1
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Parvand M, Liang JJH, Bozorgmehr T, Born D, Luna Cortes A, Rankin CH. A familial Alzheimer's disease associated mutation in presenilin-1 mediates amyloid-beta independent cell specific neurodegeneration. PLoS One 2024; 19:e0289435. [PMID: 39240956 PMCID: PMC11379242 DOI: 10.1371/journal.pone.0289435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 08/23/2024] [Indexed: 09/08/2024] Open
Abstract
Mutations in the presenilin (PS) genes are a predominant cause of familial Alzheimer's disease (fAD). An ortholog of PS in the genetic model organism Caenorhabditis elegans (C. elegans) is sel-12. Mutations in the presenilin genes are commonly thought to lead to fAD by upregulating the expression of amyloid beta (Aβ), however this hypothesis has been challenged by recent evidence. As C. elegans lack amyloid beta (Aβ), the goal of this work was to examine Aβ-independent effects of mutations in sel-12 and PS1/PS2 on behaviour and sensory neuron morphology across the lifespan in a C. elegans model. Olfactory chemotaxis experiments were conducted on sel-12(ok2078) loss-of-function mutant worms. Adult sel-12 mutant worms showed significantly lower levels of chemotaxis to odorants compared to wild-type worms throughout their lifespan, and this deficit increased with age. The chemotaxis phenotype in sel-12 mutant worms is rescued by transgenic over-expression of human wild-type PS1, but not the classic fAD-associated variant PS1C410Y, when expression was driven by either the endogenous sel-12 promoter (Psel-12), a pan-neuronal promoter (Primb-1), or by a promoter whose primary expression was in the sensory neurons responsible for the chemotaxis behavior (Psra-6, Podr-10). The behavioural phenotype was also rescued by over-expressing an atypical fAD-linked mutation in PS1 (PS1ΔS169) that has been reported to leave the Notch pathway intact. An examination of the morphology of polymodal nociceptive (ASH) neurons responsible for the chemotaxis behavior also showed increased neurodegeneration over time in sel-12 mutant worms that could be rescued by the same transgenes that rescued the behaviour, demonstrating a parallel with the observed behavioral deficits. Thus, we report an Aβ-independent neurodegeneration in C. elegans that was rescued by cell specific over-expression of wild-type human presenilin.
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Affiliation(s)
- Mahraz Parvand
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Joseph J H Liang
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tahereh Bozorgmehr
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dawson Born
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alvaro Luna Cortes
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Catharine H Rankin
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Psychology, University of British Columbia, Vancouver, BC, Canada
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2
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Panska L, Nedvedova S, Vacek V, Krivska D, Konecny L, Knop F, Kutil Z, Skultetyova L, Leontovyc A, Ulrychova L, Sakanari J, Asahina M, Barinka C, Macurkova M, Dvorak J. Uncovering the essential roles of glutamate carboxypeptidase 2 orthologs in Caenorhabditis elegans. Biosci Rep 2024; 44:BSR20230502. [PMID: 38108122 PMCID: PMC10794815 DOI: 10.1042/bsr20230502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 12/13/2023] [Accepted: 12/15/2023] [Indexed: 12/19/2023] Open
Abstract
Human glutamate carboxypeptidase 2 (GCP2) from the M28B metalloprotease group is an important target for therapy in neurological disorders and an established tumor marker. However, its physiological functions remain unclear. To better understand general roles, we used the model organism Caenorhabditis elegans to genetically manipulate its three existing orthologous genes and evaluate the impact on worm physiology. The results of gene knockout studies showed that C. elegans GCP2 orthologs affect the pharyngeal physiology, reproduction, and structural integrity of the organism. Promoter-driven GFP expression revealed distinct localization for each of the three gene paralogs, with gcp-2.1 being most abundant in muscles, intestine, and pharyngeal interneurons, gcp-2.2 restricted to the phasmid neurons, and gcp-2.3 located in the excretory cell. The present study provides new insight into the unique phenotypic effects of GCP2 gene knockouts in C. elegans, and the specific tissue localizations. We believe that elucidation of particular roles in a non-mammalian organism can help to explain important questions linked to physiology of this protease group and in extension to human GCP2 involvement in pathophysiological processes.
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Affiliation(s)
- Lucie Panska
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
- Faculty of Environmental Sciences, Center of Infectious Animal Diseases, Czech University of Life Sciences in Prague, Kamycka 129, Prague 165 00, Czech Republic
| | - Stepanka Nedvedova
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
- Department of Chemistry, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
| | - Vojtech Vacek
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
| | - Daniela Krivska
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
- Department of Chemistry, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
| | - Lukas Konecny
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
- Department of Parasitology, Faculty of Science, Charles University, Vinicna 7, Prague 2 128 00, Czech Republic
| | - Filip Knop
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, Prague 2 128 00, Czech Republic
| | - Zsofia Kutil
- Laboratory of Structural Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, Vestec 252 50, Czech Republic
| | - Lubica Skultetyova
- Laboratory of Structural Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, Vestec 252 50, Czech Republic
| | - Adrian Leontovyc
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo n. 2, Prague 160 00, Czech Republic
| | - Lenka Ulrychova
- Department of Parasitology, Faculty of Science, Charles University, Vinicna 7, Prague 2 128 00, Czech Republic
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo n. 2, Prague 160 00, Czech Republic
| | - Judy Sakanari
- Department of Pharmaceutical Chemistry, University of California, San Francisco, 1700 4th Street, CA 94143, USA
| | - Masako Asahina
- Department of Physiology, University of California, San Francisco, 600 16th Street, CA 94143, U.S.A
| | - Cyril Barinka
- Laboratory of Structural Biology, Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, Vestec 252 50, Czech Republic
| | - Marie Macurkova
- Department of Cell Biology, Faculty of Science, Charles University, Vinicna 7, Prague 2 128 00, Czech Republic
| | - Jan Dvorak
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 165 00, Czech Republic
- Faculty of Environmental Sciences, Center of Infectious Animal Diseases, Czech University of Life Sciences in Prague, Kamycka 129, Prague 165 00, Czech Republic
- Institute of Organic Chemistry and Biochemistry, The Czech Academy of Sciences, Flemingovo n. 2, Prague 160 00, Czech Republic
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3
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Barmaver SN, Muthaiyan Shanmugam M, Chang Y, Bayansan O, Bhan P, Wu GH, Wagner OI. Loss of intermediate filament IFB-1 reduces mobility, density and physiological function of mitochondria in C. elegans sensory neurons. Traffic 2022; 23:270-286. [PMID: 35261124 DOI: 10.1111/tra.12838] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 03/03/2022] [Accepted: 03/06/2022] [Indexed: 11/26/2022]
Abstract
Mitochondria and intermediate filament (IF) accumulations often occur during imbalanced axonal transport leading to various types of neurological diseases. It is still poorly understood whether a link between neuronal IFs and mitochondrial mobility exist. In C. elegans, among the 11 cytoplasmic IF family proteins, IFB-1 is of particular interest as it is expressed in a subset of sensory neurons. Depletion of IFB-1 leads to mild dye-filling and significant chemotaxis defects as well as reduced life span. Sensory neuron development is affected and mitochondria transport is slowed down leading to reduced densities of these organelles. Mitochondria tend to cluster in neurons of IFB-1 mutants likely independent of the fission and fusion machinery. Oxygen consumption and mitochondrial membrane potential is measurably reduced in worms carrying mutations in the ifb-1 gene. Membrane potential also seems to play a role in transport such as FCCP treatment led to increased directional switching of mitochondria. Mitochondria colocalize with IFB-1 in worm neurons and appear in a complex with IFB-1 in pull-down assays. In summary, we propose a model in which neuronal intermediate filaments may serve as critical (transient) anchor points for mitochondria during their long-range transport in neurons for steady and balanced transport. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Syed Nooruzuha Barmaver
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan (R.O.C.)
| | - Muniesh Muthaiyan Shanmugam
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan (R.O.C.)
| | - Yen Chang
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan (R.O.C.)
| | - Odvogmed Bayansan
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan (R.O.C.)
| | - Prerana Bhan
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan (R.O.C.).,Research Center for Healthy Aging, China Medical University, Taichung, Taiwan (R.O.C.)
| | - Gong-Her Wu
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan (R.O.C.)
| | - Oliver I Wagner
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan (R.O.C.)
