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Liu H, Earley B, Mendoza A, Hunt P, Teng S, Schneider DL, Kornfeld K. A single high-zinc activation enhancer can control two genes oriented head-to-head in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2025:jkaf089. [PMID: 40408183 DOI: 10.1093/g3journal/jkaf089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2025] [Accepted: 04/04/2025] [Indexed: 05/25/2025]
Abstract
Enhancers play critical roles in gene expression, but a full understanding of their complex functions has yet to be defined. The cellular response to excess zinc levels in Caenorhabditis elegans requires the HIZR-1 transcription factor, which binds the high-zinc activation (HZA) enhancer in the promoters of multiple target genes. Cadmium hijacks the excess zinc response by binding and activating HIZR-1. By analyzing the genome-wide transcriptional response to excess zinc and cadmium, we identified two positions in the genome where head-to-head oriented genes are both induced by metals. In both examples, a single predicted HZA enhancer is positioned between the two translational start sites. We hypothesized that a single enhancer can control both head-to-head genes, an arrangement that has not been extensively characterized. To test this hypothesis, we used CRISPR genome editing to precisely delete the HZAmT enhancer positioned between mtl-2 and T08G5.1; in this mutant, both head-to-head genes display severely reduced zinc-activated transcription, whereas zinc-activated transcription of more distant genes was not strongly affected. Deleting the HZAcF enhancer positioned between cdr-1 and F35E8.10 caused both head-to-head genes to display reduced cadmium-activated transcription, whereas cadmium-activated transcription of more distant genes was not strongly affected. These studies rigorously document that a single HZA enhancer can control two head-to-head genes, advancing our understanding of the diverse functions of enhancers.
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Affiliation(s)
- Hanwenheng Liu
- Department of Developmental Biology, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Brian Earley
- Department of Developmental Biology, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Adelita Mendoza
- Department of Developmental Biology, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Patrick Hunt
- Department of Developmental Biology, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Sean Teng
- Department of Developmental Biology, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Daniel Luke Schneider
- Department of Developmental Biology, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, Washington University in St. Louis, St. Louis, MO 63110, USA
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2
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Liu H, Earley B, Mendoza A, Hunt P, Teng S, Schneider DL, Kornfeld K. A single high-zinc activation enhancer can control two genes orientated head-to-head in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2024.11.19.624376. [PMID: 40196504 PMCID: PMC11974713 DOI: 10.1101/2024.11.19.624376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 04/09/2025]
Abstract
Enhancers play critical roles in gene expression, but a full understanding of their complex functions has yet to be defined. The cellular response to excess zinc levels in C. elegans requires the HIZR-1 transcription factor, which binds the high-zinc activation (HZA) enhancer in the promoters of multiple target genes. Cadmium hijacks the excess zinc response by binding and activating HIZR-1. By analyzing the genome-wide transcriptional response to excess zinc and cadmium, we identified two positions in the genome where head-to-head oriented genes are both induced by metals. In both examples, a single predicted HZA enhancer is positioned between the two translational start sites. We hypothesized that a single enhancer can control both head-to-head genes, an arrangement that has not been extensively characterized. To test this hypothesis, we used CRISPR genome editing to precisely delete the HZAmT enhancer positioned between mtl-2 and T08G5.1; in this mutant, both head-to-head genes display severely reduced zinc-activated transcription, whereas zinc-activated transcription of more distant genes was not strongly affected. Deleting the HZAcF enhancer positioned between cdr-1 and F35E8.10 caused both head-to-head genes to display reduced cadmium-activated transcription, whereas cadmium-activated transcription of more distant genes was not strongly affected. These studies rigorously document that a single HZA enhancer can control two head-to-head genes, advancing our understanding of the diverse functions of enhancers.
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Affiliation(s)
- Hanwenheng Liu
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO 63130, USA
| | - Brian Earley
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO 63130, USA
- Current address: Blackfoot High School, 870 S. Fisher Avenue, Blackfoot, Idaho 83221, USA
| | - Adelita Mendoza
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO 63130, USA
- Current address: University of Colorado at Boulder, 3415 Colorado Ave, Boulder, CO 80303, USA
| | - Patrick Hunt
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO 63130, USA
| | - Sean Teng
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO 63130, USA
- Current address: Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702-1201, USA
| | - Daniel L. Schneider
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO 63130, USA
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave, St. Louis, MO 63130, USA
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3
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Shahid S, Klein C, Meyer JN, Huayta J. Glowing worms: A low-cost fluorescence kit for toxicological education using Caenorhabditis elegans. MICROPUBLICATION BIOLOGY 2025; 2025:10.17912/micropub.biology.001506. [PMID: 39967796 PMCID: PMC11833463 DOI: 10.17912/micropub.biology.001506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2025] [Revised: 01/27/2025] [Accepted: 02/01/2025] [Indexed: 02/20/2025]
Abstract
Exposures to metals such as lead and cadmium due to environmental pollution cause cardiovascular, liver, kidney, and other diseases. We used the nematode Caenorhabditis elegans paired with an inexpensive "do-it-yourself" fluorescent microscopy setup to highlight the effects of cadmium exposure on expression of the metallothionein-producing gene mtl-2 to enhance education on the effects of heavy metals. This approach enables observation of GFP fluorescence in worms outside of laboratory settings, while also allowing quantification of gene expression after chemical exposure. We developed an activity centering this experiment for the Museum of Life and Science located in Durham, NC. Participants successfully observed the effects of cadmium on C. elegans and made meaningful connections to both environmental and human health.
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Affiliation(s)
- Sakina Shahid
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States
| | - Chiara Klein
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States
| | - Joel N. Meyer
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States
| | - Javier Huayta
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States
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4
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Andric A, Niederwanger M, Albertini E, Jansen-Dürr P, Stürzenbaum SR, Dallinger R, Pedrini-Martha V, Weiss AKH. A multi-domain snail metallothionein increases cadmium resistance and fitness in Caenorhabditis elegans. Sci Rep 2024; 14:25589. [PMID: 39462019 PMCID: PMC11513058 DOI: 10.1038/s41598-024-76268-2] [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: 04/23/2024] [Accepted: 10/11/2024] [Indexed: 10/28/2024] Open
Abstract
Metallothioneins (MTs) are a family of mostly low-molecular weight, cysteine-rich proteins capable of specific metal-ion binding that are involved in metal detoxification and homeostasis, as well as in stress response. In contrast to most other animal species which possess two-domain (bidominial) MTs, some gastropod species have evolved Cd2+-selective multidomain MTs (md-MTs) consisting of several concatenated β3 domains and a single C-terminal β1 domain. Each domain contains three-metal ion clusters and binds three metal ions. The terrestrial snail Alinda biplicata possesses, among other MT isoforms, an md-MT with nine β3 domains and a C-terminal β1 domain (termed 10md-MT), capable of binding up to 30 Cd2+ ions per protein molecule. In the present study, the Alinda biplicata 10md-MT gene and a truncated version consisting of one β3 domain and a single C-terminal β1 domain (2d-MT) were introduced into a Caenorhabditis elegans knock-out strain lacking a native MT gene (mtl-1). The two snail MT constructs consistently increased Cd2+ resistance, and partially improved morphological, life history and physiological fitness traits in the nematode model host Caenorhabditis elegans. This highlights how the engineering of transgenic Caenorhabditis elegans strains expressing snail MTs provides an enhancement of the innate metal detoxification mechanism and in doing so provides a platform for enhanced mechanistic toxicology.
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Affiliation(s)
- Andreas Andric
- Institute for Biomedical Aging Research, University of Innsbruck, Innsbruck, Austria
| | | | - Eva Albertini
- Institute for Biomedical Aging Research, University of Innsbruck, Innsbruck, Austria
| | - Pidder Jansen-Dürr
- Institute for Biomedical Aging Research, University of Innsbruck, Innsbruck, Austria
- Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| | - Stephen R Stürzenbaum
- Department of Analytical, Environmental and Forensic Sciences, King's College London, London, UK
| | - Reinhard Dallinger
- Department of Zoology, University of Innsbruck, Innsbruck, Austria.
- Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria.
| | | | - Alexander K H Weiss
- Institute for Biomedical Aging Research, University of Innsbruck, Innsbruck, Austria.
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5
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Abraham E, Athapaththu AMGK, Atanasova KR, Chen QY, Corcoran TJ, Piloto J, Wu CW, Ratnayake R, Luesch H, Choe KP. Chemical Genetics in C. elegans Identifies Anticancer Mycotoxins Chaetocin and Chetomin as Potent Inducers of a Nuclear Metal Homeostasis Response. ACS Chem Biol 2024; 19:1180-1193. [PMID: 38652683 PMCID: PMC11102292 DOI: 10.1021/acschembio.4c00131] [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] [Indexed: 04/25/2024]
Abstract
C. elegans numr-1/2 (nuclear-localized metal-responsive) is an identical gene pair encoding a nuclear protein previously shown to be activated by cadmium and disruption of the integrator RNA metabolism complex. We took a chemical genetic approach to further characterize regulation of this novel metal response by screening 41,716 compounds and extracts for numr-1p::GFP activation. The most potent activator was chaetocin, a fungal 3,6-epidithiodiketopiperazine (ETP) with promising anticancer activity. Chaetocin activates numr-1/2 strongly in the alimentary canal but is distinct from metal exposure, because it represses canonical cadmium-responsive metallothionine genes. Chaetocin has diverse targets in cancer cells including thioredoxin reductase, histone lysine methyltransferase, and acetyltransferase p300/CBP; further work is needed to identify the mechanism in C. elegans as genetic disruption and RNAi screening of homologues did not induce numr-1/2 in the alimentary canal and chaetocin did not affect markers of integrator dysfunction. We demonstrate that disulfides in chaetocin and chetomin, a dimeric ETP analog, are required to induce numr-1/2. ETP monomer gliotoxin, despite possessing a disulfide linkage, had almost no effect on numr-1/2, suggesting a dimer requirement. Chetomin inhibits C. elegans growth at low micromolar levels, and loss of numr-1/2 increases sensitivity; C. elegans and Chaetomiaceae fungi inhabit similar environments raising the possibility that numr-1/2 functions as a defense mechanism. There is no direct orthologue of numr-1/2 in humans, but RNaseq suggests that chaetocin affects expression of cellular processes linked to stress response and metal homeostasis in colorectal cancer cells. Our results reveal interactions between metal response gene regulation and ETPs and identify a potential mechanism of resistance to this versatile class of preclinical compounds.
