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Dranchak PK, Oliphant E, Queme B, Lamy L, Wang Y, Huang R, Xia M, Tao D, Inglese J. In vivo quantitative high-throughput screening for drug discovery and comparative toxicology. Dis Model Mech 2023; 16:dmm049863. [PMID: 36786055 PMCID: PMC10067442 DOI: 10.1242/dmm.049863] [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: 08/26/2022] [Accepted: 02/01/2023] [Indexed: 02/15/2023] Open
Abstract
Quantitative high-throughput screening (qHTS) pharmacologically evaluates chemical libraries for therapeutic uses, toxicological risk and, increasingly, for academic probe discovery. Phenotypic high-throughput screening assays interrogate molecular pathways, often relying on cell culture systems, historically less focused on multicellular organisms. Caenorhabditis elegans has served as a eukaryotic model organism for human biology by virtue of genetic conservation and experimental tractability. Here, a paradigm enabling C. elegans qHTS using 384-well microtiter plate laser-scanning cytometry is described, in which GFP-expressing organisms revealing phenotype-modifying structure-activity relationships guide subsequent life-stage and proteomic analyses, and Escherichia coli bacterial ghosts, a non-replicating nutrient source, allow compound exposures over two life cycles, mitigating bacterial overgrowth complications. We demonstrate the method with libraries of anti-infective agents, or substances of toxicological concern. Each was tested in seven-point titration to assess the feasibility of nematode-based in vivo qHTS, and examples of follow-up strategies were provided to study organism-based chemotype selectivity and subsequent network perturbations with a physiological impact. We anticipate that this qHTS approach will enable analysis of C. elegans orthologous phenotypes of human pathologies to facilitate drug library profiling for a range of therapeutic indications.
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Affiliation(s)
- Patricia K. Dranchak
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Erin Oliphant
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Bryan Queme
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Laurence Lamy
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Yuhong Wang
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Ruili Huang
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Menghang Xia
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - Dingyin Tao
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
| | - James Inglese
- Department of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD 20850, USA
- Metabolic Medicine Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20817, USA
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Duran-Izquierdo M, Taboada-Alquerque M, Sierra-Marquez L, Alvarez-Ortega N, Stashenko E, Olivero-Verbel J. Hydroalcoholic extract of Haematoxylum brasiletto protects Caenorhabditis elegans from cadmium-induced toxicity. BMC Complement Med Ther 2022; 22:184. [PMID: 35818043 PMCID: PMC9272861 DOI: 10.1186/s12906-022-03654-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 06/09/2022] [Indexed: 11/20/2022] Open
Abstract
Background H. brasiletto is used in popular culture due to its therapeutic properties, including antioxidant, anti-inflammatory and antiproliferative properties, although little is known about its role as a protector against metal toxicity. This study aimed to investigate the chemical composition and efficacy of the hydroalcoholic extract from H. brasiletto (HAE-Hbrasiletto) collected in northern Colombia to defend against cadmium (Cd)-induced toxicity. Methods Phytochemical characterization was performed using HPLC-ESI-QTOF. Caenorhabditis elegans was employed to assess the shielding effect of HAE-Hbrasiletto against Cd toxicity in vivo, and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was utilized to measure radical scavenging activity. Results The main secondary metabolites identified by HPLC-ESI-QTOF in the extracts were hematoxylins (brazilein and hematein) and protosappanins (protosappanin A, B and C, 10-O-methylprotosappanin B, and protosappanin A dimethyl acetal). The HAE-Hbrasiletto elicited low lethality in N2 worms and significantly reduced the Cd-induced death of the nematodes. It also improved Cd-induced motility inhibition, as well as body length and reproduction reduction provoked by the heavy metal. The extract displayed a good capacity to halt Cd-induced DAF-16 translocation. As this last process was associated with lethality (r = 0.962, p < 0.01), the antioxidant properties of the extract may contribute to ameliorating tissue damage induced by oxidative stress from Cd exposure. Conclusion HAE-Hbrasiletto has remarkable properties to protect against Cd-induced toxicity. Supplementary Information The online version contains supplementary material available at 10.1186/s12906-022-03654-6. Most secondary metabolites tentatively identified in H. brasiletto are homoisoflavones. Hidroalcoholic extract of H. brasiletto protects C. elegans from Cd toxicity The extract diminished Cd-induced damage to reproduction, growth, and locomotion. Cd-induced oxidative stress and translocation of DAF-16 are blocked by the extract.
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In Vivo Simultaneous Analysis of Gene Expression by Dual-Color Luciferases in Caenorhabditis elegans. Int J Mol Sci 2020; 22:ijms22010119. [PMID: 33374403 PMCID: PMC7795788 DOI: 10.3390/ijms22010119] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 11/17/2022] Open
Abstract
Both fluorescent and luminescent observation are widely used to examine real-time gene expression patterns in living organisms. Several fluuorescent and luminescent proteins with specific optical properties have been developed and applied for simultaneous, multi-color observation of more than two gene expression profiles. Compared to fluorescent proteins, however, the application of multi-color luminescent imaging in living organisms is still limited. In this study, we introduced two-color luciferases into the soil nematode C. elegans and performed simultaneous analysis of two gene expression profiles. Using a green-emitting luciferase Eluc (emerald luciferase) and red-emitting luciferase SLR (stable luciferase red), the expression patterns of two genes were simultaneously observed in single animals from embryonic to adult stages over its whole life span. In addition, dual gene activities were observed at the single embryo level, with the simultaneous observation of morphological changes. These are the first application of a two-color luciferase system into a whole animal and suggest that precise relationship of expression patterns of multiple genes of interest can be analyzed over the whole life of the animal, dependent on the changes in genetic and/or environmental conditions.
