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Russ T, Enders L, Zbiegly JM, Potru PS, Wurm J, Spittau B. 2,4-Dichlorophenoxyacetic Acid Induces Degeneration of mDA Neurons In Vitro. Biomedicines 2023; 11:2882. [PMID: 38001883 PMCID: PMC10669833 DOI: 10.3390/biomedicines11112882] [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: 09/26/2023] [Revised: 10/18/2023] [Accepted: 10/19/2023] [Indexed: 11/26/2023] Open
Abstract
Background: Parkinson's disease (PD) affects 1-2% of the population over the age of 60 and the majority of PD cases are sporadic, without any family history of the disease. Neuroinflammation driven by microglia has been shown to promote the progression of midbrain dopaminergic (mDA) neuron loss through the release of neurotoxic factors. Interestingly, the risk of developing PD is significantly higher in distinct occupations, such as farming and agriculture, and is linked to the use of pesticides and herbicides. Methods: The neurotoxic features of 2,4-Dichlorophenoxyacetic acid (2,4D) at concentrations of 10 µM and 1 mM were analyzed in two distinct E14 midbrain neuron culture systems and in primary microglia. Results: The application of 1 mM 2,4D resulted in mDA neuron loss in neuron-enriched cultures. Notably, 2,4D-induced neurotoxicity significantly increased in the presence of microglia in neuron-glia cultures, suggesting that microglia-mediated neurotoxicity could be one mechanism for progressive neuron loss in this in vitro setup. However, 2,4D alone was unable to trigger microglia reactivity. Conclusions: Taken together, we demonstrate that 2,4D is neurotoxic for mDA neurons and that the presence of glia cells enhances 2,4D-induced neuron death. These data support the role of 2,4D as a risk factor for the development and progression of PD and further suggest the involvement of microglia during 2,4D-induced mDA neuron loss.
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Affiliation(s)
- Tamara Russ
- Medical School OWL, Anatomy and Cell Biology, Bielefeld University, 33615 Bielefeld, Germany; (T.R.)
- Institute of Anatomy, University of Rostock, 18051 Rostock, Germany
| | - Lennart Enders
- Institute for Anatomy and Cell Biology, Department of Molecular Embryology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany (J.M.Z.)
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, 1090 Vienna, Austria
| | - Julia M. Zbiegly
- Institute for Anatomy and Cell Biology, Department of Molecular Embryology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany (J.M.Z.)
- UK Dementia Research Institute and Department of Clinical Neurosciences, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0SL, UK
| | - Phani Sankar Potru
- Medical School OWL, Anatomy and Cell Biology, Bielefeld University, 33615 Bielefeld, Germany; (T.R.)
- Institute of Anatomy, University of Rostock, 18051 Rostock, Germany
| | - Johannes Wurm
- Medical School OWL, Anatomy and Cell Biology, Bielefeld University, 33615 Bielefeld, Germany; (T.R.)
- Institute of Anatomy, University of Rostock, 18051 Rostock, Germany
| | - Björn Spittau
- Medical School OWL, Anatomy and Cell Biology, Bielefeld University, 33615 Bielefeld, Germany; (T.R.)
- Institute of Anatomy, University of Rostock, 18051 Rostock, Germany
- Institute for Anatomy and Cell Biology, Department of Molecular Embryology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany (J.M.Z.)
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Nanni W, Porto GDS, Pereira JNB, Gonçalves ARN, Marinsek GP, Stabille SR, Favetta PM, Germano RDM, Mari RDB. Evaluation of myenteric neurons in the colon of rats exposed to 2,4 dichlorophenoxyacetic acid herbicide. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2022; 57:421-429. [PMID: 35440284 DOI: 10.1080/03601234.2022.2064674] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The assessment of the enteric nervous system provides a better understanding of the effects that contaminants can have on the health and well-being of organisms. It has been reported that 2,4-dichlorophenoxyacetic acid (2,4-D) is a highly persistent herbicide in the environment that is responsible for neurotoxic changes in different myenteric neuronal subpopulations. The current study aimed to evaluate the effects of 2,4-D on myenteric neurons in the colon of Rattus norvegicus for the first time. A dose of 2,4-D (5 mg/kg/day) was administered to the experimental group (2,4-D) for 15 days. Then, the proximal colon was collected and submitted to Giemsa and NADPH-d histochemical techniques for the disclosure of total and nitrergic neurons. The 2,4-D group presented a higher density of total neurons (p = 0.05, t-test), which together with the maintenance of nitrergic neuronal density, may be related to the increase in the expression of the neurotransmitter acetylcholine by colocalization, responsible for stimulating the intestinal smooth muscle and increasing the chances of the expulsion of the harmful content present in the lumen. Over 15 days, the neurotoxic effects of 2,4-D in the myenteric plexus influenced an increase in the general population of myenteric neurons in the colon.
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Affiliation(s)
- Wagner Nanni
- Post-graduate Programme in Animal Science, Universidade Paranaense, Umuarama, Paraná, Brazil
| | - Gisele da Silva Porto
- Laboratory of Animal Virology, Department of Veterinary Preventive Medicine, Universidade Estadual de Londrina, Londrina, Paraná, Brazil
| | | | | | | | - Sandra Regina Stabille
- Post-graduate Programme in Animal Science, Universidade Paranaense, Umuarama, Paraná, Brazil
| | | | - Ricardo de Melo Germano
- Post-graduate Programme in Animal Science, Universidade Paranaense, Umuarama, Paraná, Brazil
| | - Renata de Britto Mari
- Department of Biological and Environmental Sciences, São Paulo State University (UNESP), São Paulo, Brazil
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Andrew A, Zhou J, Gui J, Harrison A, Shi X, Li M, Guetti B, Nathan R, Tischbein M, Pioro EP, Stommel E, Bradley W. Pesticides applied to crops and amyotrophic lateral sclerosis risk in the U.S. Neurotoxicology 2021; 87:128-135. [PMID: 34562505 PMCID: PMC10756230 DOI: 10.1016/j.neuro.2021.09.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 09/20/2021] [Accepted: 09/20/2021] [Indexed: 01/25/2023]
Abstract
BACKGROUND Environmental exposures are implicated in the etiology of amyotrophic lateral sclerosis (ALS). Application of insecticides, herbicides, and fungicides with neurotoxic properties to crops is permitted in the U.S., however reporting of the quantities is government mandated. OBJECTIVE To identify pesticides that may be associated with ALS etiology for future study. METHODS We geospatially estimated exposure to crop-applied pesticides as risk factors for ALS in a large de-identified medical claims database, the SYMPHONY Integrated Dataverse®. We extracted residence at diagnosis of ∼26,000 nationally distributed ALS patients, and matched non-ALS controls. We mapped county-level U.S. Geological Survey data on applications of 423 pesticides to estimate local residential exposure. We randomly broke the SYMPHONY dataset into two groups to form independent discovery and validation cohorts, then confirmed top hits using residential history information from a study of NH, VT, and OH. RESULTS Pesticides with the largest positive statistically significant associations in both the discovery and the validation studies and evidence of neurotoxicity in the literature were the herbicides 2,4-D (OR 1.25 95 % CI 1.17-1.34) and glyphosate (OR 1.29 95 %CI 1.19-1.39), and the insecticides carbaryl (OR 1.32 95 %CI 1.23-1.42) and chlorpyrifos (OR 1.25 95 %CI 1.17-1.33). SIGNIFICANCE Our geospatial analysis results support potential neurotoxic pesticide exposures as risk factors for sporadic ALS. Focused studies to assess these identified potential relationships are warranted.
