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Glutamate Signaling and Filopodiagenesis of Astrocytoma Cells in Brain Cancers: Survey and Questions. Cells 2022; 11:cells11172657. [PMID: 36078065 PMCID: PMC9454653 DOI: 10.3390/cells11172657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/19/2022] [Accepted: 08/24/2022] [Indexed: 11/22/2022] Open
Abstract
Astrocytes are non-excitable cells in the CNS that can cause life-threatening astrocytoma tumors when they transform to cancerous cells. Perturbed homeostasis of the neurotransmitter glutamate is associated with astrocytoma tumor onset and progression, but the factors that govern this phenomenon are less known. Herein, we review possible mechanisms by which glutamate may act in facilitating the growth of projections in astrocytic cells. This review discusses the similarities and differences between the morphology of astrocytes and astrocytoma cells, and the role that dysregulation in glutamate and calcium signaling plays in the aberrant morphology of astrocytoma cells. Converging reports suggest that ionotropic glutamate receptors and voltage-gated calcium channels expressed in astrocytes may be responsible for the abnormal filopodiagenesis or process extension leading to astrocytoma cells’ infiltration throughout the brain.
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Chen D, Cheng H, Liu S, Al-Sheikh U, Fan Y, Duan D, Zou W, Zhu L, Kang L. The Voltage-Gated Calcium Channel EGL-19 Acts on Glia to Drive Olfactory Adaptation. Front Mol Neurosci 2022; 15:907064. [PMID: 35782381 PMCID: PMC9247319 DOI: 10.3389/fnmol.2022.907064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
Calcium channelopathies have been strongly linked to cardiovascular, muscular, neurological and psychiatric disorders. The voltage-gated calcium channels (VGCC) are vital transducers of membrane potential changes to facilitate the dynamics of calcium ions and release of neurotransmitter. Whether these channels function in the glial cell to mediate calcium variations and regulate behavioral outputs, is poorly understood. Our results showed that odorant and mechanical stimuli evoked robust calcium increases in the amphid sheath (AMsh) glia from C. elegans, which were largely dependent on the L-Type VGCC EGL-19. Moreover, EGL-19 modulates the morphologies of both ASH sensory neurons and AMsh glia. Tissue-specific knock-down of EGL-19 in AMsh glia regulated sensory adaptability of ASH neurons and promoted olfactory adaptation. Our results reveal a novel role of glial L-Type VGCC EGL-19 on olfaction, lead to improved understanding of the functions of VGCCs in sensory transduction.
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Affiliation(s)
- Du Chen
- Department of Neurobiology and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Hankui Cheng
- Department of Neurobiology and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Siyan Liu
- Department of Neurobiology and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Umar Al-Sheikh
- Department of Neurobiology and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Yuedan Fan
- Department of Neurobiology and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Duo Duan
- Department of Neurobiology and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Wenjuan Zou
- Department of Neurobiology and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Linhui Zhu
- Department of Neurobiology and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Lijun Kang
- Department of Neurobiology and Department of Neurology of the Fourth Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
- *Correspondence: Lijun Kang
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Ye S, Zeng R, Zhou J, An M, Ding Z. Molecular characterization of Ditylenchus destructor voltage-gated calcium channel α1 subunits and analysis of the effect of their knockdown on nematode activity. Biochimie 2020; 171-172:91-102. [PMID: 32109501 DOI: 10.1016/j.biochi.2020.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 02/19/2020] [Indexed: 01/17/2023]
Abstract
Voltage-gated calcium channels (VGCCs) mediate the entry of Ca2+ ions into cells in response to membrane depolarization and play fundamental roles in the nervous system, and the α1 subunits are the main subunits of Ca2+ channels. Caenorhabditis elegans possesses genes encoding α1 subunits; however, very few of these genes have been cloned in plant-parasitic nematodes (PPNs). Ditylenchus destructor is a PPN that has been proposed as a new model for studying the biology and control of PPNs. To understand the structure and function of the VGCCs of this PPN, we first cloned and identified three full-length cDNAs of VGCC α1 subunit genes in D. destructor with the defining structural and conserved features of Cav1 (L-type), Cav2 (non-L-type) and Cav3 (T-type). In situ hybridization assays demonstrated that the Cav1 VGCC α1 subunit gene (DdCα1D) was expressed within body wall muscles. The Cav2 VGCC α1 subunit (DdCα1A) was expressed in the oesophageal gland, vulva and vas deferens of the worm, and the Cav3 VGCC α1 subunit (DdCα1G) was localized to the oesophagus and median bulb. In addition, on the basis of the in vitro knockdown of L-, non-L- and T-type genes via RNAi, these genes were predicted to play a key role in the modulation of locomotion, feeding and reproduction. After the silencing of DdCα1G, the median bulb muscle of D. destructor was obviously contracted, and its feeding and reproduction abilities were significantly inhibited. This study provides insight into the structure and function of VGCC α1 subunits in D. destructor.
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Affiliation(s)
- Shan Ye
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan, 410128, China; Hunan Provincial Engineering & Technology Research Center for Bio-pesticide and Formulation Processing, Changsha, Hunan, 410128, China
| | - Rune Zeng
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Jianyu Zhou
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Mingwei An
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan, 410128, China
| | - Zhong Ding
- College of Plant Protection, Hunan Agricultural University, Changsha, Hunan, 410128, China; Hunan Provincial Engineering & Technology Research Center for Bio-pesticide and Formulation Processing, Changsha, Hunan, 410128, China.
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Webb SE, Kelu JJ, Miller AL. Role of Two-Pore Channels in Embryonic Development and Cellular Differentiation. Cold Spring Harb Perspect Biol 2020; 12:a035170. [PMID: 31358517 PMCID: PMC6942120 DOI: 10.1101/cshperspect.a035170] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Since the identification of nicotinic acid adenine dinucleotide phosphate (NAADP) and its putative target, the two-pore channel (TPC), the NAADP/TPC/Ca2+ signaling pathway has been reported to play a role in a diverse range of functions in a variety of different cell types. TPCs have also been associated with a number of diseases, which arise when their activity is perturbed. In addition, TPCs have been shown to play key roles in various embryological processes and during the differentiation of a variety of cell types. Here, we review the role of NAADP/TPC/Ca2+ signaling during early embryonic development and cellular differentiation. We pay particular attention to the role of TPC2 in the development and maturation of early neuromuscular activity in zebrafish, and during the differentiation of isolated osteoclasts, endothelial cells, and keratinocytes. Our aim is to emphasize the conserved features of TPC-mediated Ca2+ signaling in a number of selected examples.
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Affiliation(s)
- Sarah E Webb
- Division of Life Science & State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology (HKUST), Clearwater Bay, Hong Kong, PRC
| | - Jeffrey J Kelu
- Division of Life Science & State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology (HKUST), Clearwater Bay, Hong Kong, PRC
| | - Andrew L Miller
- Division of Life Science & State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology (HKUST), Clearwater Bay, Hong Kong, PRC
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Kurshan PT, Merrill SA, Dong Y, Ding C, Hammarlund M, Bai J, Jorgensen EM, Shen K. γ-Neurexin and Frizzled Mediate Parallel Synapse Assembly Pathways Antagonized by Receptor Endocytosis. Neuron 2018; 100:150-166.e4. [PMID: 30269993 PMCID: PMC6181781 DOI: 10.1016/j.neuron.2018.09.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 07/30/2018] [Accepted: 09/04/2018] [Indexed: 12/12/2022]
Abstract
Synapse formation defines neuronal connectivity and is thus essential for neuronal circuit assembly. Trans-synaptic interactions of cell adhesion molecules are thought to induce synapse assembly. Here we demonstrate that a recently discovered and conserved short form of neurexin, γ-neurexin, which lacks canonical extracellular domains, is nonetheless sufficient to promote presynaptic assembly in the nematode C. elegans. γ- but not α-neurexin is required for assembling active zone components, recruiting synaptic vesicles, and clustering calcium channels at release sites to promote evoked synaptic transmission. Furthermore, we find that neurexin functions in parallel with the transmembrane receptor Frizzled, as the absence of both proteins leads to an enhanced phenotype-the loss of most synapses. Frizzled's pro-synaptogenic function is independent of its ligand, Wnt. Wnt binding instead eliminates synapses by inducing Frizzled's endocytosis and the downregulation of neurexin. These results reveal how pro- and anti-synaptogenic factors converge to precisely sculpt circuit formation in vivo.
