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Gaur AV, Agarwal R. Risperidone induced alterations in feeding and locomotion behavior of Caenorhabditis elegans. Curr Res Toxicol 2021; 2:367-374. [PMID: 34806037 PMCID: PMC8585583 DOI: 10.1016/j.crtox.2021.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/14/2021] [Accepted: 10/14/2021] [Indexed: 11/19/2022] Open
Abstract
Antipsychotic drugs (APDs) are prescribed for the treatment of psychiatric illness. However, these drugs can also contribute to several developmental and behavioral disorders. Contemporary studies to evaluate the toxic effects of numerous atypical antipsychotics are reported to cause behavioral alteration at variable doses in mammals and nematodes. Risperidone, the second most prescribed drug in India, requires more exploration of its adverse effects on humans. Here, we explore effects on feeding behavior and locomotion patterns due to risperidone exposure in C. elegans model. The study targets to work out the toxic effects of risperidone exposure on feeding and locomotion behavior in addition to the expected pharmacological effects. N2 wild type strain was exposed in liquid culture assay for 2, 4, 6, 8, 10, and 12 hours with fixed 50 µM concentration. Feeding behavior was depleted due to inhibition in pharyngeal pumping varying from 11.05% - 45.67% in a time-dependent manner. Results of locomotion assay also show time-varying increase in reversals (4.9%-34.03%) and omega bends (26.23%-62.17%) with reduction in turn counts (29.07%- 42.2%) and peristaltic speed (31.38%-42.22%) amongst exposed groups as to control. The present work shows behavioral alterations due to risperidone exposure (50 µM) in C. elegans is in a time-dependent manner. The study concludes that risperidone exposure in C. elegans produces toxic effects with time, possibly caused by antagonizing other receptors apart from serotonin (5-H2T) and dopamine (D2) adding to its expected pharmacological effects.
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Key Words
- 5-H2T
- 5-HT, 5-hydroxytryptamine
- ADF, Amphid Neuron
- APDs, Antipsychotic drugs
- Antipsychotic drugs
- Behavioral alteration
- C, Control Group
- C-0h, Control Group at 0 h
- C-10h, Control Group at 10 h
- C-12h, Control Group at 12 h. E-2h, Exposure Group at 2 h
- C-2h, Control Group at 2 h
- C-4h, Control Group at 4 h
- C-6h, Control Group at 6 h
- C-8h, Control Group at 8 h
- C. elegans
- C. elegans, Caenorhabditis elegans
- D2
- D2, Dopamine Receptor 2
- E, Exposed Group
- E-10h, Exposure Group at ten
- E-12h, Exposure Group at 12 h
- E-4h, Exposure Group at 4 h
- E-6h, Exposure Group at 6 h
- E-8h, Exposure Group at 8 h
- E. coli, Escherichia coli BOD-Biochemical Oxygen Demand
- GPR, G coupled Protein Receptor
- HSN, Hermaphrodite Specific Neuron
- Min., Minutes
- N2 Wild type
- NSM, Neurosecretory Motor Neuron
- Peristaltic speed
- Pharyngeal pumping
- Reversals
- Risperidone
- SD, Standard Deviation
- SDA, Serotonin Dopamine Antagonist
- Turn counts
- omega bends
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Affiliation(s)
- Aaditya Vikram Gaur
- Laboratory of Analytical & Molecular Toxicology (Forensic Chemistry & Toxicology Laboratory), School of Forensic Science, National Forensic Sciences University, Sector 09, Gandhinagar 382007, Gujarat, India
- Forensic Science Laboratory, Kirumampakkam, Puducherry 607402, India
| | - Rakhi Agarwal
- Laboratory of Analytical & Molecular Toxicology (Forensic Chemistry & Toxicology Laboratory), School of Forensic Science, National Forensic Sciences University, Sector 09, Gandhinagar 382007, Gujarat, India
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Izuogu NB, Bello OE, Bello OM. A review on Borreria verticillata: A potential bionematicide, channeling its significant antimicrobial activity against root-knot nematodes. Heliyon 2020; 6:e05322. [PMID: 33134589 PMCID: PMC7586115 DOI: 10.1016/j.heliyon.2020.e05322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/26/2020] [Accepted: 10/19/2020] [Indexed: 11/24/2022] Open
Abstract
Phytopesticides are human-friendly beside been easily accessible and bio-degradable, are therefore environmentally friendly compared to the synthetic pesticides which huge adverse effects on human, animals and the ecosystem. Plants are large reservoir of secondary metabolites largely untapped or under-tapped for use as pesticides. One problem associated with this is to identify plants which can be assessed and further exploited for this use. Borreria verticillata belongs to Rubiaceae, it is native to South Americas but gained popularity globally. It is known as a weed, showing resistance to many synthetic pesticides and can be grown on a wide range of soil types. B. verticillata is used traditionally against skin diseases such as eczema, infectious dermatitis and scabies. Its antimicrobial application is large and efficient as revealed by most authors. This article inclines to propose and offer current studies with information on the various application of this plant species against various microorganisms, thereby extending its use against plant parasitic nematodes which cause severe yield losses to numerous agricultural crops. Most search engines, journals and dissertation search engines i.e. Google scholar, pubmed, sciencedirect, scopus, web of science, springer, elsevier, like Open-thesis, OATD, ProQuest and EthOs were queried by employing titles such as B. verticillata, Borreria verticillata and biological activity of B. verticillata. The most synonymous name was queried too i.e. Spermacoce verticillata. This review suggests a main point about this resistant weed i.e. its significant antimicrobial activity. It further emphases the need exploits this useful effect against nematodes since they are microorganisms. Phytochemistry of the B. verticillata was gathered in this study and the compounds isolated from the plant i.e. terpenes, iridoids, flavonoids and alkaloids (29 compounds) further provide a basis for a significant antihelmintic effect. The review concludes on the need to extends its antimicrobial activity to sustainable agriculture. Since it is a very common plant in Nigeria, it is easily accessible to farmer protect their cultivations from plant-parasitic nematode attacks.