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Prato E, Parlapiano I, Biandolino F, Rotini A, Manfra L, Berducci MT, Maggi C, Libralato G, Paduano L, Carraturo F, Trifuoggi M, Carotenuto M, Migliore L. Chronic sublethal effects of ZnO nanoparticles on Tigriopus fulvus (Copepoda, Harpacticoida). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:30957-30968. [PMID: 31814077 DOI: 10.1007/s11356-019-07006-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 11/11/2019] [Indexed: 06/10/2023]
Abstract
This study investigated for the first time the effects of ZnO nanoparticle (NP) chronic exposure (28 days) on Tigriopus fulvus. Acute toxicity (48 h) of three Zn chemical forms was assessed as well including the following: (a) ZnO nanoparticles (NPs), (b) Zn2+ from ZnO NP suspension after centrifugation (supernatant) and (c) ZnSO4 H2O. Physical-chemical and electronic microscopies were used to characterize spiked exposure media. Results showed that the dissolution of ZnO NPs was significant, with a complete dissolution at lowest test concentrations, but nano- and micro-aggregates were always present. Acute test evidenced a significant higher toxicity of Zn2+ and ZnSO4 compared to ZnO NPs. The chronic exposure to ZnO NPs caused negative effects on the reproductive traits, i.e. brood duration, brood size and brood number at much lower concentrations (≥ 100 μg/L). The appearance of ovigerous females was delayed at higher concentrations of ZnO NPs, while the time required for offspring release and the percentage of non-viable eggs per female were significantly increased. ZnO NP subchronic exposure evidenced its ability to reduce T. fulvus individual reproductive fitness, suggesting that ZnO NPs use and release must be carefully monitored. Graphical abstract Graphical Abstract.
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Affiliation(s)
| | | | | | - Alice Rotini
- Department of Biology, Tor Vergata University, Rome, Italy
- Institute for Environmental Protection and Research (ISPRA), Rome, Italy
| | - Loredana Manfra
- Institute for Environmental Protection and Research (ISPRA), Rome, Italy
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Naples, Italy
| | | | - Chiara Maggi
- Institute for Environmental Protection and Research (ISPRA), Rome, Italy
| | - Giovanni Libralato
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Naples, Italy.
- Department of Biology, University of Naples Federico II, Via Cinthia, 21, 80126, Naples, Italy.
| | - Luigi Paduano
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia, 21, 80126, Naples, Italy
- CSGI - Consorzio interuniversitario per lo sviluppo dei Sistemi a Grande Interfase, Sesto Fiorentino (FI), Italy
| | - Federica Carraturo
- Department of Biology, University of Naples Federico II, Via Cinthia, 21, 80126, Naples, Italy
| | - Marco Trifuoggi
- Department of Chemical Sciences, University of Naples Federico II, Via Cinthia, 21, 80126, Naples, Italy
| | - Maurizio Carotenuto
- Department of Chemistry and Biology "Adolfo Zambelli", University of Salerno, 84084 Fisciano, Salerno, Italy
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Moyson S, Town RM, Vissenberg K, Blust R. The effect of metal mixture composition on toxicity to C. elegans at individual and population levels. PLoS One 2019; 14:e0218929. [PMID: 31237916 PMCID: PMC6592602 DOI: 10.1371/journal.pone.0218929] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 06/12/2019] [Indexed: 11/18/2022] Open
Abstract
The toxicity of zinc (Zn), copper (Cu), and cadmium (Cd) to the nematode Caenorhabditis elegans was characterised under single metal and mixture scenarios at different organisational levels. The effects on population size and body length were investigated at two concentrations corresponding to the 24 h LC5 and LC20 levels. Metal toxicity was dependent on metal concentration, exposure time and mixture composition. Populations exposed to LC20 levels of Cd, ZnCu, CuCd and ZnCuCd plummeted, while for all LC5 concentrations, population size continued to increase, albeit that single metals were less harmful than mixtures. Combinations of the LC20 concentration of Cd with a range of Zn concentrations showed concentration dependent mitigating effects on population size and antagonistic effects on mortality. By combining effects at different organisational levels, more insight into metal toxicity was obtained. Metal effects were more evident on population size than on body length or mortality, suggesting that population size could be considered as a sensitive endpoint. Furthermore, our observations of ZnCd mixture effects at the individual and population levels are consistent with literature data on the dose-dependent expression of the cdf-2 gene, which is involved in mediation of Zn and Cd toxicity.
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Affiliation(s)
- Sofie Moyson
- Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Raewyn M. Town
- Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Antwerp, Belgium
- * E-mail:
| | - Kris Vissenberg
- Integrated Molecular Plant Physiology Research, Department of Biology, University of Antwerp, Antwerp, Belgium
- Plant Biochemistry & Biotechnology Laboratory, University of Applied Sciences Crete – Technological Educational Institute, Department of Agriculture, School of Agriculture, Food & Nutrition, Stavromenos, Heraklion, Crete, Greece
| | - Ronny Blust
- Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Antwerp, Belgium
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Xia M, Huang R, Shi Q, Boyd WA, Zhao J, Sun N, Rice JR, Dunlap PE, Hackstadt AJ, Bridge MF, Smith MV, Dai S, Zheng W, Chu PH, Gerhold D, Witt KL, DeVito M, Freedman JH, Austin CP, Houck KA, Thomas RS, Paules RS, Tice RR, Simeonov A. Comprehensive Analyses and Prioritization of Tox21 10K Chemicals Affecting Mitochondrial Function by in-Depth Mechanistic Studies. ENVIRONMENTAL HEALTH PERSPECTIVES 2018; 126:077010. [PMID: 30059008 PMCID: PMC6112376 DOI: 10.1289/ehp2589] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 06/15/2018] [Accepted: 06/16/2018] [Indexed: 05/18/2023]
Abstract
BACKGROUND A central challenge in toxicity testing is the large number of chemicals in commerce that lack toxicological assessment. In response, the Tox21 program is re-focusing toxicity testing from animal studies to less expensive and higher throughput in vitro methods using target/pathway-specific, mechanism-driven assays. OBJECTIVES Our objective was to use an in-depth mechanistic study approach to prioritize and characterize the chemicals affecting mitochondrial function. METHODS We used a tiered testing approach to prioritize for more extensive testing 622 compounds identified from a primary, quantitative high-throughput screen of 8,300 unique small molecules, including drugs and industrial chemicals, as potential mitochondrial toxicants by their ability to significantly decrease the mitochondrial membrane potential (MMP). Based on results from secondary MMP assays in HepG2 cells and rat hepatocytes, 34 compounds were selected for testing in tertiary assays that included formation of reactive oxygen species (ROS), upregulation of p53 and nuclear erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE), mitochondrial oxygen consumption, cellular Parkin translocation, and larval development and ATP status in the nematode Caenorhabditis elegans. RESULTS A group of known mitochondrial complex inhibitors (e.g., rotenone) and uncouplers (e.g., chlorfenapyr), as well as potential novel complex inhibitors and uncouplers, were detected. From this study, we identified four not well-characterized potential mitochondrial toxicants (lasalocid, picoxystrobin, pinacyanol, and triclocarban) that merit additional in vivo characterization. CONCLUSIONS The tier-based approach for identifying and mechanistically characterizing mitochondrial toxicants can potentially reduce animal use in toxicological testing. https://doi.org/10.1289/EHP2589.
