1
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Marquina-Solis J, Feng L, Vandewyer E, Beets I, Hawk J, Colón-Ramos DA, Yu J, Fox BW, Schroeder FC, Bargmann CI. Antagonism between neuropeptides and monoamines in a distributed circuit for pathogen avoidance. Cell Rep 2024; 43:114042. [PMID: 38573858 PMCID: PMC11063628 DOI: 10.1016/j.celrep.2024.114042] [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: 04/16/2022] [Revised: 02/06/2024] [Accepted: 03/19/2024] [Indexed: 04/06/2024] Open
Abstract
Pathogenic infection elicits behaviors that promote recovery and survival of the host. After exposure to the pathogenic bacterium Pseudomonas aeruginosa PA14, the nematode Caenorhabditis elegans modifies its sensory preferences to avoid the pathogen. Here, we identify antagonistic neuromodulators that shape this acquired avoidance behavior. Using an unbiased cell-directed neuropeptide screen, we show that AVK neurons upregulate and release RF/RYamide FLP-1 neuropeptides during infection to drive pathogen avoidance. Manipulations that increase or decrease AVK activity accelerate or delay pathogen avoidance, respectively, implicating AVK in the dynamics of avoidance behavior. FLP-1 neuropeptides drive pathogen avoidance through the G protein-coupled receptor DMSR-7, as well as other receptors. DMSR-7 in turn acts in multiple neurons, including tyraminergic/octopaminergic neurons that receive convergent avoidance signals from the cytokine DAF-7/transforming growth factor β. Neuromodulators shape pathogen avoidance through multiple mechanisms and targets, in agreement with the distributed neuromodulatory connectome of C. elegans.
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Affiliation(s)
- Javier Marquina-Solis
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA
| | - Likui Feng
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA
| | | | - Isabel Beets
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Josh Hawk
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Daniel A Colón-Ramos
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Departments of Neuroscience and of Cell Biology, Yale University School of Medicine, New Haven, CT 06511, USA; Instituto de Neurobiología José del Castillo, Recinto de Ciencias Médicas, Universidad de Puerto Rico, San Juan, PR 00901, USA; Wu Tsai Institute, Yale University, New Haven, CT 06510, USA
| | - Jingfang Yu
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Bennett W Fox
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Frank C Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Cornelia I Bargmann
- Lulu and Anthony Wang Laboratory of Neural Circuits and Behavior, The Rockefeller University, New York, NY 10065, USA.
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2
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Fricker LD. Neuropeptidomics of Genetically Defined Cell Types in Mouse Brain. Methods Mol Biol 2024; 2758:213-225. [PMID: 38549016 DOI: 10.1007/978-1-0716-3646-6_11] [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: 04/02/2024]
Abstract
Peptidomic techniques are powerful tools to identify peptides in a biological sample. In the case of brain, which contains a complex mixture of cell types, standard peptidomics procedures reveal the major peptides in a dissected brain region. It is difficult to obtain information on peptides within a specific cell type using standard approaches, unless that cell type can be isolated. This protocol describes a targeted peptidomic approach that uses affinity chromatography to purify peptides that are substrates of carboxypeptidase E (CPE), an enzyme present in the secretory pathway of neuroendocrine cells. Many CPE products function as neuropeptides and/or peptide hormones, and therefore represent an important subset of the peptidome. Because CPE removes C-terminal Lys and Arg residues from peptide processing intermediates, organisms lacking CPE show a large decrease in the levels of the mature forms of most neuropeptides and peptide hormones, and a very large increase in the levels of the processing intermediates that contain C-terminal Lys and/or Arg (i.e., the CPE substrates). These CPE substrates can be purified on an anhydrotrypsin-agarose affinity resin, which specifically binds peptides with C-terminal basic residues. When this method is used with mice lacking CPE activity in genetically defined cell types, it allows the detection of peptides specifically produced in that cell type.
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Affiliation(s)
- Lloyd D Fricker
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA.
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3
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Beets I, Zels S, Vandewyer E, Demeulemeester J, Caers J, Baytemur E, Courtney A, Golinelli L, Hasakioğulları İ, Schafer WR, Vértes PE, Mirabeau O, Schoofs L. System-wide mapping of peptide-GPCR interactions in C. elegans. Cell Rep 2023; 42:113058. [PMID: 37656621 PMCID: PMC7615250 DOI: 10.1016/j.celrep.2023.113058] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 07/19/2023] [Accepted: 08/16/2023] [Indexed: 09/03/2023] Open
Abstract
Neuropeptides and peptide hormones are ancient, widespread signaling molecules that underpin almost all brain functions. They constitute a broad ligand-receptor network, mainly by binding to G protein-coupled receptors (GPCRs). However, the organization of the peptidergic network and roles of many peptides remain elusive, as our insight into peptide-receptor interactions is limited and many peptide GPCRs are still orphan receptors. Here we report a genome-wide peptide-GPCR interaction map in Caenorhabditis elegans. By reverse pharmacology screening of over 55,384 possible interactions, we identify 461 cognate peptide-GPCR couples that uncover a broad signaling network with specific and complex combinatorial interactions encoded across and within single peptidergic genes. These interactions provide insights into peptide functions and evolution. Combining our dataset with phylogenetic analysis supports peptide-receptor co-evolution and conservation of at least 14 bilaterian peptidergic systems in C. elegans. This resource lays a foundation for system-wide analysis of the peptidergic network.
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Affiliation(s)
- Isabel Beets
- Department of Biology, KU Leuven, 3000 Leuven, Belgium.
| | - Sven Zels
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | | | - Jonas Demeulemeester
- The Francis Crick Institute, London NW1 1AT, UK; VIB - KU Leuven Center for Cancer Biology, 3000 Leuven, Belgium; Department of Oncology, KU Leuven, 3000 Leuven, Belgium
| | - Jelle Caers
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Esra Baytemur
- Department of Biology, KU Leuven, 3000 Leuven, Belgium
| | - Amy Courtney
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | | | | | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
| | - Petra E Vértes
- Department of Psychiatry, Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge CB2 3EB, UK
| | - Olivier Mirabeau
- Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, Inserm U1224, Brain-Immune Communication Lab, 75015 Paris, France
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4
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Cockx B, Van Bael S, Boelen R, Vandewyer E, Yang H, Le TA, Dalzell JJ, Beets I, Ludwig C, Lee J, Temmerman L. Mass Spectrometry-Driven Discovery of Neuropeptides Mediating Nictation Behavior of Nematodes. Mol Cell Proteomics 2023; 22:100479. [PMID: 36481452 PMCID: PMC9881375 DOI: 10.1016/j.mcpro.2022.100479] [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: 08/08/2022] [Revised: 10/27/2022] [Accepted: 11/20/2022] [Indexed: 12/12/2022] Open
Abstract
Neuropeptides regulate animal physiology and behavior, making them widely studied targets of functional genetics research. While the field often relies on differential -omics approaches to build hypotheses, no such method exists for neuropeptidomics. It would nonetheless be valuable for studying behaviors suspected to be regulated by neuropeptides, especially when little information is otherwise available. This includes nictation, a phoretic strategy of Caenorhabditis elegans dauers that parallels host-finding strategies of infective juveniles of many pathogenic nematodes. We here developed a targeted peptidomics method for the model organism C. elegans and show that 161 quantified neuropeptides are more abundant in its dauer stage compared with L3 juveniles. Many of these have orthologs in the commercially relevant pathogenic nematode Steinernema carpocapsae, in whose infective juveniles, we identified 126 neuropeptides in total. Through further behavioral genetics experiments, we identify flp-7 and flp-11 as novel regulators of nictation. Our work advances knowledge on the genetics of nictation behavior and adds comparative neuropeptidomics as a tool to functional genetics workflows.
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Affiliation(s)
- Bram Cockx
- Animal Physiology & Neurobiology, Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Sven Van Bael
- Animal Physiology & Neurobiology, Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Rose Boelen
- Animal Physiology & Neurobiology, Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Elke Vandewyer
- Animal Physiology & Neurobiology, Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Heeseung Yang
- Department of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Tuan Anh Le
- Animal Physiology & Neurobiology, Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Johnathan J Dalzell
- School of Biological Sciences, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Isabel Beets
- Animal Physiology & Neurobiology, Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Christina Ludwig
- Bavarian Center for Biomolecular Mass Spectrometry (BayBioMS), Technical University of Munich (TUM), Freising, Germany
| | - Junho Lee
- Department of Biological Sciences, Seoul National University, Seoul, South Korea
| | - Liesbet Temmerman
- Animal Physiology & Neurobiology, Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium.
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5
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Savini M, Folick A, Lee YT, Jin F, Cuevas A, Tillman MC, Duffy JD, Zhao Q, Neve IA, Hu PW, Yu Y, Zhang Q, Ye Y, Mair WB, Wang J, Han L, Ortlund EA, Wang MC. Lysosome lipid signalling from the periphery to neurons regulates longevity. Nat Cell Biol 2022; 24:906-916. [PMID: 35681008 PMCID: PMC9203275 DOI: 10.1038/s41556-022-00926-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 04/25/2022] [Indexed: 12/13/2022]
Abstract
Lysosomes are key cellular organelles that metabolize extra- and intracellular substrates. Alterations in lysosomal metabolism are implicated in ageing-associated metabolic and neurodegenerative diseases. However, how lysosomal metabolism actively coordinates the metabolic and nervous systems to regulate ageing remains unclear. Here we report a fat-to-neuron lipid signalling pathway induced by lysosomal metabolism and its longevity-promoting role in Caenorhabditis elegans. We discovered that induced lysosomal lipolysis in peripheral fat storage tissue upregulates the neuropeptide signalling pathway in the nervous system to promote longevity. This cell-non-autonomous regulation is mediated by a specific polyunsaturated fatty acid, dihomo-γ-linolenic acid, and LBP-3 lipid chaperone protein transported from the fat storage tissue to neurons. LBP-3 binds to dihomo-γ-linolenic acid, and acts through NHR-49 nuclear receptor and NLP-11 neuropeptide in neurons to extend lifespan. These results reveal lysosomes as a signalling hub to coordinate metabolism and ageing, and lysosomal signalling mediated inter-tissue communication in promoting longevity.
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Affiliation(s)
- Marzia Savini
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA.,Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
| | - Andrew Folick
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA.,Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA.,Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Yi-Tang Lee
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Integrative Program of Molecular and Biochemical Sciences, Baylor College of Medicine, Houston, TX, USA
| | - Feng Jin
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA.,Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, USA
| | - André Cuevas
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
| | - Matthew C Tillman
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
| | - Jonathon D Duffy
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA.,Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA
| | - Qian Zhao
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Isaiah A Neve
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Pei-Wen Hu
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Yong Yu
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Xiamen, China
| | - Qinghao Zhang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Youqiong Ye
- Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - William B Mair
- Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Jin Wang
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, USA
| | - Leng Han
- Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX, USA.,Center of Epigenetics and Disease Prevention, Institute of Bioscience and Technology, Texas A&M University, Houston, TX, USA
| | - Eric A Ortlund
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
| | - Meng C Wang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA. .,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA. .,Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA.
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6
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The interplay of helminthic neuropeptides and proteases in parasite survival and host immunomodulation. Biochem Soc Trans 2022; 50:107-118. [PMID: 35076687 PMCID: PMC9042389 DOI: 10.1042/bst20210405] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 11/17/2022]
Abstract
Neuropeptides comprise a diverse and broad group of neurotransmitters in vertebrates and invertebrates, with critical roles in neuronal signal transduction. While their role in controlling learning and memory in the brains of mammals is known, their extra-synaptic function in infection and inflammation with effects on distinct tissues and immune cells is increasingly recognized. Helminth infections especially of the central nervous system (CNS), such as neurocysticercosis, induce neuropeptide production by both host and helminth, but their role in host–parasite interplay or host inflammatory response is unclear. Here, we review the neurobiology of helminths, and discuss recent studies on neuropeptide synthesis and function in the helminth as well as the host CNS and immune system. Neuropeptides are summarized according to structure and function, and we discuss the complex enzyme processing for mature neuropeptides, focusing on helminth enzymes as potential targets for novel anthelminthics. We next describe known immunomodulatory effects of mammalian neuropeptides discovered from mouse infection models and draw functional parallels with helminth neuropeptides. Last, we discuss the anti-microbial properties of neuropeptides, and how they may be involved in host–microbiota changes in helminth infection. Overall, a better understanding of the biology of helminth neuropeptides, and whether they affect infection outcomes could provide diagnostic and therapeutic opportunities for helminth infections.
