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Martin R, Hazemi M, Flynn K, Villeneuve D, Wehmas L. Short-Term Transcriptomic Points of Departure Are Consistent with Chronic Points of Departure for Three Organophosphate Pesticides across Mouse and Fathead Minnow. TOXICS 2023; 11:820. [PMID: 37888672 PMCID: PMC10611195 DOI: 10.3390/toxics11100820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/28/2023]
Abstract
New approach methods (NAMs) can reduce the need for chronic animal studies. Here, we apply benchmark dose (concentration) (BMD(C))-response modeling to transcriptomic changes in the liver of mice and in fathead minnow larvae after short-term exposures (7 days and 1 day, respectively) to several dose/concentrations of three organophosphate pesticides (OPPs): fenthion, methidathion, and parathion. The mouse liver transcriptional points of departure (TPODs) for fenthion, methidathion, and parathion were 0.009, 0.093, and 0.046 mg/Kg-bw/day, while the fathead minnow larva TPODs were 0.007, 0.115, and 0.046 mg/L, respectively. The TPODs were consistent across both species and reflected the relative potencies from traditional chronic toxicity studies with fenthion identified as the most potent. Moreover, the mouse liver TPODs were more sensitive than or within a 10-fold difference from the chronic apical points of departure (APODs) for mammals, while the fathead minnow larva TPODs were within an 18-fold difference from the chronic APODs for fish species. Short-term exposure to OPPs significantly impacted acetylcholinesterase mRNA abundance (FDR p-value <0.05, |fold change| ≥2) and canonical pathways (IPA, p-value <0.05) associated with organism death and neurological/immune dysfunctions, indicating the conservation of key events related to OPP toxicity. Together, these results build confidence in using short-term, molecular-based assays for the characterization of chemical toxicity and risk, thereby reducing reliance on chronic animal studies.
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Affiliation(s)
- Rubia Martin
- Office of Research and Development, Center for Computational Toxicology and Exposure, Chemical Characterization and Exposure Division, Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Durham, NC 27709, USA;
| | - Monique Hazemi
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Ecology Division, Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Duluth, MN 55804, USA;
| | - Kevin Flynn
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Ecology Division, U.S. Environmental Protection Agency, Duluth, MN 55804, USA; (K.F.); (D.V.)
| | - Daniel Villeneuve
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Ecology Division, U.S. Environmental Protection Agency, Duluth, MN 55804, USA; (K.F.); (D.V.)
| | - Leah Wehmas
- Office of Research and Development, Center for Computational Toxicology and Exposure, Chemical Characterization and Exposure Division, U.S. Environmental Protection Agency, Durham, NC 27709, USA
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2
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Characterization of the rat Acetylcholinesterase readthrough (AChE-R) splice variant: Implications for toxicological studies. Biochem Biophys Res Commun 2020; 532:528-534. [PMID: 32896378 DOI: 10.1016/j.bbrc.2020.08.065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 11/23/2022]
Abstract
Exposure to chemicals and other environmental stressors can differentially impact the expression of Acetylcholinesterase (AChE) splice variants. Surprisingly, despite the widespread use of the rat model in toxicological studies and the wealth of literature on this important biomarker of neurotoxicity, AChE coding exons and splice variants are not yet fully annotated in this species. To address this knowledge gap, a short problematic region of the rat AChE genomic DNA present in GenBank was first re-sequenced. This revised genomic sequence was then aligned to rat AChE RefSeq mRNA and compared to orthologous mammalian sequences, in order to map the coding exon and intron boundaries of the rat AChE gene. Based on these bioinformatics analyses, a sequence was predicted for the yet-unannotated rat Acetylcholinesterase readthrough (AChE-R) splice variant. PCR primers designed to specifically amplify rat AChE-R were used to confirm its expression in rat PC12 cells. Compared to the canonical AChE-S splice variant, AChE-R was expressed at much lower levels but presented distinct regulation patterns in PC12 cells and rat primary cerebral granule cells (CGCs) following exposure to Chlorpyrifos (a well-known neurotoxic organophosphate pesticide). Taken together, these observations point to the evolutionary conservation of the AChE-R splicing event between rodents and human and to the distinct regulation of AChE splice variants in response to toxicological challenges.
