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Tomasello DL, Wlodkowic D. Noninvasive Electrophysiology: Emerging Prospects in Aquatic Neurotoxicity Testing. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:4788-4794. [PMID: 35196004 DOI: 10.1021/acs.est.1c08471] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The significance of neurotoxicological risks associated with anthropogenic pollution is gaining increasing recognition worldwide. In this regard, perturbations in behavioral traits upon exposure to environmentally relevant concentrations of neurotoxic and neuro-modulating contaminants have been linked to diminished ecological fitness of many aquatic species. Despite an increasing interest in behavioral testing in aquatic ecotoxicology there is, however, a notable gap in understanding of the neurophysiological foundations responsible for the altered behavioral phenotypes. One of the canonical approaches to explain the mechanisms of neuro-behavioral changes is functional analysis of neuronal transmission. In aquatic animals it requires, however, invasive, complex, and time-consuming electrophysiology techniques. In this perspective, we highlight emerging prospects of noninvasive, in situ electrophysiology based on multielectrode arrays (MEAs). This technology has only recently been pioneered for the detection and analysis of transient electrical signals in the central nervous system of small model organisms such as zebrafish. The analysis resembles electroencephalography (EEG) applications and provides an appealing strategy for mechanistic explorative studies as well as routine neurotoxicity risk assessment. We outline the prospective future applications and existing challenges of this emerging analytical strategy that is poised to bring new vistas for aquatic ecotoxicology such as greater mechanistic understanding of eco-neurotoxicity and thus more robust risk assessment protocols.
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Affiliation(s)
- Danielle L Tomasello
- Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142, United States
| | - Donald Wlodkowic
- The Neurotox Lab, School of Science, RMIT University, Melbourne, Victoria 3083, Australia
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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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Jacob J, Tan G, Lange I, Saeed H, Date A, Jarvi S. In vitro efficacy of anthelmintics on Angiostrongylus cantonensis L3 larvae. Parasitology 2021; 148:240-250. [PMID: 32799943 PMCID: PMC8173162 DOI: 10.1017/s0031182020001146] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/10/2020] [Accepted: 07/01/2020] [Indexed: 12/25/2022]
Abstract
Angiostrongylus cantonensis is the leading cause of eosinophilic meningitis worldwide, with life-threatening complications if not managed correctly. Previous in vitro studies have utilized change in motility patterns of adult female worms to assess the efficacy of anthelmintics qualitatively. However, it is the third stage larvae (L3) that are infectious to humans. With differential staining using propidium iodide penetration as the indicator of death, we can distinguish between dead and live larvae. This assay has enabled us to quantify the in vitro efficacy of nine clinically established anthelmintics on A. cantonensis L3. All drugs were tested at a 1 mm concentration. Piperazine and niclosamide were ineffective in inducing larval death; however, albendazole sulfoxide, pyrantel pamoate, diethylcarbamazine, levamisole and praziquantel were effective as compared to unexposed controls (P < 0.05). Ivermectin and moxidectin did not induce significant levels of mortality, but they considerably reduced larval motility almost immediately. This study indicates the need for further in vivo studies to determine the optimal dose and time frame for post-infection treatment with anthelmintics that demonstrated efficacy.
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Affiliation(s)
- John Jacob
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, The University of Hawai‘i at Hilo, Hawai‘i96720, USA
| | - Ghee Tan
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, The University of Hawai‘i at Hilo, Hawai‘i96720, USA
| | - Ingo Lange
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, The University of Hawai‘i at Hilo, Hawai‘i96720, USA
| | - Hiwa Saeed
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, The University of Hawai‘i at Hilo, Hawai‘i96720, USA
| | - Abhijit Date
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, The University of Hawai‘i at Hilo, Hawai‘i96720, USA
| | - Susan Jarvi
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, The University of Hawai‘i at Hilo, Hawai‘i96720, USA
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Fagundez DDA, Câmara DF, Salgueiro WG, Noremberg S, Luiz Puntel R, Piccoli JE, Garcia SC, da Rocha JBT, Aschner M, Ávila DS. Behavioral and dopaminergic damage induced by acute iron toxicity in Caenorhabditis elegans. Toxicol Res (Camb) 2015. [DOI: 10.1039/c4tx00120f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Iron (Fe) exposure, results in multiple biological defects in C. elegans, including reproductive and motor impairment, which may be related to oxidative stress and neuronal damage.
