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Singh N, Golime R, Kumar A, Roy T. Attenuation of Nerve Agent Induced Neurodegenerative and Neuroinflammatory Changes in Rats with New Combination Treatment of Galantamine, Atropine and Midazolam. Mol Neurobiol 2024:10.1007/s12035-024-04294-2. [PMID: 38867111 DOI: 10.1007/s12035-024-04294-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 06/07/2024] [Indexed: 06/14/2024]
Abstract
Acute nerve agent exposure can kill a person within minutes or produce multiple neurotoxic effects and subsequent brain damage with potential long-term adverse outcomes. Recent abuse of nerve-agents on Syrian civilians, during Japan terrorist attacks, and personal assassinations in the UK, and Malaysia indicate their potential threat to world population. Existing nerve agent antidotes offer only incomplete protection especially, if the treatment is delayed. To develop the effective drugs, it is advantageous to elucidate the underlying mechanisms of nerve agent-induced multiple neurological impairments. This study aimed to investigate the molecular basis of neuroinflammation during nerve agent toxicity with focus on inflammasome-associated proteins and neurodegeneration. In rats, NOD-like receptor family pyrin domain containing 3 (NLRP3), and glial fibrillary acidic protein (GFAP) immunoreactivity levels were considerably increased in the hippocampus, piriform cortex, and amygdala areas after single subcutaneous soman exposure (90 µg/kg-1). Western analysis indicated a notable increase in the neuroinflammatory indicator proteins, high mobility group box 1 (HMGB1) and inducible nitric oxide synthase (iNOS) levels. The presence of fluorojade-C-stained degenerating neurons in distinct rat brain areas is indicating the neurodegeneration during nerve agent toxicity. Pre-treatment with galantamine (3 mg/kg, - 30 min) followed by post-treatment of atropine (10 mg/kg, i.m.) and midazolam (5 mg/kg, i.m.), has completely protected animals from death induced by supra-lethal dose of soman (2XLD50) and reduced the neuroinflammatory and neurodegenerative changes. Results highlight that this new prophylactic and therapeutic drug combination might be an effective treatment option for soldiers deployed in conflict areas and first responders dealing with accidental/deliberate release of nerve agents.
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Affiliation(s)
- Naveen Singh
- Biomedical Verification Division, Defence Research and Development Establishment (DRDE), Jhansi Road, Gwalior, M.P, India
| | - RamaRao Golime
- Biomedical Verification Division, Defence Research and Development Establishment (DRDE), Jhansi Road, Gwalior, M.P, India.
- Department of Epidemiology and Public Health, Central University of Tamil Nadu, Thiruvarur, India.
| | - Abdhesh Kumar
- Animal Facility Division, DRDE, Jhansi Road, Gwalior, M.P, India
| | - Tuhin Roy
- Process Technology Development Division, DRDE, Jhansi Road, Gwalior, M.P, India
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Saya L, Ratandeep, Arya B, Rastogi K, Verma M, Rani S, Sahu PK, Singh MR, Singh WR, Hooda S. Recent advances in sensing toxic nerve agents through DMMP model simulant using diverse nanomaterials-based chemical sensors. Talanta 2024; 272:125785. [PMID: 38394750 DOI: 10.1016/j.talanta.2024.125785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 02/08/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024]
Abstract
Recent terrorist assaults have demonstrated the need for the exploration and design of sustainable and stable chemical sensors with quick reaction times combined with great sensitivity. Among several classes of chemical warfare agents, nerve agents have been proven to be the most hazardous. Even short-term exposure to them can result in severe toxic effects. Human beings inadvertently face the after-effects of these chemicals even several years after these chemicals were used. Due to the extreme toxicity and difficulty in handling, dimethyl methylphosphonate (DMMP), a simulant of nerve agents with much lesser toxicity, is frequently used in laboratories as a substitute. Having a chemical structure almost identical to those of nerve agents, DMMP can mimic the properties of nerve agents. Through this paper, authors have attempted to introduce the evolution of several chemical sensors used to detect DMMP in recent years, including field-effect transistors, chemicapacitors, chemiresistors, and mass-sensitive sensors. A detailed discussion of the role of nanomaterials as chemical sensors in the detection of DMMP has been the main focus of the work through a comprehensive overview of the research on gas sensors that have been reported making use of the properties of a wide range of nanomaterials.
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Affiliation(s)
- Laishram Saya
- Department of Chemistry, Sri Venkateswara College (University of Delhi), Dhaula Kuan, New Delhi 110021, India; Department of Chemistry, Manipur University, Canchipur, Imphal 795003, Manipur, India; Polymer Research Laboratory, Department of Chemistry, Acharya Narendra Dev College (University of Delhi), Govindpuri, Kalkaji, New Delhi, 110019, India.
| | - Ratandeep
- School of Chemical Sciences and Advanced Materials Research Center, Indian Institute of Technology Mandi, Kamand, Mandi 175075, Himachal Pradesh, India
| | - Bipasa Arya
- Polymer Research Laboratory, Department of Chemistry, Acharya Narendra Dev College (University of Delhi), Govindpuri, Kalkaji, New Delhi, 110019, India
| | - Kanjika Rastogi
- Polymer Research Laboratory, Department of Chemistry, Acharya Narendra Dev College (University of Delhi), Govindpuri, Kalkaji, New Delhi, 110019, India
| | - Manisha Verma
- Department of Physics, Acharya Narendra Dev College, (University of Delhi), Govindpuri, Kalkaji, New Delhi, 110019, India
| | - Sanjeeta Rani
- Department of Physics, Acharya Narendra Dev College, (University of Delhi), Govindpuri, Kalkaji, New Delhi, 110019, India
| | - Prasanta Kumar Sahu
- Department of Chemistry, Shivaji College, (University of Delhi), Raja Garden, New Delhi, 110027, India
| | - M Ramananda Singh
- Department of Chemistry, Kirorimal College, (University of Delhi), Delhi, 110007, India
| | - W Rameshwor Singh
- Department of Chemistry, Manipur University, Canchipur, Imphal 795003, Manipur, India.
| | - Sunita Hooda
- Polymer Research Laboratory, Department of Chemistry, Acharya Narendra Dev College (University of Delhi), Govindpuri, Kalkaji, New Delhi, 110019, India.
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Kirkland AE, Baron M, VanMeter JW, Baraniuk JN, Holton KF. The low glutamate diet improves cognitive functioning in veterans with Gulf War Illness and resting-state EEG potentially predicts response. Nutr Neurosci 2022; 25:2247-2258. [PMID: 34282720 DOI: 10.1080/1028415x.2021.1954292] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Objectives: Gulf War Illness (GWI) is a chronic, multi-symptom disorder with underlying central nervous system dysfunction and cognitive impairments. The objective of this study was to test the low glutamate diet as a novel treatment for cognitive dysfunction among those with GWI, and to explore if baseline resting-state electroencephalography (EEG) could predict cognitive outcomes.Methods: Cognitive functioning was assessed at baseline, after one-month on the diet, and across a two-week double-blind, placebo-controlled crossover challenge with monosodium glutamate (MSG) relative to placebo.Results: Significant improvements were seen after one-month on the diet in overall cognitive functioning, and in all other domains tested (FDR p < 0.05), except for memory. Challenge with MSG resulted in significant inter-individual response variability (p < 0.0001). Participants were clustered according to baseline resting-state EEG using k-means clustering to explore the inter-individual response variability. Three distinct EEG clusters were observed, and each corresponded with differential cognitive effects during challenge with MSG: cluster 1 had cognitive benefit (24% of participants), cluster 2 had cognitive detriment (42% of participants), and cluster 3 had mild/mixed effects (33% of participants).Discussion: These findings suggest that the low glutamate diet may be a beneficial treatment for cognitive impairment in GWI. Future research is needed to understand the extent to which resting-state EEG can predict response to the low glutamate diet and to explore the mechanisms behind the varied response to acute glutamate challenge.
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Affiliation(s)
- Anna E Kirkland
- Behavior, Cognition and Neuroscience Program, American University, Washington, DC, USA
| | - Michael Baron
- Mathematics & Statistics Department, American University, Washington, DC, USA
| | - John W VanMeter
- Department of Neurology, Center for Functional & Molecular Imaging, Georgetown University, Washington, DC, USA
| | - James N Baraniuk
- Department of Medicine, Georgetown University, Washington, DC, USA
| | - Kathleen F Holton
- Department of Health Studies, American University, Washington, DC, USA
- Center for Behavioral Neuroscience, American University, Washington, DC, USA
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Langan MT, Kirkland AE, Rice LC, Mucciarone VC, Baraniuk J, VanMeter A, Holton KF. Low glutamate diet improves working memory and contributes to altering BOLD response and functional connectivity within working memory networks in Gulf War Illness. Sci Rep 2022; 12:18004. [PMID: 36289291 PMCID: PMC9606252 DOI: 10.1038/s41598-022-21837-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 10/04/2022] [Indexed: 01/24/2023] Open
Abstract
Gulf War Illness is a chronic multi-symptom disorder with severe cognitive impairments which may be related to glutamate excitotoxicity and central nervous system dysfunction. The low glutamate diet has been proposed as a comprehensive intervention for Gulf War Illness. We examined the effects of the low glutamate diet on verbal working memory using a fMRI N-back task. Accuracy, whole-brain blood oxygen level dependency (BOLD) response, and task-based functional connectivity were assessed at baseline and after 1 month on the diet (N = 24). Multi-voxel pattern analysis identified regions of whole-brain BOLD pattern differences after the diet to be used as seeds for subsequent seed-to-voxel functional connectivity analyses. Verbal working memory accuracy improved after the diet (+ 13%; p = 0.006). Whole-brain BOLD signal changes were observed, revealing lower activation within regions of the frontoparietal network and default mode network after the low glutamate diet. Multi-voxel pattern analysis resulted in 3 clusters comprising parts of the frontoparietal network (clusters 1 and 2) and ventral attention network (cluster 3). The seed-to-voxel analyses identified significant functional connectivity changes post-diet for clusters 1 and 2 (peak p < 0.001, cluster FDR p < 0.05). Relative to baseline, clusters 1 and 2 had decreased functional connectivity with regions in the ventral attention and somatomotor networks. Cluster 2 also had increased functional connectivity with regions of the default mode and frontoparietal networks. These findings suggest that among veterans with Gulf War Illness, the low glutamate diet improves verbal working memory accuracy, alters BOLD response, and alters functional connectivity within two networks central to working memory.
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Affiliation(s)
| | - Anna E Kirkland
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Laura C Rice
- Department of Neuroscience, American University, Washington, DC, USA
| | - Veronica C Mucciarone
- Department of Neurology, Center for Functional and Molecular Imaging, Georgetown University, Washington, DC, USA
| | - James Baraniuk
- Department of Medicine, Georgetown University, Washington, DC, USA
| | - Ashley VanMeter
- Department of Neurology, Center for Functional and Molecular Imaging, Georgetown University, Washington, DC, USA
| | - Kathleen F Holton
- Department of Neuroscience, American University, Washington, DC, USA.