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Affiliation(s)
- Angeline Andrew
- Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States.
| | - Jie Zhou
- Dartmouth College, Hanover, NH, United States
| | - Jiang Gui
- Dartmouth College, Hanover, NH, United States
| | | | - Xun Shi
- Dartmouth College, Hanover, NH, United States
| | - Meifang Li
- Dartmouth College, Hanover, NH, United States
| | - Bart Guetti
- Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | | | - Maeve Tischbein
- Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Erik P Pioro
- Center for ALS and Related Disorders, Cleveland Clinic, Cleveland, OH, United States
| | - Elijah Stommel
- Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Walter Bradley
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, United States
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Dehnert GK, Karasov WH, Wolman MA. 2,4-Dichlorophenoxyacetic acid containing herbicide impairs essential visually guided behaviors of larval fish. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 209:1-12. [PMID: 30684730 DOI: 10.1016/j.aquatox.2019.01.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 01/15/2019] [Accepted: 01/17/2019] [Indexed: 06/09/2023]
Abstract
Aquatic herbicides are used worldwide to eradicate nuisance and invasive plants despite limited knowledge of their toxicity to non-target organisms. 2,4-Dichlorophenoxyacetic acid (2,4-D) is a common active ingredient in commercial herbicide formulations, which triggers plant cell death by mimicking the plant-specific hormone auxin. Application practices of 2,4-D commercial herbicides typically coincide with yearly freshwater fish spawning periods. This practice exposes fish to xenobiotics at their vulnerable larval stages. The full impacts of 2,4-D on larval fish remains poorly understood, and hence, whether it may alter larval survival, larval behavior, fish populations, and ecosystem dynamics. In the present study, we exposed embryonic and larval zebrafish (Danio rerio) to the active ingredient 2,4-D (pure 2,4-D) or a 2,4-D containing commercial herbicide DMA4®IVM (DMA4) and evaluated morphology, survival, behavior, and nervous system function. At 2,4-D concentrations producing no overt morphological defects during embryonic or early larval stages, we observed reduced survival throughout a 21-day larval assay (4-8 ppm DMA4 and 0.75-4 ppm pure 2,4-D). Notably, prey capture, a behavior essential to survival, was reduced in 2,4-D-exposed larval zebrafish (4-8 ppm DMA4 and 0.75-4 ppm pure 2,4-D) and yellow perch (Perca flavescens) (4-20 ppm DMA4). In zebrafish, 8 ppm DMA4 exposure reduced prey capture when exposure was restricted to the period of visual system development. Consistent with these results, larval zebrafish exposed to 8 ppm DMA4 showed reduced neural activity within the optic tectum following prey exposure. Together, our results suggest that 2,4-D alters the development and function of neural circuits underlying vision of larval fish, and thereby reduces visually guided behaviors required for survival.
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Affiliation(s)
- Gavin K Dehnert
- Department of Integrative Biology, University of Wisconsin - Madison, Madison, WI, USA
| | - William H Karasov
- Department of Forest and Wildlife Ecology, University of Wisconsin - Madison, Madison, WI, USA
| | - Marc A Wolman
- Department of Integrative Biology, University of Wisconsin - Madison, Madison, WI, USA.
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Lushchak VI, Matviishyn TM, Husak VV, Storey JM, Storey KB. Pesticide toxicity: a mechanistic approach. EXCLI JOURNAL 2018; 17:1101-1136. [PMID: 30564086 PMCID: PMC6295629 DOI: 10.17179/excli2018-1710] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 10/24/2018] [Indexed: 12/04/2022]
Abstract
Pesticides are known for their high persistence and pervasiveness in the environment, and along with products of their biotransformation, they may remain in and interact with the environment and living organisms in multiple ways, according to their nature and chemical structure, dose and targets. In this review, the classifications of pesticides based on their nature, use, physical state, pathophysiological effects, and sources are discussed. The effects of these xenobiotics on the environment, their biotransformation in terms of bioaccumulation are highlighted with special focus on the molecular mechanisms deciphered to date. Basing on targeted organisms, most pesticides are classified as herbicides, fungicides, and insecticides. Herbicides are known as growth regulators, seedling growth inhibitors, photosynthesis inhibitors, inhibitors of amino acid and lipid biosynthesis, cell membrane disrupters, and pigment biosynthesis inhibitors, whereas fungicides include inhibitors of ergosterol biosynthesis, protein biosynthesis, and mitochondrial respiration. Insecticides mainly affect nerves and muscle, growth and development, and energy production. Studying the impact of pesticides and other related chemicals is of great interest to animal and human health risk assessment processes since potentially everyone can be exposed to these compounds which may cause many diseases, including metabolic syndrome, malnutrition, atherosclerosis, inflammation, pathogen invasion, nerve injury, and susceptibility to infectious diseases. Future studies should be directed to investigate influence of long term effects of low pesticide doses and to minimize or eliminate influence of pesticides on non-target living organisms, produce more specific pesticides and using modern technologies to decrease contamination of food and other goods by pesticides.
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Affiliation(s)
- Volodymyr I. Lushchak
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine
| | - Tetiana M. Matviishyn
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine
| | - Viktor V. Husak
- Department of Biochemistry and Biotechnology, Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine
| | - Janet M. Storey
- Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Kenneth B. Storey
- Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
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Sun H, Shao W, Liu H, Jiang Z. Exposure to 2,4-dichlorophenoxyacetic acid induced PPARβ-dependent disruption of glucose metabolism in HepG2 cells. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:17050-17057. [PMID: 29633193 DOI: 10.1007/s11356-018-1921-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 04/02/2018] [Indexed: 06/08/2023]
Abstract
2,4-Dichlorophenoxyacetic acid is one of the most widely used herbicides. Its impact on health is increasingly attracting great attentions. This study aimed to investigate the effect of 2,4-dichlorophenoxyacetic acid on glucose metabolism in HepG2 cells and the underlying mechanism. After 24 h exposure to 2,4-dichlorophenoxyacetic acid, glycogen was measured by PAS staining and glucose by ELISA in HepG2 cells. The expression of genes involved in glucose metabolism was measured by real-time PCR, Western blotting, and immunofluorescence. HepG2 cells presented more extracellular glucose consumption and glycogen content after exposed to 2,4-dichlorophenoxyacetic acid. Expression of gluconeogenesis-related genes, FoxO1, and CREB is significantly elevated. Moreover, PPARβ was up-regulated dose-dependently. SiRNA knockdown of PPARβ completely rescued the increase of glycogen accumulation and glucose uptake, and the up-regulation of FOXO1 and CREB expression. Our findings propose novel mechanisms that 2,4-dichlorophenoxyacetic acid causes glucose metabolism dysfunction through PPARβ in HepG2 cells.
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Affiliation(s)
- Haidong Sun
- Department of Surgery, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 125 Ruijin Er Road, Shanghai, 200025, China
| | - Wentao Shao
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing, 211166, Jiangsu Province, China
| | - Hui Liu
- State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing, 211166, Jiangsu Province, China
| | - Zhaoyan Jiang
- Department of Surgery, Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 125 Ruijin Er Road, Shanghai, 200025, China.
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Bhat SV, Sultana T, Körnig A, McGrath S, Shahina Z, Dahms TES. Correlative atomic force microscopy quantitative imaging-laser scanning confocal microscopy quantifies the impact of stressors on live cells in real-time. Sci Rep 2018; 8:8305. [PMID: 29844489 PMCID: PMC5973941 DOI: 10.1038/s41598-018-26433-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 05/04/2018] [Indexed: 11/14/2022] Open
Abstract
There is an urgent need to assess the effect of anthropogenic chemicals on model cells prior to their release, helping to predict their potential impact on the environment and human health. Laser scanning confocal microscopy (LSCM) and atomic force microscopy (AFM) have each provided an abundance of information on cell physiology. In addition to determining surface architecture, AFM in quantitative imaging (QI) mode probes surface biochemistry and cellular mechanics using minimal applied force, while LSCM offers a window into the cell for imaging fluorescently tagged macromolecules. Correlative AFM-LSCM produces complimentary information on different cellular characteristics for a comprehensive picture of cellular behaviour. We present a correlative AFM-QI-LSCM assay for the simultaneous real-time imaging of living cells in situ, producing multiplexed data on cell morphology and mechanics, surface adhesion and ultrastructure, and real-time localization of multiple fluorescently tagged macromolecules. To demonstrate the broad applicability of this method for disparate cell types, we show altered surface properties, internal molecular arrangement and oxidative stress in model bacterial, fungal and human cells exposed to 2,4-dichlorophenoxyacetic acid. AFM-QI-LSCM is broadly applicable to a variety of cell types and can be used to assess the impact of any multitude of contaminants, alone or in combination.
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Affiliation(s)
- Supriya V Bhat
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2, Canada
| | - Taranum Sultana
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2, Canada
| | - André Körnig
- JPK Instruments, JPK Instruments AG, Colditzstr. 34-36, 12099, Berlin, Germany
| | - Seamus McGrath
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2, Canada
| | - Zinnat Shahina
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2, Canada
| | - Tanya E S Dahms
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2, Canada.