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Affiliation(s)
- Nkechi B. Izuogu
- Department of Crop Protection, University of Ilorin, Ilorin, Kwara State, Nigeria
| | - Oluwatoyin E. Bello
- Department of Crop Protection, University of Ilorin, Ilorin, Kwara State, Nigeria
| | - Oluwasesan M. Bello
- Department of Applied Chemistry, Federal University Dutsin-Ma, Dutsin-Ma, Katsina State, Nigeria
- Corresponding author.
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3
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Investigation of feeding behaviour in C. elegans reveals distinct pharmacological and antibacterial effects of nicotine. INVERTEBRATE NEUROSCIENCE 2018; 18:14. [DOI: 10.1007/s10158-018-0219-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 10/24/2018] [Indexed: 12/31/2022]
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Engleman EA, Steagall KB, Bredhold KE, Breach M, Kline HL, Bell RL, Katner SN, Neal-Beliveau BS. Caenorhabditis elegans Show Preference for Stimulants and Potential as a Model Organism for Medications Screening. Front Physiol 2018; 9:1200. [PMID: 30214414 PMCID: PMC6125605 DOI: 10.3389/fphys.2018.01200] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 08/10/2018] [Indexed: 12/20/2022] Open
Abstract
The nematode Caenorhabditis elegans (C. elegans) is a popular invertebrate model organism to study neurobiological disease states. This is due in part to the intricate mapping of all neurons and synapses of the entire animal, the wide availability of mutant strains, and the genetic and molecular tools that can be used to manipulate the genome and gene expression. We have shown that, C. elegans develops a conditioned preference for cues that had previously been paired with either cocaine or methamphetamine exposure that is dependent on dopamine neurotransmission, similar to findings using place conditioning with rats and mice. In the current study, we show C. elegans also display a preference for, and self-exposure to, cocaine and nicotine. This substance of abuse (SOA) preference response can be selectively blocked by pretreatment with naltrexone and is consistent with the recent discovery of an opioid receptor system in C. elegans. In addition, pre-exposure to the smoking cessation treatment varenicline also inhibits self-exposure to nicotine. Exposure to concentrations of treatments that inhibit SOA preference/self-exposure did not induce any significant inhibition of locomotor activity or affect food or benzaldehyde chemotaxis. These data provide predictive validity for the development of high-throughput C. elegans behavioral medication screens. These screens could enable fast and accurate generation of data to identify compounds that may be effective in treating human addiction. The successful development and validation of such models would introduce powerful and novel tools in the search for new pharmacological treatments for substance use disorders, and provide a platform to study the mechanisms that underlie addictions.
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Affiliation(s)
- Eric A Engleman
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Kevin B Steagall
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Kristin E Bredhold
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Michaela Breach
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Hannah L Kline
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Richard L Bell
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Simon N Katner
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Bethany S Neal-Beliveau
- Department of Psychology, School of Science, Indiana University-Purdue University Indianapolis, Indianapolis, IN, United States
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Sobkowiak R, Bojarska N, Krzyżaniak E, Wągiel K, Ntalli N. Chemoreception of botanical nematicides by Meloidogyne incognita and Caenorhabditis elegans. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2018; 53:493-502. [PMID: 29708833 DOI: 10.1080/03601234.2018.1462936] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Plant-parasitic nematodes, such as Meloidogyne incognita, cause serious damage to various agricultural crops worldwide, and their control necessitates environmentally safe measures. We have studied the effects of plant secondary metabolites on M. incognita locomotion, as it is an important factor affecting host inoculation inside the soil. We compared the effects to the respective behavioral responses of the model saprophytic nematode Caenorhabditis elegans. The tested botanical nematicides, all reported to be active against Meloidogyne sp. in our previous works, are small molecular weight molecules (acids, alcohols, aldehydes, and ketones). Here, we specifically report on the attractant or repellent properties of trans-anethole, (E,E)-2,4-decadienal, (E)-2-decenal, fosthiazate, and 2-undecanone. The treatments for both nematode species were made at sublethal concentration levels, namely, 1 mM (<EC50), and the chemical controls used for the experiments were the commercial nematicides fosthiazate and oxamyl. According to our results, trans-anethole, decenal, and oxamyl attract C. elegans, while 2-undecanone strongly attracts M. incognita. These findings can be of use in the development of nematicidal formulations, contributing to the disruption of nematode chemotaxis to root systems.