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Affiliation(s)
- Elijah Abraham
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | | | - Kalina R. Atanasova
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
- Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, Florida 32610, United States
| | - Qi-Yin Chen
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
- Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, Florida 32610, United States
| | - Taylor J. Corcoran
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
- Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, Florida 32610, United States
| | - Juan Piloto
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Cheng-Wei Wu
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S&N 5B4 Canada
| | - Ranjala Ratnayake
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
- Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, Florida 32610, United States
| | - Hendrik Luesch
- Department of Medicinal Chemistry, University of Florida, Gainesville, Florida 32610, United States
- Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, Florida 32610, United States
| | - Keith P. Choe
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
- Center for Natural Products, Drug Discovery and Development, University of Florida, Gainesville, Florida 32610, United States
- Genetics Institute, University of Florida, Gainesville, FL 32610, USA
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Hernández-Cruz EY, Aparicio-Trejo OE, Eugenio-Pérez D, Juárez-Peredo E, Zurita-León M, Valdés VJ, Pedraza-Chaverri J. Sulforaphane Exposure Prevents Cadmium-Induced Toxicity and Mitochondrial Dysfunction in the Nematode Caenorhabditis elegans by Regulating the Insulin/Insulin-like Growth Factor Signaling (IIS) Pathway. Antioxidants (Basel) 2024; 13:584. [PMID: 38790689 PMCID: PMC11117759 DOI: 10.3390/antiox13050584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 05/05/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024] Open
Abstract
Cadmium (Cd) is a heavy metal that is highly toxic to humans and animals. Its adverse effects have been widely associated with mitochondrial alterations. However, there are not many treatments that target mitochondria. This study aimed to evaluate the impact of sulforaphane (SFN) pre-exposure against cadmium chloride (CdCl2)-induced toxicity and mitochondrial alterations in the nematode Caenorhabditis elegans (C. elegans), by exploring the role of the insulin/insulin-like growth factor signaling pathway (IIS). The results revealed that prior exposure to SFN protected against CdCl2-induced mortality and increased lifespan, body length, and mobility while reducing lipofuscin levels. Furthermore, SFN prevented mitochondrial alterations by increasing mitochondrial membrane potential (Δψm) and restoring mitochondrial oxygen consumption rate, thereby decreasing mitochondrial reactive oxygen species (ROS) production. The improvement in mitochondrial function was associated with increased mitochondrial mass and the involvement of the daf-16 and skn-1c genes of the IIS signaling pathway. In conclusion, exposure to SFN before exposure to CdCl2 mitigates toxic effects and mitochondrial alterations, possibly by increasing mitochondrial mass, which may be related to the regulation of the IIS pathway. These discoveries open new possibilities for developing therapies to reduce the damage caused by Cd toxicity and oxidative stress in biological systems, highlighting antioxidants with mitochondrial action as promising tools.
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Affiliation(s)
- Estefani Yaquelin Hernández-Cruz
- Laboratorio F-315, Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico; (E.Y.H.-C.); (D.E.-P.); (E.J.-P.)
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, Mexico City 04510, Mexico
| | - Omar Emiliano Aparicio-Trejo
- Departamento de Fisiopatología Cardio-Renal, Instituto Nacional de Cardiología “Ignacio Chávez”, Mexico City 14080, Mexico;
| | - Dianelena Eugenio-Pérez
- Laboratorio F-315, Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico; (E.Y.H.-C.); (D.E.-P.); (E.J.-P.)
- Posgrado en Ciencias Bioquímicas, Universidad Nacional Autónoma de México (UNAM), Biochemical Sciences, Ciudad Universitaria, Mexico City 04510, Mexico
| | - Elí Juárez-Peredo
- Laboratorio F-315, Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico; (E.Y.H.-C.); (D.E.-P.); (E.J.-P.)
| | - Mariana Zurita-León
- Departamento de Biología y Desarrollo Celular, Instituto de Fisiología Celular (IFC), Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico; (M.Z.-L.); (V.J.V.)
| | - Víctor Julián Valdés
- Departamento de Biología y Desarrollo Celular, Instituto de Fisiología Celular (IFC), Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico; (M.Z.-L.); (V.J.V.)
| | - José Pedraza-Chaverri
- Laboratorio F-315, Departamento de Biología, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico; (E.Y.H.-C.); (D.E.-P.); (E.J.-P.)
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7
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Almutairi N, Khan N, Harrison-Smith A, Arlt VM, Stürzenbaum SR. Stage-specific exposure of Caenorhabditis elegans to cadmium identifies unique transcriptomic response cascades and an uncharacterized cadmium responsive transcript. Metallomics 2024; 16:mfae016. [PMID: 38549424 PMCID: PMC11066929 DOI: 10.1093/mtomcs/mfae016] [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: 10/31/2023] [Accepted: 03/26/2024] [Indexed: 05/04/2024]
Abstract
Age/stage sensitivity is considered a significant factor in toxicity assessments. Previous studies investigated cadmium (Cd) toxicosis in Caenorhabditis elegans, and a plethora of metal-responsive genes/proteins have been identified and characterized in fine detail; however, most of these studies neglected age sensitivity and stage-specific response to toxicants at the molecular level. This present study compared the transcriptome response between C. elegans L3 vs L4 larvae exposed to 20 µM Cd to explore the transcriptional hallmarks of stage sensitivity. The results showed that the transcriptome of the L3 stage, despite being exposed to Cd for a shorter period, was more affected than the L4 stage, as demonstrated by differences in transcriptional changes and magnitude of induction. Additionally, T08G5.1, a hitherto uncharacterized gene located upstream of metallothionein (mtl-2), was transcriptionally hyperresponsive to Cd exposure. Deletion of one or both metallothioneins (mtl-1 and/or mtl-2) increased T08G5.1 expression, suggesting that its expression is linked to the loss of metallothionein. The generation of an extrachromosomal transgene (PT08G5.1:: GFP) revealed that T08G5.1 is constitutively expressed in the head neurons and induced in gut cells upon Cd exposure, not unlike mtl-1 and mtl-2. The low abundance of cysteine residues in T08G5.1 suggests, however, that it may not be involved directly in Cd sequestration to limit its toxicity like metallothionein, but might be associated with a parallel pathway, possibly an oxidative stress response.
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Affiliation(s)
- Norah Almutairi
- Department of Analytical, Environmental and Forensic Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Naema Khan
- Department of Analytical, Environmental and Forensic Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Alexandra Harrison-Smith
- Department of Analytical, Environmental and Forensic Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Volker M Arlt
- Department of Analytical, Environmental and Forensic Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Stephen R Stürzenbaum
- Department of Analytical, Environmental and Forensic Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
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Niu S, Wang J, Chang X, Shang M, Guo M, Sun Z, Li Y, Xue Y. Comparative oxidative damages induced by silver nanoparticles with different sizes and coatings in Caenorhabditis elegans. Toxicol Res (Camb) 2023; 12:833-842. [PMID: 37915475 PMCID: PMC10615808 DOI: 10.1093/toxres/tfad074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/10/2023] [Accepted: 08/23/2023] [Indexed: 11/03/2023] Open
Abstract
Silver nanoparticles (AgNPs) are widely used in many commercial and medical products. Serious concerns are paid on their adverse potentials to the environment and human health. In this study, toxic effects and oxidative stress induced by AgNPs with different sizes and coatings (20 nm AgNPs, 20 nm polyvinylpyrrolidone (PVP) -AgNPs and 50 nm AgNPs) in Caenorhabditis elegans (C. elegans) were investigated. The toxic effects including the shortened lifespan and decreased frequency of head thrashes and body bends of C. elegans were induced in a dose-dependent manner by AgNPs. The reactive oxygen species (ROS) production and the oxidative stress-related indicators including malondialdehyde (MDA) and glutathione (GSH) in nematodes were changed after exposure to three kinds of AgNPs. These effects were the most obvious in a 20 nm PVP-AgNPs exposure group. AgNPs could also induce the expression of genes related to oxidative stress in nematodes. In addition, the up-regulation of mtl-1 and mtl-2 in nematodes might reduce the oxidative damage caused by AgNPs, by using transgenic strains CF2222 and CL2120 nematodes. Metallothionein (MT), an antioxidant, could relieve the oxidative damage caused by AgNPs. These results suggested that 20 nm PVP-AgNPs with a smaller particle size and better dispersion have stronger toxic effects and the oxidative damage to nematodes. Mtl-1 and mtl-2 might be involved in alleviating the oxidative damage caused by AgNPs. Our findings provide clues for the safety evaluation and mechanism information of metal nanoparticles.