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Hunt ND, Liebman M, Thakrar SK, Hill JD. Fossil Energy Use, Climate Change Impacts, and Air Quality-Related Human Health Damages of Conventional and Diversified Cropping Systems in Iowa, USA. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11002-11014. [PMID: 32786565 DOI: 10.1021/acs.est.9b06929] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cropping system diversification can reduce the negative environmental impacts of agricultural production, including soil erosion and nutrient discharge. Less is known about how diversification affects energy use, climate change, and air quality, when considering farm operations and supply chain activities. We conducted a life cycle study using measurements from a nine-year Iowa field experiment to estimate fossil energy (FE) use, greenhouse gas (GHG) emissions, PM2.5-related emissions, human health impacts, and other agronomic and economic metrics of contrasting crop rotation systems and herbicide regimes. Rotation systems consisted of 2-year corn-soybean, 3-year corn-soybean-oat/clover, and 4-year corn-soybean-oat/alfalfa-alfalfa systems. Each was managed with conventional and low-herbicide treatments. FE consumption was 56% and 64% lower in the 3-year and 4-year rotations than in the 2-year rotation, and GHG emissions were 54% and 64% lower. Diversification reduced combined monetized damages from GHG and PM2.5-related emissions by 42% and 57%. Herbicide treatment had no significant impact on environmental outcomes, while corn and soybean yields and whole-rotation economic returns improved significantly under diversification. Results suggest that diversification via shifting from conventional corn-soybean rotations to longer rotations with small grain and forage crops substantially reduced FE use, GHG emissions, and air quality damages, without compromising economic or agronomic performance.
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Affiliation(s)
- Natalie D Hunt
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, Minnesota 55108, United States
| | - Matt Liebman
- Department of Agronomy, Iowa State University, Ames, Iowa 50011, United States
| | - Sumil K Thakrar
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, Minnesota 55108, United States
| | - Jason D Hill
- Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, Minnesota 55108, United States
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4
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Jin E, Al Fahel N, Mondal P, Li H, Archer CL. Energy footprint of food: The case of corn production in Delaware. Food Energy Secur 2020. [DOI: 10.1002/fes3.222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Enze Jin
- College of Earth, Ocean, and Environment University of Delaware Newark DE USA
| | - Nicolas Al Fahel
- Department of Energy and Environmental Policy University of Delaware Newark DE USA
| | - Pinki Mondal
- Department of Geography and Spatial Sciences University of Delaware Newark DE USA
- Department of Plant and Soil Sciences University of Delaware Newark DE USA
| | - Hong Li
- Department of Animal and Food Sciences University of Delaware Newark DE USA
| | - Cristina L. Archer
- College of Earth, Ocean, and Environment University of Delaware Newark DE USA
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Kim JH, Sohn S, Kim SK, Hur YB. Effects on hematological parameters, antioxidant and immune responses, AChE, and stress indicators of olive flounders, Paralichthys olivaceus, raised in bio-floc and seawater challenged by Edwardsiella tarda. FISH & SHELLFISH IMMUNOLOGY 2020; 97:194-203. [PMID: 31830567 DOI: 10.1016/j.fsi.2019.12.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/21/2019] [Accepted: 12/08/2019] [Indexed: 06/10/2023]
Abstract
Studies on the resistance of fish raised in bio-floc systems against bacterial infection are limited. We aimed to evaluate the changes in hematological parameters, antioxidant and immune responses, stress indicators, and acetylcholinesterase (AChE) in olive flounder, Paralichthys olivaceus, raised in bio-floc and seawater for 10 months and, then, infected with Edwardsiella tarda at concentrations of 0 (control), 6.61 × 104, 6.61 × 105, 6.61 × 106, and 6.61 × 107 CFU/g fish for 7 days. The lethal concentration 50% was 4.32 × 107 in bio-floc and 3.11 × 106 in seawater. Hematological parameters were significantly decreased by E. tarda challenge, and plasma components were significantly changed. The superoxide dismutase, catalase, and glutathione-S-transferase activities, as antioxidant responses, were significantly increased after infection, whereas the reduced glutathione level was significantly decreased. The lysozyme activity was significantly increased and the AChE level was significantly decreased after infection. Cortisol and HSP 70, as stress indicators, were also significantly increased. The results indicate that E. tarda infection affected various physiological factors in P. olivaceus. Additionally, P. olivaceus raised in seawater were more susceptible to E. tarda infection than those raised in bio-floc.
