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Martins AC, Virgolini MB, Ávila DS, Scharf P, Li J, Tinkov AA, Skalny AV, Bowman AB, Rocha JBT, Aschner M. Mitochondria in the Spotlight: C. elegans as a Model Organism to Evaluate Xenobiotic-Induced Dysfunction. Cells 2023; 12:2124. [PMID: 37681856 PMCID: PMC10486742 DOI: 10.3390/cells12172124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/19/2023] [Accepted: 08/20/2023] [Indexed: 09/09/2023] Open
Abstract
Mitochondria play a crucial role in cellular respiration, ATP production, and the regulation of various cellular processes. Mitochondrial dysfunctions have been directly linked to pathophysiological conditions, making them a significant target of interest in toxicological research. In recent years, there has been a growing need to understand the intricate effects of xenobiotics on human health, necessitating the use of effective scientific research tools. Caenorhabditis elegans (C. elegans), a nonpathogenic nematode, has emerged as a powerful tool for investigating toxic mechanisms and mitochondrial dysfunction. With remarkable genetic homology to mammals, C. elegans has been used in studies to elucidate the impact of contaminants and drugs on mitochondrial function. This review focuses on the effects of several toxic metals and metalloids, drugs of abuse and pesticides on mitochondria, highlighting the utility of C. elegans as a model organism to investigate mitochondrial dysfunction induced by xenobiotics. Mitochondrial structure, function, and dynamics are discussed, emphasizing their essential role in cellular viability and the regulation of processes such as autophagy, apoptosis, and calcium homeostasis. Additionally, specific toxins and toxicants, such as arsenic, cadmium, and manganese are examined in the context of their impact on mitochondrial function and the utility of C. elegans in elucidating the underlying mechanisms. Furthermore, we demonstrate the utilization of C. elegans as an experimental model providing a promising platform for investigating the intricate relationships between xenobiotics and mitochondrial dysfunction. This knowledge could contribute to the development of strategies to mitigate the adverse effects of contaminants and drugs of abuse, ultimately enhancing our understanding of these complex processes and promoting human health.
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Affiliation(s)
- Airton C. Martins
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
| | - Miriam B. Virgolini
- Departamento de Farmacología Otto Orsingher, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5000, Argentina
- Instituto de Farmacología Experimental de Córdoba-Consejo Nacional de Investigaciones Técnicas (IFEC-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba 5000, Argentina
| | - Daiana Silva Ávila
- Laboratory of Biochemistry and Toxicology in Caenorhabditis Elegans, Universidade Federal do Pampa, Campus Uruguaiana, BR-472 Km 592, Uruguaiana 97500-970, RS, Brazil
| | - Pablo Scharf
- Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo 05508-000, SP, Brazil
| | - Jung Li
- College of Osteopathic Medicine, Des Moines University, Des Moines, IA 50312, USA
| | - Alexey A. Tinkov
- Laboratory of Ecobiomonitoring and Quality Control, Yaroslavl State University, Yaroslavl 150003, Russia
- Laboratory of Molecular Dietetics, IM Sechenov First Moscow State Medical University (Sechenov University), Moscow 119435, Russia
| | - Anatoly V. Skalny
- Laboratory of Ecobiomonitoring and Quality Control, Yaroslavl State University, Yaroslavl 150003, Russia
- Laboratory of Molecular Dietetics, IM Sechenov First Moscow State Medical University (Sechenov University), Moscow 119435, Russia
- Peoples Friendship University of Russia (RUDN University), Moscow 117198, Russia
| | - Aaron B. Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907-2051, USA
| | - João B. T. Rocha
- Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria 97105-900, RS, Brazil
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
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van Wijk MH, Davies AG, Sterken MG, Mathies LD, Quamme EC, Blackwell GG, Riksen JAG, Kammenga JE, Bettinger JC. Natural allelic variation modifies acute ethanol response phenotypes in wild strains of C. elegans. ALCOHOL, CLINICAL & EXPERIMENTAL RESEARCH 2023; 47:1505-1517. [PMID: 37356915 DOI: 10.1111/acer.15139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/12/2023] [Accepted: 06/20/2023] [Indexed: 06/27/2023]
Abstract
BACKGROUND Genetic variation contributes to the likelihood that an individual will develop an alcohol use disorder (AUD). Traditional laboratory studies in animal models have elucidated the molecular pharmacology of ethanol, but laboratory-derived genetic manipulations rarely model the naturally occurring genetic variation observed in wild populations. Rather, these manipulations are biased toward identifying genes of central importance in the phenotypes. Because changes in such genes can confer selective disadvantages, they are not ideal candidates for carrying AUD risk alleles in humans. We sought to exploit Caenorhabditis elegans to identify allelic variation existing in the wild that modulates ethanol response behaviors. METHODS We tested the acute ethanol responses of four strains recently isolated from the wild (JU1511, JU1926, JU1931, and JU1941) and 41 multiparental recombinant inbred lines (mpRILs) derived from them. We assessed locomotion at 10, 30, and 50 min on low and high ethanol concentrations. We performed principal component analyses (PCA) on the different phenotypes, tested for transgressive behavior, calculated heritability, and determined the correlations between behavioral responses. RESULTS We observed a range of responses to ethanol across the strains. We detected a low-concentration locomotor activation effect in some of the mpRILs not seen in the laboratory wild-type strain. PCA showed different ethanol response behaviors to be independent. We observed transgressive behavior for many of the measured phenotypes and found that multiple behaviors were uncorrelated. The average broad-sense heritability for all phenotypes was 23.2%. CONCLUSIONS Genetic variation significantly affects multiple acute ethanol response behaviors, many of which are independent of one another. This suggests that the genetic variation captured by these strains likely affects multiple biological mechanisms through which ethanol acts. Further study of these strains may allow these distinct mechanisms to be identified.
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Affiliation(s)
- Marijke H van Wijk
- Laboratory of Nematology, Wageningen University & Research, Wageningen, The Netherlands
| | - Andrew G Davies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Mark G Sterken
- Laboratory of Nematology, Wageningen University & Research, Wageningen, The Netherlands
| | - Laura D Mathies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Elizabeth C Quamme
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - GinaMari G Blackwell
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Joost A G Riksen
- Laboratory of Nematology, Wageningen University & Research, Wageningen, The Netherlands
| | - Jan E Kammenga
- Laboratory of Nematology, Wageningen University & Research, Wageningen, The Netherlands
| | - Jill C Bettinger
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, Virginia, USA
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Albrecht PA, Fernandez-Hubeid LE, Deza-Ponzio R, Romero VL, Gonzales-Moreno C, Carranza AD, Moran Y, Asis R, Virgolini MB. Reduced acute functional tolerance and enhanced preference for ethanol in Caenorhabditis elegans exposed to lead during development: Potential role of alcohol dehydrogenase. Neurotoxicol Teratol 2022; 94:107131. [DOI: 10.1016/j.ntt.2022.107131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 09/13/2022] [Accepted: 09/29/2022] [Indexed: 11/24/2022]
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Guzman DM, Chakka K, Shi T, Marron A, Fiorito AE, Rahman NS, Ro S, Sucich DG, Pierce JT. Transgenerational effects of alcohol on behavioral sensitivity to alcohol in Caenorhabditis elegans. PLoS One 2022; 17:e0271849. [PMID: 36256641 PMCID: PMC9578632 DOI: 10.1371/journal.pone.0271849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 09/29/2022] [Indexed: 11/06/2022] Open
Abstract
Alcohol abuse and dependence have a substantial heritable component. Although the genome has been considered the sole vehicle of heritable phenotypes, recent studies suggest that drug or alcohol exposure may induce alterations in gene expression that are transmitted across generations. Still, the transgenerational impact of alcohol use (and abuse) remains largely unexplored in part because multigenerational studies using rodent models present challenges for time, sample size, and genetic heterogeneity. Here, we took advantage of the extremely short generation time, large broods, and clonal form of reproduction of the nematode Caenorhabditis elegans. We developed a model of pre-fertilization parental alcohol exposure to test alterations in behavioral responses to acute alcohol treatment (referred to in short as intoxication) in subsequent F1, F2 and F3 generations. We found that chronic and intermittent alcohol-treatment paradigms resulted in opposite changes to intoxication sensitivity of F3 progeny that were only apparent when controlling for yoked trials. Chronic alcohol-treatment paradigm in the parental generation resulted in alcohol-naïve F3 progeny displaying moderate resistance to intoxication. Intermittent treatment resulted in alcohol-naïve F3 progeny displaying moderate hypersensitivity to intoxication. Further study of these phenomena using this new C. elegans model may yield mechanistic insights into how transgenerational effects may occur in other animals.
