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Hobson BA, Rowland DJ, Dou Y, Saito N, Harmany ZT, Bruun DA, Harvey DJ, Chaudhari AJ, Garbow JR, Lein PJ. A longitudinal MRI and TSPO PET-based investigation of brain region-specific neuroprotection by diazepam versus midazolam following organophosphate-induced seizures. Neuropharmacology 2024; 251:109918. [PMID: 38527652 PMCID: PMC11250911 DOI: 10.1016/j.neuropharm.2024.109918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/01/2024] [Accepted: 03/13/2024] [Indexed: 03/27/2024]
Abstract
Acute poisoning with organophosphorus cholinesterase inhibitors (OPs), such as OP nerve agents and pesticides, can cause life threatening cholinergic crisis and status epilepticus (SE). Survivors often experience significant morbidity, including brain injury, acquired epilepsy, and cognitive deficits. Current medical countermeasures for acute OP poisoning include a benzodiazepine to mitigate seizures. Diazepam was long the benzodiazepine included in autoinjectors used to treat OP-induced seizures, but it is now being replaced in many guidelines by midazolam, which terminates seizures more quickly, particularly when administered intramuscularly. While a direct correlation between seizure duration and the extent of brain injury has been widely reported, there are limited data comparing the neuroprotective efficacy of diazepam versus midazolam following acute OP intoxication. To address this data gap, we used non-invasive imaging techniques to longitudinally quantify neuropathology in a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) with and without post-exposure intervention with diazepam or midazolam. Magnetic resonance imaging (MRI) was used to monitor neuropathology and brain atrophy, while positron emission tomography (PET) with a radiotracer targeting translocator protein (TSPO) was utilized to assess neuroinflammation. Animals were scanned at 3, 7, 28, 65, 91, and 168 days post-DFP and imaging metrics were quantitated for the hippocampus, amygdala, piriform cortex, thalamus, cerebral cortex and lateral ventricles. In the DFP-intoxicated rat, neuroinflammation persisted for the duration of the study coincident with progressive atrophy and ongoing tissue remodeling. Benzodiazepines attenuated neuropathology in a region-dependent manner, but neither benzodiazepine was effective in attenuating long-term neuroinflammation as detected by TSPO PET. Diffusion MRI and TSPO PET metrics were highly correlated with seizure severity, and early MRI and PET metrics were positively correlated with long-term brain atrophy. Collectively, these results suggest that anti-seizure therapy alone is insufficient to prevent long-lasting neuroinflammation and tissue remodeling.
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Affiliation(s)
- Brad A Hobson
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA; Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, Davis, CA 95616, USA.
| | - Douglas J Rowland
- Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, Davis, CA 95616, USA.
| | - Yimeng Dou
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA.
| | - Naomi Saito
- Department of Public Health Sciences, University of California, Davis, School of Medicine, California 95616, USA.
| | - Zachary T Harmany
- Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, Davis, CA 95616, USA.
| | - Donald A Bruun
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA.
| | - Danielle J Harvey
- Department of Public Health Sciences, University of California, Davis, School of Medicine, California 95616, USA.
| | - Abhijit J Chaudhari
- Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, Davis, CA 95616, USA; Department of Radiology, University of California, Davis, School of Medicine, California 95817, USA.
| | - Joel R Garbow
- Biomedical Magnetic Resonance Center, Mallinckrodt Institute of Radiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, 63110, USA.
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA.
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Armoo A, Diemer T, Donkor A, Fedorchik J, Van Slambrouck S, Willand-Charnley R, Logue BA. Methimazole, an Effective Neutralizing Agent of the Sulfur Mustard Derivative 2-Chloroethyl Ethyl Sulfide. ACS BIO & MED CHEM AU 2023; 3:448-460. [PMID: 37876493 PMCID: PMC10591301 DOI: 10.1021/acsbiomedchemau.2c00087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 10/26/2023]
Abstract
Sulfur mustard (SM), designated by the military as HD, is a highly toxic and dangerous vesicant that has been utilized as a chemical warfare agent since World War I. Despite SM's extensive history, an effective antidote does not exist. The effects of SM are predominantly based on its ability to alkylate important biomolecules. Also, with the potential for a fraction of SM to remain unreacted up to days after initial contact, a window of opportunity exists for direct neutralization of unreacted SM over the days following exposure. In this study, we evaluated the structure-activity relationship of multiple nucleophilic molecules to neutralize the toxic effects of 2-chloroethyl ethyl sulfide (CEES), a monofunctional analogue of SM, on human keratinocyte (HaCaT) cells. Cell viability, relative loss of extracellular matrix adhesions, and apoptosis caused by CEES were measured via MTT, cell-matrix adhesion (CMA), and apoptosis protein marker assays, respectively. A set of five two-carbon compounds with various functional groups served as a preliminary group of first-generation neutralizing agents to survey the correlation between mitigation of CEES's toxic effects and functional group nucleophilicity. Apart from thioacids, which produced additive toxicity, we generally observed the trend of increasing protection from cytotoxicity with increasing nucleophilicity. We extended this treatment strategy to second-generation agents which contained advantageous structural features identified from the first-generation molecules. Our results show that methimazole (MIZ), a currently FDA-approved drug used to treat hyperthyroidism, effectively reduced cytotoxicity, increased CMA, and decreased apoptosis resulting from CEES toxicity. MIZ selectively reacts with CEES to produce 2-(2-(ethylthio)ethylthio)-1-methyl-1H-imidazole (EEMI) in media and cell lysate treatments resulting in the reduction of toxicity. Based on these results, future development of MIZ as an SM therapeutic may provide a viable approach to reduce both the immediate and long-term toxicity of SM and may also help mitigate slower developing SM toxicity due to residual intact SM.
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Affiliation(s)
- Albert Armoo
- Department of Chemistry & Biochemistry, South Dakota State University, Brookings, South Dakota 57007, United States
| | - Tanner Diemer
- Department of Chemistry & Biochemistry, South Dakota State University, Brookings, South Dakota 57007, United States
| | - Abigail Donkor
- Department of Chemistry & Biochemistry, South Dakota State University, Brookings, South Dakota 57007, United States
| | - Jerrod Fedorchik
- Department of Chemistry & Biochemistry, South Dakota State University, Brookings, South Dakota 57007, United States
| | | | - Rachel Willand-Charnley
- Department of Chemistry & Biochemistry, South Dakota State University, Brookings, South Dakota 57007, United States
| | - Brian A Logue
- Department of Chemistry & Biochemistry, South Dakota State University, Brookings, South Dakota 57007, United States
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Neurotoxicity evoked by organophosphates and available countermeasures. Arch Toxicol 2023; 97:39-72. [PMID: 36335468 DOI: 10.1007/s00204-022-03397-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/11/2022] [Indexed: 11/07/2022]
Abstract
Organophosphorus compounds (OP) are a constant problem, both in the military and in the civilian field, not only in the form of acute poisoning but also for their long-lasting consequences. No antidote has been found that satisfactorily protects against the toxic effects of organophosphates. Likewise, there is no universal cure to avert damage after poisoning. The key mechanism of organophosphate toxicity is the inhibition of acetylcholinesterase. The overstimulation of nicotinic or muscarinic receptors by accumulated acetylcholine on a synaptic cleft leads to activation of the glutamatergic system and the development of seizures. Further consequences include generation of reactive oxygen species (ROS), neuroinflammation, and the formation of various other neuropathologists. In this review, we present neuroprotection strategies which can slow down the secondary nerve cell damage and alleviate neurological and neuropsychiatric disturbance. In our opinion, there is no unequivocal approach to ensure neuroprotection, however, sooner the neurotoxicity pathway is targeted, the better the results which can be expected. It seems crucial to target the key propagation pathways, i.e., to block cholinergic and, foremostly, glutamatergic cascades. Currently, the privileged approach oriented to stimulating GABAAR by benzodiazepines is of limited efficacy, so that antagonizing the hyperactivity of the glutamatergic system could provide an even more efficacious approach for terminating OP-induced seizures and protecting the brain from permanent damage. Encouraging results have been reported for tezampanel, an antagonist of GluK1 kainate and AMPA receptors, especially in combination with caramiphen, an anticholinergic and anti-glutamatergic agent. On the other hand, targeting ROS by antioxidants cannot or already developed neuroinflammation does not seem to be very productive as other processes are also involved.