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Direct synthesis of 4-organylsulfenyl-7-chloro quinolines and their toxicological and pharmacological activities in Caenorhabditis elegans. Eur J Med Chem 2014; 75:448-59. [PMID: 24561673 DOI: 10.1016/j.ejmech.2014.01.037] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 01/15/2014] [Accepted: 01/17/2014] [Indexed: 12/30/2022]
Abstract
We describe herein our results on the synthesis and biological properties in Caenorhabditis elegans of a range of 4-organylsulfenyl-7-chloroquinolines. This class of compounds have been easily synthesized in high yields by direct reaction of 4,7-dichloroquinoline with organylthiols using DMSO as solvent at room temperature under air atmosphere and tolerates a range of substituents in the organylsulfenyl moiety. We have performed a toxicological and pharmacological screening of the synthesized 4-organylsulfenyl-7-chloroquinolines in vivo in C. elegans acutely exposed to these compounds, under per se and stress conditions. Hence, we determined the lethal dose 50% (LD50), in order to choose a nonlethal concentration (10 μM) and verified that at that concentration some of the compounds depicted protective action against the induced damage inflicted by paraquat, a superoxide generator. Two compounds (3c and 3h) reduced the toxicity inflicted by paraquat above survival, reproduction and longevity of the worms, at least in part, by reducing the reactive oxygen species (ROS) generated by the toxicant exposure. Besides, these compounds increased the quantities of superoxide dismutase (SOD-3::GFP) and catalase (CTL-1,2,3::GFP), antioxidant enzymes. We concluded that the protective effects of the compounds observed in this study might have been a hormetic response dependent of the transcriptional factor DAF-16/FOXO, causing a non-lethal oxidative stress that protects against the subsequently damage induced by paraquat.
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Wollenhaupt SGN, Soares AT, Salgueiro WG, Noremberg S, Reis G, Viana C, Gubert P, Soares FA, Affeldt RF, Lüdtke DS, Santos FW, Denardin CC, Aschner M, Avila DS. Seleno- and telluro-xylofuranosides attenuate Mn-induced toxicity in C. elegans via the DAF-16/FOXO pathway. Food Chem Toxicol 2013; 64:192-9. [PMID: 24296137 DOI: 10.1016/j.fct.2013.11.030] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 11/04/2013] [Accepted: 11/22/2013] [Indexed: 01/12/2023]
Abstract
Organochalcogens are promising pharmacological agents that possess significant biological activities. Nevertheless, because of the complexity of mammalian models, it has been difficult to determine the molecular pathways and specific proteins that are modulated in response to treatments with these compounds. The nematode worm Caenorhabditis elegans is an alternative experimental model that affords easy genetic manipulations, green fluorescent protein tagging and in vivo live analysis of toxicity. Abundant evidence points to oxidative stress in mediating manganese (Mn)-induced toxicity. In this study we challenged worms with Mn, and investigated the efficacy of inedited selenium- and tellurium-xylofuranosides in reversing and/or protecting the worms from Mn-induced toxicity. In addition, we investigated their putative mechanism of action. First, we determined the lethal dose 50% (LD50) and the effects of the xylofuranosides on various toxic parameters. This was followed by studies on the ability of xylofuranosides to afford protection against Mn-induced toxicity. Both Se- and Te-xylofuranosides increased the expression of superoxide dismutase (SOD-3). Furthermore, we observed that the xylofuranosides induced nuclear translocation of the transcription factor DAF-16/FOXO, which in the worm is known to regulate stress responsiveness, aging and metabolism. These findings suggest that xylofuranosides attenuate toxicity Mn-induced, by regulating the DAF-16/FOXO signaling pathway.
