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Almeida AJD, Hobson BA, Saito N, Bruun DA, Porter VA, Harvey DJ, Garbow JR, Chaudhari AJ, Lein PJ. Quantitative T 2 mapping-based longitudinal assessment of brain injury and therapeutic rescue in the rat following acute organophosphate intoxication. Neuropharmacology 2024; 249:109895. [PMID: 38437913 DOI: 10.1016/j.neuropharm.2024.109895] [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: 09/08/2023] [Revised: 02/07/2024] [Accepted: 02/29/2024] [Indexed: 03/06/2024]
Abstract
Acute intoxication with organophosphate (OP) cholinesterase inhibitors poses a significant public health risk. While currently approved medical countermeasures can improve survival rates, they often fail to prevent chronic neurological damage. Therefore, there is need to develop effective therapies and quantitative metrics for assessing OP-induced brain injury and its rescue by these therapies. In this study we used a rat model of acute intoxication with the OP, diisopropylfluorophosphate (DFP), to test the hypothesis that T2 measures obtained from brain magnetic resonance imaging (MRI) scans provide quantitative metrics of brain injury and therapeutic efficacy. Adult male Sprague Dawley rats were imaged on a 7T MRI scanner at 3, 7 and 28 days post-exposure to DFP or vehicle (VEH) with or without treatment with the standard of care antiseizure drug, midazolam (MDZ); a novel antiseizure medication, allopregnanolone (ALLO); or combination therapy with MDZ and ALLO (DUO). Our results show that mean T2 values in DFP-exposed animals were: (1) higher than VEH in all volumes of interest (VOIs) at day 3; (2) decreased with time; and (3) decreased in the thalamus at day 28. Treatment with ALLO or DUO, but not MDZ alone, significantly decreased mean T2 values relative to untreated DFP animals in the piriform cortex at day 3. On day 28, the DUO group showed the most favorable T2 characteristics. This study supports the utility of T2 mapping for longitudinally monitoring brain injury and highlights the therapeutic potential of ALLO as an adjunct therapy to mitigate chronic morbidity associated with acute OP intoxication.
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Affiliation(s)
- Alita Jesal D Almeida
- Department of Biomedical Engineering, University of California-Davis College of Engineering, Davis, CA, 95616, USA; Department of Radiology, University of California-Davis School of Medicine, Sacramento, CA, 95817, USA.
| | - Brad A Hobson
- Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California-Davis College of Engineering, Davis, CA, 95616, USA.
| | - Naomi Saito
- Department of Public Health Sciences, University of California-Davis School of Medicine, Davis, CA, 95616, USA
| | - Donald A Bruun
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA, 95616, USA.
| | - Valerie A Porter
- Department of Biomedical Engineering, University of California-Davis College of Engineering, Davis, CA, 95616, USA; Department of Radiology, University of California-Davis School of Medicine, Sacramento, CA, 95817, USA.
| | - Danielle J Harvey
- Department of Public Health Sciences, University of California-Davis School of Medicine, Davis, CA, 95616, USA.
| | - Joel R Garbow
- Department of Radiology, Washington University School of Medicine, St Louis, MO, 63110, USA.
| | - Abhijit J Chaudhari
- Department of Radiology, University of California-Davis School of Medicine, Sacramento, CA, 95817, USA; Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California-Davis College of Engineering, Davis, CA, 95616, USA.
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California-Davis School of Veterinary Medicine, Davis, CA, 95616, USA.
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Porter VA, Hobson BA, Foster B, Lein PJ, Chaudhari AJ. Fully automated whole brain segmentation from rat MRI scans with a convolutional neural network. J Neurosci Methods 2024; 405:110078. [PMID: 38340902 PMCID: PMC11000587 DOI: 10.1016/j.jneumeth.2024.110078] [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: 11/14/2023] [Revised: 01/27/2024] [Accepted: 02/05/2024] [Indexed: 02/12/2024]
Abstract
BACKGROUND Whole brain delineation (WBD) is utilized in neuroimaging analysis for data preprocessing and deriving whole brain image metrics. Current automated WBD techniques for analysis of preclinical brain MRI data show limited accuracy when images present with significant neuropathology and anatomical deformations, such as that resulting from organophosphate intoxication (OPI) and Alzheimer's Disease (AD), and inadequate generalizability. METHODS A modified 2D U-Net framework was employed for WBD of MRI rodent brains, consisting of 27 convolutional layers, batch normalization, two dropout layers and data augmentation, after training parameter optimization. A total of 265 T2-weighted 7.0 T MRI scans were utilized for the study, including 125 scans of an OPI rat model for neural network training. For testing and validation, 20 OPI rat scans and 120 scans of an AD rat model were utilized. U-Net performance was evaluated using Dice coefficients (DC) and Hausdorff distances (HD) between the U-Net-generated and manually segmented WBDs. RESULTS The U-Net achieved a DC (median[range]) of 0.984[0.936-0.990] and HD of 1.69[1.01-6.78] mm for OPI rat model scans, and a DC (mean[range]) of 0.975[0.898-0.991] and HD of 1.49[0.86-3.89] for the AD rat model scans. COMPARISON WITH EXISTING METHODS The proposed approach is fully automated and robust across two rat strains and longitudinal brain changes with a computational speed of 8 seconds/scan, overcoming limitations of manual segmentation. CONCLUSIONS The modified 2D U-Net provided a fully automated, efficient, and generalizable segmentation approach that achieved high accuracy across two disparate rat models of neurological diseases.