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Affiliation(s)
- Menghang Xia
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, Maryland, USA
| | - Ruili Huang
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, Maryland, USA
| | - Qiang Shi
- Division of Systems Biology, National Center for Toxicological Research, U. S. Food and Drug Administration, Jefferson, Arkansas, USA
| | - Windy A Boyd
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Jinghua Zhao
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, Maryland, USA
| | - Nuo Sun
- National Heart, Lung, and Blood Institute, NIH, DHHS, Bethesda, Maryland, USA
| | - Julie R Rice
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Paul E Dunlap
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | | | - Matt F Bridge
- Social & Scientific Systems, Inc., Durham, North Carolina, USA
| | | | - Sheng Dai
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, Maryland, USA
| | - Wei Zheng
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, Maryland, USA
| | - Pei-Hsuan Chu
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, Maryland, USA
| | - David Gerhold
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, Maryland, USA
| | - Kristine L Witt
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Michael DeVito
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Jonathan H Freedman
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Christopher P Austin
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, Maryland, USA
| | - Keith A Houck
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Russell S Thomas
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - Richard S Paules
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Raymond R Tice
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Anton Simeonov
- National Center for Advancing Translational Sciences, National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, Maryland, USA
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Rodríguez-Palero MJ, López-Díaz A, Marsac R, Gomes JE, Olmedo M, Artal-Sanz M. An automated method for the analysis of food intake behaviour in Caenorhabditis elegans. Sci Rep 2018; 8:3633. [PMID: 29483540 PMCID: PMC5832146 DOI: 10.1038/s41598-018-21964-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 02/09/2018] [Indexed: 11/24/2022] Open
Abstract
The study of mechanisms that govern feeding behaviour and its related disorders is a matter of global health interest. The roundworm Caenorhabditis elegans is becoming a model organism of choice to study these conserved pathways. C. elegans feeding depends on the contraction of the pharynx (pumping). Thanks to the worm transparency, pumping can be directly observed under a stereoscope. Therefore, C. elegans feeding has been historically investigated by counting pharyngeal pumping or by other indirect approaches. However, those methods are short-term, time-consuming and unsuitable for independent measurements of sizable numbers of individuals. Although some particular devices and long-term methods have been lately reported, they fail in the automated, scalable and/or continuous aspects. Here we present an automated bioluminescence-based method for the analysis and continuous monitoring of worm feeding in a multi-well format. We validate the method using genetic, environmental and pharmacological modulators of pharyngeal pumping. This flexible methodology allows studying food intake at specific time-points or during longer periods of time, in single worms or in populations at any developmental stage. Additionally, changes in feeding rates in response to differential metabolic status or external environmental cues can be monitored in real time, allowing accurate kinetic measurements.
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Affiliation(s)
- Mª Jesús Rodríguez-Palero
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Departament of Molecular Biology and Biochemical Engineering, Carretera de Utrera, km 1, 41013, Seville, Spain
| | - Ana López-Díaz
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Departament of Molecular Biology and Biochemical Engineering, Carretera de Utrera, km 1, 41013, Seville, Spain
| | - Roxane Marsac
- Institut de Biochimie et Génétique Cellulaires - C.N.R.S. UMR 5095 and Université de Bordeaux, 1, rue Camille Saint-Saëns, 33077, Bordeaux Cedex, France
| | - José-Eduardo Gomes
- Institut de Biochimie et Génétique Cellulaires - C.N.R.S. UMR 5095 and Université de Bordeaux, 1, rue Camille Saint-Saëns, 33077, Bordeaux Cedex, France
| | - María Olmedo
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Departament of Molecular Biology and Biochemical Engineering, Carretera de Utrera, km 1, 41013, Seville, Spain.
- Department of Genetics, University of Seville, Avenida Reina Mercedes s/n, 41012, Seville, Spain.
| | - Marta Artal-Sanz
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Departament of Molecular Biology and Biochemical Engineering, Carretera de Utrera, km 1, 41013, Seville, Spain.
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8
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Moyson S, Vissenberg K, Fransen E, Blust R, Husson SJ. Mixture effects of copper, cadmium, and zinc on mortality and behavior of Caenorhabditis elegans. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2018; 37:145-159. [PMID: 28786503 DOI: 10.1002/etc.3937] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 06/02/2017] [Accepted: 08/07/2017] [Indexed: 05/24/2023]
Abstract
The toxicity effects of zinc (Zn), copper (Cu), and cadmium (Cd), both as single metals and in combination, were examined in the nematode Caenorhabditis elegans. Metal effects on lethality were analyzed in a time-dependent manner using different concentrations in K-medium. To investigate the effects on locomotion and chemosensation, lethal concentration at 20% (LC20) values were used. The results showed that Cu toxicity was higher compared with Cd and Zn, resulting in higher mortality rates and a more reduced locomotion. Lethality increased over time for all metals. When Cd was added to Cu, and vice versa, significant increases in toxicity were noted. Different interaction effects were observed for the mixtures ZnCd, ZnCu, CuCd, and ZnCuCd. Zinc seemed to have a neutral toxic effect on Cd, while in combination with Cu, a similar additive effect was seen as for the CuCd combination. Binary and tertiary metal mixtures caused a strong decrease in locomotion, except for the ZnCd combination, where Zn seemed to have a neutral effect. After LC2024 h exposure, reduced crawling speed (except for Zn) and reduced thrashing behavior (except for Zn and the ZnCd mixture) were observed. Almost no significant effects were observed on chemosensation. Because the same trend of mixture effects was noted in locomotion and in lethality tests, locomotion can probably be considered a sensitive endpoint for metal toxicities. Environ Toxicol Chem 2018;37:145-159. © 2017 SETAC.