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Affiliation(s)
- Suzi G N Wollenhaupt
- Laboraterio do Grupo de Pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCe), Universidade Federal do Pampa - UNIPAMPA, CEP 97500-970, Uruguaiana, RS, Brazil
| | - Ana Thalita Soares
- Laboraterio do Grupo de Pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCe), Universidade Federal do Pampa - UNIPAMPA, CEP 97500-970, Uruguaiana, RS, Brazil
| | - Willian G Salgueiro
- Laboraterio do Grupo de Pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCe), Universidade Federal do Pampa - UNIPAMPA, CEP 97500-970, Uruguaiana, RS, Brazil
| | - Simone Noremberg
- Departamento de Química, Universidade Federal de Santa Maria - UFSM, CEP 97105-900, Santa Maria, RS, Brazil
| | - Gabriel Reis
- Departamento de Química, Universidade Federal de Santa Maria - UFSM, CEP 97105-900, Santa Maria, RS, Brazil
| | - Carine Viana
- Departamento de Química, Universidade Federal de Santa Maria - UFSM, CEP 97105-900, Santa Maria, RS, Brazil
| | - Priscila Gubert
- Departamento de Química, Universidade Federal de Santa Maria - UFSM, CEP 97105-900, Santa Maria, RS, Brazil
| | - Felix A Soares
- Departamento de Química, Universidade Federal de Santa Maria - UFSM, CEP 97105-900, Santa Maria, RS, Brazil
| | - Ricardo F Affeldt
- Instituto de Química, Universidade Federal do Rio Grande do Sul - UFRGS, CEP 91501-970, Porto Alegre, RS, Brazil
| | - Diogo S Lüdtke
- Instituto de Química, Universidade Federal do Rio Grande do Sul - UFRGS, CEP 91501-970, Porto Alegre, RS, Brazil
| | - Francielli W Santos
- Laboratório de Biotecnologia da Reprodução (Biotech), Campus Uruguaiana, Universidade Federal do Pampa - UNIPAMPA, CEP 97500-970, Uruguaiana, RS, Brazil
| | - Cristiane C Denardin
- Laboraterio do Grupo de Pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCe), Universidade Federal do Pampa - UNIPAMPA, CEP 97500-970, Uruguaiana, RS, Brazil
| | - Michael Aschner
- Division of Clinical Pharmacology and Pediatric Toxicology, Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Daiana S Avila
- Laboraterio do Grupo de Pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCe), Universidade Federal do Pampa - UNIPAMPA, CEP 97500-970, Uruguaiana, RS, Brazil.
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Karmacharya R, Lynn SK, Demarco S, Ortiz A, Wang X, Lundy MY, Xie Z, Cohen BM, Miller GM, Buttner EA. Behavioral effects of clozapine: involvement of trace amine pathways in C. elegans and M. musculus. Brain Res 2011; 1393:91-9. [PMID: 21529784 PMCID: PMC3107707 DOI: 10.1016/j.brainres.2011.04.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 04/02/2011] [Accepted: 04/04/2011] [Indexed: 11/27/2022]
Abstract
Clozapine is an antipsychotic medication with superior efficacy in treatment refractory schizophrenia. The molecular basis of clozapine's therapeutic profile is not well understood. We studied behavioral effects of clozapine in Caenorhabditis elegans to identify novel pathways that modulate clozapine's biological effects. Clozapine stimulated egg laying in C. elegans in a dose-dependent manner. This effect was clozapine-specific, as it was not observed with exposure to a typical antipsychotic, haloperidol or an atypical antipsychotic, olanzapine. A candidate gene screen of biogenic amine neurotransmitter systems identified signaling pathways that mediate this clozapine-specific effect on egg laying. Specifically, we found that clozapine-induced increase in egg laying requires tyramine biosynthesis. To test the implications of this finding across species, we explored whether trace amine systems modulate clozapine's behavioral effects in mammals by studying trace amine-associated receptor 1 (TAAR1) knockout mice. Clozapine increased prepulse inhibition (PPI) in wild-type mice. This increase in PPI was abrogated in TAAR1 knockout mice, implicating TAAR1 in clozapine-induced PPI enhancement. In transfected mammalian cell lines, we found no TAAR activation by antipsychotics, suggesting that modulation of trace amine signaling in mice does not occur directly at the receptor itself. In summary, we report a heretofore-unknown role for trace amine systems in clozapine-mediated effects across two species: C. elegans and mice.