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Affiliation(s)
- Robert Sobkowiak
- a Department of Cell Biology , Faculty of Biology, Institute of Experimental Biology, Adam Mickiewicz University , Poznań , Poland
| | - Natalia Bojarska
- a Department of Cell Biology , Faculty of Biology, Institute of Experimental Biology, Adam Mickiewicz University , Poznań , Poland
| | - Emilia Krzyżaniak
- a Department of Cell Biology , Faculty of Biology, Institute of Experimental Biology, Adam Mickiewicz University , Poznań , Poland
| | - Karolina Wągiel
- a Department of Cell Biology , Faculty of Biology, Institute of Experimental Biology, Adam Mickiewicz University , Poznań , Poland
| | - Nikoletta Ntalli
- b Department of Pesticides Control & Phytopharmacy , Benaki Phytopathological Institute, Laboratory of Biological Control of Pesticides , Kifissia , Athens , Greece
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Rauthan M, Gong J, Liu J, Li Z, Wescott SA, Liu J, Xu XZS. MicroRNA Regulation of nAChR Expression and Nicotine-Dependent Behavior in C. elegans. Cell Rep 2018; 21:1434-1441. [PMID: 29117550 DOI: 10.1016/j.celrep.2017.10.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 05/14/2017] [Accepted: 10/11/2017] [Indexed: 10/18/2022] Open
Abstract
Chronic exposure to nicotine upregulates nicotinic acetylcholine receptors (nAChRs), and such upregulation is critical for the development of nicotine dependence in humans and animal models. However, how nicotine upregulates nAChRs is not well understood. Here, we identify a key role for microRNA in regulating nicotine-dependent behavior by modulating nAChR expression in C. elegans. We show that the nAChR gene acr-19 and alg-1, a key Argonaute-family member in the microRNA machinery, are specifically required for nicotine withdrawal response following chronic nicotine treatment. Chronic exposure to nicotine downregulates alg-1, leading to upregulation of acr-19. This effect is mediated by the microRNA miR-238 that recognizes the 3' UTR of acr-19 transcript. Our results unveil a previously unrecognized role for microRNA in nicotine signaling, providing insights into how chronic nicotine administration leads to upregulation of nAChR and ultimately nicotine dependence.
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Affiliation(s)
- Manish Rauthan
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jianke Gong
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jinzhi Liu
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Zhaoyu Li
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Seth A Wescott
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jianfeng Liu
- College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - X Z Shawn Xu
- Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI 48109, USA.
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7
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Sobkowiak R, Kaczmarek P, Kowalski M, Kabaciński R, Lesicki A. Behavior of Caenorhabditis elegans in a nicotine gradient modulated by food. Drug Chem Toxicol 2017; 42:451-462. [DOI: 10.1080/01480545.2017.1405971] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Robert Sobkowiak
- Department of Cell Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
| | - Piotr Kaczmarek
- Faculty of Electrical Engineering, Institute of Control and Information Engineering, Poznan University of Technology, Poznań, Poland
| | - Mateusz Kowalski
- Faculty of Electrical Engineering, Institute of Control and Information Engineering, Poznan University of Technology, Poznań, Poland
| | - Rafał Kabaciński
- Faculty of Electrical Engineering, Institute of Control and Information Engineering, Poznan University of Technology, Poznań, Poland
| | - Andrzej Lesicki
- Department of Cell Biology, Faculty of Biology, Adam Mickiewicz University, Poznań, Poland
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8
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Urushihata T, Wakabayashi T, Osato S, Yamashita T, Matsuura T. Short-term nicotine exposure induces long-lasting modulation of gustatory plasticity in Caenorhabditis elegans. Biochem Biophys Rep 2017; 8:41-47. [PMID: 28955940 PMCID: PMC5613740 DOI: 10.1016/j.bbrep.2016.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 06/23/2016] [Accepted: 08/02/2016] [Indexed: 02/04/2023] Open
Abstract
Nicotine administration induces many effects on animal behavior. In wild-type Caenorhabditis elegans, gustatory plasticity results in reduced chemotaxis toward NaCl of otherwise attractive concentrations after pre-exposure to 100 mM NaCl in the absence of food. However, acute nicotine administration during a 15 min pre-exposure period inhibits gustatory plasticity, whereas chronic nicotine administration during worm development facilitates the plasticity. To investigate the relationship between the duration of nicotine administration and its effects, we exposed worms to nicotine for various periods during development. The modulatory effect of nicotine on gustatory plasticity was gradually switched from inhibition to facilitation with increased duration of nicotine administration. Moreover, inhibition of plasticity was sustained after relatively short-term chronic administration, with effects lasting for 45 h after the removal of nicotine. Similar to the acute inhibitory effect after 15 min nicotine pre-exposure, the inhibitory effect after short-term chronic administration was dependent on the nicotinic acetylcholine receptor subunit genes lev-1 and unc-29, and genes involved in serotonin biosynthesis bas-1 and tph-1. The impaired inhibition in bas-1 and tph-1mutants was recovered by exogenous serotonin, demonstrating that serotonin plays an important role in the long-lasting inhibitory effects of short-term chronic nicotine exposure. We analyzed gustatory plasticity of C. elegans after nicotine administration. Nicotine modulates gustatory plasticity in various ways. Nicotine inhibits gustatory plasticity after short-term chronic administration. The inhibitory effect was long-lasting even after removal of nicotine.