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Hassanpour M, Hajihassani F, Abdollahpourasl M, Cheraghi O, Aghamohamadzade N, Rahbargazi R, Nouri M, Pilehvar-Soltanahmadi Y, Zarghami N, Akbarzadeh A, Panahi Y, Sahebkar A. Pathophysiological Effects of Sulfur Mustard on Skin and its Current Treatments: Possible Application of Phytochemicals. Comb Chem High Throughput Screen 2020; 24:3-19. [PMID: 32679016 DOI: 10.2174/1386207323666200717150414] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 04/21/2020] [Accepted: 06/03/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Sulfur-(SM) and nitrogen (NM)-based mustards are the mutagenic incapacitating compounds which are widely used in vesicating the chemical warfare and cause toxicity in many organs, especially skin. SM, as a potent vesicating agent, contributes to the destruction of skin in dermis and epidermis layers. The progression of the lesion depends on the concentration of SM and the duration of exposure. Body responses start with pruritus, erythema, edema and xerosis, which lead to the accumulation of immune cells in the target sites and recruitment of mast cells and paracrine-mediated activity. Pro-inflammatory effectors are accumulated in the epidermis, hair follicles, and sebaceous glands resulting in the destruction of the basement membrane beneath the epidermis. There is still no satisfactory countermeasure against SM-induced lesions in clinical therapy, and the symptomatic or supportive treatments are routine management approaches. OBJECTIVE The current review highlights the recent progression of herbal medicines application in SM-induced injuries through the illustrative examples and also demonstrates their efficacies, properties and mechanism of actions as therapeutic agents. CONCLUSION Phytochemicals and herbal extracts with anti-bacterial, anti-inflammatory and antioxidant properties have been recently shown to hold therapeutic promise against the SM-induced cutaneous complications. The present review discusses the possible application of herbal medicines in the healing of SM-induced injuries.
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Affiliation(s)
- Mehdi Hassanpour
- Department of Clinical Biochemistry and Laboratory Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Fateme Hajihassani
- Department of Health Management, School of Management and Medical informatics, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Omid Cheraghi
- Department of Biochemistry, Faculty of Biological Science, Tarbiat Modares University, Tehran, Iran
| | - Nasser Aghamohamadzade
- Endocrine and Metabolism Section, Department of Internal Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Reza Rahbargazi
- Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Nouri
- Department of Clinical Biochemistry and Laboratory Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Younes Pilehvar-Soltanahmadi
- Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Nosratollah Zarghami
- Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Abolfazl Akbarzadeh
- Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Yunes Panahi
- Pharmacotherapy Department, Faculty of Pharmacy, Baqiyatallah University of Medical Sciences, Tehran, Iran
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Li F, Wang Y, Li C, Marquez-Lago TT, Leier A, Rawlings ND, Haffari G, Revote J, Akutsu T, Chou KC, Purcell AW, Pike RN, Webb GI, Ian Smith A, Lithgow T, Daly RJ, Whisstock JC, Song J. Twenty years of bioinformatics research for protease-specific substrate and cleavage site prediction: a comprehensive revisit and benchmarking of existing methods. Brief Bioinform 2019; 20:2150-2166. [PMID: 30184176 PMCID: PMC6954447 DOI: 10.1093/bib/bby077] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/26/2018] [Accepted: 08/01/2018] [Indexed: 01/06/2023] Open
Abstract
The roles of proteolytic cleavage have been intensively investigated and discussed during the past two decades. This irreversible chemical process has been frequently reported to influence a number of crucial biological processes (BPs), such as cell cycle, protein regulation and inflammation. A number of advanced studies have been published aiming at deciphering the mechanisms of proteolytic cleavage. Given its significance and the large number of functionally enriched substrates targeted by specific proteases, many computational approaches have been established for accurate prediction of protease-specific substrates and their cleavage sites. Consequently, there is an urgent need to systematically assess the state-of-the-art computational approaches for protease-specific cleavage site prediction to further advance the existing methodologies and to improve the prediction performance. With this goal in mind, in this article, we carefully evaluated a total of 19 computational methods (including 8 scoring function-based methods and 11 machine learning-based methods) in terms of their underlying algorithm, calculated features, performance evaluation and software usability. Then, extensive independent tests were performed to assess the robustness and scalability of the reviewed methods using our carefully prepared independent test data sets with 3641 cleavage sites (specific to 10 proteases). The comparative experimental results demonstrate that PROSPERous is the most accurate generic method for predicting eight protease-specific cleavage sites, while GPS-CCD and LabCaS outperformed other predictors for calpain-specific cleavage sites. Based on our review, we then outlined some potential ways to improve the prediction performance and ease the computational burden by applying ensemble learning, deep learning, positive unlabeled learning and parallel and distributed computing techniques. We anticipate that our study will serve as a practical and useful guide for interested readers to further advance next-generation bioinformatics tools for protease-specific cleavage site prediction.
