, CEP 97.105-900 Santa Maria, RS, Brazil
| | - Sílvio T Stefanello
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, CEP 97.105-900 Santa Maria, RS, Brazil
| | - Félix A A Soares
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, CEP 97.105-900 Santa Maria, RS, Brazil.
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Spontaneous Vesicle Fusion Is Differentially Regulated at Cholinergic and GABAergic Synapses. Cell Rep 2019; 22:2334-2345. [PMID: 29490270 DOI: 10.1016/j.celrep.2018.02.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 01/11/2018] [Accepted: 02/06/2018] [Indexed: 12/23/2022] Open
Abstract
The locomotion of C. elegans is balanced by excitatory and inhibitory neurotransmitter release at neuromuscular junctions. However, the molecular mechanisms that maintain the balance of synaptic transmission remain enigmatic. Here, we investigated the function of voltage-gated Ca2+ channels in triggering spontaneous release at cholinergic and GABAergic synapses. Recordings of the miniature excitatory/inhibitory postsynaptic currents (mEPSCs and mIPSCs, respectively) showed that UNC-2/CaV2 and EGL-19/CaV1 channels are the two major triggers for spontaneous release. Notably, however, Ca2+-independent spontaneous release was observed at GABAergic but not cholinergic synapses. Functional screening led to the identification of hypomorphic unc-64/Syntaxin-1A and snb-1/VAMP2 mutants in which mEPSCs are severely impaired, whereas mIPSCs remain unaltered, indicating differential regulation of these currents at cholinergic and GABAergic synapses. Moreover, Ca2+-independent spontaneous GABA release was nearly abolished in the hypomorphic unc-64 and snb-1 mutants, suggesting distinct mechanisms for Ca2+-dependent and Ca2+-independent spontaneous release.
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25
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mir-234 controls neuropeptide release at the Caenorhabditis elegans neuromuscular junction. Mol Cell Neurosci 2019; 98:70-81. [PMID: 31200102 DOI: 10.1016/j.mcn.2019.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 06/05/2019] [Accepted: 06/06/2019] [Indexed: 01/16/2023] Open
Abstract
miR-137 is a highly conserved microRNA (miRNA) that is associated with the control of brain function and the etiology of psychiatric disorders including schizophrenia and bipolar disorder. The Caenorhabditis elegans genome encodes a single miR-137 ortholog called mir-234, the function of which is unknown. Here we show that mir-234 is expressed in a subset of sensory, motor and interneurons in C. elegans. Using a mir-234 deletion strain, we systematically examined the development and function of these neurons in addition to global C. elegans behaviors. We were however unable to detect phenotypes associated with loss of mir-234, possibly due to genetic redundancy. To circumvent this issue, we overexpressed mir-234 in mir-234-expressing neurons to uncover possible phenotypes. We found that mir-234-overexpression endows resistance to the acetylcholinesterase inhibitor aldicarb, suggesting modification of neuromuscular junction (NMJ) function. Further analysis revealed that mir-234 controls neuropeptide levels, therefore positing a cause of NMJ dysfunction. Together, our data suggest that mir-234 functions to control the expression of target genes that are important for neuropeptide maturation and/or transport in C. elegans. SIGNIFICANCE STATEMENT: The miR-137 family of miRNAs is linked to the control of brain function in humans. Defective regulation of miR-137 is associated with psychiatric disorders that include schizophrenia and bipolar disorder. Previous studies have revealed that miR-137 is required for the development of dendrites and for controlling the release of fast-acting neurotransmitters. Here, we analyzed the function a miR-137 family member (called mir-234) in the nematode animal model using anatomical, behavioral, electrophysiological and neuropeptide analysis. We reveal for the first time that mir-234/miR-137 is required for the release of slow-acting neuropeptides, which may also be of relevance for controlling human brain function.
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López-Cruz A, Sordillo A, Pokala N, Liu Q, McGrath PT, Bargmann CI. Parallel Multimodal Circuits Control an Innate Foraging Behavior. Neuron 2019; 102:407-419.e8. [PMID: 30824353 PMCID: PMC9161785 DOI: 10.1016/j.neuron.2019.01.053] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 08/27/2018] [Accepted: 01/25/2019] [Indexed: 11/20/2022]
Abstract
Foraging strategies emerge from genetically encoded programs that are similar across animal species. Here, we examine circuits that control a conserved foraging state, local search behavior after food removal, in Caenorhabditis elegans. We show that local search is triggered by two parallel groups of chemosensory and mechanosensory glutamatergic neurons that detect food-related cues. Each group of sensory neurons suppresses distinct integrating neurons through a G protein-coupled metabotropic glutamate receptor, MGL-1, to release local search. The chemosensory and mechanosensory modules are separate and redundant; glutamate release from either module can drive the full behavior. A transition from local search to global search over several minutes after food removal is associated with two changes in circuit function. First, the spontaneous activity of sensory neurons falls. Second, the motor pattern generator for local search becomes less responsive to sensory input. This multimodal, distributed short-term food memory provides robust control of an innate behavior.
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Affiliation(s)
- Alejandro López-Cruz
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Aylesse Sordillo
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Navin Pokala
- New York Institute of Technology, Old Westbury, NY 11568, USA
| | - Qiang Liu
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Patrick T McGrath
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Cornelia I Bargmann
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA; Chan Zuckerberg Initiative, Redwood City, CA 94063, USA.
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27
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Giles AC, Desbois M, Opperman KJ, Tavora R, Maroni MJ, Grill B. A complex containing the O-GlcNAc transferase OGT-1 and the ubiquitin ligase EEL-1 regulates GABA neuron function. J Biol Chem 2019; 294:6843-6856. [PMID: 30858176 DOI: 10.1074/jbc.ra119.007406] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/07/2019] [Indexed: 12/16/2022] Open
Abstract
Inhibitory GABAergic transmission is required for proper circuit function in the nervous system. However, our understanding of molecular mechanisms that preferentially influence GABAergic transmission, particularly presynaptic mechanisms, remains limited. We previously reported that the ubiquitin ligase EEL-1 preferentially regulates GABAergic presynaptic transmission. To further explore how EEL-1 functions, here we performed affinity purification proteomics using Caenorhabditis elegans and identified the O-GlcNAc transferase OGT-1 as an EEL-1 binding protein. This observation was intriguing, as we know little about how OGT-1 affects neuron function. Using C. elegans biochemistry, we confirmed that the OGT-1/EEL-1 complex forms in neurons in vivo and showed that the human orthologs, OGT and HUWE1, also bind in cell culture. We observed that, like EEL-1, OGT-1 is expressed in GABAergic motor neurons, localizes to GABAergic presynaptic terminals, and functions cell-autonomously to regulate GABA neuron function. Results with catalytically inactive point mutants indicated that OGT-1 glycosyltransferase activity is dispensable for GABA neuron function. Consistent with OGT-1 and EEL-1 forming a complex, genetic results using automated, behavioral pharmacology assays showed that ogt-1 and eel-1 act in parallel to regulate GABA neuron function. These findings demonstrate that OGT-1 and EEL-1 form a conserved signaling complex and function together to affect GABA neuron function.
