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Srinivasan S, Illera PA, Kukhtar D, Benseny-Cases N, Cerón J, Álvarez J, Fonteriz RI, Montero M, Laromaine A. Arrhythmic Effects Evaluated on Caenorhabditis elegans: The Case of Polypyrrole Nanoparticles. ACS NANO 2023; 17:17273-17284. [PMID: 37624669 PMCID: PMC10510705 DOI: 10.1021/acsnano.3c05245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023]
Abstract
Experimental studies and clinical trials of nanoparticles for treating diseases are increasing continuously. However, the reach to the market does not correlate with these efforts due to the enormous cost, several years of development, and off-target effects like cardiotoxicity. Multicellular organisms such as the Caenorhabditis elegans (C. elegans) can bridge the gap between in vitro and vertebrate testing as they can provide extensive information on systemic toxicity and specific harmful effects through facile experimentation following 3R EU directives on animal use. Since the nematodes' pharynx shares similarities with the human heart, we assessed the general and pharyngeal effects of drugs and polypyrrole nanoparticles (Ppy NPs) using C. elegans. The evaluation of FDA-approved drugs, such as Propranolol and Racepinephrine reproduced the arrhythmic behavior reported in humans and supported the use of this small animal model. Consequently, Ppy NPs were evaluated due to their research interest in cardiac arrhythmia treatments. The NPs' biocompatibility was confirmed by assessing survival, growth and development, reproduction, and transgenerational toxicity in C. elegans. Interestingly, the NPs increased the pharyngeal pumping rate of C. elegans in two slow-pumping mutant strains, JD21 and DA464. Moreover, the NPs increased the pumping rate over time, which sustained up to a day post-excretion. By measuring pharyngeal calcium levels, we found that the impact of Ppy NPs on the pumping rate could be mediated through calcium signaling. Thus, evaluating arrhythmic effects in C. elegans offers a simple system to test drugs and nanoparticles, as elucidated through Ppy NPs.
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Affiliation(s)
- Sumithra
Yasaswini Srinivasan
- Universitat
de Autonoma de Barcelona, Institut de Ciència
de Materials de Barcelona (ICMAB), 08193, Bellaterra, Barcelona, Spain
| | - Pilar Alvarez Illera
- Universidad
de Valladolid, Instituto de Biomedicina
y Genética Molecular (IBGM), 47005, Valladolid, Spain
| | - Dmytro Kukhtar
- Modeling
Human Diseases in C. elegans Group - Genes, Disease
and Therapy Program, Bellvitge Biomedical
Research Institute - IDIBELL, 08908 L’Hospitalet de Llobregat, Barcelona, Spain
| | | | - Julián Cerón
- Modeling
Human Diseases in C. elegans Group - Genes, Disease
and Therapy Program, Bellvitge Biomedical
Research Institute - IDIBELL, 08908 L’Hospitalet de Llobregat, Barcelona, Spain
| | - Javier Álvarez
- Universidad
de Valladolid, Instituto de Biomedicina
y Genética Molecular (IBGM), 47005, Valladolid, Spain
| | - Rosalba I. Fonteriz
- Universidad
de Valladolid, Instituto de Biomedicina
y Genética Molecular (IBGM), 47005, Valladolid, Spain
| | - Mayte Montero
- Universidad
de Valladolid, Instituto de Biomedicina
y Genética Molecular (IBGM), 47005, Valladolid, Spain
| | - Anna Laromaine
- Universitat
de Autonoma de Barcelona, Institut de Ciència
de Materials de Barcelona (ICMAB), 08193, Bellaterra, Barcelona, Spain
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2
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Busack I, Bringmann H. A sleep-active neuron can promote survival while sleep behavior is disturbed. PLoS Genet 2023; 19:e1010665. [PMID: 36917595 PMCID: PMC10038310 DOI: 10.1371/journal.pgen.1010665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/24/2023] [Accepted: 02/13/2023] [Indexed: 03/16/2023] Open
Abstract
