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Wang B, He J, Meng Q. Detection of minimal extended driver nodes in energetic costs reduction. CHAOS (WOODBURY, N.Y.) 2024; 34:083122. [PMID: 39146454 DOI: 10.1063/5.0214746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Accepted: 07/29/2024] [Indexed: 08/17/2024]
Abstract
Structures of complex networks are fundamental to system dynamics, where node state and connectivity patterns determine the cost of a control system, a key aspect in unraveling complexity. However, minimizing the energy required to control a system with the fewest input nodes remains an open problem. This study investigates the relationship between the structure of closed-connected function modules and control energy. We discovered that small structural adjustments, such as adding a few extended driver nodes, can significantly reduce control energy. Thus, we propose MInimal extended driver nodes in Energetic costs Reduction (MIER). Next, we transform the detection of MIER into a multi-objective optimization problem and choose an NSGA-II algorithm to solve it. Compared with the baseline methods, NSGA-II can approximate the optimal solution to the greatest extent. Through experiments using synthetic and real data, we validate that MIER can exponentially decrease control energy. Furthermore, random perturbation tests confirm the stability of MIER. Subsequently, we applied MIER to three representative scenarios: regulation of differential expression genes affected by cancer mutations in the human protein-protein interaction network, trade relations among developed countries in the world trade network, and regulation of body-wall muscle cells by motor neurons in Caenorhabditis elegans nervous network. The results reveal that the involvement of MIER significantly reduces control energy required for these original modules from a topological perspective. Additionally, MIER nodes enhance functionality, supplement key nodes, and uncover potential mechanisms. Overall, our work provides practical computational tools for understanding and presenting control strategies in biological, social, and neural systems.
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Affiliation(s)
- Bingbo Wang
- School of Computer Science and Technology, Xidian University, Xi'an 710071, China
| | - Jiaojiao He
- School of Computer Science and Technology, Xidian University, Xi'an 710071, China
| | - Qingdou Meng
- School of Computer Science and Technology, Xidian University, Xi'an 710071, China
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2
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Ramadan YH, Hobert O. Visualization of gene expression in Pristionchus pacificus with smFISH and in situ HCR. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001274. [PMID: 39132051 PMCID: PMC11316217 DOI: 10.17912/micropub.biology.001274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Revised: 07/11/2024] [Accepted: 07/24/2024] [Indexed: 08/13/2024]
Abstract
Single molecule fluorescence in situ hybridization (smFISH) and in situ hybridization chain reaction (HCR) have become powerful tools to visualize gene expression in many different animal species. We show here that smFISH and in situ HCR can be put to effective use in the satellite nematode model organism Pristionchus pacificus . Examining the expression of a homeobox gene ( Ppa-unc-30) , we found that HCR is more sensitive than smFISH. We confirmed the robustness of HCR by visualization of the expression of several genes involved in neurotransmitter synthesis or transport ( Ppa-unc-25 /GAD, Ppa-unc-17/VAChT, Ppa-eat-4 /VGLUT). Combined with its relative cost-effectiveness compared to smFISH analysis, in situ HCR constitutes a useful addition to the toolbox for P. pacificus research .
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Affiliation(s)
| | - Oliver Hobert
- Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, United States
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3
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Mo A, Liang Y, Cao X, Jiang J, Liu Y, Cao X, Qiu Y, He D. Polymer chain extenders induce significant toxicity through DAF-16 and SKN-1 pathways in Caenorhabditis elegans: A comparative analysis. JOURNAL OF HAZARDOUS MATERIALS 2024; 473:134730. [PMID: 38797076 DOI: 10.1016/j.jhazmat.2024.134730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 05/19/2024] [Accepted: 05/23/2024] [Indexed: 05/29/2024]
Abstract
Polymer chain extenders, commonly used in plastic production, have garnered increasing attention due to their potential environmental impacts. However, a comprehensive understanding of their ecological risks remains largely unknown. In this study, we employed the model organism Caenorhabditis elegans to investigate toxicological profiles of ten commonly-used chain extenders. Exposure to environmentally relevant concentrations of these chain extenders (ranging from 0.1 µg L-1 to 10 mg L-1) caused significant variations in toxicity. Lethality assays demonstrated the LC50 values ranged from 92.42 µg L-1 to 1553.65 mg L-1, indicating marked differences in acute toxicity. Sublethal exposures could inhibit nematodes' growth, shorten lifespan, and induce locomotor deficits, neuronal damage, and reproductive toxicity. Molecular analyses further elucidated the involvement of the DAF-16 and SKN-1 signaling pathways, as evidenced by upregulated expression of genes including ctl-1,2,3, sod-3, gcs-1, and gst-4. It implicates these pathways in mediating oxidative stress and toxicities induced by chain extenders. Particularly, hexamethylene diisocyanate and diallyl maleate exhibited markedly high toxicity among the chain extenders, as revealed through a comparative analysis of multiple endpoints. These findings demonstrate the potential ecotoxicological risks of polymer chain extenders, and suggest the need for more rigorous environmental safety assessments.
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Affiliation(s)
- Aoyun Mo
- School of Ecological and Environmental Sciences, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, East China Normal University, Shanghai 200241, China
| | - Yuqing Liang
- School of Ecological and Environmental Sciences, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, East China Normal University, Shanghai 200241, China
| | - Xiaomu Cao
- School of Ecological and Environmental Sciences, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, East China Normal University, Shanghai 200241, China; Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai 200241, China
| | - Jie Jiang
- School of Ecological and Environmental Sciences, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, East China Normal University, Shanghai 200241, China; Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai 200241, China
| | - Yan Liu
- School of Ecological and Environmental Sciences, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, East China Normal University, Shanghai 200241, China
| | - Xuelong Cao
- School of Ecological and Environmental Sciences, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, East China Normal University, Shanghai 200241, China
| | - Yuping Qiu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Defu He
- School of Ecological and Environmental Sciences, Shanghai Engineering Research Center of Biotransformation of Organic Solid Waste, East China Normal University, Shanghai 200241, China; Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai 200241, China; Technology Innovation Center for Land Spatial Eco-restoration in Metropolitan Area, Ministry of Natural Resources, Shanghai 200062, China.
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4
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Wang C, Vidal B, Sural S, Loer C, Aguilar GR, Merritt DM, Toker IA, Vogt MC, Cros C, Hobert O. A neurotransmitter atlas of C. elegans males and hermaphrodites. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.24.573258. [PMID: 38895397 PMCID: PMC11185579 DOI: 10.1101/2023.12.24.573258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Mapping neurotransmitter identities to neurons is key to understanding information flow in a nervous system. It also provides valuable entry points for studying the development and plasticity of neuronal identity features. In the C. elegans nervous system, neurotransmitter identities have been largely assigned by expression pattern analysis of neurotransmitter pathway genes that encode neurotransmitter biosynthetic enzymes or transporters. However, many of these assignments have relied on multicopy reporter transgenes that may lack relevant cis-regulatory information and therefore may not provide an accurate picture of neurotransmitter usage. We analyzed the expression patterns of 16 CRISPR/Cas9-engineered knock-in reporter strains for all main types of neurotransmitters in C. elegans (glutamate, acetylcholine, GABA, serotonin, dopamine, tyramine, and octopamine) in both the hermaphrodite and the male. Our analysis reveals novel sites of expression of these neurotransmitter systems within both neurons and glia, as well as non-neural cells. The resulting expression atlas defines neurons that may be exclusively neuropeptidergic, substantially expands the repertoire of neurons capable of co-transmitting multiple neurotransmitters, and identifies novel neurons that uptake monoaminergic neurotransmitters. Furthermore, we also observed unusual co-expression patterns of monoaminergic synthesis pathway genes, suggesting the existence of novel monoaminergic transmitters. Our analysis results in what constitutes the most extensive whole-animal-wide map of neurotransmitter usage to date, paving the way for a better understanding of neuronal communication and neuronal identity specification in C. elegans.
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Affiliation(s)
- Chen Wang
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, USA
| | - Berta Vidal
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, USA
| | - Surojit Sural
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, USA
| | - Curtis Loer
- Department of Biology, University of San Diego, San Diego, California, USA
| | - G. Robert Aguilar
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, USA
| | - Daniel M. Merritt
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, USA
| | - Itai Antoine Toker
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, USA
| | - Merly C. Vogt
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, USA
| | - Cyril Cros
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, USA
| | - Oliver Hobert
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, USA
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5
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Kramer TS, Flavell SW. Building and integrating brain-wide maps of nervous system function in invertebrates. Curr Opin Neurobiol 2024; 86:102868. [PMID: 38569231 DOI: 10.1016/j.conb.2024.102868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 02/13/2024] [Accepted: 03/07/2024] [Indexed: 04/05/2024]
Abstract
The selection and execution of context-appropriate behaviors is controlled by the integrated action of neural circuits throughout the brain. However, how activity is coordinated across brain regions, and how nervous system structure enables these functional interactions, remain open questions. Recent technical advances have made it feasible to build brain-wide maps of nervous system structure and function, such as brain activity maps, connectomes, and cell atlases. Here, we review recent progress in this area, focusing on C. elegans and D. melanogaster, as recent work has produced global maps of these nervous systems. We also describe neural circuit motifs elucidated in studies of specific networks, which highlight the complexities that must be captured to build accurate models of whole-brain function.
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Affiliation(s)
- Talya S Kramer
- Picower Institute for Learning and Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA; MIT Biology Graduate Program, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Steven W Flavell
- Picower Institute for Learning and Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
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6
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Kumar S, Sharma AK, Leifer AM. An inhibitory acetylcholine receptor gates context dependent mechanosensory processing in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.21.586204. [PMID: 38585821 PMCID: PMC10996507 DOI: 10.1101/2024.03.21.586204] [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
An animal's current behavior influences its response to sensory stimuli, but the molecular and circuit-level mechanisms of this context-dependent decision-making is not well understood. In the nematode C. elegans, inhibitory feedback from turning associated neurons alter downstream mechanosensory processing to gate the animal's response to stimuli depending on whether the animal is turning or moving forward [1-3]. Until now, the specific neurons and receptors that mediate this inhibitory feedback were not known. We use genetic manipulations, single-cell rescue experiments and high-throughput closed-loop optogenetic perturbations during behavior to reveal the specific neuron and receptor responsible for receiving inhibition and altering sensorimotor processing. An inhibitory acetylcholine gated chloride channel comprised of lgc-47 and acc-1 expressed in neuron RIM receives inhibitory signals from turning neurons and performs the gating that disrupts the worm's mechanosensory evoked reversal response.
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Affiliation(s)
- Sandeep Kumar
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
| | - Anuj K Sharma
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Andrew M Leifer
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
- Lead contact
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7
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Smith JJ, Taylor SR, Blum JA, Feng W, Collings R, Gitler AD, Miller DM, Kratsios P. A molecular atlas of adult C. elegans motor neurons reveals ancient diversity delineated by conserved transcription factor codes. Cell Rep 2024; 43:113857. [PMID: 38421866 PMCID: PMC11091551 DOI: 10.1016/j.celrep.2024.113857] [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: 08/18/2023] [Revised: 01/17/2024] [Accepted: 02/08/2024] [Indexed: 03/02/2024] Open
Abstract
Motor neurons (MNs) constitute an ancient cell type targeted by multiple adult-onset diseases. It is therefore important to define the molecular makeup of adult MNs in animal models and extract organizing principles. Here, we generate a comprehensive molecular atlas of adult Caenorhabditis elegans MNs and a searchable database. Single-cell RNA sequencing of 13,200 cells reveals that ventral nerve cord MNs cluster into 29 molecularly distinct subclasses. Extending C. elegans Neuronal Gene Expression Map and Network (CeNGEN) findings, all MN subclasses are delineated by distinct expression codes of either neuropeptide or transcription factor gene families. Strikingly, combinatorial codes of homeodomain transcription factor genes succinctly delineate adult MN diversity in both C. elegans and mice. Further, molecularly defined MN subclasses in C. elegans display distinct patterns of connectivity. Hence, our study couples the connectivity map of the C. elegans motor circuit with a molecular atlas of its constituent MNs and uncovers organizing principles and conserved molecular codes of adult MN diversity.
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Affiliation(s)
- Jayson J Smith
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA; University of Chicago Neuroscience Institute, Chicago, IL 60637, USA
| | - Seth R Taylor
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA; Department of Cell Biology and Physiology, Brigham Young University, Provo, UT 84602, USA
| | - Jacob A Blum
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Weidong Feng
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA; University of Chicago Neuroscience Institute, Chicago, IL 60637, USA
| | - Rebecca Collings
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
| | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - David M Miller
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA; Program in Neuroscience, Vanderbilt University, Nashville, TN 37240, USA.
| | - Paschalis Kratsios
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA; University of Chicago Neuroscience Institute, Chicago, IL 60637, USA.