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Affiliation(s)
- Takuya Urushihata
- Department of Applied Chemistry and Biosciences, Faculty of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551, Japan.,Division of Bioprocess Engineering, United Graduate School of Agricultural Science, Iwate University, Morioka, Japan
| | - Tokumitsu Wakabayashi
- Department of Applied Chemistry and Biosciences, Faculty of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551, Japan.,Division of Bioprocess Engineering, United Graduate School of Agricultural Science, Iwate University, Morioka, Japan
| | - Shoichi Osato
- Department of Applied Chemistry and Biosciences, Faculty of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551, Japan
| | - Tetsuro Yamashita
- Division of Bioprocess Engineering, United Graduate School of Agricultural Science, Iwate University, Morioka, Japan
| | - Tetsuya Matsuura
- Department of Applied Chemistry and Biosciences, Faculty of Engineering, Iwate University, 4-3-5 Ueda, Morioka 020-8551, Japan.,Division of Bioprocess Engineering, United Graduate School of Agricultural Science, Iwate University, Morioka, Japan
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Kudelska MM, Holden-Dye L, O'Connor V, Doyle DA. Concentration-dependent effects of acute and chronic neonicotinoid exposure on the behaviour and development of the nematode Caenorhabditis elegans. PEST MANAGEMENT SCIENCE 2017; 73:1345-1351. [PMID: 28261957 DOI: 10.1002/ps.4564] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/13/2017] [Accepted: 02/27/2017] [Indexed: 06/06/2023]
Abstract
BACKGROUND Neonicotinoid insecticides are under review owing to emerging toxicity to non-target species. Interest has focused on biological pollinators while their effects on other organisms that are key contributors to the ecosystem remain largely unknown. To advance this, we have tested the effects of representatives of three major classes of neonicotinoids, thiacloprid, clothianidin and nitenpyram, on the free-living nematode Caenorhabditis elegans (C. elegans), as a representative of the Nematoda, an ecologically important phylum contributing to biomass. RESULTS Concentrations that are several-fold higher than those with effects against target species had limited impact on locomotor function. However, increased potency was observed in a mutant with a hyperpermeable cuticle, which shows that drug access limits the effects of the neonicotinoids in C. elegans. Thiacloprid was most potent (EC50 714 μm). In addition, it selectively delayed larval development in wild-type worms at 1 mm. CONCLUSION C. elegans is less susceptible to neonicotinoids than target species of pest insect. We discuss an approach in which this defined low sensitivity may be exploited by heterologous expression of insect nicotinic acetylcholine receptors from both pest and beneficial insects in transgenic C. elegans with increased cuticle permeability to provide a whole organism assay for species-dependent neonicotinoid effects. © 2017 Society of Chemical Industry.
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Affiliation(s)
| | | | | | - Declan A Doyle
- Biological Sciences, University of Southampton, Southampton, UK
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Sobkowiak R, Zielezinski A, Karlowski WM, Lesicki A. Nicotine affects protein complex rearrangement in Caenorhabditis elegans cells. Drug Chem Toxicol 2017; 40:470-483. [PMID: 28049353 DOI: 10.1080/01480545.2016.1264411] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Nicotine may affect cell function by rearranging protein complexes. We aimed to determine nicotine-induced alterations of protein complexes in Caenorhabditis elegans (C. elegans) cells, thereby revealing links between nicotine exposure and protein complex modulation. We compared the proteomic alterations induced by low and high nicotine concentrations (0.01 mM and 1 mM) with the control (no nicotine) in vivo by using mass spectrometry (MS)-based techniques, specifically the cetyltrimethylammonium bromide (CTAB) discontinuous gel electrophoresis coupled with liquid chromatography (LC)-MS/MS and spectral counting. As a result, we identified dozens of C. elegans proteins that are present exclusively or in higher abundance in either nicotine-treated or untreated worms. Based on these results, we report a possible network that captures the key protein components of nicotine-induced protein complexes and speculate how the different protein modules relate to their distinct physiological roles. Using functional annotation of detected proteins, we hypothesize that the identified complexes can modulate the energy metabolism and level of oxidative stress. These proteins can also be involved in modulation of gene expression and may be crucial in Alzheimer's disease. The findings reported in our study reveal putative intracellular interactions of many proteins with the cytoskeleton and may contribute to the understanding of the mechanisms of nicotinic acetylcholine receptor (nAChR) signaling and trafficking in cells.