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Affiliation(s)
- Andrew C Giles
- From the Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458 and
| | - Muriel Desbois
- From the Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458 and
| | - Karla J Opperman
- From the Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458 and
| | - Rubens Tavora
- the Harriet L. Wilkes Honors College, Florida Atlantic University, Jupiter, Florida 33458
| | - Marissa J Maroni
- From the Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458 and
| | - Brock Grill
- From the Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458 and
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28
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Blanco MG, Vela Gurovic MS, Silbestri GF, Garelli A, Giunti S, Rayes D, De Rosa MJ. Diisopropylphenyl-imidazole (DII): A new compound that exerts anthelmintic activity through novel molecular mechanisms. PLoS Negl Trop Dis 2018; 12:e0007021. [PMID: 30557347 PMCID: PMC6312359 DOI: 10.1371/journal.pntd.0007021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/31/2018] [Accepted: 11/26/2018] [Indexed: 11/26/2022] Open
Abstract
Nematode parasites cause substantial morbidity to billions of people and considerable losses in livestock and food crops. The repertoire of effective anthelmintic compounds for treating these parasitoses is very limited, as drug development has been delayed for decades. Moreover, resistance has become a global concern in livestock parasites and is an emerging issue for human helminthiasis. Therefore, anthelmintics with novel mechanisms of action are urgently needed. Taking advantage of Caenorhabditis elegans as an established model system, we here screened the nematicidal potential of novel imidazolium and imidazole derivatives. One of these derivatives, diisopropylphenyl-imidazole (DII), is lethal to C. elegans at both mature and immature stages. This lethal effect appears to be specific because DII concentrations which prove to be toxic to C. elegans do not induce significant lethality on bacteria, Drosophila melanogaster, and HEK-293 cells. Our analysis of DII action on C. elegans mutant strains determined that, in the adult stage, null mutants of unc-29 are resistant to the drug. Muscle expression of this gene completely restores DII sensitivity. UNC-29 has been largely reported as an essential constituent of the levamisole-sensitive muscle nicotinic receptor (L-AChR). Nevertheless, null mutants in unc-63 and lev-8 (essential and non-essential subunits of L-AChRs, respectively) are as sensitive to DII as the wild-type strain. Therefore, our results suggest that DII effects on adult nematodes rely on a previously unidentified UNC-29-containing muscle AChR, different from the classical L-AChR. Interestingly, DII targets appear to be different between larvae and adults, as unc-29 null mutant larvae are sensitive to the drug. The existence of more than one target could delay resistance development. Its lethality on C. elegans, its harmlessness in non-nematode species and its novel and dual mechanism of action make DII a promising candidate compound for anthelmintic therapy. Intestinal helminth infections affect approximately one-third of the world’s population, particularly in developing countries. Paradoxically, drug development in this area has been delayed for years. In addition, resistance to currently available drugs is also an emerging global concern. Therefore, there is an urgent need for new and effective anthelmintics. In this work, we used C. elegans as a model for parasitic nematodes to screen the anthelmintic activity of several imidazole-derivative compounds. We found a compound, diisopropylphenyl-imidazole (DII), that is lethal to both mature and immature stages of C. elegans. The DII nematicidal mechanism of action depends on a novel UNC-29-containing AChR in adult C. elegans muscle. Since this mechanism is different from those of currently used anthelmintics, it could constitute a therapeutic option when traditional anthelmintic agents fail. In addition, we found that the DII larvicidal effect depends on a different target to that of adult stages. The fact that DII produces lethality through different targets may delay resistance development. The specificity and novel mode of action of DII, which includes differential targeting in larvae and adult nematodes, support its potential as a promising drug candidate to treat helminthiasis.
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Affiliation(s)
- María Gabriela Blanco
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB) CCT UNS-CONICET, Bahía Blanca, Argentina.,Dpto de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - María Soledad Vela Gurovic
- Dpto de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina.,CERZOS UNS-CONICET CCT, Bahía Blanca, Argentina
| | - Gustavo Fabián Silbestri
- Dpto de Química, Universidad Nacional del Sur (UNS)-CONICET, Instituto de Química del Sur (INQUISUR), Bahía Blanca, Argentina
| | - Andrés Garelli
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB) CCT UNS-CONICET, Bahía Blanca, Argentina.,Dpto de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Sebastián Giunti
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB) CCT UNS-CONICET, Bahía Blanca, Argentina.,Dpto de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Diego Rayes
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB) CCT UNS-CONICET, Bahía Blanca, Argentina.,Dpto de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - María José De Rosa
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB) CCT UNS-CONICET, Bahía Blanca, Argentina.,Dpto de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
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29
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Koelle MR. Neurotransmitter signaling through heterotrimeric G proteins: insights from studies in C. elegans. WORMBOOK : THE ONLINE REVIEW OF C. ELEGANS BIOLOGY 2018; 2018:1-52. [PMID: 26937633 PMCID: PMC5010795 DOI: 10.1895/wormbook.1.75.2] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Neurotransmitters signal via G protein coupled receptors (GPCRs) to modulate activity of neurons and muscles. C. elegans has ∼150 G protein coupled neuropeptide receptor homologs and 28 additional GPCRs for small-molecule neurotransmitters. Genetic studies in C. elegans demonstrate that neurotransmitters diffuse far from their release sites to activate GPCRs on distant cells. Individual receptor types are expressed on limited numbers of cells and thus can provide very specific regulation of an individual neural circuit and behavior. G protein coupled neurotransmitter receptors signal principally via the three types of heterotrimeric G proteins defined by the G alpha subunits Gαo, Gαq, and Gαs. Each of these G alpha proteins is found in all neurons plus some muscles. Gαo and Gαq signaling inhibit and activate neurotransmitter release, respectively. Gαs signaling, like Gαq signaling, promotes neurotransmitter release. Many details of the signaling mechanisms downstream of Gαq and Gαs have been delineated and are consistent with those of their mammalian orthologs. The details of the signaling mechanism downstream of Gαo remain a mystery. Forward genetic screens in C. elegans have identified new molecular components of neural G protein signaling mechanisms, including Regulators of G protein Signaling (RGS proteins) that inhibit signaling, a new Gαq effector (the Trio RhoGEF domain), and the RIC-8 protein that is required for neuronal Gα signaling. A model is presented in which G proteins sum up the variety of neuromodulator signals that impinge on a neuron to calculate its appropriate output level.
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Affiliation(s)
- Michael R Koelle
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven CT 06520 USA
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30
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Blazie SM, Jin Y. Pharming for Genes in Neurotransmission: Combining Chemical and Genetic Approaches in Caenorhabditis elegans. ACS Chem Neurosci 2018; 9:1963-1974. [PMID: 29432681 DOI: 10.1021/acschemneuro.7b00509] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Synaptic transmission is central to nervous system function. Chemical and genetic screens are valuable approaches to probe synaptic mechanisms in living animals. The nematode Caenorhabditis elegans is a prime system to apply these methods to discover genes and dissect the cellular pathways underlying neurotransmission. Here, we review key approaches to understand neurotransmission and the action of psychiatric drugs in C. elegans. We start with early studies on cholinergic excitatory signaling at the neuromuscular junction, and move into mechanisms mediated by biogenic amines. Finally, we discuss emerging work toward understanding the mechanisms driving synaptic plasticity with a focus on regulation of protein translation.
