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Soto-Perez J, Cleary CM, Sobrinho CR, Mulkey SB, Carroll JL, Tzingounis AV, Mulkey DK. Phox2b-expressing neurons contribute to breathing problems in Kcnq2 loss- and gain-of-function encephalopathy models. Nat Commun 2023; 14:8059. [PMID: 38052789 PMCID: PMC10698053 DOI: 10.1038/s41467-023-43834-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 11/21/2023] [Indexed: 12/07/2023] Open
Abstract
Loss- and gain-of-function variants in the gene encoding KCNQ2 channels are a common cause of developmental and epileptic encephalopathy, a condition characterized by seizures, developmental delays, breathing problems, and early mortality. To understand how KCNQ2 dysfunction impacts behavior in a mouse model, we focus on the control of breathing by neurons expressing the transcription factor Phox2b which includes respiratory neurons in the ventral parafacial region. We find Phox2b-expressing ventral parafacial neurons express Kcnq2 in the absence of other Kcnq isoforms, thus clarifying why disruption of Kcnq2 but not other channel isoforms results in breathing problems. We also find that Kcnq2 deletion or expression of a recurrent gain-of-function variant R201C in Phox2b-expressing neurons increases baseline breathing or decreases the central chemoreflex, respectively, in mice during the light/inactive state. These results uncover mechanisms underlying breathing abnormalities in KCNQ2 encephalopathy and highlight an unappreciated vulnerability of Phox2b-expressing ventral parafacial neurons to KCNQ2 pathogenic variants.
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Affiliation(s)
- J Soto-Perez
- Dept of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - C M Cleary
- Dept of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - C R Sobrinho
- Dept of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA
| | - S B Mulkey
- Prenatal Pediatrics Institute, Children's National Hospital, Departments of Neurology and Pediatrics, The George Washington Univ. School of Medicine and Health Sciences, Washington, DC, USA
| | - J L Carroll
- Dept. of Pediatrics, Univ. Arkansas for Medical Sciences, Little Rock, AR, USA
| | - A V Tzingounis
- Dept of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA.
| | - D K Mulkey
- Dept of Physiology and Neurobiology, University of Connecticut, Storrs, CT, USA.
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2
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Joshi P, Patel R, Kang SY, Serbinowski E, Lee MY. Establishment of ion channel and ABC transporter assays in 3D-cultured ReNcell VM on a 384-pillar plate for neurotoxicity potential. Toxicol In Vitro 2022; 82:105375. [PMID: 35550413 DOI: 10.1016/j.tiv.2022.105375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 04/05/2022] [Accepted: 05/03/2022] [Indexed: 10/18/2022]
Abstract
Neurotoxicity potential of compounds by inhibition of ion channels and efflux transporters has been studied traditionally using two-dimensionally (2D) cultured cell lines such as CHO and HEK-293 overexpressing the protein of interest. However, these approaches are time consuming and do not recapitulate the activity of ion channels and efflux transporters indigenously expressed in neural stem cells (NSCs) in vivo. To overcome these issues, we established ion channel and transporter assays on a 384-pillar plate with three-dimensionally (3D) cultured ReNcell VM and demonstrated high-throughput measurement of ion channel and transporter activity. RNA sequencing analysis identified major ion channels and efflux transporters expressed in ReNcell VM, followed by validating 3D ReNcell-based ion channel and transporter assays with model compounds. Major ion channel activities were measured by specifically inhibiting potassium channels Kv 7.2 with XE-991 and Kv 4.3 with fluoxetine, and a calcium channel with 2-APB. Activities of major efflux transporters, MDR1, MRP1, and BCRP, were assessed using their respective blockers, verapamil, probenecid, and novobiocin. From this study, we demonstrated that 3D-cultured ReNcell VM on the 384-pillar plate could be a good alternative to rapidly identify environmental chemicals and therapeutic compounds for their role in modulating the activity of ion channels and efflux transporters, potentially leading to neurotoxicity.
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Affiliation(s)
- Pranav Joshi
- Department of Chemical and Biomedical Engineering, Cleveland State University, Cleveland, OH, USA; Bioprinting Laboratories Inc, Denton, TX, USA
| | - Rushabh Patel
- Department of Chemical and Biomedical Engineering, Cleveland State University, Cleveland, OH, USA; College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Soo-Yeon Kang
- Department of Chemical and Biomedical Engineering, Cleveland State University, Cleveland, OH, USA; Department of Biomedical Engineering, University of North Texas, Denton, TX, USA
| | - Emily Serbinowski
- Department of Chemical and Biomedical Engineering, Cleveland State University, Cleveland, OH, USA; College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Moo-Yeal Lee
- Department of Chemical and Biomedical Engineering, Cleveland State University, Cleveland, OH, USA; Department of Biomedical Engineering, University of North Texas, Denton, TX, USA.