Sleep is controlled by neurons that induce behavioral quiescence and physiological restoration. It is not known, however, how sleep neurons link sleep behavior and survival. In Caenorhabditis elegans, the sleep-active RIS neuron induces sleep behavior and is required for survival of starvation and wounding. Sleep-active neurons such as RIS might hypothetically promote survival primarily by causing sleep behavior and associated conservation of energy. Alternatively, RIS might provide a survival benefit that does not depend on behavioral sleep. To probe these hypotheses, we tested how activity of the sleep-active RIS neuron in Caenorhabditis elegans controls sleep behavior and survival during larval starvation. To manipulate the activity of RIS, we expressed constitutively active potassium channel (twk-18gf and egl-23gf) or sodium channel (unc-58gf) mutant alleles in this neuron. Low levels of unc-58gf expression in RIS increased RIS calcium transients and sleep. High levels of unc-58gf expression in RIS elevated baseline calcium activity and inhibited calcium activation transients, thus locking RIS activity at a high but constant level. This manipulation caused a nearly complete loss of sleep behavior but increased survival. Long-term optogenetic activation also caused constantly elevated RIS activity and a small trend towards increased survival. Disturbing sleep by lethal blue-light stimulation also overactivated RIS, which again increased survival. FLP-11 neuropeptides were important for both, induction of sleep behavior and starvation survival, suggesting that FLP-11 might have divergent roles downstream of RIS. These results indicate that promotion of sleep behavior and survival are separable functions of RIS. These two functions may normally be coupled but can be uncoupled during conditions of strong RIS activation or when sleep behavior is impaired. Through this uncoupling, RIS can provide survival benefits under conditions when behavioral sleep is disturbed. Promoting survival in the face of impaired sleep might be a general function of sleep neurons.
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Affiliation(s)
- Inka Busack
- BIOTEC, Technical University Dresden, Dresden, Germany
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3
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Choudhary S, Kashyap SS, Martin RJ, Robertson AP. Advances in our understanding of nematode ion channels as potential anthelmintic targets. Int J Parasitol Drugs Drug Resist 2022; 18:52-86. [PMID: 35149380 PMCID: PMC8841521 DOI: 10.1016/j.ijpddr.2021.12.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 12/15/2022]
Abstract
Ion channels are specialized multimeric proteins that underlie cell excitability. These channels integrate with a variety of neuromuscular and biological functions. In nematodes, the physiological behaviors including locomotion, navigation, feeding and reproduction, are regulated by these protein entities. Majority of the antinematodal chemotherapeutics target the ion channels to disrupt essential biological functions. Here, we have summarized current advances in our understanding of nematode ion channel pharmacology. We review cys-loop ligand gated ion channels (LGICs), including nicotinic acetylcholine receptors (nAChRs), acetylcholine-chloride gated ion channels (ACCs), glutamate-gated chloride channels (GluCls), and GABA (γ-aminobutyric acid) receptors, and other ionotropic receptors (transient receptor potential (TRP) channels and potassium ion channels). We have provided an update on the pharmacological properties of these channels from various nematodes. This article catalogs the differences in ion channel composition and resulting pharmacology in the phylum Nematoda. This diversity in ion channel subunit repertoire and pharmacology emphasizes the importance of pursuing species-specific drug target research. In this review, we have provided an overview of recent advances in techniques and functional assays available for screening ion channel properties and their application.