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7
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Bhat US, Shahi N, Surendran S, Babu K. Neuropeptides and Behaviors: How Small Peptides Regulate Nervous System Function and Behavioral Outputs. Front Mol Neurosci 2021; 14:786471. [PMID: 34924955 PMCID: PMC8674661 DOI: 10.3389/fnmol.2021.786471] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/11/2021] [Indexed: 11/13/2022] Open
Abstract
One of the reasons that most multicellular animals survive and thrive is because of the adaptable and plastic nature of their nervous systems. For an organism to survive, it is essential for the animal to respond and adapt to environmental changes. This is achieved by sensing external cues and translating them into behaviors through changes in synaptic activity. The nervous system plays a crucial role in constantly evaluating environmental cues and allowing for behavioral plasticity in the organism. Multiple neurotransmitters and neuropeptides have been implicated as key players for integrating sensory information to produce the desired output. Because of its simple nervous system and well-established neuronal connectome, C. elegans acts as an excellent model to understand the mechanisms underlying behavioral plasticity. Here, we critically review how neuropeptides modulate a wide range of behaviors by allowing for changes in neuronal and synaptic signaling. This review will have a specific focus on feeding, mating, sleep, addiction, learning and locomotory behaviors in C. elegans. With a view to understand evolutionary relationships, we explore the functions and associated pathophysiology of C. elegans neuropeptides that are conserved across different phyla. Further, we discuss the mechanisms of neuropeptidergic signaling and how these signals are regulated in different behaviors. Finally, we attempt to provide insight into developing potential therapeutics for neuropeptide-related disorders.
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Affiliation(s)
- Umer Saleem Bhat
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | - Navneet Shahi
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| | - Siju Surendran
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| | - Kavita Babu
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
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8
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Behavioral and molecular response of the insect parasitic nematode Steinernema carpocapsae to cues emitted by a host, the red palm weevil, Rhynchophorus ferrugineus. Mol Biochem Parasitol 2020; 241:111345. [PMID: 33290763 DOI: 10.1016/j.molbiopara.2020.111345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 11/14/2020] [Accepted: 11/30/2020] [Indexed: 11/20/2022]
Abstract
As the larvae of the date palm pest, the red palm weevil, Rhynchophorus ferrugineus, feeds on the host tissue, they emit a distinctive sound which can be recorded outside of the infected tree. We evaluated the response of infective juveniles (IJs) of the entomopathogenic nematodes Steinernema carpocapsae to the R. ferrugineus larvae and it's sound source, separately. In the presence of the insect larvae, 50.2 % of total IJs moved toward those larvae. Recorded insect larvae sound emitted by the speaker resulted in 7% of total IJs near the sound source. RNA-Seq data indicated that more genes were downregulated in S. carpocapsae IJs exposed to insect and speaker compared to non-stimulated IJs. IJs exposed to insect exhibited more up-regulated genes than IJs exposed to speaker. Enriched pathways and biological processes in IJs were similar for both stimuli. The inhibition of locomotion, regulation of neurotransmitter secretion, response to biotic stimulus, and cellular response to chemical stimuli were enriched with unique GO terms for speaker treatment. The regulation of localization, sodium ion transmembrane transport, regulation of response to stress and response to organic substances were the GO categories enriched unique to insect. The host-parasitic interaction was regulated by the differential expression of Ras/MAP kinase, TGF-beta signaling, insulin signaling, AMPK signaling, PPAR signaling pathways and many developmental pathways. More prominent R. ferrugineus host localization by S. carpocapsae was primarily due to the differential transcriptional regulation of olfactory signal transduction, FOXO-family proteins, calcium signaling, WNT and mTOR signaling pathway. The neural basis for the nematode attraction to insect host is based on the chemosensation and the mechanosensation. Many neuropeptides and neuromodulators are involved in regulating the foraging behavior of S. carpocapsae. The results of this study provide new insights into the molecular mechanisms that allow these nematodes to seek insect hosts. Our finding, especially the molecular ones suggest that chemical cues emitted by the active insect host are stimulants of nematodes attraction. Whereas the sound emitted by the insect has minor effects on the nematode behavior.
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9
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McCulloch KA, Zhou K, Jin Y. Neuronal transcriptome analyses reveal novel neuropeptide modulators of excitation and inhibition imbalance in C. elegans. PLoS One 2020; 15:e0233991. [PMID: 32497060 PMCID: PMC7272019 DOI: 10.1371/journal.pone.0233991] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 05/16/2020] [Indexed: 01/06/2023] Open
Abstract
Neuropeptides are secreted molecules that have conserved roles modulating many processes, including mood, reproduction, and feeding. Dysregulation of neuropeptide signaling is also implicated in neurological disorders such as epilepsy. However, much is unknown about the mechanisms regulating specific neuropeptides to mediate behavior. Here, we report that the expression levels of dozens of neuropeptides are up-regulated in response to circuit activity imbalance in C. elegans. acr-2 encodes a homolog of human nicotinic receptors, and functions in the cholinergic motoneurons. A hyperactive mutation, acr-2(gf), causes an activity imbalance in the motor circuit. We performed cell-type specific transcriptomic analysis and identified genes differentially expressed in acr-2(gf), compared to wild type. The most over-represented class of genes are neuropeptides, with insulin-like-peptides (ILPs) the most affected. Moreover, up-regulation of neuropeptides occurs in motoneurons, as well as sensory neurons. In particular, the induced expression of the ILP ins-29 occurs in the BAG neurons, which were previously shown to function in gas-sensing. We also show that this up-regulation of ins-29 in acr-2(gf) animals is activity-dependent. Our genetic and molecular analyses support cooperative effects for ILPs and other neuropeptides in promoting motor circuit activity in the acr-2(gf) background. Together, this data reveals that a major transcriptional response to motor circuit dysregulation is in up-regulation of multiple neuropeptides, and suggests that BAG sensory neurons can respond to intrinsic activity states to feedback on the motor circuit.
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Affiliation(s)
- Katherine A. McCulloch
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, California, United States of America
| | - Kingston Zhou
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, California, United States of America
| | - Yishi Jin
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, California, United States of America
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10
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Mutlu AS, Gao SM, Zhang H, Wang MC. Olfactory specificity regulates lipid metabolism through neuroendocrine signaling in Caenorhabditis elegans. Nat Commun 2020; 11:1450. [PMID: 32193370 PMCID: PMC7081233 DOI: 10.1038/s41467-020-15296-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 02/20/2020] [Indexed: 01/01/2023] Open
Abstract
Olfactory and metabolic dysfunctions are intertwined phenomena associated with obesity and neurodegenerative diseases; yet how mechanistically olfaction regulates metabolic homeostasis remains unclear. Specificity of olfactory perception integrates diverse environmental odors and olfactory neurons expressing different receptors. Here, we report that specific but not all olfactory neurons actively regulate fat metabolism without affecting eating behaviors in Caenorhabditis elegans, and identified specific odors that reduce fat mobilization via inhibiting these neurons. Optogenetic activation or inhibition of the responsible olfactory neural circuit promotes the loss or gain of fat storage, respectively. Furthermore, we discovered that FLP-1 neuropeptide released from this olfactory neural circuit signals through peripheral NPR-4/neuropeptide receptor, SGK-1/serum- and glucocorticoid-inducible kinase, and specific isoforms of DAF-16/FOXO transcription factor to regulate fat storage. Our work reveals molecular mechanisms underlying olfactory regulation of fat metabolism, and suggests the association between olfactory perception specificity of each individual and his/her susceptibility to the development of obesity.
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Affiliation(s)
- Ayse Sena Mutlu
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA.
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
| | - Shihong Max Gao
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Haining Zhang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Meng C Wang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, 77030, USA.
- Graduate Program in Developmental Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, 77030, USA.
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11
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Packer JS, Zhu Q, Huynh C, Sivaramakrishnan P, Preston E, Dueck H, Stefanik D, Tan K, Trapnell C, Kim J, Waterston RH, Murray JI. A lineage-resolved molecular atlas of C. elegans embryogenesis at single-cell resolution. Science 2019; 365:eaax1971. [PMID: 31488706 PMCID: PMC7428862 DOI: 10.1126/science.aax1971] [Citation(s) in RCA: 242] [Impact Index Per Article: 48.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 08/21/2019] [Indexed: 12/18/2022]
Abstract
Caenorhabditis elegans is an animal with few cells but a wide diversity of cell types. In this study, we characterize the molecular basis for their specification by profiling the transcriptomes of 86,024 single embryonic cells. We identify 502 terminal and preterminal cell types, mapping most single-cell transcriptomes to their exact position in C. elegans' invariant lineage. Using these annotations, we find that (i) the correlation between a cell's lineage and its transcriptome increases from middle to late gastrulation, then falls substantially as cells in the nervous system and pharynx adopt their terminal fates; (ii) multilineage priming contributes to the differentiation of sister cells at dozens of lineage branches; and (iii) most distinct lineages that produce the same anatomical cell type converge to a homogenous transcriptomic state.
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Affiliation(s)
- Jonathan S Packer
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Qin Zhu
- Genomics and Computational Biology Graduate Group, University of Pennsylvania, Philadelphia, PA, USA
| | - Chau Huynh
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Priya Sivaramakrishnan
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Elicia Preston
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Hannah Dueck
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Derek Stefanik
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Kai Tan
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Division of Oncology and Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Cole Trapnell
- Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Junhyong Kim
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.
| | - Robert H Waterston
- Department of Genome Sciences, University of Washington, Seattle, WA, USA.
| | - John I Murray
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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12
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Pauls D, Hamarat Y, Trufasu L, Schendzielorz TM, Gramlich G, Kahnt J, Vanselow JT, Schlosser A, Wegener C. Drosophila carboxypeptidase D (SILVER) is a key enzyme in neuropeptide processing required to maintain locomotor activity levels and survival rate. Eur J Neurosci 2019; 50:3502-3519. [PMID: 31309630 DOI: 10.1111/ejn.14516] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/19/2019] [Accepted: 07/05/2019] [Indexed: 11/27/2022]
Abstract
Neuropeptides are processed from larger preproproteins by a dedicated set of enzymes. The molecular and biochemical mechanisms underlying preproprotein processing and the functional importance of processing enzymes are well-characterised in mammals, but little studied outside this group. In contrast to mammals, Drosophila melanogaster lacks a gene for carboxypeptidase E (CPE), a key enzyme for mammalian peptide processing. By combining peptidomics and neurogenetics, we addressed the role of carboxypeptidase D (dCPD) in global neuropeptide processing and selected peptide-regulated behaviours in Drosophila. We found that a deficiency in dCPD results in C-terminally extended peptides across the peptidome, suggesting that dCPD took over CPE function in the fruit fly. dCPD is widely expressed throughout the nervous system, including peptidergic neurons in the mushroom body and neuroendocrine cells expressing adipokinetic hormone. Conditional hypomorphic mutation in the dCPD-encoding gene silver in the larva causes lethality, and leads to deficits in starvation-induced hyperactivity and appetitive gustatory preference, as well as to reduced viability and activity levels in adults. A phylogenomic analysis suggests that loss of CPE is not common to insects, but only occurred in Hymenoptera and Diptera. Our results show that dCPD is a key enzyme for neuropeptide processing and peptide-regulated behaviour in Drosophila. dCPD thus appears as a suitable target to genetically shut down total neuropeptide production in peptidergic neurons. The persistent occurrence of CPD in insect genomes may point to important further CPD functions beyond neuropeptide processing which cannot be fulfilled by CPE.