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Affiliation(s)
- Stephen M. Blazie
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, United States
| | - Yishi Jin
- Neurobiology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093, United States
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31
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LIN-12/Notch Regulates GABA Signaling at the Caenorhabditis elegans Neuromuscular Junction. G3-GENES GENOMES GENETICS 2018; 8:2825-2832. [PMID: 29950427 PMCID: PMC6071610 DOI: 10.1534/g3.118.200202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The role of Notch signaling in cell-fate decisions has been studied extensively; however, this pathway is also active in adult tissues, including the nervous system. Notch signaling modulates a wide range of behaviors and processes of the nervous system in the nematode Caenorhabditis elegans, but there is no evidence for Notch signaling directly altering synaptic strength. Here, we demonstrate Notch-mediated regulation of synaptic activity at the C. elegans neuromuscular junction (NMJ). For this, we used aldicarb, an inhibitor of the enzyme acetylcholinesterase, and assessed paralysis rates of animals with altered Notch signaling. Notch receptors LIN-12 and GLP-1 are required for normal NMJ function; they regulate NMJ activity in an opposing fashion. Complete loss of LIN-12 skews the excitation/inhibition balance at the NMJ toward increased activity, whereas partial loss of GLP-1 has the opposite effect. Specific Notch ligands and co-ligands are also required for proper NMJ function. The role of LIN-12 is independent of cell-fate decisions; manipulation of LIN-12 signaling through RNAi knockdown or overexpression of the co-ligand OSM-11 after development alters NMJ activity. We demonstrate that LIN-12 modulates GABA signaling in this paradigm, as loss of GABA signaling suppresses LIN-12 gain-of-function defects. Further analysis, in vivo and in silico, suggests that LIN-12 may modulate transcription of the GABAB receptor GBB-2 Our findings confirm a non-developmental role for the LIN-12/Notch receptor in regulating synaptic signaling and identify the GABAB receptor GBB-2 as a potential Notch transcriptional target in the C. elegans nervous system.
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32
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The Claudin-like Protein HPO-30 Is Required to Maintain LAChRs at the C. elegans Neuromuscular Junction. J Neurosci 2018; 38:7072-7087. [PMID: 29950505 PMCID: PMC6083452 DOI: 10.1523/jneurosci.3487-17.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 06/07/2018] [Accepted: 06/07/2018] [Indexed: 12/22/2022] Open
Abstract
Communications across chemical synapses are primarily mediated by neurotransmitters and their postsynaptic receptors. There are diverse molecular systems to localize and regulate the receptors at the synapse. Here, we identify HPO-30, a member of the claudin superfamily of membrane proteins, as a positive regulator for synaptic localization of levamisole-dependent AChRs (LAChRs) at the Caenorhabditis elegans neuromuscular junction (NMJ). The HPO-30 protein localizes at the NMJ and shows genetic and physical association with the LAChR subunits LEV-8, UNC-29, and UNC-38. Using genetic and electrophysiological assays in the hermaphrodite C. elegans, we demonstrate that HPO-30 functions through Neuroligin at the NMJ to maintain postsynaptic LAChR levels at the synapse. Together, this work suggests a novel function for a tight junction protein in maintaining normal receptor levels at the NMJ. SIGNIFICANCE STATEMENT Claudins are a large superfamily of membrane proteins. Their role in maintaining the functional integrity of tight junctions has been widely explored. Our experiments suggest a critical role for the claudin-like protein, HPO-30, in maintaining synaptic levamisole-dependent AChR (LAChR) levels. LAChRs contribute to <20% of the acetylcholine-mediated conductance in adult Caenorhabditis elegans; however, they play a significant functional role in worm locomotion. This study provides a new perspective in the study of LAChR physiology.
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33
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Zhang S, Fan Z, Qiao P, Zhao Y, Wang Y, Jiang D, Wang X, Zhu X, Zhang Y, Huang B, Lu J, Li X. miR-51 regulates GABAergic synapses by targeting Rab GEF GLO-4 and lysosomal trafficking-related GLO/AP-3 pathway in Caenorhabditis elegans. Dev Biol 2018; 436:66-74. [DOI: 10.1016/j.ydbio.2018.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 01/30/2018] [Accepted: 02/17/2018] [Indexed: 01/22/2023]
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34
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Thapliyal S, Vasudevan A, Dong Y, Bai J, Koushika SP, Babu K. The C-terminal of CASY-1/Calsyntenin regulates GABAergic synaptic transmission at the Caenorhabditis elegans neuromuscular junction. PLoS Genet 2018. [PMID: 29529030 PMCID: PMC5864096 DOI: 10.1371/journal.pgen.1007263] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The C. elegans ortholog of mammalian calsyntenins, CASY-1, is an evolutionarily conserved type-I transmembrane protein that is highly enriched in the nervous system. Mammalian calsyntenins are strongly expressed at inhibitory synapses, but their role in synapse development and function is still elusive. Here, we report a crucial role for CASY-1 in regulating GABAergic synaptic transmission at the C. elegans neuromuscular junction (NMJ). The shorter isoforms of CASY-1; CASY-1B and CASY-1C, express and function in GABA motor neurons where they regulate GABA neurotransmission. Using pharmacological, behavioral, electrophysiological, optogenetic and imaging approaches we establish that GABA release is compromised at the NMJ in casy-1 mutants. Further, we demonstrate that CASY-1 is required to modulate the transport of GABAergic synaptic vesicle (SV) precursors through a possible interaction with the SV motor protein, UNC-104/KIF1A. This study proposes a possible evolutionarily conserved model for the regulation of GABA synaptic functioning by calsyntenins. GABA acts as a major inhibitory neurotransmitter in both vertebrate and invertebrate nervous systems. Despite the potential deregulation of GABA signaling in several neurological disorders, our understanding of the genetic factors that regulate GABAergic synaptic transmission has just started to evolve. Here, we identify a role for a cell adhesion molecule, CASY-1, in regulating GABA signaling at the C. elegans NMJ. We show that the mutants in casy-1 have reduced number of GABA vesicles at the synapse resulting in less GABA release from the presynaptic GABAergic motor neurons. Further, we show that the shorter isoforms of the casy-1 gene; casy-1b and casy-1c that carry a potential kinesin-motor binding domain are responsible for maintaining GABAergic signaling at the synapse. We show a novel interaction of the CASY-1 isoforms with the C- terminal of the UNC-104/KIF1A motor protein that mediates the trafficking of GABAergic synaptic vesicle precursors to the synapse, thus maintaining normal inhibitory signaling at the NMJ.