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Affiliation(s)
- Dawn M. Guzman
- Department of Neuroscience, Waggoner Center for Alcohol and Addiction Research, Center for Learning and Memory, University of Texas at Austin, Austin, Texas, United States of America
| | - Keerthana Chakka
- Department of Neuroscience, Waggoner Center for Alcohol and Addiction Research, Center for Learning and Memory, University of Texas at Austin, Austin, Texas, United States of America
| | - Ted Shi
- Department of Neuroscience, Waggoner Center for Alcohol and Addiction Research, Center for Learning and Memory, University of Texas at Austin, Austin, Texas, United States of America
| | - Alyssa Marron
- Department of Neuroscience, Waggoner Center for Alcohol and Addiction Research, Center for Learning and Memory, University of Texas at Austin, Austin, Texas, United States of America
| | - Ansley E. Fiorito
- Department of Neuroscience, Waggoner Center for Alcohol and Addiction Research, Center for Learning and Memory, University of Texas at Austin, Austin, Texas, United States of America
| | - Nima S. Rahman
- Department of Neuroscience, Waggoner Center for Alcohol and Addiction Research, Center for Learning and Memory, University of Texas at Austin, Austin, Texas, United States of America
| | - Stephanie Ro
- Department of Neuroscience, Waggoner Center for Alcohol and Addiction Research, Center for Learning and Memory, University of Texas at Austin, Austin, Texas, United States of America
| | - Dylan G. Sucich
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Jonathan T. Pierce
- Department of Neuroscience, Waggoner Center for Alcohol and Addiction Research, Center for Learning and Memory, University of Texas at Austin, Austin, Texas, United States of America
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Bhat US, Shahi N, Surendran S, Babu K. Neuropeptides and Behaviors: How Small Peptides Regulate Nervous System Function and Behavioral Outputs. Front Mol Neurosci 2021; 14:786471. [PMID: 34924955 PMCID: PMC8674661 DOI: 10.3389/fnmol.2021.786471] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/11/2021] [Indexed: 11/13/2022] Open
Abstract
One of the reasons that most multicellular animals survive and thrive is because of the adaptable and plastic nature of their nervous systems. For an organism to survive, it is essential for the animal to respond and adapt to environmental changes. This is achieved by sensing external cues and translating them into behaviors through changes in synaptic activity. The nervous system plays a crucial role in constantly evaluating environmental cues and allowing for behavioral plasticity in the organism. Multiple neurotransmitters and neuropeptides have been implicated as key players for integrating sensory information to produce the desired output. Because of its simple nervous system and well-established neuronal connectome, C. elegans acts as an excellent model to understand the mechanisms underlying behavioral plasticity. Here, we critically review how neuropeptides modulate a wide range of behaviors by allowing for changes in neuronal and synaptic signaling. This review will have a specific focus on feeding, mating, sleep, addiction, learning and locomotory behaviors in C. elegans. With a view to understand evolutionary relationships, we explore the functions and associated pathophysiology of C. elegans neuropeptides that are conserved across different phyla. Further, we discuss the mechanisms of neuropeptidergic signaling and how these signals are regulated in different behaviors. Finally, we attempt to provide insight into developing potential therapeutics for neuropeptide-related disorders.
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Affiliation(s)
- Umer Saleem Bhat
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | - Navneet Shahi
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| | - Siju Surendran
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| | - Kavita Babu
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
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Chávez-Pérez C, Jafari N, Keenan BT, Raizen DM, Rohacek AM. Motivated displacement assay distinguishes ALA neuron mutants from RIS neuron mutants during recovery from heat stress in Caenorhabditis elegans. MICROPUBLICATION BIOLOGY 2021; 2021:10.17912/micropub.biology.000468. [PMID: 34557657 PMCID: PMC8453304 DOI: 10.17912/micropub.biology.000468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/06/2021] [Accepted: 09/14/2021] [Indexed: 11/06/2022]
Abstract
The interneurons ALA and RIS both regulate stress induced sleep in C. elegans but their roles in awake animal movement has been reported to differ. We describe the development of a motivated mobility-based assay that distinguishes between animals mutant for ALA function and those mutant for RIS function.
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Affiliation(s)
- Carlos Chávez-Pérez
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania
| | - Niusha Jafari
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania
| | - Brendan T Keenan
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania
| | - David M Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania,
Correspondence to: David M Raizen ()
| | - Alex M Rohacek
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania
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7
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Ke W, Reed JN, Yang C, Higgason N, Rayyan L, Wählby C, Carpenter AE, Civelek M, O’Rourke EJ. Genes in human obesity loci are causal obesity genes in C. elegans. PLoS Genet 2021; 17:e1009736. [PMID: 34492009 PMCID: PMC8462697 DOI: 10.1371/journal.pgen.1009736] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/24/2021] [Accepted: 07/23/2021] [Indexed: 12/13/2022] Open
Abstract
Obesity and its associated metabolic syndrome are a leading cause of morbidity and mortality. Given the disease's heavy burden on patients and the healthcare system, there has been increased interest in identifying pharmacological targets for the treatment and prevention of obesity. Towards this end, genome-wide association studies (GWAS) have identified hundreds of human genetic variants associated with obesity. The next challenge is to experimentally define which of these variants are causally linked to obesity, and could therefore become targets for the treatment or prevention of obesity. Here we employ high-throughput in vivo RNAi screening to test for causality 293 C. elegans orthologs of human obesity-candidate genes reported in GWAS. We RNAi screened these 293 genes in C. elegans subject to two different feeding regimens: (1) regular diet, and (2) high-fructose diet, which we developed and present here as an invertebrate model of diet-induced obesity (DIO). We report 14 genes that promote obesity and 3 genes that prevent DIO when silenced in C. elegans. Further, we show that knock-down of the 3 DIO genes not only prevents excessive fat accumulation in primary and ectopic fat depots but also improves the health and extends the lifespan of C. elegans overconsuming fructose. Importantly, the direction of the association between expression variants in these loci and obesity in mice and humans matches the phenotypic outcome of the loss-of-function of the C. elegans ortholog genes, supporting the notion that some of these genes would be causally linked to obesity across phylogeny. Therefore, in addition to defining causality for several genes so far merely correlated with obesity, this study demonstrates the value of model systems compatible with in vivo high-throughput genetic screening to causally link GWAS gene candidates to human diseases.
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Affiliation(s)
- Wenfan Ke
- Department of Biology, College of Arts and Sciences, University of Virginia, Charlottesville, Virginia, United States of America
| | - Jordan N. Reed
- Department of Biomedical Engineering, School of Engineering and Applied Science, University of Virginia, Charlottesville, Virginia, United States of America
| | - Chenyu Yang
- Department of Biology, College of Arts and Sciences, University of Virginia, Charlottesville, Virginia, United States of America
| | - Noel Higgason
- Department of Biology, College of Arts and Sciences, University of Virginia, Charlottesville, Virginia, United States of America
| | - Leila Rayyan
- Department of Biology, College of Arts and Sciences, University of Virginia, Charlottesville, Virginia, United States of America
| | - Carolina Wählby
- Department of Information Technology and SciLifeLab, Uppsala University, Uppsala, Sweden
| | - Anne E. Carpenter
- Imaging Platform, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Mete Civelek
- Department of Biomedical Engineering, School of Engineering and Applied Science, University of Virginia, Charlottesville, Virginia, United States of America
- Center for Public Health Genomics, School of Medicine, University of Virginia, Charlottesville, Virginia, United States of America
| | - Eyleen J. O’Rourke
- Department of Biology, College of Arts and Sciences, University of Virginia, Charlottesville, Virginia, United States of America
- Department of Cell Biology, School of Medicine, University of Virginia, Charlottesville, Virginia, United States of America
- * E-mail:
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8
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Calahorro F, Holden-Dye L, O'Connor V. Impact of drug solvents on C. elegans pharyngeal pumping. Toxicol Rep 2021; 8:1240-1247. [PMID: 34195015 PMCID: PMC8233170 DOI: 10.1016/j.toxrep.2021.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 05/20/2021] [Accepted: 06/14/2021] [Indexed: 02/05/2023] Open
Abstract
Caenorhabditis elegans provides a multi-cellular model organism for toxicology and drug discovery. These studies usually require solvents such as dimethyl sulfoxide (DMSO), ethanol or acetone as a vehicle. This raises the need to carefully consider whether the chemical vehicles used in these screens are anodyne towards C. elegans. Here, we use pharyngeal pumping as a bioassay to assess this. Pharyngeal pumping is a visually scoreable behaviour that is controlled by environmental cues activating sensory and integrative neural signalling to coordinate pharyngeal activity. As such it serves as a rich bioassay to screen for chemical modulation. We found that while pumping was insensitive to high concentrations of the widely used drug solvents ethanol and acetone, it was perturbed by concentrations of DMSO above 0.5 % v/v encompassing concentrations used as drug vehicle. This was manifested as an inhibition of pharyngeal pump rate followed by a slow recovery in the continued presence of the solvent. The inhibition was not observed in a neuroligin mutant, nlg-1, consistent with DMSO acting at the level of sensory processing that modulates pumping. We found that bus-17 mutants, which have enhanced cuticle penetration to drugs are more sensitive to DMSO. The effect of DMSO is accompanied by a progressive morphological disruption in which internal membrane-like structures of varying size accumulate. These internal structures are seen in all three genotypes investigated in this study and likely arise independent of the effects on pharyngeal pumping. Overall, these results highlight sensory signalling and strain dependent vehicle sensitivity. Although we define concentrations at which this can be mitigated, it highlights the need to consider time-dependent vehicle effects when evaluating control responses in C. elegans chemical biology.
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Sterken MG, van Wijk MH, Quamme EC, Riksen JAG, Carnell L, Mathies LD, Davies AG, Kammenga JE, Bettinger JC. Transcriptional analysis of the response of C. elegans to ethanol exposure. Sci Rep 2021; 11:10993. [PMID: 34040055 PMCID: PMC8155136 DOI: 10.1038/s41598-021-90282-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 05/07/2021] [Indexed: 11/30/2022] Open
Abstract
Ethanol-induced transcriptional changes underlie important physiological responses to ethanol that are likely to contribute to the addictive properties of the drug. We examined the transcriptional responses of Caenorhabditis elegans across a timecourse of ethanol exposure, between 30 min and 8 h, to determine what genes and genetic pathways are regulated in response to ethanol in this model. We found that short exposures to ethanol (up to 2 h) induced expression of metabolic enzymes involved in metabolizing ethanol and retinol, while longer exposure (8 h) had much more profound effects on the transcriptome. Several genes that are known to be involved in the physiological response to ethanol, including direct ethanol targets, were regulated at 8 h of exposure. This longer exposure to ethanol also resulted in the regulation of genes involved in cilia function, which is consistent with an important role for the effects of ethanol on cilia in the deleterious effects of chronic ethanol consumption in humans. Finally, we found that food deprivation for an 8-h period induced gene expression changes that were somewhat ameliorated by the presence of ethanol, supporting previous observations that worms can use ethanol as a calorie source.
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Affiliation(s)
- Mark G Sterken
- Laboratory of Nematology, Wageningen University and Research, 6708 PB, Wageningen, The Netherlands
| | - Marijke H van Wijk
- Laboratory of Nematology, Wageningen University and Research, 6708 PB, Wageningen, The Netherlands
| | - Elizabeth C Quamme
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Box 980613, Richmond, VA, 23298, USA
| | - Joost A G Riksen
- Laboratory of Nematology, Wageningen University and Research, 6708 PB, Wageningen, The Netherlands
| | - Lucinda Carnell
- Department of Biological Sciences, Central Washington University, Ellensburg, WA, 98926, USA
| | - Laura D Mathies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Box 980613, Richmond, VA, 23298, USA
- Virginia Commonwealth University Alcohol Research Center, Richmond, VA, USA
| | - Andrew G Davies
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Box 980613, Richmond, VA, 23298, USA
- Virginia Commonwealth University Alcohol Research Center, Richmond, VA, USA
| | - Jan E Kammenga
- Laboratory of Nematology, Wageningen University and Research, 6708 PB, Wageningen, The Netherlands
| | - Jill C Bettinger
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Box 980613, Richmond, VA, 23298, USA.