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Affiliation(s)
- Valerie A Porter
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA; Department of Radiology, University of California, Davis, CA 95817, USA
| | - Brad A Hobson
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA; Center for Molecular and Genomic Imaging, University of California, Davis, CA 95616, USA
| | - Brent Foster
- TechMah Medical LLC, 2099 Thunderhead Rd, Knoxville, TN 37922, USA
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California, Davis, CA 95616, USA
| | - Abhijit J Chaudhari
- Department of Radiology, University of California, Davis, CA 95817, USA; Center for Molecular and Genomic Imaging, University of California, Davis, CA 95616, USA.
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Pan S, Bruun DA, Lein PJ, Chen CY. Cardiovascular responses of adult male Sprague-Dawley rats following acute organophosphate intoxication and post-exposure treatment with midazolam with or without allopregnanolone. Arch Toxicol 2024; 98:1177-1189. [PMID: 38305864 PMCID: PMC10944447 DOI: 10.1007/s00204-023-03679-x] [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: 09/11/2023] [Accepted: 12/20/2023] [Indexed: 02/03/2024]
Abstract
Recent experimental evidence suggests combined treatment with midazolam and allopregnanolone is more effective than midazolam alone in terminating seizures triggered by acute organophosphate (OP) intoxication. However, there are concerns that combined midazolam and allopregnanolone increases risk of adverse cardiovascular events. To address this, we used telemetry devices to record cardiovascular responses in adult male Sprague-Dawley rats acutely intoxicated with diisopropylfluorophosphate (DFP). Animals were administered DFP (4 mg/kg, sc), followed immediately by atropine (2 mg/kg, i.m.) and 2-PAM (25 mg/kg, i.m.). At 40 min post-exposure, a subset of animals received midazolam (0.65 mg/kg, im); at 50 min, these rats received a second dose of midazolam or allopregnanolone (12 mg/kg, im). DFP significantly increased blood pressure by ~ 80 mmHg and pulse pressure by ~ 34 mmHg that peaked within 12 min. DFP also increased core temperature by ~ 3.5 °C and heart rate by ~ 250 bpm that peaked at ~ 2 h. Heart rate variability (HRV), an index of autonomic function, was reduced by ~ 80%. All acute (within 15 min of exposure) and two-thirds of delayed (hours after exposure) mortalities were associated with non-ventricular cardiac events within 10 min of cardiovascular collapse, suggesting that non-ventricular events should be closely monitored in OP-poisoned patients. Compared to rats that survived DFP intoxication without treatment, midazolam significantly improved recovery of cardiovascular parameters and HRV, an effect enhanced by allopregnanolone. These data demonstrate that midazolam improved recovery of cardiovascular and autonomic function and that the combination of midazolam and allopregnanolone may be a better therapeutic strategy than midazolam alone.
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Affiliation(s)
- Shiyue Pan
- Department of Pharmacology, Davis, School of Medicine, University of California, Davis, CA, USA
| | - Donald A Bruun
- Department of Molecular Biosciences, Davis, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Pamela J Lein
- Department of Molecular Biosciences, Davis, School of Veterinary Medicine, University of California, Davis, CA, USA
- Davis, School of Medicine, MIND Institute, University of California, Sacramento, CA, USA
| | - Chao-Yin Chen
- Department of Pharmacology, Davis, School of Medicine, University of California, Davis, CA, USA.
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Andrew PM, Feng W, Calsbeek JJ, Antrobus SP, Cherednychenko GA, MacMahon JA, Bernardino PN, Liu X, Harvey DJ, Lein PJ, Pessah IN. The α4 Nicotinic Acetylcholine Receptor Is Necessary for the Initiation of Organophosphate-Induced Neuronal Hyperexcitability. TOXICS 2024; 12:263. [PMID: 38668486 PMCID: PMC11054284 DOI: 10.3390/toxics12040263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/20/2024] [Accepted: 03/27/2024] [Indexed: 04/29/2024]
Abstract
Acute intoxication with organophosphorus (OP) cholinesterase inhibitors can produce seizures that rapidly progress to life-threatening status epilepticus. Significant research effort has been focused on investigating the involvement of muscarinic acetylcholine receptors (mAChRs) in OP-induced seizure activity. In contrast, there has been far less attention on nicotinic AChRs (nAChRs) in this context. Here, we address this data gap using a combination of in vitro and in vivo models. Pharmacological antagonism and genetic deletion of α4, but not α7, nAChR subunits prevented or significantly attenuated OP-induced electrical spike activity in acute hippocampal slices and seizure activity in mice, indicating that α4 nAChR activation is necessary for neuronal hyperexcitability triggered by acute OP exposures. These findings not only suggest that therapeutic strategies for inhibiting the α4 nAChR subunit warrant further investigation as prophylactic and immediate treatments for acute OP-induced seizures, but also provide mechanistic insight into the role of the nicotinic cholinergic system in seizure generation.
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Affiliation(s)
- Peter M. Andrew
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA; (P.M.A.); (W.F.); (J.J.C.); (S.P.A.); (G.A.C.); (J.A.M.); (P.N.B.); (X.L.)
| | - Wei Feng
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA; (P.M.A.); (W.F.); (J.J.C.); (S.P.A.); (G.A.C.); (J.A.M.); (P.N.B.); (X.L.)
| | - Jonas J. Calsbeek
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA; (P.M.A.); (W.F.); (J.J.C.); (S.P.A.); (G.A.C.); (J.A.M.); (P.N.B.); (X.L.)
| | - Shane P. Antrobus
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA; (P.M.A.); (W.F.); (J.J.C.); (S.P.A.); (G.A.C.); (J.A.M.); (P.N.B.); (X.L.)
| | - Gennady A. Cherednychenko
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA; (P.M.A.); (W.F.); (J.J.C.); (S.P.A.); (G.A.C.); (J.A.M.); (P.N.B.); (X.L.)