- Department of Health Studies, American University, Washington, DC, USA.
- Center for Neuroscience and Behavior, American University, Washington, DC, USA.
- Nutritional Neuroscience Lab, American University, 4400 Massachusetts Ave NW, Washington, DC, 20016, USA.
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Brandley ET, Kirkland AE, Baron M, Baraniuk JN, Holton KF. The Effect of the Low Glutamate Diet on the Reduction of Psychiatric Symptoms in Veterans With Gulf War Illness: A Pilot Randomized-Controlled Trial. Front Psychiatry 2022; 13:926688. [PMID: 35795023 PMCID: PMC9251130 DOI: 10.3389/fpsyt.2022.926688] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
The objective of this pilot study was to examine the effects of the low glutamate diet on anxiety, post-traumatic stress disorder (PTSD), and depression in veterans with Gulf War Illness (GWI). The low glutamate diet removes dietary excitotoxins and increases consumption of micronutrients which are protective against glutamatergic excitotoxicity. This study was registered at ClinicalTrials.gov (NCT#03342482). Forty veterans with GWI completed psychiatric questionnaires at baseline and after 1-month following the low glutamate diet. Participants were then randomized into a double-blind, placebo-controlled crossover challenge with monosodium glutamate (MSG; a dietary excitotoxin) vs. placebo over three consecutive days per week, with assessments on day three. Data were analyzed across the full sample and with participants categorized by baseline symptom severity. Pre-post-dietary intervention change scores were analyzed with Wilcoxon signed-rank tests and paired sample t-tests across the full sample, and changes across symptom severity categories were analyzed using ANOVA. Crossover challenge results were analyzed with linear mixed modeling accounting for challenge material (MSG v. placebo), sequence (MSG/placebo v. placebo/MSG), period (challenge week 1 v. week 2), pre-diet baseline symptom severity category (minimal/mild, moderate, or severe), and the challenge material*symptom severity category interaction. A random effect of ID (sequence) was also included. All three measures showed significant improvement after 1 month on the diet, with significant differences between baseline severity categories. Individuals with severe psychological symptoms at baseline showed the most improvement after 1 month on the diet, while those with minimal/mild symptoms showed little to no change. Modeling results from the challenge period demonstrated a significant worsening of anxiety from MSG in only the most severe group, with no significant effects of MSG challenge on depression nor PTSD symptoms. These results suggest that the low glutamate diet may be an effective treatment for depression, anxiety, and PTSD, but that either (a) glutamate is only a direct cause of symptoms in anxiety, or (b) underlying nutrient intake may prevent negative psychiatric effects from glutamate exposure. Future, larger scale clinical trials are needed to confirm these findings and to further explore the potential influence of increased micronutrient intake on the improvements observed across anxiety, PTSD, and depression.
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Affiliation(s)
- Elizabeth T Brandley
- Department of Health Studies, American University, Washington, DC, United States
| | - Anna E Kirkland
- Medical University of South Carolina, Charleston, SC, United States
| | - Michael Baron
- Department of Mathematics and Statistics, American University, Washington, DC, United States
| | - James N Baraniuk
- Department of Medicine, Georgetown University, Washington, DC, United States
| | - Kathleen F Holton
- Department of Health Studies, American University, Washington, DC, United States.,Department of Neuroscience, American University, Washington, DC, United States.,Center for Neuroscience and Behavior, American University, Washington, DC, United States
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Saidani W, Wahbi A, Sellami B, Helali MA, Khazri A, Mahmoudi E, Touil S, Joubert O, Beyrem H. Toxicity assessment of organophosphorus in Ruditapes decussatus via physiological, chemical and biochemical determination: A case study with the compounds γ-oximo- and γ-amino-phosphonates and phosphine oxides. MARINE POLLUTION BULLETIN 2021; 169:112556. [PMID: 34082359 DOI: 10.1016/j.marpolbul.2021.112556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/21/2021] [Accepted: 05/23/2021] [Indexed: 06/12/2023]
Abstract
Organophosphorus derivatives are widely used in human health care and have been detected in aquatic ecosystems. These compounds may pose significant risks to non-target exposed organisms and only limited studies are available on bioconcentration and the effects of organophosphorus derivatives on marine organisms. The aim of this work was to evaluate the possible toxic effects of two concentrations (20 and 40 μg/L) of γ-oximo- and γ-amino-phosphonates and phosphine oxides in mediterranean clams Ruditapes decussatus exposed for 14 days using different biomarkers and the changes of filtration and respiration rate. The use of clams in ecotoxicity evaluation is thus mandatory to assess the feasibility of assessing oxidative stress on R. decussatus after being exposed to γ-oximo- and γ-amino-phosphonates and phosphine oxides. The oxidative status was analyzed by measuring oxidative stress biomarkers RNS and ROS production in mitochondria, superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferases (GSTs), lipid peroxidation (LPO) and acetylcholinesterase (AChE), whose alteration was indicative of organophosphorus exposure, in both gills and digestive gland of the clams. No significant alterations in RNS, ROS production, SOD, CAT and AChE activities and MDA content were observed in both organs of clams treated with γ-oximophosphine oxides. It was possible then to hypothesize that γ-oximophosphine oxides may have probably exerted an incomplete alteration of antioxidant defenses and damage, which was changed by the activation of defense mechanisms. On the contrary, oxidative stress parameters were changed after exposure to γ-amino-phosphonates and phosphine oxides. In addition, metals accumulation, filtration and respiration rates were altered following exposure to all the studied organophosphorus compounds.
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Affiliation(s)
- Wiem Saidani
- Laboratory of Environment Biomonitoring, Unit of coastal Ecology and Ecotoxicology, Faculty of Sciences of Bizerte, Jarzouna 7021, University of Carthage, Tunisia
| | - Aymen Wahbi
- Laboratory of Hetero-Organic Compounds and Nanostructured Materials (LR18ES11), University of Carthage, Faculty of Sciences of Bizerte, CP 7021 Jarzouna, Tunisia
| | - Badreddine Sellami
- National Institute of Science and Technology of the Sea, Tabarka, Tunisia
| | - Mohamed Amine Helali
- Laboratory of Mineral Resources and Environment, Department of Geology, Faculty of Sciences of Tunis, University of Tunis-El Manar, 2092, Tunisia
| | - Abdelhafidh Khazri
- Laboratory of Environment Biomonitoring, Unit of coastal Ecology and Ecotoxicology, Faculty of Sciences of Bizerte, Jarzouna 7021, University of Carthage, Tunisia
| | - Ezzeddine Mahmoudi
- Laboratory of Environment Biomonitoring, Unit of coastal Ecology and Ecotoxicology, Faculty of Sciences of Bizerte, Jarzouna 7021, University of Carthage, Tunisia
| | - Soufiane Touil
- Laboratory of Hetero-Organic Compounds and Nanostructured Materials (LR18ES11), University of Carthage, Faculty of Sciences of Bizerte, CP 7021 Jarzouna, Tunisia
| | - Olivier Joubert
- Institute Jean Lamour, UMR 7198, University of Lorraine, CNRS, IJL, F-54000 Nancy, France
| | - Hamouda Beyrem
- Laboratory of Environment Biomonitoring, Unit of coastal Ecology and Ecotoxicology, Faculty of Sciences of Bizerte, Jarzouna 7021, University of Carthage, Tunisia
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Bennion BJ, Malfatti MA, Be NA, Enright HA, Hok S, Cadieux CL, Carpenter TS, Lao V, Kuhn EA, McNerney MW, Lightstone FC, Nguyen TH, Valdez CA. Development of a CNS-permeable reactivator for nerve agent exposure: an iterative, multi-disciplinary approach. Sci Rep 2021; 11:15567. [PMID: 34330964 PMCID: PMC8324913 DOI: 10.1038/s41598-021-94963-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 07/19/2021] [Indexed: 11/09/2022] Open
Abstract
Nerve agents have experienced a resurgence in recent times with their use against civilian targets during the attacks in Syria (2012), the poisoning of Sergei and Yulia Skripal in the United Kingdom (2018) and Alexei Navalny in Russia (2020), strongly renewing the importance of antidote development against these lethal substances. The current standard treatment against their effects relies on the use of small molecule-based oximes that can efficiently restore acetylcholinesterase (AChE) activity. Despite their efficacy in reactivating AChE, the action of drugs like 2-pralidoxime (2-PAM) is primarily limited to the peripheral nervous system (PNS) and, thus, provides no significant protection to the central nervous system (CNS). This lack of action in the CNS stems from their ionic nature that, on one end makes them very powerful reactivators and on the other renders them ineffective at crossing the Blood Brain Barrier (BBB) to reach the CNS. In this report, we describe the use of an iterative approach composed of parallel chemical and in silico syntheses, computational modeling, and a battery of detailed in vitro and in vivo assays that resulted in the identification of a promising, novel CNS-permeable oxime reactivator. Additional experiments to determine acute and chronic toxicity are ongoing.
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Affiliation(s)
- Brian J Bennion
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Michael A Malfatti
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Nicholas A Be
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Heather A Enright
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Saphon Hok
- Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
- Forensic Science Center, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - C Linn Cadieux
- United States Army Medical Research Institute of Chemical Defense, Aberdeen, MD, 21010, USA
| | - Timothy S Carpenter
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Victoria Lao
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Edward A Kuhn
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - M Windy McNerney
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
- Affiliation: Mental Illness Research, Education and Clinical Center, Veterans Affairs, Palo Alto, CA, 94304, USA
- Affiliation: Department of Psychiatry, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Felice C Lightstone
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Tuan H Nguyen
- Global Security Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Carlos A Valdez
- Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
- Forensic Science Center, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
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Brenet A, Somkhit J, Hassan-Abdi R, Yanicostas C, Romain C, Bar O, Igert A, Saurat D, Taudon N, Dal-Bo G, Nachon F, Dupuis N, Soussi-Yanicostas N. Organophosphorus diisopropylfluorophosphate (DFP) intoxication in zebrafish larvae causes behavioral defects, neuronal hyperexcitation and neuronal death. Sci Rep 2020; 10:19228. [PMID: 33154418 PMCID: PMC7645799 DOI: 10.1038/s41598-020-76056-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 10/19/2020] [Indexed: 11/09/2022] Open
Abstract
With millions of intoxications each year and over 200,000 deaths, organophosphorus (OP) compounds are an important public health issue worldwide. OP poisoning induces cholinergic syndrome, with respiratory distress, hypertension, and neuron damage that may lead to epileptic seizures and permanent cognitive deficits. Existing countermeasures are lifesaving but do not prevent long-lasting neuronal comorbidities, emphasizing the urgent need for animal models to better understand OP neurotoxicity and identify novel antidotes. Here, using diisopropylfluorophosphate (DFP), a prototypic and moderately toxic OP, combined with zebrafish larvae, we first showed that DFP poisoning caused major acetylcholinesterase inhibition, resulting in paralysis and CNS neuron hyperactivation, as indicated by increased neuronal calcium transients and overexpression of the immediate early genes fosab, junBa, npas4b, and atf3. In addition to these epileptiform seizure-like events, DFP-exposed larvae showed increased neuronal apoptosis, which were both partially alleviated by diazepam treatment, suggesting a causal link between neuronal hyperexcitation and cell death. Last, DFP poisoning induced an altered balance of glutamatergic/GABAergic synaptic activity with increased NR2B-NMDA receptor accumulation combined with decreased GAD65/67 and gephyrin protein accumulation. The zebrafish DFP model presented here thus provides important novel insights into the pathophysiology of OP intoxication, making it a promising model to identify novel antidotes.