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Affiliation(s)
- Robert Sobkowiak
- a Department of Cell Biology , Adam Mickiewicz University , Poznań , Poland and
| | - Andrzej Zielezinski
- b Department of Computational Biology , Faculty of Biology, Adam Mickiewicz University , Poznań , Poland
| | - Wojciech M Karlowski
- b Department of Computational Biology , Faculty of Biology, Adam Mickiewicz University , Poznań , Poland
| | - Andrzej Lesicki
- a Department of Cell Biology , Adam Mickiewicz University , Poznań , Poland and
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Insulin signaling genes modulate nicotine-induced behavioral responses in Caenorhabditis elegans. Behav Pharmacol 2016; 27:44-9. [PMID: 26317299 DOI: 10.1097/fbp.0000000000000186] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Insulin signaling has been suggested to modulate nicotine dependence, but the underlying genetic evidence has been lacking. Here, we used the nematode, Caenorhabditis elegans, to investigate whether genetic alterations in the insulin signaling pathway affect behavioral responses to nicotine. For this, we challenged drug-naive C. elegans with an acute dose of nicotine (100 μmol/l) while recording changes in their locomotion speed. Although nicotine treatment stimulated locomotion speed in wild-type C. elegans, the same treatment reduced locomotion speed in mutants defective in insulin signaling. This phenotype could be suppressed by mutations in daf-16, a gene encoding a FOXO transcription factor that acts downstream of insulin signaling. Our data suggest that insulin signaling genes, daf-2, age-1, pdk-1, akt-1, and akt-2, modulate behavioral responses to nicotine in C. elegans, indicating a genetic link between nicotine behavior and insulin signaling.
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12
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Doh JH, Moore AB, Çelen İ, Moore MT, Sabanayagam CR. ChIP and Chips: Introducing the WormPharm for correlative studies employing pharmacology and genome-wide analyses in C. elegans. J Biol Methods 2016; 3:e44. [PMID: 31453211 PMCID: PMC6706132 DOI: 10.14440/jbm.2016.109] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/25/2016] [Accepted: 04/29/2016] [Indexed: 12/21/2022] Open
Abstract
We present the WormPharm, an automated microfluidic platform that utilizes an axenic medium to culture C. elegans. The WormPharm is capable of sustaining C. elegans for extended periods, while recording worm development and growth with high temporal resolution ranging from seconds to minutes over several days to months. We demonstrate the utility of the device to monitor C. elegans growth in the presence of varying doses of nicotine and alcohol. Furthermore, we show that C. elegans cultured in the WormPharm are amendable for high-throughput genomic assays, i.e. chromatin-immunoprecipitation followed by next generation sequencing, and confirm that nematodes grown in monoxenic and axenic cultures exhibit genetic modifications that correlate with observed phenotypes. The WormPharm is a powerful tool for analyzing the effects of chemical, nutritional and environmental variations on organism level responses in conjunction with genome-wide changes in C. elegans.
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Affiliation(s)
- Jung H Doh
- University of Delaware, Delaware Biotechnology Institute, Newark, DE, USA
| | - Andrew B Moore
- University of Delaware, Department of Biological Sciences, Newark, DE, USA
| | - İrem Çelen
- University of Delaware, Center for Bioinformatics and Computational Biology, Newark, DE, USA
| | - Michael T Moore
- University of Delaware, Delaware Biotechnology Institute, Newark, DE, USA
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Tejeda-Benitez L, Olivero-Verbel J. Caenorhabditis elegans, a Biological Model for Research in Toxicology. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2016; 237:1-35. [PMID: 26613986 DOI: 10.1007/978-3-319-23573-8_1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Caenorhabditis elegans is a nematode of microscopic size which, due to its biological characteristics, has been used since the 1970s as a model for research in molecular biology, medicine, pharmacology, and toxicology. It was the first animal whose genome was completely sequenced and has played a key role in the understanding of apoptosis and RNA interference. The transparency of its body, short lifespan, ability to self-fertilize and ease of culture are advantages that make it ideal as a model in toxicology. Due to the fact that some of its biochemical pathways are similar to those of humans, it has been employed in research in several fields. C. elegans' use as a biological model in environmental toxicological assessments allows the determination of multiple endpoints. Some of these utilize the effects on the biological functions of the nematode and others use molecular markers. Endpoints such as lethality, growth, reproduction, and locomotion are the most studied, and usually employ the wild type Bristol N2 strain. Other endpoints use reporter genes, such as green fluorescence protein, driven by regulatory sequences from other genes related to different mechanisms of toxicity, such as heat shock, oxidative stress, CYP system, and metallothioneins among others, allowing the study of gene expression in a manner both rapid and easy. These transgenic strains of C. elegans represent a powerful tool to assess toxicity pathways for mixtures and environmental samples, and their numbers are growing in diversity and selectivity. However, other molecular biology techniques, including DNA microarrays and MicroRNAs have been explored to assess the effects of different toxicants and samples. C. elegans has allowed the assessment of neurotoxic effects for heavy metals and pesticides, among those more frequently studied, as the nematode has a very well defined nervous system. More recently, nanoparticles are emergent pollutants whose toxicity can be explored using this nematode. Overall, almost every type of known toxicant has been tested with this animal model. In the near future, the available knowledge on the life cycle of C. elegans should allow more studies on reproduction and transgenerational toxicity for newly developed chemicals and materials, facilitating their introduction in the market. The great diversity of endpoints and possibilities of this animal makes it an easy first-choice for rapid toxicity screening or to detail signaling pathways involved in mechanisms of toxicity.
