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Ying J, Zhou T, Liu Y, Zhou L, Wan JP. Transition-Metal-Free C-H Trifluoromethylthiolation of N,N-Disubstituted Enaminones To Access CF 3S-Functionalized Enaminones and Their Application in the Synthesis of CF 3S-Heteroaryls. J Org Chem 2024; 89:9078-9085. [PMID: 38830227 DOI: 10.1021/acs.joc.4c00704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
The α-C-H trifluoromethylthiolation of N,N-disubstituted enaminones has been achieved with simple and cheap CF3SO2Na as the CF3S source. The reactions were run at mild temperature (0 °C to rt) using POCl3 as the only reducing reagent. The work represents the first example on the synthesis of α-trifluoromethylthio enaminones via direct C-H functionalization. In addition, the resulting CF3S-functionalized enaminones have been proven as useful building blocks in the synthesis of various CF3S-functionalized heteroaromatic compounds by simple annulation reactions.
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Affiliation(s)
- Jinbiao Ying
- College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330033, China
| | - Tao Zhou
- College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330033, China
| | - Yunyun Liu
- College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330033, China
| | - Liyun Zhou
- College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330033, China
| | - Jie-Ping Wan
- College of Chemistry and Chemical Engineering, Jiangxi Normal University, Nanchang 330033, China
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Riluzole and novel naphthalenyl substituted aminothiazole derivatives prevent acute neural excitotoxic injury in a rat model of temporal lobe epilepsy. Neuropharmacology 2023; 224:109349. [PMID: 36436594 PMCID: PMC9843824 DOI: 10.1016/j.neuropharm.2022.109349] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 11/07/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022]
Abstract
Epileptogenic seizures, or status epilepticus (SE), leads to excitotoxic injury in hippocampal and limbic neurons in the kainic acid (KA) animal model of temporal lobe epilepsy (TLE). Here, we have further characterized neural activity regulated methylaminoisobutryic acid (MeAIB)/glutamine transport activity in mature rat hippocampal neurons in vitro that is inhibited by riluzole (IC50 = 1 μM), an anti-convulsant benzothiazole agent. We screened a library of riluzole derivatives and identified SKA-41 followed by a second screen and synthesized several novel chlorinated aminothiazoles (SKA-377, SKA-378, SKA-379) that are also potent MeAIB transport inhibitors in vitro, and brain penetrant following systemic administration. When administered before KA, SKA-378 did not prevent seizures but still protected the hippocampus and several other limbic areas against SE-induced neurodegeneration at 3d. When SKA-377 - 379, (30 mg/kg) were administered after KA-induced SE, acute neural injury in the CA3, CA1 and CA4/hilus was also largely attenuated. Riluzole (10 mg/kg) blocks acute neural injury. Kinetic analysis of SKA-378 and riluzoles' blockade of Ca2+-regulated MeAIB transport in neurons in vitro indicates that inhibition occurs via a non-competitive, indirect mechanism. Sodium channel NaV1.6 antagonism blocks neural activity regulated MeAIB/Gln transport in vitro (IC50 = 60 nM) and SKA-378 is the most potent inhibitor of NaV1.6 (IC50 = 28 μM) compared to NaV1.2 (IC50 = 118 μM) in heterologous cells. However, pharmacokinetic analysis suggests that sodium channel blockade may not be the predominant mechanism of neuroprotection here. Riluzole and our novel aminothiazoles are agents that attenuate acute neural hippocampal injury following KA-induced SE and may help to understand mechanisms involved in the progression of epileptic disease.
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Malik S, Miana G, Ata A, Kanwal M, Maqsood S, Malik I, Kazmi Z. SYNTHESIS, CHARACTERIZATION, IN-SILICO, AND PHARMACOLOGICAL EVALUATION OF NEW 2-AMINO-6-TRIFLUOROMETHOXY BENZOTHIAZOLE DERIVATIVES. Bioorg Chem 2022; 130:106175. [PMID: 36410112 DOI: 10.1016/j.bioorg.2022.106175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 09/18/2022] [Accepted: 09/21/2022] [Indexed: 11/28/2022]
Abstract
Alzheimer's disease (AD), a relentless neurodegenerative disorder, is still waiting for safer profile drugs, risk factors affecting AD's pathogenesis include aβ accumulation, tau protein hyperphosphorylation, and neuroinflammation. This research aimed to synthesize 2-amino-6‑trifluoromethoxy benzothiazole schiff bases. Synthesis was straightforward, combining the riluzole skeleton with compounds containing the azomethine group. Schiff bases synthesized were characterized spectroscopically using proton NMR (1H NMR), and FTIR. In-vivo biological evaluation against scopolamine-induced neuronal damage revealed that these newly synthesized schiff bases were effective in protecting neurons against neuroinflammatory mediators. In-vitro results revealed that these compounds had remarkable potential in improving the anti-oxidant levels. It downregulated glutathione (GSH), glutathione S-transferase (GST), catalase levels, and upregulated lipid peroxidation (LPO) levels. Immunohistochemical studies revealed that groups treated with the newly synthesized schiff bases had reduced expression of inflammatory mediators such as cyclooxygenase 2 (COX-2), JNK, tumor necrosis factor (TNF-α), nuclear factor kappa B (NF-kB) in contrast to the disease group. Moreover, molecular docking studies on these compounds also showed that they possessed a better binding affinity for above mentioned inflammatory mediators. The results of these studies showed that 2-amino-6-trifluoromethoxy benzothiazole schiff bases are remarkably effective against oxidative stress-mediated neuroinflammation.
