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Paruch K, Kaproń B, Łuszczki JJ, Paneth A, Plech T. Effect of Linker Elongation on the VGSC Affinity and Anticonvulsant Activity among 4-Alkyl-5-aryl-1,2,4-triazole-3-thione Derivatives. Molecules 2023; 28:5287. [PMID: 37446948 DOI: 10.3390/molecules28135287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/04/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
The main aim of the current project was to investigate the effect of the linker size in 4-alkyl-5-aryl-1,2,4-triazole-3-thione derivatives, known as a group of antiepileptic drug candidates, on their affinity towards voltage-gated sodium channels (VGSCs). The rationale of the study was based both on the SAR observations and docking simulations of the interactions between the designed ligands and the binding site of human VGSC. HYDE docking scores, which describe hydrogen bonding, desolvation, and hydrophobic effects, obtained for 5-[(3-chlorophenyl)ethyl]-4-butyl/hexyl-1,2,4-triazole-3-thiones, justified their beneficial sodium channel blocking activity. The results of docking simulations were verified using a radioligand binding assay with [3H]batrachotoxin. Unexpectedly, although the investigated triazole-based compounds acted as VGSC ligands, their affinities were lower than those of the respective analogs containing shorter alkyl linkers. Since numerous sodium channel blockers are recognized as antiepileptic agents, the obtained 1,2,4-triazole derivatives were examined for antiepileptic potential using an experimental model of tonic-clonic seizures in mice. Median effective doses (ED50) of the compounds examined in MES test reached 96.6 ± 14.8 mg/kg, while their median toxic doses (TD50), obtained in the rotarod test, were even as high as 710.5 ± 47.4 mg/kg.
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Affiliation(s)
- Kinga Paruch
- Department of Pharmacology, Faculty of Health Sciences, Medical University of Lublin, Radziwiłłowska 11, 20-080 Lublin, Poland
| | - Barbara Kaproń
- Department of Clinical Genetics, Faculty of Medicine, Medical University of Lublin, Radziwiłłowska 11, 20-080 Lublin, Poland
| | - Jarogniew J Łuszczki
- Department of Occupational Medicine, Faculty of Medical Sciences, Medical University of Lublin, Jaczewskiego 8B, 20-090 Lublin, Poland
| | - Agata Paneth
- Department of Organic Chemistry, Faculty of Pharmacy, Medical University of Lublin, Chodźki 4A, 20-059 Lublin, Poland
| | - Tomasz Plech
- Department of Pharmacology, Faculty of Health Sciences, Medical University of Lublin, Radziwiłłowska 11, 20-080 Lublin, Poland
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The Antiarrhythmic Activity of Novel Pyrrolidin-2-one Derivative S-75 in Adrenaline-Induced Arrhythmia. Pharmaceuticals (Basel) 2021; 14:ph14111065. [PMID: 34832847 PMCID: PMC8625052 DOI: 10.3390/ph14111065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 11/29/2022] Open
Abstract
Arrhythmia is a quivering or irregular heartbeat that can often lead to blood clots, stroke, heart failure, and other heart-related complications. The limited efficacy and safety of antiarrhythmic drugs require the design of new compounds. Previous research indicated that pyrrolidin-2-one derivatives possess an affinity for α1-adrenergic receptors. The blockade of α1-adrenoceptor may play a role in restoring normal sinus rhythm; therefore, we aimed to verify the antiarrhythmic activity of novel pyrrolidin-2-one derivative S-75. In this study, we assessed the influence on sodium, calcium, potassium channels, and β1-adrenergic receptors to investigate the mechanism of action of S-75. Lack of affinity for β1-adrenoceptors and weak effects on ion channels decreased the role of these adrenoceptors and channels in the pharmacological activity of S-75. Next, we evaluated the influence of S-75 on normal ECG in rats and isolated rat hearts, and the tested derivative did not prolong the QTc interval, which may confirm the lack of the proarrhythmic potential. We tested antiarrhythmic activity in adrenaline-, aconitine- and calcium chloride-induced arrhythmia models in rats. The studied compound showed prophylactic antiarrhythmic activity in the adrenaline-induced arrhythmia, but no significant activity in the model of aconitine- or calcium chloride-induced arrhythmia. In addition, S-75 was not active in the model of post-reperfusion arrhythmias of the isolated rat hearts. Conversely, the compound showed therapeutic antiarrhythmic properties in adrenaline-induced arrhythmia, reducing post-arrhythmogen heart rhythm disorders, and decreasing animal mortality. Thus, we suggest that the blockade of α1-adrenoceptor might be beneficial in restoring normal heart rhythm in adrenaline-induced arrhythmia.
