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Ijomone OM, Iroegbu JD, Aschner M, Bornhorst J. Impact of environmental toxicants on p38- and ERK-MAPK signaling pathways in the central nervous system. Neurotoxicology 2021; 86:166-171. [PMID: 34389354 PMCID: PMC8440482 DOI: 10.1016/j.neuro.2021.08.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/06/2021] [Accepted: 08/07/2021] [Indexed: 12/16/2022]
Abstract
There are several candidate signalling pathways that mediate the response of the central nervous system (CNS) cells to environmental toxins. However, much is still to be learned on how these pathways modulate neurotoxicity. The mitogen-activated protein kinases (MAPKs) signalling pathways, which include the extracellular signal-regulated protein kinase (ERK) and the p38-MAPK, are potentially key pathways to regulate CNS responses to environmental toxins. The pathways play leading roles in the transmission of extracellular signals into the cell nucleus, leading to cell differentiation, cell growth, and apoptosis, to name a few. Moreover, exposure to environmental toxins induces p38- and ERK-MAPK activation, which leads to oxidative stress, inflammation, and apoptosis in the CNS. Here, we provide a concise review of the recent evidence demonstrating the role of p38- and ERK-MAPK signaling pathways and their downstream targets in the CNS following exposure to environmental toxicants such as metals, organophosphorus and persistent organic pollutants.
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Affiliation(s)
- Omamuyovwi M Ijomone
- Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany; The Neuro- Lab, Department of Human Anatomy, School of Health and Health Technology, Federal University of Technology Akure, Akure, Nigeria.
| | - Joy D Iroegbu
- The Neuro- Lab, Department of Human Anatomy, School of Health and Health Technology, Federal University of Technology Akure, Akure, Nigeria
| | - Michael Aschner
- Departments of Molecular Pharmacology and Neurosciences, Albert Einstein College of Medicine, NY, USA
| | - Julia Bornhorst
- Food Chemistry, Faculty of Mathematics and Natural Sciences, University of Wuppertal, Wuppertal, Germany
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Penatzer JA, Miller JV, Prince N, Shaw M, Lynch C, Newman M, Hobbs GR, Boyd JW. Differential phosphoprotein signaling in the cortex in mouse models of Gulf War Illness using corticosterone and acetylcholinesterase inhibitors. Heliyon 2021; 7:e07552. [PMID: 34307952 PMCID: PMC8287240 DOI: 10.1016/j.heliyon.2021.e07552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/16/2021] [Accepted: 07/08/2021] [Indexed: 11/29/2022] Open
Abstract
Aims Veterans from the 1990–91 Gulf War were exposed to acetylcholinesterase inhibitors (AChEIs), and, following service, an estimated one-third began suffering from a medically unexplained, multi-symptom illness termed Gulf War Illness (GWI). Previous research has developed validated rodent models that include exposure to exogenous corticosterone (CORT) and AChEIs to simulate high stress and chemical exposures encountered in theater. This combination of exposures in mice resulted in a marked increase in neuroinflammation, which is a common symptom of veterans suffering from GWI. To further elucidate the mechanisms associated with these mouse models of GWI, an investigation into intracellular responses in the cortex were performed to characterize the early cellular signaling changes associated with this exposure-initiated neuroinflammation. Main methods Adult male C57BL/6J mice were exposed to CORT in the drinking water (200 μg/mL) for 7 days followed by a single intraperitoneal injection of diisopropyl fluorophosphate (DFP; 4.0 mg/kg) or chlorpyrifos oxon (CPO; 8.0 mg/kg), on day 8 and euthanized 0.5, 2, and 24 h post-injection. Eleven post-translationally modified protein targets were measured using a multiplexed ELISA. Key findings Phosphoprotein responses were found to be exposure specific following AChEI insult, with and without CORT. Specifically, CORT + CPO exposure was found to sequentially activate several phosphoproteins involved in mitogen activated protein kinase signaling (p-MEK1/2, p-ERK1/2, and p-JNK). DFP alone similarly increased proteins in this pathway (p-RPS6, and p-JNK), but the addition of CORT ameliorated these affects. Significance The results of this study provide insight into differentially activated pathways depending on AChEI in these GWI models.