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8
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Essmann CL, Elmi M, Rekatsinas C, Chrysochoidis N, Shaw M, Pawar V, Srinivasan MA, Vavourakis V. The influence of internal pressure and neuromuscular agents on C. elegans biomechanics: an empirical and multi-compartmental in silico modelling study. Front Bioeng Biotechnol 2024; 12:1335788. [PMID: 38558792 PMCID: PMC10978802 DOI: 10.3389/fbioe.2024.1335788] [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: 11/09/2023] [Accepted: 02/20/2024] [Indexed: 04/04/2024] Open
Abstract
The function of a specific tissue and its biomechanics are interdependent, with pathologies or ageing often being intertwined with structural decline. The biomechanics of Caenorhabditis elegans, a model organism widely used in pharmacological and ageing research, has been established as biomarker for healthy ageing. However, the properties of the constituent tissues, and their contribution to the overall mechanical characteristics of the organism, remain relatively unknown. In this study we investigated the biomechanics of healthy C. elegans cuticle, muscle tissue, and pseudocoelom using a combination of indentation experiments and in silico modelling. We performed stiffness measurements using an atomic force microscope. To approximate the nematode's cylindrical body we used a novel three-compartment nonlinear finite element model, enabling us to analyse of how changes in the elasticity of individual compartments affect the bulk stiffness. We then fine-tuned the parameters of the model to match the simulation force-indentation output to the experimental data. To test the finite element model, we modified distinct compartments experimentally. Our in silico results, in agreement with previous studies, suggest that hyperosmotic shock reduces stiffness by decreasing the internal pressure. Unexpectedly, treatment with the neuromuscular agent aldicarb, traditionally associated with muscle contraction, reduced stiffness by decreasing the internal pressure. Furthermore, our finite element model can offer insights into how drugs, mutations, or processes such as ageing target individual tissues.
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Affiliation(s)
- Clara L. Essmann
- Department of Bioinformatics and Molecular Genetics, University of Freiburg, Freiburg, Baden-Wuerttemberg, Germany
- Department of Computer Science, University College London, London, United Kingdom
| | - Muna Elmi
- Department of Computer Science, University College London, London, United Kingdom
| | | | - Nikolaos Chrysochoidis
- Department of Mechanical Engineering and Aeronautics, University of Patras, Patras, Greece
| | - Michael Shaw
- Department of Computer Science, University College London, London, United Kingdom
- National Physical Laboratory, Teddington, United Kingdom
| | - Vijay Pawar
- Department of Computer Science, University College London, London, United Kingdom
| | | | - Vasileios Vavourakis
- Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
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Britz S, Luccardini C, Markert SM, Merrill SA, Bessereau JL, Stigloher C. Array tomography of in vivo labeled synaptic receptors. Methods Cell Biol 2024; 187:139-174. [PMID: 38705623 DOI: 10.1016/bs.mcb.2024.02.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
Array tomography (AT) allows one to localize sub-cellular components within the structural context of cells in 3D through the imaging of serial sections. Using this technique, the z-resolution can be improved physically by cutting ultra-thin sections. Nevertheless, conventional immunofluorescence staining of those sections is time consuming and requires relatively large amounts of costly antibody solutions. Moreover, epitopes are only readily accessible at the section's surface, leaving the volume of the serial sections unlabeled. Localization of receptors at neuronal synapses in 3D in their native cellular ultrastructural context is important for understanding signaling processes. Here, we present in vivo labeling of receptors via fluorophore-coupled tags in combination with super-resolution AT. We present two workflows where we label receptors at the plasma membrane: first, in vivo labeling via microinjection with a setup consisting of readily available components and self-manufactured microscope table equipment and second, live receptor labeling by using a cell-permeable tag. To take advantage of a near-to-native preservation of tissues for subsequent scanning electron microscopy (SEM), we also apply high-pressure freezing and freeze substitution. The advantages and disadvantages of our workflows are discussed.
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Affiliation(s)
- Sebastian Britz
- Imaging Core Facility, Theodor-Boveri-Institute, Biocenter of the Julius-Maximilians-Universität Würzburg (JMU), Würzburg, Germany.
| | - Camilla Luccardini
- Centre d'Imagerie Quantitative Lyon Est (CIQLE), SFR Santé Lyon-Est CNRS UAR3453-INSERM US7, Université Claude Bernard Lyon 1, Lyon, France
| | - Sebastian M Markert
- Imaging Core Facility, Theodor-Boveri-Institute, Biocenter of the Julius-Maximilians-Universität Würzburg (JMU), Würzburg, Germany
| | - Sean A Merrill
- Department of Biology, University of Utah, Salt Lake City, UT, United States
| | - Jean-Louis Bessereau
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS UMR-5284, INSERM U-1314, MeLiS, Institut NeuroMyoGene, Lyon, France
| | - Christian Stigloher
- Imaging Core Facility, Theodor-Boveri-Institute, Biocenter of the Julius-Maximilians-Universität Würzburg (JMU), Würzburg, Germany.
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10
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Destain H, Prahlad M, Kratsios P. Maintenance of neuronal identity in C. elegans and beyond: Lessons from transcription and chromatin factors. Semin Cell Dev Biol 2024; 154:35-47. [PMID: 37438210 PMCID: PMC10592372 DOI: 10.1016/j.semcdb.2023.07.001] [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: 04/26/2023] [Revised: 06/30/2023] [Accepted: 07/01/2023] [Indexed: 07/14/2023]
Abstract
Neurons are remarkably long-lived, non-dividing cells that must maintain their functional features (e.g., electrical properties, chemical signaling) for extended periods of time - decades in humans. How neurons accomplish this incredible feat is poorly understood. Here, we review recent advances, primarily in the nematode C. elegans, that have enhanced our understanding of the molecular mechanisms that enable post-mitotic neurons to maintain their functionality across different life stages. We begin with "terminal selectors" - transcription factors necessary for the establishment and maintenance of neuronal identity. We highlight new findings on five terminal selectors (CHE-1 [Glass], UNC-3 [Collier/Ebf1-4], LIN-39 [Scr/Dfd/Hox4-5], UNC-86 [Acj6/Brn3a-c], AST-1 [Etv1/ER81]) from different transcription factor families (ZNF, COE, HOX, POU, ETS). We compare the functions of these factors in specific neuron types of C. elegans with the actions of their orthologs in other invertebrate (D. melanogaster) and vertebrate (M. musculus) systems, highlighting remarkable functional conservation. Finally, we reflect on recent findings implicating chromatin-modifying proteins, such as histone methyltransferases and Polycomb proteins, in the control of neuronal terminal identity. Altogether, these new studies on transcription factors and chromatin modifiers not only shed light on the fundamental problem of neuronal identity maintenance, but also outline mechanistic principles of gene regulation that may operate in other long-lived, post-mitotic cell types.
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Affiliation(s)
- Honorine Destain
- Department of Neurobiology, University of Chicago, Chicago, IL, USA; Committee on Development, Regeneration and Stem Cell Biology, University of Chicago, Chicago, IL, USA; University of Chicago Neuroscience Institute, Chicago, IL, USA
| | - Manasa Prahlad
- Department of Neurobiology, University of Chicago, Chicago, IL, USA; Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA; University of Chicago Neuroscience Institute, Chicago, IL, USA
| | - Paschalis Kratsios
- Department of Neurobiology, University of Chicago, Chicago, IL, USA; Committee on Development, Regeneration and Stem Cell Biology, University of Chicago, Chicago, IL, USA; Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL, USA; University of Chicago Neuroscience Institute, Chicago, IL, USA.
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11
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Correa E, Mialon M, Cizeron M, Bessereau JL, Pinan-Lucarre B, Kratsios P. UNC-30/PITX coordinates neurotransmitter identity with postsynaptic GABA receptor clustering. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.14.580278. [PMID: 38405977 PMCID: PMC10888783 DOI: 10.1101/2024.02.14.580278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Terminal selectors are transcription factors that control neuronal identity by regulating the expression of key effector molecules, such as neurotransmitter (NT) biosynthesis proteins, ion channels and neuropeptides. Whether and how terminal selectors control neuronal connectivity is poorly understood. Here, we report that UNC-30 (PITX2/3), the terminal selector of GABA motor neuron identity in C. elegans , is required for NT receptor clustering, a hallmark of postsynaptic differentiation. Animals lacking unc-30 or madd-4B, the short isoform of the MN-secreted synapse organizer madd-4 ( Punctin/ADAMTSL ), display severe GABA receptor type A (GABA A R) clustering defects in postsynaptic muscle cells. Mechanistically, UNC-30 acts directly to induce and maintain transcription of madd-4B and GABA biosynthesis genes (e.g., unc-25/GAD , unc-47/VGAT ). Hence, UNC-30 controls GABA A R clustering on postsynaptic muscle cells and GABA biosynthesis in presynaptic cells, transcriptionally coordinating two critical processes for GABA neurotransmission. Further, we uncover multiple target genes and a dual role for UNC-30 both as an activator and repressor of gene transcription. Our findings on UNC-30 function may contribute to our molecular understanding of human conditions, such as Axenfeld-Rieger syndrome, caused by PITX2 and PITX3 gene mutations.
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12
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Pohl F, Lindsay-McGee V, Kong Thoo Lin P, Maciel P, Teixeira-Castro A. Pharmacological inhibition of acetylcholinesterase improves the locomotion defective phenotype of a SCA3 C. elegans model. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001086. [PMID: 38404918 PMCID: PMC10884831 DOI: 10.17912/micropub.biology.001086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 12/22/2023] [Accepted: 02/02/2024] [Indexed: 02/27/2024]
Abstract
Inhibition of acetylcholinesterase (AChE) is a common used treatment option for Alzheimer's disease. However, there has been limited research on the potential use of AChE inhibitors for the treatment of Machado-Joseph disease (MJD)/Spinocerebellar Ataxia 3 (SCA3), in spite of the positive results using AChE inhibitors in patients with other inherited ataxias. MJD/SCA3, the most common form of dominant Spinocerebellar Ataxia worldwide, is caused by an expansion of the polyglutamine tract within the ataxin-3 protein, and is characterized by motor impairments. Our study shows that administration of the AChE inhibitor neostigmine is beneficial in treating the locomotion defective phenotype of a SCA3/MJD model of C. elegans and highlights the potential contribution of AChE enzymes to mutant ataxin-3-mediated toxicity.
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Affiliation(s)
- Franziska Pohl
- School of Pharmacy and Life Science, Robert Gordon University, Aberdeen, Scotland, United Kingdom
- Oncology/Dev. Biology, Washington University in St. Louis, St Louis, Missouri, United States
| | - Victoria Lindsay-McGee
- School of Pharmacy and Life Science, Robert Gordon University, Aberdeen, Scotland, United Kingdom
- The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Paul Kong Thoo Lin
- School of Pharmacy and Life Science, Robert Gordon University, Aberdeen, Scotland, United Kingdom
| | - Patricia Maciel
- Life and Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- Braga/Guimarães, Portugal, ICVS/3B’s-PT Government Associate Laboratory
| | - Andreia Teixeira-Castro
- Life and Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- Braga/Guimarães, Portugal, ICVS/3B’s-PT Government Associate Laboratory
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Panska L, Nedvedova S, Vacek V, Krivska D, Konecny L, Knop F, Kutil Z, Skultetyova L, Leontovyc A, Ulrychova L, Sakanari J, Asahina M, Barinka C, Macurkova M, Dvorak J. Uncovering the essential roles of glutamate carboxypeptidase 2 orthologs in Caenorhabditis elegans. Biosci Rep 2024; 44:BSR20230502. [PMID: 38108122 PMCID: PMC10794815 DOI: 10.1042/bsr20230502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 12/13/2023] [Accepted: 12/15/2023] [Indexed: 12/19/2023] Open
Abstract
Human glutamate carboxypeptidase 2 (GCP2) from the M28B metalloprotease group is an important target for therapy in neurological disorders and an established tumor marker. However, its physiological functions remain unclear. To better understand general roles, we used the model organism Caenorhabditis elegans to genetically manipulate its three existing orthologous genes and evaluate the impact on worm physiology. The results of gene knockout studies showed that C. elegans GCP2 orthologs affect the pharyngeal physiology, reproduction, and structural integrity of the organism. Promoter-driven GFP expression revealed distinct localization for each of the three gene paralogs, with gcp-2.1 being most abundant in muscles, intestine, and pharyngeal interneurons, gcp-2.2 restricted to the phasmid neurons, and gcp-2.3 located in the excretory cell. The present study provides new insight into the unique phenotypic effects of GCP2 gene knockouts in C. elegans, and the specific tissue localizations. We believe that elucidation of particular roles in a non-mammalian organism can help to explain important questions linked to physiology of this protease group and in extension to human GCP2 involvement in pathophysiological processes.