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Kaproń B, Czarnomysy R, Wysokiński M, Andrys R, Musilek K, Angeli A, Supuran CT, Plech T. 1,2,4-Triazole-based anticonvulsant agents with additional ROS scavenging activity are effective in a model of pharmacoresistant epilepsy. J Enzyme Inhib Med Chem 2020; 35:993-1002. [PMID: 32253957 PMCID: PMC7178883 DOI: 10.1080/14756366.2020.1748026] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 03/20/2020] [Accepted: 03/23/2020] [Indexed: 12/16/2022] Open
Abstract
There are numerous studies supporting the contribution of oxidative stress to the pathogenesis of epilepsy. Prolonged oxidative stress is associated with the overexpression of ATP-binding cassette transporters, which results in antiepileptic drugs resistance. During our studies, three 1,2,4-triazole-3-thione derivatives were evaluated for the antioxidant activity and anticonvulsant effect in the 6 Hz model of pharmacoresistant epilepsy. The investigated compounds exhibited 2-3 times more potent anticonvulsant activity than valproic acid in 6 Hz test in mice, which is well-established preclinical model of pharmacoresistant epilepsy. The antioxidant/ROS scavenging activity was confirmed in both single-electron transfer-based methods (DPPH and CUPRAC) and during flow cytometric analysis of total ROS activity in U-87 MG cells. Based on the enzymatic studies on human carbonic anhydrases (CAs), acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), one can assume that the herein investigated drug candidates will not impair the cognitive processes mediated by CAs and will have minimal off-target cholinergic effects.
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Affiliation(s)
- Barbara Kaproń
- Department of Clinical Genetics, I Faculty of Medicine with Dentistry Division, Medical University of Lublin, Lublin, Poland
| | - Robert Czarnomysy
- Department of Synthesis and Technology of Drugs, Faculty of Pharmacy, Medical University of Białystok, Bialystok, Poland
| | - Mariusz Wysokiński
- Department of Basic Nursing and Medical Teaching, Chair of Development in Nursing, Faculty of Health Sciences, Medical University of Lublin, Lublin, Poland
| | - Rudolf Andrys
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Kamil Musilek
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, Hradec Kralove, Czech Republic
| | - Andrea Angeli
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Firenze, Italy
| | - Claudiu T. Supuran
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Firenze, Italy
| | - Tomasz Plech
- Department of Pharmacology, Faculty of Health Sciences, Medical University of Lublin, Lublin, Poland
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Pytka K, Socała K, Rapacz A, Nieoczym D, Pieróg M, Gryboś A, Siwek A, Waszkielewicz A, Wlaź P. HBK-14 and HBK-15, triple 5-HT 1A, 5-HT 7 and 5-HT 3 antagonists with potent antidepressant- and anxiolytic-like properties, increase seizure threshold in various seizure tests in mice. Prog Neuropsychopharmacol Biol Psychiatry 2017; 79:378-385. [PMID: 28729118 DOI: 10.1016/j.pnpbp.2017.07.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/12/2017] [Accepted: 07/15/2017] [Indexed: 02/02/2023]
Abstract
Most antidepressants lower seizure threshold, which might be due to the modulation of serotonergic neurotransmission. Here, we investigated the effects of two 5-HT1A, 5-HT7 and 5-HT3 antagonists, i.e., 1-(2-(2-(2,6-dimethylphenoxy)ethoxy)ethyl)-4-(2-methoxyphenyl)piperazine hydrochloride (HBK-14) and 1-{2-[2-(2-chloro-6-methylphenoxy)ethoxy]ethyl}-4-(2-methoxyphenyl)piperazine hydrochloride (HBK-15), with antidepressant- and anxiolytic-like properties, on seizure thresholds in three acute seizure tests, i.e., the intravenous pentylenetetrazole, maximal electroshock seizure threshold (MEST), and 6-Hz corneal stimulation test in mice. We also evaluated their affinity for voltage-gated sodium channels. Our results indicate that HBK-14 increased seizure thresholds in three seizure tests in mice, while HBK-15 was active in the MEST and 6-Hz tests. None of the compounds affected neuromuscular strength or motor coordination at active doses. We showed that both compounds had high affinity for voltage-dependent sodium channels, which combined with the influence on 5-HT1A, 5-HT7 and 5-HT3 receptors, might underlie their anticonvulsant effects. Since most antidepressants lower the seizure threshold, the fact that both compounds with potent antidepressant-like activity, increased or had no influence on seizure threshold is worth investigating.