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Affiliation(s)
- Dennis Pauls
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Yasin Hamarat
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany.,'Santaka' Valley I Health Telematics Science Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Luisa Trufasu
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Tim M Schendzielorz
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Gertrud Gramlich
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jörg Kahnt
- Max-Planck-Institute of Terrestrial Microbiology, Marburg, Germany
| | - Jens T Vanselow
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Andreas Schlosser
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
| | - Christian Wegener
- Neurobiology and Genetics, Theodor-Boveri-Institute, Biocenter, University of Würzburg, Würzburg, Germany
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13
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Nagashima T, Iino Y, Tomioka M. DAF-16/FOXO promotes taste avoidance learning independently of axonal insulin-like signaling. PLoS Genet 2019; 15:e1008297. [PMID: 31323047 PMCID: PMC6668909 DOI: 10.1371/journal.pgen.1008297] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 07/31/2019] [Accepted: 07/08/2019] [Indexed: 12/12/2022] Open
Abstract
The avoidance of starvation is critical for the survival of most organisms, thus animals change behavior based on past nutritional conditions. Insulin signaling is important for nutritional state-dependent behavioral plasticity, yet the underlying regulatory mechanism at the cellular level remains unclear. Previous studies showed that insulin-like signaling is required for taste avoidance learning, in which the nematode Caenorhabditis elegans avoids salt concentrations encountered under starvation conditions. DAF-2c, a splice isoform of the DAF-2 insulin receptor, functions in the axon of the ASER sensory neuron, which senses changes in salt concentrations. In addition, mutants of a major downstream factor of DAF-2, the forkhead transcription factor O (FOXO) homolog DAF-16, show defects in taste avoidance learning. Interestingly, the defect of the daf-2 mutant is not suppressed by daf-16 mutations in the learning, unlike those in other phenomena, such as longevity and development. Here we show that multiple DAF-16 isoforms function in ASER. By epistasis analysis using a DAF-2c isoform-specific mutant and an activated form of DAF-16, we found that DAF-16 acts in the nucleus in parallel with the DAF-2c-dependent pathway in the axon, indicating that insulin-like signaling acts both in the cell body and axon of a single neuron, ASER. Starvation conditioning induces nuclear translocation of DAF-16 in ASER and degradation of DAF-16 before starvation conditioning causes defects in taste avoidance learning. Forced nuclear localization of DAF-16 in ASER biased chemotaxis towards lower salt concentrtions and this effect required the Gq/PKC pathway and neuropeptide processing enzymes. These data imply that DAF-16/FOXO transmits starvation signals and modulates neuropeptide transmission in the learning. Animals change behavior based on remembered experiences of hunger and appetite. Signaling by insulin and insulin-like peptides in the nervous system plays key roles in behavioral responses to hunger and satiety. In C. elegans, insulin-like signaling in the gustatory sensory neuron ASER regulates learned avoidance of salt concentrations experienced during fasting, which we call taste avoidance learning. DAF-2c, an isoform of the insulin receptor homolog, is localized to the axon of ASER and regulates taste avoidance learning. Here, we show that DAF-16, the forkhead transcription factor O (FOXO) homolog, translocates into the nucleus of ASER during fasting and promotes taste avoidance learning. DAF-16 is negatively regulated by insulin-like signaling independently of axonal DAF-2c signaling. This dual function of insulin-like signaling in the cell body and the axon ensures dynamic changes in behavioral responses after experience of hunger. By genetic analyses using constitutively nuclear-translocated DAF-16, we show that DAF-16 in ASER regulates taste avoidance learning via modulating neuropeptide signaling in the nervous system, which is reminiscent of the function of FOXO in the hypothalamus in the regulation of food-seeking behavior in mammals.
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Affiliation(s)
- Takashi Nagashima
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Yuichi Iino
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Masahiro Tomioka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- * E-mail:
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14
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Fadda M, Hasakiogullari I, Temmerman L, Beets I, Zels S, Schoofs L. Regulation of Feeding and Metabolism by Neuropeptide F and Short Neuropeptide F in Invertebrates. Front Endocrinol (Lausanne) 2019; 10:64. [PMID: 30837946 PMCID: PMC6389622 DOI: 10.3389/fendo.2019.00064] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/23/2019] [Indexed: 12/19/2022] Open
Abstract
Numerous neuropeptide systems have been implicated to coordinately control energy homeostasis, both centrally and peripherally. However, the vertebrate neuropeptide Y (NPY) system has emerged as the best described one regarding this biological process. The protostomian ortholog of NPY is neuropeptide F, characterized by an RXRF(Y)amide carboxyterminal motif. A second neuropeptide system is short NPF, characterized by an M/T/L/FRF(W)amide carboxyterminal motif. Although both short and long NPF neuropeptide systems display carboxyterminal sequence similarities, they are evolutionary distant and likely already arose as separate signaling systems in the common ancestor of deuterostomes and protostomes, indicating the functional importance of both. Both NPF and short-NPF systems seem to have roles in the coordination of feeding across bilaterian species, but during chordate evolution, the short NPF system appears to have been lost or evolved into the prolactin releasing peptide signaling system, which regulates feeding and has been suggested to be orthologous to sNPF. Here we review the roles of both NPF and sNPF systems in the regulation of feeding and metabolism in invertebrates.
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Affiliation(s)
| | | | | | | | | | - Liliane Schoofs
- Department of Biology, Functional Genomics and Proteomics, KU Leuven, Leuven, Belgium
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15
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Nkambeu B, Salem JB, Leonelli S, Marashi FA, Beaudry F. EGL-3 and EGL-21 are required to trigger nocifensive response of Caenorhabditis elegans to noxious heat. Neuropeptides 2019; 73:41-48. [PMID: 30454862 DOI: 10.1016/j.npep.2018.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/09/2018] [Accepted: 11/12/2018] [Indexed: 02/06/2023]
Abstract
Caenorhabditis elegans (C. elegans) is a widely used model organism to examine nocifensive response to noxious stimuli, including heat avoidance. Recently, comprehensive analysis of the genome sequence revealed several pro-neuropeptide genes, encoding a series of bioactive neuropeptides. C. elegans neuropeptides are involved in the modulation of essentially all behaviors including locomotion, mechanosensation, thermosensation and chemosensation. The maturation of pro-neuropeptide to neuropeptide is performed by ortholog pro-protein convertases and carboxypeptidase E (e.g. EGL-3 and EGL-21). We hypothesized that C. elegans egl-3 or egl-21 mutants will have a significant decrease in mature neuropeptides and they will display an impaired heat avoidance behavior. Our data has shown that thermal avoidance behavior of egl-3 and egl-21 mutants was significantly hampered compared to WT(N2) C. elegans. Moreover, flp-18, flp-21 and npr-1 mutant C. elegans displayed a similar phenotype. EGL-3 pro-protein convertase and EGL-21 carboxypeptidase E are essential enzymes for the maturation of pro-neuropeptides to active neuropeptides in C. elegans. Quantitative mass spectrometry analyses with egl-3 and egl-21 mutant C. elegans homogenates demonstrated that proteolysis of ProFLP-18 and ProFLP-21 are severely impeded, leading to a lack of mature bioactive neuropeptides. Not only FLP-21 but also FLP-18 related mature neuropeptides, both are ligands of NPR-1 and are needed to trigger nocifensive response of C. elegans to noxious heat.
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Affiliation(s)
- Bruno Nkambeu
- Département de Biomédecine Vétérinaire, Groupe de Recherche en Pharmacologie Animal du Québec (GREPAQ), Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Montréal, QC J2S 2M2, Canada
| | - Jennifer Ben Salem
- Département de Biomédecine Vétérinaire, Groupe de Recherche en Pharmacologie Animal du Québec (GREPAQ), Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Montréal, QC J2S 2M2, Canada
| | - Sophie Leonelli
- Département de Biomédecine Vétérinaire, Groupe de Recherche en Pharmacologie Animal du Québec (GREPAQ), Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Montréal, QC J2S 2M2, Canada
| | - Fatemeh Amin Marashi
- Département de Biomédecine Vétérinaire, Groupe de Recherche en Pharmacologie Animal du Québec (GREPAQ), Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Montréal, QC J2S 2M2, Canada
| | - Francis Beaudry
- Département de Biomédecine Vétérinaire, Groupe de Recherche en Pharmacologie Animal du Québec (GREPAQ), Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Montréal, QC J2S 2M2, Canada.
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16
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Edwards SL, Mergan L, Parmar B, Cockx B, De Haes W, Temmerman L, Schoofs L. Exploring neuropeptide signalling through proteomics and peptidomics. Expert Rev Proteomics 2018; 16:131-137. [DOI: 10.1080/14789450.2019.1559733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
| | - Lucas Mergan
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
| | - Bhavesh Parmar
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
| | - Bram Cockx
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
| | - Wouter De Haes
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
| | - Liesbet Temmerman
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
| | - Liliane Schoofs
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven, Leuven, Belgium
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17
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Chew YL, Tanizawa Y, Cho Y, Zhao B, Yu AJ, Ardiel EL, Rabinowitch I, Bai J, Rankin CH, Lu H, Beets I, Schafer WR. An Afferent Neuropeptide System Transmits Mechanosensory Signals Triggering Sensitization and Arousal in C. elegans. Neuron 2018; 99:1233-1246.e6. [PMID: 30146306 PMCID: PMC6162336 DOI: 10.1016/j.neuron.2018.08.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/22/2018] [Accepted: 08/02/2018] [Indexed: 11/05/2022]
Abstract
Sensitization is a simple form of behavioral plasticity by which an initial stimulus, often signaling danger, leads to increased responsiveness to subsequent stimuli. Cross-modal sensitization is an important feature of arousal in many organisms, yet its molecular and neural mechanisms are incompletely understood. Here we show that in C. elegans, aversive mechanical stimuli lead to both enhanced locomotor activity and sensitization of aversive chemosensory pathways. Both locomotor arousal and cross-modal sensitization depend on the release of FLP-20 neuropeptides from primary mechanosensory neurons and on their receptor FRPR-3. Surprisingly, the critical site of action of FRPR-3 for both sensory and locomotor arousal is RID, a single neuroendocrine cell specialized for the release of neuropeptides that responds to mechanical stimuli in a FLP-20-dependent manner. Thus, FLP-20 peptides function as an afferent arousal signal that conveys mechanosensory information to central neurons that modulate arousal and other behavioral states.
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Affiliation(s)
- Yee Lian Chew
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK
| | - Yoshinori Tanizawa
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK
| | - Yongmin Cho
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA
| | - Buyun Zhao
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK
| | - Alex J Yu
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T, Canada
| | - Evan L Ardiel
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T, Canada
| | - Ithai Rabinowitch
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Department of Medical Neurobiology, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Jihong Bai
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Catharine H Rankin
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC V6T, Canada; Department of Psychology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Hang Lu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA
| | - Isabel Beets
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK; Department of Biology, Division of Animal Physiology and Neurobiology, KU Leuven, B-3000, Leuven, Belgium
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, Cambridgeshire, CB2 0QH, UK.
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18
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Salem JB, Nkambeu B, Arvanitis DN, Beaudry F. Deciphering the Role of EGL-3 for Neuropeptides Processing in Caenorhabditis elegans Using High-Resolution Quadrupole–Orbitrap Mass Spectrometry. Neurochem Res 2018; 43:2121-2131. [DOI: 10.1007/s11064-018-2636-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 09/07/2018] [Accepted: 09/10/2018] [Indexed: 01/13/2023]
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19
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Genetic dissection of neuropeptide cell biology at high and low activity in a defined sensory neuron. Proc Natl Acad Sci U S A 2018; 115:E6890-E6899. [PMID: 29959203 PMCID: PMC6055185 DOI: 10.1073/pnas.1714610115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neuropeptides are ubiquitous modulators of behavior and physiology. They are packaged in specialized secretory organelles called dense core vesicles (DCVs) that are released upon neural stimulation. Whereas local recycling of synaptic vesicles has been investigated intensively, there are few studies on recycling of DCV proteins. We set up a paradigm to study DCVs in a neuron whose activity we can control. We validate our model by confirming many previous observations on DCV cell biology. We identify a set of genes involved in recycling of DCV proteins. We also find evidence that different mechanisms of DCV priming and exocytosis may operate at high and low neural activity. Neuropeptides are ubiquitous modulators of behavior and physiology. They are packaged in specialized secretory organelles called dense core vesicles (DCVs) that are released upon neural stimulation. Unlike synaptic vesicles, which can be recycled and refilled close to release sites, DCVs must be replenished by de novo synthesis in the cell body. Here, we dissect DCV cell biology in vivo in a Caenorhabditis elegans sensory neuron whose tonic activity we can control using a natural stimulus. We express fluorescently tagged neuropeptides in the neuron and define parameters that describe their subcellular distribution. We measure these parameters at high and low neural activity in 187 mutants defective in proteins implicated in membrane traffic, neuroendocrine secretion, and neuronal or synaptic activity. Using unsupervised hierarchical clustering methods, we analyze these data and identify 62 groups of genes with similar mutant phenotypes. We explore the function of a subset of these groups. We recapitulate many previous findings, validating our paradigm. We uncover a large battery of proteins involved in recycling DCV membrane proteins, something hitherto poorly explored. We show that the unfolded protein response promotes DCV production, which may contribute to intertissue communication of stress. We also find evidence that different mechanisms of priming and exocytosis may operate at high and low neural activity. Our work provides a defined framework to study DCV biology at different neural activity levels.