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Affiliation(s)
- Sofie Moyson
- Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Kris Vissenberg
- Integrated Molecular Plant Physiology Research, Department of Biology, University of Antwerp, Antwerp, Belgium
- Plant Biochemistry & Biotechnology Lab, Department of Agriculture, School of Agriculture, Food & Nutrition, University of Applied Sciences Crete-Technological Educational Institute, Stavromenos, Heraklion, Crete, Greece
| | - Erik Fransen
- StatUa Center for Statistics, University of Antwerp, Antwerp, Belgium
| | - Ronny Blust
- Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Steven J Husson
- Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Antwerp, Belgium
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Wyatt LH, Luz AL, Cao X, Maurer LL, Blawas AM, Aballay A, Pan WKY, Meyer JN. Effects of methyl and inorganic mercury exposure on genome homeostasis and mitochondrial function in Caenorhabditis elegans. DNA Repair (Amst) 2017; 52:31-48. [PMID: 28242054 PMCID: PMC5394729 DOI: 10.1016/j.dnarep.2017.02.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 12/05/2016] [Accepted: 02/06/2017] [Indexed: 12/21/2022]
Abstract
Mercury toxicity mechanisms have the potential to induce DNA damage and disrupt cellular processes, like mitochondrial function. Proper mitochondrial function is important for cellular bioenergetics and immune signaling and function. Reported impacts of mercury on the nuclear genome (nDNA) are conflicting and inconclusive, and mitochondrial DNA (mtDNA) impacts are relatively unknown. In this study, we assessed genotoxic (mtDNA and nDNA), metabolic, and innate immune impacts of inorganic and organic mercury exposure in Caenorhabditis elegans. Genotoxic outcomes measured included DNA damage, DNA damage repair (nucleotide excision repair, NER; base excision repair, BER), and genomic copy number following MeHg and HgCl2 exposure alone and in combination with known DNA damage-inducing agents ultraviolet C radiation (UVC) and hydrogen peroxide (H2O2), which cause bulky DNA lesions and oxidative DNA damage, respectively. Following exposure to both MeHg and HgCl2, low-level DNA damage (∼0.25 lesions/10kb mtDNA and nDNA) was observed. Unexpectedly, a higher MeHg concentration reduced damage in both genomes compared to controls. However, this observation was likely the result of developmental delay. In co-exposure treatments, both mercury compounds increased initial DNA damage (mtDNA and nDNA) in combination with H2O2 exposure, but had no impact in combination with UVC exposure. Mercury exposure both increased and decreased DNA damage removal via BER. DNA repair after H2O2 exposure in mercury-exposed nematodes resulted in damage levels lower than measured in controls. Impacts to NER were not detected. mtDNA copy number was significantly decreased in the MeHg-UVC and MeHg-H2O2 co-exposure treatments. Mercury exposure had metabolic impacts (steady-state ATP levels) that differed between the compounds; HgCl2 exposure decreased these levels, while MeHg slightly increased levels or had no impact. Both mercury species reduced mRNA levels for immune signaling-related genes, but had mild or no effects on survival on pathogenic bacteria. Overall, mercury exposure disrupted mitochondrial endpoints in a mercury-compound dependent fashion.
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Affiliation(s)
- Lauren H Wyatt
- Nicholas School of the Environment, Duke University, Durham, NC, United States.
| | - Anthony L Luz
- Nicholas School of the Environment, Duke University, Durham, NC, United States
| | - Xiou Cao
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
| | - Laura L Maurer
- Nicholas School of the Environment, Duke University, Durham, NC, United States
| | - Ashley M Blawas
- Nicholas School of the Environment, Duke University, Durham, NC, United States
| | - Alejandro Aballay
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
| | - William K Y Pan
- Nicholas School of the Environment, Duke University, Durham, NC, United States; Duke Global Health Institute, Duke University, Durham, NC, United States
| | - Joel N Meyer
- Nicholas School of the Environment, Duke University, Durham, NC, United States.
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Huang CW, Li SW, Hsiu-Chuan Liao V. Chronic ZnO-NPs exposure at environmentally relevant concentrations results in metabolic and locomotive toxicities in Caenorhabditis elegans. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 220:1456-1464. [PMID: 27839994 DOI: 10.1016/j.envpol.2016.10.086] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/20/2016] [Accepted: 10/28/2016] [Indexed: 05/29/2023]
Abstract
ZnO nanoparticles (ZnO-NPs) are emerging contaminants that raise the concerns of potential risk in the aquatic environment. It has been estimated that the environmental ZnO-NPs concentration is 76 μg/l in the aquatic environment. Our aim was to determine the aquatic toxicity of ZnO-NPs with chronic exposure at environmentally relevant concentrations using the nematode Caenorhabditis elegans. Two simulated environmentally relevant mediums-moderately hard reconstituted water (EPA water) and simulated soil pore water (SSPW)-were used to represent surface water and pore water in sediment, respectively. The results showed that the ZnO-NPs in EPA water has a much smaller hydrodynamic diameter than that in SSPW. Although the ionic release of Zn ions increased time-dependently in both mediums, the Zn ions concentrations in EPA water increased two-fold more than that in SSPW at 48 h and 72 h. The ZnO-NPs did not induce growth defects or decrease head thrashes in C. elegans in either media. However, chronic exposure to ZnO-NPs caused a significant reduction in C. elegans body bends in EPA water even with a relatively low concentration (0.05 μg/l); similar results were not observed in SSPW. Moreover, at the same concentrations (50 and 500 μg/l), body bends in C. elegans were reduced more severely in ZnO-NPs than in ZnCl2 in EPA water. The ATP levels were consistently and significantly decreased, and ROS was induced after ZnO-NPs exposure (50 and 500 μg/l) in EPA water. Our results provide evidences that chronic exposure to ZnO-NPs under environmentally relevant concentrations causes metabolic and locomotive toxicities implicating the potential ecotoxicity of ZnO-NPs at low concentrations in aquatic environments.
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Affiliation(s)
- Chi-Wei Huang
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan
| | - Shang-Wei Li
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan
| | - Vivian Hsiu-Chuan Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei 106, Taiwan.