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4
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Garg P, Tan CH, Sternberg PW. DiI staining of sensory neurons in the entomopathogenic nematode Steinernema hermaphroditum. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000516. [PMID: 35224464 PMCID: PMC8874337 DOI: 10.17912/micropub.biology.000516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 01/26/2022] [Accepted: 02/10/2022] [Indexed: 11/06/2022]
Abstract
Steinernema hermaphroditum entomopathogenic nematodes (EPN) and their Xenorhabdus griffiniae symbiotic bacteria have recently been shown to be a genetically tractable system for the study of both parasitic and mutualistic symbiosis. In their infective juvenile (IJ) stage, EPNs search for insect hosts to invade and quickly kill them with the help of the symbiotic bacteria they contain. The mechanisms behind these behaviors have not been well characterized, including how the nematodes sense their insect hosts. In the well-studied free‑living soil nematode Caenorhabditis elegans, ciliated amphid neurons enable the worms to sense their environment, including chemosensation. Some of these neurons have also been shown to control the decision to develop as a stress-resistant dauer larva, analogous to the infective juveniles of EPNs, or to exit from dauer and resume larval development. In C. elegans and other nematodes, dye-filling with DiI is an easy and efficient method to label these neurons. We developed a protocol for DiI staining of S. hermaphroditum sensory neurons. Using this method, we could identify neurons positionally analogous to the C. elegans amphid neurons ASI, ADL, ASK, ASJ, as well as inner labial neurons IL1 and IL2. Similar to findings in other EPNs, we also found that the IJs of S. hermaphroditum are dye-filling resistant.
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Affiliation(s)
- Pranjal Garg
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA,
Current Address: All India Institutes of Medical Sciences, Rishikesh, Virbhadra Road, Rishikesh, Uttarakhand 249203, India
| | - Chieh-Hsiang Tan
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA
| | - Paul W. Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA,
Correspondence to: Paul W. Sternberg ()
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5
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Emmons SW, Yemini E, Zimmer M. Methods for analyzing neuronal structure and activity in Caenorhabditis elegans. Genetics 2021; 218:6303616. [PMID: 34151952 DOI: 10.1093/genetics/iyab072] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 04/20/2021] [Indexed: 11/12/2022] Open
Abstract
The model research animal Caenorhabditis elegans has unique properties making it particularly advantageous for studies of the nervous system. The nervous system is composed of a stereotyped complement of neurons connected in a consistent manner. Here, we describe methods for studying nervous system structure and function. The transparency of the animal makes it possible to visualize and identify neurons in living animals with fluorescent probes. These methods have been recently enhanced for the efficient use of neuron-specific reporter genes. Because of its simple structure, for a number of years, C. elegans has been at the forefront of connectomic studies defining synaptic connectivity by electron microscopy. This field is burgeoning with new, more powerful techniques, and recommended up-to-date methods are here described that encourage the possibility of new work in C. elegans. Fluorescent probes for single synapses and synaptic connections have allowed verification of the EM reconstructions and for experimental approaches to synapse formation. Advances in microscopy and in fluorescent reporters sensitive to Ca2+ levels have opened the way to observing activity within single neurons across the entire nervous system.
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Affiliation(s)
- Scott W Emmons
- Department of Genetics and Dominick Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 1041, USA
| | - Eviatar Yemini
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, NY 10027, USA
| | - Manuel Zimmer
- Department of Neuroscience and Developmental Biology, University of Vienna, Vienna 1090, Austria and.,Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna 1030, Austria
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6
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Niemuth N, Williams DN, Mensch AC, Cui Y, Orr G, Rosenzweig Z, Klaper RD. Redesign of hydrophobic quantum dots mitigates ligand-dependent toxicity in the nematode C. elegans. NANOIMPACT 2021; 22:100318. [PMID: 35559975 DOI: 10.1016/j.impact.2021.100318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/22/2021] [Accepted: 04/12/2021] [Indexed: 06/15/2023]
Abstract
Surface properties of engineered nanomaterials (ENMs) have been shown to influence their interaction with biological systems. However, studies to date have largely focused on hydrophilic materials, likely due to biocompatibility concerns and aqueous exposure conditions necessary for many model systems. Therefore, a knowledge gap exists in nanotoxicity literature for impacts of hydrophobic ENMs, with studies of hydrophobic materials largely limited to carbon ENMs. Here we demonstrate testing of hydrophobic quantum dots (QDs) using the nematode C. elegans, a model soil organism cultured on solid media and amenable to hydrophobic exposures. To evaluate the influence of hydrophobicity, we compared CdSe/ZnS QDs functionalized with hydrophobic trioctylphosphine oxide (TOPO) to identical QDs functionalized with hydrophilic dihydrolipoic acid-polyethylene glycol (DHLA-PEG) and alternative hydrophobic CdSe/ZnS QDs functionalized with oleic acid (OA). Results show that hydrophobic TOPO QDs are significantly more toxic than hydrophilic DHLA-PEG QDs, and substitution of TOPO with OA yields relatively non-toxic hydrophobic QDs. Fluorescence microscopy shows TOPO QDs loosely associated with the organism's cuticle, but atomic force microscopy shows no difference in cuticle structure from exposure. Importantly, TOPO ligand alone is as toxic as TOPO QDs, and our data suggests that TOPO may impact neuromuscular function, perhaps upon displacement from the QD surface. This study demonstrates the importance of examining ligand-specific impacts of hydrophobic ENMs and indicates OA-functionalized QDs as a potential alternative to TOPO QDs for reduced toxicity.
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Affiliation(s)
- NicholasJ Niemuth
- School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 E Greenfield Ave., Milwaukee, WI 53204, United States
| | - Denise N Williams
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, United States
| | - Arielle C Mensch
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Yi Cui
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Galya Orr
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Ze'ev Rosenzweig
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County, Baltimore, MD 21250, United States
| | - Rebecca D Klaper
- School of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 E Greenfield Ave., Milwaukee, WI 53204, United States.
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7
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Guha S, Pujol A, Dalfo E. Anti-oxidant MitoQ rescue of AWB chemosensory neuron impairment in a C. elegans model of X-linked Adrenoleukodystrophy. MICROPUBLICATION BIOLOGY 2021; 2021. [PMID: 33474532 PMCID: PMC7812386 DOI: 10.17912/micropub.biology.000346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
X-linked Adrenoleukodystrophy (X-ALD) is a neurometabolic disorder caused by a defective peroxisomal ABCD1 transporter of very long-chain fatty acids (VLCFAs). We have characterized a nematode model of X-ALD with loss of the pmp-4 gene, the worm orthologue of ABCD1. These mutants recapitulated the key hallmarks of X-ALD and importantly mitochondria targeted antioxidant MitoQ prevented axonal degeneration and locomotor disability. In this study, we further demonstrated that the AWB chemosensory neuron of the pmp-4 mutant worm is defective, both in morphology and function. Interestingly, MitoQ could rescue both the phenotypes. Collectively, our results suggest that C. elegans’ chemosensation might provide a novel setting for exploring peroxisomal disease related disorders.
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Affiliation(s)
- Sanjib Guha
- University of Rochester, Department of Anesthesiology & Perioperative Medicine, Rochester, NY
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain.,Catalan Institution of Research and Advanced Studies (ICREA), Barcelona, Catalonia, Spain
| | - Esther Dalfo
- Faculty of Medicine, University of Vic-Central University of Catalonia (UVic-UCC), 08500 Vic, Spain.,Institut de Neurociències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.,Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
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8
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Podraza-Farhanieh A, Natarajan B, Raj D, Kao G, Naredi P. ENPL-1, the Caenorhabditis elegans homolog of GRP94, promotes insulin secretion via regulation of proinsulin processing and maturation. Development 2020; 147:dev190082. [PMID: 33037039 PMCID: PMC10666919 DOI: 10.1242/dev.190082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 09/28/2020] [Indexed: 12/27/2022]
Abstract
Insulin/IGF signaling in Caenorhabditis elegans is crucial for proper development of the dauer larva and growth control. Mutants disturbing insulin processing, secretion and downstream signaling perturb this process and have helped identify genes that affect progression of type 2 diabetes. Insulin maturation is required for its proper secretion by pancreatic β cells. The role of the endoplasmic reticulum (ER) chaperones in insulin processing and secretion needs further study. We show that the C. elegans ER chaperone ENPL-1/GRP94 (HSP90B1), acts in dauer development by promoting insulin secretion and signaling. Processing of a proinsulin likely involves binding between the two proteins via a specific domain. We show that, in enpl-1 mutants, an unprocessed insulin exits the ER lumen and is found in dense core vesicles, but is not secreted. The high ER stress in enpl-1 mutants does not cause the secretion defect. Importantly, increased ENPL-1 levels result in increased secretion. Taken together, our work indicates that ENPL-1 operates at the level of insulin availability and is an essential modulator of insulin processing and secretion.
