1
|
Graziano B, Wang L, White OR, Kaplan DH, Fernandez-Abascal J, Bianchi L. Glial KCNQ K + channels control neuronal output by regulating GABA release from glia in C. elegans. Neuron 2024; 112:1832-1847.e7. [PMID: 38460523 PMCID: PMC11156561 DOI: 10.1016/j.neuron.2024.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 01/22/2024] [Accepted: 02/16/2024] [Indexed: 03/11/2024]
Abstract
KCNQs are voltage-gated K+ channels that control neuronal excitability and are mutated in epilepsy and autism spectrum disorder (ASD). KCNQs have been extensively studied in neurons, but their function in glia is unknown. Using voltage, calcium, and GABA imaging, optogenetics, and behavioral assays, we show here for the first time in Caenorhabditis elegans (C. elegans) that glial KCNQ channels control neuronal excitability by mediating GABA release from glia via regulation of the function of L-type voltage-gated Ca2+ channels. Further, we show that human KCNQ channels have the same role when expressed in nematode glia, underscoring conservation of function across species. Finally, we show that pathogenic loss-of-function and gain-of-function human KCNQ2 mutations alter glia-to-neuron GABA signaling in distinct ways and that the KCNQ channel opener retigabine exerts rescuing effects. This work identifies glial KCNQ channels as key regulators of neuronal excitability via control of GABA release from glia.
Collapse
Affiliation(s)
- Bianca Graziano
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Lei Wang
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Olivia R White
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Daryn H Kaplan
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Jesus Fernandez-Abascal
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Laura Bianchi
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| |
Collapse
|
2
|
Ray S, Gurung P, Manning RS, Kravchuk AA, Singhvi A. Neuron cilia restrain glial KCC-3 to a microdomain to regulate multisensory processing. Cell Rep 2024; 43:113844. [PMID: 38421867 DOI: 10.1016/j.celrep.2024.113844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 12/15/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
Glia interact with multiple neurons, but it is unclear whether their interactions with each neuron are different. Our interrogation at single-cell resolution reveals that a single glial cell exhibits specificity in its interactions with different contacting neurons. Briefly, C. elegans amphid sheath (AMsh) glia apical-like domains contact 12 neuron-endings. At these ad-neuronal membranes, AMsh glia localize the K/Cl transporter KCC-3 to a microdomain exclusively around the thermosensory AFD neuron to regulate its properties. Glial KCC-3 is transported to ad-neuronal regions, where distal cilia of non-AFD glia-associated chemosensory neurons constrain it to a microdomain at AFD-contacting glial membranes. Aberrant KCC-3 localization impacts both thermosensory (AFD) and chemosensory (non-AFD) neuron properties. Thus, neurons can interact non-synaptically through a shared glial cell by regulating microdomain localization of its cues. As AMsh and glia across species compartmentalize multiple cues like KCC-3, we posit that this may be a broadly conserved glial mechanism that modulates information processing across multimodal circuits.
Collapse
Affiliation(s)
- Sneha Ray
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Neuroscience Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - Pralaksha Gurung
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Neuroscience Graduate Program, University of Washington, Seattle, WA 98195, USA
| | - R Sean Manning
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA
| | - Alexandra A Kravchuk
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biology, University of Washington, Seattle, WA 98195, USA
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA 98109, USA; Department of Biological Structure, University of Washington School of Medicine, Seattle, WA 98195, USA.
| |
Collapse
|
3
|
Logan DR, Hall J, Bianchi L. A helping hand: roles for accessory cells in the sense of touch across species. Front Cell Neurosci 2024; 18:1367476. [PMID: 38433863 PMCID: PMC10904576 DOI: 10.3389/fncel.2024.1367476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 02/05/2024] [Indexed: 03/05/2024] Open
Abstract
During touch, mechanical forces are converted into electrochemical signals by tactile organs made of neurons, accessory cells, and their shared extracellular spaces. Accessory cells, including Merkel cells, keratinocytes, lamellar cells, and glia, play an important role in the sensation of touch. In some cases, these cells are intrinsically mechanosensitive; however, other roles include the release of chemical messengers, the chemical modification of spaces that are shared with neurons, and the tuning of neural sensitivity by direct physical contact. Despite great progress in the last decade, the precise roles of these cells in the sense of touch remains unclear. Here we review the known and hypothesized contributions of several accessory cells to touch by incorporating research from multiple organisms including C. elegans, D. melanogaster, mammals, avian models, and plants. Several broad parallels are identified including the regulation of extracellular ions and the release of neuromodulators by accessory cells, as well as the emerging potential physical contact between accessory cells and sensory neurons via tethers. Our broader perspective incorporates the importance of accessory cells to the understanding of human touch and pain, as well as to animal touch and its molecular underpinnings, which are underrepresented among the animal welfare literature. A greater understanding of touch, which must include a role for accessory cells, is also relevant to emergent technical applications including prosthetics, virtual reality, and robotics.
Collapse
Affiliation(s)
| | | | - Laura Bianchi
- Department of Physiology and Biophysics, University of Miami, Miami, FL, United States
| |
Collapse
|
4
|
Elkhatib W, Yanez-Guerra LA, Mayorova TD, Currie MA, Singh A, Perera M, Gauberg J, Senatore A. Function and phylogeny support the independent evolution of an ASIC-like Deg/ENaC channel in the Placozoa. Commun Biol 2023; 6:951. [PMID: 37723223 PMCID: PMC10507113 DOI: 10.1038/s42003-023-05312-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 09/01/2023] [Indexed: 09/20/2023] Open
Abstract
ASIC channels are bilaterian proton-gated sodium channels belonging to the large and functionally-diverse Deg/ENaC family that also includes peptide- and mechanically-gated channels. Here, we report that the non-bilaterian invertebrate Trichoplax adhaerens possesses a proton-activated Deg/ENaC channel, TadNaC2, with a unique combination of biophysical features including tachyphylaxis like ASIC1a, reduced proton sensitivity like ASIC2a, biphasic macroscopic currents like ASIC3, as well as low sensitivity to the Deg/ENaC channel blocker amiloride and Ca2+ ions. Structural modeling and mutation analyses reveal that TadNaC2 proton gating is different from ASIC channels, lacking key molecular determinants, and involving unique residues within the palm and finger regions. Phylogenetic analysis reveals that a monophyletic clade of T. adhaerens Deg/ENaC channels, which includes TadNaC2, is phylogenetically distinct from ASIC channels, instead forming a clade with BASIC channels. Altogether, this work suggests that ASIC-like channels evolved independently in T. adhaerens and its phylum Placozoa. Our phylogenetic analysis also identifies several clades of uncharacterized metazoan Deg/ENaC channels, and provides phylogenetic evidence for the existence of Deg/ENaC channels outside of Metazoa, present in the gene data of select unicellular heterokont and filasterea-related species.
Collapse
Affiliation(s)
- Wassim Elkhatib
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 3G5, Canada
| | - Luis A Yanez-Guerra
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, England
| | | | - Mark A Currie
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 3G5, Canada
| | - Anhadvir Singh
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 3G5, Canada
| | - Maria Perera
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 3G5, Canada
| | - Julia Gauberg
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 3G5, Canada
| | - Adriano Senatore
- Department of Biology, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON, L5L 1C6, Canada.
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON, M5S 3G5, Canada.
| |
Collapse
|
5
|
Petratou D, Gjikolaj M, Kaulich E, Schafer W, Tavernarakis N. A proton-inhibited DEG/ENaC ion channel maintains neuronal ionstasis and promotes neuronal survival under stress. iScience 2023; 26:107117. [PMID: 37416472 PMCID: PMC10320524 DOI: 10.1016/j.isci.2023.107117] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 03/28/2023] [Accepted: 06/09/2023] [Indexed: 07/08/2023] Open
Abstract
The nervous system participates in the initiation and modulation of systemic stress. Ionstasis is of utmost importance for neuronal function. Imbalance in neuronal sodium homeostasis is associated with pathologies of the nervous system. However, the effects of stress on neuronal Na+ homeostasis, excitability, and survival remain unclear. We report that the DEG/ENaC family member DEL-4 assembles into a proton-inactivated sodium channel. DEL-4 operates at the neuronal membrane and synapse to modulate Caenorhabditis elegans locomotion. Heat stress and starvation alter DEL-4 expression, which in turn alters the expression and activity of key stress-response transcription factors and triggers appropriate motor adaptations. Similar to heat stress and starvation, DEL-4 deficiency causes hyperpolarization of dopaminergic neurons and affects neurotransmission. Using humanized models of neurodegenerative diseases in C. elegans, we showed that DEL-4 promotes neuronal survival. Our findings provide insights into the molecular mechanisms by which sodium channels promote neuronal function and adaptation under stress.
Collapse
Affiliation(s)
- Dionysia Petratou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion, 70013 Crete, Greece
- Department of Basic Sciences, Medical School, University of Crete, Heraklion, 71003 Crete, Greece
| | - Martha Gjikolaj
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion, 70013 Crete, Greece
- Department of Basic Sciences, Medical School, University of Crete, Heraklion, 71003 Crete, Greece
| | - Eva Kaulich
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, CB2 0QH Cambridge, UK
| | - William Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, CB2 0QH Cambridge, UK
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, Heraklion, 70013 Crete, Greece
- Department of Basic Sciences, Medical School, University of Crete, Heraklion, 71003 Crete, Greece
| |
Collapse
|
6
|
Kaulich E, McCubbin PTN, Schafer WR, Walker DS. Physiological insight into the conserved properties of Caenorhabditis elegans acid-sensing degenerin/epithelial sodium channels. J Physiol 2023; 601:1625-1653. [PMID: 36200489 PMCID: PMC10424705 DOI: 10.1113/jp283238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 09/28/2022] [Indexed: 11/08/2022] Open
Abstract
Acid-sensing ion channels (ASICs) are members of the diverse family of degenerin/epithelial sodium channels (DEG/ENaCs). They perform a wide range of physiological roles in healthy organisms, including in gut function and synaptic transmission, but also play important roles in disease, as acidosis is a hallmark of painful inflammatory and ischaemic conditions. We performed a screen for acid sensitivity on all 30 subunits of the Caenorhabditis elegans DEG/ENaC family using two-electrode voltage clamp in Xenopus oocytes. We found two groups of acid-sensitive DEG/ENaCs characterised by being either inhibited or activated by increasing proton concentrations. Three of these acid-sensitive C. elegans DEG/ENaCs were activated by acidic pH, making them functionally similar to the vertebrate ASICs. We also identified three new members of the acid-inhibited DEG/ENaC group, giving a total of seven additional acid-sensitive channels. We observed sensitivity to the anti-hypertensive drug amiloride as well as modulation by the trace element zinc. Acid-sensitive DEG/ENaCs were found to be expressed in both neurons and non-neuronal tissue, highlighting the likely functional diversity of these channels. Our findings provide a framework to exploit the C. elegans channels as models to study the function of these acid-sensing channels in vivo, as well as to study them as potential targets for anti-helminthic drugs. KEY POINTS: Acidosis plays many roles in healthy physiology, including synaptic transmission and gut function, but is also a key feature of inflammatory pain, ischaemia and many other conditions. Cells monitor acidosis of their surroundings via pH-sensing channels, including the acid-sensing ion channels (ASICs). These are members of the degenerin/epithelial sodium channel (DEG/ENaC) family, along with, as the name suggests, vertebrate ENaCs and degenerins of the roundworm Caenorhabditis elegans. By screening all 30 C. elegans DEG/ENaCs for pH dependence, we describe, for the first time, three acid-activated members, as well as three additional acid-inhibited channels. We surveyed both groups for sensitivity to amiloride and zinc; like their mammalian counterparts, their currents can be blocked, enhanced or unaffected by these modulators. Likewise, they exhibit diverse ion selectivity. Our findings underline the diversity of acid-sensitive DEG/ENaCs across species and provide a comparative resource for better understanding the molecular basis of their function.