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Affiliation(s)
- Fuyi Li
- Biomedicine Discovery Institute and Department of Biochemistry & Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
| | - Yanan Wang
- Biomedicine Discovery Institute and Department of Biochemistry & Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
- Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chen Li
- Biomedicine Discovery Institute and Department of Biochemistry & Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
- Department of Biology, Institute of Molecular Systems Biology,ETH Zürich, Zürich 8093, Switzerland
| | - Tatiana T Marquez-Lago
- Department of Genetics and Department of Cell, Developmental and Integrative Biology, School of Medicine, University of Alabama at Birmingham, AL, USA
| | - André Leier
- Department of Genetics and Department of Cell, Developmental and Integrative Biology, School of Medicine, University of Alabama at Birmingham, AL, USA
| | - Neil D Rawlings
- EMBL European Bioinformatics Institute, Wellcome Trust Genome Campus, Wellcome Trust Genome Campus,Hinxton, Cambridgeshire CB10 1SD, UK
| | - Gholamreza Haffari
- Monash Centre for Data Science, Faculty of Information Technology, Monash University, Melbourne, VIC 3800, Australia
| | - Jerico Revote
- Biomedicine Discovery Institute and Department of Biochemistry & Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
| | - Tatsuya Akutsu
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Kyoto 611-0011, Japan
| | - Kuo-Chen Chou
- Gordon Life Science Institute, Boston, MA 02478, USA
- Center for Informational Biology, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Anthony W Purcell
- Biomedicine Discovery Institute and Department of Biochemistry & Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
| | - Robert N Pike
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, VIC 3800, Australia
| | - Geoffrey I Webb
- Monash Centre for Data Science, Faculty of Information Technology, Monash University, Melbourne, VIC 3800, Australia
| | - A Ian Smith
- Biomedicine Discovery Institute and Department of Biochemistry & Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, VIC 3800, Australia
| | - Trevor Lithgow
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia
| | - Roger J Daly
- Biomedicine Discovery Institute and Department of Biochemistry & Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
| | - James C Whisstock
- Biomedicine Discovery Institute and Department of Biochemistry & Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, VIC 3800, Australia
| | - Jiangning Song
- Biomedicine Discovery Institute and Department of Biochemistry & Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
- Monash Centre for Data Science, Faculty of Information Technology, Monash University, Melbourne, VIC 3800, Australia
- ARC Centre of Excellence in Advanced Molecular Imaging, Monash University, Melbourne, VIC 3800, Australia
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6
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Flannery BM, Bruun DA, Rowland DJ, Banks CN, Austin AT, Kukis DL, Li Y, Ford BD, Tancredi DJ, Silverman JL, Cherry SR, Lein PJ. Persistent neuroinflammation and cognitive impairment in a rat model of acute diisopropylfluorophosphate intoxication. J Neuroinflammation 2016; 13:267. [PMID: 27733171 PMCID: PMC5062885 DOI: 10.1186/s12974-016-0744-y] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 10/06/2016] [Indexed: 12/19/2022] Open
Abstract
Background Acute intoxication with organophosphorus (OP) cholinesterase inhibitors can trigger convulsions that progress to life-threatening status epilepticus. Survivors face long-term morbidity including mild-to-severe decline in memory. It is posited that neuroinflammation plays a key role in the pathogenesis of OP-induced neuropsychiatric deficits. Rigorous testing of this hypothesis requires preclinical models that recapitulate relevant phenotypic outcomes. Here, we describe a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) that exhibits persistent neuroinflammation and cognitive impairment. Methods Neuroinflammation, neurodegeneration, and cognitive function were compared in adult male Sprague Dawley rats injected with an acutely toxic dose of DFP vs. vehicle controls at multiple time points up to 36 days post-exposure. Neuroinflammation was quantified using immunohistochemical biomarkers of microglia (ionized calcium-binding adapter molecule 1, IBA1) and activated astrocytes (glial fibrillary acidic protein, GFAP) and positron emission tomography (PET) imaging of [11C]-(R)-PK11195, a ligand for the 18-kDa mitochondrial membrane translocator protein (TSPO). FluoroJade-B staining was used to assess neurodegeneration; Pavlovian conditioning, to assess cognitive function. Results Animals exhibited moderate-to-severe seizures within minutes of DFP injection that continued for up to 6 h post-injection. As indicated by IBA1 and GFAP immunoreactivity and by PET imaging of TSPO, acute DFP intoxication triggered neuroinflammation in the hippocampus and cortex during the first 3 days that peaked at 7 days and persisted to 21 days post-exposure in most animals. Neurodegeneration was detected in multiple brain regions from 1 to 14 days post-exposure. All DFP-intoxicated animals exhibited significant deficits in contextual fear conditioning at 9 and 20 days post-exposure compared to vehicle controls. Whole-brain TSPO labeling positively correlated with seizure severity score, but did not correlate with performance in the contextual fear-conditioning task. Conclusions We describe a preclinical model in which acute DFP intoxication causes seizures, persistent neuroinflammation, neurodegeneration, and memory impairment. The extent of the neuroinflammatory response is influenced by seizure severity. However, the observation that a subset of animals with moderate seizures and minimal TSPO labeling exhibited cognitive deficits comparable to those of animals with severe seizures and significant TSPO labeling suggests that DFP may impair learning and memory circuitry via mechanisms independent of seizures or neuroinflammation.
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Affiliation(s)
- Brenna M Flannery
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, 95616, USA
| | - Donald A Bruun
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, 95616, USA
| | - Douglas J Rowland
- Center for Molecular and Genomic Imaging, University of California-Davis, Davis, CA, 95616, USA
| | - Christopher N Banks
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, 95616, USA.,Current address: Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Sacramento, CA, 95812, USA
| | - Adam T Austin
- Department of Pediatrics, University of California-Davis Medical Center, Sacramento, CA, 95817, USA.,Current address: Navistar, Inc., 2701 Navistar Drive, Lisle, IL, 60532, USA
| | - David L Kukis
- Center for Molecular and Genomic Imaging, University of California-Davis, Davis, CA, 95616, USA
| | - Yonggang Li
- Division of Biomedical Sciences, University of California-Riverside School of Medicine, Riverside, CA, 92521, USA
| | - Byron D Ford
- Division of Biomedical Sciences, University of California-Riverside School of Medicine, Riverside, CA, 92521, USA
| | - Daniel J Tancredi
- Department of Pediatrics, University of California-Davis Medical Center, Sacramento, CA, 95817, USA
| | - Jill L Silverman
- Department of Psychiatry and Behavioral Sciences, University of California-Davis Medical Center, Sacramento, CA, 95817, USA
| | - Simon R Cherry
- Center for Molecular and Genomic Imaging, University of California-Davis, Davis, CA, 95616, USA
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, Davis, CA, 95616, USA.
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7
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Liu F, Jiang N, Xiao ZY, Cheng JP, Mei YZ, Zheng P, Wang L, Zhang XR, Zhou XB, Zhou WX, Zhang YX. Effects of poly (ADP-ribose) polymerase-1 (PARP-1) inhibition on sulfur mustard-induced cutaneous injuries in vitro and in vivo. PeerJ 2016; 4:e1890. [PMID: 27077006 PMCID: PMC4830333 DOI: 10.7717/peerj.1890] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/14/2016] [Indexed: 01/13/2023] Open
Abstract
Early studies with first-generation poly (ADP-ribose) polymerase (PARP) inhibitors have already indicated some therapeutic potential for sulfur mustard (SM) injuries. The available novel and more potential PARP inhibitors, which are undergoing clinical trials as drugs for cancer treatment, bring it back to the centre of interest. However, the role of PARP-1 in SM-induced injury is not fully understood. In this study, we selected a high potent specific PARP inhibitor ABT-888 as an example to investigate the effect of PARP inhibitor in SM injury. The results showed that in both the mouse ear vesicant model (MEVM) and HaCaT cell model, PARP inhibitor ABT-888 can reduce cell damage induced by severe SM injury. ABT-888 significantly reduced SM induced edema and epidermal necrosis in MEVM. In the HaCaT cell model, ABT-888 can reduce SM-induced NAD(+)/ATP depletion and apoptosis/necrosis. Then, we studied the mechanism of PARP-1 in SM injury by knockdown of PARP-1 in HaCaT cells. Knockdown of PARP-1 protected cell viability and downregulated the apoptosis checkpoints, including p-JNK, p-p53, Caspase 9, Caspase 8, c-PARP and Caspase 3 following SM-induced injury. Furthermore, the activation of AKT can inhibit autophagy via the regulation of mTOR. Our results showed that SM exposure could significantly inhibit the activation of Akt/mTOR pathway. Knockdown of PARP-1 reversed the SM-induced suppression of the Akt/mTOR pathway. In summary, the results of our study indicated that the protective effects of downregulation of PARP-1 in SM injury may be due to the regulation of apoptosis, necrosis, energy crisis and autophagy. However, it should be noticed that PARP inhibitor ABT-888 further enhanced the phosphorylation of H2AX (S139) after SM exposure, which indicated that we should be very careful in the application of PARP inhibitors in SM injury treatment because of the enhancement of DNA damage.