- Virginia Commonwealth University Alcohol Research Center, Richmond, VA, USA.
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Pandey P, Singh A, Kaur H, Ghosh-Roy A, Babu K. Increased dopaminergic neurotransmission results in ethanol dependent sedative behaviors in Caenorhabditis elegans. PLoS Genet 2021; 17:e1009346. [PMID: 33524034 PMCID: PMC7877767 DOI: 10.1371/journal.pgen.1009346] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 02/11/2021] [Accepted: 01/06/2021] [Indexed: 12/19/2022] Open
Abstract
Ethanol is a widely used drug, excessive consumption of which could lead to medical conditions with diverse symptoms. Ethanol abuse causes dysfunction of memory, attention, speech and locomotion across species. Dopamine signaling plays an essential role in ethanol dependent behaviors in animals ranging from C. elegans to humans. We devised an ethanol dependent assay in which mutants in the dopamine autoreceptor, dop-2, displayed a unique sedative locomotory behavior causing the animals to move in circles while dragging the posterior half of their body. Here, we identify the posterior dopaminergic sensory neuron as being essential to modulate this behavior. We further demonstrate that in dop-2 mutants, ethanol exposure increases dopamine secretion and functions in a DVA interneuron dependent manner. DVA releases the neuropeptide NLP-12 that is known to function through cholinergic motor neurons and affect movement. Thus, DOP-2 modulates dopamine levels at the synapse and regulates alcohol induced movement through NLP-12.
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Affiliation(s)
- Pratima Pandey
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Anuradha Singh
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
| | - Harjot Kaur
- National Brain Research Centre, Gurgaon, India
| | | | - Kavita Babu
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India
- Centre for Neuroscience, Indian Institute of Science (IISc), Bangalore, India
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11
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Scholz H. Unraveling the Mechanisms of Behaviors Associated With AUDs Using Flies and Worms. Alcohol Clin Exp Res 2019; 43:2274-2284. [PMID: 31529787 DOI: 10.1111/acer.14199] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 09/11/2019] [Indexed: 12/11/2022]
Abstract
Alcohol use disorders (AUDs) are very common worldwide and negatively affect both individuals and societies. To understand how normal behavior turns into uncontrollable use of alcohol, several approaches have been utilized in the last decades. However, we still do not completely understand how AUDs evolve or how they are maintained in the brains of affected individuals. In addition, efficient and effective treatment is still in need of development. This review focuses on alternative approaches developed over the last 20 years using Drosophila melanogaster (Drosophila) and Caenorhabditis elegans (C. elegans) as genetic model systems to determine the mechanisms underlying the action of ethanol (EtOH) and behaviors associated with AUDs. All the results and insights of studies over the last 20 years cannot be comprehensively summarized. Thus, a few prominent examples are provided highlighting the principles of the genes and mechanisms that have been uncovered and are involved in the action of EtOH at the cellular level. In addition, examples are provided of the genes and mechanisms that regulate behaviors relevant to acquiring and maintaining excessive alcohol intake, such as decision making, reward and withdrawal, and/or relapse regulation. How the insight gained from the results of Drosophila and C. elegans models can be translated to higher organisms, such as rodents and/or humans, is discussed, as well as whether these insights have any relevance or impact on our understanding of the mechanisms underlying AUDs in humans. Finally, future directions are presented that might facilitate the identification of drugs to treat AUDs.
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Affiliation(s)
- Henrike Scholz
- From the, Department of Biology, Institute for Zoology, Albertus-Magnus University of Cologne, Cologne, Germany
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12
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Monte GG, Nani JV, de Almeida Campos MR, Dal Mas C, Marins LAN, Martins LG, Tasic L, Mori MA, Hayashi MAF. Impact of nuclear distribution element genes in the typical and atypical antipsychotics effects on nematode Caenorhabditis elegans: Putative animal model for studying the pathways correlated to schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2019; 92:19-30. [PMID: 30578843 DOI: 10.1016/j.pnpbp.2018.12.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 12/17/2018] [Accepted: 12/19/2018] [Indexed: 12/18/2022]
Abstract
The nuclear distribution element genes are conserved from fungus to humans. The nematode Caenorhabditis elegans expresses two isoforms of nuclear distribution element genes, namely nud-1 and nud-2. While nud-1 was functionally demonstrated to be the worm nudC ortholog, bioinformatic analysis revealed that the nud-2 gene encodes the worm ortholog of the mammalian NDE1 (Nuclear Distribution Element 1 or NudE) and NDEL1 (NDE-Like 1 or NudEL) genes, which share overlapping roles in brain development in mammals and also mediate the axon guidance in mammalian and C. elegans neurons. A significantly higher NDEL1 enzyme activity was shown in treatment non-resistant compared to treatment resistant SCZ patients, who essentially present response to the therapy with atypical clozapine but not with typical antipsychotics. Using C. elegans as a model, we tested the consequence of nud genes suppression in the effects of typical and atypical antipsychotics. To assess the role of nud genes and antipsychotic drugs over C. elegans behavior, we measured body bend frequency, egg laying and pharyngeal pumping, which traits are controlled by specific neurons and neurotransmitters known to be involved in SCZ, as dopamine and serotonin. Evaluation of metabolic and behavioral response to the pharmacotherapy with these antipsychotics demonstrates an important unbalance in serotonin pathway in both nud-1 and nud-2 knockout worms, with more significant effects for nud-2 knockout. The present data also show an interesting trend of mutant knockout worm strains to present a metabolic profile closer to that observed for the wild-type animals after the treatment with the typical antipsychotic haloperidol, but which was not observed for the treatment with the atypical antipsychotic clozapine. Paradoxically, behavioral assays showed more evident effects for clozapine than for haloperidol, which is in line with previous studies with rodent animal models and clinical evaluations with SCZ patients. In addition, the validity and reliability of using this experimental animal model to further explore the convergence between the dopamine/serotonin pathways and neurodevelopmental processes was demonstrated here, and the potential usefulness of this model for evaluating the metabolic consequences of treatments with antipsychotics is also suggested.
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Affiliation(s)
- Gabriela Guilherme Monte
- Department of Pharmacology, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP) São Paulo, Brazil
| | - João V Nani
- Department of Pharmacology, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP) São Paulo, Brazil
| | | | - Caroline Dal Mas
- Department of Pharmacology, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP) São Paulo, Brazil
| | - Lucas Augusto Negri Marins
- Department of Pharmacology, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP) São Paulo, Brazil
| | - Lucas Gelain Martins
- Chemical Biology Laboratory, Department of Organic Chemistry, Institute of Chemistry, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Ljubica Tasic
- Chemical Biology Laboratory, Department of Organic Chemistry, Institute of Chemistry, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Marcelo A Mori
- Departament of Biochemistry and Tissue Biology, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil
| | - Mirian A F Hayashi
- Department of Pharmacology, Escola Paulista de Medicina (EPM), Universidade Federal de São Paulo (UNIFESP) São Paulo, Brazil.
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Small molecule modulators of σ2R/Tmem97 reduce alcohol withdrawal-induced behaviors. Neuropsychopharmacology 2018; 43:1867-1875. [PMID: 29728649 PMCID: PMC6046036 DOI: 10.1038/s41386-018-0067-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 03/09/2018] [Accepted: 04/05/2018] [Indexed: 12/29/2022]
Abstract
Repeated cycles of intoxication and withdrawal enhance the negative reinforcing properties of alcohol and lead to neuroadaptations that underlie withdrawal symptoms driving alcohol dependence. Pharmacotherapies that target these neuroadaptations may help break the cycle of dependence. The sigma-1 receptor (σ1R) subtype has attracted interest as a possible modulator of the rewarding and reinforcing effects of alcohol. However, whether the sigma-2 receptor, recently cloned and identified as transmembrane protein 97 (σ2R/TMEM97), plays a role in alcohol-related behaviors is currently unknown. Using a Caenorhabditis elegans model, we identified two novel, selective σ2R/Tmem97 modulators that reduce alcohol withdrawal behavior via an ortholog of σ2R/TMEM97. We then show that one of these compounds blunted withdrawal-induced excessive alcohol drinking in a well-established rodent model of alcohol dependence. These discoveries provide the first evidence that σ2R/TMEM97 is involved in alcohol withdrawal behaviors and that this receptor is a potential new target for treating alcohol use disorder.
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Ethanol Stimulates Locomotion via a G αs-Signaling Pathway in IL2 Neurons in Caenorhabditis elegans. Genetics 2017; 207:1023-1039. [PMID: 28951527 PMCID: PMC5676223 DOI: 10.1534/genetics.117.300119] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 09/23/2017] [Indexed: 01/21/2023] Open
Abstract
Alcohol abuse is among the top causes of preventable death, generating considerable financial, health, and societal burdens. Paradoxically, alcohol... Alcohol is a potent pharmacological agent when consumed acutely at sufficient quantities and repeated overuse can lead to addiction and deleterious effects on health. Alcohol is thought to modulate neuronal function through low-affinity interactions with proteins, in particular with membrane channels and receptors. Paradoxically, alcohol acts as both a stimulant and a sedative. The exact molecular mechanisms for the acute effects of ethanol on neurons, as either a stimulant or a sedative, however remain unclear. We investigated the role that the heat shock transcription factor HSF-1 played in determining a stimulatory phenotype of Caenorhabditis elegans in response to physiologically relevant concentrations of ethanol (17 mM; 0.1% v/v). Using genetic techniques, we demonstrate that either RNA interference of hsf-1 or use of an hsf-1(sy441) mutant lacked the enhancement of locomotion in response to acute ethanol exposure evident in wild-type animals. We identify that the requirement for HSF-1 in this phenotype was IL2 neuron-specific and required the downstream expression of the α-crystallin ortholog HSP-16.48. Using a combination of pharmacology, optogenetics, and phenotypic analyses we determine that ethanol activates a Gαs-cAMP-protein kinase A signaling pathway in IL2 neurons to stimulate nematode locomotion. We further implicate the phosphorylation of a specific serine residue (Ser322) on the synaptic protein UNC-18 as an end point for the Gαs-dependent signaling pathway. These findings establish and characterize a distinct neurosensory cell signaling pathway that determines the stimulatory action of ethanol and identifies HSP-16.48 and HSF-1 as novel regulators of this pathway.