| | - Jeremy A. MacMahon
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA; (P.M.A.); (W.F.); (J.J.C.); (S.P.A.); (G.A.C.); (J.A.M.); (P.N.B.); (X.L.)
| | - Pedro N. Bernardino
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA; (P.M.A.); (W.F.); (J.J.C.); (S.P.A.); (G.A.C.); (J.A.M.); (P.N.B.); (X.L.)
| | - Xiuzhen Liu
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA; (P.M.A.); (W.F.); (J.J.C.); (S.P.A.); (G.A.C.); (J.A.M.); (P.N.B.); (X.L.)
| | - Danielle J. Harvey
- Department of Public Health Sciences, UC Davis School of Medicine, Davis, CA 95616, USA;
| | - Pamela J. Lein
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA; (P.M.A.); (W.F.); (J.J.C.); (S.P.A.); (G.A.C.); (J.A.M.); (P.N.B.); (X.L.)
| | - Isaac N. Pessah
- Department of Molecular Biosciences, UC Davis School of Veterinary Medicine, Davis, CA 95616, USA; (P.M.A.); (W.F.); (J.J.C.); (S.P.A.); (G.A.C.); (J.A.M.); (P.N.B.); (X.L.)
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Neff MJ, Reddy DS. Long-Term Neuropsychiatric Developmental Defects after Neonatal Organophosphate Exposure: Mitigation by Synthetic Neurosteroids. J Pharmacol Exp Ther 2024; 388:451-468. [PMID: 37863488 PMCID: PMC10806574 DOI: 10.1124/jpet.123.001763] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 07/25/2023] [Accepted: 07/31/2023] [Indexed: 10/22/2023] Open
Abstract
Children are much more susceptible to the neurotoxic effects of organophosphate (OP) pesticides and nerve agents than adults. OP poisoning in children leads to acute seizures and neuropsychiatric sequela, including the development of long-term disabilities and cognitive impairments. Despite these risks, there are few chronic rodent models that use pediatric OP exposure for studying neurodevelopmental consequences and interventions. Here, we investigated the protective effect of the neurosteroid ganaxolone (GX) on the long-term developmental impact of neonatal exposure to the OP compound, diisopropyl-fluorophosphate (DFP). Pediatric postnatal day-28 rats were acutely exposed to DFP, and at 3 and 10 months after exposure, they were evaluated using a series of cognitive and behavioral tests with or without the postexposure treatment of GX. Analysis of the neuropathology was performed after 10 months. DFP-exposed animals displayed significant long-term deficits in mood, anxiety, depression, and aggressive traits. In spatial and nonspatial cognitive tests, they displayed striking impairments in learning and memory. Analysis of brain sections showed significant loss of neuronal nuclei antigen(+) principal neurons, parvalbumin(+) inhibitory interneurons, and neurogenesis, along with increased astrogliosis, microglial neuroinflammation, and mossy fiber sprouting. These detrimental neuropathological changes are consistent with behavioral dysfunctions. In the neurosteroid GX-treated cohort, behavioral and cognitive deficits were significantly reduced and were associated with strong protection against long-term neuroinflammation and neurodegeneration. In conclusion, this pediatric model replicates the salient features of children exposed to OPs, and the protective outcomes from neurosteroid intervention support the viability of developing this strategy for mitigating the long-term effects of acute OP exposure in children. SIGNIFICANCE STATEMENT: An estimated 3 million organophosphate exposures occur annually worldwide, with children comprising over 30% of all victims. Our understanding of the neurodevelopmental consequences in children exposed to organophosphates is limited. Here, we investigated the long-term impact of neonatal exposure to diisopropyl-fluorophosphate in pediatric rats. Neurosteroid treatment protected against major deficits in behavior and memory and was well correlated with neuropathological changes. Overall, this pediatric model is helpful to screen novel therapies to mitigate long-term developmental deficits of organophosphate exposure.
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Affiliation(s)
- Michael James Neff
- Department of Neuroscience and Experimental Therapeutics (M.J.N., D.S.R.) and Institute of Pharmacology and Neurotherapeutics (M.J.N., D.S.R.), School of Medicine, Texas A&M University Health Science Center, Bryan, Texas
| | - Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics (M.J.N., D.S.R.) and Institute of Pharmacology and Neurotherapeutics (M.J.N., D.S.R.), School of Medicine, Texas A&M University Health Science Center, Bryan, Texas
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Bhattacharya D, Barille R, Toukam DK, Gawali VS, Kallay L, Ahmed T, Brown H, Rezvanian S, Karve A, Desai PB, Medvedovic M, Wang K, Ionascu D, Harun N, Wang C, Baschnagel AM, Kritzer JA, Cook JM, Pomeranz Krummel DA, Sengupta S. GABA(A) receptor activation drives GABARAP-Nix mediated autophagy to radiation-sensitize primary and brain-metastatic lung adenocarcinoma tumors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.29.569295. [PMID: 38076805 PMCID: PMC10705483 DOI: 10.1101/2023.11.29.569295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2024]
Abstract
In non-small cell lung cancer (NSCLC) treatment, targeted therapies benefit only a subset of NSCLC, while radiotherapy responses are not durable and toxicity limits therapy. We find that a GABA(A) receptor activator, AM-101, impairs viability and clonogenicity of NSCLC primary and brain metastatic cells. Employing an ex vivo 'chip', AM-101 is as efficacious as the chemotherapeutic docetaxel, which is used with radiotherapy for advanced-stage NSCLC. In vivo , AM-101 potentiates radiation, including conferring a survival benefit to mice bearing NSCLC intracranial tumors. GABA(A) receptor activation stimulates a selective-autophagic response via multimerization of GABA(A) Receptor-Associated Protein (GABARAP), stabilization of mitochondrial receptor Nix, and utilization of ubiquitin-binding protein p62. A targeted-peptide disrupting Nix binding to GABARAP inhibits AM-101 cytotoxicity. This supports a model of GABA(A) receptor activation driving a GABARAP-Nix multimerization axis triggering autophagy. In patients receiving radiotherapy, GABA(A) receptor activation may improve tumor control while allowing radiation dose de-intensification to reduce toxicity. Highlights Activating GABA(A) receptors intrinsic to lung primary and metastatic brain cancer cells triggers a cytotoxic response. GABA(A) receptor activation works as well as chemotherapeutic docetaxel in impairing lung cancer viability ex vivo . GABA(A) receptor activation increases survival of mice bearing lung metastatic brain tumors.A selective-autophagic response is stimulated by GABA(A) receptor activation that includes multimerization of GABARAP and Nix.Employing a new nanomolar affinity peptide that abrogates autophagosome formation inhibits cytotoxicity elicited by GABA(A) receptor activation.
