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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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2
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George S, Cassidy RN, Saintilnord WN, Fondufe-Mittendorf Y. Epigenomic reprogramming in iAs-mediated carcinogenesis. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2022; 96:319-365. [PMID: 36858778 DOI: 10.1016/bs.apha.2022.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Arsenic is a naturally occurring metal carcinogen found in the Earth's crust. Millions of people worldwide are chronically exposed to arsenic through drinking water and food. Exposure to inorganic arsenic has been implicated in many diseases ranging from acute toxicities to malignant transformations. Despite the well-known deleterious health effects of arsenic exposure, the molecular mechanisms in arsenic-mediated carcinogenesis are not fully understood. Since arsenic is non-mutagenic, the mechanism by which arsenic causes carcinogenesis is via alterations in epigenetic-regulated gene expression. There are two possible ways by which arsenic may modify the epigenome-indirectly through an arsenic-induced generation of reactive oxygen species which then impacts chromatin remodelers, or directly through interaction and modulation of chromatin remodelers. Whether directly or indirectly, arsenic modulates epigenetic gene regulation and our understanding of the direct effect of this modulation on chromatin structure is limited. In this chapter we will discuss the various ways by which inorganic arsenic affects the epigenome with consequences in health and disease.
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Affiliation(s)
- Smitha George
- Department of Epigenetics, Van Andel Institute, Grand Rapids, MI, United States
| | - Richard N Cassidy
- Department of Epigenetics, Van Andel Institute, Grand Rapids, MI, United States
| | - Wesley N Saintilnord
- Department of Epigenetics, Van Andel Institute, Grand Rapids, MI, United States; Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, United States
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3
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Servello FA, Fernandes R, Eder M, Harris N, Martin OMF, Oswal N, Lindberg A, Derosiers N, Sengupta P, Stroustrup N, Apfeld J. Neuronal temperature perception induces specific defenses that enable C. elegans to cope with the enhanced reactivity of hydrogen peroxide at high temperature. eLife 2022; 11:e78941. [PMID: 36226814 PMCID: PMC9635881 DOI: 10.7554/elife.78941] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 10/12/2022] [Indexed: 11/30/2022] Open
Abstract
Hydrogen peroxide is the most common reactive chemical that organisms face on the microbial battlefield. The rate with which hydrogen peroxide damages biomolecules required for life increases with temperature, yet little is known about how organisms cope with this temperature-dependent threat. Here, we show that Caenorhabditis elegans nematodes use temperature information perceived by sensory neurons to cope with the temperature-dependent threat of hydrogen peroxide produced by the pathogenic bacterium Enterococcus faecium. These nematodes preemptively induce the expression of specific hydrogen peroxide defenses in response to perception of high temperature by a pair of sensory neurons. These neurons communicate temperature information to target tissues expressing those defenses via an insulin/IGF1 hormone. This is the first example of a multicellular organism inducing their defenses to a chemical when they sense an inherent enhancer of the reactivity of that chemical.
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Affiliation(s)
| | - Rute Fernandes
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
| | - Matthias Eder
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
| | - Nathan Harris
- Department of Biology, Brandeis UniversityWalthamUnited States
| | - Olivier MF Martin
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
| | - Natasha Oswal
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
| | - Anders Lindberg
- Biology Department, Northeastern UniversityBostonUnited States
| | | | - Piali Sengupta
- Department of Biology, Brandeis UniversityWalthamUnited States
| | - Nicholas Stroustrup
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
| | - Javier Apfeld
- Biology Department, Northeastern UniversityBostonUnited States
- Bioengineering Department, Northeastern UniversityBostonUnited States
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4
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Mangu JCK, Rai N, Mandal A, Olsson PE, Jass J. Lysinibacillus sphaericus mediates stress responses and attenuates arsenic toxicity in Caenorhabditis elegans. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 835:155377. [PMID: 35460794 DOI: 10.1016/j.scitotenv.2022.155377] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 03/15/2022] [Accepted: 04/14/2022] [Indexed: 06/14/2023]
Abstract
Exposure to toxic metals alters host response and that leads to disease development. Studies have revealed the effects of metals on microbial physiology, however, the role of metal resistant bacteria on host response to metals is unclear. The hypothesis that xenobiotic interactions between gut microbes and arsenic influence the host physiology and toxicity was assessed in a Caenorhabditis elegans model. The arsenic-resistant Lysinibacillus sphaericus B1CDA was fed to C. elegans to determine the host responses to arsenic in comparison to Escherichia coli OP50 food. L. sphaericus diet extended C. elegans lifespan compared to E. coli diet, with an increased expression of genes involved in lifespan, stress response and immunity (hif-1, hsp-16.2, mtl-2, abf-2, clec-60), as well as reduced fat accumulation. Arsenic-exposed worms fed L. sphaericus also had a longer lifespan than those fed E. coli and had an increased expression of genes involved in cytoprotection, stress resistance (mtl-1, mtl-2) and oxidative stress response (cyp-35A2, isp-1, ctl-2, sod-1), together with a decreased accumulation of reactive oxygen species (ROS). In comparison with E. coli, L. sphaericus B1CDA diet increased C. elegans fitness while detoxifying arsenic induced ROS and extending lifespan.
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Affiliation(s)
| | - Neha Rai
- The Life Science Centre-Biology, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Abul Mandal
- Systems Biology Research Center, School of Bioscience, University of Skövde, Skövde, Sweden
| | - Per-Erik Olsson
- The Life Science Centre-Biology, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Jana Jass
- The Life Science Centre-Biology, School of Science and Technology, Örebro University, Örebro, Sweden.