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Lembke HK, Carlson EE. Activity-based ATP analog probes for bacterial histidine kinases. Methods Enzymol 2022; 664:59-84. [PMID: 35331379 DOI: 10.1016/bs.mie.2022.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Histidine kinases (HKs) are sensor proteins found ubiquitously in prokaryotes. They are the first protein in two-component systems (TCSs), signaling pathways that respond to a myriad of environmental stimuli. TCSs are typically comprised of a HK and its cognate response regulator (RR) which often acts as a transcription factor. RRs will bind DNA and ultimately lead to a cellular response. These cellular outputs vary widely, but HKs are particularly interesting as they are tied to antibiotic resistance and virulence pathways in pathogenic bacteria, making them promising drug targets. We anticipate that HK inhibitors could serve as either standalone antibiotics or antivirulence therapies. Additionally, while the cellular response mediated by the HKs is often well-characterized, very little is known about which stimuli trigger the sensor kinase to begin the phosphorylation cascade. Studying HK activity and enrichment of active HKs through activity-based protein profiling will enable these stimuli to be elucidated, filling this fundamental gap in knowledge. Here, we describe methods to evaluate the potency of putative HK inhibitors in addition to methods to calculate kinetic parameters of various activity-based probes designed for the HKs.
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Affiliation(s)
- Hannah K Lembke
- Department of Chemistry, University of Minnesota, Minneapolis, MN, United States
| | - Erin E Carlson
- Department of Chemistry, University of Minnesota, Minneapolis, MN, United States; Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, United States; Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, United States; Department of Pharmacology, University of Minnesota, Minneapolis, MN, United States.
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Morales JF, Chuguransky S, Alberca LN, Alice JI, Goicoechea S, Ruiz ME, Bellera CL, Talevi A. Positive Predictive Value Surfaces as a Complementary Tool to Assess the Performance of Virtual Screening Methods. Mini Rev Med Chem 2021; 20:1447-1460. [PMID: 32072906 DOI: 10.2174/1871525718666200219130229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Since their introduction in the virtual screening field, Receiver Operating Characteristic (ROC) curve-derived metrics have been widely used for benchmarking of computational methods and algorithms intended for virtual screening applications. Whereas in classification problems, the ratio between sensitivity and specificity for a given score value is very informative, a practical concern in virtual screening campaigns is to predict the actual probability that a predicted hit will prove truly active when submitted to experimental testing (in other words, the Positive Predictive Value - PPV). Estimation of such probability is however, obstructed due to its dependency on the yield of actives of the screened library, which cannot be known a priori. OBJECTIVE To explore the use of PPV surfaces derived from simulated ranking experiments (retrospective virtual screening) as a complementary tool to ROC curves, for both benchmarking and optimization of score cutoff values. METHODS The utility of the proposed approach is assessed in retrospective virtual screening experiments with four datasets used to infer QSAR classifiers: inhibitors of Trypanosoma cruzi trypanothione synthetase; inhibitors of Trypanosoma brucei N-myristoyltransferase; inhibitors of GABA transaminase and anticonvulsant activity in the 6 Hz seizure model. RESULTS Besides illustrating the utility of PPV surfaces to compare the performance of machine learning models for virtual screening applications and to select an adequate score threshold, our results also suggest that ensemble learning provides models with better predictivity and more robust behavior. CONCLUSION PPV surfaces are valuable tools to assess virtual screening tools and choose score thresholds to be applied in prospective in silico screens. Ensemble learning approaches seem to consistently lead to improved predictivity and robustness.
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Affiliation(s)
- Juan F Morales
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Sara Chuguransky
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Lucas N Alberca
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Juan I Alice
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Sofía Goicoechea
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - María E Ruiz
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Carolina L Bellera
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Alan Talevi
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
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Zou X, Wang Y, Yu Y, He J, Zhao F, Xi C, Zhang C, Cao Z. BmK NSP, a new sodium channel activator from Buthus martensii Karsch, promotes neurite outgrowth in primary cultured spinal cord neurons. Toxicon 2020; 182:13-20. [PMID: 32353571 DOI: 10.1016/j.toxicon.2020.04.096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 03/26/2020] [Accepted: 04/24/2020] [Indexed: 12/24/2022]
Abstract
Scorpion venom is a rich source of bioactive compounds that affect neuronal excitability by modulating the activities of various channels/receptors. In the current study, guided by a Ca2+ mobilization assay, we purified a new neuroactive peptide designated as BmK NSP (Buthus martensii Karsch neurite-stimulating peptide, MW: 7064.30 Da). The primary structure of BmK NSP was determined by Edman degradation. BmK NSP concentration-dependently elevated intracellular Ca2+ concentration ([Ca2+]i) with an EC50 value of 4.18 μM in primary cultured spinal cord neurons (SCNs). Depletion of extracellular Ca2+ abolished BmK NSP-triggered Ca2+ response. Moreover, we demonstrated that BmK NSP-induced Ca2+ response was partially suppressed by the inhibitors of L-type Ca2+ channels, Na+-Ca2+ exchangers and NMDA receptors and was abolished by voltage-gated sodium channel (VGSC) blocker, tetrodotoxin. Whole-cell patch clamp recording demonstrated that BmK NSP delayed VGSC inactivation (EC50 = 1.10 μM) in SCNs. BmK NSP enhanced neurite outgrowth in a non-monotonic manner that peaked at ~30 nM in SCNs. BmK NSP-promoted neurite outgrowth was suppressed by the inhibitors of L-type Ca2+ channels, NMDA receptors, and VGSCs. Considered together, these data demonstrate that BmK NSP is a new α-scorpion toxin that enhances neurite outgrowth through main routes of Ca2+ influx. Modulation of VGSC activity by α-scorpion toxin might represent a novel strategy to regulate the neurogenesis in SCNs.
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Affiliation(s)
- Xiaohan Zou
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Yujing Wang
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Yiyi Yu
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Jing He
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Fang Zhao
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China.
| | - Chuchu Xi
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Chi Zhang
- Jiangsu Provincial Supervision & Inspection Center of Green & Degradable Materials, Nanjing Institute of Product Quality Inspection, No. 3 E. Jialingjiang Street, Nanjing, Jiangsu, 210019, China
| | - Zhengyu Cao
- Department of TCM Pharmacology, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China.