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20
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Yuan S, Sharma AK, Richart A, Lee J, Kim BE. CHCA-1 is a copper-regulated CTR1 homolog required for normal development, copper accumulation, and copper-sensing behavior in Caenorhabditis elegans. J Biol Chem 2018; 293:10911-10925. [PMID: 29784876 DOI: 10.1074/jbc.ra118.003503] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Indexed: 01/11/2023] Open
Abstract
Copper plays key roles in catalytic and regulatory biochemical reactions essential for normal growth, development, and health. Dietary copper deficiencies or mutations in copper homeostasis genes can lead to abnormal musculoskeletal development, cognitive disorders, and poor growth. In yeast and mammals, copper is acquired through the activities of the CTR1 family of high-affinity copper transporters. However, the mechanisms of systemic responses to dietary or tissue-specific copper deficiency remain unclear. Here, taking advantage of the animal model Caenorhabditis elegans for studying whole-body copper homeostasis, we investigated the role of a C. elegans CTR1 homolog, CHCA-1, in copper acquisition and in worm growth, development, and behavior. Using sequence homology searches, we identified 10 potential orthologs to mammalian CTR1 Among these genes, we found that chca-1, which is transcriptionally up-regulated in the intestine and hypodermis of C. elegans during copper deficiency, is required for normal growth, reproduction, and maintenance of systemic copper balance under copper deprivation. The intestinal copper transporter CUA-1 normally traffics to endosomes to sequester excess copper, and we found here that loss of chca-1 caused CUA-1 to mislocalize to the basolateral membrane under copper overload conditions. Moreover, animals lacking chca-1 exhibited significantly reduced copper avoidance behavior in response to toxic copper conditions compared with WT worms. These results establish that CHCA-1-mediated copper acquisition in C. elegans is crucial for normal growth, development, and copper-sensing behavior.
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Affiliation(s)
- Sai Yuan
- From the Department of Animal and Avian Sciences and
| | | | | | - Jaekwon Lee
- the Redox Biology Center, Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68588
| | - Byung-Eun Kim
- From the Department of Animal and Avian Sciences and .,Biological Sciences Graduate Program, University of Maryland, College Park, Maryland 20742 and
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21
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Van Bael S, Watteyne J, Boonen K, De Haes W, Menschaert G, Ringstad N, Horvitz HR, Schoofs L, Husson SJ, Temmerman L. Mass spectrometric evidence for neuropeptide-amidating enzymes in Caenorhabditis elegans. J Biol Chem 2018; 293:6052-6063. [PMID: 29487130 DOI: 10.1074/jbc.ra117.000731] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 02/18/2018] [Indexed: 12/18/2022] Open
Abstract
Neuropeptides constitute a vast and functionally diverse family of neurochemical signaling molecules and are widely involved in the regulation of various physiological processes. The nematode Caenorhabditis elegans is well-suited for the study of neuropeptide biochemistry and function, as neuropeptide biosynthesis enzymes are not essential for C. elegans viability. This permits the study of neuropeptide biosynthesis in mutants lacking certain neuropeptide-processing enzymes. Mass spectrometry has been used to study the effects of proprotein convertase and carboxypeptidase mutations on proteolytic processing of neuropeptide precursors and on the peptidome in C. elegans However, the enzymes required for the last step in the production of many bioactive peptides, the carboxyl-terminal amidation reaction, have not been characterized in this manner. Here, we describe three genes that encode homologs of neuropeptide amidation enzymes in C. elegans and used tandem LC-MS to compare neuropeptides in WT animals with those in newly generated mutants for these putative amidation enzymes. We report that mutants lacking both a functional peptidylglycine α-hydroxylating monooxygenase and a peptidylglycine α-amidating monooxygenase had a severely altered neuropeptide profile and also a decreased number of offspring. Interestingly, single mutants of the amidation enzymes still expressed some fully processed amidated neuropeptides, indicating the existence of a redundant amidation mechanism in C. elegans All MS data are available via ProteomeXchange with the identifier PXD008942. In summary, the key steps in neuropeptide processing in C. elegans seem to be executed by redundant enzymes, and loss of these enzymes severely affects brood size, supporting the need of amidated peptides for C. elegans reproduction.
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Affiliation(s)
- Sven Van Bael
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium,
| | - Jan Watteyne
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium
| | - Kurt Boonen
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium
| | - Wouter De Haes
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium
| | - Gerben Menschaert
- the Laboratory of Bioinformatics and Computational Genomics (BioBix), Department of Mathematical Modelling, Ghent University, B-9000 Ghent, Belgium
| | - Niels Ringstad
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, Department of Cell Biology, NYU Langone Medical Center, New York, New York 10016
| | - H Robert Horvitz
- the Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and
| | - Liliane Schoofs
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium
| | - Steven J Husson
- SPHERE-Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
| | - Liesbet Temmerman
- From the Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59, B-3000 Leuven, Belgium,
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22
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Xu D, Gao Y, Guo L, Lin C, Sun Y. Effect of dys-1 mutation on gene expression profile in space-flown Caenorhabditis elegans. Muscle Nerve 2018; 58:114-122. [PMID: 29346705 DOI: 10.1002/mus.26076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2018] [Indexed: 11/09/2022]
Abstract
INTRODUCTION Dystrophin-like dys-1 gene expression increases in the body wall muscles of Caenorhabditis elegans after spaceflight (SF). Here we used a dys-1(cx18) mutant to analyze the molecular adaptive responses of C. elegans to SF. METHODS DNA microarrays were performed to identify differentially expressed genes between wild-type (WT) and dys-1 mutant worms after SF. We performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses, predicted human diseases, and screened out key genes for human muscle diseases with NextBio. RESULTS Gene expression was less affected by SF in the dys-1 mutant than in the WT worms. The dys-1 mutation influenced neuromuscular gene expression (neuropeptide genes, muscle-related genes, and dystrophin-related genes) under SF conditions, among which 15 genes were specifically regulated by dys-1. NextBio analysis predicted that cdka-1, lev-11, unc-27, and unc-94 genes might play critical roles in muscle atrophy. DISCUSSION dys-1 Potentially regulates the neuromuscular system in space. Muscle Nerve, 2018.
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Affiliation(s)
- Dan Xu
- Institute of Environmental Systems Biology, Dalian Maritime University, Linghai Road 1 Dalian, 116026, People's Republic of China
| | - Ying Gao
- Institute of Environmental Systems Biology, Dalian Maritime University, Linghai Road 1 Dalian, 116026, People's Republic of China
- Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, People's Republic of China
| | - Lin Guo
- Institute of Environmental Systems Biology, Dalian Maritime University, Linghai Road 1 Dalian, 116026, People's Republic of China
| | - Chenggang Lin
- Institute of Environmental Systems Biology, Dalian Maritime University, Linghai Road 1 Dalian, 116026, People's Republic of China
| | - Yeqing Sun
- Institute of Environmental Systems Biology, Dalian Maritime University, Linghai Road 1 Dalian, 116026, People's Republic of China
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23
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Fricker L. Affinity Purification of Neuropeptide Precursors from Mice Lacking Carboxypeptidase E Activity. Methods Mol Biol 2018; 1719:199-208. [PMID: 29476513 DOI: 10.1007/978-1-4939-7537-2_13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Peptidomic techniques are powerful tools to identify peptides in a biological sample. This protocol describes a targeted peptidomic approach that uses affinity chromatography to purify peptides that are substrates of carboxypeptidase E (CPE), an enzyme present in the secretory pathway of neuroendocrine cells. Many CPE products function as neuropeptides and/or peptide hormones, and therefore represent an important subset of the peptidome. Because CPE removes C-terminal Lys and Arg residues from peptide-processing intermediates, organisms lacking CPE show a large decrease in the levels of the mature forms of most neuropeptides and peptide hormones, and a very large increase in the levels of the processing intermediates that contain C-terminal Lys and/or Arg (i.e., the CPE substrates). These CPE substrates can be purified on an anhydrotrypsin-agarose affinity resin, which specifically binds peptides with C-terminal basic residues. Not all peptides with basic C-terminal residues within a cell are CPE substrates, and these other peptides will also be purified on the anhydrotrypsin affinity column. However, a comparison of peptides purified from wild-type mice and from mice lacking CPE allows for the rapid identification of CPE substrates based on their large increase in the absence of CPE.
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Affiliation(s)
- Lloyd Fricker
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA.
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24
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Van Bael S, Edwards SL, Husson SJ, Temmerman L. Identification of Endogenous Neuropeptides in the Nematode C. elegans Using Mass Spectrometry. Methods Mol Biol 2018; 1719:271-291. [PMID: 29476518 DOI: 10.1007/978-1-4939-7537-2_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The nematode Caenorhabditis elegans lends itself as an excellent model organism for peptidomics studies. Its ease of cultivation and quick generation time make it suitable for high-throughput studies. Adult hermaphrodites contain 959 somatic nuclei that are ordered in defined, differentiated tissues. The nervous system, with its 302 neurons, is probably the most known and studied endocrine tissue. Moreover, its neuropeptidergic signaling pathways display a large number of similarities with those observed in other metazoans. However, various other tissues have also been shown to express several neuropeptides. This includes the hypodermis, gonad, gut, and even muscle. Hence, whole mount peptidomics of C. elegans cultures provides an integral overview of peptidergic signaling between the different tissues of the entire organism. Here, we describe a peptidomics approach used for the identification of endogenous (neuro)peptides in C. elegans. Starting from a detailed peptide extraction procedure, we will outline the setup for an online liquid chromatography-mass spectrometry (LC-MS) analysis and describe subsequent data analysis approaches.
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Affiliation(s)
- Sven Van Bael
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59 box 2456, 3000, Leuven, Belgium
| | - Samantha L Edwards
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59 box 2456, 3000, Leuven, Belgium
| | - Steven J Husson
- Department of Biology, University of Antwerp, Groenenborgerlaan 171, G.U.758, 2020, Antwerp, Belgium
| | - Liesbet Temmerman
- Animal Physiology and Neurobiology, Department of Biology, KU Leuven (University of Leuven), Naamsestraat 59 box 2456, 3000, Leuven, Belgium.
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25
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Ardiel EL, Yu AJ, Giles AC, Rankin CH. Habituation as an adaptive shift in response strategy mediated by neuropeptides. NPJ SCIENCE OF LEARNING 2017; 2:9. [PMID: 30631455 PMCID: PMC6161508 DOI: 10.1038/s41539-017-0011-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 07/12/2017] [Accepted: 07/25/2017] [Indexed: 06/09/2023]
Abstract
Habituation is a non-associative form of learning characterized by a decremented response to repeated stimulation. It is typically framed as a process of selective attention, allowing animals to ignore irrelevant stimuli in order to free up limited cognitive resources. However, habituation can also occur to threatening and toxic stimuli, suggesting that habituation may serve other functions. Here we took advantage of a high-throughput Caenorhabditis elegans learning assay to investigate habituation to noxious stimuli. Using real-time computer vision software for automated behavioral tracking and optogenetics for controlled activation of a polymodal nociceptor, ASH, we found that neuropeptides mediated habituation and performed an RNAi screen to identify candidate receptors. Through subsequent mutant analysis and cell-type-specific gene expression, we found that pigment-dispersing factor (PDF) neuropeptides function redundantly to promote habituation via PDFR-1-mediated cAMP signaling in both neurons and muscles. Behavioral analysis during learning acquisition suggests that response habituation and sensitization of locomotion are parts of a shifting behavioral strategy orchestrated by pigment dispersing factor signaling to promote dispersal away from repeated aversive stimuli.