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Affiliation(s)
- Agnieszka Podraza-Farhanieh
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, SE413 45 Gothenburg, Sweden
| | | | - Dorota Raj
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, SE413 45 Gothenburg, Sweden
| | - Gautam Kao
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, SE413 45 Gothenburg, Sweden
| | - Peter Naredi
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, SE413 45 Gothenburg, Sweden
- Department of Surgery, Sahlgrenska University Hospital, SE413 45 Gothenburg, Sweden
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9
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Fadda M, De Fruyt N, Borghgraef C, Watteyne J, Peymen K, Vandewyer E, Naranjo Galindo FJ, Kieswetter A, Mirabeau O, Chew YL, Beets I, Schoofs L. NPY/NPF-Related Neuropeptide FLP-34 Signals from Serotonergic Neurons to Modulate Aversive Olfactory Learning in Caenorhabditis elegans. J Neurosci 2020; 40:6018-6034. [PMID: 32576621 PMCID: PMC7392509 DOI: 10.1523/jneurosci.2674-19.2020] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 04/26/2020] [Accepted: 06/12/2020] [Indexed: 02/03/2023] Open
Abstract
Aversive learning is fundamental for animals to increase chances of survival. In addition to classical neurotransmitters, neuropeptides have emerged to modulate such complex behaviors. Among them, neuropeptide Y (NPY) is well known to promote aversive memory acquisition in mammals. Here we identify an NPY/neuropeptide F (NPF)-related neuropeptide system in Caenorhabditis elegans and show that this FLP-34/NPR-11 system is required for learning negative associations, a process that is reminiscent of NPY signaling in mammals. The Caenorhabditis elegans NPY/NPF ortholog FLP-34 displays conserved structural hallmarks of bilaterian-wide NPY/NPF neuropeptides. We show that it is required for aversive olfactory learning after pairing diacetyl with the absence of food, but not for appetitive olfactory learning in response to butanone. To mediate diacetyl learning and thus integrate the aversive food context with the diacetyl odor, FLP-34 is released from serotonergic neurons and signals through its evolutionarily conserved NPY/NPF GPCR, NPR-11, in downstream AIA interneurons. NPR-11 activation in the AIA integration center results in avoidance of a previously attractive stimulus. This study opens perspectives for a deeper understanding of stress conditions in which aversive learning results in excessive avoidance.SIGNIFICANCE STATEMENT Aversive learning evolved early in evolution to promote avoidance of dangerous and stressful situations. In addition to classical neurotransmitters, neuropeptides are emerging as modulators of complex behaviors, including learning and memory. Here, we identified the evolutionary ortholog of neuropeptide Y/neuropeptide F in the nematode Caenorhabditis elegans, and we discovered that it is required for olfactory aversive learning. In addition, we elucidated the neural circuit underlying this avoidance behavior, and we discovered a novel coordinated action of Caenorhabditis elegans neuropeptide Y/neuropeptide F and serotonin that could aid in our understanding of the molecular mechanisms underlying stress disorders in which excessive avoidance results in maladaptive behaviors.
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Affiliation(s)
- Melissa Fadda
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
| | | | | | - Jan Watteyne
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
| | | | | | | | | | - Olivier Mirabeau
- Genetics and Biology of Cancers Unit, Institut Curie, Institut National de la Santé et de la Recherche Médicale U830, Paris Sciences et Lettres Research University, Paris, 75005, France
| | - Yee Lian Chew
- Illawarra Health & Medical Research Institute School of Chemistry & Molecular Bioscience, University of Wollongong, Wollongong, 2522 New South Wales, Australia
| | - Isabel Beets
- Department of Biology, KU Leuven, Leuven, 3000, Belgium
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10
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Bai X, Melesse M, Sorensen Turpin CG, Sloan DE, Chen CY, Wang WC, Lee PY, Simmons JR, Nebenfuehr B, Mitchell D, Klebanow LR, Mattson N, Betzig E, Chen BC, Cheerambathur D, Bembenek JN. Aurora B functions at the apical surface after specialized cytokinesis during morphogenesis in C. elegans. Development 2020; 147:dev.181099. [PMID: 31806662 PMCID: PMC6983721 DOI: 10.1242/dev.181099] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 11/26/2019] [Indexed: 12/18/2022]
Abstract
Although cytokinesis has been intensely studied, the way it is executed during development is not well understood, despite a long-standing appreciation that various aspects of cytokinesis vary across cell and tissue types. To address this, we investigated cytokinesis during the invariant Caenorhabditis elegans embryonic divisions and found several parameters that are altered at different stages in a reproducible manner. During early divisions, furrow ingression asymmetry and midbody inheritance is consistent, suggesting specific regulation of these events. During morphogenesis, we found several unexpected alterations to cytokinesis, including apical midbody migration in polarizing epithelial cells of the gut, pharynx and sensory neurons. Aurora B kinase, which is essential for several aspects of cytokinesis, remains apically localized in each of these tissues after internalization of midbody ring components. Aurora B inactivation disrupts cytokinesis and causes defects in apical structures, even if inactivated post-mitotically. Therefore, we demonstrate that cytokinesis is implemented in a specialized way during epithelial polarization and that Aurora B has a role in the formation of the apical surface.
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Affiliation(s)
- Xiaofei Bai
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Michael Melesse
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | | | - Dillon E. Sloan
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA,Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Chin-Yi Chen
- Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan
| | - Wen-Cheng Wang
- Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan
| | - Po-Yi Lee
- Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan
| | - James R. Simmons
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Benjamin Nebenfuehr
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Diana Mitchell
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lindsey R. Klebanow
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Nicholas Mattson
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Eric Betzig
- Janelia Research Campus, HHMI, Ashburn, VA 20147, USA
| | - Bi-Chang Chen
- Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan,Janelia Research Campus, HHMI, Ashburn, VA 20147, USA
| | - Dhanya Cheerambathur
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
| | - Joshua N. Bembenek
- Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA,Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA,Author for correspondence ()
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11
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The NALCN Channel Regulator UNC-80 Functions in a Subset of Interneurons To Regulate Caenorhabditis elegans Reversal Behavior. G3-GENES GENOMES GENETICS 2020; 10:199-210. [PMID: 31690562 PMCID: PMC6945035 DOI: 10.1534/g3.119.400692] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
NALCN (Na+leak channel, non-selective) is a conserved, voltage-insensitive cation channel that regulates resting membrane potential and neuronal excitability. UNC79 and UNC80 are key regulators of the channel function. However, the behavioral effects of the channel complex are not entirely clear and the neurons in which the channel functions remain to be identified. In a forward genetic screen for C. elegans mutants with defective avoidance response to the plant hormone methyl salicylate (MeSa), we isolated multiple loss-of-function mutations in unc-80 and unc-79. C. elegans NALCN mutants exhibited similarly defective MeSa avoidance. Interestingly, NALCN, unc-80 and unc-79 mutants all showed wild type-like responses to other attractive or repelling odorants, suggesting that NALCN does not broadly affect odor detection or related forward and reversal behaviors. To understand in which neurons the channel functions, we determined the identities of a subset of unc-80-expressing neurons. We found that unc-79 and unc-80 are expressed and function in overlapping neurons, which verified previous assumptions. Neuron-specific transgene rescue and knockdown experiments suggest that the command interneurons AVA and AVE and the anterior guidepost neuron AVG can play a sufficient role in mediating unc-80 regulation of the MeSa avoidance. Though primarily based on genetic analyses, our results further imply that MeSa might activate NALCN by direct or indirect actions. Altogether, we provide an initial look into the key neurons in which the NALCN channel complex functions and identify a novel function of the channel in regulating C. elegans reversal behavior through command interneurons.
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12
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Sellegounder D, Liu Y, Wibisono P, Chen CH, Leap D, Sun J. Neuronal GPCR NPR-8 regulates C. elegans defense against pathogen infection. SCIENCE ADVANCES 2019; 5:eaaw4717. [PMID: 31799388 PMCID: PMC6867885 DOI: 10.1126/sciadv.aaw4717] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 09/17/2019] [Indexed: 05/18/2023]
Abstract
Increasing evidence indicates that infection-triggered host defenses are regulated by the nervous system. However, the precise mechanisms of this regulation are not well understood. Here, we demonstrate that neuronal G protein-coupled receptor NPR-8 negatively regulates Caenorhabditis elegans defense against pathogen infection by suppressing cuticular collagen expression. NPR-8 controls the dynamics of cuticle structure in response to infection, likely through its regulation of cuticular collagen genes which, in turn, affects the nematode's defense. We further show that the defense activity of NPR-8 is confined to amphid sensory neurons AWB, ASJ, and AWC. It is generally believed that physical barrier defenses are not a response to infections but are part of the body's basic innate defense against pathogens. Our results challenge this view by showing not only that C. elegans cuticle structure dynamically changes in response to infection but also that the cuticle barrier defense is regulated by the nervous system.