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5
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Camacho J, de Conti A, Pogribny IP, Sprando RL, Hunt PR. Assessment of the effects of organic vs. inorganic arsenic and mercury in Caenorhabditis elegans. Curr Res Toxicol 2022; 3:100071. [PMID: 35602005 PMCID: PMC9118485 DOI: 10.1016/j.crtox.2022.100071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/26/2022] [Accepted: 04/20/2022] [Indexed: 01/03/2023] Open
Abstract
Exposures to mercury and arsenic are known to pose significant threats to human health. Effects specific to organic vs. inorganic forms of these toxic elements are less understood however, especially for organic dimethylarsinic acid (DMA), which has recently been detected in pups of rodent dams orally exposed to inorganic sodium (meta)arsenite (NaAsO2). Caenorhabditis elegans is a small animal alternative toxicity model. To fill data gaps on the effects of DMA relative to NaAsO2, C. elegans were exposed to these two compounds alongside more thoroughly researched inorganic mercury chloride (HgCl2) and organic methylmercury chloride (meHgCl). For timing of developmental milestone acquisition in C. elegans, meHgCl was 2 to 4-fold more toxic than HgCl2, and NaAsO2 was 20-fold more toxic than DMA, ranking the four compounds meHgCl > HgCl2 > NaAsO2 ≫ DMA for developmental toxicity. Methylmercury induced significant decreases in population locomotor activity levels in developing C. elegans. DMA was also associated with developmental hypoactivity, but at >100-fold higher concentrations than meHgCl. Transcriptional alterations in native genes were observed in wild type C. elegans adults exposed to concentrations equitoxic for developmental delay in juveniles. Both forms of arsenic induced genes involved in immune defense and oxidative stress response, while the two mercury species induced proportionally more genes involved in transcriptional regulation. A transgenic bioreporter for activation of conserved proteosome specific unfolded protein response was strongly activated by NaAsO2, but not DMA at tested concentrations. HgCl2 and meHgCl had opposite effects on a bioreporter for unfolded protein response in the endoplasmic reticulum. Presented experiments indicating low toxicity for DMA in C. elegans are consistent with human epidemiologic data correlating higher arsenic methylation capacity with resistance to arsenic toxicity. This work contributes to the understanding of the accuracy and fit-for-use categories for C. elegans toxicity screening and its usefulness to prioritize compounds of concern for further testing.
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Key Words
- Alternative Toxicity Model
- Arsenic
- DEGs, Differentially Expressed Genes
- DMA, dimethylarsinic acid
- ER, endoplasmic reticulum
- EXT, extinction (a measure of optical density)
- GO, gene ontology
- HgCl2, mercury(ii) chloride
- Inorganic
- L1, first larval stage C. elegans
- LD50, the median lethal dose per kilogram of body weight
- LOEL, lowest observed effect level
- Mercury
- NOEL, no observed effect level
- NaAsO2, sodium (meta)arsenite
- Organic
- OxStrR, Oxidative Stress Response
- Predictive Toxicology
- TOF, time of flight (a measure of size)
- UPR, Unfolded Protein Response
- iAs, inorganic arsenic
- meHgCl, methylmercury chloride
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Affiliation(s)
- Jessica Camacho
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Applied Research and Safety Assessment, 8301 Muirkirk Road, Laurel, MD 20708, United States
| | - Aline de Conti
- Food and Drug Administration, National Center for Toxicological Research, 3900 NCTR Rd, Jefferson, AR 72079, United States
| | - Igor P. Pogribny
- Food and Drug Administration, National Center for Toxicological Research, 3900 NCTR Rd, Jefferson, AR 72079, United States
| | - Robert L. Sprando
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Applied Research and Safety Assessment, 8301 Muirkirk Road, Laurel, MD 20708, United States
| | - Piper Reid Hunt
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Applied Research and Safety Assessment, 8301 Muirkirk Road, Laurel, MD 20708, United States
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6
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Shih SR, Bach DM, Rondeau NC, Sam J, Lovinger NL, Lopatkin AJ, Snow JW. Honey bee sHSP are responsive to diverse proteostatic stresses and potentially promising biomarkers of honey bee stress. Sci Rep 2021; 11:22087. [PMID: 34764357 PMCID: PMC8586346 DOI: 10.1038/s41598-021-01547-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 10/29/2021] [Indexed: 11/09/2022] Open
Abstract
The pollination services provided by the honey bee are critical in both natural and agricultural ecosystems. Honey bee colonies in the United States have suffered from an increased rate of die-off in recent years, stemming from a complex set of interacting stresses that remain poorly described. Defining specific common cellular processes and cellular stress responses impacted by multiple stressors represent a key step in understanding these synergies. Proteotoxic stresses negatively impact protein synthesis, folding, and degradation. Diverse proteotoxic stresses induce expression of genes encoding small heat shock proteins (sHSP) of the expanded lethal (2) essential for life (l(2)efl) gene family. In addition to upregulation by the Integrated Stress Response (ISR), the Heat Shock Response (HSR), and the Oxidative Stress Response (OSR), our data provide first evidence that sHSP genes are upregulated by the Unfolded Protein Response (UPR). As these genes appear to be part of a core stress response that could serve as a useful biomarker for cellular stress in honey bees, we designed and tested an RT-LAMP assay to detect increased l(2)efl gene expression in response to heat-stress. While this assay provides a powerful proof of principle, further work will be necessary to link changes in sHSP gene expression to colony-level outcomes, to adapt our preliminary assay into a Point of Care Testing (POCT) assay appropriate for use as a diagnostic tool for use in the field, and to couple assay results to management recommendations.