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Islam F, Wang J, Farooq MA, Khan MSS, Xu L, Zhu J, Zhao M, Muños S, Li QX, Zhou W. Potential impact of the herbicide 2,4-dichlorophenoxyacetic acid on human and ecosystems. ENVIRONMENT INTERNATIONAL 2018; 111:332-351. [PMID: 29203058 DOI: 10.1016/j.envint.2017.10.020] [Citation(s) in RCA: 169] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/18/2017] [Accepted: 10/20/2017] [Indexed: 05/03/2023]
Abstract
The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is applied directly to aquatic and conventional farming systems to control weeds, and is among the most widely distributed pollutants in the environment. Non-target organisms are exposed to 2,4-D via several ways, which could produce toxic effects depending on the dose, frequency of exposure, and the host factors that influence susceptibility and sensitivity. An increasing number of experimental evidences have shown concerns about its presence/detection in the environment, because several investigations have pointed out its potential lethal effects on non-target organisms. In this review, we critically evaluated the environmental fate and behavior of 2,4-D along with its eco-toxicological effects on aquatic, plants and human life to provide concise assessment in the light of recently published reports. The findings demonstrate that 2,4-D is present in a low concentration in surface water of regions where its usage is high. The highest concentrations of 2,4-D were detected in soil, air and surface water surrounded by crop fields, which suggest that mitigation strategies must be implanted locally to prevent the entry of 2,4-D into the environment. A general public may have frequent exposure to 2,4-D due to its wide applications at home lawns and public parks, etc. Various in vivo and in vitro investigations suggest that several species (or their organs) at different trophic levels are extremely sensitive to the 2,4-D exposure, which may explain variation in outcomes of reported investigations. However, implications for the prenatal exposure to 2,4-D remain unknown because 2,4-D-induced toxicity thresholds in organism have only been derived from juveniles or adults. In near future, introduction of 2,4-D resistant crops will increase its use in agriculture, which may cause relatively high and potentially unsafe residue levels in the environment. The recent findings indicate the urgent need to further explore fate, accumulation and its continuous low level exposure impacts on the environment to generate reliable database which is key in drafting new regulation and policies to protect the population from further exposure.
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Affiliation(s)
- Faisal Islam
- College of Agriculture and Biotechnology, Zhejiang Key Laboratory of Crop Germplasm, Institute of Crop Science, Zhejiang University, Hangzhou 310058, China
| | - Jian Wang
- College of Agriculture and Biotechnology, Zhejiang Key Laboratory of Crop Germplasm, Institute of Crop Science, Zhejiang University, Hangzhou 310058, China
| | - Muhammad A Farooq
- College of Agriculture and Biotechnology, Zhejiang Key Laboratory of Crop Germplasm, Institute of Crop Science, Zhejiang University, Hangzhou 310058, China; Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan 60800, Pakistan
| | - Muhammad S S Khan
- College of Agriculture and Biotechnology, Zhejiang Key Laboratory of Crop Germplasm, Institute of Crop Science, Zhejiang University, Hangzhou 310058, China
| | - Ling Xu
- Zhejiang Key Laboratory of Plant Secondary Metabolism and Regulation, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Jinwen Zhu
- College of Agriculture and Biotechnology, Zhejiang Key Laboratory of Crop Germplasm, Institute of Crop Science, Zhejiang University, Hangzhou 310058, China
| | - Min Zhao
- Zhejiang Key Laboratory for Subtropical Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou 325035, China
| | - Stéphane Muños
- Laboratoire des Interactions Plantes Micro-organismes, Université de Toulouse, CNRS-INRA, 441-2594, France
| | - Qing X Li
- Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu 96822, USA
| | - Weijun Zhou
- College of Agriculture and Biotechnology, Zhejiang Key Laboratory of Crop Germplasm, Institute of Crop Science, Zhejiang University, Hangzhou 310058, China.
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Bhat SV, Kamencic B, Körnig A, Shahina Z, Dahms TES. Exposure to Sub-lethal 2,4-Dichlorophenoxyacetic Acid Arrests Cell Division and Alters Cell Surface Properties in Escherichia coli. Front Microbiol 2018; 9:44. [PMID: 29472899 PMCID: PMC5810288 DOI: 10.3389/fmicb.2018.00044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 01/09/2018] [Indexed: 11/13/2022] Open
Abstract
Escherichia coli is a robust, easily adaptable and culturable bacterium in vitro, and a model bacterium for studying the impact of xenobiotics in the environment. We have used correlative atomic force – laser scanning confocal microscopy (AFM-LSCM) to characterize the mechanisms of cellular response to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). One of the most extensively used herbicides world-wide, 2,4-D is known to cause hazardous effects in diverse non-target organisms. Sub-lethal concentrations of 2,4-D caused DNA damage in E. coli WM1074 during short exposure periods which increased significantly over time. In response to 2,4-D, FtsZ and FtsA relocalized within seconds, coinciding with the complete inhibition of cell septation and cell elongation. Exposure to 2,4-D also resulted in increased activation of the SOS response. Changes to cell division were accompanied by concomitant changes to surface roughness, elasticity and adhesion in a time-dependent manner. This is the first study describing the mechanistic details of 2,4-D at sub-lethal levels in bacteria. Our study suggests that 2,4-D arrests E. coli cell division within seconds after exposure by disrupting the divisome complex, facilitated by dissipation of membrane potential. Over longer exposures, 2,4-D causes filamentation as a result of an SOS response to oxidative stress induced DNA damage.
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Affiliation(s)
- Supriya V Bhat
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | - Belma Kamencic
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | | | - Zinnat Shahina
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
| | - Tanya E S Dahms
- Department of Chemistry and Biochemistry, University of Regina, Regina, SK, Canada
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10
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Epi/perineural and Schwann Cells as Well as Perineural Sheath Integrity are Affected Following 2,4-D Exposure. Neurotox Res 2017; 32:624-638. [PMID: 28699141 DOI: 10.1007/s12640-017-9777-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 06/24/2017] [Accepted: 06/28/2017] [Indexed: 01/18/2023]
Abstract
2,4-dicholorophenoxy acetic acid (2,4-D) is a worldwide-known hormone herbicide. However, there are increasing concerns about its exposure and risks of developing pathological conditions for the peripheral nervous system. The aim of this study was to investigate the mechanism(s) involved in the toxicity of 2,4-D on peripheral nerve's cellular components. The epi/perineural and Schwann cells and a total of three cell lines were treated with 2,4-D. The viability of cells at different doses of 2,4-D was measured by MTT assay. The cell cycle analyses, cumulative cell counting, fluorescent staining, antioxidant and caspase enzymes activity were examined on epi/perineural and Schwann cells. The epi/perineural cells were assessed as having biological macromolecular changes. Some tight junction-related genes and proteins were also tested on explants of 2,4-D treated epi/perineural tissue. The viability of 2,4-D treated cells was reduced in a dose-dependent manner. Reduced growth rate and G1 cell cycle arrest were verified in 2,4-D treated epi/perineural and Schwann cells. The use of staining methods (acridine orange/ethidium bromide and DAPI) and caspase 3/7 activity assay along with malondialdehyde, glutathione peroxidase, and superoxide dismutase activity assays indicated the apoptotic and oxidant effects of 2,4-D on epi/perineural and Schwann cells. Data obtained from FTIR revealed changes in epi/perineural proteins and cell membrane lipids. Additionally, claudin-1, occludin, and ZO-1 gene/protein expression profiles were significantly reduced in 2,4-D-treated epi/perineural pieces. Our data indicated that oxidative stress, apoptosis of epi/perineural and Schwann cell and impaired blood-nerve barrier may have contributed to nerve damage following 2,4-D exposure.
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Brunden KR, Lee VMY, Smith AB, Trojanowski JQ, Ballatore C. Altered microtubule dynamics in neurodegenerative disease: Therapeutic potential of microtubule-stabilizing drugs. Neurobiol Dis 2016; 105:328-335. [PMID: 28012891 DOI: 10.1016/j.nbd.2016.12.021] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 12/12/2016] [Accepted: 12/21/2016] [Indexed: 02/04/2023] Open
Abstract
Many neurodegenerative diseases are characterized by deficiencies in neuronal axonal transport, a process in which cellular cargo is shuttled with the aid of molecular motors from the cell body to axonal termini and back along microtubules (MTs). Proper axonal transport is critical to the normal functioning of neurons, and impairments in this process could contribute to the neuronal damage and death that is characteristic of neurodegenerative disease. Although the causes of axonal transport abnormalities may vary among the various neurodegenerative conditions, in many cases it appears that the transport deficiencies result from a diminution of axonal MT stability. Here we review the evidence of MT abnormalities in a number of neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and traumatic brain injury, and highlight the potential benefit of MT-stabilizing agents in improving axonal transport and nerve function in these diseases. Moreover, we discuss the challenges associated with the utilization of MT-stabilizing drugs as therapeutic candidates for neurodegenerative conditions.