Collapse
Affiliation(s)
- Eva Kaulich
- Neurobiology DivisionMRC Laboratory of Molecular BiologyCambridgeUK
| | | | - William R. Schafer
- Neurobiology DivisionMRC Laboratory of Molecular BiologyCambridgeUK
- Department of BiologyKU LeuvenLeuvenBelgium
| | - Denise S. Walker
- Neurobiology DivisionMRC Laboratory of Molecular BiologyCambridgeUK
| |
Collapse
|
7
|
Aguilar-Camacho JM, Foreman K, Jaimes-Becerra A, Aharoni R, Gründer S, Moran Y. Functional analysis in a model sea anemone reveals phylogenetic complexity and a role in cnidocyte discharge of DEG/ENaC ion channels. Commun Biol 2023; 6:17. [PMID: 36609696 PMCID: PMC9822975 DOI: 10.1038/s42003-022-04399-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 12/21/2022] [Indexed: 01/09/2023] Open
Abstract
Ion channels of the DEG/ENaC family share a similar structure but serve strikingly diverse biological functions, such as Na+ reabsorption, mechanosensing, proton-sensing, chemosensing and cell-cell communication via neuropeptides. This functional diversity raises the question of the ancient function of DEG/ENaCs. Using an extensive phylogenetic analysis across many different animal groups, we found a surprising diversity of DEG/ENaCs already in Cnidaria (corals, sea anemones, hydroids and jellyfish). Using a combination of gene expression analysis, electrophysiological and functional studies combined with pharmacological inhibition as well as genetic knockout in the model cnidarian Nematostella vectensis, we reveal an unanticipated role for a proton-sensitive DEG/ENaC in discharge of N. vectensis cnidocytes, the stinging cells typifying all cnidarians. Our study supports the view that DEG/ENaCs are versatile channels that have been co-opted for diverse functions since their early occurrence in animals and that respond to simple and ancient stimuli, such as omnipresent protons.
Collapse
Affiliation(s)
- Jose Maria Aguilar-Camacho
- grid.9619.70000 0004 1937 0538Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel ,grid.40803.3f0000 0001 2173 6074Present Address: Department of Biological Sciences, North Carolina State University, Raleigh, NC USA
| | - Katharina Foreman
- grid.1957.a0000 0001 0728 696XInstitute of Physiology, RWTH Aachen University, Aachen, Germany
| | - Adrian Jaimes-Becerra
- grid.9619.70000 0004 1937 0538Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Reuven Aharoni
- grid.9619.70000 0004 1937 0538Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Stefan Gründer
- grid.1957.a0000 0001 0728 696XInstitute of Physiology, RWTH Aachen University, Aachen, Germany
| | - Yehu Moran
- grid.9619.70000 0004 1937 0538Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
8
|
Wang L, Graziano B, Encalada N, Fernandez-Abascal J, Kaplan DH, Bianchi L. Glial regulators of ions and solutes required for specific chemosensory functions in Caenorhabditis elegans. iScience 2022; 25:105684. [PMID: 36567707 PMCID: PMC9772852 DOI: 10.1016/j.isci.2022.105684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 09/11/2022] [Accepted: 11/24/2022] [Indexed: 12/03/2022] Open
Abstract
Glia and accessory cells regulate the microenvironment around neurons and primary sensory cells. However, the impact of specific glial regulators of ions and solutes on functionally diverse primary cells is poorly understood. Here, we systemically investigate the requirement of ion channels and transporters enriched in Caenorhabditis elegans Amsh glia for the function of chemosensory neurons. Although Amsh glia ablated worms show reduced function of ASH, AWC, AWA, and ASE neurons, we show that the loss of glial enriched ion channels and transporters impacts these neurons differently, with nociceptor ASH being the most affected. Furthermore, our analysis underscores the importance of K+, Cl-, and nucleoside homeostasis in the Amphid sensory organ and uncovers the contribution of glial genes implicated in neurological disorders. Our findings build a unique fingerprint of each glial enriched ion channel and transporter and may provide insights into the function of supporting cells of mammalian sensory organs.
Collapse
Affiliation(s)
- Lei Wang
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
| | - Bianca Graziano
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
| | - Nicole Encalada
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
| | - Jesus Fernandez-Abascal
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
| | - Daryn H. Kaplan
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
| | - Laura Bianchi
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Rm 5133 Rosenstiel Building, 1600 NW 10 Avenue, Miami, FL33136, USA
| |
Collapse
|
9
|
Kaulich E, Grundy LJ, Schafer WR, Walker DS. The diverse functions of the DEG/ENaC family: linking genetic and physiological insights. J Physiol 2022; 601:1521-1542. [PMID: 36314992 PMCID: PMC10148893 DOI: 10.1113/jp283335] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 10/25/2022] [Indexed: 11/06/2022] Open
Abstract
The DEG/ENaC family of ion channels was defined based on the sequence similarity between degenerins (DEG) from the nematode Caenorhabditis elegans and subunits of the mammalian epithelial sodium channel (ENaC), and also includes a diverse array of non-voltage-gated cation channels from across animal phyla, including the mammalian acid-sensing ion channels (ASICs) and Drosophila pickpockets. ENaCs and ASICs have wide ranging medical importance; for example, ENaCs play an important role in respiratory and renal function, and ASICs in ischaemia and inflammatory pain, as well as being implicated in memory and learning. Electrophysiological approaches, both in vitro and in vivo, have played an essential role in establishing the physiological properties of this diverse family, identifying an array of modulators and implicating them in an extensive range of cellular functions, including mechanosensation, acid sensation and synaptic modulation. Likewise, genetic studies in both invertebrates and vertebrates have played an important role in linking our understanding of channel properties to function at the cellular and whole animal/behavioural level. Drawing together genetic and physiological evidence is essential to furthering our understanding of the precise cellular roles of DEG/ENaC channels, with the diversity among family members allowing comparative physiological studies to dissect the molecular basis of these diverse functions.
Collapse
Affiliation(s)
- Eva Kaulich
- Neurobiology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
| | - Laura J Grundy
- Neurobiology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK.,Department of Biology, KU Leuven, Leuven, Belgium
| | - Denise S Walker
- Neurobiology Division, MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
| |
Collapse
|
10
|
Booth LN, Shi C, Tantilert C, Yeo RW, Miklas JW, Hebestreit K, Hollenhorst CN, Maures TJ, Buckley MT, Murphy CT, Brunet A. Males induce premature demise of the opposite sex by multifaceted strategies. NATURE AGING 2022; 2:809-823. [PMID: 37118502 PMCID: PMC10154206 DOI: 10.1038/s43587-022-00276-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 08/03/2022] [Indexed: 04/30/2023]
Abstract
Interactions between the sexes negatively impact health in many species. In Caenorhabditis, males shorten the lifespan of the opposite sex-hermaphrodites or females. Here we use transcriptomic profiling and targeted screens to systematically uncover conserved genes involved in male-induced demise in C. elegans. Some genes (for example, delm-2, acbp-3), when knocked down, are specifically protective against male-induced demise. Others (for example, sri-40), when knocked down, extend lifespan with and without males, suggesting general mechanisms of protection. In contrast, many classical long-lived mutants are impacted more negatively than wild type by the presence of males, highlighting the importance of sexual environment for longevity. Interestingly, genes induced by males are triggered by specific male components (seminal fluid, sperm and pheromone), and manipulating these genes in combination in hermaphrodites induces stronger protection. One of these genes, the conserved ion channel delm-2, acts in the nervous system and intestine to regulate lipid metabolism. Our analysis reveals striking differences in longevity in single sex versus mixed sex environments and uncovers elaborate strategies elicited by sexual interactions that could extend to other species.
Collapse
Affiliation(s)
- Lauren N Booth
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Calico Life Sciences, South San Francisco, CA, USA
| | - Cheng Shi
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
- LSI Genomics, Princeton University, Princeton, NJ, USA
| | - Cindy Tantilert
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Robin W Yeo
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Jason W Miklas
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Katja Hebestreit
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Travis J Maures
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Matthew T Buckley
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Coleen T Murphy
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
- LSI Genomics, Princeton University, Princeton, NJ, USA.
| | - Anne Brunet
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
- Glenn Laboratories for the Biology of Aging and Stanford University, Stanford, CA, USA.
| |
Collapse
|
11
|
Kaulich E, Carroll T, Ackley B, Tang YQ, Hardege I, Nehrke K, Schafer WR, Walker DS. Distinct roles for two Caenorhabditis elegans acid-sensing ion channels in an ultradian clock. eLife 2022; 11:75837. [PMID: 35666106 PMCID: PMC9374441 DOI: 10.7554/elife.75837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 06/01/2022] [Indexed: 11/13/2022] Open
Abstract
Biological clocks are fundamental to an organism's health, controlling periodicity of behaviour and metabolism. Here, we identify two acid-sensing ion channels, with very different proton sensing properties, and describe their role in an ultradian clock, the defecation motor program (DMP) of the nematode Caenorhabditis elegans. An ACD-5-containing channel, on the apical membrane of the intestinal epithelium, is essential for maintenance of luminal acidity, and thus the rhythmic oscillations in lumen pH. In contrast, the second channel, composed of FLR-1, ACD-3 and/or DEL-5, located on the basolateral membrane, controls the intracellular Ca2+ wave and forms a core component of the master oscillator that controls timing and rhythmicity of the DMP. flr-1 and acd-3/del-5 mutants show severe developmental and metabolic defects. We thus directly link the proton-sensing properties of these channels to their physiological roles in pH regulation and Ca2+ signalling, the generation of an ultradian oscillator, and its metabolic consequences.