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Affiliation(s)
- Evan L. Ardiel
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC Canada V6T 2B5
| | - Alex J. Yu
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC Canada V6T 2B5
| | - Andrew C. Giles
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC Canada V6T 2B5
| | - Catharine H. Rankin
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC Canada V6T 2B5
- Department of Psychology, University of British Columbia, 2136 West Mall, Vancouver, BC Canada V6T 1Z4
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26
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Memory of recent oxygen experience switches pheromone valence in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2017; 114:4195-4200. [PMID: 28373553 DOI: 10.1073/pnas.1618934114] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Animals adjust their behavioral priorities according to momentary needs and prior experience. We show that Caenorhabditis elegans changes how it processes sensory information according to the oxygen environment it experienced recently. C. elegans acclimated to 7% O2 are aroused by CO2 and repelled by pheromones that attract animals acclimated to 21% O2 This behavioral plasticity arises from prolonged activity differences in a circuit that continuously signals O2 levels. A sustained change in the activity of O2-sensing neurons reprograms the properties of their postsynaptic partners, the RMG hub interneurons. RMG is gap-junctionally coupled to the ASK and ADL pheromone sensors that respectively drive pheromone attraction and repulsion. Prior O2 experience has opposite effects on the pheromone responsiveness of these neurons. These circuit changes provide a physiological correlate of altered pheromone valence. Our results suggest C. elegans stores a memory of recent O2 experience in the RMG circuit and illustrate how a circuit is flexibly sculpted to guide behavioral decisions in a context-dependent manner.
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27
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McCloskey RJ, Fouad AD, Churgin MA, Fang-Yen C. Food responsiveness regulates episodic behavioral states in Caenorhabditis elegans. J Neurophysiol 2017; 117:1911-1934. [PMID: 28228583 DOI: 10.1152/jn.00555.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 02/16/2017] [Accepted: 02/16/2017] [Indexed: 02/04/2023] Open
Abstract
Animals optimize survival and reproduction in part through control of behavioral states, which depend on an organism's internal and external environments. In the nematode Caenorhabditis elegans a variety of behavioral states have been described, including roaming, dwelling, quiescence, and episodic swimming. These states have been considered in isolation under varied experimental conditions, making it difficult to establish a unified picture of how they are regulated. Using long-term imaging, we examined C. elegans episodic behavioral states under varied mechanical and nutritional environments. We found that animals alternate between high-activity (active) and low-activity (sedentary) episodes in any mechanical environment, while the incidence of episodes and their behavioral composition depend on food levels. During active episodes, worms primarily roam, as characterized by continuous whole body movement. During sedentary episodes, animals exhibit dwelling (slower movements confined to the anterior half of the body) and quiescence (a complete lack of movement). Roaming, dwelling, and quiescent states are manifest not only through locomotory characteristics but also in pharyngeal pumping (feeding) and in egg-laying behaviors. Next, we analyzed the genetic basis of behavioral states. We found that modulation of behavioral states depends on neuropeptides and insulin-like signaling in the nervous system. Sensory neurons and the Foraging homolog EGL-4 regulate behavior through control of active/sedentary episodes. Optogenetic stimulation of dopaminergic and serotonergic neurons induced dwelling, implicating dopamine as a dwell-promoting neurotransmitter. Our findings provide a more unified description of behavioral states and suggest that perception of nutrition is a conserved mechanism for regulating animal behavior.NEW & NOTEWORTHY One strategy by which animals adapt to their internal states and external environments is by adopting behavioral states. The roundworm Caenorhabditis elegans is an attractive model for investigating how behavioral states are genetically and neuronally controlled. Here we describe the hierarchical organization of behavioral states characterized by locomotory activity, feeding, and egg-laying. We show that decisions to engage in these behaviors are controlled by the nervous system through insulin-like signaling and the perception of food.
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Affiliation(s)
- Richard J McCloskey
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Anthony D Fouad
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Matthew A Churgin
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania; and
| | - Christopher Fang-Yen
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania; and .,Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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28
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The Role of Hypothalamic Neuropeptides in Neurogenesis and Neuritogenesis. Neural Plast 2016; 2016:3276383. [PMID: 26881105 PMCID: PMC4737468 DOI: 10.1155/2016/3276383] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 11/18/2015] [Accepted: 11/22/2015] [Indexed: 01/23/2023] Open
Abstract
The hypothalamus is a source of neural progenitor cells which give rise to different populations of specialized and differentiated cells during brain development. Newly formed neurons in the hypothalamus can synthesize and release various neuropeptides. Although term neuropeptide recently undergoes redefinition, small-size hypothalamic neuropeptides remain major signaling molecules mediating short- and long-term effects on brain development. They represent important factors in neurite growth and formation of neural circuits. There is evidence suggesting that the newly generated hypothalamic neurons may be involved in regulation of metabolism, energy balance, body weight, and social behavior as well. Here we review recent data on the role of hypothalamic neuropeptides in adult neurogenesis and neuritogenesis with special emphasis on the development of food intake and social behavior related brain circuits.
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29
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Rabinowitch I, Laurent P, Zhao B, Walker D, Beets I, Schoofs L, Bai J, Schafer WR, Treinin M. Neuropeptide-Driven Cross-Modal Plasticity following Sensory Loss in Caenorhabditis elegans. PLoS Biol 2016; 14:e1002348. [PMID: 26745270 PMCID: PMC4712962 DOI: 10.1371/journal.pbio.1002348] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 12/03/2015] [Indexed: 02/02/2023] Open
Abstract
Sensory loss induces cross-modal plasticity, often resulting in altered performance in remaining sensory modalities. Whereas much is known about the macroscopic mechanisms underlying cross-modal plasticity, only scant information exists about its cellular and molecular underpinnings. We found that Caenorhabditis elegans nematodes deprived of a sense of body touch exhibit various changes in behavior, associated with other unimpaired senses. We focused on one such behavioral alteration, enhanced odor sensation, and sought to reveal the neuronal and molecular mechanisms that translate mechanosensory loss into improved olfactory acuity. To this end, we analyzed in mechanosensory mutants food-dependent locomotion patterns that are associated with olfactory responses and found changes that are consistent with enhanced olfaction. The altered locomotion could be reversed in adults by optogenetic stimulation of the touch receptor (mechanosensory) neurons. Furthermore, we revealed that the enhanced odor response is related to a strengthening of inhibitory AWC→AIY synaptic transmission in the olfactory circuit. Consistently, inserting in this circuit an engineered electrical synapse that diminishes AWC inhibition of AIY counteracted the locomotion changes in touch-deficient mutants. We found that this cross-modal signaling between the mechanosensory and olfactory circuits is mediated by neuropeptides, one of which we identified as FLP-20. Our results indicate that under normal function, ongoing touch receptor neuron activation evokes FLP-20 release, suppressing synaptic communication and thus dampening odor sensation. In contrast, in the absence of mechanosensory input, FLP-20 signaling is reduced, synaptic suppression is released, and this enables enhanced olfactory acuity; these changes are long lasting and do not represent ongoing modulation, as revealed by optogenetic experiments. Our work adds to a growing literature on the roles of neuropeptides in cross-modal signaling, by showing how activity-dependent neuropeptide signaling leads to specific cross-modal plastic changes in neural circuit connectivity, enhancing sensory performance. Touch-sensing neurons in the nematode Caenorhabditis elegans secrete neuropeptides to suppress olfaction via a specific synapse in the olfactory circuit. Loss of touch releases this suppression, enhancing the sense of smell. The brain has the remarkable capacity to respond to sensory loss by boosting remaining functioning senses. For example, certain features of hearing are improved in blind people. What are the cellular and molecular mechanisms underlying this effect? How is a certain sense strengthened? If it is possible to hear better, why don’t we hear better in the first place? To simplify these problems, we examined them in an organism with a substantially less complicated nervous system than our own, the roundworm C. elegans. We discovered that C. elegans mutants that cannot sense touch to the body exhibit an improved sense of smell. We were able to pinpoint this change in sensory performance to a change in strength of a specific synapse in the olfactory circuit. We further found that in normal worms, this olfactory synapse is suppressed through a neuropeptide signal transmitted from the touch sensing neurons. In contrast, without any touch input, the touch neurons secrete less neuropeptide, the olfactory synapse becomes stronger, and the sense of smell improves. We were able to reverse these effects by artificially stimulating the touch neurons and by engineering a new synapse into the olfactory circuit.
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Affiliation(s)
- Ithai Rabinowitch
- Department of Medical Neurobiology, Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem, Israel
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- * E-mail: (IR); (WRT); (MT)
| | - Patrick Laurent
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
- ULB Neuroscience Institute, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Buyun Zhao
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Denise Walker
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Isabel Beets
- Functional Genomics and Proteomics, KU Leuven, Leuven, Belgium
| | - Liliane Schoofs
- Functional Genomics and Proteomics, KU Leuven, Leuven, Belgium
| | - Jihong Bai
- Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - William R. Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
- * E-mail: (IR); (WRT); (MT)
| | - Millet Treinin
- Department of Medical Neurobiology, Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem, Israel
- * E-mail: (IR); (WRT); (MT)
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30
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Husson SJ, Moyson S, Valkenborg D, Baggerman G, Mertens I. Proteomics applications in Caenorhabditis elegans research. Biochem Biophys Res Commun 2015; 468:519-24. [DOI: 10.1016/j.bbrc.2015.11.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 11/04/2015] [Indexed: 01/04/2023]
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31
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Seidel HS, Kimble J. Cell-cycle quiescence maintains Caenorhabditis elegans germline stem cells independent of GLP-1/Notch. eLife 2015; 4. [PMID: 26551561 PMCID: PMC4718729 DOI: 10.7554/elife.10832] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 11/07/2015] [Indexed: 12/13/2022] Open
Abstract
Many types of adult stem cells exist in a state of cell-cycle quiescence, yet it has remained unclear whether quiescence plays a role in maintaining the stem cell fate. Here we establish the adult germline of Caenorhabditis elegans as a model for facultative stem cell quiescence. We find that mitotically dividing germ cells--including germline stem cells--become quiescent in the absence of food. This quiescence is characterized by a slowing of S phase, a block to M-phase entry, and the ability to re-enter M phase rapidly in response to re-feeding. Further, we demonstrate that cell-cycle quiescence alters the genetic requirements for stem cell maintenance: The signaling pathway required for stem cell maintenance under fed conditions--GLP-1/Notch signaling--becomes dispensable under conditions of quiescence. Thus, cell-cycle quiescence can itself maintain stem cells, independent of the signaling pathway otherwise essential for such maintenance.