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Affiliation(s)
- Kurt R Brunden
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States.
| | - Virginia M-Y Lee
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Amos B Smith
- Department of Chemistry, School of Arts and Science, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - John Q Trojanowski
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Carlo Ballatore
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, United States
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12
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Abstract
Parkinson’s disease (PD) is characterized by the selective loss of nigral dopaminergic (DA) neurons, which have long axons enriched with microtubules. Depolymerization of microtubules by PD toxins such as rotenone disrupts vesicular transport. The ensuing accumulation of vesicles in the cell body leads to increased cytosolic concentration of dopamine due to leakage of the vesicles. Elevated oxidative stress induced by dopamine oxidation may thus trigger the selective demise of DA neurons. Many strategies have been developed to protect DA neurons by stabilizing microtubules either directly or through intracellular signaling cascades. On the other hand, parkin, one of the most frequently mutated genes in PD, encodes for a protein-ubiquitin E3 ligase that strongly binds to microtubules. Parkin stabilizes microtubules through three domains that provide strong and independent interactions with tubulin and microtubules. These interactions anchor parkin on microtubules and may facilitate its E3 ligase activity on misfolded proteins transported along microtubules. Thus, parkin and rotenone, two prominent genetic and environmental factors linked to PD, act in an opposing manner on the same molecular target in the cell, microtubules, whose destruction underlies the selective vulnerability of dopaminergic neurons.
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Affiliation(s)
- Jian Feng
- Department of Physiology and Biophysics, State University of New York, Buffalo, NY 14214, USA.
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13
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Rosero A, Oulehlová D, Stillerová L, Schiebertová P, Grunt M, Žárský V, Cvrčková F. Arabidopsis FH1 Formin Affects Cotyledon Pavement Cell Shape by Modulating Cytoskeleton Dynamics. PLANT & CELL PHYSIOLOGY 2016; 57:488-504. [PMID: 26738547 DOI: 10.1093/pcp/pcv209] [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: 05/07/2015] [Accepted: 12/24/2015] [Indexed: 05/03/2023]
Abstract
Plant cell morphogenesis involves concerted rearrangements of microtubules and actin microfilaments. We previously reported that FH1, the main Arabidopsis thaliana housekeeping Class I membrane-anchored formin, contributes to actin dynamics and microtubule stability in rhizodermis cells. Here we examine the effects of mutations affecting FH1 (At3g25500) on cell morphogenesis and above-ground organ development in seedlings, as well as on cytoskeletal organization and dynamics, using a combination of confocal and variable angle epifluorescence microscopy with a pharmacological approach. Homozygous fh1 mutants exhibited cotyledon epinasty and had larger cotyledon pavement cells with more pronounced lobes than the wild type. The pavement cell shape alterations were enhanced by expression of the fluorescent microtubule marker GFP-microtubule-associated protein 4 (MAP4). Mutant cotyledon pavement cells exhibited reduced density and increased stability of microfilament bundles, as well as enhanced dynamics of microtubules. Analogous results were also obtained upon treatments with the formin inhibitor SMIFH2 (small molecule inhibitor of formin homology 2 domains). Pavement cell shape in wild-type (wt) and fh1 plants in some situations exhibited a differential response towards anti-cytoskeletal drugs, especially the microtubule disruptor oryzalin. Our observations indicate that FH1 participates in the control of microtubule dynamics, possibly via its effects on actin, subsequently influencing cell morphogenesis and macroscopic organ development.
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Affiliation(s)
- Amparo Rosero
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic Colombian Institute for Agricultural Research-CORPOICA-Turipana, Km 13 via Monteria, Cereté, Cordoba, Colombia Department of Cell Biology, Faculty of Science, Palacký University Olomouc, Centre of the Region Haná for Biotechnological and Agricultural Research, Šlechtitelů 586/11, CZ 783 71 Olomouc-Holice, Czech Republic
| | - Denisa Oulehlová
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 135, CZ 160 00 Prague 6, Czech Republic
| | - Lenka Stillerová
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic
| | - Petra Schiebertová
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic
| | - Michal Grunt
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic
| | - Viktor Žárský
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 135, CZ 160 00 Prague 6, Czech Republic
| | - Fatima Cvrčková
- Department of Experimental Plant Biology, Faculty of Sciences, Charles University, Viničná 5, CZ 128 44 Praha 2, Czech Republic
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Pochettino AA, Hapon MB, Biolatto SM, Madariaga MJ, Jahn GA, Konjuh CN. Effects of 2,4-dichlorophenoxyacetic acid on the ventral prostate of rats during the peri-pubertal, pubertal and adult stage. Drug Chem Toxicol 2016; 39:392-9. [PMID: 26759115 DOI: 10.3109/01480545.2015.1130718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is used on a wide variety of terrestrial and aquatic broadleaf weeds. 2,4-D has been shown to produce a wide range of adverse effects on animal and human health. The aim of the current study was to evaluate the effects of pre- and postnatal exposure to 2,4-D on rat ventral prostate (VP). Pregnant rats were exposed daily to oral doses of 70 mg/kg/day of 2,4-D from 16 days of gestation up to 23 days after delivery. Then, the treated groups (n = 8) were fed with a 2,4-D added diet until sacrificed by decapitation on postnatal day (PND) 45, 60, or 90. Morphometric studies were performed and androgen receptor (AR) protein levels in the VP were determined. AR, insulin-like growth factor-I (IGF-1) and insulin-like growth factor-I receptor (IGF-1R) mRNA expression in the VP along with testosterone (T), dihydroxytestosterone (DHT), growth hormone (GH) and IGF-1 serum levels were also determined to ascertain whether these parameters were differentially affected. Results of this study showed that 2,4-D exposure during gestation and until adulthood altered development of the prostate gland in male rats, delaying it at early ages while increasing its size in adults, indicate that 2,4-D could behave as endocrine disruptors (EDs).
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Affiliation(s)
- Arístides A Pochettino
- a Laboratorio De Toxicología Experimental , Facultad De Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional De Rosario , Rosario , Argentina and
| | - María Belén Hapon
- b Laboratorio De Reproducción Y Lactancia , IMBECU, CONICET, CCT CONICET Mendoza , Mendoza , Argentina
| | - Silvana M Biolatto
- a Laboratorio De Toxicología Experimental , Facultad De Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional De Rosario , Rosario , Argentina and
| | - María José Madariaga
- a Laboratorio De Toxicología Experimental , Facultad De Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional De Rosario , Rosario , Argentina and
| | - Graciela A Jahn
- b Laboratorio De Reproducción Y Lactancia , IMBECU, CONICET, CCT CONICET Mendoza , Mendoza , Argentina
| | - Cintia N Konjuh
- a Laboratorio De Toxicología Experimental , Facultad De Ciencias Bioquímicas Y Farmacéuticas, Universidad Nacional De Rosario , Rosario , Argentina and
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15
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Coullery RP, Ferrari ME, Rosso SB. Neuronal development and axon growth are altered by glyphosate through a WNT non-canonical signaling pathway. Neurotoxicology 2016; 52:150-61. [PMID: 26688330 DOI: 10.1016/j.neuro.2015.12.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 12/04/2015] [Accepted: 12/04/2015] [Indexed: 01/25/2023]
Abstract
The growth and morphological differentiation of neurons are critical events in the establishment of proper neuronal connectivity and functioning. The developing nervous system is highly susceptible to damage caused by exposure to environmental contaminants. Glyphosate-containing herbicides are the most used agrochemicals in the world, particularly on genetically modified plants. Previous studies have demonstrated that glyphosate induces neurotoxicity in mammals. Therefore, its action mechanism on the nervous system needs to be determined. In this study, we report about impaired neuronal development caused by glyphosate exposure. Particularly, we observed that the initial axonal differentiation and growth of cultured neurons is affected by glyphosate since most treated cells remained undifferentiated after 1 day in culture. Although they polarized at 2 days in vitro, they elicited shorter and unbranched axons and they also developed less complex dendritic arbors compared to controls. To go further, we attempted to identify the cellular mechanism by which glyphosate affected neuronal morphology. Biochemical approaches revealed that glyphosate led to a decrease in Wnt5a level, a key factor for the initial neurite development and maturation, as well as inducing a down-regulation of CaMKII activity. This data suggests that the morphological defects would likely be a consequence of the decrease in both Wnt5a expression and CaMKII activity induced by glyphosate. Additionally, these changes might be reflected in a subsequent neuronal dysfunction. Therefore, our findings highlight the importance of establishing rigorous control on the use of glyphosate-based herbicides in order to protect mammals' health.
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Affiliation(s)
- Romina P Coullery
- Experimental Toxicology Laboratory, School of Biochemical and Pharmaceutical Sciences, National University of Rosario, Suipacha 531, S2002LRK Rosario, Argentina
| | - María E Ferrari
- Experimental Toxicology Laboratory, School of Biochemical and Pharmaceutical Sciences, National University of Rosario, Suipacha 531, S2002LRK Rosario, Argentina
| | - Silvana B Rosso
- Experimental Toxicology Laboratory, School of Biochemical and Pharmaceutical Sciences, National University of Rosario, Suipacha 531, S2002LRK Rosario, Argentina.