Collapse
Affiliation(s)
- Eva Kaulich
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Trae Carroll
- Department of Pathology and Lab Medicine, University of Rochester, Rochester, United States
| | - Brian Ackley
- Department of Molecular Biosciences, University of Kansas, Lawrence, United States
| | - Yi-Quan Tang
- Institutes of Brain Science, Fudan University, Shanghai, China
| | - Iris Hardege
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Keith Nehrke
- Department of Medicine, University of Rochester, Rochester, United States
| | - William R Schafer
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Denise S Walker
- Neurobiology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| |
Collapse
|
12
|
Fernandez-Abascal J, Johnson CK, Graziano B, Wang L, Encalada N, Bianchi L. A glial ClC Cl - channel mediates nose touch responses in C. elegans. Neuron 2022; 110:470-485.e7. [PMID: 34861150 PMCID: PMC8813913 DOI: 10.1016/j.neuron.2021.11.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 09/28/2021] [Accepted: 11/09/2021] [Indexed: 02/04/2023]
Abstract
In touch receptors, glia and accessory cells play a key role in mechanosensation. However, the mechanisms underlying such regulation are poorly understood. We show, for the first time, that the chloride channel CLH-1 is needed in glia of C. elegans nose touch receptors for touch responses and for regulation of excitability. Using in vivo Ca2+ and Cl- imaging, behavioral assays, and combined genetic and pharmacological manipulations, we show that CLH-1 mediates Cl- flux needed for glial GABA inhibition of ASH sensory neuron function and for regulation of cyclic AMP levels in ASH neurons. Finally, we show that the rat ClC-2 channel rescues the clh-1 nose-touch-insensitive phenotype, underscoring conservation of function across species. Our work identifies a glial Cl- channel as a novel regulator of touch sensitivity. We propose that glial CLH-1 regulates the interplay between Ca2+ and cAMP signaling in ASH neurons to control the sensitivity of the worm's nose touch receptors.
Collapse
|
13
|
Fernandez-Abascal J, Bianchi L. The ClC Cl - channel CLH-1 mediates HCO 3 - efflux from the amphid sheath glia in C. elegans. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000510. [PMID: 35047763 PMCID: PMC8758995 DOI: 10.17912/micropub.biology.000510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/29/2021] [Accepted: 01/03/2022] [Indexed: 11/21/2022]
Abstract
Cellular function is regulated by the concentration of intracellular and extracellular ions, including pH. Ion channels and transporters that mediate the flux/transport of protons and bicarbonate (HCO3 -) are the chief regulators of pH. In the nervous system, due to their high electrical activity, neurons tend to produce and excrete large amounts of acids. On the contrary, glial cells have been proposed to be key contributors of pH buffering. We published that the Cl-/HCO3 - permeable channel CLH-1 mediates intracellular pH buffering of C. elegans Amphid sheath (AMsh) glia at baseline. We show here that, under physiological conditions, clh-1 knock out worms show reduced HCO3 - extrusion from AMsh glia, suggesting that CLH-1 may help prevent cellular alkalinization. This function becomes even more apparent when animals are grown on plates enriched with HCO3 -. We speculate that CLH-1 might function as a regulator of extracellular pH.
Collapse
Affiliation(s)
- Jesus Fernandez-Abascal
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, 1600 NW 10th Ave, Mimi, FL, USA
| | - Laura Bianchi
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, 1600 NW 10th Ave, Mimi, FL, USA
| |
Collapse
|
14
|
Prelic S, Pal Mahadevan V, Venkateswaran V, Lavista-Llanos S, Hansson BS, Wicher D. Functional Interaction Between Drosophila Olfactory Sensory Neurons and Their Support Cells. Front Cell Neurosci 2022; 15:789086. [PMID: 35069116 PMCID: PMC8777253 DOI: 10.3389/fncel.2021.789086] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/15/2021] [Indexed: 01/14/2023] Open
Abstract
Insects detect volatile chemicals using antennae, which house a vast variety of olfactory sensory neurons (OSNs) that innervate hair-like structures called sensilla where odor detection takes place. In addition to OSNs, the antenna also hosts various support cell types. These include the triad of trichogen, tormogen, and thecogen support cells that lie adjacent to their respective OSNs. The arrangement of OSN supporting cells occurs stereotypically for all sensilla and is widely conserved in evolution. While insect chemosensory neurons have received considerable attention, little is known about the functional significance of the cells that support them. For instance, it remains unknown whether support cells play an active role in odor detection, or only passively contribute to homeostasis, e.g., by maintaining sensillum lymph composition. To investigate the functional interaction between OSNs and support cells, we used optical and electrophysiological approaches in Drosophila. First, we characterized the distribution of various supporting cells using genetic markers. By means of an ex vivo antennal preparation and genetically-encoded Ca2+ and K+ indicators, we then studied the activation of these auxiliary cells during odor presentation in adult flies. We observed acute responses and distinct differences in Ca2+ and K+ fluxes between support cell types. Finally, we observed alterations in OSN responses upon thecogen cell ablation in mature adults. Upon inducible ablation of thecogen cells, we notice a gain in mechanical responsiveness to mechanical stimulations during single-sensillum recording, but a lack of change to the neuronal resting activity. Taken together, these results demonstrate that support cells play a more active and responsive role during odor processing than previously thought. Our observations thus reveal that support cells functionally interact with OSNs and may be important for the extraordinary ability of insect olfactory systems to dynamically and sensitively discriminate between odors in the turbulent sensory landscape of insect flight.
Collapse
Affiliation(s)
- Sinisa Prelic
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Venkatesh Pal Mahadevan
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Vignesh Venkateswaran
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Sofia Lavista-Llanos
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
- CIFASIS-CONICET Franco-Argentine International Center for Information and Systems Sciences—National Council for Scientific and Technical Research, Rosario, Argentina
| | - Bill S. Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Dieter Wicher
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
- *Correspondence: Dieter Wicher
| |
Collapse
|
15
|
Ray S, Singhvi A. Charging Up the Periphery: Glial Ionic Regulation in Sensory Perception. Front Cell Dev Biol 2021; 9:687732. [PMID: 34458255 PMCID: PMC8385785 DOI: 10.3389/fcell.2021.687732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/30/2021] [Indexed: 12/25/2022] Open
Abstract
The peripheral nervous system (PNS) receives diverse sensory stimuli from the environment and transmits this information to the central nervous system (CNS) for subsequent processing. Thus, proper functions of cells in peripheral sense organs are a critical gate-keeper to generating appropriate animal sensory behaviors, and indeed their dysfunction tracks sensory deficits, sensorineural disorders, and aging. Like the CNS, the PNS comprises two major cell types, neurons (or sensory cells) and glia (or glia-like supporting neuroepithelial cells). One classic function of PNS glia is to modulate the ionic concentration around associated sensory cells. Here, we review current knowledge of how non-myelinating support cell glia of the PNS regulate the ionic milieu around sensory cell endings across species and systems. Molecular studies reviewed here suggest that, rather than being a passive homeostatic response, glial ionic regulation may in fact actively modulate sensory perception, implying that PNS glia may be active contributors to sensorineural information processing. This is reminiscent of emerging studies suggesting analogous roles for CNS glia in modulating neural circuit processing. We therefore suggest that deeper molecular mechanistic investigations into critical PNS glial functions like ionic regulation are essential to comprehensively understand sensorineural health, disease, and aging.
Collapse
Affiliation(s)
- Sneha Ray
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, United States.,Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States
| | - Aakanksha Singhvi
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, United States.,Graduate Program in Neuroscience, University of Washington, Seattle, WA, United States.,Department of Biological Structure, School of Medicine, University of Washington, Seattle, WA, United States
| |
Collapse
|
16
|
Rappaport Y, Achache H, Falk R, Murik O, Ram O, Tzur YB. Bisection of the X chromosome disrupts the initiation of chromosome silencing during meiosis in Caenorhabditis elegans. Nat Commun 2021; 12:4802. [PMID: 34376665 PMCID: PMC8355143 DOI: 10.1038/s41467-021-24815-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 07/01/2021] [Indexed: 01/04/2023] Open
Abstract
During meiosis, gene expression is silenced in aberrantly unsynapsed chromatin and in heterogametic sex chromosomes. Initiation of sex chromosome silencing is disrupted in meiocytes with sex chromosome-autosome translocations. To determine whether this is due to aberrant synapsis or loss of continuity of sex chromosomes, we engineered Caenorhabditis elegans nematodes with non-translocated, bisected X chromosomes. In early meiocytes of mutant males and hermaphrodites, X segments are enriched with euchromatin assembly markers and active RNA polymerase II staining, indicating active transcription. Analysis of RNA-seq data showed that genes from the X chromosome are upregulated in gonads of mutant worms. Contrary to previous models, which predicted that any unsynapsed chromatin is silenced during meiosis, our data indicate that unsynapsed X segments are transcribed. Therefore, our results suggest that sex chromosome chromatin has a unique character that facilitates its meiotic expression when its continuity is lost, regardless of whether or not it is synapsed.
Collapse
Affiliation(s)
- Yisrael Rappaport
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Hanna Achache
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Roni Falk
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Omer Murik
- Medical Genetics Institute, Shaare Zedek Medical Center, Jerusalem, Israel
| | - Oren Ram
- Department of Biological Chemistry, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yonatan B Tzur
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
| |
Collapse
|
17
|
Ferkey DM, Sengupta P, L’Etoile ND. Chemosensory signal transduction in Caenorhabditis elegans. Genetics 2021; 217:iyab004. [PMID: 33693646 PMCID: PMC8045692 DOI: 10.1093/genetics/iyab004] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/05/2021] [Indexed: 12/16/2022] Open
Abstract
Chemosensory neurons translate perception of external chemical cues, including odorants, tastants, and pheromones, into information that drives attraction or avoidance motor programs. In the laboratory, robust behavioral assays, coupled with powerful genetic, molecular and optical tools, have made Caenorhabditis elegans an ideal experimental system in which to dissect the contributions of individual genes and neurons to ethologically relevant chemosensory behaviors. Here, we review current knowledge of the neurons, signal transduction molecules and regulatory mechanisms that underlie the response of C. elegans to chemicals, including pheromones. The majority of identified molecules and pathways share remarkable homology with sensory mechanisms in other organisms. With the development of new tools and technologies, we anticipate that continued study of chemosensory signal transduction and processing in C. elegans will yield additional new insights into the mechanisms by which this animal is able to detect and discriminate among thousands of chemical cues with a limited sensory neuron repertoire.