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Affiliation(s)
- Shuyan Niu
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, 87 Dingjiaqiao, Nanjing 210009, China
| | - Junjun Wang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, 87 Dingjiaqiao, Nanjing 210009, China
| | - Xiaoru Chang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, 87 Dingjiaqiao, Nanjing 210009, China
| | - Mengting Shang
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, 87 Dingjiaqiao, Nanjing 210009, China
| | - Menghao Guo
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, 87 Dingjiaqiao, Nanjing 210009, China
| | - Zuoyi Sun
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, 87 Dingjiaqiao, Nanjing 210009, China
| | - Yunjing Li
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, 87 Dingjiaqiao, Nanjing 210009, China
| | - Yuying Xue
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, Southeast University, 87 Dingjiaqiao, Nanjing 210009, China
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9
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Sharma AK, Finney L, Vogt S, Vatamaniuk OK, Kim S. Cadmium alters whole animal ionome and promotes the re-distribution of iron in intestinal cells of Caenorhabditis elegans. Front Physiol 2023; 14:1258540. [PMID: 37822680 PMCID: PMC10562743 DOI: 10.3389/fphys.2023.1258540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 09/12/2023] [Indexed: 10/13/2023] Open
Abstract
The chronic exposure of humans to the toxic metal cadmium (Cd), either occupational or from food and air, causes various diseases, including neurodegenerative conditions, dysfunction of vital organs, and cancer. While the toxicology of Cd and its effect on the homeostasis of biologically relevant elements is increasingly recognized, the spatial distribution of Cd and other elements in Cd toxicity-caused diseases is still poorly understood. Here, we use Caenorhabditis elegans as a non-mammalian multicellular model system to determine the distribution of Cd at the tissue and cellular resolution and its effect on the internal levels and the distribution of biologically relevant elements. Using inductively coupled plasma-mass spectrophotometry (ICP-MS), we show that exposure of worms to Cd not only led to its internal accumulation but also significantly altered the C. elegans ionome. Specifically, Cd treatment was associated with increased levels of toxic elements such as arsenic (As) and rubidium (Rb) and a decreased accumulation of essential elements such as zinc (Zn), copper (Cu), manganese (Mn), calcium (Ca), cobalt (Co) and, depending on the Cd-concentration used in the assay, iron (Fe). We regarded these changes as an ionomic signature of Cd toxicity in C. elegans. We also show that supplementing nematode growth medium with Zn but not Cu, rescues Cd toxicity and that mutant worms lacking Zn transporters CDF-1 or SUR-7, or both are more sensitive to Cd toxicity. Finally, using synchrotron X-Ray fluorescence Microscopy (XRF), we showed that Cd significantly alters the spatial distribution of mineral elements. The effect of Cd on the distribution of Fe was particularly striking: while Fe was evenly distributed in intestinal cells of worms grown without Cd, in the presence of Cd, Fe, and Cd co-localized in punctum-like structures in the intestinal cells. Together, this study advances our understanding of the effect of Cd on the accumulation and distribution of biologically relevant elements. Considering that C. elegans possesses the principal tissues and cell types as humans, our data may have important implications for future therapeutic developments aiming to alleviate Cd-related pathologies in humans.
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Affiliation(s)
- Anuj Kumar Sharma
- Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - Lydia Finney
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, United States
| | - Stefan Vogt
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, United States
| | - Olena K. Vatamaniuk
- Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - Sungjin Kim
- Section of Plant Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
- Department of Microbiology & Molecular Biology, Chungnam National University, Daejeon, Republic of Korea
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10
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Wang Q, Zhu Y, Song B, Fu R, Zhou Y. The In Vivo Toxicity Assessments of Water-Dispersed Fluorescent Silicon Nanoparticles in Caenorhabditis elegans. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19074101. [PMID: 35409783 PMCID: PMC8998271 DOI: 10.3390/ijerph19074101] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 03/27/2022] [Accepted: 03/29/2022] [Indexed: 12/17/2022]
Abstract
Fluorescent silicon nanoparticles (SiNPs), resembling a typical zero-dimensional silicon nanomaterial, have shown great potential in a wide range of biological and biomedical applications. However, information regarding the toxicity of this material in live organisms is still very scarce. In this study, we utilized Caenorhabditis elegans (C. elegans), a simple but biologically and anatomically well-described model, as a platform to systematically investigate the in vivo toxicity of SiNPs in live organisms at the whole-animal, cellular, subcellular, and molecular levels. We calculated the effect of SiNPs on C. elegans body length (N ≥ 75), lifespan (N ≥ 30), reproductive capacity (N ≥ 10), endocytic sorting (N ≥ 20), endoplasmic reticulum (ER) stress (N ≥ 20), mitochondrial stress (N ≥ 20), oxidative stress (N ≥ 20), immune response (N ≥ 20), apoptosis (N ≥ 200), hypoxia response (N ≥ 200), metal detoxification (N ≥ 200), and aging (N ≥ 200). The studies showed that SiNPs had no significant effect on development, lifespan, or reproductive ability (p > 0.05), even when the worms were treated with a high concentration (e.g., 50 mg/mL) of SiNPs at all growth and development stages. Subcellular analysis of the SiNP-treated worms revealed that the intracellular processes of the C. elegans intestine were not disturbed by the presence of SiNPs (p > 0.05). Toxicity analyses at the molecular level also demonstrated that the SiNPs did not induce harmful or defensive cellular events, such as ER stress, mitochondria stress, or oxidative stress (p > 0.05). Together, these findings confirmed that the SiNPs are low in toxicity and biocompatible, supporting the suggestion that the material is an ideal fluorescent nanoprobe for wide-ranging biological and biomedical applications.
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Affiliation(s)
- Qin Wang
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences (IBMS), Soochow University, Suzhou 215123, China; (Q.W.); (Y.Z.); (R.F.)
| | - Yi Zhu
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences (IBMS), Soochow University, Suzhou 215123, China; (Q.W.); (Y.Z.); (R.F.)
| | - Bin Song
- Institute of Functional Nano & Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou 215123, China;
| | - Rong Fu
- Jiangsu Key Laboratory of Infection and Immunity, Institutes of Biology and Medical Sciences (IBMS), Soochow University, Suzhou 215123, China; (Q.W.); (Y.Z.); (R.F.)
| | - Yanfeng Zhou
- Institute of Functional Nano & Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology, Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou 215123, China;
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- Correspondence:
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11
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Cadmium hijacks the high zinc response by binding and activating the HIZR-1 nuclear receptor. Proc Natl Acad Sci U S A 2021; 118:2022649118. [PMID: 34649987 DOI: 10.1073/pnas.2022649118] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2021] [Indexed: 11/18/2022] Open
Abstract
Cadmium is an environmental pollutant and significant health hazard that is similar to the physiological metal zinc. In Caenorhabditis elegans, high zinc homeostasis is regulated by the high zinc activated nuclear receptor (HIZR-1) transcription factor. To define relationships between the responses to high zinc and cadmium, we analyzed transcription. Many genes were activated by both high zinc and cadmium, and hizr-1 was necessary for activation of a subset of these genes; in addition, many genes activated by cadmium did not require hizr-1, indicating there are at least two mechanisms of cadmium-regulated transcription. Cadmium directly bound HIZR-1, promoted nuclear accumulation of HIZR-1 in intestinal cells, and activated HIZR-1-mediated transcription via the high zinc activation (HZA) enhancer. Thus, cadmium binding promotes HIZR-1 activity, indicating that cadmium acts as a zinc mimetic to hijack the high zinc response. To elucidate the relationships between high zinc and cadmium detoxification, we analyzed genes that function in three pathways: the pcs-1/phytochelatin pathway strongly promoted cadmium resistance but not high zinc resistance, the hizr-1/HZA pathway strongly promoted high zinc resistance but not cadmium resistance, and the mek-1/sek-1/kinase signaling pathway promoted resistance to high zinc and cadmium. These studies identify resistance pathways that are specific for high zinc and cadmium, as well as a shared pathway.
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12
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Li LL, Wu QZ, Chen JJ, Cui YH, Zhu CM, Li BY, Guo Z, Li WW. Mechanical Insights into Thiol-Mediated Synergetic Biotransformation of Cadmium and Selenium in Nematodes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:7531-7540. [PMID: 33974407 DOI: 10.1021/acs.est.1c00686] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Cadmium ion (Cd2+) is a common environmental pollutant with high biotoxicity. Interestingly, the Cd2+ biotoxicity can be alleviated by the coexisting selenite (SeO32-), which induces the formation of cadmium selenide-rich nanoparticles (CdSe NPs) under the function of thiol-capping peptides. However, the detailed biochemical mechanisms by which Cd and Se are synergistically transformed into CdSe NPs in living organisms remain unclear so far. Here, we shed light on the molecular basis of such biotransformation processes in Caenorhabditis elegans by focusing on the roles of several key thiol-capping peptides. By monitoring the compositional and structural changes of the Cd and Se species and the genetic-level responses of nematodes, we revealed the specific roles of glutathione (GSH) and phytochelatins (PCs) in mediating the CdSe NP formation. With the aid of in vitro bioassembly assay and density functional theory calculations, the detailed Cd-Se interaction pathways were further deciphered: the ingested Cd binds predominantly to GSH and PCs in sequence, then further interacts with selenocysteine to form tetrahedral-structured PC2-Cd2-Sec2 complex, and ultimately grows into CdSe NPs. This work provides molecular-level insights into the Cd-Se interaction in C. elegans and lays a basis for controlling the ecological and health risks of heavy metals in polluted environment.
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Affiliation(s)
- Ling-Li Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China
- College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500, China
| | - Qi-Zhong Wu
- School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Jie-Jie Chen
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Yin-Hua Cui
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China
| | - Cheng-Ming Zhu
- School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Bing-Yan Li
- School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Zhen Guo
- School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
| | - Wen-Wei Li
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei 230026, China
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13
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Bovio F, Sciandrone B, Urani C, Fusi P, Forcella M, Regonesi ME. Superoxide dismutase 1 (SOD1) and cadmium: A three models approach to the comprehension of its neurotoxic effects. Neurotoxicology 2021; 84:125-135. [PMID: 33774064 DOI: 10.1016/j.neuro.2021.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/19/2021] [Accepted: 03/19/2021] [Indexed: 12/13/2022]
Abstract
Cadmium (Cd) is a widespread toxic environmental contaminant, released by anthropogenic activities. It interferes with essential metal ions homeostasis and affects protein structures and functions by substituting zinc, copper and iron. In this study, the effect of cadmium on SOD1, a CuZn metalloenzyme catalyzing superoxide conversion into hydrogen peroxide, has been investigated in three different biological models. We first evaluated the effects of cadmium combined with copper and/or zinc on the recombinant GST-SOD1, expressed in E. coli BL21. The enzyme activity and expression were investigated in the presence of fixed copper and/or zinc doses with different cadmium concentrations, in the cellular medium. Cadmium caused a dose-dependent reduction in SOD1 activity, while the expression remains constant. Similar results were obtained in the cellular model represented by the human SH-SY5Y neuronal cell line. After cadmium treatment for 24 and 48 h, SOD1 enzymatic activity decreased in a dose- and time-dependent way, while the protein expression remained constant. Finally, a 16 h cadmium treatment caused a 25 % reduction of CuZn-SOD activity without affecting the protein expression in the Caenorhabditis elegans model. Taken together our results show an inhibitory effect of cadmium on SOD1 enzymatic activity, without affecting the protein expression, in all the biological models used, suggesting that cadmium can displace zinc from the enzyme catalytic site.