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3
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Naffaa MM, Al-Ewaidat OA. Ligand modulation of KCNQ-encoded (K V7) potassium channels in the heart and nervous system. Eur J Pharmacol 2021; 906:174278. [PMID: 34174270 DOI: 10.1016/j.ejphar.2021.174278] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 06/06/2021] [Accepted: 06/18/2021] [Indexed: 10/21/2022]
Abstract
KCNQ-encoded (KV7) potassium channels are diversely distributed in the human tissues, associated with many physiological processes and pathophysiological conditions. These channels are increasingly used as drug targets for treating diseases. More selective and potent molecules on various types of the KV7 channels are desirable for appropriate therapies. The recent knowledge of the structure and function of human KCNQ-encoded channels makes it more feasible to achieve these goals. This review discusses the role and mechanism of action of many molecules in modulating the function of the KCNQ-encoded potassium channels in the heart and nervous system. The effects of these compounds on KV7 channels help to understand their involvement in many diseases, and to search for more selective and potent ligands to be used in the treatment of many disorders such as various types of cardiac arrhythmias, epilepsy, and pain.
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Affiliation(s)
- Moawiah M Naffaa
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, 27710, USA; Department of Psychology and Neuroscience, Duke University, Durham, NC 27708, USA.
| | - Ola A Al-Ewaidat
- Faculty of Medicine, The University of Jordan, Amman, 11942, Jordan
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4
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Therapeutic Antibodies Targeting Potassium Ion Channels. Handb Exp Pharmacol 2021; 267:507-545. [PMID: 33963460 DOI: 10.1007/164_2021_464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Monoclonal antibodies combine specificity and high affinity binding with excellent pharmacokinetic properties and are rapidly being developed for a wide range of drug targets including clinically important potassium ion channels. Nonetheless, while therapeutic antibodies come with great promise, K+ channels represent particularly difficult targets for biologics development for a variety of reasons that include their dynamic structures and relatively small extracellular loops, their high degree of sequence conservation (leading to immune tolerance), and their generally low-level expression in vivo. The process is made all the more difficult when large numbers of antibody candidates must be screened for a given target, or when lead candidates fail to cross-react with orthologous channels in animal disease models due to their highly selective binding properties. While the number of antibodies targeting potassium channels in preclinical or clinical development is still modest, significant advances in the areas of protein expression and antibody screening are converging to open the field to an avalanche of new drugs. Here, the opportunities and constraints associated with the discovery of antibodies against K+ channels are discussed, with an emphasis on novel technologies that are opening the field to exciting new possibilities for biologics development.
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5
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Borgini M, Mondal P, Liu R, Wipf P. Chemical modulation of Kv7 potassium channels. RSC Med Chem 2021; 12:483-537. [PMID: 34046626 PMCID: PMC8128042 DOI: 10.1039/d0md00328j] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/01/2020] [Indexed: 01/10/2023] Open
Abstract
The rising interest in Kv7 modulators originates from their ability to evoke fundamental electrophysiological perturbations in a tissue-specific manner. A large number of therapeutic applications are, in part, based on the clinical experience with two broad-spectrum Kv7 agonists, flupirtine and retigabine. Since precise molecular structures of human Kv7 channel subtypes in closed and open states have only very recently started to emerge, computational studies have traditionally been used to analyze binding modes and direct the development of more potent and selective Kv7 modulators with improved safety profiles. Herein, the synthetic and medicinal chemistry of small molecule modulators and the representative biological properties are summarized. Furthermore, new therapeutic applications supported by in vitro and in vivo assay data are suggested.