Collapse
Affiliation(s)
- Denise M Ferkey
- Department of Biological Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, MA 02454, USA
| | - Noelle D L’Etoile
- Department of Cell and Tissue Biology, University of California, San Francisco, CA 94143, USA
| |
Collapse
|
18
|
Bowles SN, Johnson CM. Inferences of glia-mediated control in Caenorhabditis elegans. J Neurosci Res 2021; 99:1191-1206. [PMID: 33559247 DOI: 10.1002/jnr.24803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 01/12/2021] [Indexed: 12/22/2022]
Abstract
Astrocytes modulate synaptic transmission; yet, it remains unclear how glia influence complex behaviors. Here, we explore the effects of Caenorhabditis elegans astrocyte-like cephalic glia (CEPglia ) and the glia-specific bHLH transcription factor HLH-17 on mating behavior and the defecation motor program (DMP). In C. elegans, male mating has been explicitly described through the male tail circuit and is characterized by coordination of multiple independent behaviors to ensure that copulation is achieved. Furthermore, the sex-specific male mating circuitry shares similar components with the DMP, which is complex and rhythmic, and requires a fixed sequence of behaviors to be activated periodically. We found that loss of CEPglia reduced persistence in executing mating behaviors and hindered copulation, while males that lacked HLH-17 demonstrated repetitive prodding behavior that increased the time spent in mating but did not hinder copulation. During the DMP, we found that posterior body wall contractions (pBocs) and enteric muscle contractions (EMCs) were differentially affected by loss of HLH-17 or CEPglia in males and hermaphrodites. pBocs and EMCs required HLH-17 activity in both sexes, whereas loss of CEPglia alone did not affect DMP in males. Our data suggest that CEPglia mediate complex behaviors by signaling to the GABAergic DVB neuron, and that HLH-17 activity influences those discrete steps within those behaviors. Collectively, these data provide evidence of glia as a link in cooperative regulation of complex and rhythmic behavior that, in C. elegans links circuitry in the head and the tail.
Collapse
Affiliation(s)
| | - Casonya M Johnson
- Department of Biology, Georgia State University, Atlanta, GA, USA.,Department of Biology, James Madison University, Harrisonburg, VA, USA
| |
Collapse
|
19
|
Abstract
There is increasing evidence that supporting/glial cells in sensory systems function in sensory transduction. Duan et al. demonstrate that the glial cells of the C. elegans amphid apparatus serve as odorant receptor cells and regulate neuronal output and behavior.
Collapse
Affiliation(s)
- Laura Bianchi
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| |
Collapse
|
20
|
DEG/ENaC Ion Channels in the Function of the Nervous System: From Worm to Man. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1349:165-192. [DOI: 10.1007/978-981-16-4254-8_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
21
|
Nagai J, Yu X, Papouin T, Cheong E, Freeman MR, Monk KR, Hastings MH, Haydon PG, Rowitch D, Shaham S, Khakh BS. Behaviorally consequential astrocytic regulation of neural circuits. Neuron 2020; 109:576-596. [PMID: 33385325 DOI: 10.1016/j.neuron.2020.12.008] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
Astrocytes are a large and diverse population of morphologically complex cells that exist throughout nervous systems of multiple species. Progress over the last two decades has shown that astrocytes mediate developmental, physiological, and pathological processes. However, a long-standing open question is how astrocytes regulate neural circuits in ways that are behaviorally consequential. In this regard, we summarize recent studies using Caenorhabditis elegans, Drosophila melanogaster, Danio rerio, and Mus musculus. The data reveal diverse astrocyte mechanisms operating in seconds or much longer timescales within neural circuits and shaping multiple behavioral outputs. We also refer to human diseases that have a known primary astrocytic basis. We suggest that including astrocytes in mechanistic, theoretical, and computational studies of neural circuits provides new perspectives to understand behavior, its regulation, and its disease-related manifestations.
Collapse
Affiliation(s)
- Jun Nagai
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; RIKEN Center for Brain Science, 2-1 Hirosawa Wako City, Saitama 351-0198, Japan
| | - Xinzhu Yu
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, 514 Burrill Hall, 407 S. Goodwin Ave, Urbana, IL 61801, USA
| | - Thomas Papouin
- Department of Neuroscience, Washington University in St. Louis, School of Medicine, Campus Box 8108, 660 South Euclid Ave., St. Louis, MO 63110, USA
| | - Eunji Cheong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, South Korea
| | - Marc R Freeman
- The Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Kelly R Monk
- The Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA
| | - Michael H Hastings
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Philip G Haydon
- Department of Neuroscience, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - David Rowitch
- Department of Paediatrics, Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK; Departments of Pediatrics and Neurosurgery, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095-1751, USA.
| |
Collapse
|
22
|
Fung W, Wexler L, Heiman MG. Cell-type-specific promoters for C. elegans glia. J Neurogenet 2020; 34:335-346. [PMID: 32696701 PMCID: PMC7855602 DOI: 10.1080/01677063.2020.1781851] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 06/08/2020] [Indexed: 12/26/2022]
Abstract
Glia shape the development and function of the C. elegans nervous system, especially its sense organs and central neuropil (nerve ring). Cell-type-specific promoters allow investigators to label or manipulate individual glial cell types, and therefore provide a key tool for deciphering glial function. In this technical resource, we compare the specificity, brightness, and consistency of cell-type-specific promoters for C. elegans glia. We identify a set of promoters for the study of seven glial cell types (F16F9.3, amphid and phasmid sheath glia; F11C7.2, amphid sheath glia only; grl-2, amphid and phasmid socket glia; hlh-17, cephalic (CEP) sheath glia; and grl-18, inner labial (IL) socket glia) as well as a pan-glial promoter (mir-228). We compare these promoters to promoters that are expressed more variably in combinations of glial cell types (delm-1 and itx-1). We note that the expression of some promoters depends on external conditions or the internal state of the organism, such as developmental stage, suggesting glial plasticity. Finally, we demonstrate an approach for prospectively identifying cell-type-specific glial promoters using existing single-cell sequencing data, and we use this approach to identify two novel promoters specific to IL socket glia (col-53 and col-177).
Collapse
Affiliation(s)
- Wendy Fung
- These authors contributed equally to this work
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children’s Hospital, Boston MA 02115
| | - Leigh Wexler
- These authors contributed equally to this work
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children’s Hospital, Boston MA 02115
| | - Maxwell G. Heiman
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children’s Hospital, Boston MA 02115
| |
Collapse
|
23
|
Johnson CK, Fernandez-Abascal J, Wang Y, Wang L, Bianchi L. The Na +-K +-ATPase is needed in glia of touch receptors for responses to touch in C. elegans. J Neurophysiol 2020; 123:2064-2074. [PMID: 32292107 DOI: 10.1152/jn.00636.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Four of the five types of mammalian mechanosensors are composed of nerve endings and accessory cells. In Caenorhabditis elegans we showed that glia support the function of nose touch neurons via the activity of glial Na+ and K+ channels. We show here that a third regulator of Na+ and K+, the Na+-K+-ATPase, is needed in glia of nose touch neurons for touch. Importantly, we show that two Na+-K+-ATPase genes are needed for the function rather than structural integrity and that their ion transport activity is crucial for touch. Finally, when glial Na+-K+-ATPase genes are knocked out, touch can be restored by activation of a third Na+-K+-ATPase. Taken together, these data show the requirement in glia of touch neurons of the function of the Na+-K+-ATPase. These data underscore the importance of the homeostasis of Na+ and K+, most likely in the space surrounding touch neurons, in touch sensation, a function that might be conserved across species.NEW & NOTEWORTHY Increasing evidence supports that accessory cells in mechanosensors regulate neuronal output; however, the glial molecular mechanisms that control this regulation are not fully understood. We show here in Caenorhabditis elegans that specific glial Na+-K+-ATPase genes are needed for nose touch-avoidance behavior. Our data support the requirement of these Na+-K+-ATPases for homeostasis of Na+ and K+ in nose touch receptors. Our data add to our understanding of glial regulation of mechanosensors.
Collapse
Affiliation(s)
- Christina K Johnson
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida
| | - Jesus Fernandez-Abascal
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida
| | - Ying Wang
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida
| | - Lei Wang
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida
| | - Laura Bianchi
- Department Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida
| |
Collapse
|
24
|
Takagaki N, Ohta A, Ohnishi K, Kawanabe A, Minakuchi Y, Toyoda A, Fujiwara Y, Kuhara A. The mechanoreceptor DEG-1 regulates cold tolerance in Caenorhabditis elegans. EMBO Rep 2020; 21:e48671. [PMID: 32009302 PMCID: PMC7054665 DOI: 10.15252/embr.201948671] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 12/19/2019] [Accepted: 12/20/2019] [Indexed: 12/13/2022] Open
Abstract
Caenorhabditis elegans mechanoreceptors located in ASG sensory neurons have been found to sense ambient temperature, which is a key trait for animal survival. Here, we show that experimental loss of xanthine dehydrogenase (XDH-1) function in AIN and AVJ interneurons results in reduced cold tolerance and atypical neuronal response to changes in temperature. These interneurons connect with upstream neurons such as the mechanoreceptor-expressing ASG. Ca2+ imaging revealed that ASG neurons respond to warm temperature via the mechanoreceptor DEG-1, a degenerin/epithelial Na+ channel (DEG/ENaC), which in turn affects downstream AIN and AVJ circuits. Ectopic expression of DEG-1 in the ASE gustatory neuron results in the acquisition of warm sensitivity, while electrophysiological analysis revealed that DEG-1 and human MDEG1 were involved in warm sensation. Taken together, these results suggest that cold tolerance is regulated by mechanoreceptor-mediated circuit calculation.