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Naylor DE. In the fast lane: Receptor trafficking during status epilepticus. Epilepsia Open 2023; 8 Suppl 1:S35-S65. [PMID: 36861477 PMCID: PMC10173858 DOI: 10.1002/epi4.12718] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 02/23/2023] [Indexed: 03/03/2023] Open
Abstract
Status epilepticus (SE) remains a significant cause of morbidity and mortality and often is refractory to standard first-line treatments. A rapid loss of synaptic inhibition and development of pharmacoresistance to benzodiazepines (BZDs) occurs early during SE, while NMDA and AMPA receptor antagonists remain effective treatments after BZDs have failed. Multimodal and subunit-selective receptor trafficking within minutes to an hour of SE involves GABA-A, NMDA, and AMPA receptors and contributes to shifts in the number and subunit composition of surface receptors with differential impacts on the physiology, pharmacology, and strength of GABAergic and glutamatergic currents at synaptic and extrasynaptic sites. During the first hour of SE, synaptic GABA-A receptors containing γ2 subunits move to the cell interior while extrasynaptic GABA-A receptors with δ subunits are preserved. Conversely, NMDA receptors containing N2B subunits are increased at synaptic and extrasynaptic sites, and homomeric GluA1 ("GluA2-lacking") calcium permeant AMPA receptor surface expression also is increased. Molecular mechanisms, largely driven by NMDA receptor or calcium permeant AMPA receptor activation early during circuit hyperactivity, regulate subunit-specific interactions with proteins involved with synaptic scaffolding, adaptin-AP2/clathrin-dependent endocytosis, endoplasmic reticulum (ER) retention, and endosomal recycling. Reviewed here is how SE-induced shifts in receptor subunit composition and surface representation increase the excitatory to inhibitory imbalance that sustains seizures and fuels excitotoxicity contributing to chronic sequela such as "spontaneous recurrent seizures" (SRS). A role for early multimodal therapy is suggested both for treatment of SE and for prevention of long-term comorbidities.
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Affiliation(s)
- David E Naylor
- VA Greater Los Angeles Healthcare System, Department of Neurology, David Geffen School of Medicine at UCLA, and The Lundquist Institute at Harbor-UCLA Medical Center, Los Angeles, California, USA
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Guignet M, Schmuck M, Harvey DJ, Nguyen D, Bruun D, Echeverri A, Gurkoff G, Lein PJ. Novel image analysis tool for rapid screening of cell morphology in preclinical animal models of disease. Heliyon 2023; 9:e13449. [PMID: 36873154 PMCID: PMC9975095 DOI: 10.1016/j.heliyon.2023.e13449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 12/18/2022] [Accepted: 01/30/2023] [Indexed: 02/10/2023] Open
Abstract
The field of cell biology has seen major advances in both cellular imaging modalities and the development of automated image analysis platforms that increase rigor, reproducibility, and throughput for large imaging data sets. However, there remains a need for tools that provide accurate morphometric analysis of single cells with complex, dynamic cytoarchitecture in a high-throughput and unbiased manner. We developed a fully automated image-analysis algorithm to rapidly detect and quantify changes in cellular morphology using microglia cells, an innate immune cell within the central nervous system, as representative of cells that exhibit dynamic and complex cytoarchitectural changes. We used two preclinical animal models that exhibit robust changes in microglia morphology: (1) a rat model of acute organophosphate intoxication, which was used to generate fluorescently labeled images for algorithm development; and (2) a rat model of traumatic brain injury, which was used to validate the algorithm using cells labeled using chromogenic detection methods. All ex vivo brain sections were immunolabeled for IBA-1 using fluorescence or diaminobenzidine (DAB) labeling, images were acquired using a high content imaging system and analyzed using a custom-built algorithm. The exploratory data set revealed eight statistically significant and quantitative morphometric parameters that distinguished between phenotypically distinct groups of microglia. Manual validation of single-cell morphology was strongly correlated with the automated analysis and was further supported by a comparison with traditional stereology methods. Existing image analysis pipelines rely on high-resolution images of individual cells, which limits sample size and is subject to selection bias. However, our fully automated method integrates quantification of morphology and fluorescent/chromogenic signals in images from multiple brain regions acquired using high-content imaging. In summary, our free, customizable image analysis tool provides a high-throughput, unbiased method for accurately detecting and quantifying morphological changes in cells with complex morphologies.