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16
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Brunden KR, Trojanowski JQ, Smith AB, Lee VMY, Ballatore C. Microtubule-stabilizing agents as potential therapeutics for neurodegenerative disease. Bioorg Med Chem 2014; 22:5040-9. [PMID: 24433963 PMCID: PMC4076391 DOI: 10.1016/j.bmc.2013.12.046] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 12/04/2013] [Accepted: 12/16/2013] [Indexed: 01/18/2023]
Abstract
Microtubules (MTs), cytoskeletal elements found in all mammalian cells, play a significant role in cell structure and in cell division. They are especially critical in the proper functioning of post-mitotic central nervous system neurons, where MTs serve as the structures on which key cellular constituents are trafficked in axonal projections. MTs are stabilized in axons by the MT-associated protein tau, and in several neurodegenerative diseases, including Alzheimer's disease, frontotemporal lobar degeneration, and Parkinson's disease, tau function appears to be compromised due to the protein dissociating from MTs and depositing into insoluble inclusions referred to as neurofibrillary tangles. This loss of tau function is believed to result in alterations of MT structure and function, resulting in aberrant axonal transport that likely contributes to the neurodegenerative process. There is also evidence of axonal transport deficiencies in other neurodegenerative diseases, including amyotrophic lateral sclerosis and Huntington's disease, which may result, at least in part, from MT alterations. Accordingly, a possible therapeutic strategy for such neurodegenerative conditions is to treat with MT-stabilizing agents, such as those that have been used in the treatment of cancer. Here, we review evidence of axonal transport and MT deficiencies in a number of neurodegenerative diseases, and summarize the various classes of known MT-stabilizing agents. Finally, we highlight the growing evidence that small molecule MT-stabilizing agents provide benefit in animal models of neurodegenerative disease and discuss the desired features of such molecules for the treatment of these central nervous system disorders.
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Affiliation(s)
- Kurt R Brunden
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, 3600 Spruce Street, Maloney 3, Philadelphia, PA 19104-6323, USA.
| | - John Q Trojanowski
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, 3600 Spruce Street, Maloney 3, Philadelphia, PA 19104-6323, USA
| | - Amos B Smith
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104-6323, USA
| | - Virginia M-Y Lee
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, 3600 Spruce Street, Maloney 3, Philadelphia, PA 19104-6323, USA
| | - Carlo Ballatore
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, 3600 Spruce Street, Maloney 3, Philadelphia, PA 19104-6323, USA; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104-6323, USA
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17
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Kalipci E, Ozdemir C, Oztas H. Assessing eco-toxicological effects of industrial 2,4-D acid iso-octylester herbicide on rat pancreas and liver. Biotech Histochem 2013; 88:202-7. [PMID: 23398176 DOI: 10.3109/10520295.2012.758312] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
We studied the eco-toxic and carcinogenic effects of a commonly used 2,4-D acid iso-octylester herbicide on rat liver and pancreas. The rats in Group 1 were fed a standard feed and the rats in Group 2 were fed with standard feed to which was added 200 mg/kg/day 2,4-D acid iso-octylester for 16 weeks. Azaserine, 30 mg/kg/body weight, was injected into rats of Groups 3 and 4 to investigate the effects of 2,4-D acid iso-octylester on the development of neoplasms. After feeding the rats with neoplasms in Group 4 with food including 200 mg/kg/day 2,4-D acid iso-octylester for 16 weeks, an autopsy was carried out on all animals. We found that 2,4-D acid iso-octylester caused the formation of atypical cell foci (ACF) in the pancreata and livers of rats. ACF that were formed experimentally by exposure to azaserine had increased diameter, volume and number of atypical cell foci/mm(2) and mm(3) after exposure to 2,4-D acid iso-octylester. Our observations indicated that this herbicide potentially is a cancer initiator.
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Affiliation(s)
- E Kalipci
- Nevsehir University, Faculty of Engineering & Architecture, Department of Environmental Engineering , Nevsehir, Turkey.
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18
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Pochettino AA, Bongiovanni B, Duffard RO, Evangelista de Duffard AM. Oxidative stress in ventral prostate, ovary, and breast by 2,4-dichlorophenoxyacetic acid in pre- and postnatal exposed rats. ENVIRONMENTAL TOXICOLOGY 2013; 28:1-10. [PMID: 21374790 DOI: 10.1002/tox.20690] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 11/23/2010] [Accepted: 11/26/2010] [Indexed: 05/30/2023]
Abstract
The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been widely used in agriculture and forestry since the 1940s. 2,4-D has been shown to produce a wide range of adverse effects-from embryotoxicity and teratogenicity to neurotoxicity-on animal and human health. The purpose of this study was to determine the possible effects of pre- and postnatal exposure to 2,4-D on oxidative stress in ventral prostate, ovary and breast. Pregnant rats were daily exposed to oral doses of 70 mg/kg/day of 2,4-D from 16 days of gestation up to 23 days after delivery. Then, the pups were sacrificed by decapitation at postnatal day (PND) 45, 60, or 90. Antioxidant enzyme activities and some parameters of the oxidative stress were assessed in ventral prostate, breast, and ovary. Results show that 2,4-D produced three different effects. First, it increased the concentration of some radical oxygen species and the rates of lipid peroxidation and protein oxidation in ventral prostate, thereby causing oxidative stress at all ages studied. Although an increase in the activity of some antioxidant enzymes was detected, this seemed to have been not enough to counteract the oxidative stress. Second, 2,4-D promoted the oxidative stress in the breasts, mainly during puberty and adulthood, probably because the developing gland is more sensitive to xenobiotics than the adult organ. Third, 2,4-D altered the activity of some antioxidant enzymes and increased lipid peroxide concentration in the ovary. This effect could reflect the variety of ovarian cell types and their different responses to endocrine changes during development.
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Affiliation(s)
- Aristides A Pochettino
- Experimental Toxicology Laboratory, School of Biochemical and Pharmaceutical Sciences, Department of Food Science and Environment, National University of Rosario, Rosario, Argentina.
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19
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Krieg EF. The relationships between pesticide metabolites and neurobehavioral test performance in the third National Health and Nutrition Examination Survey. ARCHIVES OF ENVIRONMENTAL & OCCUPATIONAL HEALTH 2013; 68:39-46. [PMID: 23298423 DOI: 10.1080/19338244.2011.633125] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Regression analysis was used to estimate and test for relationships between urinary pesticide metabolites and neurobehavioral test performance in adults, 20 to 59 years old, participating in the third National Health and Nutrition Examination Survey. The 12 pesticide metabolites included 2 naphthols, 8 phenols, a phenoxyacetic acid, and a pyridinol. The 3 neurobehavioral tests included in the survey were simple reaction time, symbol-digit substitution, and serial digit learning. As the 2,4-dichlorophenol, 2,5-dichlorophenol, and the pentachlorophenol concentrations increased, performance on the serial digit learning test improved. As the 2,5-dichlorophenol concentration increased, performance on the symbol-digit substitution test improved. At low concentrations, the parent compounds of these metabolites may act at acetylcholine and γ-aminobutyric acid synapses in the central nervous system to improve neurobehavioral test performance.
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Affiliation(s)
- Edward F Krieg
- National Institute for Occupational Safety and Health, Cincinnati, OH 45226, USA.
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20
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Aronzon CM, Sandoval MT, Herkovits J, Pérez-Coll CS. Stage-dependent toxicity of 2,4-dichlorophenoxyacetic on the embryonic development of a South American toad, Rhinella arenarum. ENVIRONMENTAL TOXICOLOGY 2011; 26:373-81. [PMID: 20112415 DOI: 10.1002/tox.20564] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 12/03/2009] [Accepted: 12/06/2009] [Indexed: 05/03/2023]
Abstract
The acute and short term chronic toxicity of both the herbicide butyl ester of 2,4-Dichlorophenoxyacetic acid (2,4-D) and a commercial formulation (CF) were evaluated on Rhinella (= Bufo) arenarum embryos at different developmental stages. Adverse effects were analyzed by means of the isotoxicity curves for lethality, malformations, stage-dependent susceptibility, and ultrastructural features. For all experimental conditions, the CF was more toxic, up to 10 times, than the active ingredient, being the open mouth stage (S.21) the most susceptible to the herbicide. For continuous treatment conditions, the early embryonic development was the most susceptible to 2,4-D and the LC50s for 96 and 168 h were 9.06 and 7.76 mg L(-1) respectively. In addition, both the active ingredient and the CF were highly teratogenic, resulting in reduced body size, delayed development, microcephaly, agenesis of gills, and abnormal cellular proliferation processes as the main adverse effects. According to US EPA, 2,4-D in agricultural scenarios may be up to three times higher than the NOEC values for teratogenic effects reported in this study. Therefore, they might represent a risk for amphibians. This study also points out the relevance of reporting the susceptibility of embryos at different developmental stages to both the active ingredient and the CF of agrochemicals in order to protect nontarget organisms.