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15
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An oxytocin-dependent social interaction between larvae and adult C. elegans. Sci Rep 2017; 7:10122. [PMID: 28860630 PMCID: PMC5579267 DOI: 10.1038/s41598-017-09350-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 07/26/2017] [Indexed: 12/21/2022] Open
Abstract
Oxytocin has a conserved role in regulating animal social behaviour including parental-offspring interactions. Recently an oxytocin-like neuropeptide, nematocin, and its cognate receptors have been identified in the nematode Caenorhabditis elegans. We provide evidence for a pheromone signal produced by C. elegans larvae that modifies the behaviour of adult animals in an oxytocin-dependent manner increasing their probability of leaving a food patch which the larvae are populating. This increase is positively correlated to the size of the larval population but cannot be explained by food depletion nor is it modulated by biogenic amines, which suggest it is not an aversive behaviour. Moreover, the food-leaving behaviour is conspecific and pheromone dependent: C. elegans adults respond more strongly to C. elegans larvae compared to other nematode species and this effect is absent in C. elegans daf-22 larvae which are pheromone deficient. Neurotransmitter receptors previously implicated in C. elegans foraging decisions NPR-1 and TYRA-3, for NPY-like neuropeptides and tyramine respectively, do not appear to be involved in oxytocin-dependent adult food-leaving. We conclude oxytocin signals within a novel neural circuit that regulates parental-offspring social behaviour in C. elegans and that this provides evidence for evolutionary conservation of molecular components of a parental decision making behaviour.
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16
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Campbell JC, Chin-Sang ID, Bendena WG. A Caenorhabditis elegans Nutritional-status Based Copper Aversion Assay. J Vis Exp 2017:55939. [PMID: 28784963 PMCID: PMC5612601 DOI: 10.3791/55939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
To ensure survival, organisms must be capable of avoiding unfavorable habitats while ensuring a consistent food source. Caenorhabditis elegans alter their locomotory patterns upon detection of diverse environmental stimuli and can modulate their suite of behavioral responses in response to starvation conditions. Nematodes typically exhibit a decreased aversive response when removed from a food source for over 30 min. Observation of behavioral changes in response to a changing nutritional status can provide insight into the mechanisms that regulate the transition from a well-fed to starved state. We have developed an assay that measures a nematode's ability to cross an aversive barrier (i.e. copper) then reach a food source over a prolonged period of time. This protocol builds upon previous work by integrating multiple variables in a manner that allows for continued data collection as the organisms shift towards an increasingly starved condition. Moreover, this assay permits an increased sample size so that larger populations of nematodes can be simultaneously evaluated. Organisms defective for the ability to detect or respond to copper immediately cross the chemical barrier, while wild type nematodes are initially repelled. As wild type worms are increasingly starved, they begin to cross the barrier and reach the food source. We designed this assay to evaluate a mutant that is incapable of responding to diverse environmental cues, including food sensation or detection of aversive chemicals. When evaluated via this protocol, the defective organisms immediately crossed the barrier, but were also incapable of detecting a food source. Hence, these mutants repeatedly cross the chemical barrier despite temporarily reaching a food source. This assay can straightforwardly test populations of worms to evaluate potential pathway defects related to aversion and starvation.
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Affiliation(s)
| | | | - William G Bendena
- Department of Biology, Queen's University; Centre for Neuroscience, Queen's University
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17
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Behavioral Deficits Following Withdrawal from Chronic Ethanol Are Influenced by SLO Channel Function in Caenorhabditis elegans. Genetics 2017; 206:1445-1458. [PMID: 28546434 DOI: 10.1534/genetics.116.193102] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 04/29/2017] [Indexed: 01/03/2023] Open
Abstract
Symptoms of withdrawal from chronic alcohol use are a driving force for relapse in alcohol dependence. Thus, uncovering molecular targets to lessen their severity is key to breaking the cycle of dependence. Using the nematode Caenorhabditis elegans, we tested whether one highly conserved ethanol target, the large-conductance, calcium-activated potassium channel (known as the BK channel or Slo1), modulates ethanol withdrawal. Consistent with a previous report, we found that C. elegans displays withdrawal-related behavioral impairments after cessation of chronic ethanol exposure. We found that the degree of impairment is exacerbated in worms lacking the worm BK channel, SLO-1, and is reduced by selective rescue of this channel in the nervous system. Enhanced SLO-1 function, via gain-of-function mutation or overexpression, also dramatically reduced behavioral impairment during withdrawal. Consistent with these results, we found that chronic ethanol exposure decreased SLO-1 expression in a subset of neurons. In addition, we found that the function of a distinct, conserved Slo family channel, SLO-2, showed an inverse relationship to withdrawal behavior, and this influence depended on SLO-1 function. Together, our findings show that modulation of either Slo family ion channel bidirectionally regulates withdrawal behaviors in worm, supporting further exploration of the Slo family as targets for normalizing behaviors during alcohol withdrawal.
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18
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Campbell JC, Polan-Couillard LF, Chin-Sang ID, Bendena WG. NPR-9, a Galanin-Like G-Protein Coupled Receptor, and GLR-1 Regulate Interneuronal Circuitry Underlying Multisensory Integration of Environmental Cues in Caenorhabditis elegans. PLoS Genet 2016; 12:e1006050. [PMID: 27223098 PMCID: PMC4880332 DOI: 10.1371/journal.pgen.1006050] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 04/21/2016] [Indexed: 11/27/2022] Open
Abstract
C. elegans inhabit environments that require detection of diverse stimuli to modulate locomotion in order to avoid unfavourable conditions. In a mammalian context, a failure to appropriately integrate environmental signals can lead to Parkinson’s, Alzheimer’s, and epilepsy. Provided that the circuitry underlying mammalian sensory integration can be prohibitively complex, we analyzed nematode behavioral responses in differing environmental contexts to evaluate the regulation of context dependent circuit reconfiguration and sensorimotor control. Our work has added to the complexity of a known parallel circuit, mediated by interneurons AVA and AIB, that integrates sensory cues and is responsible for the initiation of backwards locomotion. Our analysis of the galanin-like G-protein coupled receptor NPR-9 in C. elegans revealed that upregulation of galanin signaling impedes the integration of sensory evoked neuronal signals. Although the expression pattern of npr-9 is limited to AIB, upregulation of the receptor appears to impede AIB and AVA circuits to broadly prevent backwards locomotion, i.e. reversals, suggesting that these two pathways functionally interact. Galanin signaling similarly plays a broadly inhibitory role in mammalian models. Moreover, our identification of a mutant, which rarely initiates backwards movement, allowed us to interrogate locomotory mechanisms underlying chemotaxis. In support of the pirouette model of chemotaxis, organisms that did not exhibit reversal behavior were unable to navigate towards an attractant peak. We also assessed ionotropic glutamate receptor GLR-1 cell-specifically within AIB and determined that GLR-1 fine-tunes AIB activity to modify locomotion following reversal events. Our research highlights that signal integration underlying the initiation and fine-tuning of backwards locomotion is AIB and NPR-9 dependent, and has demonstrated the suitability of C. elegans for analysis of multisensory integration and sensorimotor control. Multiple environmental cues are sensed by an organism in order to coordinate behavioral responses. Consequently, organisms must be able to simultaneously detect and integrate multiple external stimuli in order to appropriately modify their behavior. Identifying the unique circuits mediating the response to individual stimuli and points of overlap is essential to understanding how multiple signals can be integrated for a coordinated behavioral response. In order to analyze individual circuits, we have used the model organism C. elegans. We have identified that a C. elegans neuropeptide receptor (NPR-9) and a glutamate receptor (GLR-1) function in a single interneuron to play a broad regulatory role in multiple neural circuits. Our research has identified that interneuron AIB is involved in the integration of signals from numerous sensory neurons. Moreover, regulation of AIB via a neuropeptide receptor (NPR-9) and a glutamate receptor (GLR-1) coordinates AIB activity in the context of multisensory integration. Long-range chemotaxis behavior, in which an organism alters locomotory patterns based on odorant sensation, is also regulated by NPR-9. Our analysis indicates that reversals, and thus the pirouette model, are sufficient for chemotaxis.
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Affiliation(s)
- Jason C. Campbell
- Department of Biology, Queen’s University, Kingston, Ontario, Canada
| | | | - Ian D. Chin-Sang
- Department of Biology, Queen’s University, Kingston, Ontario, Canada
| | - William G. Bendena
- Department of Biology, Queen’s University, Kingston, Ontario, Canada
- Centre for Neuroscience, Queen’s University, Kingston, Ontario, Canada
- * E-mail:
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Report on the 13th symposium on invertebrate neurobiology held 26-30 August 2015 at the Balaton Limnological Institute, MTA Centre for ecological research of the Hungarian Academy of Sciences, Tihany, Hungary. INVERTEBRATE NEUROSCIENCE 2016; 16:3. [PMID: 27149972 DOI: 10.1007/s10158-016-0186-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
This report summarizes the lectures and posters presented at the International Society for Invertebrate Neurobiology's 13th symposium held 26-30 August 2015, at the Balaton Limnological Institute, MTA Centre for Ecological Research, Tihany, Hungary. The symposium provided an opportunity for scientists working on a range of topics in invertebrate neurobiology to meet and present their research and discuss ways to advance the discipline.