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Affiliation(s)
- Shivani Choudhary
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Sudhanva S Kashyap
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Richard J Martin
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Alan P Robertson
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
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4
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Engel MA, Wörmann YR, Kaestner H, Schüler C. An Optogenetic Arrhythmia Model—Insertion of Several Catecholaminergic Polymorphic Ventricular Tachycardia Mutations Into Caenorhabditis elegans UNC-68 Disturbs Calstabin-Mediated Stabilization of the Ryanodine Receptor Homolog. Front Physiol 2022; 13:691829. [PMID: 35399287 PMCID: PMC8990320 DOI: 10.3389/fphys.2022.691829] [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: 04/08/2021] [Accepted: 02/15/2022] [Indexed: 11/14/2022] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited disturbance of the heart rhythm (arrhythmia) that is induced by stress or that occurs during exercise. Most mutations that have been linked to CPVT are found in two genes, i.e., ryanodine receptor 2 (RyR2) and calsequestrin 2 (CASQ2), two proteins fundamentally involved in the regulation of intracellular Ca2+ in cardiac myocytes. We inserted six CPVT-causing mutations via clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 into unc-68 and csq-1, the Caenorhabditis elegans homologs of RyR and CASQ, respectively. We characterized those mutations via video-microscopy, electrophysiology, and calcium imaging in our previously established optogenetic arrhythmia model. In this study, we additionally enabled high(er) throughput recordings of intact animals by combining optogenetic stimulation with a microfluidic chip system. Whereas only minor/no pump deficiency of the pharynx was observed at baseline, three mutations of UNC-68 (S2378L, P2460S, Q4623R; RyR2-S2246L, -P2328S, -Q4201R) reduced the ability of the organ to follow 4 Hz optogenetic stimulation. One mutation (Q4623R) was accompanied by a strong reduction of maximal pump rate. In addition, S2378L and Q4623R evoked an altered calcium handling during optogenetic stimulation. The 1,4-benzothiazepine S107, which is suggested to stabilize RyR2 channels by enhancing the binding of calstabin2, reversed the reduction of pumping ability in a mutation-specific fashion. However, this depends on the presence of FKB-2, a C. elegans calstabin2 homolog, indicating the involvement of calstabin2 in the disease-causing mechanisms of the respective mutations. In conclusion, we showed for three CPVT-like mutations in C. elegans RyR a reduced pumping ability upon light stimulation, i.e., an arrhythmia-like phenotype, that can be reversed in two cases by the benzothiazepine S107 and that depends on stabilization via FKB-2. The genetically amenable nematode in combination with optogenetics and high(er) throughput recordings is a promising straightforward system for the investigation of RyR mutations and the selection of mutation-specific drugs.
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Affiliation(s)
- Marcial Alexander Engel
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Yves René Wörmann
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Hanna Kaestner
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
| | - Christina Schüler
- Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University Frankfurt, Frankfurt, Germany
- *Correspondence: Christina Schüler,
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5
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Widaad A, Zulkipli IN, Petalcorin MIR. Anthelmintic Effect of Leucaena leucocephala Extract and Its Active Compound, Mimosine, on Vital Behavioral Activities in Caenorhabditis elegans. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27061875. [PMID: 35335240 PMCID: PMC8950933 DOI: 10.3390/molecules27061875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/22/2022] [Accepted: 03/07/2022] [Indexed: 12/03/2022]
Abstract
Helminth infections continue to be a neglected global threat in tropical regions, and there have been growing cases of anthelmintic resistance reported towards the existing anthelmintic drugs. Thus, the search for a novel anthelmintic agent has been increasing, especially those derived from plants. Leucaena leucocephala (LL) is a leguminous plant that is known to have several pharmacological activities, including anthelmintic activity. It is widely known to contain a toxic compound called mimosine, which we believed could be a potential lead candidate that could exert a potent anthelmintic effect. Hence, this study aimed to validate the presence of mimosine in LL extract and to investigate the anthelmintic effect of LL extract and mimosine on head thrashing, egg-laying, and pharyngeal pumping activities using the animal model Caenorhabditis elegans (C. elegans). Mimosine content in LL extract was confirmed through an HPLC analysis of spiking LL extract with different mimosine concentrations, whereby an increasing trend in peak heights was observed at a retention time of 0.9 min. LL extract and mimosine caused a significant dose-dependent increase in the percentage of worm mortality, which produced LC50s of 73 mg/mL and 6.39 mg/mL, respectively. Exposure of C. elegans to different concentrations of LL extract and mimosine significantly decreased the head thrashing, egg-laying, and mean pump amplitude of pharyngeal pumping activity. We speculated that these behavioral changes are due to the inhibitory effect of LL extract and mimosine on an L-type calcium channel called EGL-19. Our findings provide evidential support for the potential of LL extract and its active compound, mimosine, as novel anthelmintic candidates. However, the underlying mechanism of the anthelmintic action has yet to be elucidated.