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Affiliation(s)
- Rakesh Karmacharya
- Department of Psychiatry, Harvard Medical School, Boston, MA 02115 USA
- Mailman Research Center and Frazier Research Institute, McLean Hospital, 115 Mill Street, Belmont, MA 02478 USA
- Chemical Biology Program, Broad Institute of Harvard and MIT, 7 Cambridge Center, Cambridge, MA 02142 USA
| | - Spencer K. Lynn
- Department of Psychiatry, Harvard Medical School, Boston, MA 02115 USA
- Mailman Research Center and Frazier Research Institute, McLean Hospital, 115 Mill Street, Belmont, MA 02478 USA
- Department of Psychology, Boston College, Chestnut Hill, MA 02467 USA
| | - Sarah Demarco
- Mailman Research Center and Frazier Research Institute, McLean Hospital, 115 Mill Street, Belmont, MA 02478 USA
| | - Angelica Ortiz
- Mailman Research Center and Frazier Research Institute, McLean Hospital, 115 Mill Street, Belmont, MA 02478 USA
| | - Xin Wang
- Mailman Research Center and Frazier Research Institute, McLean Hospital, 115 Mill Street, Belmont, MA 02478 USA
| | - Miriam Y. Lundy
- Mailman Research Center and Frazier Research Institute, McLean Hospital, 115 Mill Street, Belmont, MA 02478 USA
| | - Zhihua Xie
- Department of Psychiatry, Harvard Medical School, Boston, MA 02115 USA
- Division of Neuroscience, New England Primate Research Center, Southborough, MA 01772 USA
| | - Bruce M. Cohen
- Department of Psychiatry, Harvard Medical School, Boston, MA 02115 USA
- Mailman Research Center and Frazier Research Institute, McLean Hospital, 115 Mill Street, Belmont, MA 02478 USA
| | - Gregory M. Miller
- Department of Psychiatry, Harvard Medical School, Boston, MA 02115 USA
- Division of Neuroscience, New England Primate Research Center, Southborough, MA 01772 USA
| | - Edgar A. Buttner
- Department of Psychiatry, Harvard Medical School, Boston, MA 02115 USA
- Mailman Research Center and Frazier Research Institute, McLean Hospital, 115 Mill Street, Belmont, MA 02478 USA
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Mathur P, Guo S. Differences of acute versus chronic ethanol exposure on anxiety-like behavioral responses in zebrafish. Behav Brain Res 2011; 219:234-9. [PMID: 21255611 DOI: 10.1016/j.bbr.2011.01.019] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 01/06/2011] [Accepted: 01/10/2011] [Indexed: 12/28/2022]
Abstract
Zebrafish, a vertebrate model organism amenable to high throughput screening, is an attractive system to model and study the mechanisms underlying human diseases. Alcoholism and alcoholic medical disorders are among the most debilitating diseases, yet the mechanisms by which ethanol inflicts the disease states are not well understood. In recent years zebrafish behavior assays have been used to study learning and memory, fear and anxiety, and social behavior. It is important to characterize the effects of ethanol on zebrafish behavioral repertoires in order to successfully harvest the strength of zebrafish for alcohol research. One prominent effect of alcohol in humans is its effect on anxiety, with acute intermediate doses relieving anxiety and withdrawal from chronic exposure increasing anxiety, both of which have significant contributions to alcohol dependence. In this study, we assess the effects of both acute and chronic ethanol exposure on anxiety-like behaviors in zebrafish, using two behavioral paradigms, the Novel Tank Diving Test and the Light/Dark Choice Assay. Acute ethanol exposure exerted significant dose-dependent anxiolytic effects. However, withdrawal from repeated intermittent ethanol exposure disabled recovery from heightened anxiety. These results demonstrate that zebrafish exhibit different anxiety-like behavioral responses to acute and chronic ethanol exposure, which are remarkably similar to these effects of alcohol in humans. Because of the accessibility of zebrafish to high throughput screening, our results suggest that genes and small molecules identified in zebrafish will be of relevance to understand how acute versus chronic alcohol exposure have opposing effects on the state of anxiety in humans.