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Affiliation(s)
- Shruti Thapliyal
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, SAS Nagar, Manauli, Punjab, India
| | - Amruta Vasudevan
- Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | - Yongming Dong
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109 and Department of Biochemistry, University of Washington, Seattle, WA, United Sttaes of America
| | - Jihong Bai
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109 and Department of Biochemistry, University of Washington, Seattle, WA, United Sttaes of America
| | - Sandhya P. Koushika
- Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | - Kavita Babu
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, SAS Nagar, Manauli, Punjab, India
- * E-mail: ,
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35
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Systematic Functional Characterization of Human 21st Chromosome Orthologs in Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2018; 8:967-979. [PMID: 29367452 PMCID: PMC5844316 DOI: 10.1534/g3.118.200019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Individuals with Down syndrome have neurological and muscle impairments due to an additional copy of the human 21st chromosome (HSA21). Only a few of ∼200 HSA21 genes encoding proteins have been linked to specific Down syndrome phenotypes, while the remainder are understudied. To identify poorly characterized HSA21 genes required for nervous system function, we studied behavioral phenotypes caused by loss-of-function mutations in conserved HSA21 orthologs in the nematode Caenorhabditis elegans. We identified 10 HSA21 orthologs that are required for neuromuscular behaviors: cle-1 (COL18A1), cysl-2 (CBS), dnsn-1 (DONSON), eva-1 (EVA1C), mtq-2 (N6ATM1), ncam-1 (NCAM2), pad-2 (POFUT2), pdxk-1 (PDXK), rnt-1 (RUNX1), and unc-26 (SYNJ1). We also found that three of these genes are required for normal release of the neurotransmitter acetylcholine. This includes a known synaptic gene unc-26 (SYNJ1), as well as uncharacterized genes pdxk-1 (PDXK) and mtq-2 (N6ATM1). As the first systematic functional analysis of HSA21 orthologs, this study may serve as a platform to understand genes that underlie phenotypes associated with Down syndrome.
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36
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Regulation of Glutamate Signaling in the Sensorimotor Circuit by CASY-1A/Calsyntenin in Caenorhabditis elegans. Genetics 2018; 208:1553-1564. [PMID: 29475851 PMCID: PMC5887148 DOI: 10.1534/genetics.118.300834] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 02/21/2018] [Indexed: 12/02/2022] Open
Abstract
Locomotion is one of the most prominent behaviors in the nematode Caenorhabditis elegans. Neuronal circuits that ultimately produce coordinated dorso-ventral sinusoidal bends mediate this behavior. Synchronized locomotion requires an intricate balance between excitation and inhibition at the neuromuscular junctions (NMJ), the complex cellular and molecular mechanisms of which are not fully understood. Here, we describe the role of a cell adhesion molecule CASY-1, which functions to maintain this balance at the NMJ. In this study, we dissect out mechanisms by which the longer CASY-1A isoform could be affecting the excitatory cholinergic signaling at the NMJ by modulating the activity of sensory neurons. Mutants in casy-1 appear to have hyperactive sensory neurons, resulting in accelerated locomotion and motor circuit activity. These sensory neurons mediate increased motor activity via enhanced glutamate release. Using genetic, pharmacological, and optogenetic manipulations, we establish that CASY-1A is required to monitor the activity of these neurons. Our study illustrates a novel neuromodulatory role of CASY-1-mediated signaling in regulating the excitation-inhibition balance of the motor circuit.
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37
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Opperman KJ, Mulcahy B, Giles AC, Risley MG, Birnbaum RL, Tulgren ED, Dawson-Scully K, Zhen M, Grill B. The HECT Family Ubiquitin Ligase EEL-1 Regulates Neuronal Function and Development. Cell Rep 2018; 19:822-835. [PMID: 28445732 DOI: 10.1016/j.celrep.2017.04.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/01/2017] [Accepted: 03/31/2017] [Indexed: 12/21/2022] Open
Abstract
Genetic changes in the HECT ubiquitin ligase HUWE1 are associated with intellectual disability, but it remains unknown whether HUWE1 functions in post-mitotic neurons to affect circuit function. Using genetics, pharmacology, and electrophysiology, we show that EEL-1, the HUWE1 ortholog in C. elegans, preferentially regulates GABAergic presynaptic transmission. Decreasing or increasing EEL-1 function alters GABAergic transmission and the excitatory/inhibitory (E/I) balance in the worm motor circuit, which leads to impaired locomotion and increased sensitivity to electroshock. Furthermore, multiple mutations associated with intellectual disability impair EEL-1 function. Although synaptic transmission defects did not result from abnormal synapse formation, sensitizing genetic backgrounds revealed that EEL-1 functions in the same pathway as the RING family ubiquitin ligase RPM-1 to regulate synapse formation and axon termination. These findings from a simple model circuit provide insight into the molecular mechanisms required to obtain E/I balance and could have implications for the link between HUWE1 and intellectual disability.
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Affiliation(s)
- Karla J Opperman
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Ben Mulcahy
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Andrew C Giles
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA
| | - Monica G Risley
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Rayna L Birnbaum
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA; Harriet L. Wilkes Honors College, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Erik D Tulgren
- Department of Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA
| | - Ken Dawson-Scully
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Mei Zhen
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics and Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Brock Grill
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL 33458, USA.
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38
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TGF-β Signaling in Dopaminergic Neurons Regulates Dendritic Growth, Excitatory-Inhibitory Synaptic Balance, and Reversal Learning. Cell Rep 2017; 17:3233-3245. [PMID: 28009292 DOI: 10.1016/j.celrep.2016.11.068] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 09/26/2016] [Accepted: 11/22/2016] [Indexed: 12/21/2022] Open
Abstract
Neural circuits involving midbrain dopaminergic (DA) neurons regulate reward and goal-directed behaviors. Although local GABAergic input is known to modulate DA circuits, the mechanism that controls excitatory/inhibitory synaptic balance in DA neurons remains unclear. Here, we show that DA neurons use autocrine transforming growth factor β (TGF-β) signaling to promote the growth of axons and dendrites. Surprisingly, removing TGF-β type II receptor in DA neurons also disrupts the balance in TGF-β1 expression in DA neurons and neighboring GABAergic neurons, which increases inhibitory input, reduces excitatory synaptic input, and alters phasic firing patterns in DA neurons. Mice lacking TGF-β signaling in DA neurons are hyperactive and exhibit inflexibility in relinquishing learned behaviors and re-establishing new stimulus-reward associations. These results support a role for TGF-β in regulating the delicate balance of excitatory/inhibitory synaptic input in local microcircuits involving DA and GABAergic neurons and its potential contributions to neuropsychiatric disorders.