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Affiliation(s)
- Federica Bovio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milan, Italy
| | - Barbara Sciandrone
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milan, Italy
| | - Chiara Urani
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milan, Italy; Integrated Models for Prevention and Protection in Environmental and Occupational Health, (MISTRAL), Interuniversity Research Center, Italy
| | - Paola Fusi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milan, Italy; Integrated Models for Prevention and Protection in Environmental and Occupational Health, (MISTRAL), Interuniversity Research Center, Italy.
| | - Matilde Forcella
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milan, Italy.
| | - Maria Elena Regonesi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, 2, 20126, Milan, Italy; Milan Center of Neuroscience (NeuroMI), 20126, Milan, Italy
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14
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Earley BJ, Mendoza AD, Tan CH, Kornfeld K. Zinc homeostasis and signaling in the roundworm C. elegans. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118882. [PMID: 33017595 DOI: 10.1016/j.bbamcr.2020.118882] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 09/11/2020] [Accepted: 09/25/2020] [Indexed: 12/14/2022]
Abstract
C. elegans is a powerful model for studies of zinc biology. Here we review recent discoveries and emphasize the advantages of this model organism. Methods for manipulating and measuring zinc levels have been developed in or adapted to the worm. The C. elegans genome encodes highly conserved zinc transporters, and their expression and function are beginning to be characterized. Homeostatic mechanisms have evolved to respond to high and low zinc conditions. The pathway for high zinc homeostasis has been recently elucidated based on the discovery of the master regulator of high zinc homeostasis, HIZR-1. A parallel pathway for low zinc homeostasis is beginning to emerge based on the discovery of the Low Zinc Activation promoter element. Zinc has been established to play a role in two cell fate determination events, and accumulating evidence suggests zinc may function as a second messenger signaling molecule during vulval cell development and sperm activation.
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Affiliation(s)
- Brian J Earley
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, United States of America
| | - Adelita D Mendoza
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, United States of America
| | - Chieh-Hsiang Tan
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, United States of America
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, MO 63110, United States of America.
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15
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Evans KS, Andersen EC. The cadmium-responsive gene, cdr-6, does not influence Caenorhabditis elegans responses to exogenous zinc. MICROPUBLICATION BIOLOGY 2020; 2020:10.17912/micropub.biology.000305. [PMID: 33005884 PMCID: PMC7520126 DOI: 10.17912/micropub.biology.000305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 09/04/2020] [Accepted: 09/05/2020] [Indexed: 11/22/2022]
Affiliation(s)
- Kathryn S Evans
- Molecular Biosciences, Northwestern University, Evanston, IL 60208
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL 60208
| | - Erik C. Andersen
- Molecular Biosciences, Northwestern University, Evanston, IL 60208
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611
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16
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Shomer N, Kadhim AZ, Grants JM, Cheng X, Alhusari D, Bhanshali F, Poon AFY, Lee MYY, Muhuri A, Park JI, Shih J, Lee D, Lee SJV, Lynn FC, Taubert S. Mediator subunit MDT-15/MED15 and Nuclear Receptor HIZR-1/HNF4 cooperate to regulate toxic metal stress responses in Caenorhabditis elegans. PLoS Genet 2019; 15:e1008508. [PMID: 31815936 PMCID: PMC6922464 DOI: 10.1371/journal.pgen.1008508] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 12/19/2019] [Accepted: 11/04/2019] [Indexed: 02/06/2023] Open
Abstract
Zinc is essential for cellular functions as it is a catalytic and structural component of many proteins. In contrast, cadmium is not required in biological systems and is toxic. Zinc and cadmium levels are closely monitored and regulated as their excess causes cell stress. To maintain homeostasis, organisms induce metal detoxification gene programs through stress responsive transcriptional regulatory complexes. In Caenorhabditis elegans, the MDT-15 subunit of the evolutionarily conserved Mediator transcriptional coregulator is required to induce genes upon exposure to excess zinc and cadmium. However, the regulatory partners of MDT-15 in this response, its role in cellular and physiological stress adaptation, and the putative role for mammalian MED15 in the metal stress responses remain unknown. Here, we show that MDT-15 interacts physically and functionally with the Nuclear Hormone Receptor HIZR-1 to promote molecular, cellular, and organismal adaptation to cadmium and excess zinc. Using gain- and loss-of-function mutants and qRT-PCR and reporter analysis, we find that mdt-15 and hizr-1 cooperate to induce zinc and cadmium responsive genes. Moreover, the two proteins interact physically in yeast-two-hybrid assays and this interaction is enhanced by the addition of zinc or cadmium, the former a known ligand of HIZR-1. Functionally, mdt-15 and hizr-1 mutants show defective storage of excess zinc in the gut and are hypersensitive to zinc-induced reductions in egg-laying. Furthermore, mdt-15 but not hizr-1 mutants are hypersensitive to cadmium-induced reductions in egg-laying, suggesting potential divergence of regulatory pathways. Lastly, mammalian MDT-15 orthologs bind genomic regulatory regions of metallothionein and zinc transporter genes in a cadmium and zinc-stimulated fashion, and human MED15 is required to induce a metallothionein gene in lung adenocarcinoma cells exposed to cadmium. Collectively, our data show that mdt-15 and hizr-1 cooperate to regulate cadmium detoxification and zinc storage and that this mechanism is at least partially conserved in mammals.
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Affiliation(s)
- Naomi Shomer
- Graduate Program in Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Alexandre Zacharie Kadhim
- Graduate Program in Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Jennifer Margaret Grants
- Graduate Program in Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Xuanjin Cheng
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Deema Alhusari
- Graduate Program in Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Forum Bhanshali
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Amy Fong-Yuk Poon
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Michelle Ying Ya Lee
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Anik Muhuri
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Jung In Park
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - James Shih
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Dongyeop Lee
- Department of Life Sciences, School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, South Korea
| | - Seung-Jae V. Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Yuseong-Gu, Daejeon, South Korea
| | - Francis Christopher Lynn
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
- Department of Surgery, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Stefan Taubert
- Graduate Program in Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
- Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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17
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Sun Y, Huang X, Wang Y, Shi Z, Liao Y, Cai P. Lipidomic alteration and stress-defense mechanism of soil nematode Caenorhabditis elegans in response to extremely low-frequency electromagnetic field exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 170:611-619. [PMID: 30579161 DOI: 10.1016/j.ecoenv.2018.11.137] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 10/14/2018] [Accepted: 11/30/2018] [Indexed: 06/09/2023]
Abstract
To assess the impacts of man-made extremely low-frequency electromagnetic field (ELF-EMF) on soil ecosystems, the soil nematode was applied as a biological indicator to characterize ecotoxicity of ELF-EMF. In this paper, a soil-living model organism, Caenorhabditis elegans (C. elegans) was exposed to 50 Hz, 3 mT ELF-EMF. The integrated lipidome, proteome and transcriptome analysis were applied to elucidate physiological acclimations. Lipidomic analysis showed that ELF-EMF exposure induced significant alterations of 64 lipids, including significant elevation of triacylglycerols (TGs). Proteome results implied 157 changed protein expressions under ELF-EMF exposure. By transcriptomic analysis, 456 differently expressed genes were identified. Gene Ontology (GO) function and pathway analyses showed lipidomic alteration, mitochondrial dysfunction and the stress defense responses following ELF-EMF exposure in C. elegans. Conjoint analysis of proteome and transcriptome data showed that a higher expression of genes (sip-1, mtl-1 and rpl-11.1, etc.) were involved in stress defense responses to ELF-EMF exposure. These results indicated that ELF-EMF can induce effects on soil nematodes, mainly through disturbing lipid metabolism such as increasing TGs content, and eliciting stress defense responses. This study provided a new understanding in ELF-EMF exposure effects on soil nematodes and suggested a potential way of interpreting ELF-EMF influences on soil ecosystems.
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Affiliation(s)
- Yongyan Sun
- Physical Environment Group, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, PR China; University of Chinese Academy of Sciences, Beijing, PR China; Xiamen Key Laboratory of Physical Environment, Xiamen, PR China
| | - Xiaomei Huang
- Physical Environment Group, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, PR China; University of Chinese Academy of Sciences, Beijing, PR China; Xiamen Key Laboratory of Physical Environment, Xiamen, PR China
| | - Yahong Wang
- Physical Environment Group, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, PR China; University of Chinese Academy of Sciences, Beijing, PR China; Xiamen Key Laboratory of Physical Environment, Xiamen, PR China
| | - Zhenhua Shi
- University of Chinese Academy of Sciences, Beijing, PR China; Environmental Bioelectrochemistry Center, Fujian Agriculture and Forestry University, Fuzhou, PR China
| | - Yanyan Liao
- Physical Environment Group, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, PR China; University of Chinese Academy of Sciences, Beijing, PR China; Xiamen Key Laboratory of Physical Environment, Xiamen, PR China
| | - Peng Cai
- Physical Environment Group, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, PR China; Xiamen Key Laboratory of Physical Environment, Xiamen, PR China; Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, PR China.