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Affiliation(s)
- Feng Liu
- Beijing Institute of Pharmacology and Toxicology , Beijing , China
| | - Ning Jiang
- Beijing Institute of Pharmacology and Toxicology , Beijing , China
| | - Zhi-Yong Xiao
- Beijing Institute of Pharmacology and Toxicology , Beijing , China
| | - Jun-Ping Cheng
- Beijing Institute of Pharmacology and Toxicology , Beijing , China
| | - Yi-Zhou Mei
- Beijing Institute of Pharmacology and Toxicology , Beijing , China
| | - Pan Zheng
- Beijing Institute of Pharmacology and Toxicology , Beijing , China
| | - Li Wang
- Beijing Institute of Pharmacology and Toxicology , Beijing , China
| | - Xiao-Rui Zhang
- Beijing Institute of Pharmacology and Toxicology , Beijing , China
| | - Xin-Bo Zhou
- Beijing Institute of Pharmacology and Toxicology , Beijing , China
| | - Wen-Xia Zhou
- Beijing Institute of Pharmacology and Toxicology , Beijing , China
| | - Yong-Xiang Zhang
- Beijing Institute of Pharmacology and Toxicology , Beijing , China
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8
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Sulfur mustard-stimulated proteases and their inhibitors in a cultured normal human epidermal keratinocytes model: A potential approach for anti-vesicant drug development. Toxicol Rep 2016; 3:393-400. [PMID: 28959561 PMCID: PMC5615839 DOI: 10.1016/j.toxrep.2016.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 03/10/2016] [Accepted: 03/11/2016] [Indexed: 11/24/2022] Open
Abstract
Protease stimulation in cultured normal human epidermal keratinocytes (NHEK) due to sulfur mustard (SM) exposure is well documented. However, the specific protease(s) stimulated by SM and the protease substrates remain to be determined. In this study, we observed that SM stimulates several proteases and the epidermal-dermal attachment protein laminin-5 is one of the substrates. We propose that following SM exposure of the skin, laminin-5 degradation causes the detachment of the epidermis from the dermis and, therefore, vesication. We utilized gelatin zymography, Western blotting, immuno-fluorescence staining, and real-time polymerase chain reaction (RT-PCR) analyses to study the SM-stimulated proteases and laminin-5 degradation in NHEK. Two major protease bands (64 kDa and 72 kDa) were observed by zymography in SM-exposed cells. Addition of serine protease inhibitor (aprotinin, 100 μM), or the metalloprotease inhibitor (amastatin, 100 μM) to NHEK cultures prior to SM exposure decreased the SM-stimulated protease bands seen by zymography. These inhibitors completely or partially prevented SM-induced laminin-5 γ2 degradation as seen by Western blotting as well as immuno-fluorescence staining. Our results from Western blotting and RT-PCR studies also indicated that the membrane-type matrix metalloproteinase-1 (MT-MM-1) may be involved in SM-induced skin blistering. To summarize, our results in the NHEK model indicate the following: (a) SM stimulates multiple proteases including serine protease(s), and metalloproteases; (b) SM decreases the level of laminin-5 γ2, which is prevented by either a serine protease inhibitor or a metalloprotease inhibitor and (c) MT-MMP-1 maybe one of the proteases that is involved in skin blistering due to SM exposure.
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Eisenkraft A, Falk A. The possible role of intravenous lipid emulsion in the treatment of chemical warfare agent poisoning. Toxicol Rep 2016; 3:202-210. [PMID: 28959540 PMCID: PMC5615427 DOI: 10.1016/j.toxrep.2015.12.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 11/29/2015] [Accepted: 12/24/2015] [Indexed: 12/19/2022] Open
Abstract
Organophosphates (OPs) are cholinesterase inhibitors that lead to a characteristic toxidrome of hypersecretion, miosis, dyspnea, respiratory insufficiency, convulsions and, without proper and early antidotal treatment, death. Most of these compounds are highly lipophilic. Sulfur mustard is a toxic lipophilic alkylating agent, exerting its damage through alkylation of cellular macromolecules (e.g., DNA, proteins) and intense activation of pro-inflammatory pathways. Currently approved antidotes against OPs include the peripheral anticholinergic drug atropine and an oxime that reactivates the inhibited cholinesterase. Benzodiazepines are used to stop organophosphate-induced seizures. Despite these approved drugs, efforts have been made to introduce other medical countermeasures in order to attenuate both the short-term and long-term clinical effects following exposure. Currently, there is no antidote against sulfur mustard poisoning. Intravenous lipid emulsions are used as a source of calories in parenteral nutrition. In recent years, efficacy of lipid emulsions has been shown in the treatment of poisoning by fat-soluble compounds in animal models as well as clinically in humans. In this review we discuss the usefulness of intravenous lipid emulsions as an adjunct to the in-hospital treatment of chemical warfare agent poisoning.
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Affiliation(s)
- Arik Eisenkraft
- NBC Protection Division, IMOD, Israel.,Israel Defense Forces Medical Corps, Israel.,The Institute for Research in Military Medicine, The Faculty of Medicine, The Hebrew University, Jerusalem, Israel
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10
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Debiak M, Lex K, Ponath V, Burckhardt-Boer W, Thiermann H, Steinritz D, Schmidt A, Mangerich A, Bürkle A. Immunochemical analysis of poly(ADP-ribosyl)ation in HaCaT keratinocytes induced by the mono-alkylating agent 2-chloroethyl ethyl sulfide (CEES): Impact of experimental conditions. Toxicol Lett 2015; 244:72-80. [PMID: 26383632 DOI: 10.1016/j.toxlet.2015.09.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 10/23/2022]
Abstract
Sulfur mustard (SM) is a bifunctional alkylating agent with a long history of use as a chemical weapon. Although its last military use is dated for the eighties of the last century, a potential use in terroristic attacks against civilians remains a significant threat. Thus, improving medical therapy of mustard exposed individuals is still of particular interest. PARP inhibitors were recently brought into the focus as a potential countermeasure for mustard-induced pathologies, supported by the availability of efficient compounds successfully tested in cancer therapy. PARP activation after SM treatment was reported in several cell types and tissues under various conditions; however, a detailed characterization of this phenomenon is still missing. This study provides the basis for such studies by developing and optimizing experimental conditions to investigate poly(ADP-ribosyl)ation (PARylation) in HaCaT keratinocytes upon treatment with the monofunctional alkylating agent 2-chloroethyl ethyl sulfide ("half mustard", CEES). By using an immunofluorescence-based approach, we show that optimization of experimental conditions with regards to the type of solvent, dilution factors and treatment procedure is essential to obtain a homogenous PAR staining in HaCaT cell cultures. Furthermore, we demonstrate that different CEES treatment protocols significantly influence the cytotoxicity profiles of treated cells. Using an optimized treatment protocol, our data reveals that CEES induces a dose- and time-dependent dynamic PARylation response in HaCaT cells that could be completely blocked by treating cells with the clinically relevant pharmacological PARP inhibitor ABT888 (also known as veliparib). Finally, siRNA experiments show that CEES-induced PAR formation is predominantly due to the activation of PARP1. In conclusion, this study provides a detailed analysis of the CEES-induced PARylation response in HaCaT keratinocytes, which forms an experimental basis to study the molecular mechanism of PARP1 activation and its functional consequences after mustard treatment in general. Such a study is presented in an accompanying article (Mangerich et al., 2016).
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Affiliation(s)
- Malgorzata Debiak
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Kirsten Lex
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Viviane Ponath
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Waltraud Burckhardt-Boer
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, 80937 Munich, Germany
| | - Dirk Steinritz
- Bundeswehr Institute of Pharmacology and Toxicology, 80937 Munich, Germany; Walther Straub Institute of Pharmacology and Toxicology, 80336 Munich, Germany
| | - Annette Schmidt
- Bundeswehr Institute of Pharmacology and Toxicology, 80937 Munich, Germany
| | - Aswin Mangerich
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Alexander Bürkle
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany.
