1
|
Lauková M, Velíšková J, Velíšek L, Shakarjian MP. Tetramethylenedisulfotetramine neurotoxicity: What have we learned in the past 70 years? Neurobiol Dis 2019; 133:104491. [PMID: 31176716 DOI: 10.1016/j.nbd.2019.104491] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/27/2019] [Accepted: 06/05/2019] [Indexed: 12/21/2022] Open
Abstract
Tetramethylenedisulfotetramine (tetramine, TETS, TMDT) is a seizure-producing neurotoxic chemical formed by the condensation of sulfamide and formaldehyde. Serendipitously discovered through an occupational exposure in 1949, it was promoted as a rodenticide but later banned worldwide due to its danger to human health. However, exceptional activity of the agent against rodent pests resulted in its clandestine manufacture with large numbers of inadvertent, intentional, and mass poisonings, which continue to this day. Facile synthesis, extreme potency, persistence, lack of odor, color, and taste identify it as an effective food adulterant and potential chemical agent of terror. No known antidote or targeted treatment is currently available. In this review we examine the origins of tetramethylenedisulfotetramine, from its identification as a neurotoxicant 70 years ago, through early research, to the most recent findings including the risk it poses in the post-911 world. Included is the information known regarding its in vitro pharmacology as a GABAA receptor channel antagonist, the toxic syndrome it produces in vivo, and its effect upon vulnerable populations. We also summarize the available information about potential therapeutic countermeasures and treatment strategies as well as the contribution of clinical development of TMDT poisoning to our understanding of epileptogenesis. Finally we identify gaps in our knowledge and suggest potentially fruitful directions for continued research on this dangerous, yet intriguing compound.
Collapse
Affiliation(s)
- Marcela Lauková
- Department of Public Health, Division of Environmental Health Science, School of Health Sciences and Practice, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Pediatrics, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84505, Slovakia
| | - Jana Velíšková
- Department of Cell Biology and Anatomy, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Obstetrics and Gynecology, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Neurology, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA
| | - Libor Velíšek
- Department of Cell Biology and Anatomy, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Neurology, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Pediatrics, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA
| | - Michael P Shakarjian
- Department of Public Health, Division of Environmental Health Science, School of Health Sciences and Practice, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Cell Biology and Anatomy, New York Medical College, 40 Sunshine Cottage Rd, Valhalla, NY 10595, USA; Department of Medicine, Division of Pulmonary and Critical Care Medicine, Rutgers-Robert Wood Johnson Medical School, 675 Hoes Ln W, Piscataway, NJ 08854, USA.
| |
Collapse
|
2
|
Abstract
Creating an automated assay team with multiple skills that can support diverse screening responsibilities is a key challenge for drug discovery research sites. Development of ultra high throughput screening (uHTS) screens, development of lead identification and lead optimization assays within medicinal chemistry supported projects, and automation and miniaturization of assays are best performed by a dedicated team of varying backgrounds, experience, and skill sets. This article discusses how integration with therapeutic franchises, regular communication processes, and formal and informal cross-training facilitate the establishment of a streamlined and efficient model at our site for supporting multiple projects at relatively modest financial outlay and recruitment levels.
Collapse
|
3
|
Shakarjian MP, Laukova M, Velíšková J, Stanton PK, Heck DE, Velíšek L. Tetramethylenedisulfotetramine: pest control gone awry. Ann N Y Acad Sci 2016; 1378:68-79. [PMID: 27384716 DOI: 10.1111/nyas.13120] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 05/07/2016] [Accepted: 05/10/2016] [Indexed: 01/01/2023]
Abstract
Incidences of pesticide poisonings are a significant cause of morbidity and mortality worldwide. The seizure-inducing rodenticide tetramethylenedisulfotetramine is one of the most toxic of these agents. Although banned, it has been responsible for thousands of accidental, intentional, and mass poisonings in mainland China and elsewhere. An optimal regimen for treatment of poisoning has not been established. Its facile synthesis from easily obtained starting materials, extreme potency, and lack of odor, color, or taste make it a potential chemical threat agent. This review describes the toxicologic properties of this agent, more recent advances in our understanding of its properties, and recommendations for future research.