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Affiliation(s)
- Julia A Penatzer
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morvantown, WV, USA
| | | | - Nicole Prince
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morvantown, WV, USA
| | - Misa Shaw
- Department of Orthopaedics, West Virginia University School of Medicine, Morgantown, WV, USA.,Clinical and Translational Science Institute, West Virginia University School of Medicine, Morgantown, WV, USA
| | - Cayla Lynch
- Department of Orthopaedics, West Virginia University School of Medicine, Morgantown, WV, USA
| | - Mackenzie Newman
- Department of Orthopaedics, West Virginia University School of Medicine, Morgantown, WV, USA
| | - Gerald R Hobbs
- Department of Statistics, West Virginia University, Morgantown, WV, USA
| | - Jonathan W Boyd
- Department of Orthopaedics, West Virginia University School of Medicine, Morgantown, WV, USA
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González EA, Rindy AC, Guignet MA, Calsbeek JJ, Bruun DA, Dhir A, Andrew P, Saito N, Rowland DJ, Harvey DJ, Rogawski MA, Lein PJ. The chemical convulsant diisopropylfluorophosphate (DFP) causes persistent neuropathology in adult male rats independent of seizure activity. Arch Toxicol 2020; 94:2149-2162. [PMID: 32303805 PMCID: PMC7305973 DOI: 10.1007/s00204-020-02747-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 04/08/2020] [Indexed: 12/27/2022]
Abstract
Organophosphate (OP) threat agents can trigger seizures that progress to status epilepticus, resulting in persistent neuropathology and cognitive deficits in humans and preclinical models. However, it remains unclear whether patients who do not show overt seizure behavior develop neurological consequences. Therefore, this study compared two subpopulations of rats with a low versus high seizure response to diisopropylfluorophosphate (DFP) to evaluate whether acute OP intoxication causes persistent neuropathology in non-seizing individuals. Adult male Sprague Dawley rats administered DFP (4 mg/kg, sc), atropine sulfate (2 mg/kg, im), and pralidoxime (25 mg/kg, im) were monitored for seizure activity for 4 h post-exposure. Animals were separated into groups with low versus high seizure response based on behavioral criteria and electroencephalogram (EEG) recordings. Cholinesterase activity was evaluated by Ellman assay, and neuropathology was evaluated at 1, 2, 4, and 60 days post-exposure by Fluoro-Jade C (FJC) staining and micro-CT imaging. DFP significantly inhibited cholinesterase activity in the cortex, hippocampus, and amygdala to the same extent in low and high responders. FJC staining revealed significant neurodegeneration in DFP low responders albeit this response was delayed, less persistent, and decreased in magnitude compared to DFP high responders. Micro-CT scans at 60 days revealed extensive mineralization that was not significantly different between low versus high DFP responders. These findings highlight the importance of considering non-seizing patients for medical care in the event of acute OP intoxication. They also suggest that OP intoxication may induce neurological damage via seizure-independent mechanisms, which if identified, might provide insight into novel therapeutic targets.
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Affiliation(s)
- Eduardo A González
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Alexa C Rindy
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Michelle A Guignet
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Jonas J Calsbeek
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Donald A Bruun
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Ashish Dhir
- Department of Neurology, University of California, Davis, School of Medicine, 4860 Y Street, Sacramento, CA, 95817, USA
| | - Peter Andrew
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Naomi Saito
- Department of Public Health Sciences, University of California, Davis, School of Medicine, One Shields Avenue, Davis, CA, 95616, USA
| | - Douglas J Rowland
- Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, 451 Health Sciences Drive, Davis, CA, 95616, USA
| | - Danielle J Harvey
- Department of Public Health Sciences, University of California, Davis, School of Medicine, One Shields Avenue, Davis, CA, 95616, USA
| | - Michael A Rogawski
- Department of Neurology, University of California, Davis, School of Medicine, 4860 Y Street, Sacramento, CA, 95817, USA
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA.
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Zare Z, Zarbakhsh S, Tehrani M, Mohammadi M. Paraoxon-induced damage in rat hippocampus is associated with alterations in the expression of apoptosis-related proteins. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2020; 166:104580. [PMID: 32448426 DOI: 10.1016/j.pestbp.2020.104580] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 03/02/2020] [Accepted: 04/06/2020] [Indexed: 06/11/2023]
Abstract
To determine the possible role of apoptosis in the development of paraoxon-induced brain damage, we evaluated expression of apoptosis-related proteins, the extent of neuronal damage, and activation of astrocytes in rat hippocampus. Adult male Wistar rats were intraperitoneally injected with one of three doses of paraoxon (0.3, 0.7, or 1 mg/kg) or corn oil (vehicle). After 14 or 28 days, expression of apoptosis-related proteins, including B-cell leukemia/lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), and caspase-3, as well as the number of neurons and glial fibrillary acidic protein (GFAP) positive cells in hippocampus were examined by western blot, cresyl blue staining, and immunohistochemistry, respectively. After 14 and 28 days, Bax and caspase-3 proteins were significantly increased in rats receiving 0.7 and 1 mg/kg of paraoxon. A significant decrease in Bcl-2 protein levels was also observed in 0.7 and 1 mg/kg groups after 14 days and in 1 mg/kg group after 28 days. Animals treated with 1 mg/kg of paraoxon showed a significant decrease in the number of neurons in the CA1 area. Also, those treated with 0.7 and 1 mg/kg of paraoxon showed an increase in the number of GFAP positive cells in both CA1 and CA3 areas as well as a significant decrease in survived neurons in the CA3 area. Our results indicated that neuronal damage induced by convulsive doses of paraoxon in rat hippocampus is mediated in part through apoptosis mechanism. Activation of astrocytes might lead to reduced extent of damage and damage and consequently increased neuronal survival.