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Roach KM, Bradding P. Ca 2+ signalling in fibroblasts and the therapeutic potential of K Ca3.1 channel blockers in fibrotic diseases. Br J Pharmacol 2020; 177:1003-1024. [PMID: 31758702 DOI: 10.1111/bph.14939] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/23/2019] [Accepted: 11/13/2019] [Indexed: 12/13/2022] Open
Abstract
The role of Ca2+ signalling in fibroblasts is of great interest in fibrosis-related diseases. Intracellular free Ca2+ ([Ca2+ ]i ) is a ubiquitous secondary messenger, regulating a number of cellular functions such as secretion, metabolism, differentiation, proliferation and contraction. The intermediate conductance Ca2+ -activated K+ channel KCa 3.1 is pivotal in Ca2+ signalling and plays a central role in fibroblast processes including cell activation, migration and proliferation through the regulation of cell membrane potential. Evidence from a number of approaches demonstrates that KCa 3.1 plays an important role in the development of many fibrotic diseases, including idiopathic pulmonary, renal tubulointerstitial fibrosis and cardiovascular disease. The KCa 3.1 selective blocker senicapoc was well tolerated in clinical trials for sickle cell disease, raising the possibility of rapid translation to the clinic for people suffering from pathological fibrosis. This review after analysing all the data, concludes that targeting KCa 3.1 should be a high priority for human fibrotic disease.
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Affiliation(s)
- Katy M Roach
- Institute for Lung Health, Department of Respiratory Sciences, University of Leicester, Leicester, UK
| | - Peter Bradding
- Institute for Lung Health, Department of Respiratory Sciences, University of Leicester, Leicester, UK
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3'-O-Methylorobol Inhibits the Voltage-Gated Sodium Channel Nav1.7 with Anti-Itch Efficacy in A Histamine-Dependent Itch Mouse Model. Int J Mol Sci 2019; 20:ijms20236058. [PMID: 31805638 PMCID: PMC6928743 DOI: 10.3390/ijms20236058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 02/07/2023] Open
Abstract
An itch is a clinical complication that affects millions of patients. However, few treatment options are available. The voltage-gated sodium channel Nav1.7 is predominantly expressed in peripheral sensory neurons and is responsible for the rising phase of action potentials, thereby mediating nociceptive conduction. A gain-of-function mutation of Nav1.7 results in the hyperexcitability of sensory neurons and causes the inherited paroxysmal itch. Conversely, a monoclonal antibody that selectively inhibits Nav1.7 is able to effectively suppress the histamine-dependent itch in mice. Therefore, Nav1.7 inhibitors may possess the potential to relieve the itch. In the present study, using whole-cell voltage-clamp recordings, we demonstrated that 3’-O-methylorobol inhibited Na+ currents in Nav1.7-CHO cells and tetrodotoxin-sensitive Na+ currents in mouse dorsal root ganglion (DRG) neurons with IC50 (half-maximal inhibitory concentration) values of 3.46 and 6.60 μM, respectively. 3’-O-methylorobol also suppressed the tetrodotoxin-resistant Na+ currents in DRG neurons, though with reduced potency (~43% inhibition at 30 µM). 3’-O-methylorobol (10 µM) affected the Nav1.7 by shifting the half-maximal voltage (V1/2) of activation to a depolarizing direction by ~6.76 mV, and it shifted the V1/2 of inactivation to a hyperpolarizing direction by ~16.79 mV. An analysis of 3’-O-methylorobol activity toward an array of itch targets revealed that 3’-O-methylorobol was without effect on histamine H1 receptor, TRPV1, TRPV3, TRPV4, TRPC4 and TRPM8. The intrathecal administration of 3’-O-methylorobol significantly attenuated compound 48/80-induced histamine-dependent spontaneous scratching bouts and the expression level of c-fos in the nuclei of spinal dorsal horn neurons with a comparable efficacy to that of cyproheptadine. Our data illustrated the therapeutic potential for 3’-O-methylorobol for histamine-dependent itching, and the small molecule inhibition of Nav1.7 may represent a useful strategy to develop novel therapeutics for itching.
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Shim H, Brown BM, Singh L, Singh V, Fettinger JC, Yarov-Yarovoy V, Wulff H. The Trials and Tribulations of Structure Assisted Design of K Ca Channel Activators. Front Pharmacol 2019; 10:972. [PMID: 31616290 PMCID: PMC6764326 DOI: 10.3389/fphar.2019.00972] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 07/29/2019] [Indexed: 11/13/2022] Open
Abstract
Calcium-activated K+ channels constitute attractive targets for the treatment of neurological and cardiovascular diseases. To explain why certain 2-aminobenzothiazole/oxazole-type KCa activators (SKAs) are KCa3.1 selective we previously generated homology models of the C-terminal calmodulin-binding domain (CaM-BD) of KCa3.1 and KCa2.3 in complex with CaM using Rosetta modeling software. We here attempted to employ this atomistic level understanding of KCa activator binding to switch selectivity around and design KCa2.2 selective activators as potential anticonvulsants. In this structure-based drug design approach we used RosettaLigand docking and carefully compared the binding poses of various SKA compounds in the KCa2.2 and KCa3.1 CaM-BD/CaM interface pocket. Based on differences between residues in the KCa2.2 and KCa.3.1 models we virtually designed 168 new SKA compounds. The compounds that were predicted to be both potent and KCa2.2 selective were synthesized, and their activity and selectivity tested by manual or automated electrophysiology. However, we failed to identify any KCa2.2 selective compounds. Based on the full-length KCa3.1 structure it was recently demonstrated that the C-terminal crystal dimer was an artefact and suggested that the "real" binding pocket for the KCa activators is located at the S4-S5 linker. We here confirmed this structural hypothesis through mutagenesis and now offer a new, corrected binding site model for the SKA-type KCa channel activators. SKA-111 (5-methylnaphtho[1,2-d]thiazol-2-amine) is binding in the interface between the CaM N-lobe and the S4-S5 linker where it makes van der Waals contacts with S181 and L185 in the S45A helix of KCa3.1.