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Affiliation(s)
- Priya Mathur
- Department of Bioengineering and Therapeutic Sciences, Programs in Biological Sciences and Human Genetics, University of California, San Francisco, CA 94143-2811, United States
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Roh JY, Park YK, Park K, Choi J. Ecotoxicological investigation of CeO(2) and TiO(2) nanoparticles on the soil nematode Caenorhabditis elegans using gene expression, growth, fertility, and survival as endpoints. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2010; 29:167-72. [PMID: 21787599 DOI: 10.1016/j.etap.2009.12.003] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 12/23/2009] [Accepted: 12/25/2009] [Indexed: 05/20/2023]
Abstract
In this study, the potential harmful effect of cerium dioxide (CeO(2)), and titanium dioxide (TiO(2)) nanoparticles on the environment was investigated using Caenorhabditis elegans ecotoxicity tests. Multiple toxic endpoints, such as stress-response gene expression, growth, fertility, and survival, were analyzed in C. elegans, in response to the CeO(2) and TiO(2) exposure. To investigate relationship between sizes of nanoparticles and toxicity, C. elegans were exposed to nanoparticles to the different sizes of nanoparticles (15, 45nm for CeO(2) and 7, 20nm for TiO(2)). An increase in the expression of the cyp35a2 gene, decrease in fertility and survival parameters were observed in the 15 and 45nm of CeO(2) and in the 7nm of TiO(2) nanoparticles exposed to C. elegans. Gene knock-down experiment using RNA interference (RNAi) suggested that physiological level disturbances may be related with the cyp35a2 gene expression. Smaller sized nanoparticles (7nm of TiO(2) and 15nm of CeO(2)) seemed to be more toxic than larger sized ones (20nm of TiO(2) and 45nm of CeO(2)) on the observed toxicity. The size-dependent effect in CeO(2) and TiO(2) nanoparticles-induced toxicity needs to be investigated under more detailed experimental settings with the various sizes of nanoparticles. Further studies on the mechanism by which CeO(2) and TiO(2) nanoparticles affect cyp35a2 gene expression, fertility, and survival are warranted to better understand the CeO(2) and TiO(2) nanoparticles-induced ecotoxicity in C. elegans, as are studies with the causal relationships between these parameters. Overall results suggest that CeO(2) and TiO(2) nanoparticles have a potential for provoking ecotoxicity on C. elegans and the data obtained from this study can comprise a contribution to knowledge of the ecotoxicology of nanoparticles in C. elegans, about which little data are available.
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Affiliation(s)
- Ji-Yeon Roh
- Faculty of Environmental Engineering, College of Urban Science, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, Republic of Korea
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Clozapine interaction with phosphatidyl inositol 3-kinase (PI3K)/insulin-signaling pathway in Caenorhabditis elegans. Neuropsychopharmacology 2009; 34:1968-78. [PMID: 19322168 PMCID: PMC3348699 DOI: 10.1038/npp.2009.35] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Clozapine has superior and unique effects as an antipsychotic agent, but the mediators of these effects are not known. We studied behavioral and developmental effects of clozapine in Caenorhabditis elegans, as a model system to identify previously undiscovered mechanisms of drug action. Clozapine induced early larval arrest, a phenotype that was also seen with the clozapine metabolite N-desmethyl clozapine but not with any other typical or atypical antipsychotic drug tested. Mutations in the insulin receptor/daf-2 and phosphatidyl inositol 3-kinase (PI3K)/age-1 suppressed clozapine-induced larval arrest, suggesting that clozapine may activate the insulin-signaling pathway. Consistent with this notion, clozapine also increased the expression of an age-1::GFP reporter. Activation of the insulin-signaling pathway leads to cytoplasmic localization of the fork head transcription factor FOXO/daf-16. Clozapine produced cytoplasmic localization of DAF-16::GFP in arrested L1 larvae, in contrast to stressors such as starvation or high temperature, which produce nuclear localization of DAF-16::GFP in arrested L1 larvae. Clozapine also inhibited pharyngeal pumping in C. elegans, an effect that may contribute to, but did not explain, clozapine-induced larval arrest. Our findings demonstrate a drug-specific interaction between clozapine and the PI3K/insulin-signaling pathway in C. elegans. As this pathway is conserved across species, the results may have implications for understanding the unique effects of clozapine in humans.
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Choi J. Caenorhabditis elegans as a Biological Model for Multilevel Biomarker Analysis in Environmental Toxicology and Risk Assessment. Toxicol Res 2008; 24:235-243. [PMID: 32038801 PMCID: PMC7006315 DOI: 10.5487/tr.2008.24.4.235] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Revised: 11/18/2008] [Accepted: 11/19/2008] [Indexed: 11/20/2022] Open
Abstract
While in some instances, loss of diversity results from acute toxicity (e.g. major pollution incidents), in most cases it results from long-term sub-lethal effects that alter the relative competitive ability and fitness of certain organisms. In such cases the sub-lethal effects will cause a physiological response in the organism that ultimately leads to community level changes. Very sensitive tools are now available to study sub-lethal responses at the molecular level. However, relating such laboratory measurements to ecological effects represents a substantial challenge that can only be met by investigation at all scales (molecular, individual organism and community level) with an appropriate group of organisms. Among the various in vertebrates which can be used as model organisms in such a way, the soil nematode, Caenorhabditis elegans appear to be a promising biological model to diagnose environmental quality. This paper reviews the current status of multilevel biomarkers in environmental toxicology, and C. elegans as promising organisms for this approach.