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Affiliation(s)
- Matteo Borgini
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Pravat Mondal
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Ruiting Liu
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
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6
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Egyed A, Kelemen ÁA, Vass M, Visegrády A, Thee SA, Wang Z, de Graaf C, Brea J, Loza MI, Leurs R, Keserű GM. Controlling the selectivity of aminergic GPCR ligands from the extracellular vestibule. Bioorg Chem 2021; 111:104832. [PMID: 33826962 DOI: 10.1016/j.bioorg.2021.104832] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 01/18/2021] [Accepted: 03/15/2021] [Indexed: 11/18/2022]
Abstract
In addition to the orthosteric binding pocket (OBP) of GPCRs, recent structural studies have revealed that there are several allosteric sites available for pharmacological intervention. The secondary binding pocket (SBP) of aminergic GPCRs is located in the extracellular vestibule of these receptors, and it has been suggested to be a potential selectivity pocket for bitopic ligands. Here, we applied a virtual screening protocol based on fragment docking to the SBP of the orthosteric ligand-receptor complex. This strategy was employed for a number of aminergic receptors. First, we designed dopamine D3 preferring bitopic compounds from a D2 selective orthosteric ligand. Next, we designed 5-HT2B selective bitopic compounds starting from the 5-HT1B preferring ergoline core of LSD. Comparing the serotonergic profiles of the new derivatives to that of LSD, we found that these derivatives became significantly biased towards the desired 5-HT2B receptor target. Finally, addressing the known limitations of H1 antihistamines, our protocol was successfully used to eliminate the well-known side effects related to the muscarinic M1 activity of amitriptyline while preserving H1 potency in some of the designed bitopic compounds. These applications highlight the usefulness of our new virtual screening protocol and offer a powerful strategy towards bitopic GPCR ligands with designed receptor profiles.
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Affiliation(s)
- Attila Egyed
- Medicinal Chemistry Research Group, Research Center for Natural Sciences Magyar tudósok krt. 2, Budapest, H-1117, Hungary
| | - Ádám A Kelemen
- Medicinal Chemistry Research Group, Research Center for Natural Sciences Magyar tudósok krt. 2, Budapest, H-1117, Hungary
| | - Márton Vass
- Medicinal Chemistry Research Group, Research Center for Natural Sciences Magyar tudósok krt. 2, Budapest, H-1117, Hungary; Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, Amsterdam, 1081 HZ, Netherlands
| | | | - Stephanie A Thee
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, Amsterdam, 1081 HZ, Netherlands
| | - Zhiyong Wang
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, Amsterdam, 1081 HZ, Netherlands
| | - Chris de Graaf
- Sosei Heptares, Steinmetz Granta Park, Great Abington, Cambridge CB21 6DG, UK
| | - Jose Brea
- Innopharma Screening Platform, BioFarma Research Group, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Maria Isabel Loza
- Innopharma Screening Platform, BioFarma Research Group, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), University of Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Rob Leurs
- Division of Medicinal Chemistry, Faculty of Sciences, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, Amsterdam, 1081 HZ, Netherlands
| | - György M Keserű
- Medicinal Chemistry Research Group, Research Center for Natural Sciences Magyar tudósok krt. 2, Budapest, H-1117, Hungary.
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7
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Varghese N, Lauritano A, Taglialatela M, Tzingounis AV. KCNQ3 is the principal target of retigabine in CA1 and subicular excitatory neurons. J Neurophysiol 2021; 125:1440-1449. [PMID: 33729829 DOI: 10.1152/jn.00564.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Retigabine is a first-in-class potassium channel opener approved for patients with epilepsy. Unfortunately, several side effects have limited its use in clinical practice, overshadowing its beneficial effects. Multiple studies have shown that retigabine acts by enhancing the activity of members of the voltage-gated KCNQ (Kv7) potassium channel family, particularly the neuronal KCNQ channels KCNQ2-KCNQ5. However, it is currently unknown whether retigabine's action in neurons is mediated by all KCNQ neuronal channels or by only a subset. This knowledge is necessary to elucidate retigabine's mechanism of action in the central nervous system and its adverse effects and to design more effective and selective retigabine analogs. In this study, we show that the action of retigabine in excitatory neurons strongly depends on the presence of KCNQ3 channels. Deletion of Kcnq3 severely limited the ability of retigabine to reduce neuronal excitability in mouse CA1 and subiculum excitatory neurons. In addition, we report that in the absence of KCNQ3 channels, retigabine can enhance CA1 pyramidal neuron activity, leading to a greater number of action potentials and reduced spike frequency adaptation; this finding further supports a key role of KCNQ3 channels in mediating the action of retigabine. Our work provides new insight into the action of retigabine in forebrain neurons, clarifying retigabine's action in the nervous system.NEW & NOTEWORTHY Retigabine has risen to prominence as a first-in-class potassium channel opener approved by the Food and Drug Administration, with potential for treating multiple neurological disorders. Here, we demonstrate that KCNQ3 channels are the primary target of retigabine in excitatory neurons, as deleting these channels greatly diminishes the effect of retigabine in pyramidal neurons. Our data provide the first indication that retigabine controls neuronal firing properties primarily through KCNQ3 channels.