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Mangerich A, Debiak M, Birtel M, Ponath V, Balszuweit F, Lex K, Martello R, Burckhardt-Boer W, Strobelt R, Siegert M, Thiermann H, Steinritz D, Schmidt A, Bürkle A. Sulfur and nitrogen mustards induce characteristic poly(ADP-ribosyl)ation responses in HaCaT keratinocytes with distinctive cellular consequences. Toxicol Lett 2015; 244:56-71. [PMID: 26383629 DOI: 10.1016/j.toxlet.2015.09.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 11/18/2022]
Abstract
Mustard agents are potent DNA alkylating agents with mutagenic, cytotoxic and vesicant properties. They include bi-functional agents, such as sulfur mustard (SM) or nitrogen mustard (mustine, HN2), as well as mono-functional agents, such as "half mustard" (CEES). Whereas SM has been used as a chemical warfare agent, several nitrogen mustard derivatives, such as chlorambucil and cyclophosphamide, are being used as established chemotherapeutics. Upon induction of specific forms of genotoxic stimuli, several poly(ADP-ribose) polymerases (PARPs) synthesize the nucleic acid-like biopolymer poly(ADP-ribose) (PAR) by using NAD(+) as a substrate. Previously, it was shown that SM triggers cellular poly(ADP-ribosyl) ation (PARylation), but so far this phenomenon is poorly characterized. In view of the protective effects of PARP inhibitors, the latter have been proposed as a treatment option of SM-exposed victims. In an accompanying article (Debiak et al., 2016), we have provided an optimized protocol for the analysis of the CEES-induced PARylation response in HaCaT keratinocytes, which forms an experimental basis to further analyze mustard-induced PARylation and its functional consequences, in general. Thus, in the present study, we performed a comprehensive characterization of the PARylation response in HaCaT cells after treatment with four different mustard agents, i.e., SM, CEES, HN2, and chlorambucil, on a qualitative, quantitative and functional level. In particular, we recorded substance-specific as well as dose- and time-dependent PARylation responses using independent bioanalytical methods based on single-cell immuno-fluorescence microscopy and quantitative isotope dilution mass spectrometry. Furthermore, we analyzed if and how PARylation contributes to mustard-induced toxicity by treating HaCaT cells with CEES, SM, and HN2 in combination with the clinically relevant PARP inhibitor ABT888. As evaluated by a novel immunofluorescence-based protocol for the detection of N7-ETE-guanine DNA adducts, the excision rate of CEES-induced DNA adducts was not affected by PARP inhibition. Furthermore, while CEES induced moderate changes in cellular NAD(+) levels, annexin V/PI flow cytometry analysis revealed that these changes did not affect CEES-induced short-term cytotoxicity 24h after treatment. In contrast, PARP inhibition impaired cell proliferation and clonogenic survival, and potentiated micronuclei formation of HaCaT cells upon CEES treatment. Similarly, PARP inhibition affected clonogenic survival of cells treated with bi-functional mustards such as SM and HN2. In conclusion, we demonstrate that PARylation plays a functional role in mustard-induced cellular stress response with substance-specific differences. Since PARP inhibitors exhibit therapeutic potential to treat SM-related pathologies and to sensitize cancer cells for mustard-based chemotherapy, potential long-term effects of PARP inhibition on genomic stability and carcinogenesis should be carefully considered when pursuing such a strategy.
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Affiliation(s)
- Aswin Mangerich
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Malgorzata Debiak
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Matthias Birtel
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Viviane Ponath
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Frank Balszuweit
- Bundeswehr Institute of Pharmacology and Toxicology, 80937 Munich, Germany
| | - Kirsten Lex
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Rita Martello
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Waltraud Burckhardt-Boer
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany
| | - Romano Strobelt
- Bundeswehr Institute of Pharmacology and Toxicology, 80937 Munich, Germany
| | - Markus Siegert
- Bundeswehr Institute of Pharmacology and Toxicology, 80937 Munich, Germany
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, 80937 Munich, Germany
| | - Dirk Steinritz
- Bundeswehr Institute of Pharmacology and Toxicology, 80937 Munich, Germany; Walther-Straub-Institute of Pharmacology and Toxicology, 80336 Munich, Germany
| | - Annette Schmidt
- Bundeswehr Institute of Pharmacology and Toxicology, 80937 Munich, Germany
| | - Alexander Bürkle
- University of Konstanz, Molecular Toxicology Group, Department of Biology, 78457 Konstanz, Germany.
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12
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Myeloperoxidase deficiency attenuates nitrogen mustard-induced skin injuries. Toxicology 2014; 320:25-33. [PMID: 24631667 DOI: 10.1016/j.tox.2014.02.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 02/20/2014] [Accepted: 02/24/2014] [Indexed: 12/14/2022]
Abstract
The pathologic mechanisms of skin injuries, following the acute inflammatory response induced by vesicating agents sulfur mustard (SM) and nitrogen mustard (NM) exposure, are poorly understood. Neutrophils which accumulate at the site of injury, abundantly express myeloperoxidase (MPO), a heme protein that is implicated in oxidant-related antimicrobial and cytotoxic responses. Our previous studies have shown that exposure to SM analog 2-chloroethyl ethyl sulfide (CEES) or NM results in an inflammatory response including increased neutrophilic infiltration and MPO activity. To further define the role of neutrophil-derived MPO in NM-induced skin injury, here we used a genetic approach and examined the effect of NM exposure (12h and 24h) on previously established injury endpoints in C57BL/6J wild type (WT) and B6.129X1-MPOtm1Lus/J mice (MPO KO), homozygous null for MPO gene. NM exposure caused a significant increase in skin bi-fold thickness, epidermal thickness, microvesication, DNA damage and apoptosis in WT mice compared to MPO KO mice. MPO KO mice showed relatively insignificant effect. Similarly, NM induced increases in the expression of inflammatory and proteolytic mediators, including COX-2, iNOS and MMP-9 in WT mice, while having a significantly lower effect in MPO KO mice. Collectively, these results show that MPO, which generates microbicidal oxidants, plays an important role in NM-induced skin injuries. This suggests the development of mechanism-based treatments against NM- and SM-induced skin injuries that inhibit MPO activity and attenuate MPO-derived oxidants.
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13
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Qandil AM. Prodrugs of nonsteroidal anti-inflammatory drugs (NSAIDs), more than meets the eye: a critical review. Int J Mol Sci 2012; 13:17244-74. [PMID: 23247285 PMCID: PMC3546748 DOI: 10.3390/ijms131217244] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 11/29/2012] [Accepted: 12/10/2012] [Indexed: 12/15/2022] Open
Abstract
The design and the synthesis of prodrugs for nonsteroidal anti-inflammatory drugs (NSAIDs) have been given much attention by medicinal chemists, especially in the last decade. As a therapeutic group, NSAIDs are among the most widely used prescribed and over the counter (OTC) medications. The rich literature about potential NSAID prodrugs clearly shows a shift from alkyl, aryalkyl or aryl esters with the sole role of masking the carboxylic acid group, to more elaborate conjugates that contain carefully chosen groups to serve specific purposes, such as enhancement of water solubility and dissolution, nitric oxide release, hydrogen sulfide release, antioxidant activity, anticholinergic and acetylcholinesterase inhibitory (AChEI) activity and site-specific targeting and delivery. This review will focus on NSAID prodrugs that have been designed or were, later, found to possess intrinsic pharmacological activity as an intact chemical entity. Such intrinsic activity might augment the anti-inflammatory activity of the NSAID, reduce its side effects or transform the potential therapeutic use from classical anti-inflammatory action to something else. Reports discussed in this review will be those of NO-NSAIDs, anticholinergic and AChEI-NSAIDs, Phospho-NSAIDs and some miscellaneous agents. In most cases, this review will cover literature dealing with these NSAID prodrugs from the year 2006 and later. Older literature will be used when necessary, e.g., to explain the chemical and biological mechanisms of action.
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Affiliation(s)
- Amjad M Qandil
- Pharmaceutical Sciences Department, College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11426, Saudi Arabia.