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Affiliation(s)
- Jinhee Choi
- Faculty of Environmental Engineering, College of Urban Science, University of Seoul, Seoul, 130-743 Korea
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Roh JY, Jung IH, Lee JY, Choi J. Toxic effects of di(2-ethylhexyl)phthalate on mortality, growth, reproduction and stress-related gene expression in the soil nematode Caenorhabditis elegans. Toxicology 2007; 237:126-133. [PMID: 17604895 DOI: 10.1016/j.tox.2007.05.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 04/19/2007] [Accepted: 05/02/2007] [Indexed: 11/23/2022]
Abstract
In this study, di(2-ethylhexyl)phthalate (DEHP) toxicities to Caenorhabditis elegans were investigated using multiple toxic endpoints, such as mortality, growth, reproduction and stress-related gene expression, focusing on the identification of chemical-induced gene expression as a sensitive biomarker for DEHP monitoring. The possible use of C. elegans as a sentinel organism in the monitoring of soil ecosystem health was also tested by conducting the experiment on the exposure of nematode to field soil. Twenty-four-hour median lethal concentration (LC50) data suggest that DEHP has a relatively high potential of acute toxicity to C. elegans. Decreases in body length and egg number per worm observed after 24h of DEHP exposure may induce long-term alteration in the growth and reproduction of the nematode population. Based on the result from the C. elegans genome array and indicated in the literatures, stress proteins, metallothionein, vitellogenin, xenobiotic metabolism enzymes, apoptosis-related proteins, and antioxidant enzyme genes were selected as stress-related genes and their expression in C. elegans by DEHP exposure was analyzed semi-quantitatively. Expression of heat shock protein (hsp)-16.1 and hsp-16.2 genes was decreased by DEHP exposure. Expression of cytochrome P450 (cyp) 35a2 and glutathione-S-transferease (gst)-4, phase I and phase II of xenobiotic metabolism enzymes, was increased by DEHP exposure in a concentration-dependent manner. An increase in stress-related gene expressions occurred concomitantly with the deterioration on the physiological level, which suggests an increase in expression of those genes may not be considered as a homeostatic response but as a toxicity that might have physiological consequences. The experiment with the soil from the landfill site suggests that the potential of the C. elegans biomarker identified in laboratory conditions should be calibrated and validated for its use in situ.
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Affiliation(s)
- Ji-Yeon Roh
- Faculty of Environmental Engineering, College of Urban Science, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, Republic of Korea
| | - In-Ho Jung
- Faculty of Environmental Engineering, College of Urban Science, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, Republic of Korea
| | - Jai-Young Lee
- Faculty of Environmental Engineering, College of Urban Science, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, Republic of Korea
| | - Jinhee Choi
- Faculty of Environmental Engineering, College of Urban Science, University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, Republic of Korea.
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Schumacher B, Gartner A. Translational regulation of p53 as a potential tumor therapy target. Future Oncol 2006; 2:145-53. [PMID: 16556081 DOI: 10.2217/14796694.2.1.145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The tumor suppressor p53 is a central player in apoptosis induction in response to oncogenic stimuli and DNA damage. As activation of p53 has been suggested as a prime strategy for future tumor therapy, inhibition of negative regulators of p53 activity would be a similarly desirable strategy. The small worm Caenorhabditis elegans is a model organism in which many conserved biological pathways, including the core apoptotic machinery, were elucidated. The discovery of a worm p53 homolog cep-1/p53 (which stands for C. elegans p53) that specifically induces apoptosis upon DNA damage through a pathway that is conserved from worm to man opened the way for the use of C. elegans genetics to uncover regulatory mechanisms – and hence novel therapeutic targets – of p53-mediated apoptosis. The authors have recently reported a novel mechanism of C. elegans cep-1/p53 regulation through germ line defective-1-mediated translational repression. This review discusses the potential of the worm system to screen for apoptosis-inducing cancer drugs and to identify novel p53 regulators whose human counterparts might become potential tumor therapy targets.
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Affiliation(s)
- Björn Schumacher
- Department of Genetics, Erasmus MC, Dr. Molewaterplein 50, 3015GE Rotterdam, The Netherlands.
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