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Affiliation(s)
- Peri T Kurshan
- Biology Department, Stanford University, Stanford, CA 94305, USA.
| | - Sean A Merrill
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA
| | - Yongming Dong
- Division of Basic Sciences, Fred Hutchinson Cancer Institute, Seattle, WA 98109, USA
| | - Chen Ding
- Department of Genetics and Neuroscience, Yale University, New Haven, CT 06510, USA
| | - Marc Hammarlund
- Department of Genetics and Neuroscience, Yale University, New Haven, CT 06510, USA
| | - Jihong Bai
- Division of Basic Sciences, Fred Hutchinson Cancer Institute, Seattle, WA 98109, USA
| | - Erik M Jorgensen
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA; Howard Hughes Medical Institute
| | - Kang Shen
- Biology Department, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institute
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Pereira MDC, Morais S, Sequeiros J, Alonso I. Large-Scale Functional RNAi Screen in C. elegans Identifies TGF-β and Notch Signaling Pathways as Modifiers of CACNA1A. ASN Neuro 2016; 8:8/2/1759091416637025. [PMID: 27005779 PMCID: PMC4811018 DOI: 10.1177/1759091416637025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 01/31/2016] [Indexed: 01/02/2023] Open
Abstract
Variants in CACNA1A that encodes the pore-forming α1-subunit of human voltage-gated Cav2.1 (P/Q-type) Ca2+ channels cause several autosomal-dominant neurologic disorders, including familial hemiplegic migraine type 1, episodic ataxia type 2, and spinocerebellar ataxia type 6. To identify modifiers of incoordination in movement disorders, we performed a large-scale functional RNAi screen, using the Caenorhabditis elegans strain CB55, which carries a truncating mutation in the unc-2 gene, the worm ortholog for the human CACNA1A. The screen was carried out by the feeding method in 96-well liquid culture format, using the ORFeome v1.1 feeding library, and time-lapse imaging of worms in liquid culture was used to assess changes in thrashing behavior. We looked for genes that, when silenced, either ameliorated the slow and uncoordinated phenotype of unc-2, or interacted to produce a more severe phenotype. Of the 350 putative hits from the primary screen, 37 genes consistently showed reproducible results. At least 75% of these are specifically expressed in the C. elegans neurons. Functional network analysis and gene ontology revealed overrepresentation of genes involved in development, growth, locomotion, signal transduction, and vesicle-mediated transport. We have expanded the functional network of genes involved in neurodegeneration leading to cerebellar ataxia related to unc-2/CACNA1A, further confirming the involvement of the transforming growth factor β pathway and adding a novel signaling cascade, the Notch pathway.
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Affiliation(s)
- Maria da Conceição Pereira
- UnIGENe, Institute for Molecular and Cell Biology (IBMC), Instituto de Investigação e Inovação em Saúde (i3S), University of Porto, Portugal Abel Salazar Institute for the Biomedical Sciences (ICBAS), University of Porto, Portugal
| | - Sara Morais
- UnIGENe, Institute for Molecular and Cell Biology (IBMC), Instituto de Investigação e Inovação em Saúde (i3S), University of Porto, Portugal Abel Salazar Institute for the Biomedical Sciences (ICBAS), University of Porto, Portugal
| | - Jorge Sequeiros
- UnIGENe, Institute for Molecular and Cell Biology (IBMC), Instituto de Investigação e Inovação em Saúde (i3S), University of Porto, Portugal Abel Salazar Institute for the Biomedical Sciences (ICBAS), University of Porto, Portugal CGPP, Institute for Molecular and Cell Biology (IBMC), Instituto de Investigação e Inovação em Saúde (i3S), University of Porto, Portugal
| | - Isabel Alonso
- UnIGENe, Institute for Molecular and Cell Biology (IBMC), Instituto de Investigação e Inovação em Saúde (i3S), University of Porto, Portugal Abel Salazar Institute for the Biomedical Sciences (ICBAS), University of Porto, Portugal CGPP, Institute for Molecular and Cell Biology (IBMC), Instituto de Investigação e Inovação em Saúde (i3S), University of Porto, Portugal
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Alqadah A, Hsieh YW, Schumacher JA, Wang X, Merrill SA, Millington G, Bayne B, Jorgensen EM, Chuang CF. SLO BK Potassium Channels Couple Gap Junctions to Inhibition of Calcium Signaling in Olfactory Neuron Diversification. PLoS Genet 2016; 12:e1005654. [PMID: 26771544 PMCID: PMC4714817 DOI: 10.1371/journal.pgen.1005654] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 10/16/2015] [Indexed: 01/09/2023] Open
Abstract
The C. elegans AWC olfactory neuron pair communicates to specify asymmetric subtypes AWCOFF and AWCON in a stochastic manner. Intercellular communication between AWC and other neurons in a transient NSY-5 gap junction network antagonizes voltage-activated calcium channels, UNC-2 (CaV2) and EGL-19 (CaV1), in the AWCON cell, but how calcium signaling is downregulated by NSY-5 is only partly understood. Here, we show that voltage- and calcium-activated SLO BK potassium channels mediate gap junction signaling to inhibit calcium pathways for asymmetric AWC differentiation. Activation of vertebrate SLO-1 channels causes transient membrane hyperpolarization, which makes it an important negative feedback system for calcium entry through voltage-activated calcium channels. Consistent with the physiological roles of SLO-1, our genetic results suggest that slo-1 BK channels act downstream of NSY-5 gap junctions to inhibit calcium channel-mediated signaling in the specification of AWCON. We also show for the first time that slo-2 BK channels are important for AWC asymmetry and act redundantly with slo-1 to inhibit calcium signaling. In addition, nsy-5-dependent asymmetric expression of slo-1 and slo-2 in the AWCON neuron is necessary and sufficient for AWC asymmetry. SLO-1 and SLO-2 localize close to UNC-2 and EGL-19 in AWC, suggesting a role of possible functional coupling between SLO BK channels and voltage-activated calcium channels in AWC asymmetry. Furthermore, slo-1 and slo-2 regulate the localization of synaptic markers, UNC-2 and RAB-3, in AWC neurons to control AWC asymmetry. We also identify the requirement of bkip-1, which encodes a previously identified auxiliary subunit of SLO-1, for slo-1 and slo-2 function in AWC asymmetry. Together, these results provide an unprecedented molecular link between gap junctions and calcium pathways for terminal differentiation of olfactory neurons.