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Affiliation(s)
- Lucie Panska
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
- Faculty of Environmental Sciences, Center of Infectious Animal Diseases, Czech University of Life Sciences in Prague, Kamycka 129, Prague 165 00, Czech Republic
| | - Stepanka Nedvedova
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
- Department of Chemistry, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
| | - Vojtech Vacek
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
| | - Daniela Krivska
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
- Department of Chemistry, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
| | - Lukas Konecny
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
- Department of Parasitology, Faculty of Science, Charles University, Vinicna 7, Prague 2 128 00, Czech Republic
| | - Filip Knop
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, Prague 2 128 00, Czech Republic
| | - Zsofia Kutil
- Laboratory of Structural Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, Vestec 252 50, Czech Republic
| | - Lubica Skultetyova
- Laboratory of Structural Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, Vestec 252 50, Czech Republic
| | - Adrian Leontovyc
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo n. 2, Prague 160 00, Czech Republic
| | - Lenka Ulrychova
- Department of Parasitology, Faculty of Science, Charles University, Vinicna 7, Prague 2 128 00, Czech Republic
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo n. 2, Prague 160 00, Czech Republic
| | - Judy Sakanari
- Department of Pharmaceutical Chemistry, University of California, San Francisco, 1700 4th Street, CA 94143, USA
| | - Masako Asahina
- Department of Physiology, University of California, San Francisco, 600 16th Street, CA 94143, U.S.A
| | - Cyril Barinka
- Laboratory of Structural Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, Vestec 252 50, Czech Republic
| | - Marie Macurkova
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, Prague 2 128 00, Czech Republic
| | - Jan Dvorak
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
- Faculty of Environmental Sciences, Center of Infectious Animal Diseases, Czech University of Life Sciences in Prague, Kamycka 129, Prague 165 00, Czech Republic
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo n. 2, Prague 160 00, Czech Republic
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14
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Kubens L, Weishaupt AK, Michaelis V, Rohn I, Mohr F, Bornhorst J. Exposure to the environmentally relevant fungicide Maneb: Studying toxicity in the soil nematode Caenorhabditis elegans. ENVIRONMENT INTERNATIONAL 2024; 183:108372. [PMID: 38071851 DOI: 10.1016/j.envint.2023.108372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 12/02/2023] [Accepted: 12/04/2023] [Indexed: 01/25/2024]
Abstract
Maneb is a manganese-containing ethylene bisdithiocarbamate fungicide and is still commonly used as no cases of resistance have been documented. However, studies have shown that Maneb exposure has neurodegenerative potential in mammals, resulting in symptoms affecting the motor system. Despite its extensive use, structural elucidation of Maneb has only recently been accomplished by our group. This study aimed to examine the bioavailability of Maneb, the quantification of oxidative stress-related endpoints and neurotransmitters employing pure Maneb, its metabolites and structural analogues, in the model organism Caenorhabditis elegans. Exposure to Maneb did not increase the bioavailability of Mn compared to manganese chloride, although Maneb was about 8 times more toxic with regard to lethality. Maneb generated not significantly reactive oxygen and nitrogen species (RONS) but decreased the ATP level while increasing the amount of glutathione and its oxidized form in a dose-dependent manner. Nevertheless, an alteration in the neurotransmitter homeostasis of dopamine, acetylcholine, and gamma-butyric acid (GABA) was observed as well as morphological changes in the dopaminergic neurons upon Maneb exposure, which underlines the assumption of the neurotoxic potential of Maneb. This study showed that Maneb exhibits effects based on a combined interaction of the ligand and manganese.
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Affiliation(s)
- Laura Kubens
- Food Chemistry, University of Wuppertal, Germany; Inorganic Chemistry, University of Wuppertal, Germany
| | - Ann-Kathrin Weishaupt
- Food Chemistry, University of Wuppertal, Germany; TraceAge - DFG Research Unit on Interactions of Essential Trace Elements in Healthy and Diseased Elderly (FOR 2558), Berlin-Potsdam-Jena-Wuppertal, Germany
| | | | | | - Fabian Mohr
- Inorganic Chemistry, University of Wuppertal, Germany
| | - Julia Bornhorst
- Food Chemistry, University of Wuppertal, Germany; TraceAge - DFG Research Unit on Interactions of Essential Trace Elements in Healthy and Diseased Elderly (FOR 2558), Berlin-Potsdam-Jena-Wuppertal, Germany.
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15
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Wang Y, Liu J, Du LY, Wyss JL, Farrell JA, Schier AF. Gene module reconstruction elucidates cellular differentiation processes and the regulatory logic of specialized secretion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.29.573643. [PMID: 38234833 PMCID: PMC10793473 DOI: 10.1101/2023.12.29.573643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
During differentiation, cells become structurally and functionally specialized, but comprehensive views of the underlying remodeling processes are elusive. Here, we leverage scRNA-seq developmental trajectories to reconstruct differentiation using two secretory tissues as a model system - the zebrafish notochord and hatching gland. First, we present an approach to integrate expression and functional similarities for gene module identification, revealing dozens of gene modules representing known and newly associated differentiation processes and their temporal ordering. Second, we focused on the unfolded protein response (UPR) transducer module to study how general versus cell-type specific secretory functions are regulated. By profiling loss- and gain-of-function embryos, we found that the UPR transcription factors creb3l1, creb3l2, and xbp1 are master regulators of a general secretion program. creb3l1/creb3l2 additionally activate an extracellular matrix secretion program, while xbp1 partners with bhlha15 to activate a gland-specific secretion program. Our study offers a multi-source integrated approach for functional gene module identification and illustrates how transcription factors confer general and specialized cellular functions.
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Affiliation(s)
- Yiqun Wang
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
- Biozentrum, University of Basel, Basel, 4056, Switzerland
| | - Jialin Liu
- Biozentrum, University of Basel, Basel, 4056, Switzerland
- Allen Discovery Center for Cell Lineage Tracing, University of Washington, Seattle, WA, 98195, USA
| | - Lucia Y. Du
- Biozentrum, University of Basel, Basel, 4056, Switzerland
- Allen Discovery Center for Cell Lineage Tracing, University of Washington, Seattle, WA, 98195, USA
| | - Jannik L. Wyss
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Jeffrey A. Farrell
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, 20892, USA
| | - Alexander F. Schier
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
- Biozentrum, University of Basel, Basel, 4056, Switzerland
- Allen Discovery Center for Cell Lineage Tracing, University of Washington, Seattle, WA, 98195, USA
- Lead contact
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16
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Lee MB, Blue B, Muir M, Kaeberlein M. The million-molecule challenge: a moonshot project to rapidly advance longevity intervention discovery. GeroScience 2023; 45:3103-3113. [PMID: 37432607 PMCID: PMC10643437 DOI: 10.1007/s11357-023-00867-6] [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: 05/16/2023] [Accepted: 06/30/2023] [Indexed: 07/12/2023] Open
Abstract
Targeting aging is the future of twenty-first century preventative medicine. Small molecule interventions that promote healthy longevity are known, but few are well-developed and discovery of novel, robust interventions has stagnated. To accelerate longevity intervention discovery and development, high-throughput systems are needed that can perform unbiased drug screening and directly measure lifespan and healthspan metrics in whole animals. C. elegans is a powerful model system for this type of drug discovery. Combined with automated data capture and analysis technologies, truly high-throughput longevity drug discovery is possible. In this perspective, we propose the "million-molecule challenge", an effort to quantitatively assess 1,000,000 interventions for longevity within five years. The WormBot-AI, our best-in-class robotics and AI data analysis platform, provides a tool to achieve the million-molecule challenge for pennies per animal tested.
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Affiliation(s)
- Mitchell B Lee
- Ora Biomedical, Inc., 12101 Tukwila International Blvd Suite 210, Seattle, WA, 98168, USA.
| | - Benjamin Blue
- Ora Biomedical, Inc., 12101 Tukwila International Blvd Suite 210, Seattle, WA, 98168, USA
| | - Michael Muir
- Ora Biomedical, Inc., 12101 Tukwila International Blvd Suite 210, Seattle, WA, 98168, USA
| | - Matt Kaeberlein
- Ora Biomedical, Inc., 12101 Tukwila International Blvd Suite 210, Seattle, WA, 98168, USA
- Optispan Geroscience, Seattle, WA, USA
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17
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Ripoll-Sánchez L, Watteyne J, Sun H, Fernandez R, Taylor SR, Weinreb A, Bentley BL, Hammarlund M, Miller DM, Hobert O, Beets I, Vértes PE, Schafer WR. The neuropeptidergic connectome of C. elegans. Neuron 2023; 111:3570-3589.e5. [PMID: 37935195 PMCID: PMC7615469 DOI: 10.1016/j.neuron.2023.09.043] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 08/02/2023] [Accepted: 09/29/2023] [Indexed: 11/09/2023]
Abstract
Efforts are ongoing to map synaptic wiring diagrams, or connectomes, to understand the neural basis of brain function. However, chemical synapses represent only one type of functionally important neuronal connection; in particular, extrasynaptic, "wireless" signaling by neuropeptides is widespread and plays essential roles in all nervous systems. By integrating single-cell anatomical and gene-expression datasets with biochemical analysis of receptor-ligand interactions, we have generated a draft connectome of neuropeptide signaling in the C. elegans nervous system. This network is characterized by high connection density, extended signaling cascades, autocrine foci, and a decentralized topology, with a large, highly interconnected core containing three constituent communities sharing similar patterns of input connectivity. Intriguingly, several key network hubs are little-studied neurons that appear specialized for peptidergic neuromodulation. We anticipate that the C. elegans neuropeptidergic connectome will serve as a prototype to understand how networks of neuromodulatory signaling are organized.
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Affiliation(s)
- Lidia Ripoll-Sánchez
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK; Department of Psychiatry, Cambridge University, Cambridge, UK
| | - Jan Watteyne
- Department of Biology, KU Leuven, Leuven, Belgium
| | - HaoSheng Sun
- Department of Biological Sciences/HHMI, Columbia University, New York, NY, USA; Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Robert Fernandez
- Department of Biological Sciences/HHMI, Columbia University, New York, NY, USA
| | - Seth R Taylor
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Alexis Weinreb
- Departments of Genetics and Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Barry L Bentley
- Cardiff School of Technologies, Cardiff Metropolitan University, Cardiff, UK
| | - Marc Hammarlund
- Departments of Genetics and Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - David M Miller
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Oliver Hobert
- Department of Biological Sciences/HHMI, Columbia University, New York, NY, USA
| | - Isabel Beets
- Department of Biology, KU Leuven, Leuven, Belgium
| | - Petra E Vértes
- Department of Psychiatry, Cambridge University, Cambridge, UK
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK; Department of Biology, KU Leuven, Leuven, Belgium.
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18
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Huang YC, Luo J, Huang W, Baker CM, Gomes MA, Meng B, Byrne AB, Flavell SW. A single neuron in C. elegans orchestrates multiple motor outputs through parallel modes of transmission. Curr Biol 2023; 33:4430-4445.e6. [PMID: 37769660 PMCID: PMC10860333 DOI: 10.1016/j.cub.2023.08.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/24/2023] [Accepted: 08/30/2023] [Indexed: 10/03/2023]
Abstract
Animals generate a wide range of highly coordinated motor outputs, which allows them to execute purposeful behaviors. Individual neurons in the circuits that generate behaviors have a remarkable capacity for flexibility as they exhibit multiple axonal projections, transmitter systems, and modes of neural activity. How these multi-functional properties of neurons enable the generation of adaptive behaviors remains unknown. Here, we show that the HSN neuron in C. elegans evokes multiple motor programs over different timescales to enable a suite of behavioral changes during egg laying. Using HSN activity perturbations and in vivo calcium imaging, we show that HSN acutely increases egg laying and locomotion while also biasing the animals toward low-speed dwelling behavior over minutes. The acute effects of HSN on egg laying and high-speed locomotion are mediated by separate sets of HSN transmitters and different HSN axonal compartments. The long-lasting effects on dwelling are mediated in part by HSN release of serotonin, which is taken up and re-released by NSM, another serotonergic neuron class that directly evokes dwelling. Our results show how the multi-functional properties of a single neuron allow it to induce a coordinated suite of behaviors and also reveal that neurons can borrow serotonin from one another to control behavior.