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Affiliation(s)
| | - Julie Somkhit
- NeuroDiderot, Inserm, Université de Paris, 75019, Paris, France
| | | | | | | | - Olivier Bar
- NeuroDiderot, Inserm, Université de Paris, 75019, Paris, France
| | - Alexandre Igert
- Département de toxicologie et risques chimiques, Institut de Recherche Biomédicale des Armées (IRBA), 91 220, Brétigny-sur-Orge, France
| | - Dominique Saurat
- Institut de Recherche Biomédicale des Armées (IRBA), Unité de Développements Analytiques et Bioanalyse, 91 220, Brétigny-sur-Orge, France
| | - Nicolas Taudon
- Institut de Recherche Biomédicale des Armées (IRBA), Unité de Développements Analytiques et Bioanalyse, 91 220, Brétigny-sur-Orge, France
| | - Gregory Dal-Bo
- Département de toxicologie et risques chimiques, Institut de Recherche Biomédicale des Armées (IRBA), 91 220, Brétigny-sur-Orge, France
| | - Florian Nachon
- Département de toxicologie et risques chimiques, Institut de Recherche Biomédicale des Armées (IRBA), 91 220, Brétigny-sur-Orge, France
| | - Nina Dupuis
- Département de toxicologie et risques chimiques, Institut de Recherche Biomédicale des Armées (IRBA), 91 220, Brétigny-sur-Orge, France
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The neuroprotective effects of stimulation of NMDA receptors against POX-induced neurotoxicity in hippocampal cultured neurons; a morphometric study. Mol Cell Toxicol 2020. [DOI: 10.1007/s13273-020-00091-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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10
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Singh N, Golime R, Acharya J, Palit M. Quantitative Proteomic Changes after Organophosphorous Nerve Agent Exposure in the Rat Hippocampus. ACS Chem Neurosci 2020; 11:2638-2648. [PMID: 32702963 DOI: 10.1021/acschemneuro.0c00311] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The widespread use of organophosphorous (OP) compounds and recent misuse of nerve agents on civilians requires an urgent need to decode their complex biological response to develop effective drugs. Proteomic profiling of biological target tissues helps in identification of molecular toxicity mechanisms. Quantitative proteomics profiling of the rat hippocampus was studied in this study. Liquid chromatography mass spectrometry (LC-MS) analysis of tandem mass tag (TMT)-labeled lysates identified 6356 proteins. A total of 69, 61, and 77 proteins were upregulated, and 66, 35, and 70 proteins were downregulated at 30 min, 1 day, and 7 days after soman exposure. This is the first report on the soman-induced proteomic changes to the best of our knowledge. Bioinformatics analysis revealed soman-induced broad-range proteomic changes in key pathways related to glutamate, acetylcholine, GABA, 5-hydroxytryptamine, and adrenergic receptors, G-protein signaling, chemokine and cytokine-mediated inflammation, cytoskeleton, neurodegeneration (Parkinson's and Alzheimer's), Wnt signaling, synaptic vesicle trafficking, MAP kinases, proteosome degradation, metabolism, and cell death. Selected protein changes were verified by immunoblotting, and neuropathological findings indicated significant brain damage. Results demonstrate that persistent proteomic changes in the brain can cause multiple neurological effects through cholinergic and non-cholinergic pathways, and these mechanistic insights are useful in the development of novel drugs.
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Affiliation(s)
- Naveen Singh
- Biochemistry-Vertox Division, Defence Research and Development Establishment, Jhansi Road, Gwalior, M.P. 474002, India
| | - RamaRao Golime
- Biochemistry-Vertox Division, Defence Research and Development Establishment, Jhansi Road, Gwalior, M.P. 474002, India
| | | | - Meehir Palit
- Biochemistry-Vertox Division, Defence Research and Development Establishment, Jhansi Road, Gwalior, M.P. 474002, India
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11
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The Low Glutamate Diet Effectively Improves Pain and Other Symptoms of Gulf War Illness. Nutrients 2020; 12:nu12092593. [PMID: 32859032 PMCID: PMC7551234 DOI: 10.3390/nu12092593] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/17/2020] [Accepted: 08/20/2020] [Indexed: 01/19/2023] Open
Abstract
Gulf War Illness (GWI) is a multisymptom disorder including widespread chronic pain, fatigue and gastrointestinal problems. The objective of this study was to examine the low glutamate diet as a treatment for GWI. Forty veterans with GWI were recruited from across the US. Outcomes included symptom score, myalgic score, tender point count, dolorimetry and the Chalder Fatigue Scale. Subjects were randomized to the low glutamate diet or a wait-listed control group, with symptom score being compared after one month. Subjects then went onto a double-blind, placebo-controlled crossover challenge with monosodium glutamate (MSG)/placebo to test for return of symptoms. Symptom score was compared between diet intervention and wait-listed controls with an independent t-test and effect size was calculated with Cohen’s d. Change scores were analyzed with Wilcoxon Signed Rank tests. Crossover challenge results were analyzed with General Linear Models and cluster analysis. The diet intervention group reported significantly less symptoms (p = 0.0009) than wait-listed controls, with a very large effect size, d = 1.16. Significant improvements in average dolorimetry (p = 0.0006), symptom score, tender point number, myalgic score and the Chalder Fatigue Scale (all p < 0.0001) were observed after the 1-month diet. Challenge with MSG/placebo resulted in significant variability in individual response. These results suggest that the low glutamate diet can effectively reduce overall symptoms, pain and fatigue in GWI, but differential results upon challenge suggest that other aspects of the diet, or underlying differences within the population, may be driving these changes. Future research is needed to identify potential nutrient effects, biomarkers, and underlying metabolic differences between responders and non-responders.
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Gore A, Neufeld-Cohen A, Egoz I, Baranes S, Gez R, Grauer E, Chapman S, Lazar S. Efficacy of retigabine in ameliorating the brain insult following sarin exposure in the rat. Toxicol Appl Pharmacol 2020; 395:114963. [PMID: 32209366 DOI: 10.1016/j.taap.2020.114963] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 03/17/2020] [Accepted: 03/20/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Sarin is an irreversible organophosphate cholinesterase inhibitor. Following toxic signs, an extensive long-term brain damage is often reported. Thus, we evaluated the efficacy of a novel anticonvulsant drug retigabine, a modulator of neuronal voltage gated K+ channels, as a neuroprotective agent following sarin exposure. METHODS Rats were exposed to 1 LD50 or 1.2 LD50 sarin and treated at onset of convulsions with retigabine (5 mg/kg, i.p.) alone or in combination with 5 mg/kg atropine and 7.5 mg/kg TMB-4 (TA) respectively. Brain biochemical and immunohistopathological analyses were processed 24 h and 1 week following 1 LD50 sarin exposure and at 4 weeks following exposure to 1.2 LD50 sarin. EEG activity in freely moving rats was also monitored by telemetry during the first week following exposure to 1.2 LD50 and behavior in the Open Field was evaluated 3 weeks post exposure. RESULTS Treatment with retigabine following 1 LD50 sarin exposure or in combination with TA following 1.2 LD50 exposure significantly reduced mortality rate compared to the non-treated groups. In both experiments, the retigabine treatment significantly reduced gliosis, astrocytosis and brain damage as measured by translocator protein (TSPO). Following sarin exposure the combined treatment (retigabine+ TA) significantly minimized epileptiform seizure activity. Finally, in the Open Field behavioral test the non-treated sarin group showed an increased mobility which was reversed by the combined treatment. CONCLUSIONS The M current modulator retigabine has been shown to be an effective adjunct therapy following OP induced convulsion, minimizing epileptiform seizure activity and attenuating the ensuing brain damage.
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Affiliation(s)
- Ariel Gore
- Department. of Pharmacology, Israel Institute for Biological Research, Ness Ziona 74100, Israel.
| | - Adi Neufeld-Cohen
- Department. of Pharmacology, Israel Institute for Biological Research, Ness Ziona 74100, Israel
| | - Inbal Egoz
- Department. of Pharmacology, Israel Institute for Biological Research, Ness Ziona 74100, Israel
| | - Shlomi Baranes
- Department. of Pharmacology, Israel Institute for Biological Research, Ness Ziona 74100, Israel
| | - Rellie Gez
- Department. of Pharmacology, Israel Institute for Biological Research, Ness Ziona 74100, Israel
| | - Ettie Grauer
- Department. of Pharmacology, Israel Institute for Biological Research, Ness Ziona 74100, Israel
| | - Shira Chapman
- Department. of Pharmacology, Israel Institute for Biological Research, Ness Ziona 74100, Israel
| | - Shlomi Lazar
- Department. of Pharmacology, Israel Institute for Biological Research, Ness Ziona 74100, Israel.
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Gerlits O, Kong X, Cheng X, Wymore T, Blumenthal DK, Taylor P, Radić Z, Kovalevsky A. Productive reorientation of a bound oxime reactivator revealed in room temperature X-ray structures of native and VX-inhibited human acetylcholinesterase. J Biol Chem 2019; 294:10607-10618. [PMID: 31138650 DOI: 10.1074/jbc.ra119.008725] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 05/21/2019] [Indexed: 11/06/2022] Open
Abstract
Exposure to organophosphorus compounds (OPs) may be fatal if untreated, and a clear and present danger posed by nerve agent OPs has become palpable in recent years. OPs inactivate acetylcholinesterase (AChE) by covalently modifying its catalytic serine. Inhibited AChE cannot hydrolyze the neurotransmitter acetylcholine leading to its build-up at the cholinergic synapses and creating an acute cholinergic crisis. Current antidotes, including oxime reactivators that attack the OP-AChE conjugate to free the active enzyme, are inefficient. Better reactivators are sought, but their design is hampered by a conformationally rigid portrait of AChE extracted exclusively from 100K X-ray crystallography and scarcity of structural knowledge on human AChE (hAChE). Here, we present room temperature X-ray structures of native and VX-phosphonylated hAChE with an imidazole-based oxime reactivator, RS-170B. We discovered that inhibition with VX triggers substantial conformational changes in bound RS-170B from a "nonproductive" pose (the reactive aldoxime group points away from the VX-bound serine) in the reactivator-only complex to a "semi-productive" orientation in the VX-modified complex. This observation, supported by concurrent molecular simulations, suggested that the narrow active-site gorge of hAChE may be significantly more dynamic than previously thought, allowing RS-170B to reorient inside the gorge. Furthermore, we found that small molecules can bind in the choline-binding site hindering approach to the phosphorous of VX-bound serine. Our results provide structural and mechanistic perspectives on the reactivation of OP-inhibited hAChE and demonstrate that structural studies at physiologically relevant temperatures can deliver previously overlooked insights applicable for designing next-generation antidotes.