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Affiliation(s)
- Jun-Hwan Kim
- National Institute of Fisheries Science, West Sea Fisheries Research Institute, Fisheries Research & Devlopment, Taean, 32132, South Korea.
| | - Saebom Sohn
- National Institute of Fisheries Science, East Sea Fisheries Research Institute, Fisheries Research & Devlopment, Gangneung, Gangwon-do, 25435, South Korea
| | - Su Kyoung Kim
- National Institute of Fisheries Science, West Sea Fisheries Research Institute, Fisheries Research & Devlopment, Taean, 32132, South Korea
| | - Young Baek Hur
- National Institute of Fisheries Science, West Sea Fisheries Research Institute, Fisheries Research & Devlopment, Taean, 32132, South Korea
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Figueiredo TH, Apland JP, Braga MFM, Marini AM. Acute and long-term consequences of exposure to organophosphate nerve agents in humans. Epilepsia 2018; 59 Suppl 2:92-99. [PMID: 30159887 DOI: 10.1111/epi.14500] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2018] [Indexed: 12/20/2022]
Abstract
Nerve agents are organophosphate (OP) compounds and among the most powerful poisons known to man. A terrorist attack on civilian or military populations causing mass casualties is a real threat. The OP nerve agents include soman, sarin, cyclosarin, tabun, and VX. The major mechanism of acute toxicity is the irreversible inhibition of acetylcholinesterase. Acetylcholinesterase inhibition results in the accumulation of excessive acetylcholine levels in synapses, leading to progression of toxic signs including hypersecretions, tremors, status epilepticus, respiratory distress, and death. Miosis and rhinorrhea are the most common clinical findings in those individuals acutely exposed to OP nerve agents. Prolonged seizures are responsible for the neuropathology. The brain region that shows the most severe damage is the amygdala, followed by the piriform cortex, hippocampus, cortex, thalamus, and caudate/putamen. Current medical countermeasures are only modestly effective in attenuating the seizures and neuropathology. Anticonvulsants such as benzodiazepines decrease seizure activity and improve outcome, but their efficacy depends upon the administration time after exposure to the nerve agent. Administration of benzodiazepines may increase the risk for seizure recurrence. Recent studies document long-term neurologic and behavior deficits, and technological advances demonstrate structural brain changes on magnetic resonance imaging.
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Affiliation(s)
- Taiza H Figueiredo
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - James P Apland
- Neuroscience Program, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, USA
| | - Maria F M Braga
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Ann M Marini
- Department of Neurology and Program in Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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Lopes FM, Caldas SS, Primel EG, da Rosa CE. Glyphosate Adversely Affects Danio rerio Males: Acetylcholinesterase Modulation and Oxidative Stress. Zebrafish 2017; 14:97-105. [PMID: 27906609 DOI: 10.1089/zeb.2016.1341] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
It has been demonstrated that glyphosate-based herbicides are toxic to animals. In the present study, reactive oxygen species (ROS) generation, antioxidant capacity against peroxyl radicals (ACAP), and lipid peroxidation (LPO), as well as the activity and expression of the acetylcholinesterase (AChE) enzyme, were evaluated in Danio rerio males exposed to 5 or 10 mg/L of glyphosate for 24 and 96 h. An increase in ACAP in gills after 24 h was observed in the animals exposed to 5 mg/L of glyphosate. A decrease in LPO was observed in brain tissue of animals exposed to 10 mg/L after 24 h, while an increase was observed in muscle after 96 h. No significant alterations were observed in ROS generation. AChE activity was not altered in muscles or brains of animals exposed to either glyphosate concentration for 24 or 96 h. However, gene expression of this enzyme in the brain was reduced after 24 h and was enhanced in both brain and muscle tissues after 96 h. Thus, contrary to previous findings that had attributed the imbalance in the oxidative state of animals exposed to glyphosate-based herbicides to surfactants and other inert compounds, the present study demonstrated that glyphosate per se promotes this same effect in zebrafish males. Although glyphosate concentrations did not alter AChE activity, this study demonstrated for the first time that this molecule affects ache expression in male zebrafish D. rerio.