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Affiliation(s)
- Karolina Pytka
- Department of Pharmacodynamics, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland.
| | - Katarzyna Socała
- Department of Animal Physiology, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Lublin, Poland
| | - Anna Rapacz
- Department of Pharmacodynamics, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland
| | - Dorota Nieoczym
- Department of Animal Physiology, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Lublin, Poland
| | - Mateusz Pieróg
- Department of Animal Physiology, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Lublin, Poland
| | - Anna Gryboś
- Department of Pharmacobiology, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland
| | - Agata Siwek
- Department of Pharmacobiology, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland
| | - Anna Waszkielewicz
- Department of Bioorganic Chemistry, Chair of Organic Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna 9, 30-688 Krakow, Poland
| | - Piotr Wlaź
- Department of Animal Physiology, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Lublin, Poland
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Animal models of ischaemic stroke and characterisation of the ischaemic penumbra. Neuropharmacology 2017; 134:169-177. [PMID: 28923277 DOI: 10.1016/j.neuropharm.2017.09.022] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 09/08/2017] [Accepted: 09/13/2017] [Indexed: 02/07/2023]
Abstract
Over the past forty years, animal models of focal cerebral ischaemia have allowed us to identify the critical cerebral blood flow thresholds responsible for irreversible cell death, electrical failure, inhibition of protein synthesis, energy depletion and thereby the lifespan of the potentially salvageable penumbra. They have allowed us to understand the intricate biochemical and molecular mechanisms within the 'ischaemic cascade' that initiate cell death in the first minutes, hours and days following stroke. Models of permanent, transient middle cerebral artery occlusion and embolic stroke have been developed each with advantages and limitations when trying to model the complex heterogeneous nature of stroke in humans. Yet despite these advances in understanding the pathophysiological mechanisms of stroke-induced cell death with numerous targets identified and drugs tested, a lack of translation to the clinic has hampered pre-clinical stroke research. With recent positive clinical trials of endovascular thrombectomy in acute ischaemic stroke the stroke community has been reinvigorated, opening up the potential for future translation of adjunctive treatments that can be given alongside thrombectomy/thrombolysis. This review discusses the major animal models of focal cerebral ischaemia highlighting their advantages and limitations. Acute imaging is crucial in longitudinal pre-clinical stroke studies in order to identify the influence of acute therapies on tissue salvage over time. Therefore, the methods of identifying potentially salvageable ischaemic penumbra are discussed. This article is part of the Special Issue entitled 'Cerebral Ischemia'.