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Affiliation(s)
- Hannah S Seidel
- Department of Biochemistry, University of Wisconsin-Madison, Madison, United States.,The Ellison Medical Foundation Fellow of the Life Sciences Research Foundation, The Lawrence Ellison Foundation, Mount Airy, United States
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, United States.,Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, United States
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32
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Dallière N, Bhatla N, Luedtke Z, Ma DK, Woolman J, Walker RJ, Holden-Dye L, O'Connor V. Multiple excitatory and inhibitory neural signals converge to fine-tune Caenorhabditis elegans feeding to food availability. FASEB J 2015; 30:836-48. [PMID: 26514165 DOI: 10.1096/fj.15-279257] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 10/13/2015] [Indexed: 01/02/2023]
Abstract
How an animal matches feeding to food availability is a key question for energy homeostasis. We addressed this in the nematode Caenorhabditis elegans, which couples feeding to the presence of its food (bacteria) by regulating pharyngeal activity (pumping). We scored pumping in the presence of food and over an extended time course of food deprivation in wild-type and mutant worms to determine the neural substrates of adaptive behavior. Removal of food initially suppressed pumping but after 2 h this was accompanied by intermittent periods of high activity. We show pumping is fine-tuned by context-specific neural mechanisms and highlight a key role for inhibitory glutamatergic and excitatory cholinergic/peptidergic drives in the absence of food. Additionally, the synaptic protein UNC-31 [calcium-activated protein for secretion (CAPS)] acts through an inhibitory pathway not explained by previously identified contributions of UNC-31/CAPS to neuropeptide or glutamate transmission. Pumping was unaffected by laser ablation of connectivity between the pharyngeal and central nervous system indicating signals are either humoral or intrinsic to the enteric system. This framework in which control is mediated through finely tuned excitatory and inhibitory drives resonates with mammalian hypothalamic control of feeding and suggests that fundamental regulation of this basic animal behavior may be conserved through evolution from nematode to human.
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Affiliation(s)
- Nicolas Dallière
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Nikhil Bhatla
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Zara Luedtke
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Dengke K Ma
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jonathan Woolman
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Robert J Walker
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lindy Holden-Dye
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Vincent O'Connor
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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33
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Sowa JN, Mutlu AS, Xia F, Wang MC. Olfaction Modulates Reproductive Plasticity through Neuroendocrine Signaling in Caenorhabditis elegans. Curr Biol 2015; 25:2284-9. [PMID: 26279229 DOI: 10.1016/j.cub.2015.07.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 07/07/2015] [Accepted: 07/09/2015] [Indexed: 11/26/2022]
Abstract
Reproductive plasticity describes the ability of organisms to adjust parameters such as volume, rate, or timing of progeny production in order to maximize successful reproduction under different environmental conditions. Reproductive plasticity in response to environmental variation has been observed in a wide range of animals; however, the mechanisms involved in translating environmental cues into reproductive outcomes remain unknown. Here, we show that olfaction modulates reproductive timing and senescence through neuroendocrine signaling in Caenorhabditis elegans. On their preferred diet, worms demonstrate an increased rate of reproduction and an early onset of reproductive aging. Perception of the preferred diet's odor by AWB olfactory neurons elicits these adjustments by increasing germline proliferation, and optogenetic stimulation of AWB neurons is sufficient to accelerate reproductive timing in the absence of dietary inputs. Furthermore, AWB neurons act through neuropeptide signaling to regulate reproductive rate and senescence. These findings reveal a neuroendocrine nexus linking olfactory sensation and reproduction in response to environmental variation and indicate the significance of olfaction in the regulation of reproductive decline during aging.
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Affiliation(s)
- Jessica N Sowa
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ayse Sena Mutlu
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Fan Xia
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meng C Wang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA.
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34
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Yamazoe-Umemoto A, Fujita K, Iino Y, Iwasaki Y, Kimura KD. Modulation of different behavioral components by neuropeptide and dopamine signalings in non-associative odor learning of Caenorhabditis elegans. Neurosci Res 2015; 99:22-33. [PMID: 26068898 DOI: 10.1016/j.neures.2015.05.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 05/15/2015] [Accepted: 05/18/2015] [Indexed: 12/20/2022]
Abstract
An animal's behavior is modulated by learning; however, the behavioral component modulated by learning and the mechanisms of this modulation have not been fully understood. We show here that two types of neural signalings are required for the modulation of different behavioral components in non-associative odor learning in the nematode Caenorhabditis elegans. We have previously found that C. elegans avoid the repulsive odor 2-nonanone, and preexposure to the odor for 1h enhances the avoidance behavior as a type of non-associative learning. Systematic quantitative analyses of behavioral components revealed that the odor preexposure caused increases in average duration of straight migration ("runs") only when the animals were migrating away from the odor source within a certain range of bearing, which likely corresponds to odor decrement. Further, genetic analyses revealed that the genes for neuropeptide or dopamine signalings are both required for the enhanced odor avoidance. Neuropeptide signaling genes were required for the preexposure-dependent increase in run duration. In contrast, dopamine signaling genes were required not for the increase in run duration but likely for maintenance of run direction. Our results suggests that multiple behavioral components are regulated by different neuromodulators even in non-associative learning in C. elegans.
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Affiliation(s)
- Akiko Yamazoe-Umemoto
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Kosuke Fujita
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yuichi Iino
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yuishi Iwasaki
- Department of Intelligent System Engineering, Ibaraki University, Hitachi, Ibaraki 316-8511, Japan
| | - Koutarou D Kimura
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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35
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Laurent P, Soltesz Z, Nelson GM, Chen C, Arellano-Carbajal F, Levy E, de Bono M. Decoding a neural circuit controlling global animal state in C. elegans. eLife 2015; 4. [PMID: 25760081 PMCID: PMC4440410 DOI: 10.7554/elife.04241] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 03/10/2015] [Indexed: 02/05/2023] Open
Abstract
Brains organize behavior and physiology to optimize the response to threats or opportunities. We dissect how 21% O2, an indicator of surface exposure, reprograms C. elegans' global state, inducing sustained locomotory arousal and altering expression of neuropeptides, metabolic enzymes, and other non-neural genes. The URX O2-sensing neurons drive arousal at 21% O2 by tonically activating the RMG interneurons. Stimulating RMG is sufficient to switch behavioral state. Ablating the ASH, ADL, or ASK sensory neurons connected to RMG by gap junctions does not disrupt arousal. However, disrupting cation currents in these neurons curtails RMG neurosecretion and arousal. RMG signals high O2 by peptidergic secretion. Neuropeptide reporters reveal neural circuit state, as neurosecretion stimulates neuropeptide expression. Neural imaging in unrestrained animals shows that URX and RMG encode O2 concentration rather than behavior, while the activity of downstream interneurons such as AVB and AIY reflect both O2 levels and the behavior being executed. DOI:http://dx.doi.org/10.7554/eLife.04241.001 From humans to worms, animals must respond appropriately to environmental challenges to survive. Starving animals must conserve energy while they seek food; animals that encounter a predator must fight or flee. These responses involve the animals re-programming their bodies and behavior, and, in humans, are thought to coincide with feelings or emotions such as ‘hunger’ and ‘fear’. Understanding these states in humans is difficult, but studies of simpler animals may provide some insights. The microscopic worm Caenorhabditis elegans offers a unique advantage to these studies because it has the most precisely described nervous system of any animal. The worm lives in rotting fruit, but it avoids the fruit's surface, perhaps because there is an increased risk of it drying out or being eaten by predators. Microbes that grow within the rotting fruit reduce the oxygen level below the 21% oxygen found in the surrounding air, and so one strategy that C. elegans uses to avoid surface exposure is to continuously monitor the oxygen concentration. If the worm senses that the oxygen level is approaching 21%, which suggests it is nearing the surface, it reverses and turns around. If it cannot find a lower-oxygen environment, the worm switches to continuous rapid movement until it locates such an environment, and adapts its body for surface exposure. Laurent, Soltesz et al. sought to understand the circuit of neurons that controls this switch. Monitoring gene expression in the worms revealed that specific oxygen-sensing neurons help generate the widespread changes that occur in the worm's body. These neurons also control the switch in the worm's behavior. Sensory neurons relay signals to downstream neurons that act on muscles to alter behavior. Neurons typically communicate with other neurons via specific connections; but neurons can also release signaling molecules, which act like ‘wireless’ signals and can affect many other cells. Laurent, Soltesz et al. showed that both kinds of signaling are needed to change the worm's behavior, and suggest that the release of signaling molecules may explain the widespread effects of 21% oxygen on the worm. Laurent, Soltesz et al. then monitored the activity of neurons in freely moving worms, and found that some neurons appear to encode and relay specific sensory information. Other neurons encode the behavior the animal is performing, and yet others can encode both kinds of information. To confirm which neurons control particular behavioral responses, Laurent, Soltesz et al. measured changes in the worm’s behavior after destroying or altering specific cells, or while they used light-based techniques to artificially excite or inhibit specific neurons. At a simple level the worm's response to 21% oxygen resembles the response of a mammal to a dangerous environment: both become more aroused, change how they respond to other sensory cues, and adapt both their bodies and behavior. As such, C. elegans provides a great model to explore at a small and accessible scale how changes in animals' states are generated. DOI:http://dx.doi.org/10.7554/eLife.04241.002
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Affiliation(s)
| | - Zoltan Soltesz
- Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Geoffrey M Nelson
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Changchun Chen
- Laboratory of Molecular Biology, Cambridge, United Kingdom
| | | | - Emmanuel Levy
- Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Mario de Bono
- Laboratory of Molecular Biology, Cambridge, United Kingdom
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De Haes W, Van Sinay E, Detienne G, Temmerman L, Schoofs L, Boonen K. Functional neuropeptidomics in invertebrates. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1854:812-26. [PMID: 25528324 DOI: 10.1016/j.bbapap.2014.12.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/27/2014] [Accepted: 12/10/2014] [Indexed: 10/24/2022]
Abstract
Neuropeptides are key messengers in almost all physiological processes. They originate from larger precursors and are extensively processed to become bioactive. Neuropeptidomics aims to comprehensively identify the collection of neuropeptides in an organism, organ, tissue or cell. The neuropeptidome of several invertebrates is thoroughly explored since they are important model organisms (and models for human diseases), disease vectors and pest species. The charting of the neuropeptidome is the first step towards understanding peptidergic signaling. This review will first discuss the latest developments in exploring the neuropeptidome. The physiological roles and modes of action of neuropeptides can be explored in two ways, which are largely orthogonal and therefore complementary. The first way consists of inferring the functions of neuropeptides by a forward approach where neuropeptide profiles are compared under different physiological conditions. Second is the reverse approach were neuropeptide collections are used to screen for receptor-binding. This is followed by localization studies and functional tests. This review will focus on how these different functional screening methods contributed to the field of invertebrate neuropeptidomics and expanded our knowledge of peptidergic signaling. This article is part of a Special Issue entitled: Neuroproteomics: Applications in Neuroscience and Neurology.
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Affiliation(s)
- Wouter De Haes
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium
| | - Elien Van Sinay
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium
| | - Giel Detienne
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium
| | - Liesbet Temmerman
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium
| | - Liliane Schoofs
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium
| | - Kurt Boonen
- Functional Genomics and Proteomics, Department of Biology, University of Leuven (KU Leuven), Naamsestraat 59, 3000 Leuven, Belgium.