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6
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Henß T, Nagpal J, Gao S, Scheib U, Pieragnolo A, Hirschhäuser A, Schneider-Warme F, Hegemann P, Nagel G, Gottschalk A. Optogenetic tools for manipulation of cyclic nucleotides functionally coupled to cyclic nucleotide-gated channels. Br J Pharmacol 2021; 179:2519-2537. [PMID: 33733470 DOI: 10.1111/bph.15445] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 02/10/2021] [Accepted: 03/02/2021] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE The cyclic nucleotides cAMP and cGMP are ubiquitous second messengers regulating numerous biological processes. Malfunctional cNMP signalling is linked to diseases and thus is an important target in pharmaceutical research. The existing optogenetic toolbox in Caenorhabditis elegans is restricted to soluble adenylyl cyclases, the membrane-bound Blastocladiella emersonii CyclOp and hyperpolarizing rhodopsins; yet missing are membrane-bound photoactivatable adenylyl cyclases and hyperpolarizers based on K+ currents. EXPERIMENTAL APPROACH For the characterization of photoactivatable nucleotidyl cyclases, we expressed the proteins alone or in combination with cyclic nucleotide-gated channels in muscle cells and cholinergic motor neurons. To investigate the extent of optogenetic cNMP production and the ability of the systems to depolarize or hyperpolarize cells, we performed behavioural analyses, measured cNMP content in vitro, and compared in vivo expression levels. KEY RESULTS We implemented Catenaria CyclOp as a new tool for cGMP production, allowing fine-control of cGMP levels. We established photoactivatable membrane-bound adenylyl cyclases, based on mutated versions ("A-2x") of Blastocladiella and Catenaria ("Be," "Ca") CyclOp, as N-terminal YFP fusions, enabling more efficient and specific cAMP signalling compared to soluble bPAC, despite lower overall cAMP production. For hyperpolarization of excitable cells by two-component optogenetics, we introduced the cAMP-gated K+ -channel SthK from Spirochaeta thermophila and combined it with bPAC, BeCyclOp(A-2x), or YFP-BeCyclOp(A-2x). As an alternative, we implemented the B. emersonii cGMP-gated K+ -channel BeCNG1 together with BeCyclOp. CONCLUSION AND IMPLICATIONS We established a comprehensive suite of optogenetic tools for cNMP manipulation, applicable in many cell types, including sensory neurons, and for potent hyperpolarization.
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Affiliation(s)
- Thilo Henß
- Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany.,Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany
| | - Jatin Nagpal
- Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany.,Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.,APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Shiqiang Gao
- Department of Neurophysiology, Institute of Physiology, Biocentre, Julius-Maximilians-University, Würzburg, Germany
| | - Ulrike Scheib
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany.,Lead Discovery, Protein Technology, NUVISAN ICB GmbH, Berlin, Germany
| | | | - Alexander Hirschhäuser
- Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany.,Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany.,Institute for Physiology and Pathophysiology, Department of Molecular Cell Physiology, Philipps-University Marburg, Marburg, Germany
| | - Franziska Schneider-Warme
- University Heart Center, Medical Center - University of Freiburg and Faculty of Medicine, Institute for Experimental Cardiovascular Medicine, Freiburg, Germany
| | - Peter Hegemann
- Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Georg Nagel
- Department of Neurophysiology, Institute of Physiology, Biocentre, Julius-Maximilians-University, Würzburg, Germany
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt, Germany.,Institute of Biophysical Chemistry, Goethe University, Frankfurt, Germany
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7
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Klimovich A, Giacomello S, Björklund Å, Faure L, Kaucka M, Giez C, Murillo-Rincon AP, Matt AS, Willoweit-Ohl D, Crupi G, de Anda J, Wong GCL, D'Amato M, Adameyko I, Bosch TCG. Prototypical pacemaker neurons interact with the resident microbiota. Proc Natl Acad Sci U S A 2020; 117:17854-17863. [PMID: 32647059 PMCID: PMC7395494 DOI: 10.1073/pnas.1920469117] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Pacemaker neurons exert control over neuronal circuit function by their intrinsic ability to generate rhythmic bursts of action potential. Recent work has identified rhythmic gut contractions in human, mice, and hydra to be dependent on both neurons and the resident microbiota. However, little is known about the evolutionary origin of these neurons and their interaction with microbes. In this study, we identified and functionally characterized prototypical ANO/SCN/TRPM ion channel-expressing pacemaker cells in the basal metazoan Hydra by using a combination of single-cell transcriptomics, immunochemistry, and functional experiments. Unexpectedly, these prototypical pacemaker neurons express a rich set of immune-related genes mediating their interaction with the microbial environment. Furthermore, functional experiments gave a strong support to a model of the evolutionary emergence of pacemaker cells as neurons using components of innate immunity to interact with the microbial environment and ion channels to generate rhythmic contractions.