Collapse
Affiliation(s)
- Natsune Takagaki
- Graduate School of Natural Science, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Konan University, Kobe, Japan
| | - Akane Ohta
- Graduate School of Natural Science, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Konan University, Kobe, Japan.,Faculty of Science and Engineering, Konan University, Kobe, Japan
| | - Kohei Ohnishi
- Graduate School of Natural Science, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Konan University, Kobe, Japan
| | - Akira Kawanabe
- Laboratory of Molecular Physiology & Biophysics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Yohei Minakuchi
- Advanced Genomics Center, National Institute of Genetics, Mishima, Shizuoka, Japan.,Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Atsushi Toyoda
- Advanced Genomics Center, National Institute of Genetics, Mishima, Shizuoka, Japan.,Comparative Genomics Laboratory, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Yuichiro Fujiwara
- Laboratory of Molecular Physiology & Biophysics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Atsushi Kuhara
- Graduate School of Natural Science, Konan University, Kobe, Japan.,Institute for Integrative Neurobiology, Konan University, Kobe, Japan.,Faculty of Science and Engineering, Konan University, Kobe, Japan.,AMED-PRIME, Japan Agency for Medical Research and Development, Tokyo, Japan
| |
Collapse
|
25
|
Tang Y, Illes P, Verkhratsky A. Glial-neuronal Sensory Organs: Evolutionary Journey from Caenorhabditis elegans to Mammals. Neurosci Bull 2020; 36:561-564. [PMID: 31960268 DOI: 10.1007/s12264-020-00464-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 12/08/2019] [Indexed: 12/01/2022] Open
Affiliation(s)
- Yong Tang
- International Collaborative Centre on Big Science Plan for Purine Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China.
- Acupuncture and Tuina School, Chengdu University of TCM, Chengdu, 610075, China.
- Key Laboratory of Sichuan Province for Acupuncture and Chronobiology, Chengdu, 610075, China.
| | - Peter Illes
- International Collaborative Centre on Big Science Plan for Purine Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, Leipzig, 04107, Germany
| | - Alexei Verkhratsky
- International Collaborative Centre on Big Science Plan for Purine Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, China.
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK.
| |
Collapse
|
26
|
Wang Y, Bianchi L. Temperature-sensitive mosquito TRP channel rescues touch deficits caused by knock-out of a DEG/ENaC channel in C. elegans glia. MICROPUBLICATION BIOLOGY 2020; 2020. [PMID: 32550485 PMCID: PMC7252241 DOI: 10.17912/micropub.biology.000209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ying Wang
- Department of Physiology and Biophysics, University of Miami
| | - Laura Bianchi
- Department of Physiology and Biophysics, University of Miami
| |
Collapse
|
27
|
Abstract
Degenerin/Epithelial Sodium Channels (DEG/ENaCs) are a large family of animal-specific non-voltage gated ion channels, with enriched expression in neuronal and epithelial tissues. While neuronal DEG/ENaCs were originally characterized as sensory receptor channels, recent studies indicate that several DEG/ENaC family members are also expressed throughout the central nervous system. Human genome-wide association studies have linked DEG/ENaC-coding genes with several neurologic and psychiatric disorders, including epilepsy and panic disorder. In addition, studies in rodent models further indicate that DEG/ENaC activity in the brain contributes to many behaviors, including those related to anxiety and long-term memory. Although the exact neurophysiological functions of DEG/ENaCs remain mostly unknown, several key studies now suggest that multiple family members might exert their neuronal function via the direct modulation of synaptic processes. Here, we review and discuss recent findings on the synaptic functions of DEG/ENaCs in both vertebrate and invertebrate species, and propose models for their possible roles in synaptic physiology.
Collapse
Affiliation(s)
- Alexis S Hill
- a Department of Biology , Washington University in St. Louis , St. Louis , USA
| | - Yehuda Ben-Shahar
- a Department of Biology , Washington University in St. Louis , St. Louis , USA
| |
Collapse
|
28
|
Low IIC, Williams CR, Chong MK, McLachlan IG, Wierbowski BM, Kolotuev I, Heiman MG. Morphogenesis of neurons and glia within an epithelium. Development 2019; 146:dev171124. [PMID: 30683663 PMCID: PMC6398450 DOI: 10.1242/dev.171124] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 01/15/2019] [Indexed: 12/13/2022]
Abstract
To sense the outside world, some neurons protrude across epithelia, the cellular barriers that line every surface of our bodies. To study the morphogenesis of such neurons, we examined the C. elegans amphid, in which dendrites protrude through a glial channel at the nose. During development, amphid dendrites extend by attaching to the nose via DYF-7, a type of protein typically found in epithelial apical ECM. Here, we show that amphid neurons and glia exhibit epithelial properties, including tight junctions and apical-basal polarity, and develop in a manner resembling other epithelia. We find that DYF-7 is a fibril-forming apical ECM component that promotes formation of the tube-shaped glial channel, reminiscent of roles for apical ECM in other narrow epithelial tubes. We also identify a requirement for FRM-2, a homolog of EPBL15/moe/Yurt that promotes epithelial integrity in other systems. Finally, we show that other environmentally exposed neurons share a requirement for DYF-7. Together, our results suggest that these neurons and glia can be viewed as part of an epithelium continuous with the skin, and are shaped by mechanisms shared with other epithelia.
Collapse
Affiliation(s)
- Isabel I C Low
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Claire R Williams
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Megan K Chong
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Ian G McLachlan
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Bradley M Wierbowski
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| | - Irina Kolotuev
- Université de Rennes 1, Plateforme microscopie électronique, 35043 Rennes, France
| | - Maxwell G Heiman
- Department of Genetics, Blavatnik Institute, Harvard Medical School and Boston Children's Hospital, Boston, MA 02115, USA
| |
Collapse
|
29
|
Jeong J, Song T, Chatterjee N, Choi I, Cha YK, Choi J. Developing adverse outcome pathways on silver nanoparticle-induced reproductive toxicity via oxidative stress in the nematode Caenorhabditis elegans using a Bayesian network model. Nanotoxicology 2019; 12:1182-1197. [DOI: 10.1080/17435390.2018.1529835] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Jaeseong Jeong
- School of Environmental Engineering, University of Seoul, Seoul, Korea
| | - Taejun Song
- School of Environmental Engineering, University of Seoul, Seoul, Korea
| | | | - Inhee Choi
- Department of Life Science, University of Seoul, Seoul, Korea
| | - Yoon Kyung Cha
- School of Environmental Engineering, University of Seoul, Seoul, Korea
| | - Jinhee Choi
- School of Environmental Engineering, University of Seoul, Seoul, Korea
| |
Collapse
|
30
|
Kage-Nakadai E, Ohta A, Ujisawa T, Sun S, Nishikawa Y, Kuhara A, Mitani S. Caenorhabditis elegans homologue of Prox1/Prospero is expressed in the glia and is required for sensory behavior and cold tolerance. Genes Cells 2016; 21:936-48. [PMID: 27402188 DOI: 10.1111/gtc.12394] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 06/11/2016] [Indexed: 02/01/2023]
Abstract
The Caenorhabditis elegans (C. elegans) amphid sensory organ contains only 4 glia-like cells and 24 sensory neurons, providing a simple model for analyzing glia or neuron-glia interactions. To better characterize glial development and function, we carried out RNA interference screening for transcription factors that regulate the expression of an amphid sheath glial cell marker and identified pros-1, which encodes a homeodomain transcription factor homologous to Drosophila prospero/mammalian Prox1, as a positive regulator. The functional PROS-1::EGFP fusion protein was localized in the nuclei of the glia and the excretory cell but not in the amphid sensory neurons. pros-1 deletion mutants exhibited larval lethality, and rescue experiments showed that pros-1 and human Prox1 transgenes were able to rescue the larval lethal phenotype, suggesting that pros-1 is a functional homologue of mammalian Prox1, at least partially. We further found that the structure and functions of sensory neurons, such as the morphology of sensory endings, sensory behavior and sensory-mediated cold tolerance, appeared to be affected by the pros-1 RNAi. Together, our results show that the C. elegans PROS-1 is a transcriptional regulator in the glia but is involved not only in sensory behavior but also in sensory-mediated physiological tolerance.
Collapse
Affiliation(s)
- Eriko Kage-Nakadai
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, 162-8666, Japan.,The OCU Advanced Research Institute for Natural Science and Technology, Osaka City University, Osaka, 558-8585, Japan.,Graduate School of Human Life Science, Osaka City University, Osaka, 558-8585, Japan
| | - Akane Ohta
- Laboratory of Molecular and Cellular Regulation, Faculty of Science and Engineering, and Institute for Integrative Neurobiology, Konan University, Kobe, 658-8501, Japan
| | - Tomoyo Ujisawa
- Laboratory of Molecular and Cellular Regulation, Faculty of Science and Engineering, and Institute for Integrative Neurobiology, Konan University, Kobe, 658-8501, Japan
| | - Simo Sun
- Graduate School of Human Life Science, Osaka City University, Osaka, 558-8585, Japan
| | - Yoshikazu Nishikawa
- Graduate School of Human Life Science, Osaka City University, Osaka, 558-8585, Japan
| | - Atsushi Kuhara
- Laboratory of Molecular and Cellular Regulation, Faculty of Science and Engineering, and Institute for Integrative Neurobiology, Konan University, Kobe, 658-8501, Japan
| | - Shohei Mitani
- Department of Physiology, Tokyo Women's Medical University School of Medicine, Tokyo, 162-8666, Japan.
| |
Collapse
|
31
|
Yulan XU, Yadan X, Lijun K. [The effect of glial cells in the function and development of the nervous system in Caenorhabditis elegans]. Zhejiang Da Xue Xue Bao Yi Xue Ban 2016; 45:315-22. [PMID: 27651199 PMCID: PMC10396986 DOI: 10.3785/j.issn.1008-9292.2016.05.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 12/23/2015] [Indexed: 06/06/2023]
Abstract
There are three types of glial cells in Caenorhabditis elegans (C. elegans for short): sheath glia, socket glia and glutamate receptor glia. They are mainly located in four sensory organs including the amphid, the cephalic organ, the outer labial sensilla and the inner labial sensilla. C. elegans glial cells play key roles in dendrite extension, neurite guidance and extension, and are essential for synaptogenesis and maintain the normal morphology and the function of sensory nerve endings as well. A recent study shown that some nematode neurons are derived from the glial cells. Moreover, nematodes glial cells can directly modulate the function of sensory neurons. Some glial cells can also respond to certain external stimuli, such as mechanical stimulation, and adjust the accompanying neuronal activities.The article summarizes the progress on effects of nematodes glial cells on the nervous system development and function.