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11
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Luz AL, Lagido C, Hirschey MD, Meyer JN. In Vivo Determination of Mitochondrial Function Using Luciferase-Expressing Caenorhabditis elegans: Contribution of Oxidative Phosphorylation, Glycolysis, and Fatty Acid Oxidation to Toxicant-Induced Dysfunction. CURRENT PROTOCOLS IN TOXICOLOGY 2016; 69:25.8.1-25.8.22. [PMID: 27479364 PMCID: PMC5002950 DOI: 10.1002/cptx.10] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mitochondria are a target of many drugs and environmental toxicants; however, how toxicant-induced mitochondrial dysfunction contributes to the progression of human disease remains poorly understood. To address this issue, in vivo assays capable of rapidly assessing mitochondrial function need to be developed. Here, using the model organism Caenorhabditis elegans, we describe how to rapidly assess the in vivo role of the electron transport chain, glycolysis, or fatty acid oxidation in energy metabolism following toxicant exposure, using a luciferase-expressing ATP reporter strain. Alterations in mitochondrial function subsequent to toxicant exposure are detected by depleting steady-state ATP levels with inhibitors of the mitochondrial electron transport chain, glycolysis, or fatty acid oxidation. Differential changes in ATP following short-term inhibitor exposure indicate toxicant-induced alterations at the site of inhibition. Because a microplate reader is the only major piece of equipment required, this is a highly accessible method for studying toxicant-induced mitochondrial dysfunction in vivo. © 2016 by John Wiley & Sons, Inc.
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Affiliation(s)
- Anthony L. Luz
- Nicholas School of the Environment, PO Box 90328, Duke University, Durham, North Carolina, 27708
| | - Cristina Lagido
- School of Medical Sciences, Institute of Medical Sciences, Aberdeen AB25 2 ZD, UK
| | - Matthew D. Hirschey
- Department of Medicine, 500 N. Duke St., 50-201, Duke University, Durham, North Carolina, 27708
| | - Joel N. Meyer
- Nicholas School of the Environment, PO Box 90328, Duke University, Durham, North Carolina, 27708
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12
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Dietrich N, Tan CH, Cubillas C, Earley BJ, Kornfeld K. Insights into zinc and cadmium biology in the nematode Caenorhabditis elegans. Arch Biochem Biophys 2016; 611:120-133. [PMID: 27261336 DOI: 10.1016/j.abb.2016.05.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/18/2016] [Accepted: 05/28/2016] [Indexed: 10/21/2022]
Abstract
Zinc is an essential metal that is involved in a wide range of biological processes, and aberrant zinc homeostasis is implicated in multiple human diseases. Cadmium is chemically similar to zinc, but it is a nonessential environmental pollutant. Because zinc deficiency and excess are deleterious, animals require homeostatic mechanisms to maintain zinc levels in response to dietary fluctuations. The nematode Caenorhabditis elegans is emerging as a powerful model system to investigate zinc trafficking and homeostasis as well as cadmium toxicity. Here we review genetic and molecular studies that have combined to generate a picture of zinc homeostasis based on the transcriptional control of zinc transporters in intestinal cells. Furthermore, we summarize studies of cadmium toxicity that reveal intriguing parallels with zinc biology.
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Affiliation(s)
- Nicholas Dietrich
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, United States.
| | - Chieh-Hsiang Tan
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Ciro Cubillas
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Brian James Earley
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, United States
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, Campus Box 8103, 660 South Euclid Avenue, St. Louis, MO 63110, United States
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13
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Maurer LL, Ryde IT, Yang X, Meyer JN. Caenorhabditis elegans
as a Model for Toxic Effects of Nanoparticles: Lethality, Growth, and Reproduction. ACTA ACUST UNITED AC 2015; 66:20.10.1-20.10.25. [DOI: 10.1002/0471140856.tx2010s66] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Laura L. Maurer
- Nicholas School of the Environment, Duke University Durham North Carolina
| | - Ian T. Ryde
- Nicholas School of the Environment, Duke University Durham North Carolina
| | - Xinyu Yang
- Nicholas School of the Environment, Duke University Durham North Carolina
| | - Joel N. Meyer
- Nicholas School of the Environment, Duke University Durham North Carolina
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14
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Lagido C, McLaggan D, Glover LA. A Screenable In Vivo Assay for Mitochondrial Modulators Using Transgenic Bioluminescent Caenorhabditis elegans. J Vis Exp 2015:e53083. [PMID: 26554627 PMCID: PMC4692654 DOI: 10.3791/53083] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The multicellular model organism Caenorhabditis elegans is a small nematode of approximately 1 mm in size in adulthood that is genetically and experimentally tractable. It is economical and easy to culture and dispense in liquid medium which makes it well suited for medium-throughput screening. We have previously validated the use of transgenic luciferase expressing C. elegans strains to provide rapid in vivo assessment of the nematode’s ATP levels.1-3 Here we present the required materials and procedure to carry out bioassays with the bioluminescent C. elegans strains PE254 or PE255 (or any of their derivative strains). The protocol allows for in vivo detection of sublethal effects of drugs that may identify mitochondrial toxicity, as well as for in vivo detection of potential beneficial drug effects. Representative results are provided for the chemicals paraquat, rotenone, oxaloacetate and for four firefly luciferase inhibitory compounds. The methodology can be scaled up to provide a platform for screening drug libraries for compounds capable of modulating mitochondrial function. Pre-clinical evaluation of drug toxicity is often carried out on immortalized cancerous human cell lines which derive ATP mostly from glycolysis and are often tolerant of mitochondrial toxicants.4,5 In contrast, C. elegans depends on oxidative phosphorylation to sustain development into adulthood, drawing a parallel with humans and providing a unique opportunity for compound evaluation in the physiological context of a whole live multicellular organism.