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Affiliation(s)
- Amel Alqadah
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Molecular and Developmental Biology Graduate Program, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Yi-Wen Hsieh
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Jennifer A. Schumacher
- Division of Developmental Biology, Cincinnati Children’s Hospital Research Foundation, Cincinnati, Ohio, United States of America
| | - Xiaohong Wang
- Division of Developmental Biology, Cincinnati Children’s Hospital Research Foundation, Cincinnati, Ohio, United States of America
| | - Sean A. Merrill
- Department of Biology and Howard Hughes Medical Institute, University of Utah, Salt Lake City, Utah, United States of America
| | - Grethel Millington
- Molecular and Developmental Biology Graduate Program, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Brittany Bayne
- Division of Developmental Biology, Cincinnati Children’s Hospital Research Foundation, Cincinnati, Ohio, United States of America
| | - Erik M. Jorgensen
- Department of Biology and Howard Hughes Medical Institute, University of Utah, Salt Lake City, Utah, United States of America
| | - Chiou-Fen Chuang
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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Lainé V, Ségor JR, Zhan H, Bessereau JL, Jospin M. Hyperactivation of L-type voltage-gated Ca2+ channels in Caenorhabditis elegans striated muscle can result from point mutations in the IS6 or the IIIS4 segment of the α1 subunit. ACTA ACUST UNITED AC 2014; 217:3805-14. [PMID: 25214488 DOI: 10.1242/jeb.106732] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Several human diseases, including hypokalemic periodic paralysis and Timothy syndrome, are caused by mutations in voltage-gated calcium channels. The effects of these mutations are not always well understood, partially because of difficulties in expressing these channels in heterologous systems. The use of Caenorhabditis elegans could be an alternative approach to determine the effects of mutations on voltage-gated calcium channel function because all the main types of voltage-gated calcium channels are found in C. elegans, a large panel of mutations already exists and efficient genetic tools are available to engineer customized mutations in any gene. In this study, we characterize the effects of two gain-of-function mutations in egl-19, which encodes the L-type calcium channel α1 subunit. One of these mutations, ad695, leads to the replacement of a hydrophobic residue in the IIIS4 segment. The other mutation, n2368, changes a conserved glycine of IS6 segment; this mutation has been identified in patients with Timothy syndrome. We show that both egl-19 (gain-of-function) mutants have defects in locomotion and morphology that are linked to higher muscle tone. Using in situ electrophysiological approaches in striated muscle cells, we provide evidence that this high muscle tone is due to a shift of the voltage dependency towards negative potentials, associated with a decrease of the inactivation rate of the L-type Ca(2+) current. Moreover, we show that the maximal conductance of the Ca(2+) current is decreased in the strongest mutant egl-19(n2368), and that this decrease is correlated with a mislocalization of the channel.
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Affiliation(s)
- Viviane Lainé
- CNRS, UMR 5534, Université Lyon 1, Villeurbanne, F-69622, France
| | - Jean Rony Ségor
- CNRS, UMR 5534, Université Lyon 1, Villeurbanne, F-69622, France
| | - Hong Zhan
- CNRS, UMR 5534, Université Lyon 1, Villeurbanne, F-69622, France
| | | | - Maelle Jospin
- CNRS, UMR 5534, Université Lyon 1, Villeurbanne, F-69622, France
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Stock C, Ludwig FT, Hanley PJ, Schwab A. Roles of ion transport in control of cell motility. Compr Physiol 2013; 3:59-119. [PMID: 23720281 DOI: 10.1002/cphy.c110056] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell motility is an essential feature of life. It is essential for reproduction, propagation, embryonic development, and healing processes such as wound closure and a successful immune defense. If out of control, cell motility can become life-threatening as, for example, in metastasis or autoimmune diseases. Regardless of whether ciliary/flagellar or amoeboid movement, controlled motility always requires a concerted action of ion channels and transporters, cytoskeletal elements, and signaling cascades. Ion transport across the plasma membrane contributes to cell motility by affecting the membrane potential and voltage-sensitive ion channels, by inducing local volume changes with the help of aquaporins and by modulating cytosolic Ca(2+) and H(+) concentrations. Voltage-sensitive ion channels serve as voltage detectors in electric fields thus enabling galvanotaxis; local swelling facilitates the outgrowth of protrusions at the leading edge while local shrinkage accompanies the retraction of the cell rear; the cytosolic Ca(2+) concentration exerts its main effect on cytoskeletal dynamics via motor proteins such as myosin or dynein; and both, the intracellular and the extracellular H(+) concentration modulate cell migration and adhesion by tuning the activity of enzymes and signaling molecules in the cytosol as well as the activation state of adhesion molecules at the cell surface. In addition to the actual process of ion transport, both, channels and transporters contribute to cell migration by being part of focal adhesion complexes and/or physically interacting with components of the cytoskeleton. The present article provides an overview of how the numerous ion-transport mechanisms contribute to the various modes of cell motility.
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Affiliation(s)
- Christian Stock
- Institute of Physiology II, University of Münster, Münster, Germany.
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10
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Caylor RC, Jin Y, Ackley BD. The Caenorhabditis elegans voltage-gated calcium channel subunits UNC-2 and UNC-36 and the calcium-dependent kinase UNC-43/CaMKII regulate neuromuscular junction morphology. Neural Dev 2013; 8:10. [PMID: 23663262 PMCID: PMC3661369 DOI: 10.1186/1749-8104-8-10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 04/25/2013] [Indexed: 11/30/2022] Open
Abstract
Background The conserved Caenorhabditis elegans proteins NID-1/nidogen and PTP-3A/LAR-RPTP function to efficiently localize the presynaptic scaffold protein SYD-2/α-liprin at active zones. Loss of function in these molecules results in defects in the size, morphology and spacing of neuromuscular junctions. Results Here we show that the Cav2-like voltage-gated calcium channel (VGCC) proteins, UNC-2 and UNC-36, and the calmodulin kinase II (CaMKII), UNC-43, function to regulate the size and morphology of presynaptic domains in C. elegans. Loss of function in unc-2, unc-36 or unc-43 resulted in slightly larger GABAergic neuromuscular junctions (NMJs), but could suppress the synaptic morphology defects found in nid-1/nidogen or ptp-3/LAR mutants. A gain-of-function mutation in unc-43 caused defects similar to those found in nid-1 mutants. Mutations in egl-19, Cav1-like, or cca-1, Cav3-like, α1 subunits, or the second α2/δ subunit, tag-180, did not suppress nid-1, suggesting a specific interaction between unc-2 and the synaptic extracellular matrix (ECM) component nidogen. Using a synaptic vesicle marker in time-lapse microscopy studies, we observed GABAergic motor neurons adding NMJ-like structures during late larval development. The synaptic bouton addition appeared to form in at least two ways: (1) de novo formation, where a cluster of vesicles appeared to coalesce, or (2) when a single punctum became enlarged and then divided to form two discrete fluorescent puncta. In comparison to wild type animals, we found unc-2 mutants exhibited reduced NMJ dynamics, with fewer observed divisions during a similar stage of development. Conclusions We identified UNC-2/UNC-36 VGCCs and UNC-43/CaMKII as regulators of C. elegans synaptogenesis. UNC-2 has a modest role in synapse formation, but a broader role in regulating dynamic changes in the size and morphology of synapses that occur during organismal development. During the late 4th larval stage (L4), wild type animals exhibit synaptic morphologies that are similar to those found in animals lacking NID-1/PTP-3 adhesion, as well as those with constitutive activation of UNC-43. Genetic evidence indicates that the VGCCs and the NID-1/PTP-3 adhesion complex provide opposing functions in synaptic development, suggesting that modulation of synaptic adhesion may underlie synapse development in C. elegans.