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Affiliation(s)
- Durai Sellegounder
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Yiyong Liu
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
- Genomics Core, Washington State University, Spokane, WA, USA
| | - Phillip Wibisono
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Chia-Hui Chen
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - David Leap
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | - Jingru Sun
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
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13
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mir-234 controls neuropeptide release at the Caenorhabditis elegans neuromuscular junction. Mol Cell Neurosci 2019; 98:70-81. [PMID: 31200102 DOI: 10.1016/j.mcn.2019.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 06/05/2019] [Accepted: 06/06/2019] [Indexed: 01/16/2023] Open
Abstract
miR-137 is a highly conserved microRNA (miRNA) that is associated with the control of brain function and the etiology of psychiatric disorders including schizophrenia and bipolar disorder. The Caenorhabditis elegans genome encodes a single miR-137 ortholog called mir-234, the function of which is unknown. Here we show that mir-234 is expressed in a subset of sensory, motor and interneurons in C. elegans. Using a mir-234 deletion strain, we systematically examined the development and function of these neurons in addition to global C. elegans behaviors. We were however unable to detect phenotypes associated with loss of mir-234, possibly due to genetic redundancy. To circumvent this issue, we overexpressed mir-234 in mir-234-expressing neurons to uncover possible phenotypes. We found that mir-234-overexpression endows resistance to the acetylcholinesterase inhibitor aldicarb, suggesting modification of neuromuscular junction (NMJ) function. Further analysis revealed that mir-234 controls neuropeptide levels, therefore positing a cause of NMJ dysfunction. Together, our data suggest that mir-234 functions to control the expression of target genes that are important for neuropeptide maturation and/or transport in C. elegans. SIGNIFICANCE STATEMENT: The miR-137 family of miRNAs is linked to the control of brain function in humans. Defective regulation of miR-137 is associated with psychiatric disorders that include schizophrenia and bipolar disorder. Previous studies have revealed that miR-137 is required for the development of dendrites and for controlling the release of fast-acting neurotransmitters. Here, we analyzed the function a miR-137 family member (called mir-234) in the nematode animal model using anatomical, behavioral, electrophysiological and neuropeptide analysis. We reveal for the first time that mir-234/miR-137 is required for the release of slow-acting neuropeptides, which may also be of relevance for controlling human brain function.
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14
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Peymen K, Watteyne J, Borghgraef C, Van Sinay E, Beets I, Schoofs L. Myoinhibitory peptide signaling modulates aversive gustatory learning in Caenorhabditis elegans. PLoS Genet 2019; 15:e1007945. [PMID: 30779740 PMCID: PMC6380545 DOI: 10.1371/journal.pgen.1007945] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 01/07/2019] [Indexed: 11/18/2022] Open
Abstract
Aversive learning and memories are crucial for animals to avoid previously encountered stressful stimuli and thereby increase their chance of survival. Neuropeptides are essential signaling molecules in the brain and are emerging as important modulators of learned behaviors, but their precise role is not well understood. Here, we show that neuropeptides of the evolutionarily conserved MyoInhibitory Peptide (MIP)-family modify salt chemotaxis behavior in Caenorhabditis elegans according to previous experience. MIP signaling, through activation of the G protein-coupled receptor SPRR-2, is required for short-term gustatory plasticity. In addition, MIP/SPRR-2 neuropeptide-receptor signaling mediates another type of aversive gustatory learning called salt avoidance learning that depends on de novo transcription, translation and the CREB transcription factor, all hallmarks of long-term memory. MIP/SPRR-2 signaling mediates salt avoidance learning in parallel with insulin signaling. These findings lay a foundation to investigate the suggested orphan MIP receptor orthologs in deuterostomians, including human GPR139 and GPR142. All animals rely on learning and memory processes to learn from experience and thereby increase their chance of survival. Neuropeptides are essential signaling molecules in the brain and are emerging as important modulators of learning and memory processes. We found that the C. elegans receptor SPRR-2 and its ligands, the MIP-1 neuropeptides—which are members of the evolutionarily conserved myoinhibitory peptide system—are required for aversive gustatory learning. Our results provide a basis for investigations into the poorly characterized MIP systems in deuterostomians, including humans, and suggest a possible function in learning for human MIP signaling.
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Affiliation(s)
- Katleen Peymen
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Jan Watteyne
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | | | - Elien Van Sinay
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
| | - Isabel Beets
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
- * E-mail: (IB); (LS)
| | - Liliane Schoofs
- Department of Biology, University of Leuven (KU Leuven), Leuven, Belgium
- * E-mail: (IB); (LS)
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15
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Muthaiyan Shanmugam M, Bhan P, Huang HY, Hsieh J, Hua TE, Wu GH, Punjabi H, Lee Aplícano VD, Chen CW, Wagner OI. Cilium Length and Intraflagellar Transport Regulation by Kinases PKG-1 and GCK-2 in Caenorhabditis elegans Sensory Neurons. Mol Cell Biol 2018; 38:e00612-17. [PMID: 29378827 PMCID: PMC5854826 DOI: 10.1128/mcb.00612-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 12/21/2017] [Accepted: 01/18/2018] [Indexed: 12/31/2022] Open
Abstract
To understand how ciliopathies such as polycystic kidney disease or Bardet-Biedl syndrome develop, we need to understand the basic molecular mechanisms underlying cilium development. Cilium growth depends on the presence of functional intraflagellar transport (IFT) machinery, and we hypothesized that various kinases and phosphatases might be involved in this regulatory process. A candidate screen revealed two kinases, PKG-1 (a cGMP-dependent protein kinase) and GCK-2 (a mitogen-activated protein kinase kinase kinase kinase 3 [MAP4K3] kinase involved in mTOR signaling), significantly affecting dye filling, chemotaxis, cilium morphology, and IFT component distribution. PKG-1 and GCK-2 show similar expression patterns in Caenorhabditis elegans cilia and colocalize with investigated IFT machinery components. In pkg-1 mutants, a high level of accumulation of kinesin-2 OSM-3 in distal segments was observed in conjunction with an overall reduction of anterograde and retrograde IFT particle A transport, likely as a function of reduced tubulin acetylation. In contrast, in gck-2 mutants, both kinesin-2 motility and IFT particle A motility were significantly elevated in the middle segments, in conjunction with increased tubulin acetylation, possibly the cause of longer cilium growth. Observed effects in mutants can be also seen in manipulating upstream and downstream effectors of the respective cGMP and mTOR pathways. Importantly, transmission electron microscopy (TEM) analysis revealed no structural changes in cilia of pkg-1 and gck-2 mutants.
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Affiliation(s)
- Muniesh Muthaiyan Shanmugam
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Prerana Bhan
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Hsin-Yi Huang
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Jung Hsieh
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Tzu-En Hua
- Electron Microscopy Core Facility, Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Gong-Her Wu
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Helly Punjabi
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Víctor Daniel Lee Aplícano
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Chih-Wei Chen
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
| | - Oliver Ingvar Wagner
- National Tsing Hua University, Institute of Molecular and Cellular Biology, Department of Life Science, Hsinchu, Taiwan, Republic of China
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16
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Moreno E, Sieriebriennikov B, Witte H, Rödelsperger C, Lightfoot JW, Sommer RJ. Regulation of hyperoxia-induced social behaviour in Pristionchus pacificus nematodes requires a novel cilia-mediated environmental input. Sci Rep 2017; 7:17550. [PMID: 29242625 PMCID: PMC5730589 DOI: 10.1038/s41598-017-18019-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 12/04/2017] [Indexed: 01/17/2023] Open
Abstract
Social behaviours are frequently utilised for defence and stress avoidance in nature. Both Caenorhabditis elegans and Pristionchus pacificus nematodes display social behaviours including clumping and bordering, to avoid hyperoxic stress conditions. Additionally, both species show natural variation in social behaviours with “social” and “solitary” strains. While the single solitary C. elegans N2 strain has evolved under laboratory domestication due to a gain-of-function mutation in the neuropeptide receptor gene npr-1, P. pacificus solitary strains are commonplace and likely ancestral. P. pacificus therefore provides an opportunity to further our understanding of the mechanisms regulating these complex behaviours and how they evolved within an ecologically relevant system. Using CRISPR/Cas9 engineering, we show that Ppa-npr-1 has minimal influence on social behaviours, indicating independent evolutionary pathways compared to C. elegans. Furthermore, solitary P. pacificus strains show an unexpected locomotive response to hyperoxic conditions, suggesting a novel regulatory mechanism counteracting social behaviours. By utilising both forward and reverse genetic approaches we identified 10 genes of the intraflagellar transport machinery in ciliated neurons that are essential for this inhibition. Therefore, a novel cilia-mediated environmental input adds an additional level of complexity to the regulation of hyperoxia-induced social behaviours in P. pacificus, a mechanism unknown in C. elegans.