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Nagy S, Tramm N, Sanders J, Iwanir S, Shirley IA, Levine E, Biron D. Homeostasis in C. elegans sleep is characterized by two behaviorally and genetically distinct mechanisms. eLife 2014; 3:e04380. [PMID: 25474127 PMCID: PMC4273442 DOI: 10.7554/elife.04380] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 12/03/2014] [Indexed: 12/12/2022] Open
Abstract
Biological homeostasis invokes modulatory responses aimed at stabilizing internal conditions. Using tunable photo- and mechano-stimulation, we identified two distinct categories of homeostatic responses during the sleep-like state of Caenorhabditis elegans (lethargus). In the presence of weak or no stimuli, extended motion caused a subsequent extension of quiescence. The neuropeptide Y receptor homolog, NPR-1, and an inhibitory neuropeptide known to activate it, FLP-18, were required for this process. In the presence of strong stimuli, the correlations between motion and quiescence were disrupted for several minutes but homeostasis manifested as an overall elevation of the time spent in quiescence. This response to strong stimuli required the function of the DAF-16/FOXO transcription factor in neurons, but not that of NPR-1. Conversely, response to weak stimuli did not require the function of DAF-16/FOXO. These findings suggest that routine homeostatic stabilization of sleep may be distinct from homeostatic compensation following a strong disturbance. DOI:http://dx.doi.org/10.7554/eLife.04380.001 The regenerative properties of sleep are required by all animals, with even the simplest animal, the nematode Caenorhabditis elegans, displaying a sleep-like state called lethargus. During development, nematodes must pass through four larval stages en route to adulthood, and the end of each stage is preceded by a period of lethargus lasting 2 to 3 hr. Human sleep is divided into distinct stages that recur in a prescribed order throughout the night. Nematodes, on the other hand, simply experience alternating periods of activity and stillness as they sleep. Nevertheless, in both species, any disruptions to sleep automatically lead to adjustments of the rest of the sleep cycle to compensate for the disturbance and to ensure that the organism gets an adequate amount of sleep overall. To date, it has been assumed that a single mechanism is responsible for adjusting the sleep cycle after any disturbance, regardless of its severity. However, Nagy, Tramm, Sanders et al. now show that this is not the case in C. elegans. Sleeping nematodes that were lightly disturbed by exposing them to light or to vibrations—causing them to briefly increase their activity levels—compensated for the disturbance by lengthening their next inactive period. By contrast, worms that were vigorously agitated by stronger vibrations showed a different response: the alternating pattern of stillness and activity was disrupted for several minutes, followed by an overall increase in the length of time spent in the stillness phase. Experiments using genetically modified worms revealed that these two responses involve distinct molecular pathways. A signaling molecule called neuropeptide Y affects the response to minor sleep disruptions, whereas a transcription factor called DAF-16/FOXO is involved in the corresponding role after major disruptions. Given that neuropeptide Y has already been implicated in sleep regulation in humans and flies, it is not implausible that similar mechanisms may occur in response to disturbances of our own sleep. DOI:http://dx.doi.org/10.7554/eLife.04380.002
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Affiliation(s)
- Stanislav Nagy
- Institute for Biophysical Dynamics, University of Chicago, Chicago, United States
| | - Nora Tramm
- Department of Physics, University of Chicago, Chicago, United States
| | - Jarred Sanders
- Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, United States
| | - Shachar Iwanir
- Department of Physics, University of Chicago, Chicago, United States
| | - Ian A Shirley
- Department of Physics, University of Chicago, Chicago, United States
| | - Erel Levine
- Department of Physics, Harvard University, Cambridge, United States
| | - David Biron
- Institute for Biophysical Dynamics, University of Chicago, Chicago, United States
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Nelson MD, Trojanowski NF, George-Raizen JB, Smith CJ, Yu CC, Fang-Yen C, Raizen DM. The neuropeptide NLP-22 regulates a sleep-like state in Caenorhabditis elegans. Nat Commun 2014; 4:2846. [PMID: 24301180 PMCID: PMC3867200 DOI: 10.1038/ncomms3846] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 10/30/2013] [Indexed: 11/09/2022] Open
Abstract
Neuropeptides play central roles in the regulation of homeostatic behaviors such as sleep and feeding. Caenorhabditis elegans displays sleep-like quiescence of locomotion and feeding during a larval transition stage called lethargus and feeds during active larval and adult stages. Here we show that the neuropeptide NLP-22 is a regulator of Caenorhabditis elegans sleep-like quiescence observed during lethargus. nlp-22 shows cyclical mRNA expression in synchrony with lethargus; it is regulated by LIN-42, an orthologue of the core circadian protein PERIOD; and it is expressed solely in the two RIA interneurons. nlp-22 and the RIA interneurons are required for normal lethargus quiescence, and forced expression of nlp-22 during active stages causes anachronistic locomotion and feeding quiescence. Optogenetic stimulation of RIA interneurons has a movement-promoting effect, demonstrating functional complexity in a single neuron type. Our work defines a quiescence-regulating role for NLP-22 and expands our knowledge of the neural circuitry controlling Caenorhabditis elegans behavioral quiescence.
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Affiliation(s)
- M D Nelson
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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A conserved dopamine-cholecystokinin signaling pathway shapes context-dependent Caenorhabditis elegans behavior. PLoS Genet 2014; 10:e1004584. [PMID: 25167143 PMCID: PMC4148232 DOI: 10.1371/journal.pgen.1004584] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 07/08/2014] [Indexed: 12/02/2022] Open
Abstract
An organism's ability to thrive in changing environmental conditions requires the capacity for making flexible behavioral responses. Here we show that, in the nematode Caenorhabditis elegans, foraging responses to changes in food availability require nlp-12, a homolog of the mammalian neuropeptide cholecystokinin (CCK). nlp-12 expression is limited to a single interneuron (DVA) that is postsynaptic to dopaminergic neurons involved in food-sensing, and presynaptic to locomotory control neurons. NLP-12 release from DVA is regulated through the D1-like dopamine receptor DOP-1, and both nlp-12 and dop-1 are required for normal local food searching responses. nlp-12/CCK overexpression recapitulates characteristics of local food searching, and DVA ablation or mutations disrupting muscle acetylcholine receptor function attenuate these effects. Conversely, nlp-12 deletion reverses behavioral and functional changes associated with genetically enhanced muscle acetylcholine receptor activity. Thus, our data suggest that dopamine-mediated sensory information about food availability shapes foraging in a context-dependent manner through peptide modulation of locomotory output. Animal behavior is profoundly affected by contextual information about the internal state of the organism as well as sensory information about the external environment. A class of signaling molecules known as neuropeptides have been implicated in driving transitions between behavioral states (e.g., from food seeking to satiety and back) but we have only a limited understanding of how neuropeptide signaling modulates neural circuit activity and elicits context-dependent behaviors. Here we identify a novel mechanism by which C. elegans modulate their behavior in response to sensory information about food. We show that dopaminergic regulation of NLP-12, a C. elegans homolog of the mammalian neuropeptide cholecystokinin (CCK), shapes behavioral transitions that are central to food searching. Given the conserved nature of these signaling pathways, our work raises the interesting possibility that dopamine modulation of CCK signaling represents a general mechanism by which nervous systems shape context-dependent behavioral changes.
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Husson SJ, Reumer A, Temmerman L, De Haes W, Schoofs L, Mertens I, Baggerman G. Worm peptidomics. EUPA OPEN PROTEOMICS 2014. [DOI: 10.1016/j.euprot.2014.04.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Peymen K, Watteyne J, Frooninckx L, Schoofs L, Beets I. The FMRFamide-Like Peptide Family in Nematodes. Front Endocrinol (Lausanne) 2014; 5:90. [PMID: 24982652 PMCID: PMC4058706 DOI: 10.3389/fendo.2014.00090] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 05/31/2014] [Indexed: 12/31/2022] Open
Abstract
In the three decades since the FMRFamide peptide was isolated from the mollusk Macrocallista nimbosa, structurally similar peptides sharing a C-terminal RFamide motif have been identified across the animal kingdom. FMRFamide-like peptides (FLPs) represent the largest known family of neuropeptides in invertebrates. In the phylum Nematoda, at least 32 flp-genes are classified, making the FLP system of nematodes unusually complex. The diversity of the nematode FLP complement is most extensively mapped in Caenorhabditis elegans, where over 70 FLPs have been predicted. FLPs have shown to be expressed in the majority of the 302 C. elegans neurons including interneurons, sensory neurons, and motor neurons. The vast expression of FLPs is reflected in the broad functional repertoire of nematode FLP signaling, including neuroendocrine and neuromodulatory effects on locomotory activity, reproduction, feeding, and behavior. In contrast to the many identified nematode FLPs, only few peptides have been assigned a receptor and there is the need to clarify the pathway components and working mechanisms of the FLP signaling network. Here, we review the diversity, distribution, and functions of FLPs in nematodes.
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Affiliation(s)
- Katleen Peymen
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Jan Watteyne
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Lotte Frooninckx
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Liliane Schoofs
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Isabel Beets
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
- *Correspondence: Isabel Beets, Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Naamsestraat 59, Leuven 3000, Belgium e-mail:
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Stawicki TM, Takayanagi-Kiya S, Zhou K, Jin Y. Neuropeptides function in a homeostatic manner to modulate excitation-inhibition imbalance in C. elegans. PLoS Genet 2013; 9:e1003472. [PMID: 23658528 PMCID: PMC3642046 DOI: 10.1371/journal.pgen.1003472] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 03/07/2013] [Indexed: 11/18/2022] Open
Abstract
Neuropeptides play crucial roles in modulating neuronal networks, including changing intrinsic properties of neurons and synaptic efficacy. We previously reported a Caenorhabditis elegans mutant, acr-2(gf), that displays spontaneous convulsions as the result of a gain-of-function mutation in a neuronal nicotinic acetylcholine receptor subunit. The ACR-2 channel is expressed in the cholinergic motor neurons, and acr-2(gf) causes cholinergic overexcitation accompanied by reduced GABAergic inhibition in the locomotor circuit. Here we show that neuropeptides play a homeostatic role that compensates for this excitation-inhibition imbalance in the locomotor circuit. Loss of function in genes required for neuropeptide processing or release of dense core vesicles specifically modulate the convulsion frequency of acr-2(gf). The proprotein convertase EGL-3 is required in the cholinergic motor neurons to restrain convulsions. Electrophysiological recordings of neuromuscular junctions show that loss of egl-3 in acr-2(gf) causes a further reduction of GABAergic inhibition. We identify two neuropeptide encoding genes, flp-1 and flp-18, that together counteract the excitation-inhibition imbalance in acr-2(gf) mutants. We further find that acr-2(gf) causes an increased expression of flp-18 in the ventral cord cholinergic motor neurons and that overexpression of flp-18 reduces the convulsion of acr-2(gf) mutants. The effects of these peptides are in part mediated by two G-protein coupled receptors, NPR-1 and NPR-5. Our data suggest that the chronic overexcitation of the cholinergic motor neurons imposed by acr-2(gf) leads to an increased production of FMRFamide neuropeptides, which act to decrease the activity level of the locomotor circuit, thereby homeostatically modulating the excitation and inhibition imbalance. Imbalanced neuronal circuit activity is considered a major underlying cause in many neurological disorders, such as epilepsy and autism. Neuropeptides are small polypeptides that are released from neurons. They are widely known to provide neuromodulatory functions and have diverse roles in the nervous system. By investigating a C. elegans mutant that exhibits convulsions as the result of an imbalanced excitation and inhibition in the locomotor circuit, we have identified a homeostatic mechanism involving two distinct neuropeptide genes. We find that the expression of the neuropeptides is up-regulated in response to over-excitation and that, in turn, they act to increase inhibitory transmission. While current treatment strategies for epilepsy have focused on targeting fast synaptic transmission, this work supports the general notion that manipulating slow neuropeptide neurotransmission can strongly influence neural excitation and inhibition imbalance.
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Affiliation(s)
- Tamara M. Stawicki
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, California, United States of America
| | - Seika Takayanagi-Kiya
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, California, United States of America
| | - Keming Zhou
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, California, United States of America
| | - Yishi Jin
- Division of Biological Sciences, Section of Neurobiology, University of California San Diego, La Jolla, California, United States of America
- Howard Hughes Medical Institute, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
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Wang H, Girskis K, Janssen T, Chan JP, Dasgupta K, Knowles JA, Schoofs L, Sieburth D. Neuropeptide secreted from a pacemaker activates neurons to control a rhythmic behavior. Curr Biol 2013; 23:746-54. [PMID: 23583549 DOI: 10.1016/j.cub.2013.03.049] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 03/18/2013] [Accepted: 03/20/2013] [Indexed: 10/27/2022]
Abstract
BACKGROUND Rhythmic behaviors are driven by endogenous biological clocks in pacemakers, which must reliably transmit timing information to target tissues that execute rhythmic outputs. During the defecation motor program in C. elegans, calcium oscillations in the pacemaker (intestine), which occur about every 50 s, trigger rhythmic enteric muscle contractions through downstream GABAergic neurons that innervate enteric muscles. However, the identity of the timing signal released by the pacemaker and the mechanism underlying the delivery of timing information to the GABAergic neurons are unknown. RESULTS Here, we show that a neuropeptide-like protein (NLP-40) released by the pacemaker triggers a single rapid calcium transient in the GABAergic neurons during each defecation cycle. We find that mutants lacking nlp-40 have normal pacemaker function, but lack enteric muscle contractions. NLP-40 undergoes calcium-dependent release that is mediated by the calcium sensor, SNT-2/synaptotagmin. We identify AEX-2, the G-protein-coupled receptor on the GABAergic neurons, as the receptor for NLP-40. Functional calcium imaging reveals that NLP-40 and AEX-2/GPCR are both necessary for rhythmic activation of these neurons. Furthermore, acute application of synthetic NLP-40-derived peptide depolarizes the GABAergic neurons in vivo. CONCLUSIONS Our results show that NLP-40 carries the timing information from the pacemaker via calcium-dependent release and delivers it to the GABAergic neurons by instructing their activation. Thus, we propose that rhythmic release of neuropeptides can deliver temporal information from pacemakers to downstream neurons to execute rhythmic behaviors.