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39
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Yu Y, Mutlu AS, Liu H, Wang MC. High-throughput screens using photo-highlighting discover BMP signaling in mitochondrial lipid oxidation. Nat Commun 2017; 8:865. [PMID: 29021566 PMCID: PMC5636786 DOI: 10.1038/s41467-017-00944-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 08/04/2017] [Indexed: 01/22/2023] Open
Abstract
High-throughput screens at microscopic resolution can uncover molecular mechanisms of cellular dynamics, but remain technically challenging in live multicellular organisms. Here we present a genetic screening method using photo-highlighting for candidate selection on microscopes. We apply this method to stimulated Raman scattering (SRS) microscopy and systematically identify 57 Caenorhabditis elegans mutants with altered lipid distribution. Four of these mutants target the components of the Bone Morphogenetic Protein (BMP) signaling pathway, revealing that BMP signaling inactivation causes exhaustion of lipid reserves in somatic tissues. Using SRS-based isotope tracing assay to quantitatively track lipid synthesis and mobilization, we discover that the BMP signaling mutants have increased rates of lipid mobilization. Furthermore, this increase is associated with the induction of mitochondrial β-oxidation and mitochondrial fusion. Together these studies demonstrate a photo-highlighting microscopic strategy for genome-scale screens, leading to the discovery of new roles for BMP signaling in linking mitochondrial homeostasis and lipid metabolism.High-throughput genetic screens in animals could benefit from an easy way to mark positive hits. Here the authors introduce photo-highlighting using a photoconvertible fluorescent protein, and in combination with stimulated Raman scattering (SRS) microscopy, define a role for BMP signaling in lipid metabolism in C. elegans.
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Affiliation(s)
- Yong Yu
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Ayse Sena Mutlu
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Harrison Liu
- Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, San Francisco, CA, 94143, USA
| | - Meng C Wang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
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40
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The SEK-1 p38 MAP Kinase Pathway Modulates Gq Signaling in Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2017; 7:2979-2989. [PMID: 28696924 PMCID: PMC5592925 DOI: 10.1534/g3.117.043273] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Gq is a heterotrimeric G protein that is widely expressed in neurons and regulates neuronal activity. To identify pathways regulating neuronal Gq signaling, we performed a forward genetic screen in Caenorhabditis elegans for suppressors of activated Gq. One of the suppressors is an allele of sek-1, which encodes a mitogen-activated protein kinase kinase (MAPKK) in the p38 MAPK pathway. Here, we show that sek-1 mutants have a slow locomotion rate and that sek-1 acts in acetylcholine neurons to modulate both locomotion rate and Gq signaling. Furthermore, we find that sek-1 acts in mature neurons to modulate locomotion. Using genetic and behavioral approaches, we demonstrate that other components of the p38 MAPK pathway also play a positive role in modulating locomotion and Gq signaling. Finally, we find that mutants in the SEK-1 p38 MAPK pathway partially suppress an activated mutant of the sodium leak channel, NCA-1/NALCN, a downstream target of Gq signaling. Our results suggest that the SEK-1 p38 pathway may modulate the output of Gq signaling through NCA-1(unc-77).
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41
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Kautu BB, Phillips J, Steele K, Mengarelli MS, Nord EA. A Behavioral Survey of the Effects of Kavalactones on Caenorhabditis elegans Neuromuscular Transmission. J Exp Neurosci 2017; 11:1179069517705384. [PMID: 28615969 PMCID: PMC5462554 DOI: 10.1177/1179069517705384] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 03/23/2017] [Indexed: 12/16/2022] Open
Abstract
Kava is a plant root extract that is widely consumed by Pacific Islanders. Kava contains a class of lactone compounds called kavalactones. The sedative and anxiolytic effects of kava are likely attributed to the efficacies of kavalactones on the nervous system. Although some studies have implicated the potencies of certain kavalactone species on γ-aminobutyric acid transmission, evidence supporting the action of kavalactones on the eukaryotic neuromuscular junction (NMJ) and acetylcholine (ACh) transmission is scant. Here, we used behavioral assays to demonstrate the effects of kavalactones at the Caenorhabditis elegans NMJ. Our results suggest that kavalactones disrupt the inhibitory-excitatory balance at the NMJ. Such perturbation of NMJ activity is likely due to excess or prolonged ACh transmission. In addition, we found that kavain, a major constituent of kava, induced worm paralysis but not convulsions. Hence, the modulatory action of kavain could be distinct from the other kavalactone species.
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Affiliation(s)
| | | | - Kellie Steele
- Department of Biology, Greenville College, Greenville, IL, USA
| | | | - Eric A Nord
- Department of Biology, Greenville College, Greenville, IL, USA
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42
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Risley MG, Kelly SP, Dawson-Scully K. Electroshock Induced Seizures in Adult C. elegans. Bio Protoc 2017; 7:e2270. [PMID: 34541255 DOI: 10.21769/bioprotoc.2270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 02/14/2017] [Accepted: 04/06/2017] [Indexed: 11/02/2022] Open
Abstract
The nematode Caenorhabditis elegans is a useful model organism for dissecting molecular mechanisms of neurological diseases. While hermaphrodite C. elegans contains only 302 neurons, the conserved homologous neurotransmitters, simpler neuronal circuitry, and fully mapped connectome make it an appealing model system for neurological research. Here we developed an assay to induce an electroconvulsive seizure in C. elegans which can be used as a behavioral method of analyzing potential anti-epileptic therapeutics and novel genes involved in seizure susceptibility. In this assay, worms are suspended in an aqueous solution as current is passed through the liquid. At the onset of the shock, worms will briefly paralyze and twitch, and shortly after regain normal sinusoidal locomotion. The time to locomotor recovery is used as a metric of recovery from a seizure which can be reduced or extended by incorporating drugs that alter neuronal and muscular excitability.