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Affiliation(s)
- Oksana Gerlits
- From the Bredesen Center, University of Tennessee, Knoxville, Tennessee 37996
| | - Xiaotian Kong
- the Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210
| | - Xiaolin Cheng
- the Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210
| | - Troy Wymore
- the Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109
| | - Donald K Blumenthal
- the Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah 84112
| | - Palmer Taylor
- the Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California 92093-0751, and
| | - Zoran Radić
- the Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California 92093-0751, and
| | - Andrey Kovalevsky
- the Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
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Krejčová G, Kassa J. Anticholinergic Drugs – Functional Antidotes for the Treatment of Tabun Intoxication. ACTA MEDICA (HRADEC KRÁLOVÉ) 2019. [DOI: 10.14712/18059694.2018.59] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
1. To study the influence of antidotes on tabun-induced neurotoxicity, the rats were injected intramuscularly with organophosphate tabun (LD50). The efficacy of choice antidotal treatment consisting of acetylcholinesterase reactivator obidoxime and one of four anticholinergic drugs (atropine, benactyzine, biperiden, scopolamine) was compared. 2. Testing of tabun-induced neurotoxicity progress was carried out using the method Functional observational battery. The experimental animals as well as controls were observed at 24 hours and 7 days following tabun or saline administration. 3. The results were compared to the condition of animals without anticholinergic drug (oxime alone) and control rats that received physiological solution instead of tabun and treatment. Antidotal treatment involving centrally acting anticholinergic drugs (benactyzine, biperiden, scopolamine) showed significantly higher neuroprotective efficacy compared to antidotal treatment containing atropine.
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Bloch-Shilderman E, Yacov G, Cohen L, Egoz I, Gutman H, Gez R, Rabinovitz I, Nili U. Repetitive antidotal treatment is crucial in eliminating eye pathology, respiratory toxicity and death following whole-body VX vapor exposure in freely moving rats. Arch Toxicol 2019; 93:1365-1384. [DOI: 10.1007/s00204-019-02401-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 01/31/2019] [Indexed: 11/29/2022]
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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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Anju T, Smijin S, Jobin M, Paulose C. Altered muscarinic receptor expression in the cerebral cortex of epileptic rats: restorative role of Withania somnifera. Biochem Cell Biol 2018; 96:433-440. [DOI: 10.1139/bcb-2017-0198] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Temporal lobe epilepsy involves a sequence of events that can lead to neurotransmitter signalling alterations. There are many herbal extracts considered to be alternative therapeutic methods to manage epilepsy. In this study, we investigated the effect of Withania somnifera (WS) root extract and withanolide A (WA) in the management of temporal lobe epilepsy. Confocal imaging of TOPRO-3-stained cortical sections showed severe damage in the epileptic brain. We also observed a reduced antioxidant potential and increased peroxide levels in the epileptic test group of rats. Oxidative stress resulted in the down-regulation of CREB, NF-κB, and TNF-α, and with up-regulation of the apoptotic factors caspases 8 and 3 and Bax in the epileptic group. Epileptic condition also resulted in increased muscarinic receptor binding and mRNA expression in the cerebral cortex. Withania somnifera and withanolide A significantly reversed the altered muscarinic receptor expression and reversed the oxidative stress and resultant derailment in cell signalling. Thus our studies suggest that Withania somnifera and withanolide A play important roles in central muscarinic receptor functional balance and activation of the antioxidant system in the cerebral cortex in temporal lobe epilepsy. These findings can be of immense therapeutic significance for managing epilepsy.
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Affiliation(s)
- T.R. Anju
- Centre for Advanced Research, Athreya Research Foundation, Building No. VI/264, Puthenparambil Ushus, NAD P O, Aluva – 683563, Kerala, India
| | - S. Smijin
- Molecular Neurobiology and Cell Biology Unit, Department of Biotechnology, Cochin University of Science and Technology, Cochin- 682 022, Kerala, India
| | - M. Jobin
- Department of Zoology, CMS College, Kottayam, Kerala, India
| | - C.S. Paulose
- Molecular Neurobiology and Cell Biology Unit, Department of Biotechnology, Cochin University of Science and Technology, Cochin- 682 022, Kerala, India
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Full Protection Against Soman-Induced Seizures and Brain Damage by LY293558 and Caramiphen Combination Treatment in Adult Rats. Neurotox Res 2018; 34:511-524. [PMID: 29713995 DOI: 10.1007/s12640-018-9907-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 04/14/2018] [Accepted: 04/17/2018] [Indexed: 10/17/2022]
Abstract
Acute exposure to nerve agents induces status epilepticus (SE), which causes brain damage or death. LY293558, an antagonist of AMPA and GluK1 kainate receptors is a very effective anticonvulsant and neuroprotectant against soman; however, some neuronal damage is still present after treatment of soman-exposed rats with LY293558. Here, we have tested whether combining LY293558 with an NMDA receptor antagonist can eliminate the residual damage. For this purpose, we chose caramiphen (CRM), an antimuscarinic compound with NMDA receptor antagonistic properties. Adult male rats were exposed to 1.2 × LD50 soman, and at 20 min after soman exposure, were injected with atropine + HI-6, or atropine + HI-6 + LY293558 (15 mg/kg), or atropine + HI-6 + LY293558 + CRM (50 mg/kg). We found that (1) the LY293558 + CRM treatment terminated SE significantly faster than LY293558 alone; (2) after cessation of the initial SE, seizures did not return in the LY293558 + CRM-treated group, during 72 h of monitoring; (3) power spectrum analysis of continuous EEG recordings for 7 days post-exposure showed increased delta and decreased gamma power that lasted beyond 24 h post-exposure only in the rats who did not receive anticonvulsant treatment; (4) spontaneous recurrent seizures appeared on day 7 only in the group that did not receive anticonvulsant treatment; (5) significant neuroprotection was achieved by LY293558 administration, while the rats who received LY293558 + CRM displayed no neurodegeneration; (6) body weight loss and recovery in the LY293558 + CRM-treated rats did not differ from those in control rats who were not exposed to soman. The data show that treatment with LY293558 + CRM provides full antiseizure and neuroprotective efficacy against soman.
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Malfatti MA, Enright HA, Be NA, Kuhn EA, Hok S, McNerney MW, Lao V, Nguyen TH, Lightstone FC, Carpenter TS, Bennion BJ, Valdez CA. The biodistribution and pharmacokinetics of the oxime acetylcholinesterase reactivator RS194B in guinea pigs. Chem Biol Interact 2017; 277:159-167. [PMID: 28941624 DOI: 10.1016/j.cbi.2017.09.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 09/13/2017] [Accepted: 09/19/2017] [Indexed: 01/09/2023]
Abstract
Organophosphorus-based (OP) nerve agents represent some of the most toxic substances known to mankind. The current standard of care for exposure has changed very little in the past decades, and relies on a combination of atropine to block receptor activity and oxime-type acetylcholinesterase (AChE) reactivators to reverse the OP binding to AChE. Although these oximes can block the effects of nerve agents, their overall efficacy is reduced by their limited capacity to cross the blood-brain barrier (BBB). RS194B, a new oxime developed by Radic et al. (J. Biol. Chem., 2012) has shown promise for enhanced ability to cross the BBB. To fully assess the potential of this compound as an effective treatment for nerve agent poisoning, a comprehensive evaluation of its pharmacokinetic (PK) and biodistribution profiles was performed using both intravenous and intramuscular exposure routes. The ultra-sensitive technique of accelerator mass spectrometry was used to quantify the compound's PK profile, tissue distribution, and brain/plasma ratio at four dose concentrations in guinea pigs. PK analysis revealed a rapid distribution of the oxime with a plasma t1/2 of ∼1 h. Kidney and liver had the highest concentrations per gram of tissue followed by lung, spleen, heart and brain for all dose concentrations tested. The Cmax in the brain ranged between 0.03 and 0.18% of the administered dose, and the brain-to-plasma ratio ranged from 0.04 at the 10 mg/kg dose to 0.18 at the 200 mg/kg dose demonstrating dose dependent differences in brain and plasma concentrations. In vitro studies show that both passive diffusion and active transport contribute little to RS194B traversal of the BBB. These results indicate that biodistribution is widespread, but very low quantities accumulate in the guinea pig brain, indicating this compound may not be suitable as a centrally active reactivator.
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Affiliation(s)
- Michael A Malfatti
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
| | - Heather A Enright
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Nicholas A Be
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Edward A Kuhn
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Saphon Hok
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Forensic Science Center, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - M Windy McNerney
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; War Related Illness and Injury Study Center, Veterans Affairs, Palo Alto, CA 94304, USA
| | - Victoria Lao
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Tuan H Nguyen
- Global Security Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Felice C Lightstone
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Timothy S Carpenter
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Brian J Bennion
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Carlos A Valdez
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA; Forensic Science Center, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
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Greget R, Dadak S, Barbier L, Lauga F, Linossier-Pierre S, Pernot F, Legendre A, Ambert N, Bouteiller JM, Dorandeu F, Bischoff S, Baudry M, Fagni L, Moussaoui S. Modeling and simulation of organophosphate-induced neurotoxicity: Prediction and validation by experimental studies. Neurotoxicology 2016; 54:140-152. [PMID: 27108687 DOI: 10.1016/j.neuro.2016.04.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/07/2016] [Accepted: 04/19/2016] [Indexed: 02/07/2023]
Abstract
Exposure to organophosphorus (OP) compounds, either pesticides or chemical warfare agents, represents a major health problem. As potent irreversible inhibitors of cholinesterase, OP may induce seizures, as in status epilepticus, and occasionally brain lesions. Although these compounds are extremely toxic agents, the search for novel antidotes remains extremely limited. In silico modeling constitutes a useful tool to identify pharmacological targets and to develop efficient therapeutic strategies. In the present work, we developed a new in silico simulator in order to predict the neurotoxicity of irreversible inhibitors of acetyl- and/or butyrylcholinesterase (ChE) as well as the potential neuroprotection provided by antagonists of cholinergic muscarinic and glutamate N-methyl-d-aspartate (NMDA) receptors. The simulator reproduced firing of CA1 hippocampal neurons triggered by exposure to paraoxon (POX), as found in patch-clamp recordings in in vitro mouse hippocampal slices. In the case of POX intoxication, it predicted a preventing action of the muscarinic receptor antagonist atropine sulfate, as well as a synergistic action with the non-competitive NMDA receptor antagonist memantine. These in silico predictions relative to beneficial effects of atropine sulfate combined with memantine were recapitulated experimentally in an in vivo model of POX in adult male Swiss mice using electroencephalic (EEG) recordings. Thus, our simulator is a new powerful tool to identify protective therapeutic strategies against OP central effects, by screening various combinations of muscarinic and NMDA receptor antagonists.