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Affiliation(s)
- Yung-Chi Huang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jinyue Luo
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Wenjia Huang
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA 01655, USA
| | - Casey M Baker
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Matthew A Gomes
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Bohan Meng
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alexandra B Byrne
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA 01655, USA
| | - Steven W Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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19
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Koutsoumparis A, Busack I, Chen CK, Hayashi Y, Braeckman BP, Meierhofer D, Bringmann H. Reverse genetic screening during L1 arrest reveals a role of the diacylglycerol kinase 1 gene dgk-1 and sphingolipid metabolism genes in sleep regulation. Genetics 2023; 225:iyad124. [PMID: 37682641 DOI: 10.1093/genetics/iyad124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 07/01/2023] [Indexed: 09/10/2023] Open
Abstract
Sleep is a fundamental state of behavioral quiescence and physiological restoration. Sleep is controlled by environmental conditions, indicating a complex regulation of sleep by multiple processes. Our knowledge of the genes and mechanisms that control sleep during various conditions is, however, still incomplete. In Caenorhabditis elegans, sleep is increased when development is arrested upon starvation. Here, we performed a reverse genetic sleep screen in arrested L1 larvae for genes that are associated with metabolism. We found over 100 genes that are associated with a reduced sleep phenotype. Enrichment analysis revealed sphingolipid metabolism as a key pathway that controls sleep. A strong sleep loss was caused by the loss of function of the diacylglycerol kinase 1 gene, dgk-1, a negative regulator of synaptic transmission. Rescue experiments indicated that dgk-1 is required for sleep in cholinergic and tyraminergic neurons. The Ring Interneuron S (RIS) neuron is crucial for sleep in C. elegans and activates to induce sleep. RIS activation transients were abolished in dgk-1 mutant animals. Calcium transients were partially rescued by a reduction-of-function mutation of unc-13, suggesting that dgk-1 might be required for RIS activation by limiting synaptic vesicle release. dgk-1 mutant animals had impaired L1 arrest survival and dampened expression of the protective heat shock factor gene hsp-12.6. These data suggest that dgk-1 impairment causes broad physiological deficits. Microcalorimetry and metabolomic analyses of larvae with impaired RIS showed that RIS is broadly required for energy conservation and metabolic control, including for the presence of sphingolipids. Our data support the notion that metabolism broadly influences sleep and that sleep is associated with profound metabolic changes. We thus provide novel insights into the interplay of lipids and sleep and provide a rich resource of mutants and metabolic pathways for future sleep studies.
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Affiliation(s)
- Anastasios Koutsoumparis
- Chair of Cellular Circuits and Systems, Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Am Tatzberg 47/49, Dresden, Saxony 01307, Germany
| | - Inka Busack
- Chair of Cellular Circuits and Systems, Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Am Tatzberg 47/49, Dresden, Saxony 01307, Germany
| | - Chung-Kuan Chen
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Yu Hayashi
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Bart P Braeckman
- Laboratory of Aging Physiology and Molecular Evolution, Department of Biology, Ghent University, 9000 Ghent, Belgium
| | - David Meierhofer
- Mass Spectrometry Facility, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Henrik Bringmann
- Chair of Cellular Circuits and Systems, Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Am Tatzberg 47/49, Dresden, Saxony 01307, Germany
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20
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Sarparast M, Hinman J, Pourmand E, Vonarx D, Ramirez L, Ma W, Liachko NF, Alan JK, Lee KSS. Cytochrome P450 and Epoxide Hydrolase Metabolites in Aβ and tau-induced Neurodegeneration: Insights from Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.02.560527. [PMID: 37873467 PMCID: PMC10592936 DOI: 10.1101/2023.10.02.560527] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
This study aims to uncover potent cytochrome P450 (CYP) and epoxide hydrolase (EH) metabolites implicated in Aβ and/or tau-induced neurodegeneration, independent of neuroinflammation, by utilizing Caenorhabditis elegans (C. elegans) as a model organism. Our research reveals that Aβ and/or tau expression in C. elegans disrupts the oxylipin profile, and epoxide hydrolase inhibition alleviates the ensuing neurodegeneration, likely through elevating the epoxy-to-hydroxy ratio of various CYP-EH metabolites. In addition, our results indicated that the Aβ and tau likely affect the CYP-EH metabolism of PUFA through different mechanism. These findings emphasize the intriguing relationship between lipid metabolites and neurodegenerations, in particular, those linked to Aβ and/or tau aggregation. Furthermore, our investigation sheds light on the crucial and captivating role of CYP PUFA metabolites in C. elegans physiology, opening up possibilities for broader implications in mammalian and human contexts.
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Affiliation(s)
- Morteza Sarparast
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Jennifer Hinman
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
- Institute of Integrative Toxicology, Michigan State University, East Lansing, MI, USA
| | - Elham Pourmand
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Derek Vonarx
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
| | - Leslie Ramirez
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Wenjuan Ma
- Center for Statistical Training and Consulting (CSTAT), Michigan State University, East Lansing, MI, USA
| | - Nicole F. Liachko
- Geriatrics Research Education and Clinical Center, Veterrans Affairs Puget Sound Health Care System, Seattle, WA, USA
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Jamie K. Alan
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Kin Sing Stephen Lee
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
- Department of Chemistry, Michigan State University, East Lansing, MI, USA
- Institute of Integrative Toxicology, Michigan State University, East Lansing, MI, USA
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21
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Salzberg Y, Haque R, Oren-Suissa M. The synaptic basis for sexual dimorphism in the invertebrate nervous system. Curr Opin Neurobiol 2023; 82:102757. [PMID: 37572555 PMCID: PMC10506627 DOI: 10.1016/j.conb.2023.102757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 07/10/2023] [Accepted: 07/17/2023] [Indexed: 08/14/2023]
Abstract
Many animal behaviors are manifested differently in the two sexes of a given species, but how such sexual dimorphism is imprinted in the nervous system is not always clear. One mechanism involved is synaptic dimorphism, by which the same neurons exist in the two sexes, but form synapses that differ in features such as anatomy, molecular content or fate. While some evidence for synaptic dimorphism exists in humans and mammals, identifying these mechanisms in invertebrates has proven simpler, due to their smaller nervous systems and absence of external regulation by sex hormones. This review aims to present the current status of the field in invertebrates, the available toolkit for the study of synaptic dimorphism, and the standing questions that still remain incompletely answered.
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Affiliation(s)
- Yehuda Salzberg
- Department of Brain Science, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Rizwanul Haque
- Department of Brain Science, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Meital Oren-Suissa
- Department of Brain Science, Weizmann Institute of Science, Rehovot, 7610001, Israel.
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22
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Kumar S, Sharma AK, Tran A, Liu M, Leifer AM. Inhibitory feedback from the motor circuit gates mechanosensory processing in Caenorhabditis elegans. PLoS Biol 2023; 21:e3002280. [PMID: 37733772 PMCID: PMC10617738 DOI: 10.1371/journal.pbio.3002280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 10/31/2023] [Accepted: 07/27/2023] [Indexed: 09/23/2023] Open
Abstract
Animals must integrate sensory cues with their current behavioral context to generate a suitable response. How this integration occurs is poorly understood. Previously, we developed high-throughput methods to probe neural activity in populations of Caenorhabditis elegans and discovered that the animal's mechanosensory processing is rapidly modulated by the animal's locomotion. Specifically, we found that when the worm turns it suppresses its mechanosensory-evoked reversal response. Here, we report that C. elegans use inhibitory feedback from turning-associated neurons to provide this rapid modulation of mechanosensory processing. By performing high-throughput optogenetic perturbations triggered on behavior, we show that turning-associated neurons SAA, RIV, and/or SMB suppress mechanosensory-evoked reversals during turns. We find that activation of the gentle-touch mechanosensory neurons or of any of the interneurons AIZ, RIM, AIB, and AVE during a turn is less likely to evoke a reversal than activation during forward movement. Inhibiting neurons SAA, RIV, and SMB during a turn restores the likelihood with which mechanosensory activation evokes reversals. Separately, activation of premotor interneuron AVA evokes reversals regardless of whether the animal is turning or moving forward. We therefore propose that inhibitory signals from SAA, RIV, and/or SMB gate mechanosensory signals upstream of neuron AVA. We conclude that C. elegans rely on inhibitory feedback from the motor circuit to modulate its response to sensory stimuli on fast timescales. This need for motor signals in sensory processing may explain the ubiquity in many organisms of motor-related neural activity patterns seen across the brain, including in sensory processing areas.
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Affiliation(s)
- Sandeep Kumar
- Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey, United States of America
| | - Anuj K. Sharma
- Department of Physics, Princeton University, Princeton, New Jersey, United States of America
| | - Andrew Tran
- Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey, United States of America
| | - Mochi Liu
- Department of Physics, Princeton University, Princeton, New Jersey, United States of America
| | - Andrew M. Leifer
- Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey, United States of America
- Department of Physics, Princeton University, Princeton, New Jersey, United States of America
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23
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Zhan X, Chen C, Niu L, Du X, Lei Y, Dan R, Wang ZW, Liu P. Locomotion modulates olfactory learning through proprioception in C. elegans. Nat Commun 2023; 14:4534. [PMID: 37500635 PMCID: PMC10374624 DOI: 10.1038/s41467-023-40286-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 07/19/2023] [Indexed: 07/29/2023] Open
Abstract
Locomotor activities can enhance learning, but the underlying circuit and synaptic mechanisms are largely unknown. Here we show that locomotion facilitates aversive olfactory learning in C. elegans by activating mechanoreceptors in motor neurons, and transmitting the proprioceptive information thus generated to locomotion interneurons through antidromic-rectifying gap junctions. The proprioceptive information serves to regulate experience-dependent activities and functional coupling of interneurons that process olfactory sensory information to produce the learning behavior. Genetic destruction of either the mechanoreceptors in motor neurons, the rectifying gap junctions between the motor neurons and locomotion interneurons, or specific inhibitory synapses among the interneurons impairs the aversive olfactory learning. We have thus uncovered an unexpected role of proprioception in a specific learning behavior as well as the circuit, synaptic, and gene bases for this function.
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Affiliation(s)
- Xu Zhan
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China and Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, 430030, Wuhan, Hubei, China
| | - Chao Chen
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 430022, Wuhan, Hubei, China
- Department of Orthopaedics, Hefeng Central Hospital, 445800, Enshi, Hubei, China
| | - Longgang Niu
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, 06030, USA
| | - Xinran Du
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, 06030, USA
| | - Ying Lei
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China and Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, 430030, Wuhan, Hubei, China
| | - Rui Dan
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China and Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, 430030, Wuhan, Hubei, China
| | - Zhao-Wen Wang
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, 06030, USA.
| | - Ping Liu
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China and Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, 430030, Wuhan, Hubei, China.
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24
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Graur A, Sinclair P, Schneeweis AK, Pak DT, Kabbani N. The human acetylcholinesterase C-terminal T30 peptide activates neuronal growth through alpha 7 nicotinic acetylcholine receptors and the mTOR pathway. Sci Rep 2023; 13:11434. [PMID: 37454238 PMCID: PMC10349870 DOI: 10.1038/s41598-023-38637-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023] Open
Abstract
Acetylcholinesterase (AChE) is a highly conserved enzyme responsible for the regulation of acetylcholine signaling within the brain and periphery. AChE has also been shown to participate in non-enzymatic activity and contribute to cellular development and aging. In particular, enzymatic cleavage of the synaptic AChE isoform, AChE-T, is shown to generate a bioactive T30 peptide that binds to the ⍺7 nicotinic acetylcholine receptor (nAChR) at synapses. Here, we explore intracellular mechanisms of T30 signaling within the human cholinergic neural cell line SH-SY5Y using high performance liquid chromatography (HPLC) coupled to electrospray ionization mass spectrometry (ESI-MS/MS). Proteomic analysis of cells exposed to (100 nM) T30 for 3-days reveals significant changes within proteins important for cell growth. Specifically, bioinformatic analysis identifies proteins that converge onto the mammalian target of rapamycin (mTOR) pathway signaling. Functional experiments confirm that T30 regulates neural cell growth via mTOR signaling and ⍺7 nAChR activation. T30 was found promote mTORC1 pro-growth signaling through an increase in phosphorylated elF4E and S6K1, and a decrease in the autophagy LC3B-II protein. These findings are corroborated in hippocampal neurons and show that T30 promotes dendritic arborization. Taken together, our findings define mTOR as a novel pathway activated by T30 interaction with the nAChR and suggest a role for this process in human disease.
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Affiliation(s)
- Alexandru Graur
- School of Systems Biology, George Mason University, 4400 University Drive, Fairfax, VA, 22030, USA
| | - Patricia Sinclair
- Interdiscplinary Program in Neuroscience, George Mason University, Fairfax, VA, 22030, USA
| | - Amanda K Schneeweis
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Daniel T Pak
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC, USA
| | - Nadine Kabbani
- School of Systems Biology, George Mason University, 4400 University Drive, Fairfax, VA, 22030, USA.