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Affiliation(s)
- Nissi Varghese
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut
| | - Anna Lauritano
- Department of Neuroscience, University of Naples Federico II, Naples, Italy
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8
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Li K, Abbott SBG, Shi Y, Eggan P, Gonye EC, Bayliss DA. TRPM4 mediates a subthreshold membrane potential oscillation in respiratory chemoreceptor neurons that drives pacemaker firing and breathing. Cell Rep 2021; 34:108714. [PMID: 33535052 PMCID: PMC7888550 DOI: 10.1016/j.celrep.2021.108714] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 12/04/2020] [Accepted: 01/12/2021] [Indexed: 12/01/2022] Open
Abstract
Brainstem networks that control regular tidal breathing depend on excitatory drive, including from tonically active, CO2/H+-sensitive neurons of the retrotrapezoid nucleus (RTN). Here, we examine intrinsic ionic mechanisms underlying the metronomic firing activity characteristic of RTN neurons. In mouse brainstem slices, large-amplitude membrane potential oscillations are evident in synaptically isolated RTN neurons after blocking action potentials. The voltage-dependent oscillations are abolished by sodium replacement; blocking calcium channels (primarily L-type); chelating intracellular Ca2+; and inhibiting TRPM4, a Ca2+-dependent cationic channel. Likewise, oscillation voltage waveform currents are sensitive to calcium and TRPM4 channel blockers. Extracellular acidification and serotonin (5-HT) evoke membrane depolarization that augments TRPM4-dependent oscillatory activity and action potential discharge. Finally, inhibition of TRPM4 channels in the RTN of anesthetized mice reduces central respiratory output. These data implicate TRPM4 in a subthreshold oscillation that supports the pacemaker-like firing of RTN neurons required for basal, CO2-stimulated, and state-dependent breathing.
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Affiliation(s)
- Keyong Li
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Stephen B G Abbott
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Yingtang Shi
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Pierce Eggan
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Elizabeth C Gonye
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA.
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9
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Wilenkin B, Burris KD, Eastwood BJ, Sher E, Williams AC, Priest BT. Development of an Electrophysiological Assay for Kv7 Modulators on IonWorks Barracuda. Assay Drug Dev Technol 2020; 17:310-321. [PMID: 31634018 DOI: 10.1089/adt.2019.942] [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] [Indexed: 02/06/2023] Open
Abstract
Relief from chronic pain continues to represent a large unmet need. The voltage-gated potassium channel Kv7.2/7.3, also known as KCNQ2/3, is a key contributor to the control of resting membrane potential and excitability in nociceptive neurons and represents a promising target for potential therapeutics. In this study, we present a medium throughput electrophysiological assay for the identification and characterization of modulators of Kv7.2/7.3 channels, using the IonWorks Barracuda™ automated voltage clamp platform. The assay combines a family of voltage steps used to construct conductance curves with a unique analysis method. Kv7.2/7.3 modulators shift the activation voltage and/or change the maximal conductance of the current, and both parameters have been used to quantify compound mediated effects. Both effects are expected to modulate neuronal excitability in vivo. The analysis method described assigns a single potency value that combines changes in activation voltage and maximal conductance and is expected to predict compound mediated changes in excitability.