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18
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Wang S, Chu Z, Zhang K, Miao G. Cadmium-induced serotonergic neuron and reproduction damages conferred lethality in the nematode Caenorhabditis elegans. CHEMOSPHERE 2018; 213:11-18. [PMID: 30205271 DOI: 10.1016/j.chemosphere.2018.09.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 08/19/2018] [Accepted: 09/03/2018] [Indexed: 06/08/2023]
Abstract
Cadmium is a ubiquitous environmental toxicant. The use of Caenorhabditis elegans as a model for monitoring cadmium exposure has revealed several conserved signaling pathways. However, little is known about the killing process during lethality assay. In the present study, we investigated the effects serotonergic neuronal and reproductive damages on cadmium exposure in C. elegans. We found that sterile hermaphrodites, males and worms that passed reproduction span presented high cadmium resistance compared to those of young adults. The results demonstrated that reproduction process other than reproduction capacity conferred cadmium sensitivity. Cadmium exposure resulted in high ratio bagging phenotype, which was a severe reproductive deficit with embryos hatched internally that could cause worms to die early. The mechanism of bagging formation was ascribed to cadmium-induced egg laying deficiency that led embryos to retain and hatch in uterus. The addition of serotonin and imipramine promoted egg laying and thereby increased cadmium resistance. The results demonstrated that vulval muscles responsible for egg laying were still functional, while the serotonergic hermaphrodite specific neurons might be dysfunctional under cadmium exposure. Cadmium exposure resulted in shrinkage of serotonergic neuronal body and reduced expressions of tryptophan hydroxylase, the key enzyme for serotonin synthesis. The protection of serotonergic neuron through transient thermal preconditioning improved survival rate. In conclusion, our study demonstrated that damages of serotonergic neurons and reproduction conferred to cadmium-induced lethality.
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Affiliation(s)
- Shunchang Wang
- School of Biological Engineering, Huainan Normal University, Huainan 232038, China.
| | - Zhaoxia Chu
- School of Biological Engineering, Huainan Normal University, Huainan 232038, China
| | - Kegui Zhang
- School of Biological Engineering, Huainan Normal University, Huainan 232038, China
| | - Guopeng Miao
- School of Biological Engineering, Huainan Normal University, Huainan 232038, China
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19
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Qu M, Xu K, Li Y, Wong G, Wang D. Using acs-22 mutant Caenorhabditis elegans to detect the toxicity of nanopolystyrene particles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 643:119-126. [PMID: 29936155 DOI: 10.1016/j.scitotenv.2018.06.173] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/12/2018] [Accepted: 06/13/2018] [Indexed: 05/02/2023]
Abstract
In this study, we employed Caenorhabditis elegans with acs-22 mutation to examine the in vivo effect of functional deficit in intestinal barrier on toxicity and translocation of nanopolystyrene particles. Mutation of acs-22 leads to deficit in intestinal barrier. After prolonged exposure, nanopolystyrene particles at concentrations ≥1 μg/L could cause toxicity on acs-22 mutant nematodes. acs-22 mutation resulted in translocation of nanopolystyrene particles into targeted organs through intestinal barrier in nanopolystyrene particles (1 μg/L) exposed nematodes. After prolonged exposure, nanopolystyrene particles (1 μg/L) dysregulated expressions of some genes required for the control of oxidative stress and activated expression of Nrf signaling pathway. Therefore, under certain pathological conditions, our results suggest the potential toxicity of nanoplastic particles at predicted environmental concentration on organisms after long-term exposure.
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Affiliation(s)
- Man Qu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Medical School, Southeast University, Nanjing 210009, China
| | - Kangni Xu
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Medical School, Southeast University, Nanjing 210009, China
| | - Yunhui Li
- School of Public Health, Southeast University, Nanjing 210009, China
| | - Garry Wong
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Dayong Wang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, Medical School, Southeast University, Nanjing 210009, China.
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20
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Kim Y, Choudhry QN, Chatterjee N, Choi J. Immune and xenobiotic response crosstalk to chemical exposure by PA01 infection in the nematode Caenorhabditis elegans. CHEMOSPHERE 2018; 210:1082-1090. [PMID: 30208533 DOI: 10.1016/j.chemosphere.2018.07.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 07/05/2018] [Accepted: 07/06/2018] [Indexed: 06/08/2023]
Abstract
Most organisms simultaneously face various chemical and biological stresses in the environment. Herein, we investigated how pathogen infection modifies an organism's response to chemical exposure. To explore this phenomenon, we conducted a toxicity study combined with pathogen infection by using the nematode Caenorhabditis elegans, the pathogen Pseudomonas aeruginosa, and various environmental chemicals. C. elegans preinfected with PA01, when subsequently exposed to chemicals, became sensitized to the toxicity of nonylphenol (NP) and cadmium (Cd), whereas they became tolerant to the toxicity of silver nanoparticles (AgNPs); this led us to conduct a mechanistic study focusing on AgNP exposure. A gene expression profiling study revealed that most of the immune response genes activated by PA01 infection remained activated after subsequent exposure to AgNPs, thereby suggesting that the acquired tolerance of C. elegans to AgNP exposure may be due to boosted immunity resulting from PA01 preinfection. Further, a functional genetic analysis revealed that the immune response pathway (i.e., PMK-1/p38 MAPK) was involved in defense against AgNP exposure in PA01-preinfected C. elegans, thus suggesting immune and stress response crosstalk to xenobiotic exposure. This study will aid in the elucidation of how pathogen infection impacts the way the defense system responds to subsequent xenobiotic exposure.
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Affiliation(s)
- Youngho Kim
- School of Environmental Engineering, University of Seoul, 163 Siripdaero, Dongdaemun-gu, Seoul, 02504, Republic of Korea
| | - Qaisra Naheed Choudhry
- School of Environmental Engineering, University of Seoul, 163 Siripdaero, Dongdaemun-gu, Seoul, 02504, Republic of Korea
| | - Nivedita Chatterjee
- School of Environmental Engineering, University of Seoul, 163 Siripdaero, Dongdaemun-gu, Seoul, 02504, Republic of Korea
| | - Jinhee Choi
- School of Environmental Engineering, University of Seoul, 163 Siripdaero, Dongdaemun-gu, Seoul, 02504, Republic of Korea.
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21
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Dalton HM, Curran SP. Hypodermal responses to protein synthesis inhibition induce systemic developmental arrest and AMPK-dependent survival in Caenorhabditis elegans. PLoS Genet 2018; 14:e1007520. [PMID: 30020921 PMCID: PMC6066256 DOI: 10.1371/journal.pgen.1007520] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 07/30/2018] [Accepted: 06/27/2018] [Indexed: 01/08/2023] Open
Abstract
Across organisms, manipulation of biosynthetic capacity arrests development early in life, but can increase health- and lifespan post-developmentally. Here we demonstrate that this developmental arrest is not sickness but rather a regulated survival program responding to reduced cellular performance. We inhibited protein synthesis by reducing ribosome biogenesis (rps-11/RPS11 RNAi), translation initiation (ifg-1/EIF3G mutation and egl-45/EIF3A RNAi), or ribosome progression (cycloheximide treatment), all of which result in a specific arrest at larval stage 2 of C. elegans development. This quiescent state can last for weeks—beyond the normal C. elegans adult lifespan—and is reversible, as animals can resume reproduction and live a normal lifespan once released from the source of protein synthesis inhibition. The arrest state affords resistance to thermal, oxidative, and heavy metal stress exposure. In addition to cell-autonomous responses, reducing biosynthetic capacity only in the hypodermis was sufficient to drive organism-level developmental arrest and stress resistance phenotypes. Among the cell non-autonomous responses to protein synthesis inhibition is reduced pharyngeal pumping that is dependent upon AMPK-mediated signaling. The reduced pharyngeal pumping in response to protein synthesis inhibition is recapitulated by exposure to microbes that generate protein synthesis-inhibiting xenobiotics, which may mechanistically reduce ingestion of pathogen and toxin. These data define the existence of a transient arrest-survival state in response to protein synthesis inhibition and provide an evolutionary foundation for the conserved enhancement of healthy aging observed in post-developmental animals with reduced biosynthetic capacity. Protein synthesis is an essential cellular process, but post-developmental reduction of protein synthesis across multiple species leads to improved health- and lifespan. To better understand the physiological responses to impaired protein synthesis, we characterize a novel developmental arrest state that occurs when reducing protein synthesis during C. elegans development. Arrested animals have multiple survival-promoting phenotypes that are all dependent on the cellular energy sensor, AMP kinase. This survival response acts through the hypodermis and causes a reduction in pharyngeal pumping, indicating that the animal is responding to a perceived external threat, even in adults. Furthermore, exposing animals to pathogens, or xenobiotics they produce, can recapitulate these phenotypes, providing a potential evolutionary explanation for how a beneficial response in adults could evolve through the inhibition of an essential biological process such as protein synthesis.
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Affiliation(s)
- Hans M. Dalton
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California, United States of America
- Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, California, United States of America
| | - Sean P. Curran
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California, United States of America
- Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, California, United States of America
- Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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22
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Lu C, Svoboda KR, Lenz KA, Pattison C, Ma H. Toxicity interactions between manganese (Mn) and lead (Pb) or cadmium (Cd) in a model organism the nematode C. elegans. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:15378-15389. [PMID: 29564703 DOI: 10.1007/s11356-018-1752-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/13/2018] [Indexed: 05/23/2023]
Abstract
Manganese (Mn) is considered as an emerging metal contaminant in the environment. However, its potential interactions with companying toxic metals and the associated mixture effects are largely unknown. Here, we investigated the toxicity interactions between Mn and two commonly seen co-occurring toxic metals, Pb and Cd, in a model organism the nematode Caenorhabditis elegans. The acute lethal toxicity of mixtures of Mn+Pb and Mn+Cd were first assessed using a toxic unit model. Multiple toxicity endpoints including reproduction, lifespan, stress response, and neurotoxicity were then examined to evaluate the mixture effects at sublethal concentrations. Stress response was assessed using a daf-16::GFP transgenic strain that expresses GFP under the control of DAF-16 promotor. Neurotoxicity was assessed using a dat-1::GFP transgenic strain that expresses GFP in dopaminergic neurons. The mixture of Mn+Pb induced a more-than-additive (synergistic) lethal toxicity in the worm whereas the mixture of Mn+Cd induced a less-than-additive (antagonistic) toxicity. Mixture effects on sublethal toxicity showed more complex patterns and were dependent on the toxicity endpoints as well as the modes of toxic action of the metals. The mixture of Mn+Pb induced additive effects on both reproduction and lifespan, whereas the mixture of Mn+Cd induced additive effects on lifespan but not reproduction. Both mixtures seemed to induce additive effects on stress response and neurotoxicity, although a quantitative assessment was not possible due to the single concentrations used in mixture tests. Our findings demonstrate the complexity of metal interactions and the associated mixture effects. Assessment of metal mixture toxicity should take into consideration the unique property of individual metals, their potential toxicity mechanisms, and the toxicity endpoints examined.