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Affiliation(s)
| | - Selma Dadak
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, INSERM, U1191, Université de Montpellier, Montpellier F-34094, France
| | - Laure Barbier
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France
| | - Fabien Lauga
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France
| | - Sandra Linossier-Pierre
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France
| | | | | | | | | | - Frédéric Dorandeu
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France; Ecole du Val-de-Grâce, Paris, France
| | | | | | - Laurent Fagni
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, INSERM, U1191, Université de Montpellier, Montpellier F-34094, France
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Ezzi L, Belhadj Salah I, Haouas Z, Sakly A, Grissa I, Chakroun S, Kerkeni E, Hassine M, Mehdi M, Ben Cheikh H. Histopathological and genotoxic effects of chlorpyrifos in rats. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:4859-4867. [PMID: 26545888 DOI: 10.1007/s11356-015-5722-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 10/30/2015] [Indexed: 06/05/2023]
Abstract
This study aims to investigate the effects of chlorpyrifos's sub-acute exposure on male rats. Two groups with six animals each were orally treated, respectively, with 3.1 mg/kg b w and 6.2 mg/kg b w of chlorpyrifos during 4 weeks. The genotoxic effect of chlopyrifos was investigated using the comet assay and the micronucleus test. Some hematological and liver's histopathological changes were also evaluated. Results revealed that chlorpyrifos induced histopathological alterations in liver parenchyma. The lymphoid infiltration observed in liver sections and the increase in white blood cells parameter are signs of inflammation. A significant increase in the platelet' count and in polychromatic erythrocytes/normochromatic erythrocytes (PCE/NCE) ratio was observed in chlorpyrifos-treated groups which could be due to the stimulatory effect of chlorpyrifos on cell formation in the bone marrow at lower doses. In addition, the increase of bone marrow micronucleus percentage and the comet tail length revealed a genotoxic potential of chlorpyrifos in vivo.
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Affiliation(s)
- Lobna Ezzi
- Laboratory of Histology and Cytogenetic (Research Unit of Genetic, Genotoxicity and Childhood Illness UR12ES10), Faculty of Medicine, University of Monastir, Street Avicenne, Monastir, 5019, Tunisia.
| | - Imen Belhadj Salah
- Laboratory of Histology and Cytogenetic (Research Unit of Genetic, Genotoxicity and Childhood Illness UR12ES10), Faculty of Medicine, University of Monastir, Street Avicenne, Monastir, 5019, Tunisia
| | - Zohra Haouas
- Laboratory of Histology and Cytogenetic (Research Unit of Genetic, Genotoxicity and Childhood Illness UR12ES10), Faculty of Medicine, University of Monastir, Street Avicenne, Monastir, 5019, Tunisia
| | - Amina Sakly
- Laboratory of Histology and Cytogenetic (Research Unit of Genetic, Genotoxicity and Childhood Illness UR12ES10), Faculty of Medicine, University of Monastir, Street Avicenne, Monastir, 5019, Tunisia
| | - Intissar Grissa
- Laboratory of Histology and Cytogenetic (Research Unit of Genetic, Genotoxicity and Childhood Illness UR12ES10), Faculty of Medicine, University of Monastir, Street Avicenne, Monastir, 5019, Tunisia
| | - Sana Chakroun
- Laboratory of Histology and Cytogenetic (Research Unit of Genetic, Genotoxicity and Childhood Illness UR12ES10), Faculty of Medicine, University of Monastir, Street Avicenne, Monastir, 5019, Tunisia
| | - Emna Kerkeni
- Laboratory of Histology and Cytogenetic (Research Unit of Genetic, Genotoxicity and Childhood Illness UR12ES10), Faculty of Medicine, University of Monastir, Street Avicenne, Monastir, 5019, Tunisia
| | - Mohsen Hassine
- Laboratory of Hematology, Fattouma Bourguiba University Hospital Monastir, Monastir, Tunisia
| | - Meriem Mehdi
- Laboratory of Histology and Cytogenetic (Research Unit of Genetic, Genotoxicity and Childhood Illness UR12ES10), Faculty of Medicine, University of Monastir, Street Avicenne, Monastir, 5019, Tunisia
| | - Hassen Ben Cheikh
- Laboratory of Histology and Cytogenetic (Research Unit of Genetic, Genotoxicity and Childhood Illness UR12ES10), Faculty of Medicine, University of Monastir, Street Avicenne, Monastir, 5019, Tunisia
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Boussabbeh M, Ben Salem I, Hamdi M, Ben Fradj S, Abid-Essefi S, Bacha H. Diazinon, an organophosphate pesticide, induces oxidative stress and genotoxicity in cells deriving from large intestine. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:2882-2889. [PMID: 26490884 DOI: 10.1007/s11356-015-5519-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 09/29/2015] [Indexed: 06/05/2023]
Abstract
Diazinon (DZ) (O,O-diethyl-O-[2-isopropyl-6-methyl-4-pyrimidinyl]phosphorothioate) is an organophosphate pesticide which is extensively used to control household insects and fruit and vegetable crops. The exposure to this pesticide has been linked to the development of the serious problem in several experimental animals. The contamination of food by DZ may increase its danger to humans. The aim of this study was to investigate the toxic effect of DZ on intestine using an in vitro model (HCT116). Therefore, we evaluated the cell viability, elucidated the generation of free radicals, measured the mitochondrial membrane potential, and valued DNA fragmentation. Our results showed that DZ is cytotoxic to HCT116. It causes oxidative damage through the generation of free radicals and induces lipid peroxidation and DNA fragmentation. We also demonstrated that such effects can be responsible for DZ-induced apoptosis.
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Piermartiri T, Pan H, Figueiredo TH, Marini AM. α-Linolenic Acid, A Nutraceutical with Pleiotropic Properties That Targets Endogenous Neuroprotective Pathways to Protect against Organophosphate Nerve Agent-Induced Neuropathology. Molecules 2015; 20:20355-80. [PMID: 26569216 PMCID: PMC6332275 DOI: 10.3390/molecules201119698] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 10/29/2015] [Accepted: 11/03/2015] [Indexed: 01/23/2023] Open
Abstract
α-Linolenic acid (ALA) is a nutraceutical found in vegetable products such as flax and walnuts. The pleiotropic properties of ALA target endogenous neuroprotective and neurorestorative pathways in brain and involve the transcription factor nuclear factor kappa B (NF-κB), brain-derived neurotrophic factor (BDNF), a major neuroprotective protein in brain, and downstream signaling pathways likely mediated via activation of TrkB, the cognate receptor of BDNF. In this review, we discuss possible mechanisms of ALA efficacy against the highly toxic OP nerve agent soman. Organophosphate (OP) nerve agents are highly toxic chemical warfare agents and a threat to military and civilian populations. Once considered only for battlefield use, these agents are now used by terrorists to inflict mass casualties. OP nerve agents inhibit the critical enzyme acetylcholinesterase (AChE) that rapidly leads to a cholinergic crisis involving multiple organs. Status epilepticus results from the excessive accumulation of synaptic acetylcholine which in turn leads to the overactivation of muscarinic receptors; prolonged seizures cause the neuropathology and long-term consequences in survivors. Current countermeasures mitigate symptoms and signs as well as reduce brain damage, but must be given within minutes after exposure to OP nerve agents supporting interest in newer and more effective therapies. The pleiotropic properties of ALA result in a coordinated molecular and cellular program to restore neuronal networks and improve cognitive function in soman-exposed animals. Collectively, ALA should be brought to the clinic to treat the long-term consequences of nerve agents in survivors. ALA may be an effective therapy for other acute and chronic neurodegenerative disorders.
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Affiliation(s)
- Tetsade Piermartiri
- Molecular and Cellular Biology Graduate School Program, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
| | - Hongna Pan
- Department of Neurology and Program in Neuroscience, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
| | - Taiza H Figueiredo
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
| | - Ann M Marini
- Department of Neurology and Program in Neuroscience, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
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Imran I, Hillert MH, Klein J. Early metabolic responses to lithium/pilocarpine-induced status epilepticus in rat brain. J Neurochem 2015; 135:1007-18. [DOI: 10.1111/jnc.13360] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/25/2015] [Accepted: 08/29/2015] [Indexed: 01/04/2023]
Affiliation(s)
- Imran Imran
- Department of Pharmacology; School of Pharmacy; Biocenter N260; Goethe University Frankfurt; Frankfurt am Main Germany
- Faculty of Pharmacy; Bahauddin Zakariya University; Multan Pakistan
| | - Markus H. Hillert
- Department of Pharmacology; School of Pharmacy; Biocenter N260; Goethe University Frankfurt; Frankfurt am Main Germany
| | - Jochen Klein
- Department of Pharmacology; School of Pharmacy; Biocenter N260; Goethe University Frankfurt; Frankfurt am Main Germany
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Pan H, Piermartiri TCB, Chen J, McDonough J, Oppel C, Driwech W, Winter K, McFarland E, Black K, Figueiredo T, Grunberg N, Marini AM. Repeated systemic administration of the nutraceutical alpha-linolenic acid exerts neuroprotective efficacy, an antidepressant effect and improves cognitive performance when given after soman exposure. Neurotoxicology 2015; 51:38-50. [PMID: 26386148 DOI: 10.1016/j.neuro.2015.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 09/04/2015] [Accepted: 09/14/2015] [Indexed: 10/23/2022]
Abstract
Exposure to nerve agents results in severe seizures or status epilepticus caused by the inhibition of acetylcholinesterase, a critical enzyme that breaks down acetylcholine to terminate neurotransmission. Prolonged seizures cause brain damage and can lead to long-term consequences. Current countermeasures are only modestly effective against the brain damage supporting interest in the evaluation of new and efficacious therapies. The nutraceutical alpha-linolenic acid (LIN) is an essential omega-3 polyunsaturated fatty acid that has a wide safety margin. Previous work showed that a single intravenous injection of alpha-linolenic acid (500 nmol/kg) administered before or after soman significantly protected against soman-induced brain damage when analyzed 24h after exposure. Here, we show that administration of three intravenous injections of alpha-linolenic acid over a 7 day period after soman significantly improved motor performance on the rotarod, enhanced memory retention, exerted an anti-depressant-like activity and increased animal survival. This dosing schedule significantly reduced soman-induced neuronal degeneration in four major vulnerable brain regions up to 21 days. Taken together, alpha-linolenic acid reduces the profound behavioral deficits induced by soman possibly by decreasing neuronal cell death, and increases animal survival.