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Affiliation(s)
- Samantha R Shih
- Biology Department, Barnard College, New York, NY, 10027, USA
| | - Dunay M Bach
- Biology Department, Barnard College, New York, NY, 10027, USA
| | | | - Jessica Sam
- Biology Department, Barnard College, New York, NY, 10027, USA
| | | | | | - Jonathan W Snow
- Biology Department, Barnard College, New York, NY, 10027, USA.
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7
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Zhou GW, Yang XR, Zheng F, Zhang ZX, Zheng BX, Zhu YG, Xue XM. Arsenic transformation mediated by gut microbiota affects the fecundity of Caenorhabditis elegans. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 260:113991. [PMID: 31991357 DOI: 10.1016/j.envpol.2020.113991] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 12/18/2019] [Accepted: 01/13/2020] [Indexed: 05/19/2023]
Abstract
Arsenic biotransformation has been discovered in guts of soil invertebrates. Reproduction of invertebrates is sensitive to arsenic contamination in soils. However, little is known about the impact of gut microbe-mediated arsenic biotransformation on the fecundity of invertebrates. Here, Caenorhabditis elegans was firstly pre-fed with Escherichia coli BL21 possessing the capability of reducing arsenate [As(V)] or BL21M having the ability to reduce As(V) and methylate arsenite [As(III)], then inoculated worms were transferred to inactive E. coli AW3110 (harboring no arsenic transformation gene)-seeded plates treated with As(V) at different concentrations. Quantification of gut microbes showed that both E. coli BL21 and BL21M stably colonized in the guts after worms were cultured on inactive E. coli AW3110-seeded plates for 72 h. The analysis of arsenic species indicated that there was As(III) in C. elegans guts colonized with E. coli BL21, As(III) and dimethylarsinic acid [DMAs(V)] in C. elegans guts with E. coli BL21M exposed to As(V) for 6 h. After treatment of 100 μM As(V), decrease in brood sizes was observed for worms that were colonized with E. coli BL21 or BL21M compared to that with AW3110 in the guts. The levels of vitellogenin (VTG), glutathione S-transferases (GST) and superoxide dismutase (SOD), closely linked to reproduction and antioxidation-linked indicators, were the highest in worms whose guts colonized with E. coli BL21, followed by worms colonized with E. coli BL21M and worms colonized with inactive E. coli AW3110 exposed to As(V). Our results indicated the toxic impact of As(III) and DMAs(V) produced by gut microbes on reproduction of C. elegans. The work provides novel insight into the interplay between arsenic biotransformation mediated by gut microbes and the host fecundity in soils.
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Affiliation(s)
- Guo-Wei Zhou
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Xiao-Ru Yang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Fei Zheng
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Zi-Xing Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Bang-Xiao Zheng
- Faculty of Biological and Environmental Sciences, Ecosystems and Environment Research Programme, University of Helsinki, Niemenkatu 73, Lahti, 15140, Finland
| | - Yong-Guan Zhu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; State Key Lab of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xi-Mei Xue
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
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8
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Sphingosine kinase and p38 MAP kinase signaling promote resistance to arsenite-induced lethality in Caenorhabditis elegan. Mol Cell Toxicol 2019. [DOI: 10.1007/s13273-019-0045-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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9
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Jha DK, Sayrav K, Mishra GP, Mishra BB, Kumari A, Kumar A, Khan PK. Risk assessment of low arsenic exposure using biomarkers of oxidative and genotoxic stress in a piscine model. ECOTOXICOLOGY (LONDON, ENGLAND) 2019; 28:669-679. [PMID: 31256308 DOI: 10.1007/s10646-019-02060-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
The high level exposure to arsenic induces marked oxidative and genotoxic stress. However, information on the potential of low level arsenic exposure in this context is still scanty. In the present study, the extent of oxidative stress and genetic toxicity induced by low arsenic exposure was explored in freshwater fish Channa punctatus. Fish were exposed to low levels of arsenic (10 and 50 µg L-1) as well as to its high level (500 µg L-1) using sodium arsenite in aquaria water for 14 consecutive days. The TBARS assay for lipid peroxidation exhibited the increased occurrence of oxidative damage in the erythrocytes of fish at both the lower and higher levels of arsenic exposure. The level of reduced glutathione was also elevated in all the three arsenic exposed groups of fish compared to control. In contrast, significant decline was observed in the levels of three major antioxidant enzymes namely, superoxide dismutase, catalase and glutathione peroxidase, upon exposure to higher as well as lower levels of arsenic. Significant increases in micronucleus induction were found in the erythrocytes of fish even at the low levels of arsenic exposure. The study further revealed the occurrence of DNA fragmentation in the erythrocytes of fish at low arsenic exposures as well. The low level exposure to arsenic (using sodium arsenite), therefore, appeared to be capable of inducing noticeable oxidative stress as well as potential genotoxic effect in Channa punctatus. Moreover, the ability of arsenic to induce oxidative stress invariably appeared correlated with its genotoxic potential.