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Affiliation(s)
- Alexander Klimovich
- Department of Cell and Developmental Biology, Zoological Institute, University of Kiel, D-24118 Kiel, Germany;
| | - Stefania Giacomello
- Department of Biochemistry and Biophysics, National Infrastructure of Sweden, Science for Life Laboratory, Stockholm University, 17121 Solna, Sweden
- Department of Gene Technology, Science for Life Laboratory, Kungligia Tekniska Högskolan Royal Institute of Technology, 17121 Solna, Sweden
| | - Åsa Björklund
- Department of Cell and Molecular Biology, National Infrastructure of Sweden, Science for Life Laboratory, Uppsala University, 75237 Uppsala, Sweden
| | - Louis Faure
- Department of Molecular Neurosciences, Center for Brain Research, Medical University Vienna, 1090 Vienna, Austria
| | - Marketa Kaucka
- Department of Molecular Neurosciences, Center for Brain Research, Medical University Vienna, 1090 Vienna, Austria
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, SH 24306 Plön, Germany
| | - Christoph Giez
- Department of Cell and Developmental Biology, Zoological Institute, University of Kiel, D-24118 Kiel, Germany
| | - Andrea P Murillo-Rincon
- Department of Cell and Developmental Biology, Zoological Institute, University of Kiel, D-24118 Kiel, Germany
| | - Ann-Sophie Matt
- Department of Cell and Developmental Biology, Zoological Institute, University of Kiel, D-24118 Kiel, Germany
| | - Doris Willoweit-Ohl
- Department of Cell and Developmental Biology, Zoological Institute, University of Kiel, D-24118 Kiel, Germany
| | - Gabriele Crupi
- Department of Cell and Developmental Biology, Zoological Institute, University of Kiel, D-24118 Kiel, Germany
| | - Jaime de Anda
- Department of Bioengineering, California NanoSystems Institute, University of California, Los Angeles, CA 90095-1600
- Department of Chemistry and Biochemistry, California NanoSystems Institute, University of California, Los Angeles, CA 90095-1600
| | - Gerard C L Wong
- Department of Bioengineering, California NanoSystems Institute, University of California, Los Angeles, CA 90095-1600
- Department of Chemistry and Biochemistry, California NanoSystems Institute, University of California, Los Angeles, CA 90095-1600
| | - Mauro D'Amato
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia
| | - Igor Adameyko
- Department of Molecular Neurosciences, Center for Brain Research, Medical University Vienna, 1090 Vienna, Austria
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177 Stockholm, Sweden
| | - Thomas C G Bosch
- Department of Cell and Developmental Biology, Zoological Institute, University of Kiel, D-24118 Kiel, Germany;
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8
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Bruns AN, Lo SH. Tensin regulates pharyngeal pumping in Caenorhabditis elegans. Biochem Biophys Res Commun 2019; 522:599-603. [PMID: 31784086 DOI: 10.1016/j.bbrc.2019.11.153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 11/22/2019] [Indexed: 12/24/2022]
Abstract
Tensin is a focal adhesion molecule that is known to regulate cell adhesion, migration, and proliferation. Although there are four tensin homologs (TNS1, TNS2, TNS3, and CTEN/TNS4) in mammals, only one tensin gene is found in Caenorhabditis elegans. Sequence analysis suggests that Caenorhabditis elegans tensin is slightly closer aligned with human TNS1 than with other human tensins. To establish the role of TNS1 in Caenorhabditis elegans, we have generated TNS1 knockout (KO) worms by CRISPR-Cas9 and homologous recombination directed repair approaches. Lack of TNS1 does not appear to affect the development or gross morphology of the worms. Nonetheless, defecation cycles are significantly longer in TNS1 KO worms. In addition, their pharyngeal pumping rate is markedly faster, which is likely due to a shorter pump duration in the KO worms. These findings indicate that TNS1 is not required for the development and survival of Caenorhabditis elegans but point to a critical role in modulating defecation and pharyngeal pumping rates.