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Affiliation(s)
- Heesung Shim
- Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, United States.,Department of Chemistry, University of California, Davis, Davis, CA, United States
| | - Brandon M Brown
- Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, United States
| | - Latika Singh
- Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, United States
| | - Vikrant Singh
- Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, United States
| | - James C Fettinger
- Department of Chemistry, University of California, Davis, Davis, CA, United States
| | - Vladimir Yarov-Yarovoy
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, CA, United States
| | - Heike Wulff
- Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, United States
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Rodil A, Slawin AMZ, Al-Maharik N, Tomita R, O'Hagan D. Fluorine-containing substituents: metabolism of the α,α-difluoroethyl thioether motif. Beilstein J Org Chem 2019; 15:1441-1447. [PMID: 31293694 PMCID: PMC6604701 DOI: 10.3762/bjoc.15.144] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 06/17/2019] [Indexed: 11/23/2022] Open
Abstract
We report the metabolism of the recently introduced α,α-difluoroethyl thioether motif to explore further its potential as a substituent for bioactives discovery chemistry. Incubation of two aryl–SCF2CH3 ethers with the model yeast organism Cunninghamella elegans, indicates that the sulfur of the thioether is rapidly converted to the corresponding sulfoxide, and then significantly more slowly to the sulfone. When the substrate was (p-OMe)PhSCF2CH3, then the resultant (demethylated) phenol sulfoxide had an enantiomeric excess of 60%, and when the substrate was the β-substituted-SCF2CH3 naphthalene, then the enantiomeric excess of the resultant sulfoxide was 54%. There was no evidence of defluorination, unlike the corresponding oxygen ether (p-OMe)PhOCF2CH3, which was converted to the (demethylated) phenol acetate ester during C. elegans incubation. We conclude that the aryl–S–CF2CH3 motif is metabolised in a similar manner to aryl–SCF3, a motif that is being widely explored in discovery chemistry. It is however, significantly less lipophilic than aryl-SCF3 which may offer a practical advantage in tuning overall pharmacokinetic profiles of molecules in development.
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Affiliation(s)
- Andrea Rodil
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
| | - Alexandra M Z Slawin
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
| | - Nawaf Al-Maharik
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK.,An Najah National University, Nablus, Palestine
| | - Ren Tomita
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
| | - David O'Hagan
- School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST, UK
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11
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Isom LL. Is Targeting of Compensatory Ion Channel Gene Expression a Viable Therapeutic Strategy for Dravet Syndrome? Epilepsy Curr 2019; 19:193-195. [PMID: 31035820 PMCID: PMC6610383 DOI: 10.1177/1535759719844780] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Augmented Reticular Thalamic Bursting and Seizures in Scn1a-Dravet Syndrome Ritter-Makinson S, Clemente-Perez A, Higashikubo B, Cho FS, Holden SS, Bennett E, Chkhaidze A, Eelkman Rooda OHJ, Cornet MC, Hoebeek FE, Yamakawa K, Cilio MR, Delord B, Paz JT. Cell Rep. 2019;26(1):54-64.e6. doi:10.1016/j.celrep.2018.12.018. Loss of function in the Scn1a gene leads to a severe epileptic encephalopathy called Dravet syndrome (DS). Reduced excitability in cortical inhibitory neurons is thought to be the major cause of DS seizures. Here, in contrast, we show enhanced excitability in thalamic inhibitory neurons that promotes the nonconvulsive seizures that are a prominent yet poorly understood feature of DS. In a mouse model of DS with a loss of function in Scn1a, reticular thalamic cells exhibited abnormally long bursts of firing caused by the downregulation of calcium-activated potassium SK channels. Our study supports a mechanism in which loss of SK activity causes the reticular thalamic neurons to become hyperexcitable and promote nonconvulsive seizures in DS. We propose that reduced excitability of inhibitory neurons is not global in DS and that non-GABAergic mechanisms such as SK channels may be important targets for treatment.
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Lin Y, Jiang L, Yi W. Trifluoromethanesulfonyl‐Based Reagents for Direct Trifluoromethylthiolation through Deoxygenative Reduction. ASIAN J ORG CHEM 2019. [DOI: 10.1002/ajoc.201900075] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Ya‐Mei Lin
- School of Chemical EngineeringNanjing University of Science and Technology 200 Xiao Ling Wei Street Nanjing 210094 China
| | - Lv.‐Qi Jiang
- School of Chemical EngineeringNanjing University of Science and Technology 200 Xiao Ling Wei Street Nanjing 210094 China
| | - Wen‐Bin Yi
- School of Chemical EngineeringNanjing University of Science and Technology 200 Xiao Ling Wei Street Nanjing 210094 China
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Zhang F, Wu Y, Zou X, Tang Q, Zhao F, Cao Z. BmK AEP, an Anti-Epileptic Peptide Distinctly Affects the Gating of Brain Subtypes of Voltage-Gated Sodium Channels. Int J Mol Sci 2019; 20:ijms20030729. [PMID: 30744067 PMCID: PMC6387193 DOI: 10.3390/ijms20030729] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 01/26/2019] [Accepted: 01/31/2019] [Indexed: 12/12/2022] Open
Abstract
BmK AEP, a scorpion peptide purified form the venom of Buthus martensii Karsch, has been reported to display anti-epileptic activity. Voltage-gated sodium channels (VGSCs) are responsible for the rising phase of action potentials (APs) in neurons and, therefore, controlling neuronal excitability. To elucidate the potential molecular mechanisms responsible for its anti-epileptic activity, we examined the influence of BmK AEP on AP firing in cortical neurons and how BmK AEP influences brain subtypes of VGSCs (Nav1.1–1.3 and Nav1.6). BmK AEP concentration-dependently suppresses neuronal excitability (AP firing) in primary cultured cortical neurons. Consistent with its inhibitory effect on AP generation, BmK AEP inhibits Na+ peak current in cortical neurons with an IC50 value of 2.12 µM by shifting the half-maximal voltage of activation of VGSC to hyperpolarized direction by ~7.83 mV without affecting the steady-state inactivation. Similar to its action on Na+ currents in cortical neurons, BmK AEP concentration-dependently suppresses the Na+ currents of Nav1.1, Nav1.3, and Nav1.6, which were heterologously expressed in HEK-293 cells, with IC50 values of 3.20, 1.46, and 0.39 µM with maximum inhibition of 82%, 56%, and 93%, respectively. BmK AEP shifts the voltage-dependent activation in the hyperpolarized direction by ~15.60 mV, ~9.97 mV, and ~6.73 mV in Nav1.1, Nav1.3, and Nav1.6, respectively, with minimal effect on steady-state inactivation. In contrast, BmK AEP minimally suppresses Nav1.2 currents (~15%) but delays the inactivation of the channel with an IC50 value of 1.69 µM. Considered together, these data demonstrate that BmK AEP is a relatively selective Nav1.6 gating modifier which distinctly affects the gating of brain subtypes of VGSCs.