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Affiliation(s)
- Deepak K Jha
- Department of Zoology, Patna University, Patna, 800 005, India
| | - Kumar Sayrav
- Department of Zoology, Patna University, Patna, 800 005, India
| | - Gaurav P Mishra
- Department of Zoology, Patna University, Patna, 800 005, India
| | - Bipin B Mishra
- Department of Biochemistry, Patna University, Patna, 800 005, India
| | - Anupma Kumari
- Department of Zoology, Patna University, Patna, 800 005, India
| | - Amod Kumar
- Kirori Mal College, University of Delhi, New Delhi, 110 007, India
| | - Parimal K Khan
- Department of Zoology, Patna University, Patna, 800 005, India.
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10
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Association of specific gene mutations derived from machine learning with survival in lung adenocarcinoma. PLoS One 2018; 13:e0207204. [PMID: 30419062 PMCID: PMC6231670 DOI: 10.1371/journal.pone.0207204] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/27/2018] [Indexed: 12/20/2022] Open
Abstract
Lung cancer is the second most common cancer in the United States and the leading cause of mortality in cancer patients. Biomarkers predicting survival of patients with lung cancer have a profound effect on patient prognosis and treatment. However, predictive biomarkers for survival and their relevance for lung cancer are not been well known yet. The objective of this study was to perform machine learning with data from The Cancer Genome Atlas of patients with lung adenocarcinoma (LUAD) to find survival-specific gene mutations that could be used as survival-predicting biomarkers. To identify survival-specific mutations according to various clinical factors, four feature selection methods (information gain, chi-squared test, minimum redundancy maximum relevance, and correlation) were used. Extracted survival-specific mutations of LUAD were applied individually or as a group for Kaplan-Meier survival analysis. Mutations in MMRN2 and GMPPA were significantly associated with patient mortality while those in ZNF560 and SETX were associated with patient survival. Mutations in DNAJC2 and MMRN2 showed significant negative association with overall survival while mutations in ZNF560 showed significant positive association with overall survival. Mutations in MMRN2 showed significant negative association with disease-free survival while mutations in DRD3 and ZNF560 showed positive associated with disease-free survival. Mutations in DRD3, SETX, and ZNF560 showed significant positive association with survival in patients with LUAD while the opposite was true for mutations in DNAJC2, GMPPA, and MMRN2. These gene mutations were also found in other cohorts of LUAD, lung squamous cell carcinoma, and small cell lung cancer. In LUAD of Pan-Lung Cancer cohort, mutations in GMPPA, DNAJC2, and MMRN2 showed significant negative associations with survival of patients while mutations in DRD3 and SETX showed significant positive association with survival. In this study, machine learning was conducted to obtain information necessary to discover specific gene mutations associated with the survival of patients with LUAD. Mutations in the above six genes could predict survival rate and disease-free survival rate in patients with LUAD. Thus, they are important biomarker candidates for prognosis.
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11
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C. elegans as a model in developmental neurotoxicology. Toxicol Appl Pharmacol 2018; 354:126-135. [PMID: 29550512 DOI: 10.1016/j.taap.2018.03.016] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 02/28/2018] [Accepted: 03/12/2018] [Indexed: 12/22/2022]
Abstract
Due to many advantages Caenorhabditis elegans (C. elegans) has become a preferred model of choice in many fields, including neurodevelopmental toxicity studies. This review discusses the benefits of using C. elegans as an alternative to mammalian systems and gives examples of the uses of the nematode in evaluating the effects of major known neurodevelopmental toxins, including manganese, mercury, lead, fluoride, arsenic and organophosphorus pesticides. Reviewed data indicates numerous similarities with mammals in response to these toxins. Thus, C. elegans studies have the potential to predict possible effects of developmental neurotoxicants in higher animals, and may be used to identify new molecular pathways behind neurodevelopmental disruptions, as well as new toxicants.
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12
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Fu D, Bridle A, Leef M, Norte Dos Santos C, Nowak B. Hepatic expression of metal-related genes and gill histology in sand flathead (Platycephalus bassensis) from a metal contaminated estuary. MARINE ENVIRONMENTAL RESEARCH 2017; 131:80-89. [PMID: 28943068 DOI: 10.1016/j.marenvres.2017.09.014] [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: 07/06/2017] [Revised: 09/12/2017] [Accepted: 09/16/2017] [Indexed: 06/07/2023]
Abstract
Hepatic gene expression and gill histology were measured in sand flathead (Platycephalus bassensis) from a metal polluted estuary. The gene expression analyses were conducted on fish from two most polluted sites and a reference site. The metal-related genes were metal-regulatory transcription factor 1 (MTF1), transferrin (TF), ferriportin1 (FPN1), ferritin and metallothionein. The transcripts of MTF1, TF, and FPN1 were significantly higher in the liver of fish caught at polluted sites, suggesting these genes are potential biomarkers for environmental exposure to metal. Strong correlations were found between the transcripts of these three genes. Four types of gill lesions such as hyperplasia and lamellar fusion, epitheliocystis, telangiectasis, and deformed filament were observed in sampled fish. There was significant difference in the prevalence of epitheliocystis and telangiectasis between the fish from the polluted areas and reference area. Gill parasites were less prevalent in the flathead from polluted sites. The gill histopathological results indicated both pollutants and infections could contribute to gill lesions.