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Affiliation(s)
- Cailing Lu
- Joseph J. Zilber School of Public Health, University of Wisconsin-Milwaukee, 1240 N 10th St, Milwaukee, WI, USA
- School of Public Health, Guangxi Medical University, 22 Shuangyong Rd, Nanning, Guangxi, China
| | - Kurt R Svoboda
- Joseph J. Zilber School of Public Health, University of Wisconsin-Milwaukee, 1240 N 10th St, Milwaukee, WI, USA
| | - Kade A Lenz
- Joseph J. Zilber School of Public Health, University of Wisconsin-Milwaukee, 1240 N 10th St, Milwaukee, WI, USA
| | - Claire Pattison
- Joseph J. Zilber School of Public Health, University of Wisconsin-Milwaukee, 1240 N 10th St, Milwaukee, WI, USA
| | - Hongbo Ma
- Joseph J. Zilber School of Public Health, University of Wisconsin-Milwaukee, 1240 N 10th St, Milwaukee, WI, USA.
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23
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Cobb E, Hall J, Palazzolo DL. Induction of Metallothionein Expression After Exposure to Conventional Cigarette Smoke but Not Electronic Cigarette (ECIG)-Generated Aerosol in Caenorhabditis elegans. Front Physiol 2018; 9:426. [PMID: 29740339 PMCID: PMC5925786 DOI: 10.3389/fphys.2018.00426] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 04/05/2018] [Indexed: 11/21/2022] Open
Abstract
Aim: With the invention of electronic cigarettes (ECIG), many questions have been raised regarding their safety as an alternative to smoking conventional cigarettes. Conventional cigarette smoke contains a variety of toxicants including heavy metals. However, ECIG-generated aerosol contains only trace amounts of metals, adding to the argument for it being a safer alternative. In response to heavy metal exposure, metallothioneins are induced in cells to help store the metal, detoxify the body, and are also known responders to oxidative stress. In an attempt to add to the evaluation of the safety of ECIGs, metallothionein expression was quantified using the nematode Caenorhabditis elegans as an assessment of stress induced cellular damage caused by exposure. Methods: Adult nematodes were exposed to either ECIG aerosol or conventional cigarette smoke at doses of 15, 30, and 45 puffs, the equivalent of one, two, and three cigarettes, respectively. Movement, survival, and stress-induced sleep were assessed for up to 24 h after exposure. Relative expression levels for mtl-1 and mtl-2, C. elegans metallothionein genes, were analyzed after 1, 5, and 24 h post exposure using quantitative RT-PCR. Results: Nematodes exposed to conventional cigarette smoke underwent stress-induced sleep in a dose dependent manner with animals recovering to values within the range of air control after 5 h post exposure. Those exposed to ECIG aerosol did not undergo stress-induced sleep and were indistinguishable from controls. The expression of mtl-1 increased in a dose and time dependent manner in C. elegans exposed to conventional cigarette smoke, with a maximum expression observed at 5 h post exposure of 45 puffs. No induction of mtl-2 was observed in any animals. Additionally, ECIG aerosol did not induce expression of mtl-1 and mtl-2 at levels different than those of untreated. Conclusion: ECIG aerosol failed to induce a stress response in C. elegans. In contrast, conventional cigarette smoke induced the production of mtl-1 in a manner that correlates with the induction of stress-induced sleep suggesting a stress response to damage. The lack of cellular stress response to ECIG aerosol suggests it may be a safer alternative to conventional cigarettes.
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Affiliation(s)
- Eric Cobb
- School of Mathematics and Sciences, Lincoln Memorial University, Harrogate, TN, United States.,DeBusk College of Osteopathic Medicine, Lincoln Memorial University, Harrogate, TN, United States
| | - Julie Hall
- Department of Biology, School of Mathematics and Sciences, Lincoln Memorial University, Harrogate, TN, United States
| | - Dominic L Palazzolo
- Department of Physiology, DeBusk College of Osteopathic Medicine, Lincoln Memorial University, Harrogate, TN, United States
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24
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Wang X, Cao M, Dong Y. Royal jelly promotes DAF-16-mediated proteostasis to tolerate β-amyloid toxicity in C. elegans model of Alzheimer's disease. Oncotarget 2018; 7:54183-54193. [PMID: 27472466 PMCID: PMC5342333 DOI: 10.18632/oncotarget.10857] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/07/2016] [Indexed: 12/13/2022] Open
Abstract
Numerous studies have demonstrated that dietary intervention may promote health and help prevent Alzheimer's disease (AD). We recently reported that bee products of royal jelly (RJ) and enzyme-treated royal jelly (eRJ) were potent to promote healthy aging in C. elegans. Here, we examined whether RJ/eRJ consumption may benefit to mitigate the AD symptom in the disease model of C. elegans. Our results showed that RJ/eRJ supplementation significantly delayed the body paralysis in AD worms, suggesting the β-amyloid (Aβ) toxicity attenuation effects of RJ/eRJ. Genetic analyses suggested that RJ/eRJ-mediated alleviation of Aβ toxicity in AD worms required DAF-16, rather than HSF-1 and SKN-1, in an insulin/IGF signaling dependent manner. Moreover, RJ/eRJ modulated the transactivity of DAF-16 and dramatically improved the protein solubility in aged worms. Given protein solubility is a hallmark of healthy proteostasis, our findings demonstrated that RJ/eRJ supplementation improved proteostasis, and this promotion depended on the transactivity of DAF-16. Collectively, the present study not only elucidated the possible anti-AD mechanism of RJ/eRJ, but also provided evidence from a practical point of view to shed light on the extensive correlation of proteostasis and the prevention of neurodegenerative disorders.
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Affiliation(s)
- Xiaoxia Wang
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
| | - Min Cao
- Department of Biological Sciences, Clemson University, Clemson, SC, USA.,Institute for Engaged Aging, Clemson University, Clemson, SC, USA
| | - Yuqing Dong
- Department of Biological Sciences, Clemson University, Clemson, SC, USA.,Institute for Engaged Aging, Clemson University, Clemson, SC, USA
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25
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PMK-1 p38 MAPK promotes cadmium stress resistance, the expression of SKN-1/Nrf and DAF-16 target genes, and protein biosynthesis in Caenorhabditis elegans. Mol Genet Genomics 2017; 292:1341-1361. [PMID: 28766017 PMCID: PMC5682872 DOI: 10.1007/s00438-017-1351-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 07/25/2017] [Indexed: 01/01/2023]
Abstract
The mechanisms of cadmium (Cd) resistance are complex and not sufficiently understood. The present study, therefore, aimed at assessing the roles of important components of stress-signaling pathways and of ABC transporters under severe Cd stress in Caenorhabditis elegans. Survival assays on mutant and control animals revealed a significant promotion of Cd resistance by the PMK-1 p38 MAP kinase, the transcription factor DAF-16/FoxO, and the ABC transporter MRP-1. Transcriptome profiling by RNA-Seq on wild type and a pmk-1 mutant under control and Cd stress conditions revealed, inter alia, a PMK-1-dependent promotion of gene expression for the translational machinery. PMK-1 also promoted the expression of target genes of the transcription factors SKN-1/Nrf and DAF-16 in Cd-stressed animals, which included genes for molecular chaperones or immune proteins. Gene expression studies by qRT-PCR confirmed the positive effects of PMK-1 on DAF-16 activity under Cd stress and revealed negative effects of DAF-16 on the expression of genes for MRP-1 and DAF-15/raptor. Additional studies on pmk-1 RNAi-treated wild type and mutant strains provided further information on the effects of PMK-1 on SKN-1 and DAF-16, which resulted in a model of these relationships. The results of this study demonstrate a central role of PMK-1 for the processing of cellular responses to abiotic and biotic stressors, with the promoting effects of PMK-1 on Cd resistance mostly mediated by the transcription factors SKN-1 and DAF-16.
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26
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Hall JA, McElwee MK, Freedman JH. Identification of ATF-7 and the insulin signaling pathway in the regulation of metallothionein in C. elegans suggests roles in aging and reactive oxygen species. PLoS One 2017. [PMID: 28632756 PMCID: PMC5478092 DOI: 10.1371/journal.pone.0177432] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It has been proposed that aging results from the lifelong accumulation of intracellular damage via reactions with reactive oxygen species (ROS). Metallothioneins are conserved cysteine-rich proteins that function as efficient ROS scavengers and may affect longevity. To better understand mechanisms controlling metallothionein expression, the regulatory factors and pathways that controlled cadmium-inducible transcription of the C. elegans metallothionein gene, mtl-1, were identified. The transcription factor ATF-7 was identified in both ethylmethanesulfonate mutagenesis and candidate gene screens. PMK-1 and members of the insulin signaling pathway, PDK-1 and AKT-1/2, were also identified as mtl-1 regulators. Genetic and previous results support a model for the regulation of cadmium-inducible mtl-1 transcription based on the derepression of the constitutively active transcription factor ELT-2. In addition, knockdown of the mammalian homologs of PDK1 and ATF7 in HEK293 cells resulted in changes in metallothionein expression, suggesting that this pathway was evolutionarily conserved. The insulin signaling pathway is known to influence the aging process; however, various factors responsible for affecting the aging phenotype are unknown. Identification of portions of the insulin signaling pathway as regulators of metallothionein expression supports the hypothesis that longevity is affected by the expression of this efficient ROS scavenger.