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14
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Banks CN, Lein PJ. A review of experimental evidence linking neurotoxic organophosphorus compounds and inflammation. Neurotoxicology 2012; 33:575-84. [PMID: 22342984 DOI: 10.1016/j.neuro.2012.02.002] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 01/31/2012] [Accepted: 02/01/2012] [Indexed: 01/14/2023]
Abstract
Organophosphorus (OP) nerve agents and pesticides inhibit acetylcholinesterase (AChE), and this is thought to be a primary mechanism mediating the neurotoxicity of these compounds. However, a number of observations suggest that mechanisms other than or in addition to AChE inhibition contribute to OP neurotoxicity. There is significant experimental evidence that acute OP intoxication elicits a robust inflammatory response, and emerging evidence suggests that chronic repeated low-level OP exposure also upregulates inflammatory mediators. A critical question that is just beginning to be addressed experimentally is the pathophysiologic relevance of inflammation in either acute or chronic OP intoxication. The goal of this article is to provide a brief review of the current status of our knowledge linking inflammation to OP intoxication, and to discuss the implications of these findings in the context of therapeutic and diagnostic approaches to OP neurotoxicity.
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Affiliation(s)
- Christopher N Banks
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, One Shields Ave., Davis, CA 95616, USA.
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15
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Gao X, Anderson DR, Brown AW, Lin H, Amnuaysirikul J, Chua AL, Holmes WW, Ray P. Pathological studies on the protective effect of a macrolide antibiotic, roxithromycin, against sulfur mustard inhalation toxicity in a rat model. Toxicol Pathol 2011; 39:1056-64. [PMID: 21934141 DOI: 10.1177/0192623311422079] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Macrolide antibiotics have been shown to protect airway epithelial cells and macrophages from sulfur mustard (SM)-induced cytotoxicity. In the current study, the efficacy of roxithromycin in ameliorating SM-induced respiratory injury was further evaluated in a rat model. Anesthetized rats (N = 8/group) were intratracheally exposed to SM by vapor inhalation. For the drug treatment groups, rats were orally given 10, 20, or 40 mg/kg roxithromycin one hr prior to exposure and every twenty-four hr thereafter. After one, three, or seven days of treatment, sections of the lung were examined and scored for histopathological parameters. Treatment with roxithromycin ameliorated many of the symptoms caused by SM in some animals. In particular, treatment at 40 mg/kg for three days showed significant improvements (p < .05) over the untreated group. When the evaluation was focused on trachea, treatment with roxithromycin for three days showed a trend of dose-dependent protection; moreover, the groups treated with 20 or 40 mg/kg of roxithromycin were statistically different (p < .001 and p < .05, respectively) from the untreated group. These results suggest that roxithromycin protects against some damages associated with SM injury in the lung, particularly in the upper respiratory tract.
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Affiliation(s)
- Xiugong Gao
- Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
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16
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Jain AK, Tewari-Singh N, Gu M, Inturi S, White CW, Agarwal R. Sulfur mustard analog, 2-chloroethyl ethyl sulfide-induced skin injury involves DNA damage and induction of inflammatory mediators, in part via oxidative stress, in SKH-1 hairless mouse skin. Toxicol Lett 2011; 205:293-301. [PMID: 21722719 DOI: 10.1016/j.toxlet.2011.06.019] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 06/13/2011] [Accepted: 06/14/2011] [Indexed: 12/20/2022]
Abstract
Bifunctional alkyalating agent, sulfur mustard (SM)-induced cutaneous injury is characterized by inflammation and delayed blistering. Our recent studies demonstrated that 2-chloroethyl ethyl sulfide (CEES), a monofunctional analog of SM that can be used in laboratory settings, induces oxidative stress. This could be the major cause of the activation of Akt/MAP kinase and AP1/NF-κB pathways that are linked to the inflammation and microvesication, and histopathological alterations in SKH-1 hairless mouse skin. To further establish a link between CEES-induced DNA damage and signaling pathways and inflammatory responses, skin samples from mice exposed to 2 mg or 4 mg CEES for 9-48 h were subjected to molecular analysis. Our results show a strong CEES-induced phosphorylation of H2A.X and an increase in cyclooxygenase-2 (COX-2), inducible NOS (iNOS), and matrix metalloproteinase-9 (MMP-9) levels, indicating the involvement of DNA damage and inflammation in CEES-induced skin injury in male and female mice. Since, our recent studies showed reduction in CEES-induced inflammatory responses by glutathione (GSH), we further assessed the role of oxidative stress in CEES-related DNA damage and the induction of inflammatory molecules. Oral GSH (300 mg/kg) administration 1h before CEES exposure attenuated the increase in both CEES-induced H2A.X phosphorylation (59%) as well as expression of COX-2 (68%), iNOS (53%) and MMP-9 (54%). Collectively, our results indicate that CEES-induced skin injury involves DNA damage and an induction of inflammatory mediators, at least in part via oxidative stress. This study could help in identifying countermeasures that alone or in combination, can target the unveiled pathways for reducing skin injury in humans by SM.
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Affiliation(s)
- Anil K Jain
- Department of Pharmaceutical Sciences, University of Colorado Denver School of Pharmacy, Aurora, CO 80045, USA.
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17
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Designing of mouse model: a new approach for studying sulphur mustard-induced skin lesions. Burns 2011; 37:851-64. [PMID: 21334815 DOI: 10.1016/j.burns.2010.12.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 10/20/2010] [Accepted: 12/10/2010] [Indexed: 01/12/2023]
Abstract
This study was planned to design a mouse model for studying sulphur mustard (SM)-induced skin injury. SM was applied dermally at dose of 5 or 10 mg kg(-1) in polyethyleneglycol-300 (PEG-300) or dimethylsulphoxide (DMSO) or acetone once. The changes in body weight, organ body weight indices (OBWI) and haematological and oxidative stress parameters were investigated over a period of 3-7 days and supported by histopathological observations. Exposure to SM in PEG-300 or DMSO resulted in a significant depletion in body weight, OBWI, hepatic glutathione (GSH) and elevation in hepatic lipid peroxidation, without affecting the blood GSH and hepatic oxidised glutathione (GSSG) levels. Interestingly, no aforesaid change was observed after dermal application of SM diluted in acetone. These biochemical changes were supported by the histological observations, which revealed pronounced toxic effect and damage to liver, kidney and spleen after dermal application of SM diluted in PEG-300 or DMSO. The skin showed similar microscopic changes after dermal application of SM in all the three diluents, however; the severity of lesions was found to be time and dose dependent. It can be concluded that dermal exposure of SM diluted in acetone can be used to mimic SM-induced skin toxicity without systemic toxicity in a mouse model.
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Young SC, Fabio KM, Huang MT, Saxena J, Harman MP, Guillon CD, Vetrano AM, Heck DE, Flowers RA, Heindel ND, Laskin JD. Investigation of anticholinergic and non-steroidal anti-inflammatory prodrugs which reduce chemically induced skin inflammation. J Appl Toxicol 2011; 32:135-41. [PMID: 21319177 DOI: 10.1002/jat.1645] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 11/08/2010] [Accepted: 11/22/2010] [Indexed: 12/28/2022]
Abstract
As part of a continuous effort to develop efficient counter measures against sulfur mustard injuries, several unique NSAID prodrugs have been developed and screened for anti-inflammatory properties. Presented herein are three classes of prodrugs which dually target inflammation and cholinergic dysfunction. Compounds 1-28 contain common NSAIDs linked either to choline bioisosteres or to structural analogs of acetylcholinesterase (AChE) inhibitors. These agents have shown utility as anti-vesicants and anti-inflammatory agents when screened in a mouse ear vesicant model (MEVM) against both 2-chloroethyl ethyl sulfide (CEES), a blistering agent, and 12-O-tetradecanoylphorbol-13-acetate (TPA), a common topical irritant. Many of the prodrugs have activity against CEES, with 5, 18, 22 and 27 reducing inflammation by more than 75% compared with a control. Compounds 12, 13, 15 and 22 show comparable activity against TPA. Promising activity in the MEVM is related to half-lives of NSAID release in plasma, moderate to high lipophilicity, and some degree of inhibition of AChE, a potential contributor to sulfur mustard-mediated tissue damage.