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Affiliation(s)
- Fan Zhang
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
| | - Ying Wu
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
| | - Xiaohan Zou
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
| | - Qinglian Tang
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
| | - Fang Zhao
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
| | - Zhengyu Cao
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key Laboratory for TCM Evaluation and Translational Development, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
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14
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Liu J, Zhao X, Jiang L, Yi W. Tf2
O-Promoted Trifluoromethythiolation of Various Arenes Using NaSO2
CF3. Adv Synth Catal 2018. [DOI: 10.1002/adsc.201800702] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jie Liu
- Chemical Enginering college; Nanjing University of Science and Technology; 200 Xiao Ling Wei Street, Nanjing, Jiangsu People's Republic of China
| | - Xiaochun Zhao
- Chemical Enginering college; Nanjing University of Science and Technology; 200 Xiao Ling Wei Street, Nanjing, Jiangsu People's Republic of China
| | - Lvqi Jiang
- Chemical Enginering college; Nanjing University of Science and Technology; 200 Xiao Ling Wei Street, Nanjing, Jiangsu People's Republic of China
| | - Wenbin Yi
- Chemical Enginering college; Nanjing University of Science and Technology; 200 Xiao Ling Wei Street, Nanjing, Jiangsu People's Republic of China
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15
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Wu XL, Liu L, Li YJ, Luo J, Gai DW, Lu TL, Mei QB. Synthesis, crystal structure, and antinociceptive effects of some new riluzole derivatives. Med Chem Res 2018. [DOI: 10.1007/s00044-018-2154-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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16
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Farinato A, Altamura C, Desaphy JF. Effects of Benzothiazolamines on Voltage-Gated Sodium Channels. Handb Exp Pharmacol 2018; 246:233-250. [PMID: 28939972 DOI: 10.1007/164_2017_46] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Benzothiazole is a versatile fused heterocycle that aroused much interest in drug discovery as anticonvulsant, neuroprotective, analgesic, anti-inflammatory, antimicrobial, and anticancer. Two benzothiazolamines, riluzole and lubeluzole, are known blockers of voltage-gated sodium (Nav) channels. Riluzole is clinically used as a neuroprotectant in amyotrophic lateral sclerosis. Inhibition of Nav channels by riluzole is voltage-dependent due to preferential binding to inactivated sodium channels. Yet the drug exerts little use-dependent block, probably because it lacks protonable amine. One important property is riluzole ability to inhibit persistent Na+ currents, which likely contributes to its neuroprotective activity. Lubeluzole showed promising neuroprotective effects in animal stroke models, but failed to show benefits in acute ischemic stroke in humans. One important concern is its propensity to prolong the cardiac QT interval, due to hERG K+ channel block. Lubeluzole very potently inhibits Nav channels in a voltage- and use-dependent manner, due to its great preferential affinity for inactivated channels and the presence of a protonable amine group. Patch-clamp experiments suggest that the binding sites of both drugs overlap the local anesthetic receptor within the ion-conducting pathway. Riluzole and lubeluzole displayed very potent antimyotonic activity in a rat model of myotonia, a pathological skeletal muscle condition characterized by high-frequency runs of action potentials. Such results well support the repurposing of riluzole as an antimyotonic drug, allowing the launch of a pilot study in myotonic patients. Riluzole, lubeluzole, and new Nav channel blockers built on the benzothiazolamine scaffold will certainly continue to be investigated for possible clinical applications.
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Affiliation(s)
- Alessandro Farinato
- Section of Pharmacology, Department of Biomedical Sciences and Human Oncology, University of Bari Aldo Moro, Policlinico, Piazza G. Cesare 11, 70124, Bari, Italy
| | - Concetta Altamura
- Section of Pharmacology, Department of Biomedical Sciences and Human Oncology, University of Bari Aldo Moro, Policlinico, Piazza G. Cesare 11, 70124, Bari, Italy
| | - Jean-François Desaphy
- Section of Pharmacology, Department of Biomedical Sciences and Human Oncology, University of Bari Aldo Moro, Policlinico, Piazza G. Cesare 11, 70124, Bari, Italy.
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17
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Tomita R, Al-Maharik N, Rodil A, Bühl M, O'Hagan D. Synthesis of aryl α,α-difluoroethyl thioethers a novel structure motif in organic chemistry, and extending to aryl α,α-difluoro oxyethers. Org Biomol Chem 2018; 16:1113-1117. [DOI: 10.1039/c7ob02987j] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A method for the preparation of aryl α,α-difluoroethyl thioethers (ArSCF2CH3) is reported and the synthesis approach is extended to aryl α,α-difluoroethyl oxygen ethers.