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Affiliation(s)
- Eduardo Moreno
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, 72076, Tübingen, Germany
| | - Bogdan Sieriebriennikov
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, 72076, Tübingen, Germany
| | - Hanh Witte
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, 72076, Tübingen, Germany
| | - Christian Rödelsperger
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, 72076, Tübingen, Germany
| | - James W Lightfoot
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, 72076, Tübingen, Germany
| | - Ralf J Sommer
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, 72076, Tübingen, Germany.
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17
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Dube S, Dube H, Green NB, Larsen EM, White A, Johnson RJ, Kowalski JR. In Vivo Delivery and Activation of Masked Fluorogenic Hydrolase Substrates by Endogenous Hydrolases in C. elegans. Chembiochem 2017; 18:1807-1813. [PMID: 28703362 DOI: 10.1002/cbic.201700278] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Indexed: 01/01/2023]
Abstract
Protein expression and localization are often studied in vivo by tagging molecules with green fluorescent protein (GFP), yet subtle changes in protein levels are not easily detected. To develop a sensitive in vivo method to amplify fluorescence signals and allow cell-specific quantification of protein abundance changes, we sought to apply an enzyme-activated cellular fluorescence system in vivo by delivering ester-masked fluorophores to Caenorhabditis elegans neurons expressing porcine liver esterase (PLE). To aid uptake into sensory neuron membranes, we synthesized two novel fluorogenic hydrolase substrates with long hydrocarbon tails. Recombinant PLE activated these fluorophores in vitro. In vivo activation occurred in sensory neurons, along with potent activation in intestinal lysosomes quantifiable by imaging and microplate and partially attributable to gut esterase 1 (GES-1) activity. These data demonstrate the promise of biorthogonal hydrolases and their fluorogenic substrates as in vivo neuronal imaging tools and for characterizing endogenous C. elegans hydrolase substrate specificities.
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Affiliation(s)
- Shataakshi Dube
- Department of Biological Sciences, Butler University, 4600 Sunset Avenue, Indianapolis, IN, 46208, USA
| | - Hitesh Dube
- Department of Biological Sciences, Butler University, 4600 Sunset Avenue, Indianapolis, IN, 46208, USA.,Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Avenue, Indianapolis, IN, 46208, USA
| | - Nicole B Green
- Department of Biological Sciences, Butler University, 4600 Sunset Avenue, Indianapolis, IN, 46208, USA.,Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Avenue, Indianapolis, IN, 46208, USA
| | - Erik M Larsen
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Avenue, Indianapolis, IN, 46208, USA
| | - Alex White
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Avenue, Indianapolis, IN, 46208, USA
| | - R Jeremy Johnson
- Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Avenue, Indianapolis, IN, 46208, USA
| | - Jennifer R Kowalski
- Department of Biological Sciences, Butler University, 4600 Sunset Avenue, Indianapolis, IN, 46208, USA
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18
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The Bright Fluorescent Protein mNeonGreen Facilitates Protein Expression Analysis In Vivo. G3-GENES GENOMES GENETICS 2017; 7:607-615. [PMID: 28108553 PMCID: PMC5295605 DOI: 10.1534/g3.116.038133] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The Green Fluorescent Protein (GFP) has been tremendously useful in investigating cell architecture, protein localization, and protein function. Recent developments in transgenesis and genome editing methods now enable working with fewer transgene copies and, consequently, with physiological expression levels. However, lower signal intensity might become a limiting factor. The recently developed mNeonGreen protein is a brighter alternative to GFP in vitro. The goal of the present study was to determine how mNeonGreen performs in vivo in Caenorhabditis elegans—a model used extensively for fluorescence imaging in intact animals. We started with a side-by-side comparison between cytoplasmic forms of mNeonGreen and GFP expressed in the intestine, and in different neurons, of adult animals. While both proteins had similar photostability, mNeonGreen was systematically 3–5 times brighter than GFP. mNeonGreen was also used successfully to trace endogenous proteins, and label specific subcellular compartments such as the nucleus or the plasma membrane. To further demonstrate the utility of mNeonGreen, we tested transcriptional reporters for nine genes with unknown expression patterns. While mNeonGreen and GFP reporters gave overall similar expression patterns, low expression tissues were detected only with mNeonGreen. As a whole, our work establishes mNeonGreen as a brighter alternative to GFP for in vivo imaging in a multicellular organism. Furthermore, the present research illustrates the utility of mNeonGreen to tag proteins, mark subcellular regions, and describe new expression patterns, particularly in tissues with low expression.
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19
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Grussendorf KA, Trezza CJ, Salem AT, Al-Hashimi H, Mattingly BC, Kampmeyer DE, Khan LA, Hall DH, Göbel V, Ackley BD, Buechner M. Facilitation of Endosomal Recycling by an IRG Protein Homolog Maintains Apical Tubule Structure in Caenorhabditis elegans. Genetics 2016; 203:1789-806. [PMID: 27334269 PMCID: PMC4981278 DOI: 10.1534/genetics.116.192559] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 06/15/2016] [Indexed: 02/08/2023] Open
Abstract
Determination of luminal diameter is critical to the function of small single-celled tubes. A series of EXC proteins, including EXC-1, prevent swelling of the tubular excretory canals in Caenorhabditis elegans In this study, cloning of exc-1 reveals it to encode a homolog of mammalian IRG proteins, which play roles in immune response and autophagy and are associated with Crohn's disease. Mutants in exc-1 accumulate early endosomes, lack recycling endosomes, and exhibit abnormal apical cytoskeletal structure in regions of enlarged tubules. EXC-1 interacts genetically with two other EXC proteins that also affect endosomal trafficking. In yeast two-hybrid assays, wild-type and putative constitutively active EXC-1 binds to the LIM-domain protein EXC-9, whose homolog, cysteine-rich intestinal protein, is enriched in mammalian intestine. These results suggest a model for IRG function in forming and maintaining apical tubule structure via regulation of endosomal recycling.