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Affiliation(s)
- Hongna Pan
- Department of Neurology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Tetsade C B Piermartiri
- Molecular and Cellular Biology Graduate School Program, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Jun Chen
- Department of Neurology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - John McDonough
- Department of Medical and Clinical Psychology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Craig Oppel
- Department of Medical and Clinical Psychology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Wafae Driwech
- Pharmacology Branch, Research Division, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, United States
| | - Kristin Winter
- Pharmacology Branch, Research Division, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, United States
| | - Emylee McFarland
- Pharmacology Branch, Research Division, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, United States
| | - Katelyn Black
- Pharmacology Branch, Research Division, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, United States
| | - Taiza Figueiredo
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Neil Grunberg
- Department of Medical and Clinical Psychology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Ann M Marini
- Department of Neurology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.
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Alpha-Linolenic Acid-Induced Increase in Neurogenesis is a Key Factor in the Improvement in the Passive Avoidance Task After Soman Exposure. Neuromolecular Med 2015; 17:251-69. [DOI: 10.1007/s12017-015-8353-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 04/11/2015] [Indexed: 02/01/2023]
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Meade ML, Hoffmann A, Makley MK, Snider TH, Schlager JJ, Gearhart JM. Quantitative proteomic analysis of the brainstem following lethal sarin exposure. Brain Res 2015; 1611:101-13. [PMID: 25842371 DOI: 10.1016/j.brainres.2015.03.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 03/11/2015] [Accepted: 03/24/2015] [Indexed: 11/15/2022]
Abstract
The brainstem represents a major tissue area affected by sarin organophosphate poisoning due to its function in respiratory and cardiovascular control. While the acute toxic effects of sarin on brainstem-related responses are relatively unknown, other brain areas e.g., cortex or cerebellum, have been studied more extensively. The study objective was to analyze the guinea pig brainstem toxicology response following sarin (2×LD50) exposure by proteome pathway analysis to gain insight into the complex regulatory mechanisms that lead to impairment of respiratory and cardiovascular control. Guinea pig exposure to sarin resulted in the typical acute behavior/physiology outcomes with death between 15 and 25min. In addition, brain and blood acetylcholinesterase activity was significantly reduced in the presence of sarin to 95%, and 89%, respectively, of control values. Isobaric-tagged (iTRAQ) liquid chromatography tandem mass spectrometry (LC-MS/MS) identified 198 total proteins of which 23% were upregulated, and 18% were downregulated following sarin exposure. Direct gene ontology (GO) analysis revealed a sarin-specific broad-spectrum proteomic profile including glutamate-mediated excitotoxicity, calcium overload, energy depletion responses, and compensatory carbohydrate metabolism, increases in ROS defense, DNA damage and chromatin remodeling, HSP response, targeted protein degradation (ubiquitination) and cell death response. With regards to the sarin-dependent effect on respiration, our study supports the potential interference of sarin with CO2/H(+) sensitive chemoreceptor neurons of the brainstem retrotrapezoid nucleus (RTN) that send excitatory glutamergic projections to the respiratory centers. In conclusion, this study gives insight into the brainstem broad-spectrum proteome following acute sarin exposure and the gained information will assist in the development of novel countermeasures.
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Affiliation(s)
- Mitchell L Meade
- Henry M. Jackson Foundation for the Advancement of Military Medicine, 2729 R Street, Wright Patterson AFB, Dayton, OH 45433, USA; Molecular Bioeffects Branch, Bioeffects Division, 711 Human Performance Wing, Human Effectiveness Directorate, Air Force Research Laboratory (711 HPW/RHDJ), WPAFB, Dayton, OH 45433, USA.
| | - Andrea Hoffmann
- Henry M. Jackson Foundation for the Advancement of Military Medicine, 2729 R Street, Wright Patterson AFB, Dayton, OH 45433, USA.
| | - Meghan K Makley
- Henry M. Jackson Foundation for the Advancement of Military Medicine, 2729 R Street, Wright Patterson AFB, Dayton, OH 45433, USA.
| | - Thomas H Snider
- Battelle Biomedical Research Center, 1425 Plain City Georgesville Road, West Jefferson, OH 43162, USA.
| | - John J Schlager
- Molecular Bioeffects Branch, Bioeffects Division, 711 Human Performance Wing, Human Effectiveness Directorate, Air Force Research Laboratory (711 HPW/RHDJ), WPAFB, Dayton, OH 45433, USA.
| | - Jeffery M Gearhart
- Henry M. Jackson Foundation for the Advancement of Military Medicine, 2729 R Street, Wright Patterson AFB, Dayton, OH 45433, USA; BoonShoft School of Medicine, Wright State University, 3640 Col. Glenn Highway, Dayton, OH 45433, USA.
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MRS of brain metabolite levels demonstrates the ability of scavenging of excess brain glutamate to protect against nerve agent induced seizures. Int J Mol Sci 2015; 16:3226-36. [PMID: 25648322 PMCID: PMC4346891 DOI: 10.3390/ijms16023226] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/29/2015] [Indexed: 11/16/2022] Open
Abstract
This study describes the use of in vivo magnetic resonance spectrocopy (MRS) to monitor brain glutamate and lactate levels in a paraoxon (PO) intoxication model. Our results show that the administration of recombinant glutamate-oxaloacetate transaminase (rGOT) in combination with oxaloacetate (OxAc) significantly reduces the brain-accumulated levels of glutamate. Previously we have shown that the treatment causes a rapid decrease of blood glutamate levels and creates a gradient between the brain and blood glutamate levels which leads to the efflux of excess brain glutamate into the blood stream thereby reducing its potential to cause neurological damage. The fact that this treatment significantly decreased the brain glutamate and lactate levels following PO intoxication suggests that it could become a new effective neuroprotective agent.
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Kaur S, Singh S, Chahal KS, Prakash A. Potential pharmacological strategies for the improved treatment of organophosphate-induced neurotoxicity. Can J Physiol Pharmacol 2014; 92:893-911. [DOI: 10.1139/cjpp-2014-0113] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Organophosphates (OP) are highly toxic compounds that cause cholinergic neuronal excitotoxicity and dysfunction by irreversible inhibition of acetylcholinesterase, resulting in delayed brain damage. This delayed secondary neuronal destruction, which arises primarily in the cholinergic areas of the brain that contain dense accumulations of cholinergic neurons and the majority of cholinergic projection, could be largely responsible for persistent profound neuropsychiatric and neurological impairments such as memory, cognitive, mental, emotional, motor, and sensory deficits in the victims of OP poisoning. The therapeutic strategies for reducing neuronal brain damage must adopt a multifunctional approach to the various steps of brain deterioration: (i) standard treatment with atropine and related anticholinergic compounds; (ii) anti-excitotoxic therapies to prevent cerebral edema, blockage of calcium influx, inhibition of apoptosis, and allow for the control of seizure; (iii) neuroprotection by aid of antioxidants and N-methyl-d-aspartate (NMDA) antagonists (multifunctional drug therapy), to inhibit/limit the secondary neuronal damage; and (iv) therapies targeting chronic neuropsychiatric and neurological symptoms. These neuroprotective strategies may prevent secondary neuronal damage in both early and late stages of OP poisoning, and thus may be a beneficial approach to treating the neuropsychological and neuronal impairments resulting from OP toxicity.
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Affiliation(s)
- Shamsherjit Kaur
- Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India
- Punjab Technical University, Kapurthala 144601, Punjab, India
| | - Satinderpal Singh
- Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India
| | - Karan Singh Chahal
- Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India
| | - Atish Prakash
- Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India
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Caramiphen edisylate: an optimal antidote against organophosphate poisoning. Toxicology 2014; 325:115-24. [PMID: 25201353 DOI: 10.1016/j.tox.2014.09.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 08/21/2014] [Accepted: 09/04/2014] [Indexed: 11/30/2022]
Abstract
Potent cholinesterase inhibitors such as sarin, induce an array of harmful effects including hypersecretion, convulsions and ultimately death. Surviving subjects demonstrate damage in specific brain regions that lead to cognitive and neurological dysfunctions. An early accumulation of acetylcholine in the synaptic clefts was suggested as the trigger of a sequence of neurochemical events such as an excessive outpour of glutamate and activation of its receptors. Indeed, alterations in NMDA and AMPA central receptors' densities were detected in brains of poisoned animals. Attempts to improve the current cholinergic-based treatment by adding potent anticonvulsants or antiglutamatergic drugs produced unsatisfactory results. In light of recent events in Syria and the probability of various scenarios of military or terrorist attacks involving organophosphate (OP) nerve agent, research should focus on finding markedly improved countermeasures. Caramiphen, an antimuscarinic drug with antiglutamatergic and GABAergic facilitating properties, was evaluated in a wide range of animals and experimental protocols against OP poisoning. Its remarkable efficacy against OP exposure was established both in prophylactic and post-exposure therapies in both small and large animals. The present review will highlight the outstanding neuroprotective effect of caramiphen as the optimal candidate for the treatment of OP-exposed subjects.
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Hillert MH, Imran I, Zimmermann M, Lau H, Weinfurter S, Klein J. Dynamics of hippocampal acetylcholine release during lithium-pilocarpine-induced status epilepticus in rats. J Neurochem 2014; 131:42-52. [PMID: 24909269 DOI: 10.1111/jnc.12787] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 05/23/2014] [Accepted: 05/27/2014] [Indexed: 01/30/2023]
Abstract
The lithium-pilocarpine model is a rat model of epilepsy that mimics status epilepticus in humans. Here, we report changes of acetylcholine (ACh) release in the hippocampus before, during and after status epilepticus as monitored by microdialysis in unanesthetized rats. Administration of pilocarpine (30 mg/kg s.c.) to rats pretreated with lithium chloride (127 mg/kg i.p.) caused a massive, six-fold increase of hippocampal ACh release, paralleling the development of tonic seizures. When seizures were stopped by administration of diazepam (10 mg/kg i.p.) or ketamine (75 mg/kg i.p.), ACh levels returned to normal. Extracellular concentrations of glutamate remained unchanged during this procedure. Administration of atropine (1 mg/kg i.p.) 2 h after pilocarpine caused a further increase of ACh but did not affect seizures, whereas injection of mecamylamine (5 mg/kg i.p.) reduced ACh levels and seizures in a delayed fashion. Local infusion of tetrodotoxin, 1 μM locally) or hemicholinium (10 μM locally) strongly reduced ACh release and had delayed effects on seizures. Administration of glucose or inositol (250 mg/kg each i.p.) had no visible consequences. In parallel experiments, lithium-pilocarpine-induced status epilepticus also enhanced striatal ACh release, and hippocampal ACh levels equally increased when status epilepticus was induced by kainate (30 mg/kg i.p.). Taken together, our results demonstrate that seizure development in status epilepticus models is accompanied by massive increases of extracellular ACh, but not glutamate, levels. Treatments that reduce seizure activity also reliably reduce extracellular ACh levels.