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Affiliation(s)
- Ren Tomita
- EaStChem School of Chemistry
- School of Chemistry
- University of St Andrews
- St Andrews
- UK
| | - Nawaf Al-Maharik
- EaStChem School of Chemistry
- School of Chemistry
- University of St Andrews
- St Andrews
- UK
| | - Andrea Rodil
- EaStChem School of Chemistry
- School of Chemistry
- University of St Andrews
- St Andrews
- UK
| | - Michael Bühl
- EaStChem School of Chemistry
- School of Chemistry
- University of St Andrews
- St Andrews
- UK
| | - David O'Hagan
- EaStChem School of Chemistry
- School of Chemistry
- University of St Andrews
- St Andrews
- UK
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18
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Mahrous AA, Elbasiouny SM. Modulation of SK channels regulates locomotor alternating bursting activity in the functionally-mature spinal cord. Channels (Austin) 2017; 12:9-14. [PMID: 28991505 PMCID: PMC5972800 DOI: 10.1080/19336950.2017.1389825] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The spinal cord contains specialized groups of cells called pattern generators, which are capable of orchestrating rhythmic firing activity in an isolated preparation. Different patterns of activity could be generated in vitro including right-left alternating bursting and bursting in which both sides are synchronized. The cellular and network mechanisms that enable these behaviors are not fully understood. We have recently shown that Ca2+-activated K+ channels (SK channels) control the initiation and amplitude of synchronized bursting in the spinal cord. It is unclear, however, whether SK channels play a similar role in the alternating rhythmic pattern. In the current study, we used a spinal cord preparation from functionally mature mice capable of weight bearing and walking. The present results extend our previous work and show that SK channel inhibition initiates and modulates the amplitude of alternating bursting. We also show that addition of methoxamine, an α1-adrenergic agonist, to a cocktail of serotonin, dopamine, and NMDA evokes robust and consistent alternating bursting throughout the cord.
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Affiliation(s)
- Amr A Mahrous
- a Department of Neuroscience , Cell Biology, and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University , Dayton , Ohio , USA
| | - Sherif M Elbasiouny
- a Department of Neuroscience , Cell Biology, and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University , Dayton , Ohio , USA.,b Department of Biomedical , Industrial, and Human Factors Engineering, College of Engineering and Computer Science, Wright State University , Dayton , Ohio , USA
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19
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Synthesis and anticonvulsant activity of some novel 7-(benzylamino) -1H-benzo[b][1,4]diazepine-2,4(3H, 5H)-dione derivatives. Med Chem Res 2017. [DOI: 10.1007/s00044-017-2089-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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20
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Erickson JD. Functional identification of activity-regulated, high-affinity glutamine transport in hippocampal neurons inhibited by riluzole. J Neurochem 2017; 142:29-40. [PMID: 28423185 DOI: 10.1111/jnc.14046] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/17/2017] [Accepted: 04/05/2017] [Indexed: 12/23/2022]
Abstract
Glutamine (Gln) is considered the preferred precursor for the neurotransmitter pool of glutamate (Glu), the major excitatory transmitter in the mammalian CNS. Here, an activity-regulated, high-affinity Gln transport system is described in developing and mature neuron-enriched hippocampal cultures that is potently inhibited by riluzole (IC50 1.3 ± 0.5 μM), an anti-glutamatergic drug, and is blocked by low concentrations of 2-(methylamino)isobutyrate (MeAIB), a system A transport inhibitor. K+ -stimulated MeAIB transport displays an affinity (Km ) for MeAIB of 37 ± 1.2 μM, saturates at ~ 200 μM, is dependent on extracellular Ca2+ , and is blocked by inhibition of voltage-gated Ca2+ channels. Spontaneous MeAIB transport is also dependent on extracellullar Ca2+ and voltage-gated calcium channels, but is also blocked by the Na+ channel blocker tetrodotoxin, by Glu receptor antagonists, and by GABA indicating its dependence on intact neural circuits driven by endogenous glutamatergic activity. The transport of MeAIB itself does not rely on Ca2+ , but on Na+ ions, and is pH sensitive. Activity-regulated, riluzole-sensitive spontaneous and K+ -stimulated transport is minimal at 7-8 days in vitro, coordinately induced during the next 2 weeks and is maximally expressed by days in vitro > 20; the known period for maturation of the Glu/Gln cycle and regulated pre-synaptic Glu release. Competition analyses with various amino acids indicate that Gln is the most likely physiological substrate. Activity-regulated Gln/MeAIB transport is not observed in astrocytes. The functional identification of activity-regulated, high-affinity, riluzole-sensitive Gln/MeAIB transport in hippocampal neurons may have important ramifications in the neurobiology of activity-stimulated pre-synaptic Glu release, the Glu/Gln cycle between astrocytes and neurons, and neuronal Glu-induced excitotoxicity. Cover Image for this issue: doi: 10.1111/jnc.13805.
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Affiliation(s)
- Jeffrey D Erickson
- Neuroscience Center of Excellence, School of Medicine, Lousiania State University Health New Orleans, New Orleans, Louisiana, USA
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21
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Mukherjee S, Maji B, Tlahuext-Aca A, Glorius F. Visible-Light-Promoted Activation of Unactivated C(sp 3)-H Bonds and Their Selective Trifluoromethylthiolation. J Am Chem Soc 2016; 138:16200-16203. [PMID: 27935270 DOI: 10.1021/jacs.6b09970] [Citation(s) in RCA: 203] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Selective functionalization of ubiquitous C(sp3)-H bonds using visible light is a highly challenging yet desirable goal in organic synthesis. The development of such processes relies on both rational design and serendipitous discoveries from innovative tools such as screening technologies. Applying a mechanism-based screening strategy, we herein report photoredox-mediated hydrogen atom transfer catalysis for the selective activation of otherwise unactivated C(sp3)-H bonds, followed by their trifluoromethylthiolation, which has high potential as a late-stage functionalization tool. The generality of this method is exhibited through incorporation of the trifluoromethylthio group in a large number of C(sp3)-H bonds with high selectivity without the need for an excess of valuable substrate.