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Affiliation(s)
| | | | - L Anne Glover
- Institute of Medical Sciences, University of Aberdeen
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15
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A High-Throughput Method for the Analysis of Larval Developmental Phenotypes in Caenorhabditis elegans. Genetics 2015; 201:443-8. [PMID: 26294666 PMCID: PMC4596660 DOI: 10.1534/genetics.115.179242] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 08/17/2015] [Indexed: 11/20/2022] Open
Abstract
Caenorhabditis elegans postembryonic development consists of four discrete larval stages separated by molts. Typically, the speed of progression through these larval stages is investigated by visual inspection of the molting process. Here, we describe an automated method to monitor the timing of these discrete phases of C. elegans maturation, from the first larval stage through adulthood, using bioluminescence. The method was validated with a lin-42 mutant strain that shows delayed development relative to wild-type animals and with a daf-2 mutant that shows an extended second larval stage. This new method is inherently high-throughput and will finally allow dissecting the molecular machinery governing the speed of the developmental clock, which has so far been hampered by the lack of a method suitable for genetic screens.
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16
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Rooney JP, Luz AL, González-Hunt CP, Bodhicharla R, Ryde IT, Anbalagan C, Meyer JN. Effects of 5'-fluoro-2-deoxyuridine on mitochondrial biology in Caenorhabditis elegans. Exp Gerontol 2014; 56:69-76. [PMID: 24704715 DOI: 10.1016/j.exger.2014.03.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 03/15/2014] [Accepted: 03/26/2014] [Indexed: 12/17/2022]
Abstract
5-Fluoro-2'-deoxyuridine (FUdR) is a DNA synthesis inhibitor commonly used to sterilize Caenorhabditis elegans in order to maintain a synchronized aging population of nematodes, without contamination by their progeny, in lifespan experiments. All somatic cells in the adult nematode are post-mitotic and therefore do not require nuclear DNA synthesis. However, mitochondrial DNA (mtDNA) replicates independently of the cell cycle and thus represents a potential target for FUdR toxicity. Inhibition of mtDNA synthesis can lead to mtDNA depletion, which is linked to a number of diseases in humans. Furthermore, alterations in mitochondrial biology can affect lifespan in C. elegans. We characterized the effects of FUdR exposure on mtDNA and nuclear DNA (nucDNA) copy numbers, DNA damage, steady state ATP levels, nematode size, mitochondrial morphology, and lifespan in the germ line deficient JK1107 glp-1(q244) and PE255 glp-4(bn2) strains. Lifespan was increased very slightly by 25 μM FUdR, but was reduced by 400 μM. Both concentrations reduced mtDNA and nucDNA copy numbers, but did not change their ratio. There was no detectable effect of FUdR on mitochondrial morphology. Although both concentrations of FUdR resulted in smaller sized animals, changes to steady-state ATP levels were either not detected or restricted to the higher dose and/or later timepoints, depending on the method employed and strain tested. Finally, we determined the half-life of mtDNA in somatic cells of adult C. elegans to be between 8 and 13 days; this long half-life very likely explains the small or undetectable impact of FUdR on mitochondrial endpoints in our experiments. We discuss the relative pitfalls associated with using FUdR and germline deficient mutant strains as tools for the experimental elimination of progeny.
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Affiliation(s)
- J P Rooney
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, LSRC, PO Box 90328, Durham, NC 27708, USA
| | - A L Luz
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, LSRC, PO Box 90328, Durham, NC 27708, USA
| | - C P González-Hunt
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, LSRC, PO Box 90328, Durham, NC 27708, USA
| | - R Bodhicharla
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, LSRC, PO Box 90328, Durham, NC 27708, USA
| | - I T Ryde
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, LSRC, PO Box 90328, Durham, NC 27708, USA
| | - C Anbalagan
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, LSRC, PO Box 90328, Durham, NC 27708, USA
| | - J N Meyer
- Duke University, Nicholas School of the Environment, Integrated Toxicology and Environmental Health Program, LSRC, PO Box 90328, Durham, NC 27708, USA.
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17
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Wang Y, Ezemaduka AN. Combined effect of temperature and zinc on Caenorhabditis elegans wild type and daf-21 mutant strains. J Therm Biol 2014; 41:16-20. [DOI: 10.1016/j.jtherbio.2014.02.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2013] [Revised: 01/12/2014] [Accepted: 02/03/2014] [Indexed: 11/25/2022]
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18
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Bodhicharla R, Ryde IT, Prasad GL, Meyer JN. The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) induces mitochondrial and nuclear DNA damage in Caenorhabditis elegans. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2014; 55:43-50. [PMID: 24014178 DOI: 10.1002/em.21815] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 08/09/2013] [Accepted: 08/09/2013] [Indexed: 06/02/2023]
Abstract
The metabolites of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) form DNA adducts in animal models. While there are many reports of formation of nuclear DNA adducts, one report also detected NNK-induced damage to the mitochondrial genome in rats. Using a different DNA damage detection technology, we tested whether this finding could be repeated in the nematode Caenorhabditis elegans. We treated N2 strain (wild-type) nematodes with NNK in liquid culture, and applied quantitative PCR to analyze NNK-induced nuclear and mitochondrial DNA (mtDNA) damage. Our results confirm that NNK causes both nuclear and mtDNA damage. However, we did not detect a difference in the level of nuclear versus mtDNA damage in C. elegans. To test whether the mtDNA damage was associated with mitochondrial dysfunction, we used a transgenic nematode strain that permits in vivo measurement of ATP levels and found lower levels of ATP in NNK-exposed animals when compared with the unexposed controls. To test whether the lower levels of ATP could be attributed to inhibition of respiratory chain components, we investigated oxygen consumption in whole C. elegans and found reduced oxygen consumption in exposed animals when compared with the unexposed controls. Our data suggest a model in which NNK exposure causes damage to both C. elegans nuclear and mitochondrial genomes, and support the hypothesis that the mitochondrial damage is functionally important in this model. These results also represent a first step in developing this genetically tractable organism as a model for assessing NNK toxicity.