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Affiliation(s)
- Raymond C Caylor
- Department of Molecular Biosciences, University of Kansas, 5004 Haworth Hall, 1200 Sunnyside Ave, Lawrence, KS 66045, USA
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11
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Zhang J, Wei J, Kanada M, Yan L, Zhang Z, Watanabe H, Terakawa S. Inhibition of store-operated Ca2+ entry suppresses EGF-induced migration and eliminates extravasation from vasculature in nasopharyngeal carcinoma cell. Cancer Lett 2013; 336:390-7. [PMID: 23623984 DOI: 10.1016/j.canlet.2013.03.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 03/20/2013] [Accepted: 03/25/2013] [Indexed: 11/30/2022]
Abstract
Store-operated Ca(2+) entry (SOCE) mediates Ca(2+) responses evoked by extracellular signaling molecules to promote increases in cytosolic Ca(2+), thereby triggering downstream signal transduction. Here we demonstrated that either the pharmacological blockage of Ca(2+) influx through SOCE or the knockdown of Orai1, a key molecule of SOCE, suppressed the epidermal growth factor-induced migration by disturbing Ca(2+) signaling in nasopharyngeal carcinoma (NPC) cell. Furthermore, Orai1 depletion led to a delayed cell attachment to the extracellular matrix surface in vitro and eliminated the extravasation of microinjected cells from vasculature in a zebrafish hematogenous metastasis model. Our findings thus indicate that SOCE acts as a predominant Ca(2+) signaling involved in NPC cell metastasis, and may serve as a candidate target for anti-metastasis therapy in NPC.
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Affiliation(s)
- Jinyan Zhang
- Medical Photonics Research Center, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu 431-3192, Japan
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12
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Ronjat M, Kiyonaka S, Barbado M, De Waard M, Mori Y. Nuclear life of the voltage-gated Cacnb4 subunit and its role in gene transcription regulation. Channels (Austin) 2013; 7:119-25. [PMID: 23511121 DOI: 10.4161/chan.23895] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The pore-forming subunit of voltage-gated calcium channels is associated to auxiliary subunits among which the cytoplasmic β subunit. The different isoforms of this subunit control both the plasma membrane targeting and the biophysical properties of the channel moiety. In a recent study, we demonstrated that the Cacnb4 (β 4) isoform is at the center of a new signaling pathway that connects neuronal excitability and gene transcription. This mechanism relies on nuclear targeting of β 4 triggered by neuronal electrical stimulation. This re-localization of β 4 is promoted by its interaction with Ppp2r5d a regulatory subunit of PP2A in complex with PP2A itself. The formation, as well as the nuclear translocation, of the β 4/ Ppp2r5d/ PP2A complex is totally impaired by the premature R482X stops mutation of β 4 that has been previously associated with juvenile epilepsy. Taking as a case study the tyrosine hydroxylase gene that is strongly upregulated in brain of lethargic mice, deficient for β 4 expression, we deciphered the molecular steps presiding to this signaling pathway. Here we show that expression of wild-type β 4 in HEK293 cells results in the regulation of several genes, while expression of the mutated β 4 (β 1-481) produces a different set of gene regulation. Several genes regulated by β 4 in HEK293 cells were also regulated upon neuronal differentiation of NG108-15 cells that induces nuclear translocation of β 4 suggesting a link between β 4 nuclear targeting and gene regulation.
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Affiliation(s)
- Michel Ronjat
- Unité Inserm U836, Grenoble Institute of Neuroscience, La Tronche, France.
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13
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Stout RF, Parpura V. Voltage-gated calcium channel types in cultured C. elegans CEPsh glial cells. Cell Calcium 2011; 50:98-108. [PMID: 21684004 DOI: 10.1016/j.ceca.2011.05.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Revised: 05/12/2011] [Accepted: 05/15/2011] [Indexed: 12/20/2022]
Abstract
The four cephalic sensilla sheath (CEPsh) glial cells are important for development of the nervous system of Caenorhabditis elegans. Whether these invertebrate glia can generate intracellular Ca(2+) increases, a hallmark of mammalian glial cell excitability, is not known. To address this issue, we developed a transgenic worm with the specific co-expression of genetically encoded red fluorescent protein and green Ca(2+) sensor in CEPsh glial cells. This allowed us to identify CEPsh cells in culture and monitor their Ca(2+) dynamics. We show that CEPsh glial cells, in response to depolarization, generate various intracellular Ca(2+) increases mediated by voltage-gated Ca(2+) channels (VGCCs). Using a pharmacological approach, we find that the L-type is the preponderant VGCC type mediating Ca(2+) dynamics. Additionally, using a genetic approach we demonstrate that mutations in three known VGCC α(1)-subunit genes, cca-1, egl-19 and unc-2, can affect Ca(2+) dynamics of CEPsh glial cells. We suggest that VGCC-mediated Ca(2+) dynamics in the CEPsh glial cells are complex and display heterogeneity. These findings will aid understanding of how CEPsh glial cells contribute to the operation of the C. elegans nervous system.
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Affiliation(s)
- Randy F Stout
- Department of Neurobiology, Center for Glial Biology in Medicine, Atomic Force Microscopy & Nanotechnology Laboratories, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama, Birmingham, AL 35294, USA
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14
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Lainé V, Frøkjær-Jensen C, Couchoux H, Jospin M. The alpha1 subunit EGL-19, the alpha2/delta subunit UNC-36, and the beta subunit CCB-1 underlie voltage-dependent calcium currents in Caenorhabditis elegans striated muscle. J Biol Chem 2011; 286:36180-7. [PMID: 21878625 DOI: 10.1074/jbc.m111.256149] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Voltage-gated calcium channels, which play key roles in many physiological processes, are composed of a pore-forming α1 subunit associated with up to three auxiliary subunits. In vertebrates, the role of auxiliary subunits has mostly been studied in heterologous systems, mainly because of the severe phenotypes of knock-out animals. The genetic model Caenorhabditis elegans has all main types of voltage-gated calcium channels and strong loss-of-function mutations in all pore-forming and auxiliary subunits; it is therefore a useful model to investigate the roles of auxiliary subunits in their native context. By recording calcium currents from channel and auxiliary subunit mutants, we molecularly dissected the voltage-dependent calcium currents in striated muscle of C. elegans. We show that EGL-19 is the only α1 subunit that carries calcium currents in muscle cells. We then demonstrate that the α2/δ subunit UNC-36 modulates the voltage dependence, the activation kinetics, and the conductance of calcium currents, whereas another α2/δ subunit TAG-180 has no effect. Finally, we characterize mutants of the two β subunits, CCB-1 and CCB-2. CCB-1 is necessary for viability, and voltage-dependent calcium currents are abolished in the absence of CCB-1 whereas CCB-2 does not affect currents. Altogether these results show that EGL-19, UNC-36, and CCB-1 underlie voltage-dependent calcium currents in C. elegans striated muscle.
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15
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Yao L, Pandit A, Yao S, McCaig CD. Electric field-guided neuron migration: a novel approach in neurogenesis. TISSUE ENGINEERING PART B-REVIEWS 2011; 17:143-53. [PMID: 21275787 DOI: 10.1089/ten.teb.2010.0561] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Effective directional neuron migration is crucial in development of the central nervous system and for neurogenesis. Endogenous electrical signals are present in many developing systems and crucial cellular behaviors such as neuronal cell division, cell migration, and cell differentiation are all under the influence of such endogenous electrical cues. Preclinical in vivo studies have used electric fields (EFs) to attempt to enhance regrowth of damaged spinal cord axons with some success. Recent evidence shows that small EFs not only guide axonal growth, but also direct the earlier events of neuronal migration and neuronal cell division. This raises the possibility that applied or endogenous EFs, perhaps in combination, may direct transplanted neural stem cells, or regenerating neurons, to the desired site after brain injury or neuron degeneration. The high complexity of both structure and function of the nervous system, however, poses significant challenges to techniques for applying EFs to promote neurogenesis. The evolution of functional biomaterials and nanotechnology may provide promising solutions for the application of EFs in guiding neuron migration and neurogenesis within the central nervous system.