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Affiliation(s)
- Satobhisha Mukherjee
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Corrensstrasse 40, 48149 Münster, Germany
| | - Biplab Maji
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Corrensstrasse 40, 48149 Münster, Germany
| | - Adrian Tlahuext-Aca
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Corrensstrasse 40, 48149 Münster, Germany
| | - Frank Glorius
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Corrensstrasse 40, 48149 Münster, Germany
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22
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Pessah IN, Rogawski MA, Tancredi DJ, Wulff H, Zolkowska D, Bruun DA, Hammock BD, Lein PJ. Models to identify treatments for the acute and persistent effects of seizure-inducing chemical threat agents. Ann N Y Acad Sci 2016; 1378:124-136. [PMID: 27467073 DOI: 10.1111/nyas.13137] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 05/15/2016] [Accepted: 05/19/2016] [Indexed: 12/27/2022]
Abstract
Exposures to seizure-inducing chemical threat agents are a major public health concern. Of particular need is improved treatment to terminate convulsions and to prevent the long-term neurological sequelae in survivors. We are studying the organophosphorus cholinesterase inhibitor diisopropyl fluorophosphate (DFP) and the GABA receptor inhibitor tetramethylenedisulfotetramine (TETS), which arguably encompass the mechanistic spectrum of seizure-inducing chemical threats, with the goal of identifying therapeutic approaches with broad-spectrum efficacy. Research efforts have focused on developing translational models and translational diagnostic approaches, including (1) in vivo models of DFP- and TETS-induced seizures for studying neuropathological mechanisms and identifying treatment approaches; (2) in vivo imaging modalities for noninvasive longitudinal monitoring of neurological damage and response to therapeutic candidates; and (3) higher-throughput in vitro platforms for rapid screening of compounds to identify potential antiseizure and neuroprotective agents, as well as mechanistically relevant novel drug targets. This review summarizes our progress toward realizing these goals and discusses best practices and mechanistic insights derived from our modeling efforts.
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Affiliation(s)
- Isaac N Pessah
- Department of Molecular Biosciences, School of Veterinary Medicine
| | | | | | - Heike Wulff
- Department of Pharmacology, School of Medicine
| | | | - Donald A Bruun
- Department of Molecular Biosciences, School of Veterinary Medicine
| | - Bruce D Hammock
- Department of Entomology, College of Agricultural and Environmental Sciences, University of California, Davis, Davis, California
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine.
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23
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Glenadel Q, Alazet S, Baert F, Billard T. Multigram Scale Syntheses of First and Second Generation of Trifluoromethanesulfenamide Reagents. Org Process Res Dev 2016. [DOI: 10.1021/acs.oprd.6b00062] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Quentin Glenadel
- Institute
of Chemistry and Biochemistry (ICBMS − UMR CNRS 5246), Univ
Lyon, Université Lyon 1, CNRS, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne, France
| | - Sébastien Alazet
- Institute
of Chemistry and Biochemistry (ICBMS − UMR CNRS 5246), Univ
Lyon, Université Lyon 1, CNRS, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne, France
| | - François Baert
- Institute
of Chemistry and Biochemistry (ICBMS − UMR CNRS 5246), Univ
Lyon, Université Lyon 1, CNRS, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne, France
| | - Thierry Billard
- Institute
of Chemistry and Biochemistry (ICBMS − UMR CNRS 5246), Univ
Lyon, Université Lyon 1, CNRS, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne, France
- CERMEP −
In Vivo Imaging, Groupement Hospitalier Est, 59 Bd Pinel, F-69003 Lyon, France
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24
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Zhao F, Li X, Jin L, Zhang F, Inoue M, Yu B, Cao Z. Development of a Rapid Throughput Assay for Identification of hNav1.7 Antagonist Using Unique Efficacious Sodium Channel Agonist, Antillatoxin. Mar Drugs 2016; 14:md14020036. [PMID: 26891306 PMCID: PMC4771989 DOI: 10.3390/md14020036] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 01/21/2016] [Accepted: 01/26/2016] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels (VGSCs) are responsible for the generation of the action potential. Among nine classified VGSC subtypes (Nav1.1–Nav1.9), Nav1.7 is primarily expressed in the sensory neurons, contributing to the nociception transmission. Therefore Nav1.7 becomes a promising target for analgesic drug development. In this study, we compared the influence of an array of VGSC agonists including veratridine, BmK NT1, brevetoxin-2, deltamethrin and antillatoxin (ATX) on membrane depolarization which was detected by Fluorescence Imaging Plate Reader (FLIPR) membrane potential (FMP) blue dye. In HEK-293 cells heterologously expressing hNav1.7 α-subunit, ATX produced a robust membrane depolarization with an EC50 value of 7.8 ± 2.9 nM whereas veratridine, BmK NT1, and deltamethrin produced marginal response. Brevetoxin-2 was without effect on membrane potential change. The ATX response was completely inhibited by tetrodotoxin suggesting that the ATX response was solely derived from hNav1.7 activation, which was consistent with the results where ATX produced a negligible response in null HEK-293 cells. Six VGSC antagonists including lidocaine, lamotrigine, phenytoin, carbamazepine, riluzole, and 2-amino-6-trifluoromethylthiobenzothiazole all concentration-dependently inhibited ATX response with IC50 values comparable to that reported from patch-clamp experiments. Considered together, we demonstrate that ATX is a unique efficacious hNav1.7 activator which offers a useful probe to develop a rapid throughput screening assay to identify hNav1.7 antagonists.
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Affiliation(s)
- Fang Zhao
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China.
- Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing 211198, China.
| | - Xichun Li
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China.
- Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing 211198, China.
| | - Liang Jin
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China.
- School of Life Science and Technology, China Pharmaceutical University, Nanjing 211198, China.
| | - Fan Zhang
- Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing 211198, China.
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan.
| | - Boyang Yu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China.
- Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing 211198, China.
| | - Zhengyu Cao
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China.
- Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing 211198, China.