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Affiliation(s)
- Fernanda Moreira Lopes
- 1 Programa de Pós-Graduação em Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande-FURG , Rio Grande, Brazil
| | - Sergiane Souza Caldas
- 2 Escola de Química e Alimentos, Universidade Federal do Rio Grande-FURG , Rio Grande, Brazil
| | - Ednei Gilberto Primel
- 2 Escola de Química e Alimentos, Universidade Federal do Rio Grande-FURG , Rio Grande, Brazil
| | - Carlos Eduardo da Rosa
- 1 Programa de Pós-Graduação em Ciências Fisiológicas, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande-FURG , Rio Grande, Brazil
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8
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Nalivaeva NN, Turner AJ. AChE and the amyloid precursor protein (APP) – Cross-talk in Alzheimer's disease. Chem Biol Interact 2016; 259:301-306. [DOI: 10.1016/j.cbi.2016.04.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 03/18/2016] [Accepted: 04/04/2016] [Indexed: 01/27/2023]
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9
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Cadmium-induced cell death of basal forebrain cholinergic neurons mediated by muscarinic M1 receptor blockade, increase in GSK-3β enzyme, β-amyloid and tau protein levels. Arch Toxicol 2015; 90:1081-92. [DOI: 10.1007/s00204-015-1540-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 05/05/2015] [Indexed: 01/02/2023]
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10
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Makhaeva GF, Rudakova EV, Hein ND, Serebryakova OG, Kovaleva NV, Boltneva NP, Fink JK, Richardson RJ. Further studies toward a mouse model for biochemical assessment of neuropathic potential of organophosphorus compounds. J Appl Toxicol 2014; 34:1426-35. [PMID: 24395470 PMCID: PMC4085144 DOI: 10.1002/jat.2977] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 11/17/2013] [Accepted: 11/17/2013] [Indexed: 12/20/2022]
Abstract
Inhibition and aging of neuropathy target esterase (NTE) by neuropathic organophosphorus (OP) compounds triggers OP compound-induced delayed neuropathy (OPIDN), whereas inhibition of acetylcholinesterase (AChE) produces cholinergic toxicity. The neuropathic potential of an OP compound is defined by its relative inhibitory potency toward NTE vs. AChE assessed by enzyme assays following dosing in vivo or after incubations of direct-acting compounds or active metabolites with enzymes in vitro. The standard animal model of OPIDN is the adult hen, but its large size and high husbandry costs make this species a burdensome model for assessing neuropathic potential. Although the mouse does not readily exhibit clinical signs of OPIDN, it displays axonal lesions and expresses brain AChE and NTE. Therefore, the present research was performed as a further test of the hypothesis that inhibition of mouse brain AChE and NTE could be used to assess neuropathic potential using mouse brain preparations in vitro or employing mouse brain assays following dosing of OP compounds in vivo. Excellent correlations were obtained for inhibition kinetics in vitro of mouse brain enzymes vs. hen brain and human recombinant enzymes. Furthermore, inhibition of mouse brain AChE and NTE after dosing with OP compounds afforded ED(50) ratios that agreed with relative inhibitory potencies assessed in vitro. Taken together, results with mouse brain enzymes demonstrated consistent correspondence between in vitro and in vivo predictors of neuropathic potential, thus adding to previous studies supporting the validity of a mouse model for biochemical assessment of the ability of OP compounds to produce OPIDN.
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Affiliation(s)
- Galina F. Makhaeva
- Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Moscow Region, 142432, Russia
| | - Elena V. Rudakova
- Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Moscow Region, 142432, Russia
| | - Nichole D. Hein
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109 USA
| | - Olga G. Serebryakova
- Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Moscow Region, 142432, Russia
| | - Nadezhda V. Kovaleva
- Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Moscow Region, 142432, Russia
| | - Natalia P. Boltneva
- Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Moscow Region, 142432, Russia
| | - John K. Fink
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109 USA
| | - Rudy J. Richardson
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109 USA
- Toxicology Program, University of Michigan, Ann Arbor, Michigan 48109, USA
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11
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Sánchez S, Vera B, Montagna C, Magnarelli G. Characterization of placental cholinesterases and activity induction associated to environmental organophosphate exposure. Toxicol Rep 2014; 2:437-442. [PMID: 28962379 PMCID: PMC5598449 DOI: 10.1016/j.toxrep.2014.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 11/14/2014] [Accepted: 11/17/2014] [Indexed: 02/04/2023] Open
Abstract
Although non-innervated, the placenta contains both cholinesterases (ChEs), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE). These enzymes are well-known for their multiple molecular forms. In a first approach, we used recognized specific inhibitors, substrate preferences and non-denaturating gel electrophoresis in order to characterize the ChE profile of term placenta from uncomplicated pregnancy. Results strongly suggest that the predominant cholinesterasic form present was tetrameric BChE. It is well established that both ChEs are targets of cholinesterase-inhibiting organophosphates (OP), one of the most important classes of chemicals actively applied to the environment. However, we have previously reported increased ChEs activity in placenta of rural residents exposed to OP. In the present work, we have studied: 1) whether this finding was reproducible and, 2) whether AChE or BChE up regulation is behind the increase of placental ChE activity. The population studied included forty healthy women who live in an agricultural area. Samples were collected during both the OP pulverization period (PP) and the recess period (RP). The placental ChEs activity increased in PP, evidencing reproducibility of previous results. The analysis of non-denaturating gels revealed that increased activity of total ChE activity in placenta from women exposed to OP may be attributable to tetrameric BChE up-regulation.