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Affiliation(s)
- Li Yao
- Network of Excellence for Functional Biomaterials, National Center for Biomedical Engineering Science, National University of Ireland, Galway, Ireland
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16
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Brain-derived neurotrophic factor mediates non-cell-autonomous regulation of sensory neuron position and identity. J Neurosci 2010; 30:14513-21. [PMID: 20980609 DOI: 10.1523/jneurosci.4025-10.2010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
During development, neurons migrate considerable distances to reside in locations that enable their individual functional roles. Whereas migration mechanisms have been extensively studied, much less is known about how neurons remain in their ideal locations. We sought to identify factors that maintain the position of postmigratory dorsal root ganglion neurons, neural crest derivatives for which migration and final position play an important developmental role. We found that an early developing population of sensory neurons maintains the position of later born dorsal root ganglia neurons in an activity-dependent manner. Further, inhibiting or increasing the function of brain-derived neurotrophic factor induces or prevents, respectively, migration of dorsal root ganglia neurons out of the ganglion to locations where they acquire a new identity. Overall, the results demonstrate that neurotrophins mediate non-cell-autonomous maintenance of position and thereby the identity of differentiated neurons.
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17
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Golli myelin basic proteins regulate oligodendroglial progenitor cell migration through voltage-gated Ca2+ influx. J Neurosci 2009; 29:6663-76. [PMID: 19458236 DOI: 10.1523/jneurosci.5806-08.2009] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Migration of oligodendrocyte progenitor cells (OPCs) from proliferative zones to their final location in the brain is an essential step in nervous system development. Golli proteins, products of the myelin basic protein gene, can modulate voltage-gated Ca(2+) uptake in OPCs during process extension and retraction. Given the importance of process extension/retraction on movement, the consequences of golli expression on OPC migration were examined in vivo and in vitro using time-lapse imaging of isolated OPCs and acute brain slice preparations from golli KO and golli J37 overexpressing mice (JOE). The results indicated that golli stimulated migration, and this enhanced motility was associated with increases in the activity of voltage operated Ca(2+) channels (VOCCs). Activation of VOCCs by high K(+) resulted in a significant increase in the migration speed of JOE OPCs versus control cells and golli-mediated modulation of OPC migration disappeared in the presence of VOCC antagonists. During migration, OPCs generated Ca(2+) oscillations that were dependent on voltage-calcium influx and both the amplitude and frequency of these Ca(2+) transients correlated positively with the rate of cell movement under a variety of pharmacological treatments. The Ca(2+) transient amplitude and the rate of cell movement were significantly lower in KO cells and significantly higher in JOE cells suggesting that the presence of golli promotes OPC migration by increasing the size of voltage-mediated Ca(2+) oscillations. These data define a new molecule that regulates Ca(2+) homeostasis in OPCs, and are the first to demonstrate that voltage-gated Ca(2+) channels can regulate an OPC function, such as migration.
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18
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Yeh E, Ng S, Zhang M, Bouhours M, Wang Y, Wang M, Hung W, Aoyagi K, Melnik-Martinez K, Li M, Liu F, Schafer WR, Zhen M. A putative cation channel, NCA-1, and a novel protein, UNC-80, transmit neuronal activity in C. elegans. PLoS Biol 2008; 6:e55. [PMID: 18336069 PMCID: PMC2265767 DOI: 10.1371/journal.pbio.0060055] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Accepted: 01/18/2008] [Indexed: 11/19/2022] Open
Abstract
Voltage-gated cation channels regulate neuronal excitability through selective ion flux. NALCN, a member of a protein family that is structurally related to the alpha1 subunits of voltage-gated sodium/calcium channels, was recently shown to regulate the resting membrane potentials by mediating sodium leak and the firing of mouse neurons. We identified a role for the Caenorhabditis elegans NALCN homologues NCA-1 and NCA-2 in the propagation of neuronal activity from cell bodies to synapses. Loss of NCA activities leads to reduced synaptic transmission at neuromuscular junctions and frequent halting in locomotion. In vivo calcium imaging experiments further indicate that while calcium influx in the cell bodies of egg-laying motorneurons is unaffected by altered NCA activity, synaptic calcium transients are significantly reduced in nca loss-of-function mutants and increased in nca gain-of-function mutants. NCA-1 localizes along axons and is enriched at nonsynaptic regions. Its localization and function depend on UNC-79, and UNC-80, a novel conserved protein that is also enriched at nonsynaptic regions. We propose that NCA-1 and UNC-80 regulate neuronal activity at least in part by transmitting depolarization signals to synapses in C. elegans neurons.
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Affiliation(s)
- Edward Yeh
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Sharon Ng
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Mi Zhang
- Division of Biology, University of California San Diego, San Diego, California, United States of America
| | - Magali Bouhours
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Ying Wang
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Min Wang
- Department of Neuroscience, Centre for Addiction and Mental Health, Clarke Division, University of Toronto, Toronto, Ontario, Canada
| | - Wesley Hung
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Kyota Aoyagi
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Katya Melnik-Martinez
- Division of Biology, University of California San Diego, San Diego, California, United States of America
| | - Michelle Li
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Fang Liu
- Department of Neuroscience, Centre for Addiction and Mental Health, Clarke Division, University of Toronto, Toronto, Ontario, Canada
| | - William R Schafer
- Division of Biology, University of California San Diego, San Diego, California, United States of America
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Mei Zhen
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- * To whom correspondence should be addressed. E-mail:
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19
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Bryden J, Cohen N. Neural control of Caenorhabditis elegans forward locomotion: the role of sensory feedback. BIOLOGICAL CYBERNETICS 2008; 98:339-351. [PMID: 18350313 DOI: 10.1007/s00422-008-0212-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Accepted: 01/25/2008] [Indexed: 05/26/2023]
Abstract
This paper presents a simple yet biologically-grounded model for the neural control of Caenorhabditis elegans forward locomotion. We identify a minimal circuit within the C. elegans ventral cord that is likely to be sufficient to generate and sustain forward locomotion in vivo. This limited subcircuit appears to contain no obvious central pattern generated control. For that subcircuit, we present a model that relies on a chain of oscillators along the body which are driven by local and proximate mechano-sensory input. Computer simulations were used to study the model under a variety of conditions and to test whether it is behaviourally plausible. Within our model, we find that a minimal circuit of AVB interneurons and B-class motoneurons is sufficient to generate and sustain fictive forward locomotion patterns that are robust to significant environmental perturbations. The model predicts speed and amplitude modulation by the AVB command interneurons. An extended model including D-class motoneurons is included for comparison.
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Affiliation(s)
- John Bryden
- School of Computing, University of Leeds, Leeds, UK
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20
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Affiliation(s)
- James Q. Zheng
- Department of Neuroscience and Cell Biology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854;
| | - Mu-ming Poo
- Division of Neuroscience, Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720;
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21
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Abstract
Genetic studies of behavior in the nematode Caenorhabditis elegans have provided an effective approach to investigate the molecular and cellular basis of nervous system function and development. Among the best studied behaviors is egg-laying, the process by which hermaphrodites deposit developing embryos into the environment. Egg-laying involves a simple motor program involving a small network of motorneurons and specialized smooth muscle cells, which is regulated by a variety of sensory stimuli. Analysis of egg-laying-defective mutants has provided insight into a number of conserved processes in nervous system development, including neurogenesis, cell migration, and synaptic patterning, as well as aspects of excitable cell signal transduction and neuromodulation.