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Affiliation(s)
- Dingkun Fu
- Institute for Marine and Antarctic Studies, University of Tasmania, Locked Bag 1370, Launceston, Tasmania 7250, Australia.
| | - Andrew Bridle
- Institute for Marine and Antarctic Studies, University of Tasmania, Locked Bag 1370, Launceston, Tasmania 7250, Australia
| | - Melanie Leef
- Institute for Marine and Antarctic Studies, University of Tasmania, Locked Bag 1370, Launceston, Tasmania 7250, Australia
| | - Catarina Norte Dos Santos
- Institute for Marine and Antarctic Studies, University of Tasmania, Locked Bag 1370, Launceston, Tasmania 7250, Australia
| | - Barbara Nowak
- Institute for Marine and Antarctic Studies, University of Tasmania, Locked Bag 1370, Launceston, Tasmania 7250, Australia
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13
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Shaw JLA, Judy JD, Kumar A, Bertsch P, Wang MB, Kirby JK. Incorporating Transgenerational Epigenetic Inheritance into Ecological Risk Assessment Frameworks. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:9433-9445. [PMID: 28745897 DOI: 10.1021/acs.est.7b01094] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Chronic exposure to environmental contaminants can induce heritable "transgenerational" modifications to organisms, potentially affecting future ecosystem health and functionality. Incorporating transgenerational epigenetic heritability into risk assessment procedures has been previously suggested. However, a critical review of existing literature yielded numerous studies claiming transgenerational impacts, with little compelling evidence. Therefore, contaminant-induced epigenetic inheritance may be less common than is reported in the literature. We identified a need for multigeneration epigenetic studies that extend beyond what could be deemed "direct exposure" to F1 and F2 gametes and also include subsequent multiple nonexposed generations to adequately evaluate transgenerational recovery times. Also, increased experimental replication is required to account for the highly variable nature of epigenetic responses and apparent irreproducibility of current studies. Further, epigenetic end points need to be correlated with observable detrimental organism changes before a need for risk management can be properly determined. We suggest that epigenetic-based contaminant studies include concentrations lower than current "EC10-20" or "Lowest Observable Effect Concentrations" for the organism's most sensitive phenotypic end point, as higher concentrations are likely already regulated. Finally, we propose a regulatory framework and optimal experimental design that enables transgenerational epigenetic effects to be assessed and incorporated into conventional ecotoxicological testing.
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Affiliation(s)
- Jennifer L A Shaw
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Land and Water, Environmental Contaminant Mitigation and Technologies Research Program, Waite Road, Urrbrae, Adelaide Australia , 5064
| | - Jonathan D Judy
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Land and Water, Environmental Contaminant Mitigation and Technologies Research Program, Waite Road, Urrbrae, Adelaide Australia , 5064
- University of Florida , Soil and Water Sciences Department, 1692 McCarthy Drive, Gainesville, Florida 32611, United States
| | - Anupama Kumar
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Land and Water, Environmental Contaminant Mitigation and Technologies Research Program, Waite Road, Urrbrae, Adelaide Australia , 5064
| | - Paul Bertsch
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Land and Water , Brisbane, Queensland Australia , 4001
| | - Ming-Bo Wang
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Agriculture and Food Unit, Black Mountain, Canberra, Australian Capital Territory, Australia , 2601
| | - Jason K Kirby
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) , Land and Water, Environmental Contaminant Mitigation and Technologies Research Program, Waite Road, Urrbrae, Adelaide Australia , 5064
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14
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Luz AL, Godebo TR, Smith LL, Leuthner TC, Maurer LL, Meyer JN. Deficiencies in mitochondrial dynamics sensitize Caenorhabditis elegans to arsenite and other mitochondrial toxicants by reducing mitochondrial adaptability. Toxicology 2017; 387:81-94. [PMID: 28602540 PMCID: PMC5535741 DOI: 10.1016/j.tox.2017.05.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Revised: 05/10/2017] [Accepted: 05/30/2017] [Indexed: 01/06/2023]
Abstract
Mitochondrial fission, fusion, and mitophagy are interlinked processes that regulate mitochondrial shape, number, and size, as well as metabolic activity and stress response. The fundamental importance of these processes is evident in the fact that mutations in fission (DRP1), fusion (MFN2, OPA1), and mitophagy (PINK1, PARK2) genes can cause human disease (collectively >1/10,000). Interestingly, however, the age of onset and severity of clinical manifestations varies greatly between patients with these diseases (even those harboring identical mutations), suggesting a role for environmental factors in the development and progression of certain mitochondrial diseases. Using the model organism Caenorhabditis elegans, we screened ten mitochondrial toxicants (2, 4-dinitrophenol, acetaldehyde, acrolein, aflatoxin B1, arsenite, cadmium, cisplatin, doxycycline, paraquat, rotenone) for increased or decreased toxicity in fusion (fzo-1, eat-3)-, fission (drp-1)-, and mitophagy (pdr-1, pink-1)-deficient nematodes using a larval growth assay. In general, fusion-deficient nematodes were the most sensitive to toxicants, including aflatoxin B1, arsenite, cisplatin, paraquat, and rotenone. Because arsenite was particularly potent in fission- and fusion-deficient nematodes, and hundreds of millions of people are chronically exposed to arsenic, we investigated the effects of these genetic deficiencies on arsenic toxicity in more depth. We found that deficiencies in fission and fusion sensitized nematodes to arsenite-induced lethality throughout aging. Furthermore, low-dose arsenite, which acted in a "mitohormetic" fashion by increasing mitochondrial function (in particular, basal and maximal oxygen consumption) in wild-type nematodes by a wide range of measures, exacerbated mitochondrial dysfunction in fusion-deficient nematodes. Analysis of multiple mechanistic changes suggested that disruption of pyruvate metabolism and Krebs cycle activity underlie the observed arsenite-induced mitochondrial deficits, and these disruptions are exacerbated in the absence of mitochondrial fusion. This research demonstrates the importance of mitochondrial dynamics in limiting arsenite toxicity by permitting mitochondrial adaptability. It also suggests that individuals suffering from deficiencies in mitodynamic processes may be more susceptible to the mitochondrial toxicity of arsenic and other toxicants.