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25
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Chang AS, Wirak GS, Li D, Gabel CV, Connor CW. Measures of Information Content during Anesthesia and Emergence in the Caenorhabditis elegans Nervous System. Anesthesiology 2023; 139:49-62. [PMID: 37027802 PMCID: PMC10266588 DOI: 10.1097/aln.0000000000004579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2023]
Abstract
BACKGROUND Suppression of behavioral and physical responses defines the anesthetized state. This is accompanied, in humans, by characteristic changes in electroencephalogram patterns. However, these measures reveal little about the neuron or circuit-level physiologic action of anesthetics nor how information is trafficked between neurons. This study assessed whether entropy-based metrics can differentiate between the awake and anesthetized state in Caenorhabditis elegans and characterize emergence from anesthesia at the level of interneuronal communication. METHODS Volumetric fluorescence imaging measured neuronal activity across a large portion of the C. elegans nervous system at cellular resolution during distinct states of isoflurane anesthesia, as well as during emergence from the anesthetized state. Using a generalized model of interneuronal communication, new entropy metrics were empirically derived that can distinguish the awake and anesthetized states. RESULTS This study derived three new entropy-based metrics that distinguish between stable awake and anesthetized states (isoflurane, n = 10) while possessing plausible physiologic interpretations. State decoupling is elevated in the anesthetized state (0%: 48.8 ± 3.50%; 4%: 66.9 ± 6.08%; 8%: 65.1 ± 5.16%; 0% vs. 4%, P < 0.001; 0% vs. 8%, P < 0.001), while internal predictability (0%: 46.0 ± 2.94%; 4%: 27.7 ± 5.13%; 8%: 30.5 ± 4.56%; 0% vs. 4%, P < 0.001; 0% vs. 8%, P < 0.001), and system consistency (0%: 2.64 ± 1.27%; 4%: 0.97 ± 1.38%; 8%: 1.14 ± 0.47%; 0% vs. 4%, P = 0.006; 0% vs. 8%, P = 0.015) are suppressed. These new metrics also resolve to baseline during gradual emergence of C. elegans from moderate levels of anesthesia to the awake state (n = 8). The results of this study show that early emergence from isoflurane anesthesia in C. elegans is characterized by the rapid resolution of an elevation in high frequency activity (n = 8, P = 0.032). The entropy-based metrics mutual information and transfer entropy, however, did not differentiate well between the awake and anesthetized states. CONCLUSIONS Novel empirically derived entropy metrics better distinguish the awake and anesthetized states compared to extant metrics and reveal meaningful differences in information transfer characteristics between states. EDITOR’S PERSPECTIVE
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Affiliation(s)
- Andrew S Chang
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston University, Boston, Massachusetts
| | - Gregory S Wirak
- Department of Physiology and Biophysics, Boston University, Boston, Massachusetts
| | - Duan Li
- Center for Consciousness Science, Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, Michigan
| | - Christopher V Gabel
- Department of Physiology and Biophysics, Boston University, Boston, Massachusetts
| | - Christopher W Connor
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, Massachusetts; Department of Biomedical Engineering, Physiology and Biophysics, Boston University, Boston, Massachusetts
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26
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Jacques MT, Soares MV, Farina M, Bornhorst J, Schwerdtle T, Ávila DS. Impaired Physiological Responses and Neurotoxicity Induced by a Chlorpyrifos-Based Formulation in Caenorhabditis elegans are not Solely Dependent on the Active Ingredient. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023:104196. [PMID: 37354962 DOI: 10.1016/j.etap.2023.104196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 06/01/2023] [Accepted: 06/20/2023] [Indexed: 06/26/2023]
Abstract
The current massive and indiscriminate agrochemicals usage, which is inexorably linked to the toxic consequences to the environment and people, represents a great concern. Our work aimed to compare the toxicity induced by chlorpyrifos in its pure form (CPF) with that of a commercial formulation containing allegedly inert ingredients (CBCF) using Caenorhabditis elegans as in vivo model. After a 48h exposure period, CBCF was 14 times more lethal than CPF; Hatching, brood size, body length and motor-related behavioral parameters were decreased, but these effects were significantly higher in CBCF-exposed worms. Additionally, CBCF induced significant morphological changes in cholinergic neurons, which are associated with the motor-related behavioral parameters. Finally, by analyzing the CBCF, were detected the presence of potentially-toxic metals that were not specified in the label. The presented results highlight the toxicological relevance of components present in the commercial formulations of pesticides, which have been claimed as inert compounds.
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Affiliation(s)
- Mauricio Tavares Jacques
- Laboratory of Biochemistry and Toxicology in Caenorhabditis elegans, Graduation Program in Biochemistry, Federal University of Pampa, BR 472, Km 592, PO BOX 118, Uruguaiana, RS, Brazil; Laboratory of Experimental Neuropathology, Department of Biochemistry, CCB, Federal University of Santa Catarina, Block C, Trindade, Florianópolis, SC, CEP 88040-900, Brazil
| | - Marcell Valandro Soares
- Laboratory of Biochemistry and Toxicology in Caenorhabditis elegans, Graduation Program in Biochemistry, Federal University of Pampa, BR 472, Km 592, PO BOX 118, Uruguaiana, RS, Brazil; Laboratory of Neurotoxicology and Neuroprotection Experimental, Departament of Biochemistry and Molecular Biology, Federal University of Santa Maria, Camobi, 97105-900, Santa Maria, RS, Brasil
| | - Marcelo Farina
- Laboratory of Experimental Neuropathology, Department of Biochemistry, CCB, Federal University of Santa Catarina, Block C, Trindade, Florianópolis, SC, CEP 88040-900, Brazil
| | - Julia Bornhorst
- Department of Food Chemistry, Institute of Nutritional Science, University of Potsdam, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany; TraceAge-DFG Research Unit on Interactions of Essential Trace Elements in Healthy and Diseased Elderly (FOR 2558), Berlin-Potsdam-Jena-Wuppertal; Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Gaußstraße 20, 42119 Wuppertal, Germany
| | - Tanja Schwerdtle
- Department of Food Chemistry, Institute of Nutritional Science, University of Potsdam, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany; TraceAge-DFG Research Unit on Interactions of Essential Trace Elements in Healthy and Diseased Elderly (FOR 2558), Berlin-Potsdam-Jena-Wuppertal
| | - Daiana Silva Ávila
- Laboratory of Biochemistry and Toxicology in Caenorhabditis elegans, Graduation Program in Biochemistry, Federal University of Pampa, BR 472, Km 592, PO BOX 118, Uruguaiana, RS, Brazil.
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27
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Levichev A, Faumont S, Berner RZ, Purcell Z, White AM, Chicas-Cruz K, Lockery SR. The conserved endocannabinoid anandamide modulates olfactory sensitivity to induce hedonic feeding in C. elegans. Curr Biol 2023; 33:1625-1639.e4. [PMID: 37084730 PMCID: PMC10175219 DOI: 10.1016/j.cub.2023.03.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/28/2023] [Accepted: 03/06/2023] [Indexed: 04/23/2023]
Abstract
The ability of cannabis to increase food consumption has been known for centuries. In addition to producing hyperphagia, cannabinoids can amplify existing preferences for calorically dense, palatable food sources, a phenomenon called hedonic amplification of feeding. These effects result from the action of plant-derived cannabinoids that mimic endogenous ligands called endocannabinoids. The high degree of conservation of cannabinoid signaling at the molecular level across the animal kingdom suggests hedonic feeding may also be widely conserved. Here, we show that exposure of Caenorhabditis elegans to anandamide, an endocannabinoid common to nematodes and mammals, shifts both appetitive and consummatory responses toward nutritionally superior food, an effect analogous to hedonic feeding. We find that anandamide's effect on feeding requires the C. elegans cannabinoid receptor NPR-19 but can also be mediated by the human CB1 cannabinoid receptor, indicating functional conservation between the nematode and mammalian endocannabinoid systems for the regulation of food preferences. Furthermore, anandamide has reciprocal effects on appetitive and consummatory responses to food, increasing and decreasing responses to inferior and superior foods, respectively. Anandamide's behavioral effects require the AWC chemosensory neurons, and anandamide renders these neurons more sensitive to superior foods and less sensitive to inferior foods, mirroring the reciprocal effects seen at the behavioral level. Our findings reveal a surprising degree of functional conservation in the effects of endocannabinoids on hedonic feeding across species and establish a new system to investigate the cellular and molecular basis of endocannabinoid system function in the regulation of food choice.
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Affiliation(s)
- Anastasia Levichev
- University of Oregon, Institute of Neuroscience, 1245 University of Oregon, Eugene, OR 97403, USA
| | - Serge Faumont
- University of Oregon, Institute of Neuroscience, 1245 University of Oregon, Eugene, OR 97403, USA
| | - Rachel Z Berner
- University of Oregon, Institute of Neuroscience, 1245 University of Oregon, Eugene, OR 97403, USA
| | - Zhifeng Purcell
- University of Oregon, Institute of Neuroscience, 1245 University of Oregon, Eugene, OR 97403, USA
| | - Amanda M White
- University of Oregon, Institute of Neuroscience, 1245 University of Oregon, Eugene, OR 97403, USA
| | - Kathy Chicas-Cruz
- University of Oregon, Institute of Neuroscience, 1245 University of Oregon, Eugene, OR 97403, USA
| | - Shawn R Lockery
- University of Oregon, Institute of Neuroscience, 1245 University of Oregon, Eugene, OR 97403, USA.
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28
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Huang YC, Luo J, Huang W, Baker CM, Gomes MA, Byrne AB, Flavell SW. A single neuron in C. elegans orchestrates multiple motor outputs through parallel modes of transmission. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.02.532814. [PMID: 37034579 PMCID: PMC10081309 DOI: 10.1101/2023.04.02.532814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Animals generate a wide range of highly coordinated motor outputs, which allows them to execute purposeful behaviors. Individual neuron classes in the circuits that generate behavior have a remarkable capacity for flexibility, as they exhibit multiple axonal projections, transmitter systems, and modes of neural activity. How these multi-functional properties of neurons enable the generation of highly coordinated behaviors remains unknown. Here we show that the HSN neuron in C. elegans evokes multiple motor programs over different timescales to enable a suite of behavioral changes during egg-laying. Using HSN activity perturbations and in vivo calcium imaging, we show that HSN acutely increases egg-laying and locomotion while also biasing the animals towards low-speed dwelling behavior over longer timescales. The acute effects of HSN on egg-laying and high-speed locomotion are mediated by separate sets of HSN transmitters and different HSN axonal projections. The long-lasting effects on dwelling are mediated by HSN release of serotonin that is taken up and re-released by NSM, another serotonergic neuron class that directly evokes dwelling. Our results show how the multi-functional properties of a single neuron allow it to induce a coordinated suite of behaviors and also reveal for the first time that neurons can borrow serotonin from one another to control behavior.
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Affiliation(s)
- Yung-Chi Huang
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jinyue Luo
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Wenjia Huang
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA, USA
| | - Casey M. Baker
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Matthew A. Gomes
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alexandra B. Byrne
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA, USA
| | - Steven W. Flavell
- Picower Institute for Learning & Memory, Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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29
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Hardege I, Morud J, Courtney A, Schafer WR. A Novel and Functionally Diverse Class of Acetylcholine-Gated Ion Channels. J Neurosci 2023; 43:1111-1124. [PMID: 36604172 PMCID: PMC9962794 DOI: 10.1523/jneurosci.1516-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 12/02/2022] [Accepted: 12/14/2022] [Indexed: 01/07/2023] Open
Abstract
Fast cholinergic neurotransmission is mediated by acetylcholine-gated ion channels; in particular, excitatory nicotinic acetylcholine receptors play well established roles in virtually all nervous systems. Acetylcholine-gated inhibitory channels have also been identified in some invertebrate phyla, yet their roles in the nervous system are less well understood. We report the existence of multiple new inhibitory ion channels with diverse ligand activation properties in Caenorhabditis elegans We identify three channels, LGC-40, LGC-57, and LGC-58, whose primary ligand is choline rather than acetylcholine, as well as the first evidence of a truly polymodal channel, LGC-39, which is activated by both cholinergic and aminergic ligands. Using our new ligand-receptor pairs we uncover the surprising extent to which single neurons in the hermaphrodite nervous system express both excitatory and inhibitory channels, not only for acetylcholine but also for the other major neurotransmitters. The results presented in this study offer new insight into the potential evolutionary benefit of a vast and diverse repertoire of ligand-gated ion channels to generate complexity in an anatomically compact nervous system.SIGNIFICANCE STATEMENT Here we describe the diversity of cholinergic signaling in the nematode Caenorhabditis elegans We identify and characterize a novel family of ligand-gated ion channels and show that they are preferentially gated by choline rather than acetylcholine and expressed broadly in the nervous system. Interestingly, we also identify one channel gated by chemically diverse ligands including acetylcholine and aminergic ligands. By using our new knowledge of these ligand-gated ion channels, we built a model to predict the synaptic polarity in the C. elegans connectome. This model can be used for generating hypotheses on neural circuit function.
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Affiliation(s)
- Iris Hardege
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Julia Morud
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Amy Courtney
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - William R Schafer
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
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30
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Goel V, Sharma S, Chakroborty NK, Singla LD, Choudhury D. Targeting the nervous system of the parasitic worm, Haemonchus contortus with quercetin. Heliyon 2023; 9:e13699. [PMID: 36852031 PMCID: PMC9957779 DOI: 10.1016/j.heliyon.2023.e13699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 01/20/2023] [Accepted: 02/07/2023] [Indexed: 02/14/2023] Open
Abstract
Prevalence of infection, limited choice of drugs, and emerging resistance against contemporary medications lead to a pressing need to develop new anthelmintic drugs and drug targets. However, little understanding of worms' physiology has substantially delayed the process. Here, we are reporting the tissue morphology of Haemonchus contortus, intestinal parasitic helminths found in small ruminants, and targeting its nervous system with quercetin, a naturally occurring flavonoid. Quercetin showed anthelmintic activity against all of the developmental stages of H. contortus. Further, histological analysis demonstrated damage to various body parts, including isthmus, brut, pseudocoele, and other organs. Mechanistic studies revealed the generation of oxidative stress and alterations in the activities of the stress response enzymes, such as catalase, superoxide dismutase, and glutathione peroxidase. Moreover, the time-dependent imaging of reactive oxygen species (ROS) generated due to quercetin treatment disclosed neuropils as the primary targets of quercetin in adult worms, which eventually lead to the paralysis and death of the worms. Thus, this work demonstrates that the nervous system of the parasitic helminth, H. contortus, is a novel target of the drug quercetin.