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Affiliation(s)
- Rakesh Bodhicharla
- Nicholas School of the Environment, Duke University, Durham, North Carolina
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19
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Xu C, Zhang J, Mihai DM, Washington I. Light-harvesting chlorophyll pigments enable mammalian mitochondria to capture photonic energy and produce ATP. J Cell Sci 2013; 127:388-99. [PMID: 24198392 DOI: 10.1242/jcs.134262] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Sunlight is the most abundant energy source on this planet. However, the ability to convert sunlight into biological energy in the form of adenosine-5'-triphosphate (ATP) is thought to be limited to chlorophyll-containing chloroplasts in photosynthetic organisms. Here we show that mammalian mitochondria can also capture light and synthesize ATP when mixed with a light-capturing metabolite of chlorophyll. The same metabolite fed to the worm Caenorhabditis elegans leads to increase in ATP synthesis upon light exposure, along with an increase in life span. We further demonstrate the same potential to convert light into energy exists in mammals, as chlorophyll metabolites accumulate in mice, rats and swine when fed a chlorophyll-rich diet. Results suggest chlorophyll type molecules modulate mitochondrial ATP by catalyzing the reduction of coenzyme Q, a slow step in mitochondrial ATP synthesis. We propose that through consumption of plant chlorophyll pigments, animals, too, are able to derive energy directly from sunlight.
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Affiliation(s)
- Chen Xu
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA
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20
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Leung MCK, Rooney JP, Ryde IT, Bernal AJ, Bess AS, Crocker TL, Ji AQ, Meyer JN. Effects of early life exposure to ultraviolet C radiation on mitochondrial DNA content, transcription, ATP production, and oxygen consumption in developing Caenorhabditis elegans. BMC Pharmacol Toxicol 2013; 14:9. [PMID: 23374645 PMCID: PMC3621653 DOI: 10.1186/2050-6511-14-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 01/14/2013] [Indexed: 11/25/2022] Open
Abstract
Background Mitochondrial DNA (mtDNA) is present in multiple copies per cell and undergoes dramatic amplification during development. The impacts of mtDNA damage incurred early in development are not well understood, especially in the case of types of mtDNA damage that are irreparable, such as ultraviolet C radiation (UVC)-induced photodimers. Methods We exposed first larval stage nematodes to UVC using a protocol that results in accumulated mtDNA damage but permits nuclear DNA (nDNA) repair. We then measured the transcriptional response, as well as oxygen consumption, ATP levels, and mtDNA copy number through adulthood. Results Although the mtDNA damage persisted to the fourth larval stage, we observed only a relatively minor ~40% decrease in mtDNA copy number. Transcriptomic analysis suggested an inhibition of aerobic metabolism and developmental processes; mRNA levels for mtDNA-encoded genes were reduced ~50% at 3 hours post-treatment, but recovered and, in some cases, were upregulated at 24 and 48 hours post-exposure. The mtDNA polymerase γ was also induced ~8-fold at 48 hours post-exposure. Moreover, ATP levels and oxygen consumption were reduced in response to UVC exposure, with marked reductions of ~50% at the later larval stages. Conclusions These results support the hypothesis that early life exposure to mitochondrial genotoxicants could result in mitochondrial dysfunction at later stages of life, thereby highlighting the potential health hazards of time-delayed effects of these genotoxicants in the environment.
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Affiliation(s)
- Maxwell C K Leung
- Nicholas School of the Environment, Duke University, Durham, NC, USA
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21
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Li Y, Gao S, Jing H, Qi L, Ning J, Tan Z, Yang K, Zhao C, Ma L, Li G. Correlation of chemical acute toxicity between the nematode and the rodent. Toxicol Res (Camb) 2013. [DOI: 10.1039/c3tx50039j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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22
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McLaggan D, Amezaga MR, Petra E, Frost A, Duff EI, Rhind SM, Fowler PA, Glover LA, Lagido C. Impact of sublethal levels of environmental pollutants found in sewage sludge on a novel Caenorhabditis elegans model biosensor. PLoS One 2012; 7:e46503. [PMID: 23056324 PMCID: PMC3463613 DOI: 10.1371/journal.pone.0046503] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 08/31/2012] [Indexed: 01/12/2023] Open
Abstract
A transgenic strain of the model nematode Caenorhabditis elegans in which bioluminescence reports on relative, whole-organism ATP levels was used to test an environmentally-relevant mixture of pollutants extracted from processed sewage sludge. Changes in bioluminescence, following exposure to sewage sludge extract, were used to assess relative ATP levels and overall metabolic health. Reproductive function and longevity were also monitored. A short (up to 8 h) sublethal exposure of L4 larval stage worms to sewage sludge extract had a concentration-dependent, detrimental effect on energy status, with bioluminescence decreasing to 50-60% of the solvent control (1% DMSO). Following longer exposure (22-24 h), the energy status of the nematodes showed recovery as assessed by bioluminescence. Continuous exposure to sewage sludge extract from the L4 stage resulted in a shorter median lifespan relative to that of solvent or medium control animals, but only in the presence of 400-600 µM 5-fluoro-2'-deoxyuridine (FUdR), which was incorporated to inhibit reproduction. This indicated that FUdR increased lifespan, and that the effect was counteracted by SSE. Exposure to sewage sludge extract from the L1 stage led to slower growth and a delayed onset of egg laying. When L1 exposed nematodes reached the reproductive stage, no effect on egg laying rate or egg number in the uterus was observed. DMSO itself (1%) had a significant inhibitory effect on growth and development of C. elegans exposed from the L1 stage and on reproduction when exposed from the L4 stage. Results demonstrate subtle adverse effects on C. elegans of a complex mixture of environmental pollutants that are present, individually, in very low concentrations and indicate that our biosensor of energy status is a novel, sensitive, rapid, quantitative, whole-organism test system which is suitable for high throughput risk assessment of complex pollutant mixtures.