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Kaproń B, Łuszczki J, Paneth A, Wujec M, Siwek A, Karcz T, Mordyl B, Głuch-Lutwin M, Gryboś A, Nowak G, Pająk K, Jóźwiak K, Tomczykowski A, Plech T. Molecular mechanism of action and safety of 5-(3-chlorophenyl)-4-hexyl-2,4-dihydro-3 H-1,2,4-triazole-3-thione - a novel anticonvulsant drug candidate. Int J Med Sci 2017; 14:741-749. [PMID: 28824309 PMCID: PMC5562128 DOI: 10.7150/ijms.20001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/06/2017] [Indexed: 11/17/2022] Open
Abstract
Previously, it was found that 5-(3-chlorophenyl)-4-hexyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (TP-315) effectively protects mice from maximal electroshock-induced seizures. The aim of this study was to determine possible interactions between TP-315 and different molecular targets, i.e. GABAA receptors, voltage-gated sodium channels, and human neuronal α7 and α4β2 nicotinic acetylcholine receptors. The influence of TP-315 on the viability of human hepatic HepG2 cells was also established using PrestoBlue and ToxiLight assays. It was found that the anticonvulsant activity of TP-315 results (at least partially) from its influence on voltage-gated sodium channels (VGSCs). Moreover, the title compound slightly affected the viability of human hepatic cells.
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Affiliation(s)
- Barbara Kaproń
- Department of Organic Chemistry, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
| | - Jarogniew Łuszczki
- Department of Pathophysiology, Medical University of Lublin, Jaczewskiego 8, Lublin 20-090, Poland.,Isobolographic Analysis Laboratory, Institute of Rural Health, Jaczewskiego 2, Lublin 20-950, Poland
| | - Agata Paneth
- Department of Organic Chemistry, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
| | - Monika Wujec
- Department of Organic Chemistry, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
| | - Agata Siwek
- Department of Pharmacobiology, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland
| | - Tadeusz Karcz
- Department of Technology and Biotechnology of Drugs, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland
| | - Barbara Mordyl
- Department of Pharmacobiology, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland
| | - Monika Głuch-Lutwin
- Department of Pharmacobiology, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland
| | - Anna Gryboś
- Department of Pharmacobiology, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland
| | - Gabriel Nowak
- Department of Pharmacobiology, Jagiellonian University Medical College, Medyczna 9, 30-688 Kraków, Poland
| | - Karolina Pająk
- Department of Biopharmacy, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
| | - Krzysztof Jóźwiak
- Department of Biopharmacy, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
| | - Adam Tomczykowski
- Department of Organic Chemistry, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
| | - Tomasz Plech
- Department of Pharmacology, Medical University of Lublin, Chodzki 4A, 20-093 Lublin, Poland
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Animal Models of Stroke for Preclinical Drug Development: A Comparative Study of Flavonols for Cytoprotection. Transl Stroke Res 2012. [DOI: 10.1007/978-1-4419-9530-8_25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Glendenning ML, Lovekamp-Swan T, Schreihofer DA. Protective effect of estrogen in endothelin-induced middle cerebral artery occlusion in female rats. Neurosci Lett 2008; 445:188-92. [PMID: 18790008 DOI: 10.1016/j.neulet.2008.09.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Revised: 09/02/2008] [Accepted: 09/03/2008] [Indexed: 10/21/2022]
Abstract
Estrogen is a powerful endogenous and exogenous neuroprotective agent in animal models of brain injury, including focal cerebral ischemia. Although this protection has been demonstrated in several different treatment and injury paradigms, it has not been demonstrated in focal cerebral ischemia induced by intraparenchymal endothelin-1 injection, a model with many advantages over other models of experimental focal ischemia. Reproductively mature female Sprague-Dawley rats were ovariectomized and divided into placebo and estradiol-treated groups. Two weeks later, halothane-anesthetized rats underwent middle cerebral artery (MCA) occlusion by interparenchymal stereotactic injection of the potent vasoconstrictor endothelin 1 (180pmoles/2microl) near the middle cerebral artery. Laser-Doppler flowmetry (LDF) revealed similar reductions in cerebral blood flow in both groups. Animals were behaviorally evaluated before, and 2 days after, stroke induction, and infarct size was evaluated. In agreement with other models, estrogen treatment significantly reduced infarct size evaluated by both TTC and Fluoro-Jade staining and behavioral deficits associated with stroke. Stroke size was significantly correlated with LDF in both groups, suggesting that cranial perfusion measures can enhance success in this model.