Collapse
Affiliation(s)
- Michael P Shakarjian
- Department of Environmental Health Science, School of Health Sciences and Practice, Institute of Public Health, New York Medical College, Valhalla, New York. .,Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York. .,Department of Medicine, Division of Pulmonary and Critical Care Medicine, Rutgers-Robert Wood Johnson Medical School, Piscataway, New Jersey.
| | - Marcela Laukova
- Department of Environmental Health Science, School of Health Sciences and Practice, Institute of Public Health, New York Medical College, Valhalla, New York.,Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Jana Velíšková
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York.,Department of Obstetrics and Gynecology, New York Medical College, Valhalla, New York.,Department of Neurology, New York Medical College, Valhalla, New York
| | - Patric K Stanton
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York.,Department of Neurology, New York Medical College, Valhalla, New York
| | - Diane E Heck
- Department of Environmental Health Science, School of Health Sciences and Practice, Institute of Public Health, New York Medical College, Valhalla, New York
| | - Libor Velíšek
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York.,Department of Neurology, New York Medical College, Valhalla, New York.,Department of Pediatrics, New York Medical College, Valhalla, New York
| |
Collapse
|
4
|
|
5
|
Pillai GV, Smith AJ, Hunt PA, Simpson PB. Multiple structural features of steroids mediate subtype-selective effects on human α4β3δ GABAA receptors. Biochem Pharmacol 2004; 68:819-31. [PMID: 15294445 DOI: 10.1016/j.bcp.2004.05.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2004] [Accepted: 05/10/2004] [Indexed: 11/18/2022]
Abstract
Neurosteroids have been shown to mediate some of their physiological effects via a modulatory site on type A inhibitory gamma-aminobutyric acid (GABAA) receptors. In particular, recent evidence has implicated selective potentiation of the delta subunit of GABAA receptors as an important mediator of in vitro and in vivo neurosteroid activity. However, this has been demonstrated for only a very small number of steroids, so both the generality of this finding, and the structural features of steroids which mediate functional delta-selectivity, are unclear. We have used a potentiometric assay based on fluorescence resonance energy transfer to measure GABA-activated responses in L(tk-) cells stably transfected with human GABAA receptor alpha4beta3delta and alpha4beta3gamma2 receptor subtypes. A set of 28 steroids were evaluated on these subtypes to characterise their functional potency and efficacy in modulating GABA responses. For most compounds there was a clear separation of their efficacy profiles between the receptor subtypes, with a substantially larger maximal response at the alpha4beta3delta receptor. 5beta-Pregnan-3beta-ol-20-one, 5beta-pregnane-3alpha,20beta-diol and 5beta-pregnane-3alpha,17alpha-diol-11,20-dione showed particularly high efficacy for alpha4beta3delta. No compounds were identified that simply inhibited responses at delta-containing receptors. However, 5beta-pregnane-3alpha,17alpha,20beta-triol, prednisolone 21-acetate, 4-pregnene-17alpha,20alpha-diol-3-one-20-acetate, 4-pregnen-20alpha-ol-3-one, and 5beta-pregnane-3alpha,17alpha,21-triol-20-one inhibited, though did not abolish, GABA responses at the alpha4beta3gamma2 subtype, while evoking modest-amplitude potentiation of alpha4beta3delta responses. Molecular modelling on this compound series using principal components analysis indicates that several structural features of steroids underlie their relative functional selectivity for potentiation of delta-containing GABAA receptors.
Collapse
Affiliation(s)
- Gopalan V Pillai
- Neuroscience Research Centre, Merck Sharp and Dohme, Terlings Park, Harlow, Essex CM20 2QR, UK.
| | | | | | | |
Collapse
|
6
|
Lanctôt KL, Herrmann N, Mazzotta P, Khan LR, Ingber N. GABAergic function in Alzheimer's disease: evidence for dysfunction and potential as a therapeutic target for the treatment of behavioural and psychological symptoms of dementia. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2004; 49:439-53. [PMID: 15362248 DOI: 10.1177/070674370404900705] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Alzheimer's disease (AD) is characterized by disruptions in multiple major neurotransmitters. While many studies have attempted to establish whether GABA is disrupted in AD patients, findings have varied. We review evidence for disruptions in GABA among patients with AD and suggest that the variable findings reflect subtypes of the disease that are possibly manifested clinically by differing behavioural symptoms. GABA, the major inhibitory neurotransmitter, has long been a target for anxiolytics, hypnotic sedatives, and anticonvulsants. We review the clinical use of GABAergic agents in treating persons with AD symptoms. While newer generation GABAergic medications are now available, they have yet to be evaluated among patients with AD.