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Affiliation(s)
- Carolina M Aronzon
- Programa de Seguridad Química, Instituto de Ciencias Ambientales y Salud (ICAS), Fundación PROSAMA, Paysandú 752, (1405) Buenos Aires, Argentina
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21
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Bongiovanni B, Ferri A, Brusco A, Rassetto M, Lopez LM, Evangelista de Duffard AM, Duffard R. Adverse Effects of 2,4-Dichlorophenoxyacetic Acid on Rat Cerebellar Granule Cell Cultures Were Attenuated by Amphetamine. Neurotox Res 2010; 19:544-55. [DOI: 10.1007/s12640-010-9188-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 03/09/2010] [Accepted: 03/29/2010] [Indexed: 11/28/2022]
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22
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In Vitro Study of Damaging Effects of 2,4-Dichlorophenoxyacetic Acid on DNA Structure by Spectroscopic and Voltammetric Techniques. DNA Cell Biol 2009; 28:527-33. [DOI: 10.1089/dna.2009.0892] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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23
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Bjørling-Poulsen M, Andersen HR, Grandjean P. Potential developmental neurotoxicity of pesticides used in Europe. Environ Health 2008; 7:50. [PMID: 18945337 PMCID: PMC2577708 DOI: 10.1186/1476-069x-7-50] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2008] [Accepted: 10/22/2008] [Indexed: 05/18/2023]
Abstract
Pesticides used in agriculture are designed to protect crops against unwanted species, such as weeds, insects, and fungus. Many compounds target the nervous system of insect pests. Because of the similarity in brain biochemistry, such pesticides may also be neurotoxic to humans. Concerns have been raised that the developing brain may be particularly vulnerable to adverse effects of neurotoxic pesticides. Current requirements for safety testing do not include developmental neurotoxicity. We therefore undertook a systematic evaluation of published evidence on neurotoxicity of pesticides in current use, with specific emphasis on risks during early development. Epidemiologic studies show associations with neurodevelopmental deficits, but mainly deal with mixed exposures to pesticides. Laboratory experimental studies using model compounds suggest that many pesticides currently used in Europe--including organophosphates, carbamates, pyrethroids, ethylenebisdithiocarbamates, and chlorophenoxy herbicides--can cause neurodevelopmental toxicity. Adverse effects on brain development can be severe and irreversible. Prevention should therefore be a public health priority. The occurrence of residues in food and other types of human exposures should be prevented with regard to the pesticide groups that are known to be neurotoxic. For other substances, given their widespread use and the unique vulnerability of the developing brain, the general lack of data on developmental neurotoxicity calls for investment in targeted research. While awaiting more definite evidence, existing uncertainties should be considered in light of the need for precautionary action to protect brain development.
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Affiliation(s)
- Marina Bjørling-Poulsen
- Department of Environmental Medicine, University of Southern Denmark, Winslowparken 17, 5000 Odense, Denmark
| | - Helle Raun Andersen
- Department of Environmental Medicine, University of Southern Denmark, Winslowparken 17, 5000 Odense, Denmark
| | - Philippe Grandjean
- Department of Environmental Medicine, University of Southern Denmark, Winslowparken 17, 5000 Odense, Denmark
- Department of Environmental Health, Harvard School of Public Health, Landmark Building 3E-110, 401 Park Drive, Boston, MA 02215, USA
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24
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Konjuh C, García G, López L, Evangelista de Duffard AM, Brusco A, Duffard R. Neonatal Hypomyelination by the Herbicide 2,4-Dichlorophenoxyacetic Acid. Chemical and Ultrastructural Studies in Rats. Toxicol Sci 2008; 104:332-40. [DOI: 10.1093/toxsci/kfn085] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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25
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Radio NM, Mundy WR. Developmental neurotoxicity testing in vitro: models for assessing chemical effects on neurite outgrowth. Neurotoxicology 2008; 29:361-76. [PMID: 18403021 DOI: 10.1016/j.neuro.2008.02.011] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 02/13/2008] [Accepted: 02/20/2008] [Indexed: 11/15/2022]
Abstract
In vitro models may be useful for the rapid toxicological screening of large numbers of chemicals for their potential to produce toxicity. Such screening could facilitate prioritization of resources needed for in vivo toxicity testing towards those chemicals most likely to result in adverse health effects. Cell cultures derived from nervous system tissue have proven to be powerful tools for elucidating cellular and molecular mechanisms of nervous system development and function, and have been used to understand the mechanism of action of neurotoxic chemicals. Recently, it has been suggested that in vitro models could be used to screen for chemical effects on critical cellular events of neurodevelopment, including differentiation and neurite growth. This review examines the use of neuronal cell cultures as an in vitro model of neurite outgrowth. Examples of the cell culture systems that are commonly used to examine the effects of chemicals on neurite outgrowth are provided, along with a description of the methods used to quantify this neurodevelopmental process in vitro. Issues relating to the relevance of the methods and models currently used to assess neurite outgrowth are discussed in the context of hazard identification and chemical screening. To demonstrate the utility of in vitro models of neurite outgrowth for the evaluation of large numbers of chemicals, efforts should be made to: (1) develop a set of reference chemicals that can be used as positive and negative controls for comparing neurite outgrowth between model systems, (2) focus on cell cultures of human origin, with emphasis on the emerging area of neural progenitor cells, and (3) use high-throughput methods to quantify endpoints of neurite outgrowth.
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Affiliation(s)
- Nicholas M Radio
- Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protections Agency (USEPA), B105-06 Research Triangle Park, NC 27711, USA
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26
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Effect of 2,4-dichlorophenoxyacetic acid on rat maternal behavior. Toxicology 2008; 247:73-9. [PMID: 18420331 DOI: 10.1016/j.tox.2008.02.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 02/03/2008] [Accepted: 02/04/2008] [Indexed: 11/23/2022]
Abstract
Exposure to 2,4-dichlorophenoxyacetic acid (2,4-D) has several deleterious effects on the nervous system such as alterations in the concentrations of neurotransmitters in the brain and/or behavioral changes, myelination rate, ganglioside pattern [Bortolozzi, A., Duffard, R., Antonelli, M., Evangelista de Duffard, A.M., 2002. Increased sensitivity in dopamine D(2)-like brain receptors from 2,4-dichlorophenoxyacetic acid (2,4-D)-exposed and amphetamine-challenged rats. Ann. N.Y. Acad. Sci. 965, 314-323; Duffard, R., García, G., Rosso, S., Bortolozzi, A., Madariaga, M., DiPaolo, O., Evangelista de Duffard, A.M., 1996. Central nervous system myelin deficit in rats exposed to 2,4-dichlorophenoxyacetic acid throughout lactation. Neurotoxicol. Teratol. 18, 691-696; Evangelista de Duffard, A.M., Orta, C., Duffard, R., 1990. Behavioral changes in rats fed a diet containing 2,4-dichlorophenoxyacetic butyl ester. Neurotoxicology 11, 563-572; Evangelista de Duffard, A.M., Bortolozzi, A., Duffard, R.O., 1995. Altered behavioral responses in 2,4-dichlorophenoxyacetic acid treated and amphetamine challenged rats. Neurotoxicology 16, 479-488; Munro, I.C., Carlo, G.L., Orr, J.C., Sund, K., Wilson, R.M. Kennepohl, E. Lynch, B., Jablinske, M., Lee, N., 1992. A comprehensive, integrated review and evaluation of the scientific evidence relating to the safety of the herbicide 2,4-D. J. Am. Coll. Toxicol. 11, 559-664; Rosso et al., 2000], and its administration to pregnant and lactating rats adversely affects litter growth and milk quality. Since normal growth of the offspring depends on adequate maternal nursing and care, we evaluated the effect of 2,4-D on rat maternal behavior as well as the dam's monoamine levels in arcuate nucleus (AcN) and serum prolactin (PRL) levels. Wistar dams were exposed to the herbicide through the food from post partum day (PPD) 1 to PPD 7. Dams were fed either with a 2,4-D treated diet (15, 25 or 50mg 2,4-D/kg/daybw) or with a control diet. We observed that maternal nesting behavior was not modified by 2,4-D treatment. However, mother-pup interactions, specially the nursing behavior, were altered. Retrieval, crouching and licking of pups were reduced or suspended after 2,4-D treatment. We also observed an increase in the latency of retrieval and crouching in the dams treated with the herbicide. Dams showed movement along cage peripheries, food consumption during the light phase and high self-grooming. In addition of the deficits observed in maternal behavior parameters, increased catecholamine levels and a drastic decrease in indolamine levels in the AcN of treated dams were determined. Serum PRL levels were also diminished by 62%, 68% and 70% with respect to control dams in the 15, 25 and 50mg 2,4-D/kgbw treated dams, respectively. In conclusion, exposure to 2,4-D during the first post partum days produced changes in maternal behavior, serum prolactin and monoamine levels in the AcN of treated dams.