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Affiliation(s)
- Julie A. Hall
- Biomolecular Screening Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America
- * E-mail:
| | - Matthew K. McElwee
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America
| | - Jonathan H. Freedman
- Biomolecular Screening Branch, Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America
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27
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Abstract
Caenorhabditis elegans is an important model organism with many useful features, including rapid development and aging, easy cultivation, and genetic tractability. Survival assays using C. elegans are powerful methods for studying physiological processes. In this review, we describe diverse types of C. elegans survival assays and discuss the aims, uses, and advantages of specific assays. C. elegans survival assays have played key roles in identifying novel genetic factors that regulate many aspects of animal physiology, such as aging and lifespan, stress response, and immunity against pathogens. Because many genetic factors discovered using C. elegans are evolutionarily conserved, survival assays can provide insights into mechanisms underlying physiological processes in mammals, including humans.
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Affiliation(s)
- Hae-Eun H. Park
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Yoonji Jung
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
| | - Seung-Jae V. Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673,
Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang 37673,
Korea
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28
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Winter SA, Dölling R, Knopf B, Mendelski MN, Schäfers C, Paul RJ. Detoxification and sensing mechanisms are of similar importance for Cd resistance in Caenorhabditis elegans. Heliyon 2016; 2:e00183. [PMID: 27822562 PMCID: PMC5090194 DOI: 10.1016/j.heliyon.2016.e00183] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 09/30/2016] [Accepted: 10/18/2016] [Indexed: 11/26/2022] Open
Abstract
The present study employed mass spectrometry (ICP-MS) to measure the internal cadmium concentrations (Cdint) in Caenorhabditis elegans to determine Cd uptake from a Cd-containing environment as well as Cd release under Cd-free conditions. To analyze the functional role of several ATP binding cassette (ABC) transporters (e.g., HMT-1 and MRP-1) and phytochelatin synthase (PCS), we compared wild-type (WT) and different mutant strains of C. elegans. As a pre-test on selected mutant strains, several time-resolved experiments were performed to determine the survival rate and avoidance behavior of C. elegans under Cd stress, which confirmed the already known Cd sensitivity of the deletion mutants mrp-1Δ, pcs-1Δ, and hmt-1Δ. In addition, these experiments revealed flight reactions under Cd stress to be almost completely absent in mrp-1Δ mutants. The ICP-MS studies showed Cd uptake to be significantly higher in mrp-1Δ and WT than in hmt-1Δ. As Cd is ingested with food, food refusal due to very early Cd stress and its perception was likely the reason for the reduced Cd uptake of hmt-1Δ. Cd release (detoxification) was found to be maximal in mrp-1Δ, minimal in hmt-1Δ, and intermediate in WT. High mortality under Cd stress, food refusal, and minimal Cd release in the case of hmt-1Δ suggest a vital importance of the HMT-1/PCS-1 detoxification system for the survival of C. elegans under Cd stress. High mortality under Cd stress, absence of an avoidance behavior, missing food refusal, and maximal Cd release in the case of mrp-1Δ indicate that MRP-1 is less important for Cd detoxification under severe stress, but is probably important for Cd perception. Accordingly, our results suggest that the survival of WT under Cd stress (or possibly other forms of metal stress) primarily depends on the function of the HMT-1/PCS-1 detoxification system and the presence of a sensing mechanism to control the uptake of Cd (or other metals), which keeps internal Cd (or metal) concentrations under control, to some extent, for the timely mobilization of protection and repair systems.
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Affiliation(s)
- Sarah A. Winter
- Institute of Zoophysiology, University of Münster (WWU), Münster 48143, Germany
| | - Ramona Dölling
- Institute of Zoophysiology, University of Münster (WWU), Münster 48143, Germany
| | - Burkhard Knopf
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Schmallenberg 57392, Germany
| | - Martha N. Mendelski
- Institute of Zoophysiology, University of Münster (WWU), Münster 48143, Germany
| | - Christoph Schäfers
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Schmallenberg 57392, Germany
| | - Rüdiger J. Paul
- Institute of Zoophysiology, University of Münster (WWU), Münster 48143, Germany
- Corresponding author at: Institute of Zoophysiology, University of Münster, Schlossplatz 8, Münster 48143, Germany.Institute of ZoophysiologyUniversity of Münster (WWU)Münster48143Germany
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29
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Sf G, Sk D, Bennett M, Raab A, Feldmann J, Kille P, Loureiro S, Dj S, Jg B. Sub-lethal cadmium exposure increases phytochelatin concentrations in the aquatic snail Lymnaea stagnalis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 568:1054-1058. [PMID: 27358197 DOI: 10.1016/j.scitotenv.2016.06.149] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/19/2016] [Accepted: 06/19/2016] [Indexed: 06/06/2023]
Abstract
Phytochelatins are metal-binding metabolites found in almost all plant species and some animal groups, including nematodes and annelids, where they can play an important role in detoxifying metals such as cadmium. Species from several other taxa contain a phytochelatin synthase (PCS) gene orthologue, including molluscs, indicating they may have the potential to synthesize phytochelatins. However, the presence of a gene alone does not demonstrate that it plays a functional role in metal detoxification. In the present study, we show that the aquatic snail Lymnaea stagnalis produced both penta- and heptapeptide phytochelatins (i.e. phytochelatin-2 and phytochelatin-3), and their levels increased in response to sub-lethal levels of cadmium.
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Affiliation(s)
- Gonçalves Sf
- Department of Biology & CESAM, Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Davies Sk
- Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ, UK
| | - M Bennett
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ, UK
| | - A Raab
- TESLA, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland, UK
| | - J Feldmann
- TESLA, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland, UK
| | - P Kille
- Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3US, UK
| | - S Loureiro
- Department of Biology & CESAM, Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Spurgeon Dj
- Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Wallingford OX10 8BB, UK
| | - Bundy Jg
- Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ, UK.
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30
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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: 2.3] [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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31
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Sandbichler AM, Höckner M. Cadmium Protection Strategies--A Hidden Trade-Off? Int J Mol Sci 2016; 17:ijms17010139. [PMID: 26805823 PMCID: PMC4730378 DOI: 10.3390/ijms17010139] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Revised: 01/15/2016] [Accepted: 01/18/2016] [Indexed: 12/12/2022] Open
Abstract
Cadmium (Cd) is a non-essential transition metal which is introduced into the biosphere by various anthropogenic activities. Environmental pollution with Cd poses a major health risk and Cd toxicity has been extensively researched over the past decades. This review aims at changing the perspective by discussing protection mechanisms available to counteract a Cd insult. Antioxidants, induction of antioxidant enzymes, and complexation of Cd to glutathione (GSH) and metallothionein (MT) are the most potent protective measures to cope with Cd-induced oxidative stress. Furthermore, protection mechanisms include prevention of endoplasmic reticulum (ER) stress, mitophagy and metabolic stress, as well as expression of chaperones. Pre-exposure to Cd itself, or co-exposure to other metals or trace elements can improve viability under Cd exposure and cells have means to reduce Cd uptake and improve Cd removal. Finally, environmental factors have negative or positive effects on Cd toxicity. Most protection mechanisms aim at preventing cellular damage. However, this might not be possible without trade-offs like an increased risk of carcinogenesis.
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Affiliation(s)
| | - Martina Höckner
- University of Innsbruck, Institute of Zoology, Technikerstraße 25, 6020 Innsbruck, Austria.
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32
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Kumar R, Pradhan A, Khan FA, Lindström P, Ragnvaldsson D, Ivarsson P, Olsson PE, Jass J. Comparative Analysis of Stress Induced Gene Expression in Caenorhabditis elegans following Exposure to Environmental and Lab Reconstituted Complex Metal Mixture. PLoS One 2015; 10:e0132896. [PMID: 26168046 PMCID: PMC4500601 DOI: 10.1371/journal.pone.0132896] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 06/22/2015] [Indexed: 02/04/2023] Open
Abstract
Metals are essential for many physiological processes and are ubiquitously present in the environment. However, high metal concentrations can be harmful to organisms and lead to physiological stress and diseases. The accumulation of transition metals in the environment due to either natural processes or anthropogenic activities such as mining results in the contamination of water and soil environments. The present study used Caenorhabditis elegans to evaluate gene expression as an indicator of physiological response, following exposure to water collected from three different locations downstream of a Swedish mining site and a lab reconstituted metal mixture. Our results indicated that the reconstituted metal mixture exerted a direct stress response in C. elegans whereas the environmental waters elicited either a diminished or abrogated response. This suggests that it is not sufficient to use the biological effects observed from laboratory mixtures to extrapolate the effects observed in complex aquatic environments and apply this to risk assessment and intervention.
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Affiliation(s)
- Ranjeet Kumar
- School of Science and Technology, The Life Science Center-Biology, Örebro University, Örebro, Sweden
| | - Ajay Pradhan
- School of Science and Technology, The Life Science Center-Biology, Örebro University, Örebro, Sweden
| | - Faisal Ahmad Khan
- School of Science and Technology, The Life Science Center-Biology, Örebro University, Örebro, Sweden
| | | | | | | | - Per-Erik Olsson
- School of Science and Technology, The Life Science Center-Biology, Örebro University, Örebro, Sweden
| | - Jana Jass
- School of Science and Technology, The Life Science Center-Biology, Örebro University, Örebro, Sweden
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Bundy JG, Kille P. Metabolites and metals in Metazoa--what role do phytochelatins play in animals? Metallomics 2015; 6:1576-82. [PMID: 24926533 DOI: 10.1039/c4mt00078a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Phytochelatins are sulfur-rich metal-binding peptides, and phytochelatin synthesis is one of the key mechanisms by which plants protect themselves against toxic soft metal ions such as cadmium. It has been known for a while now that some invertebrates also possess functional phytochelatin synthase (PCS) enzymes, and that at least one species, the nematode Caenorhabditis elegans, produces phytochelatins to help detoxify cadmium, and probably also other metal and metalloid ions including arsenic, zinc, selenium, silver, and copper. Here, we review recent studies on the occurrence, utilization, and regulation of phytochelatin synthesis in invertebrates. The phytochelatin synthase gene has a wide phylogenetic distribution, and can be found in species that cover almost all of the animal tree of life. The evidence to date, though, suggests that the occurrence is patchy, and even though some members of particular taxonomic groups may contain PCS genes, there are also many species without these genes. For animal species that do possess PCS genes, some of them (e.g. earthworms) do synthesize phytochelatins in response to potentially toxic elements, whereas others (e.g. Schistosoma mansoni, a parasitic helminth) do not appear to do so. Just how (and if) phytochelatins in invertebrates complement the function of metallothioneins remains to be elucidated, and the temporal, spatial, and metal specificity of the two systems is still unknown.