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Key Words
- ACh, acetylcholine
- AChE, acetylcholinesterase
- ASCh, acetylthiocholine iodide
- Acetylcholinesterase
- BChE, butyrylcholinesterase
- BSCh, butyrylthiocholine iodide
- BW284C51, 1,5-bis (4-allyldimethyl ammoniumphenyl)-pentan-3-one dibromide
- Butyrylcholinesterase
- ChE, cholinesterase
- ChEs, cholinesterases
- OP, organophosphates
- Organophosphates
- PP, pulverization period
- Placenta
- RP, recess period
- iso-OMPA, tetraisopropylpyrophosphoramide
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Affiliation(s)
- S. Sánchez
- Facultad de CienciasMédicas, Universidad NacionaldelComahue, Cipolletti, Río Negro, Argentina
| | - B. Vera
- LIBIQUIMA, Facultad de Ingeniería, Universidad NacionaldelComahue, Neuquén, Argentina
- Facultad de CienciasMédicas, Universidad NacionaldelComahue, Cipolletti, Río Negro, Argentina
| | - C. Montagna
- LIBIQUIMA, Facultad de Ingeniería, Universidad NacionaldelComahue, Neuquén, Argentina
- Facultad de CienciasdelAmbiente y la Salud, Universidad Nacional del Comahue, Neuquén, Argentina
| | - G. Magnarelli
- LIBIQUIMA, Facultad de Ingeniería, Universidad NacionaldelComahue, Neuquén, Argentina
- Facultad de CienciasMédicas, Universidad NacionaldelComahue, Cipolletti, Río Negro, Argentina
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Zimmermann M. Neuronal AChE splice variants and their non-hydrolytic functions: redefining a target of AChE inhibitors? Br J Pharmacol 2014; 170:953-67. [PMID: 23991627 DOI: 10.1111/bph.12359] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 08/04/2013] [Accepted: 08/12/2013] [Indexed: 12/11/2022] Open
Abstract
AChE enzymatic inhibition is a core focus of pharmacological intervention in Alzheimer's disease (AD). Yet, AChE has also been ascribed non-hydrolytic functions, which seem related to its appearance in various isoforms. Neuronal AChE presents as a tailed form (AChE-T) predominantly found on the neuronal synapse, and a facultatively expressed readthough form (AChE-R), which exerts short to medium-term protective effects. Notably, this latter form is also found in the periphery. While these non-hydrolytic functions of AChE are most controversially discussed, there is evidence for them being additional targets of AChE inhibitors. This review aims to provide clarification as to the role of these AChE splice variants and their interplay with other cholinergic parameters and their being targets of AChE inhibition: AChE-R is particularly involved in the mediation of (anti-)apoptotic events in cholinergic cells, involving adaptation of various cholinergic parameters and a time-dependent link to the expression of neuroprotective factors. The AChE-T C-terminus is central to AChE activity regulation, while isolated AChE-T C-terminal fragments mediate toxic effects via the α7 nicotinic acetylcholine receptor. There is direct evidence for roles of AChE-T and AChE-R in neurodegeneration and neuroprotection, with these roles involving AChE as a key modulator of the cholinergic system: in vivo data further encourages the use of AChE inhibitors in the treatment of neurodegenerative conditions such as AD since effects on both enzymatic activity and the enzyme's non-hydrolytic functions can be postulated. It also suggests that novel AChE inhibitors should enhance protective AChE-R, while avoiding the concomitant up-regulation of AChE-T.
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Affiliation(s)
- M Zimmermann
- Department of Pharmacology, School of Pharmacy, Goethe University Frankfurt, Frankfurt am Main, Germany
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(60)Co-γ irradiation affects the enzymatic antioxidant system of the citrus red mite Panonychus citri (Acari: Tetranychidae). Molecules 2014; 19:6382-92. [PMID: 24853454 PMCID: PMC6271183 DOI: 10.3390/molecules19056382] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 05/06/2014] [Accepted: 05/09/2014] [Indexed: 11/17/2022] Open
Abstract
Radio-(60Co), which emits γ rays, has been used worldwide in pest control. The aim of the present study was to analyze the effect of effective-low-power 60Co-γ irradiation on the enzymatic antioxidant system of the citrus red mite Panonychus citri. One day old female adults were exposed to 0.4 kGy 60Co-γ irradiation and on the, 6th h, 1st day, 2nd day, and 5th day post treatment, the mites were euthanized for biochemical analysis. The activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), phenoloxidase (PO) and acetylocholinesterase (AchE) were investigated. POD and CAT activities, as well as SOD were higher in the irradiated mites. We found that exposure to 60Co-γ radiation resulted in increased activities of SOD, CAT, POD and decreased AchE activity. When the recovery time lasted till the 5th day, the activities of POD and PO were significantly lower than the control, whereas the SOD, CAT and AchE activities returned to control levels. Cells possess protein repair pathways to rescue oxidized proteins and restore their functions, but if these repair processes fail, oxidized proteins may become cytotoxic. Our results confirm the hypothesis that low dosages of 60Co-γ irradiation increase the level of oxidative stress in P. citri adults in a short time, causing meanwhile damage and sterility. The results of this study also indicate that stress caused by exposure to irradiation could inhibit the cholinergic system in P. citri.