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Affiliation(s)
- Monica G Risley
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, USA.,International Max Planck Research School (IMPRS) for Brain and Behavior, Boca Raton, USA
| | - Stephanie P Kelly
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, USA
| | - Ken Dawson-Scully
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, USA
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43
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O'Hern PJ, do Carmo G Gonçalves I, Brecht J, López Soto EJ, Simon J, Chapkis N, Lipscombe D, Kye MJ, Hart AC. Decreased microRNA levels lead to deleterious increases in neuronal M2 muscarinic receptors in Spinal Muscular Atrophy models. eLife 2017; 6. [PMID: 28463115 PMCID: PMC5413352 DOI: 10.7554/elife.20752] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 04/01/2017] [Indexed: 12/17/2022] Open
Abstract
Spinal Muscular Atrophy (SMA) is caused by diminished Survival of Motor Neuron (SMN) protein, leading to neuromuscular junction (NMJ) dysfunction and spinal motor neuron (MN) loss. Here, we report that reduced SMN function impacts the action of a pertinent microRNA and its mRNA target in MNs. Loss of the C. elegans SMN ortholog, SMN-1, causes NMJ defects. We found that increased levels of the C. elegans Gemin3 ortholog, MEL-46, ameliorates these defects. Increased MEL-46 levels also restored perturbed microRNA (miR-2) function in smn-1(lf) animals. We determined that miR-2 regulates expression of the C. elegans M2 muscarinic receptor (m2R) ortholog, GAR-2. GAR-2 loss ameliorated smn-1(lf) and mel-46(lf) synaptic defects. In an SMA mouse model, m2R levels were increased and pharmacological inhibition of m2R rescued MN process defects. Collectively, these results suggest decreased SMN leads to defective microRNA function via MEL-46 misregulation, followed by increased m2R expression, and neuronal dysfunction in SMA. DOI:http://dx.doi.org/10.7554/eLife.20752.001 Spinal muscular atrophy is a genetic disease that causes muscles to gradually weaken. In people with the disease, the nerve cells that control the movement of muscles – called motor neurons – deteriorate over time, hindering the person’s mobility and shortening their life expectancy. Spinal muscular atrophy is usually caused by genetic faults affecting a protein called SMN (which is short for “Survival of motor neuron”) and recent research suggested that disrupting this protein alters the function of short pieces of genetic material called microRNAs. However, the precise role that microRNAs play in the disease and their connection to the SMN protein was not clear. MicroRNAs interfere with the production of proteins by disrupting molecules called messenger RNAs, which are temporary strings of genetic code that carry the instructions for making protein. By disrupting messenger RNAs, microRNAs can delay or halt the production of specific proteins. This is an important part of the normal behavior of a cell, but disturbing the activity of microRNAs can lead to an unwanted rise or fall in crucial proteins. O’Hern et al. made use of engineered nematode worms and mice that share genetic features with spinal muscular atrophy patients, including disruption of the gene responsible for producing the SMN protein. These animal models of the disease were used to examine the relationship between decreased SMN levels and microRNAs in motor neurons. The experiments showed that reduced SMN activity affects a specific microRNA, which in turn causes motor neurons to produce more of a protein called m2R. This protein is a receptor for a molecule, called acetylcholine, which motor neurons use to send signals to muscle cells. Increased m2R may be detrimental to motor neurons. As such, O’Hern et al. decreased m2R protein activity to determine whether this could reverse the defects in motor neurons that arise in the animal models of the disease. Indeed, blocking this receptor rescued some of the defects seen in the animal models, supporting the link to spinal muscular atrophy. Several treatments that block m2R are already available to treat other conditions. As such, the next step is to determine whether these existing treatments are able to protect mice models of spinal muscular atrophy against muscle deterioration or increase their lifespan. If successful, this could open new avenues for the development of treatments in people. DOI:http://dx.doi.org/10.7554/eLife.20752.002
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Affiliation(s)
- Patrick J O'Hern
- Department of Neuroscience, Brown University, Providence, United States
| | | | - Johanna Brecht
- Institute of Human Genetics, University of Cologne, Cologne, Germany
| | | | - Jonah Simon
- Department of Neuroscience, Brown University, Providence, United States
| | - Natalie Chapkis
- Department of Neuroscience, Brown University, Providence, United States
| | - Diane Lipscombe
- Department of Neuroscience, Brown University, Providence, United States.,Brown Institute for Brain Science, Providence, United States
| | - Min Jeong Kye
- Institute of Human Genetics, University of Cologne, Cologne, Germany
| | - Anne C Hart
- Department of Neuroscience, Brown University, Providence, United States
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Schmeisser K, Fardghassemi Y, Parker JA. A rapid chemical-genetic screen utilizing impaired movement phenotypes in C. elegans: Input into genetics of neurodevelopmental disorders. Exp Neurol 2017; 293:101-114. [PMID: 28373024 DOI: 10.1016/j.expneurol.2017.03.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 03/23/2017] [Accepted: 03/27/2017] [Indexed: 11/17/2022]
Abstract
Autism spectrum disorder (ASD) is the most common neurodevelopmental disorder with a constantly increasing prevalence. Model organisms may be tools to identify underlying cellular and molecular mechanisms, as well as aid the discovery and development of novel therapeutic approaches. A simple animal such as the nematode Caenorhabditis elegans may provide insights into the extreme complexity of ASD genetics. Despite its potential, using C. elegans in ASD research is a controversial approach and has not yet been used extensively in this context. In this study, we present a screening approach of potential C. elegans mutants as potential ASD models. We screened these mutants for motor-deficiency phenotypes, which can be exploited to study underlying mechanisms of the disorder. Selected motor-deficient mutants were then used in a comprehensive drug screen of over 3900 compounds, including many FDA-approved and natural molecules, that were analyzed for their ability to suppress motility defects caused by ASD-associated gene orthologues. This genetic-chemical approach, i.e. establishing C. elegans models for ASD and screening of a well-characterized compound library, might be a promising first step to understand the mechanisms of how gene variations cause neuronal dysfunction, leading to ASD and other neurological disorders. Positively acting compounds could also be promising candidates for preclinical studies.
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Affiliation(s)
- Kathrin Schmeisser
- Centre de Recherche du Centre Hospitalier de l'Université de Montreál (CRCHUM), 900 St-Denis Street, Montreál, Québec H2X 0A9, Canada
| | - Yasmin Fardghassemi
- Centre de Recherche du Centre Hospitalier de l'Université de Montreál (CRCHUM), 900 St-Denis Street, Montreál, Québec H2X 0A9, Canada; Department of Biochemistry and Molecular Medicine, Université de Montreál, 2960 Chemin de la Tour, Montreál, Québec H3T 1J4, Canada
| | - J Alex Parker
- Centre de Recherche du Centre Hospitalier de l'Université de Montreál (CRCHUM), 900 St-Denis Street, Montreál, Québec H2X 0A9, Canada; Department of Neuroscience, Université de Montreál, 2960 Chemin de la Tour, Montreál, Québec H3T 1J4, Canada.
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45
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Risley MG, Kelly SP, Jia K, Grill B, Dawson-Scully K. Modulating Behavior in C. elegans Using Electroshock and Antiepileptic Drugs. PLoS One 2016; 11:e0163786. [PMID: 27668426 PMCID: PMC5036823 DOI: 10.1371/journal.pone.0163786] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 09/14/2016] [Indexed: 12/14/2022] Open
Abstract
The microscopic nematode Caenorhabditis elegans has emerged as a valuable model for understanding the molecular and cellular basis of neurological disorders. The worm offers important physiological similarities to mammalian models such as conserved neuron morphology, ion channels, and neurotransmitters. While a wide-array of behavioral assays are available in C. elegans, an assay for electroshock/electroconvulsion remains absent. Here, we have developed a quantitative behavioral method to assess the locomotor response following electric shock in C. elegans. Electric shock impairs normal locomotion, and induces paralysis and muscle twitching; after a brief recovery period, shocked animals resume normal locomotion. We tested electric shock responses in loss-of-function mutants for unc-25, which encodes the GABA biosynthetic enzyme GAD, and unc-49, which encodes the GABAA receptor. unc-25 and unc-49 mutants have decreased inhibitory GABAergic transmission to muscles, and take significantly more time to recover normal locomotion following electric shock compared to wild-type. Importantly, increased sensitivity of unc-25 and unc-49 mutants to electric shock is rescued by treatment with antiepileptic drugs, such as retigabine. Additionally, we show that pentylenetetrazol (PTZ), a GABAA receptor antagonist and proconvulsant in mammalian and C. elegans seizure models, increases susceptibility of worms to electric shock.