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Affiliation(s)
- William F Schafer
- Department of Biology, University of California at San Diego, La Jolla, California 92093-0349, USA.
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22
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Frøkjaer-Jensen C, Kindt KS, Kerr RA, Suzuki H, Melnik-Martinez K, Gerstbreih B, Driscol M, Schafer WR. Effects of voltage-gated calcium channel subunit genes on calcium influx in cultured C. elegans mechanosensory neurons. ACTA ACUST UNITED AC 2006; 66:1125-39. [PMID: 16838374 DOI: 10.1002/neu.20261] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Voltage-gated calcium channels (VGCCs) serve as a critical link between electrical signaling and diverse cellular processes in neurons. We have exploited recent advances in genetically encoded calcium sensors and in culture techniques to investigate how the VGCC alpha1 subunit EGL-19 and alpha2/delta subunit UNC-36 affect the functional properties of C. elegans mechanosensory neurons. Using the protein-based optical indicator cameleon, we recorded calcium transients from cultured mechanosensory neurons in response to transient depolarization. We observed that in these cultured cells, calcium transients induced by extracellular potassium were significantly reduced by a reduction-of-function mutation in egl-19 and significantly reduced by L-type calcium channel inhibitors; thus, a main source of touch neuron calcium transients appeared to be influx of extracellular calcium through L-type channels. Transients did not depend directly on intracellular calcium stores, although a store-independent 2-APB and gadolinium-sensitive calcium flux was detected. The transients were also significantly reduced by mutations in unc-36, which encodes the main neuronal alpha2/delta subunit in C. elegans. Interestingly, while egl-19 mutations resulted in similar reductions in calcium influx at all stimulus strengths, unc-36 mutations preferentially affected responses to smaller depolarizations. These experiments suggest a central role for EGL-19 and UNC-36 in excitability and functional activity of the mechanosensory neurons.
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23
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Schwab A, Nechyporuk-Zloy V, Fabian A, Stock C. Cells move when ions and water flow. Pflugers Arch 2006; 453:421-32. [PMID: 17021798 DOI: 10.1007/s00424-006-0138-6] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Accepted: 07/09/2006] [Indexed: 12/22/2022]
Abstract
Cell migration is a process that plays an important role throughout the entire life span. It starts early on during embryogenesis and contributes to shaping our body. Migrating cells are involved in maintaining the integrity of our body, for instance, by defending it against invading pathogens. On the other side, migration of tumor cells may have lethal consequences when tumors spread metastatically. Thus, there is a strong interest in unraveling the cellular mechanisms underlying cell migration. The purpose of this review is to illustrate the functional importance of ion and water channels as part of the cellular migration machinery. Ion and water flow is required for optimal migration, and the inhibition or genetic ablation of channels leads to a marked impairment of migration. We briefly touch cytoskeletal mechanisms of migration as well as cell-matrix interactions. We then present some general principles by which channels can affect cell migration before we discuss each channel group separately.
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Affiliation(s)
- Albrecht Schwab
- Institut für Physiologie II, Universität Münster, Robert-Koch-Str. 27b, 48149, Münster, Germany.
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24
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Donohoe DR, Aamodt EJ, Osborn E, Dwyer DS. Antipsychotic drugs disrupt normal development in Caenorhabditis elegans via additional mechanisms besides dopamine and serotonin receptors. Pharmacol Res 2006; 54:361-72. [PMID: 16962336 PMCID: PMC1694634 DOI: 10.1016/j.phrs.2006.07.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2005] [Revised: 07/07/2006] [Accepted: 07/10/2006] [Indexed: 01/13/2023]
Abstract
Antipsychotic drugs may produce adverse effects during development in humans and rodents. However, the extent of these effects has not been systematically characterized nor have molecular mechanisms been identified. Consequently, we sought to evaluate the effects of an extensive panel of antipsychotic drugs in a model organism, Caenorhabditis elegans, whose development is well characterized and which offers the possibility of identifying novel molecular targets. For these studies, animals were grown from hatching in the presence of vehicle (control) or antipsychotic drugs over a range of concentrations (20-160microM) and growth was analyzed by measuring head-to-tail length at various intervals. First-generation antipsychotics (e.g., fluphenazine) generally slowed growth and maturation more than second-generation drugs such as quetiapine and olanzapine. This is consistent with in vitro effects on human neuronal cell lines. Clozapine, a second-generation drug, produced similar growth deficits as haloperidol. Converging lines of evidence, including the failure to rescue growth with high concentrations of agonists, suggested that the drug-induced delay in development was not mediated by the major neurotransmitter receptors recognized by the antipsychotic drugs. Moreover, in serotonin-deficient tph-1 mutants, the drugs dramatically slowed development and led to larval arrest (including dauer formation) and neuronal abnormalities. Evaluation of alternative targets of the antipsychotics revealed a potential role for calmodulin and underscored the significance of Ca(2+)-calmodulin signaling in development. These findings suggest that antipsychotic drugs may interfere with normal developmental processes and provide a tool for investigating the key signaling pathways involved.
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Affiliation(s)
| | | | - Elizabeth Osborn
- Department of Psychiatry, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA, 71130, USA
| | - Donard S. Dwyer
- Department of Pharmacology, Toxicology and Neuroscience
- Department of Psychiatry, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA, 71130, USA
- *Address correspondence to: Dr. Donard S. Dwyer, Department of Psychiatry, LSU Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130, USA, PH: 318 675-7612; FAX: 318 675-6148; EMAIL:
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25
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Estevez AO, Cowie RH, Gardner KL, Estevez M. Both insulin and calcium channel signaling are required for developmental regulation of serotonin synthesis in the chemosensory ADF neurons of Caenorhabditis elegans. Dev Biol 2006; 298:32-44. [PMID: 16860310 DOI: 10.1016/j.ydbio.2006.06.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Revised: 06/04/2006] [Accepted: 06/05/2006] [Indexed: 11/18/2022]
Abstract
Proper calcium channel and insulin signaling are essential for normal brain development. Leaner mice with a mutation in the P/Q-type voltage-gated calcium channel, Cacna1a, develop cerebellar atrophy and mutations in the homologous human gene are associated with increased migraine and seizure tendency. Similarly, abnormalities in insulin signaling are associated with abnormal brain growth and migraine tendency. Previously, we have shown that in the ADF chemosensory neurons of Caenorhabditis elegans UNC-2/Ca(2+) channel function affects TGF-beta-dependent developmental regulation of tryptophan hydroxylase, the rate-limiting enzyme in serotonin synthesis. Here we show that developmental expression of a tryptophan hydroxylase: :GFP reporter construct is similarly decreased by reduction-of-function mutations in the daf-2/insulin receptor. This decreased expression of tryptophan hydroxylase observed in both the daf-2 and unc-2 mutant backgrounds is suppressible either genetically by reduction-of-function mutations in the daf-16/forkhead transcription factor, an effector of the DAF-2/insulin receptor, or pharmacologically by the serotonin receptor antagonist cyproheptadine. Overall, these data suggest that both UNC-2 and DAF-2 function are required in the developmental regulation of DAF-16 and serotonin-dependent inhibition of tryptophan hydroxylase expression.