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López-Granero C, Cardona D, Giménez E, Lozano R, Barril J, Aschner M, Sánchez-Santed F, Cañadas F. Comparative study on short- and long-term behavioral consequences of organophosphate exposure: Relationship to AChE mRNA expression. Neurotoxicology 2014; 40:57-64. [DOI: 10.1016/j.neuro.2013.11.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 11/17/2013] [Accepted: 11/18/2013] [Indexed: 12/13/2022]
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15
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López-Granero C, Cardona D, Giménez E, Lozano R, Barril J, Sánchez-Santed F, Cañadas F. Chronic dietary exposure to chlorpyrifos causes behavioral impairments, low activity of brain membrane-bound acetylcholinesterase, and increased brain acetylcholinesterase-R mRNA. Toxicology 2013; 308:41-9. [PMID: 23545134 DOI: 10.1016/j.tox.2013.03.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 03/19/2013] [Accepted: 03/21/2013] [Indexed: 01/20/2023]
Abstract
Chlorpyrifos (CPF) is an organophosphate (OP) insecticide that is metabolically activated to the highly toxic chlorpyrifos oxon. Dietary exposure is the main route of intoxication for non-occupational exposures. However, only limited behavioral effects of chronic dietary exposure have been investigated. Therefore, male Wistar rats were fed a dose of 5mg/kg/day of CPF for thirty-one weeks. Animals were evaluated in spatial learning and impulsivity tasks after 21 weeks of CPF dietary exposure and one week after exposure ended, respectively. In addition, the degree of inhibition of brain acetylcholinesterase (AChE) was evaluated for both the soluble and particulate forms of the enzyme, as well as AChE gene expression. Also, brain acylpeptide hydrolase (APH) was investigated as an alternative target for OP-mediated effects. All variables were evaluated at various time points in response to CPF diet and after exposure ended. Results from behavioral procedures suggest cognitive and emotional disorders. Moreover, low levels of activity representing membrane-bound oligomeric forms (tetramers) were also observed. In addition, increased brain AChE-R mRNA levels were detected after four weeks of CPF dietary exposure. However, no changes in levels of brain APH were observed among groups. In conclusion, our data point to a relationship between cognitive impairments and changes in AChE forms, specifically to a high inhibition of the particulate form and a modification of alternative splicing of mRNA during CPF dietary exposure.
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Affiliation(s)
- Caridad López-Granero
- Departamento de Psicología, Universidad de Almería, Campus de Excelencia Internacional Agroalimentario CeiA3, La Cañada, 04120, Almería, Spain
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16
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McGarry KG, Bartlett RA, Machesky NJ, Snider TH, Moyer RA, Yeung DT, Brittain MK. Evaluation of HemogloBind™ treatment for preparation of samples for cholinesterase analysis. ACTA ACUST UNITED AC 2013; 4:1020-1023. [PMID: 24749000 PMCID: PMC3989896 DOI: 10.4236/abb.2013.412136] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Acetylcholine is an essential neurotransmitter found throughout the nervous system. Its action on postsynaptic receptors is regulated through hydrolysis by various carboxylesterases, especially cholinesterases (ChEs). The acute toxicity of organophosphate (OP) compounds is directly linked to their action as inhibitors of ChE. One widely used assay for evaluating ChE activity is a spectrophotometric method developed by Ellman et al. When the enzyme source is from tissues or, in particular, blood, hemoglobin displays a spectrophotometric peak at the same wavelength used to analyze cholinergic activity. This creates a substantial background that interferes with the Ellman's assay and must be overcome in order to accurately monitor cholinesterase activity. Herein, we directly compare blood processing methods: classical method (1.67 ± 0.30 U/mL) and HemogloBind™ treatment (1.51 ± 0.17 U/mL), and clearly demonstrate that pretreatment of blood samples with Hemoglobind™ is both a sufficient and rapid sample preparation method for the assessment of ChE activity using the Ellman's method.