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25
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Wolfart J, Laker D. Homeostasis or channelopathy? Acquired cell type-specific ion channel changes in temporal lobe epilepsy and their antiepileptic potential. Front Physiol 2015; 6:168. [PMID: 26124723 PMCID: PMC4467176 DOI: 10.3389/fphys.2015.00168] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 05/19/2015] [Indexed: 01/16/2023] Open
Abstract
Neurons continuously adapt the expression and functionality of their ion channels. For example, exposed to chronic excitotoxicity, neurons homeostatically downscale their intrinsic excitability. In contrast, the “acquired channelopathy” hypothesis suggests that proepileptic channel characteristics develop during epilepsy. We review cell type-specific channel alterations under different epileptic conditions and discuss the potential of channels that undergo homeostatic adaptations, as targets for antiepileptic drugs (AEDs). Most of the relevant studies have been performed on temporal lobe epilepsy (TLE), a widespread AED-refractory, focal epilepsy. The TLE patients, who undergo epilepsy surgery, frequently display hippocampal sclerosis (HS), which is associated with degeneration of cornu ammonis subfield 1 pyramidal cells (CA1 PCs). Although the resected human tissue offers insights, controlled data largely stem from animal models simulating different aspects of TLE and other epilepsies. Most of the cell type-specific information is available for CA1 PCs and dentate gyrus granule cells (DG GCs). Between these two cell types, a dichotomy can be observed: while DG GCs acquire properties decreasing the intrinsic excitability (in TLE models and patients with HS), CA1 PCs develop channel characteristics increasing intrinsic excitability (in TLE models without HS only). However, thorough examination of data on these and other cell types reveals the coexistence of protective and permissive intrinsic plasticity within neurons. These mechanisms appear differentially regulated, depending on the cell type and seizure condition. Interestingly, the same channel molecules that are upregulated in DG GCs during HS-related TLE, appear as promising targets for future AEDs and gene therapies. Hence, GCs provide an example of homeostatic ion channel adaptation which can serve as a primer when designing novel anti-epileptic strategies.
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Affiliation(s)
- Jakob Wolfart
- Oscar Langendorff Institute of Physiology, University of Rostock Rostock, Germany
| | - Debora Laker
- Oscar Langendorff Institute of Physiology, University of Rostock Rostock, Germany
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26
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Cao Z, Zou X, Cui Y, Hulsizer S, Lein PJ, Wulff H, Pessah IN. Rapid throughput analysis demonstrates that chemicals with distinct seizurogenic mechanisms differentially alter Ca2+ dynamics in networks formed by hippocampal neurons in culture. Mol Pharmacol 2015; 87:595-605. [PMID: 25583085 DOI: 10.1124/mol.114.096701] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Primary cultured hippocampal neurons (HN) form functional networks displaying synchronous Ca(2+) oscillations (SCOs) whose patterns influence plasticity. Whether chemicals with distinct seizurogenic mechanisms differentially alter SCO patterns was investigated using mouse HN loaded with the Ca(2+) indicator fluo-4-AM. Intracellular Ca(2+) dynamics were recorded from 96 wells simultaneously in real-time using fluorescent imaging plate reader. Although quiescent at 4 days in vitro (DIV), HN acquired distinctive SCO patterns as they matured to form extensive dendritic networks by 16 DIV. Challenge with kainate, a kainate receptor (KAR) agonist, 4-aminopyridine (4-AP), a K(+) channel blocker, or pilocarpine, a muscarinic acetylcholine receptor agonist, caused distinct changes in SCO dynamics. Kainate at <1 µM produced a rapid rise in baseline Ca(2+) (Phase I response) associated with high-frequency and low-amplitude SCOs (Phase II response), whereas SCOs were completely repressed with >1 µM kainate. KAR competitive antagonist CNQX [6-cyano-7-nitroquinoxaline-2,3-dione] (1-10 µM) normalized Ca(2+) dynamics to the prekainate pattern. Pilocarpine lacked Phase I activity but caused a sevenfold prolongation of Phase II SCOs without altering either their frequency or amplitude, an effect normalized by atropine (0.3-1 µM). 4-AP (1-30 µM) elicited a delayed Phase I response associated with persistent high-frequency, low-amplitude SCOs, and these disturbances were mitigated by pretreatment with the KCa activator SKA-31 [naphtho[1,2-d]thiazol-2-ylamine]. Consistent with its antiepileptic and neuroprotective activities, nonselective voltage-gated Na(+) and Ca(2+) channel blocker lamotrigine partially resolved kainate- and pilocarpine-induced Ca(2+) dysregulation. This rapid throughput approach can discriminate among distinct seizurogenic mechanisms that alter Ca(2+) dynamics in neuronal networks and may be useful in screening antiepileptic drug candidates.
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Affiliation(s)
- Zhengyu Cao
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, P.R. China (Z.C., X.Z., Y.C.); Department of Molecular Biosciences, School of Veterinary Medicine (Z.C., Y.C., S.H., P.J.L., I.N.P.) and Department of Pharmacology, School of Medicine (H.W.),University of California, Davis, California
| | - Xiaohan Zou
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, P.R. China (Z.C., X.Z., Y.C.); Department of Molecular Biosciences, School of Veterinary Medicine (Z.C., Y.C., S.H., P.J.L., I.N.P.) and Department of Pharmacology, School of Medicine (H.W.),University of California, Davis, California
| | - Yanjun Cui
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, P.R. China (Z.C., X.Z., Y.C.); Department of Molecular Biosciences, School of Veterinary Medicine (Z.C., Y.C., S.H., P.J.L., I.N.P.) and Department of Pharmacology, School of Medicine (H.W.),University of California, Davis, California
| | - Susan Hulsizer
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, P.R. China (Z.C., X.Z., Y.C.); Department of Molecular Biosciences, School of Veterinary Medicine (Z.C., Y.C., S.H., P.J.L., I.N.P.) and Department of Pharmacology, School of Medicine (H.W.),University of California, Davis, California
| | - Pamela J Lein
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, P.R. China (Z.C., X.Z., Y.C.); Department of Molecular Biosciences, School of Veterinary Medicine (Z.C., Y.C., S.H., P.J.L., I.N.P.) and Department of Pharmacology, School of Medicine (H.W.),University of California, Davis, California
| | - Heike Wulff
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, P.R. China (Z.C., X.Z., Y.C.); Department of Molecular Biosciences, School of Veterinary Medicine (Z.C., Y.C., S.H., P.J.L., I.N.P.) and Department of Pharmacology, School of Medicine (H.W.),University of California, Davis, California
| | - Isaac N Pessah
- State Key Laboratory of Natural Medicines and Jiangsu Provincial Key laboratory for TCM Evaluation and Translational Development, China Pharmaceutical University, Nanjing, P.R. China (Z.C., X.Z., Y.C.); Department of Molecular Biosciences, School of Veterinary Medicine (Z.C., Y.C., S.H., P.J.L., I.N.P.) and Department of Pharmacology, School of Medicine (H.W.),University of California, Davis, California
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