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20
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Harlow PH, Perry SJ, Widdison S, Daniels S, Bondo E, Lamberth C, Currie RA, Flemming AJ. The nematode Caenorhabditis elegans as a tool to predict chemical activity on mammalian development and identify mechanisms influencing toxicological outcome. Sci Rep 2016; 6:22965. [PMID: 26987796 PMCID: PMC4796825 DOI: 10.1038/srep22965] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/19/2016] [Indexed: 01/08/2023] Open
Abstract
To determine whether a C. elegans bioassay could predict mammalian developmental activity, we selected diverse compounds known and known not to elicit such activity and measured their effect on C. elegans egg viability. 89% of compounds that reduced C. elegans egg viability also had mammalian developmental activity. Conversely only 25% of compounds found not to reduce egg viability in C. elegans were also inactive in mammals. We conclude that the C. elegans egg viability assay is an accurate positive predictor, but an inaccurate negative predictor, of mammalian developmental activity. We then evaluated C. elegans as a tool to identify mechanisms affecting toxicological outcomes among related compounds. The difference in developmental activity of structurally related fungicides in C. elegans correlated with their rate of metabolism. Knockdown of the cytochrome P450s cyp-35A3 and cyp-35A4 increased the toxicity to C. elegans of the least developmentally active compounds to the level of the most developmentally active. This indicated that these P450s were involved in the greater rate of metabolism of the less toxic of these compounds. We conclude that C. elegans based approaches can predict mammalian developmental activity and can yield plausible hypotheses for factors affecting the biological potency of compounds in mammals.
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Affiliation(s)
- Philippa H Harlow
- Syngenta Ltd., Jealott's Hill Research Station, Bracknell, Berkshire, RG42 6EY, UK
| | - Simon J Perry
- Syngenta Ltd., Jealott's Hill Research Station, Bracknell, Berkshire, RG42 6EY, UK
| | - Stephanie Widdison
- General Bioinformatics, Jealott's Hill Research Station, Bracknell, Berkshire, RG42 6EY, UK
| | - Shannon Daniels
- Syngenta, 3054 East Cornwallis Road, Research Triangle Park, NC 27709-2257, USA
| | - Eddie Bondo
- Syngenta, 3054 East Cornwallis Road, Research Triangle Park, NC 27709-2257, USA
| | - Clemens Lamberth
- Syngenta Crop Protection AG, Chemical Research, Schaffhauserstrasse 101, 4332 Stein, Switzerland
| | - Richard A Currie
- Syngenta Ltd., Jealott's Hill Research Station, Bracknell, Berkshire, RG42 6EY, UK
| | - Anthony J Flemming
- Syngenta Ltd., Jealott's Hill Research Station, Bracknell, Berkshire, RG42 6EY, UK
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21
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Practical and low cost whole-organism motility assay: A step-by-step protocol. Mol Cell Probes 2016; 30:13-7. [DOI: 10.1016/j.mcp.2015.08.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 08/25/2015] [Accepted: 08/25/2015] [Indexed: 01/09/2023]
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22
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Caenorhabditis elegans as a Model to Study the Molecular and Genetic Mechanisms of Drug Addiction. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 137:229-52. [PMID: 26810004 DOI: 10.1016/bs.pmbts.2015.10.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Drug addiction takes a massive toll on society. Novel animal models are needed to test new treatments and understand the basic mechanisms underlying addiction. Rodent models have identified the neurocircuitry involved in addictive behavior and indicate that rodents possess some of the same neurobiologic mechanisms that mediate addiction in humans. Recent studies indicate that addiction is mechanistically and phylogenetically ancient and many mechanisms that underlie human addiction are also present in invertebrates. The nematode Caenorhabditis elegans has conserved neurobiologic systems with powerful molecular and genetic tools and a rapid rate of development that enables cost-effective translational discovery. Emerging evidence suggests that C. elegans is an excellent model to identify molecular mechanisms that mediate drug-induced behavior and potential targets for medications development for various addictive compounds. C. elegans emit many behaviors that can be easily quantitated including some that involve interactions with the environment. Ethanol (EtOH) is the best-studied drug-of-abuse in C. elegans and at least 50 different genes/targets have been identified as mediating EtOH's effects and polymorphisms in some orthologs in humans are associated with alcohol use disorders. C. elegans has also been shown to display dopamine and cholinergic system-dependent attraction to nicotine and demonstrate preference for cues previously associated with nicotine. Cocaine and methamphetamine have been found to produce dopamine-dependent reward-like behaviors in C. elegans. These behavioral tests in combination with genetic/molecular manipulations have led to the identification of dozens of target genes/systems in C. elegans that mediate drug effects. The one target/gene identified as essential for drug-induced behavioral responses across all drugs of abuse was the cat-2 gene coding for tyrosine hydroxylase, which is consistent with the role of dopamine neurotransmission in human addiction. Overall, C. elegans can be used to model aspects of drug addiction and identify systems and molecular mechanisms that mediate drug effects. The findings are surprisingly consistent with analogous findings in higher-level organisms. Further, model refinement is warranted to improve model validity and increase utility for medications development.
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Kanteti R, Dhanasingh I, El-Hashani E, Riehm JJ, Stricker T, Nagy S, Zaborin A, Zaborina O, Biron D, Alverdy JC, Im HK, Siddiqui S, Padilla PA, Salgia R. C. elegans and mutants with chronic nicotine exposure as a novel model of cancer phenotype. Cancer Biol Ther 2015; 17:91-103. [PMID: 26574927 PMCID: PMC6093410 DOI: 10.1080/15384047.2015.1108495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We previously investigated MET and its oncogenic mutants relevant to lung cancer
in C. elegans. The inactive orthlogues of the receptor tyrosine
kinase Eph and MET, namely vab-1 and RB2088 respectively, the
temperature sensitive constitutively active form of KRAS, SD551
(let-60; GA89) and the inactive c-CBL equivalent mutants in
sli-1 (PS2728, PS1258, and MT13032) when subjected to
chronic exposure of nicotine resulted in a significant loss in egg-laying
capacity and fertility. While the vab-1 mutant revealed
increased circular motion in response to nicotine, the other mutant strains
failed to show any effect. Overall locomotion speed increased with increasing
nicotine concentration in all tested mutant strains except in the
vab-1 mutants. Moreover, chronic nicotine exposure, in
general, upregulated kinases and phosphatases. Taken together, these studies
provide evidence in support of C. elegans as initial in
vivo model to study nicotine and its effects on oncogenic mutations
identified in humans.
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Affiliation(s)
- Rajani Kanteti
- a Department of Medicine , Section of Hematology/Oncology, University of Chicago , Chicago , IL , USA
| | - Immanuel Dhanasingh
- a Department of Medicine , Section of Hematology/Oncology, University of Chicago , Chicago , IL , USA
| | | | - Jacob J Riehm
- a Department of Medicine , Section of Hematology/Oncology, University of Chicago , Chicago , IL , USA
| | - Thomas Stricker
- c Department of Pathology , Microbiology and Immunology, Vanderbilt University School of Medicine , Nashville , TN , USA
| | - Stanislav Nagy
- d Department of Physics , James Franck Institute, and the College, University of Chicago , Chicago , IL , USA
| | - Alexander Zaborin
- e Department of Surgery , Pritzker School of Medicine, University of Chicago , Chicago , IL , USA
| | - Olga Zaborina
- e Department of Surgery , Pritzker School of Medicine, University of Chicago , Chicago , IL , USA
| | - David Biron
- d Department of Physics , James Franck Institute, and the College, University of Chicago , Chicago , IL , USA
| | - John C Alverdy
- e Department of Surgery , Pritzker School of Medicine, University of Chicago , Chicago , IL , USA
| | - Hae Kyung Im
- f Department of Medicine , Section of Genetic Medicine, University of Chicago , Chicago , IL , USA
| | - Shahid Siddiqui
- g Department of Medicine , University of Chicago, Chicago, IL and Department of Basic and Oral Biology, UQUDENT, U. Q. University , Makkah , KSA
| | - Pamela A Padilla
- h Department of Biological Sciences , University of North- Texas , Denton , TX , USA
| | - Ravi Salgia
- a Department of Medicine , Section of Hematology/Oncology, University of Chicago , Chicago , IL , USA
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Dallière N, Bhatla N, Luedtke Z, Ma DK, Woolman J, Walker RJ, Holden-Dye L, O'Connor V. Multiple excitatory and inhibitory neural signals converge to fine-tune Caenorhabditis elegans feeding to food availability. FASEB J 2015; 30:836-48. [PMID: 26514165 DOI: 10.1096/fj.15-279257] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 10/13/2015] [Indexed: 01/02/2023]
Abstract
How an animal matches feeding to food availability is a key question for energy homeostasis. We addressed this in the nematode Caenorhabditis elegans, which couples feeding to the presence of its food (bacteria) by regulating pharyngeal activity (pumping). We scored pumping in the presence of food and over an extended time course of food deprivation in wild-type and mutant worms to determine the neural substrates of adaptive behavior. Removal of food initially suppressed pumping but after 2 h this was accompanied by intermittent periods of high activity. We show pumping is fine-tuned by context-specific neural mechanisms and highlight a key role for inhibitory glutamatergic and excitatory cholinergic/peptidergic drives in the absence of food. Additionally, the synaptic protein UNC-31 [calcium-activated protein for secretion (CAPS)] acts through an inhibitory pathway not explained by previously identified contributions of UNC-31/CAPS to neuropeptide or glutamate transmission. Pumping was unaffected by laser ablation of connectivity between the pharyngeal and central nervous system indicating signals are either humoral or intrinsic to the enteric system. This framework in which control is mediated through finely tuned excitatory and inhibitory drives resonates with mammalian hypothalamic control of feeding and suggests that fundamental regulation of this basic animal behavior may be conserved through evolution from nematode to human.