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Affiliation(s)
- Kevin G McGarry
- Battelle Biomedical Research Center, Battelle Memorial Institute, Columbus, USA
| | - Ryan A Bartlett
- Battelle Biomedical Research Center, Battelle Memorial Institute, Columbus, USA
| | - Nicholas J Machesky
- Battelle Biomedical Research Center, Battelle Memorial Institute, Columbus, USA
| | - Thomas H Snider
- Battelle Biomedical Research Center, Battelle Memorial Institute, Columbus, USA
| | - Robert A Moyer
- Battelle Biomedical Research Center, Battelle Memorial Institute, Columbus, USA
| | - David T Yeung
- National Institutes of Health/National Institute of Neurological Disorders and Stroke, Bethesda, USA
| | - Matthew K Brittain
- Battelle Biomedical Research Center, Battelle Memorial Institute, Columbus, USA
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López-Granero C, Cañadas F, Cardona D, Yu Y, Giménez E, Lozano R, Avila DS, Aschner M, Sánchez-Santed F. Chlorpyrifos-, diisopropylphosphorofluoridate-, and parathion-induced behavioral and oxidative stress effects: are they mediated by analogous mechanisms of action? Toxicol Sci 2013; 131:206-16. [PMID: 22986948 PMCID: PMC3537130 DOI: 10.1093/toxsci/kfs280] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 09/11/2012] [Indexed: 12/12/2022] Open
Abstract
Exposure to organophosphates (OPs) can lead to cognitive deficits and oxidative damage. Little is known about the relationship between behavioral deficits and oxidative stress within the context of such exposures. Accordingly, the first experiment was carried out to address this issue. Male Wistar rats were administered 250 mg/kg of chlorpyrifos (CPF), 1.5 mg/kg of diisopropylphosphorofluoridate (DFP), or 15 mg/kg of parathion (PTN). Spatial learning in the water maze task was evaluated, and F(2)-isoprostanes (F(2)-IsoPs) and prostaglandin (PGE(2)) were analyzed in the hippocampus. A second experiment was designed to determine the degree of inhibition of brain acetylcholinesterase (AChE) activity, both the soluble and particulate forms of the enzyme, and to assess changes in AChE gene expression given evidence on alternative splicing of the gene in response to OP exposures. In addition, brain acylpeptide hydrolase (APH) activity was evaluated as a second target for OP-mediated effects. In both experiments, rats were sacrificed at various points to determine the time course of OPs toxicity in relation to their mechanism of action. Results from the first experiment suggest cognitive and emotional deficits after OPs exposure, which could be due to, at least in part, increased F(2)-IsoPs levels. Results from the second experiment revealed inhibition of brain AChE and APH activity at various time points post OP exposure. In addition, we observed increased brain read-through splice variant AChE (AChE-R) mRNA levels after 48 h PTN exposure. In conclusion, this study provides novel data on the relationship between cognitive alterations and oxidative stress, and the diverse mechanisms of action along a temporal axis in response to OP exposures in the rat.
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Affiliation(s)
- Caridad López-Granero
- Departamento de Neurociencia y Ciencias de la Salud, Universidad de Almería, La Cañada, 04120 Almería, Spain
| | - Fernando Cañadas
- Departamento de Neurociencia y Ciencias de la Salud, Universidad de Almería, La Cañada, 04120 Almería, Spain
| | - Diana Cardona
- Departamento de Neurociencia y Ciencias de la Salud, Universidad de Almería, La Cañada, 04120 Almería, Spain
| | - Yingchun Yu
- Department of Pediatrics/Pediatric Toxicology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-0414
| | - Estela Giménez
- Departamento de Biología Vegetal y Ecología, E. Politécnica Superior; and
| | - Rafael Lozano
- Departamento de Biología Aplicada, Centro de Investigación en Biotecnología Agroalimentaria, Universidad de Almería, La Cañada, 04120 Almería, Spain
| | - Daiana Silva Avila
- Department of Pediatrics/Pediatric Toxicology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-0414
| | - Michael Aschner
- Department of Pediatrics/Pediatric Toxicology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-0414
| | - Fernando Sánchez-Santed
- Departamento de Neurociencia y Ciencias de la Salud, Universidad de Almería, La Cañada, 04120 Almería, Spain
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MicroRNA-132 potentiates cholinergic anti-inflammatory signaling by targeting acetylcholinesterase. Immunity 2009; 31:965-73. [PMID: 20005135 DOI: 10.1016/j.immuni.2009.09.019] [Citation(s) in RCA: 324] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 06/18/2009] [Accepted: 09/24/2009] [Indexed: 01/12/2023]
Abstract
MicroRNAs (miRNAs) contribute to both neuronal and immune cell fate, but their involvement in intertissue communication remained unexplored. The brain, via vagal secretion of acetylcholine (ACh), suppresses peripheral inflammation by intercepting cytokine production; therefore, we predicted that microRNAs targeting acetylcholinesterase (AChE) can attenuate inflammation. Here, we report that inflammatory stimuli induced leukocyte overexpression of the AChE-targeting miR-132. Injected locked nucleic acid (LNA)-modified anti-miR-132 oligonucleotide depleted miR-132 amounts while elevating AChE in mouse circulation and tissues. In transfected cells, a mutated 3'UTR miR-132 binding site increased AChE mRNA expression, whereas cells infected with a lentivirus expressing pre-miR-132 showed suppressed AChE. Transgenic mice overexpressing 3'UTR null AChE showed excessive inflammatory mediators and impaired cholinergic anti-inflammatory regulation, in spite of substantial miR-132 upregulation in brain and bone marrow. Our findings identify the AChE mRNA-targeting miR-132 as a functional regulator of the brain-to-body resolution of inflammation, opening avenues for study and therapeutic manipulations of the neuro-immune dialog.