Collapse
Affiliation(s)
- X U Yulan
- Institute of Neuroscience, Zhengjiang University School of Medicine, Hangzhou 310058, China
| | - Xue Yadan
- Institute of Neuroscience, Zhengjiang University School of Medicine, Hangzhou 310058, China
| | - Kang Lijun
- Institute of Neuroscience, Zhengjiang University School of Medicine, Hangzhou 310058, China.
| |
Collapse
|
32
|
A Novel Mechanism of pH Buffering in C. elegans Glia: Bicarbonate Transport via the Voltage-Gated ClC Cl- Channel CLH-1. J Neurosci 2016; 35:16377-97. [PMID: 26674864 DOI: 10.1523/jneurosci.3237-15.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED An important function of glia is the maintenance of the ionic composition and pH of the synaptic microenvironment. In terms of pH regulation, HCO3 (-) buffering has been shown to be important in both glia and neurons. Here, we used in vivo fluorescent pH imaging and RNA sequencing of the amphid sheath glia of Caenorhabditis elegans to reveal a novel mechanism of cellular HCO3 (-) uptake. While the classical mechanism of HCO3 (-) uptake involves Na(+)/HCO3 (-) cotransporters, here we demonstrate that the C. elegans ClC Cl(-) channel CLH-1 is highly permeable to HCO3 (-) and mediates HCO3 (-) uptake into amphid sheath glia. CLH-1 has homology and electrophysiological properties similar to the mammalian ClC-2 Cl(-) channel. Our data suggest that, in addition to maintaining synaptic Cl(-) concentration, these channels may also be involved in maintenance of synaptic pH via HCO3 (-) flux. These findings provide an exciting new facet of study regarding how pH is regulated in the brain. SIGNIFICANCE STATEMENT Maintenance of pH is essential for the physiological function of the nervous system. HCO3 (-) is crucial for pH regulation and is transported into the cell via ion transporters, including ion channels, the molecular identity of which remains unclear. In this manuscript, we describe our discovery that the C. elegans amphid sheath glia regulate intracellular pH via HCO3 (-) flux through the voltage-gated ClC channel CLH-1. This represents a novel function for ClC channels, which has implications for their possible role in mammalian glial pH regulation. This discovery may also provide a novel therapeutic target for pathologic conditions, such as ischemic stroke where acidosis leads to widespread death of glia and subsequently neurons.
Collapse
|
33
|
MEC-10 and MEC-19 Reduce the Neurotoxicity of the MEC-4(d) DEG/ENaC Channel in Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2016; 6:1121-30. [PMID: 27172609 PMCID: PMC4825646 DOI: 10.1534/g3.115.023507] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The Caenorhabditis elegans DEG/ENaC proteins MEC-4 and MEC-10 transduce gentle touch in the six touch receptor neurons .
Gain-of-function mutations of mec-4 and mec-4(d) result in a hyperactive channel and
neurodegeneration in vivo. Loss of MEC-6, a putative DEG/ENaC-specific chaperone, and of the similar
protein POML-1 suppresses the neurodegeneration caused by a mec-4(d) mutation. We find that mutation of two genes,
mec-10 and a new gene mec-19 (previously named C49G9.1), prevents this action of POML-1, allowing the touch receptor neurons to die in
poml-1mec-4(d) animals. The proteins encoded by these genes
normally inhibit mec-4(d) neurotoxicity through different mechanisms.
MEC-10, a subunit of the mechanosensory transduction channel with
MEC-4, inhibits MEC-4(d) activity without affecting MEC-4 expression. In contrast, MEC-19, a membrane protein specific to nematodes, inhibits MEC-4(d) activity and reduces MEC-4 surface expression.
Collapse
|
34
|
Environmental CO2 inhibits Caenorhabditis elegans egg-laying by modulating olfactory neurons and evokes widespread changes in neural activity. Proc Natl Acad Sci U S A 2015; 112:E3525-34. [PMID: 26100886 DOI: 10.1073/pnas.1423808112] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Carbon dioxide (CO2) gradients are ubiquitous and provide animals with information about their environment, such as the potential presence of prey or predators. The nematode Caenorhabditis elegans avoids elevated CO2, and previous work identified three neuron pairs called "BAG," "AFD," and "ASE" that respond to CO2 stimuli. Using in vivo Ca(2+) imaging and behavioral analysis, we show that C. elegans can detect CO2 independently of these sensory pathways. Many of the C. elegans sensory neurons we examined, including the AWC olfactory neurons, the ASJ and ASK gustatory neurons, and the ASH and ADL nociceptors, respond to a rise in CO2 with a rise in Ca(2+). In contrast, glial sheath cells harboring the sensory endings of C. elegans' major chemosensory neurons exhibit strong and sustained decreases in Ca(2+) in response to high CO2. Some of these CO2 responses appear to be cell intrinsic. Worms therefore may couple detection of CO2 to that of other cues at the earliest stages of sensory processing. We show that C. elegans persistently suppresses oviposition at high CO2. Hermaphrodite-specific neurons (HSNs), the executive neurons driving egg-laying, are tonically inhibited when CO2 is elevated. CO2 modulates the egg-laying system partly through the AWC olfactory neurons: High CO2 tonically activates AWC by a cGMP-dependent mechanism, and AWC output inhibits the HSNs. Our work shows that CO2 is a more complex sensory cue for C. elegans than previously thought, both in terms of behavior and neural circuitry.
Collapse
|
35
|
Mizeracka K, Heiman MG. The many glia of a tiny nematode: studying glial diversity using Caenorhabditis elegans. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 4:151-60. [PMID: 25611728 DOI: 10.1002/wdev.171] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 11/20/2014] [Accepted: 12/02/2014] [Indexed: 11/06/2022]
Abstract
UNLABELLED Glia constitute a major, understudied population of cells in the nervous system. Currently, it is appreciated that these cells exhibit vast morphological, functional, and molecular diversity, but our understanding of glial biology is limited. Some key unanswered questions include how glial diversity is generated during development and what functions distinct glial subtypes serve in the mature nervous system. The nematode Caenorhabditis elegans contains a defined set of glia, which have clear morphological and molecular differences, and thus provides a simplified model for understanding glial diversity. In addition, recent experiments suggest that the molecular mechanisms underlying the generation of glial diversity in C. elegans are conserved with those in mammals. In this review, we summarize the surprising diversity of glial subtypes present in this simple organism, and highlight current thinking about what roles they perform in the nervous system. We emphasize how genetic approaches may be used to identify the mechanistic origins of glial diversity, which is key to understanding how glia function in health and disease. For further resources related to this article, please visit the WIREs website. CONFLICT OF INTEREST The authors have declared no conflicts of interest for this article.
Collapse
Affiliation(s)
- Karolina Mizeracka
- Division of Genetics, Boston Children's Hospital, Boston, MA, USA; Department of Genetics, Harvard Medical School, Boston, MA, USA
| | | |
Collapse
|
36
|
Shaham S. Glial development and function in the nervous system of Caenorhabditis elegans. Cold Spring Harb Perspect Biol 2015; 7:a020578. [PMID: 25573712 DOI: 10.1101/cshperspect.a020578] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The nematode, Caenorhabditis elegans, has served as a fruitful setting for understanding conserved biological processes. The past decade has seen the rise of this model organism as an important tool for uncovering the mysteries of the glial cell, which partners with neurons to generate a functioning nervous system in all animals. C. elegans affords unparalleled single-cell resolution in vivo in examining glia-neuron interactions, and similarities between C. elegans and vertebrate glia suggest that lessons learned from this nematode are likely to have general implications. Here, I summarize what has been gleaned over the past decade since C. elegans glia research became a concerted area of focus. Studies have revealed that glia are essential elements of a functioning C. elegans nervous system and play key roles in its development. Importantly, glial influence on neuronal function appears to be dynamic. Key questions for the field to address in the near- and long-term have emerged, and these are discussed within.
Collapse
Affiliation(s)
- Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, New York, New York 10065
| |
Collapse
|
37
|
Mechanosensory molecules and circuits in C. elegans. Pflugers Arch 2014; 467:39-48. [PMID: 25053538 PMCID: PMC4281349 DOI: 10.1007/s00424-014-1574-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 06/30/2014] [Accepted: 07/02/2014] [Indexed: 01/28/2023]
Abstract
Mechanosensory neurons, whose activity is controlled by mechanical force, underlie the senses of touch, hearing, and proprioception, yet despite their importance, the molecular basis of mechanotransduction is poorly understood. Genetic studies in Caenorhabditis elegans have provided a useful approach for identifying potential components of mechanotransduction complexes that might be conserved in more complex organisms. This review describes the mechanosensory systems of C. elegans, including the sensory neurons and circuitry involved in body touch, nose touch, and proprioception. In addition, the roles of genes encoding known and potential mechanosensory receptors, including members of the broadly conserved transient receptor potential (TRP) and degerin/epithelial Na+ channel (DEG/ENaC) channel families, are discussed.
Collapse
|
38
|
Stout RF, Verkhratsky A, Parpura V. Caenorhabditis elegans glia modulate neuronal activity and behavior. Front Cell Neurosci 2014; 8:67. [PMID: 24672428 PMCID: PMC3954127 DOI: 10.3389/fncel.2014.00067] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 02/15/2014] [Indexed: 11/26/2022] Open
Abstract
Glial cells of Caenorhabditis elegans can modulate neuronal activity and behavior, which is the focus of this review. Initially, we provide an overview of neuroglial evolution, making a comparison between C. elegans glia and their genealogical counterparts. What follows is a brief discussion on C. elegans glia characteristics in terms of their exact numbers, germ layers origin, their necessity for proper development of sensory organs, and lack of their need for neuronal survival. The more specific roles that various glial cells have on neuron-based activity/behavior are succinctly presented. The cephalic sheath glia are important for development, maintenance and activity of central synapses, whereas the amphid glia seem to set the tone of sensory synapses; these glial cell types are ectoderm-derived. Mesoderm-derived Glial-Like cells in the nerve Ring (GLRs) appear to be a part of the circuit for production of motor movement of the worm anterior. Finally, we discuss tools and approaches utilized in studying C. elegans glia, which are assets available for this animal, making it an appealing model, not only in neurosciences, but in biology in general.