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Affiliation(s)
- Anthony L Luz
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC, 27708, USA
| | - Tewodros R Godebo
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC, 27708, USA
| | - Latasha L Smith
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC, 27708, USA
| | - Tess C Leuthner
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC, 27708, USA
| | - Laura L Maurer
- ExxonMobil Biomedical Sciences, Inc., Annandale, NJ, 08801-3059, USA
| | - Joel N Meyer
- Nicholas School of the Environment, Box 90328, Duke University, Durham, NC, 27708, USA.
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15
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Detection of Burkholderia pseudomallei toxin-mediated inhibition of protein synthesis using a Caenorhabditis elegans ugt-29 biosensor. Sci Rep 2016; 6:27475. [PMID: 27273550 PMCID: PMC4895344 DOI: 10.1038/srep27475] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 05/19/2016] [Indexed: 01/07/2023] Open
Abstract
Toxins are believed to play a crucial role in Burkholderia pseudomallei pathogenicity, however to date, only a few have been identified. The discovery of additional toxic molecules is limited by the lack of a sensitive indicator of B. pseudomallei toxicity. Previously, from a whole genome transcriptome analysis of B. pseudomallei-infected Caenorhabditis elegans, we noted significant overexpression of a number of worm genes encoding detoxification enzymes, indicating the host's attempt to clear bacterial toxic molecules. One of these genes, ugt-29, a family member of UDP-glucuronosyltransferases, was the most robustly induced phase II detoxification gene. In this study, we show that strong induction of ugt-29 is restricted to infections by the most virulent species among the pathogens tested. We also noted that ugt-29 is activated upon disruption of host protein synthesis. Hence, we propose that UGT-29 could be a promising biosensor to detect B. pseudomallei toxins that compromise host protein synthesis. The identification of bactobolin, a polyketide-peptide hybrid molecule, as a toxic molecule of B. pseudomallei further verifies the utilization of this surveillance system to search for bacterial toxins. Hence, a ugt-29 based reporter should be useful in screening for other molecules that inhibit host protein synthesis.
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16
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Yu CW, How CM, Liao VHC. Arsenite exposure accelerates aging process regulated by the transcription factor DAF-16/FOXO in Caenorhabditis elegans. CHEMOSPHERE 2016; 150:632-638. [PMID: 26796881 DOI: 10.1016/j.chemosphere.2016.01.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 01/01/2016] [Accepted: 01/04/2016] [Indexed: 06/05/2023]
Abstract
Arsenic is a known human carcinogen and high levels of arsenic contamination in food, soils, water, and air are of toxicology concerns. Nowadays, arsenic is still a contaminant of emerging interest, yet the effects of arsenic on aging process have received little attention. In this study, we investigated the effects and the underlying mechanisms of chronic arsenite exposure on the aging process in Caenorhabditis elegans. The results showed that prolonged arsenite exposure caused significantly decreased lifespan compared to non-exposed ones. In addition, arsenite exposure (100 μM) caused significant changes of age-dependent biomarkers, including a decrease of defecation frequency, accumulations of intestinal lipofuscin and lipid peroxidation in an age-dependent manner in C. elegans. Further evidence revealed that intracellular reactive oxygen species (ROS) level was significantly increased in an age-dependent manner upon 100 μM arsenite exposure. Moreover, the mRNA levels of transcriptional makers of aging (hsp-16.1, hsp-16.49, and hsp-70) were increased in aged worms under arsenite exposure (100 μM). Finally, we showed that daf-16 mutant worms were more sensitive to arsenite exposure (100 μM) on lifespan and failed to induce the expression of its target gene sod-3 in aged daf-16 mutant under arsenite exposure (100 μM). Our study demonstrated that chronic arsenite exposure resulted in accelerated aging process in C. elegans. The overproduction of intracellular ROS and the transcription factor DAF-16/FOXO play roles in mediating the accelerated aging process by arsenite exposure in C. elegans. This study implicates a potential ecotoxicological and health risk of arsenic in the environment.
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Affiliation(s)
- Chan-Wei Yu
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1 Roosevelt Road, Sec. 4, Taipei 106, Taiwan
| | - Chun Ming How
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1 Roosevelt Road, Sec. 4, Taipei 106, Taiwan
| | - Vivian Hsiu-Chuan Liao
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1 Roosevelt Road, Sec. 4, Taipei 106, Taiwan.
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17
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Aloia L, Demajo S, Di Croce L. ZRF1: a novel epigenetic regulator of stem cell identity and cancer. Cell Cycle 2015; 14:510-5. [PMID: 25665097 DOI: 10.4161/15384101.2014.988022] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The Zuotin-related factor 1, ZRF1, has recently been identified as an epigenetic regulator of gene transcription in stem cells and cancer. During differentiation of human teratocarcinoma cells, ZRF1 promotes transcriptional induction of developmental genes that are repressed by Polycomb complexes. Importantly, ZRF1 has recently been shown to be required for both neural differentiation of embryonic stem cells (ESCs) and for maintenance of neural progenitor cell (NPC) identity. Moreover, a dual role has now emerged for ZRF1 in cancer: on the one hand, ZRF1 plays a crucial role in oncogene-induced senescence (OIS) by activating the INK4/ARF locus, thus working as a tumor suppressor; on the other hand, ZRF1 promotes leukemogenesis in acute myeloid leukemia (AML) in a Polycomb-independent fashion. Therefore, increasing evidence points to ZRF1 as a novel target for therapy of neurodegenerative diseases and cancer.