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Tyagi E, Agrawal R, Nath C, Shukla R. Cholinergic protection via alpha7 nicotinic acetylcholine receptors and PI3K-Akt pathway in LPS-induced neuroinflammation. Neurochem Int 2009; 56:135-42. [PMID: 19781587 DOI: 10.1016/j.neuint.2009.09.011] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 09/16/2009] [Accepted: 09/17/2009] [Indexed: 12/14/2022]
Abstract
The present study was planned to investigate the effect of anti-cholinesterase drugs donepezil and neostigmine on neuroinflammation induced by intracerebroventricular administration of lipopolysaccharide (LPS, 50 microg) in rat. Proinflammatory cytokines (TNF-alpha and IL-1beta), expressions of iNOS and COX-2, acetylcholinesterase activity, malondialdehyde and reduced glutathione were studied in different brain regions at 24h of LPS injection. Donepezil was found to decrease the LPS-induced AChE activity and oxidative stress in all the brain regions. It also inhibited the LPS-induced proinflammatory cytokines and iNOS expression but did not affect the increased COX-2 expression whereas neostigmine treatment had no effect on LPS-induced proinflammatory cytokines. Methyllycaconitine (MLA), a alpha7 nicotinic acetylcholine receptor antagonist, significantly antagonized the donepezil mediated inhibition of LPS-induced proinflammatory cytokines, indicating that alpha7 nicotinic acetylcholine receptor subunit was playing a role in regulation of neuroinflammation. The phosphorylation of Akt, an effector of PI3K, increased with donepezil treatment. These results suggest that increased cholinergic activity in brain by donepezil prevents LPS-induced neuroinflammation via alpha7-nAChRs, followed by the PI3K-Akt pathway and this system may form the basis for the development of novel agents for reversing neuroinflammation or provide new indications for existing drugs.
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Affiliation(s)
- Ethika Tyagi
- Division of Pharmacology, Central Drug Research Institute, Lucknow, Uttar Pradesh, India
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Bond CE, Zimmermann M, Greenfield SA. Upregulation of alpha7 Nicotinic Receptors by Acetylcholinesterase C-Terminal Peptides. PLoS One 2009; 4:e4846. [PMID: 19287501 PMCID: PMC2654408 DOI: 10.1371/journal.pone.0004846] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 01/29/2009] [Indexed: 11/25/2022] Open
Abstract
Background The alpha-7 nicotinic acetylcholine receptor (α7-nAChR) is well known as a potent calcium ionophore that, in the brain, has been implicated in excitotoxicity and hence in the underlying mechanisms of neurodegenerative disorders such as Alzheimer's disease. Previous research implied that the activity of this receptor may be modified by exposure to a peptide fragment derived from the C-terminal region of the enzyme acetylcholinesterase. This investigation was undertaken to determine if the functional changes observed could be attributed to peptide binding interaction with the α7-nAChR, or peptide modulation of receptor expression. Methodology/Principal Findings This study provides evidence that two peptides derived from the C-terminus of acetylcholinesterase, not only selectively displace specific bungarotoxin binding at the α7-nAChR, but also alter receptor binding properties for its familiar ligands, including the alternative endogenous agonist choline. Of more long-term significance, these peptides also induce upregulation of α7-nAChR mRNA and protein expression, as well as enhancing receptor trafficking to the plasma membrane. Conclusions/Significance The results reported here demonstrate a hitherto unknown relationship between the α7-nAChR and the non-enzymatic functions of acetylcholinesterase, mediated independently by its C-terminal domain. Such an interaction may prove valuable as a pharmacological tool, prompting new approaches for understanding, and combating, the process of neurodegeneration.
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Affiliation(s)
- Cherie E Bond
- Institute for the Future of the Mind, Department of Pharmacology, Oxford University, Oxford, UK.
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Shaked I, Zimmerman G, Soreq H. Stress-induced Alternative Splicing Modulations in Brain and Periphery. Ann N Y Acad Sci 2008; 1148:269-81. [DOI: 10.1196/annals.1410.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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