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Affiliation(s)
- Benjamin Wilenkin
- Department of Quantitative Biology, Eli Lilly and Company, Indianapolis, Indiana
| | - Kevin D Burris
- Department of Quantitative Biology, Eli Lilly and Company, Indianapolis, Indiana
| | - Brian J Eastwood
- Department of Statistics, Eli Lilly and Company, Indianapolis, Indiana
| | - Emanuele Sher
- Department of Discovery Pain Group, Eli Lilly and Company, Indianapolis, Indiana
| | - Andrew C Williams
- Department of Medicinal Chemistry, Eli Lilly and Company, Indianapolis, Indiana
| | - Birgit T Priest
- Department of Quantitative Biology, Eli Lilly and Company, Indianapolis, Indiana
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10
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Porter JD, Vivas O, Weaver CD, Alsafran A, DiMilo E, Arnold LA, Dickson EJ, Dockendorff C. An anthrone-based Kv7.2/7.3 channel blocker with improved properties for the investigation of psychiatric and neurodegenerative disorders. Bioorg Med Chem Lett 2019; 29:126681. [PMID: 31668424 PMCID: PMC6858848 DOI: 10.1016/j.bmcl.2019.126681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 09/09/2019] [Indexed: 12/22/2022]
Abstract
A set of novel Kv7.2/7.3 (KCNQ2/3) channel blockers was synthesized to address several liabilities of the known compounds XE991 (metabolic instability and CYP inhibition) and the clinical compound DMP 543 (acid instability, insolubility, and lipophilicity). Using the anthrone scaffold of the prior channel blockers, alternative heteroarylmethyl substituents were installed via enolate alkylation reactions. Incorporation of a pyridazine and a fluorinated pyridine gave an analog (compound 18, JDP-107) with a promising combination of potency (IC50 = 0.16 μM in a Kv7.2 thallium flux assay), efficacy in a Kv7.2/7.3 patch clamp assay, and drug-like properties.
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Affiliation(s)
- Jacob D Porter
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, USA
| | - Oscar Vivas
- Department of Physiology & Membrane Biology, University of California, 1 Shields Avenue, Davis, CA 95616, USA
| | - C David Weaver
- Departments of Pharmacology and Chemistry, Vanderbilt University, Vanderbilt Institute of Chemical Biology, Nashville, TN 37232, USA
| | - Abdulmohsen Alsafran
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, USA
| | - Elliot DiMilo
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin, Milwaukee, WI 53211, USA
| | - Leggy A Arnold
- Department of Chemistry and Biochemistry, Milwaukee Institute for Drug Discovery, University of Wisconsin, Milwaukee, WI 53211, USA
| | - Eamonn J Dickson
- Department of Physiology & Membrane Biology, University of California, 1 Shields Avenue, Davis, CA 95616, USA
| | - Chris Dockendorff
- Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, USA.
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11
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Begam HM, Choudhury R, Behera A, Jana R. Copper-Catalyzed Electrophilic Ortho C(sp 2)-H Amination of Aryl Amines: Dramatic Reactivity of Bicyclic System. Org Lett 2019; 21:4651-4656. [PMID: 31184191 DOI: 10.1021/acs.orglett.9b01546] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A practical copper-catalyzed, 2-picolinamide-directed ortho C-H amination of anilines with benzoyl-protected hydroxylamines has been disclosed that proceeds smoothly without any external stoichiometric oxidant or additives. Remarkably, besides anilines, bicyclic naphthyl or heterocyclic amines furnished amination products with five- and six-membered cyclic and acyclic amines at the ortho position selectively. This electrophilic C-H amination also proceeds smoothly in water under slightly modified reaction conditions.
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Affiliation(s)
- Hasina Mamataj Begam
- Organic and Medicinal Chemistry Division , CSIR-Indian Institute of Chemical Biology , 4 Raja S. C. Mullick Road, Jadavpur , Kolkata - 700032 , West Bengal , India
| | - Rajarshee Choudhury
- Organic and Medicinal Chemistry Division , CSIR-Indian Institute of Chemical Biology , 4 Raja S. C. Mullick Road, Jadavpur , Kolkata - 700032 , West Bengal , India.,National Institute of Pharmaceutical Education and Research (NIPER) , Kolkata - 700054 , West Bengal , India
| | - Ashok Behera
- Organic and Medicinal Chemistry Division , CSIR-Indian Institute of Chemical Biology , 4 Raja S. C. Mullick Road, Jadavpur , Kolkata - 700032 , West Bengal , India
| | - Ranjan Jana
- Organic and Medicinal Chemistry Division , CSIR-Indian Institute of Chemical Biology , 4 Raja S. C. Mullick Road, Jadavpur , Kolkata - 700032 , West Bengal , India
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12
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Beutner GL, Young IS, Davies ML, Hickey MR, Park H, Stevens JM, Ye Q. TCFH-NMI: Direct Access to N-Acyl Imidazoliums for Challenging Amide Bond Formations. Org Lett 2018; 20:4218-4222. [PMID: 29956545 DOI: 10.1021/acs.orglett.8b01591] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Challenging couplings of hindered carboxylic acids with non-nucleophilic amines to form amide bonds can be accomplished in high yields, and in many cases, with complete retention of the adjacent stereogenic centers using the combination of N, N, N', N'-tetramethylchloroformamidinium hexafluorophosphate (TCFH) and N-methylimidazole (NMI). This method allows for in situ generation of highly reactive acyl imidazolium ions, which have been demonstrated to be intermediates in the reaction. The reagent delivers high reactivity similar to acid chlorides with the ease of use of modern uronium reagents.