Collapse
Affiliation(s)
- Randy F Stout
- Department of Neuroscience, Albert Einstein College of Medicine Bronx, NY, USA
| | - Alexei Verkhratsky
- Faculty of Life Sciences, The University of Manchester Manchester, UK ; IKERBASQUE, Basque Foundation for Science Bilbao, Spain ; Department of Neurosciences, University of the Basque Country UPV/EHU Leioa, Spain
| | - Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine, Civitan International Research Center, Atomic Force Microscopy and Nanotechnology Laboratories, and Evelyn F. McKnight Brain Institute, University of Alabama Birmingham, AL, USA ; Department of Biotechnology, University of Rijeka Rijeka, Croatia
| |
Collapse
|
39
|
Wang Y, Matthewman C, Han L, Miller T, Miller DM, Bianchi L. Neurotoxic unc-8 mutants encode constitutively active DEG/ENaC channels that are blocked by divalent cations. ACTA ACUST UNITED AC 2014; 142:157-69. [PMID: 23898007 PMCID: PMC3727304 DOI: 10.1085/jgp.201310974] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Ion channels of the DEG/ENaC family can induce neurodegeneration under conditions in which they become hyperactivated. The Caenorhabditis elegans DEG/ENaC channel MEC-4(d) encodes a mutant channel with a substitution in the pore domain that causes swelling and death of the six touch neurons in which it is expressed. Dominant mutations in the C. elegans DEG/ENaC channel subunit UNC-8 result in uncoordinated movement. Here we show that this unc-8 movement defect is correlated with the selective death of cholinergic motor neurons in the ventral nerve cord. Experiments in Xenopus laevis ooctyes confirm that these mutant proteins, UNC-8(G387E) and UNC-8(A586T), encode hyperactivated channels that are strongly inhibited by extracellular calcium and magnesium. Reduction of extracellular divalent cations exacerbates UNC-8(G387E) toxicity in oocytes. We suggest that inhibition by extracellular divalent cations limits UNC-8 toxicity and may contribute to the selective death of neurons that express UNC-8 in vivo.
Collapse
Affiliation(s)
- Ying Wang
- Department of Physiology and Biophysics, University of Miami, Miller School of Medicine, Miami, FL 33136, USA
| | | | | | | | | | | |
Collapse
|
40
|
Two novel DEG/ENaC channel subunits expressed in glia are needed for nose-touch sensitivity in Caenorhabditis elegans. J Neurosci 2013; 33:936-49. [PMID: 23325233 DOI: 10.1523/jneurosci.2749-12.2013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Neuronal DEG/ENaC (degenerin and epithelial Na(+) channel) Na(+) channels have been implicated in touch sensation. For example, MEC-4 is expressed in touch neurons in Caenorhabditis elegans and mediates gentle-touch response. Similarly, homologous mammalian ASIC2 and ASIC3 are expressed in sensory neurons and produce touch phenotypes when knocked out in mice. Here, we show that novel DEG/ENaC subunits DELM-1 and DELM-2 (degenerin-like channel mechanosensory linked-1 and degenerin-like channel mechanosensory linked-2) are expressed in glia associated with touch neurons in C. elegans and that their knock-out causes defects in mechanosensory behaviors related to nose touch and foraging, which are mediated by OLQ and IL1 sensory neurons. Cell-specific rescue supports that DELM-1 and DELM-2 are required cell-autonomously in glia to orchestrate mechanosensory behaviors. Electron microscopy reveals that in delm-1 knock-outs, OLQ and IL1 sensory neurons and associated glia are structurally normal. Furthermore, we show that knock-out of DELM-1 and DELM-2 does not disrupt the expression or cellular localization of TRPA-1, a TRP channel needed in OLQ and IL1 neurons for touch behaviors. Rather, rescue of the delm-1 nose-touch-insensitive phenotype by expression of a K(+) channel in socket glia and of a cationic channel in OLQ neurons suggests that DELM channels set basal neuronal excitability. Together, our data show that DELM-1 and DELM-2 are expressed in glia associated with touch neurons where they are not needed for neuronal structural integrity or cellular distribution of neuronal sensory channels, but rather for their function.
Collapse
|
41
|
Toda H, Zhao X, Dickson B. The Drosophila Female Aphrodisiac Pheromone Activates ppk23+ Sensory Neurons to Elicit Male Courtship Behavior. Cell Rep 2012; 1:599-607. [DOI: 10.1016/j.celrep.2012.05.007] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 04/17/2012] [Accepted: 05/14/2012] [Indexed: 11/26/2022] Open
|
42
|
Oikonomou G, Perens EA, Lu Y, Shaham S. Some, but not all, retromer components promote morphogenesis of C. elegans sensory compartments. Dev Biol 2012; 362:42-9. [PMID: 22138055 PMCID: PMC3254776 DOI: 10.1016/j.ydbio.2011.11.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 10/31/2011] [Accepted: 11/12/2011] [Indexed: 12/26/2022]
Abstract
The endings of sensory receptor cells often lie within specialized compartments formed by glial cells. The main sensory organ of Caenorhabditis elegans, the amphid, provides a powerful setting for studying glial compartment morphogenesis. Our previous studies showed that amphid compartment size is controlled by opposing activities of the Nemo-like kinase LIT-1, which promotes compartment expansion, and the Patched-related protein DAF-6, which restricts compartment growth. From a genetic screen for mutations able to suppress the bloated sensory compartments of daf-6 mutants, we identified an allele of the sorting nexin gene snx-1. SNX-1 protein is a component of the retromer, a protein complex that facilitates recycling of transmembrane proteins from the endosome to the Golgi network. We find that snx-1 functions cell autonomously within glia to promote sensory compartment growth, and that SNX-1 protein is enriched near the surface of the sensory compartment. snx-1 interacts genetically with lit-1 and another regulator of compartment size, the Dispatched-related gene che-14. Mutations in snx-3 and vps-29, also retromer genes, can suppress daf-6 defects. Surprisingly, however, remaining retromer components seem not to be involved. Our results suggest that a novel assembly of retromer components is important for determining sensory compartment dimensions.
Collapse
Affiliation(s)
- Grigorios Oikonomou
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065 USA
| | - Elliot A. Perens
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065 USA
| | - Yun Lu
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065 USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065 USA
| |
Collapse
|
43
|
Jee C, Choi TW, Kalichamy K, Yee JZ, Song HO, Ji YJ, Lee J, Lee JI, L'Etoile ND, Ahnn J, Lee SK. CNP-1 (ARRD-17), a novel substrate of calcineurin, is critical for modulation of egg-laying and locomotion in response to food and lysine sensation in Caenorhabditis elegans. J Mol Biol 2012; 417:165-78. [PMID: 22300764 DOI: 10.1016/j.jmb.2012.01.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 12/19/2011] [Accepted: 01/13/2012] [Indexed: 10/14/2022]
Abstract
Calcineurin is a Ca(2+)/calmodulin-dependent protein phosphatase involved in calcium signaling pathways. In Caenorhabditis elegans, the loss of calcineurin activity causes pleiotropic defects including hyperadaptation of sensory neurons, hypersensation to thermal difference and hyper-egg-laying when worms are refed after starvation. In this study, we report on arrd-17 as calcineurin-interacting protein-1 (cnp-1), which is a novel molecular target of calcineurin. CNP-1 interacts with the catalytic domain of the C. elegans calcineurin A subunit, TAX-6, in a yeast two-hybrid assay and is dephosphorylated by TAX-6 in vitro. cnp-1 is expressed in ASK, ADL, ASH and ASJ sensory neurons as TAX-6. It acts downstream of tax-6 in regulation of locomotion and egg-laying after starvation, ASH sensory neuron adaptation and lysine chemotaxis, that is known to be mediated by ASK neurons. Altogether, our biochemical and genetic evidence indicates that CNP-1 is a direct target of calcineurin and required in stimulated egg-laying and locomotion after starvation, adaptation to hyperosmolarity and attraction to lysine, which is modulated by calcineurin. We suggest that the phosphorylation status of CNP-1 plays an important role in regulation of refed stimulating behaviors after starvation and attraction to amino acid, which provides valuable nutritious information.
Collapse
Affiliation(s)
- Changhoon Jee
- Department of Life Science, Gwangju Institute of Science and Technology, Gwangju 500-712, Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Blaustein MP, Leenen FHH, Chen L, Golovina VA, Hamlyn JM, Pallone TL, Van Huysse JW, Zhang J, Wier WG. How NaCl raises blood pressure: a new paradigm for the pathogenesis of salt-dependent hypertension. Am J Physiol Heart Circ Physiol 2011; 302:H1031-49. [PMID: 22058154 DOI: 10.1152/ajpheart.00899.2011] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Excess dietary salt is a major cause of hypertension. Nevertheless, the specific mechanisms by which salt increases arterial constriction and peripheral vascular resistance, and thereby raises blood pressure (BP), are poorly understood. Here we summarize recent evidence that defines specific molecular links between Na(+) and the elevated vascular resistance that directly produces high BP. In this new paradigm, high dietary salt raises cerebrospinal fluid [Na(+)]. This leads, via the Na(+)-sensing circumventricular organs of the brain, to increased sympathetic nerve activity (SNA), a major trigger of vasoconstriction. Plasma levels of endogenous ouabain (EO), the Na(+) pump ligand, also become elevated. Remarkably, high cerebrospinal fluid [Na(+)]-evoked, locally secreted (hypothalamic) EO participates in a pathway that mediates the sustained increase in SNA. This hypothalamic signaling chain includes aldosterone, epithelial Na(+) channels, EO, ouabain-sensitive α(2) Na(+) pumps, and angiotensin II (ANG II). The EO increases (e.g.) hypothalamic ANG-II type-1 receptor and NADPH oxidase and decreases neuronal nitric oxide synthase protein expression. The aldosterone-epithelial Na(+) channel-EO-α(2) Na(+) pump-ANG-II pathway modulates the activity of brain cardiovascular control centers that regulate the BP set point and induce sustained changes in SNA. In the periphery, the EO secreted by the adrenal cortex directly enhances vasoconstriction via an EO-α(2) Na(+) pump-Na(+)/Ca(2+) exchanger-Ca(2+) signaling pathway. Circulating EO also activates an EO-α(2) Na(+) pump-Src kinase signaling cascade. This increases the expression of the Na(+)/Ca(2+) exchanger-transient receptor potential cation channel Ca(2+) signaling pathway in arterial smooth muscle but decreases the expression of endothelial vasodilator mechanisms. Additionally, EO is a growth factor and may directly participate in the arterial structural remodeling and lumen narrowing that is frequently observed in established hypertension. These several central and peripheral mechanisms are coordinated, in part by EO, to effect and maintain the salt-induced elevation of BP.