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Affiliation(s)
- Michelle Guignet
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Martin Schmuck
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Danielle J. Harvey
- Department of Public Health Sciences, University of California-Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Danh Nguyen
- Division of General Internal Medicine, Department of Medicine, School of Medicine, University of California-Irvine, 100 Theory, Suite 120, Irvine, CA, 92617, USA
| | - Donald Bruun
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Angela Echeverri
- Department of Neurological Surgery, School of Medicine, University of California-Davis, 4800 Y Street, Sacramento, CA, 95817, USA
| | - Gene Gurkoff
- Department of Neurological Surgery, School of Medicine, University of California-Davis, 4800 Y Street, Sacramento, CA, 95817, USA
- Center for Neuroscience, University of California-Davis, 1544 Newton Court, Davis, CA, 95618, USA
| | - Pamela J. Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
- MIND Institute, School of Medicine, University of California-Davis, 2825 50th Street, Sacramento, CA, 95817, USA
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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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Cerne R, Lippa A, Poe MM, Smith JL, Jin X, Ping X, Golani LK, Cook JM, Witkin JM. GABAkines - Advances in the discovery, development, and commercialization of positive allosteric modulators of GABA A receptors. Pharmacol Ther 2022; 234:108035. [PMID: 34793859 PMCID: PMC9787737 DOI: 10.1016/j.pharmthera.2021.108035] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 11/08/2021] [Indexed: 12/25/2022]
Abstract
Positive allosteric modulators of γ-aminobutyric acid-A (GABAA) receptors or GABAkines have been widely used medicines for over 70 years for anxiety, epilepsy, sleep, and other disorders. Traditional GABAkines like diazepam have safety and tolerability concerns that include sedation, motor-impairment, respiratory depression, tolerance and dependence. Multiple GABAkines have entered clinical development but the issue of side-effects has not been fully solved. The compounds that are presently being developed and commercialized include several neuroactive steroids (an allopregnanolone formulation (brexanolone), an allopregnanolone prodrug (LYT-300), Sage-324, zuranolone, and ganaxolone), the α2/3-preferring GABAkine, KRM-II-81, and the α2/3/5-preferring GABAkine PF-06372865 (darigabat). The neuroactive steroids are in clinical development for post-partum depression, intractable epilepsy, tremor, status epilepticus, and genetic epilepsy disorders. Darigabat is in development for epilepsy and anxiety. The imidazodiazepine, KRM-II-81 is efficacious in animal models for the treatment of epilepsy and post-traumatic epilepsy, acute and chronic pain, as well as anxiety and depression. The efficacy of KRM-II-81 in models of pharmacoresistant epilepsy, preventing the development of seizure sensitization, and in brain tissue of intractable epileptic patients bodes well for improved therapeutics. Medicinal chemistry efforts are also ongoing to identify novel and improved GABAkines. The data document gaps in our understanding of the molecular pharmacology of GABAkines that drive differential pharmacological profiles, but emphasize advancements in the ability to successfully utilize GABAA receptor potentiation for therapeutic gain in neurology and psychiatry.
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Affiliation(s)
- Rok Cerne
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent, Indianapolis, IN USA,Faculty of Medicine, University of Ljubljana, Zaloška cesta 4, Ljubljana, Slovenia.,RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA,Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, IN, USA
| | - Arnold Lippa
- RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA
| | | | - Jodi L. Smith
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent, Indianapolis, IN USA
| | - Xiaoming Jin
- Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, IN, USA
| | - Xingjie Ping
- Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, IN, USA
| | - Lalit K. Golani
- Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - James M. Cook
- RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA,Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Jeffrey M. Witkin
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent, Indianapolis, IN USA,RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA,Department of Chemistry and Biochemistry, Milwaukee Institute of Drug Discovery, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
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11
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Time-dependent neuropathology in rats following organophosphate-induced status epilepticus. Neurotoxicology 2022; 91:45-59. [DOI: 10.1016/j.neuro.2022.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 04/11/2022] [Accepted: 04/24/2022] [Indexed: 11/17/2022]
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12
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Vuu I, Patterson EE, Wu CY, Zolkowska D, Leppik IE, Rogawski MA, Worrell GA, Kremen V, Cloyd JC, Coles LD. Intravenous and Intramuscular Allopregnanolone for Early Treatment of Status Epilepticus: Pharmacokinetics, Pharmacodynamics, and Safety in Dogs. J Pharmacol Exp Ther 2022; 380:104-113. [PMID: 34862270 PMCID: PMC11048262 DOI: 10.1124/jpet.121.000736] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 11/30/2021] [Indexed: 11/22/2022] Open
Abstract
Allopregnanolone (ALLO) is a neurosteroid that modulates synaptic and extrasynaptic GABAA receptors. We hypothesize that ALLO may be useful as first-line treatment of status epilepticus (SE). Our objectives were to (1) characterize ALLO pharmacokinetics-pharmacodynamics PK-PD after intravenous (IV) and intramuscular (IM) administration and (2) compare IV and IM ALLO safety and tolerability. Three healthy dogs and two with a history of epilepsy were used. Single ALLO IV doses ranging from 1-6 mg/kg were infused over 5 minutes or injected IM. Blood samples, vital signs, and sedation assessment were collected up to 8 hours postdose. Intracranial EEG (iEEG) was continuously recorded in one dog. IV ALLO exhibited dose-proportional increases in exposure, which were associated with an increase in absolute power spectral density in all iEEG frequency bands. This relationship was best described by an indirect link PK-PD model where concentration-response was described by a sigmoidal maximum response (Emax) equation. Adverse events included site injection pain with higher IM volumes and ataxia and sedation associated with higher doses. IM administration exhibited incomplete absorption and volume-dependent bioavailability. Robust iEEG changes after IM administration were not observed. Based on PK-PD simulations, a 2 mg/kg dose infused over 5 minutes is predicted to achieve plasma concentrations above the EC50, but below those associated with heavy sedation. This study demonstrates that ALLO is safe and well tolerated when administered at 1-4 mg/kg IV and up to 2 mg/kg IM. The rapid onset of effect after IV infusion suggests that ALLO may be useful in the early treatment of SE. SIGNIFICANCE STATEMENT: The characterization of the pharmacokinetics and pharmacodynamics of allopregnanolone is essential in order to design clinical studies evaluating its effectiveness as an early treatment for status epilepticus in dogs and people. This study has proposed a target dose/therapeutic range for a clinical trial in canine status epilepticus.