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Affiliation(s)
- Han Wang
- Graduate Program in Genetic, Molecular and Cellular Biology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
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McVeigh P, Atkinson L, Marks NJ, Mousley A, Dalzell JJ, Sluder A, Hammerland L, Maule AG. Parasite neuropeptide biology: Seeding rational drug target selection? Int J Parasitol Drugs Drug Resist 2012; 2:76-91. [PMID: 24533265 PMCID: PMC3862435 DOI: 10.1016/j.ijpddr.2011.10.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 10/25/2011] [Accepted: 10/28/2011] [Indexed: 01/16/2023]
Abstract
The rationale for identifying drug targets within helminth neuromuscular signalling systems is based on the premise that adequate nerve and muscle function is essential for many of the key behavioural determinants of helminth parasitism, including sensory perception/host location, invasion, locomotion/orientation, attachment, feeding and reproduction. This premise is validated by the tendency of current anthelmintics to act on classical neurotransmitter-gated ion channels present on helminth nerve and/or muscle, yielding therapeutic endpoints associated with paralysis and/or death. Supplementary to classical neurotransmitters, helminth nervous systems are peptide-rich and encompass associated biosynthetic and signal transduction components - putative drug targets that remain to be exploited by anthelmintic chemotherapy. At this time, no neuropeptide system-targeting lead compounds have been reported, and given that our basic knowledge of neuropeptide biology in parasitic helminths remains inadequate, the short-term prospects for such drugs remain poor. Here, we review current knowledge of neuropeptide signalling in Nematoda and Platyhelminthes, and highlight a suite of 19 protein families that yield deleterious phenotypes in helminth reverse genetics screens. We suggest that orthologues of some of these peptidergic signalling components represent appealing therapeutic targets in parasitic helminths.
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Affiliation(s)
- Paul McVeigh
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Louise Atkinson
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Nikki J. Marks
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Angela Mousley
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Johnathan J. Dalzell
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
| | - Ann Sluder
- Scynexis Inc., P.O. Box 12878, Research Triangle Park, NC 27709-2878, USA
| | | | - Aaron G. Maule
- Molecular Biosciences–Parasitology, Institute of Agri-Food and Land Use, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL, UK
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Meelkop E, Temmerman L, Janssen T, Suetens N, Beets I, Van Rompay L, Shanmugam N, Husson SJ, Schoofs L. PDF receptor signaling in Caenorhabditis elegans modulates locomotion and egg-laying. Mol Cell Endocrinol 2012; 361:232-40. [PMID: 22579613 DOI: 10.1016/j.mce.2012.05.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 03/26/2012] [Accepted: 05/02/2012] [Indexed: 01/22/2023]
Abstract
In Caenorhabditis elegans, pdfr-1 encodes three receptors of the secretin receptor family. These G protein-coupled receptors are activated by three neuropeptides, pigment dispersing factors 1a, 1b and 2, which are encoded by pdf-1 and pdf-2. We isolated a PDF receptor loss-of-function allele (lst34) by means of a mutagenesis screen and show that the PDF signaling system is involved in locomotion and egg-laying. We demonstrate that the pdfr-1 mutant phenocopies the defective locomotor behavior of the pdf-1 mutant and that pdf-1 and pdf-2 behave antagonistically. All three PDF receptor splice variants are involved in the regulation of locomotor behavior. Cell specific rescue experiments show that this pdf mediated behavior is regulated by neurons rather than body wall muscles. We also show that egg-laying patterns of pdf-1 and pdf-2 mutants are affected, but not those of pdfr-1 mutants, pointing to a novel role for the PDF-system in the regulation of egg-laying.
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Affiliation(s)
- Ellen Meelkop
- Research Group of Functional Genomics and Proteomics, Department of Biology, KU Leuven, Leuven, Belgium.
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Tonic signaling from O₂ sensors sets neural circuit activity and behavioral state. Nat Neurosci 2012; 15:581-91. [PMID: 22388961 PMCID: PMC3564487 DOI: 10.1038/nn.3061] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 01/31/2012] [Indexed: 12/15/2022]
Abstract
Tonic receptors convey stimulus duration and intensity and are implicated in homeostatic control. However, how tonic homeostatic signals are generated and how they reconfigure neural circuits and modify animal behavior is poorly understood. Here we show that Caenorhabditis elegans O(2)-sensing neurons are tonic receptors that continuously signal ambient [O(2)] to set the animal's behavioral state. Sustained signaling relied on a Ca(2+) relay involving L-type voltage-gated Ca(2+) channels, the ryanodine and the inositol-1,4,5-trisphosphate receptors. Tonic activity evoked continuous neuropeptide release, which helps elicit the enduring behavioral state associated with high [O(2)]. Sustained O(2) receptor signaling was propagated to downstream neural circuits, including the hub interneuron RMG. O(2) receptors evoked similar locomotory states at particular O(2) concentrations, regardless of previous d[O(2)]/dt. However, a phasic component of the URX receptors' response to high d[O(2)]/dt, as well as tonic-to-phasic transformations in downstream interneurons, enabled transient reorientation movements shaped by d[O(2)]/dt. Our results highlight how tonic homeostatic signals can generate both transient and enduring behavioral change.
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Frooninckx L, Van Rompay L, Temmerman L, Van Sinay E, Beets I, Janssen T, Husson SJ, Schoofs L. Neuropeptide GPCRs in C. elegans. Front Endocrinol (Lausanne) 2012; 3:167. [PMID: 23267347 PMCID: PMC3527849 DOI: 10.3389/fendo.2012.00167] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 12/04/2012] [Indexed: 12/19/2022] Open
Abstract
Like most organisms, the nematode Caenorhabditis elegans relies heavily on neuropeptidergic signaling. This tiny animal represents a suitable model system to study neuropeptidergic signaling networks with single cell resolution due to the availability of powerful molecular and genetic tools. The availability of the worm's complete genome sequence allows researchers to browse through it, uncovering putative neuropeptides and their cognate G protein-coupled receptors (GPCRs). Many predictions have been made about the number of C. elegans neuropeptide GPCRs. In this review, we report the state of the art of both verified as well as predicted C. elegans neuropeptide GPCRs. The predicted neuropeptide GPCRs are incorporated into the receptor classification system based on their resemblance to orthologous GPCRs in insects and vertebrates. Appointing the natural ligand(s) to each predicted neuropeptide GPCR (receptor deorphanization) is a crucial step during characterization. The development of deorphanization strategies resulted in a significant increase in the knowledge of neuropeptidergic signaling in C. elegans. Complementary localization and functional studies demonstrate that neuropeptides and their GPCRs represent a rich potential source of behavioral variability in C. elegans. Here, we review all neuropeptidergic signaling pathways that so far have been functionally characterized in C. elegans.
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Affiliation(s)
- Lotte Frooninckx
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Liesbeth Van Rompay
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Liesbet Temmerman
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Elien Van Sinay
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Isabel Beets
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Tom Janssen
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Steven J. Husson
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Liliane Schoofs
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
- *Correspondence: Liliane Schoofs, Laboratory of Functional Genomics and Proteomics, Zoological Institute, Naamsestraat 59, 3000 Leuven, Belgium. e-mail:
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Monje JM, Brokate-Llanos AM, Pérez-Jiménez MM, Fidalgo MA, Muñoz MJ. pkc-1 regulates daf-2 insulin/IGF signalling-dependent control of dauer formation in Caenorhabditis elegans. Aging Cell 2011; 10:1021-31. [PMID: 21933341 DOI: 10.1111/j.1474-9726.2011.00747.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
In Caenorhabditis elegans, the insulin/IGF pathway participates in the decision to initiate dauer development. Dauer is a diapause stage that is triggered by environmental stresses, such as a lack of nutrients. Insulin/IGF receptor mutants arrest constitutively in dauer, an effect that can be suppressed by mutations in other elements of the insulin/IGF pathway or by a reduction in the activity of the nuclear hormone receptor daf-12. We have isolated a pkc-1 mutant that acts as a novel suppressor of the dauer phenotypes caused by insulin/IGF receptor mutations. Interactions between insulin/IGF mutants and the pkc-1 suppressor mutant are similar to those described for daf-12 or the DAF-12 coregulator din-1. Moreover, we show that the expression of the DAF-12 target daf-9, which is normally elevated upon a reduction in insulin/IGF receptor activity, is suppressed in a pkc-1 mutant background, suggesting that pkc-1 could link the daf-12 and insulin/IGF pathways. pkc-1 has been implicated in the regulation of peptide neurosecretion in C. elegans. Although we demonstrate that pkc-1 expression in the nervous system regulates dauer formation, our results suggest that the requirement for pkc-1 in neurosecretion is independent of its role in modulating insulin/IGF signalling. pkc-1 belongs to the novel protein kinase C (nPKC) family, members of which have been implicated in insulin resistance and diabetes in mammals, suggesting a conserved role for pkc-1 in the regulation of the insulin/IGF pathway.
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Affiliation(s)
- José M Monje
- Centro Andaluz de Biología del Desarrollo (CABD), CSIC/Universidad Pablo de Olavide, Seville, Spain
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Hu Z, Pym ECG, Babu K, Vashlishan Murray AB, Kaplan JM. A neuropeptide-mediated stretch response links muscle contraction to changes in neurotransmitter release. Neuron 2011; 71:92-102. [PMID: 21745640 DOI: 10.1016/j.neuron.2011.04.021] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/01/2011] [Indexed: 11/27/2022]
Abstract
Although Caenorhabditis elegans has been utilized extensively to study synapse formation and function, relatively little is known about synaptic plasticity in C. elegans. We show that a brief treatment with the cholinesterase inhibitor aldicarb induces a form of presynaptic potentiation whereby ACh release at neuromuscular junctions (NMJs) is doubled. Aldicarb-induced potentiation was eliminated by mutations that block processing of proneuropeptides, by mutations inactivating a single proneuropeptide (NLP-12), and by those inactivating an NLP-12 receptor (CKR-2). NLP-12 expression is limited to a single stretch-activated neuron, DVA. Analysis of a YFP-tagged NLP-12 suggests that aldicarb stimulates DVA secretion of NLP-12. Mutations disrupting the DVA mechanoreceptor (TRP-4) decreased aldicarb-induced NLP-12 secretion and blocked aldicarb-induced synaptic potentiation. Mutants lacking NLP-12 or CKR-2 have decreased locomotion rates. Collectively, these results suggest that NLP-12 mediates a mechanosensory feedback loop that couples muscle contraction to changes in presynaptic release, thereby providing a mechanism for proprioceptive control of locomotion.
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Affiliation(s)
- Zhitao Hu
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
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Neuropeptide gene families in Caenorhabditis elegans. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 692:98-137. [PMID: 21189676 DOI: 10.1007/978-1-4419-6902-6_6] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Neuropeptides are short sequences ofamino acids that function in all multicellular organisms to communicate information between cells. The first sequence ofa neuropeptide was reported in 1970' and the number of identified neuropeptides remained relatively small until the 1990s when the DNA sequence of multiple genomes revealed treasure troves ofinformation. Byblasting away at the genome, gene families, the sizes ofwhich were previously unknown, could now be determined. This information has led to an exponential increase in the number of putative neuropeptides and their respective gene families. The molecular biology age greatly benefited the neuropeptide field in the nematode Caenorhabditis elegans. Its genome was among the first to be sequenced and this allowed us the opportunity to screen the genome for neuropeptide genes. Initially, the screeningwas slow, as the Genefinder and BLAST programs had difficulty identifying small genes and peptides. However, as the bioinformatics programs improved, the extent of the neuropeptide gene families in C. elegans gradually emerged.
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