Collapse
Affiliation(s)
- Mordecai P Blaustein
- Dept. of Physiology, Univ. of Maryland School of Medicine, 655 W. Baltimore St., Baltimore, MD, 21201, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Tsui H, Paltser G, Chan Y, Dorfman R, Dosch HM. 'Sensing' the link between type 1 and type 2 diabetes. Diabetes Metab Res Rev 2011; 27:913-8. [PMID: 22069284 DOI: 10.1002/dmrr.1279] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Obesity-associated insulin resistance is a core element of metabolic syndrome and type 2 diabetes (T2D). Notably, insulin resistance is also a feature of type 1 diabetes (T1D), where findings in the non-obese diabetic mouse model have implicated transient receptor potential vanilloid-1 (TRPV1+) sensory neurons in local islet inflammation and glucose metabolism. Here, we briefly review the role of TRPV1 in non-obese diabetic (NOD) T1D pathogenesis, highlighting commonalities that suggest TRPV1 may contribute to obesity and T2D as well. With the recently discovered importance of adipose infiltrating lymphocytes in the metabolic disturbances of obesity and T2D, sensory innervation of fat may thus play an analogous role to sensory neurons in the islet--modulating neuroendocrine homeostasis and inflammation. In such a scenario, TRPV1+ sensory nerves would provide the pathoaetiological link connecting the shared metabolic and immunologic features of type 1 diabetes and T2D.
Collapse
Affiliation(s)
- Hubert Tsui
- The Research Institute, Hospital For Sick Children, University of Toronto, Neuroscience and Mental Health Program, Toronto, ON M5G 1X8, Canada.
| | | | | | | | | |
Collapse
|
46
|
Geffeney SL, Cueva JG, Glauser DA, Doll JC, Lee THC, Montoya M, Karania S, Garakani AM, Pruitt BL, Goodman MB. DEG/ENaC but not TRP channels are the major mechanoelectrical transduction channels in a C. elegans nociceptor. Neuron 2011; 71:845-57. [PMID: 21903078 DOI: 10.1016/j.neuron.2011.06.038] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2011] [Indexed: 01/01/2023]
Abstract
Many nociceptors detect mechanical cues, but the ion channels responsible for mechanotransduction in these sensory neurons remain obscure. Using in vivo recordings and genetic dissection, we identified the DEG/ENaC protein, DEG-1, as the major mechanotransduction channel in ASH, a polymodal nociceptor in Caenorhabditis elegans. But DEG-1 is not the only mechanotransduction channel in ASH: loss of deg-1 revealed a minor current whose properties differ from those expected of DEG/ENaC channels. This current was independent of two TRPV channels expressed in ASH. Although loss of these TRPV channels inhibits behavioral responses to noxious stimuli, we found that both mechanoreceptor currents and potentials were essentially wild-type in TRPV mutants. We propose that ASH nociceptors rely on two genetically distinct mechanotransduction channels and that TRPV channels contribute to encoding and transmitting information. Because mammalian and insect nociceptors also coexpress DEG/ENaCs and TRPVs, the cellular functions elaborated here for these ion channels may be conserved.
Collapse
Affiliation(s)
- Shana L Geffeney
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Nelson AM, Marshall KL, Lumpkin EA. DEG/ENaCs lead by a nose: mechanotransduction in a polymodal sensory neuron. Neuron 2011; 71:763-5. [PMID: 21903069 DOI: 10.1016/j.neuron.2011.08.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Degenerin/epithelial sodium channels (DEG/ENaCs) are luminaries of gentle touch in Caenorhabditis elegans. In this issue of Neuron, Geffeney et al. demonstrate that eponymous DEG-1 channels carry mechanotransduction currents in a polymodal neuron, where they act upstream of transient receptor potential (TRP) channels.
Collapse
Affiliation(s)
- Aislyn M Nelson
- Department of Dermatology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | | | | |
Collapse
|
48
|
Wang Y, D'Urso G, Bianchi L. Knockout of glial channel ACD-1 exacerbates sensory deficits in a C. elegans mutant by regulating calcium levels of sensory neurons. J Neurophysiol 2011; 107:148-58. [PMID: 21994266 DOI: 10.1152/jn.00299.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Degenerin/epithelial Na(+) channels (DEG/ENaCs) are voltage-independent Na(+) or Na(+)/Ca(2+) channels expressed in many tissues and are needed for a wide range of physiological functions, including sensory perception and transepithelial Na(+) transport. In the nervous system, DEG/ENaCs are expressed in both neurons and glia. However, the role of glial vs. neuronal DEG/ENaCs remains unclear. We recently reported the characterization of a novel DEG/ENaC in Caenorhabditis elegans that we named ACD-1. ACD-1 is expressed in glial amphid sheath cells. The glial ACD-1, together with the neuronal DEG/ENaC DEG-1, is necessary for acid avoidance and attraction to lysine. We report presently that knockout of acd-1 in glia exacerbates sensory deficits caused by another mutant: the hypomorphic allele of the cGMP-gated channel subunit tax-2. Furthermore, sensory deficits caused by mutations in G(i) protein odr-3 and guanylate cyclase daf-11, which regulate the activity of TAX-2/TAX-4 channels, are worsened by knockout of acd-1. We also show that sensory neurons of acd-1 tax-2(p694) double mutants fail to undergo changes in intracellular Ca(2+) when animals are exposed to low concentrations of attractant. Finally, we show that exogenous expression of TRPV1 in sensory neurons and exposure to capsaicin rescue sensory deficits of acd-1 tax-2(p694) mutants, suggesting that sensory deficits of these mutants are bypassed by increasing neuronal excitability. Our data suggest a role of glial DEG/ENaC channel ACD-1 in supporting neuronal activity.
Collapse
Affiliation(s)
- Ying Wang
- Rm. 5133, Rosenstiel Bldg., Dept. of Physiology and Biophysics, Miller School of Medicine, Univ. of Miami, 1600 NW 10th Ave., Miami, FL 33136, USA
| | | | | |
Collapse
|
49
|
Oikonomou G, Perens EA, Lu Y, Watanabe S, Jorgensen EM, Shaham S. Opposing activities of LIT-1/NLK and DAF-6/patched-related direct sensory compartment morphogenesis in C. elegans. PLoS Biol 2011; 9:e1001121. [PMID: 21857800 PMCID: PMC3153439 DOI: 10.1371/journal.pbio.1001121] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 06/28/2011] [Indexed: 12/23/2022] Open
Abstract
Glial cells surround neuronal endings to create enclosed compartments required for neuronal function. This architecture is seen at excitatory synapses and at sensory neuron receptive endings. Despite the prevalence and importance of these compartments, how they form is not known. We used the main sensory organ of C. elegans, the amphid, to investigate this issue. daf-6/Patched-related is a glia-expressed gene previously implicated in amphid sensory compartment morphogenesis. By comparing time series of electron-microscopy (EM) reconstructions of wild-type and daf-6 mutant embryos, we show that daf-6 acts to restrict compartment size. From a genetic screen, we found that mutations in the gene lit-1/Nemo-like kinase (NLK) suppress daf-6. EM and genetic studies demonstrate that lit-1 acts within glia, in counterbalance to daf-6, to promote sensory compartment expansion. Although LIT-1 has been shown to regulate Wnt signaling, our genetic studies demonstrate a novel, Wnt-independent role for LIT-1 in sensory compartment size control. The LIT-1 activator MOM-4/TAK1 is also important for compartment morphogenesis and both proteins line the glial sensory compartment. LIT-1 compartment localization is important for its function and requires neuronal signals. Furthermore, the conserved LIT-1 C-terminus is necessary and sufficient for this localization. Two-hybrid and co-immunoprecipitation studies demonstrate that the LIT-1 C-terminus binds both actin and the Wiskott-Aldrich syndrome protein (WASP), an actin regulator. We use fluorescence light microscopy and fluorescence EM methodology to show that actin is highly enriched around the amphid sensory compartment. Finally, our genetic studies demonstrate that WASP is important for compartment expansion and functions in the same pathway as LIT-1. The studies presented here uncover a novel, Wnt-independent role for the conserved Nemo-like kinase LIT-1 in controlling cell morphogenesis in conjunction with the actin cytoskeleton. Our results suggest that the opposing daf-6 and lit-1 glial pathways act together to control sensory compartment size. The nervous system of most animals consists of two related cell types, neurons and glia. A striking property of glia is their ability to ensheath neuronal cells, which can help increase the efficiency of synaptic communication between neurons. Sensory neuron receptive endings in the periphery, as well as excitatory synapses in the central nervous system, often lie within specialized compartments formed by glial processes. Despite the prevalence of these compartments, and their importance for neuronal function and signal transmission, little is known about how they form. We have used the amphid, the main sensory organ of the worm Caenorhabditis elegans, to investigate glial sensory compartment morphogenesis. We demonstrate that the glia-expressed gene daf-6/Patched-related acts to restrict the size of the sensory compartment, while the Nemo-like kinase lit-1 acts within glia in the opposite direction, to promote sensory compartment expansion. We show that LIT-1 localizes to the sensory compartment through a highly conserved domain. This domain can interact both with actin, which outlines the compartment, and with the regulator of actin polymerization WASP, which acts in the same pathway as lit-1. We postulate that Nemo-like kinases could have broader roles as regulators of cellular morphogenesis, in addition to their traditional role in regulating the Wnt signaling pathway.
Collapse
Affiliation(s)
- Grigorios Oikonomou
- Laboratory of Developmental Genetics, The Rockefeller University, New York, New York, United States of America
| | - Elliot A. Perens
- Laboratory of Developmental Genetics, The Rockefeller University, New York, New York, United States of America
| | - Yun Lu
- Laboratory of Developmental Genetics, The Rockefeller University, New York, New York, United States of America
| | - Shigeki Watanabe
- Howard Hughes Medical Institute, Department of Biology, University of Utah, Salt Lake City, Utah, United States of America
| | - Erik M. Jorgensen
- Howard Hughes Medical Institute, Department of Biology, University of Utah, Salt Lake City, Utah, United States of America
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
50
|
Sun X, Cao YB, Hu LF, Yang YP, Li J, Wang F, Liu CF. ASICs mediate the modulatory effect by paeoniflorin on alpha-synuclein autophagic degradation. Brain Res 2011; 1396:77-87. [DOI: 10.1016/j.brainres.2011.04.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 04/02/2011] [Accepted: 04/05/2011] [Indexed: 11/28/2022]
|