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Affiliation(s)
- Michele L Glendenning
- Department of Physiology, CA3145, Medical College of Georgia, 1120 15th Street, Augusta, GA 30912-3000, United States
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Nicolazzo JA, Nguyen TT, Katneni K, Steuten JA, Smith G, Jarrott B, Callaway JK, Charman SA. Pharmacokinetics and brain uptake of AM-36, a novel neuroprotective agent, following intravenous administration to rats. J Pharm Pharmacol 2008; 60:171-8. [PMID: 18237464 DOI: 10.1211/jpp.60.2.0005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The plasma pharmacokinetics and brain uptake of the novel neuroprotective agent AM-36 (1-(2-(4-chlorophenyl)-2-hydroxy)ethyl-4-(3,5-bis-(1,1dimethylethyl)-4-hydroxyphenyl) methylpiperazine) were assessed over 72 h following i.v. administration to male Sprague-Dawley rats. At nominal i.v. doses of 0.2, 1 and 3mg kg(-1), AM-36 exhibited an extremely large volume of distribution (18.2-24.6 L kg(-1)) and a long terminal elimination half-life, ranging from 25.2 to 37.7 h. Over this dose range, AM-36 exhibited linear pharmacokinetics, with no apparent change in clearance, volume of distribution or dose-normalised area under the plasma concentration - time curve. AM-36 was very highly bound to plasma proteins (> 99.6%); however, this did not appear to affect the ability of AM-36 to permeate the blood-brain barrier. Following a single i.v. dose of AM-36 at 3mg kg(-1) to rats, brain concentrations were detected for up to 72 h, and the brain-to-plasma ratios were high at all time points (ranging from 8.2 at 5 min post-dose to 0.9 at 72 h post-dose). The very high brain uptake of AM-36 supports previous in-vivo efficacy studies demonstrating the neuroprotective effects of this compound when administered to rats with middle cerebral artery occlusion.
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Affiliation(s)
- Joseph A Nicolazzo
- Centre for Drug Candidate Optimisation, Victorian College of Pharmacy, Monash University, Parkville, Victoria 3052, Australia
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Ferrante M, Blackwell KT, Migliore M, Ascoli GA. Computational models of neuronal biophysics and the characterization of potential neuropharmacological targets. Curr Med Chem 2008; 15:2456-71. [PMID: 18855673 PMCID: PMC3560392 DOI: 10.2174/092986708785909094] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The identification and characterization of potential pharmacological targets in neurology and psychiatry is a fundamental problem at the intersection between medicinal chemistry and the neurosciences. Exciting new techniques in proteomics and genomics have fostered rapid progress, opening numerous questions as to the functional consequences of ligand binding at the systems level. Psycho- and neuro-active drugs typically work in nerve cells by affecting one or more aspects of electrophysiological activity. Thus, an integrated understanding of neuropharmacological agents requires bridging the gap between their molecular mechanisms and the biophysical determinants of neuronal function. Computational neuroscience and bioinformatics can play a major role in this functional connection. Robust quantitative models exist describing all major active membrane properties under endogenous and exogenous chemical control. These include voltage-dependent ionic channels (sodium, potassium, calcium, etc.), synaptic receptor channels (e.g. glutamatergic, GABAergic, cholinergic), and G protein coupled signaling pathways (protein kinases, phosphatases, and other enzymatic cascades). This brief review of neuromolecular medicine from the computational perspective provides compelling examples of how simulations can elucidate, explain, and predict the effect of chemical agonists, antagonists, and modulators in the nervous system.