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Affiliation(s)
- Debbie McLaggan
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom
- * E-mail: (DM); (CL)
| | - Maria R. Amezaga
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom
| | - Eleni Petra
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom
| | - Andrew Frost
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom
| | - Elizabeth I. Duff
- Biomathematics and Statistics Scotland, Aberdeen, Scotland, United Kingdom
| | | | - Paul A. Fowler
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom
| | - L. Anne Glover
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom
| | - Cristina Lagido
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland, United Kingdom
- * E-mail: (DM); (CL)
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Ellegaard-Jensen L, Jensen KA, Johansen A. Nano-silver induces dose-response effects on the nematode Caenorhabditis elegans. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2012; 80:216-223. [PMID: 22475389 DOI: 10.1016/j.ecoenv.2012.03.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 03/06/2012] [Accepted: 03/07/2012] [Indexed: 05/31/2023]
Abstract
Toxicity of nano-formulated silver to eukaryotes was assessed by exposing nematodes (Caenorhabditis elegans) to two types of silver nanoparticles (AgNPs): with average primary particle diameters of 1 nm (AgNP1) and 28nm (AgNP28, PVP coated), respectively. Tests were performed with and without presence of Escherichia coli to evaluate how the presence of a food bacterium affects the AgNP toxicity. A pre-exposure experiment was also conducted with nematodes pre-exposed to 0 and 1mgAgNPL(-1), respectively, for 20 h prior to exposure at higher concentrations of AgNP. Both AgNP1 and AgNP28 showed adverse dose-response effects and mortality on C. elegans. LC(50) for AgNP28 was lower than for AgNP1 and, hence, at the present test conditions the PVP-coated AgNP28 was more toxic than AgNP1. Including E. coli in the test medium as a food source increased AgNPs toxicity towards nematodes compared to when bacteria were not present. Pre-exposure to a low-level AgNP1 concentration made the nematodes slightly more sensitive to further exposure at higher concentrations compared to no pre-exposure, indicating that nematodes have no efficient physiological ability to counteract nano-silver toxicity by acclimation. The amount of dissolved Ag(+) was 0.18 to 0.21 mg L(-1) after 20 h at the highest AgNP1 (10 mg L(-1)) and AgNP28 (3 mg L(-1)) doses in the exposure medium, respectively. The upper limit of Ag(+) solubility cannot immediately explain the dose-response-related toxic effects of the AgNP nor the difference between AgNP1 and AgNP28. Higher toxicity of AgNP28 than AgNP1 may be explained by a combination of effects of coating, Ag-solubility and higher uptake rates due to agglomeration into μm-size agglomerates in the exposure medium.
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Affiliation(s)
- Lea Ellegaard-Jensen
- Department of Biology, Copenhagen University, Øster Farimagsgade 2D, DK-1353 Copenhagen K, Denmark
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24
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Mongkoldhumrongkul N, Swain SC, Jayasinghe SN, Stürzenbaum S. Bio-electrospraying the nematode Caenorhabditis elegans: studying whole-genome transcriptional responses and key life cycle parameters. J R Soc Interface 2010; 7:595-601. [PMID: 19776148 PMCID: PMC2842783 DOI: 10.1098/rsif.2009.0364] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 08/24/2009] [Indexed: 01/26/2023] Open
Abstract
Bio-electrospray, the direct jet-based cell handling approach, is able to handle a wide range of cells (spanning immortalized, primary to stem cells). Studies at the genomic, genetic and the physiological levels have shown that, post-treatment, cellular integrity is unperturbed and a high percentage (more than 70%, compared with control) of cells remain viable. Although, these results are impressive, it may be argued that cell-based systems are oversimplistic. Therefore, it is important to evaluate the bio-electrospray technology using sensitive and dynamically developing multi-cellular organisms that share, at least some, similarities with multi-cell microenvironments encountered with tissues and organs. This study addressed this issue by using a well-characterized model organism, the non-parasitic nematode Caenorhabditis elegans. Nematode cultures were subjected to bio-electrospraying and compared with positive (heat shock) and negative controls (appropriate laboratory culture controls). Overall, bio-electrospraying did not modulate the reproductive output or induce significant changes in in vivo stress-responsive biomarkers (heat shock proteins). Likewise, whole-genome transcriptomics could not identify any biological processes, cellular components or molecular functions (gene ontology terms) that were significantly enriched in response to bio-electrospraying. This demonstrates that bio-electrosprays can be safely applied directly to nematodes and underlines its potential future use in the creation of multi-cellular environments within clinical applications.
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Affiliation(s)
- Napachanok Mongkoldhumrongkul
- BioPhysics Group, Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Suresh C. Swain
- Pharmaceutical Science Division, King's College London, School of Biomedical and Health Sciences, 150 Stamford Street, London SE1 9NH, UK
| | - Suwan N. Jayasinghe
- BioPhysics Group, Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Stephen Stürzenbaum
- Pharmaceutical Science Division, King's College London, School of Biomedical and Health Sciences, 150 Stamford Street, London SE1 9NH, UK
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Nwose EU, Ewing GW. Computer diagnosis in cardiology: oxidative stress hypothesis. NORTH AMERICAN JOURNAL OF MEDICAL SCIENCES 2009; 1:220-5. [PMID: 22666699 PMCID: PMC3364613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Virtual scanning is one of the emerging technologies in complementary medicine practice. The diagnostic principle is hinged on perception and ultra weak light emission, while the treatment options associated with it includes diet, flash light, exercise and relaxation. However, a mechanism that links the diagnostic and treatment principles has yet to be elucidated. AIMS The objective here is to further explanation of oxidative stress concept as the biochemical basis of the technology. MATERIALS AND METHODS Using available literature and basic science textbook, the function of the hypothalamus-pituitary-adrenalin axis as neuro-endocrine physiological system that is strongly linked to the rate of alterations in biochemical processes through to cardiovascular complications is articulated. RESULTS The hypothesis brings to fore the potential of using the alterations in biochemical processes associated with cognition as tool to validate the Virtual Scanning technology for possible incorporation into clinical practice. Or vice versa to use Virtual Scanning technology to determine the chemiluminescence-related biochemical changes resulting from pathologies that could benefit from relaxation, light therapy, exercise and antioxidant nutrition. CONCLUSIONS This article advances the applicability of cognitive test procedure for indication of the disease(s) affecting heart function. The implication for some laboratory indices that are already available in clinical practice is highlighted. Investigation of this hypothesis will help provide clear link between plausible mechanism and the theory proposed.
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Affiliation(s)
- Ezekiel Uba Nwose
- Institute of Clinical Pathology and Medical Research, South West Pathology Service, 590 Smollett Albury NSW 2640, Australia.,Correspondence to: Ezekiel Uba Nwose, Institute of Clinical Pathology and Medical Research (ICPMR), South West Pathology Service, 590 Smollett Albury, NSW 2640, Australia. Tel.: +61 260581651, Fax: +61 260581680.
| | - Graham Wilfred Ewing
- Montague Healthcare, Mulberry House, 6 Vine Farm Close – Cotgrave, Nottinghamshire, England
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