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Affiliation(s)
- Lesly Tejeda-Benitez
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, Zaragocilla Campus, University of Cartagena, Cartagena, 130014, Colombia.
| | - Jesus Olivero-Verbel
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, Zaragocilla Campus, University of Cartagena, Cartagena, 130014, Colombia.
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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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Matsuura T, Urushihata T. Chronic nicotine exposure augments gustatory plasticity in Caenorhabditis elegans: involvement of dopamine signaling. Biosci Biotechnol Biochem 2015; 79:462-9. [DOI: 10.1080/09168451.2014.980220] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Abstract
The chemotaxis of wild-type NaCl-conditioned nematodes exposed to 100 mM NaCl, maintained on a growth medium containing 0.3 mM nicotine from first larva to young adult (YA) hermaphrodite, was significantly weaker than the chemotaxis of those maintained on a medium without nicotine. The result indicates that chronic nicotine exposure augments gustatory plasticity. The gustatory plasticity was also augmented when tph-1 mutants, with a defect in serotonin biosynthesis, were maintained on a medium containing nicotine until the YA stage. Chronic nicotine exposure did not augment gustatory plasticity in bas-1 mutants, which had defects in both serotonin and dopamine biosynthesis, and in cat-2 mutants, which had a defect in dopamine biosynthesis. However, augmentation of gustatory plasticity was observed when bas-1 and cat-2 mutants were maintained on a growth medium containing nicotine along with dopamine, suggesting that dopamine signaling is involved in the augmentation of gustatory plasticity due to chronic nicotine exposure.
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Affiliation(s)
- Tetsuya Matsuura
- Laboratory of Behavioral Physiology, Faculty of Engineering, Iwate University, Morioka, Japan
| | - Takuya Urushihata
- Laboratory of Behavioral Physiology, Faculty of Engineering, Iwate University, Morioka, Japan
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Drug-dependent behaviors and nicotinic acetylcholine receptor expressions in Caenorhabditis elegans following chronic nicotine exposure. Neurotoxicology 2014; 47:27-36. [PMID: 25530353 DOI: 10.1016/j.neuro.2014.12.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 12/09/2014] [Accepted: 12/11/2014] [Indexed: 12/18/2022]
Abstract
Nicotine, the major psychoactive compound in tobacco, targets nicotinic acetylcholine receptors (nAChRs) and results in drug dependence. The nematode Caenorhabditis elegans' (C. elegans) genome encodes conserved and extensive nicotinic receptor subunits, representing a useful system to investigate nicotine-induced nAChR expressions in the context of drug dependence. However, the in vivo expression pattern of nAChR genes under chronic nicotine exposure has not been fully investigated. To define the role of nAChR genes involved in nicotine-induced locomotion changes and the development of tolerance to these effects, we characterized the locomotion behavior combining the use of two systems: the Worm Tracker hardware and the WormLab software. Our results indicate that the combined system is an advantageous alternative to define drug-dependent locomotion behavior in C. elegans. Chronic (24-h dosing) nicotine exposure at 6.17 and 61.7μM induced nicotine-dependent behaviors, including drug stimulation, tolerance/adaption, and withdrawal responses. Specifically, the movement speed of naïve worms on nicotine-containing environments was significantly higher than on nicotine-free environments, suggesting locomotion stimulation by nicotine. In contrast, the 24-h 6.17μM nicotine-treated worms exhibited significantly higher speeds on nicotine-free plates than on nicotine-containing plates. Furthermore significantly increased locomotion behavior during nicotine cessation was observed in worms treated with a higher nicotine concentration of 61.7μM. The relatively low locomotion speed of nicotine-treated worms on nicotine-containing environments also indicates adaption/tolerance of worms to nicotine following chronic nicotine exposure. In addition, this study provides useful information regarding the comprehensive in vivo expression profile of the 28 "core" nAChRs following different dosages of chronic nicotine treatments. Eleven genes (lev-1, acr-6, acr-7, acr-11, lev-8, acr-14, acr-16, acr-20, acr-21, ric-3, and unc-29) were significantly up-regulated following 61.7μM nicotine treatment, in which worms showed significantly increased locomotion behavior. This study provides insights into the linkage between nicotine-induced locomotion behavior and the regulation of nicotinic acetylcholine receptors.