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Key Words
- AML, acute myeloid leukemia
- ChIP, chromatin immunoprecipitation
- ESC, embryonic stem cells
- H2Aub1, mono-ubiquitinated histone H2A
- HDAC, histone deacetylase
- NPC, neural progenitor cells
- OIS, oncogene-induced senescence
- PRC1, polycomb repressive complex 1
- PRC2, polycomb repressive complex 2
- RA, retinoic acid
- RARa, retinoic acid receptor a
- UBD, ubiquitin binding domain
- ZRF1
- cancer
- cell fate
- development
- differentiation
- epigenetics
- polycomb
- retinoic acid
- senescence
- stem cell
- transcription
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Affiliation(s)
- Luigi Aloia
- a Centre for Genomic Regulation (CRG) ; Barcelona , Spain
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18
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Rhoads TW, Prasad A, Kwiecien NW, Merrill AE, Zawack K, Westphall MS, Schroeder FC, Kimble J, Coon JJ. NeuCode Labeling in Nematodes: Proteomic and Phosphoproteomic Impact of Ascaroside Treatment in Caenorhabditis elegans. Mol Cell Proteomics 2015; 14:2922-35. [PMID: 26392051 DOI: 10.1074/mcp.m115.049684] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Indexed: 01/05/2023] Open
Abstract
The nematode Caenorhabditis elegans is an important model organism for biomedical research. We previously described NeuCode stable isotope labeling by amino acids in cell culture (SILAC), a method for accurate proteome quantification with potential for multiplexing beyond the limits of traditional stable isotope labeling by amino acids in cell culture. Here we apply NeuCode SILAC to profile the proteomic and phosphoproteomic response of C. elegans to two potent members of the ascaroside family of nematode pheromones. By consuming labeled E. coli as part of their diet, C. elegans nematodes quickly and easily incorporate the NeuCode heavy lysine isotopologues by the young adult stage. Using this approach, we report, at high confidence, one of the largest proteomic and phosphoproteomic data sets to date in C. elegans: 6596 proteins at a false discovery rate ≤ 1% and 6620 phosphorylation isoforms with localization probability ≥75%. Our data reveal a post-translational signature of pheromone sensing that includes many conserved proteins implicated in longevity and response to stress.
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Affiliation(s)
| | - Aman Prasad
- ‖Biochemistry, and **Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, 53706
| | | | | | - Kelson Zawack
- ‡‡Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, 14853
| | | | - Frank C Schroeder
- ‡‡Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, 14853
| | - Judith Kimble
- ‖Biochemistry, and **Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, 53706
| | - Joshua J Coon
- From the Departments of ‡Chemistry, §Biomolecular Chemistry, ¶Genome Center,
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19
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Burke SL, Hammell M, Ambros V. Robust Distal Tip Cell Pathfinding in the Face of Temperature Stress Is Ensured by Two Conserved microRNAS in Caenorhabditis elegans. Genetics 2015; 200:1201-18. [PMID: 26078280 PMCID: PMC4574240 DOI: 10.1534/genetics.115.179184] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 06/10/2015] [Indexed: 12/26/2022] Open
Abstract
Biological robustness, the ability of an organism to maintain a steady-state output as genetic or environmental inputs change, is critical for proper development. MicroRNAs have been implicated in biological robustness mechanisms through their post-transcriptional regulation of genes and gene networks. Previous research has illustrated examples of microRNAs promoting robustness as part of feedback loops and genetic switches and by buffering noisy gene expression resulting from environmental and/or internal changes. Here we show that the evolutionarily conserved microRNAs mir-34 and mir-83 (homolog of mammalian mir-29) contribute to the robust migration pattern of the distal tip cells in Caenorhabditis elegans by specifically protecting against stress from temperature changes. Furthermore, our results indicate that mir-34 and mir-83 may modulate the integrin signaling involved in distal tip cell migration by potentially targeting the GTPase cdc-42 and the beta-integrin pat-3. Our findings suggest a role for mir-34 and mir-83 in integrin-controlled cell migrations that may be conserved through higher organisms. They also provide yet another example of microRNA-based developmental robustness in response to a specific environmental stress, rapid temperature fluctuations.
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Affiliation(s)
- Samantha L Burke
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Molly Hammell
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724
| | - Victor Ambros
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
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20
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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: 1.9] [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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21
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Hunt PR, Keltner Z, Gao X, Oldenburg SJ, Bushana P, Olejnik N, Sprando RL. Bioactivity of nanosilver in Caenorhabditis elegans: Effects of size, coat, and shape. Toxicol Rep 2014; 1:923-944. [PMID: 28962305 PMCID: PMC5598322 DOI: 10.1016/j.toxrep.2014.10.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/23/2014] [Accepted: 10/24/2014] [Indexed: 01/18/2023] Open
Abstract
The in vivo toxicity to eukaryotes of nanosilver (AgNP) spheres and plates in two sizes each was assessed using the simple model organism Caenorhabditis elegans. For each shape, smaller AgNP size correlated with higher toxicity, as indicated by reduced larval growth. Smaller size also correlated with significant increases in silver uptake for silver nanospheres. Citrate coated silver spheres of 20 nm diameter induced an innate immune response that increased or held steady over 24 h, while regulation of genes involved in metal metabolism peaked at 4 h and subsequently decreased. For AgNP spheres, coating altered bioactivity, with a toxicity ranking of polyethylene glycol (PEG) > polyvinylpyrrolidone (PVP) ≅ branched polyethyleneimine (BPEI) > citrate, but silver uptake ranking of PEG > PVP > citrate > BPEI. Our findings in C. elegans correlate well with findings in rodents for AgNP size vs. uptake and toxicity, as well as for induction of immune effectors, while using methods that are faster and far less expensive, supporting the use of C. elegans as an alternative model for early toxicity screening.