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Affiliation(s)
- Markus H Hillert
- Department of Pharmacology, School of Pharmacy, Biocenter N260, Goethe University Frankfurt, Frankfurt am Main, Germany
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Efficacy of antidotes (midazolam, atropine and HI-6) on nerve agent induced molecular and neuropathological changes. BMC Neurosci 2014; 15:47. [PMID: 24708580 PMCID: PMC3984638 DOI: 10.1186/1471-2202-15-47] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 03/24/2014] [Indexed: 11/10/2022] Open
Abstract
Background Recent alleged attacks with nerve agent sarin on civilians in Syria indicate their potential threat to both civilian and military population. Acute nerve agent exposure can cause rapid death or leads to multiple and long term neurological effects. The biochemical changes that occur following nerve agent exposure needs to be elucidated to understand the mechanisms behind their long term neurological effects and to design better therapeutic drugs to block their multiple neurotoxic effects. In the present study, we intend to study the efficacy of antidotes comprising of HI-6 (1-[[[4-(aminocarbonyl)-pyridinio]-methoxy]-methyl]-2-[(hydroxyimino) methyl] pyridinium dichloride), atropine and midazolam on soman induced neurodegeneration and the expression of c-Fos, Calpain, and Bax levels in discrete rat brain areas. Results Therapeutic regime consisting of HI-6 (50 mg/kg, i.m), atropine (10 mg/kg, i.m) and midazolam (5 mg/kg, i.m) protected animals against soman (2 × LD50, s.c) lethality completely at 2 h and 80% at 24 h. HI-6 treatment reactivated soman inhibited plasma and RBC cholinesterase up to 40%. Fluoro-Jade B (FJ-B) staining of neurodegenerative neurons showed that soman induced significant necrotic neuronal cell death, which was reduced by this antidotal treatment. Soman increased the expression of neuronal proteins including c-Fos, Bax and Calpain levels in the hippocampus, cerebral cortex and cerebellum regions of the brain. This therapeutic regime also reduced the soman induced Bax, Calpain expression levels to near control levels in the different brain regions studied, except a mild induction of c-Fos expression in the hippocampus. Conclusion Rats that received antidotal treatment after soman exposure were protected from mortality and showed reduction in the soman induced expression of c-Fos, Bax and Calpain and necrosis. Results highlight the need for timely administration of better antidotes than standard therapy in order to prevent the molecular and biochemical changes and subsequent long term neurological effects induced by nerve agents.
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Blood glutamate scavenging as a novel neuroprotective treatment for paraoxon intoxication. J Cereb Blood Flow Metab 2014; 34:221-7. [PMID: 24149933 PMCID: PMC3915200 DOI: 10.1038/jcbfm.2013.186] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/25/2013] [Accepted: 10/03/2013] [Indexed: 11/08/2022]
Abstract
Organophosphate-induced brain damage is an irreversible neuronal injury, likely because there is no pharmacological treatment to prevent or block secondary damage processes. The presence of free glutamate (Glu) in the brain has a substantial role in the propagation and maintenance of organophosphate-induced seizures, thus contributing to the secondary brain damage. This report describes for the first time the ability of blood glutamate scavengers (BGS) oxaloacetic acid in combination with glutamate oxaloacetate transaminase to reduce the neuronal damage in an animal model of paraoxon (PO) intoxication. Our method causes a rapid decrease of blood Glu levels and creates a gradient that leads to the efflux of the excess brain Glu into the blood, thus reducing neurotoxicity. We demonstrated that BGS treatment significantly prevented the peripheral benzodiazepine receptor (PBR) density elevation, after PO exposure. Furthermore, we showed that BGS was able to rescue neurons in the piriform cortex of the treated rats. In conclusion, these results suggest that treatment with BGS has a neuroprotective effect in the PO intoxication. This is the first time that this approach is used in PO intoxication and it may be of high clinical significance for the future treatment of the secondary neurologic damage post organophosphates exposure.
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Acetylcholinesterase inhibitors as Alzheimer therapy: From nerve toxins to neuroprotection. Eur J Med Chem 2013; 70:165-88. [DOI: 10.1016/j.ejmech.2013.09.050] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 09/24/2013] [Accepted: 09/28/2013] [Indexed: 11/22/2022]
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Ghanemi A. Targeting G protein coupled receptor-related pathways as emerging molecular therapies. Saudi Pharm J 2013; 23:115-29. [PMID: 25972730 PMCID: PMC4420995 DOI: 10.1016/j.jsps.2013.07.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 07/29/2013] [Indexed: 12/20/2022] Open
Abstract
G protein coupled receptors (GPCRs) represent the most important targets in modern pharmacology because of the different functions they mediate, especially within brain and peripheral nervous system, and also because of their functional and stereochemical properties. In this paper, we illustrate, via a variety of examples, novel advances about the GPCR-related molecules that have been shown to play diverse roles in GPCR pathways and in pathophysiological phenomena. We have exemplified how those GPCRs’ pathways are, or might constitute, potential targets for different drugs either to stimulate, modify, regulate or inhibit the cellular mechanisms that are hypothesized to govern some pathologic, physiologic, biologic and cellular or molecular aspects both in vivo and in vitro. Therefore, influencing such pathways will, undoubtedly, lead to different therapeutical applications based on the related pharmacological implications. Furthermore, such new properties can be applied in different fields. In addition to offering fruitful directions for future researches, we hope the reviewed data, together with the elements found within the cited references, will inspire clinicians and researchers devoted to the studies on GPCR’s properties.
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Affiliation(s)
- Abdelaziz Ghanemi
- Department of Pharmacology, China Pharmaceutical University, Nanjing 210009, China
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Gunosewoyo H, Tipparaju SK, Pieroni M, Wang Y, Doctor BP, Nambiar MP, Kozikowski AP. Structural analogs of huperzine A improve survival in guinea pigs exposed to soman. Bioorg Med Chem Lett 2012; 23:1544-7. [PMID: 23395652 DOI: 10.1016/j.bmcl.2012.11.083] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 11/15/2012] [Accepted: 11/20/2012] [Indexed: 11/25/2022]
Abstract
Chemical warfare nerve agents such as soman exert their toxic effects through an irreversible inhibition of acetylcholinesterase (AChE) and subsequently glutamatergic function, leading to uncontrolled seizures. The natural alkaloid (-)-huperzine A is a potent inhibitor of AChE and has been demonstrated to exert neuroprotection at an appropriate dose. It is hypothesized that analogs of both (+)- and (-)-huperzine A with an improved ability to interact with NMDA receptors together with reduced AChE inhibition will exhibit more effective neuroprotection against nerve agents. In this manuscript, the tested huperzine A analogs 2 and 3 were demonstrated to improve survival of guinea pigs exposed to soman at either 1.2 or 2×LD(50).
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Affiliation(s)
- Hendra Gunosewoyo
- Department of Medicinal Chemistry & Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, 833 S Wood Street, Chicago, IL 60612, USA
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Highlight report. Arch Toxicol 2012. [DOI: 10.1007/s00204-012-0898-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Pan H, Hu XZ, Jacobowitz DM, Chen C, McDonough J, Van Shura K, Lyman M, Marini AM. Alpha-linolenic acid is a potent neuroprotective agent against soman-induced neuropathology. Neurotoxicology 2012; 33:1219-29. [PMID: 22884490 DOI: 10.1016/j.neuro.2012.07.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 07/09/2012] [Accepted: 07/09/2012] [Indexed: 11/28/2022]
Abstract
Nerve agents are deadly threats to military and civilian populations around the world. Nerve agents cause toxicity to peripheral and central sites through the irreversible inhibition of acetylcholinesterase, the enzyme that metabolizes acetylcholine. Excessive acetylcholine accumulation in synapses results in status epilepticus in the central nervous system. Prolonged status epilepticus leads to brain damage, neurological dysfunction and poor outcome. Anticonvulsants are effective but must be given rapidly following exposure. Because these agents cause mass casualties, effective neuroprotective agents are needed to reduce brain damage and improve cognitive outcome. α-Linolenic acid is an omega-3 fatty acid that is found in vegetable products and has no known side effects. α-Linolenic acid is neuroprotective against kainic acid-induced brain damage in vivo, but its neuroprotective efficacy against nerve agents is unknown. α-Linolenic acid also exerts anti-depressant and anti-inflammatory activities and enhances synaptic plasticity in vivo. These properties make this polyunsaturated fatty acid (PUFA) a potential candidate against nerve agent-induced neuropathology. Here we show that α-linolenic acid is neuroprotective against soman-induced neuropathology in either a pretreatment or post-treatment paradigm. We also show that subcutaneous injection of α-linolenic acid shows greater neuroprotective efficacy compared with intravenous injection in a brain region-specific manner.
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Affiliation(s)
- Hongna Pan
- Department of Neurology and Program in Neuroscience, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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Cyclooxygenase-2 contributes to VX-induced cell death in cultured cortical neurons. Toxicol Lett 2012; 210:71-7. [PMID: 22306367 DOI: 10.1016/j.toxlet.2012.01.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 01/20/2012] [Accepted: 01/21/2012] [Indexed: 11/23/2022]
Abstract
The link between cell death and increased cyclooxygenases-2 (COX-2) activity has not been clearly established. In this study, we examined whether COX-2 activation contributed to the mechanism of neurotoxicity produced by an organophosphorous nerve agent in cultured rat cortical neurons. Exposure of neuronal cells to the nerve agent, VX resulted in an increase in COX enzyme activity in the culture media. A concentration dependent increase in the activity levels of COX-2 enzyme was observed while there was little to no effect on COX-1. In addition, COX-2 mRNA and protein levels increased several hours post-VX exposure. Pre-treatment of the cortical cells with the COX-2 selective inhibitor, NS 398 resulted in a decrease in both the enzyme activity and prostaglandin (PGE(2) and PGF(2α)) release, as well as in a reduction in cell death. These findings indicate that the increase in COX-2 activity may contribute to the mechanism of VX-induced neurotoxicity in cultured rat cortical neuron.
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Wang Y, Oguntayo S, Wei Y, Wood E, Brown A, Jensen N, Auta J, Guiodotti A, Doctor BP, Nambiar MP. Neuroprotective effects of imidazenil against chemical warfare nerve agent soman toxicity in guinea pigs. Neurotoxicology 2012; 33:169-77. [DOI: 10.1016/j.neuro.2011.12.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 11/11/2011] [Accepted: 12/29/2011] [Indexed: 01/01/2023]
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41
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Gupta RC, Milatovic D. Toxicity of Organophosphates and Carbamates. MAMMALIAN TOXICOLOGY OF INSECTICIDES 2012. [DOI: 10.1039/9781849733007-00104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Organophosphate (OP) and carbamate (CM) compounds are commonly used as insecticides around the world. Some of them are extremely toxic to non-target species, including mammals. OP and CM insecticides are acetylcholinesterase (AChE) inhibitors and are commonly referred to as anticholinesterase agents. In addition to their cholinergic mechanisms, these insecticides exert toxicity through non-cholinergic mechanisms, thereby affecting several vital organs and body systems. The brain and skeletal muscles are the major target organs. Cardiovascular, respiratory and immune systems are also affected. There are similarities and differences between and among the toxicity profiles of OPs and CMs. This is due in part to variability in the interaction of each OP or CM with target and non-target receptors, enzymes and proteins. Treatment of CM poisoning rests with atropine, while the treatment of OP poisoning includes atropine in combination with an oxime.