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Affiliation(s)
- J G Bundy
- Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ, UK.
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Song S, Zhang X, Wu H, Han Y, Zhang J, Ma E, Guo Y. Molecular basis for antioxidant enzymes in mediating copper detoxification in the nematode Caenorhabditis elegans. PLoS One 2014; 9:e107685. [PMID: 25243607 PMCID: PMC4171499 DOI: 10.1371/journal.pone.0107685] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Accepted: 08/15/2014] [Indexed: 11/21/2022] Open
Abstract
Antioxidant enzymes play a major role in defending against oxidative damage by copper. However, few studies have been performed to determine which antioxidant enzymes respond to and are necessary for copper detoxification. In this study, we examined both the activities and mRNA levels of SOD, CAT, and GPX under excessive copper stress in Caenorhabditis elegans, which is a powerful model for toxicity studies. Then, taking advantage of the genetics of this model, we assessed the lethal concentration (LC50) values of copper for related mutant strains. The results showed that the SOD, CAT, and GPX activities were significantly greater in treated groups than in controls. The mRNA levels of sod-3, sod-5, ctl-1, ctl-2, and almost all gpx genes were also significantly greater in treated groups than in controls. Among tested mutants, the sod-5, ctl-1, gpx-3, gpx-4, and gpx-6 variants exhibited hypersensitivity to copper. The strains with SOD or CAT over expression were reduced sensitive to copper. Mutations in daf-2 and age-1, which are involved in the insulin/insulin-like growth factor-1 signaling pathway, result in reduced sensitivity to stress. Here, we showed that LC50 values for copper in daf-2 and age-1 mutants were significantly greater than in N2 worms. However, the LC50 values in daf-16;daf-2 and daf-16;age-1 mutants were significantly reduced than in daf-2 and age-1 mutants, implying that reduced copper sensitivity is influenced by DAF-16-related functioning. SOD, CAT, and GPX activities and the mRNA levels of the associated copper responsive genes were significantly increased in daf-2 and age-1 mutants compared to N2. Additionally, the activities of SOD, CAT, and GPX were greater in these mutants than in N2 when treated with copper. Our results not only support the theory that antioxidant enzymes play an important role in copper detoxification but also identify the response and the genes involved in these processes.
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Affiliation(s)
- Shaojuan Song
- Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, China
| | - Xueyao Zhang
- Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, China
| | - Haihua Wu
- Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, China
| | - Yan Han
- School of Life Science, Shanxi University, Taiyuan, Shanxi, China
| | - Jianzhen Zhang
- Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, China
| | - Enbo Ma
- Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi, China
| | - Yaping Guo
- School of Life Science, Shanxi University, Taiyuan, Shanxi, China
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Elran R, Raam M, Kraus R, Brekhman V, Sher N, Plaschkes I, Chalifa-Caspi V, Lotan T. Early and late response of Nematostella vectensis transcriptome to heavy metals. Mol Ecol 2014; 23:4722-36. [PMID: 25145541 DOI: 10.1111/mec.12891] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/22/2014] [Accepted: 08/13/2014] [Indexed: 12/28/2022]
Abstract
Environmental contamination from heavy metals poses a global concern for the marine environment, as heavy metals are passed up the food chain and persist in the environment long after the pollution source is contained. Cnidarians play an important role in shaping marine ecosystems, but environmental pollution profoundly affects their vitality. Among the cnidarians, the sea anemone Nematostella vectensis is an advantageous model for addressing questions in molecular ecology and toxicology as it tolerates extreme environments and its genome has been published. Here, we employed a transcriptome-wide RNA-Seq approach to analyse N. vectensis molecular defence mechanisms against four heavy metals: Hg, Cu, Cd and Zn. Altogether, more than 4800 transcripts showed significant changes in gene expression. Hg had the greatest impact on up-regulating transcripts, followed by Cu, Zn and Cd. We identified, for the first time in Cnidaria, co-up-regulation of immediate-early transcription factors such as Egr1, AP1 and NF-κB. Time-course analysis of these genes revealed their early expression as rapidly as one hour after exposure to heavy metals, suggesting that they may complement or substitute for the roles of the metal-mediating Mtf1 transcription factor. We further characterized the regulation of a large array of stress-response gene families, including Hsp, ABC, CYP members and phytochelatin synthase, that may regulate synthesis of the metal-binding phytochelatins instead of the metallothioneins that are absent from Cnidaria genome. This study provides mechanistic insight into heavy metal toxicity in N. vectensis and sheds light on ancestral stress adaptations.
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Affiliation(s)
- Ron Elran
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
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Wang X, Cook LF, Grasso LM, Cao M, Dong Y. Royal Jelly-Mediated Prolongevity and Stress Resistance in Caenorhabditis elegans Is Possibly Modulated by the Interplays of DAF-16, SIR-2.1, HCF-1, and 14-3-3 Proteins. J Gerontol A Biol Sci Med Sci 2014; 70:827-38. [PMID: 25073462 DOI: 10.1093/gerona/glu120] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 06/11/2014] [Indexed: 12/27/2022] Open
Abstract
Recent studies suggest that royal jelly (RJ) and its related substances may have antiaging properties. However, the molecular mechanisms underlying the beneficial effects remain elusive. We report that the effects of RJ and enzyme-treated RJ (eRJ) on life span and health span in Caenorhabditis elegans (C elegans) are modulated by the sophisticated interplays of DAF-16, SIR-2.1, HCF-1, and 14-3-3 proteins. Dietary supplementation with RJ or eRJ increased C. elegans life span in a dose-dependent manner. The RJ and eRJ consumption increased the tolerance of C elegans to oxidative stress, ultraviolet irradiation, and heat shock stress. Our genetic analyses showed that RJ/eRJ-mediated life-span extension requires insulin/IGF-1 signaling and the activities of DAF-16, SIR-2.1, HCF-1, and FTT-2, a 14-3-3 protein. Earlier studies reported that DAF-16/FOXO, SIR-2.1/SIRT1, FTT-2, and HCF-1 have extensive interplays in worms and mammals. Our present findings suggest that RJ/eRJ-mediated promotion of longevity and stress resistance in C elegans is dependent on these conserved interplays. From an evolutionary point of view, this study not only provides new insights into the molecular mechanisms of RJ's action on health span promotion in C elegans, but also has imperative implications in using RJ/eRJ as nutraceuticals to delay aging and age-related disorders.
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Affiliation(s)
| | | | | | - Min Cao
- Department of Biological Sciences and Institute for Engaged Aging, Clemson University, South Carolina
| | - Yuqing Dong
- Department of Biological Sciences and Institute for Engaged Aging, Clemson University, South Carolina.
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Liebeke M, Garcia-Perez I, Anderson CJ, Lawlor AJ, Bennett MH, Morris CA, Kille P, Svendsen C, Spurgeon DJ, Bundy JG. Earthworms produce phytochelatins in response to arsenic. PLoS One 2013; 8:e81271. [PMID: 24278409 PMCID: PMC3838358 DOI: 10.1371/journal.pone.0081271] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 10/10/2013] [Indexed: 12/13/2022] Open
Abstract
Phytochelatins are small cysteine-rich non-ribosomal peptides that chelate soft metal and metalloid ions, such as cadmium and arsenic. They are widely produced by plants and microbes; phytochelatin synthase genes are also present in animal species from several different phyla, but there is still little known about whether these genes are functional in animals, and if so, whether they are metal-responsive. We analysed phytochelatin production by direct chemical analysis in Lumbricus rubellus earthworms exposed to arsenic for a 28 day period, and found that arsenic clearly induced phytochelatin production in a dose-dependent manner. It was necessary to measure the phytochelatin metabolite concentrations directly, as there was no upregulation of phytochelatin synthase gene expression after 28 days: phytochelatin synthesis appears not to be transcriptionally regulated in animals. A further untargetted metabolomic analysis also found changes in metabolites associated with the transsulfuration pathway, which channels sulfur flux from methionine for phytochelatin synthesis. There was no evidence of biological transformation of arsenic (e.g. into methylated species) as a result of laboratory arsenic exposure. Finally, we compared wild populations of earthworms sampled from the field, and found that both arsenic-contaminated and cadmium-contaminated mine site worms had elevated phytochelatin concentrations.
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Affiliation(s)
- Manuel Liebeke
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Isabel Garcia-Perez
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Craig J. Anderson
- Centre for Ecology and Hydrology, Wallingford, United Kingdom
- School of Biosciences, University of Cardiff, Cardiff, United Kingdom
| | - Alan J. Lawlor
- Centre for Ecology and Hydrology, Lancaster, United Kingdom
| | - Mark H. Bennett
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Ceri A. Morris
- School of Biosciences, University of Cardiff, Cardiff, United Kingdom
| | - Peter Kille
- School of Biosciences, University of Cardiff, Cardiff, United Kingdom
| | - Claus Svendsen
- Centre for Ecology and Hydrology, Wallingford, United Kingdom
| | | | - Jacob G. Bundy
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
- * E-mail:
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