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Horikoshi S, Miura T, Kajitani M, Serpone N. Microwave discharge electrodeless lamps (MDEL). III. A novel tungsten-triggered MDEL device emitting VUV and UVC radiation for use in wastewater treatment. Photochem Photobiol Sci 2008; 7:303-10. [PMID: 18389147 DOI: 10.1039/b715774f] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Exposure to low doses of the xenoestrogen bisphenol A (BPA) and to the hormonal 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide, an environmental endocrine disruptor, can have serious health consequences such as the induction of mammary gland ductal hyperplasias and carcinoma (LaChapelle et al., Reprod. Toxicol., 2007, 23, 20; Murray et al., Reprod. Toxicol., 2007, 23, 383). To the extent that these toxins are present in wastewaters (Donald et al., Sci. Total Environ. 1999, 231, 173; Brotons et al., Environ. Health Perspect. 1994, 103, 608; Olea et al., Environ. Health Perspect. 1996, 104, 298; Biles et al., J. Agric. Food Chem. 1997, 45, 3541; Markey et al., J. Steroid Biochem. Mol. Biol., 2003, 83, 235), we examined their oxidative destruction in aqueous media by a novel light source. A tungsten-triggered microwave discharge electrodeless lamp (W-MDEL) was fabricated for possible use in wastewater treatment using vacuum UV-transparent quartz in which a tungsten trigger, also embedded in quartz, was attached to the MDEL to aid in the self-ignition of the lamp on irradiation at low microwave power levels. The quantity of mercury gas in the W-MDEL was optimized by monitoring the continuous radiation and peak intensities of the emitted light in the vacuum UV (VUV) and UVC regions. The usefulness of the W-MDEL device was assessed through the degradation of 2,4-D and BPA in air-equilibrated aqueous media and in oxygen-saturated aqueous media. Enhanced degradation of these two xenoestrogenic toxins was achieved by increasing the number of W-MDEL devices while keeping constant the microwave radiation feeding each W-MDEL lamp. This novel lamp provides an additional light source in the photooxidation of environmental contaminants without the need for a metal-oxide photocatalyst. Under our conditions, process dynamics using the W-MDEL light source are greater than with the more conventional photochemical methods that employ low-pressure Hg arc electrode lamps in synthetic quartz to degrade these two toxic contaminants.
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Affiliation(s)
- Satoshi Horikoshi
- Department of Chemistry, Faculty of Science and Technology, Sophia University, 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan.
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Abstract
As a major co-morbidity of Parkinson's disease (PD), depression is associated with the loss of serotonergic neurons. Our recent study has shown that midbrain dopaminergic neurons are particularly vulnerable to microtubule-depolymerizing agents including rotenone, an environmental toxin linked to PD. Here we show that rotenone also selectively killed serotonergic neurons in midbrain neuronal cultures. Its selective toxicity was significantly decreased by the microtubule-stabilizing drug taxol and mimicked by microtubule-depolymerizing agents such as colchicine and nocodazole. Microtubule depolymerization induced by rotenone or colchicine caused vesicle accumulation in the soma and killed serotonergic neurons through a mechanism dependent on serotonin metabolism in the cytosol. Blocking serotonin synthesis or degradation, as well as application of antioxidants, significantly reduced the selective toxicity of rotenone or colchicine. Inhibition of vesicular sequestration of serotonin exerted a selective toxicity on serotonergic neurons that was mitigated by blocking serotonin metabolism. Over-expression of parkin, a protein-ubiquitin E3 ligase that strongly binds to microtubules, greatly attenuated the selective toxicity of rotenone or colchicine. The protective effects of parkin were abrogated by its PD-linked mutations. Together, our results suggest that rotenone and parkin affect the survival of serotonergic neurons by impacting on microtubules in opposing manners.
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Affiliation(s)
- Yong Ren
- Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York, USA
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Zafeiridou G, Geronikaki A, Papaefthimiou C, Tryfonos M, Kosmidis EK, Theophilidis G. Assessing the effects of the three herbicides acetochlor, 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and 2,4-dichlorophenoxyacetic acid on the compound action potential of the sciatic nerve of the frog (Rana ridibunda). CHEMOSPHERE 2006; 65:1040-8. [PMID: 16674996 DOI: 10.1016/j.chemosphere.2006.03.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Revised: 02/21/2006] [Accepted: 03/18/2006] [Indexed: 05/09/2023]
Abstract
To assess the relative toxicity of the herbicides acetochlor and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) on the nervous system, the sciatic nerve of the frog (Rana ridibunda) nerve was incubated in saline inside a specially designed recording chamber. This chamber permits monitoring of the evoked compound action potential (CAP) of the nerve, a parameter that could be used to quantify the vitality of the nerve in normal conditions as well as when the nerve was exposed to the compounds under investigation. Thus, when the nerve was exposed to acetochlor, the EC(50) was estimated to be 0.22mM, while for 2,4,5-T the EC(50) was 0.90mM. Using the identical nerve preparation, the EC(50) of 2,4-D was estimated to be 3.80mM [Kouri, G., Theophilidis, G., 2002. The action of the herbicide 2,4-dichlorophenoxyacetic acid on the isolated sciatic nerve of the frog (Rana ridibunda). Neurotoxicol. Res. 4, 25-32]. The ratio of the relative toxicity for acetochlor, 2,4,5-T and 2,4-D was found to be 1:4:17.2. However, because it is well-known that the action of 2,4-D is dependent on the pH, the relative toxicity of the three compounds was tested at pH 3.3, since it has been found that the sciatic nerve of the frog is tolerant of such a low pH. Under these conditions, the EC(50) was 0.77mM (from 0.22mM at pH 7.2) for acetochlor, 0.20mM (from 0.90mM) for 2,4,5-T and 0.24mM (from 3.80mM at pH 7.2) for 2,4-D. Thus, the relative toxicity of the three compounds changed drastically to 1:0.25:0.31. This change in the relative toxicity is due not only to the increase in the toxicity of 2,4,5-T and 2,4-D at low pH levels, but also to the decrease in the toxicity of acetochlor at pH 3.3.
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Affiliation(s)
- Georgia Zafeiridou
- Laboratory of Animal Physiology, Department of Zoology, School of Biology, Aristotle University, Thessaloniki 54124, Hellas, Greece
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Kim HJ, Park YI, Dong MS. Effects of 2,4-D and DCP on the DHT-induced androgenic action in human prostate cancer cells. Toxicol Sci 2005; 88:52-9. [PMID: 16107550 DOI: 10.1093/toxsci/kfi287] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
2,4-Dichlorophenoxyacetic acid (2,4-D) and its metabolite 2,4-dichlorophenol (DCP) are used extensively in agriculture as herbicides, and are suspected of potential endocrine disruptor activity. In a previous study, we showed that these compounds exhibited synergistic androgenic effects by co-treatment with testosterone in the Hershberger assay. To elucidate the mechanisms of the synergistic effects of these compounds on the androgenicity of testosterone, the androgenic action of 2,4-D and DCP was characterized using a mammalian detection system in prostate cancer cell lines. In in vitro assay systems, while 2,4-D or DCP alone did not show androgenic activity, 2,4-D or DCP with 5alpha-dihydroxytestosterone (DHT) exhibited synergistic androgenic activities. Co-treatment of 10 nM 2,4-D or DCP with 10 nM DHT was shown to stimulate the cell proliferation by 1.6-fold, compared to 10 nM DHT alone. In addition, in transient transfection assays, androgen-induced transactivation was also increased to a maximum of 32-fold or 1.28-fold by co-treatment of 2,4-D or DCP with DHT, respectively. However, 2,4-D and DCP exerted no effects on either mRNA or protein levels of AR. In a competitive AR binding assay, 2,4-D and DCP inhibited androgen binding to AR, up to 50% at concentrations of approximately 0.5 microM for both compounds. The nuclear translocation of green fluorescent protein-AR fusion protein in the presence of DHT was promoted as the result of the addition of 2,4-D and DCP. Collectively, these results that 2,4-D and DCP enhanced DHT-induced AR transcriptional activity might be attributable, at least in part, to the promotion of AR nuclear translocation.