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Affiliation(s)
- Vanshita Goel
- School of Chemistry and Biochemistry, Thapar Institute of Engineering & Technology, Patiala, 147004, Punjab, India
| | - Sunidhi Sharma
- School of Chemistry and Biochemistry, Thapar Institute of Engineering & Technology, Patiala, 147004, Punjab, India
| | - Neloy Kumar Chakroborty
- Thapar School of Liberal Arts & Sciences, Thapar Institute of Engineering & Technology, Patiala, 147004, Punjab, India
| | - Lachhman Das Singla
- Department of Veterinary Parasitology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab 141001, India
| | - Diptiman Choudhury
- School of Chemistry and Biochemistry, Thapar Institute of Engineering & Technology, Patiala, 147004, Punjab, India.,Thapar Institute of Engineering & Technology-Virginia Tech Center of Excellence in Emerging Materials, Thapar Institute of Engineering & Technology, Patiala, 147004, Punjab, India
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31
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Masoudi N, Schnabel R, Yemini E, Leyva-Díaz E, Hobert O. Cell-specific effects of the sole C. elegans Daughterless/E protein homolog, HLH-2, on nervous system development. Development 2023; 150:286219. [PMID: 36595352 PMCID: PMC10108603 DOI: 10.1242/dev.201366] [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: 10/10/2022] [Accepted: 11/30/2022] [Indexed: 01/04/2023]
Abstract
Are there common mechanisms of neurogenesis used throughout an entire nervous system? We explored to what extent canonical proneural class I/II bHLH complexes are responsible for neurogenesis throughout the entire Caenorhabditis elegans nervous system. Distinct, lineage-specific proneural class II bHLH factors are generally thought to operate via interaction with a common, class I bHLH subunit, encoded by Daughterless in flies, the E proteins in vertebrates and HLH-2 in C. elegans. To eliminate function of all proneuronal class I/II bHLH complexes, we therefore genetically removed maternal and zygotic hlh-2 gene activity. We observed broad effects on neurogenesis, but still detected normal neurogenesis in many distinct neuron-producing lineages of the central and peripheral nervous system. Moreover, we found that hlh-2 selectively affects some aspects of neuron differentiation while leaving others unaffected. Although our studies confirm the function of proneuronal class I/II bHLH complexes in many different lineages throughout a nervous system, we conclude that their function is not universal, but rather restricted by lineage, cell type and components of differentiation programs affected.
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Affiliation(s)
- Neda Masoudi
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, NY 10027, USA
| | - Ralf Schnabel
- Institute of Genetics, Technische Universität Braunschweig, 38106 Braunschweig, Germany
| | - Eviatar Yemini
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, NY 10027, USA.,University of Massachusetts, Department of Neurobiology, Worcester, MA 1605-2324, USA
| | - Eduardo Leyva-Díaz
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, NY 10027, USA
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, NY 10027, USA
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32
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Özel MN, Gibbs CS, Holguera I, Soliman M, Bonneau R, Desplan C. Coordinated control of neuronal differentiation and wiring by sustained transcription factors. Science 2022; 378:eadd1884. [PMID: 36480601 DOI: 10.1126/science.add1884] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The large diversity of cell types in nervous systems presents a challenge in identifying the genetic mechanisms that encode it. Here, we report that nearly 200 distinct neurons in the Drosophila visual system can each be defined by unique combinations of on average 10 continuously expressed transcription factors. We show that targeted modifications of this terminal selector code induce predictable conversions of neuronal fates that appear morphologically and transcriptionally complete. Cis-regulatory analysis of open chromatin links one of these genes to an upstream patterning factor that specifies neuronal fates in stem cells. Experimentally validated network models describe the synergistic regulation of downstream effectors by terminal selectors and ecdysone signaling during brain wiring. Our results provide a generalizable framework of how specific fates are implemented in postmitotic neurons.
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Affiliation(s)
| | - Claudia Skok Gibbs
- Flatiron Institute, Center for Computational Biology, Simons Foundation, New York, NY 10010, USA.,Center for Data Science, New York University, New York, NY 10003, USA
| | - Isabel Holguera
- Department of Biology, New York University, New York, NY 10003, USA
| | - Mennah Soliman
- Department of Biology, New York University, New York, NY 10003, USA
| | - Richard Bonneau
- Department of Biology, New York University, New York, NY 10003, USA.,Flatiron Institute, Center for Computational Biology, Simons Foundation, New York, NY 10010, USA.,Center for Data Science, New York University, New York, NY 10003, USA
| | - Claude Desplan
- Department of Biology, New York University, New York, NY 10003, USA.,New York University Abu Dhabi, Saadiyat Island, Abu Dhabi, United Arab Emirates
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33
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Sexually dimorphic architecture and function of a mechanosensory circuit in C. elegans. Nat Commun 2022; 13:6825. [PMID: 36369281 PMCID: PMC9652301 DOI: 10.1038/s41467-022-34661-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 11/01/2022] [Indexed: 11/13/2022] Open
Abstract
How sensory perception is processed by the two sexes of an organism is still only partially understood. Despite some evidence for sexual dimorphism in auditory and olfactory perception, whether touch is sensed in a dimorphic manner has not been addressed. Here we find that the neuronal circuit for tail mechanosensation in C. elegans is wired differently in the two sexes and employs a different combination of sex-shared sensory neurons and interneurons in each sex. Reverse genetic screens uncovered cell- and sex-specific functions of the alpha-tubulin mec-12 and the sodium channel tmc-1 in sensory neurons, and of the glutamate receptors nmr-1 and glr-1 in interneurons, revealing the underlying molecular mechanisms that mediate tail mechanosensation. Moreover, we show that only in males, the sex-shared interneuron AVG is strongly activated by tail mechanical stimulation, and accordingly is crucial for their behavioral response. Importantly, sex reversal experiments demonstrate that the sexual identity of AVG determines both the behavioral output of the mechanosensory response and the molecular pathways controlling it. Our results present extensive sexual dimorphism in a mechanosensory circuit at both the cellular and molecular levels.
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34
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Lu Y, Ahamed T, Mulcahy B, Meng J, Witvliet D, Guan SA, Holmyard D, Hung W, Wen Q, Chisholm AD, Samuel ADT, Zhen M. Extrasynaptic signaling enables an asymmetric juvenile motor circuit to produce symmetric undulation. Curr Biol 2022; 32:4631-4644.e5. [PMID: 36182701 PMCID: PMC9643663 DOI: 10.1016/j.cub.2022.09.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 06/17/2022] [Accepted: 09/01/2022] [Indexed: 01/28/2023]
Abstract
In many animals, there is a direct correspondence between the motor patterns that drive locomotion and the motor neuron innervation. For example, the adult C. elegans moves with symmetric and alternating dorsal-ventral bending waves arising from symmetric motor neuron input onto the dorsal and ventral muscles. In contrast to the adult, the C. elegans motor circuit at the juvenile larval stage has asymmetric wiring between motor neurons and muscles but still generates adult-like bending waves with dorsal-ventral symmetry. We show that in the juvenile circuit, wiring between excitatory and inhibitory motor neurons coordinates the contraction of dorsal muscles with relaxation of ventral muscles, producing dorsal bends. However, ventral bending is not driven by analogous wiring. Instead, ventral muscles are excited uniformly by premotor interneurons through extrasynaptic signaling. Ventral bends occur in anti-phasic entrainment to activity of the same motor neurons that drive dorsal bends. During maturation, the juvenile motor circuit is replaced by two motor subcircuits that separately drive dorsal and ventral bending. Modeling reveals that the juvenile's immature motor circuit is an adequate solution to generate adult-like dorsal-ventral bending before the animal matures. Developmental rewiring between functionally degenerate circuit solutions, which both generate symmetric bending patterns, minimizes behavioral disruption across maturation.
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Affiliation(s)
- Yangning Lu
- Department of Physiology, University of Toronto, Toronto, ON M5G 1X5, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Tosif Ahamed
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Ben Mulcahy
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Jun Meng
- Department of Physiology, University of Toronto, Toronto, ON M5G 1X5, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Daniel Witvliet
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1X5, Canada
| | - Sihui Asuka Guan
- Department of Physiology, University of Toronto, Toronto, ON M5G 1X5, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Douglas Holmyard
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Wesley Hung
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada
| | - Quan Wen
- Department of Physics and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; School of Life Sciences, University of Science and Technology, Hefei, Anhui 230027, China
| | - Andrew D Chisholm
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Aravinthan D T Samuel
- Department of Physics and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Mei Zhen
- Department of Physiology, University of Toronto, Toronto, ON M5G 1X5, Canada; Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1X5, Canada.
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Fragoso-Luna A, Romero-Bueno R, Eibl M, Ayuso C, Muñoz-Jiménez C, Benes V, Cases I, Askjaer P. Expanded FLP toolbox for spatiotemporal protein degradation and transcriptomic profiling in Caenorhabditis elegans. Genetics 2022; 223:6793861. [PMID: 36321973 PMCID: PMC9836023 DOI: 10.1093/genetics/iyac166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 10/24/2022] [Indexed: 11/05/2022] Open
Abstract
Control of gene expression in specific tissues and/or at certain stages of development allows the study and manipulation of gene function with high precision. Site-specific genome recombination by the flippase (FLP) and cyclization recombination (Cre) enzymes has proved particularly relevant. Joint efforts of many research groups have led to the creation of efficient FLP and Cre drivers to regulate gene expression in a variety of tissues in Caenorhabditis elegans. Here, we extend this toolkit by the addition of FLP lines that drive recombination specifically in distal tip cells, the somatic gonad, coelomocytes, and the epithelial P lineage. In some cases, recombination-mediated gene knockouts do not completely deplete protein levels due to persistence of long-lived proteins. To overcome this, we developed a spatiotemporally regulated degradation system for green fluorescent fusion proteins based on FLP-mediated recombination. Using 2 stable nuclear pore proteins, MEL-28/ELYS and NPP-2/NUP85 as examples, we report the benefit of combining tissue-specific gene knockout and protein degradation to achieve complete protein depletion. We also demonstrate that FLP-mediated recombination can be utilized to identify transcriptomes in a C. elegans tissue of interest. We have adapted RNA polymerase DamID for the FLP toolbox and by focusing on a well-characterized tissue, the hypodermis, we show that the vast majority of genes identified by RNA polymerase DamID are known to be expressed in this tissue. These tools allow combining FLP activity for simultaneous gene inactivation and transcriptomic profiling, thus enabling the inquiry of gene function in various complex biological processes.
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Affiliation(s)
| | | | | | - Cristina Ayuso
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | - Celia Muñoz-Jiménez
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | | | - Ildefonso Cases
- Andalusian Centre for Developmental Biology, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Pablo de Olavide, Junta de Andalucía, 41013 Sevilla, Spain
| | - Peter Askjaer
- Corresponding author: Andalusian Centre for Developmental Biology, Gene Regulation and Morphogenesis, CSIC—Universidad Pablo de Olavide, Carretera de Utrera, km 1, 41013 Seville, Spain.
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36
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Ren J, Sang Y, Aballay A. Cholinergic receptor-Wnt pathway controls immune activation by sensing intestinal dysfunction. Cell Rep 2022; 41:111575. [DOI: 10.1016/j.celrep.2022.111575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 09/09/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022] Open
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Gadenne MJ, Hardege I, Yemini E, Suleski D, Jaggers P, Beets I, Schafer WR, Chew YL. Neuropeptide signalling shapes feeding and reproductive behaviours in male Caenorhabditis elegans. Life Sci Alliance 2022; 5:5/10/e202201420. [PMID: 35738805 PMCID: PMC9233197 DOI: 10.26508/lsa.202201420] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/03/2022] [Accepted: 06/03/2022] [Indexed: 11/24/2022] Open
Abstract
LURY-1 peptides are expressed in distinct cells in different sexes and have sex-specific effects on feeding and mating, providing further evidence for the role of neuromodulators in sexual dimorphism. Sexual dimorphism occurs where different sexes of the same species display differences in characteristics not limited to reproduction. For the nematode Caenorhabditis elegans, in which the complete neuroanatomy has been solved for both hermaphrodites and males, sexually dimorphic features have been observed both in terms of the number of neurons and in synaptic connectivity. In addition, male behaviours, such as food-leaving to prioritise searching for mates, have been attributed to neuropeptides released from sex-shared or sex-specific neurons. In this study, we show that the lury-1 neuropeptide gene shows a sexually dimorphic expression pattern; being expressed in pharyngeal neurons in both sexes but displaying additional expression in tail neurons only in the male. We also show that lury-1 mutant animals show sex differences in feeding behaviours, with pharyngeal pumping elevated in hermaphrodites but reduced in males. LURY-1 also modulates male mating efficiency, influencing motor events during contact with a hermaphrodite. Our findings indicate sex-specific roles of this peptide in feeding and reproduction in C. elegans, providing further insight into neuromodulatory control of sexually dimorphic behaviours.