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Affiliation(s)
- Gregory L Beutner
- Chemical and Synthetic Development, Bristol-Myers Squibb Company, One Squibb Drive , New Brunswick , New Jersey 08903 , United States
| | - Ian S Young
- Chemical and Synthetic Development, Bristol-Myers Squibb Company, One Squibb Drive , New Brunswick , New Jersey 08903 , United States
| | - Merrill L Davies
- Chemical and Synthetic Development, Bristol-Myers Squibb Company, One Squibb Drive , New Brunswick , New Jersey 08903 , United States
| | - Matthew R Hickey
- Chemical and Synthetic Development, Bristol-Myers Squibb Company, One Squibb Drive , New Brunswick , New Jersey 08903 , United States
| | - Hyunsoo Park
- Chemical and Synthetic Development, Bristol-Myers Squibb Company, One Squibb Drive , New Brunswick , New Jersey 08903 , United States
| | - Jason M Stevens
- Chemical and Synthetic Development, Bristol-Myers Squibb Company, One Squibb Drive , New Brunswick , New Jersey 08903 , United States
| | - Qingmei Ye
- Chemical and Synthetic Development, Bristol-Myers Squibb Company, One Squibb Drive , New Brunswick , New Jersey 08903 , United States
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13
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Yu HB, Zou BY, Wang XL, Li M. Investigation of miscellaneous hERG inhibition in large diverse compound collection using automated patch-clamp assay. Acta Pharmacol Sin 2016; 37:111-23. [PMID: 26725739 DOI: 10.1038/aps.2015.143] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 12/09/2015] [Indexed: 01/22/2023] Open
Abstract
AIM hERG potassium channels display miscellaneous interactions with diverse chemical scaffolds. In this study we assessed the hERG inhibition in a large compound library of diverse chemical entities and provided data for better understanding of the mechanisms underlying promiscuity of hERG inhibition. METHODS Approximately 300 000 compounds contained in Molecular Library Small Molecular Repository (MLSMR) library were tested. Compound profiling was conducted on hERG-CHO cells using the automated patch-clamp platform-IonWorks Quattro(™). RESULTS The compound library was tested at 1 and 10 μmol/L. IC50 values were predicted using a modified 4-parameter logistic model. Inhibitor hits were binned into three groups based on their potency: high (IC50<1 μmol/L), intermediate (1 μmol/L< IC50<10 μmol/L), and low (IC50>10 μmol/L) with hit rates of 1.64%, 9.17% and 16.63%, respectively. Six physiochemical properties of each compound were acquired and calculated using ACD software to evaluate the correlation between hERG inhibition and the properties: hERG inhibition was positively correlative to the physiochemical properties ALogP, molecular weight and RTB, and negatively correlative to TPSA. CONCLUSION Based on a large diverse compound collection, this study provides experimental evidence to understand the promiscuity of hERG inhibition. This study further demonstrates that hERG liability compounds tend to be more hydrophobic, high-molecular, flexible and polarizable.
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14
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High throughput screening technologies for ion channels. Acta Pharmacol Sin 2016; 37:34-43. [PMID: 26657056 DOI: 10.1038/aps.2015.108] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 10/12/2015] [Indexed: 11/08/2022] Open
Abstract
Ion channels are involved in a variety of fundamental physiological processes, and their malfunction causes numerous human diseases. Therefore, ion channels represent a class of attractive drug targets and a class of important off-targets for in vitro pharmacological profiling. In the past decades, the rapid progress in developing functional assays and instrumentation has enabled high throughput screening (HTS) campaigns on an expanding list of channel types. Chronologically, HTS methods for ion channels include the ligand binding assay, flux-based assay, fluorescence-based assay, and automated electrophysiological assay. In this review we summarize the current HTS technologies for different ion channel classes and their applications.
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Abstract
There are many reported examples of small structural modifications to GPCR-targeted ligands leading to major changes in their functional activity, converting agonists into antagonists or vice versa. These shifts in functional activity are often accompanied by negligible changes in binding affinity. The current perspective focuses on outlining and analyzing various approaches that have been used to interconvert GPCR agonists, partial agonists, and antagonists in order to achieve the intended functional activity at a GPCR of therapeutic interest. An improved understanding of specific structural modifications that are likely to alter the functional activity of a GPCR ligand may be of use to researchers designing GPCR-targeted drugs and/or probe compounds, specifically in cases where a particular ligand exhibits good potency but not the preferred functional activity at the GPCR of choice.