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Affiliation(s)
- Hyun-Jung Kim
- School of Life Sciences & Biotechnology, Korea University, 1, 5-Ka, Anam-dong, Sungbuk-ku, Seoul 136-701, Korea
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Garcia G, Tagliaferro P, Ferri A, Evangelista de Duffard AM, Duffard R, Brusco A. Study of tyrosine hydroxylase immunoreactive neurons in neonate rats lactationally exposed to 2,4-dichlorophenoxyacetic Acid. Neurotoxicology 2005; 25:951-7. [PMID: 15474613 DOI: 10.1016/j.neuro.2004.05.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2003] [Accepted: 04/16/2004] [Indexed: 11/28/2022]
Abstract
Dopaminergic neurons from the midbrain nuclei substantia nigra (SN; A9) and ventral tegmental area (VTA; A10) were investigated by tyrosine hydroxylase (TH) immunostaining in neonate rat brains exposed to 2,4-dichlorophenoxyacetic acid (2,4-D) through lactation. Dorsal raphe serotonin (5-HT) projections to SN and VTA were also studied by 5-HT transporter (5-HTT) immunostaining and results were quantified by image analysis. Twenty-five-day-old pups exposed to 2,4-D through mothers milk were used. Dams were intraperitoneally administered 70 or 100mg/kg/day of 2,4-D from the 9th to the 25th postpartum day. After 100mg/kg of 2,4-D exposure, a 25% diminution in the SN and a 33% diminution in the VTA neurons' TH immunostaining along with a significantly 5-HT fiber density diminution were observed. The present work supports previous reports which suggest that exposure to 2,4-D during development has multiple effects on CNS.
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Affiliation(s)
- G Garcia
- Experimental Toxicology Laboratory, School of Biochemical and Pharmaceutical Sciences, National University of Rosario, Suipacha 531, Rosario 2000, Argentina
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Tuschl H, Schwab C. Cytotoxic effects of the herbicide 2,4-dichlorophenoxyacetic acid in HepG2 cells. Food Chem Toxicol 2003; 41:385-93. [PMID: 12504171 DOI: 10.1016/s0278-6915(02)00238-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
2,4-Dichlorophenoxyacetic acid (2,4-D) and its derivatives are herbicides widely used to control the growth of broadleaf and woody plants. Although 2,4-D is well known to be moderately toxic, little information is available on the mechanisms of its toxicity. Results on carcinogenicity, genotoxicity and mutagenicity are contradictory, but neurotoxic, immunosuppressive and hepatotoxic effects have been defined. The aim of the present study was to investigate the cytotoxic effects of 2,4-D on a human hepatoma cell line. HepG2 cells were treated with different concentrations of 2,4-D, and cell viability, induction of apoptosis/necrosis and cell cycle phases were determined. Apoptosis was detected in flow cytometric light scatter histograms, the annexin V assay, the determination of DNA strand breaks with the TUNEL assay and the occurrence of a sub G(0) peak after propidium iodide (PI) staining. The induction of apoptosis by 2,4-D was accompanied by a disruption of the mitochondrial membrane potential as verified by staining with the cationic JC-1 probe. In addition, 2,4-D affected the cell cycle in a concentration-dependent manner. Our investigation suggested that 2,4-D exerts its cytotoxic effects by the induction of apoptosis via a direct effect on the mitochondrial membrane potential.
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Affiliation(s)
- H Tuschl
- Department of Toxicology, ARC Seibersdorf Research, A 2444 Seibersdorf, Austria.
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Stebbins-Boaz B, Fortner K, Frazier J, Piluso S, Pullen S, Rasar M, Reid W, Sinclair K, Winger E. Oocyte maturation inXenopus laevis is blocked by the hormonal herbicide, 2,4-dichlorophenoxy acetic acid. Mol Reprod Dev 2003; 67:233-42. [PMID: 14694440 DOI: 10.1002/mrd.10396] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Oocyte maturation is dependent on a complex program of morphological, ultrastructural, and biochemical signaling events, and if disrupted could lead to decreased fertility and population decline. The in vitro sensitivity of amphibian oocytes and oocyte maturation to plant growth factor and widely used hormonal herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), was examined in this study to determine its potential impact on early development and possible contribution to the global amphibian decline. Progesterone, which acts through a membrane receptor, triggers meiotic maturation in full grown (stage VI) Xenopus oocytes, characterized by cytoskeletal reorganization, nuclear dissolution, chromosome condensation, and spindle formation. Biochemically, the Mos/MAPK/MPF signaling pathway is activated, in part dependent on translational activation of specific maternal mRNAs such as c-Mos. Light microscopy revealed unusual asymmetric morphotypes in oocytes exposed to 2,4-D alone characterized by a white spot and bulge, termed coning, in the animal pole where the germinal vesicle (nucleus) persisted intact. Treatment of oocytes with cytochalasin B, a microfilament inhibitor, blocked these morphotypes but nocodazole, a microtubule depolymerizing agent, did not. Confocal microscopy showed that 2,4-D, itself, caused substantial depolymerization of perinuclear microtubules. Importantly, 2,4-D blocked progesterone-induced maturation as measured by the lack of nuclear breakdown, confirmed by the lack of Mos expression, MPF activation, and cytoplasmic polyadenylation of cyclin B1 mRNA. However, Western blot analysis and U0126 inhibitor studies showed that 2,4-D, either alone or in the presence of progesterone, induced MAPK phosphorylation through MAPKK. These results show that 2,4-D disrupts oocyte cytoskeletal organization and blocks maturation while stimulating an independent MAPK signaling pathway.
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De Moliner KL, Evangelista de Duffard AM, Soto E, Duffard R, Adamo AM. Induction of apoptosis in cerebellar granule cells by 2,4-dichlorophenoxyacetic acid. Neurochem Res 2002; 27:1439-46. [PMID: 12512947 DOI: 10.1023/a:1021665720446] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
2,4-Dichlorophenoxyacetic acid (2,4-D) and derivatives are herbicides widely used in Argentina and other parts of the world. Exposure to 2,4-D, its ester and salt formulations, have been associated with a range of adverse health effects in humans and different animal species, from embryotoxicity and teratogenicity to neurotoxicity. In this work, we demonstrate that after 24 hs of treatment with 1 and 2 mM 2,4-D there is an induction of apoptosis in cerebellar granule cells (CGC) in culture. However, with 2 mM 2,4-D one population of CGC developed features of apoptosis while another appeared to die by necrosis. This process is associated with an increase in caspase-3 activity after 12 hs of treatment with the herbicide, which is preceded by cytochrome c release from the mitochondria. Treatment of CGC with 2,4-D appears to induce apoptosis by a direct effect on mitochondria producing cytochrome c release and consequently activation of caspase-3, being mitochondrial damage sufficient for triggering the events that may cause apoptosis.
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Affiliation(s)
- K L De Moliner
- Departamento de Química Biológica. IQUIFIB, Universidad de Buenos Aires, CONICET, Junín 956, Buenos Aires (1113), Argentina
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Papaefthimiou C, Pavlidou V, Gregorc A, Theophilidis G. The action of 2,4-Dichlorophenoxyacetic acid on the isolated heart of insect and amphibia. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2002; 11:127-140. [PMID: 21782594 DOI: 10.1016/s1382-6689(01)00113-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2001] [Revised: 11/14/2001] [Accepted: 11/15/2001] [Indexed: 05/31/2023]
Abstract
The action of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on the isolated heart of the frog (Rana ridibunda) and two insects, the honeybee (Apis mellifera macedonica) and the beetle (Tenebrio molitor), was investigated using basic electrophysiological methods. The results of this study showed that a concentration of 1 μM 2,4-D was required to reduce the force and the frequency of the isolated heart of the honeybee to about 70% of the initial contraction in less than 20 min. To cause the same effects on the atria of the frog, 45 μM 2,4-D was required and on the isolated heart of the beetle, over 1000 μM of 2,4-D. The presence of an extensive system of gap junctions found in the honeybee is most probably the cause of the unusual sensitivity of its heart to 2,4-D, compared with the heart of the beetle, where no gap junctions were identified.
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Affiliation(s)
- Chrisovalantis Papaefthimiou
- Department of Zoology, Laboratory of Animal Physiology, School of Biology, Aristotle University, Thessaloniki 54006, Greek Macedonia, Greece
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Kouri G, Theophilidis G. The action of the herbicide 2,4-dichlorophenoxyacetic acid on the isolated sciatic nerve of the frog (Rana ridibunda). Neurotox Res 2002; 4:25-32. [PMID: 12826490 DOI: 10.1080/10298420290007592] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
The isolated sciatic nerve of the frog was used to assess the effects of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on the peripheral nervous system. For each experiment, both sciatic nerves were used. The evoked compound action potentials of the nerves were monitored for over 48 h as an indication of their viability. The viability of nerve incubated in control saline was compared to the viability of the nerve incubated in saline where 2,4-D was diluted. The minimum effective concentration (minEC) of 2,4-D was estimated to be between 2 and 4 mM.
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Affiliation(s)
- G Kouri
- Laboratory of Animal Physiology, Department of Zoology, School of Biology, Aristotle University, Thessaloniki 54006, Greek Macedonia, Hellas, Greece.
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