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Affiliation(s)
- Matthew J Gadenne
- Molecular Horizons, University of Wollongong and Illawarra Health and Medical Research Institute, Wollongong, Australia
| | - Iris Hardege
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Eviatar Yemini
- Department of Neurobiology, UMass Chan Medical School, Worcester, MA, USA
| | - Djordji Suleski
- Molecular Horizons, University of Wollongong and Illawarra Health and Medical Research Institute, Wollongong, Australia
| | - Paris Jaggers
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Isabel Beets
- Department of Biology, KU Leuven, Leuven, Belgium
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, UK.,Department of Biology, KU Leuven, Leuven, Belgium
| | - Yee Lian Chew
- Flinders Health and Medical Research Institute and College of Medicine and Public Health, Flinders University, Adelaide, Australia
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38
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Widespread employment of conserved C. elegans homeobox genes in neuronal identity specification. PLoS Genet 2022; 18:e1010372. [PMID: 36178933 PMCID: PMC9524666 DOI: 10.1371/journal.pgen.1010372] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 08/03/2022] [Indexed: 11/20/2022] Open
Abstract
Homeobox genes are prominent regulators of neuronal identity, but the extent to which their function has been probed in animal nervous systems remains limited. In the nematode Caenorhabditis elegans, each individual neuron class is defined by the expression of unique combinations of homeobox genes, prompting the question of whether each neuron class indeed requires a homeobox gene for its proper identity specification. We present here progress in addressing this question by extending previous mutant analysis of homeobox gene family members and describing multiple examples of homeobox gene function in different parts of the C. elegans nervous system. To probe homeobox function, we make use of a number of reporter gene tools, including a novel multicolor reporter transgene, NeuroPAL, which permits simultaneous monitoring of the execution of multiple differentiation programs throughout the entire nervous system. Using these tools, we add to the previous characterization of homeobox gene function by identifying neuronal differentiation defects for 14 homeobox genes in 24 distinct neuron classes that are mostly unrelated by location, function and lineage history. 12 of these 24 neuron classes had no homeobox gene function ascribed to them before, while in the other 12 neuron classes, we extend the combinatorial code of transcription factors required for specifying terminal differentiation programs. Furthermore, we demonstrate that in a particular lineage, homeotic identity transformations occur upon loss of a homeobox gene and we show that these transformations are the result of changes in homeobox codes. Combining the present with past analyses, 113 of the 118 neuron classes of C. elegans are now known to require a homeobox gene for proper execution of terminal differentiation programs. Such broad deployment indicates that homeobox function in neuronal identity specification may be an ancestral feature of animal nervous systems.
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Head-tail-head neural wiring underlies gut fat storage in Caenorhabditis elegans temperature acclimation. Proc Natl Acad Sci U S A 2022; 119:e2203121119. [PMID: 35914124 PMCID: PMC9371718 DOI: 10.1073/pnas.2203121119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Animals maintain the ability to survive and reproduce by acclimating to environmental temperatures. We showed here that Caenorhabditis elegans exhibited temperature acclimation plasticity, which was regulated by a head-tail-head neural circuitry coupled with gut fat storage. After experiencing cold, C. elegans individuals memorized the experience and were prepared against subsequent cold stimuli. The cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) regulated temperature acclimation in the ASJ thermosensory neurons and RMG head interneurons, where it modulated ASJ thermosensitivity in response to past cultivation temperature. The PVQ tail interneurons mediated the communication between ASJ and RMG via glutamatergic signaling. Temperature acclimation occurred via gut fat storage regulation by the triglyceride lipase ATGL-1, which was activated by a neuropeptide, FLP-7, downstream of CREB. Thus, a head-tail-head neural circuit coordinated with gut fat influenced experience-dependent temperature acclimation.
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40
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Dhakal P, Chaudhry SI, Signorelli R, Collins KM. Serotonin signals through postsynaptic Gαq, Trio RhoGEF, and diacylglycerol to promote Caenorhabditis elegans egg-laying circuit activity and behavior. Genetics 2022; 221:iyac084. [PMID: 35579369 PMCID: PMC9252285 DOI: 10.1093/genetics/iyac084] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 04/26/2022] [Indexed: 11/12/2022] Open
Abstract
Activated Gαq signals through phospholipase-Cβ and Trio, a Rho GTPase exchange factor (RhoGEF), but how these distinct effector pathways promote cellular responses to neurotransmitters like serotonin remains poorly understood. We used the egg-laying behavior circuit of Caenorhabditis elegans to determine whether phospholipase-Cβ and Trio mediate serotonin and Gαq signaling through independent or related biochemical pathways. Our genetic rescue experiments suggest that phospholipase-Cβ functions in neurons while Trio Rho GTPase exchange factor functions in both neurons and the postsynaptic vulval muscles. While Gαq, phospholipase-Cβ, and Trio Rho GTPase exchange factor mutants fail to lay eggs in response to serotonin, optogenetic stimulation of the serotonin-releasing HSN neurons restores egg laying only in phospholipase-Cβ mutants. Phospholipase-Cβ mutants showed vulval muscle Ca2+ transients while strong Gαq and Trio Rho GTPase exchange factor mutants had little or no vulval muscle Ca2+ activity. Treatment with phorbol 12-myristate 13-acetate that mimics 1,2-diacylglycerol, a product of PIP2 hydrolysis, rescued egg-laying circuit activity and behavior defects of Gαq signaling mutants, suggesting both phospholipase-C and Rho signaling promote synaptic transmission and egg laying via modulation of 1,2-diacylglycerol levels. 1,2-Diacylglycerol activates effectors including UNC-13; however, we find that phorbol esters, but not serotonin, stimulate egg laying in unc-13 and phospholipase-Cβ mutants. These results support a model where serotonin signaling through Gαq, phospholipase-Cβ, and UNC-13 promotes neurotransmitter release, and that serotonin also signals through Gαq, Trio Rho GTPase exchange factor, and an unidentified, phorbol 12-myristate 13-acetate-responsive effector to promote postsynaptic muscle excitability. Thus, the same neuromodulator serotonin can signal in distinct cells and effector pathways to coordinate activation of a motor behavior circuit.
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Affiliation(s)
- Pravat Dhakal
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
| | - Sana I Chaudhry
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
| | | | - Kevin M Collins
- Department of Biology, University of Miami, Coral Gables, FL 33146, USA
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41
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Kim D, Kim B. Anatomical and Functional Differences in the Sex-Shared Neurons of the Nematode C. elegans. Front Neuroanat 2022; 16:906090. [PMID: 35601998 PMCID: PMC9121059 DOI: 10.3389/fnana.2022.906090] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 04/20/2022] [Indexed: 11/13/2022] Open
Abstract
Studies on sexual dimorphism in the structure and function of the nervous system have been pivotal to understanding sex differences in behavior. Such studies, especially on invertebrates, have shown the importance of neurons specific to one sex (sex-specific neurons) in shaping sexually dimorphic neural circuits. Nevertheless, recent studies using the nematode C. elegans have revealed that the common neurons that exist in both sexes (sex-shared neurons) also play significant roles in generating sex differences in the structure and function of neural circuits. Here, we review the anatomical and functional differences in the sex-shared neurons of C. elegans. These sexually dimorphic characteristics include morphological differences in neurite projection or branching patterns with substantial changes in synaptic connectivity, differences in synaptic connections without obvious structural changes, and functional modulation in neural circuits with no or minimal synaptic connectivity changes. We also cover underlying molecular mechanisms whereby these sex-shared neurons contribute to the establishment of sexually dimorphic circuits during development and function differently between the sexes.
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42
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Lee KM, Linskens AM, Doe CQ. Hunchback activates Bicoid in Pair1 neurons to regulate synapse number and locomotor circuit function. Curr Biol 2022; 32:2430-2441.e3. [PMID: 35512697 PMCID: PMC9178783 DOI: 10.1016/j.cub.2022.04.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/01/2022] [Accepted: 04/08/2022] [Indexed: 12/26/2022]
Abstract
Neural circuit function underlies cognition, sensation, and behavior. Proper circuit assembly depends on the identity of the neurons in the circuit (gene expression, morphology, synapse targeting, and biophysical properties). Neuronal identity is established by spatial and temporal patterning mechanisms, but little is known about how these mechanisms drive circuit formation in postmitotic neurons. Temporal patterning involves the sequential expression of transcription factors (TFs) in neural progenitors to diversify neuronal identity, in part through the initial expression of homeodomain TF combinations. Here, we address the role of the Drosophila temporal TF Hunchback and the homeodomain TF Bicoid in the assembly of the Pair1 (SEZ_DN1) descending neuron locomotor circuit, which promotes larval pausing and head casting. We find that both Hunchback and Bicoid are expressed in larval Pair1 neurons, Hunchback activates Bicoid in Pair1 (opposite of their embryonic relationship), and the loss of Hunchback function or Bicoid function from Pair1 leads to ectopic presynapse numbers in Pair1 axons and an increase in Pair1-induced pausing behavior. These phenotypes are highly specific, as the loss of Bicoid or Hunchback has no effect on Pair1 neurotransmitter identity, dendrite morphology, or axonal morphology. Importantly, the loss of Hunchback or Bicoid in Pair1 leads to the addition of new circuit partners that may underlie the exaggerated locomotor pausing behavior. These data are the first to show a role for Bicoid outside of embryonic patterning and the first to demonstrate a cell-autonomous role for Hunchback and Bicoid in interneuron synapse targeting and locomotor behavior.
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Affiliation(s)
- Kristen M Lee
- Howard Hughes Medical Institute, Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA.
| | - Amanda M Linskens
- Howard Hughes Medical Institute, Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Chris Q Doe
- Howard Hughes Medical Institute, Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA.
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Chai CM, Torkashvand M, Seyedolmohadesin M, Park H, Venkatachalam V, Sternberg PW. Interneuron control of C. elegans developmental decision-making. Curr Biol 2022; 32:2316-2324.e4. [PMID: 35447086 DOI: 10.1016/j.cub.2022.03.077] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 03/13/2022] [Accepted: 03/30/2022] [Indexed: 01/18/2023]
Abstract
Natural environments are highly dynamic, and this complexity challenges animals to accurately integrate external cues to shape their responses. Adaptive developmental plasticity enables organisms to remodel their physiology, morphology, and behavior to better suit the predicted future environment and ultimately enhance their ecological success.1 Understanding how an animal generates a neural representation of current and forecasted environmental conditions and converts these circuit computations into a predictive adaptive physiological response may provide fundamental insights into the molecular and cellular basis of decision-making over developmentally relevant timescales. Although it is known that sensory cues usually trigger the developmental switch and that downstream inter-tissue signaling pathways enact the alternative developmental phenotype, the integrative neural mechanisms that transduce external inputs into effector pathways are less clear.2,3 In adverse environments, Caenorhabditis elegans larvae can enter a stress-resistant diapause state with arrested metabolism and reproductive physiology.4 Amphid sensory neurons feed into both rapid chemotactic and short-term foraging mode decisions, mediated by amphid and pre-motor interneurons, as well as the long-term diapause entry decision. Here, we identify amphid interneurons that integrate pheromone cues and propagate this information via a neuropeptidergic pathway to influence larval developmental fate, bypassing the pre-motor system. AIA interneuron-derived FLP-2 neuropeptide signaling promotes reproductive growth, and AIA activity is suppressed by pheromones. FLP-2 signaling is inhibited by upstream glutamatergic transmission via the metabotropic receptor MGL-1 and mediated by the broadly expressed neuropeptide G-protein-coupled receptor NPR-30. Thus, metabotropic signaling allows the reuse of parts of a sensory system for a decision with a distinct timescale.
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Affiliation(s)
- Cynthia M Chai
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA.
| | - Mahdi Torkashvand
- Department of Physics, Northeastern University, 360 Huntington Ave, Boston, MA 02115, USA
| | | | - Heenam Park
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA
| | - Vivek Venkatachalam
- Department of Physics, Northeastern University, 360 Huntington Ave, Boston, MA 02115, USA.
| | - Paul W Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA.