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Taki FA, Pan X, Lee MH, Zhang B. Nicotine exposure and transgenerational impact: a prospective study on small regulatory microRNAs. Sci Rep 2014; 4:7513. [PMID: 25515333 PMCID: PMC4894410 DOI: 10.1038/srep07513] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 11/24/2014] [Indexed: 12/22/2022] Open
Abstract
Early developmental stages are highly sensitive to stress and it has been reported that pre-conditioning with tobacco smoking during adolescence predisposes those youngsters to become smokers as adults. However, the molecular mechanisms of nicotine-induced transgenerational consequences are unknown. In this study, we genome-widely investigated the impact of nicotine exposure on small regulatory microRNAs (miRNAs) and its implication on health disorders at a transgenerational aspect. Our results demonstrate that nicotine exposure, even at the low dose, affected the global expression profiles of miRNAs not only in the treated worms (F0 parent generation) but also in two subsequent generations (F1 and F2, children and grandchildren). Some miRNAs were commonly affected by nicotine across two or more generations while others were specific to one. The general miRNA patterns followed a “two-hit” model as a function of nicotine exposure and abstinence. Target prediction and pathway enrichment analyses showed daf-4, daf-1, fos-1, cmk-1, and unc-30 to be potential effectors of nicotine addiction. These genes are involved in physiological states and phenotypes that paralleled previously published nicotine induced behavior. Our study offered new insights and further awareness on the transgenerational effects of nicotine exposed during the vulnerable post-embryonic stages, and identified new biomarkers for nicotine addiction.
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Affiliation(s)
- Faten A Taki
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Xiaoping Pan
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Myon-Hee Lee
- Department of Medicine, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| | - Baohong Zhang
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
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Taki FA, Pan X, Zhang B. Chronic nicotine exposure systemically alters microRNA expression profiles during post-embryonic stages in Caenorhabditis elegans. J Cell Physiol 2014; 229:79-89. [PMID: 23765240 PMCID: PMC3925673 DOI: 10.1002/jcp.24419] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 06/06/2013] [Indexed: 01/04/2023]
Abstract
Tobacco smoking is associated with many diseases. Addiction is of the most notorious tobacco-related syndrome and is mainly attributed to nicotine. In this study, we employed Caenorhabditis elegans as a biological model to systemically investigate the effect of chronic nicotine exposure on microRNA (miRNA) expression profile and their regulated biochemical pathways. Nicotine treatment (20 µM and 20 mM) was limited to the post-embryonic stage from L1 to L4 (∼31 h) period after which worms were collected for genome-wide miRNA profiling. Our results show that nicotine significantly altered the expression patterns of 40 miRNAs. The effect was proportional to the nicotine dose and was expected to have an additive, more robust response. Based on pathway enrichment analyses coupled with nicotine-induced miRNA patterns, we inferred that miRNAs as a system mediates "regulatory hormesis", manifested in biphasic behavioral and physiological phenotypes. We proposed a model where nicotine addiction is mediated by miRNAs' regulation of fos-1 and is maintained by epigenetic factors. Thus, our study offers new insights for a better understanding of the sensitivity of early developmental stages to nicotine.