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Affiliation(s)
| | - Kim T. Blackwell
- Krasnow Institute for Advanced Study, George Mason University
- Department of Molecular Neuroscience, George Mason University, Fairfax, Virginia
| | - Michele Migliore
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Giorgio A. Ascoli
- Krasnow Institute for Advanced Study, George Mason University
- Department of Molecular Neuroscience, George Mason University, Fairfax, Virginia
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Weston RM, Jarrott B, Ishizuka Y, Callaway JK. AM-36 modulates the neutrophil inflammatory response and reduces breakdown of the blood brain barrier after endothelin-1 induced focal brain ischaemia. Br J Pharmacol 2006; 149:712-23. [PMID: 17016500 PMCID: PMC2014659 DOI: 10.1038/sj.bjp.0706918] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND AND PURPOSE Following transient focal stroke, rapid accumulation and activation of neutrophils in the ischaemic region is deleterious due to release of reactive oxygen species and myeloperoxidase (MPO). The purpose of this study was to examine whether AM-36, both a Na+ channel blocker and an antioxidant, afforded neuroprotection by modulating neutrophil accumulation into brain, following endothelin-1 (ET-1) induced middle cerebral artery occlusion (MCAo) in conscious rats. EXPERIMENTAL APPROACH AM-36 was administered at 3 and 24 h after ET-1-induced MCAo. Functional recovery was determined using grid-walking and cylinder tests. Image analysis of brain sections was used to determine infarct volume. The effect of AM-36 on neutrophil infiltration and their interaction with macrophages was examined in rats at 48 h following MCAo by both an MPO assay and double-label immunofluorescence. Blood brain barrier (BBB) breakdown was measured by the area stained by intravenous Evans Blue. KEY RESULTS AM-36 reduced functional deficits in both tests such that no difference existed from pre-ischaemic values at 48 h. Neutrophil infiltration, assessed by MPO activity, and infarct volume were significantly reduced following AM-36 administration by 54 and 60% respectively. Similarly, immunofluorescence revealed that AM-36 reduced neutrophil infiltration by approximately 50% in selected brain regions, when compared to controls, and also modulated macrophage phagocytosis of neutrophils. Breakdown of the BBB was significantly reduced by 60% following AM-36 treatment. CONCLUSIONS AND IMPLICATIONS These findings suggest that AM-36 can directly modulate the neutrophil inflammatory response and reduce BBB breakdown following MCAo.
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Affiliation(s)
- R M Weston
- Department of Pharmacology, Monash University Clayton, Australia
- Howard Florey Institute, The University of Melbourne Parkville, Australia
| | - B Jarrott
- Howard Florey Institute, The University of Melbourne Parkville, Australia
| | - Y Ishizuka
- Department of Pharmacology, Monash University Clayton, Australia
- Department of Psychiatry, Miyazaki Medical College Kihara, Kiyotake, Miyazaki, Japan
| | - J K Callaway
- Howard Florey Institute, The University of Melbourne Parkville, Australia
- Author for correspondence:
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Shih AY, Li P, Murphy TH. A small-molecule-inducible Nrf2-mediated antioxidant response provides effective prophylaxis against cerebral ischemia in vivo. J Neurosci 2006; 25:10321-35. [PMID: 16267240 PMCID: PMC6725780 DOI: 10.1523/jneurosci.4014-05.2005] [Citation(s) in RCA: 341] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) coordinates expression of genes required for free radical scavenging, detoxification of xenobiotics, and maintenance of redox potential. Previously, activation of this pleiotropic response was neuroprotective in cell culture models that simulate components of stroke damage. However, the role of Nrf2 in limiting stroke damage in vivo remained unclear. We report that Nrf2 activation protects the brain from cerebral ischemia in vivo. Acute (1-3 d) intracerebroventricular or intraperitoneal pretreatment with tert-butylhydroquinone (tBHQ), an Nrf2 activity inducer, reduced cortical damage and sensorimotor deficit at 24 h and even 1 month after ischemia-reperfusion in rats. Cortical glutathione levels robustly increased with tBHQ administration to rats and Nrf2-expressing mice, but not Nrf2(-/-) mice. Basal and inducible activities of antioxidant/detoxification enzymes in Nrf2(-/-) mice were reduced when compared with Nrf2(+/+) controls. Interestingly, larger infarcts were observed in Nrf2(-/-) mice at 7 d after stroke, but not at 24 h, suggesting that Nrf2 may play a role in shaping the penumbra well after the onset of ischemia. Neuronal death caused by a "penumbral" model of stroke, using intracortical endothelin-1 microinjection, was attenuated by tBHQ administration to Nrf2(+/+), but not to Nrf2(-/-) mice, confirming the Nrf2-specific action of tBHQ in vivo. We conclude that Nrf2 plays a role in modulating ischemic injury in vivo. Accordingly, Nrf2 activation by small molecule inducers may be a practical preventative treatment for stroke-prone patients.