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Affiliation(s)
- Ramesh C Gupta
- Murray State University, Breathitt Veterinary Center, Toxicology Department Hopkinsville, KY USA.
| | - Dejan Milatovic
- Vanderbilt University, Department of Pediatrics Nashville, TN USA
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Yuan Y. Methylmercury: a potential environmental risk factor contributing to epileptogenesis. Neurotoxicology 2012; 33:119-26. [PMID: 22206970 PMCID: PMC3285480 DOI: 10.1016/j.neuro.2011.12.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 12/12/2011] [Accepted: 12/14/2011] [Indexed: 12/29/2022]
Abstract
Epilepsy or seizure disorder is one of the most common neurological diseases in humans. Although genetic mutations in ion channels and receptors and some other risk factors such as brain injury are linked to epileptogenesis, the underlying cause for the majority of epilepsy cases remains unknown. Gene-environment interactions are thought to play a critical role in the etiology of epilepsy. Exposure to environmental chemicals is an important risk factor. Methylmercury (MeHg) is a prominent environmental neurotoxicant, which targets primarily the central nervous system (CNS). Patients or animals with acute or chronic MeHg poisoning often display epileptic seizures or show increased susceptibility to seizures, suggesting that MeHg exposure may be associated with epileptogenesis. This mini-review highlights the effects of MeHg exposure, especially developmental exposure, on the susceptibility of humans and animals to seizures, and discusses the potential role of low level MeHg exposure in epileptogenesis. This review also proposes that a preferential effect of MeHg on the inhibitory GABAergic system, leading to disinhibition of excitatory glutamatergic function, may be one of the potential mechanisms underlying MeHg-induced changes in seizure susceptibility.
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Affiliation(s)
- Yukun Yuan
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA.
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43
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Multifunctional drugs as novel antidotes for organophosphates’ poisoning. Toxicology 2011; 290:149-55. [DOI: 10.1016/j.tox.2011.09.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Revised: 09/17/2011] [Accepted: 09/19/2011] [Indexed: 11/21/2022]
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44
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RamaRao G, Bhattacharya BK. Multiple signal transduction pathways alterations during nerve agent toxicity. Toxicol Lett 2011; 208:16-22. [PMID: 22001750 DOI: 10.1016/j.toxlet.2011.09.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 09/21/2011] [Accepted: 09/22/2011] [Indexed: 02/06/2023]
Abstract
Nerve agent toxicity is primarily due to the synaptic build up of toxic levels of acetylcholine. The acute lethal effects of the nerve agents are generally attributed to respiratory failure caused by a combination of effects at both central and peripheral levels and are further complicated by copious secretions, muscle fasciculations, and convulsions. In addition to this, a range of non cholinergic effects have been observed. The development of effective treatment to block multiple effects resulting from nerve agent exposure is hampered by a limited understanding of the molecular changes responsible for their persistent effects. Excessive accumulation of acetylcholine leads to activation nicotinic and muscarinic acetylcholine receptors, these receptors activate diverse kind of cellular responses by distinct signaling pathways. Metabolism of cyclic nucleotides, membrane phospholipids, activation of a multitude of protein kinases and the induction of transcription factors are the key biochemical steps and pathways that have been investigated. This review will focus on the effects of nerve agents on signal transduction pathways; particularly, MAP kinases, protein kinase C isozymes, calcium calmodulin dependent protein kinase II (CaMKII) and on cytoskeletal proteins, calpain, and certain transcription factors and discusses how such changes may be involved in nerve agent induced neurotoxicity. Alterations in these key brain proteins could explain the neurological impairments following nerve agent exposure. A better understanding of the whole picture may lead to new pharmacological interventions aimed to improve or modulate those signal transduction pathways affected during nerve agent poisoning or associated pathologies that are responsible for neuronal disturbances.
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Affiliation(s)
- G RamaRao
- Biochemistry Division, Defence Research and Development Establishment, Jhansi Road, Gwalior, M.P., India.
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Kadriu B, Gocel J, Larson J, Guidotti A, Davis JM, Nambiar MP, Auta J. Absence of tolerance to the anticonvulsant and neuroprotective effects of imidazenil against DFP-induced seizure and neuronal damage. Neuropharmacology 2011; 61:1463-9. [PMID: 21903116 DOI: 10.1016/j.neuropharm.2011.08.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 08/15/2011] [Accepted: 08/24/2011] [Indexed: 11/18/2022]
Abstract
The clinical use of diazepam or midazolam to control organophosphate (OP) nerve agent-induced seizure activity is limited by their unwanted effects including sedation, amnesia, withdrawal, and anticonvulsant tolerance. Imidazenil is an imidazo-benzodiazepine derivative with high intrinsic efficacy and selectivity for α2-, α3-, and α5- but low intrinsic efficacy for α1-containing GABA(A) receptors. We have previously shown that imidazenil is more efficacious than diazepam at protecting rats and mice from diisopropyl fluorophosphate (DFP)-induced seizures and neuronal damage without producing sedation. In the present study, we compared the tolerance liability of imidazenil and diazepam to attenuate the seizure activity and neurotoxic effects of DFP. Rats received protracted (14 days) oral treatment with increasing doses of imidazenil (1-4 mg/kg), diazepam (5-20 mg/kg), or vehicle. Eighteen hours after the last dose of the protracted treatment schedule, rats were tested for anticonvulsant tolerance after a 30 min pretreatment with a single test dose of imidazenil (0.5 mg/kg) or diazepam (5 mg/kg) prior to a DFP challenge (1.5 mg/kg). The anticonvulsant (modified Racine score scale) and neuroprotective (fluoro-jade B staining) effects of diazepam were significantly reduced in protracted diazepam-treated animals whereas the effects of imidazenil were not altered in protracted imidazenil-treated animals. The present findings indicate that protracted imidazenil treatment does not produce tolerance to its protective action against the neurotoxic effects of OP exposure.
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Affiliation(s)
- Bashkim Kadriu
- The Psychiatric Institute, Department of Psychiatry, College of Medicine, University of Illinois at Chicago, 1601 W. Taylor St., Chicago, IL 60612, USA
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RamaRao G, Waghmare C, Kumar Gupta A, Bhattacharya BK. Soman-induced alterations of protein kinase C isozymes expression in five discrete areas of the rat brain. Drug Chem Toxicol 2011; 34:221-32. [DOI: 10.3109/01480545.2010.511647] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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47
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Changes of protein oxidation, calpain and cytoskeletal proteins (alpha tubulin and pNF-H) levels in rat brain after nerve agent poisoning. Toxicol Lett 2011; 203:227-36. [DOI: 10.1016/j.toxlet.2011.03.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2011] [Revised: 03/14/2011] [Accepted: 03/14/2011] [Indexed: 11/22/2022]
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48
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Nogueira CRA, Damasceno FM, de Aquino-Neto MR, de Andrade GM, Fontenele JB, de Medeiros TA, Viana GSDB. Doxycycline protects against pilocarpine-induced convulsions in rats, through its antioxidant effect and modulation of brain amino acids. Pharmacol Biochem Behav 2011; 98:525-32. [PMID: 21382396 DOI: 10.1016/j.pbb.2011.02.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 02/18/2011] [Accepted: 02/25/2011] [Indexed: 01/01/2023]
Abstract
This work evaluated doxycycline (2nd generation tetracycline) protection against pilocarpine-induced convulsions in rats. The animals were treated with doxycycline (Dox: 10 to100 mg/kg, i.p., 7days), 30min before the pilocarpine injection (P: 300mg/kg, i.p.) and observed for cholinergic signs, latencies to the first convulsion and death. Amino acid concentrations, lipid peroxidation and nitrite levels in temporal cortices were determined as well as the radical scavenging activity. Doxycycline increased latencies to the first convulsion and death as compared to the untreated P300 group. It also decreased glutamate and aspartate, increased GABA, blocked nitrite formation, reduced TBARS contents and showed a radical scavenging activity. Finally, doxycycline decreased the number of degenerating neurons (evaluated by fluoro-jade staining) and increased the number of viable neurons (assessed by cresyl violet staining) as compared do the P300 group. The antioxidant effect associated with decreased levels of excitatory and increased levels of inhibitory amino acids could explain the neuroprotective effect of doxycycline.
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Affiliation(s)
- Carlos Renato Alves Nogueira
- Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Rua Cel. Nunes de Melo, 1127, CEP 60430-270, Fortaleza, Brazil
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Gubert P, Ávila DS, Bridi JC, Saurin S, Lugokenski TH, Villarinho JG, Fachinetto R, Pereira ME, Ferreira J, da Rocha JBT, Soares FAA. Low concentrations of methamidophos do not alter AChE activity but modulate neurotransmitters uptake in hippocampus and striatum in vitro. Life Sci 2011; 88:89-95. [DOI: 10.1016/j.lfs.2010.10.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 09/25/2010] [Accepted: 10/26/2010] [Indexed: 11/24/2022]
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50
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RamaRao G, Waghmare CK, Srivastava N, Bhattacharya BK. Regional alterations of JNK3 and CaMKIIα subunit expression in the rat brain after soman poisoning. Hum Exp Toxicol 2010; 30:448-59. [DOI: 10.1177/0960327110386814] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Calcium/calmodulin-dependent protein kinase II (CaMKII) and c-Jun N-terminal kinases (JNKs) exert numerous and diverse functions in the brain. However, their role in nerve agent poisoning is poorly understood. In the present study, rats were exposed to soman (80 µg/kg) subcutaneously to study the changes in the protein levels of calcium/calmodulin-dependent protein kinase II alpha subunit (CaMKIIα) and JNK3 and activities of acetylcholinestarase (AChE) and CaMKII in the rat brain. Western blot analysis revealed that significant changes were found in both the protein kinases expression. Immunoreactivity levels of neural specific JNK3 isoform increased from 2.5 hours to 30 days after soman exposure in cerebral cortex, hippocampus, striatum and thalamus regions and decreased in the case of cerebellum. CaMKIIα expression levels were also increased from 2.5 hours to 30 days after soman exposure in cerebral cortex, hippocampus, thalamus and down regulated in cerebellum. AChE activity remained inhibited in plasma and brain up to 3 days post exposure. CaMKII activity was increased in cerebrum and decreased in cerebellum. Results suggest that altered expression of both the protein kinases play a role in nerve agent-induced long-term neurotoxic effects.
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Affiliation(s)
- G. RamaRao
- Division of Biochemistry, Defense Research and Development Establishment, Gwalior, Madhya Pradesh, India,
| | - CK Waghmare
- Division of Biochemistry, Defense Research and Development Establishment, Gwalior, Madhya Pradesh, India
| | - Nalini Srivastava
- Division of Biochemistry, Defense Research and Development Establishment, Gwalior, Madhya Pradesh, India
| | - BK Bhattacharya
- Division of Biochemistry, Defense Research and Development Establishment, Gwalior, Madhya Pradesh, India
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