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Affiliation(s)
- Piper Reid Hunt
- Center for Food Safety and Applied Nutrition, FDA, Laurel, MD, United States
| | - Zachary Keltner
- Center for Food Safety and Applied Nutrition, FDA, Laurel, MD, United States
| | - Xiugong Gao
- Center for Food Safety and Applied Nutrition, FDA, Laurel, MD, United States
| | | | - Priyanka Bushana
- Center for Food Safety and Applied Nutrition, FDA, Laurel, MD, United States
| | - Nicholas Olejnik
- Center for Food Safety and Applied Nutrition, FDA, Laurel, MD, United States
| | - Robert L Sprando
- Center for Food Safety and Applied Nutrition, FDA, Laurel, MD, United States
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22
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Glover-Cutter KM, Alderman S, Dombrowski JE, Martin RC. Enhanced oxidative stress resistance through activation of a zinc deficiency transcription factor in Brachypodium distachyon. PLANT PHYSIOLOGY 2014; 166:1492-505. [PMID: 25228396 PMCID: PMC4226367 DOI: 10.1104/pp.114.240457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 09/15/2014] [Indexed: 05/07/2023]
Abstract
Identification of viable strategies to increase stress resistance of crops will become increasingly important for the goal of global food security as our population increases and our climate changes. Considering that resistance to oxidative stress is oftentimes an indicator of health and longevity in animal systems, characterizing conserved pathways known to increase oxidative stress resistance could prove fruitful for crop improvement strategies. This report argues for the usefulness and practicality of the model organism Brachypodium distachyon for identifying and validating stress resistance factors. Specifically, we focus on a zinc deficiency B. distachyon basic leucine zipper transcription factor, BdbZIP10, and its role in oxidative stress in the model organism B. distachyon. When overexpressed, BdbZIP10 protects plants and callus tissue from oxidative stress insults, most likely through distinct and direct activation of protective oxidative stress genes. Increased oxidative stress resistance and cell viability through the overexpression of BdbZIP10 highlight the utility of investigating conserved stress responses between plant and animal systems.
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Affiliation(s)
- Kira M Glover-Cutter
- United States Department of Agriculture, Agricultural Research Service, National Forage Seed Production Research Center, Corvallis, Oregon 97331
| | - Stephen Alderman
- United States Department of Agriculture, Agricultural Research Service, National Forage Seed Production Research Center, Corvallis, Oregon 97331
| | - James E Dombrowski
- United States Department of Agriculture, Agricultural Research Service, National Forage Seed Production Research Center, Corvallis, Oregon 97331
| | - Ruth C Martin
- United States Department of Agriculture, Agricultural Research Service, National Forage Seed Production Research Center, Corvallis, Oregon 97331
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23
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Keith SA, Amrit FRG, Ratnappan R, Ghazi A. The C. elegans healthspan and stress-resistance assay toolkit. Methods 2014; 68:476-86. [PMID: 24727065 DOI: 10.1016/j.ymeth.2014.04.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 04/01/2014] [Accepted: 04/03/2014] [Indexed: 12/22/2022] Open
Abstract
A wealth of knowledge on the genetic mechanisms that govern aging has emerged from the study of mutants that exhibit enhanced longevity and exceptional resilience to adverse environmental conditions. In these studies, lifespan has been an excellent proxy for establishing the rate of aging, but it is not always correlated with qualitative measures of healthy aging or 'healthspan'. Although the attributes of healthspan have been challenging to define, they share some universal features that are increasingly being incorporated into aging studies. Here we describe methods used to determine Caenorhabditis elegans healthspan. These include assessments of tissue integrity and functionality and resistance to a variety of biotic and abiotic stressors. We have chosen to include simple, rapid assays in this collection that can be easily undertaken in any C. elegans laboratory, and can be relied on to provide a preliminary but thorough insight into the healthspan of a population.
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Affiliation(s)
- Scott Alexander Keith
- Department of Pediatrics, University of Pittsburgh School of Medicine, 7129 Rangos Research Centre, Children's Hospital of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA 15224, United States
| | - Francis Raj Gandhi Amrit
- Department of Pediatrics, University of Pittsburgh School of Medicine, 7129 Rangos Research Centre, Children's Hospital of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA 15224, United States
| | - Ramesh Ratnappan
- Department of Pediatrics, University of Pittsburgh School of Medicine, 7129 Rangos Research Centre, Children's Hospital of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA 15224, United States
| | - Arjumand Ghazi
- Department of Pediatrics, University of Pittsburgh School of Medicine, 7129 Rangos Research Centre, Children's Hospital of Pittsburgh, 4401 Penn Avenue, Pittsburgh, PA 15224, United States.
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