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Affiliation(s)
- Andy Y Shih
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research and Brain Research Center, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
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Bentley P, Sharma P. Pharmacological treatment of ischemic stroke. Pharmacol Ther 2005; 108:334-52. [PMID: 16135384 DOI: 10.1016/j.pharmthera.2005.05.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Accepted: 05/07/2005] [Indexed: 11/17/2022]
Abstract
Current pharmacological strategies for acute ischemic stroke largely mirror those employed in acute coronary syndromes. However, important differences in the effectiveness and versatility of the principal agents have emerged between these 2 clinical settings. In general, the level of success achieved with drugs in acute coronary syndromes has not carried over to the same extent when the same drug types are used in stroke. The principal reason is that reperfusion or anticoagulant therapies in the setting of brain infarction run a significant risk of hemorrhagic transformation that has no direct equivalent in myocardial infarction. Consequently, a significant challenge in acute stroke therapeutics is the ability to select patients for drugs where only a narrow therapeutic margin exists and to identify methods that can minimize hemorrhage risk. Other brain-specific vascular factors also pertain in explaining differences in outcome of drugs generally regarded as having a broad cardiovascular remit. The relatively limited efficacy of antiplatelets in stroke might relate to the composition and heterogeneity of the cerebrovascular lesion, while the poor outcome associated with acute anti-hypertensive use is partly due to loss of cerebrovascular autoregulation. Finally, downstream consequences of arterial occlusion within the brain such as excitotoxicity and plasticity are organ specific and, as such, deserve their own pharmacological approaches. In this review, we describe the general mechanism of each drug class used in ischemic stroke and then report on the clinical experience and application for each.
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Affiliation(s)
- Paul Bentley
- Hammersmith Hospitals Acute Stroke Unit (HHASU), Imperial College, Fulham Palace Road, London W6 8RF, United Kingdom
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Gribkoff VK, Winquist RJ. Voltage-gated cation channel modulators for the treatment of stroke. Expert Opin Investig Drugs 2005; 14:579-92. [PMID: 15926865 DOI: 10.1517/13543784.14.5.579] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Neuronal voltage-gated cation channels regulate the transmembrane flux of calcium, sodium and potassium. Neuronal ischaemia occurring during acute ischaemic stroke results in the breakdown in the normal function of these ion channels, contributing to a series of pathological events leading to cell death. A dramatic increase in the intracellular concentration of calcium during neuronal ischaemia plays a particularly important role in the neurotoxic cascade resulting in stroke-related acute neurodegeneration. One approach to provide therapeutic benefit following ischaemic stroke has been to target neuronal voltage-gated cation channels, and particularly blockers of calcium and sodium channels, for post-stroke neuroprotection. A recent development has been the identification of openers of large-conductance calcium- and voltage-dependent potassium channels (maxi-K channels), which hyperpolarize ischaemic neurons, reduce excitatory amino acid release, and reduce ischaemic calcium entry. Thus far, targeting these voltage-gated cation channels has not yet yielded significant clinical benefit. The reasons for this may involve the lack of small-molecule blockers of many neuronal members of these ion channel families and the design of preclinical stroke models, which do not adequately emulate the clinical condition and hence lack sufficient rigor to predict efficacy in human stroke. Furthermore, there may be a need for changes in clinical trial designs to optimise the selection of patients and the course of drug treatment to protect neurons during all periods of potential neuronal sensitivity to neuro-protectants. Clinical trials may also have to be powered to detect small effect sizes or be focused on patients more likely to respond to a particular therapy. The development of future solutions to these problems should result in an improved probability of success for the treatment of stroke.
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Affiliation(s)
- Valentin K Gribkoff
- Department of Biology, Scion Pharmaceuticals, Inc., 200 Boston Avenue, Suite 3600, Medford, MA 02155, USA.
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