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Affiliation(s)
- Aaron N Bruns
- Department of Biochemistry and Molecular Medicine, University of California-Davis, Sacramento, CA, 95817, USA
| | - Su Hao Lo
- Department of Biochemistry and Molecular Medicine, University of California-Davis, Sacramento, CA, 95817, USA.
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9
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Steuer Costa W, Van der Auwera P, Glock C, Liewald JF, Bach M, Schüler C, Wabnig S, Oranth A, Masurat F, Bringmann H, Schoofs L, Stelzer EHK, Fischer SC, Gottschalk A. A GABAergic and peptidergic sleep neuron as a locomotion stop neuron with compartmentalized Ca2+ dynamics. Nat Commun 2019; 10:4095. [PMID: 31506439 PMCID: PMC6736843 DOI: 10.1038/s41467-019-12098-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 08/21/2019] [Indexed: 11/09/2022] Open
Abstract
Animals must slow or halt locomotion to integrate sensory inputs or to change direction. In Caenorhabditis elegans, the GABAergic and peptidergic neuron RIS mediates developmentally timed quiescence. Here, we show RIS functions additionally as a locomotion stop neuron. RIS optogenetic stimulation caused acute and persistent inhibition of locomotion and pharyngeal pumping, phenotypes requiring FLP-11 neuropeptides and GABA. RIS photoactivation allows the animal to maintain its body posture by sustaining muscle tone, yet inactivating motor neuron oscillatory activity. During locomotion, RIS axonal Ca2+ signals revealed functional compartmentalization: Activity in the nerve ring process correlated with locomotion stop, while activity in a branch correlated with induced reversals. GABA was required to induce, and FLP-11 neuropeptides were required to sustain locomotion stop. RIS attenuates neuronal activity and inhibits movement, possibly enabling sensory integration and decision making, and exemplifies dual use of one cell across development in a compact nervous system.
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Affiliation(s)
- Wagner Steuer Costa
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany.,Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Petrus Van der Auwera
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany.,Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany.,Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Naamsestraat 59 - box 2465, 3000, Leuven, Belgium
| | - Caspar Glock
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany.,Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany.,Max-Planck-Institute for Brain Research, Max-von-Laue-Strasse 4, 60438, Frankfurt, Germany
| | - Jana F Liewald
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany.,Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Maximilian Bach
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany.,Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Christina Schüler
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany.,Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Sebastian Wabnig
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany.,Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany.,od green GmbH, Passauerstrasse 34, 4780, Schärding am Inn, Austria
| | - Alexandra Oranth
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany.,Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany
| | - Florentin Masurat
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany
| | - Henrik Bringmann
- Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany.,Department of Biology, University of Marburg, Karl-von-Frisch-Strasse 8, 35043, Marburg, Germany
| | - Liliane Schoofs
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Naamsestraat 59 - box 2465, 3000, Leuven, Belgium
| | - Ernst H K Stelzer
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany.,Institute of Cell Biology and Neuroscience, Goethe University, Max-von-Laue-Strasse 13, 60439, Frankfurt, Germany
| | - Sabine C Fischer
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany.,Institute of Cell Biology and Neuroscience, Goethe University, Max-von-Laue-Strasse 13, 60439, Frankfurt, Germany.,Center for Computational and Theoretical Biology (CCTB), University of Würzburg, Campus Hubland Nord 32, 97074, Würzburg, Germany
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438, Frankfurt, Germany. .,Institute for Biophysical Chemistry, Goethe University, Max-von-Laue-Strasse 9, 60438, Frankfurt, Germany.