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Affiliation(s)
- Peter I Dosa
- Institute for Therapeutics Discovery and Development, Department of Medicinal Chemistry, University of Minnesota , 717 Delaware Street SE, Minneapolis, Minnesota 55414, United States
| | - Elizabeth Ambrose Amin
- Department of Medicinal Chemistry and Minnesota Supercomputing Institute for Advanced Computational Research, University of Minnesota , 717 Delaware Street SE, Minneapolis, Minnesota 55414, United States
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Intriguing possibilities and beneficial aspects of transporter-conscious drug design. Bioorg Med Chem 2015; 23:4119-4131. [PMID: 26138194 DOI: 10.1016/j.bmc.2015.06.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 06/02/2015] [Accepted: 06/10/2015] [Indexed: 01/11/2023]
Abstract
It has been revealed that many types of drugs interact with transporter proteins within an organism. Transporter proteins absorb or excrete materials, including drugs and nutrients, across the cell membrane. Some hydrophobic drugs are excreted from the cell as xenobiotics by ATP-binding cassette (ABC) transporters. However, solute carrier (SLC) transporters are tissue-specifically expressed and have substrate specificities. Thus, transporter-conscious drug design is an excellent method of delivering drugs to pharmaceutical target organs and provides advantages in absorption, distribution, excretion, and toxicity of drugs (ADMET) due to transport systems. In fact, based on this strategy, the bioavailability of prodrugs designed as peptide transporter 1 (PEPT1) substrates was better than that of the corresponding parent compounds due to the transport system in the small intestine. Furthermore, in central nervous system (CNS) drug developing, drug delivery into brain across the blood-brain barrier (BBB) is a serious problem. However, this problem can be also solved by the use of the transport systems at the BBB. Therefore, transporter-consciously designed drugs not only may effectively elicit activity but also may control adverse side effects caused by off-targets and drug-drug interactions and, consequently, may show good performance in clinical trials. In this review, I introduce possibilities and advantages of transporter-conscious drug designs.
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Li F, Zou X, Wang N. Direct Coupling of Arylacetonitriles and Primary Alcohols to α-Alkylated Arylacetamides with Complete Atom Economy Catalyzed by a Rhodium Complex-Triphenylphosphine- Potassium Hydroxide System. Adv Synth Catal 2015. [DOI: 10.1002/adsc.201401013] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Lindsley CW. 2013 Philip S. Portoghese Medicinal Chemistry Lectureship: drug discovery targeting allosteric sites. J Med Chem 2014; 57:7485-98. [PMID: 25180768 PMCID: PMC4174999 DOI: 10.1021/jm5011786] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Indexed: 02/06/2023]
Abstract
The identification of sites on receptors topographically distinct from the orthosteric sites, so-called allosteric sites, has heralded novel approaches and modes of pharmacology for target modulation. Over the past 20 years, our understanding of allosteric modulation has grown significantly, and numerous advantages, as well as caveats (e.g., flat structure-activity relationships, species differences, "molecular switches"), have been identified. For multiple receptors and proteins, numerous examples have been described where unprecedented levels of selectivity are achieved along with improved physiochemical properties. While not a panacea, these novel approaches represent exciting opportunities for tool compound development to probe the pharmacology and therapeutic potential of discrete molecular targets, as well as new medicines. In this Perspective, in commemoration of the 2013 Philip S. Portoghese Medicinal Chemistry Lectureship ( Lindsley , C. W. Adventures in allosteric drug discovery . Presented at the 246th National Meeting of the American Chemical Society, Indianapolis, IN, September 10, 2013 ; The 2013 Portoghese Lectureship ), several vignettes of drug discovery campaigns targeting novel allosteric mechanisms will be recounted, along with lessons learned and guidelines that have emerged for successful lead optimization.