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Affiliation(s)
- Nicolas Dallière
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Nikhil Bhatla
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Zara Luedtke
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Dengke K Ma
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Jonathan Woolman
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Robert J Walker
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lindy Holden-Dye
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Vincent O'Connor
- *Centre for Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton, United Kingdom; and Howard Hughes Medical Institute and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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Grotewiel M, Bettinger JC. Drosophila and Caenorhabditis elegans as Discovery Platforms for Genes Involved in Human Alcohol Use Disorder. Alcohol Clin Exp Res 2015; 39:1292-311. [PMID: 26173477 PMCID: PMC4656040 DOI: 10.1111/acer.12785] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 05/18/2015] [Indexed: 01/08/2023]
Abstract
BACKGROUND Despite the profound clinical significance and strong heritability of alcohol use disorder (AUD), we do not yet have a comprehensive understanding of the naturally occurring genetic variance within the human genome that drives its development. This lack of understanding is likely to be due in part to the large phenotypic and genetic heterogeneities that underlie human AUD. As a complement to genetic studies in humans, many laboratories are using the invertebrate model organisms (iMOs) Drosophila melanogaster (fruit fly) and Caenorhabditis elegans (nematode worm) to identify genetic mechanisms that influence the effects of alcohol (ethanol) on behavior. While these extremely powerful models have identified many genes that influence the behavioral responses to alcohol, in most cases it has remained unclear whether results from behavioral-genetic studies in iMOs are directly applicable to understanding the genetic basis of human AUD. METHODS In this review, we critically evaluate the utility of the fly and worm models for identifying genes that influence AUD in humans. RESULTS Based on results published through early 2015, studies in flies and worms have identified 91 and 50 genes, respectively, that influence 1 or more aspects of behavioral responses to alcohol. Collectively, these fly and worm genes correspond to 293 orthologous genes in humans. Intriguingly, 51 of these 293 human genes have been implicated in AUD by at least 1 study in human populations. CONCLUSIONS Our analyses strongly suggest that the Drosophila and C. elegans models have considerable utility for identifying orthologs of genes that influence human AUD.
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Affiliation(s)
- Mike Grotewiel
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, Virginia
- Virginia Commonwealth University Alcohol Research Center, Richmond, Virginia
| | - Jill C Bettinger
- Department of Pharmacology and Toxicology , Virginia Commonwealth University, Richmond, Virginia
- Virginia Commonwealth University Alcohol Research Center, Richmond, Virginia
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Buckingham SD, Partridge FA, Sattelle DB. Automated, high-throughput, motility analysis in Caenorhabditis elegans and parasitic nematodes: Applications in the search for new anthelmintics. Int J Parasitol Drugs Drug Resist 2014; 4:226-32. [PMID: 25516833 PMCID: PMC4266775 DOI: 10.1016/j.ijpddr.2014.10.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The scale of the damage worldwide to human health, animal health and agricultural crops resulting from parasitic nematodes, together with the paucity of treatments and the threat of developing resistance to the limited set of widely-deployed chemical tools, underlines the urgent need to develop novel drugs and chemicals to control nematode parasites. Robust chemical screens which can be automated are a key part of that discovery process. Hitherto, the successful automation of nematode behaviours has been a bottleneck in the chemical discovery process. As the measurement of nematode motility can provide a direct scalar readout of the activity of the neuromuscular system and an indirect measure of the health of the animal, this omission is acute. Motility offers a useful assay for high-throughput, phenotypic drug/chemical screening and several recent developments have helped realise, at least in part, the potential of nematode-based drug screening. Here we review the challenges encountered in automating nematode motility and some important developments in the application of machine vision, statistical imaging and tracking approaches which enable the automated characterisation of nematode movement. Such developments facilitate automated screening for new drugs and chemicals aimed at controlling human and animal nematode parasites (anthelmintics) and plant nematode parasites (nematicides).
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Affiliation(s)
| | | | - David B. Sattelle
- Wolfson Institute for Biomedical Research, Division of Medicine, University College London, Cruciform Building, Gower Street, London WC1E 6BT, United Kingdom
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Kashyap SS, Johnson JR, McCue HV, Chen X, Edmonds MJ, Ayala M, Graham ME, Jenn RC, Barclay JW, Burgoyne RD, Morgan A. Caenorhabditis elegans dnj-14, the orthologue of the DNAJC5 gene mutated in adult onset neuronal ceroid lipofuscinosis, provides a new platform for neuroprotective drug screening and identifies a SIR-2.1-independent action of resveratrol. Hum Mol Genet 2014; 23:5916-27. [PMID: 24947438 PMCID: PMC4204773 DOI: 10.1093/hmg/ddu316] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 06/10/2014] [Accepted: 06/16/2014] [Indexed: 12/20/2022] Open
Abstract
Adult onset neuronal lipofuscinosis (ANCL) is a human neurodegenerative disorder characterized by progressive neuronal dysfunction and premature death. Recently, the mutations that cause ANCL were mapped to the DNAJC5 gene, which encodes cysteine string protein alpha. We show here that mutating dnj-14, the Caenorhabditis elegans orthologue of DNAJC5, results in shortened lifespan and a small impairment of locomotion and neurotransmission. Mutant dnj-14 worms also exhibited age-dependent neurodegeneration of sensory neurons, which was preceded by severe progressive chemosensory defects. A focussed chemical screen revealed that resveratrol could ameliorate dnj-14 mutant phenotypes, an effect mimicked by the cAMP phosphodiesterase inhibitor, rolipram. In contrast to other worm neurodegeneration models, activation of the Sirtuin, SIR-2.1, was not required, as sir-2.1; dnj-14 double mutants showed full lifespan rescue by resveratrol. The Sirtuin-independent neuroprotective action of resveratrol revealed here suggests potential therapeutic applications for ANCL and possibly other human neurodegenerative diseases.
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Affiliation(s)
- Sudhanva S Kashyap
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
| | - James R Johnson
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
| | - Hannah V McCue
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
| | - Xi Chen
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
| | - Matthew J Edmonds
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
| | - Mimieveshiofuo Ayala
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
| | - Margaret E Graham
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
| | - Robert C Jenn
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
| | - Jeff W Barclay
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
| | - Robert D Burgoyne
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
| | - Alan Morgan
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Crown St, Liverpool L69 3BX, UK
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A novel cholinergic action of alcohol and the development of tolerance to that effect in Caenorhabditis elegans. Genetics 2014; 199:135-49. [PMID: 25342716 DOI: 10.1534/genetics.114.171884] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Understanding the genes and mechanisms involved in acute alcohol responses has the potential to allow us to predict an individual's predisposition to developing an alcohol use disorder. To better understand the molecular pathways involved in the activating effects of alcohol and the acute functional tolerance that can develop to such effects, we characterized a novel ethanol-induced hypercontraction response displayed by Caenorhabditis elegans. We compared body size of animals prior to and during ethanol treatment and showed that acute exposure to ethanol produced a concentration-dependent decrease in size followed by recovery to their untreated size by 40 min despite continuous treatment. An increase in cholinergic signaling, leading to muscle hypercontraction, is implicated in this effect because pretreatment with mecamylamine, a nicotinic acetylcholine receptor (nAChR) antagonist, blocked ethanol-induced hypercontraction, as did mutations causing defects in cholinergic signaling (cha-1 and unc-17). Analysis of mutations affecting specific subunits of nAChRs excluded a role for the ACR-2R, the ACR-16R, and the levamisole-sensitive AChR and indicated that this excitation effect is dependent on an uncharacterized nAChR that contains the UNC-63 α-subunit. We performed a forward genetic screen and identified eg200, a mutation that affects a conserved glycine in EAT-6, the α-subunit of the Na(+)/K(+) ATPase. The eat-6(eg200) mutant fails to develop tolerance to ethanol-induced hypercontraction and remains contracted for at least 3 hr of continuous ethanol exposure. These data suggest that cholinergic signaling through a specific α-subunit-containing nAChR is involved in ethanol-induced excitation and that tolerance to this ethanol effect is modulated by Na(+)/K(+) ATPase function.
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Topper SM, Aguilar SC, Topper VY, Elbel E, Pierce-Shimomura JT. Alcohol disinhibition of behaviors in C. elegans. PLoS One 2014; 9:e92965. [PMID: 24681782 PMCID: PMC3969370 DOI: 10.1371/journal.pone.0092965] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 02/27/2014] [Indexed: 11/30/2022] Open
Abstract
Alcohol has a wide variety of effects on physiology and behavior. One of the most well-recognized behavioral effects is disinhibition, where behaviors that are normally suppressed are displayed following intoxication. A large body of evidence has shown that alcohol-induced disinhibition in humans affects attention, verbal, sexual, and locomotor behaviors. Similar behavioral disinhibition is also seen in many animal models of ethanol response, from invertebrates to mammals and primates. Here we describe several examples of disinhibition in the nematode C. elegans. The nematode displays distinct behavioral states associated with locomotion (crawling on land and swimming in water) that are mediated by dopamine. On land, animals crawl and feed freely, but these behaviors are inhibited in water. We found that additional behaviors, including a variety of escape responses are also inhibited in water. Whereas alcohol non-specifically impaired locomotion, feeding, and escape responses in worms on land, alcohol specifically disinhibited these behaviors in worms immersed in water. Loss of dopamine signaling relieved disinhibition of feeding behavior, while loss of the D1-like dopamine receptor DOP-4 impaired the ethanol-induced disinhibition of crawling. The powerful genetics and simple nervous system of C. elegans may help uncover conserved molecular mechanisms that underlie alcohol-induced disinhibition of behaviors in higher animals.