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10
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Rhodopsin-based voltage imaging tools for use in muscles and neurons of Caenorhabditis elegans. Proc Natl Acad Sci U S A 2019; 116:17051-17060. [PMID: 31371514 PMCID: PMC6708366 DOI: 10.1073/pnas.1902443116] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Neuronal and other excitable cell activity is characterized by alteration in membrane voltage, while intracellular Ca2+ levels and transmitter release are affected downstream of electrical activity. Thus, the most direct way of monitoring neuronal activity is by membrane voltage. Electrophysiology is demanding for multiple cells or cell ensembles and difficult to use in live animals, thus imaging methods are desirable. Yet, genetically encoded voltage indicators fell behind Ca2+ indicators until recently, when microbial rhodopsins and derivatives were introduced as genetically encoded voltage indicators. We evaluated rhodopsin tools for voltage imaging in muscles and neurons of Caenorhabditis elegans, a prime animal model in neuro- and cell biology, showing robust performance and the ability to characterize genetic mutants. Genetically encoded voltage indicators (GEVIs) based on microbial rhodopsins utilize the voltage-sensitive fluorescence of all-trans retinal (ATR), while in electrochromic FRET (eFRET) sensors, donor fluorescence drops when the rhodopsin acts as depolarization-sensitive acceptor. In recent years, such tools have become widely used in mammalian cells but are less commonly used in invertebrate systems, mostly due to low fluorescence yields. We systematically assessed Arch(D95N), Archon, QuasAr, and the eFRET sensors MacQ-mCitrine and QuasAr-mOrange, in the nematode Caenorhabditis elegans. ATR-bearing rhodopsins reported on voltage changes in body wall muscles (BWMs), in the pharynx, the feeding organ [where Arch(D95N) showed approximately 128% ΔF/F increase per 100 mV], and in neurons, integrating circuit activity. ATR fluorescence is very dim, yet, using the retinal analog dimethylaminoretinal, it was boosted 250-fold. eFRET sensors provided sensitivities of 45 to 78% ΔF/F per 100 mV, induced by BWM action potentials, and in pharyngeal muscle, measured in simultaneous optical and sharp electrode recordings, MacQ-mCitrine showed approximately 20% ΔF/F per 100 mV. All sensors reported differences in muscle depolarization induced by a voltage-gated Ca2+-channel mutant. Optogenetically evoked de- or hyperpolarization of motor neurons increased or eliminated action potential activity and caused a rise or drop in BWM sensor fluorescence. Finally, we analyzed voltage dynamics across the entire pharynx, showing uniform depolarization but compartmentalized repolarization of anterior and posterior parts. Our work establishes all-optical, noninvasive electrophysiology in live, intact C. elegans.
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11
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Fischer E, Gottschalk A, Schüler C. An optogenetic arrhythmia model to study catecholaminergic polymorphic ventricular tachycardia mutations. Sci Rep 2017; 7:17514. [PMID: 29235522 PMCID: PMC5727474 DOI: 10.1038/s41598-017-17819-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/01/2017] [Indexed: 11/08/2022] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a condition of abnormal heart rhythm (arrhythmia), induced by physical activity or stress. Mutations in ryanodine receptor 2 (RyR2), a Ca2+ release channel located in the sarcoplasmic reticulum (SR), or calsequestrin 2 (CASQ2), a SR Ca2+ binding protein, are linked to CPVT. For specific drug development and to study distinct arrhythmias, simple models are required to implement and analyze such mutations. Here, we introduced CPVT inducing mutations into the pharynx of Caenorhabditis elegans, which we previously established as an optogenetically paced heart model. By electrophysiology and video-microscopy, we characterized mutations in csq-1 (CASQ2 homologue) and unc-68 (RyR2 homologue). csq-1 deletion impaired pharynx function and caused missed pumps during 3.7 Hz pacing. Deletion mutants of unc-68, and in particular the point mutant UNC-68(R4743C), analogous to the established human CPVT mutant RyR2(R4497C), were unable to follow 3.7 Hz pacing, with progressive defects during long stimulus trains. The pharynx either locked in pumping at half the pacing frequency or stopped pumping altogether, possibly due to UNC-68 leakiness and/or malfunctional SR Ca2+ homeostasis. Last, we could reverse this 'worm arrhythmia' by the benzothiazepine S107, establishing the nematode pharynx for studying specific CPVT mutations and for drug screening.
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Affiliation(s)
- Elisabeth Fischer
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany
- Institute of Biophysical Chemistry, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany
- University of Edinburgh, Centre for Integrative Physiology, Hugh Robson Building, George Square, Edinburgh, EH8 9XE, UK
| | - Alexander Gottschalk
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany.