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Affiliation(s)
- Annette O Estevez
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260, USA
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26
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Toba Y, Pakiam JG, Wray S. Voltage-gated calcium channels in developing GnRH-1 neuronal system in the mouse. Eur J Neurosci 2005; 22:79-92. [PMID: 16029198 DOI: 10.1111/j.1460-9568.2005.04194.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Migration of gonadotropin-releasing hormone-1 (GnRH-1) neurons from the nasal placode into the central nervous system occurs in all vertebrates. This study characterizes the expression of L- and N-type voltage-gated calcium channels (VGCCs) in migrating GnRH-1 neurons in mice. Class C (L-type) and class B (N-type) VGCGs were detected in GnRH-1 cells and cells in the olfactory and vomeronasal epithelium during prenatal development. This expression pattern was mimicked in a nasal explant model known to retain many characteristics of GnRH-1 development in vivo. Using this in vitro system, perturbation studies were performed to elucidate the role of VGCCs in GnRH-1 neuronal development. This report shows that olfactory axon outgrowth and GnRH-1 neuronal migration are attenuated when nasal explants are grown in calcium-free media, and that this effect is temporally restricted to an early developmental period. Blockade of either the L- or the N-type channel did not alter GnRH-1 cell number or overall olfactory axon outgrowth. However, blockade of N-type channels altered the distribution of GnRH-1 neurons in the periphery of the nasal explants. In these explants, more GnRH-1 neurons were located proximal to, and fewer GnRH-1 neurons distal to, the main tissue mass, suggesting a general decrease in the rate of GnRH-1 neuronal migration. These results indicate that extracellular calcium is required for initiating GnRH-1 neuronal migration and that these events are partially dependent on N-type VGCC signals.
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Affiliation(s)
- Yoko Toba
- Cellular and Developmental Neurobiology Section, NINDS, NIH, Bethesda, MD 20892, USA
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27
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Moody WJ, Bosma MM. Ion Channel Development, Spontaneous Activity, and Activity-Dependent Development in Nerve and Muscle Cells. Physiol Rev 2005; 85:883-941. [PMID: 15987798 DOI: 10.1152/physrev.00017.2004] [Citation(s) in RCA: 274] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
At specific stages of development, nerve and muscle cells generate spontaneous electrical activity that is required for normal maturation of intrinsic excitability and synaptic connectivity. The patterns of this spontaneous activity are not simply immature versions of the mature activity, but rather are highly specialized to initiate and control many aspects of neuronal development. The configuration of voltage- and ligand-gated ion channels that are expressed early in development regulate the timing and waveform of this activity. They also regulate Ca2+influx during spontaneous activity, which is the first step in triggering activity-dependent developmental programs. For these reasons, the properties of voltage- and ligand-gated ion channels expressed by developing neurons and muscle cells often differ markedly from those of adult cells. When viewed from this perspective, the reasons for complex patterns of ion channel emergence and regression during development become much clearer.
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Affiliation(s)
- William J Moody
- Department of Biology, University of Washington, Seattle, Washington 98195, USA.
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28
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Yang S, Huang XY. Ca2+ influx through L-type Ca2+ channels controls the trailing tail contraction in growth factor-induced fibroblast cell migration. J Biol Chem 2005; 280:27130-7. [PMID: 15911622 DOI: 10.1074/jbc.m501625200] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Growth factor-induced cell migration underlies various physiological and pathological processes. The mechanisms by which growth factors regulate cell migration are not completely understood. Although intracellular elevation of Ca2+ is known to be critical in cell migration, the source of this Ca2+ elevation and the mechanism by which Ca2+ modulates this process in fibroblast cells are not well defined. Here we show that increase of cellular Ca2+ through Ca2+ influx, rather than Ca2+ release from intracellular stores, is essential for growth factor-induced fibroblast cell migration. Voltage-gated L-type Ca2+ channels, previously known to exist in excitable cells such as neurons and muscle cells, are shown here to be present in fibroblasts as well. Furthermore, these channels are responsible for the Ca2+ influx. L-type Ca2+ channel inhibitors block growth factor-induced Ca2+ influx and fibroblast cell migration. One mechanism by which Ca2+ signals control cell migration is to regulate the contraction of the trailing edge of migrating fibroblasts; this process is controlled by the small GTPase Rho in fast migrating cells such as leukocytes. Downstream of Ca2+, both calmodulin and myosin light chain kinase, but not calcineurin, are involved leading to phosphorylation of the myosin light chain at the trailing end. Thus, trailing edge contraction is critically regulated by Ca2+ influx through L-type Ca2+ channels in growth factor-induced fibroblast cell migration.
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Affiliation(s)
- Shengyu Yang
- Department of Physiology, Cornell University Weill Medical College, New York, New York 10021, USA
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29
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Abstract
Pathfinding by growing axons in the developing or regenerating nervous system is guided by gradients of molecular guidance cues. The neuronal growth cone, located at the ends of axons, uses surface receptors to sense these cues and to transduce guidance information to cellular machinery that mediates growth and turning responses. Cytoplasmic Ca2+ signals have key roles in regulating this motility. Global growth cone Ca2+ signals can regulate cytoskeletal elements and membrane dynamics to control elongation, whereas Ca2+ signals localized to one side of the growth cone can cause asymmetric activation of effector enzymes to steer the growth cone. Modulating Ca2+ levels in the growth cone might overcome inhibitory signals that normally prevent regeneration in the central nervous system.
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Affiliation(s)
- John Henley
- Division of Neurobiology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3200, USA
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Qin H, Powell-Coffman JA. The Caenorhabditis elegans aryl hydrocarbon receptor, AHR-1, regulates neuronal development. Dev Biol 2004; 270:64-75. [PMID: 15136141 DOI: 10.1016/j.ydbio.2004.02.004] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2003] [Revised: 02/11/2004] [Accepted: 02/11/2004] [Indexed: 11/24/2022]
Abstract
The mammalian aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that mediates the toxic effects of dioxins and related compounds. Dioxins have been shown to cause a range of neurological defects, but the role of AHR during normal neuronal development is not known. Here we investigate the developmental functions of ahr-1, the Caenorhabditis elegans aryl hydrocarbon receptor homolog. We show that ahr-1:GFP is expressed in a subset of neurons, and we demonstrate that animals lacking ahr-1 function have specific defects in neuronal differentiation, as evidenced by changes in gene expression, aberrant cell migration, axon branching, or supernumerary neuronal processes. In ahr-1-deficient animals, the touch receptor neuron AVM and its sister cell, the interneuron SDQR, exhibit cell and axonal migration defects. We show that dorsal migration of SDQR is mediated by UNC-6/Netrin, SAX-3/Robo, and UNC-129/TGFbeta, and this process requires the functions of both ahr-1 and its transcription factor dimerization partner aha-1. We also document a role for ahr-1 during the differentiation of the neurons that contact the pseudocoelomic fluid. In ahr-1-deficient animals, these neurons are born but they do not express the cell-type-specific markers gcy-32:GFP and npr-1:GFP at appropriate levels. Additionally, we show that ahr-1 expression is regulated by the UNC-86 transcription factor. We propose that the AHR-1 transcriptional complex acts in combination with other intrinsic and extracellular factors to direct the differentiation of distinct neuronal subtypes. These data, when considered with the neurotoxic effects of AHR-activating pollutants, support the hypothesis that AHR has an evolutionarily conserved role in neuronal development.