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Affiliation(s)
- Kelly A Grussendorf
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045 Department of Biological Sciences, Minnesota State University, Mankato, Minnesota 56001
| | - Christopher J Trezza
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Alexander T Salem
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Hikmat Al-Hashimi
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Brendan C Mattingly
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Drew E Kampmeyer
- Department of Biological Sciences, Minnesota State University, Mankato, Minnesota 56001
| | - Liakot A Khan
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114
| | - David H Hall
- Department of Neuroscience, Center for Caenorhabditis elegans Anatomy, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Verena Göbel
- Mucosal Immunology and Biology Research Center, Developmental Biology and Genetics Core, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114
| | - Brian D Ackley
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
| | - Matthew Buechner
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045
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20
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Li C, Jensen VL, Park K, Kennedy J, Garcia-Gonzalo FR, Romani M, De Mori R, Bruel AL, Gaillard D, Doray B, Lopez E, Rivière JB, Faivre L, Thauvin-Robinet C, Reiter JF, Blacque OE, Valente EM, Leroux MR. MKS5 and CEP290 Dependent Assembly Pathway of the Ciliary Transition Zone. PLoS Biol 2016; 14:e1002416. [PMID: 26982032 PMCID: PMC4794247 DOI: 10.1371/journal.pbio.1002416] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 02/24/2016] [Indexed: 11/19/2022] Open
Abstract
Cilia have a unique diffusion barrier (“gate”) within their proximal region, termed transition zone (TZ), that compartmentalises signalling proteins within the organelle. The TZ is known to harbour two functional modules/complexes (Meckel syndrome [MKS] and Nephronophthisis [NPHP]) defined by genetic interaction, interdependent protein localisation (hierarchy), and proteomic studies. However, the composition and molecular organisation of these modules and their links to human ciliary disease are not completely understood. Here, we reveal Caenorhabditis elegans CEP-290 (mammalian Cep290/Mks4/Nphp6 orthologue) as a central assembly factor that is specific for established MKS module components and depends on the coiled coil region of MKS-5 (Rpgrip1L/Rpgrip1) for TZ localisation. Consistent with a critical role in ciliary gate function, CEP-290 prevents inappropriate entry of membrane-associated proteins into cilia and keeps ARL-13 (Arl13b) from leaking out of cilia via the TZ. We identify a novel MKS module component, TMEM-218 (Tmem218), that requires CEP-290 and other MKS module components for TZ localisation and functions together with the NPHP module to facilitate ciliogenesis. We show that TZ localisation of TMEM-138 (Tmem138) and CDKL-1 (Cdkl1/Cdkl2/Cdkl3/Cdlk4 related), not previously linked to a specific TZ module, similarly depends on CEP-290; surprisingly, neither TMEM-138 or CDKL-1 exhibit interdependent localisation or genetic interactions with core MKS or NPHP module components, suggesting they are part of a distinct, CEP-290-associated module. Lastly, we show that families presenting with Oral-Facial-Digital syndrome type 6 (OFD6) have likely pathogenic mutations in CEP-290-dependent TZ proteins, namely Tmem17, Tmem138, and Tmem231. Notably, patient fibroblasts harbouring mutated Tmem17, a protein not yet ciliopathy-associated, display ciliogenesis defects. Together, our findings expand the repertoire of MKS module-associated proteins—including the previously uncharacterised mammalian Tmem80—and suggest an MKS-5 and CEP-290-dependent assembly pathway for building a functional TZ. The transition zone is a barrier structure required to maintain the dynamic composition and functional integrity of the cilium. This study describes the pathway by which the transition zone is assembled during cilium formation. The primary cilium is a structure found in most animal cell types. Much like an antenna, it is responsible for sensing extracellular signals, including light and small molecules, and conveying this information to the receiving cell and respective tissue or organ. At the base of the cilium is the transition zone (TZ), which acts as a “gate” to regulate the entry and exit of ciliary proteins required for signal transduction. Here, we use the nematode Caenorhabditis elegans as a model system to dissect how different proteins within the TZ assemble to form a functional barrier. We find that the TZ protein MKS-5 (Rpgrip1/Rpgrip1L orthologue) forms the foundation for two different assembly pathways involving two distinct modules: Nephronophthisis (NPHP) and Meckel syndrome (MKS). We show that at the base of the MKS module is CEP-290, another TZ protein that assembles MKS module proteins, including a novel TZ protein we identify as TMEM-218. CEP-290 also helps assemble a potentially separate submodule containing TMEM-138 and CDKL-1. Notably, we provide evidence that the MKS module protein TMEM-17 facilitates cilium formation and is disrupted in the human disorder (ciliopathy) Oral-Facial-Digital Syndrome type 6 (OFD6). Together, our findings provide essential insights into the assembly pathway of the ciliary TZ and suggest further connections between the transition zone and human health.
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Affiliation(s)
- Chunmei Li
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Victor L. Jensen
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Kwangjin Park
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Julie Kennedy
- School of Biomolecular & Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Francesc R. Garcia-Gonzalo
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, United States of America
| | - Marta Romani
- Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Roberta De Mori
- Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Ange-Line Bruel
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
| | | | - Bérénice Doray
- Service de Génétique clinique, CHRU Strasbourg, Strasbourg, France
| | - Estelle Lopez
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
| | - Jean-Baptiste Rivière
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
- Laboratoire de Génétique moléculaire, Plateau Technique de Biologie, CHU Dijon, Dijon, France
| | - Laurence Faivre
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
- Centre de Génétique, FHU-TRANSLAD, Hôpital d’Enfants, CHU Dijon, Dijon, France
| | - Christel Thauvin-Robinet
- EA4271 GAD Génétique des Anomalies du Développement, FHU-TRANSLAD, Université Fédérale Bourgogne Franche-Comté, Dijon, France
- Centre de Génétique, FHU-TRANSLAD, Hôpital d’Enfants, CHU Dijon, Dijon, France
| | - Jeremy F. Reiter
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California, United States of America
| | - Oliver E. Blacque
- School of Biomolecular & Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Enza Maria Valente
- Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
- Department of Medicine and Surgery, University of Salerno, Salerno, Italy
| | - Michel R. Leroux
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, British Columbia, Canada
- * E-mail:
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21
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Han Z, Boas S, Schroeder NE. Unexpected Variation in Neuroanatomy among Diverse Nematode Species. Front Neuroanat 2016; 9:162. [PMID: 26778973 PMCID: PMC4700257 DOI: 10.3389/fnana.2015.00162] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 11/30/2015] [Indexed: 12/31/2022] Open
Abstract
Nematodes are considered excellent models for understanding fundamental aspects of neuron function. However, nematodes are less frequently used as models for examining the evolution of nervous systems. While the habitats and behaviors of nematodes are diverse, the neuroanatomy of nematodes is often considered highly conserved. A small number of nematode species greatly influences our understanding of nematode neurobiology. The free-living species Caenorhabditis elegans and, to a lesser extent, the mammalian gastrointestinal parasite Ascaris suum are, historically, the primary sources of knowledge regarding nematode neurobiology. Despite differences in size and habitat, C. elegans and A. suum share a surprisingly similar neuroanatomy. Here, we examined species across several clades in the phylum Nematoda and show that there is a surprising degree of neuroanatomical variation both within and among nematode clades when compared to C. elegans and Ascaris. We found variation in the numbers of neurons in the ventral nerve cord and dye-filling pattern of sensory neurons. For example, we found that Pristionchus pacificus, a bacterial feeding species used for comparative developmental research had 20% fewer ventral cord neurons compared to C. elegans. Steinernema carpocapsae, an insect-parasitic nematode capable of jumping behavior, had 40% more ventral cord neurons than C. elegans. Interestingly, the non-jumping congeneric nematode, S. glaseri showed an identical number of ventral cord neurons as S. carpocapsae. There was also variability in the timing of neurodevelopment of the ventral cord with two of five species that hatch as second-stage juveniles showing delayed neurodevelopment. We also found unexpected variation in the dye-filling of sensory neurons among examined species. Again, sensory neuron dye-filling pattern did not strictly correlate with phylogeny. Our results demonstrate that variation in nematode neuroanatomy is more prevalent than previously assumed and recommend this diverse phylum for future "evo-devo-neuro" studies.
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Affiliation(s)
- Ziduan Han
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana IL, USA
| | - Stephanie Boas
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana IL, USA
| | - Nathan E Schroeder
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, UrbanaIL, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, UrbanaIL, USA
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22
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Rompay LV, Borghgraef C, Beets I, Caers J, Temmerman L. New genetic regulators question relevance of abundant yolk protein production in C. elegans. Sci Rep 2015; 5:16381. [PMID: 26553710 PMCID: PMC4639837 DOI: 10.1038/srep16381] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 09/24/2015] [Indexed: 11/25/2022] Open
Abstract
Vitellogenesis or maternal yolk formation is considered critical to the reproduction of egg-laying animals. In invertebrates, however, most of its regulatory genes are still unknown. Via a combined mapping and whole-genome sequencing strategy, we performed a forward genetic screen to isolate novel regulators of yolk production in the nematode model system Caenorhabditis elegans. In addition to isolating new alleles of rab-35, rab-10 and M04F3.2, we identified five mutant alleles corresponding to three novel regulatory genes potently suppressing the expression of a GFP-based yolk reporter. We confirmed that mutations in vrp-1, ceh-60 and lrp-2 disrupt endogenous yolk protein synthesis at the transcriptional and translational level. In contrast to current beliefs, our discovered set of mutants with strongly reduced yolk proteins did not show serious reproduction defects. This raises questions as to whether yolk proteins per se are needed for ultimate reproductive success.