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Affiliation(s)
- Irene Vuu
- Clinical Pharmacology Modeling and Simulation, Amgen Inc., Thousand Oaks, California (I.V.); Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota (E.E.P.); Department of Neurology, University of California Davis School of Medicine, Sacramento, California (C.-Y.W., D.Z., M.A.R.); Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, Minnesota (I.E.L., J.C.C., L.D.C.); and Department of Neurology, Mayo Clinic, Rochester, Minnesota (G.A.W., V.K.)
| | - Edward E Patterson
- Clinical Pharmacology Modeling and Simulation, Amgen Inc., Thousand Oaks, California (I.V.); Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota (E.E.P.); Department of Neurology, University of California Davis School of Medicine, Sacramento, California (C.-Y.W., D.Z., M.A.R.); Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, Minnesota (I.E.L., J.C.C., L.D.C.); and Department of Neurology, Mayo Clinic, Rochester, Minnesota (G.A.W., V.K.)
| | - Chun-Yi Wu
- Clinical Pharmacology Modeling and Simulation, Amgen Inc., Thousand Oaks, California (I.V.); Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota (E.E.P.); Department of Neurology, University of California Davis School of Medicine, Sacramento, California (C.-Y.W., D.Z., M.A.R.); Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, Minnesota (I.E.L., J.C.C., L.D.C.); and Department of Neurology, Mayo Clinic, Rochester, Minnesota (G.A.W., V.K.)
| | - Dorota Zolkowska
- Clinical Pharmacology Modeling and Simulation, Amgen Inc., Thousand Oaks, California (I.V.); Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota (E.E.P.); Department of Neurology, University of California Davis School of Medicine, Sacramento, California (C.-Y.W., D.Z., M.A.R.); Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, Minnesota (I.E.L., J.C.C., L.D.C.); and Department of Neurology, Mayo Clinic, Rochester, Minnesota (G.A.W., V.K.)
| | - Ilo E Leppik
- Clinical Pharmacology Modeling and Simulation, Amgen Inc., Thousand Oaks, California (I.V.); Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota (E.E.P.); Department of Neurology, University of California Davis School of Medicine, Sacramento, California (C.-Y.W., D.Z., M.A.R.); Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, Minnesota (I.E.L., J.C.C., L.D.C.); and Department of Neurology, Mayo Clinic, Rochester, Minnesota (G.A.W., V.K.)
| | - Michael A Rogawski
- Clinical Pharmacology Modeling and Simulation, Amgen Inc., Thousand Oaks, California (I.V.); Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota (E.E.P.); Department of Neurology, University of California Davis School of Medicine, Sacramento, California (C.-Y.W., D.Z., M.A.R.); Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, Minnesota (I.E.L., J.C.C., L.D.C.); and Department of Neurology, Mayo Clinic, Rochester, Minnesota (G.A.W., V.K.)
| | - Gregory A Worrell
- Clinical Pharmacology Modeling and Simulation, Amgen Inc., Thousand Oaks, California (I.V.); Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota (E.E.P.); Department of Neurology, University of California Davis School of Medicine, Sacramento, California (C.-Y.W., D.Z., M.A.R.); Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, Minnesota (I.E.L., J.C.C., L.D.C.); and Department of Neurology, Mayo Clinic, Rochester, Minnesota (G.A.W., V.K.)
| | - Vaclav Kremen
- Clinical Pharmacology Modeling and Simulation, Amgen Inc., Thousand Oaks, California (I.V.); Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota (E.E.P.); Department of Neurology, University of California Davis School of Medicine, Sacramento, California (C.-Y.W., D.Z., M.A.R.); Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, Minnesota (I.E.L., J.C.C., L.D.C.); and Department of Neurology, Mayo Clinic, Rochester, Minnesota (G.A.W., V.K.)
| | - James C Cloyd
- Clinical Pharmacology Modeling and Simulation, Amgen Inc., Thousand Oaks, California (I.V.); Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota (E.E.P.); Department of Neurology, University of California Davis School of Medicine, Sacramento, California (C.-Y.W., D.Z., M.A.R.); Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, Minnesota (I.E.L., J.C.C., L.D.C.); and Department of Neurology, Mayo Clinic, Rochester, Minnesota (G.A.W., V.K.)
| | - Lisa D Coles
- Clinical Pharmacology Modeling and Simulation, Amgen Inc., Thousand Oaks, California (I.V.); Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St. Paul, Minnesota (E.E.P.); Department of Neurology, University of California Davis School of Medicine, Sacramento, California (C.-Y.W., D.Z., M.A.R.); Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, Minneapolis, Minnesota (I.E.L., J.C.C., L.D.C.); and Department of Neurology, Mayo Clinic, Rochester, Minnesota (G.A.W., V.K.)