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Affiliation(s)
- Craig W. Lindsley
- Departments of Pharmacology
and Chemistry, Vanderbilt Center for Neuroscience Drug Discovery,
Vanderbilt Specialized Chemistry Center (MLPCN), Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
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Abstract
The presence of druggable, topographically distinct allosteric sites on a wide range of receptor families has offered new paradigms for small molecules to modulate receptor function. Moreover, ligands that target allosteric sites offer significant advantages over the corresponding orthosteric ligands in terms of selectivity, including subtype selectivity within receptor families, and can also impart improved physicochemical properties. However, allosteric ligands are not a panacea. Many chemical issues (e.g., flat structure-activity relationships) and pharmacological issues (e.g., ligand-biased signaling) that are allosteric centric have emerged. Notably, the fact that allosteric sites are less evolutionarily conserved leads to improved selectivity; however, this can also lead to species differences that can hinder safety assessment. Many allosteric ligands possess molecular switches, wherein a small structural change (chemical or metabolic) can modulate the mode of pharmacology or receptor subtype selectivity. As the field has matured, as described here, key principles and strategies have emerged for the design of ligands/drugs for allosteric sites.
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Affiliation(s)
- Cody J Wenthur
- Department of Pharmacology, Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232-6600;
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Discovery of a retigabine derivative that inhibits KCNQ2 potassium channels. Acta Pharmacol Sin 2013; 34:1359-66. [PMID: 23933653 DOI: 10.1038/aps.2013.79] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 05/16/2013] [Indexed: 11/08/2022] Open
Abstract
AIM Retigabine, an activator of KCNQ2-5 channels, is currently used to treat partial-onset seizures. The aim of this study was to explore the possibility that structure modification of retigabine could lead to novel inhibitors of KCNQ2 channels, which were valuable tools for KCNQ channel studies. METHODS A series of retigabine derivatives was designed and synthesized. KCNQ2 channels were expressed in CHO cells. KCNQ2 currents were recorded using whole-cell voltage clamp technique. Test compound in extracellular solution was delivered to the recorded cell using an ALA 8 Channel Solution Exchange System. RESULTS A total of 23 retigabine derivatives (HN31-HN410) were synthesized and tested electrophysiologically. Among the compounds, HN38 was the most potent inhibitor of KCNQ2 channels (its IC50 value=0.10 ± 0.05 μmol/L), and was 7-fold more potent than the classical KCNQ inhibitor XE991. Further analysis revealed that HN38 (3 μmol/L) had no detectable effect on channel activation, but accelerated deactivation at hyperpolarizing voltages. In contrast, XE991 (3 μmol/L) did not affect the kinetics of channel activation and deactivation. CONCLUSION The retigabine derivative HN38 is a potent KCNQ2 inhibitor, which differs from XE991 in its influence on the channel kinetics. Our study provides a new strategy for the design and development of potent KCNQ2 channel inhibitors.
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Wen W, Wu W, Romaine IM, Kaufmann K, Du Y, Sulikowski GA, Weaver CD, Lindsley CW. Discovery of 'molecular switches' within a GIRK activator scaffold that afford selective GIRK inhibitors. Bioorg Med Chem Lett 2013; 23:4562-6. [PMID: 23838260 PMCID: PMC3816575 DOI: 10.1016/j.bmcl.2013.06.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 06/03/2013] [Accepted: 06/11/2013] [Indexed: 12/28/2022]
Abstract
This letter describes a multi-dimensional SAR campaign based on a potent, efficacious and selective GIRK1/2 activator (~10-fold versus GIRK1/4 and inactive on nonGIRK 1-containing GIRKs, GIRK 2 or GIRK2/3). Further chemical optimization through an iterative parallel synthesis effort identified multiple 'molecular switches' that modulated the mode of pharmacology from activator to inhibitor, as well as engendering varying selectivity profiles for GIRK1/2 and GIRK1/4. Importantly, these compounds were all inactive on nonGIRK1 containing GIRK channels. However, SAR was challenging as subtle structural modifications had large effects on both mode of pharmacology and GIRK1/2 and GIRK1/4 channel selectivity.
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Affiliation(s)
- Wandong Wen
- College of Science, Northwest Agriculture & Forestry University, Yangling, Shaanxi 712100, China
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Wenjun Wu
- College of Science, Northwest Agriculture & Forestry University, Yangling, Shaanxi 712100, China
| | - Ian M. Romaine
- Vanderbilt Institute of Chemical Biology, Vanderbilt University/Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Kristian Kaufmann
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Yu Du
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Gary A. Sulikowski
- Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University/Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - C. David Weaver
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University/Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Craig W. Lindsley
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN 37232, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37232, USA
- Vanderbilt Institute of Chemical Biology, Vanderbilt University/Vanderbilt University Medical Center, Nashville, TN 37232, USA
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