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Affiliation(s)
- Stephen M. Topper
- Waggoner Center for Alcohol and Addiction Research, Cell & Molecular Biology, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, United States of America
| | - Sara C. Aguilar
- Waggoner Center for Alcohol and Addiction Research, Cell & Molecular Biology, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, United States of America
| | - Viktoria Y. Topper
- Waggoner Center for Alcohol and Addiction Research, Cell & Molecular Biology, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, United States of America
| | - Erin Elbel
- Waggoner Center for Alcohol and Addiction Research, Cell & Molecular Biology, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, United States of America
| | - Jonathan T. Pierce-Shimomura
- Waggoner Center for Alcohol and Addiction Research, Cell & Molecular Biology, Department of Neuroscience, The University of Texas at Austin, Austin, Texas, United States of America
- * E-mail:
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30
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Dillon J, Andrianakis I, Mould R, Ient B, Liu W, James C, O'Connor V, Holden-Dye L. Distinct molecular targets including SLO-1 and gap junctions are engaged across a continuum of ethanol concentrations in Caenorhabditis elegans. FASEB J 2013; 27:4266-78. [PMID: 23882127 DOI: 10.1096/fj.11-189340] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Ethanol (alcohol) interacts with diverse molecular effectors across a range of concentrations in the brain, eliciting intoxication through to sedation. Invertebrate models including the nematode worm Caenorhabditis elegans have been deployed for molecular genetic studies to inform on key components of these alcohol signaling pathways. C. elegans studies have typically employed external dosing with high (>250 mM) ethanol concentrations: A careful analysis of responses to low concentrations is lacking. Using the C. elegans pharyngeal system as a paradigm, we report a previously uncharacterized continuum of cellular and behavioral responses to ethanol from low (10 mM) to high (300 mM) concentrations. The complexity of these responses indicates that the pleiotropic action of ethanol observed in mammalian brain is conserved in this invertebrate model. We investigated two candidate ethanol effectors, the calcium-activated K(+) channel SLO-1 and gap junctions, and show that they contribute to, but are not sole determinants of, the low- and high-concentration effects, respectively. Notably, this study shows cellular and whole organismal behavioral responses to ethanol in C. elegans that directly equate to intoxicating through to supralethal blood alcohol concentrations in humans and provides an important benchmark for interpretation of paradigms that seek to inform on human alcohol use disorders.
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Affiliation(s)
- James Dillon
- 1Current address: Institute of Digital Healthcare, Warwick Manufacturing Group, University of Warwick, Coventry CV4 7AL, UK
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31
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Peltonen J, Aarnio V, Heikkinen L, Lakso M, Wong G. Chronic ethanol exposure increases cytochrome P-450 and decreases activated in blocked unfolded protein response gene family transcripts in caenorhabditis elegans. J Biochem Mol Toxicol 2013; 27:219-28. [PMID: 23381935 DOI: 10.1002/jbt.21473] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 12/19/2012] [Indexed: 02/02/2023]
Abstract
Ethanol is a widely consumed and rapidly absorbed toxin. While the physiological effects of ethanol consumption are well known, the underlying biochemical and molecular changes at the gene expression level in whole animals remain obscure. We exposed the model organism Caenorhabditis elegans to 0.2 M ethanol from the embryo to L4 larva stage and assayed gene expression changes in whole animals using RNA-Seq and quantitative real-time PCR. We observed gene expression changes in 1122 genes (411 up, 711 down). Cytochrome P-450 (CYP) gene family members (12 of 78) were upregulated, whereas activated in blocked unfolded protein response (ABU) (7 of 15) were downregulated. Other detoxification gene family members were also regulated including four glutathione-S-transferases and three flavin monooxygenases. The results presented show specific gene expression changes following chronic ethanol exposure in C. elegans that indicate both persistent upregulation of detoxification response genes and downregulation of endoplasmic reticulum stress pathway genes.
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Affiliation(s)
- Juhani Peltonen
- A. I. Virtanen Institute for Molecular Sciences, Department of Neurobiology, University of Eastern Finland, Yliopistonranta 1E, 70210, Kuopio, Finland
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Kearn J, Dallière N, Dillon J. Meeting report: 2012 Caenorhabditis elegans Neurobiology meeting, EMBL Advanced Training Centre, Germany. INVERTEBRATE NEUROSCIENCE 2012; 13:85-90. [PMID: 23242591 DOI: 10.1007/s10158-012-0146-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 12/04/2012] [Indexed: 10/27/2022]
Abstract
Some of the finest minds in the field of Caenorhabditis elegans neurobiology were brought together from 14 June to 17 June 2012 in the small, quaint and picturesque German city of Heidelberg for the biannual C. elegans neurobiology conference. Held at the EMBL Advanced Training Centre and wonderfully organised by Diah Yulianti, Jean-Louis Bessereau, Gert Jansen and William Schafer, the meeting contained 62 verbal presentations and hundreds of posters that were displayed around the double-helical walkways that looped throughout the conference centre. Presentations on recent advances in microfluidics, cell ablation and targeted gene expression exemplified the strengths of C. elegans as a model organism, with these advances allowing detailed high-throughput analysis and study. Interesting behaviours that were previously poorly characterised were widely discussed, as were the advantages of C. elegans as a model for neurodevelopment and neurodegeneration and the investigation of neuropeptide function. The examples discussed in this meeting report seek to illustrate the breadth and depth of presentations given on these recurring topics.
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Affiliation(s)
- James Kearn
- Centre for Biological Sciences, University of Southampton, Building 85, University Road, Southampton SO17 1BJ, UK.
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Formation and regulation of adaptive response in nematode Caenorhabditis elegans. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:564093. [PMID: 22997543 PMCID: PMC3446806 DOI: 10.1155/2012/564093] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 06/24/2012] [Indexed: 01/11/2023]
Abstract
All organisms respond to environmental stresses (e.g., heavy metal, heat, UV irradiation, hyperoxia, food limitation, etc.) with coordinated adjustments in order to deal with the consequences and/or injuries caused by the severe stress. The nematode Caenorhabditis elegans often exerts adaptive responses if preconditioned with low concentrations of agents or stressor. In C. elegans, three types of adaptive responses can be formed: hormesis, cross-adaptation, and dietary restriction. Several factors influence the formation of adaptive responses in nematodes, and some mechanisms can explain their response formation. In particular, antioxidation system, heat-shock proteins, metallothioneins, glutathione, signaling transduction, and metabolic signals may play important roles in regulating the formation of adaptive responses. In this paper, we summarize the published evidence demonstrating that several types of adaptive responses have converged in C. elegans and discussed some possible alternative theories explaining the adaptive response control.
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Jee C, Lee J, Lim JP, Parry D, Messing RO, McIntire SL. SEB-3, a CRF receptor-like GPCR, regulates locomotor activity states, stress responses and ethanol tolerance in Caenorhabditis elegans. GENES BRAIN AND BEHAVIOR 2012; 12:250-62. [PMID: 22853648 DOI: 10.1111/j.1601-183x.2012.00829.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 02/15/2012] [Accepted: 07/21/2012] [Indexed: 11/27/2022]
Abstract
The CRF (corticotropin-releasing factor) system is a key mediator of the stress response. Alterations in CRF signaling have been implicated in drug craving and ethanol consumption. The development of negative reinforcement via activation of brain stress systems has been proposed as a mechanism that contributes to alcohol dependence. Here, we isolated a gain-of-function allele of seb-3, a CRF receptor-like GPCR in Caenorhabditis elegans, providing an in vivo model of a constitutively activated stress system. We also characterized a loss-of-function allele of seb-3 and showed that SEB-3 positively regulates a stress response that leads to an enhanced active state of locomotion, behavioral arousal and tremor. SEB-3 also contributed to acute tolerance to ethanol and to the development of tremor during ethanol withdrawal. Furthermore, we found that a specific CRF(1) receptor antagonist reduced acute functional tolerance to ethanol in mice. These findings demonstrate functional conservation of the CRF system in responses to stress and ethanol in vertebrates and invertebrates.
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Affiliation(s)
- C Jee
- The Ernest Gallo Clinic and Research Center, Department of Neurology, University of California, San Francisco, Emeryville, CA, USA.
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HSP-4 endoplasmic reticulum (ER) stress pathway is not activated in a C. elegans model of ethanol intoxication and withdrawal. INVERTEBRATE NEUROSCIENCE 2012; 12:93-102. [PMID: 22661239 DOI: 10.1007/s10158-012-0136-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Accepted: 05/19/2012] [Indexed: 02/06/2023]
Abstract
Acute and chronic exposure of Caenorhabditis elegans to concentrations of ethanol in the range 250-350 mM elicits distinct behaviours. Previous genetic analysis highlights specific neurobiological substrates for these effects. However, ethanol may also elicit cellular stress responses which may contribute to the repertoire of ethanol-induced behaviours. Here, we have studied the effect of ethanol on an important arm of the cellular stress pathways, which emanates from the endoplasmic reticulum (ER) in response to several conditions including heat shock and chemical or genetic perturbations that lead to protein misfolding. HSP-4 is a heat shock protein and homologue of mammalian BiP. It is a pivotal upstream component of the ER stress response. Therefore, we used a C. elegans heat shock protein mutant, hsp-4, and a strain carrying a transcriptional reporter, Phsp-4::gfp, to test the role of the ER following chronic ethanol conditioning. We found no evidence for an overt ER response during acute or prolonged exposure to concentrations of ethanol that lead to defined ethanol-induced behaviours. Furthermore, whilst hsp-4 was strongly induced by tunicamycin, pre-exposure of C. elegans to low doses of tunicamycin followed by ethanol was not sufficient to induce an additive ER stress response. Behavioural analysis of an hsp-4 mutant indicated no difference compared to wild type in susceptibility to ethanol intoxication and withdrawal. There is a clear precedent for a significance of ER stress pathways particularly in clinical conditions associated with toxic or pathological effects of high doses of alcohol consumption. The concentrations of ethanol used in this C. elegans study equate to the highest blood alcohol levels measured in patients with chronic alcohol dependency. Taken together, these observations imply that the classic ER stress pathway in C. elegans is relatively refractory to induction by ethanol.
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Musselman HN, Neal-Beliveau B, Nass R, Engleman EA. Chemosensory cue conditioning with stimulants in a Caenorhabditis elegans animal model of addiction. Behav Neurosci 2012; 126:445-56. [PMID: 22642886 PMCID: PMC3367381 DOI: 10.1037/a0028303] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The underlying molecular mechanisms of drug abuse and addiction behaviors are poorly understood. Caenorhabditis elegans (C. elegans) provide a simple, whole animal model with conserved molecular pathways well suited for studying the foundations of complex diseases. Historically, chemotaxis has been a measure used to examine sensory approach and avoidance behavior in worms. Chemotaxis can be modulated by previous experience, and cue-dependent conditioned learning has been demonstrated in C. elegans, but such conditioning with drugs of abuse has not been reported. Here we show that pairing a distinctive salt cue with a drug (cocaine or methamphetamine) results in a concentration-dependent change in preference for the cue that was paired with the drug during conditioning. Further, we demonstrate that pairing of either drug with a distinctive food type can also increase preference for the drug-paired food in the absence of the drug. Dopamine-deficient mutants did not develop drug-paired, cue-conditioned responses. The findings suggest that, like vertebrates, C. elegans display a conditioned preference for environments containing cues previously associated with drugs of abuse, and this response is dependent on dopamine neurotransmission. This model provides a new and powerful method to study the genetic and molecular mechanisms that mediate drug preference.