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Affiliation(s)
- Monica G. Risley
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, United States of America
| | - Stephanie P. Kelly
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, United States of America
| | - Kailiang Jia
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, United States of America
| | - Brock Grill
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, Florida, United States of America
| | - Ken Dawson-Scully
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, United States of America
- * E-mail:
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Colin E, Daniel J, Ziegler A, Wakim J, Scrivo A, Haack TB, Khiati S, Denommé AS, Amati-Bonneau P, Charif M, Procaccio V, Reynier P, Aleck KA, Botto LD, Herper CL, Kaiser CS, Nabbout R, N'Guyen S, Mora-Lorca JA, Assmann B, Christ S, Meitinger T, Strom TM, Prokisch H, Miranda-Vizuete A, Hoffmann GF, Lenaers G, Bomont P, Liebau E, Bonneau D. Biallelic Variants in UBA5 Reveal that Disruption of the UFM1 Cascade Can Result in Early-Onset Encephalopathy. Am J Hum Genet 2016; 99:695-703. [PMID: 27545681 DOI: 10.1016/j.ajhg.2016.06.030] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 06/28/2016] [Indexed: 01/10/2023] Open
Abstract
Via whole-exome sequencing, we identified rare autosomal-recessive variants in UBA5 in five children from four unrelated families affected with a similar pattern of severe intellectual deficiency, microcephaly, movement disorders, and/or early-onset intractable epilepsy. UBA5 encodes the E1-activating enzyme of ubiquitin-fold modifier 1 (UFM1), a recently identified ubiquitin-like protein. Biochemical studies of mutant UBA5 proteins and studies in fibroblasts from affected individuals revealed that UBA5 mutations impair the process of ufmylation, resulting in an abnormal endoplasmic reticulum structure. In Caenorhabditis elegans, knockout of uba-5 and of human orthologous genes in the UFM1 cascade alter cholinergic, but not glutamatergic, neurotransmission. In addition, uba5 silencing in zebrafish decreased motility while inducing abnormal movements suggestive of seizures. These clinical, biochemical, and experimental findings support our finding of UBA5 mutations as a pathophysiological cause for early-onset encephalopathies due to abnormal protein ufmylation.
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Affiliation(s)
- Estelle Colin
- Department of Biochemistry and Genetics, University Hospital, 49933 Angers Cedex 9, France; UMR CNRS 6214-INSERM 1083 and PREMMI, University of Angers, 49933 Angers Cedex 9, France
| | - Jens Daniel
- Department of Molecular Physiology, Westfälische Wilhelms-University Münster, 48143 Münster, Germany
| | - Alban Ziegler
- Department of Biochemistry and Genetics, University Hospital, 49933 Angers Cedex 9, France; UMR CNRS 6214-INSERM 1083 and PREMMI, University of Angers, 49933 Angers Cedex 9, France
| | - Jamal Wakim
- UMR CNRS 6214-INSERM 1083 and PREMMI, University of Angers, 49933 Angers Cedex 9, France
| | - Aurora Scrivo
- Avenir-Atip team, INSERM U1051, Institute of Neurosciences of Montpellier, University of Montpellier, 34091 Montpellier Cedex 5, France
| | - Tobias B Haack
- Institute of Human Genetics, Technische Universität München, 81675 München, Germany
| | - Salim Khiati
- UMR CNRS 6214-INSERM 1083 and PREMMI, University of Angers, 49933 Angers Cedex 9, France
| | - Anne-Sophie Denommé
- Department of Biochemistry and Genetics, University Hospital, 49933 Angers Cedex 9, France; UMR CNRS 6214-INSERM 1083 and PREMMI, University of Angers, 49933 Angers Cedex 9, France
| | - Patrizia Amati-Bonneau
- Department of Biochemistry and Genetics, University Hospital, 49933 Angers Cedex 9, France; UMR CNRS 6214-INSERM 1083 and PREMMI, University of Angers, 49933 Angers Cedex 9, France
| | - Majida Charif
- UMR CNRS 6214-INSERM 1083 and PREMMI, University of Angers, 49933 Angers Cedex 9, France
| | - Vincent Procaccio
- Department of Biochemistry and Genetics, University Hospital, 49933 Angers Cedex 9, France; UMR CNRS 6214-INSERM 1083 and PREMMI, University of Angers, 49933 Angers Cedex 9, France
| | - Pascal Reynier
- Department of Biochemistry and Genetics, University Hospital, 49933 Angers Cedex 9, France; UMR CNRS 6214-INSERM 1083 and PREMMI, University of Angers, 49933 Angers Cedex 9, France
| | - Kyrieckos A Aleck
- Department of Genetics and Metabolism, Phoenix Children's Medical Group, Phoenix, AZ 85016, USA
| | - Lorenzo D Botto
- Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, UT 84132, USA
| | - Claudia Lena Herper
- Department of Molecular Physiology, Westfälische Wilhelms-University Münster, 48143 Münster, Germany
| | - Charlotte Sophia Kaiser
- Department of Molecular Physiology, Westfälische Wilhelms-University Münster, 48143 Münster, Germany
| | - Rima Nabbout
- Department of Pediatric Neurology, National Reference Center for Rare Epilepsies, University Hospital Necker-Enfants-Malades, 75015 Paris, France
| | - Sylvie N'Guyen
- Department of Pediatric Neurology, University Hospital, 49933 Angers Cedex 9, France
| | - José Antonio Mora-Lorca
- Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, 41013 Seville, Spain
| | - Birgit Assmann
- Department of General Pediatrics, Division of Pediatric Metabolic Medicine and Neuropediatrics, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Stine Christ
- Department of General Pediatrics, Division of Pediatric Metabolic Medicine and Neuropediatrics, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Technische Universität München, 81675 München, Germany; Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Tim M Strom
- Institute of Human Genetics, Technische Universität München, 81675 München, Germany; Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Holger Prokisch
- Institute of Human Genetics, Technische Universität München, 81675 München, Germany; Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Antonio Miranda-Vizuete
- Institute of Biomedicine of Seville, University Hospital Virgen del Rocío/CSIC/University of Seville, 41013 Seville, Spain
| | - Georg F Hoffmann
- Department of General Pediatrics, Division of Pediatric Metabolic Medicine and Neuropediatrics, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Guy Lenaers
- UMR CNRS 6214-INSERM 1083 and PREMMI, University of Angers, 49933 Angers Cedex 9, France
| | - Pascale Bomont
- Avenir-Atip team, INSERM U1051, Institute of Neurosciences of Montpellier, University of Montpellier, 34091 Montpellier Cedex 5, France
| | - Eva Liebau
- Department of Molecular Physiology, Westfälische Wilhelms-University Münster, 48143 Münster, Germany
| | - Dominique Bonneau
- Department of Biochemistry and Genetics, University Hospital, 49933 Angers Cedex 9, France; UMR CNRS 6214-INSERM 1083 and PREMMI, University of Angers, 49933 Angers Cedex 9, France.