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Affiliation(s)
- Liesbeth Van Rompay
- Functional Genomics and Proteomics, Department of Biology, KU Leuven, Naamsestraat 59 bus 2465, 3000 Leuven, Belgium
| | - Charline Borghgraef
- Functional Genomics and Proteomics, Department of Biology, KU Leuven, Naamsestraat 59 bus 2465, 3000 Leuven, Belgium
| | - Isabel Beets
- Functional Genomics and Proteomics, Department of Biology, KU Leuven, Naamsestraat 59 bus 2465, 3000 Leuven, Belgium
| | - Jelle Caers
- Functional Genomics and Proteomics, Department of Biology, KU Leuven, Naamsestraat 59 bus 2465, 3000 Leuven, Belgium
| | - Liesbet Temmerman
- Functional Genomics and Proteomics, Department of Biology, KU Leuven, Naamsestraat 59 bus 2465, 3000 Leuven, Belgium
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23
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Luo J, Xu Z, Tan Z, Zhang Z, Ma L. Neuropeptide receptors NPR-1 and NPR-2 regulate Caenorhabditis elegans avoidance response to the plant stress hormone methyl salicylate. Genetics 2015; 199:523-31. [PMID: 25527285 PMCID: PMC4317659 DOI: 10.1534/genetics.114.172239] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 12/16/2014] [Indexed: 11/18/2022] Open
Abstract
Methyl salicylate (MeSa) is a stress hormone released by plants under attack by pathogens or herbivores . MeSa has been shown to attract predatory insects of herbivores and repel pests. The molecules and neurons underlying animal response to MeSa are not known. Here we found that the nematode Caenorhabditis elegans exhibits a strong avoidance response to MeSa, which requires the activities of two closely related neuropeptide receptors NPR-1 and NPR-2. Molecular analyses suggest that NPR-1 expressed in the RMG inter/motor neurons is required for MeSa avoidance. An NPR-1 ligand FLP-18 is also required. Using a rescuing npr-2 promoter to drive a GFP transgene, we identified that NPR-2 is expressed in multiple sensory and interneurons. Genetic rescue experiments suggest that NPR-2 expressed in the AIZ interneurons is required for MeSa avoidance. We also provide evidence that the AWB sensory neurons might act upstream of RMGs and AIZs to detect MeSa. Our results suggest that NPR-2 has an important role in regulating animal behavior and that NPR-1 and NPR-2 act on distinct interneurons to affect C. elegans avoidance response to MeSa.
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Affiliation(s)
- Jintao Luo
- The State Key Laboratory of Medical Genetics, School of Life Sciences
| | - Zhaofa Xu
- The State Key Laboratory of Medical Genetics, School of Life Sciences
| | - Zhiping Tan
- Clinical Center for Gene Diagnosis and Therapy of the Second Xiangya Hospital, Central South University, Changsha, Hunan, China, 410008
| | - Zhuohua Zhang
- The State Key Laboratory of Medical Genetics, School of Life Sciences
| | - Long Ma
- The State Key Laboratory of Medical Genetics, School of Life Sciences
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24
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Urdaneta-Marquez L, Bae SH, Janukavicius P, Beech R, Dent J, Prichard R. A dyf-7 haplotype causes sensory neuron defects and is associated with macrocyclic lactone resistance worldwide in the nematode parasite Haemonchus contortus. Int J Parasitol 2014; 44:1063-71. [PMID: 25224687 DOI: 10.1016/j.ijpara.2014.08.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Revised: 07/14/2014] [Accepted: 08/01/2014] [Indexed: 11/15/2022]
Abstract
Heavy reliance on macrocyclic lactones to treat parasitic nematodes has resulted in the evolution of widespread drug resistance that threatens human and animal health. Management strategies have been proposed that would slow the rise of resistance, however testing these strategies has been hampered by the lack of identified strong-effect resistance markers in parasites. We show that the Caenorhabditis elegans gene Cel_dyf-7, necessary for amphid sensory neuron development, also confers macrocyclic lactone sensitivity. In the sheep parasite Haemonchus contortus: (i) strains selected for macrocyclic lactone resistance were enriched in a Hco_dyf-7 haplotype that was rare in the drug-naïve population, (ii) the resistant haplotype correlated with the sensory neuron defects, and (iii) the resistant haplotype was associated with decreased Hco_dyf-7 expression. Resistant field isolates of H. contortus from five continents were enriched for the resistant haplotype, demonstrating the relevance of the Hco_dyf-7 haplotype to practise and indicating that it is a locus of strong effect. Hemizygosity resulting from sex linkage of dyf-7 likely contributes to the rise of resistance in treated populations.
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Affiliation(s)
- Ludmel Urdaneta-Marquez
- Institute of Parasitology, 21111 Lakeshore, McGill University, Ste-Anne de Bellevue H9X3V9, Canada
| | - Seong Han Bae
- Department of Biology, 1205 Ave. Docteur Penfield, McGill University, Montreal H3A1B1, Canada
| | - Patrick Janukavicius
- Department of Biology, 1205 Ave. Docteur Penfield, McGill University, Montreal H3A1B1, Canada
| | - Robin Beech
- Institute of Parasitology, 21111 Lakeshore, McGill University, Ste-Anne de Bellevue H9X3V9, Canada
| | - Joseph Dent
- Department of Biology, 1205 Ave. Docteur Penfield, McGill University, Montreal H3A1B1, Canada
| | - Roger Prichard
- Institute of Parasitology, 21111 Lakeshore, McGill University, Ste-Anne de Bellevue H9X3V9, Canada.
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25
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Zhang F, Bhattacharya A, Nelson JC, Abe N, Gordon P, Lloret-Fernandez C, Maicas M, Flames N, Mann RS, Colón-Ramos DA, Hobert O. The LIM and POU homeobox genes ttx-3 and unc-86 act as terminal selectors in distinct cholinergic and serotonergic neuron types. Development 2013; 141:422-35. [PMID: 24353061 DOI: 10.1242/dev.099721] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Transcription factors that drive neuron type-specific terminal differentiation programs in the developing nervous system are often expressed in several distinct neuronal cell types, but to what extent they have similar or distinct activities in individual neuronal cell types is generally not well explored. We investigate this problem using, as a starting point, the C. elegans LIM homeodomain transcription factor ttx-3, which acts as a terminal selector to drive the terminal differentiation program of the cholinergic AIY interneuron class. Using a panel of different terminal differentiation markers, including neurotransmitter synthesizing enzymes, neurotransmitter receptors and neuropeptides, we show that ttx-3 also controls the terminal differentiation program of two additional, distinct neuron types, namely the cholinergic AIA interneurons and the serotonergic NSM neurons. We show that the type of differentiation program that is controlled by ttx-3 in different neuron types is specified by a distinct set of collaborating transcription factors. One of the collaborating transcription factors is the POU homeobox gene unc-86, which collaborates with ttx-3 to determine the identity of the serotonergic NSM neurons. unc-86 in turn operates independently of ttx-3 in the anterior ganglion where it collaborates with the ARID-type transcription factor cfi-1 to determine the cholinergic identity of the IL2 sensory and URA motor neurons. In conclusion, transcription factors operate as terminal selectors in distinct combinations in different neuron types, defining neuron type-specific identity features.
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Affiliation(s)
- Feifan Zhang
- Department of Biochemistry and Molecular Biophysics, Columbia University Medical Center, New York, NY 10032, USA
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26
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CLHM-1 is a functionally conserved and conditionally toxic Ca2+-permeable ion channel in Caenorhabditis elegans. J Neurosci 2013; 33:12275-86. [PMID: 23884934 DOI: 10.1523/jneurosci.5919-12.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Disruption of neuronal Ca(2+) homeostasis contributes to neurodegenerative diseases through mechanisms that are not fully understood. A polymorphism in CALHM1, a recently described ion channel that regulates intracellular Ca(2+) levels, is a possible risk factor for late-onset Alzheimer's disease. Since there are six potentially redundant CALHM family members in humans, the physiological and pathophysiological consequences of CALHM1 function in vivo remain unclear. The nematode Caenorhabditis elegans expresses a single CALHM1 homolog, CLHM-1. Here we find that CLHM-1 is expressed at the plasma membrane of sensory neurons and muscles. Like human CALHM1, C. elegans CLHM-1 is a Ca(2+)-permeable ion channel regulated by voltage and extracellular Ca(2+). Loss of clhm-1 in the body-wall muscles disrupts locomotory kinematics and biomechanics, demonstrating that CLHM-1 has a physiologically significant role in vivo. The motility defects observed in clhm-1 mutant animals can be rescued by muscle-specific expression of either C. elegans CLHM-1 or human CALHM1, suggesting that the function of these proteins is conserved in vivo. Overexpression of either C. elegans CLHM-1 or human CALHM1 in neurons is toxic, causing degeneration through a necrotic-like mechanism that is partially Ca(2+) dependent. Our data show that CLHM-1 is a functionally conserved ion channel that plays an important but potentially toxic role in excitable cell function.