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Affiliation(s)
- Sherri C Young
- Department of Chemistry, Lehigh University, Bethlehem, PA 18015, USA
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Rohlman DS, Anger WK, Lein PJ. Correlating neurobehavioral performance with biomarkers of organophosphorous pesticide exposure. Neurotoxicology 2010; 32:268-76. [PMID: 21182866 DOI: 10.1016/j.neuro.2010.12.008] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 12/03/2010] [Accepted: 12/13/2010] [Indexed: 12/20/2022]
Abstract
There is compelling evidence that adverse neurobehavioral effects are associated with occupational organophosphorous pesticide (OP) exposure in humans. Behavioral studies of pesticide applicators, greenhouse workers, agricultural workers and farm residents exposed repeatedly over months or years to low levels of OPs reveal a relatively consistent pattern of neurobehavioral deficits. However, only two studies have demonstrated a link between neurobehavioral performance and current biomarkers of OP exposure including blood cholinesterase (ChE) activity and urinary levels of OP metabolites. A variety of reasons may explain why so few studies have reported such correlations, including differing individual and group exposure histories, differing methodologies for assessing behavior and exposure, and lack of a reliable index of exposure. Alternatively, these data may suggest that current biomarkers (ChE, urine metabolites) are neither predictive nor diagnostic of the neurobehavioral effects of chronic OP pesticide exposures. This review focuses on the evidence that neurobehavioral performance deficits are associated with occupational OP pesticide exposure and concludes that research needs to return to the basics and rigorously test the relationships between neurobehavioral performance and both current (ChE and urine metabolites) and novel (e.g., inflammation and oxidative stress) biomarkers using human and animal models. The results of such studies are critically important because OP pesticides are widely and extensively used throughout the world, including situations where exposure controls and personal protective equipment are not routinely used.
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Affiliation(s)
- Diane S Rohlman
- Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, OR 97239, USA.
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20
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Debiak M, Kehe K, Bürkle A. Role of poly(ADP-ribose) polymerase in sulfur mustard toxicity. Toxicology 2009; 263:20-5. [DOI: 10.1016/j.tox.2008.06.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2008] [Revised: 06/06/2008] [Accepted: 06/09/2008] [Indexed: 01/27/2023]
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21
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Tewari-Singh N, Rana S, Gu M, Pal A, Orlicky DJ, White CW, Agarwal R. Inflammatory biomarkers of sulfur mustard analog 2-chloroethyl ethyl sulfide-induced skin injury in SKH-1 hairless mice. Toxicol Sci 2008; 108:194-206. [PMID: 19075041 DOI: 10.1093/toxsci/kfn261] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Sulfur mustard (HD) is an alkylating and cytotoxic chemical warfare agent, which inflicts severe skin toxicity and an inflammatory response. Effective medical countermeasures against HD-caused skin toxicity are lacking due to limited knowledge of related mechanisms, which is mainly attributed to the requirement of more applicable and efficient animal skin toxicity models. Using a less toxic analog of HD, chloroethyl ethyl sulfide (CEES), we identified quantifiable inflammatory biomarkers of CEES-induced skin injury in dose- (0.05-2 mg) and time- (3-168 h) response experiments, and developed a CEES-induced skin toxicity SKH-1 hairless mouse model. Topical CEES treatment at high doses caused a significant dose-dependent increase in skin bi-fold thickness indicating edema. Histopathological evaluation of CEES-treated skin sections revealed increases in epidermal and dermal thickness, number of pyknotic basal keratinocytes, dermal capillaries, neutrophils, macrophages, mast cells, and desquamation of epidermis. CEES-induced dose-dependent increases in epidermal cell apoptosis and basal cell proliferation were demonstrated by the terminal deoxynucleotidyl transferase (tdt)-mediated dUTP-biotin nick end labeling and proliferative cell nuclear antigen stainings, respectively. Following an increase in the mast cells, myeloperoxidase activity in the inflamed skin peaked at 24 h after CEES exposure coinciding with neutrophil infiltration. F4/80 staining of skin integuments revealed an increase in the number of macrophages after 24 h of CEES exposure. In conclusion, these results establish CEES-induced quantifiable inflammatory biomarkers in a more applicable and efficient SKH-1 hairless mouse model, which could be valuable for agent efficacy studies to develop potential prophylactic and therapeutic interventions for HD-induced skin toxicity.
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Affiliation(s)
- Neera Tewari-Singh
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Denver, Aurora, Colorado 80045, USA
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22
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Lindsay CD, Gentilhomme E, Mathieu JD. The use of doxycycline as a protectant against sulphur mustard in HaCaT cells. J Appl Toxicol 2008; 28:665-73. [PMID: 18069744 DOI: 10.1002/jat.1320] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
As part of an ongoing programme on medical countermeasures against the chemical warfare agent sulphur mustard (HD) and set against the background of the involvement of matrix metalloproteinases (MMPs) in the pathology of HD-induced vesication processes, the potentially beneficial effects of doxycycline on cell attachment was determined in confluent HaCaT cell cultures exposed to HD. Doxycycline was found to inhibit to a significant extent the tendency of HD-exposed cells to detach from the growth substrate, however, analysis of the metabolic activity of the adherent cells indicated that doxycycline treatment did not maintain cell viability. It was confirmed that apoptosis was the predominant mode of HD-induced cell death. The results suggested that doxycycline and other MMP inhibitors may have a role to play in therapeutic intervention against HD exposure, but only as part of a combination therapy. The specific value of protease inhibitors in this capacity remains to be determined.
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Affiliation(s)
- Christopher D Lindsay
- Biomedical Sciences Department, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK.
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Inhibition of poly(ADP-ribose) polymerase (PARP) influences the mode of sulfur mustard (SM)-induced cell death in HaCaT cells. Arch Toxicol 2007; 82:461-70. [PMID: 18046540 DOI: 10.1007/s00204-007-0265-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 11/13/2007] [Indexed: 10/22/2022]
Abstract
Sulfur mustard (SM) is a bifunctional alkylating agent. Its primary toxic consequence is severe skin damage with blisters, occurring after skin contact. These vesicant properties of SM have been linked to cell death of proliferating keratinocytes in the basal layer of the skin. Catalytic activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP-1) has been demonstrated to be a major event in response to high levels of DNA damage, and PARP-1 activation may be part of apoptotic signaling. In other contexts, overstimulation of PARP-1 triggers necrotic cell death because of rapid consumption of its substrate, beta-nicotinamide adenine dinucleotide (NAD+) and the consequent depletion of ATP. These findings prompted us to evaluate whether SM induces apoptosis in keratinocytes like HaCaT cells and to determine whether blocking of PARP enzyme activity with 3-aminobenzamide (3AB) can influence the mode of cell death. HaCaT cells were exposed to SM (10-1,000 microM; 30 min) and then cultivated in SM-free medium with or without 3AB for up to 48 h. This treatment resulted in a time and SM dose-dependent increase of apoptotic cell death characterized by PARP-1 cleavage and DNA fragmentation during the experimental period. After just 45 min of exposure to 1 mM SM, we observed a significant increase in PARP-1 activity in HaCaT cells. About 6 h after exposure, intracellular ATP levels were diminished by 22%, which seemed to be completely prevented by the addition of 3AB directly after exposure. However, 18 h later, this 3AB effect on the SM concentration-dependent loss of ATP was no longer detectable. Interestingly, the effect of SM on total cell viability was not changed by 3AB. However, the mode of cell death was influenced by 3AB exhibiting an increase of apoptotic cells and a concomitant decrease of necrotic HaCaT cells during the first 24 h after SM exposure. Our results indicate that SM concentrations of 1 mM or higher induce a prominent PARP activation leading to ATP depletion and necrosis. In contrast, lower concentrations of SM cause minor PARP activation and, especially, PARP-1 cleavage by caspase 3 without ATP depletion. Because ATP is required for apoptosis, we suggest that ATP acts as an early molecular switch from apoptotic to necrotic modes of SM-induced cell death, at least at high concentrations (> or =1 mM). Thus, the observed early proapoptotic effect of 3AB at lower SM concentrations may point to the influence of ATP-independent cell-death regulating mechanisms.