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Affiliation(s)
- Zohreh Zare
- Department of Anatomical Sciences, Molecular and Cell Biology Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Sam Zarbakhsh
- Nervous System Stem Cells Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | - Mohsen Tehrani
- Department of Immunology, Gastrointestinal Cancer Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Moslem Mohammadi
- Department of Physiology, Molecular and Cell Biology Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
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Lazar S, Egoz I, Brandeis R, Chapman S, Bloch-Shilderman E, Grauer E. Propagation of damage in the rat brain following sarin exposure: Differential progression of early processes. Toxicol Appl Pharmacol 2016; 310:87-97. [DOI: 10.1016/j.taap.2016.09.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 09/07/2016] [Accepted: 09/12/2016] [Indexed: 02/07/2023]
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Ferchmin PA, Pérez D, Cuadrado BL, Carrasco M, Martins AH, Eterović VA. Neuroprotection Against Diisopropylfluorophosphate in Acute Hippocampal Slices. Neurochem Res 2015; 40:2143-51. [PMID: 26438150 DOI: 10.1007/s11064-015-1729-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 09/23/2015] [Indexed: 12/12/2022]
Abstract
Diisopropylfluorophosphate (DFP) is an irreversible inhibitor of acetylcholine esterase and a surrogate of the organophosphorus (OP) nerve agent sarin. The neurotoxicity of DFP was assessed as a reduction of population spike (PS) area elicited by synaptic stimulation in acute hippocampal slices. Two classical antidotes, atropine, and pralidoxime, and two novel antidotes, 4R-cembranotriene-diol (4R) and a caspase nine inhibitor, were tested. Atropine, pralidoxime, and 4R significantly protected when applied 30 min after DFP. The caspase inhibitor was neuroprotective when applied 5-10 min before or after DFP, suggesting that early synaptic apoptosis is responsible for the loss of PSs. It is likely that apoptosis starts at the synapses and, if antidotes are not applied, descends to the cell bodies, causing death. The acute slice is a reliable tool for mechanistic studies, and the assessment of neurotoxicity and neuroprotection with PS areas is, in general, pharmacologically congruent with in vivo results and predicts the effect of drugs in vivo. 4R was first found to be neuroprotective in slices and later we demonstrated that 4R is neuroprotective in vivo. The mechanism of neurotoxicity of OPs is not well understood, and there is a need for novel antidotes that could be discovered using acute slices.
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Affiliation(s)
- P A Ferchmin
- Department of Biochemistry, Universidad Central Del Caribe, School of Medicine, Ave. Laurel, Santa Juanita, Bayamón, PR, 00956, USA. .,, PO BOX 60327, Bayamón, PR, 00960-6032, USA.
| | - Dinely Pérez
- Department of Biochemistry, Universidad Central Del Caribe, School of Medicine, Ave. Laurel, Santa Juanita, Bayamón, PR, 00956, USA
| | - Brenda L Cuadrado
- Department of Biochemistry, Universidad Central Del Caribe, School of Medicine, Ave. Laurel, Santa Juanita, Bayamón, PR, 00956, USA
| | - Marimée Carrasco
- Department of Biochemistry, Universidad Central Del Caribe, School of Medicine, Ave. Laurel, Santa Juanita, Bayamón, PR, 00956, USA
| | - Antonio H Martins
- Department of Pharmacology and Toxicology, Medical Science Campus UPR, San Juan, PR, USA
| | - Vesna A Eterović
- Department of Biochemistry, Universidad Central Del Caribe, School of Medicine, Ave. Laurel, Santa Juanita, Bayamón, PR, 00956, USA
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