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13
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Gore A, Neufeld-Cohen A, Egoz I, Baranes S, Gez R, Efrati R, David T, Dekel Jaoui H, Yampolsky M, Grauer E, Chapman S, Lazar S. Neuroprotection by delayed triple therapy following sarin nerve agent insult in the rat. Toxicol Appl Pharmacol 2021; 419:115519. [PMID: 33823148 DOI: 10.1016/j.taap.2021.115519] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/25/2021] [Accepted: 04/01/2021] [Indexed: 02/08/2023]
Abstract
The development of refractory status epilepticus (SE) induced by sarin intoxication presents a therapeutic challenge. In our current research we evaluate the efficacy of a delayed combined triple treatment in ending the abnormal epileptiform seizure activity (ESA) and the ensuing of long-term neuronal insult. SE was induced in male Sprague-Dawley rats by exposure to 1.2LD50 sarin insufficiently treated by atropine and TMB4 (TA) 1 min later. Triple treatment of ketamine, midazolam and valproic acid was administered 30 min or 1 h post exposure and was compared to a delayed single treatment with midazolam alone. Toxicity and electrocorticogram activity were monitored during the first week and behavioral evaluation performed 3 weeks post exposure followed by brain biochemical and immunohistopathological analyses. The addition of both single and triple treatments reduced mortality and enhanced weight recovery compared to the TA-only treated group. The triple treatment also significantly minimized the duration of the ESA, reduced the sarin-induced increase in the neuroinflammatory marker PGE2, the brain damage marker TSPO, decreased the gliosis, astrocytosis and neuronal damage compared to the TA+ midazolam or only TA treated groups. Finally, the triple treatment eliminated the sarin exposed increased open field activity, as well as impairing recognition memory as seen in the other experimental groups. The delayed triple treatment may serve as an efficient therapy, which prevents brain insult propagation following sarin-induced refractory SE, even if treatment is postponed for up to 1 h.
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Affiliation(s)
- Ariel Gore
- Department of Pharmacology, Israel Institute for Biological, Chemical and Environmental Sciences, Ness-Ziona 74100, Israel.
| | - Adi Neufeld-Cohen
- Department of Pharmacology, Israel Institute for Biological, Chemical and Environmental Sciences, Ness-Ziona 74100, Israel
| | - Inbal Egoz
- Department of Pharmacology, Israel Institute for Biological, Chemical and Environmental Sciences, Ness-Ziona 74100, Israel
| | - Shlomi Baranes
- Department of Pharmacology, Israel Institute for Biological, Chemical and Environmental Sciences, Ness-Ziona 74100, Israel
| | - Rellie Gez
- Department of Pharmacology, Israel Institute for Biological, Chemical and Environmental Sciences, Ness-Ziona 74100, Israel
| | - Rahav Efrati
- Department of Pharmacology, Israel Institute for Biological, Chemical and Environmental Sciences, Ness-Ziona 74100, Israel
| | - Tse'ela David
- The Veterinary Center for Pre-clinical Research, Israel Institute for Biological, Chemical and Environmental Sciences, Ness- Ziona 74100, Israel
| | - Hani Dekel Jaoui
- The Veterinary Center for Pre-clinical Research, Israel Institute for Biological, Chemical and Environmental Sciences, Ness- Ziona 74100, Israel
| | - Michael Yampolsky
- The Veterinary Center for Pre-clinical Research, Israel Institute for Biological, Chemical and Environmental Sciences, Ness- Ziona 74100, Israel
| | - Ettie Grauer
- Department of Pharmacology, Israel Institute for Biological, Chemical and Environmental Sciences, Ness-Ziona 74100, Israel
| | - Shira Chapman
- Department of Pharmacology, Israel Institute for Biological, Chemical and Environmental Sciences, Ness-Ziona 74100, Israel
| | - Shlomi Lazar
- Department of Pharmacology, Israel Institute for Biological, Chemical and Environmental Sciences, Ness-Ziona 74100, Israel.
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14
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Abstract
The canonical mechanism of organophosphate (OP) neurotoxicity is the inhibition of acetylcholinesterase (AChE). However, multiple lines of evidence suggest that mechanisms in addition to or other than AChE inhibition contribute to the neurotoxic effects associated with acute and chronic OP exposures. Characterizing the role(s) of AChE inhibition versus noncholinergic mechanisms in OP neurotoxicity remains an active area of research with significant diagnostic and therapeutic implications. Here, we review recently published studies that provide mechanistic insights regarding (1) OP-induced status epilepticus, (2) long-term neurologic consequences of acute OP exposures, and (3) neurotoxic effects associated with repeated low-level OP exposures. Key data gaps and challenges are also discussed.
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Affiliation(s)
- Yi-Hua Tsai
- Department of Molecular Sciences, University of California, Davis School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Pamela J Lein
- Department of Molecular Sciences, University of California, Davis School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
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15
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Zolkowska D, Dhir A, Rogawski MA. Perampanel, a potent AMPA receptor antagonist, protects against tetramethylenedisulfotetramine-induced seizures and lethality in mice: comparison with diazepam. Arch Toxicol 2021; 95:2459-2468. [PMID: 33914090 PMCID: PMC8241714 DOI: 10.1007/s00204-021-03053-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/15/2021] [Indexed: 11/08/2022]
Abstract
Tetramethylenedisulfotetramine (TETS), a noncompetitive GABAA receptor antagonist, is a potent, highly lethal convulsant that is considered to be a chemical threat agent. Here, we assessed the ability of the AMPA receptor antagonist perampanel to protect against TETS-induced seizures and lethality in mice when administered before or after treatment with the toxicant. For comparison, we conducted parallel testing with diazepam, which is a first-line treatment for chemically induced seizures in humans. Pre-treatment of mice with either perampanel (1–4 mg/kg, i.p.) or diazepam (1–5 mg/kg, i.p.) conferred protection in a dose-dependent fashion against tonic seizures and lethality following a dose of TETS (0.2 mg/kg, i.p.) that rapidly induces seizures and death. The ED50 values for protection against mortality were 1.6 mg/kg for perampanel and 2.1 mg/kg for diazepam. Clonic seizures were unaffected by perampanel and only prevented in a minority of animals by high-dose diazepam. Neither treatment prevented myoclonic body twitches. Perampanel and diazepam also conferred protection against tonic seizures and lethality when administered 15 min following a 0.14 mg/kg, i.p., dose of TETS and 5 min following a 0.2 mg/kg, i.p., dose of TETS. Both posttreatments were highly potent at reducing tonic seizures and lethality in animals exposed to the lower dose of TETS whereas greater doses of both treatments were required in animals exposed to the larger dose of TETS. Neither treatment was as effective suppressing clonic seizures. In an experiment where 0.4 mg/kg TETS was administered by oral gavage and the treatment drugs were administered 5 min later, perampanel only partially protected against lethality whereas diazepam produced nearly complete protection. We conclude that perampanel and diazepam protect against TETS-induced tonic seizures and lethality but have less impact on clonic seizures. Both drugs could have utility in the treatment of TETS intoxication but neither eliminates all seizure activity.