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Amitai G, Adani R, Fishbein E, Meshulam H, Laish I, Dachir S. Bifunctional compounds eliciting anti-inflammatory and anti-cholinesterase activity as potential treatment of nerve and blister chemical agents poisoning. J Appl Toxicol 2006; 26:81-7. [PMID: 16167317 DOI: 10.1002/jat.1111] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Certain organophosphorus (OP) nerve agents (e.g. soman) induce neuroinflammatory processes during acute poisoning. An increased level of typical inflammation markers was also observed in poisoning by alkylating agents such as sulfur mustard (HD). The therapeutic potential of new bifunctional compounds was investigated, eliciting activity of non-steroidal anti-inflammatory drug (NSAID) and anti-cholinesterase (anti-ChE) activity, as an antidotal treatment for both soman and HD poisoning in mice. Three bifunctional compounds were used that include the ChE inhibitor pyridostigmine (PYR) coupled to either ibuprofen (IBU) or diclofenac (DICLO) through an eight (octyl) or ten (decyl) hydrocarbon chain spacer: IBU-PO, IBU-PD and DICLO-PD. These compounds are 15-25 fold less toxic than PYR in mice and exert peripheral and central anti-inflammatory and anti-ChE activity in vivo. IBU-PO (4 mg kg(-1), i.p.), IBU-PD (4 mg kg(-1), i.p.) and PYR (0.13 mg kg(-1), i.p.) reduced to control levels the brain edema in soman-poisoned mice (1.1 LD50, s.c.). Pre-treatment with IBU-PO, IBU-PD and DICLO-PD 4-5 h before soman challenge (2.2-2.3 LD50, s.c.) combined with antidotal treatment (atropine, 11 mg kg(-1), 2-PAM-Cl, 25 mg kg(-1), i.m.) afforded a longer 24 h survival rate (SR) than with PYR pre-treatment. DICLO-PD exhibited the largest protection efficacy (SR = 70% vs 17% with PYR). These results indicate a longer duration of action of bifunctional compounds compared with PYR. DICLO-PD (5% in propyleneglycol) reduced significantly the HD-induced edema in mouse ear-skin (51% increase in biopsy weight compared with 100% without treatment). Quantitative evaluation of ear-skin sections showed that only following DICLO-PD treatment was there a marked decrease in edema. DICLO-PD also elicited a significant decrease in HD-induced vesication as displayed by the reduced sub-epidermal blister level. The data indicate possible use of NSAID-ChEI bifunctional compounds for the medical treatment of both nerve and alkylating chemical agents.
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Affiliation(s)
- Gabi Amitai
- Division of Medicinal Chemistry, Israel Institute for Biological Research, PO Box 19, Ness Ziona 74100, Israel.
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Rogers JV, Choi YW, Kiser RC, Babin MC, Casillas RP, Schlager JJ, Sabourin CLK. Microarray analysis of gene expression in murine skin exposed to sulfur mustard. J Biochem Mol Toxicol 2005; 18:289-99. [PMID: 15674843 DOI: 10.1002/jbt.20043] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The chemical warfare agent sulfur mustard [bis-(2-chloroethyl)-sulfide; SM] produces a delayed inflammatory response followed by blister formation in skin of exposed individuals. Studies are underway evaluating the efficacy of pharmacological compounds to protect against SM skin injury. Microarray analysis provides the opportunity to identify multiple transcriptional biomarkers associated with SM exposure. This study examined SM-induced changes in gene expression in skin from mice cutaneously exposed to SM using cDNA microarrays. Ear skin from five mice, paired as SM-exposed right ear and dichloromethane vehicle-exposed left ear at six dose levels (0.005, 0.01, 0.02, 0.04, 0.08, and 0.16 mg; 6 mM to 195 mM range), was harvested at 24 h post-exposure. SM-induced gene expression was analyzed using cDNA microarrays that included 1,176 genes. Genes were selected on the basis of all mice (N=5) in the same dose group demonstrating a > or =2-fold increase or decrease in gene expression for the SM-exposed tissue compared to the dichloromethane vehicle control ear tissue at all six SM doses. When skin exposed to all six concentrations of SM was compared to controls, a total of 19 genes within apoptosis, transcription factors, cell cycle, inflammation, and oncogenes and tumor suppressors categories were found to be upregulated; no genes were observed to be downregulated. Differences in the number and category of genes that were up- or down-regulated in skin exposed to low (0.005-0.01 mg) and high (0.08-0.16 mg) doses of SM were also observed. The results of this study provide a further understanding of the molecular responses to cutaneous SM exposure, and enable the identification of potential diagnostic markers and therapeutic targets for treating SM injury.
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Affiliation(s)
- James V Rogers
- Battelle Memorial Institute, Medical Research and Evaluation Facility, Columbus, OH 43201, USA
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Sabourin CLK, Rogers JV, Choi YW, Kiser RC, Casillas RP, Babin MC, Schlager JJ. Time- and dose-dependent analysis of gene expression using microarrays in sulfur mustard-exposed mice. J Biochem Mol Toxicol 2005; 18:300-12. [PMID: 15674844 DOI: 10.1002/jbt.20047] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The chemical warfare agent sulfur mustard (SM) produces blister formation with a severe inflammatory reaction in skin of exposed individuals. The development of efficacious countermeasures against SM vesication requires an understanding of the cellular and molecular mechanism of SM-induced tissue injury. This study examined SM-induced alterations in gene expression using Atlas Mouse 5K DNA microarrays (5002 genes) to identify transcriptional events associated with SM skin injury. Mice (N=3) were exposed topically to SM (0.04, 0.08, and 0.16 mg; 48.8, 97.5, and 195 mM) on the inner surface of the right ear and skin tissues were harvested at 1.5, 3, 6, and 12 h. Genes were selected based on the three mice in the same dose group demonstrating a > or =2-fold increase or decrease in gene expression for the SM-exposed tissue when compared to the dichloromethane vehicle control ear at all three doses and four time points. At the 0.04 mg SM dose, the genes observed were primarily involved in inflammation, apoptosis, and cell cycle regulation. Exposure to 0.08 mg SM increased the expression of genes related to inflammation and cell cycle regulation. Exposure to 0.16 mg SM led to a total of six genes that were changed at all observed time periods; however, these genes do not appear to be directly influential in biological mechanisms such as inflammation, apoptosis, and cell cycle regulation as was observed at the lower SM doses of 0.04 and 0.08 mg. These functional categories have been observed in previous studies utilizing both in vivo and in vitro model systems of SM-induced dermal injury, suggesting that molecular mechanisms associated with inflammation, apoptosis, and cell cycle regulation may be appropriate targets for developing prophylactic/therapeutic treatments for SM skin injury.
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Affiliation(s)
- Carol L K Sabourin
- Battelle Memorial Institute, Medical Research and Evaluation Facility, Columbus, OH 43201, USA.
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