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Affiliation(s)
- Faten A Taki
- Department of Biology, East Carolina University, Greenville, NC 27858
| | - Xiaoping Pan
- Department of Biology, East Carolina University, Greenville, NC 27858
| | - Baohong Zhang
- Department of Biology, East Carolina University, Greenville, NC 27858
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Matsuura T, Miura H, Nishino A. Inhibition of gustatory plasticity due to acute nicotine exposure in the nematode Caenorhabditis elegans. Neurosci Res 2013; 77:155-61. [DOI: 10.1016/j.neures.2013.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 08/30/2013] [Accepted: 09/02/2013] [Indexed: 10/26/2022]
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Wen Y, Meyer SLF, Masler EP, Zhang F, Liao J, Wei X, Chitwood DJ. Nematotoxicity of drupacine and a Cephalotaxus alkaloid preparation against the plant-parasitic nematodes Meloidogyne incognita and Bursaphelenchus xylophilus. PEST MANAGEMENT SCIENCE 2013; 69:1026-1033. [PMID: 23785026 DOI: 10.1002/ps.3548] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 03/14/2013] [Accepted: 04/05/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND Species of Cephalotaxus (the plum yews) produce nematotoxic compounds of unknown identity. Consequently, bioassay-guided fractionation was employed to identify the compound(s) in Cephalotaxus fortunei twigs and leaves with activity against plant-parasitic nematodes. RESULTS A crude alkaloid extract, particularly drupacine, was responsible for much of the nematotoxicity. The ED50 of drupacine for Bursaphelenchus xylophilus was 27.1 µg mL⁻¹, and for Meloidogyne incognita it was 76.3 µg mL⁻¹. Immersion of M. incognita eggs in 1.0 mg mL⁻¹ crude alkaloid extract (the highest tested concentration) reduced hatch by 36%; immersion of second-stage juveniles (J2) resulted in 72-98% immobility. Crude alkaloid extract and drupacine suppressed protease activity in extracts of the microbivorous nematode Panagrellus redivivus by 50% and 80%, respectively. Application of 0.02-0.5 mg mL⁻¹ crude alkaloid extract to soil with M. incognita inoculum did not significantly reduce pepper plant shoot length or weight, compared with nematode-inoculated, water-treated controls, but the number of eggs and J2 per root system respectively decreased by 69% and 73% at 0.5 mg mL⁻¹. CONCLUSION Drupacine and a crude alkaloid extract suppress nematode hatch, activity of mixed life stages, and population numbers on plant roots. This is the first demonstration of nematotoxicity of crude Cephalotaxus alkaloids and drupacine.
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Affiliation(s)
- Yanhua Wen
- College of Natural Resources and Environment, South China Agricultural University, Tianhe District, Guangzhou City 510642, Guangdong Province, China
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Smith MA, Zhang Y, Polli JR, Wu H, Zhang B, Xiao P, Farwell MA, Pan X. Impacts of chronic low-level nicotine exposure on Caenorhabditis elegans reproduction: identification of novel gene targets. Reprod Toxicol 2013; 40:69-75. [PMID: 23735997 DOI: 10.1016/j.reprotox.2013.05.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 04/25/2013] [Accepted: 05/24/2013] [Indexed: 12/17/2022]
Abstract
Effects and mechanisms of chronic exposure to low levels of nicotine is an area fundamentally important however less investigated. We employed the model organism Caenorhabditis elegans to investigate potential impacts of chronic (24h) and low nicotine exposure (6.17-194.5 μM) on stimulus-response, reproduction, and gene expressions. Nicotine significantly affects the organism's response to touch stimulus (p=0.031), which follows a dose-dependent pattern. Chronic nicotine exposure promotes early egg-laying events and slightly increased egg productions during the first 72 h of adulthood. The expressions of 10 (egl-10, egl-44, hlh-14, ric-3, unc-103, unc-50, unc-68, sod-1, oxi-1, and old-1) out of 18 selected genes were affected significantly. Other tested genes were cat-4, egl-19, egl-47, egl-5, lin-39, unc-43, pink-1, and age-1. Changes in gene expression were more evident at low dosages than at relatively high levels. Genes implicated in reproduction, cholinergic signaling, and stress response were regulated by nicotine, suggesting widespread physiological impacts of nicotine.
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Affiliation(s)
- Michael A Smith
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
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Sellings L, Pereira S, Qian C, Dixon-McDougall T, Nowak C, Zhao B, Tyndale RF, van der Kooy D. Nicotine-motivated behavior in Caenorhabditis elegans requires the nicotinic acetylcholine receptor subunits acr-5 and acr-15. Eur J Neurosci 2013; 37:743-56. [PMID: 23351035 DOI: 10.1111/ejn.12099] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 10/19/2012] [Accepted: 11/19/2012] [Indexed: 11/28/2022]
Abstract
Signaling at nicotinic acetylcholine receptors in Caenorhabditis elegans controls many behaviors, including egg-laying and locomotor activity. Here, we show that C. elegans approaches a point source of nicotine in a time-, concentration- and age-dependent manner. Additionally, nicotine paired with butanone under starvation conditions prevented the reduced approach to butanone that is observed when butanone is paired with starvation alone and pairing with nicotine generates a preference for the tastes of either sodium or chloride over baseline. These results suggest nicotine acts as a rewarding substance in C. elegans. Furthermore, the nicotinic receptor antagonist mecamylamine, the smoking cessation pharmacotherapy varenicline, mutation of the dop-1 and dop-2 dopamine receptors, and mutations of either acr-5 or acr-15, two nicotinic receptor subunit genes with sequence homology to the mammalian α7 subunit, all reduced the nicotine approach behavior. These two mutants also were defective at associating the presence of nicotine with butanone under starvation conditions and acr-5 mutation could obviate the effect of pairing nicotine with salts. Furthermore, the approach deficit in acr-15 mutants was rescued by selective re-expression in a subset of neurons, but not in muscle. Caenorhabditis elegans may therefore serve as a useful model organism for nicotine-motivated behaviors that could aid in the identification of novel nicotine motivational molecular pathways and consequently the development of novel cessation aids.
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Affiliation(s)
- Laurie Sellings
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
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