- Institute of Biophysical Chemistry, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany.
- Cluster of Excellence Frankfurt - Macromolecular Complexes, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany.
| | - Christina Schüler
- Buchmann Institute for Molecular Life Sciences, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany.
- Institute of Biophysical Chemistry, Goethe University, Max von Laue Strasse 15, D-60438, Frankfurt, Germany.
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12
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Over-expression of microRNA-1 causes arrhythmia by disturbing intracellular trafficking system. Sci Rep 2017; 7:46259. [PMID: 28397788 PMCID: PMC5387686 DOI: 10.1038/srep46259] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/13/2017] [Indexed: 11/08/2022] Open
Abstract
Dysregulation of intracellular trafficking system plays a fundamental role in the progression of cardiovascular disease. Up-regulation of miR-1 contributes to arrhythmia, we sought to elucidate whether intracellular trafficking contributes to miR-1-driven arrhythmia. By performing microarray analyses of the transcriptome in the cardiomyocytes-specific over-expression of microRNA-1 (miR-1 Tg) mice and the WT mice, we found that these differentially expressed genes in miR-1 Tg mice were significantly enrichment with the trafficking-related biological processes, such as regulation of calcium ion transport. Also, the qRT-PCR and western blot results validated that Stx6, Braf, Ube3a, Mapk8ip3, Ap1s1, Ccz1 and Gja1, which are the trafficking-related genes, were significantly down-regulated in the miR-1 Tg mice. Moreover, we found that Stx6 was decreased in the heart of mice after myocardial infarction and in the hypoxic cardiomyocytes, and further confirmed that Stx6 is a target of miR-1. Meanwhile, knockdown of Stx6 in cardiomyocytes resulted in the impairments of PLM and L-type calcium channel, which leads to the increased resting ([Ca2+]i). On the contrary, overexpression of Stx6 attenuated the impairments of miR-1 or hypoxia on PLM and L-type calcium channel. Thus, our studies reveals that trafficking-related gene Stx6 may regulate intracellular calcium and is involved in the occurrence of cardiac arrhythmia, which provides new insights in that miR-1 participates in arrhythmia by regulating the trafficking-related genes and pathway.
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13
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Trojanowski NF, Raizen DM, Fang-Yen C. Pharyngeal pumping in Caenorhabditis elegans depends on tonic and phasic signaling from the nervous system. Sci Rep 2016; 6:22940. [PMID: 26976078 PMCID: PMC4791602 DOI: 10.1038/srep22940] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 02/23/2016] [Indexed: 02/02/2023] Open
Abstract
Rhythmic movements are ubiquitous in animal locomotion, feeding, and circulatory systems. In some systems, the muscle itself generates rhythmic contractions. In others, rhythms are generated by the nervous system or by interactions between the nervous system and muscles. In the nematode Caenorhabditis elegans, feeding occurs via rhythmic contractions (pumping) of the pharynx, a neuromuscular feeding organ. Here, we use pharmacology, optogenetics, genetics, and electrophysiology to investigate the roles of the nervous system and muscle in generating pharyngeal pumping. Hyperpolarization of the nervous system using a histamine-gated chloride channel abolishes pumping, and optogenetic stimulation of pharyngeal muscle in these animals causes abnormal contractions, demonstrating that normal pumping requires nervous system function. In mutants that pump slowly due to defective nervous system function, tonic muscle stimulation causes rapid pumping, suggesting tonic neurotransmitter release may regulate pumping. However, tonic cholinergic motor neuron stimulation, but not tonic muscle stimulation, triggers pumps that electrophysiologically resemble typical rapid pumps. This suggests that pharyngeal cholinergic motor neurons are normally rhythmically, and not tonically active. These results demonstrate that the pharynx generates a myogenic rhythm in the presence of tonically released acetylcholine, and suggest that the pharyngeal nervous system entrains contraction rate and timing through phasic neurotransmitter release.
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Affiliation(s)
- Nicholas F Trojanowski
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104 PA, USA.,Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, 19104 PA, USA.,Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104 PA, USA
| | - David M Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104 PA, USA
| | - Christopher Fang-Yen
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, 19104 PA, USA.,Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104 PA, USA
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