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Holden-Dye L, Walker RJ. Report on the 12th symposium on invertebrate neurobiology held 31 August-4 September 2011 at the Balaton Limnological Research Institute of the Hungarian Academy of Sciences, Tihany, Hungary. INVERTEBRATE NEUROSCIENCE 2012; 12:69-79. [PMID: 22481213 DOI: 10.1007/s10158-012-0131-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 03/22/2012] [Indexed: 10/28/2022]
Abstract
In August 2011, the 12th international symposium of ISIN was held by Lake Balaton in Tihany, Hungary. This convivial and stimulating meeting provided a forum for discussion of a range of invertebrate organisms in neuroscience research. Here the main topics covered at the meeting are reviewed.
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Affiliation(s)
- Lindy Holden-Dye
- Centre for Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK.
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Alaimo JT, Davis SJ, Song SS, Burnette CR, Grotewiel M, Shelton KL, Pierce-Shimomura JT, Davies AG, Bettinger JC. Ethanol metabolism and osmolarity modify behavioral responses to ethanol in C. elegans. Alcohol Clin Exp Res 2012; 36:1840-50. [PMID: 22486589 DOI: 10.1111/j.1530-0277.2012.01799.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 02/10/2012] [Indexed: 12/29/2022]
Abstract
BACKGROUND Ethanol (EtOH) is metabolized by a 2-step process in which alcohol dehydrogenase (ADH) oxidizes EtOH to acetaldehyde, which is further oxidized to acetate by aldehyde dehydrogenase (ALDH). Although variation in EtOH metabolism in humans strongly influences the propensity to chronically abuse alcohol, few data exist on the behavioral effects of altered EtOH metabolism. Here, we used the nematode Caenorhabditis elegans to directly examine how changes in EtOH metabolism alter behavioral responses to alcohol during an acute exposure. Additionally, we investigated EtOH solution osmolarity as a potential explanation for contrasting published data on C. elegans EtOH sensitivity. METHODS We developed a gas chromatography assay and validated a spectrophotometric method to measure internal EtOH in EtOH-exposed worms. Further, we tested the effects of mutations in ADH and ALDH genes on EtOH tissue accumulation and behavioral sensitivity to the drug. Finally, we tested the effects of EtOH solution osmolarity on behavioral responses and tissue EtOH accumulation. RESULTS Only a small amount of exogenously applied EtOH accumulated in the tissues of C. elegans and consequently their tissue concentrations were similar to those that intoxicate humans. Independent inactivation of an ADH-encoding gene (sodh-1) or an ALDH-encoding gene (alh-6 or alh-13) increased the EtOH concentration in worms and caused hypersensitivity to the acute sedative effects of EtOH on locomotion. We also found that the sensitivity to the depressive effects of EtOH on locomotion is strongly influenced by the osmolarity of the exogenous EtOH solution. CONCLUSIONS Our results indicate that EtOH metabolism via ADH and ALDH has a statistically discernable but surprisingly minor influence on EtOH sedation and internal EtOH accumulation in worms. In contrast, the osmolarity of the medium in which EtOH is delivered to the animals has a more substantial effect on the observed sensitivity to EtOH.
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Affiliation(s)
- Joseph T Alaimo
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298, USA
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39
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Frooninckx L, Van Rompay L, Temmerman L, Van Sinay E, Beets I, Janssen T, Husson SJ, Schoofs L. Neuropeptide GPCRs in C. elegans. Front Endocrinol (Lausanne) 2012; 3:167. [PMID: 23267347 PMCID: PMC3527849 DOI: 10.3389/fendo.2012.00167] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 12/04/2012] [Indexed: 12/19/2022] Open
Abstract
Like most organisms, the nematode Caenorhabditis elegans relies heavily on neuropeptidergic signaling. This tiny animal represents a suitable model system to study neuropeptidergic signaling networks with single cell resolution due to the availability of powerful molecular and genetic tools. The availability of the worm's complete genome sequence allows researchers to browse through it, uncovering putative neuropeptides and their cognate G protein-coupled receptors (GPCRs). Many predictions have been made about the number of C. elegans neuropeptide GPCRs. In this review, we report the state of the art of both verified as well as predicted C. elegans neuropeptide GPCRs. The predicted neuropeptide GPCRs are incorporated into the receptor classification system based on their resemblance to orthologous GPCRs in insects and vertebrates. Appointing the natural ligand(s) to each predicted neuropeptide GPCR (receptor deorphanization) is a crucial step during characterization. The development of deorphanization strategies resulted in a significant increase in the knowledge of neuropeptidergic signaling in C. elegans. Complementary localization and functional studies demonstrate that neuropeptides and their GPCRs represent a rich potential source of behavioral variability in C. elegans. Here, we review all neuropeptidergic signaling pathways that so far have been functionally characterized in C. elegans.
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Affiliation(s)
- Lotte Frooninckx
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Liesbeth Van Rompay
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Liesbet Temmerman
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Elien Van Sinay
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Isabel Beets
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Tom Janssen
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Steven J. Husson
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
| | - Liliane Schoofs
- Laboratory of Functional Genomics and Proteomics, Department of Biology, Katholieke Universiteit LeuvenLeuven, Belgium
- *Correspondence: Liliane Schoofs, Laboratory of Functional Genomics and Proteomics, Zoological Institute, Naamsestraat 59, 3000 Leuven, Belgium. e-mail:
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Wang Y, Tang L, Feng X, Du W, Liu BF. Ethanol interferes with gustatory plasticity in Caenorhabditis elegans. Neurosci Res 2011; 71:341-7. [DOI: 10.1016/j.neures.2011.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 07/25/2011] [Accepted: 08/18/2011] [Indexed: 12/01/2022]
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Yu X, Zhao W, Ma J, Fu X, Zhao ZJ. Beneficial and harmful effects of alcohol exposure on Caenorhabditis elegans worms. Biochem Biophys Res Commun 2011; 412:757-62. [PMID: 21871869 DOI: 10.1016/j.bbrc.2011.08.053] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 08/11/2011] [Indexed: 12/31/2022]
Abstract
Alcoholic beverages are consumed widely throughout the world. While the harmful effects of alcoholism are well recognized, the beneficial effects of moderate alcohol consumption to human health remain debatable. In this study, we investigated the effects of long-term ethanol exposure on nematode Caenorhabditis elegans worms. At high concentrations (≥ 4%), ethanol significantly impaired mobility, reduced fertility, and shortened lifespan. Interestingly, at low concentrations (1-2%), it extended lifespan, accompanied with a slower decline of mobility during aging, although it slightly impaired development, fertility, and chemotaxis. The lifespan-prolonging effects of ethanol at the low concentrations were seen in normal worms exposed to ethanol from egg, young larva, and young adult stages but were not observed in age-1 and sir-2.1 mutant worms. Our study demonstrated hormetic effects of ethanol and further established C. elegans as a suitable animal model to study ethanol related problems.
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Affiliation(s)
- Xiaokun Yu
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
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Mulcahy B, Ient B. Meeting report: 2010 Caenorhabditis elegans Neurobiology Meeting, University of Wisconsin, USA. INVERTEBRATE NEUROSCIENCE 2010; 10:53-61. [PMID: 21069413 DOI: 10.1007/s10158-010-0110-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 10/26/2010] [Indexed: 10/18/2022]
Abstract
Against the backdrop of the scenic Lake Mendota, the C. elegans Neurobiology Meeting came to a head. Expertly organised by Brian Ackley and Bruce Bamber and hosted at the accommodating University of Wisconsin, the meeting brought together recent contributions from many of the major research groups working on the neurobiology of C. elegans. With seven keynote speakers, 57 verbal presentations and hundreds of posters, this exciting event spanned a fascinating 3 days from 27 June to 30 June 2010. In keeping with the tradition of this conference, the event on the whole was spearheaded by young investigators from several research institutions. The meeting served to emphasise the gains enjoyed by taking advantage of the genetic tractability of the worm. A thread that ran through the meeting was the importance of integrating data across different levels of biological organisation to permit delineation of the physiology underpinning discrete behavioural states. Recent advances in optogenetics and microfluidics were at the forefront of refining these analyses. The presentations discussed in this meeting report are a selection which reflects this overarching theme.
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Affiliation(s)
- Ben Mulcahy
- School of Biological Sciences, University of Southampton, Building 85, Highfield Campus, Southampton SO17 1BJ, UK.
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Acute ethanol exposure disrupts actin cytoskeleton and generates reactive oxygen species in c6 cells. Toxicol In Vitro 2010; 25:28-36. [PMID: 20837132 DOI: 10.1016/j.tiv.2010.09.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 09/02/2010] [Accepted: 09/07/2010] [Indexed: 02/02/2023]
Abstract
Central nervous system dysfunctions are among the most significant effects of exposure to ethanol and the glial cells that play an important role in maintaining neuronal function, are extremely involved with these effects. The actin cytoskeleton plays a crucial role in a wide variety of cellular functions, especially when there is some injury. Therefore the aim of the present study was to analyze the short-term effects of ethanol (50, 100 and 200 mM) on the cytoskeleton of C6 glioma cells. Here we report that acute ethanol exposure profoundly disrupts the actin cytoskeleton in C6 cells decreasing stress fiber formation and downregulating RhoA and vinculin immunocontent. In contrast, microtubule and GFAP networks were not altered. We further demonstrate that anti-oxidants prevent ethanol-induced actin alterations, suggesting that the actions of ethanol on the actin cytoskeleton are related with generation of reactive oxygen species (ROS) in these cells. Our results show that ethanol at concentrations described to be toxic to the central nervous system was able to target the cytoskeleton of C6 cells and this effect could be related with increased ROS generation. Therefore, we propose that the dynamic restructuring of the cytoskeleton of glial cells might contribute to the response to the injury provoked by binge-like ethanol exposure in brain.
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