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Affiliation(s)
- Hongtao Qin
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA 50011-3260, USA
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Xu HT, Yuan XB, Guan CB, Duan S, Wu CP, Feng L. Calcium signaling in chemorepellant Slit2-dependent regulation of neuronal migration. Proc Natl Acad Sci U S A 2004; 101:4296-301. [PMID: 15020772 PMCID: PMC384735 DOI: 10.1073/pnas.0303893101] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Migration of neuronal precursor cells in the developing brain is guided by extracellular cues, but intracellular signaling processes underlying the guidance of neuronal migration are largely unknown. By examining the migration of cerebellar granule neurons along the surface of cocultured astroglial cells, we found that an extracellular gradient of Slit2, a chemorepellant for neuronal migration in vivo, caused a reversal in the direction of migration without affecting the migration speed. A Slit2 gradient elevated the intracellular concentration of Ca2+, probably due to calcium release from the internal store, led to a reversal of the preexisting asymmetric intracellular Ca2+ distribution in the soma of migrating neurons, and this reversal was closely related with its action of reversing the migrating direction. Asymmetric Ca2+ distribution in the soma was both necessary and sufficient for directing neuronal migration. These results have demonstrated an important role for Ca2+ in mediating neuronal responses to Slit2 and suggest a general mechanism for neuronal guidance.
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Affiliation(s)
- Hua-Tai Xu
- Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China
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Estevez M, Estevez AO, Cowie RH, Gardner KL. The voltage-gated calcium channel UNC-2 is involved in stress-mediated regulation of tryptophan hydroxylase. J Neurochem 2004; 88:102-13. [PMID: 14675154 DOI: 10.1046/j.1471-4159.2003.02140.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Migraine is an episodic pain disorder whose pathophysiology is related to deficiency of serotonin signaling and abnormal function of the P/Q-type calcium channel, CACNA1A. Because the relationship of the CACNA1A channel to serotonin signaling is unknown and potentially of therapeutic interest we have used genetic analysis of the Caenorhabditis elegans ortholog of this calcium channel, UNC-2, to help identify candidate downstream effectors of the human channel. By genetic dissection of the lethargic mutant phenotype of unc-2, we have established an epistasis pathway showing that UNC-2 function antagonizes a transforming growth factor (TGF)-beta pathway influencing movement rate. This same UNC-2/TGF-beta pathway is required for accumulation of normal serotonin levels and stress-induced modulation of tryptophan hydroxylase (tph) expression in the serotonergic chemosensory ADF neurons, but not the NSM neurons. We also show that transgenic expression of the migraine-associated Ca2+ channel, CACNA1A, in unc-2 animals can functionally substitute for UNC-2 in stress-activated regulation of tph expression. The demonstration that these evolutionarily related channels share a conserved ability to modulate tph expression through their effects on TGF-beta signaling provides the first specific example of how CACNA1A function may influence levels of the critical migraine neurotransmitter serotonin.
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Affiliation(s)
- Miguel Estevez
- Veterans Administration Hospital Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
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Critical residues of the Caenorhabditis elegans unc-2 voltage-gated calcium channel that affect behavioral and physiological properties. J Neurosci 2003. [PMID: 12878695 DOI: 10.1523/jneurosci.23-16-06537.2003] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The Caenorhabditis elegans unc-2 gene encodes a voltage-gated calcium channel alpha1 subunit structurally related to mammalian dihydropyridine-insensitive high-threshold channels. In the present paper we describe the characterization of seven alleles of unc-2. Using an unc-2 promoter-tagged green fluorescent protein construct, we show that unc-2 is primarily expressed in motor neurons, several subsets of sensory neurons, and the HSN and VC neurons that control egg laying. Examination of behavioral phenotypes, including defecation, thrashing, and sensitivities to aldicarb and nicotine suggests that UNC-2 acts presynaptically to mediate both cholinergic and GABAergic neurotransmission. Sequence analysis of the unc-2 alleles shows that e55, ra605, ra606, ra609, and ra610 all are predicted to prematurely terminate and greatly reduce or eliminate unc-2 function. In contrast, the ra612 and ra614 alleles are missense mutations resulting in the substitution of highly conserved residues in the C terminus and the domain IVS4-IVS5 linker, respectively. Heterologous expression of a rat brain P/Q-type channel containing the ra612 mutation shows that the glycine to arginine substitution affects a variety of channel characteristics, including the voltage dependence of activation, steady-state inactivation, as well as channel kinetics. Overall, our findings suggest that UNC-2 plays a pivotal role in mediating a number of physiological processes in the nematode and also defines a number of critical residues important for calcium channel function in vivo.
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Affiliation(s)
- Alexander Kraev
- Charles H. Best Institute, University of Toronto, Toronto, M5G 1X5 Canada.
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Kindt KS, Tam T, Whiteman S, Schafer WR. Serotonin promotes G(o)-dependent neuronal migration in Caenorhabditis elegans. Curr Biol 2002; 12:1738-47. [PMID: 12401168 DOI: 10.1016/s0960-9822(02)01199-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND The directed migration of neurons during development requires attractive and repulsive cues that control the direction of migration as well as permissive cues that potentiate cell motility and responsiveness to guidance molecules. RESULTS Here, we show that the neurotransmitter serotonin functions as a permissive signal for embryonic and postembryonic neuronal migration in the nematode C. elegans. In serotonin-deficient mutants, the migrations of the ALM, BDU, SDQR, and AVM neurons were often foreshortened or misdirected, indicating a serotonin requirement for normal migration. Moreover, exogenous serotonin could restore motility to AVM neurons in serotonin-deficient mutants as well as induce AVM-like migrations in the normally nonmotile neuron PVM; this indicates that serotonin was functioning as a permissive cue to enable neuronal motility. The migration defects of serotonin-deficient mutants were mimicked by ablations of serotonergic neuroendocrine cells, implicating humoral release of serotonin in these processes. Mutants defective in G(q) and G(o) signaling, or in N-type voltage-gated calcium channels, showed migration phenotypes similar to serotonin-deficient mutants, and these molecules appeared to genetically function downstream of serotonin in the control of neuronal migration. CONCLUSIONS Thus, serotonin is important for promoting directed neuronal migration in the developing C. elegans nervous system. We hypothesize that serotonin may promote cell motility through G protein-dependent modulation of voltage-gated calcium channels in the migrating cell.
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Affiliation(s)
- Katie S Kindt
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0349, USA
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The C domain of netrin UNC-6 silences calcium/calmodulin-dependent protein kinase- and diacylglycerol-dependent axon branching in Caenorhabditis elegans. J Neurosci 2002. [PMID: 11896167 DOI: 10.1523/jneurosci.22-06-02274.2002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Second messenger systems mediate neuronal responses to extracellular factors that elicit axon branching, turning, and guidance. We found that mutations in Caenorhabditis elegans that affect components of second messenger systems, a G-protein subunit, phospholipase Cbeta, diacylglycerol (DAG) kinase, and calcium/calmodulin-dependent protein kinase (CaMKII), have no obvious effect on axon responses to UNC-6 except in animals in which the N-terminal fragment, UNC-6DeltaC, is expressed. In these animals, the mutations enhance or suppress ectopic branching of certain axons. Netrin UNC-6 is an extracellular protein that guides circumferential migrations, and UNC-6DeltaC has UNC-6 guidance activity. We propose that the guidance response elicited by the UNC-6 N-terminal domains involves mechanisms that can induce branching that is sensitive to CaMKII- and DAG-dependent signaling, and that the UNC-6 C domain is required in cis to the N-terminal domains to silence the branching and to maintain proper axon morphology.
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