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Comfort JJ, Chomyshen SC, Waddell BM, Tabarraei H, Wu CW. Molecular characterization of ethyl carbamate toxicity in Caenorhabditis elegans. Toxicol Rep 2022; 9:619-627. [PMID: 35399212 PMCID: PMC8990054 DOI: 10.1016/j.toxrep.2022.03.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 03/14/2022] [Accepted: 03/26/2022] [Indexed: 01/05/2023] Open
Abstract
Ethyl carbamate is a common contaminant prevalent in fermented food with probable carcinogenic effects in animals. To date, other toxicological properties of ethyl carbamate are not well characterized. Using the genetic model Caenorhabditis elegans, we found that chronic exposure to ethyl carbamate during larval development impedes growth while exposure during adulthood inhibits reproduction, shortens lifespan, and promotes degeneration to dopaminergic neurons. Through whole-transcriptome RNA-sequencing, we found that ethyl carbamate invokes a widespread transcriptomic response inducing the differential expression of > 4,000 genes by at least 2-fold. Functional analysis of RNA-sequencing data revealed that up-regulated genes enrich to various neuron regulatory processes and xenobiotic defense. Gene expression analysis confirms that various genes encoding antioxidant enzymes and those functioning within phase I and II detoxification responses along with ABC transporters are highly up-regulated after ethyl carbamate exposure, suggesting the onset of oxidative stress. Overall, these findings report new toxicological properties of chronic ethyl carbamate exposure and provide new insights on its effects on transcriptome regulation in the C. elegans model.
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Affiliation(s)
- Jordan J. Comfort
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Samantha C. Chomyshen
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Brandon M. Waddell
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Hadi Tabarraei
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Cheng-Wei Wu
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
- Department of Biochemistry, Microbiology and Immunology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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Choudhary S, Kashyap SS, Martin RJ, Robertson AP. Advances in our understanding of nematode ion channels as potential anthelmintic targets. Int J Parasitol Drugs Drug Resist 2022; 18:52-86. [PMID: 35149380 PMCID: PMC8841521 DOI: 10.1016/j.ijpddr.2021.12.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 12/15/2022]
Abstract
Ion channels are specialized multimeric proteins that underlie cell excitability. These channels integrate with a variety of neuromuscular and biological functions. In nematodes, the physiological behaviors including locomotion, navigation, feeding and reproduction, are regulated by these protein entities. Majority of the antinematodal chemotherapeutics target the ion channels to disrupt essential biological functions. Here, we have summarized current advances in our understanding of nematode ion channel pharmacology. We review cys-loop ligand gated ion channels (LGICs), including nicotinic acetylcholine receptors (nAChRs), acetylcholine-chloride gated ion channels (ACCs), glutamate-gated chloride channels (GluCls), and GABA (γ-aminobutyric acid) receptors, and other ionotropic receptors (transient receptor potential (TRP) channels and potassium ion channels). We have provided an update on the pharmacological properties of these channels from various nematodes. This article catalogs the differences in ion channel composition and resulting pharmacology in the phylum Nematoda. This diversity in ion channel subunit repertoire and pharmacology emphasizes the importance of pursuing species-specific drug target research. In this review, we have provided an overview of recent advances in techniques and functional assays available for screening ion channel properties and their application.
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Affiliation(s)
- Shivani Choudhary
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Sudhanva S Kashyap
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Richard J Martin
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Alan P Robertson
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
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Vidal B, Gulez B, Cao WX, Leyva-Diaz E, Reilly MB, Tekieli T, Hobert O. The enteric nervous system of the C. elegans pharynx is specified by the Sine oculis-like homeobox gene ceh-34. eLife 2022; 11:76003. [PMID: 35324425 PMCID: PMC8989417 DOI: 10.7554/elife.76003] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/23/2022] [Indexed: 11/29/2022] Open
Abstract
Overarching themes in the terminal differentiation of the enteric nervous system, an autonomously acting unit of animal nervous systems, have so far eluded discovery. We describe here the overall regulatory logic of enteric nervous system differentiation of the nematode Caenorhabditis elegans that resides within the foregut (pharynx) of the worm. A C. elegans homolog of the Drosophila Sine oculis homeobox gene, ceh-34, is expressed in all 14 classes of interconnected pharyngeal neurons from their birth throughout their life time, but in no other neuron type of the entire animal. Constitutive and temporally controlled ceh-34 removal shows that ceh-34 is required to initiate and maintain the neuron type-specific terminal differentiation program of all pharyngeal neuron classes, including their circuit assembly. Through additional genetic loss of function analysis, we show that within each pharyngeal neuron class, ceh-34 cooperates with different homeodomain transcription factors to individuate distinct pharyngeal neuron classes. Our analysis underscores the critical role of homeobox genes in neuronal identity specification and links them to the control of neuronal circuit assembly of the enteric nervous system. Together with the pharyngeal nervous system simplicity as well as its specification by a Sine oculis homolog, our findings invite speculations about the early evolution of nervous systems.
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Affiliation(s)
- Berta Vidal
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, United States
| | - Burcu Gulez
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, United States
| | - Wen Xi Cao
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, United States
| | - Eduardo Leyva-Diaz
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, United States
| | - Molly B Reilly
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, United States
| | - Tessa Tekieli
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, United States
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, United States
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Rapti G. Open Frontiers in Neural Cell Type Investigations; Lessons From Caenorhabditis elegans and Beyond, Toward a Multimodal Integration. Front Neurosci 2022; 15:787753. [PMID: 35321480 PMCID: PMC8934944 DOI: 10.3389/fnins.2021.787753] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/30/2021] [Indexed: 11/13/2022] Open
Abstract
Nervous system cells, the building blocks of circuits, have been studied with ever-progressing resolution, yet neural circuits appear still resistant to schemes of reductionist classification. Due to their sheer numbers, complexity and diversity, their systematic study requires concrete classifications that can serve reduced dimensionality, reproducibility, and information integration. Conventional hierarchical schemes transformed through the history of neuroscience by prioritizing criteria of morphology, (electro)physiological activity, molecular content, and circuit function, influenced by prevailing methodologies of the time. Since the molecular biology revolution and the recent advents in transcriptomics, molecular profiling gains ground toward the classification of neurons and glial cell types. Yet, transcriptomics entails technical challenges and more importantly uncovers unforeseen spatiotemporal heterogeneity, in complex and simpler nervous systems. Cells change states dynamically in space and time, in response to stimuli or throughout their developmental trajectory. Mapping cell type and state heterogeneity uncovers uncharted terrains in neurons and especially in glial cell biology, that remains understudied in many aspects. Examining neurons and glial cells from the perspectives of molecular neuroscience, physiology, development and evolution highlights the advantage of multifaceted classification schemes. Among the amalgam of models contributing to neuroscience research, Caenorhabditis elegans combines nervous system anatomy, lineage, connectivity and molecular content, all mapped at single-cell resolution, and can provide valuable insights for the workflow and challenges of the multimodal integration of cell type features. This review reflects on concepts and practices of neuron and glial cells classification and how research, in C. elegans and beyond, guides nervous system experimentation through integrated multidimensional schemes. It highlights underlying principles, emerging themes, and open frontiers in the study of nervous system development, regulatory logic and evolution. It proposes unified platforms to allow integrated annotation of large-scale datasets, gene-function studies, published or unpublished findings and community feedback. Neuroscience is moving fast toward interdisciplinary, high-throughput approaches for combined mapping of the morphology, physiology, connectivity, molecular function, and the integration of information in multifaceted schemes. A closer look in mapped neural circuits and understudied terrains offers insights for the best implementation of these approaches.
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Leyva-Díaz E, Hobert O. Robust regulatory architecture of pan-neuronal gene expression. Curr Biol 2022; 32:1715-1727.e8. [PMID: 35259341 PMCID: PMC9050922 DOI: 10.1016/j.cub.2022.02.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/04/2022] [Accepted: 02/10/2022] [Indexed: 12/17/2022]
Abstract
Pan-neuronally expressed genes, such as genes involved in the synaptic vesicle cycle or in neuropeptide maturation, are critical for proper function of all neurons, but the transcriptional control mechanisms that direct such genes to all neurons of a nervous system remain poorly understood. We show here that six members of the CUT family of homeobox genes control pan-neuronal identity specification in Caenorhabditis elegans. Single CUT mutants show barely any effects on pan-neuronal gene expression or global nervous system function, but such effects become apparent and progressively worsen upon removal of additional CUT family members, indicating a critical role of gene dosage. Overexpression of each individual CUT gene rescued the phenotype of compound mutants, corroborating that gene dosage, rather than the activity of specific members of the gene family, is critical for CUT gene family function. Genome-wide binding profiles, as well as mutation of CUT homeodomain binding sites by CRISPR/Cas9 genome engineering show that CUT genes directly control the expression of pan-neuronal features. Moreover, CUT genes act in conjunction with neuron-type-specific transcription factors to control pan-neuronal gene expression. Our study, therefore, provides a previously missing key insight into how neuronal gene expression programs are specified and reveals a highly buffered and robust mechanism that controls the most critical functional features of all neuronal cell types.
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Moseley-Alldredge M, Sheoran S, Yoo H, O’Keefe C, Richmond JE, Chen L. A role for the Erk MAPK pathway in modulating SAX-7/L1CAM-dependent locomotion in Caenorhabditis elegans. Genetics 2022; 220:iyab215. [PMID: 34849872 PMCID: PMC9097276 DOI: 10.1093/genetics/iyab215] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 11/11/2021] [Indexed: 01/13/2023] Open
Abstract
L1CAMs are immunoglobulin cell adhesion molecules that function in nervous system development and function. Besides being associated with autism and schizophrenia spectrum disorders, impaired L1CAM function also underlies the X-linked L1 syndrome, which encompasses a group of neurological conditions, including spastic paraplegia and congenital hydrocephalus. Studies on vertebrate and invertebrate L1CAMs established conserved roles that include axon guidance, dendrite morphogenesis, synapse development, and maintenance of neural architecture. We previously identified a genetic interaction between the Caenorhabditis elegans L1CAM encoded by the sax-7 gene and RAB-3, a GTPase that functions in synaptic neurotransmission; rab-3; sax-7 mutant animals exhibit synthetic locomotion abnormalities and neuronal dysfunction. Here, we show that this synergism also occurs when loss of SAX-7 is combined with mutants of other genes encoding key players of the synaptic vesicle (SV) cycle. In contrast, sax-7 does not interact with genes that function in synaptogenesis. These findings suggest a postdevelopmental role for sax-7 in the regulation of synaptic activity. To assess this possibility, we conducted electrophysiological recordings and ultrastructural analyses at neuromuscular junctions; these analyses did not reveal obvious synaptic abnormalities. Lastly, based on a forward genetic screen for suppressors of the rab-3; sax-7 synthetic phenotypes, we determined that mutants in the ERK Mitogen-activated Protein Kinase (MAPK) pathway can suppress the rab-3; sax-7 locomotion defects. Moreover, we established that Erk signaling acts in a subset of cholinergic neurons in the head to promote coordinated locomotion. In combination, these results suggest a modulatory role for Erk MAPK in L1CAM-dependent locomotion in C. elegans.
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Affiliation(s)
- Melinda Moseley-Alldredge
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
- Developmental Biology Center, University of Minnesota, Minneapolis, MN 55455, USA
| | - Seema Sheoran
- Department of Biological Sciences, University of Illinois, Chicago, IL 60607, USA
| | - Hayoung Yoo
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Calvin O’Keefe
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Janet E Richmond
- Department of Biological Sciences, University of Illinois, Chicago, IL 60607, USA
| | - Lihsia Chen
- Department of Genetics, Cell Biology & Development, University of Minnesota, Minneapolis, MN 55455, USA
- Developmental Biology Center, University of Minnesota, Minneapolis, MN 55455, USA
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Hori S, Mitani S. The transcription factor unc-130/FOXD3/4 contributes to the biphasic calcium response required to optimize avoidance behavior. Sci Rep 2022; 12:1907. [PMID: 35115609 PMCID: PMC8814005 DOI: 10.1038/s41598-022-05942-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 01/13/2022] [Indexed: 11/12/2022] Open
Abstract
The central neural network optimizes avoidance behavior depending on the nociceptive stimulation intensity and is essential for survival. How the property of hub neurons that enables the selection of behaviors is genetically defined is not well understood. We show that the transcription factor unc-130, a human FOXD3/4 ortholog, is required to optimize avoidance behavior depending on stimulus strength in Caenorhabditis elegans. unc-130 is necessary for both ON responses (calcium decreases) and OFF responses (calcium increases) in AIBs, central neurons of avoidance optimization. Ablation of predicted upstream inhibitory neurons reduces the frequency of turn behavior, suggesting that optimization needs both calcium responses. At the molecular level, unc-130 upregulates the expression of at least three genes: nca-2, a homolog of the vertebrate cation leak channel NALCN; glr-1, an AMPA-type glutamate receptor; and eat-4, a hypothetical L-glutamate transmembrane transporter in the central neurons of optimization. unc-130 shows more limited regulation in optimizing behavior than an atonal homolog lin-32, and unc-130 and lin-32 appear to act in parallel molecular pathways. Our findings suggest that unc-130 is required for the establishment of some AIB identities to optimize avoidance behavior.
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Affiliation(s)
- Sayaka Hori
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, 162-8666, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, 162-8666, Japan.
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