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47
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Safdie G, Liewald JF, Kagan S, Battat E, Gottschalk A, Treinin M. RIC-3 phosphorylation enables dual regulation of excitation and inhibition of Caenorhabditis elegans muscle. Mol Biol Cell 2016; 27:2994-3003. [PMID: 27489343 PMCID: PMC5042584 DOI: 10.1091/mbc.e16-05-0265] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/26/2016] [Indexed: 01/25/2023] Open
Abstract
Excitation–inhibition balance is essential for normal brain function. Calcineurin-dependent dephosphorylation of RIC-3, a chaperone of nicotinic acetylcholine receptors, disinhibits GABAA receptors, enabling fine-tuning of excitation–inhibition balance. Brain function depends on a delicate balance between excitation and inhibition. Similarly, Caenorhabditis elegans motor system function depends on a precise balance between excitation and inhibition, as C. elegans muscles receive both inhibitory, GABAergic and excitatory, cholinergic inputs from motor neurons. Here we show that phosphorylation of the ER-resident chaperone of nicotinic acetylcholine receptors, RIC-3, leads to increased muscle excitability. RIC-3 phosphorylation at Ser-164 depends on opposing functions of the phosphatase calcineurin (TAX-6), and of the casein kinase II homologue KIN-10. Effects of calcineurin down-regulation and of phosphorylated RIC-3 on muscle excitability are mediated by GABAA receptor inhibition. Thus RIC-3 phosphorylation enables effects of this chaperone on GABAA receptors in addition to nAChRs. This dual effect provides coordinated regulation of excitation and inhibition and enables fine-tuning of the excitation–inhibition balance. Moreover, regulation of inhibitory GABAA signaling by calcineurin, a calcium- and calmodulin-dependent phosphatase, enables homeostatic balancing of excitation and inhibition.
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Affiliation(s)
- Gracia Safdie
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Jana F Liewald
- Buchmann Institute for Molecular Life Sciences and Institute of Biochemistry, Goethe-University, D-60438 Frankfurt, Germany
| | - Sarah Kagan
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Emil Battat
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences and Institute of Biochemistry, Goethe-University, D-60438 Frankfurt, Germany
| | - Millet Treinin
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
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48
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Therrien M, Rouleau GA, Dion PA, Parker JA. FET proteins regulate lifespan and neuronal integrity. Sci Rep 2016; 6:25159. [PMID: 27117089 PMCID: PMC4846834 DOI: 10.1038/srep25159] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 04/12/2016] [Indexed: 11/09/2022] Open
Abstract
The FET protein family includes FUS, EWS and TAF15 proteins, all of which have been linked to amyotrophic lateral sclerosis, a fatal neurodegenerative disease affecting motor neurons. Here, we show that a reduction of FET proteins in the nematode Caenorhabditis elegans causes synaptic dysfunction accompanied by impaired motor phenotypes. FET proteins are also involved in the regulation of lifespan and stress resistance, acting partially through the insulin/IGF-signalling pathway. We propose that FET proteins are involved in the maintenance of lifespan, cellular stress resistance and neuronal integrity.
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Affiliation(s)
- Martine Therrien
- CHUM Research Center, Montreal, H2X 3H8, Canada
- Pathology and Cell biology department, University of Montreal, Montreal, H3T 1J4, Canada
| | - Guy A. Rouleau
- Neurology and Neurosurgery department, McGill University, Montreal, H3A 0G4, Canada
- Montreal Neurological Hospital, Montreal, H3A 2B4, Canada
| | - Patrick A. Dion
- Neurology and Neurosurgery department, McGill University, Montreal, H3A 0G4, Canada
- Montreal Neurological Hospital, Montreal, H3A 2B4, Canada
| | - J. Alex Parker
- CHUM Research Center, Montreal, H2X 3H8, Canada
- Department of Neuroscience, University of Montreal, Montreal, H3T 1J4, Canada
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49
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Grill B, Murphey RK, Borgen MA. The PHR proteins: intracellular signaling hubs in neuronal development and axon degeneration. Neural Dev 2016; 11:8. [PMID: 27008623 PMCID: PMC4806438 DOI: 10.1186/s13064-016-0063-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 03/15/2016] [Indexed: 11/10/2022] Open
Abstract
During development, a coordinated and integrated series of events must be accomplished in order to generate functional neural circuits. Axons must navigate toward target cells, build synaptic connections, and terminate outgrowth. The PHR proteins (consisting of mammalian Phr1/MYCBP2, Drosophila Highwire and C. elegans RPM-1) function in each of these events in development. Here, we review PHR function across species, as well as the myriad of signaling pathways PHR proteins regulate. These findings collectively suggest that the PHR proteins are intracellular signaling hubs, a concept we explore in depth. Consistent with prominent developmental functions, genetic links have begun to emerge between PHR signaling networks and neurodevelopmental disorders, such as autism, schizophrenia and intellectual disability. Finally, we discuss the recent and important finding that PHR proteins regulate axon degeneration, which has further heightened interest in this fascinating group of molecules.
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Affiliation(s)
- Brock Grill
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, 33458, USA.
| | - Rodney K Murphey
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL, 33458, USA
| | - Melissa A Borgen
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, FL, 33458, USA
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50
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Giles AC, Opperman KJ, Rankin CH, Grill B. Developmental Function of the PHR Protein RPM-1 Is Required for Learning in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2015; 5:2745-57. [PMID: 26464359 PMCID: PMC4683646 DOI: 10.1534/g3.115.021410] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 10/06/2015] [Indexed: 12/12/2022]
Abstract
The PAM/Highwire/RPM-1 (PHR) proteins are signaling hubs that function as important regulators of neural development. Loss of function in Caenorhabditis elegans rpm-1 and Drosophila Highwire results in failed axon termination, inappropriate axon targeting, and abnormal synapse formation. Despite broad expression in the nervous system and relatively dramatic defects in synapse formation and axon development, very mild abnormalities in behavior have been found in animals lacking PHR protein function. Therefore, we hypothesized that large defects in behavior might only be detected in scenarios in which evoked, prolonged circuit function is required, or in which behavioral plasticity occurs. Using quantitative approaches in C. elegans, we found that rpm-1 loss-of-function mutants have relatively mild abnormalities in exploratory locomotion, but have large defects in evoked responses to harsh touch and learning associated with tap habituation. We explored the nature of the severe habituation defects in rpm-1 mutants further. To address what part of the habituation circuit was impaired in rpm-1 mutants, we performed rescue analysis with promoters for different neurons. Our findings indicate that RPM-1 function in the mechanosensory neurons affects habituation. Transgenic expression of RPM-1 in adult animals failed to rescue habituation defects, consistent with developmental defects in rpm-1 mutants resulting in impaired habituation. Genetic analysis showed that other regulators of neuronal development that function in the rpm-1 pathway (including glo-4, fsn-1, and dlk-1) also affected habituation. Overall, our findings suggest that developmental defects in rpm-1 mutants manifest most prominently in behaviors that require protracted or plastic circuit function, such as learning.
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Affiliation(s)
- Andrew C Giles
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458
| | - Karla J Opperman
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458
| | - Catharine H Rankin
- Department of Psychology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada Brain Research Centre, University of British Columbia, Vancouver, British Columbia V6T 2B5, Canada
| | - Brock Grill
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida, Jupiter, Florida 33458
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