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27
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Kagoshima H, Cassata G, Tong YG, Pujol N, Niklaus G, Bürglin TR. The LIM homeobox gene ceh-14 is required for phasmid function and neurite outgrowth. Dev Biol 2013; 380:314-23. [PMID: 23608457 DOI: 10.1016/j.ydbio.2013.04.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 03/29/2013] [Accepted: 04/04/2013] [Indexed: 11/29/2022]
Abstract
Transcription factors play key roles in cell fate specification and cell differentiation. Previously, we showed that the LIM homeodomain factor CEH-14 is expressed in the AFD neurons where it is required for thermotaxis behavior in Caenorhabditis elegans. Here, we show that ceh-14 is expressed in the phasmid sensory neurons, PHA and PHB, a number of neurons in the tail, i.e., PHC, DVC, PVC, PVN, PVQ, PVT, PVW and PVR, as well as the touch neurons. Analysis of the promoter region shows that important regulatory elements for the expression in most neurons reside from -4kb to -1.65kb upstream of the start codon. Further, within the first introns are elements for expression in the hypodermis. Phylogenetic footprinting revealed numerous conserved motifs in these regions. In addition to the existing deletion mutation ceh-14(ch3), we isolated a new allele, ceh-14(ch2), in which only one LIM domain is disrupted. The latter mutant allele is partially defective for thermosensation. Analysis of both mutant alleles showed that they are defective in phasmid dye-filling. However, the cell body, dendritic outgrowth and ciliated endings of PHA and PHB appear normal, indicating that ceh-14 is not required for growth. The loss of a LIM domain in the ceh-14(ch2) allele causes a partial loss-of-function phenotype. Examination of the neurites of ALA and tail neurons using a ceh-14::GFP reporter shows abnormal axonal outgrowth and pathfinding.
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Affiliation(s)
- Hiroshi Kagoshima
- Biozentrum, Universität Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland
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28
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Ritter AD, Shen Y, Fuxman Bass J, Jeyaraj S, Deplancke B, Mukhopadhyay A, Xu J, Driscoll M, Tissenbaum HA, Walhout AJM. Complex expression dynamics and robustness in C. elegans insulin networks. Genome Res 2013; 23:954-65. [PMID: 23539137 PMCID: PMC3668363 DOI: 10.1101/gr.150466.112] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Gene families expand by gene duplication, and resulting paralogs diverge through mutation. Functional diversification can include neofunctionalization as well as subfunctionalization of ancestral functions. In addition, redundancy in which multiple genes fulfill overlapping functions is often maintained. Here, we use the family of 40 Caenorhabditis elegans insulins to gain insight into the balance between specificity and redundancy. The insulin/insulin-like growth factor (IIS) pathway comprises a single receptor, DAF-2. To date, no single insulin-like peptide recapitulates all DAF-2-associated phenotypes, likely due to redundancy between insulin-like genes. To provide a first-level annotation of potential patterns of redundancy, we comprehensively delineate the spatiotemporal and conditional expression of all 40 insulins in living animals. We observe extensive dynamics in expression that can explain the lack of simple patterns of pairwise redundancy. We propose a model in which gene families evolve to attain differential alliances in different tissues and in response to a range of environmental stresses.
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Affiliation(s)
- Ashlyn D Ritter
- Program in Systems Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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29
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Warburton-Pitt SRF, Jauregui AR, Li C, Wang J, Leroux MR, Barr MM. Ciliogenesis in Caenorhabditis elegans requires genetic interactions between ciliary middle segment localized NPHP-2 (inversin) and transition zone-associated proteins. J Cell Sci 2012; 125:2592-603. [PMID: 22393243 DOI: 10.1242/jcs.095539] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The cystic kidney diseases nephronophthisis (NPHP), Meckel-Gruber syndrome (MKS) and Joubert syndrome (JBTS) share an underlying etiology of dysfunctional cilia. Patients diagnosed with NPHP type II have mutations in the gene INVS (also known as NPHP2), which encodes inversin, a cilia localizing protein. Here, we show that the C. elegans inversin ortholog, NPHP-2, localizes to the middle segment of sensory cilia and that nphp-2 is partially redundant with nphp-1 and nphp-4 (orthologs of human NPHP1 and NPHP4, respectively) for cilia placement within the head and tail sensilla. nphp-2 also genetically interacts with MKS ciliopathy gene orthologs, including mks-1, mks-3, mks-6, mksr-1 and mksr-2, in a sensilla-dependent manner to control cilia formation and placement. However, nphp-2 is not required for correct localization of the NPHP- and MKS-encoded ciliary transition zone proteins or for intraflagellar transport (IFT). We conclude that INVS/NPHP2 is conserved in C. elegans and that nphp-2 plays an important role in C. elegans cilia by acting as a modifier of the NPHP and MKS pathways to control cilia formation and development.
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30
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Ohkura K, Bürglin TR. Dye-filling of the amphid sheath glia: implications for the functional relationship between sensory neurons and glia in Caenorhabditis elegans. Biochem Biophys Res Commun 2011; 406:188-93. [PMID: 21295547 DOI: 10.1016/j.bbrc.2011.02.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 02/01/2011] [Indexed: 10/18/2022]
Abstract
The nervous system is composed of cells including neurons and glia. It has been believed that the former cells play central roles in various neural functions while the latter ones have only supportive functions for neurons. However, recent findings suggest that glial cells actively participate in neural activities, and the cooperation between neurons and glia is important for nervous system functions. In Caenorhabditis elegans, amphid sensory organs in the head also consist of sensory neurons and glia-like support cells (amphid socket and amphid sheath cells). Ciliary endings of some sensory neurons exposed to the environment detect various chemicals, molecules and signals, and the cilia of some neurons can also take up fluorescent dyes such as DiI. Here, we show that the amphid sheath glia are also stained with DiI and that its uptake by the amphid sheath cells correlates with DiI-filling of sensory neurons, suggesting that the amphid sheath glia might interact with sensory neurons. Furthermore, the localization of the amphid sheath cell reporter F52E1.2SP::YFP is abnormal in che-2 mutants, which have defective cilia. These findings imply that sensory neurons might affect amphid sheath glia functions in the amphid sensory organ of C. elegans.
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Affiliation(s)
- Kiyotaka Ohkura
- Department of Biosciences and Nutrition, and Center for Biosciences, Karolinska Institutet, Hälsovägen 7, Novum, SE 141 83 Huddinge, Sweden
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31
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Aitlhadj L, Ávila DS, Benedetto A, Aschner M, Stürzenbaum SR. Environmental exposure, obesity, and Parkinson's disease: lessons from fat and old worms. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:20-8. [PMID: 20797931 PMCID: PMC3018495 DOI: 10.1289/ehp.1002522] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 08/25/2010] [Indexed: 05/02/2023]
Abstract
BACKGROUND A common link has been exposed, namely, that metal exposure plays a role in obesity and in Parkinson's disease (PD). This link may help to elucidate mechanisms of neurotoxicity. OBJECTIVE We reviewed the utility of the nematode, Caenorhabditis elegans, as a model organism to study neurodegeneration in obesity and Parkinson's disease (PD), with an emphasis on the neurotransmitter, dopamine (DA). DATA SOURCES A PubMed literature search was performed using the terms "obesity" and any of the following: "C. elegans," "central nervous system," "neurodegeneration," "heavy metals," "dopamine" or "Parkinson's disease." We reviewed the identified studies, including others cited therein, to summarize the current evidence of neurodegeneration in obesity and PD, with an emphasis on studies carried out in C. elegans and environmental toxins in the etiology of both diseases. DATA EXTRACTION AND DATA SYNTHESIS Heavy metals and DA have both been linked to diet-induced obesity, which has led to the notion that the mechanism of environmentally induced neurodegeneration in PD may also apply to obesity. C. elegans has been instrumental in expanding our mechanism-based knowledge of PD, and this species is emerging as a good model of obesity. With well-established toxicity and neurogenetic assays, it is now feasible to explore the putative link between metal- and chemical-induced neurodegeneration. CONCLUSIONS One side effect of an aging population is an increase in the prevalence of obesity, metabolic disorders, and neurodegenerative orders, diseases that are likely to co-occur. Environmental toxins, especially heavy metals, may prove to be a previously neglected part of the puzzle.
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Affiliation(s)
- Layla Aitlhadj
- King’s College London, Pharmaceutical Science Division, London, United Kingdom
| | - Daiana Silva Ávila
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Alexandre Benedetto
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Michael Aschner
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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