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Affiliation(s)
- Dorota Zolkowska
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA
| | - Ashish Dhir
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA
| | - Michael A Rogawski
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA. .,Department of Pharmacology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA.
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16
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Maupu C, Enderlin J, Igert A, Oger M, Auvin S, Hassan-Abdi R, Soussi-Yanicostas N, Brazzolotto X, Nachon F, Dal Bo G, Dupuis N. Diisopropylfluorophosphate-induced status epilepticus drives complex glial cell phenotypes in adult male mice. Neurobiol Dis 2021; 152:105276. [PMID: 33529768 DOI: 10.1016/j.nbd.2021.105276] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 12/14/2020] [Accepted: 01/24/2021] [Indexed: 12/11/2022] Open
Abstract
Organophosphate pesticides and nerve agents (OPs), are characterized by cholinesterase inhibition. In addition to severe peripheral symptoms, high doses of OPs can lead to seizures and status epilepticus (SE). Long lasting seizure activity and subsequent neurodegeneration promote neuroinflammation leading to profound pathological alterations of the brain. The aim of this study was to characterize neuroinflammatory responses at key time points after SE induced by the OP, diisopropylfluorophosphate (DFP). Immunohistochemistry (IHC) analysis and RT-qPCR on cerebral tissue are often insufficient to identity and quantify precise neuroinflammatory alterations. To address these needs, we performed RT-qPCR quantification after whole brain magnetic-activated cell-sorting (MACS) of CD11B (microglia/infiltrated macrophages) and GLAST (astrocytes)-positive cells at 1, 4, 24 h and 3 days post-SE. In order to compare these results to those obtained by IHC, we performed, classical Iba1 (microglia/infiltrated macrophages) and GFAP (astrocytes) IHC analysis in parallel, focusing on the hippocampus, a brain region affected by seizure activity and neurodegeneration. Shortly after SE (1-4 h), an increase in pro-inflammatory (M1-like) markers and A2-specific markers, proposed as neurotrophic, were observed in CD11B and GLAST-positive isolated cells, respectively. Microglial cells successively expressed immuno-regulatory (M2b-like) and anti-inflammatory (M2a-like) at 4 h and 24 h post-SE induction. At 24 h and 3 days, A1-specific markers, proposed as neurotoxic, were increased in isolated astrocytes. Although IHC analysis presented no modification in terms of percentage of marked area and cell number at 1 and 4 h after SE, at 24 h and 3 days after SE, microglial and astrocytic activation was visible by IHC as an increase in Iba1 and GFAP-positive area and Iba1-positive cells in DFP animals when compared to the control. Our work identified sequential microglial and astrocytic phenotype activation. Although the role of each phenotype in SE cerebral outcomes requires further study, targeting specific markers at specific time point could be a beneficial strategy for DFP-induced SE treatment.
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Affiliation(s)
- Clémence Maupu
- Département de Toxicologie et risques chimiques, Institut de recherche biomédicale des armées, BP73, F-91223 Brétigny sur Orge cedex, France
| | - Julie Enderlin
- Université de Paris, NeuroDiderot, Inserm, F-75019 Paris, France; Service de neurologie pédiatrique, AP-HP, Hôpital Robert Debré, F-75019 Paris, France
| | - Alexandre Igert
- Département de Toxicologie et risques chimiques, Institut de recherche biomédicale des armées, BP73, F-91223 Brétigny sur Orge cedex, France
| | - Myriam Oger
- Unité Imagerie, Institut de recherche biomédicale des armées, BP73, F-91223 Brétigny sur Orge cedex, France
| | - Stéphane Auvin
- Université de Paris, NeuroDiderot, Inserm, F-75019 Paris, France; Service de neurologie pédiatrique, AP-HP, Hôpital Robert Debré, F-75019 Paris, France
| | | | | | - Xavier Brazzolotto
- Département de Toxicologie et risques chimiques, Institut de recherche biomédicale des armées, BP73, F-91223 Brétigny sur Orge cedex, France
| | - Florian Nachon
- Département de Toxicologie et risques chimiques, Institut de recherche biomédicale des armées, BP73, F-91223 Brétigny sur Orge cedex, France
| | - Grégory Dal Bo
- Département de Toxicologie et risques chimiques, Institut de recherche biomédicale des armées, BP73, F-91223 Brétigny sur Orge cedex, France
| | - Nina Dupuis
- Département de Toxicologie et risques chimiques, Institut de recherche biomédicale des armées, BP73, F-91223 Brétigny sur Orge cedex, France.
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