Collapse
Affiliation(s)
- Krista L Lanctôt
- Department of Psychiatry, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Ontario.
| | | | | | | | | |
Collapse
|
7
|
Adkins CE, Pillai GV, Kerby J, Bonnert TP, Haldon C, McKernan RM, Gonzalez JE, Oades K, Whiting PJ, Simpson PB. alpha4beta3delta GABA(A) receptors characterized by fluorescence resonance energy transfer-derived measurements of membrane potential. J Biol Chem 2001; 276:38934-9. [PMID: 11495904 DOI: 10.1074/jbc.m104318200] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Selective modulators of gamma-aminobutyric acid, type A (GABA(A)) receptors containing alpha(4) subunits may provide new treatments for epilepsy and premenstrual syndrome. Using mouse L(-tk) cells, we stably expressed the native GABA(A) receptor subunit combinations alpha(3)beta(3)gamma(2,) alpha(4)beta(3)gamma(2), and, for the first time, alpha(4)beta(3)delta and characterized their properties using a novel fluorescence resonance energy transfer assay of GABA-evoked depolarizations. GABA evoked concentration-dependent decreases in fluorescence resonance energy transfer that were blocked by GABA(A) receptor antagonists and, for alpha(3)beta(3)gamma(2) and alpha(4)beta(3)gamma(2) receptors, modulated by benzodiazepines with the expected subtype specificity. When combined with alpha(4) and beta(3), delta subunits, compared with gamma(2), conferred greater sensitivity to the agonists GABA, 4,5,6,7-tetrahydroisoxazolo-[5,4-c]pyridin-3-ol (THIP), and muscimol and greater maximal efficacy to THIP. alpha(4)beta(3)delta responses were markedly modulated by steroids and anesthetics. Alphaxalone, pentobarbital, and pregnanolone were all 3-7-fold more efficacious at alpha(4)beta(3)delta compared with alpha(4)beta(3)gamma(2.) The fluorescence technique used in this study has proven valuable for extensive characterization of a novel GABA(A) receptor. For GABA(A) receptors containing alpha(4) subunits, our experiments reveal that inclusion of delta instead of gamma(2) subunits can increase the affinity and in some cases the efficacy of agonists and can increase the efficacy of allosteric modulators. Pregnanolone was a particularly efficacious modulator of alpha(4)beta(3)delta receptors, consistent with a central role for this subunit combination in premenstrual syndrome.
Collapse
Affiliation(s)
- C E Adkins
- Neuroscience Research Centre, Terlings Park, Merck Sharp & Dohme, Eastwick Road, Harlow, Essex, United Kingdom.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Shaffer KM, Lin HJ, Maric D, Pancrazio JJ, Stenger DA, Barker JL, Ma W. The use of GABA(A) receptors expressed in neural precursor cells for cell-based assays. Biosens Bioelectron 2001; 16:481-9. [PMID: 11544042 DOI: 10.1016/s0956-5663(01)00162-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
GABA(A) receptors are known targets for certain classes of environmental neurotoxins and pharmaceutical compounds. Since few neural cell lines express functional GABA(A) receptors, the capacity to rapidly screen for compounds that affect GABA(A) receptor function is presently limited. Previous work has demonstrated that rat neural precursor cells express functional GABA(A) receptors that can be monitored via Ca(2+) imaging. This study examined GABA(A) receptor subunit expression to determine whether GABA(A) receptor function and its interactions with neurotoxins is preserved after passaging. Neural precursor cells isolated from embryonic day 13 rat brain were expanded in serum-free medium containing basic fibroblast growth factor and passaged three times. Reverse transcription-polymerase chain reaction analysis demonstrated early expression of abundant mRNAs encoding various GABA(A) receptor subunits. Ca(2+) imaging showed that the highly proliferating precursor cells in passaged cultures maintained expression of functional GABA(A) receptors. In addition, we showed that trimethylolpropane phosphate, a neurotoxin generated during partial pyrolysis of a synthetic ester turbine engine lubricant, potently inhibited muscimol (GABA(A) receptor agonist) but not depolarization-induced cytosolic Ca(2+) increase. The findings of this study suggest that neural precursor cells may be well suited for the evaluation of certain environmental neurotoxins with convulsant activity. The potential use of neural precursor cells in high-throughput screens for compounds acting on GABA(A) receptors is discussed.
Collapse
Affiliation(s)
- K M Shaffer
- Center for Bio/Molecular Science and Engineering, Code 6900, Naval Research Laboratory, Washington, DC 20375, USA
| | | | | | | | | | | | | |
Collapse
|